Perfusion (procedure) (Total 951371 Papers Found)

A new model of transient, bilateral hemispheric ischemia in the unanesthetized rat is described. During ether anesthesia the rat's vertebral arteries were electrocauterized through the alar foramina of the first cervical vertebra and reversible clasps placed loosely around the common carotid arteries. Twenty-four hr later, the awake rats were restrained and the carotid clasps tightened to produce 4-vessel occlusion. The carotid clasps were removed after 10, 20 or 30 min of 4-vessel occlusion and ...
BACKGROUND AND PURPOSE Continuous arterial spin-labeled perfusion MRI (CASL-PI) uses electromagnetically labeled arterial blood water as a diffusible tracer to noninvasively measure cerebral blood flow (CBF). We hypothesized that CASL-PI could detect perfusion deficits and perfusion/diffusion mismatches and predict outcome in acute ischemic stroke. METHODS We studied 15 patients with acute ischemic stroke within 24 hours of symptom onset. With the use of a 6-minute imaging protocol, CASL-PI wa ...
LY2090314 (3-[9-fluoro-2-(piperidin-1-ylcarbonyl)-1,2,3,4-tetrahydro[1,4]diazepino[6,7,1-hi]indol-7-yl]-4-imidazo[1,2-a]pyridin-3-yl-1H-pyrrole-2,5-dione) is an intravenous glycogen synthase kinase-3 inhibitor in oncology trials. Drug disposition was characterized after intravenous infusion of [(14)C]LY2090314 to rats and dogs, and was related to available clinical data. LY2090314 exhibited high clearance (approximating hepatic blood flow) and a moderate volume of distribution (∼1-2 l/kg) resu ...
OBJECTIVES Acute kidney injury develops in a large proportion of patients after cardiac surgery because of the low cardiac output syndrome. The inodilator levosimendan increases cardiac output after cardiac surgery with cardiopulmonary bypass, but a detailed analysis of its effects on renal perfusion, glomerular filtration, and renal oxygenation in this group of patients is lacking. We therefore evaluated the effects of levosimendan on renal blood flow, glomerular filtration rate, renal oxygen c ...
Carpal tunnel syndrome (CTS) is a common focal peripheral neuropathy. Increased pressure in the carpal tunnel results in median nerve compression and impaired nerve perfusion, leading to discomfort and paresthesia in the affected hand. Surgical division of the transverse carpal ligament is preferred in severe cases of CTS and should be considered when conservative measures fail. A through knowledge of the normal and variant anatomy of the median nerve in the wrist is fundamental in avoiding comp ...
BACKGROUND There has been a growing need for an imaging method for the accurate diagnosis and staging of liver fibrosis as a non-invasive alternative to liver biopsy. PURPOSE To evaluate the feasibility of intra-voxel incoherent motion (IVIM) imaging for classifying the severity of liver fibrosis. MATERIAL AND METHODS Fifty-seven patients who underwent navigator-triggered, diffusion-weighted imaging (DWI) of the liver on a 1.5-T system using nine b-values and had a reliable reference standar ...
Isolated hepatocytes, harvested from normal rat livers by portal vein collagenase perfusion, can be attached to collagen-coated dextran microcarriers and transplanted by intraperitoneal injection into rats. Survival and function of the transplanted hepatocytes have been demonstrated in mutant rats lacking bilirubin-uridine diphosphate glucuronosyltransferase activity (Gunn strain) and rats with inherited lack of plasma albumin (Nagase analbuminemia rat strain). This simple technique promises to ...
Brain reperfusion causes prompt, severe, and prolonged protein synthesis suppression and increased phosphorylation of eukaryotic initiation factor 2alpha [eIF2alpha(P)] in hippocampal CA1 and hilar neurons. The authors hypothesized that eIF2alpha(P) dephosphorylation would lead to recovery of protein synthesis. Here the effects of insulin, which activates phosphatases, were examined by immunostaining for eIF2alpha(P) and autoradiography of in vivo 35S amino acid incorporation. Rats resuscitated ...
In the late 1990s, totally endoscopic coronary artery bypass grafting was successfully introduced into the heart surgery armamentarium using robotic techniques. Surgeons have applied the da Vinci telemanipulation system in order to develop completely endoscopic placement of internal mammary artery bypass grafts, mainly to the left anterior descending artery system. Multivessel procedures are currently under development. These operations can be carried out on the arrested heart using remote acces ...
The trend in development of X-ray computed tomography systems over the past decade has been toward faster and faster scanners, with comcomitant improvement in image quality. The preliminary results from the DSR scanner suggest the advent of two new, powerful dimensions in X-ray computed tomography¿high temporal resolution and synchronous volume scanning. That is, true stop-action, full three-dimensional imaging at a high repetition rate is possible with CT scanners. Such capabilities promise to ...
Thirteen patients (mean age 8.4 + 5.3 years) with Rett syndrome (RS) were studied with EEG and 99mTc-HMPAO SPECT. Eleven patients had background abnormalities and 10 patients paroxysmal activity in EEG. Hypoperfusion of varying severity was detected in 11 patients, 7 patients having multiple lesions. Bifrontal hypoperfusion, observed in 6 patients, was the most distinctive finding. Hypoperfusion was observed also in other cortical regions, except for the occipital lobes. There was no correlation ...
BACKGROUND Fluid overload is frequently found in acute kidney injury patients in critical care units. Recent studies have shown the relationship of fluid overload with adverse outcomes; hence, manage and optimization of fluid balance becomes a central component of the management of critically ill patients. DISCUSSION In critically ill patients, in order to restore cardiac output, systemic blood pressure and renal perfusion an adequate fluid resuscitation is essential. Achieving an appropriate ...
OBJECTIVES The present study was undertaken to determine whether sustained manual abdominal compression (SMAC) using left paramedian compression technique can improve coronary perfusion pressure (CPP) during cardiopulmonary resuscitation (CPR) and resuscitation outcomes without causing liver laceration. METHODS Ventricular fibrillation was induced in 14 pigs, and circulatory arrest was maintained for 6 min. Animals were resuscitated either by standard CPR (control group) or by standard CPR wit ...
UNLABELLED Conventional cardiovascular imaging is invaluable for the assessment of late sequelae of atherosclerosis, such as diminished perfusion reserve and luminal stenosis. Molecular imaging provides complementary information about plaque composition and ongoing biologic processes in the vessel wall, allowing the early diagnosis and risk stratification of patients. Detection of enhanced glucose uptake, using (18)F-FDG PET, has been proposed as a noninvasive approach to track macrophage activa ...
Therapeutic angiogenesis is a novel promising strategy that uses angiogenic factors and stem cell transplantation to increase blood perfusion in ischaemic lower limbs. In preliminary studies short term safety and feasibility of gene therapy by recombinant protein administration or gene transfer were proven. Early reports mostly fail to show an convincing efficacy. In the largest placebo-controlled study of therapeutic angiogenesis in severe PAD reported to date, the plasmid-based fibroblast grow ...
Whether the increased capillary permeability characteristic of diabetes extends to the blood-brain barrier is presently unclear. We have examined in streptozotocin-diabetic rats the permeability of the blood-brain barrier at the level of 12 discrete brain regions employing 3 intravenous tracers of different molecular weight: sucrose, inulin and horseradish peroxidase. In animals killed 5 min after tracer injection both the sucrose and the inulin spaces were similar to controls. In order to asses ...
  • Mark Blair,
  • The American journal of physiology
  • 1983
This study was designed to determine whether stimulation of intrarenal alpha-adrenoceptors can increase renin secretion rate (RSR) in the absence of increased renal vascular resistance and to identify the accompanying changes in renal function. Experiments were performed in pentobarbital-anesthetized dogs in which renal perfusion pressure was maintained at approximately 90 mmHg and the infused kidney was acutely denervated. Renal artery infusion of the alpha-adrenoceptor agonist methoxamine (0.5 ...
The inotropic agents, dopamine (DP) and dobutamine (DB), both decrease PaO2, probably by a resistribution of the $${{\dot VA} \mathord{\left/ {\vphantom {{\dot VA} {\dot Q}}} \right. \kern-\nulldelimiterspace} {\dot Q}}$$ ratio. The aim of this study was to assess the effect of both drugs on the $${{\dot VA} \mathord{\left/ {\vphantom {{\dot VA} {\dot Q}}} \right. \kern-\nulldelimiterspace} {\dot Q}}$$ ratio, using the multiple inert gas elimination method. Ten artificially ventilated patients ( ...
Recently, we showed that neutral sphingomyelinase (N-SMase) is concentrated at the endothelial cell surface in caveolae and is activated to produce ceramide in an acute and transient manner by increase in flow rate and pressure in rat lung vasculature (Czarny M, Liu J, Oh P, and Schnitzer JE, J Biol Chem 278: 4424-4430, 2003). Here, we report further on our investigations of this new acute mechanotransduction pathway. We employed three experimental models to explore the role of N-SMase and ceram ...
BACKGROUND Recent studies found that edema, histology, and left ventricular diastolic compliance exhibit quantitative relationships in rats. Edema due to low osmolarity coronary perfusates increases myocardial water content and histologic edema score and decreases left ventricular filling. The present study examined effects of perfusate osmolarity and chemical composition on rat hearts. METHODS Arrested American Cancer Institute (ACI) rat hearts (4 degrees C) were perfused with different cardi ...
OBJECTIVE To address the ability and reliability of the INVOS 3100A (Somanetics, Troy, MI) cerebral oximeter to detect cerebral desaturation in patients and the interpretation of cerebral oximetry measurements using the INVOS 3100A in stroke and cardiac arrest. DESIGN Case reports of two patients. SETTING Neurologic Intensive Care Unit of a University Hospital. PATIENTS Two patients suffering occlusive strokes of the middle cerebral artery. One later suffered a cardiac arrest. RESULTS Th ...
Based on the Corticosteroid Randomisation after Significant Head Injury (CRASH) trial database, a prognosis calculator has been developed for the prediction of outcome in an individual patient with a head injury. In 47 patients with severe traumatic brain injury (sTBI) prospectively treated using an intracranial pressure (ICP) targeted therapy, the individual prognosis for mortality at 14 days and unfavourable outcome at 6 months was calculated and compared with the actual outcome. An overestima ...
Using the whole-cell recording technique, we have investigated some properties of the membrane currents induced by depolarization of Leydig cells isolated from mature rat testis. Internal perfusions with cyclic AMP or calcium induce currents which reveal the properties of the cyclic AMP-activated and calcium-activated chloride conductances. Both currents are sensitive to EC1 displacement and are similarly affected by SITS and DIDS, two stilbene-derived chloride channel blockers. However, at the ...
There are primary and secondary malignant liver tumors for which principal treatment is surgical resection. There is no established treatment for unresectable malignant liver tumors, however, and the prognosis for these is quite poor. An effective treatment for malignant liver tumors is thus urgently needed. Recent advances in molecular biology have uncovered the structures and/or functions of many cytokines thought to have a strong relation with the mechanisms of the antitumor effect of biologi ...
BACKGROUND The hemodynamic state of the posterior dominant vasogenic edema in posterior reversible encephalopathy syndrome (PRES) is controversial. The aim of this retrospective study was to examine the contribution of epileptic ictal hyperperfusion in patients with PRES using combined magnetic resonance perfusion imaging with arterial spin labeling (ASL) and diffusion-weighted magnetic resonance imaging (MRI). METHODS A detailed review of chronological MRI findings in 2 patients, including di ...
Using a continuous perfusion system, synaptosomes prepared from rat brain released [3H]norepinephrine in a Ca2+-dependent manner when pulse depolarized by briefly elevating external potassium concentrations. Tetrodotoxin (10(-7) M), a sodium channel blocker, inhibited 48% of this pulsed release, and D595 (10(-5) M), a phenethylamine-type calcium channel blocker, inhibited 21%. In combination, these two specific ion channel antagonists appear to function independently of each other in an additive ...
This paper describes the fabrication of a novel stretchable fingernail sensor prototype, mounted on the fingernail for detecting fingertip touch force direction. Fingernail sensors are optical reflectance photoplethysmograph sensors that detect the change in blood perfusion in the nail bed, as the finger pad touches a planar surface with various forces. The original fingernail sensor was rigidly attached to the human fingernail and accordingly needed to be customized to the geometry of the finge ...
Currently available intracoronary stents are permanent and their placement may be complicated by thrombosis and restenosis. We have developed a new bioresorbable stent constructed of type I collagen. This stent has a compliant tubular structure that is self expanding and carries a net negative surface charge to increase hemocompatibility. In vitro histologic and morphometric examination was performed by deploying the stent in six pressure fixed explanted porcine arteries. Morphometry revealed ...
I thank the Association and its President Craig Miller for the honor of inviting me to address the meeting. I will concentrate on the topic that captivated my interest for many years. Some of you might be skeptical about such a talk, and I do not blame you. We have all sat through the tedious ramblings of elderly surgeons, sometimes coupled with bad jokes, and hoped that their talk would not be too long. I will try to show you that it is not only interesting but also important to study the histo ...
BACKGROUND In patients with typical angina but angiographically normal coronary arteries, abnormal vasomotor function is assumed to be a major underlying cause. However, data on this issue are conflicting, and recent studies suggest that fluid dynamic abnormalities exist in these patients. The aim of the study was to evaluate whether early stages of atherosclerosis are characterized by alterations of baseline coronary hemodynamics and endothelium-independent vasomotion. Besides established intra ...
BACKGROUND AND PURPOSE Transcranial Doppler sonography (TCD) can evaluate noninvasively the blood flow velocities and patency of the main trunk of the middle cerebral artery (MCA). Using TCD we evaluated MCA patency and patterns of flow through the circle of Willis in patients with acute stroke. METHODS Patients with symptoms of hemispheric stroke were evaluated with serial TCD tests during admission. The Canadian Neurological Scale was used to assess neurological deficits. In all cases comput ...
OBJECTIVES To assess re-endothelialisation of denuded human arteries by two different seeding techniques using adhesion molecule induction and a dynamic flow-seeding. DESIGN Prospective, open study. SETTING University Department of Cardiovascular Surgery. MATERIALS AND METHODS In the first group (I) segments of human common carotid arteries (n = 4) were balloon-denuded, short-time seeded with cultured adult human venous endothelial cells (EC) and exposed to a mock circulation. In the secon ...
OBJECTIVES Atrial fibrillation (AF) is a common problem in cardiac surgery patients. We evaluated the mid-term results of patients who underwent open heart surgery and radiofrequency ablation (RFA). STUDY DESIGN The study included 79 patients (53 females, 26 males; mean age 53+/-11 years; range 32 to 76 years) who underwent concomitant RFA for AF during open heart surgery under cardiopulmonary bypass. The majority of patients were in NYHA class III (n=68, 86.1%) and had (n=67, 84.8%) rheumatic ...
This review will provide a comprehensive overview of the interactions between dietary isoflavones and the ATP-binding cassette (ABC) G2 efflux transporter, which is also named the breast cancer resistance protein (BCRP). Expressed in a variety of organs including the liver, kidneys, intestine, and placenta, BCRP mediates the disposition and excretion of numerous endogenous chemicals and xenobiotics. Isoflavones are a class of naturallyoccurring compounds that are found at high concentrations in ...
Recent studies indicate that the human choroid has a considerable capacity to keep blood flow constant despite exercise-induced increases in perfusion pressure. The mechanisms underlying this vasoconstrictor response remain unclear. We hypothesized that pharmacological modulation of the autonomic nervous system may alter the choroidal pressure/flow relationship during squatting. To test this hypothesis, we performed a randomized, double-masked, placebo-controlled, three-way crossover study in 15 ...
OBJECTIVE We sought to determine the prognostic value of myocardial contrast echocardiography (MCE) in patients with known or suggested coronary artery disease compared with technetium-99m sestamibi single photon emission computed tomography (SPECT)-myocardial perfusion imaging (MPI). BACKGROUND The prognostic value of SPECT-MPI is well established for patients with coronary artery disease. It is less well defined by MCE. METHODS In all, 51 consecutive patients with suggested coronary artery ...
Blood flow to the tissues of the gastric lesser curvature has been compared with the flow to the rest of the body of the canine stomach by means of the radiopotassium clearance method. Under all the circumstances examined, the lesser curvature had at least as great a perfusion rate as the rest of the stomach. These observations lend no support to the suggestion that ulcer localization on the lesser curve is due to a normally existing relative ischemia in that area. ...
Stem cell therapy has shown therapeutic benefit in dilated cardiomyopathy (DCM), but doubt remains about the most appropriate stem cell subpopulation. The current study compared the efficacy of intracoronary administration of bone marrow mononuclear cells (BMMC) or mesenchymal stem cells (BMSC) in patients with DCM.Fifty-three patients with DCM and reduced (< 40%) left ventricular ejection fraction (LVEF), were randomized to intracoronary infusion of BMMC (BMMC group, n = 16) or BMSC (BMSC gr ...
Although xenon is classically taught to be a "perfusion-limited" gas, (129)Xe in its hyperpolarized (HP) form, when detected by magnetic resonance (MR), can probe diffusion limitation. Inhaled HP (129)Xe diffuses across the pulmonary blood-gas barrier, and, depending on its tissue environment, shifts its resonant frequency relative to the gas-phase reference (0 ppm) by 198 ppm in tissue/plasma barrier and 217 ppm in red blood cells (RBCs). In this work, we hypothesized that in patients with idio ...
The experiments on normal mongrel dogs and those with chronic experimental pancreatitis were performed to reveal the early changes of the endocrine pancreas function. The concentration of immunoreactive insulin and glucagon were studied in afferent vessels of the organ after intraarterial glucose-loading during pancreatic perfusion in situ. The data obtained have shown that in chronic pancreatitis the maximum secretion of insulin is decreased and delayed, as compared to normal animals. At the sa ...
A new concept in the design of a push-pull cannula device for localized perfusion of brain tissue in the conscious and/or unrestrained animal is described. A catheter, consisting of a single strand of polyethylene tubing, contains an internal dividing septum which runs longitudinally throughout its length. The orifice of each lumen is of equal diameter and provides an integrated system for simultaneous delivery and withdrawal of a perfusate from the perfusion locus. The principal features of the ...
Diffuse cerebral ischemia was created in pentobarbital-anesthetized cats by basilar and bilateral carotid artery occlusions and hypotension. Local cerebral blood flow (ICBF) was assessed autoradiographically with 14C-antipyrine, and local cerebral glucose utilization with 14C-2-deoxyglucose. In animals without glucose pretreatment, 15 min of ischemia led to a homogeneous reduction of post-ischemic cerebral perfusion to 31% of control; ischemia of 30 min produced post-ischemic perfusion heterogen ...
Severe microcirculatory disturbances due to endothelial cell damage and leukocyte adherence during reperfusion of transplanted livers are considered to contribute to early graft failure. Since the degree of reperfusion injury after liver transplantation depends on the length of preservation time and the solution used for preservation, the aim of our study was to assess three solutions with respect to microvascular perfusion and leukocyte adhesion. Therefore, rat livers were stored up to 24 h in ...
UNLABELLED The goals of this review were to summarize the published data from the National Heart, Lung and Blood Institute sponsored Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study, present new data from the entire population and provide a comprehensive criteria for ventilation-perfusion (V/Q) lung scan interpretation. METHODS Data from the PIOPED frequent user tape and journal articles published between 1990 and 1994 and indexed on Medline that presented data from the ...
Behavioral sensitization to chronic amphetamine develops in parallel with an enhancement of amphetamine-stimulated efflux of acetylcholine (ACh) in striatum. The present study investigated the role of NMDA receptors in the latter phenomenon. Rats were treated with either saline (1.0 ml/kg, i.p.) or amphetamine (4.0 mg/kg, i.p., b.i.d.) for 12 days followed by a withdrawal period of 2-3 weeks. In vivo microdialysis was employed to measure striatal ACh efflux. Amphetamine challenge (4.0 mg/kg, i.p ...
A contractile-based model was constructed to represent responses to changes in left ventricular (LV) volume in a heart with constantly activated myocardium. Hearts were isolated from rabbits, the myocardium was put into a state of constant activation by perfusion with Krebs Henseleit solution containing 0.5 mM Ba2+, and recordings were taken of LV pressure responses to step and sinusoidal changes in LV volume. Pressure responses to volume steps were divided into five characteristic phases. An el ...
The hepatic perfusion index (HPI) may be of value in the detection of both overt and occult hepatic metastases in patients with colorectal carcinoma. Using the standard technique, the low counts obtained in each region of interest can produce statistical unreliability in the curve generation and render many studies unsuitable for analysis. In this study the effects of a high administered activity (400 MBq) on the inter- and intra-observer reproducibility of dynamic hepatic scintigraphy was inves ...
AIM To probe the changes of vascular responsiveness and intracellular signaling during opiate withdrawal syndrome. METHODS Morphine withdrawal syndrome in rats was precipitated by iv naloxone following daily injection of increasing dose of morphine for 2 weeks, the changes in mean arterial blood pressure (MBP) caused by acetylcholine (ACh) were recorded. Isolated mesenteric vascular beds were perfused with Kreb's solution containing different concentration of drugs. The cytoplasmic Ca2+ ([Ca2+ ...
Noncardiogenic pulmonary edema in liver transplant recipients is usually secondary to TRALI (transfusion related acute lung injury) or liver ischemic-reperfusion injury. If persistent, the resultant hypoxemia is associated with increased ventilator days, prolonged length of stay (intensive care and hospital) and increased 28-day mortality. Ventilation strategies for the management of hypoxemia in acute lung injury include moderate to high levels of PEEP (positive and expiratory pressure) and pro ...