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Zimmer Heinz-Gerd - - 2002
In 1866 at Carl Ludwig's Physiological Institute at Leipzig, Elias Cyon described the influence of diastolic filling of the isolated perfused frog heart on ejection volume. A study performed at the institute of the effect of filling pressure on contraction amplitude was published in 1869 by Joseph Coats, based on ...
Kellogg D L DL - - 2002
To test the hypothesis that bradykinin effects cutaneous active vasodilation during hyperthermia, we examined whether the increase in skin blood flow (SkBF) during heat stress was affected by blockade of bradykinin B(2) receptors with the receptor antagonist HOE-140. Two adjacent sites on the forearm were instrumented with intradermal microdialysis probes ...
Bax Jeroen J - - 2002
BACKGROUND: Chronic dysfunctional but viable myocardium may exhibit contractile reserve and/or intact perfusion. Segments with intact perfusion without contractile reserve are frequently observed inpatients with ischemic cardiomyopathy. The clinical relevance of this observation is unclear; in particular, the functional outcome after revascularization is unknown. Thus, contractile reserve (using low-dose dobutamine ...
Brunsden A M - - 2002
Using novel in vitro preparations of vascularly perfused rat ileum, we investigated mesenteric afferent sensitivity to vascular perfusion. Gut (GPP) and vascular (VPP) perfusion pressures were recorded simultaneously with afferent discharge (AD). After preconstriction (L-phenylephrine), capsaicin (100 microM, gut lumen) caused a transient increase in AD and a sustained fall ...
Bainbridge S A - - 2002
Carbon monoxide (CO) is one of the metabolites formed via heme oxidation catalysed by the enzyme heme oxygenase (HO). Endogenous formation of CO, mediated by HO, has been noted in both placental and umbilical vessels. In blood vessels from different mammalian sources, it has been proposed that the vasodilator effect ...
Zeitlin I J - - 2002
It has been postulated that the mammary kinin system may play a role in modulating mammary blood flow. Until the present study, the local release of bradykinin (BK) or other kinin system constituents into the mammary vasculature had not been reported and there were also conflicting findings on the action ...
Wang Q-D - - 2002
During the development of a Langendorff preparation of isolated mouse hearts, hitherto undescribed cyclic fluctuations in left ventricular pressure and coronary flow were independently observed in three laboratories. Isolated mouse hearts were perfused with crystalloid glucose-containing Krebs-Hensleit buffer in a constant pressure model, and left ventricular pressures were measured via ...
Bilston Lynne E - - 2002
Some simple finite element models were constructed to investigate the magnitude and character of changes in mechanical properties of very soft tissues due to the loss of perfusion. Changes in the apparent stress-strain curve were used to characterise the effect of simulated blood perfusion pressure on the engineering stress-strain curve. ...
Fisher David - - 2002
In this study the effects of perfusing isolated seminiferous tubules of the testes are reported for the first time. Initial perfusion studies (fast rate perfusion) resulted in gross morphological damage to the seminiferous tubules. The recorded transepithelial potential (V(t)) was close to 0 mV. Slow perfusion rates eliminated morphological damage ...
Mayrovitz Harvey N - - 2002
OBJECTIVE: It was hypothesized that a device or support surface providing intermittent cycles of pressurization and pressure relief might minimize the impact of blood flow deficits in the heels resulting from the application of pressure. Because this possibility depends on whether pressure-relief hyperemia can adequately compensate for blood flow deficits, ...
Parra Augusto - - 2002
The transgenic mouse has been used to study subarachnoid hemorrhage (SAH) induced delayed cerebral vasospasm (DCV). Methodological parameters have not been analyzed to validate this model and associated neurological deficits have not been described. We introduce a technique to quantify DCV and associated neurological deficits. C57BL/6J mice were subjected to ...
Graf Bernhard M - - 2002
BACKGROUND: Ropivacaine is believed to have a lower incidence of clinical cardiac side effects than bupivacaine. The aim of this study was to compare the direct cardiac effects of the optically pure S(-)-ropivacaine isomer and its nonclinically used R(+)-isomer with both optically pure bupivacaine isomers in isolated hearts. The hypothesis ...
Sack F U - - 2002
BACKGROUND: Cardio-thoracic surgery with the use of extracorporeal circulation may lead to an impairment of splanchnic perfusion. The aim of this study was to investigate the effect of dopexamine on gastrointestinal microvascular perfusion failure due to extracorporeal circulation. METHODS: Twenty landrace pigs served as laboratory animals. A loop of the ...
Lima Alexandre Pinto - - 2002
OBJECTIVE: Peripheral perfusion in critically ill patients frequently is assessed by use of clinical signs. Recently, the pulse oximetry signal has been suggested to reflect changes in peripheral perfusion. A peripheral perfusion index based on analysis of the pulse oximetry signal has been implemented in monitoring systems as an index ...
Tolstykh Gleb P - - 2002
BACKGROUND: Technology that can implement the basic requirements for successful organ preservation in a portable configuration has yet to be realized. METHODS: This work evaluates kidney preservation in a new class of portable organ preservation technology based on fluidics principles. During hypothermic pulsatile perfusion preservation (HPPP), oxygen consumption, renal vascular ...
Victorino Gregory P - - 2002
BACKGROUND: The effect of hypertonic saline (HS) on microvascular permeability is unclear. We hypothesized that varying degrees of tonicity and HS solutions alter microvascular fluid flux across the endothelium. METHODS: Hydraulic permeability (L(p)) is a measure of water flow across the endothelial barrier. L(p) was measured in cannulated rat mesenteric ...
Moriya Toshihiro - - 2002
We are developing an original nonroller extracorporeal circulation system (NRECC). However, this NRECC could not perform selective cerebral perfusion (SCP). Therefore, we added cerebral perfusion lines and an automatic pressure controller to the system. The purpose of this study was to evaluate the stability and response of the pressure controller ...
Fulep Eva E - - 2002
OBJECTIVE: Our purpose was to study the effects of inhibition of nitric oxide synthesis on perfusion pressure and flow rate-perfusion pressure relationships in the rat uterine circulation in situ. STUDY DESIGN: Nonpregnant, midpregnant (day 14), and late pregnant (day 21) Sprague-Dawley rats were studied. The vascular bed of the intact ...
Hoff Tracy K - - 2002
OBJECTIVE: To evaluate the clinical efficacy of topically administered glyceryl trinitrate (GTN) for inducing digital submural vasodilation in clinically normal horses. ANIMALS: 7 adult horses without foot abnormalities. PROCEDURES: A concurrent-control crossover design was used to determine whether topical application of GTN ointment for prevention or treatment of laminitis would ...
Haugen Guttorm - - 2002
BACKGROUND: Pregnancy is feasible in organ-transplanted women, but little is known about possible effects of ciclosporine A on the circulation in the fetus and placenta. AIM: To investigate the influence of ciclosporine A (CsA) on the vasoactive effects of serotonin in human umbilical arteries. STUDY DESIGN AND SUBJECTS: In vitro ...
Demiryürek A Tuncay - - 2002
Reactive oxygen species, generated and released during digoxin-induced cardiotoxicity, can produce an activation of poly (ADP-ribose) synthase (PARS). Our objective was to examine the effects of PARS inhibitors, 3-aminobenzamide (3-AB ) and nicotinamide, on digoxin-induced arrhythmias in guinea-pig isolated hearts. 3-AB (0.1-0.3 mM) and nicotinamide (0.3 mM) were added to ...
Pakulski Cezary - - 2002
BACKGROUND: The aim of our research was to evaluate the influence of general anesthesia with controlled nitroglycerin-induced hypotension on splanchnic mucosal perfusion using gastric tonometry. MATERIAL/METHODS: In six patients (1 female, 5 males, median age 46 years, range 32-62) undergoing elective resection of meningiomas, measurements of gastric mucosal perfusion were ...
Walsh Edward G - - 2002
Myocardial perfusion imaging using Gd contrast agents is typically performed with bolus injections of the contrast agent using a power injector to provide for consistent and sufficiently rapid injection rates for all patients. For protocols in which a peripheral venous injection is called for (e.g. antecubital vein) injection catheters of ...
Hirose Satoshi - - 2002
We previously successfully developed a simple nonroller extracorporeal circulation system (NRECC). In aortic arch surgery, more than two pumps are generally used for systemic perfusion and selective cerebral perfusion (SCP); we developed a new pressure-dependent perfusion system for SCP based on our NRECC and operated by a single centrifugal pump. ...
Hamrin K - - 2002
Microdialysis catheters (CMA-60 with a polyamide dialysis membrane; 20,000-molecular wt cutoff) were either immersed in an external medium or were inserted in the quadriceps femoris muscle of healthy subjects, using perfusate with or without dextran 70. Varying the position of the outflow tubing induced changes in hydrostatic pressure. The sample ...
SkoczyƄski M - - 2001
Increased systemic vascular resistance and blood pressure during pregnancy may be due to impaired prostacycline PGI(2)-thromboxan (TX) A(2) balance. The aim of the study was to compare the influence of magnesium sulphate and isradipine on the placental vascular resistance induced by stable thromboxan A(2) analogue U 46619 in experimental bilateral ...
Hartman J M - - 2001
OBJECTIVES: To correlate supraclavicular left internal mammary artery (LIMA) to left anterior descending artery (LAD) area Doppler characteristics with angiographically perfused area. METHODS: Sixty patients (50 male, mean age 62+/-7.3 years) with LIMA to LAD area grafting were prospectively entered in a follow up study. Supraclavicular echo Doppler of the ...
Hillis A E - - 2001
We report a series of six single subject studies examining the effects of pharmacological blood pressure elevation on regional brain perfusion and language function. Previous reports indicate that hypoperfusion of specific brain regions, as delineated by magnetic resonance perfusion weighted imaging (PWI), is associated with disruption of selective lexical functions. ...
Kranenburg-Lakeman P - - 2001
OBJECTIVE: To study pressure-flow behaviour of in vitro placentas under normal simulated conditions and during raised external pressures, to simulate in vivo placental hemodynamic function, and as a model for polyhydramnios and the supine hypotension syndrome. DESIGN: Eleven normal term human singleton in vitro placentas were perfused under optimal physiologic ...
Vincent M A - - 2001
There are two vascular flow routes in skeletal muscle that can be accessed by different vasoconstrictors acting at selective sites in the vascular tree. Thus, angiotensin II (AII) and serotonin (5-HT), which stimulate and inhibit metabolism, do so by directing flow to nutritive and nonnutritive routes, respectively. In the present ...
Lin W - - 2001
OBJECTIVE: When arterial and venous pressures are increased to equal values in "stop-flow" studies, perfusate continues to enter the pulmonary vasculature from the arterial and venous reservoirs. Losses of fluid from the pulmonary vasculature are due to ultrafiltration and flow through disrupted anastomotic (bronchial) vessels. This study compared the relative ...
Stavrou B M - - 2001
1. The structural conformation of diadenosine tetraphosphate (Ap(4)A) and pentaphosphate (Ap(5)A) has been reported to alter as pH is reduced. As such, it is possible that the cardiac effects of Ap(4)A and Ap(5)A vary during acidosis and myocardial ischaemia due to changes in ligand structure, receptor proteins or intracellular signalling. ...
Jin Q H - - 2001
To elucidate neurochemical mechanisms responsible for cardiovascular responses induced by central salt loading, we directly perfused the paraventricular nucleus (PVN) of the hypothalamus region with hypertonic saline (0.3 or 0.45 M) by using an in vivo brain microdialysis technique. We then measured the extracellular concentrations of glutamate in the PVN ...
Yang T - - 2001
With surrogate tolerogenesis. the recipient immune system is engrafted within the donor pig before organ transplant. Chimeric pig hearts may resist hyperacute rejection by inducing accommodation. This hypothesis was tested using an ex vivo isolated piglet heart perfusion model. Processed sheep marrow was infused into fetal pigs at 45 days ...
Van Wijk M J - - 2001
OBJECTIVE: To investigate the effects of syncytiotrophoblast microvillous membranes (STBM) in concentrations, found in vivo in women with pre-eclampsia, on endothelial function in isolated resistance arteries. SETTING: Department of Obstetrics and Gynaecology, Huddinge University Hospital, Stockholm. SAMPLE: Twenty-nine myometrial resistance arteries isolated from biopsies of healthy term pregnant women, obtained ...
Kinnunen P - - 2001
Endothelin-1 (ET-1) elicits a vasoconstrictor response via ET(A) receptors, whereas simultaneous activation of ET(B) receptors triggers the release of nitric oxide (NO), which may limit the constrictor effect of ET-1. Recently, stimulation of ET(B) receptors has been shown to increase the secretion of adrenomedullin (AM), a newly identified vasorelaxing peptide. ...
Yamamoto Y - - 2001
The effects of hypercapnia (CO(2)) confined to either the alveolar space or the intravascular perfusate on exhaled nitric oxide (NO), perfusate NO metabolites (NOx), and pulmonary arterial pressure (Ppa) were examined during normoxia and progressive 20-min hypoxia in isolated blood- and buffer-perfused rabbit lungs. In blood-perfused lungs, when alveolar CO(2) ...
Brilakis H S - - 2001
PURPOSE: A quantitative study was conducted to estimate the survival time of giant vacuoles of the endothelial wall of Schlemm's canal once perfusion pressure has dropped to zero. Vacuoles are known to be sensitive to intraocular pressure and could serve as real-time markers of aqueous pressure in the juxtacanalicular tissue ...
Gibbons S - - 2001
The effects of an aqueous extract of Zygophyllum coccineum L. on rat blood pressure (BP) and on the mesenteric vascular bed were investigated. The extract dose-dependently reduced BP and heart rate in normotensive and spontaneously hypertensive rats (SHRs). It also reduced BP in pithed SHRs. In vitro, the extract had ...
Daryanani D - - 2001
BACKGROUND: Continuous measurement of perfusate leakage into the systemic circulation is of the utmost importance and can be performed with the help of radioactive tracers. The purpose of this study was to assess changes in the perfusion leakage rate between two periods: 1977-1990 and 1991-2000, and to determine the factors ...
Ay T - - 2001
BACKGROUND: Recent experimental data indicate that ultrasound-induced destruction of ultrasound contrast microbubbles can cause immediate rupture of the microvessels in which these microbubbles are located. METHODS AND RESULTS: To examine the functional and morphological significance of these findings in the heart, isolated rabbit hearts were perfused retrogradely with buffer containing ...
Bitner J B - - 2001
Barnacle muscle cells regulate their volume when exposed to anisotonic conditions. Due to their large size, these cells can be internally perfused. Interestingly, perfused cells maintain their volume regulatory properties (17,21). Thus, the osmotic properties of barnacle muscle cells can be studied under conditions in which the intracellular and extracellular ...
Peyton P J - - 2001
Ventilation-perfusion (VA/Q) inhomogeneity was modeled to measure its effect on overall gas exchange during maintenance-phase N(2)O anesthesia with an inspired O(2) concentration of 30%. A multialveolar compartment computer model was used based on physiological log normal distributions of VA/Q inhomogeneity. Increasing the log standard deviation of the distribution of perfusion ...
Mailman D - - 2001
The objective of this research was to determine the amount and timing of nitric oxide (NO, nitrogen monoxide) gas produced by the lungs, intestinal mucosa, and organ surfaces facing the peritoneal cavity after iv injection of a bacterial toxin, lipopolysaccharide (LPS). Some of the deleterious effects of LPS on organ ...
Cattel L - - 2001
BACKGROUND: The kinetics of melphalan leakage from extracorporeal fluid to the peripheral blood was studied in ten patients undergoing hyperthermic isolation perfusion of the lower limbs as an adjuvant treatment in high-risk melanoma. MATERIALS AND METHODS: Systemic leakage was monitored by a new technique using 99mTc-albumin microcolloid. Serial samples were ...
Szczesny G - - 2001
Prolonged immobilization of severely ill, bed-ridden patients results in formation of pressure ulcers following inappropriate tissue blood perfusion, and local activation of leukocyte - endothelial cell interactions (L/EC). Various treatment modalities were implemented to improve local microcirculation with controversial results. The aim of our study was to investigate the influence ...
Le Duc G - - 2001
Long-distance effects of a superparamagnetic contrast agent (AMI227) were investigated by phosphorus-31 NMR spectroscopy at 7.05 Tesla. In an initial methodological approach, the effects observed on phantoms were compared to the results of theoretical calculations. In a second step, the particles were administered to excised and perfused rat livers (N ...
Waller C - - 2001
INTRODUCTION: A MR imaging (MRI) method has been developed to determine quantitatively myocardial perfusion (P) in the rat heart in vivo. This method has the potential to non-invasively measure cardiac perfusion without the use of a contrast agent by exploiting the endogenous contrast from flowing blood itself. METHOD AND RESULTS: ...
Deem S - - 2001
Free hemoglobin (Hb) augments hypoxic pulmonary vasoconstriction (HPV), ostensibly by scavenging nitric oxide (NO). However, recent evidence suggests that Hb that is S-nitrosated may act as an NO donor and vasodilator. We studied the effects of oxyHb, Hb that is chemically modified to prevent heme binding or oxidation of NO ...
Jones A T - - 2001
Acute respiratory distress syndrome is characterized by alterations in the ventilation-perfusion ratio. Present techniques for studying regional pulmonary perfusion are difficult to apply in the critically ill. Electron-beam computed tomography was used to study the effects of prone positioning on regional pulmonary perfusion in six healthy subjects. Contrast-enhanced sections were ...
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