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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.
181

Die Regulation der ANP-Freisetzung bei Herzinsuffizienz

Model, Angela Nikola 13 September 2005 (has links)
HINTERGRUND: Im Zustand der Herzinsuffizienz sind die Plasmaspiegel des atrialen natriuretischen Peptids (ANP) erhöht. ANP wird durch Herzmuskelzellen bei atrialer (und dadurch kardiomyozytärer) Dehnung freigesetzt. Eine Reihe von Plasmafaktoren, welche bei der Herzinsuffizienz aktiviert sind, bewirken ebenfalls eine ANP-Freisetzung durch die Interaktion mit G(alpha-q)-gekoppelten Rezeptoren und der daraus resultierenden Aktivierung der Proteinkinase C (PKC). Ziel der vorliegenden Studie war es, im Vergleich von normalen und insuffizienten Rattenherzen die dehnungsinduzierte ANP-Sekretion sowie die Rolle der PKC bei der basalen ANP-Freisetzung zu analysieren. METHODIK: Durch Anlegen eines infrarenalen aortokavalen Shunts (4 Wochen) wurde eine volumeninduzierte Herzinsuffizienz in Wistar Ratten erzeugt. Die ANP-Freisetzung wurde am isoliert, retrograd perfundierten Herzmodell analysiert. Durch Umstellen auf anterograde Perfusion (Perfusionsdruck: 10mmHg) wurde eine atriale De! hnung induziert. Die Aktivierung der PKC fand durch Zugabe von PMA (Phorbol-12-Myristat-13-Azetat) zum Perfusat im Vergleich zu Vehikel statt. Alle Versuchsreihen wurden mit Herzen von shunt- sowie scheinoperierten Tieren durchgeführt. ERGEBNISSE UND DISKUSSION: Nach Shuntoperation war die ANP-Basalfreisetzung deutlich gesteigert und könnte die erhöhten ANP-Plasmaspiegel bei Patienten mit Herzinsuffizienz erklären. Dagegen wurde durch atriale Dehnung (als adäquaten Freisetzungsreiz am gesunden Herzen) keine weitere Steigerung der ANP-Freisetzung in der Shuntgruppe bewirkt. Die ANP-Freisetzung am insuffizienten Herzen ist im Vergleich zur normalen Herzfunktion somit verändert. Unter PKC-Stimulation sank die Freisetzung von ANP in der Shuntgruppe erheblich ab, wogegen es in der Kontrollgruppe zu keiner signifikanten Änderung der ANP-Sekretion kam. Damit wurde der Verdacht erhärtet, dass die Proteinkinase C in die abweichende Regulation der ANP-Freisetzung bei Herzinsuffizie! nz involviert ist. / BJECTIVE: Plasma levels of atrial natriuretic peptide (ANP) are markedly increased in congestive heart failure. ANP has been shown to be released by cardiomyocytes during atrial (and thereby cardiomyocytical) stretch. Several factors that are activated in heart failure as well enhance ANP release through the interaction with G(alpha-q)-coupled receptors and the consequent activation of proteinkinase C (PKC). The goal of this study was to analyse stretch induced ANP secretion and to investigate the involvement of PKC in the regulation of ANP release in heart failure compared to normal hearts. METHODS: Volume overload induced heart failure was produced by an infrarenal aortocaval shunt (4 weeks) in Wistar rats. ANP release was analysed in an isolated retrogradly perfused heart preparation. Atrial stretch was induced by switching to anterograd perfusion (perfusion pressure: 10mmHg). For PKC activation PMA (phorbol 12 myristate 13 acetate) was added to the perfusate and compar! ed to vehicle treatment. All experiments were performed with shunt and sham operated rats. RESULTS AND CONCLUSIONS: After shunt operation ANP baseline release was considerably augmented and could thus explain elevated ANP plasma levels in heart failure patients. In contrast, atrial stretch as an adequate secretion stimulus in control hearts did not further enhance ANP release in hearts of shunt operated animals. The ANP secretion in heart failure therefore seems to differ from the ANP secretion in the healthy state. Stimulation of PKC markedly decreased ANP release in the shunt group, whereas it did not have any significant effect on ANP release in the control group. In conclusion, the role of the proteinkinase C in ANP release differs between normal and failing hearts and seems to be involved in the deviating regulation of ANP release in states of heart failure.
182

Papel dos lípides plasmáticos e fatores pró-inflamatórios na fisiopatologia da insuficiência cardíaca / Role of plasma lipids and pro inflammatory factors in the patho physiology of heart failure

Martinelli, Ana Elisa Marabini 19 May 2017 (has links)
Introdução: A Organização Mundial da Saúde estimou em 2015 que 23 milhões de pessoas em todo o mundo sofrem de insuficiência cardíaca (IC), com taxas de mortalidade equivalentes às do câncer. Níveis mais elevados de HDL-colesterol têm sido associados com maior sobrevivência na IC. É consensual que as várias funções protetoras da HDL devem ser exploradas além da concentração de HDL-colesterol. Transferência de lípides para HDL, mediada por proteínas de transferência CETP e PLTP, é uma etapa importante no transporte reverso de colesterol e metabolismo de HDL.,Desenvolvemos um ensaio in vitro para avaliar as transferências de lípides para a HDL, mostrando que esse fenômeno é alterado em várias condições, como na doença arterial coronária, no diabetes mellitus e pelo estilo de vida sedentário. Recentemente, tem sido descrito que a HDL transporta pequenos RNAs não codificadores de proteína, os chamados microRNAs (miRNAs). Alguns miRNAs foram descritos como reguladores críticos do metabolismo das lipoproteínas. O objetivo deste estudo foi comparar lípides plasmáticos, transferência lipídica para HDL, perfil inflamatório, miRNAs relacionados ao metabolismo de lipoproteínas obtidos de pacientes com IC e de pacientes sem IC (sem-IC). Métodos: Quarenta e oito pacientes com IC foram avaliados, 25 em classe funcional NYHA I e II (IC-I/II) e 23 em NYHA III e IV (IC-III/IV), bem como 50 pacientes sem-IC pareados por gênero e idade. Todos os pacientes com IC apresentavam uma fração de ejeção <=40%. Foram determinadas as concentrações plasmáticas de CETP, LCAT, LDL oxidada (LDLox) e atividade de paraoxonase 1 (PON-1). Transferências de lípides para a HDL foi avaliada a partir da incubação de uma nanopartícula artificial com plasma total. A expressão de miRNAs circulantes envolvidos no metabolismo das lipoproteínas também foi analisada. Resultados: Os níveis de colesterol total, LDL e HDL e triglicérides não diferiram entre os três grupos. A concentração da apolipoproteína A-I foi menor no grupo IC-I/II em comparação ao grupo sem-IC (125±23 versus 142±19; p < 0,05), enquanto que a concentração da apolipoproteína B foi menor em ICIII/ IV comparado ao sem-IC (81±35 versus 114±40; p < 0,001). A transferência de colesterol esterificado (5,44±1,76 versus 6,26±0,85), fosfolípides (19,05±2,5 versus 20,21±1,45) e de triglicérides (6,29±2,05 versus 7,40±1,47) foi menor no grupo IC-III/IV do que no grupo sem-IC (p < 0,05). No entanto, não houve diferença nas transferências entre IC-I/II e sem-IC. A concentração de LDLox foi menor em ambos os grupos com IC comparados ao sem-IC (p < 0,0001). A massa de CETP foi menor em IC-III/IV do que em IC-I/II (2,77±1,3 versus 3,78±1,3; p=0,021). A concentração de LCAT e a atividade de PON-1 não foram diferentes entre os grupos. A análise da expressão dos miRNAs circulantes miR-33a, miR-144, miR-185, miR-125, miR-758, miR-26a, miR- 106b, miR-122 e miR-30c, mostrou-se significantemente aumentada nos indivíduos com IC em comparação aos indivíduos sem-IC, ao passo que o miR- 10b foi o único encontrado diminuído na IC comparado com indivíduos sem-IC (p=0,007). Conclusão: Em pacientes com IC mais severa e sintomática da IC, o processo de transferência de lípides para a HDL está deficiente, bem como alguns dos mecanismos que o regulam, e possivelmente estas alterações influenciem no transporte reverso do colesterol e nas funções protetoras da HDL desses pacientes / Background: World Health Organization estimated that there were twentythree million subjects worldwide suffering from heart failure (HF) in 2015, with mortality rates equivalent to those of cancer. Higher HDL-cholesterol levels have been associated with longer survival in HF. It is now consensual that the various protective functions of HDL should be explored beyond HDLcholesterol. Transfer of lipids to HDL, mediated by transfer proteins CETP and PLTP, is an important step in reverse cholesterol transport and HDL metabolism. Previously, we developed an in vitro assay to test those lipid transfers and showed that transfer of cholesterol to HDL is altered in several conditions, such as coronary artery disease (CAD), diabetes and sedentary lifestyle. Recently, HDL transports small non-coding RNA molecule, called micro RNAs (miRNAs). Some miRNA are critical regulators of lipoprotein metabolism. The aim of this study was compare plasma lipids, lipid transfers to HDL, inflammatory profile, miRNAs related to plasma lipids from patients with HF with those from patients with without HF (non-HF). Methods: Forty-eight HF patients were studied, 25 with functional class NYHA I and II (HF I/II) and 23 with NYHA III and IV (HF III/IV), as well as 50 non-HF patients matched for gender, age and BMI. All HF had ejection fraction <= 40%. CETP, LCAT, oxidized LDL (oxLDL) and paraoxonase 1 (PON-1) activity were determined. Transfers of lipids from a donor artificial nanoparticle to HDL was determined by an in vitro assay in which the emulsion was incubated with whole plasma. Expression of circulating miRNAs involved in cholesterol metabolism was also analyzed. Results: Total, LDL and HDL cholesterol and triglycerides did not differ among the 3 groups. Apolipoprotein A-I was lower in NYHA I/II group compared to non- HF (125±23 versus 142±19; p < 0.05) and apo B was lower in NYHA III/IV group compared to non-HF (81±35 versus 114±40, p < 0.001). The transfer of esterified cholesterol (5.44±1.76 versus 6.26±0.85), phospholipids (19.05±2.5 versus 20.21±1.45) and of triglycerides (6.29±2.05 versus 7.40±1.47) to HDL was lower in HF-III/IV than in non-HF (p < 0.05), but lipid transfers were not different between HF-I/II and non-HF. oxLDL was lower in both HF groups compared to non-HF (p < 0.0001). CETP mass was lower in HF-III/IV than in HF-I/II (2.77±1.3 versus 3.78±1.3; p=0.021). LCAT and PON-1 activity was not different among the groups. Regarding to miRNA, miR-33a, miR-144, miR-185, miR-125, miR- 758, miR-26a, miR-106b, miR-122 e miR-30c were significantly increased in HF compared to non-HF subjects, whereas miR-10b was the only one found to be decreased in HF compared to non-HF subjects (p=0.007). Conclusion: In patients with the more severe and symptomatic HF, the lipid transfer to HDL is deficient, as well as some mechanisms that regulate it, and possibly these changes influence reverse cholesterol transport and the protective functions of HDL in these patients
183

Early Risk Stratification, Treatment and Outcome in ST-elevation Myocardial Infarction

Björklund, Erik January 2005 (has links)
<p>We evaluated, in patients with ST-elevation myocardial infarction (STEMI) treated with thrombolytics, admission Troponin T (tnT), ST-segment resolution and admission N-terminal pro-brain natriuretic peptide (NT-proBNP) for early risk stratification as well as time delays and outcome in real life patients according to prehospital or in-hospital thrombolytic treatment. Also, baseline characteristics, treatments and outcome in patients enrolled in the ASSENT-2 trial in Sweden and in patients not enrolled were evaluated. </p><p>TnT (n=881) and NT-proBNP (n=782) on admission and ST-resolution at 60 minutes (n=516) in patients from the ASSENT-2 and ASSENT-PLUS trials were analysed. Elevated levels of NT-proBNP and tnT on admission were both independently related to one-year mortality. However, when adding information on ST-resolution (</≥50%) 60 minutes after initiation of thrombolytic treatment, tnT no longer contributed independently to mortality prediction. High and low risk patients were best identified by a combination of NT-proBNP and ST-resolution at 60 minutes.</p><p>We investigated consecutive STEMI patients included in the RIKS-HIA registry between 2001 and 2004, if they were ambulance transported and had received prehospital (n=1690) or in-hospital (n=3685) thrombolytic treatment. Prehospital diagnosis and thrombolysis reduced the time to thrombolysis by almost one hour, were associated with better left ventricular function and fewer complications and reduced the adjusted one-year mortality by 30% compared with in-hospital thrombolysis. </p><p>Prospective data from the RIKS-HIA registry on STEMI patients treated with thrombolytics were linked to data on trial participants in the ASSENT-2 trial of thrombolytic agents and used for direct comparisons. Patients treated with thrombolytics and not enrolled in a clinical trial at trial hospitals (n=2048) had higher risk characteristics, more early complications and twice as high adjusted one-year mortality compared to those enrolled (n=729). One major reason for the difference in outcome appeared to be the selection of less critically ill patients to the trial.</p>
184

Coagulation, Inflammation and Myocardial Dysfunction in Unstable Coronary Artery Disease and the Influence of Glycoprotein IIb/IIIa Inhibition and Low Molecular Weight Heparin

James, Stefan January 2003 (has links)
Hjärt-kärl sjukdom är den vanligaste dödsorsaken i västvärlden. Samtidigt som antalet patienter med hjärtinfarkt har minskat, har antalet patienter med instabil kranskärlsjukdom d.v.s. svår kärlkramp ökat påtagligt. Diagnosen är nu den vanligaste orsaken till vård på hjärtinfarktavdelningar i Sverige. Modern behandling av instabil kranskärlssjukdom består av en kombination av läkemedel för att minska blodproppsbildning och avlasta hjärtarbetet samt, i de flesta fall, s.k. ballongvidning eller operation av hjärtats kranskärl. Trots stora behandlingsframsteg är risken för hjärtinfarkt och död hög, såväl på kort som lång sikt. Det finns därför ett stort behov av ytterligare förbättrad behandling utan att samtidigt erhålla oacceptabelt hög risk för allvarliga biverkningar. För att erbjuda en effektiv behandling till patienter med hög risk och samtidigt undvika dyr och potentiellt riskfylld behandling till patienter med låg risk behövs också bättre instrument för tidig riskbedömning. Syftet med avhandlingen var att undersöka en stor grupp patienter med instabil kranskärlssjukdom avseende säkerhet och effektivitet av en behandlingskombination av två moderna blodproppshämmande läkemedel, dalteparin och abciximab (ca 1000 patienter). Syftet var också att studera hur denna behandling påverkar system för inflammation och koagulation (ca 400 patienter). Dessutom ville vi värdera hur blodnivåer av markörer för inflammation, hjärtmuskelskada och nedsatt hjärtfunktion kan förutsäga risken för framtida komplikationer (ca 7000 patienter). Tillägg av abciximab till dalteparin minskade inte risken för dödsfall eller hjärtinfarkt inom trettio dagar. Däremot ökade antalet blödningskomplikationer. Totala antalet blödningar var emellertid relativt lågt och behandlingen syntes vara lika säker som kombinationen av abciximab och det internationellt mycket använda blodproppshämmande medlet heparin. Trots den kraftfulla behandlingskombinationen skedde en samtidig aktivering av system för såväl inflammation som koagulation. Detta kan vara en orsak till den observerade avsaknaden av behandlingseffekt av abciximab. Att hindra denna aktivering skulle samtidigt kunna innebära möjligheter för nya behandlingsstrategier. Förhöjda nivåer av markörer för hjärtmuskelskada (troponin T), inflammation (CRP), nedsatt hjärtfunktion (proBNP) eller nedsatt njurfunktion (kreatininclearance) ökade risken för dödlig utgång både på kort och lång sikt, oberoende av andra riskfaktorer. En kombination av två av dessa markörer gav den högsta risken för dödlig utgång. Således dog endast 0.3 % av patienter med låga nivåer av proBNP och normal njurfunktion inom ett år, jämfört med 25.7 % av patienter med höga nivåer av proBNP och nedsatt njurfunktion. Förhöjda nivåer av troponin T eller nedsatt kreatininclearance (men inte av CRP eller proBNP) ökade dessutom risken för hjärtinfarkt. Resultaten i avhandlingsarbetet har givit kliniskt tillämpbar kunskap om hur kärlkrampspatienter med hög respektive låg risk kan selekteras tidigt efter inkomst till sjukhus och ny kunskap om behandlingseffekt av abciximab och dalteparin. Resultaten har redovisats på internationella kongresser och i högt rankade medicinska tidskrifter och har citerats i europeiska och amerikanska ”guidelines” för behandling av instabil kranskärlssjukdom. / Patients with unstable coronary artery disease (CAD) have an increased risk of subsequent myocardial infarction and death. This study evaluated the safety and efficacy of treatment with glycoprotein IIb/IIIa inhibition in addition to aspirin, low molecular-weight heparin and its influence on coagulation and inflammation. Also, early and differentiated risk assessment utilising markers of inflammation, myocardial damage and dysfunction were evaluated. The Global Utilisation of Strategies To open Occluded arteries- IV (GUSTO-IV) trial randomised 7800 patients with unstable CAD to 24 or 48 hours infusion of abciximab or placebo in addition to routine treatment with aspirin and unfactionated heparin or dalteparin. Baseline levels of creatinine, C-reactive protein (CRP), Troponin-T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were analysed. At selected sites, all patients received subcutaneous dalteparin (n=974), in stead of unfractionated heparin infusion (n=6826). In a sub-population of dalteparin treated patients (n=404), serial measurements of markers of inflammation , coagulation and fibrinolysis were also performed. Addition of abciximab to dalteparin as the primary treatment of unstable CAD was not associated with any significant reduction in cardiac events but a doubled risk of bleedings. The combination of abciximab and dalteparin seemed to be as safe as when used with unfractionated heparin. Despite full dose dalteparin and aspirin there was a simultaneous activation of the inflammation, coagulation and fibrinolysis systems without any influence of the abciximab treatment. Elevated levels of CRP, TnT, and NT-proBNP and reduced creatinine clearance were independently related to short and long-term mortality. The best prediction of high and low risk was provided by a combination of NT-proBNP and creatinine clearance. Any detectable elevation of TnT and reduced creatinine clearance, but neither elevation of CRP nor NT-proBNP, were also independently associated to a raised risk of subsequent myocardial infarction.
185

Early Risk Stratification, Treatment and Outcome in ST-elevation Myocardial Infarction

Björklund, Erik January 2005 (has links)
We evaluated, in patients with ST-elevation myocardial infarction (STEMI) treated with thrombolytics, admission Troponin T (tnT), ST-segment resolution and admission N-terminal pro-brain natriuretic peptide (NT-proBNP) for early risk stratification as well as time delays and outcome in real life patients according to prehospital or in-hospital thrombolytic treatment. Also, baseline characteristics, treatments and outcome in patients enrolled in the ASSENT-2 trial in Sweden and in patients not enrolled were evaluated. TnT (n=881) and NT-proBNP (n=782) on admission and ST-resolution at 60 minutes (n=516) in patients from the ASSENT-2 and ASSENT-PLUS trials were analysed. Elevated levels of NT-proBNP and tnT on admission were both independently related to one-year mortality. However, when adding information on ST-resolution (&lt;/≥50%) 60 minutes after initiation of thrombolytic treatment, tnT no longer contributed independently to mortality prediction. High and low risk patients were best identified by a combination of NT-proBNP and ST-resolution at 60 minutes. We investigated consecutive STEMI patients included in the RIKS-HIA registry between 2001 and 2004, if they were ambulance transported and had received prehospital (n=1690) or in-hospital (n=3685) thrombolytic treatment. Prehospital diagnosis and thrombolysis reduced the time to thrombolysis by almost one hour, were associated with better left ventricular function and fewer complications and reduced the adjusted one-year mortality by 30% compared with in-hospital thrombolysis. Prospective data from the RIKS-HIA registry on STEMI patients treated with thrombolytics were linked to data on trial participants in the ASSENT-2 trial of thrombolytic agents and used for direct comparisons. Patients treated with thrombolytics and not enrolled in a clinical trial at trial hospitals (n=2048) had higher risk characteristics, more early complications and twice as high adjusted one-year mortality compared to those enrolled (n=729). One major reason for the difference in outcome appeared to be the selection of less critically ill patients to the trial.
186

Prävalenz, Risikofaktoren und klinische Ausprägung der systolischen und diastolischen Herzinsuffizienz in einem hausärztlichen Risikokollektiv sowie Wertigkeit echokardiographischer Parameter und natriuretischer Peptide zur Diagnosestellung der diastolischen Herzinsuffizienz / Prevalence, risk factors and clinical characteristics of systolic and diastolic heart failure in patients with risk factors for heart failure from general practitioner`s practice and diagnostic relevance of echocardiography and natriuretic peptides for diastolic heart failure.

Scheele, Frauke 10 August 2011 (has links)
No description available.
187

Modulation of Oxytocin Receptors in Right Ventricular Hypertrophy

Wang, Yang 04 1900 (has links)
L’hypertension pulmonaire (HP) est une maladie dont l’étiologie est inconnue et qui entraîne ultimement une défaillance du ventricule droit (VD) et le décès. L’HP peut être induite chez le rat par la la monocrotaline (MCT), un alcaloïde pyrrolizidique extrait de la plante Crotalaria Spectabilis, causant des lésions à l’endothélium des artères pulmonaires, menant à un épaississement de ces dernières et à une augmentation de la résistance vasculaire. Ceci à pour conséquence de causer une hypertrophie du VD, de l’inflammation, une dysfonction endothéliale NO-dépendante des artères coronariennes et une augmentation des peptides natriurétiques circulants. Objectif: Nous avons testé l’hypothèse selon laquelle l’étiopathologie de l’HP impliquerait le récepteur à ocytocine (OTR) dû à son implication fonctionnelle avec les cytokines inflammatoires et la libération du peptide natriurétique atrial (ANP) et du NO. Méthodes: Des rats mâles Sprague-Dawley pesant 220-250g reçurent une seule injection sous-cutanée de MCT (60 mg/kg). 6 à 7 semaines (46±1 jours) suivant l’injection, les rats furent sacrifiés et l’expression génique et protéique fut déterminée par PCR en temps réel et par western blot, respectivement, dans le VD et le ventricule gauche (VG) Résultats: Les rats traités au MCT démontrèrent une augmentation significative du VD. Une hypertrophie du VD était évidente puisque le ratio du VD sur le VG ainsi que le poids du septum étaient près de 77% plus élevés chez les rats traités au MCT que chez les rats contrôles. Le traitement au MCT augmenta l’expression génique d’ANP (3.7-fois dans le VG et 8-fois dans le VD) ainisi que le NP du cerveau (2.7-fois dans le VG et 10-fois dans le VD). Les transcrits de trois récepteurs de NP augmentèrent significativement (0.3-2 fois) seulement dans le VD. L’expression protéique de la NO synthase (iNOS) fut également augmentée de façon sélective dans le VD. Par contre, les transcripts de NOS endothéliale et de NOS neuronale étaient plus élevés (0.5-2 fold) dans le VG. L’ARNm et l’expression protéique d’OTR furent diminués de 50% dans le VD, tandis qu’une augmentation de l’expression des cytokines IL-1β and IL-6 fut observée. L’ARNm de Nab1, un marqueur d’hypertrophie pathologique, fut augmentée de deux-fois dans le VD. Conclusion: L’augmentation d’expression génique de NP dans le VD des rats traités au MCT est associée à une augmentation des transcripts du récepteur NP, suggérant une action locale de NP dans le VD durant l’HP. L’expression d’OTR est atténuée dans le VD, possiblement par des cytokines inflammatoires puisque le promoteur du gène de l’OTR contient de multiples éléments de réponse aux interleukines. Diminuer l’expression d’OTR dans le VD durant l’hypertension pulmonaire pourrait influencer de manière positive la fonction cardiaque car l’OTR régule la contractilité et le rythme cardiaque. Mots clés: hypertension pulmonaire, hypertrophie du ventricule droit monocrotaline, récepteur à ocytocine, inflammation, peptides natriurétiques. / Pulmonary hypertension (PH) is a disease of unknown etiology that ultimately causes failure of right ventricle (RV) with a lethal outcome. PH can be induced in the rat with monocrotaline (MCT), a pyrrolizidine alkaloid from the plant Crotolaria spectabilis that damages the pulmonary artery endothelium leading to thickening of the pulmonary arteries and increased vascular resistance. This subsequently results in RV hypertrophy, inflammation, nitric oxide (NO)-associated coronary endothelial dysfunction and increment of natriuretic peptides (NP) in the circulation. Objective: We verified hypothesis that the etiopathogenesis of PH involves the oxytocin receptor (OTR) because of its functional association with inflammatory cytokines and release of atrial natriuretic peptide (ANP) and NO. Methods: Male Sprague-Dawley rats weighing 220-250g received a single subcutaneous injection of 60 mg/kg of MCT. Six to 7 weeks (46±1 days) following the injection, rats were sacrificed and gene and protein expression were detected by real-time PCR and western-blot analysis, respectively, in the RV and LV (left ventricle). Results: MCT-treated rats displayed significant increases in RV weight. RV hypertrophy was evident as the ratio of the RV to LV plus septum weight was nearly 77% higher in MCT-treated rats compared to control rats. MCT treatment increased transcripts of ANP (3.7-fold in the LV and 8-fold in RV) and brain NP (2.7-fold in the LV and 10-fold in RV). Transcripts for three NP receptors significantly increased (0.3-2 fold) only in the RV. iNOS (inducible NO synthase) protein expression also increased selectively in the RV. In contrast, the endothelial NOS and neural NOS transcripts heightened (0.5-2 fold) in the LV. Both OTR mRNA and protein were decreased by 50% in the RV, whereas an up-regulation of cytokines IL-1β and IL-6 was observed. Nab1 mRNA, a marker of pathological hypertrophy, increased two-fold in the RV. Conclusion: Increased gene expression of NP in the RV of the MCT-treated rat correlates with upregulation of NP receptor transcripts indicating local NP action in the RV during PH. OTR expression is decreased in the RV possibly by inflammatory cytokines, IL-1 and IL-6 because OTR promoter region contains multiple putative interleukin-response elements. Lowering OTR in RV during pulmonary hypertension can influence cardiac function since OT regulates heart rate and cardiac contractility and is linked with cardioprotective system ANP and NO. Keywords: pulmonary hypertension, right ventricular hypertrophy, monocrotaline, oxytocin receptor, inflammation, natriuretic peptides.
188

Le syndrome métabolique chez les congéniques du rat Dahl : influence de la diète et rôle du récepteur de l'ANP

Fillion-Forté, Valérie 03 1900 (has links)
L’hypertension artérielle et l’obésité sont deux composantes conjointement reliées du syndrome métabolique. Les récepteurs de l’ANP (GCA) et de l’oxyde nitrique (GCs) ont des propriétés diurétiques, natriurétiques, vasodilatatrices et sont liés au contrôle de la pression. Des études récentes ont démontré leur implication dans l’obésité. Hypothèse : Une différence génétique au niveau du gène GCA pourrait contribuer à des différences physiologiques. La composante lipidique et/ou sodique de la diète pourrait influencer la fonction rénale, cardiaque et les valeurs anthropométriques différemment chez les souches congéniques. Objectifs : (1) Déterminer l’effet de la composante lipidique et sodique des diètes; (2) Évaluer l’influence de GCA sur la réponse physiologique des souches congéniques; (3) Expliquer les mécanismes physiologiques procurant une réduction de la pression artérielle chez la souche SM9. Méthodologie : Des modèles congéniques du rat Dahl (DSS) hypertendu, nourri avec une diète riche en gras (HF) ou normale (NF), ont été utilisés pour démontrer l’impact d’un segment chromosomique d’origine normotendue. Résultats : La souche SM9 a une prise de poids plus importante que SM12 et DSS sur diète HF malgré un apport alimentaire équivalent. La souche SM9 présente également un ratio masse adipeuse/masse maigre plus élevé que SM12 et DSS. Nous n’avons observé aucune augmentation de la pression artérielle en réponse à la diète HF pour les 3 souches malgré une augmentation du dommage rénal pour les 3 souches. Le dommage rénal est plus important chez DSS que pour les 2 congéniques. La réponse diurétique à l’ANP est plus élevée chez SM9 et est influencée par le contenu en sel dand la diète. La perte glomérulaire plus importante chez le rat DSS semble compensée par une augmentation de la réponse à l’ANP par les glomérules résiduels. Il y a une corrélation entre l’activité de GCA en réponse à l’ANP, les niveaux d’ARNm et le nombre de répétition du dinucléotide TA dans son promoteur. Le rat DSS présente une hypertrophie cardiaque plus importante que les deux souches congénique et ceci n’est pas modifié par la diète HF. Conclusion : Nos études ont permis de mettre en évidence un effet génétique impliquant le segment chromosomique normotendu contenant GCA dans la réponse à une diète HF chez le rat DSS. / Hypertension and obesity are two related components of the metabolic syndrome. The ANP receptor (GCA) and nitric oxide receptor (sGC) have diuretic, natriuretic, vasodilatory properties, and are linked to blood pressure control. Furthermore a recent study has demonstrated the implication of GCA and sGC in the development of obesity. Hypothesis: A genetic difference in GCA gene could contribute to physiological differences. The differencial lipid and/or sodium composition of the diet could influence the renal, cardiac and anthropometric values. Objectives: (1) To determine the effect of fat and sodium on the physiological parameters; (2) To evaluate the influence of GCA on the physiological response of the congenic rat; (3) To explain the mechanisms of the blood pressure reduction in SM9 rats. Methodology: Congenic model of DSS rat, fed with either high fat (HF) or normal (NF) diet, were used to demonstrate the impact of a chromosome segment from normotensive origin on physiological functions. C2SM9 contains GCA and sGC from normotensive origin while C2SM12 harbours only sGC from normotensive origin. Results: HF diet had negative feature on body composition, renal damage, creatinine clearance and inhibited the diuretic/natriuretic effect of ANP. The normotensive segment including GCA and sGC has reduced the blood pressure, improve the renal damage and increased the diuretic/natriuretic capacity of SM9 in response to ANP injection when compared to SM12 and DSS. GCA mRNA and the clearance receptor ratio were reduced in SM9 in the renal cortex and retroperitoneal fat. SM12 and SM9, containing the chromosomal segment that includes sGC, improve their lipid profile compared with DSS. Conclusion: Our results suggested a compensatory increase in the GCA levels for SM12 and DSS that is insufficient to improve their pathophysiologic status as observed in SM9. HF diet increases the metabolic syndrome in those rats.
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Biomarkers for cardiovascular risk prediction in people with type 2 diabetes

Price, Anna Helen January 2017 (has links)
Introduction: Type 2 diabetes continues to be one of the most common non-communicable diseases worldwide and complications due to type 2 diabetes, such as cardiovascular disease (CVD) can cause severe disability and even death. Despite advances in the development and validation of cardiovascular risk scores, those used in clinical practice perform inadequately for people with type 2 diabetes. Research has suggested that particular non-traditional biomarkers and novel omics data may provide additional value to risk scores over-and-above traditional predictors. Aims: To determine whether a small panel of non-traditional biomarkers improve prediction models based on a current cardiovascular risk score (QRISK2), either individually or in combination, in people with type 2 diabetes. Furthermore, to investigate a set of 228 metabolites and their associations with CVD, independent of well-established cardiovascular risk factors, in order to identify potential new predictors of CVD for future research. Methods: Analyses used the Edinburgh Type 2 Diabetes Study (ET2DS), a prospective cohort of 1066 men and women with type 2 diabetes aged 60-75 years at baseline. Participants were followed for eight years, during which time 205 had a cardiovascular event. Additionally, for omics analyses, four cohorts from the UCL-LSHTM-Edinburgh-Bristol (UCLEB) consortium were combined with the ET2DS. Across all studies, 1005 (44.73%) participants had CVD at baseline or experienced a cardiovascular event during follow-up. Results: In the ET2DS, higher levels of high sensitivity cardiac troponin (hs-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) and lower levels of ankle brachial pressure index (ABI) were associated with incident cardiovascular events, independent of QRISK2 and pre-existing cardiovascular disease (odds ratios per one SD increase in biomarker 1.35 (95% CI: 1.13, 1.61), 1.23 (1.02, 1.49) and 0.86 (0.73, 1.00) respectively). The addition of each biomarker to a model including just QRISK2 variables improved the c-statistic, with the biggest increase for hs-cTnT (from 0.722 (0.681, 0.763) to 0.732 (0.690, 0.774)). When multiple biomarkers were considered in combination, the greatest c-statistic was found for a model which included ABI, hs-cTnT and gamma-glutamyl transpeptidase (0.740 (0.699, 0.781)). In the combined cohorts from the UCLEB consortium, a small number of high-density lipoprotein (HDL) particles were found to be significantly associated with CVD: concentration of medium HDL particles, total lipids in medium HDL, phospholipids in medium HDL and phospholipids in small HDL. These associations persisted after adjustment for a range of traditional cardiovascular risk factors including age, sex, blood pressure, smoking and HDL to total cholesterol ratio. Conclusions: In older people with type 2 diabetes, a range of non-traditional biomarkers increased predictive ability for cardiovascular events over-and-above the commonly used QRISK2 score, and a combination of biomarkers may provide the best improvement. Furthermore, a small number of novel omics biomarkers were identified which may further improve risk scores or provide better prediction than traditional lipid measurements such as HDL cholesterol.
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Příspěvek vyšetření BNP ke zpřesnění prognózy nemocných s pokročilým srdečním selháním / Contribution of BNP to prognostic stratification of patients with advanced heart failure.

Hegarová, Markéta January 2017 (has links)
Plasma levels of B-type natriuretic peptide (BNP) are a strong and independent predictor of prognosis in patients with advanced heart failure (CHF). However, the importance of this biomarker has been documented only in CHF of common causes such as dilated or ischemic cardiomyopathy. We hypothesized that BNP can serve as a strong predictor of end-stage CHF in group of patients with advanced CHF due to congenital heart disease (CHD) with the right ventricle in systemic position (SRV). The second hypothesis was that BNP monitoring in patients with implanted left ventricular assist device (LVAD) Heart Mate II could detect serious complications which negatively affect prognosis. We performed a retrospective analysis in 28 consecutive patients with severe systolic dysfunction of the SRV (ejection fraction 23 ± 6%) evaluated as heart transplant (HTx) candidates between May 2007 and October 2014. During a median follow-up of 29 months (interquartile range, 9-50), 14 pts reached primary endpoints of the study (death, urgent HTx, and LVAD implantation). We have considered these events equivalent to end-stage CHF. Using ROC analysis, we identified the first measured value of BNP as the strongest predictor of prognosis with the area under the curve (AUC) of 1.00, followed by the New York Heart Association...

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