Circulatory assist devices are used to treat patients awaiting cardiac transplantation to preserve life as well as to permit recovery of end-organ function. The efficacy of pulseless perfusion versus pulsatile perfusion in the recovery of end-organ function has not been fully determined. In this study, the efficacy of pulseless perfusion ...

1. Reproducibility and sensitivity of responses of isolated perfused rabbit renal vascular bed to bolus administration of histamine was compared for the conditions of constant-flow and constant-pressure perfusion by Krebs-Henseleit solution. Two other vasoactive agents (noradrenaline and angiotensin II) were also tested in the same preparation for comparison with the ...

BACKGROUND AND OBJECTIVE: This study is concerned with perfusion-pressure videoangiographic investigations, performed by combining oculo-oscillo-dynamography and videoangiography. Perfusion-pressure videoangiography permits an evaluation of local vascular resistance in the choroid relative to ciliary perfusion pressure. PATIENTS AND METHODS: Twelve healthy subjects, 21 patients with primary open angle glaucoma (POAG), and 27 ...

The effects of treppe on left ventricular function in the isolated mouse heart perfused with physiological buffer or with erythrocyte-rich buffer were compared. Left ventricular systolic and diastolic pressures were measured in the isovolumically contracting (balloon in the left ventricle) mouse hearts. Hearts were isolated from 12 adult Swiss-Webster mice ...

BACKGROUND: We have investigated the vascular perfusion of a wide variety of conditions of the anterior segment using fluorescein angiography. METHODS: The conditions were classified and findings reported according to the system set out below. Patients underwent full ocular examination. Fluorescein angiography of the anterior segment was carried out when ...

Radioactive microspheres (MS) injected into the systemic circulation shunt to the venous side of the circulation and are trapped in the lung vasculature. We hypothesized that regional pulmonary perfusion could be determined by using systemically injected shunted MS. In seven anesthetized mechanically ventilated foxhounds, regional pulmonary perfusion was measured at ...

Elevation of cell iron content was produced by use of a lipophilic iron ligand, 8-hydroxyquinoline (HQ), capable of transferring catalytically active iron into cells. The Fe(3+)-HQ complex labeled with 59Fe was avidly taken up by isolated perfused hearts contrary to the hydrophilic complex Fe(3+)-citrate. Hearts perfused in aerobic conditions with ...

Effects of crystalloid buffer and blood-buffer perfusates on cardiac electrophysiological parameters were compared in four groups of isolated, working rabbit hearts. Hearts were perfused with Krebs-Henseleit buffer or blood plus Krebs-Henseleit buffer (10% hematocrit) over a range of left ventricular afterload (30-100 cmH2O) and cardiac outputs (30-180 ml/min). Left ventricular ...

A model of cardiac dysfunction induced by reactive oxygen species (ROS) was established by adding hydrogen peroxide (H2O2) to the perfusate of isolated, Langendorff-perfused rat hearts, and the mechanism of functional injury was investigated. The following groups were included: 1 (n = 7), control perfusion; 2 (n = 11), perfusion ...

BACKGROUND: Cardiac transplantation is limited to an ischemic time of around 6 hours by available preservation solution and technique. Complex organ preservation devices have been developed that extend this time to 24 hours or more, but are clinically impractical. This study evaluates a portable oxygen-driven organ perfusion device weighing approximately ...

PURPOSE: To assess the feasibility of large-bore tube colostomy in the presence of bowel obstruction in a pig model. MATERIALS AND METHODS: Porcine spiral colon was isolated, obstructed, pressurized to 18 mm Hg, punctured with 24-F radial dilators or balloon-sheath combinations in randomized sequences, and assessed for leakage. In another ...

1. The effects of cirrhosis on mesenteric vascular reactivity were assessed in constantly perfused mesenteric arterial beds isolated from cirrhotic rats (carbon tetrachloride with phenobarbitone, n = 6), and from phenobarbitone-treated and untreated age-matched controls (n = 4,5). 2. At a constant flow rate of 5 ml min-1 there was ...

Perfusion of the isolated rabbit heart with 5 x 10(6) human polymorphonuclear leukocytes (PMNL), under recirculating conditions (50 ml) and challenge with A-23187 (0.5 mu M) increased coronary perfusion pressure (CPP) sixfold, accompanied by increased levels of sulfidopeptide leukotrienes (CY-SLT), which had previously shown to correlate linearly with the increase ...

The pulmonary vascular responses to changes in perfusate viscosity were studied in isolated rat lungs treated with the nitric oxide synthase (NOS) inhibitors, N omega-nitro-L-arginine methyl ester (L-NAME) and N omega- monomethyl-L-arginine (L-NMMA). Lungs were isolated according to standard protocols and perfused with varying concentrations of albumin in physiological salt ...

This paper presents a "working" isolated perfused rat heart. A special double cannula was designed consisting of an outer cannula that is inserted in the aorta and an inner cannula that is advanced into the left ventricle. The perfusion fluid flows through the inner cannula into the left ventricle, and ...

Side effects of isolated limb perfusion (ILP) include rhabdomyolysis, paresthesia, or nerve palsy. The increase in intracompartmental pressure during ILP is thought to be linked to neuro- and muscular toxicity, and fasciotomy is recommended for protection. In 24 patients, intracompartmental pressure was measured. A flexible 5 F probe was placed ...

Inositol levels have been studied in cellular cultures and recently by perfusion of isolated hearts. The study was aimed to assess inositol turnover in rabbit hearts from intact animals. Thirty rabbits were injected i.v. three times (every 12 hr) with 25 microCi/kg of myo-3H-inositol. The rabbits 12 hr after the ...

RATIONALE AND OBJECTIVES: Atelectasis is a frequent concomitant of pulmonary embolism (PE) and other conditions that mimic PE. Accordingly, we developed an animal model to study the effect of regional loss of pulmonary volume on the size and configuration of experimentally induced perfusion defects that simulated PE. METHODS: After baseline ...

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-meta-iodobenzylguanidine (123I-MIBG) and 201Tl in various organs was performed in 13 patients with congestive heart failure (CHF) and 13 subjects without heart failure. In order to reduce the crosstalk of 201Tl to the 123I energy window to less than 5%, a ...

The effects of hypothermic perfusion have been studied by using different perfusates in 24 isolated rabbit lung preparations, divided into three groups: G1, perfused with blood (hematocrit of 10%) and G2 and G3, perfused with erythrocyte-free plasma plus 6% protein in saline. In both G1 and G2 groups left atrial ...

The aim of this study was to compare the effects of the blockade of nitric oxide (NO) and of endothelium-derived hyperpolarizing factor (EDHF) on the response to vasoconstrictors (VC) and on the flow-pressure curve in the isolated perfused rat kidney. To this end, dose-response curves to phenylephrine and BaCl2 were ...

We tested the hypothesis that diaspirin cross-linked hemoglobin (DCLHb; Baxter Healthcare Corp.) would improve blood pressure, organ perfusion, and mortality during sepsis. Rats were catheterized to assess general hemodynamics (protocol 1) or regional blood flow (protocol 2). Sepsis was induced by intraperitoneal introduction of a cecal slurry (100 mg/kg). In ...

Extract IV, a partially purified preparation of the toxin from the sea anemone Tealia felina, produced marked bradycardia and arrhythmias in the rat in vivo. In the Langendorff rat heart preparation perfused at constant pressure extract IV (0.0224 AU/ml) reduced the force of contraction by 81.3 +/- 7.2%, n = ...

We have constructed and performed initial validation of an innovative perfusion system that allows exposure of intact segments of vascular tissue to realistic physiological and hemodynamic environments ex vivo. Computer-controlled opening and closing of an in-line gate valve allows generation of arterial pressure waveforms. The control algorithm predicted resultant pressure ...

It is still controversial whether to pulse or not to pulse for the establishment of ideal extracorporeal circulation. We directly measured the renal sympathetic nerve activity in mongrel dogs (n = 10, weighing from 13 to 21 kg) to determine the effects of pulsatile and nonpulsatile systemic perfusion on the ...

Jugular bulb oximetry provides the first bedside, continuously available information on cerebral perfusion adequacy. An extensive analysis was made of all jugular bulb oxygen saturation (SjO2) data obtained in 50 patients suffering from severe head injury. A total of 176 periods (more than 30 minutes) with reliable, abnormal SjO2-values was ...

Twenty-one dogs (group 1) had retrograde brain perfusion for 90 minutes through the sagittal sinus and superior vena cava with pressure-regulated cardiopulmonary bypass, and 10 dogs (group 2) had 60 minutes of circulatory arrest with an additional 30-minute evaluation of brain slices, both at 20 degrees C. In group 1, ...

Extracorporeal perfusion of isolated sheep lungs with blood after 30 min of ischemia caused injury manifested by polymorphonuclear (PMN) leukocyte sequestration, pulmonary hypertension, thromboxane release, and increased pulmonary vascular permeability. To determine the roles of ischemia, extracorporeal perfusion, and oxygen in this injury, lungs ventilated with 28% O2-5% CO2 and ...

Myocardial uptake of thiopental enantiomers by an isolated perfused rat heart preparation was examined after perfusion with protein-free perfusate. Outflow perfusate samples were collected at frequent intervals for 20 min during single-pass perfusion with 10 micrograms/ml racemic thiopental (washin phase) and for another 45 min during perfusion with drug-free perfusate ...

To investigate the independent effect of myocardial wall thickness and myocardial perfusion pressure on integrated backscatter, experiments were designed in which integrated backscatter of normally perfused myocardial tissue was measured while changes in wall thickness during the cardiac cycle were reduced to a minimum. In nine blood-perfused isolated pig hearts, ...

We measured the specific hydraulic conductivity (K) of the human and bovine aortic wall, two tissues for which K has not been previously reported in the literature, and examined the effects of aging (human) and development (bovine) on K. As part of the study, we also examined the effects of ...

An improved method for long-term perfusion of the isolated human term placental lobule has been developed to investigate the maternofetal transfer of infectious agents, in particular the human immunodeficiency virus (HIV). The purpose of this paper is to describe those modifications that allow for substantially prolonged perfusions in in a ...

The mammalian small intestine is extensively innervated by cholinergic nerve fibers, including projections to the muscular and submucosal layers. This study tested the hypothesis that cholinergic agents modulate ileal transport independent of alterations in intestinal vascular resistance and motility. Ten-centimeter segments of rabbit ileum (n = 32) were vascularly perfused ...

OBJECTIVE: To investigate the possible etiologies of elevated tubal perfusion pressures. DESIGN: Analysis of 48 consecutive female patients with infertility who underwent laparoscopy and a gynecoradiological investigation as part of their infertility work-up. SETTING: Academically affiliated infertility center. INTERVENTIONS: A gynecoradiological investigation was performed using a previously reported standardized contrast ...

STUDY OBJECTIVES: To assess the effects of two contrasting vasoactive agents (dobutamine [DOB] and norepinephrine [NE]) on (1) global and regional cardiorespiratory variables, (2) acid base status, and (3) bladder epithelial oxygen tension (BEOT), a putative marker of organ perfusion. DESIGN: Measurement of aortic blood flow (ABF) and renal blood ...

BACKGROUND: The objectives of this study were (1) to assess glyceryl trinitrate (GTN)-derived nitric oxide (NO) formation in vascular tissues and organs of anesthetized rabbits in vivo, (2) to establish a correlation between tissue NO levels and a biological response, and (3) to verify biotransformation of GTN to NO by ...

PURPOSE: To evaluate the relationship among feeding arterial pressure, lesion size, and perfusion in cerebral cortex adjacent to cerebral arteriovenous malformations (AVMs). METHODS: Eleven patients with hemispheric AVMs underwent 99mTc hexamethyl-propyleneamine oxime single-photon emission CT before and after 1 g of acetazolamide was administered intravenously. AVM volume was estimated from ...

To define the relation between phosphoryl transfer via creatine kinase (CK) and the ability of the intact beating heart to do work, we chemically inhibited CK activity and then measured cardiac performance under physiological and acute stress conditions. Isolated perfused rat hearts were exposed to iodoacetamide (IA) and subjected to ...

Intracellular free sodium levels ([Na+]i) were assessed with 23Na nuclear magnetic resonance (NMR) spectroscopy in isolated, Langendorff-perfused normal, compensated hypertrophied, and hypertrophied failing guinea pig hearts under several conditions. Baseline [Na+]i measured with a shift reagent was significantly greater than normal in the compensated hypertrophied hearts (12.8 +/- 1.2 mmol/L ...

The purpose of this study was to compare coronary and interstitial endothelin-1 (ET-1) levels in perfused rat hearts under several experimental conditions, because the cardiac tissue concentration of ET-1 is not clear. Hearts were perfused in an upside-down position with a colloid-free buffer at a constant flow rate of 9 ...

In this study we investigated the effect of work and substrate supply on mitochondrial NADH/NAD+ using epicardial autofluorescence in rat hearts perfused according to Langendorff. To avoid vasoconstrictor effects during high work output, nitroprusside-containing Tyrode solution was used. Photobleaching was avoided by using discontinuous ultraviolet excitation for NADH fluorescence measurements. ...

Sprague-Dawley rat hearts were perfused under constant flow conditions, and a balloon was inserted into the left ventricle to measure heart rate (HR) and left ventricular pressures. Left ventricular generated pressure (LVGP) was calculated as peak systolic minus end diastolic pressure. Three substrate groups, pyruvate (5 mM), glucose (15 mM) ...

BACKGROUND: Isolated single-lung perfusion with doxorubicin hydrochloride was shown to be effective in clearing experimental sarcoma lung metastases in the rat. The best perfusate to be used for isolated lung perfusion and factors affecting the final lung concentration of doxorubicin are the subject of the present study. METHODS: In experiment ...

The effects of low-dose chronic scopolamine on measures of cerebral perfusion and muscarinic receptors were tested in eight Alzheimer's disease (AD) subjects and eight elderly controls. Single photon emission computed tomography (SPECT) scans using technetium-labelled hexamethypropylene amine oxide (99mTc-HMPAO) to measure cerebral perfusion before and after chronic scopolamine revealed a ...

BACKGROUND: Experimental data have indicated that [99mTc]-nitroimidazole (BMS-181321) is preferentially taken up in hypoxic tissue; its kinetics, however, has not been fully investigated. The purpose of this study was to address the relation between perfusate oxygen level and myocardial retention of [99mTc]nitroimidazole. METHODS AND RESULTS: Bolus injection and constant infusion ...

Many techniques are used to reduce brain damage during surgery for dissecting aneurysms of the ascending aorta and arch. Recently, new techniques of protection were proposed, consistent with hypothermic circulatory arrest in association with retrograde cerebral perfusion via superior vena cava. We propose a simple, time-saving method, which does not ...

We have previously shown that raising the capillary transmural pressure (Ptm) in rabbit lung causes disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers of the wall. In those studies the lungs were perfused with autologous blood (1 min), then saline/dextran (3 min), followed by glutaraldehyde fixative (10 ...

Developed pressure and intracellular Ca2+ ([Ca2+i) decay in postextrasystolic beats following multiple extrasystolic contractions (ESCs) was evaluated with surface fluorometry in atrioventricular-blocked perfused rat hearts loaded with Indo-1. After priming pacing at 400 ms intervals, 1-25 ESCs were interposed with a 160 ms interval, followed by 30 postextrasystolic beats with ...

We found that ventilation with nitric oxide (NO, 50 ppm) significantly (P < 0.05) reduced capillary leak (as reflected by weight gain and Ficoll retention) in isolated rat lungs perfused for 60 min with N-formyl-methionyl-leucyl-phenylalanine (fMLP; 10(-7) M) and human neutrophils (1,300/microliters). Perfusion with previously heated neutrophils (48 degrees C ...

This work reports a low-cost and versatile electronic device designed to trigger NMR acquisitions from the cardiac cycle of an isolated perfused heart, or to perform electrical stimulation of the heart. The triggering is synchronised with the pressure curve of the perfused heart. The cardiac pacing is achieved from pulses ...