Search results for "Middle Cerebral Artery"
showing 9 items of 79 documents
Which is the best ultrasound parameter for the prediction of adverse perinatal outcome within 1 day of delivery?
2021
To compare the accuracies of several sonographic parameters for the prediction of adverse perinatal outcome (APO) prior to delivery.This was a prospective study of fetuses attending the day hospital unit of a tertiary referral hospital that were scanned at 34-41 weeks and gave birth within 24 h of examination. APO was defined as a composite of abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH7.20 requiring urgent cesarean section, neonatal umbilical cord pH7.10, 5' Apgar score7 and postpartum admission to neonatal or pediatric intensive care units. The accuracies of the middle cerebral, vertebral and umbilical arteries pulsatility index multiples of the median (MoM), the c…
Birth-weight differences at term are explained by placental dysfunction and not by maternal ethnicity. Study in newborns of first generation immigran…
2020
The aim of the study was to investigate the influence of ethnicity and cerebroplacental ratio (CPR) on the birth weight (BW) of first generation Indo-Pakistan immigrants' newborns.This was a retrospective study in a mixed population of 620 term Caucasian and Indo-Pakistan pregnancies, evaluated in two reference hospitals of Spain and Italy. All fetuses underwent a scan and Doppler examination within two weeks of delivery. The influence of fetal gender, ethnicity, GA at delivery, CPR, maternal age, height, weight and parity on BW was evaluated by multivariable regression analysis.Newborns of first generation Indo-Pakistan immigrants were smaller than local Caucasian newborns (mean BW mean= 3…
Ca2+ entry blockers inhibit prostaglandin F2 alpha-induced cerebrovascular contractile responses in goats.
1991
We examined the effects of extracellular Ca2+ withdrawal and of Ca2+ entry blockers on goat cerebrovascular responses to prostaglandin F2 alpha (PGF2 alpha). We measured isometric tension in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. PGF2 alpha produced concentration-dependent contractions of isolated arteries. The contractions were partially inhibited by incubation in Ca(2+)-free medium (by 63.1 +/- 1.8% without ethyleneglycol-bis-(beta-amino-ethylether)-N,N,N',N'-tetra-a cetate (EGTA), and by 82.4 +/- 3.7% with EGTA). The Ca2+ entry blockers inhibited PGF2 alpha-elicited contraction and relaxed PGF2 alpha-precontracted arteries (nicardipine…
Endothelial modulation of 5-hydroxytryptamine-induced contraction in goat cerebral arteries.
1993
Abstract 1. 1. In isolated goat middle cerebral artery segments, 5-hydroxytryptamine (5-HT, 10 −8 −3 × 10 −5 M) caused concentration-dependent contractions, with EC 50 = 2.1 (1.9−2.5) × 10 −7 M and E max = 60 ± 2% of 50 mM KCl-induced contraction. 2. 2. Mechanical removal of endothelium significantly increased the E max (91 ± 8%) and did not change the EC 50 value of 5-HT-elicited contractions. 3. 3. Incubation of unrubbed arteries with the irreversible inhibitor of EDRF, gossypol (10 −5 M), significantly increased the contractile response to 5-HT ( E max = 77 ± 4%). 4. 4. Incubation of unrubbed arteries with the competitive inhibitor of the NO synthesis, N G -nitro - l -arginine (L-NOARG) …
Stroke and cardiac arrhythmias.
2001
Stroke is frequently followed by electrocardiographic (ECG) changes. The aim of the present study was to evaluate the global incidence of these changes after ischemic or hemorrhagic strokes, but it focused on cardiac arrhythmias. In ischemic strokes, these were correlated with the side of the lesion(s). The study was retrospective, and 450 patients (out of 971 examined) were entered in the study based on the following inclusion criteria: (1) "completed" stroke (352 ischemic and 98 hemorrhagic), (2) ECG on admission, and (3) at least 1 previous ECG. We also examined 71 patients with carotid or vertebro-basilar transient ischemic attacks (TIA). As controls, 71 patients suffering from nonvascu…
Possible Adverse Effects of Hyperventilation on rCBF during the Acute Phase of Total Proximal Occlusion of a Main Cerebral Artery
1969
Recent studies seem to favor a beneficial effect of hyperventilation (HV) in cases of cerebrovascular occlusion [1, 4] and brain trauma [2, 5]. On the other hand, it seems that, at least under certain circumstances, HV may exert an adverse effect upon cerebral blood flow and metabolism [3]. Since this question is not settled yet, it seems worthwhile to report briefly the present case of reversible total occlusion of the middle cerebral artery closely followed by successive rCBF studies (133Xe-gamma-clearance method), in which, during the acute phase, HV caused a latent ischemia to become manifest.
Vasomotor reactivity in dementia of alzheimer type
1994
The objective of this study was to examine the cerebral blood flow and the vasomotor function of CO2-responsive intracerebral vessels in Alzheimer's disease. Patients met DSM-III-R criteria for dementia of Alzheimer type and had neither symptoms nor signs of cardiovascular or cerebrovascular disease. Blood flow velocities in both middle cerebral arteries (MCA) were recorded using transcranial Doppler sonography during hypercapnia, normocapnia and hypocapnia. Several psychometric tests were performed. Patients' age, disease duration and severity of dementia did not correlate with vasomotor reactivity. Exploratory analysis revealed that mean flow velocities under hypercapnia correlated with s…
Modelling of the Ischemic Penumbra
1999
What happens to the ischemic penumbra – defined as a territory of critically reduced blood flow in the close neighborhood of an ischemic core – determines outcome after stroke. Currently the pathophysiology of the penumbra is studied predominantly in rat models with occlusion of the middle cerebral artery. Here we propose two other rat models with distinct advantages. One produces a large territory of critical flow reduction in the cortex of one hemisphere without presence of an infarct core: this model is suited to study mediator mechanisms that may transform the penumbra into necrotic tissue. It is produced by occluding one carotid artery and in addition reducing arterial pressure to 50mm…
Transkranielle Dopplersonographie bei Kopf-Hals-Tumoren*
1991
Transcranial Doppler ultrasound (TCD) recording is a non-invasive diagnostic procedure for the evaluation of the cerebral collateral flow in patients, in whom therapeutic ligation or resection of the common and/or internal carotid artery is planned. Patients are first examined under resting conditions, and then under manual compression of the ipsilateral carotid artery. Since January 1989, 31 ENT and neurosurgical patients have been examined. In all patients an immediate decrease in flow velocity in the middle cerebral artery (mca) of about 25% to 90% was recorded. In 42.8% of the patients the mca flow velocity reached 90% or more of its value under normal conditions within a short period. …