The translaminar pressure gradient (TLPG) is largely influenced by the difference between intraocular pressure (IOP) and cerebrospinal fluid pressure (CSFP), but modulated by the buffering effect of orbital tissue and pia mater, which limits the reduction in retrolaminar tissue pressure as intracranial CSFP falls below 0 mm Hg. Across the ...

Classic canine studies suggest that central great vein distension evokes an autonomic reflex tachycardia ("Bainbridge reflex"). It is unclear whether central venous distension in humans is a necessary and sufficient stimulus to evoke a reflex increase in heart rate (HR), blood pressure (BP) and muscle sympathetic nerve activity (MSNA). Prior ...

Penicillium roqueforti plays an important role in the ripening of blue-veined cheeses, mostly due to lactic acid consumption and to its extracellular enzymes. The strong activity of P. roqueforti proteinases may bring about cheese over-ripening. Also, free amino acids at high concentrations serve as substrates for biogenic amine formation. Both ...

OBJECTIVES: Venous pressure measurement using an intravenous catheter is the sole method for the diagnosis of venous hypertension in patients with chronic venous insufficiency. A noninvasive tool to quantify increased venous pressure is essential for studying venous pathophysiology. Aim of the study was to investigate the value of controlled compression ...

OBJECTIVE/BACKGROUND: Treatment for leg oedema conventionally starts with compression bandaging followed by elastic stockings once swelling is reduced. The aim was to investigate if a kit consisting of a liner and outer stocking, each exerting 20 mmHg of pressure, would be equally effective in achieving and maintaining volume reduction compared with ...

OBJECTIVES: Miniaturized cardiopulmonary bypass (MCPB) is increasingly used in cardiac surgery, because it can lower clinically significant complications such as systemic inflammatory response, haemolysis and high transfusion requirements. A limitation of MCPB is the risk of excessive negative pressure in the venous line during volume depletion, probably leading to gaseous ...

We report a patient with intracranial hemorrhage secondary to venous hypertension as a result of a giant aortic pseudoaneurysm that compressed the superior vena cava and caused obstruction of the venous return from the brain. To our knowledge, this is the first patient reported to have an intracranial hemorrhage secondary ...

PURPOSE: The difference between mean systemic filling (Pmsf) and central venous pressure (CVP) is the venous return gradient (dVR). The aim of this study is to assess the significance of the Pmsf analogue (Pmsa) and the dVR during a fluid challenge. METHODS: We performed a prospective observational study in postsurgical ...

Aim: Although medical compression stockings (MCSs) represent the cornerstone of conservative treatment for patients with chronic venous disease, high rates of noncompliance exist. This study compared comfort levels and the difficulty associated with putting on/removing two different MCSs; a conventional degressive MCS (ankle pressure: 24-28 mmHg; calf pressure: 14-18 mmHg) ...

Long-haul flights (LHF) are known to be connected with an increased risk of deep vein thrombosis. There is still some lack of clarity about the impact of hypoxia and lower levels of air pressure and humidity on passengers during flight. This cross-over study researched interstitial fluid shifts traced by measurements ...

<b>Purpose: </b>To investigate<b> </b>the factors influencing the hydrostatic pressure exerted within the venous aneurysms (VA) of an arteriovenous fistula (AVF). <b>Methods:</b> Ideal models of a side-to-end brachial-cephalic AVF were computationally constructed and typical values for the length and the local diameters were considered for both the artery and vein sections ...

We aimed to test two hypotheses: 1) isolated small veins develop substantial myogenic tone in response to elevation of intraluminal pressure, 2) H2O2 contributes to the mediation of myogenic response via activation of arachidonic acid (AA) cascade and release constrictor prostaglandins. METHODS: Small veins were isolated from gracilis muscle of ...

BACKGROUND:The effects of maneuvers to increase intrathoracic pressure and of Trendelenburg position on the cross-sectional area (CSA) of the subclavian vein (SCV) and the relationship between the SCV and adjacent structures have not been investigated.METHODS:In ultrasonography-guided SCV catheterization (N = 30), the CSA of the SCV and the distance between ...

BACKGROUND: Recently, various hemostatic devices, such as metal or plastic clips, ultrasonic coagulating shears, and electrothermal bipolar vessel sealer, have been widely applied during an operation. The purpose of this study was to analyze the mechanical, histological, and biochemical differences of vessels sealed with various hemostatic devices. METHODS: Thirty New ...

Next to severely decreased pump flow, hypovolemia in extracorporeal life support (ELS) can result in subatmospheric venous line pressure. Such pressure may lead to degassing and resultant gaseous microemboli (GME), with potential changes in neurological clinical outcome. CME activity resulting from degassing was investigated in relation to subatmospheric venous line ...

BACKGROUND: Graduated elastic compression (GEC) stockings have been demonstrated to reduce the morbidity associated with post-thrombotic syndrome. The ideal length or compression strength required to achieve this is speculative and related to physician preference and patient compliance. The aim of this study was to evaluate the hemodynamic performance of four ...

Objectives To prospectively assess changes in spleen stiffness and splenoportal venous flow before and after transjugular intrahepatic portosystemic shunt (TIPS) placement. Methods We prospectively evaluated spleen stiffness measured by the mean shear wave velocity with acoustic radiation force impulse imaging and the splenoportal venous velocity with color Doppler sonography in ...

Objective: To investigate the potential value of measuring mean arterial pressure (MAP), systolic (sBP) and diastolic (dBP) blood pressure at 30-33 weeks' gestation in the prediction of preeclampsia (PE) developing at or after 34 weeks. Methods: Screening study in singleton pregnancies at 30-33 weeks' gestation including 4,294 that were unaffected ...

OBJECTIVE:: To determine the most accurate predictor of central venous pressure among three point-of-care venous ultrasound techniques. DESIGN:: Cross-sectional study. SETTING:: Medical ICU in an academic medical center. PATIENTS:: Convenience sample of 67 spontaneously breathing patients who had an intrathoracic central venous catheter to allow measurement of central venous pressure. ...

Cryoballoon ablation (CBA) is an established therapy for atrial fibrillation (AF). Pulmonary vein (PV) occlusion is essential for achieving antral contact and PV isolation and is typically assessed by contrast injection. We present a novel method of direct pressure monitoring for assessment of PV occlusion. Transcatheter pressure is monitored during ...

The goal of this study was to investigate the contribution of splanchnic volume redistribution and lower limb vasoconstriction in the maintenance of blood pressure during progressive central hypovolemia induced by graded lower body negative pressure (LBNP). It was hypothesized that splanchnic blood volume loss during LBNP would buffer decreases in ...

Isolated giant varicocele has been reported with portal hypertension that results in abnormal communication between portal venous system and testicular vein venous system resulting in retrograde backflow of blood into the testicular venous system which leads to varicosity of the pampiniform plexuses. 65-year-old male with no past medical or surgical ...

Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous ...

A new plastic self-expanding Smartcanula (Smartcanula LLC, Lausanne, Switzerland) is designed for central insertion and prevention of caval collapse. The objective of our work is to assess the influence of the new design on atrial chatter. Caval collapse over the entire caval axis, right atrial, hepatic, renal vein, and iliac ...

Worsening renal function (WRF) during the treatment of acute decompensated heart failure (ADHF) occurs in up to a third of patients and is associated with worse survival. Venous congestion is increasingly being recognized as a key player associated with WRF in ADHF. Understanding the hemodynamic effects of venous congestion and ...

In many intracranial disease states, monitoring of intracranial pressure (ICP) is essential to evaluate response to the therapeutic measures as well as estimation of prognosis. Although, direct estimation of ICP is reliable, it is invasive and not possible in all patients. Transcranial Doppler (TCD) ultrasonography is a bedside and noninvasive ...

BACKGROUND: Different filtering devices are used during mechanical ventilation to avoid dysfunction of flow and pressure transducers or for airborne micro7organisms containment. Water condensates resulting from the use of humidifiers, but also residual nebulization particles, may have a major influence on expiratory limb resistances. OBJECTIVES: To evaluate the influence of ...

To study the anaphylaxis of Qingkailing injection (QI) and its components. Experimental anaphylactoid and allergic reactions were used. Changes in the behaviors of Beagles and serum levels of histamine, immunoglobulin (Ig)E, IgG, IgM, eosinophil cationic protein (ECP), and interleukin (IL)-4, as well as blood pressure, after injecting QI and its ...

Objective-To evaluate the use of the oxygen content-based index, Fshunt, as an indicator of venous admixture ([Formula: see text]s/[Formula: see text]t) at various fractions of inspired oxygen (Fio(2)s) in anesthetized sheep undergoing Flung or 2-lung ventilation. Animals-6 healthy adult female sheep. Procedures-Sheep were anesthetized and administered 5 different Fio(2)s (0.21, ...

Norepinephrine exerts venoconstriction that could increase both the mean systemic pressure and the resistance to venous return, but this has not yet been investigated in human septic shock. We examined the relative importance of both effects and the resulting effect on venous return when decreasing the dose of norepinephrine. Intensive ...

Object The authors examined the role of venous sinus obstruction in the etiology of idiopathic intracranial hypertension (IIH) by reviewing more than 200 MR venograms performed in suspected cases of IIH. Methods Individual MR venograms performed in cases of suspected IIH at the Children's Hospital at Westmead in Sydney, Australia, ...

A patient-specific finite-element (FE) model of the human leg is developed to model the stress distribution in and around a vein wall in order to determine the biomechanical response of varicose veins to compression treatment. The aim is to investigate the relationship between the local pressure on the soft tissues ...

The purpose of this study was to assess immediate changes in the partial pressure of nitric oxide (NO) in exhaled gas (PE(NO) ) in healthy trained subjects who were acutely exposed to moderate altitude. One group of nine and another group of 20 healthy subjects were exposed to an ambient ...

PurposeTo assess the variability of interface pressure and changes in this pressure over one month time interval under ready-to-use compression stockings. METHODS: Fifteen healthy volunteers with a broad range of sizes and shapes of the calves were included in final analysis. Each volunteer sequentially used six pairs of stockings daily ...

Although arterio-venous grafts (AVGs) are the second best option as long-term vascular access for hemodialysis, they suffer from complications caused by intimal hyperplasia, mainly located in vessel regions of low and oscillating wall shear stress. However, certain flow patterns in the bulk may reduce these unfavorable hemodynamic conditions. We therefore ...

Vagal reflex initiated by esophageal stimulation and microaspiration can cause chronic cough in patients with gastroesophageal reflux disease (GERD). By raising intraabdominal pressure,cough can, in turn, predispose to GERD. The role of the upper esophageal sphincter (UES)in preventing esophagopharyngeal reflux during coughing is not well known. The aim of this ...

A pleated filter bag is often used to treat exhaust gas in many industrial applications, due to its fairly high dust collection efficiency and relatively low pressure drop. This work deals with the optimum pleating geometries of a pleated filter made with a newly developed PTFE/glass composite filter. It was ...

Objective:This study was carried out to determine high pressure and pulsatile flow perfusion effects on human saphenous vein (HSV) segments obtained from diabetic and non-diabetic patients.Methods:The veins were perfused with oxygenated Krebs solution for 3 h, with a pulsatile flow rate of 100 mL/min and pressures of 250 × 200 ...

Longstanding experimental evidence supports the role of renal venous hypertension in causing kidney dysfunction and "congestive renal failure." A focus has been heart failure, in which the cardiorenal syndrome may partly be due to high venous pressure, rather than traditional mechanisms involving low cardiac output. Analogous diseases are intra-abdominal hypertension ...

We report on the sensing characteristics of rocking filters fabricated in two microstructured fibers with enhanced polarimetric sensitivity to hydrostatic pressure. The filter fabricated in the first fiber shows a very high sensitivity to pressure ranging from 16.2 to 43.4 nm/MPa, depending on the resonance order and features an extremely ...

Ventilator-induced lung injury is a crucial determinant of the outcome of mechanically ventilated patients. Increasing numbers of mouse studies have identified numerous pathways and mediators that are modulated by ventilation, but it is conceptually difficult to reconcile these into a single paradigm. There is substantial variability in tidal volumes used ...

Veno-venous extracorporeal membrane oxygenation (vvECMO) conventionally requires the cannulation of two vessels. Here we report our initial experience with the "Wang-Zwische" (WZ) double-lumen cannula.In a group of n = 36 patients single venous cannulation for vvECMO was performed. A retrospective analysis was executed. A comparison of flow characteristics to standard ...

Background. Imaging methods for diagnosis of pulmonary embolism (PE) are not available at small medical or rural centres as well as during night time. Herein, we evaluated the diagnostic value of brachial venous pressure measurement in the diagnosis of PE in patients with deep vein thrombosis. Materials and Methods. One-hundred ...

The efficacy of using subharmonic emissions from Sonazoid microbubbles (GE Healthcare, Oslo, Norway) to track portal vein pressures and pressure changes was investigated in 14 canines using either slow- or high-flow models of portal hypertension (PH). A modified Logiq 9 scanner (GE Healthcare, Milwaukee, WI, USA) operating in subharmonic mode ...

Cardiovascular collapse is the major factor contributing to the mortality of trauma-hemorrhage (T-H) patients. Toll-like receptors (TLRs) play a critical role in T-H-induced cardiac dysfunction. This study evaluated the role of TLR9 agonist, CpG-oligodeoxynucleotide (ODN) 1826, in cardiac functional recovery after T-H. Trauma-hemorrhage was induced in a murine model by ...

The purpose was to investigate the acute effects of blood flow restriction (BFR) on arterial and venous hemodynamic parameters. Nine participants completed a 10-min time control (resting condition) and then a lower body BFR protocol. The protocol was five, 5-min bouts of restrictive cuff inflation with 3-min of deflation between ...

Pressure-induced vasodilation (PIV) delays the decrease in cutaneous blood flow produced by local application of low pressure to the skin, a physiologically appropriate adjustment of local vasomotor function. Individuals without a normal PIV response have a high risk of ulceration. Here we demonstrate that acid-sensing ion channel 3 (Asic3) is ...

High pressure is an important dimension for the emergent phenomena in transition metal oxides, including high-temperature superconductivity, colossal magnetoresistance, and magnetoelectric coupling. In these multiply correlated systems, the interplay between lattice, charge, orbital, and spin is extremely susceptible to external pressure. Magnetite (Fe3O4), as one of oldest known magnetic materials ...

Congestive heart failure is associated with increased expression of pro-inflammatory cytokines, and the levels of these cytokines correlate with heart failure severity and prognosis. Chronic interleukin 6 (IL-6) stimulation leads to left ventricular (LV) hypertrophy and dysfunction, and deletion of IL-6 reduces LV hypertrophy after angiotensin II infusion. In this ...

The effect of high pressure on the structural stability of oxamide has been investigated in a diamond anvil cell by Raman spectroscopy up to ~14.6 GPa and angle-dispersive X-ray diffraction (ADXRD) up to ~17.5 GPa. The discontinuity in Raman shifts around 9.6 GPa indicates a pressure-induced structural phase transition. This ...