Dilatation of rat pial arterioles at constant arteriolar wall strain during autoregulation of cerebral circulation was shown by the method of biomicroscopy. Wavelet-analysis of cerebral blood flow oscillations during this period revealed increased oscillation amplitude in the endothelial and neurogenic frequency ranges and unchanged amplitude at myogenic frequency range. These ...

After an aneurysmal subarachnoid hemorrhage, cerebral microcirculatory changes occur as a result cerebral vasospasm. The objective of this study is to investigate, with a computational model, how various degrees of vasospasm are influenced by increasing the mean blood pressure and decreasing the blood viscosity. Using ANSYS CFX software, a computational ...

Thickening agents based primarily on granulated maize starch are widely used in the care of patients with swallowing difficulties, increasing viscosity of consumed fluids. This slows bolus flow during swallowing, allowing airway protection to be more properly engaged. Thickened fluids have been shown to exhibit time-varying behavior and are non-Newtonian, ...

After the introduction of blood banks and better storage techniques blood is more widely used in patients for various indications. In Pakistan more than 1.5 million pints of blood are collected each year. Hepatitis B and C virus infections are known to occur in the general population and due to ...

BACKGROUND: Peritoneal fluid analysis in cattle traditionally includes the classic parameters despite the fact that they have only moderate diagnostic accuracy and often fail to identify the pathogenesis or etiological factors. Therefore additional parameters recently have been established to improve diagnostic precision. In a recent study, reference ranges for several ...

Moxifloxacin and levofloxacin are wide spectrum quinolones and cefixime is a third-generation cephalosporin with a wider spectrum of activity against gram-positive and gram-negative bacteria and anaerobics. Although they are widely used, little is known about the amniotic fluid levels of these antibiotics. The aim of the present investigation was to ...

AIM: To describe the histological changes in the optic nerve (ON) after experimental segregation of cerebrospinal fluid (CSF). METHODS: In seven sheep, a silicone band was placed around one ON to compress the subarachnoid space (SAS) surrounding the nerve, thus blocking the flow of CSF without compressing the ON itself. ...

The blood-brain barrier, the blood-cerebrospinal fluid barrier (BCB) and other specialized brain barriers are increasingly recognized as a major obstacle to the treatment of most brain disorders. The impairment of these barriers has been implicated in neuropathology of several diseases, such as autism, ischemia, multiple sclerosis and Alzheimer disease. This ...

In vertebrates, brain development takes place at the expanded anterior end of the neural tube. After closure of the anterior neuropore, the brain wall forms a physiologically sealed cavity that encloses embryonic cerebrospinal fluid (E-CSF), a complex and protein-rich fluid. E-CSF has several crucial roles in brain anlagen development. In ...

The Karlsruhe Heart Model (KaHMo) is a patient-specific simulation tool for a three-dimensional blood flow evaluation inside the human heart. Whereas KaHMo MRT is based on geometry movement identified from MRT data, KaHMo FSI allows the consideration of structural properties and the analysis of FSI. Previous investigations by Oertel et ...

OBJECT: The mechanisms of syringomyelia have long puzzled neurosurgeons and researchers alike due to difficulties in identifying the driving forces behind fluid flow into a syrinx, apparently against a pressure gradient between the spinal cord and the subarachnoid space (SAS). Recently, the synchronization between CSF flow and the cardiac cycle ...

Cilia drive fluid flow in development and physiology, but this requires that all cilia in a tissue orient the same way. Earlier studies indicated that both planar cell polarity (PCP) signalling and cilia-generated fluid flows could influence ciliary orientation. We now learn how asymmetric localization of PCP proteins influences the ...

We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity-sucrose solution and water. Possible applications include blood ...

There are many different methods for the assessment of whole blood viscosity, but not every pathology unit has equipment for any of the methods. However, a validated arithmetic method exists whereby whole blood viscosity can be extrapolated from haematocrit and total serum proteins. The objective of this work is to ...

Abnormal cerebrospinal fluid (CSF) flow is suspected to be a contributor to the pathogenesis of neurodegenerative diseases such as Alzheimer's through the accumulation of toxic metabolites, and to the malfunction of intracranial pressure regulation, possibly through disruption of neuroendocrine communication. For the understanding of transport processes involved in either, knowledge ...

MRI has previously provided conflicting results when used to search for brain abnormalities in sufferers of chronic fatigue syndrome (CFS). Eighteen CFS patients and nine healthy volunteers each underwent MRI on two occasions, one year apart. The resulting images were examined for abnormalities in brain atrophy, deep white matter hyperintensities ...

CSF flow has been shown to exhibit complex patterns in MR images in both healthy subjects and in patients with Chiari I. Abnormal CSF flow oscillations, according to prevailing opinion, cause syringomyelia and other clinical manifestations that affect some patients with the Chiari I malformation. For this article, we reviewed ...

In the field of fluid flow within the human body, focus has been placed on the transportation of blood in the systemic circulation since the discovery of that system; but, other fluids and fluid flow phenomena pervade the body. Some of the most fascinating fluid flow phenomena within the human ...

In a world without inertia, Purcell's scallop theorem states that in a Newtonian fluid a time-reversible motion cannot produce any net force or net flow. Here we consider the extent to which the nonlinear rheological behavior of viscoelastic fluids can be exploited to break the constraints of the scallop theorem ...

Brain development and health depends upon the efficient movement of the cerebrospinal fluid inside of brain ventricles. When disrupted either through mutation, disease, or physiological damage, brain function becomes significantly impaired. Here I present a simple method of following cerebrospinal fluid circulation in Xenopus tadpoles using fluorescent microspheres which can ...

The patterns of cerebrospinal fluid (CSF) flow within the human ventricular system are still not fully understood in all their complexity. Knowledge is based on either the interpretation of CSF flow curves or computational simulations. Both approaches only provide an incomplete insight into the spatial and temporal dynamics of CSF ...

This study examined the effect of vapor lock on canal debridement efficacy by testing the null hypothesis that there is no difference between a "closed" and an "open" system design in smear layer and debris removal by using a side-vented needle for irrigant delivery. Roots in the closed system were ...

OBJECTIVE: The aim of the study was to develop a computational method for the assessment of brain pressure compensation of cerebrospinal arterial blood inflow. The method was verified using clinical recordings performed during infusion studies in a group of patients diagnosed with hydrocephalus. MATERIALS AND METHODS: We studied 27 patients ...

In the field of fluid flow within the human body, focus has been placed on the transportation of blood in the systemic circulation since the discovery of that system; but, other fluids and fluid flow phenomena pervade the body. Some of the most fascinating fluid flow phenomena within the human ...

In nature, dissipative fluxes of fluid, heat and/or reacting species couple to each other and may also couple to deformation of a surrounding porous matrix. We use the well-known analogy of Hele-Shaw flow to Darcy flow to make a model porous medium with porosity proportional to local cell height. Time- ...

We present a 3D code-coupling approach which has been specialized towards cardiovascular blood flow. For the first time, the prescribed geometry movement of the cardiovascular flow model KaHMo (Karlsruhe Heart Model) has been replaced by a myocardial composite model. Deformation is driven by fluid forces and myocardial response, i.e., both ...

Samples of peritoneal fluid and jugular venous blood were taken simultaneously from 95 clinically healthy Holstein-Friesian cows. The concentrations of total protein, albumin, glucose, cholesterol, fibrinogen, L-lactate and D-dimer, the activities of lactate dehydrogenase (LDH), alkaline phosphatase and creatine kinase, and the white blood cell count were determined in the ...

Terrestrial and aquatic arthropods sense fluid flow in many behavioral and ecological contexts, using dedicated, highly sensitive mechanosensory hairs, which are often abundant. Strong similarities exist in the biomechanics of flow sensors and in the sensory ecology of insects, arachnids, and crustaceans in their respective fluid environments. We extend these ...

SPECT allows registration of regional cerebral blood flow (rCBF) which is altered in a characteristic temporoparietal pattern in Alzheimer's Dementia. Numerous studies have shown the diagnostic value of reduced cerebral blood flow and metabolic changes using perfusion SPECT and FDG-PEPT in AD diagnosis as well as in differential diagnosis against ...

A new drip infusion solution monitoring system has been developed for hospital and care facility use. The system detects the fall of each drip chamber drop of fluid and also a free-flow situation. Three non-contacting copper foil electrodes are used. The electrodes are wrapped around the infusion supply polyvinyl chloride ...

Mesenteric ischemia is caused by a reduction in intestinal blood flow with potential catastrophic clinical consequences: sepsis, bowel infarction, and death. In the recent years, the incidence of mesenteric ischemia increased, now accounting for 0.1% of hospital admissions. Among the multiple factors responsible for this change is the heightened awareness ...

This work proposes a new theoretical framework for the water transport in the cerebral environment. The approach is based on Multiple-Network Poroelastic Theory (MPET) and is a natural extension of poroelasticity, a well reported technique applied to cerebrospinal fluid (CSF) transport. MPET accounts for the transport of CSF and blood ...

Following brain injury, S100B is released from damaged astrocytes but also yields repair mechanisms. We measured S100B in the cerebrospinal fluid (CSF) and serum (Cobas e411 electrochemiluminescence assay, Roche) longitudinally in a large cohort of patients treated with a ventricular drainage following traumatic brain injury (TBI) or subarachnoid hemorrhage (SAH). ...

To evaluate the systemic exposure of pimecrolimus cream 1% applied under occlusion in atopic dermatitis (AD) patients. A noncomparative, open-label study conducted in 3 groups of moderate to severe AD patients: A (adults, n = 9), B (adolescents, n = 4) and C (children, n = 6). Pimecrolimus cream 1% ...

Dysphagia is a medical condition in which the safety or efficiency of eating and drinking is compromised. Thin, watery fluids flow too quickly through the oral anatomy during an abnormal swallow, pre-empting airway protective mechanisms, and potentially resulting in fluid entry into the lung. Dysphagia therapy consists of reducing flow ...

Extracellular gelsolin (GSN) and GC-globulin/Vitamin D-binding protein (DBP) appear to play an important role in clearing the actin from extracellular fluids and in modulating cellular responses to anionic bioactive lipids. In this study we hypothesized that cellular actin release and/or increase in bioactive lipids associated with multiple sclerosis (MS) development ...

Acetazolamide (ACZ) was used to stimulate the cerebral vasculature on ten healthy volunteers to assess the cerebral vasomotor reactivity (CVR). We have combined near infrared spectroscopy (NIRS), diffuse correlation spectroscopy (DCS) and transcranial Doppler (TCD) technologies to non-invasively assess CVR in real-time by measuring oxy- and deoxy-hemoglobin concentrations, using NIRS, ...

Cerebral blood flow (CBF) during stepped hypercapnia was measured simultaneously in the rat brain using near-infrared diffuse correlation spectroscopy (DCS) and arterial spin labeling MRI (ASL). DCS and ASL CBF values agree very well, with high correlation (R=0.86, p< 10(-9)), even when physiological instability perturbed the vascular response. A partial ...

ABSTRACT : INTRODUCTION : This prospective, randomized, controlled, experimental animal study looks at the effects of recombinant human activated protein C (rhAPC) on global hemodynamics and microcirculation in ovine acute lung injury (ALI) and septic shock, resulting from smoke inhalation injury. METHODS : Twenty-one sheep (37 ± 2 kg) were ...

It is well established that ABO and rhesus (Rh) genes and phenotypes vary widely between ethnic groups and both within and between geographical areas. The aim of this study was to determine the distribution of ABO and Rh blood groups in Kurds and to compare it with those of other ...

Detection and identification of blood, semen and saliva stains, the most common body fluids encountered at a crime scene, are very important aspects of forensic science today. This study targets the development of a nondestructive, confirmatory method for body fluid identification based on Raman spectroscopy coupled with advanced statistical analysis. ...

Hemodynamic changes in the cerebral circulation in presence of coarctation of aorta (CoA) and their significance in the increased intracranial aneurysms (IAs) formation in these patients remain unclear. In the present study, we measured the flow-rate waveforms in the cerebral arteries of a patient with CoA, followed by an analysis ...

The choroid plexus is an epithelial-endothelial vascular convolute within the ventricular system of the vertebrate brain. It consists of epithelial cells, fenestrated blood vessels, and the stroma, dependent on various physiological or pathological conditions, which may contain fibroblasts, mast cells, macrophages, granulocytes or other infiltrates, and a rich extracellular matrix. ...

Major blood loss usually occurs in both hip and knee arthroplasty, frequently leading to the need for blood transfusion. This study was performed to determine blood transfusion rates and analyze the factors which affected the need for blood transfusion in patients who underwent primary unilateral total knee and hip arthroplasties ...

We investigate the flow of various non-newtonian fluids through three-dimensional disordered porous media by direct numerical simulation of momentum transport and continuity equations. Remarkably, our results for power-law (PL) fluids indicate that the flow, when quantified in terms of a properly modified permeability-like index and Reynolds number, can be successfully ...

Perioperative fluid management remains controversial. Nevertheless, its optimization is essential to reducing the risk of postoperative complications, which have been shown to profoundly affect patients' short- and long-term outcomes. Current evidence favors a "flow-guided" approach to perioperative fluid administration, which uses variables such as stroke volume and cardiac output as ...

Traditional flow cytometers use a sheath fluid to position particles or cells for cytometric measurements, but the need for sheath fluid greatly complicates flow cytometric instrumentation. A cytometric detector that is free of the requirements of sheath fluid can simplify the design of flow cytometers and can extend their use ...

In this study the feasibility of a time-resolved, three-dimensional (3D), three-directional flow-sensitive balanced steady-state free precession (bSSFP) sequence is demonstrated. Due to its high signal-to-noise ratio (SNR) in blood and cerebrospinal fluid (CSF) this type of sequence is particularly effective for acquisition of blood and CSF flow velocities. Flow sensitivity ...

This work set out to establish the response equations for hepatic blood flows in sheep and the contribution of hepatic arterial flow to hepatic venous blood flow due to changes in intake levels at constant diet composition. The FLORA (FLuxes across Organs and tissues in Ruminant Animals) database was used, ...

BACKGROUND: Peritoneal D-Dimer concentration can be determined to assess peritoneal fibrinolysis activity in horses with gastrointestinal disorders. However, blood contamination of peritoneal fluid may occur during collection and could alter peritoneal D-Dimer concentration. HYPOTHESIS/OBJECTIVES: Blood contamination in peritoneal fluid does not affect interpretation of peritoneal D-Dimer concentration in horses with ...