In cerebral ischemia, measurement of cerebral blood flow (CBF) alone is not a sensitive or specific predictor of tissue survival. Measurements of oxygen metabolism, which are directly related to cellular energy metabolism, are better predictors of tissue survival and the best of these is the "oxygen extraction fraction" (OEF). Elevation ...

As a resource, allogenic blood has never been more in demand than it is today. Escalating elective surgery, shortages arising from a fall in supply, a lack of national blood transfusion services, policies, appropriate infrastructure, trained personnel, and financial resources to support the running of a voluntary nonremunerated donor transfusion ...

Refractory post cardiopulmonary bypass (CPB) bleeding continues to cause concern for cardiac surgeons and intensivists. Massive postoperative hemorrhage following CPB is multifactorial and not fully understood, and it is also associated with increased mortality and morbidity. Activated recombinant factor VII (rFVIIa) has emerged as possible salvage medication in refractory post ...

The aim of this study was to use transnasal endoscopy to observe transport through the maxillary ostia in the ethmoid infundibulum, to gain more basic scientific information about the nasal cavity and paranasal sinus. Transnasal observation of 512 patients in a supine or seated position was conducted with 0- and ...

Esophageal replacement is major procedure with high risk for perioperative allogeneic blood transfusion (ABT), especially in pediatric patients due to nutritive deficiency, anemia, small body weight and blood volume. Autologous blood policy is particularly important in female children. We present treatment strategy with the aim of avoiding ABT, that have ...

The influence of caprine arthritis-encephalitis (CAE) virus infection on the population of peripheral blood leukocytes in goats was evaluated. For this purpose two groups of adult dairy female goats were formed. The experimental group consisted of 17 goats, which had been naturally infected for many years. The control group comprised ...

Atherosclerosis is characterized by infiltration of inflammatory cells from circulating blood. Blood cell activation could play an important role in plaque formation. We analyzed the relationship between blood cellular markers and quantitative measures of carotid wall components in 1,546 participants from the ARIC (Atherosclerosis Risk in Communities) Carotid MRI Study. ...

S-nitrosylated hemoglobin (S-nitrosohemoglobin) has been implicated in the delivery of O(2) to tissues through the regulation of microvascular blood flow. This study tested the hypothesis that enhancement of S-nitrosylated hemoglobin by ethyl nitrite inhalation improves outcome after experimental subarachnoid hemorrhage (SAH). A preliminary dosing study identified 20 ppm ethyl nitrite ...

ABSTRACT: Study Design: Sham-operation-controlled animal study to assess alterations in blood flow in the spinal cord in a chronic compression model. Laboratory investigation.Objective: Cervical myelopathy is a common cause of disability in elderly patients. Hypothesis was made that ischemia subsequent to the spinal cord compression plays an important role in ...

Cerebral autoregulation (CA) describes the mechanism responsible for maintaining cerebral blood flow (CBF) relatively constant, despite changes in mean arterial blood pressure (ABP). This paper introduces a novel method for assessing CA using magnetic resonance imaging (MRI). Images are rapidly and repeatedly acquired using a gradient-echo echo-planar imaging pulse sequence ...

During liver resection surgery for cancer or liver transplantation, the liver is subject to ischaemia (reduction in blood flow) followed by reperfusion (restoration of blood flow), which results in liver injury [ischemia-reperfusion (IR) or IR injury]. Modulation of IR injury can be achieved in various ways. These include hypothermia, ischaemic ...

BACKGROUND: Effective chest compressions during prolonged ventricular fibrillation (VF) have been shown to increase the chances of successful defibrillation to a rhythm associated with a sustainable cardiac output. There is currently no effective method of recording the degree of antegrade coronary artery flow during chest compression in VF. OBJECTIVE: To ...

BACKGROUND: Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. METHODS: 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from transcranial Doppler were ...

Arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) are widely used to image cerebral blood flow (CBF) in stroke. This study examined how changes in tissue spin-lattice relaxation-time constant (T(1)), blood-brain barrier (BBB) permeability, and transit time affect CBF quantification by ASL and DSC in ...

Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO(2)) in cortical microvessels of ...

Determination of compartment-specific cerebral blood volume (CBV) changes is important for understanding neurovascular physiology and quantifying blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI). In isoflurane-anesthetized cats, we measured the spatiotemporal responses of arterial CBV (CBV(a)) and total CBV (CBV(t)) induced by a 40-second visual stimulation, using magnetization transfer ...

Intra-arterial (IA) injection represents an experimental avenue for minimally invasive delivery of stem cells to the injured brain. It has however been reported that IA injection of stem cells carries the risk of reduction in cerebral blood flow (CBF) and microstrokes. Here we evaluate the safety of IA neural progenitor ...

Collateral circulation in intracranial atherosclerosis has never been systematically characterized. We investigated collaterals in a multicenter trial of symptomatic intracranial atherosclerotic disease. Baseline angiography was reviewed for information on collaterals in stenoses of the internal carotid, middle cerebral, vertebral, and basilar arteries. A battery of angiographic scales was utilized to ...

Blood is life. Transfusion of blood and blood components, as a specialized modality of patient management saves millions of lives worldwide each year and reduce morbidity. It is well known that blood transfusion is associated with a large number of complications, some are only trivial and others are potentially life ...

The use prevalence of the highly addictive psychostimulant methamphetamine (MA) has been steadily increasing over the past decade. MA abuse has been associated with both transient and permanent alterations in cerebral blood flow (CBF), hemorrhage, cerebrovascular accidents and death. To understand MA-induced changes in CBF, we exposed C56BL/6 mice to ...

Isolated hearts used in the study of ischemia-reperfusion induced myocardial reactive oxygen species (ROS) have typically been perfused with crystalloid buffer. Limitations of crystalloid buffer which may exaggerate the production of ROS, include a requirement for higher oxygen tension and the absence of the intrinsic erythrocyte antioxidant defenses. Using a ...

The effect of selective head cooling on cerebral blood flow (CBF) and cerebral metabolism rate (CMR) was investigated in newborn piglets. Seven days old newborn piglets were randomly assigned to one of the following three groups: Selective head cooling in normal piglets (n=4), selective head cooling after HI (n=6) and ...

Astrocytes are increasingly believed to play an important role in neurovascular coupling. Recent in vivo studies have shown that intracellular calcium levels in astrocytes correlate with reactivity in adjacent diving arterioles. However, the hemodynamic response to stimulation involves a complex orchestration of vessel dilations and constrictions that spread rapidly over ...

Hydrogen sulfide (H2S) is a gaseous signaling molecule that appears to be involved in numerous biological processes, including regulation of blood pressure and vascular tone. The present study is designed to address the hypothesis that H2S is a functionally significant, endogenous dilator in the newborn cerebrovascular circulation. In vivo experiments ...

Hemoglobin-based oxygen carriers (HBOC) are being developed to provide the oxygen necessary in clinical situations when whole blood is not available. The safety and effectiveness of each HBOC must be determined before clinical approval. In the past several years animal studies have been conducted with zero-linked polymers to evaluate their ...

The establishment of cerebral protection has matured conceptually and clinically in recent years. We have accepted that some type of cerebral protection is desirable. We have some choices in whether to use filters, proximal occlusion, or proximal occlusion with reversed flow. There are anatomical and clinical factors that drive the ...

To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. High temperature spots on the anterior ectosylvian and low temperature spots on the posterior suprasylvian on the cortical surface of 20 cats were identified ...

Violet laser acupuncture using a wavelength of 405 nm has been investigated in only a few scientific studies. The aim of this study was to provide selective evidence of a specific effect of violet laser acupuncture on mean cerebral blood flow velocity using a Doppler ultrasound technique. A transcranial Doppler ...

The brain is most sensitively dependent on oxygen to maintain its normal function. Methods to assess the degree of its oxygenation have generally been invasive and indirect. Rapid assessment of brain oxygenation is particularly vital during cerebrospinal ischemia and hypoxia. We have developed a noninvasive electro-optical method using pulsed near-infrared ...

BACKGROUND: Blood hyperviscosity has been acknowledged to be a complicating factor in polycythaemia and hyperproteinaemia. Hyperleucocytosis has also been implicated in hyperviscosity and may be a basis for therapeutic leukapheresis. AIMS: This issue in the series seeks to determine the association and correlation between whole blood viscosity and white blood ...

Extracorporeal membrane oxygenation (ECMO) can be instituted centrally, through the right atrium and ascending aorta, or peripherally, most commonly using the femoral artery and vein. We sought to investigate the impact of the mode of cannulation on the incidence of limb ischemia, perfusion and overall morbidity. A retrospective analysis of ...

In cerebral ischemia, transmission by the inhibitory neurotransmitter, γ-aminobutyric acid (GABA) is altered. This study was performed to determine whether blockade of GABA(A) receptor would affect regional cerebral blood flow (rCBF) and blood-brain barrier (BBB) permeability in a focal ischemic area of the brain. Rats were anesthetized with isoflurane and ...

Background  Although drooling of saliva is considered abnormal in a child over 4 years of age, it has been estimated to occur in approximately in 10-37% of children with cerebral palsy. Aim  The aim of this study was to evaluate the flow rate, pH and buffering capacity in saliva of ...

Cerebral blood flow (CBF) is disrupted after focal ischemia in rats. We examined long-term hemodynamic and cerebrovascular changes in the rat thalamus after focal cerebral ischemia. Cerebral blood flow quantified by arterial spin labeling magnetic resonance imaging was decreased in the ipsilateral and contralateral thalamus 2 days after cerebral ischemia. ...

In vitro study of genipin crosslinking effect on disc water content changes under compressive loading and unloading. To investigate the influence of collagen crosslinking on hydration and fluid flow in different regions of intact discs, and to evaluate the nutritional implications. Age-related reductions of nutrient supply and waste product removal ...

Laboratory identification of cytoplasmic inclusions in leucocytes as unusual manifestation of cryoglobulinemia has been previously reported (Maitra et al., 2000 American Journal of Clinical Pathology, 113, 107-112; Fohlen-Walter et al., 2002American Journal of Clinical Pathology, 117, 606-614.). We would like to add two observations highlighting the following: (i) the peculiar picture of ...

Hemorheological activity of 4-methyl-2,6-di-isobornyl phenol, a new o-isobornyl phenol derivative, was studied under conditions of experimental prolonged partial cerebral ischemia. Brain ischemia is associated with hemorheological disorders which can be characterized as blood hyperviscosity syndrome: increased viscosity of the whole blood (within a wide range of shear rates), plasma viscosity, ...

We report the use of spectral Doppler optical coherence tomography imaging (SDOCTI) for quantitative evaluation of dynamic blood circulation before and after a localized ischemic stroke in a mouse model. Rose Bengal photodynamic therapy (PDT) is used as a noninvasive means for inducing localized ischemia in cortical microvasculature of the ...

The purpose of this population analysis was to characterize the pharmacokinetic properties of robenacoxib in blood and stifle joint synovial fluid of dogs. Data were obtained from two studies: 1) 8 healthy Beagle dogs in which an acute inflammation was induced by injection of urate crystals into one joint; 2) ...

The purpose of this study was to investigate the effect of directional fluid flow on periosteal chondrogenesis. Periosteal explants were harvested from 2-month-old rabbits and sutured onto poly-epsilon-caprolactone (PCL) scaffolds with the cambium layer facing away from the scaffolds. The periosteum/PCL composites were cultured in suspension in spinner flask bioreactors ...

This series on whole blood viscosity issues has been trying to elucidate the sensitivity, specificity and usefulness of the laboratory parameter in clinical practice. The postulation has been that since antiplatelet is used in the management of stasis, of which blood viscosity is an index, the latter would be useful ...

The entry of anti-infectives into the central nervous system (CNS) depends on the compartment studied, molecular size, electric charge, lipophilicity, plasma protein binding, affinity to active transport systems at the blood-brain/blood-cerebrospinal fluid (CSF) barrier, and host factors such as meningeal inflammation and CSF flow. Since concentrations in microdialysates and abscesses ...

The use of fluids that are significantly more viscous than water in microfluidics has been limited due to their high resistance to flow in microscale channels. This paper reports a theoretical treatment for the flow of highly viscous fluids in deforming microfluidic channels, particularly with respect to transient effects, and ...

A solid body undergoing oscillatory motion in a fluid generates an oscillating flow. Oscillating flows in Newtonian fluids were first treated by G.G. Stokes in 1851. Since then, this problem has attracted much attention, mostly due to its technological significance. Recent advances in micro- and nanotechnology require that this problem ...

Chaotic advection has served as the paradigm for mixing in fluid flows with simple time dependence. Its skeletal structure is based on analysis of invariant attracting and repelling manifolds in fluid flows. Here we develop a finite-time theory for two-dimensional incompressible fluid flows with arbitrary time dependence and introduce a ...

An analytical approach is formulated to account for the effects of mean flow on sound transmission across a simply supported rectangular aeroelastic panel. The application of the convected wave equation and the displacement continuity condition at the fluid-panel interfaces ensures the exact handling of the complex aeroelastic coupling between panel ...

In 1894 Ulsterman and pathologist Almroth Wright described the citation of blood. Twenty-one years later it was introduced into wartime and clinical practice. Harvard Medical School had a large part in providing Colonel Andrew Fullerton, later Professor of Surgery, Queen's Belfast, with the intellectual and practical help for the Allies ...

Living systems employ cilia to control and to sense the flow of fluids for many purposes, such as pumping, locomotion, feeding, and tissue morphogenesis. Beyond their use in biology, functional arrays of artificial cilia have been envisaged as a potential biomimetic strategy for inducing fluid flow and mixing in lab-on-a-chip ...

We present fundamental solutions of low Reynolds number flows in a stratified fluid, including the case of a point force (Stokeslet) and a doublet. Stratification dramatically alters the flow by creating toroidal eddies, and velocity decays much faster than in a homogeneous fluid. The fundamental length scale is set by ...

An implantable transducer for monitoring the flow of Cerebrospinal fluid (CSF) for the treatment of hydrocephalus has been developed which is based on measuring the heat dissipation of a local thermal source. The transducer uses passive telemetry at 13.56 MHz for power supply and read out of the measured flow ...