Search results for " blood flow"
showing 10 items of 305 documents
Intraoperative microvascular Doppler monitoring of blood flow within a spinal dural arteriovenous fistula: a precious surgical tool. Case report.
2001
The authors describe a case of spinal arteriovenous fistula (AVF) treated by a microvauscular Doppler–assisted surgical interruption of the arterialized vein. Microvascular Doppler monitoring represents a valid, widely available, non-invasive tool that enables identification, through flow spectrum analysis, of components of this type of vascular malformation. In this case because the location of the fistula was identified prior to opening the dura only minimally invasive surgery was required. Direct recordings of the arterialized draining vein and the nidus of the fistula demonstrated a pathological spectrum caused by the arterial supply and the disturbed venous outflow in which a high-resi…
Dopamine agonist cabergoline reduces hemoconcentration and ascites in hyperstimulated women undergoing assisted reproduction.
2007
Abstract Context: Ovarian hyperstimulation syndrome (OHSS) results from increased vascular permeability (VP) caused by ovarian hypersecretion of vascular endothelial growth factor (VEGF), which activates its receptor-2. In animals, the dopamine receptor 2 agonist cabergoline (Cb2) inactivates VEGF receptor-2 and prevents increased VP. Objective: Our objective was to test whether Cb2 reduces VP and prevents OHSS in humans. Design: We conducted a prospective, randomized, double-blind study on oocyte donors at risk of developing OHSS (>20 follicles, >12 mm developed, and >20 oocytes retrieved). Interventions: Cb2 0.5 mg/d (n = 37) or a placebo (n = 32) was administered fro…
Lactate and glucose as energy substrates and their role in traumatic brain injury and therapy
2009
Traumatic brain injury is a leading cause of disability and mortality worldwide, but no new pharmacological treatments are clinically available. A key pathophysiological development in the understanding of traumatic brain injury is the energy crisis derived from decreased cerebral blood flow, increased energy demand and mitochondrial dysfunction. Although still controversial, new findings suggest that brain cells try to cope in these conditions by metabolizing lactate as an energy substrate ‘on-demand’ in lieu of glucose. Experimental and clinical data suggest that lactate, at least when exogenously administered, is transported from astrocytes to neurons for neuronal utilization, essential…
Zum Einflu� der pr�isch�mischen Blutzuckerkonzentration auf H�modynamik und regionale Organdurchblutung w�hrend und nach kardiopulmonaler Reanimation…
1996
Gegenstand der vorliegenden Untersuchung im Schweinemodell ist der Einflus einer pra-ischamischen Normo-, Hyper- oder Hypoglykamie auf Hamodynamik, regionale Organdurchblutung und Reanimierbarkeit nach 3minuti-gem unbehandelten Herz-Kreislauf-Stillstand und anschliesender kardiopulmonalen Reanimation (CPR). Hypoglykamie (Blutzuckerkonzentration von 34±2 mg/dl) war bereits vor der Reanimation mit einer deutlichen Beeintrachtigung hamodynamischer Parameter assoziiert. Keines der hypoglykamischen Tiere konnte erfolgreich reanimiert werden, im Gegensatz zu den hyper- (Blutzucker 319±13 mg/dl) bzw. normoglykamischen Tieren, die keinen Unterschied hinsichtlich der Erfolgsrate der Reanimation aufw…
Untersuchungen �ber die Beurteilung der Hautdurchblutung durch zentrale und periphere Temperaturmessungen
1974
Zur Diagnose und Therapie eines Schockgeschehens sind neben zentralen Parametern auch Angaben uber die periphere Durchblutung notwendig. Das am einfachsten zu erreichende Capillargebiet ist das der Haut. Die Hautdurchblutung stellt den wichtigsten Regulator fur den Warmestrom dar, so das ein Zusammenhang zwischen Hauttemperatur und Hautdurchblutung zu erwarten ist. Vergleiche der tatsachlichen Hautdurchblutung gemessen durch Δλ mit verschiedenen Hauttemperaturen, integrierte Hauttemperatur und Burton-Indices liesen keinen Zusammenhang erkennen. Jedoch ist die Korrelation mit der Rectum-Zehen-Temperaturdifferenz ΔT statistisch hoch signifikant. Sie kann ohne technischen Aufwand als orientier…
Effects of tumor necrosis factor-alpha on tumor blood flow and hyperthermic treatment.
1989
The impact of recombinant human tumor necrosis factor-alpha (rhTNF-alpha), given alone or in combination with local hyperthermia, on perfusion and growth of a moderately rhTNF-alpha-sensitive rat tumor (DS-carcinosarcoma) was investigated. DS-carcinosarcomas were implanted into the hind foot dorsum of Sprague-Dawley rats. Tumor blood flow (TBF) was measured with the krypton-85 clearance technique. Treatment with either tumor necrosis factor-alpha (0.1-1.0 mg/kg) or hyperthermia (43.3 and 44.3 degrees C, 40 min) can decrease the perfusion of malignant tumors. The TBF reduction was fully established 2 h after rhTNF-alpha injection and lasted for at least 4 h. The application of local hyperthe…
Circulatory and metabolic responses of malignant tumors during localized hyperthermia
1980
The effect of localized hyperthermia on the circulatory responses and on the oxygen and glucose supply has been evaluated in tissue-isolated rat tumors utilizing an in situ perfusion system. On the average, localized hyperthermia caused a significant increase in total tumor blood flow after raising of the mean tumor temperature from 37 degrees C to 39.5 degrees C. At higher temperatures (42 degrees C) total tumor blood flow decreased to a level somewhat below the flow during normothermia. However, there were great interindividual differences in the response of blood flow to temperature. The changes in blood flow were paralleled by variations of the O2-consumption and of the glucose uptake o…
In vivo targets of recombinant human tumour necrosis factor-α: blood flow, oxygen consumption and growth of isotransplanted rat tumours
1989
The impact of recombinant human tumour necrosis factor-alpha (1 microgram kg-1 to 1 mg kg-1; 6.6 x 10(6) U mg protein-1) on blood flow, oxygen consumption and growth of a moderately TNF-sensitive rat tumour (DS-carcinosarcoma) was studied. Tumour growth was stimulated at low TNF doses (1 and 10 micrograms kg-1) and significantly retarded at higher TNF dose levels (0.1 and 1 mg kg-1). Growth changes were concomitant with variations in oxygen consumption, lactate release and acidification of the metabolic micromilieu. Both single and repeated application of low TNF doses (1-10 micrograms kg-1 i.v.) increased tumour perfusion whereas single administration of high TNF dose levels (0.1-1 mg kg-1…
Relation between autoradiographically measured blood flow and ATP concentrations obtained from imaging bioluminescence in tumors following hypertherm…
1993
The effects of moderate local hyperthermia (43.3 degrees C/30 min) on regional blood flow and regional ATP distribution in the amelanotic hamster melanoma A-Mel-3 were investigated by high-resolution techniques. Blood flow and ATP concentrations were measured simultaneously in treated and untreated tumors and in adjacent tissues by means of (14C)-Iodoantipyrine autoradiography and quantitative imaging bioluminescence in consecutive tissue sections at 3, 12 and 24 hr following treatment. Digital image processing and the use of a special algorithm allowed the regional interrelationship of the 2 parameters to be quantified. Measurements revealed a great heterogeneity of blood flow and ATP betw…
Response of tumour red blood cell flux to hyperthermia and/or hyperglycaemia.
1989
Laser Doppler flowmetry has been applied to subepidermal rat tumours during localized ultrasound hyperthermia and/or moderate, short-term hyperglycaemia. Blood glucose levels were elevated 4-fold by continuous i.v. infusion of D-glucose (4.8 g/kg/60 min). To determine whether the effects of hyperglycaemia on tumour blood flow involved increased rates of glycolysis and lactic acid production, galactose, a sugar not metabolized by the tumour, was administered using the same dose schedule. Hyperglycaemia was accompanied by a 3-fold increase in blood lactate levels and a slight hypervolaemic haemodilution without any significant systematic changes of the arterial blood pressure or respiratory b…