The intersection of two ultrasound beams with slightly different frequencies results in generation of a localized radiation force and stimulates emission of audio signals from targeted objects. Vibro-acoustography uses this phenomenon to probe elastic properties of objects. Vibro-acoustography of contrast microbubbles in degassed water produced quantitative flow measurements from analysis ...

There are no data available on the kinetics of blood concentrations of xenon during the wash-in phase of an inhalation anaesthesia aiming at 1 MAC end-expiratory concentration. Therefore, we anaesthetized eight pigs with continuous propofol and fentanyl and measured arterial, mixed venous and end-expiratory xenon concentrations by gas chromatography-mass spectrometry ...

BACKGROUND: Pentane in exhaled gas is often used as an index of lipoperoxidation, but today, there is no standardization for its measurement. In this study, with our technical experience, we determined basal production of pentane in healthy subjects, and we evaluated variability of pentane flow 1 month later. METHODS: 18 ...

Changes in blood flow after chronic compression were observed in 19 dogs after 10 mmHg compression for 1 week before and 1 hour after the intravenous administration of one of three doses of beraprost sodium (BPS; 30 ng x kg(-1) x min(-1), n = 7; 100 ng x kg(-1) x ...

OBJECTIVE: Early low systemic blood flow is common in preterm infants. This study examines the relationship among low flow, renal function, and early changes in blood potassium (K(+)). METHODS: Preterm infants (n = 119) born before 30 weeks' gestational age underwent serial Doppler echocardiographic studies. Superior vena cava flow (SVC ...

A flow-through optosensor with fluorimetric transduction has been prepared for the sensitive and selective determination of dipyridamole in aqueous solutions and biological fluids. The method is based on a monochannel flow-injection analysis system using Sephadex QAE A-25 resin, placed into a Hellma 176-QS fluorimetric flow-through cell, as an active sorbing ...

OBJECTIVE: To evaluate the effects of the stable prostacyclin analogue iloprost on hepato-splanchnic blood flow, oxygen exchange and metabolism in patients with septic shock. DESIGN: Prospective clinical study. SETTING: Intensive care unit in a university clinic. PATIENTS: Eleven patients with septic shock requiring norepinephrine to maintain mean arterial pressure above ...

Background. Liver viability depends on blood flow rate, which varies among isolated perfused livers used in different studies. We aimed to identify the minimal blood flow capable of keeping the energy charge compatible with liver viability. Materials and methods. Isolated canine livers were assigned to different groups (n = 4) ...

The interaction between nitric oxide (NO) and adrenergic activity in the cerebral circulation was studied using conscious goats, where blood flow to one brain hemisphere (cerebral blood flow) was electromagnetically measured, and the effects of phentolamine and hexamethonium on cerebrovascular resistance were evaluated before (control) and after inhibition of NO ...

Ozone removal by 16 aged (older than 1-120 months) but unused building products or materials was studied in a test system that included the field and laboratory emission cell (FLEC). The ozone removal was studied at 50 +/- 1 ppb ozone, a relative humidity of 50 +/- 5%, a temperature ...

STUDY OBJECTIVE: To evaluate the effects of an intravenous infusion of prostaglandin E1 (PGE1) on hepatic blood flow. DESIGN: Prospective clinical study. SETTING: University-affiliated hospital. PATIENTS: 16 ASA physical status I and II surgical patients who were scheduled for abdominal surgery. INTERVENTIONS: Patients were anesthetized with 1% sevoflurane and 66% ...

The role of thromboxane (Tx) in hyperacute rejection of pig lung by human blood was studied in an ex vivo model, wherein lungs from juvenile piglets were perfused with fresh heparinized human blood. In this model, hyperacute lung rejection was characterized by an abrupt rise in pulmonary vascular resistance (PVR; ...

Dependent pooling occurs in postural orthostatic tachycardia syndrome (POTS) related to defective vasoconstriction. Increased venous pressure (Pv) >20 mmHg occurs in some patients (high Pv) but not others (normal Pv). We compared 22 patients, aged 12-18 yr, with 13 normal controls. Continuous blood pressure and strain-gauge plethysmography were used to ...

An experimental silicone hollow fiber membrane oxygenator for long-term extracorporeal membrane oxygenation (ECMO) was developed in our laboratory using an ultrathin silicone hollow fiber. However, the marginal gas transfer performances and a high-pressure drop in some cases were demonstrated in the initial models. In order to improve performance the following ...

Autologous PBSC transplantation is an integral component of the management of hemato-oncology patients. In order to reduce the number of sessions needed to collect the desired number of repopulating cells there has been significant research activity in developing progressively more and more effective technologies and techniques. Recently our group has ...

To investigate precisely the fluid shifts associated with water drinking in humans, we measured continuously blood density and plasma electrolyte concentrations using the mechanical oscillator technique and ion-selective electrodes, respectively, in healthy young volunteers before (10 min) and after (48 min) water drinking for a period of 2 min. Beat-by-beat ...

Oesophageal Doppler monitoring (ODM) has been advocated as a non-invasive means of measuring cardiac output (CO). However, its reliance upon blood flow measurement in the descending aorta to estimate CO is susceptible to error if blood flow is redistributed between the upper and lower body. We hypothesize that lumbar epidural ...

The hepatic arterial buffer response (HABR) tends to maintain liver blood flow under conditions of low mesenteric perfusion. We hypothesized that systemic hypoperfusion impairs the HABR. In 12 pigs, aortic blood flow was reduced by cardiac tamponade to 50 ml. kg(-1). min(-1) for 1 h (short-term tamponade) and further to ...

OBJECTIVE: It was hypothesized that fenoldopam mesylate, a selective dopamine agonist, may preserve renal perfusion and decrease tubular oxygen consumption during states of hypoperfusion, such as hypovolemic shock. The objective of this study was to quantify the effects of fenoldopam (0.1 microg x kg(-1) x min(-1)) on renal blood flow, ...

It is unknown if nitric oxide (NO) modulates the relative levels of left (LV) and right (RV) ventricular output, fetal O2 consumption, or blood flow distribution between the body and placenta at midgestation. To address these questions, six fetal lambs were instrumented at 89-96 days gestation (term 147 days), and ...

AIMS: The aim of this study was to assess the inter- and intra-laboratory variation of the concentration-response to the GPIIb/IIIa-antagonists abciximab and eptifibatide on platelet aggregometry and to compare results with flow cytometric tests as well as the rapid platelet function analyser (RPFA). METHODS: In five different laboratory sites, blood ...

The purpose of this study was to prospectively study the human pharmacokinetics of an ultrasound (US) contrast agent through its active ingredient, dodecafluoropentane (DDFP). Expired air and blood samples were collected from 24 volunteers after IV administration from 0.01 to 0.1 mL/kg. They were analyzed by a gas chromatographic method ...

One of the disadvantages of the Laerdal resuscitator bag is that it does not deliver a high concentration of oxygen without a reservoir and an appropriate technique of ventilation. With a specific device that is able to compress a resuscitator bag mechanically at a regular volume, ventilator rate, and speed, ...

The extent to which the systemic vasculature is involved in soluble-particle uptake in the conducting airways has not been studied extensively. In anesthetized, ventilated sheep, 6-10 microl of technetium-99m-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA) was delivered through a microspray nozzle to a fourth-generation airway. Perfusion of the cannulated bronchial artery was ...

Thromboembolic complications have been attributed to the use of radiographic contrast media (CM) during interventional procedures for arterial revascularization. However, due to the low frequency of adverse events, comparisons between different CM have been difficult to perform, although it has been suggested that ionic (vs. non-ionic) CM may be associated ...

A number of different qualitative and quantitative techniques have been used to measure inner ear blood flow and all have required that the animal be anesthetized. It is well known that anesthesia can cause a variety of circulatory as well as other systemic changes. In this study, we have employed ...

The analysis of flow distribution in cartridges designed for hemoperfusion is extremely important. Taking advantage of a new imaging technique, based on the analysis of a helical scanner-generated imaging sequence, we studied the blood flow distribution in a series of cartridges for extracorporeal removal of endotoxin. Cartridges with improved design ...

PURPOSE: To evaluate the effects of catheter-directed thrombin in the peripheral arterial circulation of swine. MATERIALS AND METHODS: Thrombin was injected into a single femoral artery in 20 domestic swine. Each of five animals from four dose groups received 50, 150, 250, or 1,000 U as a single dose. Bilateral ...

We studied mesenteric arterial arcades from 3- and 35-day-old swine to determine the relationship between perfusate flow rate and release of nitric oxide (NO) into mesenteric effluent. Mesenteric arterial arcades were perfused under controlled-flow conditions with a peristaltic pump using warm oxygenated Krebs buffer. Basal rates of NO production were ...

Fat stimulates superior mesenteric artery (SMA) blood flow. Little is known, however, about the influence of fatty acid chain length on SMA flow. The present study was performed to compare the effect of long chain triglycerides (LCT, corn oil), very long chain triglycerides (VLCT, fish oil) and medium chain triglycerides ...

Propofol has been reported to affect blood coagulation. This prospective, randomized study compared coagulation and blood loss during anaesthetic maintenance with target-controlled intravenous propofol infusion vs. inhaled isoflurane. Thirty-eight ASA I-III patients undergoing head and neck surgery were allocated randomly to receive either inhaled isoflurane at end-tidal concentration 1-1.5% (group ...

A simple and inexpensive approach to convert the electrospray nebulizer of a commercial liquid chromatography/mass spectrometry (LC/MS) system (HP 1100) to accommodate lower flow rates has been proposed and evaluated. This modification consists of simply replacing the nebulizer needle by a commercially available stainless steel needle with a smaller internal ...

The blood vessels that contribute most to precapillary resistance are known as resistance arteries, consisting of arterioles and small arteries with diameters of less than 500 μm (1). These vessels regulate the vascular resistance, and thus the blood supply, through the adjustment of their lumen diameter, which is accomplished by ...

The objective of this study was to evaluate relative efficiency in vitro of four reusable breath-enhanced nebulizers (Pari LC Star, Medic-Aid Ventstream, Devilbiss PermaNeb, Salter Ultramist), and to integrate the in vitro performance data of the nebulizers with the respiratory patterns of four cystic fibrosis (CF) patients to compare efficiency ...

Tibial tubercle transfer is often used for the treatment of patella maltracking. Because the periosteum of both sides of the tibia is stripped off along the tibial tubercle and then the bilateral cortices are transferred, this procedure may disturb the blood supply to the tibial tubercle. However, the blood supply ...

PURPOSE: The aim of this study was to investigate the pharmacokinetics of tissue plasminogen activator (tPA) under the conditions of an isolated extracorporeal circuit. METHODS: Plasma levels of tPA were measured in the perfusion solution and in central venous blood before, during, and after the perfusion in seven patients undergoing ...

The aim of the study was to characterize the individual pharmacokinetics of (-)-R- and (+)-S-clevidipine following intravenous constant rate infusion of rac-clevidipine to essential hypertensive patients. Twenty patients received three out of five randomized treatments with clevidipine. The pharmacokinetics of the separate enantiomers were evaluated by compartmental analysis of blood ...

BACKGROUND AND OBJECTIVES: The study evaluated mixing performance for various commercial blood-mixing devices at different flow rates. MATERIALS AND METHODS: A glycerol solution with a density equal to blood was pumped into a blood bag (mounted on a mixer) that contained 70 ml of Toluidin Blue in citrate-phosphate-dextrose (CPD). After ...

OBJECTIVE: This study was designed to compare the effects of vasopressin vs. epinephrine vs. the combination of epinephrine with vasopressin on vital organ blood flow and return of spontaneous circulation in a pediatric porcine model of asphyxial arrest. DESIGN: Prospective, randomized laboratory investigation using an established porcine model for measurement ...

Chronic arm edema is a common finding after modified radical mastectomy and its pathophysiology is unclear. In a prospective study the value of increased arterial inflow and venous abnormalities after mastectomy was evaluated. Arterial and venous blood flow in axillary vessels of 39 patients with arm swelling and 16 patients ...

Monolithic supports have become the subject of extensive study in the past years. Despite their advantageous features and many successful chromatographic applications in the analytical scale, only a very few examples of larger volume monoliths were described. In the case of GMA-EDMA monoliths, this can be attributed to the fact ...

BACKGROUND: On postdilution hemodiafiltration (post-HDF), convective removal of medium-high molecular weight solutes is, at the highest ultrafiltration rates, limited by high blood viscosity and protein concentration. Prefilter reinfusion (pre-HDF) may overcome this problem, but plasma dilution may affect the overall efficiency of the technique. In this study, an experimental system ...

Using near-infrared spectroscopy (NIRS) and the tracer indocyanine green (ICG), we quantified blood flow in calf muscle and around the Achilles tendon during plantar flexion (1-9 W). For comparison, blood flow in calf muscle was determined by dye dilution in combination with magnetic resonance imaging measures of muscle volume, and, ...

BACKGROUND: Tumescent anesthesia has revolutionized the practice of liposuction. Inherent to the tumescent technique is the use of large volumes of dilute solutions of lidocaine with epinephrine instilled into subcutaneous fat deposits. Precise formulation of the tumescent anesthesia is essential to liposuction technique. OBJECTIVES: To determine the actual volumes of ...

Idle emissions of total hydrocarbon (THC), CO, NOx, and particulate matter (PM) were measured from 24 heavy-duty diesel-fueled (12 trucks and 12 buses) and 4 heavy-duty compressed natural gas (CNG)-fueled vehicles. The volatile organic fraction (VOF) of PM and aldehyde emissions were also measured for many of the diesel vehicles. ...

A new project is presented, the pumping oxygenator, functionally integrating pulsatile pumping and blood oxygenation in a single device. Solid, semipermeable silicone membranes allow gas exchange and simultaneously transfer energy from pressurized gas to blood thanks to their distensibility and to inlet and outlet 1-way valves. Two small-sized (1 m2 ...

Blood is usually irradiated by x-ray to prevent graft-versus-host-disease. However, plasma potassium levels of irradiated blood are rapidly increased during preservation in irradiated blood. The objectives of this study were to develop a rapid blood transfusion system for which irradiated blood can be used and to evaluate the capability of ...

To test the role of blood flow in tissue hypoxia-related increased veno-arterial PCO(2) difference (DeltaPCO(2)), we decreased O(2) delivery (&Ddot;O(2)) by either decreasing flow [ischemic hypoxia (IH)] or arterial PO(2) [hypoxic hypoxia (HH)] in an in situ, vascularly isolated, innervated dog hindlimb perfused with a pump-membrane oxygenator system. Twelve anesthetized ...

PURPOSE: A number of percutaneous thrombectomy devices are undergoing investigation for treatment of patients with venous thromboembolism. Use of radiopaque thrombus to monitor thrombus delivery and assess thrombectomy has been previously reported. The purpose of this project was to quantitatively test the effect of mixing different ratios of blood and ...

Glutathione (GSH) mediated metabolism of a model electrophile, 1-chloro-2,4-dintrobenzene (CDNB), by striped bass (Morone saxitilis) whole blood and reconstituted erythrocytes equilibrated to 'arterial' and 'venous' blood gas concentrations was assessed. Reduced GSH was found to be an abundant nucleophile (2-2.4 mM) in striped bass erythrocytes. Incubation of whole blood and ...