Aim: Carotid endarterectomy is a widely accepted procedure for stroke prevention, and carotid clamping is a necessary surgical step. Glutathionylated haemoglobin (HbSSG) has been recently employed as a biomarker of oxidative stress, its level being increased under several conditions, including hypoxia. This study aims to evaluating whether HbSSG level in ...

OBJECTIVESAortic arch disease can be treated with hybrid repair (extra-anatomic bypass plus placement of aortic endoprostheses), but there is controversy about whether a bypass from one relatively small vessel will provide adequate blood flow to the entire brachiocephalic system. We, therefore, compared flow volumes before and after hybrid repair.METHODSWe reviewed ...

PURPOSE: To assess the effectiveness of flow reversal as an alternative means of cerebral protection by using transcranial Doppler recordings and diffusion-weighted imaging (DWI) as surrogate markers of brain injury. MATERIALS AND METHODS: Eighteen patients with symptomatic carotid artery disease were recruited. Magnetic resonance imaging was performed before the intervention ...

BACKGROUND AND PURPOSE:4D flow MR imaging is an emerging technique that allows visualization and quantification of 3D blood flow in vivo. However, representative studies evaluating its accuracy are lacking. Therefore, we compared blood flow quantification by using 4D flow MR imaging with US within the carotid bifurcation.MATERIALS AND METHODS:Thirty-two healthy ...

ABSTRACT: BACKGROUND: Intraoperative arterial hypotension can lead to severe complications in patients undergoing carotid endarterectomy, in particular if cerebral auto-regulation is impaired. Short-acting agents, such as phenylephrine or ephedrine, commonly used to correct intra-operative hypotension, have different hemodynamic effects. Recently, it was reported that, in healthy anesthetized subjects with intact ...

Temporal insonation is not always possible for the middle cerebral artery (MCA) for blood flow velocity (BFV) measurements, to estimate cerebral autoregulation. We compared BFV and cerebral autoregulation estimates from the common-carotid (CCA) and internal-carotid arteries (ICA) with the MCA. BFV was measured at the CCA, ICA and MCA, synchronously ...

OBJECTIVE: Cardiac resynchronisation therapy (CRT) has emerged as a new treatment strategy for a subgroup of patients with heart failure. In this study, we aimed to evaluate acute effects of CRT on cerebral blood flow. MATERIAL AND METHODS: Twenty-two (six female and 16 male) patients (mean age 60.8±5.3 years) with ...

Complications due to brain edema and breakdown of blood brain barrier are an important factor affecting the treatment effects of patients with severe carotid stenosis. In this study, we investigated the protective effects of ischemic postconditioning on brain edema and disruption of blood brain barrier via establishing rat model of ...

We analyzed intracranial regional blood flows using an optical flow method (OFM) and digital subtraction angiography in patients with internal carotid artery (ICA) stenosis. We also retrospectively explored the correlation between the patients' diagnoses and the severity of the ICA stenoses. OFM, an image-processing algorithm to estimate motion, was applied ...

The benefit of carotid revascularization is hampered by occurrence of periprocedural cerebrovascular complications. Cerebral hyperperfusion syndrome (CHS) is a potentially life threatening complication occurring in approximately 3% of all patients following either carotid endarterectomy (CEA) or carotid angioplasty with stenting (CAS). CHS generally is defined as a transcranial Doppler (TCD) ...

The benefit of carotid revascularization is hampered by occurrence of periprocedural cerebrovascular complications. Cerebral hyperperfusion syndrome (CHS) is a potentially life threatening complication occurring in approximately 3% of all patients following either carotid endarterectomy (CEA) or carotid angioplasty with stenting (CAS). CHS generally is defined as a transcranial Doppler (TCD) ...

Positron emission tomography (PET) with (15)O-labeled water can provide reliable measurement of cerebral blood flow (CBF). Quantification of CBF requires knowledge of the arterial input function (AIF), which is usually provided by arterial blood sampling. However, arterial sampling is invasive. Moreover, the blood generally is sampled at the wrist, which ...

Recent studies suggest that disturbed blood flow-induced shear stress can induce atherosclerosis (ATH) in humans and animals without a high fat diet. Therefore, we hypothesize that partial ligation of the left carotid artery can generate disturbed blood flow and shear stress and would lead to ATH in a predisposed genetic ...

In this study, cerebral blood flow, oxygenation, metabolic, and electrical functional responses to forepaw stimulation were monitored in rats at different levels of global cerebral ischemia from mild to severe. Laser speckle contrast imaging and optical imaging of intrinsic signals were used to measure changes in blood flow and oxygenation, ...

Blood flow instabilities in the carotid artery bifurcation have been highly correlated to clot formation and mobilization resulting in ischemic stroke. In this work, PIV-measured flow velocities in normal and stenosed carotid artery bifurcation models were analyzed by means of proper orthogonal decomposition (POD). Through POD analysis, transition to more ...

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study is a sensitive test for predicting the outcome of permanent ICA occlusion. However, false negative results sometimes occur using single photon emission tomography (SPECT). We have recently developed a rapid positron emission tomography ...

X-ray velocimetry offers a non-invasive method by which blood flow, blood velocity and wall shear stress can be measured in arteries prone to atherosclerosis. Analytical tools for measuring haemodynamics in artificial arteries have previously been developed and here the first quantification of haemodynamics using X-ray velocimetry in a living mammalian ...

Phase-contrast (PC) MRI is a non-invasive technique to assess cardiovascular blood flow. However, this technique is not accurate for instance at the carotid bifurcation due to turbulent and disturbed blood flow in atherosclerotic disease. Flow quantification using conventional PC MRI distal to stenotic vessels suffers from intravoxel dephasing and flow ...

Obstructed sleep apnea (OSA) is a common disorder which may need surgery to widen the airway; however the success rate of surgery is limited. Here we report a finding that could be used to predict the outcome of the OSA surgery. We found that inspiratory flow oscillates due to flow ...

Total glucocorticoid hormone levels in plasma of various species, including humans, follow a circadian rhythm that is made up from an underlying series of hormone pulses. In blood most of the glucocorticoid is bound to corticosteroid-binding globulin and albumin, resulting in low levels of free hormone. Although only the free ...

Transcranial Doppler sonography allows for noninvasive assessment of dynamic cerebral autoregulation. A wider clinical use of this approach has been hampered by the need for continuous arterial blood pressure (ABP) measurements. We describe a new method of a pure Doppler signal based estimation of dynamic autoregulation using heart rate (HR) ...

Previous computational studies have suggested that the capillary blood flow oscillations frequently observed in vivo can originate spontaneously from the non-linear rheological properties of blood, without any regulatory input. Testing this hypothesis definitively in experiments involving real microvasculature has been difficult because in vivo the blood flow in capillaries is ...

Thermal management has become critical for high heat flux electronic and energy systems. Integrated microchannel liquid-cooling technology has been envisioned to be a promising solution, but with significant challenges in flow instability. In this work, silicon nanowires were synthesized in-situ in parallel silicon microchannel arrays for the first time to ...

OBJECTIVE: Functionally univentricular heart (FUH) anomalies are the leading cause of death from all structural birth defects. Total cavopulmonary connection (TCPC) is the last stage of the palliative surgical reconstruction with significant late hemodynamic complications requiring high-risk heart transplantation. Alternative therapeutic options for these critically ill patients are crucial. In ...

Direct evidence of zonal flow (ZF) predator-prey oscillations and the synergistic roles of ZF- and equilibrium E×B flow shear in triggering the low- to high-confinement (L- to H-mode) transition in the DIII-D tokamak is presented. Periodic turbulence suppression is first observed in a narrow layer at and just inside the ...

The purpose of this study was to evaluate the influence of the insertion depth of an ultrasonically oscillating file on the ability to remove dentin debris from simulated canal irregularities in an extracted tooth model of a straight root canal and its influence on the flow of irrigant in both ...

Several-day rhythmic changes in the lymphocyte subpopulation composition and peripheral blood levels of IL-2 and hydrocortisone were studied in healthy men. The samples were collected daily at 8.00. A 4-day rhythm of hydrocortisone secretion manifested synchronously in different individuals. Rhythmic changes in IL-2 level, T-helper/T-suppressor cytotoxic lymphocyte index, and percentage ...

Here we explore the role of microfabricated device geometry on frequency-dependent low Reynolds number steady streaming flow and particle trapping behavior. In our system, flow and particle trapping is induced near an obstruction or cavity located in an otherwise rectilinear oscillating flow of frequency ω and amplitude s in a ...

Background and purpose: Computational fluid dynamics method (CFDM) and optical flow method (OFM) effectively provide the hemodynamic information based on the digital subtraction angiogram (DSA). However, the quantitative analysis in comparison of CFDM and OFM is still absent. The goal of this study is to apply CFDM and OFM in ...

We have developed a simple model for pedestrians by dividing walking velocity into two parts, which are step size and pace of walking (number of steps per unit time). Theoretical analysis on pace indicates that rhythm that is slower than normal-walking pace in a low-density regime increases flow if the ...

To strengthen active dengue surveillance in Saint Martin and Saint Barthélemy, two French Caribbean islands, we evaluated the epidemiological usefulness of collecting blood samples from NS1-positive dengue patients on filter paper to identify the dengue serotypes circulating in these regions during a 27-month period. This approach allowed dengue serotypes to ...

Background  It is well known that blood transfusion is life-saving, but also that it carries a serious risk of transmitting viral infections. Introduction of new methods of testing for transmissible diseases, blood banking and dispatch regulations has considerably increased the cost of blood products. However, the clinical benefits and cost-effectiveness ...

Continuous-flow left ventricular assist devices (LVADs) have become the dominant devices for mechanical circulatory support, but their cost-effectiveness is undetermined. This study assessed the cost-effectiveness of continuous-flow devices for destination therapy versus optimal medical management in advanced heart failure and compared the results with previous estimates for pulsatile devices. A ...

Introduction: Haemodiafiltration increases convective clearances, and online haemodiafiltration (OL-HDF) was introduced to reduce costs of producing large volumes of ultrapure water. Previous reports have suggested that OL-HDF may be a cost-saving therapy by reducing recombinant human erythropoietin requirements and those for other medications. We therefore costed OL-HDF with high-flux haemodialysis. ...

Hemodynamic control can improve the outcome of surgery. Esophageal Doppler monitoring measures blood flow by ultrasound waves. This work investigates the cost-effectiveness of this procedure during colorectal resection. Meta-analyses of randomized controlled trials of esophageal Doppler monitoring used in colorectal resection were conducted to help determine its cost-effectiveness. An analytical ...

Perioperative use of a cell saver device can serve as a cost-beneficial alternative to the transfusion method, especially in countries where the cost of a single unit of blood is high. The purpose of this study, conducted in a Greek hospital, was to calculate the cost benefit of using a ...

The role of emergent intervention in prenatal testicular torsion is controversial. We report a case of successful testicular salvage of incomplete prenatal torsion. A 1-day-old male infant presented with a bluish-hued scrotum at birth. Testicular ultrasonography demonstrated right testicular torsion with minimal peripheral blood flow. Scrotal exploration was performed, confirming ...

Flow cytometry is now a recognized methodology within animal spermatology, and has moved from being a research tool to become routine in the assessment of animal semen destined to breeding. The availability of 'bench-top' flow cytometers and of newer and versatile markers for cell structure and function had allowed the ...

Blood transfusion refers to the perioperative administration of blood and blood components. Adherence to proper indications for blood component therapy is essential because of its potential adverse effects and costs of transfusion. Over the years, the significance of blood components in treating certain diseases or conditions has been recognized. In ...

Open radical retropubic prostatectomy (RRP) has an average blood loss of over 1,000 ml. This has been reported even from high volume centres of excellence. We have looked at the clinical and financial benefits of using intraoperative cell salvage (ICS) as a method of reducing the autologous blood transfusion requirements ...

To investigate blood flow changes in retinal and optic nerve diseases with Doppler Fourier domain optical coherence tomography (OCT). Sixty-two participants were divided into five groups: normal, glaucoma, nonarteritic ischemic optic neuropathy (NAION), treated proliferative diabetic retinopathy (PDR), and branch retinal vein occlusion (BRVO). Doppler OCT was used to scan ...

To determine whether subfoveal choroidal blood flow is altered in retinitis pigmentosa (RP) and whether this alteration is associated with central cone-mediated dysfunction. In 31 RP patients (age range, 15-72 years) with preserved visual acuity (range: 20/30-20/20), subfoveal choroidal blood flow was measured by real-time, confocal laser Doppler flowmetry, and ...

Genitourinary tract samples are required to investigate male HIV-1 infectivity. Because semen collection is often impractical, the acceptability, feasibility and validity of post-prostatic massage fluid/urine (post-PMF/U) was evaluated for studying male genitourinary HIV-1 shedding. HIV-1-seropositive men were evaluated after 48 h of sexual abstinence. At each visit, a clinician performed ...

Luminance flicker stimulation of the photoreceptors is known to increase retinal blood flow. Elevated blood velocity was determined using laser Doppler velocimetry, and increased vascular diameters during flicker were observed by measurements with a retinal vessel analyzer. Oxygen supply may be the target of the regulation of retinal blood flow. ...

To investigate the effects of fasudil, a Rho-associated coiled coil-forming protein kinase (ROCK) inhibitor, on normal or impaired optic nerve head (ONH) blood flow in a rabbit model. ONH blood flow was measured by laser speckle flowgraphy. Changes in ONH blood flow were examined during a continuous intravenous infusion of ...

Formation and maintenance of the blood-retinal barrier is required for proper vision and loss of this barrier contributes to the pathology of a wide number of retinal diseases. The retina is responsible for converting visible light into the electrochemical signal interpreted by the brain as vision. Multiple cell types are ...

We retrospectively reviewed the clinical and cost effectiveness of the OrthoPAT blood salvage system (Haemonetics Corp., Braintree, MA) following total knee arthroplasty (TKA). Two-hundred-and-two patients who received the OrthoPAT system were matched to 202 controls. A second match was performed for subjects weighing <75 kg. For all matched subjects, no ...

To demonstrate the 3-dimensional nature of wedge-shaped retinal nerve fiber layer (RNFL) losses. To study the impact of training glaucoma fellows in this identification technique by evaluating their rate of RNFL loss detection on stereo disc photographs. Wedge-shaped RNFL defects were identified in stereo disc photographs of early-glaucoma patients. The ...

The purpose of this study was to determine the effect of radial optic neurotomy and retinal endovascular surgery on retinal blood flow velocity in patients with central retinal vein occlusion. A prospective interventional case series. Six patients with a central retinal vein occlusion of <12 months' duration were included. Three ...

The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently ...