Search results for "Circulation"
showing 10 items of 1137 documents
Pharmacokinetics and bioavailability of diclofenac in the rat.
1991
Diclofenac sodium is a widely used drug with interesting absorption and disposition features when administered to laboratory animals. The present study was undertaken to assess the pharmacokinetics of the drug after iv and gastrointestinal dosing to rats. Renal excretion of unchanged drug was negligible, but biliary excretion of the drug (unchanged and conjugated) was detected in bile duct-cannulated rats; it accounted for 27.2 and 31.2% of the total dose following iv and intraduodenal administration, respectively. Most of the drug excreted in the bile was conjugated diclofenac; unchanged drug accounted for only 4.7 and 5.4% of total diclofenac excreted in the bile after iv and intraduodena…
Elevation of plasma viscosity induces sustained NO-mediated dilation in the hamster cremaster microcirculation in vivo
1997
We studied whether a flow-independent increase of luminal wall shear stress (WSS) could dilate hamster arterioles in vivo and which endothelial mediators are potentially involved. To this end the plasma viscosity was elevated by exchanging blood for dextran-erythrocyte solution thereby augmenting WSS. Diameters of small and large arterioles as well as red blood cell velocities were measured before and after exchange of blood for solutions of identical haematocrit containing either high- (HMWD) or low-molecular weight dextran (LMWD). The potential role of endothelial autacoids was investigated by local application of the NO-synthase inhibitor NG-nitro-L-arginine (L-NNA), the inhibitor of cyc…
Nail fold capillary diameter changes in acute systemic hypoxia.
2013
The present study was undertaken to determine the effect of arterial blood hypoxemia induced by acute systemic hypoxia (pO2=12%) on capillary recruitment and diameter, and red blood cell (RBC) velocity in human nail fold capillaries during rest, arterial post-occlusive reactive hyperemia (PRH), and venous occlusion (VO) using intravital video-capillaroscopy. Capillary recruitment was unchanged in acute systemic hypoxia (H) versus normoxia (N). There was no difference in RBC velocity measurements between normoxia and hypoxia (P<0.63). However, a statistically significant increase in nail fold capillary total width (N, 39.9±9.1 vs. H, 42.7±10.3 μm; P<0.05), apical diameter (N, 15.5±4.3 vs. H,…
NMDA receptor antagonist felbamate reduces behavioral deficits and blood-brain barrier permeability changes after experimental subarachnoid hemorrhag…
2007
Increased levels of glutamate and aspartate have been detected after subarachnoid hemorrhage (SAH) that correlate with neurological status. The NMDA receptor antagonist felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an anti-epileptic drug that elicits neuroprotective effects in different experimental models of hypoxia-ischemia. The aim of this dose-response study was to evaluate the effect of FBM after experimental SAH in rats on (1) behavioral deficits (employing a battery of assessment tasks days 1-5 post-injury) and (2) blood-brain barrier (BBB) permeability changes (quantifying microvascular alterations according to the extravasation of protein-bound Evans Blue by a spectropho…
Postoperative Costs Associated With Outcomes After Cardiac Surgery With Extracorporeal Circulation: Role of Antithrombin Levels
2012
Objective: To study the impact on postoperative costs of a patient's antithrombin levels associated with outcomes after cardiac surgery with extracorporeal circulation. Design: An analytic decision model was designed to estimate costs and clinical outcomes after cardiac surgery in a typical patient with low antithrombin levels (= 63.7%). The data used in the model were obtained from a literature review and subsequently validated by a panel of experts in cardiothoracic anesthesiology. Setting: Multi-institutional (14 Spanish hospitals). Participants: Consultant anesthesiologists. Measurements and Main Results: A sensitivity analysis of extreme scenarios was carried out to assess the impact o…
Troponin I concentrations of shed blood might influence monitoring of myocardial injury after coronary operations.
2002
Abstract In a prospective study we evaluated the concentration of cardiac troponin I (cTnI) and creatine kinase activities (CK) in shed mediastinal blood in the early postoperative period after coronary artery bypass grafting (CABG). Forty seven patients who underwent first time elective CABG were studied. CTnI levels and CK activities in arterial blood and shed mediastinal blood were measured after admission to the intensive care unit (ICU) and 6 h after unclamping the aorta. Mediastinal shed blood samples were drawn from 23 patients (group A) before the filter of the cardiotomy reservoir and from 24 patients (group B) behind. Additionally, both markers were measured in blood samples colle…
Assistance of intraoperative microvascular Doppler in the surgical obliteration of spinal dural arteriovenous fistula: cases description and technica…
2003
BACKGROUND: Intraoperative microvascular Doppler may be valuable in assisting in the surgical obliteration of dural arteriovenous fistula of the spinal cord. It enables identification, through flow spectrum analysis, of the anatomic components and haemodynamic features of this type of vascular malformation. METHODS: In two cases, intraoperative microvascular Doppler was used to assist in the surgical obliteration of dural arteriovenous fistula of the spinal cord. The fistulas were identified prior to the dura opening, and for this only minimally invasive surgery was required. Direct recordings of the arterialised draining vein and the nidus of the fistula demonstrated a pathological spectru…
Prognostic value of exercise myocardial scintigraphy in patients with coronary chronic total occlusions.
2010
Objectives: To evaluate the prognostic value of exercise myocardial scintigraphy in patients undergoing incomplete revascularization by means of percutaneous coronary intervention (PCI) with at least a residual chronic total occlusion (CTO) left untreated. Methods: Of 569 consecutive patients with multivessel disease undergoing myocardial scintigraphy after incomplete revascularization by PCI between March 1997 and December 2004, 126 (79% male, 64 ± 10 years) with ≥ 1 residual CTO fulfilled the eligibility criteria and entered in the study. Hard events defined as cardiac death and myocardial infarction, soft events defined as incidence of unstable angina and PCI procedures, and their compos…
Effect of theophylline on calcium exchangeability in ventricular myocardium.
1976
The effects of theophylline on contractile force and myocardial calcium exchangeability were studied in isolated, electrically driven Langendorff perfused guinea-pig hearts. Following a 30-min exposure to 45Ca, total cellular calcium and 45Ca activity were measured in right ventricular samples. "Nontoxic" theophylline concentrations (5 x 10(-5) -10(-3) g/ml) which augmented contractile force without producing arrhythmias or contractures had no effect on total tissue calcium and did not alter the size of the fraction of cellular calcium exchangeable under steady-state conditions. A "toxic" concentration of theophylline (2 x 10(-3) g/ml) induced contractures and increased the amount of exchan…
Usefulness of regional right ventricular and right atrial strain for prediction of early and late right ventricular failure following a left ventricu…
2019
Background: Identifying candidates for left ventricular assist device surgery at risk of right ventricular failure remains difficult. The aim was to identify the most accurate predictors of right ventricular failure among clinical, biological, and imaging markers, assessed by agreement of different supervised machine learning algorithms. Methods: Seventy-four patients, referred to HeartWare left ventricular assist device since 2010 in two Italian centers, were recruited. Biomarkers, right ventricular standard, and strain echocardiography, as well as cath-lab measures, were compared among patients who did not develop right ventricular failure (N = 56), those with acute–right ventricular fail…