• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 15
  • 13
  • 6
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 52
  • 24
  • 22
  • 22
  • 22
  • 18
  • 8
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
41

Caracterização físico-química, química e bioquímica do suco tropical de manga (Mangifera indica L.) não adoçado obtido pelo processo hot fill. / Caracterization physicochemical, chemical e biochemistry of the tropical non sweetened mango (Mangifera indica L.) juice by hot fill method.

Oliveira, Aurelice Barbosa de January 2006 (has links)
OLIVEIRA, Aurelice Barbosa de. Caracterização físico-química, química e bioquímica do suco tropical de manga (Mangifera indica L.) não adoçado obtido pelo processo hot fill. 2006. 110 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-Ce, 2006 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-01T12:11:36Z No. of bitstreams: 1 2006_dis_aboliveira.pdf: 464268 bytes, checksum: dfae11a628100cfbc737e4e4df8790a0 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-01T12:13:20Z (GMT) No. of bitstreams: 1 2006_dis_aboliveira.pdf: 464268 bytes, checksum: dfae11a628100cfbc737e4e4df8790a0 (MD5) / Made available in DSpace on 2016-06-01T12:13:20Z (GMT). No. of bitstreams: 1 2006_dis_aboliveira.pdf: 464268 bytes, checksum: dfae11a628100cfbc737e4e4df8790a0 (MD5) Previous issue date: 2006 / The present work aimed to evaluate the physicochemical and chemical parameters and polyphenoloxidase (PPO) and peroxidase (POD) activity on the processing stages and shelf life of the tropical non sweetened mango juice preserved by hot fill method. The samples were removed afterwards the pulp discharged, homogenation, pasteurization and the product in the end of the processing and after 55, 110 and 165 days of storage (28ºC ± 2ºC). Total titratable acidity, pH, total soluble solids (ºBrix), reducing and total sugar, ascorbic acid, carotenoids, anthocyanins and colour (L*, a* e b*) were analysed. The results showed that pH, total titratable acidity, total sugar content and carotenoids not have a statistical significance at a level of 5% along the storage time. It was observed a higher PPO activity during the studied processing stages and in the shelf life of the product, keeping oscillating in a general manner. The POD showed an increasing activity during the processing stages and keeping stable along the storage. In conclusion the physicochemical and chemical parameters for this product were within the limits established by the Brazilian legislation and the thermal treatment was not efficient to inactivate these enzymes probably due to the possible presence of isoforms with different thermo stability grades and/or isotypes renaturation. / O presente trabalho teve como objetivo avaliar os parâmetros físico-químicos e químicos e a atividade da polifenoloxidase (PPO) e peroxidase (POD) nas etapas de processamento e durante a vida de prateleira do suco tropical de manga não adoçado envasado pelo processo hot fill. Foram retiradas amostras após as etapas de despolpa, homogeneização e pasteurização e do produto logo após o processamento e aos 55, 110 e 165 dias de armazenamento (28ºC ± 2ºC). A acidez total titulável, pH, sólidos solúveis totais (ºBrix), açúcares redutores e totais, ácido ascórbico, carotenóides, antocianinas e cor (L*, a* e b*) foram analisados. Os resultados apresentaram que o pH, a acidez total titulável, o conteúdo de açúcar total e carotenóides não apresentaram significância estatística ao nível de 5% durante o período de armazenagem. Foi observada uma maior atividade da PPO durante as etapas de processamento estudadas bem como na vida de prateleira do produto, de um modo geral mantendo-se oscilante. A POD apresentou atividade crescente nas etapas de processamento e em seguida mantendo-se constante durante o armazenamento. Conclui-se que os parâmetros físico-químicos e químicos para esse produto encontram-se dentro dos limites estabelecidos pela Legislação Brasileira e o tratamento térmico não se apresentou eficiente para a inativação dessas enzimas, devido possivelmente a presença de isoformas com diferentes graus de termoestabilidade e/ou renaturação de isotipos.
42

CaracterizaÃÃo fÃsico-quÃmica, quÃmica e bioquÃmica do suco tropical de manga (Mangifera indica L.) nÃo adoÃado obtido pelo processo hot fill. / Caracterization physicochemical, chemical e biochemistry of the tropical non sweetened mango (Mangifera indica L.) juice by hot fill method.

Aurelice Barbosa de Oliveira 12 June 2006 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O presente trabalho teve como objetivo avaliar os parÃmetros fÃsico-quÃmicos e quÃmicos e a atividade da polifenoloxidase (PPO) e peroxidase (POD) nas etapas de processamento e durante a vida de prateleira do suco tropical de manga nÃo adoÃado envasado pelo processo hot fill. Foram retiradas amostras apÃs as etapas de despolpa, homogeneizaÃÃo e pasteurizaÃÃo e do produto logo apÃs o processamento e aos 55, 110 e 165 dias de armazenamento (28ÂC Â 2ÂC). A acidez total titulÃvel, pH, sÃlidos solÃveis totais (ÂBrix), aÃÃcares redutores e totais, Ãcido ascÃrbico, carotenÃides, antocianinas e cor (L*, a* e b*) foram analisados. Os resultados apresentaram que o pH, a acidez total titulÃvel, o conteÃdo de aÃÃcar total e carotenÃides nÃo apresentaram significÃncia estatÃstica ao nÃvel de 5% durante o perÃodo de armazenagem. Foi observada uma maior atividade da PPO durante as etapas de processamento estudadas bem como na vida de prateleira do produto, de um modo geral mantendo-se oscilante. A POD apresentou atividade crescente nas etapas de processamento e em seguida mantendo-se constante durante o armazenamento. Conclui-se que os parÃmetros fÃsico-quÃmicos e quÃmicos para esse produto encontram-se dentro dos limites estabelecidos pela LegislaÃÃo Brasileira e o tratamento tÃrmico nÃo se apresentou eficiente para a inativaÃÃo dessas enzimas, devido possivelmente a presenÃa de isoformas com diferentes graus de termoestabilidade e/ou renaturaÃÃo de isotipos. / O presente trabalho teve como objetivo avaliar os parÃmetros fÃsico-quÃmicos e quÃmicos e a atividade da polifenoloxidase (PPO) e peroxidase (POD) nas etapas de processamento e durante a vida de prateleira do suco tropical de manga nÃo adoÃado envasado pelo processo hot fill. Foram retiradas amostras apÃs as etapas de despolpa, homogeneizaÃÃo e pasteurizaÃÃo e do produto logo apÃs o processamento e aos 55, 110 e 165 dias de armazenamento (28ÂC Â 2ÂC). A acidez total titulÃvel, pH, sÃlidos solÃveis totais (ÂBrix), aÃÃcares redutores e totais, Ãcido ascÃrbico, carotenÃides, antocianinas e cor (L*, a* e b*) foram analisados. Os resultados apresentaram que o pH, a acidez total titulÃvel, o conteÃdo de aÃÃcar total e carotenÃides nÃo apresentaram significÃncia estatÃstica ao nÃvel de 5% durante o perÃodo de armazenagem. Foi observada uma maior atividade da PPO durante as etapas de processamento estudadas bem como na vida de prateleira do produto, de um modo geral mantendo-se oscilante. A POD apresentou atividade crescente nas etapas de processamento e em seguida mantendo-se constante durante o armazenamento. Conclui-se que os parÃmetros fÃsico-quÃmicos e quÃmicos para esse produto encontram-se dentro dos limites estabelecidos pela LegislaÃÃo Brasileira e o tratamento tÃrmico nÃo se apresentou eficiente para a inativaÃÃo dessas enzimas, devido possivelmente a presenÃa de isoformas com diferentes graus de termoestabilidade e/ou renaturaÃÃo de isotipos. / The present work aimed to evaluate the physicochemical and chemical parameters and polyphenoloxidase (PPO) and peroxidase (POD) activity on the processing stages and shelf life of the tropical non sweetened mango juice preserved by hot fill method. The samples were removed afterwards the pulp discharged, homogenation, pasteurization and the product in the end of the processing and after 55, 110 and 165 days of storage (28ÂC Â 2ÂC). Total titratable acidity, pH, total soluble solids (ÂBrix), reducing and total sugar, ascorbic acid, carotenoids, anthocyanins and colour (L*, a* e b*) were analysed. The results showed that pH, total titratable acidity, total sugar content and carotenoids not have a statistical significance at a level of 5% along the storage time. It was observed a higher PPO activity during the studied processing stages and in the shelf life of the product, keeping oscillating in a general manner. The POD showed an increasing activity during the processing stages and keeping stable along the storage. In conclusion the physicochemical and chemical parameters for this product were within the limits established by the Brazilian legislation and the thermal treatment was not efficient to inactivate these enzymes probably due to the possible presence of isoforms with different thermo stability grades and/or isotypes renaturation. / The present work aimed to evaluate the physicochemical and chemical parameters and polyphenoloxidase (PPO) and peroxidase (POD) activity on the processing stages and shelf life of the tropical non sweetened mango juice preserved by hot fill method. The samples were removed afterwards the pulp discharged, homogenation, pasteurization and the product in the end of the processing and after 55, 110 and 165 days of storage (28ÂC Â 2ÂC). Total titratable acidity, pH, total soluble solids (ÂBrix), reducing and total sugar, ascorbic acid, carotenoids, anthocyanins and colour (L*, a* e b*) were analysed. The results showed that pH, total titratable acidity, total sugar content and carotenoids not have a statistical significance at a level of 5% along the storage time. It was observed a higher PPO activity during the studied processing stages and in the shelf life of the product, keeping oscillating in a general manner. The POD showed an increasing activity during the processing stages and keeping stable along the storage. In conclusion the physicochemical and chemical parameters for this product were within the limits established by the Brazilian legislation and the thermal treatment was not efficient to inactivate these enzymes probably due to the possible presence of isoforms with different thermo stability grades and/or isotypes renaturation.
43

CaracterizaÃÃo fÃsico-quÃmica, quÃmica e bioquÃmica do suco tropical de manga (Mangifera indica L.) nÃo adoÃado obtido pelo processo hot fill. / Caracterization physicochemical, chemical and biochemistry of the tropical non sweetened mango (Mangifera indica L.) juice by hot fill method.

Aurelice Barbosa de Oliveira 12 June 2006 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O presente trabalho teve como objetivo avaliar os parÃmetros fÃsico-quÃmicos e quÃmicos e a atividade da polifenoloxidase (PPO) e peroxidase (POD) nas etapas de processamento e durante a vida de prateleira do suco tropical de manga nÃo adoÃado envasado pelo processo hot fill. Foram retiradas amostras apÃs as etapas de despolpa, homogeneizaÃÃo e pasteurizaÃÃo e do produto logo apÃs o processamento e aos 55, 110 e 165 dias de armazenamento (28ÂC Â 2ÂC). A acidez total titulÃvel, pH, sÃlidos solÃveis totais (ÂBrix), aÃÃcares redutores e totais, Ãcido ascÃrbico, carotenÃides, antocianinas e cor (L*, a* e b*) foram analisados. Os resultados apresentaram que o pH, a acidez total titulÃvel, o conteÃdo de aÃÃcar total e carotenÃides nÃo apresentaram significÃncia estatÃstica ao nÃvel de 5% durante o perÃodo de armazenagem. Foi observada uma maior atividade da PPO durante as etapas de processamento estudadas bem como na vida de prateleira do produto, de um modo geral mantendo-se oscilante. A POD apresentou atividade crescente nas etapas de processamento e em seguida mantendo-se constante durante o armazenamento. Conclui-se que os parÃmetros fÃsico-quÃmicos e quÃmicos para esse produto encontram-se dentro dos limites estabelecidos pela LegislaÃÃo Brasileira e o tratamento tÃrmico nÃo se apresentou eficiente para a inativaÃÃo dessas enzimas, devido possivelmente a presenÃa de isoformas com diferentes graus de termoestabilidade e/ou renaturaÃÃo de isotipos. / The present work aimed to evaluate the physicochemical and chemical parameters and polyphenoloxidase (PPO) and peroxidase (POD) activity on the processing stages and shelf life of the tropical non sweetened mango juice preserved by hot fill method. The samples were removed afterwards the pulp discharged, homogenation, pasteurization and the product in the end of the processing and after 55, 110 and 165 days of storage (28ÂC Â 2ÂC). Total titratable acidity, pH, total soluble solids (ÂBrix), reducing and total sugar, ascorbic acid, carotenoids, anthocyanins and colour (L*, a* e b*) were analysed. The results showed that pH, total titratable acidity, total sugar content and carotenoids not have a statistical significance at a level of 5% along the storage time. It was observed a higher PPO activity during the studied processing stages and in the shelf life of the product, keeping oscillating in a general manner. The POD showed an increasing activity during the processing stages and keeping stable along the storage. In conclusion the physicochemical and chemical parameters for this product were within the limits established by the Brazilian legislation and the thermal treatment was not efficient to inactivate these enzymes probably due to the possible presence of isoforms with different thermo stability grades and/or isotypes renaturation.
44

Klinische Assoziation und prognostische Relevanz eines umfassenden Algorithmus zur Diagnose der Herzinsuffizienz mit erhaltener linksventrikulärer Ejektionsfraktion - Ergebnisse der Diast-CHF-Studie / Clinical association and prognostic value of a comprehensive algorithm for the diagnosis of heart failure with preserved left ventricular ejection fraction - findings of the Diast-CHF-study

Fricke, Hannes 09 March 2015 (has links)
No description available.
45

Einfluss des lymphatischen Systems auf die Entwicklung einer Herzinsuffizienz durch Erhöhung der Nachlast / Effect of lymphoid cells on the progression of pressure overload-induced heart failure

Sasse, André 06 December 2017 (has links)
No description available.
46

Design of a Novel Wearable Ultrasound Vest for Autonomous Monitoring of the Heart Using Machine Learning

Goodman, Garrett G. January 2020 (has links)
No description available.
47

How to create and analyze a Heart Failure Registry with emphasis on Anemia and Quality of Life

Jonsson, Åsa January 2017 (has links)
Background and aims Heart failure (HF) is a major cause of serious morbidity and death in the population and one of the leading medical causes of hospitalization among people older than 60 years. The aim of this thesis was to describe how to create and how to analyze a Heart Failure Registry with emphasis on Anemia and Quality of Life. (Paper I) We described the creation of the Swedish Heart Failure Registry (SwedeHF) as an instrument, which may help to optimize the handling of HF patients and show how the registry can be used to improve the management of patients with HF. (Paper II) In order to show how to analyze a HF registry we investigated the prevalence of anemia, its predictors, and its association with mortality and morbidity in a large cohort of unselected patients with HFrEF included in the SwedeHF, and to explore if there are subgroups of HF patients identifying high--‐risk patients in need of treatment. (Paper III) In order to show another way of analyzing a HF registry we assessed the prevalence of, associations with, and prognostic impact of anemia in patients with HFmrEF and HFpEF. (Paper IV) Finally we examined the usefulness of EQ--‐ 5D as a measure of patient--‐reported outcomes among HF patients using different analytical models and data from the SwedeHF, and comparing results about HRQoL for patients with HFpEF and HFrEF. Methods An observational study based on the SwedeHF database, consisting of about 70 variables, was undertaken to describe how a registry is created and can be used (Paper I). One comorbidity (anemia) was applied to different types of HF patients, HFrEF (EF <40%) (II) and HFmrEF (EF 40--‐49% ) or HFpEF (> 50%) (III) analyzing the data with different statistical methods. The usefulness of EQ--‐5D as measure of patient--‐ reported outcomes was studied and the results about HRQoL were compared for patients with HFpEF and HFrEF (IV). Results In the first paper (Paper I) we showed how to create a HF registry and presented some characteristics of the patients included, however not adjusted since this was not the purpose of the study. In the second paper (Paper II) we studied anemia in patients with HFrEF and found that the prevalence of anemia in HFrEF were 34 % and the most important independent predictors were higher age, male gender and renal dysfunction. One--‐year survival was 75 % with anemia vs. 81 % without (p<0,001). In the matched cohort after propensity score the hazard ratio associated with anemia was for all--‐cause death 1.34. Anemia was associated with greater risk with lower age, male gender, EF 30--‐39%, and NYHA--‐class I--‐II. In the third paper (Paper III) we studied anemia in other types of HF patients and found that the prevalence in the overall cohort in patients with EF > 40% was 42 %, in HFmrEF 38 % and in HFpEF (45%). Independent associations with anemia were HFpEF, male sex, higher age, worse New York Heart Association class and renal function, systolic blood pressure <100 mmHg, heart rate ≥70 bpm, diabetes, and absence of atrial fibrillation. One--‐year survival with vs. without anemia was 74% vs. 89% in HFmrEF and 71% vs. 84% in HFpEF (p<0.001 for all). Thus very similar results in paper II and III but in different types of HF patients. In the fourth paper (Paper IV) we studied the usefulness of EQ--‐5D in two groups of patients with HF (HFpEF and HFrEF)) and found that the mean EQ--‐5D index showed small reductions in both groups at follow--‐up. The patients in the HFpEF group reported worsening in all five dimensions, while those in the HFrEF group reported worsening in only three. The Paretian classification showed that 24% of the patients in the HFpEF group and 34% of those in the HFrEF group reported overall improvement while 43% and 39% reported overall worsening. Multiple logistic regressions showed that treatment in a cardiology clinic affected outcome in the HFrEF group but not in the HFpEF group (Paper IV). Conclusions The SwedeHF is a valuable tool for improving the management of patients with HF, since it enables participating centers to focus on their own potential for improving diagnoses and medical treatment, through the online reports (Paper I). Anemia is associated with higher age, male gender and renal dysfunction and increased risk of mortality and morbidity (II, III). The influence of anemia on mortality was significantly greater in younger patients in men and in those with more stable HF (Paper II, III). The usefulness of EQ--‐5D is dependent on the analytical method used. While the index showed minor differences between groups, analyses of specific dimensions showed different patterns of change in the two groups of patients (HFpEF and HFrEF). The Paretian classification identified subgroups that improved or worsened, and can therefore help to identify needs for improvement in health services (Paper IV).
48

Einfluss von typischen Komorbiditäten auf die Ausprägung der Symptomatik bei Herzinsuffizienz mit eingeschränkter und erhaltener linksventrikulärer Funktion / The impact of co-morbidities on the burden of symptoms in heart failure with reduced versus preserved ejection fraction

Durstewitz, Kathleen 04 December 2012 (has links)
No description available.
49

VO2peak/THV-ratio differ between heart failure patients with preserved ejection fraction and healthy controls

Nilsson, Calle January 2017 (has links)
Heart failure is a term for a group of complex symtoms characterized by reduced heart function. One of these syndromes, referred to as heart failure with preserved ejection fraction (HFpEF), has increased in prevalence compared to other types of heart failures during the recent years. A concern is the difficulty in diagnosing patients with HFpEF, since current tools are considered insufficient. The aim of this thesis was to examine Peak Oxygen Uptake (VO2peak) in relation to Total Heart Volume (THV) among heart failure patients with preserved ejection fraction (HFpEF, EF >40 %) compared to healthy controls. THV was acquired by delineating images acquired using cardiovascular magnetic resonance imaging, while VO2peak was measured in oxygen curves acquired from cardiopulmonary exercise tests. Ratios were calculated by dividing VO2peak with THV. In order to determine if blood hemoglobin concentration (b-Hb) could affect the ratio, ratios were adjusted to b-Hb using an adjusting factor. Mean THV was nearly 250 ml larger in HFpEF patients compared to the controls. Patients’ mean VO2peak was more than 1000 ml lower compared to the controls. Mean VO2peak/THV ratio calculated for the patients were less than half of that calculated for the controls. Adjusting the ratio to b-Hb did not affect the ratios significantly. The study was limited by the size of the test group, but the findings suggest that a VO2peak/THV ratio can be used to separate HFpEF patients from healthy controls. / Hjärtsvikt är ett begrepp för en grupp med komplexa symtom och kännetecknas av försämrad hjärtfunktion. Ett av dessa syndrom, hjärtsvikt med bevarad ejektionsfraktion (HFpEF), har ökat i prevalens jämfört med andra varianter av hjärtsvikt under de senaste åren. Ett problem är de svårigheter som finns med att diagnosticera patienter med HFpEF, då nuvarande verktyg inte är tillräckliga. Syftet med detta examensarbete var att undersöka maximalt syreupptag (VO2peak) i förhållande till total hjärtvolym (THV) bland hjärtsviktspatienter med bevarad ejektionsfraktion (HFpEF, EF >40 %) jämfört med friska kontroller. THV erhölls genom att utlinjera bilder tagna med hjälp av magnetisk resonanstomografi, medan VO2peak mättes i syrevolymkurvor som registrerats under ergospirometri-undersökningar. Index beräknades genom att dividera VO2peak med THV. För att undersöka huruvida halten hemoglobin i blodet (b-Hb) kunde påverka index justerades index mot b-Hb med hjälp av en justeringsfaktor. Medel-THV var nästan 250 ml större hos HFpEF-patienter jämfört med kontroller. Medel-VO2peak var mer än 1000 ml lägre hos patienterna jämfört med kontroller. Medel VO2peak/THV-index som beräknats för patienter var mindre än hälften så högt som index beräknat för kontroller. Att justera index mot b-Hb påverkade inte index signifikant. Studien begränsades av mängden deltagare, men fynden indikerar att VO2peak/THV-index kan användas för att skilja HFpEF-patienter från friska kontroller.
50

Rôle des biomarqueurs dérivés des neutrophiles dans la pathologie de l’insuffisance cardiaque

Chaar, Diana 04 1900 (has links)
L’insuffisance cardiaque (IC) est définie comme l’incapacité du cœur à fournir un débit cardiaque suffisant lorsque la demande augmente. L’IC survient lors d’une diminution 1) de la fonction contractile, définie comme l’IC à fraction d’éjection réduite (IC-FER) ou 2) de remplissage reliée à une rigidité du myocarde ou du péricarde, définie comme l’IC à FE préservée (IC-FEP). Les altérations de la fonction cardiaque contribuent à l’activation neuro-hormonale et à l’inflammation sous-clinique lors de l’apparition et l’évolution de l’IC. L’IC est caractérisée par de multiples anomalies du système vasculaire et musculaire périphériques. La diminution de la perfusion périphérique peut causer de multiples désordres au niveau vasculaire et musculaire chez les IC. L’inflammation sous-clinique contribue significativement à la progression de l’IC. Puisque les neutrophiles sont les principaux acteurs dans la sécrétion de cytokines inflammatoires, l’objectif de cette thèse est de caractériser le profil pro- et anti-inflammatoire dérivé des neutrophiles chez les patients souffrant d’IC-FER et IC-FEP, ainsi que l’impact du diabète (DM) sur ce profil. Les biomarqueurs plasmatiques et relâchés par les neutrophiles isolés à partir du sang provenant de 20 volontaires sains (CTL), 52 IC-FER et 25 IC-FEP et 22 DM ont été quantifiés. L’observation majeure de notre étude est la réduction importante (>90%) des taux circulants de Vascular endothelial growth factor (VEGF) chez les patients IC-FER et IC-FEP avec ou sans DM par rapport aux CTL. En parallèle, nous avons observé une diminution significative de la sécrétion du VEGF par les neutrophiles des patients IC-FER et IC-FEP avec une réduction maximale (92%) chez les IC-FEP+DM comparé aux CTL après une stimulation avec des médiateurs pro-inflammatoires. La diminution du VEGF associée à une inflammation accrue de l'endothélium micro-vasculaire coronarien conduit à une dérégulation de la génération de l’oxyde nitrique (NO). Une diminution marquée des taux circulants de NO a été observée chez les patients diabétiques et atteints d'IC comparé aux CTL. Les niveaux circulants d'IL-6 et d'IL-8 sont significativement augmentés chez les patients IC et DM et de manière synergique chez les IC-FEP avec DM. Ces données, combinées à une diminution du VEGF et du NO, suggèrent une altération significative de la fonction macro-vasculaire et micro-vasculaire chez les patients IC-FEP, qui est intensifiée par la présence de diabète. La libération d’IL-8 et d’IL-6 par les neutrophiles était significativement augmentée chez les patients DM et IC-FEP+DM après un traitement au lipopolysaccharide (LPS). Nous avons aussi démontré une augmentation de l'IL-1RA circulante, une cytokine anti-inflammatoire dans toutes les cohortes de patients. Cependant, la sécrétion de l’IL-1RA par les neutrophiles était diminuée dans toutes les cohortes par rapport aux CTL, indépendamment de l’agoniste utilisé. Ces observations suggèrent que les neutrophiles ne sont pas les principales cellules qui secrètent l'IL-1RA, mais bien les monocytes, les hépatocytes, les cellules épithéliales et les adipocytes. Les données scientifiques provenant de ces études nous ont permis de mieux caractériser le rôle du neutrophile dans l’IC et permettront de valider l’hypothèse stipulant que les biomarqueurs dérivés des neutrophiles jouent un rôle significatif dans l’IC. / Heart failure (HF) is characterized by the inability of the heart to provide sufficient cardiac output when there is an increase in demand. This may result from a decrease in 1) contractile function, defined as heart failure with reduced ejection fraction (HF-REF) or 2) filling related to stiffness of the myocardium or pericardium, defined as HF with preserved EF (HF-PEF). Alterations in cardiac function contribute to neuro-hormonal activation and subclinical inflammation during the onset and progression of HF. HF is characterized by multiple abnormalities in the peripheral vascular and muscular system. Decreased peripheral perfusion can cause vascular and peripheral muscular disorders in HF-REF and HF-PEF. However, the cellular mechanisms involved in these observations remain unknown. Subclinical inflammation significantly contributes to the progression of HF. Since neutrophils are the first players for the inflammatory cytokines release, the main objective of this doctoral thesis is to characterize the pro and anti-inflammatory profile derived from neutrophils in patients suffering from HF-REF and HF-PEF, as well as the impact of diabetes (DM) on this profile. The plasma and neutrophil released biomarkers from the blood of 20 healthy control volunteers (CTL), 52 HF-REF and 25 HF-PEF and 22 DM were quantified. The major finding of our study is the significant reduction (>90%) of the circulating levels of vascular endothelial growth factor (VEGF) in HF-REF and HF-PEF patients with or without diabetes compared to CTL. In parallel, we observed a significant decrease of the VEGF secretion by the neutrophils from HF-REF and HF-PEF patients with a maximal reduction (92%) in HF-PEF+DM compared to CTL after pro-inflammatory agonists stimulation. The decrease of VEGF associated with an increased inflammation of the coronary microvascular endothelium leads to a deregulation of nitric oxide (NO) generation. A marked decrease in circulating NO levels was indeed observed in diabetic and HF patients compared to CTL. Circulating levels of IL-6 and IL-8 increased significantly in HF and DM patients, being maximal in HFPEF+DM. These data, when combined with a decrease in VEGF and NO, support a significant impairment of macrovascular and microvascular function in HF-PEF patients, which is increased by the presence of diabetes. The release of IL-8 and IL-6 from neutrophils was significantly increased in DM and HF-PEF+DM patients after treatment with lipopolysaccharide (LPS). We also observed an increase in circulating IL-1RA, an anti-inflammatory cytokine in all patients’ cohorts. However, IL-1RA secretion by the neutrophils was decreased in all cohorts compared to CTL, independently of the agonist used. These observations suggest that neutrophils are not the main cells that secrete IL-1RA, but rather monocytes, hepatocytes, epithelial cells and adipocytes. The scientific data from these studies have allowed us to better characterize the role of neutrophils in HF and will validate the hypothesis that biomarkers derived from neutrophils play a significant role in the HF.

Page generated in 1.3346 seconds