Search results for "Perfusion"
showing 10 items of 714 documents
On the number of measurement sites required to assess regional cerebral blood flow by laser-Doppler scanning during cerebral ischemia and reperfusion.
2001
The aim of this study was to determine whether the number of measurement sites affected the precision of regional cerebral blood flow (CBF) assessment by Laser-Doppler (LD). A simulation study was applied based on data obtained by scanning the cortex in 25 rats during baseline conditions, 15 min global cerebral ischemia and reperfusion. Random samples were repeatedly collected from 1 to 100 locations and deviations from the median of the entire CBF data pool (800 locations) were determined. Single location CBF measurements missed the true median by 24.8+/-2.2 LD-units (baseline conditions, n=100 simulations, mean+/-SEM), 2.7+/-0.6 LD-units (ischemia), and 31.9+/-2.4 LD-units (30th min reper…
Effects of zinc acexamate on blood flow and prostanoid levels in the gastric mucosa of the rat
1989
The effects of the new antiulcer compound zinc acexamate on blood flow and prostanoid levels in the gastric mucosa have been studied. Zinc acexamate (30 and 300 mg/kg) dose-dependently prevents the reduction induced by the perfusion of noradrenaline (3.5 micrograms/kg.min, 30 min) in gastric mucosal blood flow, as measured by 3H-aniline clearance. Zinc acexamate pretreatment also increases the levels of prostaglandin E2 in the gastric mucosa of the rat, both under control conditions and after infusion with noradrenaline. The levels of thromboxane A2 and prostacyclin were not modified by zinc acexamate. These results confirm the importance of microcirculation in pathogenesis and the idea tha…
Administration of transforming growth factor-α reduces infarct volume after transient focal cerebral ischemia in the rat
2001
Growth factors promote cell growth and survival and protect the brain from developing injury after ischemia. In this article, the authors examined whether transforming growth factor-α (TGF-α was protective in transient focal ischemia and whether alteration of cerebral circulation was involved. Rats received intraventricular TGF-α (50 ng, either split into 2 doses given 30 minutes before and 30 minutes after middle cerebral artery occlusion (MCAO), or 1 dose given 30 minutes after MCAO) or vehicle. Rats were subjected to 1-hour intraluminal MCAO and cerebral blood flow was recorded continuously by laser-Doppler flowmetry. Infarct volume was measured 1 and 4 days later. The effects of TGF-α o…
Positional brain ischemia with MCA occlusion successfully treated with extra-intracranial bypass.
2010
408 Positional cerebral ischemia (PCI) is an extremely rare condition in which dramatic central nervous system deficits are triggered by standing in patients with severe stenosis or occlusion of the major brain-supplying blood vessels [1] . Because PCI is generally associated with orthostatic hypotension [2, 3] , a hemodynamic mechanism has been proposed [4] . However, PCI has been reported even in patients without orthostatic hypotension [1] . The treatment is medical, but surgery can be considered in refractory cases (endarterectomy for carotid artery stenosis or either highor low-flow extra-intracranial bypass – for carotid occlusion) [3] . We report a case of PCI associated with middle …
[Myocardial echocardiography with intracoronary injection of contrast in post-infarction patients. Implications and comparison with angiography and m…
2004
We analyzed the safety and feasibility of myocardial echocardiography with intracoronary injection of contrast, its effect on left ventricular remodeling and systolic function, and its relationship with angiography and magnetic resonance imaging (MRI) for the evaluation of post-infarction coronary microcirculation.Thirty patients with a first ST-elevation myocardial infarction and a patent infarct-related artery were studied. Mean perfusion score of the infarcted area was analyzed with myocardial echocardiography. TIMI and Blush grades (angiography) were determined. Mean perfusion score (MRI-perfusion), end-diastolic volume index and ejection fraction were determined with MRI. At 6 months a…
Post-Reperfusion Lymphopenia and Microvascular Obstruction in ST-Segment Elevation Acute Myocardial Infarction
2009
The presence of microvascular obstruction after ST-segment elevation acute myocardial infarction is associated with a poor outcome. The pathophysiology of this process has not been fully defined. The aim of this study was to investigate the relationship between post-reperfusion lymphopenia and microvascular obstruction.This prospective study involved 212 patients with a first ST-segment elevation acute myocardial infarction who underwent reperfusion with thrombolytic agents or primary angioplasty and who had an open infarct-related artery. Serial measurements of lymphocyte, neutrophil and monocyte counts were taken. Cardiac magnetic resonance was used to detect microvascular obstruction dur…
Transmurality of scar influences the effect of a hybrid-intervention with autologous bone marrow cell injection and aortocoronary bypass surgery (MNC…
2010
Abstract Background Cell therapy (CTx) is a strategy to support cardiac regeneration after myocardial infarction (MI). Thus far, clinical studies provided mixed results. Here, we investigated whether transmurality of the infarct may play a relevant role. Methods 18 patients (63±3years, 15 male) undergoing elective coronary artery bypass graft (CABG) surgery 2.2±0.7months post MI participated. 10 had transmural and 8 non-transmural infarct scars assessed by Tc-99m-MIBI Single-Photon Emission Computed Tomography (SPECT) and F18-FDG-Positron-Emission-Tomography (PET). During surgery, 10ml of sternal bone marrow were obtained, mononuclear cells (MNC) were isolated. At the end of surgery MNC wer…
Increased plasma concentration of fibrin monomer in acute myocardial infarction with early reperfusion.
1996
OBJECTIVE To assess whether plasma fibrin monomer (FM) concentration, a marker of thrombin activity, is increased in the first hours after acute coronary occlusion and whether there are differences between patients with and without early reperfusion. DESIGN Thirty-five consecutive patients with acute myocardial infarction (AMI) and early coronary angiography were studied prospectively. METHODS Plasma FM samples taken on admission (< 6 h after onset of chest pain) and 6-14 h after onset of chest pain were analysed using a specific enzyme immunoassay. All of the patients were anticoagulated with heparin intravenously. RESULTS Of the 35 patients, 28 had angiographically documented reperfusion …
Prognostic Value of Myocardial Ischemia and Necrosis in Depressed Left Ventricular Function: a Multicenter Stress Cardiac Magnetic Resonance Registry
2013
A B S T R A C T Introduction and objectives: The incremental prognostic value of inducible myocardial ischemia over necrosis derived by stress cardiac magnetic resonance in depressed left ventricular function is unknown. We determined the prognostic value of necrosis and ischemia in patients with depressed left ventricular function referred for dipyridamole stress perfusion magnetic resonance. Methods: In a multicenter registry using stress magnetic resonance, the presence ( 2 segments) of late enhancement and perfusion defects and their association with major events (cardiac death and nonfatal infarction) was determined. Results: In 391 patients, perfusion defect or late enhancement were p…
Evolution of 5 cardiovascular magnetic resonance–derived viability indexes after reperfused myocardial infarction
2007
The objective of this study was to evaluate the simultaneous evolution of 5 cardiovascular magnetic resonance-derived myocardial viability indexes.We studied 72 patients with a first ST-elevation myocardial infarction and sustained TIMI 3 flow. In the first week and in the sixth month of the study, using cardiovascular magnetic resonance imaging, we determined wall thickening (WT) and the following viability indexes: wall thickness, WT with low-dose dobutamine, microvascular perfusion in first-pass imaging, microvascular obstruction in late-enhancement imaging, and transmural extent of necrosis.In 250 dysfunctional segments, the evolution outcomes for the viability indexes were as follows: …