Background  Cardiovascular disease is the primary cause of morbidity and mortality among captive chimpanzees. But there are no clinical definitions of normotension or hypertension in chimpanzees. Methods  We analyzed 1 year of blood pressure (BP) data from a population of 261 healthy captive adult chimpanzees using a consistent set of criteria ...

1. There is mounting evidence that increased oxidative stress and sympathetic nerve activity play important roles in renovascular hypertension. In the present review, we focus on the importance of oxidative stress in two distinct populations of neurons involved with cardiovascular regulation: those of the rostral ventrolateral medulla (RVLM) and those ...

BACKGROUND AND OBJECTIVES:: Our previous studies in pigs indicate that direct connections exist between the spinal epidural space and the venous circulation. We wondered if similar connections occur in humans and have extended our investigations to human cadavers awaiting autopsy. METHODS:: We studied 10 recently dead human bodies. We inserted ...

Hypertension is still presently the number one "silent killer" in the Western World, and a major risk factor for the development of secondary diseases contributing to cardiovascular disease (CVD). However, despite a broad range of therapies, the mechanisms involved in the onset of hypertension remains unclear, therefore there is a ...

Effects of pressure on glucose-ammonium sulphite solutions were investigated. The reactant (i.e. glucose), intermediate products content, and browning intensity of advanced stages were tested using an UV-Vis spectrophotometer and a high performance liquid chromatograph to gain a better understanding of the influence of pressure on the glucose-ammonium model Maillard reaction ...

During late ejection, myocardial relaxation causes systolic flow to decelerate and stop, and this phenomenon is coupled with the generation of a pressure gradient inside the left ventricle (LV). We hypothesized that the peak reverse ejection intraventricular pressure difference (REIVPD) between the LV apex and the outflow tract could be ...

Reason for performing study: Current use of acepromazine in the anaesthetic management of male horses and ponies and associated risks are largely unknown. Objectives: To explore anaesthetic acepromazine use and related adverse effects in the male horse. Methods: Of 8533 anaesthetised horses and ponies medical records of male animals treated ...

We are living in an ageing world. The prevalence of hypertension which is an established risk factor for cardiovascular disease and stroke increases with age. The aim of the study was to determine the prevalence of hypertension among the elderly Malays living in rural parts of north Malaysia. This cross-sectional ...

This chapter reviews a body of evidence concerning the anatomic pathology, pathogenesis, epidemiology and possible etiologic agents of benign essential hypertension in human populations. A core finding serves as the starting point for further reasoning: intimal fibroplasia of renal interlobular arteries (arteriosclerosis) increases with age at varying rates in all ...

In spite of the great number of observations which show the certainty of cardiovascular damage from smoking, the opinions on that are not yet unanimous. There is a discrepancy that could be attributed to the lack of reproducible data particularly in some epidemiological studies. On the contrary, experimental findings conducted ...

The paper deals with the calculations of the unsteady, impulsive pressure distributions, carrying capacities and friction forces under unsteady conditions in a super-thin layer of biological synovial fluid inside the slide biobearing gap limited by a spherical bone head. Unsteady and random flow conditions for the biobearing lubrication are given. ...

Studies have shown that permissive hypotension for uncontrolled hemorrhagic shock can result in good resuscitation outcome. The ideal target mean arterial pressure (MAP) and the tolerance time for permissive hypotension have not been determined. To elucidate the ideal target MAP and tolerance time for permissive hypotension with uncontrolled hemorrhagic shock ...

BACKGROUND: Stereology is an essential method for quantitative analysis of lung structure. Adequate fixation is a prerequisite for stereological analysis to avoid bias in pulmonary tissue, dimensions and structural details. We present a technique for in situ fixation of large animal lungs for stereological analysis, based on closed loop perfusion ...

Remote ischemic preconditioning (RIPC) consists of repeated 5' periods of blood pressure (BP) cuff inflations applied to the upper arms at pressures above the systolic blood pressure (SBP), interspersed with 5' periods of reperfusion have been shown to benefit the ischemic and infarcted myocardium in animal experiments, and human clinical ...

Diets rich in fruits and vegetables have been associated with benefits for human health. Those effects have been partially ascribed to their content in flavonoids, compounds that are present in many edible plants and its derived foods. In humans, a significant number of studies has been developed analyzing the effect ...

To assess the effect of the perfusion pressure (PP) during machine perfusion (MP) on the preservation quality of kidney grafts, we compared mean PPs of 25 and 30 mmHg using a porcine autotransplantation model. After assessment of the microcirculation, animals underwent left nephrectomy. Thereafter, kidneys were washed out followed by 20 h ...

To evaluate feasibility of a twin valve caval stent (TVCS) for functional replacement of an incompetent tricuspid valve (TV) in an acute animal study. One swine and three sheep were used in the study. TVCS placement was tested in a swine with a normal TV. TVCS function was tested in ...

Experimental evidence indicates that endothelin 1 stimulates the sympathetic nervous system by activation of the subtype A receptor. The aim of the present study was to assess whether this mechanism is active in humans and to investigate its potential role in the pathogenesis of essential hypertension. In 15 hypertensive patients ...

The purpose of this study was to evaluate the relationship between the cardiac and sympathetic baroreflex sensitivities within healthy, young humans. The sensitivities of the cardiac and sympathetic baroreflexes were compared in 53 normotensive individuals (28 men and 25 women; age: 24.0 ± 0.9 years; body mass index: 24.0 ± ...

To determine the effects of K(+) on the sensitivity of sensory receptors in teeth to fluid flow through dentine. Evoked discharges were recorded from intradental nerves in anaesthetised cats during the application of 5s hydrostatic pressure stimuli to exposed dentine through either normal Ringer's or Ringer's containing up to 255mmol/lK(+). ...

Functional preload parameters such as stroke-volume variation (SVV) and pulse-pressure variation (PPV) are superior to filling pressures when assessing volume responsiveness in mechanically ventilated patients. This investigation studied their application in the setting of acute myocardial ischemia and reperfusion (I/R). Experimental animal study in a university laboratory. Twenty anesthetized and ...

Experiments were performed on the model of chronic heart failure. Functional capacity of myocardial structures under conditions of maximum pressure overload was within the upper limit of normal after treatment with Adenocin. The myocardial functional reserve and potential capacity index were shown to increase to normal under these conditions. Dobutamine, ...

Thoracic sympathetic block has recently been performed by placement of the clips on the sympathetic chain to interrupt nerve conduction. The aim of this study was to compare clipping with 2% mepivacaine and radiofrequency thermocoagulation for the potency of sympathetic block from the results of the duration and magnitude of ...

Experimental animal data suggest that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) might reduce enhanced sympathetic activity, a hallmark of hypertensive patients. This hypothesis was tested for the first time in patients with primary hypertension. Using a prospective, randomized, placebo-controlled, double-blind, cross-over design, a proof-of-principle trial was performed in 13 ...

The fundamental role and corollary effects of neuropeptides that govern cardiorespiratory control in the brain stem are poorly understood. One such regulatory peptide, catestatin [Cts, human chromogranin A-(352-372)], noncompetitively inhibits nicotinic-cholinergic-stimulated catecholamine release. Previously, we demonstrated the presence of chromogranin A mRNA in brain stem neurons that are important for ...

Vav3 is a phosphorylation-dependent activator of Rho/Rac GTPases that has been implicated in hematopoietic, bone, cerebellar, and cardiovascular roles. Consistent with the latter function, Vav3-deficient mice develop hypertension, tachycardia, and renocardiovascular dysfunctions. The cause of those defects remains unknown as yet. Here, we show that Vav3 is expressed in GABAegic ...

Aims It has been proposed that fatigue, a troublesome symptom of multiple sclerosis (MS), may be associated with sympathetic dysfunction. The wakefulness promoting drug modafinil, which has sympathomimetic effects, can reduce fatigue in MS. We examined whether MS fatigue is associated with sympathetic impairment and, if so, whether the sympathetic ...

The sympathetic nervous system via its effect on the kidney maintains a key role in blood pressure regulation and in the pathogenesis of hypertension. In turn, the kidney receives a dense innervation of afferent sympathetic fibers allowing it to effectively modulate the sympathetic tone. Hence, the kidney can be both ...

Glossopharyngeal insufflation (lung packing) is a common maneuver among experienced apnea divers by which additional air is pumped into the lungs. It has been shown that packing may compromise cardiovascular homeostasis. We tested the hypothesis that the packing-mediated increase in intrathoracic pressure enhances the baroreflex-mediated increase in muscle sympathetic nerve ...

Arginase is an enzyme which plays a role in pathophysiology such as hypertension. Here we demonstrated for the first time the direct implication of pressure and OH° radical formation on the arginase activity via a novel analytical procedure. Pressure increased arginase activity in the range 12-52bars. Activation by OH° radical ...

The within-breath modulation of muscle sympathetic nerve activity (MSNA) is well established, with greater activity occurring during expiration and less during inspiration. Whether ventilation per se affects the longer-term (i.e., minute-to-minute) regulation of MSNA has not been determined. We sought to define the specific role of ventilation in regulating sympathetic ...

To evaluate the effect of noninvasive Bi-level Positive Airway Pressure (BiPAP) ventilation on the severe influenza A virus associated with pneumonia and acute respiratory failure (ARF). Based on conventional therapy via face mask using BiPAP ventilator positive airway pressure ventilation in the treatment of severe pneumonia caused by influenza A ...

End-stage renal disease (ESRD) is characterized by markedly increased sympathetic outflow that contributes to increased cardiovascular mortality in these patients. The central sympatholytic drug moxonidine (MOX) has been shown to reduce muscle sympathetic nerve activity (MSNA) in initial stages of chronic kidney disease; however, the effects in ESRD are not ...

Hypertension is a syndrome that extends beyond high blood pressure and often includes obesity, insulin resistance, altered lipid metabolism and other risk factors. The clustering of risk factors can place even a patient with a modestly elevated blood pressure at high risk for cardiovascular morbidity and mortality. Many of these ...

The aim of this study was to compare the potency of bupivacaine, ropivacaine, and levobupivacaine in an equal dose and concentration for sympathetic block. We measured mean arterial pressure, heart rate (HR), and right and left brachial artery blood flow (BABF) before and after cervicothoracic sympathetic block in 24 dogs. ...

The hypothalamic paraventricular nucleus (PVN) coordinates autonomic and neuroendocrine systems to maintain homeostasis and to respond to stress. Neuroanatomic and neurophysiologic experiments have provided insight into the mechanisms by which the PVN acts. The PVN projects directly to the spinal cord and brainstem and, specifically, to sites that control cardio-respiratory ...

Beyond their hypolipidemic effect, statins reduce cardiovascular risk in hypertensive subjects via various mechanisms; one suggested mechanism is that they reduce sympathetic activity. We investigated the hypothesis that simvastatin decreased muscle sympathetic nerve activity (MSNA) in 31 hypertensive subjects with hypercholesterolemia (aged 38.7 ± 10 years). In this randomized, placebo-controlled, ...

Prior research points to the importance of psychostimulants in improving self-control. However, the neural substrates underlying such improvement remain unclear. Here, in a pharmacological functional MRI study of the stop signal task, we show that methylphenidate (as compared with placebo) robustly decreased stop signal reaction time (SSRT), an index of ...

Several hemodynamic variables, such as blood pressure, vascular resistance, cardiac output, and heart rate, are regulated, among others, by sympathetic cardiovascular influences. This has led many years ago investigators to advance the hypothesis that alterations in the sympathetic modulation of the cardiovascular system may occur in hypertension and related disease. ...

Excess weight is established as a major risk factor for cardiovascular diseases, particularly in young individuals. To get a better understanding of the pathophysiology underlying increased cardiovascular disease risk, we evaluated early signs of organ damage and their possible relationship to sympathetic nervous activity. Eighteen lean (body mass index <25 ...

The hypothesis that isometric handgrip induces a progressive increase in arterial pressure and a linear increase in setpoint for arterial pressure control was tested. The continuous time course of changes in heart rate (HR), stroke volume (SV) and mean arterial pressure (MAP) was recorded during a 2-min handgrip contraction of ...

The effects of electrical stimulation of the femur, on blood pressure, were examined in anesthetized rats. Two small holes, 3-4 mm apart, were manually drilled into the femur down to the bone marrow. Following this, two stainless-steel electrodes were inserted into the holes, and an electrical square wave current was ...

Chronic intermittent hypoxia (CIH) is thought to be responsible for the cardiovascular disease associated with obstructive sleep apnea (OSA). Increased sympathetic activation, altered vascular function, and inflammation are all putative mechanisms. We recently reported (Tamisier R, Gilmartin GS, Launois SH, Pepin JL, Nespoulet H, Thomas RJ, Levy P, Weiss JW. ...

Obstructive sleep apnoea syndrome (OSAS) causes nocturnal chronic intermittent hypoxia (IH) that contributes to excess cardiovascular morbidity. To explore the consequences of IH, we used our recently developed model of nocturnal IH in healthy humans to characterise the profile of this blood pressure increase, to determine if it is sustained ...

OBJECTIVE: Previous studies have shown that smoking contributes importantly to short-term modulation of sympathetic nerve traffic. However, effect of smoking status on resting muscle sympathetic nerve activity (MSNA) in hypertension is unknown. Therefore, we tested the hypothesis that smoking is associated with chronic sympathetic activation in patients with essential hypertension. ...

Paneer is highly perishable at ambient conditions and its shelf-life is very low. At high temperature, it develops a sour smell, and bitter taste. Drying can be one of the methods to increase shelf-life. Drying experiments were conducted at 62, 72 and 82°C and 10, 14 and 18 kPa absolute ...

Following sinoaortic denervation, which eliminates arterial baroreceptor input into the brain, there are slowly developing adaptations that abolish initial sympathetic activation and hypertension. In comparison, electrical stimulation of the carotid sinus for 1 wk produces sustained reductions in sympathetic activity and arterial pressure. However, whether compensations occur subsequently to diminish ...

Apnea divers are exposed to repeated massive arterial oxygen desaturation, which could perturb chemoreflexes. An earlier study suggested that peripheral chemoreflex regulation of sympathetic vasomotor tone and ventilation may have recovered 4 or more weeks into the off season. Therefore, we tested the hypothesis that peripheral chemoreflex regulation of ventilation ...

OBJECTIVES: The objective of this study was to assess differences in brain responses between pressure and acupuncture stimulation at the same acupoint using functional magnetic resonance imaging (fMRI). SUBJECTS: A total of 10 healthy right-handed volunteers were studied. DESIGN: fMRI was performed with two different paradigms; namely, pressure and acupuncture ...

Hypertension is the most important public health problem in developing countries and one of the major risk factors for cardiovascular diseases, and it has been reported that hypertension is in part an inflammatory disorder and several workers have reported elevated levels of CRP in hypertensive individuals. The main aim of ...