Search Results
Results 1 - 50 of 712
1 2 3 4 5 6 7 8 9 10 >
Maxwell Adam D AD Department of Urology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 356510, Seattle, WA 98195; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40(th) Street, Seattle, WA, 98105. Electronic address: - - 2014
We have developed a new method of lithotripsy that uses short, broadly focused bursts of ultrasound rather than shock waves to fragment stones. This study investigated the characteristics of stone comminution by burst wave lithotripsy in vitro. Artificial and natural stones (mean 8.2±3.0 mm, range 5-15 mm) were treated with ...
Bouwmeester J Christopher JC Libin Cardiovascular Institute of Alberta and - - 2014
Conventional hemodynamic analysis of pulmonary venous and left atrial (LA) pressure waveforms yields substantial forward and backward waves throughout the cardiac cycle; the reservoir-wave model provides an alternative analysis with minimal waves during diastole. Pressure and flow in a single pulmonary vein (PV) and the main pulmonary artery (PA) were ...
Mynard Jonathan P JP Murdoch Childrens Research Institute - - 2014
Controversy exists about whether one-dimensional (1D) wave theory can explain the 'self-cancelling' waves that accompany the diastolic pressure decay and discharge of the arterial reservoir. Although it has been proposed that reservoir and wave effects be treated as separate phenomena, thus avoiding the issue of self-cancelling waves, we have argued ...
Narayanan Arjun A Department of Physics, New York University, New York 10003, - - 2014
We present simultaneous measurements of angular-dependent magnetoresistance and thermopower along all three crystal axes in (TMTSF)2PF6 for pressures to 7.4 kbar and magnetic fields to 35 T. (TMTSF)2PF6 under pressure shows the coexistence of spin density wave and metal-superconducting orders. We suggest that this coexistence results neither in microscopic coexistence nor in ...
Eterović Davor D Department of Nuclear Medicine, University Hospital Split and Department of Medical Physics, University of Split School of Medicine, Croatia. Electronic address: - - 2014
The adverse effect of shock-wave lithotripsy (SWL) for renal stones on blood pressure is currently defined as its post-treatment increase. On the contrary, we hypothesize that even mild, unilateral renal obstruction initiates an increase in blood pressure. Then, in absence of treatment-induced injury, the stone removal should decrease the blood ...
Lo Jean C Y JC Department of Toxicology, University of California, San Diego, San Diego, - - 2014
Historically, methylene blue (MB) has been used for multiple purposes, including as an antidote for toxin-induced and hereditary methemoglobinemia, ifosfamide-induced encephalopathy, and ackee fruit and cyanide poisoning; as an aniline dye derivative, antimalarial agent, and antidepressant. Most recently, the use of MB has been advocated as a potential adjunct in ...
Schmidt Mischa M 1] Research Group "Shock Waves in Soft Biological Matter", Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI, Eckerstrasse 4, 79104 Freiburg, Germany [2] Department of Stereotactic and Functional Neurosurgery, Neurocenter, University Medical Center Freiburg, Breisacher Straβe 64, 79106 Freiburg, - - 2014
The impact of pressure waves on cells may provide several possible applications in biology and medicine including the direct killing of tumors, drug delivery or gene transfection. In this study we characterize the physical properties of mechanical pressure waves generated by a nanosecond laser pulse in a setup with well-defined ...
Mobley Jonathan M JM Washington University, Urology, St. Louis, Missouri, United States ; - - 2013
To evaluate the effects of a reverse thermosensitive polymer during ureteroscopy with laser lithotripsy in an in-vivo porcine model. Six pigs underwent general anesthesia followed by bilateral ureteroscopy with laser lithotripsy of stone phantoms while measuring intrapelvic renal pressures through bilateral nephrostomy tubes. The procedures were performed in one ureter ...
Yu Cui - - 2013
Previous studies on the association between extracorporeal shock wave lithotripsy (SWL) and new onset hypertension have only illustrated contradictory results. In order to illustrate the association between SWL and new onset hypertension, a meta-analysis of case-control and cohort studies was conducted. Relevant literature was searched using PubMed, EMBASE, and the ...
Robey H F - - 2013
The first measurements of multiple, high-pressure shock waves in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility have been performed. The strength and relative timing of these shocks must be adjusted to very high precision in order to keep the DT fuel entropy low and compressibility ...
Yoshizawa Shin - - 2013
Cavitation bubbles are known to accelerate therapeutic effects of ultrasound. Although negative acoustic pressure is the principle factor of cavitation, positive acoustic pressure has a role for bubble cloud formation at a high intensity of focused ultrasound when cavitation bubbles provide pressure release surfaces converting the pressure from highly positive ...
Hughes Alun D - - 2013
Waves and wave reflections play an undoubted role in arterial hemodynamics. Wave intensity analysis and separation of pressure into forward and backward components can both be used to analyze wave phenomena in arteries, but result in different interpretations regarding the contribution of wave reflections to the aorta blood pressure waveform. ...
Pishchalnikov Yuri A YA Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr., Indianapolis, IN 46202-5120, - - 2013
Conduct a laboratory evaluation of a novel low-pressure, broad focal zone electrohydraulic lithotripter (TRT LG-380). Mapping of the acoustic field of the LG-380, along with a Dornier HM3, a Storz Modulith SLX, and a XiXin CS2012 (XX-ES) lithotripter was performed using a fiberoptic hydrophone. A pig model was used to ...
Quinn Mark Kenneth - - 2013
Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC) ...
Yoo Seong Ki SK Advanced Medical Device Research, Korea Electrotechnology Research Institute, 111 Hangaul-ro, Sangnok-gu, Ansan, Gyeonggi-do 426-910 - - 2013
In traditional Chinese and Korean medicine, doctors first observe a patient's pulse by gently and strongly pressing their fingers onto the wrist, and then make a diagnosis based on the observed pulse waves. The most common method to implement this diagnostic technique is to mechanically extract the pulse waves by ...
Heffernan Kevin S - - 2012
We examined changes in central blood pressure (BP) following resistance exercise training (RET) in men and women with prehypertension and never-treated hypertension. Both Windkessel theory and wave theory were used to provide a comprehensive examination of hemodynamic modulation with RET. Twenty-one participants (age 61±1 years, n=6 male; average systolic blood ...
Bader Kenneth B - - 2012
Recent investigations of cavitation in fluids pressurized up to 30 MPa found that the intensity of light emissions increased by 1000-fold over that measured for single bubble sonoluminescence. A series of measurements is reported here to extend this original work by resolving the static pressure dependence of the shock wave and ...
Tinguely M - - 2012
Spherically collapsing cavitation bubbles produce a shock wave followed by a rebound bubble. Here we present a systematic investigation of the energy partition between the rebound and the shock. Highly spherical cavitation bubbles are produced in microgravity, which suppresses the buoyant pressure gradient that otherwise deteriorates the sphericity of the ...
Gómez Leopoldo R - - 2012
The confining pressure P is perhaps the most important parameter controlling the properties of granular matter. Strongly compressed granular media are, in many respects, simple solids in which elastic perturbations travel as ordinary phonons. However, the speed of sound in granular aggregates continuously decreases as the confining pressure decreases, completely ...
Li Guangyan - - 2012
The fiber-optic probe hydrophone (FOPH) is the accepted standard for characterization of lithotripter shock waves, and measurements are typically conducted in water in the unconstrained free-field. To sort out potential factors that may affect in vivo measurements within the collecting system of the kidney, we assessed for the effect of ...
Muhlestein Michael B - - 2012
Multi-microphone arrays embedded in a rigid spherical housing have been used to estimate field quantities such as vector intensity. However, the measured pressure waveforms are modified by the scattering of the incident pressure wave on the sphere. The frequency response function and the corresponding impulse response function for microphones in ...
Wiklund Annaeva - - 2012
BACKGROUND: Levosimendan was hypothesized to attenuate hypoxic pulmonary vasoconstriction (HPV). METHODS: 14 anaesthetized pigs (30,9±1,0kg) were studied in normoxia (FiO2∼0,21) and hypoxia (FiO2∼0,10), before and 10-90 min after infusion of placebo (n=7) or Levosimendan (n=7). RESULTS: Compared to normoxia, hypoxia-baseline at FiO2∼0,10 (n=14) increased PVR by 1.9±0.4 WU (p<0,001), MPAP ...
Winestone John S - - 2011
Object Previous studies have shown that cervical and thoracic kyphotic deformity increases spinal cord intramedullary pressure (IMP). Using a cadaveric model, the authors investigated whether posterior decompression can adequately decrease elevated IMP in severe cervical and thoracic kyphotic deformities. Methods Using an established cadaveric model, a kyphotic deformity was created ...
Ogata Hisayoshi - - 2011
OBJECTIVE: To investigate changes in tissue oxygenation in the arm and leg during the cold pressor test in humans with spinal cord injury (SCI). METHODS: Subjects with SCI at cervical 6 (n = 7) and subjects with SCI at thoracic 5 or thoracic 6 (n = 5) experienced 3-min cold water immersion of the ...
Gao X - - 2011
High-pressure injection injuries occur infrequently but are usually work-related and involve the non-dominant hand. The neck is a very rare site for such an injury. We describe the management of a 36-year-old man with a high-pressure grease-gun injection injury to his neck causing a cervical spinal cord injury. He developed ...
Jaumard Nicolas V - - 2011
The facet joint contributes to the normal biomechanical function of the spine by transmitting loads and limiting motions via articular contact. However, little is known about the contact pressure response for this joint. Such information can provide a quantitative measure of the facet joint's local environment. The objective of this ...
Marshall Nathaniel S - - 2011
Aims:  To study the association between childhood snoring and cardiovascular risk factors. Methods:  Cross-sectional analyses of a population-based birth cohort, who had been participants in a randomised controlled trial of interventions to prevent asthma and who were assessed at age 8 years. The presence and frequency of snoring were assessed by ...
Chapman David G - - 2011
The lungs are in a constant state of motion. The dynamic nature of tidal breathing, whereby cycles of pressure changes across the lungs cause the chest wall, lung tissue and airways to repeatedly expand and contract, ventilates the lung tissue and allows respiration to occur. However, these regular cycles of ...
Reinero Carol R - - 2011
N-acetylcysteine (NAC), a mucolytic and antioxidant, is speculated to cause bronchoconstriction in cats when delivered via aerosol. We hypothesized that in cats with experimental asthma, aerosol delivery of NAC (400mg cumulative dose) via an endotracheal tube would increase airflow limitation as measured by ventilator-acquired mechanics. After endotracheal drug delivery, airway ...
Alvarez-Alvarez Beatriz - - 2010
Currently there is no consensus regarding which add-on therapy to use in resistant hypertension. This study was designed to compare two treatment options, spironolactone (SPR) versus dual blockade of the renin-angiotensin-aldosterone system (RAAS). Forty-two patients with true resistant hypertension were included in the study. An open-label prospective crossover design was ...
Mansur Sulaf J - - 2010
The renin-angiotensin-aldosterone system (RAAS) plays an important role in blood pressure control and volume homeostasis. Inappropriate activation of the RAAS has been implicated in the pathogenesis of hypertension and related cardiovascular disease. Several classes of agents that block RAAS signaling have been shown to be effective antihypertensives and to have ...
Welch Brian T - - 2011
To assess safety, technical success, complications, and hemodynamic changes associated with the adrenal cryoablation procedure. This retrospective review was approved by the institutional review board, with waiver of informed consent, and was compliant with the Health Insurance Portability and Accountability Act. Adult patients with adrenal metastasis who were treated with ...
Herd Andrew - - 2010
BACKGROUND: Primary hyperaldosteronism is a recognised cause of secondary hypertension with its aetiology most commonly due to a secreting aldosterone adenoma of the adrenal gland. Laparoscopic resection of the adrenal tumour has now become the accepted form of intervention. The aim of this study was to assess the effectiveness of ...
Ito Yuji - - 2011
Recent studies have reported a high prevalence of primary aldosteronism among patients with severe hypertension. However, the prevalence of this disease among normotensive and mildly hypertensive patients has not been determined. The aim of this study was to examine the prevalence of primary aldosteronism among prehypertensive and stage 1 hypertensive ...
Martins L C - - 2011
Resistant hypertension (RHTN) includes patients whose blood pressure (BP) is controlled with the use of four or more antihypertensive medications, and is referred to as 'controlled resistant hypertension' (CRH). While specifically comparing patients with CRH and uncontrolled resistant hypertension (UCRH), we hoped to identify distinguishing characteristics that would provide insight ...
du Cailar Guilhem - - 2010
In essential hypertension, the regression of left ventricular hypertrophy is an important goal of treatment. In addition to treatment-associated changes in blood pressure (BP), the roles of other determinants of left ventricular hypertrophy regression, including dietary sodium intake, deserve investigation. In the present study, the change in echographic left ventricular ...
Rossi Gian Paolo - - 2010
Primary aldosteronism (PA) is a common cause of arterial hypertension: in the PA Prevalence in Hypertensives (PAPY) Study, the prevalence of PA was 11.2% in consecutive referred hypertensive patients. When adrenal vein sampling (AVS) is available, two thirds of the cases can be attributed to a tumor and one third ...
Yagi Shusuke - - 2011
Cognitive impairment leading to dementia is associated with high prevalence of hypertension, decreased quality of life and poor prognosis. Aldosterone is known as a risk factor for cardiovascular and cerebrovascular diseases. In addition, mineral corticoid receptors are abundantly expressed in the hippocampus, which plays a pivotal role in cognitive function; ...
Tapolyai Mihály - - 2010
Liddle syndrome (LS) is an autosomal dominant disorder due to a gain-of-function mutation in the epithelial Na(+) channel and is perceived to be a rare condition. A cross-sectional study of 149 hypertensive patients with hypokalemia (<4 mmol/dL) or elevated serum bicarbonate (>25 mmol/dL) was conducted at a Veterans' Administration Medical ...
Grimm P Richard - - 2010
Large, Ca-activated K channels (BK) are comprised of an α pore (BKα) and one of four β subunits (BKβ1-4). When the gene for BKβ1 is knocked out (BKβ1-KO), the result is increased myogenic tone of vascular smooth muscle and hypertension. We reexamined whether the hypertension is entirely due to increased ...
Wang Qing - - 2010
The cardiovascular system is under the control of the circadian clock, and disturbed circadian rhythms can induce cardiovascular pathologies. This cyclic regulation is probably brought about by the circadian expression of genes encoding enzymes and regulators involved in cardiovascular functions. We have previously shown that the rhythmic transcription of output ...
Boschitsch E - - 2010
The age-related course of blood pressure and its gender-related difference, as well as the incidence of hypertension, have been the subject of multiple experimental, clinical and epidemiological studies over the past decades. The role of the sex hormones estradiol and testosterone within this gender dimorphism has been investigated without conclusive ...
Kurata M - - 2011
Osteopontin (OPN) has recently emerged as a key factor in both vascular remodelling and development of atherosclerosis. It has been reported that OPN is regulated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to clarify the effect of angiotensin II receptor blockade with valsartan on plasma OPN ...
Kontak Andrew C - - 2010
Aldosterone has been shown to exert a central sympathoexcitatory action in multiple animal models, but evidence in humans is still lacking. Our objective was to determine whether hyperaldosteronism causes reversible sympathetic activation in humans. We performed a cross-sectional comparison of muscle sympathetic nerve activity (SNA, intraneural microelectrodes) in 14 hypertensive ...
Gao Jian Ping - - 2010
Ventricular remodeling is an independent risk factor for many cardiovascular events. Inhibiting ventricular remodeling early may be an effective way to postpone heart failure for patients with cardiovascular illness. The study was designed to examine the effect of sodium houttuyfonate on ventricular remodeling induced by pressure overload in rats, as ...
Paulis Ludovit - - 2010
Despite the existence of established, effective therapies for hypertension, new methods of blood pressure and cardiovascular risk reduction are still needed. Novel approaches are targeted towards treating resistant hypertension, improving blood-pressure control, and achieving further risk reduction beyond blood-pressure lowering. Modulation of the renin-angiotensin-aldosterone system (RAAS) provides the rationale for ...
Sun Bei - - 2010
Beta(2)-adrenergic receptor (beta2-AR) is a susceptibility locus for hypertension, and polymorphisms at this site relate to salt sensitivity and low plasma renin activity (PRA). The Dietary Approaches to Stop Hypertension (DASH) dietary pattern lowers blood pressure and appears to interact with the renin-angiotensin-aldosterone system (RAAS). We hypothesized that the DASH ...
Fu Qi - - 2010
Approximately 500,000 American premenopausal women have the postural orthostatic tachycardia syndrome (POTS). We tested the hypothesis that in POTS women during orthostasis, activation of the renin-angiotensin-aldosterone system is greater, leading to better compensated hemodynamics in the midluteal phase (MLP) than in the early follicular phase of the menstrual cycle. Ten ...
Tomaschitz Andreas - - 2010
OBJECTIVES: With the present analysis we intended to investigate the magnitude of the effect of relative aldosterone excess in predicting peripheral as well as aortic blood pressure levels in a well-characterized cohort of patients undergoing coronary angiography. BACKGROUND: The discussion on the relationship between aldosterone concentration and blood pressure has ...
Bubien James K - - 2010
This minireview examines both the basic science and clinical observations over the past 20 years to show how and why overstimulation of the amiloride-sensitive epithelial Na(+) channel (ENaC) expressed by epithelial principal cells of the renal collecting duct may be responsible for a large portion of hypertension in modern society. ...
1 2 3 4 5 6 7 8 9 10 >