Search results for "Artery"
showing 10 items of 2026 documents
Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage.
2012
Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow.Fifteen SAH patients with secured aneurysms and cerebral vasospasm received intraarterial P, fifteen similar patients received N. As the primary endpoint, pre- and post-infusion arterial diameters and capillary blood flow were rated retrospectively on angiographies and comp…
Loss of the preconditioning effect of rosuvastatin during sustained therapy: a human in vivo study
2011
Studies have demonstrated that the acute administration of 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has protective effects in the setting of ischemia-reperfusion (IR). Previously, we demonstrated that a single dose of rosuvastatin prevented IR-induced endothelial dysfunction in humans through a cyclooxygenase-2-dependent mechanism. Whether the chronic administration of HMG-CoA reductase inhibitors provides similar protection remains controversial and is unknown in humans. Eighteen male volunteers were randomized to receive a single dose of rosuvastatin (20 mg) or placebo. Twenty-four hours later, endothelium-dependent, radial artery flow-mediated dilation (FMD) w…
Transcranial Doppler diagnosis of cerebral vasospasm following subarachnoid haemorrhage: correlation and analysis of results in relation to the age o…
1994
A retrospective analysis was undertaken to determine whether cerebral vasospasm following subarachnoid haemorrhage (SAH) correlates with the age of patients. For at least 3 weeks after bleeding 80 subjects underwent very close follow-up with clinical examination and transcranial Doppler records of the blood velocities within the basal cerebral arteries. Firstly a correlation between measured maximal mean blood flow velocities and age was made. Secondly, according to their age and the maximum of recorded mean velocities (v), the patients were divided into groups as follows: age 55 years or less, age more than 55 years; and maximum velocity v190 cm/s, 90 cm/sv2120 cm/s, 120 cm/sv3160 cm/s, v4…
Control for carbon dioxide-related changes in flow velocity by transcranial Doppler monitoring.
1994
Transcranial Doppler ultrasonography can monitor changes in intracranial blood flow velocity over time in a variety of experimental and clinical settings with excellent temporal resolution. Alterations in arterial carbon dioxide pressure exert a profound influence on blood flow velocity. Such changes exhibit important individual fluctuation depending on respiratory status. This limits the ability of transcranial Doppler to accurately study subtle changes in blood flow velocity, independent of the respiratory state of the subject. Suggested here is a method to control for the respiration artifact on blood flow velocity. The middle cerebral artery of 7 healthy male volunteers was studied with…
Diseases of the vertebral arteries.
1990
Case reports and postmortem neuropathological findings of a wide spectrum of diseases affecting the vertebral arteries, in particular vasculitis, traumatic lesions, degenerative changes and congenital abnormalities, are discussed.
Contractile responses of human thyroid arteries to vasopressin
2013
Abstract Aims In the present study we investigated the intervention of nitric oxide and prostacyclin in the responses to vasopressin of isolated thyroid arteries obtained from multi-organ donors. Main methods Paired artery rings from glandular branches of the superior thyroid artery, one normal and the other deendothelised, were mounted in organ baths for isometric recording of tension. Concentration–response curves to vasopressin were determined in the absence and in the presence of either the vasopressin V 1 receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 − 8 M), the nitric oxide synthase inhibitor N G -monomethyl- l -arginine ( L -NMMA, 10 − 4 M), or the inhibitor of prostaglandins indom…
Endothelium-independent contractions of human cerebral arteries in response to vasopressin.
1990
We studied the effects of vasopressin in isolated segments from branches (500-700 micrograms in external diameter) of human middle cerebral arteries obtained during autopsy of 15 patients who had died 3-8 hours before. Paired segments, one normal and the other de-endothelized by gentle rubbing, were mounted for isometric recording of tension in organ baths. In 11 normal segments, vasopressin produced concentration-dependent contractions with an EC50 of 7.0 X 10(-10) M. Removal of the endothelium from 12 segments did not significantly affect vasopressin-induced contractions. Vasopressin produced further contractions in arterial segments with (n = 4) or without (n = 5) endothelium precontract…
Effects of vasopressin on human renal arteries
1996
The effects of vasopressin were studied in isolated rings from branches (2-3 mm in external diameter) of human renal arteries obtained from 18 patients undergoing nephrectomy for non-obstructive neoplasia. In arterial rings under resting tension, vasopressin produced concentration-dependent and endothelium-independent contractions with an EC 50 of 9.1 x 10 -10 mol L -1 . The vasopressin V 1 receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 -6 mol L -1 ) displaced the control curve to vasopressin 564-fold to the right in a parallel manner. In precontracted arterial rings and previously treated with the V 1 antagonist (10 -6 mol L -1 ) vasopressin caused endothelium-independent relaxation. The re…
Relationship between albumin excretion rate and aortic stiffness in untreated essential hypertensive patients
2004
. Objectives. To evaluate, in a group of nondiabetic essential hypertensive patients with normal renal function, the relationship between albumin excretion rate (AER) and carotid-femoral pulse wave velocity (PWV), as an index of aortic stiffness. Design. Cross-sectional study. Setting. Outpatient hypertension clinic. Subjects. Seventy patients with mild-to-moderate essential hypertension, aged 42 ± 8 years, never pharmacologically treated. All subjects underwent routine laboratory tests, 24-h ambulatory blood pressure (BP) monitoring, measurement of carotid-femoral PWV, by means of a computerized method, and AER. Results. Microalbuminuric patients (AER ≥ 20 μg min−1; n = 19), when comp…
Terminal ligature of inferior thyroid arterhy branches during total thyroidectomy for multinodular goiter is associated with higher postoperative cal…
2010
Purpose: To evaluate the impact of truncal versus terminal branch ligature of the inferior thyroid artery (ITA) on postoperative calcium and PTH plasma levels in patients undergoing total thyroidectomy for multinodular goiter. Methods: A prospective randomized study was performed comparing a group of patients that underwent either truncal ligature of the ITA (group 1) or terminal ligature of ITA branches (group 2). Results: A series of 126 consecutive patients with non-toxic euthyroid multinodular goiter underwent total thyroidectomy. Truncal ligature of the ITA was performed in 63 patients (group 1) and terminal branch ITA ligature in 63 patients (group 2). Postoperative ionized serum calc…