Search results for "Circulatory system"
showing 10 items of 157 documents
Aestivation Motifs Explain Hypertension and Muscle Catabolism in Experimental Chronic Renal Failure
2020
Chronic renal failure leads to muscle mass loss and hypertension, which according to textbook teaching occur secondary to an inability of the kidneys to excrete solutes and water. We found instead that rats with experimental chronic renal failure constantly lost body water, because their kidneys could not sufficiently concentrate the urine. Physiological adaptation to body water loss, termed aestivation, is an evolutionary conserved survival strategy that relies on complex physiologic-metabolic adjustment across multiple organs to prevent otherwise lethal dehydration. We show that rats with chronic renal failure utilize these ancient water conservation motifs to successfully stabilize their…
Therapy with non-invasive ventilation in patients with obstructive sleep apnoea: effects on atherogenic lipoprotein phenotype.
2009
Patients with obstructive sleep apnoea are at increased risk of atherosclerotic morbidity and mortality. Abnormalities in lipid metabolism that occur in response to chronic intermittent hypoxia in patients with sleep-disordered breathing may increase the cardiovascular risk in an already susceptible population. Atherogenic lipoprotein phenotype and small, dense LDL have an independent predictive role for future cardio- and cerebro-vascular events in patients with the metabolic syndrome. Therefore, testing the hypothesis that therapy of obstructive sleep apnoea may reduce atherogenic lipoprotein phenotype might have significant clinical implications. We suggest that abolition of obstructive …
Surgical treatment of chronic thromboembolic pulmonary hypertension.
2006
Chronic thromboembolic pulmonary hypertension is a commonly overlooked cause of physical incapacity and dyspnoea, with a higher incidence than is generally appreciated and a poor prognosis. The diagnosis can be suspected based on echocardiographic examinations and ventilation perfusion scanning of the lung. Pulmonary angiography still remains the gold standard for the diagnosis of thromboembolic pulmonary hypertension and the assessment of operability. Pulmonary endarterectomy is a complex surgical procedure, which provides permanent relief of thromboembolic pulmonary hypertension and cure for most of the patients. The operation resembles a true endarterectomy of the pulmonary artery branch…
Predictors and prognosis for complex coronary lesions in patients with acute myocardial infarction
2007
Background We aimed to investigate the determinants and outcomes of multiple complex lesions (MCLs) on coronary angiography in patients with an acute myocardial infarction. Methods One thousand one hundred fifty-two consecutive nonselected myocardial infarction patients who underwent coronary angiography within 24 hours after admission were analyzed. A complex lesion was defined by the presence of thrombus, ulceration, irregular plaque, and flow impairment. Patients with ≤1 complex lesion were considered with single complex lesion (SCL), and patients with >1 complex lesions with MCLs. Results Multiple complex lesions were identified in 360 patients (31%). Patients from the MCL group were ol…
Ca2+ entry blockers inhibit prostaglandin F2 alpha-induced cerebrovascular contractile responses in goats.
1991
We examined the effects of extracellular Ca2+ withdrawal and of Ca2+ entry blockers on goat cerebrovascular responses to prostaglandin F2 alpha (PGF2 alpha). We measured isometric tension in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. PGF2 alpha produced concentration-dependent contractions of isolated arteries. The contractions were partially inhibited by incubation in Ca(2+)-free medium (by 63.1 +/- 1.8% without ethyleneglycol-bis-(beta-amino-ethylether)-N,N,N',N'-tetra-a cetate (EGTA), and by 82.4 +/- 3.7% with EGTA). The Ca2+ entry blockers inhibited PGF2 alpha-elicited contraction and relaxed PGF2 alpha-precontracted arteries (nicardipine…
Prognostic value of blood lactate in critically ill patients
1984
Hyperlactatemia is frequently observed in critically ill patients. A correlation of blood lactate concentrations and outcome of patients has been proven in circulatory shock, circulatory arrest, acute myocardial infarction, acute hypnotic drug poisoning and severe pancreatitis. However, the prognostic relevance of hyperlactatemia yields from statistical examinations in larger groups of patients. It should not be misused as a reliable prognostic sign in the individual patient, but is of high value in comparing groups of patients. In individual patients, hyperlactatemia is a useful indicator pointing to the severity of illness and to superimposed complications. Blood lactate is of considerabl…
Importance of calibration for diameter and area determination by intravascular ultrasound
1996
Intravascular ultrasound (IVUS) permits quantitative assessment of the lumen diameter and area of coronary arteries. The experimental study was performed to evaluate the accuracy of diameter and area measurements.Lumen quantitation (lumen diameter D and cross-sectional area A) in lucite tubes (lumen diameter 2.5 to 5.7 mm, Plexiglas) was performed using a mechanical IVUS system (HP console, 3.5 F catheter, Boston Scientific, 30 MHz). The influence of fluid type (blood, water and saline solution), fluid temperature (20 degrees C/37 degrees C), catheter to catheter variation, gain setting and ultrasound frequency (12, 20 and 30 MHz) was determined. In blood at 20 degrees C there was a constan…
From Clinical Imaging to Patient-Specific Computational Model: Rapid Adaptation of the Living Heart Human Model to a Case of Aortic Stenosis
2021
Aortic stenosis (AS) is the most common acquired heart valve disease in the developed world. Traditional methods of grading AS have relied on the measurement of aortic valve area and transvalvular pressure gradient. Recent research has highlighted the existence of AS variants that do not meet classic criteria for severe AS such as low-flow, low-gradient AS. With the development of sophisticated multi-scale computational models, investigation into the left ventricular (LV) biomechanics of AS offers new insights into the pathophysiology that may guide treatment decisions surrounding AS. Building upon our prior study entailing LV-aortic coupling where AS conditions were applied to the idealize…
Temporal trends in postinfarction ventricular septal rupture: the CIVIAM Registry
2020
Abstract Introduction and objectives Postinfarction ventricular septal rupture is a rare but severe complication of myocardial infarction with high mortality rates. Our goal was to analyze which factors could have an impact on mortality due to this entity over the past decade, including those related to mechanical circulatory support . Methods The CIVIAM registry is an observational, retrospective, multicenter study carried out in Spain. We designed a comparative analysis, focused on description of in-hospital management and in-hospital and 1-year total mortality as the primary endpoints, dividing the total observation time into 2 equal temporal periods (January 2008 to June2013 and July 20…
Resistance of the internal mammary artery to restenosis: a histomorphologic study of various porcine arteries.
2007
<i>Background/Aims:</i> Restenosis after percutaneous transluminal angioplasty (PTA) of the internal mammary artery (IMA) grafts is much less pronounced than in other arteries and venous grafts. The aim of the study was to test whether various arteries respond differently to dilatation. <i>Methods:</i> PTA of the IMA, carotid, renal and circumflex coronary (RCx) arteries was performed in 9 pigs (balloon to artery ratio of 1:1.5). After 8 weeks, angiography was repeated and vessels prepared for histological analysis. Immunohistochemical staining was done to examine proliferative activity (Ki67) and to identify the vasa vasorum of the adventitia (F VIII-RA). <i>R…