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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.
11

Cytokine-bearing Influenza Vaccine: Adjuvant Potential of Membrane-bound Immunomodulators

Herbert, Andrew S. 01 June 2009 (has links)
Influenza epidemics continue to cause morbidity and mortality within the human population despite widespread vaccination efforts. This, along with the ominous threat of an avian influenza pandemic (H5N1), demonstrates the need for a much improved, more sophisticated influenza vaccine. Our group has developed an in vitro model system for producing a membrane-bound Cytokine-bearing Influenza Vaccine (CYT-IVAC). Numerous cytokines are involved in directing both innate and adaptive immunity and it is our goal to utilize the properties of individual cytokines and other immunomodulatory proteins to create a more immunogenic vaccine. Here we report methodologies for the construction of membrane-bound cytokine fusion constructs in which our cytokine of interest (mouse GM-CSF, mouse IL-2, mouse IL-4) was fused to the membrane anchoring regions of viral Hemagglutinin (HA). Progeny virions, produced from influenza infected MDCK cells expressing membrane-bound cytokines, readily incorporated membrane-bound cytokines during budding and these cytokines on the virus particles retained bioactivity following viral inactivation. In vivo vaccination studies in mice showed enhanced antibody titers and improved protection following lethal challenge in those mice vaccinated with IL-2 and IL-4-bearing CYT-IVAC's compared to the conventional wild-type vaccine without membrane-bound cytokines. In addition, the immune response induced by IL-2 and IL-4-bearing CYT-IVACs was skewed toward Th1 (cellular) mediated immunity compared to the Th2 (humoral) dominated response induced with wild-type vaccination. Cellular mediated immunity afforded by IL-2 and IL-4 CYT-IVACs was manifested as enhanced influenza specific T cell proliferation and activation. In conclusion, we have developed a novel methodology to introduce bioactive membrane-bound cytokines directly into virus particles in order to augment the immunogenicity of inactivated, whole virus influenza vaccines. / Ph. D.
12

Caracterização estrutural e funcional de peptídeos isolados da derme de Hypsiboas raniceps (Anura)

Popov, Cláudia Sofia de Freitas Correia 13 December 2018 (has links)
Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-11-16T19:33:03Z No. of bitstreams: 1 ClaudiaSofiadeFreitasCorreiaPopovTeseParcial2017.pdf: 709320 bytes, checksum: 74c3fb3e34fa9828bc490124e9d19b7b (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-11-16T19:33:23Z (GMT) No. of bitstreams: 1 ClaudiaSofiadeFreitasCorreiaPopovTeseParcial2017.pdf: 709320 bytes, checksum: 74c3fb3e34fa9828bc490124e9d19b7b (MD5) / Made available in DSpace on 2018-11-16T19:33:23Z (GMT). No. of bitstreams: 1 ClaudiaSofiadeFreitasCorreiaPopovTeseParcial2017.pdf: 709320 bytes, checksum: 74c3fb3e34fa9828bc490124e9d19b7b (MD5) Previous issue date: 2018-12-13 / Anurans represent a valuable source of bioactive molecules. These substances constitute a primary line of defense against predators and pathogenic microorganisms such as bacteria and fungi. Secreted peptides by granular glands represent a source of potential pharmacological agents with diverse functions. The structural and functional characterization of these biomolecules allows a better understanding of their function and biotechnological applications. Thus, in this work, the new peptides were isolated from H. raniceps with variable size between 11 and 16 amino acid residues, all of which contain two cysteines in their primary structure and with immunomodulatory activity: AC12, DK16 and RC11. A nuclear magnetic resonance analysis allowed to determinate a structure of these β-sheet molecules, as well as the presence of disulfide bridges that gives stability to the peptides. Regarding the structural analysis, none of the samples showed effective antimicrobial action. The immunomodulatory action profile of the samples was also checked. For this, a cytotoxicity essay of the molecules was initially tested. AC12 and DK16 did not reduce the viability of RAW 264.7 cells, decreasing inflammatory markers such as NO, IL-12 and TNF-α. They also decreased IL-10 production, a pro-inflammatory cytokine, but associated with several types of neoplasms. The peptide RC11 was shown to be toxic in RAW 264.7 strain. However, all samples were shown to be safe when tested at different concentrations in erythrocytes of Balb/c mice, presenting low hemolysis rates. In the in vivo tests, the three peptides reduced the paw edema caused by carrageenan, standing out the peptide AC12. Such data were corroborated by histological analysis of paw tissue. Regarding the immunomodulatory action with carrageenan-induced peritonitis assay, peptide AC12 was again the most significant, reducing the TNF-α dosed from the peritoneal lavage and increasing IL-10. In conclusion, AC12 has shown to be a good candidate as an anti-inflammatory agent, and could be used in the treatment of several inflammatory conditions. / Os anuros representam uma fonte valiosa de moléculas bioativas. Essas substâncias constituem a linha de defesa primária contra predadores e microrganismos patogênicos como bactérias e fungos. Peptídeos secretados pelas glândulas granulares representam uma fonte de potenciais agentes farmacológicos com funções diversas. A caracterização estrutural e funcional dessas biomoléculas permite um melhor entendimento da sua função e aplicações biotecnológicas. Assim, neste trabalho foram descritos três novos peptídeos isolados de H. raniceps com tamanho variável entre 11 e 16 resíduos de aminoácidos, todos eles contendo duas cisteínas na sua estrutura primária e com propriedades imunomoduladoras: AC12, DK16 e RC11. A análise por ressonância magnética nuclear permitiu determinar a estrutura dessas moléculas em folha-β, bem como a presença de pontes de dissulfeto que fornecem resistência e estabilidade às moléculas. Referente à análise estrutural, nenhuma das amostras mostrou ter ação antimicrobiana efetiva. Foi também verificado o perfil de ação imunomoduladora das amostras. Para tal, inicialmente foi testada a citotoxicidade das moléculas. AC12 e DK16 não alteraram a viabilidade das células RAW 264.7, diminuindo marcadores inflamatórios como NO, IL-12 e TNF-α. Também diminuíram a produção de IL-10, uma citocina pró-inflamatória, porém, associada a vários tipos de neoplasias. O peptídeo RC11 mostrou ser tóxico na linhagem RAW 264.7. Porém, todas as amostras mostraram-se seguras quando testadas em diferentes concentrações em eritrócitos de camundongos Balb/c, apresentando taxas de hemólise pouco significativas. Nos testes in vivo, os três peptídeos reduziram o edema da pata provocado por carragenina, sobressaindo o peptídeo AC12. Tais dados foram corroborados pela análise histológica do tecido da pata. Relativamente à ação imunomoduladora no ensaio de peritonite provocada por carragenina, novamente, o peptídeo AC12 teve destaque, reduzindo o TNF-α dosado do lavado peritoneal e aumentando a IL-10. Deste modo, o peptídeo AC12 mostrou ser um bom candidato a agente anti-inflamatório, podendo ser utilizado no tratamento de diversos quadros inflamatórios.
13

Estudo das atividades antitumoral e imunoestimulante do polissacarÃdeo sulfatado isolado de Champia feldmannii Diaz-Pifferer (1977) / Antitumor and immunostimulant properties of a sulfated polysaccharide isolated from Champia Feldmannii Diaz-Pifferer (1977)

KÃzia Oliveira Abrantes de Lacerda Lins 15 July 2008 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O cÃncer à uma doenÃa que afeta cada vez mais um nÃmero maior de pessoas em todo o mundo. As terapias atuais utilizadas para o tratamento do cÃncer sÃo ainda insatisfatÃrias. Produtos naturais tÃm sido avaliados para seleÃÃo de compostos ativos, capazes de reduzir os tumores malignos de uma forma mais eficiente e com menos efeitos indesejÃveis. O polissacarÃdeo sulfatado extraÃdo da alga Champia feldmannii (Cf-PLS) foi testado para avaliaÃÃo do seu potencial antitumoral e imunoestimulante. AlÃm disso, foram feitos testes de toxicidade do fÃgado, rins e baÃo apÃs o tratamento com Cf-PLS. Os resultados demonstraram que Cf-PLS nÃo apresenta citotoxicidade in vitro, mas à capaz de reduzir o tumor Sarcoma 180 implantado em camundongos em 48,16% e 48,62% nas doses de 10 e 25mg/kg, respectivamente, e reduz 68,32% quando adiministrado juntamente com 5-Fluorouracil (5-FU). As anÃlises do fÃgado e rins revelaram que houve certa toxicidade no rim, com Ãreas de necrose tubular aguda na maior dose. Os testes da perfusÃo renal revelaram que Cf-PLS causa aumento da pressÃo de perfusÃo, resistÃncia vascular renal, ritmo de filtraÃÃo glomerular e fluxo urinÃrio, alÃm da excreÃÃo de sÃdio, cloreto e potÃssio. NÃo houve alteraÃÃes nos percentuais de transporte totais ou tubular proximais de sÃdio, cloreto ou potÃssio. Houve discreta deposiÃÃo protÃica nos glomÃrulos e tÃbulos renais. NÃo houve alteraÃÃes nas anÃlises bioquÃmicas e os testes hematolÃgicos revelaram uma leucopenia causada por 5-FU, entretanto esta foi revertida pelo tratamento com Cf-PLS. TambÃm foi demonstrado que Cf-PLS age como agente imunoestimulante e imunomodulador, aumentando a produÃÃo de anticorpos totais e especÃficos contra Cf-PLS e OVA, aumentando tambÃm a polpa branca e o nÃmero de megacariÃcitos nos baÃos dos animais tratados e induzindo a migraÃÃo de neutrÃfilos para a cavidade peritoneal de camundongos. Pode-se concluir que Cf-PLS apresenta atividade antitumoral e que isso pode estar relacionado com suas propriedades imunoestimulantes. / Cancer is a desease that occurs in a larger number of people each year. The therapies used to treat it are still not satisfatory. Natural products have been studied to select new compounds capable of reducing tumours and with fewer side effects. The sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf-PLS) was investigated for its antitumor and immunostimulating properties and also for the toxicological aspects related to Cf-PLS treatment. The Cf-PLS did not show any significant in vitro cytotoxic effect, but showed a strong in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.16 % and 48.62% at the doses of 10 and 25 mg/kg, respectively, and 68.32% when treated together with 5-fluorouracil (5-FU). The histopathological analysis of liver and kidney showed that the kidneys were affected by Cf-PLS-treatment, presenting some focal areas of acute tubular necrosis at the higher dose. Cf-PLS caused considerable changes in renal physiology, as shown by an increase in parameters such as perfusion pressure, renal vascular resistance, glomerular filtration rate, urinary flow and sodium, chloride and potassium excretion. Neither enzymatic activity of alanine aminotransferase, urea nor creatinin levels were significantly altered. In hematological analyses, leucopeny was observed after 5-FU treatment, but this effect was prevented when the treatment was associated with the Cf-PLS. It was also demonstrated that Cf-PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and also increasing the production of OVA-specific antibodies. In addition, it induced a discreet increase of the white pulp and nest of megakaryocytic in spleen of treated mice and the neutrophil migration to the intraperitoneal cavity of mice. In conclusion, Cf-PLS has some interesting antitumour activity that could be associated with its immunostimulanting properties.
14

Constituintes químicos bioativos de dioclea violacea.

Barreiros, André Luís Bacelar Silva January 2005 (has links)
Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-04-22T14:46:07Z No. of bitstreams: 5 André Barreiros 5.pdf: 1310338 bytes, checksum: d59dc4bf426cac1e442be4eb9ee6d894 (MD5) André Barreiros 4.pdf: 1401764 bytes, checksum: 07e4fdbbe9dd39da5506e4d366f674d3 (MD5) André Barreiros 3.pdf: 1612776 bytes, checksum: 615c8ab2914ba19f8eb7af1b4c5d83cf (MD5) André Barreiros 2.pdf: 1211895 bytes, checksum: c2f0cb1c002d0263b0c0a42dbdda2a14 (MD5) André Barreiros 1.pdf: 239109 bytes, checksum: d5ef73879c018bc308a7c7bb697a9ebc (MD5) / Made available in DSpace on 2013-04-22T14:46:07Z (GMT). No. of bitstreams: 5 André Barreiros 5.pdf: 1310338 bytes, checksum: d59dc4bf426cac1e442be4eb9ee6d894 (MD5) André Barreiros 4.pdf: 1401764 bytes, checksum: 07e4fdbbe9dd39da5506e4d366f674d3 (MD5) André Barreiros 3.pdf: 1612776 bytes, checksum: 615c8ab2914ba19f8eb7af1b4c5d83cf (MD5) André Barreiros 2.pdf: 1211895 bytes, checksum: c2f0cb1c002d0263b0c0a42dbdda2a14 (MD5) André Barreiros 1.pdf: 239109 bytes, checksum: d5ef73879c018bc308a7c7bb697a9ebc (MD5) Previous issue date: 2005 / O presente trabalho descreve o estudo fitoquímico de Dioclea violacea Mart. além da avaliação das atividades antioxidante e imunomoduladora das substâncias isoladas. Dioclea violacea é uma trepadeira pertencente à família Leguminosae (Fabaceae), subfamília Faboideae (Papilionoideae), tribo Phaseoleae, que ocorre no litoral desde a Guiana até o estado de São Paulo. O caule de um espécime foi coletado no município de Umburanas, Bahia, em área de vegetação de caatinga e relevo de tabuleiro. Após secagem e moagem o material foi submetido à maceração com metanol. O extrato metanólico obtido foi particionado fornecendo os extratos hexânico, clorofórmico e acetato de etila. Os extratos foram submetidos a purificação separadamente, sendo seus constituintes isolados e purificados através de técnicas de CC e CCDP em gel de sílica 60, 60H, 60PF, Poliamida 6 e 11 e permeação em gel de Sephadex LH20. Deste modo, as substâncias isoladas tiveram suas estruturas elucidadas através da análise de dados de RMN de 1H, 13C incluindo experimentos DEPT, ?nOe diff?, além de técnicas bidimensionais como HETCOR, HOMO/COSY, HMQC, HMBC, NOESY, auxiliadas por EMIE, FAB, UV, IV, [a]D25 e CD. Do extrato hexânico foram isolados e identificados a-tocoferol, estigmast-4-en-3-ona, b-sitosterol, estigmasterol, lupeol e b-amirina. Do extrato clorofórmico foram isolados ácido oleanólico, a nova flavanona 7,4?-diidroxi-6-metoxiflavanona, além das 7-hidroxi-6-metoxiflavanona, 5,7-diidroxiflavanona, 5,7-diidroxi-8-metoxiflavanona, 7-hidroxiflavanona, 4?,7-diidroxiflavanona, 7,3?,4?-triidroxiflavanona já anteriormente isoladas de outras fontes. Além disso, foram também isolados deste extrato o 7-hidroxi-6-metoxiflavanonol, 2?,4? diidroxichalcona, 2?,4,4?-triidroxi-3-metoxichalcona, 2?,3,4,4?-tetraidroxichalcona, além da lactona lasiodiplodina e de um novo biflavonóide a,b?-epoxi,-2,2?,4?-triidroxichalcona-(b®4?)-7,4?-diidroxi-6-metoxiflavanona. Enquanto que, do extrato acetato de etila foram isolados a epicatequina, a proantocianidina do tipo A denominada 3?,4?,7-triidroxiflavana-(2b®7,4b®8)-3-prenil-fustina, e outras duas proantocianidinas do tipo A2; epicatequina-(2b®7,4b®8)-epicatequina e epigalocatequina-(2b®7,4b®8)-epicatequina. As substâncias isoladas foram submetidas a testes de atividade antioxidante pelos métodos de inibição da autooxidação do b-caroteno, e seqüestro do radical livre DPPH, sendo que a epicatequina e as proantocianidinas epicatequina-(2b®7,4b®8)-epicatequina e epigalocatequina-(2b®7,4b®8)-epicatequina foram as mais ativas. Algumas das substâncias foram submetidas a testes de atividade imunomoduladora pelos métodos de inibição da proliferação de linfócitos e inibição da síntese de NO, onde a 7 hidroxiflavanona demonstrou maior atividade. A substância mais ativa 7-hidroxiflavanona foi sintetizada a partir da reação de esterificação do ácido cinâmico com o resorcinol em presença de ácido polifosfórico, seguida de rearranjo de Fries e ciclização, porém com baixo rendimento (1,6%). Os produtos principais da reação foram a 7-hidroxi-3,4-diidro-4-fenilcumarina (68,7%) e a 5-hidroxi-3,4-diidro-4-fenilcumarina (11,2%). / Salvador
15

Estudo das atividades antitumoral e inflamatÃria do alginato isolado da alga Sargassum Vulgare C. Agardh. / Antitumor and inflammatory properties of an alginate isolated from the seaweed Sargassum vulgare C. Agardh.

KÃzia Oliveira Abrantes de Lacerda Lins 13 January 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O cÃncer à uma doenÃa que afeta cada vez mais um nÃmero maior de pessoas em todo o mundo. As terapias atuais utilizadas para o tratamento do cÃncer sÃo ainda insatisfatÃrias. Produtos naturais tÃm sido avaliados para seleÃÃo de compostos ativos, capazes de reduzir os tumores malignos de uma forma mais eficiente e com menos efeitos indesejÃveis. O alginato extraÃdo da alga Sargassum vulgare C. AGARDH (SVHV) foi testado para avaliaÃÃo do seu potencial antitumoral e imunoestimulante. AlÃm disso, foram feitos testes de toxicidade do fÃgado, rins e baÃo apÃs o tratamento com SVHV. Os resultados demonstraram que SVHV nÃo apresenta citotoxicidade in vitro, mas à capaz de reduzir o tumor Melanoma B-16 implantado em camundongos em 75,8% na dose de 25mg/kg/dia, quando administrado por via intraperitoneal (p < 0,05), enquanto nÃo houve inibiÃÃo por via oral. As anÃlises do fÃgado e rins revelaram que houve toxicidade no rim, com Ãreas de hemorragia glomerular e intersticial nos camundongos tratados com SVHV. Essas alteraÃÃes sÃo, entretanto, consideradas reversÃveis. As anÃlises bioquÃmicas, revelaram um aumento nos nÃveis sÃricos da alanina aminotransferase (ALT) nos grupos com tumor ou tratado com SVHV por via oral e os testes hematolÃgicos revelaram um aumento na porcentagem de neutrÃfilos nestes grupos, enquanto que a porcentagem de monÃcitos foi reduzida nos grupos com tumor e nos tratados com SVHV por via intraperitoneal. TambÃm foi demonstrado que SVHV age como agente imunoestimulante e imunomodulador, ativando macrÃfagos in vitro, assim como sendo capaz de causar inflamaÃÃo atravÃs do teste do edema de pata e induzir a migraÃÃo de neutrÃfilos para a cavidade peritoneal. Conclui-se entÃo que SVHV apresenta atividade antitumoral e que esta atividade està relacionada com suas propriedades imunoestimulantes. / Cancer is a disease that occurs in a larger number of people each year. The therapies used to treat it are still not satisfatory. Natural products have been studied to select new compounds capable of reducing tumours and with fewer side effects. The alginate isolated from the seaweed S. vulgare (SVHV) was investigated for its antitumor and immunostimulating properties and also for the toxicological aspects related to SVHV treatment. The SVHV did not show any significant in vitro cytotoxic effect, but showed a strong in vivo antitumor effect. The inhibition rates of Melanoma B-16 tumor development was 75,8% at the dose of 25 mg/kg/day when treated by intraperitoneal route (p < 0,05). The histopathological analysis of liver and kidney showed that the kidneys were affected by SVHV-treatment, presenting some hemorragic areas. The enzymatic activity of alanine aminotransferase, was augmented in mice with tumor or treated with SVHV by oral route. In hematological analyses, these groups showed a higher percentage of neutrophils, while the group with tumor or treated with SVHV by intraperitoneal route showed a reduction in the percentage of monocytes. It was also demonstrated that SVHV acts as an immunomodulatory agent, stimulating macrophages in vitro, causing paw edema in rats and neutrophil migration to the intraperitoneal cavity. In conclusion, SVHV has some interesting antitumour activity that is associated with its immunostimulanting properties.
16

On the role of vitamin D in multiple sclerosis

Bowman, Derek Edward 09 November 2021 (has links)
Multiple sclerosis (MS) is among the most common neuroinflammatory diseases across the globe and is autoimmune mediated in nature. This progressive, highly debilitating disease often leaves individuals wheelchair bound within 15-25 years of onset. MS is characterized by inflammatory lesions that appear in unpredictable locations around the central nervous system. Lesions can be visualized using magnetic resonance imaging (MRI) technology. As neuroinflammation continues and lesions accumulate, patients can experience a wide array of progressively worsening symptoms including but not limited to motor impairments, sensory disturbances, loss of control of bodily functions, and/or neuropathic pain, depending on the location of lesion formations. There are different types of MS, the most common being relapsing-remitting MS (RRMS) seen in about 85% of cases and characterized by periods of symptom remission followed by flare-ups. A large majority of these patients go on to develop secondary progressive MS (SPMS) where neurological damage and patient decline is progressive and continuous. Primary progressive MS (PPMS) is seen in about 10% of cases and is characterized by progressive and continuous patient decline from the outset of disease. Other rarer forms of MS do exist but will not be discussed further. Research aimed at MS is at an all-time high and the timing could not be better: its global incidence and prevalence is climbing. For decades MS has been thought of as a disease caused by dysfunctional CD4+ T-helper 1 (Th1) cells. It is now known that many different cell types contribute to MS pathophysiology. These other cell types include macrophages and dendritic cells of the innate immune system due to their expression of MHC class II molecules that function to activate CD4+ Th1 cells. More recent research has implicated CD8+ T-cells and B-cells in contributing to disease through direct destruction of neural cells that express MHC class I molecules and through the generation of autoantibodies, respectively. While these discoveries are important and provide hope for future breakthrough treatments, there are still enormous gaps in the medical community’s knowledge of what causes MS. The epidemiologic pattern of MS prevalence has for many decades interested scientists and hinted at a potential cause of this disease. MS tends to affect white individuals with genetic ties to northern Europe, but this relationship may not still hold true, as MS incidence and prevalence may be rising faster in black populations compared to other races/ethnicities, at least in the United States. MS occurs nearly 3 times as often in females than in males, and is strongly associated with Epstein-Barr virus (EBV) infection—especially in those that go on to develop infectious mononucleosis (IM). MS prevalence increases markedly in regions north of 40 degrees North latitude or south of 40 degrees South latitude. MS risk also changes depending on body mass index (BMI) considerations, migration history, and in families with a genetic history of the disease. It is well-accepted that MS has a genetic component, the most important of which is the presence of the HLA-DRB1*1501 allele that codes for certain proteins in MHC class II molecules. However, genetics alone are unable to sufficiently account for MS risk as the concordance rate for identical twins with MS is only 25-30%. These well-established findings imply that some unknown environmental factor(s) must be contributing to MS initiation and progression. All of the environmental factors listed above have a common connecting thread that is logically and empirically verifiable: vitamin D. This fat-soluble vitamin can either be endogenously synthesized in the skin after exposure to ultraviolet B (UVB) light or consumed through the diet, the former being of more importance to humans. Epidemiologic patterns suggest a protective role for vitamin D in MS, where low or deficient levels of vitamin D may be a contributor to increased risk for MS. Populations living at greater latitudes, north or south, have significantly greater prevalence of MS which coincides with the reduction of endogenously produced vitamin D in these regions due to a lesser amount of UVB light (and of lower intensity) experienced year-round. Increases in BMI, especially increased adiposity, correlate with increased risk for MS and with prevalence of vitamin D deficiency. Women tend to naturally have greater adiposity than men, thus increasing their risk for MS. Estrogens and vitamin D have been shown to act synergistically to protect against MS, therefore vitamin D deficiency may increase risk for MS in women. Vitamin D is a known immunomodulatory agent that promotes tolerogenic immune states. Vitamin D also offsets many of the harmful effects caused by EBV, among these including repression of B-cell differentiation into plasma cells, reduced MHC II expression, and promotion of B cell apoptosis. This serves to repress deleterious immunoglobulin secretion by B-cells. Vitamin D is also immunologically beneficial as it promotes regulatory T cell function and their expression of protective cytokines, and through its inhibition of inflammatory Th1 and Th17 cell functions. In total, the immunomodulatory mechanisms of vitamin D are important as the immunological states produced by vitamin D are exactly the opposite of those observed in MS patients and MS animal models. Research in vitamin D is gaining attention as the scientific community is quickly discovering that its true physiologic role extends far beyond its classical function as a calcium regulator. Indeed, rapidly evolving research is revealing roles for vitamin D in cardiovascular function and blood pressure regulation, brain development and neurological function, and even in the prevention of certain cancers. However, this thesis will focus on its most well-known function secondary to calcium regulation: immunomodulation and its anti-inflammatory capabilities. The last portion of this thesis will present information advocating for the increase in minimum dietary intake of vitamin D from its current value of 800 IU/day to 5,000 IU/day. While a more than 5-fold increase may seem drastic, the tolerable upper limit is at least 10,000 IU/day even by the most conservative of estimates—the true upper limit is probably around 20,000 IU/day and may even be 50,000 IU/day. The global prevalence of vitamin D deficiency is so extensive that some authors have even considered it a global pandemic: upwards of 50% of the entire world population may be deficient in this crucial vitamin. Increasing vitamin D supplementation is an extremely low risk way to reduce risk for MS and other diseases.
17

Implementation of a blood conservation program in the private hospital setting in South Africa

Du Preez, Monique 22 May 2012 (has links)
Although blood products are a great deal safer these days than in the past, patients receiving allogeneic blood transfusions are still exposed to potential hazards such as infectious diseases and immunomodulatory reactions. Therefore it is important to consider alternatives to allogeneic blood use. This can be done by means of blood conservation alternatives. A successful blood conservation program consists of three integrated phases, namely pre-operative, intra-operative and post-operative stages of patient care. The main objective of this study was to create a transfusion medicine database in order to evaluate the effect of a blood conservation program on the length of hospital stay of patients and the costs incurred in such a program. Five pilot hospitals who had implemented a blood conservation program were compared to five non-pilot hospitals (no blood conservation program). The results show that the average cost related to allogeneic blood usage in pilot hospitals amounted to R 473 274.13, compared to R 777 646.22 for the non-pilot hospitals. Length of hospital stay was also significantly lower in patients receiving blood conservation alternatives compared to patients receiving allogeneic blood. The total costs related to patients of blood conservation was lower, although not significantly, than the total costs of patients using allogeneic blood or both. In this study it was seen that the outcomes were positively associated with the implementation of blood conservation techniques. The efficacy of two leukodepletion methods for allogeneic blood products namely pre-storage and post-storage filtration, were evaluated. The results revealed that the mean leukocyte count of pre-storage leukodepleted blood samples (n = 30) was 0.12 cells/μl. The mean leukocyte count of the post-storage filtered blood samples (n = 20) was 0.05 cells/μl. Both methods were shown to be successful in the efficient removal of leukocytes. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Immunology / unrestricted
18

Evolutionary History of Immunomodulatory Genes of Giant Viruses

Perez, Claudia Elizabeth 20 May 2022 (has links)
Nucleocytoplasmic large DNA viruses (NCLDVs) have genome sizes that range from around 100 kilobases (kb) to up to 2.5 megabases, and virion sizes that can reach up to 1.5 μm. Their large size in both of these contexts is atypical and defies the traditional view that viruses are streamlined, "filterable infectious agents". NCLDVs include many diverse groups, including Poxviruses, Asfarviruses, Iridoviruses, Mimiviruses, and Marseilleviruses. Poxviruses are perhaps the most well-studied; these viruses have 135-360 kbp genomes with about half of the genes encoding essential replication genes and the other half encoding genes related to host-virus interactions. Many of the genes involved in host-virus interactions are involved in immunomodulatory processes and have homology to proteins encoded by the host. These viral genes, often referred to as "mimics", are therefore believed to be the result of host-to-virus gene transfer. In this study I sought to examine if common poxvirus immunomodulatory genes were found in other NCLDV lineages, and if so, to analyze the evolutionary history of these genes. I identified 5 protein families of immunomodulatory genes that were found in both poxviruses and other NCLDV lineages, and I used phylogenetic tools to compare viral immunomodulatory genes of NCLDVs to their eukaryotic orthologs to evaluate the number of times different NCLDV lineages have acquired these genes. Our phylogenetic analyses showed that several viral immunomodulatory genes were acquired multiple times by different NCLDV lineages, while others appear to have been transferred between viral groups. Interestingly, some NCLDV genes clustered together with homologs from the unrelated Herpesviridae family, suggesting that inter-viral gene exchange can traverse vast evolutionary distances. The vast diversity of hosts infected by different NCLDV lineages suggests that these immunomodulatory genes play key roles that are useful to viruses in a variety of contexts. This research provides insight into how giant viruses acquire host genes, which contribute to their large genome size, and how those genes evolved to subvert antiviral defenses. / Master of Science / Giant viruses are a relatively recent discovery, from the beginning of this century. Nucleocytoplasmic large DNA viruses (NCLDVs) are a classification of multiple giant virus families. These viruses have large genomes from around 100 kilobases to 2.5 megabases of DNA. For reference, the genome size of the flu virus is approximately 13 kilobases. Most viruses cannot be seen by the human eye, even with microscopes, but giant viruses can get as big as bacteria, which can be seen with microscopes. It is unknown how or why these viruses get so large. One explanation is that they steal genes from their host and those genes evolve to work against the host. In this thesis, I explored some of the genes that these viruses have picked up. I curated a set of 49 previously characterized viral genes to analyze in this context. These genes have to do with modulating the host immune system and are known as "immunomodulatory genes". Viral immunomodulatory genes are often mimics of the host genes which function to help the immune system. However, a virus evolves faster than a host and the virus mimic gene can evolve to work against the immune system. This change can be visualized using phylogenetic tools; the viral genes will be more similar to each other than to the host genes and cluster separately on a phylogenetic tree. About half of the genes of Poxviruses, a giant virus family that has viruses that infect humans, are related to virus-host interactions, and include viral mimic genes. Poxviruses have been far better studied than other NCLDV families because of their public health importance. Variola virus, the virus that causes smallpox, is a poxvirus. Other NCLDV infect animals, algae, and amoeba. Though their hosts are different, their genomes have similar features. I set out to discover whether some of these previously characterized viral immunomodulatory genes that exist in poxviruses also exist in other NCLDV families. I utilized phylogenetic tools and a database of giant virus sequences to figure out which genes are being picked up by which family of NCLDV. I also sought to determine whether the individual NCLDV families have their own acquired immunomodulatory gene or have a gene very similar to all other families, suggesting an ancient acquisition. If the gene is very similar, it suggests that an ancestor of the NCLDV acquired the gene and it has stuck around as the group diverged into families. It is also interesting if different families stole the same type of gene multiple times because that indicates the importance of that gene in subverting the antiviral immune system for viral replication. This work provides insight into how giant viruses acquire host genes, which contribute to their large genome size, and how they evolved those genes to subvert antiviral defenses.
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Studies on the bioactivities of lignins from woody biomass / 木質バイオマス由来リグニンの生理活性に関する研究

Okabe, Yumi 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(農学) / 甲第25329号 / 農博第2595号 / 新制||農||1105(附属図書館) / 学位論文||R6||N5501 / DFAM / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 渡邊 隆司, 教授 阪井 康能, 教授 飛松 裕基 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
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Ocorrência e distribuição de BanLec em cultivares de banana e avaliação da sua atividade imunomoduladora in vivo / Occurrence and distribution of BanLec in banana cultivars and evaluation of its immunomodulatory activity in vivo

Sansone, Ana Claudia Miranda Brito 16 December 2014 (has links)
Lectinas são proteínas cuja principal característica é a de se ligar específica e reversivelmente a carboidratos. BanLec é a lectina presente na polpa de bananas, que se liga especificamente a manose e glicose, e é capaz de induzir a proliferação de células T, podendo estimular a resposta imune. Existem indícios de que o teor de BanLec pode variar dependendo do estádio de amadurecimento e do tipo de cultivar, o que pode afetar a quantidade de BanLec existente na fruta quando consumida in natura e a possível resposta imune frente ao consumo de banana. Por este motivo, um dos objetivos desse trabalho foi determinar os teores e a atividade hemaglutinante de BanLec em extratos de farinha de banana verde, além de bananas das cultivares Pacovan, Figo, Terra, Mysore e Nanicão, nos estádios de maturação verde e maduro, e submetidas a tratamento com 1-MCP e baixa temperatura (para cv. Nanicão). Com vista a atender ao objetivo de avaliar seus efeitos imunomoduladores in vivo, a BanLec foi purificada da cultivar Nanicão e administrada por via oral a camundongos BALB/c. Os ensaios de atividade hemaglutinante dos extratos de banana apontaram para maior quantidade de BanLec no fruto maduro, quando comparado ao verde, e ausência dessa proteína na cultivar Figo. Os parâmetros imunológicos analisados após administração de BanLec aos camundongos demonstram que a resposta imune gerada após ingestão de BanLec é dose dependente, além disso, a administração de 50 &#181;g de BanLec aos animais foi capaz de modular citocinas importantes na resposta imunológica, provavelmente causando um efeito que pode ser interpretado como mais protetor do que patogênico. Com base nos resultados obtidos, podemos concluir que existem diferenças nos teores de BanLec dependendo da cultivar e estádio de maturação analisado, sendo que essa proteína não está presente na polpa de todas as variedades de banana e finalmente, que ela tem grande potencial imunomodulador in vivo, uma vez que ativou citocinas de resposta anti-inflamatória. / Lectins are proteins which bind specifically and reversibly to carbohydrates. BanLec is the lectin present in banana pulp, and it binds to mannose and glucose, being capable of inducing T-cell proliferation, and to stimulate the immune response. There are some evidence that the amount of BanLec may vary depending on the maturation stage of the fruit and the cultivar (cv.), which may affect the amount of BanLec and the possible immune response after consumption of banana. Thus, this study aimed to evaluate the amount of BanLec and its hemagglutinating activity in crude extracts of bananas from cultivars Pacovan, Figo, Terra, Mysore and Nanicão, in both unripe and ripe maturation stage, and also fruits which were treated with 1-MCP and low temperature. In addition, in order to access their immunomodulatory effects in vivo, BanLec was purified by affinity chromatography and administered orally to BALB/c mice. The hemagglutinating activity assays indicate higher amount of BanLec in ripe fruit. Moreover, the possible was undetectable in the pulp of banana Figo. The immunological parameters of mice orally fed with BanLec showed that the immunological response is dependent on the amount of protein administrated, in agreement to previous in vitro studies. Besides, 50 &#181;g of BanLec, were able to modulate some cytokines in immune response, causing an effect that seems to be more protective than pathogenic. We conclude that there are important differences in amount of BanLec depending on the cultivar and the maturation stage, and BanLec has a dose-dependent immunomodulatory effect in vivo.

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