Search results for "Flow"
showing 10 items of 5185 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…
Two-year clinical performance of a packable posterior composite with and without a flowable composite liner
2003
The aim of the study was to evaluate the clinical performance of a packable fine hybrid dental composite (Prodigy Condensable) and the influence of the additional application of a flowable resin composite (Revolution, SDS Kerr) layer on marginal integrity after 2 years in stress-bearing posterior cavities according to the Ryge criteria. In 50 patients (40.5+/-17.5 years of age), 116 class II fillings (metal matrix system, glass ionomer-cement-base in 36%, rubberdam isolation in 70%) were placed, with at least two restorations per patient. The adhesive Optibond Solo Plus was used for all the restorations. In one of the two fillings in each patient, an additional layer of the flowable composi…
Relative sensitivity of four noninvasive methods in assessing systolic cardiovascular effects of isoproterenol in healthy volunteers.
1992
Study objective The study was performed to evaluate the relative sensitivity of various noninvasive methods to detect and describe the systolic cardiovascular effects of stepwise increasing doses of isoproterenol: two-dimensional left ventricular echocardiography (main variable, ejection fraction), ACVF (attenuation compensated volume flow)–dual-beam Doppler echoaortography (time-averaged mean velocity), electrical impedance cardiography [(dZ/dtmax)/RZ index], and systolic time intervals from mechanocar-diography (PEP and QS2c). Methods Isoproterenol was administered by constant rate intravenous infusion in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 µg/min (each for 15 minutes). Sali…
Intracellular Cytokine Staining and Flow Cytometry: Considerations for Application in Clinical Trials of Novel Tuberculosis Vaccines.
2015
Intracellular cytokine staining combined with flow cytometry is one of a number of assays designed to assess T-cell immune responses. It has the specific advantage of enabling the simultaneous assessment of multiple phenotypic, differentiation and functional parameters pertaining to responding T-cells, most notably, the expression of multiple effector cytokines. These attributes make the technique particularly suitable for the assessment of T-cell immune responses induced by novel tuberculosis vaccines in clinical trials. However, depending upon the particular nature of a given vaccine and trial setting, there are approaches that may be taken at different stages of the assay that are more s…
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…
Psychophysics, flare, and neurosecretory function in human pain models: capsaicin versus electrically evoked pain.
2007
Intradermal capsaicin injection (CAP) and electrical current stimulation (ES) are analyzed in respect to patterns and test-retest reliability of pain as well as sensory and neurosecretory changes. In 10 healthy subjects, 2 CAP (50 g) and 2 ES (5 to 30 mA) were applied to the volar forearm. The time period between 2 identical stimulations was about 4 months. Pain ratings, areas of mechanical hyperalgesia, and allodynia were assessed. The intensity of sensory changes was quantified by using quantitative sensory testing. Neurogenic flare was assessed by using laser Doppler imaging. Calcito- nin gene-related peptide (CGRP) release was quantified by dermal microdialysis in combination with an en…
Local Gingival Blood Flow at Healthy and Inflamed Sites Measured by Laser Doppler Flowmetry
2006
This investigation aimed to: 1) develop a method to obtain reproducible laser Doppler flow readings (LDFRs) at the gingiva of the maxillary front teeth; 2) evaluate regional gingival blood flow (GBF) in healthy gingiva by laser Doppler flowmetry; 3) compare hand-held LDFR (H-LDFR) with splint LDFR (S-LDFR); and 4) monitor changes in GBF in experimental gingivitis (EG) and chronic gingivitis (CG).The LDFR, gingival index (GI), and plaque index (PI) were measured at 13 gingival sites (teeth #6 to #11) in 10 healthy volunteers (five males and five females), 23 to 34 years of age, over a period of 12.5 +/- 3.27 days employing a partial-mouth EG model and in 11 patients (three males and eight fe…
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…
Exploring metrics for the characterization of the cerebral autoregulation during head-up tilt and propofol general anesthesia
2022
Techniques grounded on the simultaneous utilization of Tiecks' second order differential equations and spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV), recorded from middle cerebral arteries through a transcranial Doppler device, provide a characterization of cerebral autoregulation (CA) via the autoregulation index (ARI). These methods exploit two metrics for comparing the measured MCBFV series with the version predicted by Tiecks' model: normalized mean square prediction error (NMSPE) and normalized correlation rho. The aim of this study is to assess the two metrics for ARI computation in 13 healthy subjects (age: 27 & PLUSMN; 8 yr…
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…