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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.
51

Genetische Charakterisierung des "Leukocyte Receptor Complex" und Entwicklung einer Methode zum Nachweis seiner Produkte im Einzelzellmaßstab

Wende, Hagen January 2003 (has links)
Der "Leukocyte Receptor Complex" (LRC) ist ein DNA-Sequenzabschnitt auf dem Chromosom 19 des Menschen, der eine Länge von über 900.000 Basenpaaren umfaßt. In diesem Chromosomenabschnitt ist eine Vielzahl von Genen lokalisiert, die für die Funktion verschiedener weißer Blutzellen (Leukozyten) von entscheidender Bedeutung sind. Bei den aus diesen Genen synthetisierten Proteinen (Eiweißen) handelt es sich um Strukturen, die auf der Oberfläche dieser Zellen lokalisiert sind und zur Interaktion der Leukozyten mit ihrer Umgebung dienen. Diese auch als Rezeptoren bezeichneten Proteine können mit Oberflächenproteinen auf anderen Körperzellen wechselwirken und daraus resultierende Signale in das Innere der Blutzelle weiterleiten. <br /> In der vorliegenden Doktorarbeit wurde der LRC im Detail untersucht. Hierzu wurde zunächst der gesamte Chromosomenabschnitt aus kleineren, einander überlappenden DNA-Fragmenten rekonstruiert. Aufgrund der in diesen DNA-Fragmenten enthaltenen DNA-Sequenzen war es möglich, den gesamten Chromosomenabschnitt ähnlich einem Puzzle zusammenzusetzen. Die anschließende Analyse des LRC zeigte, daß sich dieser in drei Bereiche, sogenannte Cluster, unterteilen läßt. Diese Cluster sind dadurch gekennzeichnet, daß in ihnen jeweils nur Gene eines Rezeptortyps vorkommen. Hierbei handelt es sich um ‚immunoglobulin-like transcript′ -Gene (ILT) und ‚killer cell Ig-like receptor′-Gene (KIR). Die KIR- und ILT-Cluster werden von weiteren stammesgeschichtlich verwandten Genen unterbrochen und flankiert. Je nach Individuum können im LRC bis zu 31 solcher verwandten Rezeptorgene lokalisiert sein. Auf der Grundlage der Kartierungsdaten und von Daten des humanen Genomprojekts war es zudem möglich, evolutionäre Untersuchungen zur Entwicklung des LRC durchzuführen. Dabei wurde eine Hypothese zur Entstehung des LRC entworfen und zu anderen Spezies in Beziehung gesetzt. <br /> Im zweiten Teil der Arbeit habe ich aufbauend auf der sogenannten HRCA-Methode eine Technik entwickelt, die es erlaubt kleinste Unterschiede zwischen DNA-Sequenzen, sogenannte Einzelbasenpaaraustausche, nachzuweisen. Die entwickelte Methode kann verwendet werden, um sehr ähnliche DNA-Sequenzen, wie z.B. verschiedene KIR-Sequenzen, zu unterscheiden und ihre Menge zu bestimmen. Sie ist außerdem geeignet Mutationen, die mit bestimmten Krankheiten assoziiert sind, nachzuweisen und könnte somit in der Diagnostik Anwendung finden. / The Leukocyte Receptor Complex (LRC) is a DNA region on human chromosome 19 with a length of approximately 900.000 base pairs. A number of genes, which are located in this chromosomal region, are known to be important for the function of some types of white blood cells (leukocytes). The products of theses genes are proteins, which are located on the surface of these cells and enable them to interact with their environment. These proteins are also called receptors. They can bind to cell surface proteins on other cells and transmit resulting signals into the leukocyte. <br /> During my work I analyzed the chromosomal organization of the LRC in detail. To do so, I reconstructed the whole chromosomal region from smaller overlapping DNA fragments. Due to the DNA sequences contained within these fragments it was possible to put the whole chromosomal region together like a puzzle. The following analyses of the LRC showed that it is mainly composed of three regions, so called clusters. These clusters are characterised by the presence of only one receptor family. These are the immunoglobulin-like transcripts (ILTs) and the killer cell Ig-like receptors (KIR) respectively. In the LRC the KIR- and ILT-Clusters are flanked by additional receptor genes, which are evolutionary related to KIRs and ILTs. The number of receptor genes in the LRC varies between individuals, their can be up to 31 genes on each chromosome. <br /> On the basis of the data obtained in this work as well as data from the human genome project it was also possible to draw conclusions concerning the evolutionary development of the LRC. I developed a hypothesis of the origin of the LRC and discussed this in comparison to other species. <br /> In the second part of my thesis I developed a new technique based on the so-called ’hyper-branched rolling circle amplification′ (HRCA). This technique allows the detection of small differences between two or more DNA molecules, so called ’single nucleotide polymorphisms′ (SNPs). With this newly developed method it is possible to distinguish very similar variants of a gene, e.g. two KIR sequences, and to determine their relative concentration. The method can also be used to detect mutations, which are associated with certain diseases and could therefore be used for diagnostic purposes.
52

Modulation of dendritic cells by human neutrophil elastase and its inhibitors in pulmonary inflammation

Roghanian, Ali January 2007 (has links)
Dendritic cells (DC) are sentinels of the immune system that display an extraordinary capacity to present antigen to naïve T cells and initiate immune responses. DCs are distributed throughout the lungs in the conducting airways of the tracheobronchial tree and in the parenchymal lung, and play a pivotal role in controlling the immune response to inhaled antigens. The respiratory surface is continually exposed to potentially injurious particulates and pathogenic organisms, to which tightly regulated innate and adaptive immunological responses are made. The airways are usually sterile in healthy individuals. However, patients with chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF) have increased susceptibility to microbial infections and increased neutrophil elastase (NE) in lung secretions. This thesis was designed to test the hypotheses that; (i) excess NE may result in a dysregulation of lung DCs function in pulmonary chronic diseases, and (ii) the natural NE inhibitors in the respiratory system are able to rescue the NE-mediated dysregulation of DCs and potentially enhance their antigen presenting activity. The data in this thesis demonstrate that purified human NE down-regulated murine bone marrow (BM)-derived DC co-stimulatory molecules (CSM; CD40, CD80 and CD86), which was due to its proteolytic activity. NE-treated LPS-matured DCs were less efficient at presenting ovalbumin (OVA) peptide to naïve OVAspecific transgenic (D011.10) T cells. In addition, immature DCs (iDC) simultaneously treated with LPS and NE failed to mature fully and produced significantly less IL-12 and TNF-α than DCs matured in the presence of LPS alone. Similarly, treatment of mature DC (mDC) with pooled and individual COPD and CF sputum samples caused a reduction in CD80 and CD86 levels (but not CD40) which positively correlated with the NE concentration present in the samples. The demonstration that NE could adversely affect DC phenotype and function suggested that augmentation of NE inhibitors could reverse this process and preserve DC function in inflammatory microenvironments. Over-expression of an NE specific inhibitor (elafin) in the lungs of mice (using either replication-deficient adenovirus [Ad] or elafin transgenic [eTg] mice) increased the number (immunofluorescence) and activation status (flow cytometric measurement) of CD11c+/MHCII+ lung DCs in in vivo models. Replication-deficient Ad vectors encoding NE inhibitors, namely elafin, secretory leukocyte protease inhibitor (SLPI) and α1-protease inhibitor (α1-PI), were also used to infect DCs in vitro, to further study the effect of these NE-inhibitors on DCs in isolation. These findings suggest that purified NE and NE-containing lung inflammatory secretions are powerful down-regulators of DC maturation, resulting in reduced capacity of these potent APCs to efficiently present antigens; whereas, NE inhibitors could boost immunity by increasing the activation state and/or number of DCs.
53

Leukocyte O-GlcNAcylation : a novel diagnostic tool for the earlier detection of type 2 diabetes mellitus?

Springhorn, Clare 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Context: There are serious deficiencies in the current tests and criteria available for the diagnosis of diabetes. A novel screening method for the earlier and more efficient detection of type 2 diabetes would be a significant clinical advance. Objective: The hexosamine biosynthetic pathway (HBP) usually acts as a fuel sensor and its activation leads to O-GlcNAcylation of target proteins in a glucose-responsive manner. O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) are responsible for O-GlcNAc addition and removal, respectively. As higher HBP flux is linked to insulin resistance/type 2 diabetes, we hypothesized that increased O-GlcNAcylation of leukocyte proteins can detect the onset of pre- and overt diabetes. Materials and methods: 74 participants from Bellville and Stellenbosch (Western Cape, South Africa) were recruited and characterized as normal, pre-diabetic or diabetic. Leukocytes (granulocytes and lymphocytes) isolated from study subjects were evaluated for O-GlcNAcylation, OGA and OGT expression by flow cytometry, immunofluorescence microscopy and Western blotting. Results: Leukocyte O-GlcNAcylation increased in both pre-diabetic and diabetic individuals, with leukocyte sub-population data showing the greatest sensitivity. OGA expression and O-GlcNAc/OGA ratios elevated in parallel with increasing glucose concentrations. OGT expression did not significantly change for any of the study subjects investigated. Conclusions: The initial and significant increases in leukocyte O-GlcNAcylation demonstrate great potential for the earlier detection of pre-diabetic and diabetic individuals. OGA expression and O-GlcNAc/OGA ratios may also have diagnostic value. Together our data show strong promise for eventual diagnostic utility and the more efficient detection of type 2 diabetes. / AFRIKAANSE OPSOMMING: Die konteks: Daar is ernstige tekortkominge in die huidige toetsing en kriteria vir die diagnose van diabetes. ʼn Nuwe metode vir die vroeë en meer effektiewe opsporing van tipe 2 diabetes sal beduidende kliniese voordeel inhou. Doelstelling: Onder normale omstandighede tree die heksosamienbiosintetiese pad (HBP) as energie sensor op, en die aktivering daarvan gee aanleiding tot O-GlcNAsetilering van proteïene in ʼn glukose-afhanglike wyse. O-GlcNAs transferase (OGT) en O-GlcNAse (OGA) is onderskeidelik verantwoordelik vir O-GlcNAs toevoeging en verwydering. Aangesien hoër HBP fluks verband hou met insulienweerstandigheid /tipe 2 diabetes, stel ons ʼn hipotese voor dat opsporing van verhoogde O-GlcNAsilasie van leukosietproteïene, die aanvang van pre-diabetes en diabetes kan voorspel. Materiale en metodes: 74 vrywillige deelnemers van Bellville en Stellenbosch (Wes Kaap Provinsie, Suid Afrika) is gewerf en gekarakteriseer as normaal, pre-diabeties of diabeties. Leukosiete (granulosiete en limfosiete), uit bloed van deelnemers geïsoleer, is vir O-GlcNAsilasie, OGA en OGT uitdrukking deur vloeisitometrie, immunofluoressensie-mikroskopie en Western blotting, ondersoek. Resultate: Leukosiet O-GlcNAsetilering is verhoog in beide pre-diabetiese en diabetiese individue, met leukosiet sub-populasie wat die mees sensitiewe data gelewer het. OGA uitdrukking en O-GlcNAs/OGA verhoudings in parallel verhoog tot ʼn toename in glukose konsentrasies. OGT uitdrukking het nie betekenisvol verander in enige van die individue wat ondersoek is nie. Gevolgtrekkings: Die vroeë en betekenisvolle toename in leukosiet O-GlcNAsetilering toon groot potensiaal vir die vroeë opsporing van pre-diabetiese en diabetiese individue. OGA uitdrukking en O-GlcNAs/OGA verhoudings het ook moontlik diagnostiese waarde. Ons data toon belowende resultate vir die gevolglike diagnostiese waarde en ʼn meer effektiewe opsporing van tipe 2 diabetes.
54

HIV subtype C diversity: analysis of the relationship of sequence diversity to proposed epitope locations.

Ernstoff, Elana Ann January 2002 (has links)
<p>Southern Africa is facing one of the most serious HIV epidemics. This project contributes to the HIVNET, Network for Prevention Trials cohort for vaccine development. HIV’s biology and rapid mutation rate have made vaccine design difficult. We examined HIV-1 subtype C diversity and how it relates to CTL epitope location along viral gag sequences. We found a negative correlation between codon sites under positive selection and epitope regions / suggesting epitope regions are evolutionarily conserved. It is possible that epitopes exist in non-conserved regions, yet fail to be detected due to the reference strain diverging from the circulating viral population. To test if CTL clustering is an artifact of the reference strain, we calculated differences between the gag codons and the reference strain. We found a weak negative correlation, suggesting epitopes in less conserved regions maybe evading detection. Locating conserved and optimal epitopes that can be recognized by CTLs is essential for the design of vaccine reagents.</p>
55

Caracterização da expressão fisiológica do antígeno leucocitário humano G em órgãos humanos fetais e adultos / Characterization of the physiological expression of human leukocyte antigen-G in fetal and adult human organs

Palone, Marcos Roberto Tovani 18 April 2019 (has links)
O antígeno leucocitário humano (HLA)-G corresponde a uma molécula não clássica de classe I do complexo principal de histocompatibilidade. Segundo a literatura, tal molécula pode ser expressa em ambos os contextos patológico e fisiológico. Diversos autores têm apresentado evidências acerca do papel do HLA-G na tolerância imune do feto durante a gestação, bem como para o sucesso de alotransplantes. No entanto, até o momento, há poucas informações publicadas a respeito da expressão fisiológica dessa molécula nos diferentes órgãos humanos. Em acréscimo a isso, a participação do HLA-G em eventos fisiológicos é ainda um assunto controverso entre cientistas. Tendo em vista o exposto, o objetivo desse estudo foi investigar a expressão da proteína HLA-G em órgãos fetais durante o progredir da gestação, bem como em órgãos adultos. Trata-se de um estudo descritivo, comparativo, transversal e retrospectivo realizado com base na revisão de prontuários e análise de necropsias/biópsias de diferentes órgãos de fetos e adultos através do método de imunohistoquímica. Os resultados demonstraram a existência de diferença estatística significativa na imunomarcação da proteína HLA-G em glândulas adrenais (p= 0,0003), baço (p= 0,0276), coração (p= 0,0474), fígado (p= 0,0052), pulmões (p = 0,0367), rins (p = 0,0377) e timo (p= 0,0336) na comparação entre o primeiro e segundo trimestre gestacional; em glândulas adrenais (p= 0,0329), baço (p= 0,0095), pâncreas (p= 0,0009) e placenta (p= 0,0285) na comparação entre o segundo e terceiro trimestre gestacional; e no coração (p= 0,0304), fígado (p= 0,0055), pulmões (p= 0,0150) e rins (p= 0,0312) na comparação entre o terceiro trimestre gestacional e a fase adulta. Foi verificado um aumento na expressão do HLA-G fetal a partir do segundo trimestre gestacional em órgãos como glândulas adrenais, coração, fígado, rins, timo e pulmões. Entretanto, isso não foi uma constante, pois em outros, a exemplo do baço, pâncreas e placenta, não observouse essa tendência durante o mesmo período. Durante o terceiro trimestre gestacional e a fase adulta evidenciou-se valores mais elevados para a expressão do HLA-G nos rins, e valores bastante inferiores no fígado. A expressão fisiológica do HLA-G embora positiva em todos os órgãos avaliados, nos três trimestres gestacionais e/ou na fase adulta, apresentou diferenças na intensidade e localização nos diferentes órgãos e períodos. Os achados a partir dessa pesquisa certamente representam uma importante contribuição para um melhor entendimento do mecanismo gestacional, assim como da fisiologia do HLA-G em adultos, sobretudo no que concerne o estabelecimento da tolerância imunológica em transplante de órgãos / Human leukocyte antigen (HLA)-G is a nonclassical class I major histocompatibility complex molecule. According to the literature, this molecule can be expressed in both pathological and physiological contexts. Several authors have presented evidence about the role of HLA-G in the immune tolerance of the fetus during pregnancy, as well as for the success of allotransplants. However, until now, there are very few published data regarding the physiological expression of this molecule in different human organs. Moreover, the role of HLA-G in physiological events is still a controversial subject among scientists. In view of the above, the objective of this study was to investigate the expression of HLA-G protein in fetal organs during the progression of gestation, as well as in adult organs. This was a descriptive, comparative, cross-sectional and retrospective study based on the review of medical records and immunohistochemical analysis of different organs of fetuses and adult people. The results showed a statistically significant difference in the immunostaining of HLA-G protein in adrenal glands (p = 0.0003), spleen (p = 0.0276), heart (p = 0.0474), liver (p = 0.0367), kidneys (p = 0.0377) and thymus (p = 0.0336) in the comparison between the first and second gestational trimesters; in adrenal glands (p = 0.0329), spleen (p = 0.0095), pancreas (p = 0.0009) and placenta (p = 0.0285) in the comparison between the second and third gestational trimesters; and in the heart (p = 0.0304), liver (p = 0.0055), lungs (p = 0.0150) and kidneys (p = 0.0312) in the comparison between the third gestational trimester and the adult phase. An increase of fetal HLA-G expression was observed from the second gestational trimester in organs such as adrenal glands, heart, liver, kidneys, thymus and lungs. However, this was not a constant finding, since in other organs including spleen, pancreas and placenta, this trend was not observed during the same period. During the third gestational trimester and the adult phase, higher values for HLA-G expression in the kidneys and much lower values in the liver were observed. Although the physiological expression of HLA-G has been positive in all evaluated organs (in the three gestational trimesters and/or in adulthood), it showed differences in its intensity and location in the different organs and periods. The findings from this research certainly represent an important contribution to a better understanding of the gestational mechanism, as well as on the physiology of HLA-G in adults, especially regarding the establishment of immunological tolerance in organ transplantation
56

Relação sazonal entre reprodução, imunidade e ocorrência de endoparasitas em anfíbios anuros da Caatinga / Seasonal relationship between reproduction, immunity and occurence of endoparasites of anuran amphibians of Caatinga

Madelaire, Carla Bonetti 19 October 2012 (has links)
A grande maioria das espécies de anfíbios anuros apresenta um padrão de reprodução sazonal, caracterizado nos machos por um pico de andrógenos que desencadeia maturação testicular, bem como manutenção do comportamento sexual. No entanto, os altos níveis de andrógenos podem apresentar um efeito imunossupressor, podendo também aumentar a probabilidade de infecções parasitárias. A Caatinga brasileira é caracterizada por altas temperaturas e chuvas sazonais e imprevisíveis que determinam o padrão reprodutivo e de atividade dos anuros dessa região, algumas espécies como P. diplolister apresentam comportamento de estivação durante a seca, já Rhinella Jimi e R. granulosa permanecem ativos quanto ao forrageamento durante este período. As drásticas variações deste ambiente poderiam acentuar os ajustes fisiológicos apresentados por essas espécies, principalmente para a espécie estivadora. Foram estudadas as inter-relações entre caracteres morfológicos, fisiológicos e parasitológicos dessas três espécies de anuros, em três períodos distintos, (A) durante a temporada reprodutiva, em um período entre dois surtos reprodutivos (período entre chuvas); (B) durante um surto reprodutivo que acompanhou um evento de chuvas e (C) no período da seca. As duas espécies de Rhinella apresentaram evidências de modulações imunológicas de acordo com período, e correlações entre caracteres imunológicos, fisiológicos e número de parasitas. Pleurodema diplolister apresentou padrões imunológicos coerentes com o processo de economia energética durante a estivação, como redução do número de leucócitos totais, com concomitante aumento na contagem de eosinófilos e relação positiva entre intensidade parasitária e contagem total de leucócitos. As três espécies estudadas apresentaram depleção das reservas energéticas durante o período reprodutivo, possivelmente associada à alta demanda energética do comportamento vocal. Também apresentaram padrões similares de maturação testicular, evidenciando que as espécies estudadas possuem um padrão de reprodução oportunista, típico de espécies que ocupam ambientes áridos. As três espécies também apresentaram relação entre parâmetros imunológicos e carga parasitária, no entanto, para esclarecer as relações causais entre esses fatores, são necessários testes adicionais de desafio imunológico, bem como infecção experimental por parasitas / Most part of anurans show a seasonal pattern of reproduction, when males display high levels of androgens associated with testicular development and sexual behavior maintenance. However, high androgens levels also can shows an immunosuppressive effect resulting in increased parasitological disease. The semi-arid Caatinga is an environment characterized by high temperatures and unpredictable seasonal rains that determine the breeding season of anurans. During the dry season, Pleurodema diplolister aestivate borrowed, Rhinella granulose and R. jimi remain foraging. Drastic variation in this environment could increase the physiological adjustments displayed by these species, mainly by P. diplolister. The inter-relation between morphological, physiological and parasitological characters was studied in these three anuran species, in three different periods: (A) dry season, (B) during the rainfall, when males are calling, and (C) in the interval between rainfalls, when males are foraging within the reproductive season. The Rhinella species presented evidences of immunological modulations according to the period and correlations between immunological, physiological parameters and number of parasites. Pleurodema diplolister presented immunological patters consistent with the process of energy economy during aestivation, including total leukocyte reduction, along with eosinophil increase and positive relation between total leukocyte and parasite intensity. The three species presented depletion in energy reserves during the breeding season, possibly associated with the high energy demand of vocal behavior. They also presented a similar pattern of testicular development, indicating that these species present opportunistic reproduction pattern, typical of species that occupy arid environments. The studied species also showed correlations between immunological parameters and parasite load, however, to clarify the causal relation between these parameters, additional immunological challenges and experimental parasite infection are necessary
57

Estudo sobre a função dos domínios não catalíticos do HF3, uma metaloproteínase do veneno da serpente Bothrops jararaca, na sua interação com alvos celulares e plasmáticos. / Study on the role of the non-catalytic domains of HF3, a metalloproteinase from Bothrops jararaca venom, in the interaction with cell and plasma targets.

Santos, Milene Cristina Menezes dos 11 May 2010 (has links)
O objetivo deste trabalho foi analisar a relação entre estrutura e função dos domínios não catalíticos do HF3, uma metaloproteínase da classe P-III do veneno da Bothrops jararaca com atividades hemorrágica e pró-inflamatória. Mostramos que proteínas recombinantes contendo o domínio rico em cisteínas (domínios tipo-disintegrina/rico em cisteínas, DC, e domínio rico em cisteínas, C) são capazes de aumentar o rolamento de leucócitos na microcirculação e de inibir a agregação plaquetária induzida pelo colágeno. Por outro lado, a proteína D e a proteína DC contendo a mutação Asp/Ala no motif Glu-Cys-Asp não apresentaram estas atividades. Peptídeos derivados da região hiper variável (HVR) do domínio rico em cisteínas também promoveram o rolamento de leucócitos, sendo esta atividade foi inibida por anticorpos anti-aMb2, e ainda inibiram a agregação plaquetária. Em conjunto, estes resultados sugerem que o domínio rico em cisteínas do HF3 e sua HVR desempenham um papel em sua atividade pró-inflamatória mediada pela integrina aMb2, e na inibição da agregação plaquetária. / This aim of this study was analyze the relationship between structure and function of the non-catalytic domains of HF3, a hemorrhagic and pro-inflammatory metalloproteinase of the P-III class, from Bothrops jararaca venom. Here we show that recombinant proteins of HF3 containing the cysteine-rich domain (disintegrin-like/cysteine rich and cysteine-rich proteins) but not the disintegrin-like protein and a disintegrin-like/cysteine rich protein carrying the mutation Asp/Ala in the Glu-Cys-Asp motif were able to significantly increase leukocyte rolling in the microcirculation and to inhibit collagen-induced platelet aggregation. Peptides from the hyper variable region (HVR) of the cysteine-rich domain also promoted leukocyte rolling and this activity was inhibited by anti-aMb2 antibodies. HVR peptides also inhibited platelet-aggregation. Taken together, these results suggest that the cysteine- rich domain of HF3 and its HVR play a role in triggering pro-inflammatory effects mediated by integrin aM/b2 and in the inhibition of platelet-aggregation.
58

Frequência reduzida de genes KIR ativadores em pacientes com sepse

Oliveira, Luciana Mello de January 2016 (has links)
Base teórica: A sepse é uma síndrome heterogênea, definida como disfunção orgânica que ameaça à vida, causada por uma resposta desregulada do hospedeiro à infecção. É um problema de saúde mundial, graças à sua alta prevalência, morbimortalidade associada, além de custos para seu tratamento. As células Natural Killer (NK) fazem parte do sistema imune inato reconhecendo moléculas de HLA de classe I em células alvo, através de seus receptores de membrana killer cell immunoglobulin-like receptors (KIR). A intensidade da resposta à infecção pode variar entre indivíduos, logo pode-se considerar que esta seja determinada por bases genéticas, e estas influenciem na ocorrência de sepse e variabilidade nos desfechos. Objetivos: Avaliar a associação entre os genes KIR e os ligantes HLA em pacientes críticos, comparando pacientes com sepse e controles não sépticos internados na mesma UTI. Métodos: Foi examinado o polimorfismo de 16 genes KIR e seus ligantes HLA em 271 pacientes críticos, caucasóides, sendo 211 pacientes com sepse e 60 controles, pela técnica de PCR-SSO e PCR-SSP, respectivamente. Resultados: Os genes ativadores KIR2DS1 e KIR3DS1 foram mais frequentes nos controles que nos pacientes com sepse (41,23% versus 55,00%, e 36,49% versus 51,67%; p = 0.041 e 0,025, respectivamente). Estes resultados fornecem informação inicial sobre o papel de polimorfismos de KIR na sepse, sugerindo que este possa ser um potencial marcador diagnóstico ou prognóstico da doença. / Background: Sepsis is a heterogeneous syndrome, defined a life-threatening organic dysfunction caused by a dysregulated host response to infection. Sepsis is a global health problem, due to its high prevalence, associated morbidity and mortality, and costs for its treatment. Cells Natural Killer (NK) cells are part of the innate immune system that recognize HLA class I molecules on target cells via membrane receptors called killer cell immunoglobulin-like receptors (KIR). The intensity of the response to an infection may vary among individuals and might be influenced genetic features affecting sepsis occurrence and variability in outcomes. Objectives: To evaluate the association between KIR genes and HLA ligands in critically ill patients, comparing patients with sepsis and without sepsis admitted to the same ICU. Methods: We examined the polymorphism of 16 KIR genes and their HLA ligands in 271 critically ill patients, Caucasians, and 211 patients with sepsis and 60 controls by PCR-SSO and PCR-SSP, respectively. Results: Activating KIR2DS1 and KIR3DS1 genes were more common in controls than in patients with sepsis (41.23% versus 55.00% and 36.49% versus 51.67%, p = 0.041 and 0.025, respectively). These results provide initial information on the role of polymorphism of KIR in sepsis, suggesting that this may be a potential diagnostic or prognostic marker of the disease.
59

Avalia??o farmacol?gica das atividades antinociceptiva e anti-inflamat?ria do composto (?)-4-cloro-6-(naftaleno-1-il)-tetrahidro-2h-pirano-2-il-metanol / Antinociceptive and anti-inflammatory profile of (?)-4-chloro-6-(naphthalen-1-yl)-tetrahydro-2H-pyran-2-yl-methanol

Gon?alves, Gabriela Mastrangelo 23 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-02-14T12:00:15Z No. of bitstreams: 1 2016 - Gabriela Mastrangelo Gon?alves.pdf: 1218648 bytes, checksum: d31754b24278f68ec75382b5ff3932c0 (MD5) / Made available in DSpace on 2017-02-14T12:00:15Z (GMT). No. of bitstreams: 1 2016 - Gabriela Mastrangelo Gon?alves.pdf: 1218648 bytes, checksum: d31754b24278f68ec75382b5ff3932c0 (MD5) Previous issue date: 2016-02-23 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / Several drugs in current use were discovered during experimental tests and by observing animals. When a new compound looks promising, it usually undergoes changes in its chemical structure in order to perfect its selectivity, potency and therapeutic efficacy. The aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of a new synthetic hybrid compound (?)-4-chloro-6-(naphthalen-1-yl)-tetrahydro-2H-pyran-2-yl-methanol (CTHP) prepared from a previous prototype acid, (?) - cis- (6-ethyl-tetrahydropyran-2-yl) Formic. The compound CTHP was evaluated in acute pain induction assays. Oral administration of the compound was able to induce antinociceptive activity in models of writhing induced by acetic acid, formalin (both stages) and tail flick. To elucidate the mechanism of action of the compound, the tail flick model was used. This model was perform by prior administration of naloxone (opioid antagonist non-selective), where we observed the inhibition of the effect produced by the compound. The selective involvement of opioid receptors (?, ? and ?) was then evaluated by prior administration of methylnaltrexone, naltrindol, and nor-binaltorphimine, respectively, where only nor-binaltorphimine was able to reduce the analgesic effect of the compound. To evaluate the possible role of the NO/cGMP/KATP, animals were pretreated with N-nitro-L-arginine methyl ester (L-NAME), 1H- [1,2,4 ] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (inhibitor of guanylate cyclase sensitive to nitric oxide), and glibenclamide (blocker of the ATP-regulated potassium channels), where reduction was observed with the administration of analgesic effect prior to all of these. In the tolerance induction test, both morphine and compound developed tolerance, however the compound perform at a slower rate and developed cross-tolerance with morphine. To assess the involvement of serotonin pathway in the activity of the compound, daily administration for 3 days of 4-chloro-DL-phenylalanine (inhibitor of the enzyme tryptophan hydroxylase) was performed. No changes in the analgesic effect of the compound was noted, with regard to the involvement of serotonin pathway. The open field model was used to assess the possibility of interference from motor performance on the analgesic effect, which demonstrated absence of this interference. As for anti-inflammatory activity results in paw edema test indicate anti-oedematogenic effect of compound. There was a decrease in the number of total leukocytes, indicating that the compound was able to reduce existing inflammation in leukocyte migration in the air pouch model. The compound also demonstrated an inhibitory activity on TNF-? production and selective inhibition of COX-2 enzyme. These results indicate significant antinociceptive activity of the compound without evidence of motor impairment. The compound CTHP showed central analgesic effect, which has contribution of opioid systems (selective for the ?-like receptors) and nitrergic in its mechanism of action. It has also showed an anti-inflammatory activity, with inhibition of leukocyte migration, TNF-? production and selective inhibitory activity on COX-2. / Diversos f?rmacos de uso corrente foram descobertos durante ensaios experimentais e mediante a observa??o em animais. Quando um novo composto parece promissor, geralmente este sofre altera??es em sua estrutura qu?mica a fim de aperfei?oar a sua seletividade, pot?ncia e efic?cia terap?utica. O objetivo deste estudo foi avaliar as atividades antinociceptiva e anti-inflamat?ria de um novo composto sint?tico (?)-4-cloro-6-(naftaleno-1-il)-tetrahidro-2h-pirano-2-il-metanol (CTHP) preparado a partir de um prot?tipo anterior, ?cido (?)-cis-(6-etil-tetrahidropirano-2-il) f?rmico. O composto CTHP foi avaliado em ensaios de indu??o de dor aguda. A administra??o oral do composto foi capaz de induzir atividade antinociceptiva nos modelos de contor??es abdominais induzidas por ?cido ac?tico, formalina (em ambas as fases) e retirada da cauda. Para elucida??o do mecanismo de a??o do composto, o modelo de retirada de cauda foi utilizado. Neste modelo foi realizada a administra??o pr?via de naloxona (antagonista opioide n?o-seletivo), em que foi observada a inibi??o do efeito produzido pelo composto. Assim, foi ent?o avaliada a participa??o seletiva de receptores opioides (?, ? e ?), atrav?s de administra??o pr?via de metilnaltrexona, naltrindol e nor-binaltorfimina, respectivamente, onde somente a nor-binaltorfimina foi capaz de reduzir o efeito antinociceptivo do composto. Para avaliar a poss?vel participa??o da via NO/GMPc/KATP, os animais foram pr?-tratados com N-nitro-arginina-L-metil ?ster (L-NAME), 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalina-1-ona (ODQ) (inibidor da guanilato ciclase sens?vel ao ?xido n?trico) e glibenclamida (bloqueador de canais de pot?ssio regulados por ATP), foi observado redu??o do efeito antinociceptivo com a administra??o pr?via de todos estes. No teste de indu??o de toler?ncia, tanto a morfina quanto o composto desenvolveram toler?ncia, por?m o composto de forma mais lenta e houve desenvolvimento de toler?ncia cruzada com a morfina. Para avaliar o envolvimento da via serotonin?rgica na atividade do composto, foi realizada a administra??o di?ria por 3 dias de 4-cloro-DL-fenilalanina (inibidor da enzima triptofano hidroxilase). Nenhuma altera??o no efeito antinociceptivo do composto foi observado, no que diz respeito ao envolvimento da via serotonin?rgica. J? o modelo de campo aberto foi utilizado para avaliar a possibilidade de interfer?ncia da performance motora sobre o efeito antinociceptivo, foi demonstrada aus?ncia desta interfer?ncia. Quanto ? atividade anti-inflamat?ria, o resultado no teste de edema de pata indica efeito antiedematog?nico do composto. Houve uma diminui??o na quantidade de leuc?citos totais, indicando que o composto foi capaz de reduzir a migra??o leucocit?ria na inflama??o existente na bolsa de ar subcut?neo. O composto tamb?m demonstrou atividade inibit?ria sobre a produ??o de TNF-? e inibi??o seletiva da enzima COX-2. Esses resultados indicam atividade antinociceptiva significativa do composto, sem evid?ncias de comprometimento motor. O composto CTHP demonstrou efeito antinociceptivo central, tendo este ?ltimo contribui??o dos sistemas opioide (seletivo para receptores do tipo ?) e nitr?rgico em seu mecanismo de a??o. E ainda, atividade anti-inflamat?ria, com inibi??o da migra??o leucocit?ria, de TNF-? e atividade inibit?ria seletiva sobre COX-2.
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Three-dimensional modeling of passive and active migration of living cells in a microchannel

January 2014 (has links)
The migration of living cells plays an important role in immune response, hemostasis, cancer progression, delivery of nutrients, and microfluidic technologies such cell separation/enrichment and flow cytometry. Using three-dimensional computational algorithm for multiphase viscoelastic flow and mass transport, this study is focused on the investigation of the effects of cell size, viscoelasticity, cortical tension, fluid inertia and cell-cell interaction on passive migration and deformation of leukocytes, and active deformation of circulating cells during chemotactic migration in a rectangular microchannel. The results of the passive migration modeling show that there is an almost linear increase in the distance between the wall and the lateral equilibrium position of liquid drops or leukocytes with the particle diameter-to-channel height ratio increased from 0.1 to 0.5. Drops with different bulk viscosities can be efficiently separated if their interfacial tension is low or the flow rate is sufficiently high. The microfluidic technology is well suited for the separation of leukocytes with different cytoplasmic viscosities and relaxation times, but it is much less sensitive to cortical tension. When a series of closely spaced cells with same size are considered, they generally undergo damped oscillation in both lateral and translational directions until they reach equilibrium positions where they become evenly distributed in the flow direction (self-assembly phenomenon). For a series of cells with different sizes, bigger cells could collide repeatedly with smaller ones and enter the other side of the channel (above or below the centerline). For a series of cells with different deformability, more deformable cells upon impact with less deformable cells move to an equilibrium position closer to the centerline. The results of our study provide better understanding of cell margination in bloodstream and cell separation/enrichment in microfluidic devices. The simulation data on active migration of cells show the formation of a finger- or lamellipodium-like projection of the cell membrane towards the chemoattractant source and indicate that lowering the cortical tension facilitates cell protrusion. / acase@tulane.edu

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