Although histamine has been suggested to be involved in the control of male sexual function, including the induction of penile erection, its role in the human corpus cavernosum penis is still poorly understood. The aim of our study was to evaluate the course of histamine plasma levels through different stages ...

BACKGROUND: In this cross-sectional study we assessed the prevalence of the various blood safety sexual risk behaviours among blood donors from East Croatia and the possibilities for improving the present blood donor screening procedure. MATERIALS AND METHODS: The study included 423 blood donors of both sexes who completed a specially ...

On 8 September 2010, the Ontario Superior Court rejected a claim that Canadian Blood Services (CBS) is violating Section 15 of the Canadian Charter of Rights and Freedoms (Charter) by refusing blood donations from men who have had sex with other men (MSM) since 1977. The case arose because CBS ...

Many theories have been postulated to date regarding the mechanisms involved in the absorption of the intracranial arterial blood flow energy in the intracranial space, but it is as yet nor clearly defined. The blood flow energy that is transmitted from the heart formulates the cerebrospinal fluid (CSF) pulsatile flow, ...

OBJECTIVES: To evaluate the applicability of 4D phase contrast (4D PC) MR imaging in the assessment of cerebrospinal fluid dynamics in healthy volunteers and patients with lesions at the craniocervical junction or the cervical spinal canal. METHODS: Ten healthy volunteers and four patients with lesions including Chiari I malformation and ...

In the present work, for the first time, investigation of the initial fast step of reaction between 1,1,1-trichloro-3-methyl-3-phospholene (TCMP) and methanol was studied under a dry inert atmosphere by a newly constructed CSF apparatus by means of a further development in the configuration of the previous stopped-flow spectrophotometer (SFS). Hence, ...

The aim of this study is to investigate the feasibility of using three-directional velocity encoded 3D gradient echo (GE) phase contrast (PC) imaging to assess cerebrospinal fluid (CSF) flow connectivity in the human brain. Five healthy volunteers were scanned using low velocity sensitivity (V(enc) = 0.04-0.05 m s(-1)). Flow-time curves ...

Inflammation causes increases in the level of matrix metalloproteinases (MMPs), which, in central nervous system (CNS), are associated with neuroinflammation and disruption of blood-brain-barrier. Analysis of cerebrospinal fluid (CSF) is pivotal for detecting diseases in CNS and, although a specific diagnosis may not be achieved, this analysis is helpful to ...

SUMMARY: The purpose of this study was to analyze the CSF flow in patients with Chiari I to determine differences between patients with and without CAH. Thirty patients with Chiari I malformation underwent cine-PC CSF flow imaging in the sagittal plane. CSF flow pulsations were analyzed by placing regions of ...

Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and an altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with hematologic malignancies, 6 total ...

The human body employs a sophisticated windkessel mechanism to dampen the arterial pulse entering the brain, thus ensuring the smooth flow of blood through the cerebral capillary bed. The energy from the arterial pulse is transferred to the cerebrospinal fluid (CSF), which pulses backwards and forwards across the foramen magnum. ...

In North America, an estimated 30,000 patients annually experience an aneurysmal subarachnoid hemorrhage (SAH). In approximately five percent of these patients, the hemorrhage is not visible on computerized tomography scans due to the inability to image blood at time intervals greater than 12 hours post symptom onset. For these patients ...

Object The dynamics of fluid flow in normal pressure hydrocephalus (NPH) are poorly understood. Normally, CSF flows out of the brain through the ventricles. However, ventricular enlargement during NPH may be caused by CSF backflow into the brain through the ventricles. A previous study showed this reversal of flow; in ...

A three-dimensional model of the human cerebrospinal fluid (CSF) spaces is presented. Patient-specific brain geometries were reconstructed from magnetic resonance images. The model was validated by comparing the predicted flow rates with Cine phase-contrast MRI measurements. The model predicts the complex CSF flow patterns and pressures in the ventricular system ...

The choroid plexuses (CPs) in mammals produce the cerebrospinal fluid (CSF). In the literature, the morphology of CPs and the process that regulates the production of CSF are virtually nonexistent for domestic ruminants. Thus this study has two aims: 1. to investigate the morpho-structure of the buffalo CP microvasculature utilizing ...

We investigated the disposition of ARTCEREB(®) irrigation and perfusion solution (Artcereb) during intrathecal perfusion in a lateral ventricle-cisternal perfusion model in conscious rats. In this perfusion model, the perfusion rate was set at 0.35 ml/kg/h, taking into consideration the clinical perfusion rate (500 ml/60 kg/d). The influence of Artcereb on ...

Purpose: Cerebral palsy (CP) with a prevalence of 2.1 per 1,000 live births generates variable degrees of incurable developmental disability. The aim of the present report was to provide insight in the safety and feasibility of autologous umbilical cord blood (UCB) transfusion with low dose Granulocyte Colony Stimulating Factor (G-CSF) ...

Phase-contrast magnetic resonance imaging (PC-MRI) enables quantification of cerebrospinal fluid (CSF) flow and total cerebral blood (tCBF) flow and may be of value for the etiological diagnosis of neurodegenerative diseases. This investigation aimed to study CSF flow and intracerebral vascular flow in patients with Alzheimer's disease (AD) and patients with ...

OBJECTIVE: To investigate the feasibility of intraoperative ultrasound (IOUS) for monitoring cerebrospinal fluid (CSF) flow in patients with Chiari I malformation. METHODS: Twenty patients with Chiari I were scanned by IOUS with color Doppler flow imaging (CDFI). CSF flow status and flow velocity were monitored at different times during the ...

Spinal cord-injured (SCI) individuals demonstrate an increased baseline leg vascular resistance (LVR). In addition, despite the lack of sympathetic control, an increase in LVR is observed during orthostatic challenges. On the basis of the vasoconstrictive characteristics of angiotensin II, we examined the hypothesis that angiotensin II contributes to the LVR ...

To compare the effects of commercially sold menthol (3.5%) ointment and cold application on blood flow in the forearm. : Prospective counterbalanced design. University research laboratory. Twelve (6 men and 6 women) college-aged students. Each participant had blood flow measured in the brachial artery for 5 minutes before and 10 ...

BACKGROUND: Blood glucose testing (BGT) at the forearm minimizes the pain experienced during sampling of capillary blood. We compared the BGT results for forearm sampling with those for standard finger skin puncture and venous serum to evaluate the clinical validity of forearm BGT. METHODS: BGT was performed on the finger ...

OBJECTIVES: We investigated whether HIV-1 infected patients receiving highly active antiretroviral therapy (HAART) and HIV-1 infected patients who had never received HAART had differences in their vascular microcirculatory function. METHODS: We assessed the forearm blood flow before and after four minutes of ischemic occlusion of the brachial artery using venous ...

Peripheral arterial flow has been assessed for a variety of indications including characterization of endothelial function during reactive hyperemia. However, quantification of this blood flow as a surrogate remains an imperfect reflection of endothelial function. We sought to better characterize hyperemic reaction to (1) elucidate the influence of the endothelial ...

The present work is concerned to model the molecular signalling pathway for vasodilation and to predict the resting young human forearm blood flow under heat stress. The mechanistic electronic modelling technique has been designed and implemented using MULTISIM 8.0 and an assumption of 1V/ degrees C for prediction of forearm ...

In congestive heart failure (CHF), arterial response is regulated by endothelial molecules. The aim of this study was to evaluate whether endothelial dysfunction (ED) was a predictor of outcome in a cohort of patients with heart failure. Endothelial function was assessed in 242 patients with CHF by forearm reactive hyperaemia ...

BACKGROUND: Exposure to air pollution is associated with increased cardiorespiratory morbidity and mortality. It is unclear whether these effects are mediated through combustion-derived particulate matter or gaseous components, such as nitrogen dioxide. OBJECTIVES: To investigate the effect of nitrogen dioxide exposure on vascular vasomotor and six fibrinolytic functions. METHODS: Ten ...

PURPOSE: Vascular reactivity is involved in the regulation of vascular function either in normal conditions or in the pathophysiology of cardiovascular diseases. We tested the hypothesis that vascular reactivity evaluated by forearm blood flow may vary according to demographic and metabolic variables in a cohort of individuals without any evidence ...

Carotid-radial pulse wave velocity (CRPWV) can be measured rapidly using applanation tonometry and significantly higher values have been reported among patients with risk factors for vascular disease. Forearm blood flow responses to intrabrachial infusion of acetylcholine independently predict cardiovascular morbidity among hypertensive patients. We aimed to examine the relationship between ...

The menstrual cycle has been reported to alter mean arterial pressure (MAP), but not muscle sympathetic nerve activity (MSNA), during vestibular activation. Specifically, MAP responses to head-down rotation (HDR) are augmented during the mid-luteal (ML) phase compared to the early follicular (EF) phase in young, eumenorrheic women. The purpose of ...

PURPOSE: Although the effect of phosphodiesterase type 5 inhibitors on endothelial function in the systemic circulation has been extensively studied, its effect on penile endothelial function remains unexplored. Therefore, we evaluated the effect of daily sildenafil on penile endothelial function. MATERIALS AND METHODS: A total of 60 patients with erectile ...

Venous occlusion plethysmography (VOP) is a valid non-invasive method to assess peripheral blood flow (BF) in humans. Our aim was to determine intra- and inter-tester reproducibility of BF analysis using a traditional manual method and a novel system, based on a semi-automatic approach. Ten healthy subjects and ten subjects with ...

Impaired endothelium-dependent vasodilation has been documented in patients with sleep apnea. This impairment may result in blood flow dysregulation during apnea-induced fluctuations in arterial blood gases. To test the hypothesis that hypoxic and hypercapnic vasodilation in the forearm and cerebral circulation are impaired in patients with sleep apnea. We exposed ...

The information about the effect of mental activities on detailed cardiovascular responses is limited, though strong and chronic psychological stressors are risk factors of cardiovascular morbidity and mortality in humans. The responses of vascular resistance (VR) during fear-induced stress was studied by measuring the mean arterial pressure (MAP), heart rate ...

BACKGROUND: The aims of this study were to establish the optimum duration of blood flow occlusion to obtain maximal response and to compare the response after lower-arm and upper-arm occlusion. METHODS: Pulse wave amplitude was analysed using a novel finger plethysmograph (EndoPat; Itamar). For measuring reactive hyperaemic index (RHI) induced ...

Acute exposures of the hand to vibration result in changes in finger blood flow, but it is not clear how the changes depend on the characteristics of the vibration. To determine the effects of the magnitude and frequency of hand-transmitted vibration on finger blood flow in an exposed and a ...

To compile histological and imaging research detailing the microvascularity of the rotator cuff and determine the clinical application of these findings for clinicians. A computer-assisted literature search of MEDLINE (1966 to September 2008) using keywords related to blood flow to the shoulder and limited to humans and English language. A ...

OBJECTIVE: Sodium nitroprusside (SNP) iontophoresis is a commonly used technique to assess non endothelium-dependent skin microvascular function in the forearm. However, the lack of data on the finger pad is a limitation when studying diseases affecting the digits (e.g. systemic sclerosis, SSc). We thus aimed to validate this technique in ...

We have shown recently that repetition of ischemic preconditioning stimulus augments endothelium-dependent vasodilation in forearm circulation of healthy subjects through increases in NO production and the number of circulating progenitor cells under a local condition. The purpose of this study was to evaluate the "late" effect of ischemic preconditioning on ...

Forearm cutaneous perfusion is an established in vivo model in many clinical and basic researches to explore the peripheral circulation. The aim of our study is to characterize the dynamic properties of regional microcirculation after simultaneous denervation and revascularization in free forearm flap transplantations. Serial changes in laser Doppler flow ...

Harvesting the radial forearm flap may cause circulatory problems in the donor arm. To investigate the influence on donor hands after radial forearm flap harvesting, we assessed the process of circulatory changes prospectively by measuring skin perfusion pressure (SPP) that is clinically useful in detecting vascular lesions. The records of ...

INTRODUCTION: Intensive insulin treatment of critically ill patients was seen as a promising method of treatment, though recent studies showed that reducing the blood glucose level below 6 mmol/l had a detrimental outcome. The mechanisms of the effects of insulin in the critically ill are not completely understood. The purpose ...

BACKGROUND: orthostatic hypotension is common in older men and associated with morbidity and mortality. During orthostatic challenges, older men maintain their blood pressure by an augmented increase in total peripheral resistance. Changes in the leg vascular bed contribute importantly to blood pressure regulation during orthostatic challenges, partly because of blood ...

AIMS/HYPOTHESIS: Different ectopic fat depots, such as visceral or hepatic fat, are known to affect whole body insulin sensitivity. It has recently been hypothesised that differences in perivascular adipose tissue (PVAT) mass around resistance vessels may also contribute to insulin resistance, possibly via direct vascular effects leading to reduced capillary ...

Non-invasive evaluation of peripheral perfusion may be useful in many contexts including clinical research. We validated a novel non-invasive spectroscopy technique to quantify forearm arterial inflow. This method, which is based on the measurement of tissular total hemoglobin variations after an ischemic period, was compared to strain gauge plethysmography (SGP). ...

PURPOSE: To investigate possible differences in the time course of vasodilating effects of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in humans. METHODS: We measured forearm blood flow (FBF) by strain gauge plethymography and cyclic GMP spillover during and after intra-arterial infusions of BNP and ANP at 16.2 ...

In addition to vaso-occlusion by sickled erythrocytes, the pathophysiology of sickle cell disease (SCD) is compounded by the diminished bioavailability of nitric oxide (NO), associated with vasoconstriction, endothelial activation and cell adhesion. We tested the ability of sodium nitrite, which can be converted to NO by deoxyhaemoglobin at acid pH ...

BACKGROUND: Previous studies have associated neurohumoral excitation, as estimated by plasma norepinephrine levels, with increased mortality in heart failure. However, the prognostic value of neurovascular interplay in heart failure (HF) is unknown. We tested the hypothesis that the muscle sympathetic nerve activity (MSNA) and forearm blood flow would predict mortality ...

BACKGROUND: Local anaesthetics affect blood vessels in various ways, depending upon the site of action and the drug used. There is controversy over the vascular effects of two widely used topical local anaesthetic agents, EMLA and Ametop. We used the transient hyperaemic response (THR) to the brief compression of the ...

The clinical importance of vascular reactivity as an early marker of atherosclerosis has been well established, and a number of established and emerging techniques have been employed to provide measurements of peripheral vascular reactivity. However, relations between these methodologies are unclear as each technique evaluates different physiological aspects related to ...