Search results for " cerebral."
showing 10 items of 271 documents
Effects of Ca2+ entry blockers on CaCl2-, KCl- and noradrenaline-induced contractions of goat cerebral arteries
1990
Abstract The effects of three Ca 2+ entry blockers, nicardipine, nimodipine and verapamil, on CaCl 2 -, KCl- and noradrenaline-induced contractions were examined in isolated goat middle cerebral artery. The relationship between the effects of Ca 2+ entry blockers and the extracellular Ca 2+ dependence of the contractions was also examined. In ‘nominally’ Ca 2+ -free medium, addition of CaCl 2 induced concentration-dependent contractions of previously depolarized arteries. Withdrawal of Ca 2+ from the extracellular medium caused strong inhibition of the KCl- and noradrenaline-induced arterial contractions. Addition of EGTA to the Ca 2+ -free medium almost abolished the noradrenaline-response…
Relaxant effects of sodium nitroprusside and NONOates in goat middle cerebral artery: delayed impairment by global ischemia-reperfusion.
1999
Global cerebral ischemia and subsequent reperfusion induce early impairment of the vasodilator responses to hypercapnia and vasoactive substances. Nitric oxide (NO) is involved in the regulation of cerebral blood flow (CBF) in both health and disease. The present study was designed to assess possible changes in the cerebrovascular reactivity to NO donors induced by cerebral ischemia-reperfusion in goats. Female goats (n = 9) were subjected to 20 min global cerebral ischemia under halothane/N2O anesthesia. Sixteen additional goats were sham-operated as a control group. One week later the effects of ischemia-reperfusion on relaxations to NO donors sodium nitroprusside (SNP), diethylamine/NO (…
Heterogeneity of P2-Purinoceptors in Brain Circulation
1990
The existence of P2-purinoceptors in the cerebrovascular bed was examined by testing the effects of ATP and its stable analog, α,β-methylene-ATP, on CBF in the unanesthetized goat as well as on isometric tension in isolated goat middle cerebral artery. When injected directly into the cerebral circulation, ATP increased and α,β-methylene-ATP decreased CBF. Indomethacin did not modify either of these effects. The vasoconstrictor action of α,β-methylene-ATP was reduced by nicardipine. “In vitro,” both ATP and α,β-methylene-ATP contracted the cerebral arteries at resting tone, but the analog was more potent than ATP. Repeated application of α,β-methylene-ATP as well as indomethacin significant…
Auditory and Cognitive Deficits Associated with Acquired Amusia after Stroke: A Magnetoencephalography and Neuropsychological Follow-Up Study
2010
Acquired amusia is a common disorder after damage to the middle cerebral artery (MCA) territory. However, its neurocognitive mechanisms, especially the relative contribution of perceptual and cognitive factors, are still unclear. We studied cognitive and auditory processing in the amusic brain by performing neuropsychological testing as well as magnetoencephalography (MEG) measurements of frequency and duration discrimination using magnetic mismatch negativity (MMNm) recordings. Fifty-three patients with a left (n = 24) or right (n = 29) hemisphere MCA stroke (MRI verified) were investigated 1 week, 3 months, and 6 months after the stroke. Amusia was evaluated using the Montreal Battery of …
El Animador/A Sociocultural en la Atención a Personas con Parálisis Cerebral: el juego de la Boccia
2018
Un ocio educativo, divertido, que desarrolle a la persona y le permita desvincularse de su realidad, es un derecho de todas las personas, independientemente de nuestras diferencias o diversidades. La parálisis cerebral supone que la persona afectada es dependiente, la dependencia es una situación que supone la necesidad de ayuda para la realización de actividades de la vida diaria. Ante esta realidad, es necesario ser consciente de la necesidad de trabajar sobre el encauzamiento del ocio y el tiempo libre, vislumbrando la existencia de herramientas de juego y actividad adaptadas como la boccia, para atender las necesidades de cada usuario, desde el ámbito de la animación sociocultural, inte…
Can Orthopantomography be used as a tool for screening of carotid atheromatous pathology and thus be used to help reduce the prevalence of ischemic s…
2012
Objective: To assess the possibility of Dentists being able to screen patients with higher risk of vascular diseases. Materials: Kodak 8000C Orthopantomographer, eco-Doppler Logiq-500 General Electric at the Lisbon Hospital Particular. Methods: Assessment of orthopantomographies made to 142 patients aged 50 or more, as well as the existing risk factors. Conduction of carotid eco-Doppler to patients who appear to have calcified plaques of the atheroma. Results: Strong dependence between dichotomised age and having the pathology (p = 0.02).Smokers are twice more likely to present plaques (OR= 2). Being hypertensive increases in about 1.4 the likelihood of having a stroke (OR= 1.4). Of the 27 …
Multifocal Ischemic Brain-Stem Lesions
1993
The clinical symptoms and signs of brain-stem ischemia are far less well defined than in ischemia due to carotid or middle cerebral artery disease. They consist of many different syndromes, and it is often difficult to correlate the clinical findings with a single functional or morphological lesion within the brain-stem.
Early patterns of electrical activity in the developing cerebral cortex of humans and rodents.
2006
International audience; During prenatal and early postnatal development, the cerebral cortex exhibits synchronized oscillatory network activity that is believed to be essential for the generation of neuronal cortical circuits. The nature and functional role of these early activity patterns are of central interest in neuroscience. Much of the research is performed in rodents and in vitro, but how closely do these model systems relate to the human fetal brain? In this review, we compare observations in humans with in vivo and in vitro rodent data, focusing on particular oscillatory activity patterns that share many common features: delta brushes, spindle bursts and spindle-like oscillations. …
Possible Role of Glymphatic System of the Brain in the Pathogenesis of High-Altitude Cerebral Edema
2018
Simka, Marian, Paweł Latacz, and Joanna Czaja. Possible role of glymphatic system of the brain in the pathogenesis of high-altitude cerebral edema. High Alt Med Biol. 19:394–397, 2018.—In this article, we suggest that the glymphatic system of the brain can play an important role in the pathogenesis of high-altitude cerebral edema (HACE). Water enters the intercellular space of the brain primarily through aquaporin-4 (AQP-4) water channels, the main component of the glymphatic system, whereas acetazolamide, pharmacological agent used in the prevention of HACE, is the blocker of the AQP-4 molecule. In animal experiments, cerebral edema caused by hypobaric hypoxia was associated with an increa…
IL FATTORE IDROSTATICO
2007
La pressione idrostatica di un fluido è l’aumento della pressione in profondità rispetto a quella di superficie. Nelle arterie e vene cerebrali la pressione idrostatica del sangue se soggetta a continue oscillazioni può danneggiare il sistema capillare interposto e incidere negativamente sugli scambi di ossigeno e altre sostanze con il tessuto nervoso circostante. Il controllo vasomotorio del sistema nervoso autonomo è inefficace determinando una contrazione lenta e duratura nel tempo a livello delle arteriole di medio e piccolo calibro. Esiste perciò un importante fattore di bilanciamento della pressione sanguigna a livello cranico in grado di contenere la pressione idrostatica eccessiva: …