Search results for "Microcirculation"

Intracoronary Infusion of Thioflavin-S to Study Microvascular Obstruction in a Model of Myocardial Infarction

2015

Abstract Introduction and objectives Microvascular obstruction exerts deleterious effects after myocardial infarction. To elucidate the role of ischemia-reperfusion injury on the occurrence and dynamics of microvascular obstruction, we performed a preliminary methodological study to accurately define this process in an in vivo model. Methods Myocardial infarction was induced in swine by means of 90-min of occlusion of the mid left anterior descending coronary artery using angioplasty balloons . Intracoronary infusion of thioflavin-S was applied and compared with traditional intra-aortic or intraventricular instillation. The left anterior descending coronary artery perfused area and microvas…

Co-culture systems for vascularization — Learning from nature

2011

The endothelial cell (EC) is practically ubiquitous in the human body and forms the inner cellular lining of the entire cardiovascular system. Following tissue injury, the microcirculation becomes the stage for both the inflammatory response and the subsequent healing reaction to restore physiological function to the damaged tissue. The advent of the multidisciplinary field of Regenerative Medicine (RegMed), of which Tissue Engineering (TE) and drug delivery using modern stimuli-responsive or interactive biomaterials are important components, has opened up new approaches to the acceleration of the healing response. A central and rate-limiting role in the latter is played by the process of v…

Precapillary Servo Control of Blood Pressure and Postcapillary Adjustment of Flow to Tissue Metabolic Status

1996

Background There are several shortcomings in current understanding of how the microvasculature maintains tissue homeostasis. Presently unresolved issues include (1) integration of the potentially conflicting needs for capillary perfusion and hydrostatic pressure regulation, (2) an understanding of signal transmission pathways for conveying information about tissue energetic status from undersupplied tissue sites to the arterioles, (3) accounting for the experimentally observed interrelations between precapillary and postcapillary resistances, and (4) an explanation of how precise local adjustment of perfusion to metabolic demands is achieved. Methods and Results A novel conceptualization o…

Role of Ischemia/Reperfusion Injury in Organ Transplantation

1997

Reperfusion of oxygenated blood into previously ischemic tissue is essential to prevent the progression of cellular injury due to the decreased nutritional blood flow, i.e., the decreased delivery of oxygen and metabolic substrates, as well as the removal of harmful metabolic byproducts. However, it has become obvious that reperfusion also initiates a complex series of pathologic events that contribute to, rather than prevent, further tissue damage. Moreover, a growing body of evidence indicates that ischemia/reperfusion injury is initiated by events that occur at the level of the microcirculation. In the first part of this overview, we will delineate the major components of the microcircul…

The role of the microcirculation in multiple organ dysfunction syndrome (MODS): a review and perspective

1996

Major advances in intensive care medicine during the past two decades have altered the spectrum of disease encountered by intensive care physicians, anaesthesiologists, traumatologists and pathologists. One of the most important manifestations of severe trauma or infections is the multiple organ dysfunction syndrome (MODS), a life-threatening condition that often ends in multiple organ failure (MOF) and death. Evidence gathered from clinical and morphological observations in humans, taken together with experimental animal studies and a vast accumulation of in vitro data, clearly indicate that the microcirculation lies at the centre of this complex process, which results in peripheral vascul…

Study of Post-Infarction Coronary Perfusion Using Quantitative Analysis of Myocardial Echocardiography With Intravenous Injection of Contrast

2005

Introduction and objectives. After a myocardial infarction, damage to the microcirculation indicates a worse prognosis. We compared the usefulness of the quantitative analysis of myocardial contrast echocardiography with intravenous injection of contrast (MCE-iv) with intracoronary injection (MCE-ic) for analyzing coronary perfusion. Patients and method. We studied 42 patients with a first ST-elevation myocardial infarction, single-vessel disease and a patent artery (TIMI 3, stenosis 0.75) and MCE-iv (perfusion of SonoVue, singleimage capture in 1 out of each 6 cycles with trigger set at end-systole, perfusion considered normal if >0.9). Perfusion was considered abnormal if 2 or more segmen…

Erratum to “Anatomical evaluation of oral microcirculation: Capillary characteristics associated with sex or age group” [Ann. Anat. 191(4) (2009) 371…

2009

1043 Evaluation of Pediatric Testes After Surgery by Laser Doppler and White Light Spectroscopy

2012

Aim To evaluate testes after unilateral orchiopexy Laser Doppler and white light spectroscopy and compare microcirculation with contralaterat testis and healthy controls. Methods A combination of the laser Doppler (determination of blood flow) and white light spectroscopy (determination of oxygen saturation and hemoglobin amount) is used to determine microcirculation at two different depth levels non-invasively. Patients were recruited after unilateral orchiopexy. Controls were age-matched boys without relevant disease. Ethical approval was obtained. Results 99 patients were included after unilateral orchiopexy at the age of 3.5 years (+-2.9 years). 65% underwent surgery after their second …

Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine

1998

Myogenic effects enhance norepinephrine constriction: Inhibition by nitric oxide and felodipine. Myogenic, pressure-induced vasoconstriction may amplify the effects of circulating vasoconstrictors. Through intravital microscopy in cremaster arterioles (31 to 115 μm diameter), the relative contribution of myogenic responses (MR) to norepinephrine (NE)-induced constriction and the inhibitor potency of nitric oxide (NO) or a Ca2+ entry blocker (CEB), felodipine (F), were examined. In 24 anesthetized hamsters, a vessel occluder was placed around the aorta to control cremaster vessel inflow pressure (IP). NE infusion increased blood pressure (by 50 ± 2mm Hg) and induced significant constriction …

Assessment of Skeletal Muscle Microperfusion Using MRI

2013

Blood oxygenation level-dependent (BOLD) MRI, arterial spin labeling (ASL) and dynamic contrast enhancement (DCE) are current magnetic resonance imaging (MRI) techniques allowing the non-invasive functional assessment of peripheral microvasculature in healthy and diseased individuals. The functional imaging of skeletal muscle microvasculature helps to understand muscular and vascular physiology and alterations of microcirculation under certain pathological conditions such as peripheral arterial occlusive disease, diabetes mellitus, chronic compartment syndrome and rheumatic disorders. BOLD MRI uses blood as an endogenous contrast agent provided by the different magnetic properties of oxy- a…