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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.
1

Diagnosis of erectile dysfunction can be used to improve screening for Type 2 diabetes mellitus

Carrillo-Larco, Rodrigo M., Luza-Dueñas, Anais Casandra, Urdániga-Hung, Mónica, Bernabe-Ortiz, Antonio 11 1900 (has links)
Aims: To assess the diagnostic accuracy of four undiagnosed Type 2 diabetes mellitus risk scores accounting for erectile dysfunction status. Methods: This was a population-based cross-sectional study. Type 2 diabetes was defined according to a oral glucose tolerance test and self-reported physician diagnosis. Erectile dysfunction was defined according to the answer to the question, ‘Have you had difficulties obtaining an erection in the last 6 months?’ (yes/no). The risk scores used were the FINDRISC, LA-FINDRISC, American Diabetes Association score and the Peruvian Risk Score. A Poisson regression model was fitted to assess the association between Type 2 diabetes and erectile dysfunction. The area under the receiver-operating characteristic curve was estimated overall and by erectile dysfunction status. Results: A total of 799 men with a mean (sd) age of 48.6 (10.7) years were included in the study. The overall prevalence of Type 2 diabetes was 9.3%. Compared with healthy men, men with Type 2 diabetes had 2.71 (95% CI 1.57–4.66) higher chances of having erectile dysfunction. Having excluded men aware of Type 2 diabetes status (N=38), the area under the receiver-operating characteristic curve of three of the risk scores (not the American Diabetes Association score) improved among those who had erectile dysfunction in comparison with those who did not; for example, the area under the receiver-operating characteristic curve of the LA-FINDRISC score was 89.6 (95% CI 78.7–99.9) in men with erectile dysfunction and 76.5 (95% CI 68.5–84.4) overall. Conclusions: In a population-based study, erectile dysfunction was more common in men with Type 2 diabetes than in the otherwise healthy men. Screening for erectile dysfunction before screening for Type 2 diabetes seems to improve the accuracy of well-known risk scores for undiagnosed Type 2 diabetes. / Antonio Bernabe-Ortiz is a Research Training Fellow in Public Health and Tropical Medicine (103994/Z/14/Z), funded by the Wellcome Trust. / Revisión por pares
2

Novel Strategies in Cardioprotection against Ischemia/Reperfusion Injury

Salloum, Fadi N. 01 January 2005 (has links)
Cell damage represents a major pathomechanism in many diseases of high clinical interest, such as myocardial infarction (MI), where it plays an important role in ischemia-reperfusion (I/R) injury. Considerable progress has been made towards identifying physiological and pharmacological agents that play a key role in myocardial preconditioning against I/R injury and also elucidating the molecular changes leading to such protection.Second messengers in cellular signaling pathways, such as cGMP have been well implicated as key players in ischemic and pharmacological preconditioning (PC) of the heart. Phosphodiesterase type 5 (PDE-5) is an enzyme that specifically hydrolyzes cGMP thereby decreasing its tissue concentration. Sildenafil is a potent selective inhibitor of PDE-5 and therefore allows the accumulation of cGMP in several tissues shown to express PDE-5, including pulmonary and coronary arteries. We initially hypothesized that vasodilation induced by sildenafil may release several endogenous mediators including adenosine, bradykinin or nitric oxide (NO), that may trigger a signaling cascade leading to protection against I/R injury. Our results show that sildenafil, at a clinically relevant dose, induced powerful acute and delayed cardioprotection against I/R injury in an in vivo rabbit model via opening of mitoKATP channels. The acute cardioprotective effect of sildenafil was dependent on activation of protein kinase C in rabbits. Moreover, we observed that sildenafil induced delayed PC by NO produced through activation of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in the mouse heart. The expression of iNOS/eNOS was regulated by ERK phosphorylation and the delayed protection against I/R was blocked by PD98059, a selective ERK inhibitor. Furthermore, sildenafil-induced delayed protection was abolished in the intact heart as well as adult myocytes derived from adenosine A1 receptor knock-out mice suggesting an essential role of A1 receptor in protection. Taken together, these studies suggest that sildenafil is a powerful tool to reduce I/R injury in the animal models. Future clinical studies with relatively safe and effective PDE-5 inhibitors may have an enourmous impact on the use of these compounds in reducing I/R injury in the heart and other organs.
3

Efeitos da inibição da fosfodiesterase-5 sobre a disfunção diastólica do ventrículo esquerdo em pacientes com hipertensão arterial resistente = Phosphodiesterase 5 inhibition improves left ventricle diastolic dysfuntion in resistant hipertensive patients / Phosphodiesterase 5 inhibition improves left ventricle diastolic dysfuntion in resistant hipertensive patients

Santos, Rodrigo Cardoso, 1980- 22 August 2018 (has links)
Orientador: Heitor Moreno Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T03:24:36Z (GMT). No. of bitstreams: 1 Santos_RodrigoCardoso_D.pdf: 1300897 bytes, checksum: 316736a36c07e5e655cecc5c8f664bdd (MD5) Previous issue date: 2013 / Resumo: Introdução: A disfunção diastólica do ventrículo esquerdo (DDVE) e a hipertrofia ventricular são consideradas marcadores frequentes para lesão cardíaca e fatores de risco de progressão para insuficiência cardíaca congestiva (ICC), especialmente em pacientes com hipertensão arterial resistente (HAR). A redução dos níveis pressóricos arteriais pode melhorar a disfunção diastólica do ventrículo esquerdo e os sintomas de insuficiência cardíaca. Entretanto, frequentemente esta redução não é atingida nos pacientes com HAR. Inibidores da fosfodiesterase 5 (PDE5) apresentam efeitos vasodilatadores discretos e, recentemente, se demonstrou que a administração de sildenafil a ratos hipertensos melhorou a disfunção diastólica do ventrículo esquerdo, através de ação direta sobre os miócitos cardíacos, evidenciando a presença de PDE5 neste tecido. Objetivo: Avaliar se o uso de um inibidor de PDE5 de longa duração (tadalafil) melhora a DDVE em pacientes com HAR de maneira independente de outros mecanismos secundários. Casuística e Métodos: Realizou-se um estudo intervencionista, cego, controlado por placebo, cruzado de uma via, incluindo 19 pacientes com HAR e DDVE. Inicialmente, receberam por via oral uma dose diária de placebo por 14 dias, com realização de medidas da pressão arterial de consultório e MAPA, avaliação da função endotelial (técnica de FMD), ecocardiograma e medidas de concentrações sanguíneas de BNP-32, GMPc e nitrito, antes e após o período de administração. Posteriormente, repetimos o mesmo procedimento, mas substituindo o placebo por tadalafil 20mg por dia. Ao final, as variáveis obtidas foram comparadas antes e após os usos de tadalafil e placebo, utilizando-se o método t de student pareado, com ?<0,05. Resultados: os pacientes apresentaram melhora da DDVE, demonstrada pela velocidade da onda E de 67,8±18,3cm/s para 77,8±16,0cm/s (p=0,025); relação E/A de 0,9±0,3 para 1,08±0,3 (p=0,01); tempo de desaceleração da onda E de 234,1±46,0ms para 194,4±43,3ms (p<0,01); tempo de relaxamento isovolumétrico de 128,7±17,6ms para 96,8±26,9ms (p<0,01); velocidade de onda E' lateral de 7,7±2,1cm/s para 8,8±2,8cm/s (p=0,025); velocidade de onda S' septal de 6,3±1,4cm/s para 7,7±1,7cm/s (p<0,01) e velocidade de onda S' lateral de 7,5±2,3cm/s para 8,3±2,2cm/s (p=0,014) (todas as variáveis expressas como em média e desvio-padrão). Houve, também, redução nos níveis de BNP-32 de 143±33,3 para 119,3±31,3 pg/mL e aumento no GMPc de 62,4±32,2 para 112,6±75,3pmol/mL. A concentração de nitrito foi semelhante com o uso de placebo e tadalafil. Em relação às medidas de pressão arterial, independentemente do método, também apresentam valores semelhantes antes e após o uso do fármaco, assim como a função endotelial. Os pacientes sob ação do placebo, não mostraram alterações em nenhuma das variáveis avaliadas. Conclusões: Os resultados sugerem que o uso de tadalafil melhora o relaxamento do ventrículo esquerdo em pacientes com HAR, independente da pressão arterial e da função endotelial, podendo constituir um importante tratamento adjunto em pacientes hipertensos sintomáticos com DDVE / Abstract: Introduction: Left ventricular hypertrophy and diastolic dysfunction (LVDD) remain frequent markers of cardiac damage and risk of progression to symptomatic heart failure (HF), especially in resistant hypertension (RHTN). Lowering BP may improve diastolic function and relieve HF symptoms; however, very often this target is not achieved in RHTN subjects. PDE-5 inhibitors have mild systemic vasodilatory effects, and recently, we demonstrated that administration of sildenafil in hypertensive rats improves LVDD, acting in cardiac myocytes with PDE5 expression in this tissue. Objective: To analyze if a long-acting PDE-5 inhibitor (tadalafil) may be clinically useful for improving LVDD in RHTN patients. Methods: We developed a single- blinded, placebo-controlled, one-way crossover, interventional study that enrolled 19 patients with RHTN and LVDD. At first, subjects were given a placebo daily oral dosage, for 2 weeks and they were submitted to blood pressure measurements (both ABPM and office), endothelial function (FMD) assessment, echocardiographic study and plasmatic BNP-32, cGMP and nitrite levels, before and after this 2-week period. Next, subjects were submitted to the same protocol receiving tadalafil (20 mg) orally instead of placebo. Variables were compared before and after placebo and tadalafil administration, using the paired student's t-test. The level of significance (?) accepted was less than 0.05. Results: Patients had an improvement in LVDD represented by changes in E-wave peak velocity from 67.8±18.3cm/s to 77.8±16.0cm/s (p=0.025), E/A ration from 0.9±0.3 to 1.08±0.3 (p=0.01), E wave deceleration time from 234.1±46.0ms to 194.4±43.3ms (p<0.001), isovolumic relaxation time from 128.7±17.6ms to 96.8±26.9ms (p<0.001), lateral E' wave velocity from 7.7±2.1cm/s to 8.8±2.8cm/s (p=0.025), septal S' wave velocity from 6.3±1.4cm/s to 7.7±1.7cm/s (p<0.01) and lateral S' wave velocity from 7.5±2.3cm/s to 8.3±2.2cm/s (p=0.014) (Values are expressed as mean ± standard deviation). We also noticed a decrease in BNP-32 levels from 143±33.3 to 119.3±31.3 pg/mL and an increase in cGMP levels from 62.4±32.2 to 112.6±75.3pmol/mL. No significant differences were detected in office and ABPM measurements, in endothelial function and nitrite levels. Conclusion: The current findings suggest that tadalafil enhances LV relaxation in resistant hypertensive patients and, despite its mild antihypertensive effect, may serve as an important adjunct to treat symptomatic hypertensive patients with evident LVDD / Doutorado / Farmacologia / Doutor em Farmacologia
4

NOVEL STRATEGIES TO IMPROVE METABOLIC PARAMETERS AND PRECONDITION DIABETIC HEARTS AGAINST ISCHEMIA/REPERFUSION INJURY

VARMA, AMIT 16 November 2012 (has links)
Insulin resistance and chronic hyperglycemia promote vascular damage, increase circulating levels of inflammatory cytokines and lead to increased morbidity and mortality. MicroRNAs (miRs) -103/107 have been shown to negatively regulate insulin sensitivity and glucose homeostasis. Based on complimentary binding profiles, the downstream target gene of miR-103/107 is caveolin-1 (Cav-1). We hypothesized that daily administration of the phosphodiesterase-5 inhibitor tadalafil (TAD) ± the curcumin analogue (HO-3867) will attenuate inflammation, improve metabolic parameters and reduce infarct size after ischemia/reperfusion injury (IRI). Furthermore, we propose that TAD therapy will reduce myocardial expression of miR-103/107 and increase mRNA and protein levels of its target gene, Cav-1. Leptin receptor null mice were randomized to receive daily injections of TAD (1mg/kg), HO-3867 (25mg/Kg), combination therapy, or control for 12weeks with weight and fasting glucose monitored weekly. Upon completion, cardiomyocytes were isolated from each group and were subjected to simulated ischemia and reoxygenation (SI/RO) for cell viability and reactive oxygen species (ROS) measurement. Another set were subjected to IRI in a Langendorff model. Plasma samples were taken to measure plasma concentrations of cytokines. For miR expression, total RNA was isolated from TAD and DMSO treated mice and was subjected to reverse transcription and real time PCR using miR assay probes to determine expression. TAD, HO-3867 and the combination of both attenuated fasting glucose levels, reduced myocardial infarct size after IRI and inflammatory cytokines when compared to control (p<0.05 for each vs. control). Cardiomyocytes isolated from each treatment groups and subjected to SI/RO demonstrated reduced necrosis as shown by trypan blue exclusion assay, ROS generation, and improved mitochondrial membrane potential as compared to DMSO (control). Likewise, both mRNA and protein expression of Cav-1 were reduced in diabetic hearts but were significantly increased in TAD treated diabetic mice, which may be a mechanism to improve insulin signaling through downregulation of miR-103/107 and upregulation of Cav-1. These studies suggest that TAD alone or in combination may be a unique strategy to improve metabolic parameters and precondition diabetic hearts against IRI.
5

Η επίδραση της καθημερινής χορήγησης σιλδεναφίλης στα επίπεδα πλάσματος διαλυτών δεικτών της ενδοθηλιακής λειτουργίας σε ασθενείς με στυτική δυσλειτουργία / The impact of daily sildenafil on levels of soluble molecular markers of endothelial function in plasma in patients with erectile dysfunction

Κωνσταντινόπουλος, Αγγελής 03 August 2009 (has links)
Σκοπός: Να διερευνηθεί η επίδραση της καθημερινής χορήγησης σιλδεναφίλης στα επίπεδα διαλυτών δεικτών της ενδοθηλιακής λειτουργίας σε άνδρες με στυτική δυσλειτουργία. Μέθοδοι: Ασθενείς πάνω από 18 ετών με στυτική δυσλειτουργία αγγειακής αιτιολογίας για πάνω από 6 μήνες, είτε μόνη είτε σε συνδυασμό με νοσολογικές καταστάσεις ισχυρά συσχετιζόμενες με ενδοθηλιακή δυσλειτουργία όπως σακχαρώδης διαβήτης/μεταβολικό σύνδρομο, υπέρταση και στεφανιαία νόσος, έλαβαν σιλδεναφίλη 25 mg ημερησίως από του στόματος για 4 εβδομάδες. Δείκτες της ενδοθηλιακής λειτουργίας μετρήθηκαν στο πλάσμα στην αρχή και το τέλος της θεραπείας χρησιμοποιώντας τυπικές μεθόδους και εμπορικά διαθέσιμα υλικά. Αποτελέσματα: 112 άνδρες με μέση ηλικία (SD) 60,6 (7,3) έτη ολοκλήρωσαν το θεραπευτικό πρωτόκολλο. Η χορήγηση 25 mg σιλδεναφίλης καθημερινά για 4 εβδομάδες μείωσε σημαντικά τα επίπεδα της ενδοθηλίνης-1 σε σύγκριση με την αρχή της θεραπείας (2,83 ± 1,63 έναντι 3,24 ± 1,90 pg/ml, p<0,001). Σημαντικές αλλαγές παρατηρήθηκαν επίσης για το οξείδιο του αζώτου (ΝΟ) (35,12 ± 21,14 έναντι 31,91 ± 16,28 pmol/lt, p=0,01), τα επίπεδα της cGMP (3,79 ± 2,37 έναντι 2,70 ± 1.34 pmol/ml, p<0,001) και τον παράγοντα von Willebrand (956,08 ± 514,25 έναντι 1007,42 ± 466,25 mU/ml) αλλά όχι και για τους άλλους δείκτες που μετρήθηκαν (θρομβομοδουλίνη και Ε-σελεκτίνη). Η στυτική λειτουργία βελτιώθηκε επίσης. Συμπεράσματα: Η σιλδεναφίλη σε καθημερινή χορήγηση βελτιώνει την ενδοθηλιακή λειτουργία όπως αυτή εκτιμάται με τα επίπεδα βιολογικών δεικτών σε ασθενείς με στυτική δυσλειτουργία. Αυτά τα αποτελέσματα συμφωνούν με άλλες μελέτες που δείχνουν όμοια αποτελέσματα με θεραπεία με αναστολείς της φωσφοδιεστεράσης 5. Η κλινική σημασία των αποτελεσμάτων αυτών χρήζει περαιτέρω διερεύνησης. / Objective: To investigate the impact of daily sildenafil on levels of soluble molecular markers of endothelial function in men with erectile dysfunction. Methods: Patients over 18 years of age with erectile dysfunction of vascular aetiology for more than 6 months, either alone or in combination with disease states strongly associated with endothelial dysfunction such as diabetes/metabolic syndrome, hypertension and coronary artery disease, received sildenafil 25 mg orally for 4 weeks. Markers of endothelial function were measured in plasma at baseline and end-of-treatment using standard methods and commercially available kits. Results: 112 men with mean (SD) age of 60.6 (7.3) years completed the protocol. Sildenafil 25mg daily for 4 weeks significantly reduced endothelin-1 levels compared to baseline (2.83 ± 1.63 vs. 3.24 ± 1.90 pg/ml, p<0.001). Significant changes were also observed for nitric oxide (35.12 ± 21.14 vs. 31.91 ± 16.28 pmol/lt, p=0.01) and cyclic guanosine monophosphate (3.79 ± 2.37 vs. 2.70 ± 1.34 pmol/ml, p<0.001) and von Willebrand factor (956.08 ± 514.25 vs. 1007.42 ± 466.25 mU/ml) levels but not for the other biomarkers measured (thrombomodulin and E-selectin). Erectile function was significantly improved. Conclusions: Daily sildenafil improves endothelial function as assessed by levels of biomarkers of endothelial function in patients with erectile dysfunction. This is in agreement with other studies showing similar benefits with phosphodiesterase 5 inhibitor treatment. The clinical implications of this finding need further investigation.

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