Search results for "Circulatory system"

Influence of endothelial nitric oxide on neurogenic contraction of human pulmonary arteries.

1995

The present study was designed to investigate the contribution of the endothelium and that of the L-arginine pathway on the contractile responses of isolated human pulmonary arteries to electrical field stimulation (EFS) and noradrenaline. Isometric tension was measured in artery rings obtained from portions of human lung after thoracic surgery for removal of lung carcinoma (18 patients). Electrical field stimulation (EFS) induced frequency-dependent contractions of isolated human pulmonary arteries which were abolished by tetrodotoxin, guanethidine and prazosin (all at 10(-6) M). The increases in tension were of greater magnitude in arteries denuded of endothelium. NG-nitro-L-arginine meth…

Evidence for a negative inotropic effect of obesity in human myocardium?

2009

Objective: The present study was performed as an attempt to analyze the relationship between body weight and human myocardial performance. As overweight is frequently associated with hypertension, stenosis of epimyocardial coronary arteries and other factors that influence myocardial performance, the experimental model of isolated human atrial myocardium was selected. Atrial contractile performance does neither depend on the extent of stenosis of epicardial coronary arteries nor on the degree of hypertension and its secondary pathology. Methods:Rightatrialmusclepreparations(0.5 6 mm)of183patientsundergoingcoronaryarterybypasssurgerywereelectricallystimulatedat optimal length. Active tension…

162 Medical and Psychosocial Predictors of Mechanical Circulatory Support Device Implantation in the Waiting for a New Heart Study

2011

Red cell Ca2+ content (total and cytosolic) and erythrocyte membrane fluidity in several clinical conditions

1993

Risk-adapted management of pulmonary embolism

2017

The presence and severity of right ventricular (RV) dysfunction is a key determinant of prognosis in the acute phase of pulmonary embolism (PE). Risk-adapted treatment strategies continue to evolve, tailoring initial management to the clinical presentation and the functional status of the RV. Beyond pharmacological and, if necessary, mechanical circulatory support, systemic thrombolysis remains the mainstay of treatment for hemodynamically unstable patients; in contrast, it is not routinely recommended for intermediate-risk PE. Catheter-directed pharmacomechanical reperfusion treatment represents a promising option for minimizing bleeding risk; for reduced-dose intravenous thrombolysis, the…

Capillary enlargement, not sprouting angiogenesis, determines beneficial therapeutic effects and side effects of angiogenic gene therapy.

2010

Aims Currently, it is still unclear which mechanisms drive metabolic benefits after angiogenic gene therapy. The side-effect profile of efficient angiogenic gene therapy is also currently incompletely understood. In this study, the effects of increasing doses of adenoviral (Ad) vascular endothelial growth factor-A (VEGF-A) were evaluated on vascular growth, metabolic benefits, and systemic side effects. Methods and results Adenoviral vascular endothelial growth factor-A or AdLacZ control was injected intramuscularly (109–1011 vp/mL) or intra-arterially (5 × 1011 vp/mL) into rabbit ( n = 102) hindlimb muscles and examined 6 or 14 days later. Blood flow, tissue oedema, metabolic benefits, and…

Ultrastructure of the conus arteriosus ofScyliorhinus stellaris

1989

The functional morphology of the fourth chamber of the fish heart, the bulbus arteriosus, differs in teleosts and elasmobranchs. In elasmobranchs, this chamber is referred to as the conus arteriosus because its wall is made up of myocardial tissue in addition to elastic tissue. As a result of this feature, the function of the conus is very specialized. We report the basic ultrastructure of the wall of the conus arteriosus in the elasmobranch Scyllium stellare. The wall consists of three layers: the outer epicardial, the middle myocardial, and the inner endocardial layer. The outer layer is composed of the visceral pericardium consisting of cuboidal mesothelial cells, beneath which numerous …

2-Aryl-substituted 4H-3,1-benzoxazin-4-ones as novel active substances for the cardiovascular system

1991

4H-3,1-Benzoxazin-4-ones of the structural types 3 and 4 are accessible by cyclization reactions. The introduction of the phosphonate group was achieved by way of Wohl-Ziegler bromination and subsequent Michaelis-Arbuzow reaction with a trialkyl phosphite. Pharmacological investigations on isolated left atria, ileum specimens, and Langendorff hearts as well as in vivo circulatory studies on anesthetized rats revealed that the phosphonates 4 exert calcium antagonistic effects. Whereas 2-(arylvinyl)benzoxazinones gave rise to pronounced negative inotropic effects, compound 3e exhibited relaxing effects on smooth musculature in particular and markedly increased the coronary flow through Langen…

Does the renin-angiotensin system also regulate intra-ocular pressure?

2009

The renin-angiotensin-aldosterone system is known to play an essential role in controlling sodium balance and body fluid volumes, and thus blood pressure. In addition to the circulating system which regulates urgent cardiovascular responses, a tissue-localized renin-angiotensin system (RAS) regulates long-term changes in various organs. Many recognized RAS components have also been identified in the human eye. The highly vasoconstrictive angiotensin II (Ang II) is considered the key peptide in the circulatory RAS. However, the ultimate effect of RAS activation at tissue level is more complex, being based not only on the biological activity of Ang II but also on the activities of other produ…

Endocrine Challenges in Patients with Continuous-Flow Left Ventricular Assist Devices

2021

Heart failure (HF) remains a leading cause of morbidity, hospitalization, and mortality worldwide. Advancement of mechanical circulatory support technology has led to the use of continuous-flow left ventricular assist devices (LVADs), reducing hospitalizations, and improving quality of life and outcomes in advanced HF. Recent studies have highlighted how metabolic and endocrine dysfunction may be a consequence of, or associated with, HF, and may represent a novel (still neglected) therapeutic target in the treatment of HF. On the other hand, it is not clear whether LVAD support, may impact the outcome by also improving organ perfusion as well as improving the neuro-hormonal state of the pat…