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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.
141

Function of granulocytes after burns and trauma, associations with pulmonary vascular permeability, acute respiratory distress syndrome, and immunomodulation

Johansson, Joakim January 2013 (has links)
Background: Our innate immunesystem protects us from infections but, since its methods is not all specific for microorganisms, may also induce collateral damage. Severe physical injury often proved deadly throughout evolution. Such injuries may induce massive collateral damage. Nowadays we can initiate advanced critical care for affected patients and save them from imminent trauma-related death. We are therefore faced with the fact that the collateral damage from the immune system may pose a major threat to the patient, the pathophysiology of which is not amenable to direct medical treatment and which leaves us with only passive supportive measures. In this thesis we investigated the role of leucocytes under such circumstances. Our main aim was to understand better the role of leucocytes in the development of increased vascular permeability after burns and trauma. More specifically we investigated the impact of an injury on the function of leucocytes such as the dynamic change of certain cell-surface receptors on the leucocytes and in their numbers and immature forms. We wanted to find out if the increased pulmonary vascular permeability after a burn could be mediated through heparin binding protein (HBP) released from granuloctes, and whether HBP could be used as a biomarker for respiratory failure after trauma. We also wanted to confirm the possible role of histamine as a mediator of the systemic increase in vascular permeability after burns. Methods: The dynamic change of cell-surface receptors was measured by flow-acquired cytometer scanning (FACS) on blood samples taken after burns. The concentrations of HBP after a burn and mechanical trauma were analysed in plasma. Pulmonary vascular permeability after a burn was assessed using transpulmonary thermodilution. The histamine turnover after a burn was assessed with high performance liquid chromatography (HPLC) for concentrations of histamine and methylhistamine in urine. Results: We confirmed earlier investigations showing altered expression of receptors on leucocytes after a burn, receptors intimately associated with leucocyte functions (study I). In a pilot study of 10 patients we measured plasma concentrations of HBP and found them to be increased soon after a burn (study II). This finding was not confirmed in a larger, more extensive and specific study of 20 patients. We did, however, find an association between alterations in the number of leucocytes soon after a burn and pulmonary vascular permeability, indicating that they had a role in this process (study III). In another study of trauma (non burn) we found an association between the concentration of HBP in early plasma-samples after injury and the development of ARDS, indicating that granulocytes and HBP have a role in its aetiology (study IV). We found a small increase in urinary histamine and normal urinary methylhistamine concentrations but had anticipated a distinct increase followed by a decrease after reading the current papers on the subject. This indicates that the role of histamine as a mediator of increased vascular permeability after burns may have been exaggerated (study V). Conclusions: We conclude that leucocytes are affected by burns and trauma, and it is likely that they contribute to the development of respiratory failure and acute respiratory distress syndrome (ARDS). HBP is a candidate biomarker for the early detection of ARDS after trauma, and the white blood count (WBC) is a useful biomarker for the detection of decreased oxygenation soon after a burn.
142

Comparison of a leukocyte esterase test with endometrial cytology for the diagnosis of subclinical endometritis and correlation with first service pregnancy rate in postpartum Holstein cows

Couto, Gabriel B. 11 1900 (has links)
L’objectif de la présente étude était d’évaluer un test d’estérase leucocytaire (LE) pour le diagnostic de l’endométrite subclinique chez les vaches Holstein en période postpartum. Les tests effectués à partir d’échantillons provenant soit de l’endomètre (UtLE) ou du col utérin (CxLE) ont été comparés à la cytologie endométriale (CE). Par ailleurs, deux méthodes d’évaluation des lames ont été comparées. Deux cent quatre vingt-cinq vaches Holstein de 5 troupeaux laitiers commerciaux ont été évaluées entre 21 et 47 jours en lait (JEL). Soixante sept vaches ont été diagnostiquées avec une endométrite clinique suite à un examen transrectal et vaginoscopique et ont été exclues de l’étude. Deux cent dix-huit vaches ont eu des prélèvements pour la CE et le test LE. La fonction ovarienne a été déterminée à la palpation transrectale. La banque de données utilisée pour chacune des vaches a été effectuée à partir du logiciel DSA (Dossier de Santé Animale) laitier. Le pourcentage de neutrophiles était significativement corrélé avec les scores de LE utérin et cervical. L’activité de CxLE et UtLE diminuait significativement avec les JEL, mais n’était pas associée au risque de gestation à 90 JEL (n= 186). Le pourcentage de neutrophiles mesuré à la CE entre 32 et 47 JEL était associé significativement au risque de gestation à 90 JEL (n=94, P=0.04). Pour la même période, selon une analyse de survie, les vaches avec >2,6% de neutrophiles à la CE étaient définies comme étant atteintes d’une endométrite subclinique avec une prévalence de 56%. Les résultats indiquent que le test d’estérase utérin ou cervical a une bonne concordance avec le pourcentage de neutrophiles à la CE. Une endométrite subclinique diagnostiquée par cytologie endometriale entre 32 et 47 JEL est associée à une réduction du risque de gestation au premier service. / The point toward this study was to determine the diagnostic test characteristics of the leukocyte esterase activity test for subclinical endometritis in postpartum Holstein dairy cows. The objectives were 1) to compare uterine leukocyte esterase activity and the endometrial cytology (EC), 2) to compare leukocyte esterase activity of the cervix (CxLE) and the uterus (UtLE), 3) Compare two methods of assessing the slides (i.e. an exhaustive method and a rapid method). Two hundred eighty five post partum Holstein cows from 5 commercial dairy herds had a post partum evaluation between 21 and 47 days in milk (DIM). Sixty seven cows where diagnosed with clinical endometritis by transrectal and vaginoscopy examinations and were excluded from the study. Two hundred eighteen cows were enrolled for endometrial cytology and esterase activity test. The ovarian status was determined by transrectal examination. Computerized databank, dairy DSA (Dossier de Santé Animale) indexing all the cows was used to retrieve individual information for analysis. The percentage of neutrophils was significantly correlated with the LE from the uterus and cervix. The LE from cervix and uterus decreased significantly with DIM, however, they were not statistically associated with pregnancy risk at 90 DIM (n=186). Between 32-47 DIM, the percentage of neutrophils and risk of pregnancy at 90 DIM were associated (n=94, P=0.04). For the same period, survival analysis identified cows with > 2.6 % neutrophils on EC as subclinical endometritis cows with a prevalence of 56%. The two methods for assessing the slides were correlated by 81%. Subclinical endometritis diagnosed by endometrial cytology between 32 and 47 DIM was associated with reduced risk of pregnancy at first service.
143

Quantitative analysis of single particle tracking experiments: applying ecological methods in cellular biology

Rajani, Vishaal Unknown Date
No description available.
144

Évaluation pré-clinique et clinique de deux nouvelles stratégies dans le traitement des maladies cardiovasculaires : activité anti-thrombotique de l'inhibition du récepteur P2Y1 et activité anti-inflammatoire de l'inhibition du récepteur PAR-1.

Babin, Judith 12 1900 (has links)
Alors que la plaquette a un rôle prépondérant dans le maintient de l'hémostase, son implication dans la formation de la thrombose est également incontestée. Il existe à présent des traitements antiplaquettaires mais ceux-ci présentent quelques failles. Le but de ma maîtrise a donc été de caractériser de nouvelles voies d'inhibition de l'activité plaquettaire. Les deux études qui ont été réalisées concernent l'inhibition de récepteurs couplés aux protéines G, soit le récepteur à l'ADP P2Y1 et le récepteur à la thrombine PAR-1. Dans un premier temps, l'étude du récepteur P2Y1 suggère que l'inhibition de celui-ci seul ou en combinaison avec l'inhibition du récepteur P2Y12 présente un potentiel thérapeutique chez des patients coronariens stables. Dans un deuxième temps, l'étude d'un nouvel antiplaquettaire qui est présentement en phase III de son développement clinique, soit le SCH 530348, a été effectuée. Étant un antagoniste du récepteur PAR-1, le SCH 530348 a des effets qui se répercutent à la fois chez la plaquette et les leucocytes qui possèdent eux aussi ce récepteur. Cette deuxième étude suggère que complémentairement à son effet chez la plaquette, cet inhibiteur diminue les marqueurs de l'inflammation systémique. / Platelets have a central role in haemostasis as well as in the pathology of atherothrombotic disease. Antiplatelet therapy is the standard treatment for patients with coronary heart disease. However, the current antiplatelet agents show some disadvantages. The aim of my studies was then to describe the effect of inhibition of platelet activation pathways that are not yet the target of clinically used therapies. The two studies that were performed are regarding the inhibition of two G coupledprotein receptors, which are the ADP P2Y1 receptor and the thrombin PAR-1 receptor. First, the study of P2Y1 receptor revealed that its inhibition alone or in combination with the inhibition of P2Y12 receptor show a therapeutic potential in patients with stable coronary disease. Second, the study of a novel antiplatelet agent, SCH 530348, which is in phase III of its clinical development, has been carried out. SCH 530348, which is a PAR-1 receptor antagonist, can therefore act on platelets as well as on leukocytes which also express this receptor. This second study showed that additionally to its effect on platelet activation inhibition, SCH 530348 also reduces the cell-surface markers of systemic inflammation.
145

Blood-membrane interaction and treatment of haemodialysis patients : a study of various factors

Lundberg, Lennart January 1994 (has links)
<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser.</p> / digitalisering@umu
146

Quantitative analysis of single particle tracking experiments: applying ecological methods in cellular biology

Rajani, Vishaal 11 1900 (has links)
Single-particle tracking (SPT) is a method used to study the diffusion of various molecules within the cell. SPT involves tagging proteins with optical labels and observing their individual two-dimensional trajectories with a microscope. The analysis of this data provides important information about protein movement and mechanism, and is used to create multistate biological models. One of the challenges in SPT analysis is the variety of complex environments that contribute to heterogeneity within movement paths. In this thesis, we explore the limitations of current methods used to analyze molecular movement, and adapt analytical methods used in animal movement analysis, such as correlated random walks and first-passage time variance, to SPT data of leukocyte function-associated antigen-1 (LFA-1) integral membrane proteins. We discuss the consequences of these methods in understanding different types of heterogeneity in protein movement behaviour, and provide support to results from current experimental work. / Applied Mathematics
147

Psychotria myriantha müll arg. (rubiaceae) : caracterização dos alcalóides e avaliação das atividades antiquimiotáxica e sobre o sistema nervoso central

Farias, Fabiane Moreira January 2006 (has links)
O gênero Psychotria destaca-se na família RUBIACEAE pela produção de alcalóides bioativos e por sua taxonomia complexa, sendo muitas vezes relacionado aos gêneros Palicourea, Cephaelis, Calycodendron e Calycosia. A divisão de Psychotria nos subgêneros Psychotria, Tetramerae e Heteropsychotria foi proposta com o objetivo de auxiliar a classificação quimiotaxonômica do gênero. Estudos demonstram que o subgênero Psychotria (espécies pantropicais) produz alcalóides poliméricos, formados por duas ou mais unidades de triptamina; enquanto o subgênero Heteropsychotria parece estar envolvido com a produção de alcalóides indol monoterpênicos, de acordo com pesquisas realizadas com diferentes espécies coletadas no Sul do Brasil. O isolamento e purificação dos alcalóides estrictosamida, ácido estrictosidínico e miriantosina, a partir de Psychotria myriantha, corroboram com esta hipótese, permitindo a inclusão da espécie no subgênero Heteropsychotria. A literatura descreve várias atividades para extratos e alcalóides isolados de espécies de Psychotria, como antimicrobiana e analgésica, por exemplo. Neste trabalho, o extrato n-butanólico de alcalóides de P. myriantha, além de seus alcalóides isolados, apresentaram atividade inibidora da migração de leucócitos, sugerindo um efeito antiinflamatório, e capacidade de inibir a ação da enzima acetilcolinesterase. Extratos e alcalóides isolados da espécie foram avaliados quanto à atividade antioxidante em CCD, frente ao DPPH, apresentando resultado negativo. O extrato EBA e o alcalóide ácido estrictosidínico aumentaram o tempo de latência no teste da retirada da cauda frente ao estímulo térmico, indicando uma atividade analgésica do tipo opióide. A influência do ácido estrictosidínico, alcalóide isolado em maior quantidade em massa, sobre os níveis de DA, DOPAC, 3-MT, HVA, 5-HT e 5-HIAA em estruturas cerebrais de ratos foi verificada. Hipocampos de animais que receberam injeção intra-hipocampal bilateral de ácido estrictosidínico (20 μg/μL) apresentaram redução de 83,4 % nos níveis de serotonina, em comparação ao grupo controle, enquanto os córtices desses animais apresentaram redução nos níveis de DOPAC (35,9%), 3-MT (24,7%) e 5-HIAA (9%). Hipocampos e estriados de ratos tratados com injeção i.p. de ácido estrictosidínico (10 mg/kg) demonstraram diminuição de 63,4 e 28,7% nos níveis de 5-HT, respectivamente. As alterações nos níveis de aminas biogênicas nas estruturas avaliadas, além das atividades analgésica e inibidora da acetilcolinesterase, indicam que P. myriantha e espécies do subgênero Heteropsychotria constituem uma potencial fonte de substâncias bioativas no tratamento de distúrbios do sistema nervoso central. / Psychotria genus is an important in RUBIACEAE due to bioactive alkaloids production and complex taxonomy, being related to Palicourea, Cephaelis, Calycodendron and Calycosia genera. The division of Psychotria in Psychotria, Tetramerae and Heteropsychotria subgenera was proposed with the aim of aiding the genus chemotaxonomic classification. Studies demonstrate that Psychotria subgenus produce polyindoline alkaloids formed by two or more triptamine units; whereas Heteropsychotria subgenus seems to be involved with indole monoterpene alkaloids production, according to researches with different species collected in Southern Brazil. Isolation and purification of strictosamide, strictosidinic acid and miriantosine from Psychotria myriantha corroborated this hypothesis, allowing its inclusion into Heteropsychotria subgenus. The scientific literature describes several activities to Psychotria extracts and alkaloids, such as antimicrobial and analgesic, for example. In this work, P. myriantha n-butanolic alkaloid extract and isolated compounds inhibited the leukocyte migration, suggesting an antiinflammatory activity, and a weak ability to inhibit the action of acetylcholinesterase enzyme. Alkaloids and extracts from P. myriantha were evaluated as regards their antioxidant activity using DPPH, with no positive results. EBA and strictosidinic acid increased the latency in the tail flick model, indicating an opioid analgesic activity. The influence of strictosidinic acid on the levels of DA, DOPAC, 3-MT, HVA, 5-HT and 5-HIAA in brain structures of rats was verified. Hippocampus with intra-hippocampal injection of strictosidinic acid (20 μg/μL) displayed a decrease of 83.4% in serotonin levels, in comparison with control group; whereas the cortex showed a decrease in the levels of DOPAC (35.9%), 3-MT (24.7%) and 5-HIAA (9%). Hippocampus and striatum that received intraperitoneal injection of strictosidinic acid (10 mg/kg) showed 5-HT levels reduction of 63.4 e 28.7%, respectively. The biogenic amine levels alterations in the studied structures, associated with the analgesic and acetylcholinesterase inhibitor activities, suggest that P. myriantha and species from the Heteropsychotria subgenus constitute a font of bioactive compounds in the treatment of central nervous system disturbs.
148

Évaluation pré-clinique et clinique de deux nouvelles stratégies dans le traitement des maladies cardiovasculaires : activité anti-thrombotique de l'inhibition du récepteur P2Y1 et activité anti-inflammatoire de l'inhibition du récepteur PAR-1

Babin, Judith 12 1900 (has links)
No description available.
149

Psychotria myriantha müll arg. (rubiaceae) : caracterização dos alcalóides e avaliação das atividades antiquimiotáxica e sobre o sistema nervoso central

Farias, Fabiane Moreira January 2006 (has links)
O gênero Psychotria destaca-se na família RUBIACEAE pela produção de alcalóides bioativos e por sua taxonomia complexa, sendo muitas vezes relacionado aos gêneros Palicourea, Cephaelis, Calycodendron e Calycosia. A divisão de Psychotria nos subgêneros Psychotria, Tetramerae e Heteropsychotria foi proposta com o objetivo de auxiliar a classificação quimiotaxonômica do gênero. Estudos demonstram que o subgênero Psychotria (espécies pantropicais) produz alcalóides poliméricos, formados por duas ou mais unidades de triptamina; enquanto o subgênero Heteropsychotria parece estar envolvido com a produção de alcalóides indol monoterpênicos, de acordo com pesquisas realizadas com diferentes espécies coletadas no Sul do Brasil. O isolamento e purificação dos alcalóides estrictosamida, ácido estrictosidínico e miriantosina, a partir de Psychotria myriantha, corroboram com esta hipótese, permitindo a inclusão da espécie no subgênero Heteropsychotria. A literatura descreve várias atividades para extratos e alcalóides isolados de espécies de Psychotria, como antimicrobiana e analgésica, por exemplo. Neste trabalho, o extrato n-butanólico de alcalóides de P. myriantha, além de seus alcalóides isolados, apresentaram atividade inibidora da migração de leucócitos, sugerindo um efeito antiinflamatório, e capacidade de inibir a ação da enzima acetilcolinesterase. Extratos e alcalóides isolados da espécie foram avaliados quanto à atividade antioxidante em CCD, frente ao DPPH, apresentando resultado negativo. O extrato EBA e o alcalóide ácido estrictosidínico aumentaram o tempo de latência no teste da retirada da cauda frente ao estímulo térmico, indicando uma atividade analgésica do tipo opióide. A influência do ácido estrictosidínico, alcalóide isolado em maior quantidade em massa, sobre os níveis de DA, DOPAC, 3-MT, HVA, 5-HT e 5-HIAA em estruturas cerebrais de ratos foi verificada. Hipocampos de animais que receberam injeção intra-hipocampal bilateral de ácido estrictosidínico (20 μg/μL) apresentaram redução de 83,4 % nos níveis de serotonina, em comparação ao grupo controle, enquanto os córtices desses animais apresentaram redução nos níveis de DOPAC (35,9%), 3-MT (24,7%) e 5-HIAA (9%). Hipocampos e estriados de ratos tratados com injeção i.p. de ácido estrictosidínico (10 mg/kg) demonstraram diminuição de 63,4 e 28,7% nos níveis de 5-HT, respectivamente. As alterações nos níveis de aminas biogênicas nas estruturas avaliadas, além das atividades analgésica e inibidora da acetilcolinesterase, indicam que P. myriantha e espécies do subgênero Heteropsychotria constituem uma potencial fonte de substâncias bioativas no tratamento de distúrbios do sistema nervoso central. / Psychotria genus is an important in RUBIACEAE due to bioactive alkaloids production and complex taxonomy, being related to Palicourea, Cephaelis, Calycodendron and Calycosia genera. The division of Psychotria in Psychotria, Tetramerae and Heteropsychotria subgenera was proposed with the aim of aiding the genus chemotaxonomic classification. Studies demonstrate that Psychotria subgenus produce polyindoline alkaloids formed by two or more triptamine units; whereas Heteropsychotria subgenus seems to be involved with indole monoterpene alkaloids production, according to researches with different species collected in Southern Brazil. Isolation and purification of strictosamide, strictosidinic acid and miriantosine from Psychotria myriantha corroborated this hypothesis, allowing its inclusion into Heteropsychotria subgenus. The scientific literature describes several activities to Psychotria extracts and alkaloids, such as antimicrobial and analgesic, for example. In this work, P. myriantha n-butanolic alkaloid extract and isolated compounds inhibited the leukocyte migration, suggesting an antiinflammatory activity, and a weak ability to inhibit the action of acetylcholinesterase enzyme. Alkaloids and extracts from P. myriantha were evaluated as regards their antioxidant activity using DPPH, with no positive results. EBA and strictosidinic acid increased the latency in the tail flick model, indicating an opioid analgesic activity. The influence of strictosidinic acid on the levels of DA, DOPAC, 3-MT, HVA, 5-HT and 5-HIAA in brain structures of rats was verified. Hippocampus with intra-hippocampal injection of strictosidinic acid (20 μg/μL) displayed a decrease of 83.4% in serotonin levels, in comparison with control group; whereas the cortex showed a decrease in the levels of DOPAC (35.9%), 3-MT (24.7%) and 5-HIAA (9%). Hippocampus and striatum that received intraperitoneal injection of strictosidinic acid (10 mg/kg) showed 5-HT levels reduction of 63.4 e 28.7%, respectively. The biogenic amine levels alterations in the studied structures, associated with the analgesic and acetylcholinesterase inhibitor activities, suggest that P. myriantha and species from the Heteropsychotria subgenus constitute a font of bioactive compounds in the treatment of central nervous system disturbs.
150

Mensuração do superóxido e apoptose neutrofílica em cães azotêmicos e urêmicos /

Soeiro, Carolina Soares. January 2011 (has links)
Orientador: Paulo César Ciarlini / Banca: Mary Marcondes / Banca: Raimundo Souza Lopes / Resumo: O metabolismo oxidativo e apoptose dos neutrófilos de pacientes humanos nefropatas e sua relação com as toxinas urêmicas tem sido, nos últimos anos, amplamente investigados devido sua importância como elemento imunossupressor. Recentemente surgiram evidências de que a uremia causa disfunção neutrofílica em cães nefropatas, porém não se sabe se o acúmulo de compostos nitrogenados, que também ocorrem nas azotemias não renais, igualmente afeta a função dos neutrófilos. O objetivo do presente estudo foi testar ex vivo a hipótese de que plasmas urêmicos e azotêmicos igualmente afetam o metabolismo oxidativo e a apoptose dos neutrófilos de cães. Para tal, neutrófilos de cães sadios foram isolados e incubados com plasma autólogo, plasma de cão azotêmico e urêmico. A produção de superóxido, com e sem o estimulo com PMA, foi estimada pelo método de redução do nitroazul tetrazólio (NBT) e por citometria de fluxo capilar utilizando-se a sonda hidroetidina (HE). A taxa de neutrófilos viáveis, em apoptose inicial e final, foi quantificada por citometria utilizando-se Anexina V-PE e o índice apoptótico mensurado pelo método morfométrico. A produção de superóxido gerada pelos neutrófilos isolados, em ambos os tratamentos (plasma urêmico e azotêmico) apresentou significante redução (p<0,05). Já a apoptose dos neutrófilos de cães sadios foi acelerada, quando incubados com plasmas urêmico e azotêmico. Pode-se concluir que os componentes presentes nos plasmas urêmicos e azotêmicos alteram ex vivo o metabolismo oxidativo e a apoptose dos neutrófilos, fortalecendo a hipótese de que in vivo ambas condições podem comprometer a imunidade inata de cães / Abstract: The oxidative metabolism and apoptosis of neutrophils from human patients with nephropathy and its relation with uremic toxins has been widely investigated in the last years because of its importance as an immunosuppressive element. Recently evidences suggests that uremia causes neutrophil dysfunction in dogs with renal disease, but it is unclear whether the accumulation of nitrogen compounds, which also occur in non-renal azotemia, can as well affect the role of neutrophils. The objective of this study was to test ex vivo the hypothesis that uremic and azotemic plasma also affects the oxidative metabolism and apoptosis of neutrophils in dogs. To this end, neutrophils from healthy dogs were isolated and incubated with autologous plasma, plasma of azotemic and uremic dog. The production of superoxide, with and without PMA stimulation was estimated by the method of nitroblue tetrazolium reduction (NBT) and by capillary flow cytometry using the hydroethidine probe (HE). The rate of viable, in early and late apoptosis neutrophils was quantified by flow cytometry using Annexin V-PE and theapoptotic index was measured by morphometric method. The production of superoxide generated by isolated neutrophils in both treatments (azotemic and uremic plasma) showed a significant reduction (p <0.05). Neutrophil apoptosis of healthy dogs was accelerated when incubated with uremic and azotemic plasma. In conclusion, the components present in uremic and azotemic plasma change ex vivo the oxidative metabolism and apoptosis of neutrophils, emphasizing the hypothesis that in vivo both conditions can compromise the innate immunity of dogs / Mestre

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