WorldWideScience

Sample records for human artery measured

  1. Arterial input function in a dedicated slice for cerebral perfusion measurements in humans.

    Science.gov (United States)

    Kellner, Elias; Mader, Irina; Reisert, Marco; Urbach, Horst; Kiselev, Valerij Gennadevic

    2017-12-09

    We aimed to modify our previously published method for arterial input function measurements for evaluation of cerebral perfusion (dynamic susceptibility contrast MRI) such that it can be applied in humans in a clinical setting. Similarly to our previous work, a conventional measurement sequence for dynamic susceptibility contrast MRI is extended with an additional measurement slice at the neck. Measurement parameters at this slice were optimized for the blood signal (short echo time, background suppression, magnitude and phase images). Phase-based evaluation of the signal in the carotid arteries is used to obtain quantitative arterial input functions. In all pilot measurements, quantitative arterial input functions were obtained. The resulting absolute perfusion parameters agree well with literature values (gray and white matter mean values of 46 and 24 mL/100 g/min, respectively, for cerebral blood flow and 3.0% and 1.6%, respectively, for cerebral blood volume). The proposed method has the potential to quantify arterial input functions in the carotid arteries from a direct measurement without any additional normalization.

  2. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    OpenAIRE

    Winant, Celeste D.; Aparici, Carina Mari; Zelnik, Yuval R.; Reutter, Bryan W.; Sitek, Arkadiusz; Bacharach, Stephen L.; Gullberg, Grant T

    2011-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomograp...

  3. Measurement of the ultrasonic properties of human coronary arteries in vitro with a 50-MHz acoustic microscope

    Directory of Open Access Journals (Sweden)

    Machado J.C.

    2002-01-01

    Full Text Available Ultrasonic attenuation coefficient, wave propagation speed and integrated backscatter coefficient (IBC of human coronary arteries were measured in vitro over the -6 dB frequency bandwidth (36 to 67 MHz of a focused ultrasound transducer (50 MHz, focal distance 5.7 mm, f/number 1.7. Corrections were made for diffraction effects. Normal and diseased coronary artery sub-samples (N = 38 were obtained from 10 individuals at autopsy. The measured mean ± SD of the wave speed (average over the entire vessel wall thickness was 1581.04 ± 53.88 m/s. At 50 MHz, the average attenuation coefficient was 4.99 ± 1.33 dB/mm with a frequency dependence term of 1.55 ± 0.18 determined over the 36- to 67-MHz frequency range. The IBC values were: 17.42 ± 13.02 (sr.m-1 for thickened intima, 11.35 ± 6.54 (sr.m-1 for fibrotic intima, 39.93 ± 50.95 (sr.m-1 for plaque, 4.26 ± 2.34 (sr.m-1 for foam cells, 5.12 ± 5.85 (sr.m-1 for media and 21.26 ± 31.77 (sr.m-1 for adventitia layers. The IBC results indicate the possibility for ultrasound characterization of human coronary artery wall tissue layer, including the situations of diseased arteries with the presence of thickened intima, fibrotic intima and plaque. The mean IBC normalized with respect to the mean IBC of the media layer seems promising for use as a parameter to differentiate a plaque or a thickened intima from a fibrotic intima.

  4. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies.

    Science.gov (United States)

    Winant, Celeste D; Aparici, Carina Mari; Zelnik, Yuval R; Reutter, Bryan W; Sitek, Arkadiusz; Bacharach, Stephen L; Gullberg, Grant T

    2012-01-21

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic (94)Tc-methoxyisobutylisonitrile ((94)Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K(1) for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K(1). For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from (94)Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of (99m)Tc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The

  5. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    Science.gov (United States)

    Winant, Celeste D.; Aparici, Carina Mari; Zelnik, Yuval R.; Reutter, Bryan W.; Sitek, Arkadiusz; Bacharach, Stephen L.; Gullberg, Grant T.

    2012-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic 94Tc-methoxyisobutylisonitrile (94Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K1 for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K1. For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from 94Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of 99mTc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum

  6. In vivo measurement of volumetric strain in the human brain induced by arterial pulsation and harmonic waves.

    Science.gov (United States)

    Hirsch, Sebastian; Klatt, Dieter; Freimann, Florian; Scheel, Michael; Braun, Jürgen; Sack, Ingolf

    2013-09-01

    Motion-sensitive phase contrast magnetic resonance imaging and magnetic resonance elastography are applied for the measurement of volumetric strain and tissue compressibility in human brain. Volumetric strain calculated by the divergence operator using a biphasic effective-medium model is related to dilatation and compression of fluid spaces during harmonic stimulation of the head or during intracranial passage of the arterial pulse wave. In six volunteers, phase contrast magnetic resonance imaging showed that the central cerebrum expands at arterial pulse wave to strain values of (2.8 ± 1.9)·10(-4). The evolution of volumetric strain agrees well with the magnitude of the harmonic divergence measured in eight volunteers by magnetic resonance elastography using external activation of 25 Hz vibration frequency. Intracranial volumetric strain was proven sensitive to venous pressure altered by abdominal muscle contraction. In eight volunteers, an increase in volumetric strain due to abdominal muscle contraction of approximately 45% was observed (P = 0.0001). The corresponding compression modulus in the range of 9.5-13.5 kPa demonstrated that the compressibility of brain tissue at 25 Hz stimulation is much higher than that of water. This pilot study provides the background for compression-sensitive magnetic resonance imaging with or without external head stimulation. Volumetric strain may be sensitive to fluid flow abnormalities or pressure imbalances between vasculature and parenchyma as seen in hydrocephalus. Copyright © 2012 Wiley Periodicals, Inc.

  7. Flow measurements in the major visceral arteries

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J.; Gerhardt, P.; Terwey, B.; Krastel, A.

    1982-02-01

    Arterial flow was measured by the spill-over technique in 202 coeliac arteries and 158 superior mesenteric arteries during the course of visceral angiography in 250 patients. In the coeliac artery a mean value of 15.8 +- 4.3 ml/sec was obtained, flow in the super mesenteric artery was significantly less at 12.1 +- 3.4 ml/sec. The wide variation from 4 to 26 ml/sec in the coeliac artery was remarkable, as well as flows from six to 20 ml/sec in the superior mesenteric artery.

  8. Arterial endothelial function measurement method and apparatus

    Science.gov (United States)

    Maltz, Jonathan S; Budinger, Thomas F

    2014-03-04

    A "relaxoscope" (100) detects the degree of arterial endothelial function. Impairment of arterial endothelial function is an early event in atherosclerosis and correlates with the major risk factors for cardiovascular disease. An artery (115), such as the brachial artery (BA) is measured for diameter before and after several minutes of either vasoconstriction or vasorelaxation. The change in arterial diameter is a measure of flow-mediated vasomodification (FMVM). The relaxoscope induces an artificial pulse (128) at a superficial radial artery (115) via a linear actuator (120). An ultrasonic Doppler stethoscope (130) detects this pulse 10-20 cm proximal to the point of pulse induction (125). The delay between pulse application and detection provides the pulse transit time (PTT). By measuring PTT before (160) and after arterial diameter change (170), FMVM may be measured based on the changes in PTT caused by changes in vessel caliber, smooth muscle tone and wall thickness.

  9. Changes of blood flow velocity indicating mechanical compression of the vertebral arteries during rotation of the head in the normal human measured with transcranial Doppler sonography

    OpenAIRE

    Rossiti, Sandro; Volkmann, Reinhard

    1995-01-01

    The dynamical changes of blood flow velocity of the intracranial vertebral arteries (VA's) and proximal basilar artery (BA) provoked by rotation of the head in normal volunteers were measured using pulsed-wave transcranial Doppler sonography (TCD). In another group both VA's were examined simultaneously with 2-channel TCD. Blood flow velocities diminished compared to the neutral position in all vessels, independently of die side. Total obstruction of the flow was not observed. Our findings re...

  10. LB03.04: SPHYGMOMANOMETER CUFF CONSTRUCTION AND MATERIALS AFFECT TRANSMISSION OF PRESSURE FROM CUFF TO ARTERIAL WALL. FINITE ELEMENT ANALYSIS OF HUMAN PRESSURE MEASUREMENTS AND DICOM DATA.

    Science.gov (United States)

    Lewis, P; Naqvi, S; Mandal, P; Potluri, P

    2015-06-01

    Sphygmomanometer cuff pressure during deflation is assumed to equal systolic arterial pressure at the point of resumption of flow. Previous studies demonstrated that pressure decreases with increasing depth of soft tissues whilst visco-elastic characteristics of the arm tissue cause spatial and temporal variation in pressure magnitude. These generally used non-anatomical axisymmetrical arm simulations without incorporating arterial pressure variation. We used data from a volunteer's Magnetic Resonance (MR) arm scan and investigated the effect of variations in cuff materials and construction on the simulated transmission of pressure from under the cuff to the arterial wall under sinusoidal flow conditions. Pressure was measured under 8 different cuffs using Oxford Pressure Monitor Sensors placed at 90 degrees around the mid upper arm of a healthy male. Each cuff was inflated 3 times to 155 mmHg and then deflated to zero with 90 seconds between inflations. Young's modulus, flexural rigidity and thickness of each cuff was measured.Using DICOM data from the MR scan of the arm, a 3D model was derived using ScanIP and imported into Abaqus for Finite Element Analysis (FEA). Published mechanical properties of arm tissues and geometric non-linearity were assumed. The measured sub-cuff pressures were applied to the simulated arm and pressure was calculated around the brachial arterial wall. which was loaded with a sinusoidal pressure of 125/85 mmHg. FEA estimates of pressure around the brachial artery cuffs varied by up to 27 mmHg SBP and 17 mmHg DBP with different cuffs. Pressures within the cuffs varied up to 27 mmHg. Pressure transmission from the cuff to the arterial surface achieved a 95% transmission ratio with one rubber-bladdered cuff but varied between 76 and 88% for the others. Non-uniform pressure distribution around the arterial wall was strongly related to cuff fabric elastic modulus. Identical size cuffs with a separate rubber bladder produced peri-arterial

  11. Constitutive description of human femoropopliteal artery aging.

    Science.gov (United States)

    Kamenskiy, Alexey; Seas, Andreas; Deegan, Paul; Poulson, William; Anttila, Eric; Sim, Sylvie; Desyatova, Anastasia; MacTaggart, Jason

    2017-04-01

    Femoropopliteal artery (FPA) mechanics play a paramount role in pathophysiology and the artery's response to therapeutic interventions, but data on FPA mechanical properties are scarce. Our goal was to characterize human FPAs over a wide population to derive a constitutive description of FPA aging to be used for computational modeling. Fresh human FPA specimens ([Formula: see text]) were obtained from [Formula: see text] predominantly male (80 %) donors 54±15 years old (range 13-82 years). Morphometric characteristics including radius, wall thickness, opening angle, and longitudinal pre-stretch were recorded. Arteries were subjected to multi-ratio planar biaxial extension to determine constitutive parameters for an invariant-based model accounting for the passive contributions of ground substance, elastin, collagen, and smooth muscle. Nonparametric bootstrapping was used to determine unique sets of material parameters that were used to derive age-group-specific characteristics. Physiologic stress-stretch state was calculated to capture changes with aging. Morphometric and constitutive parameters were derived for seven age groups. Vessel radius, wall thickness, and circumferential opening angle increased with aging, while longitudinal pre-stretch decreased ([Formula: see text]). Age-group-specific constitutive parameters portrayed orthotropic FPA stiffening, especially in the longitudinal direction. Structural changes in artery wall elastin were associated with reduction of physiologic longitudinal and circumferential stretches and stresses with age. These data and the constitutive description of FPA aging shed new light on our understanding of peripheral arterial disease pathophysiology and arterial aging. Application of this knowledge might improve patient selection for specific treatment modalities in personalized, precision medicine algorithms and could assist in device development for treatment of peripheral artery disease.

  12. Innervation of the human middle meningeal artery

    DEFF Research Database (Denmark)

    Edvinsson, L; Gulbenkian, S; Barroso, C P

    1998-01-01

    The majority of nerve fibers in the middle meningeal artery and branching arterioles are sympathetic, storing norepinephrine and neuropeptide Y (NPY). A sparse supply of fibers contain acetylcholinesterase activity and immunoreactivity toward vasoactive intestinal peptide (VIP), peptidine histidine...... methionine (PHM), and calcitonin gene-related peptide (CGRP). Only few substance P and neuropeptide K immunoreactive fibers are noted. Electronmicroscopy shows axons and terminals at the adventitial medial border of the human middle meningeal artery, with a fairly large distance to the smooth muscle cells...

  13. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    DEFF Research Database (Denmark)

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...... system. The measurements were carried out during hyperventilation and with the subject breathing atmospheric air containing 5 vol. % and 7 vol. % carbon dioxide. Intracellular pH increased significantly during 15 min of hyper-ventilation and decreased significantly during 18 min respiration of air...

  14. Passive biaxial mechanical response of aged human iliac arteries.

    Science.gov (United States)

    Schulze-Bauer, Christian A J; Mörth, Christian; Holzapfel, Gerhard A

    2003-06-01

    Inflation and extension tests of arteries are essential for the understanding of arterial wall mechanics. Data for such tests of human arteries are rare. At autopsy we harvested 10 non-diseased external iliac arteries of aged subjects (52-87 yrs). Structural homogeneity was ensured by means of ultrasound imaging, and anamneses of patients were recorded. We measured the axial in situ stretches, load-free geometries and opening angles. Passive biaxial mechanical responses of preconditioned cylindrical specimens were studied in 37 degrees C calcium-free Tyrode solution under quasistatic loading conditions. Specimens were subjected to pressure cycles varying from 0 to 33.3 kPa (250 mmHg) at nine fixed axial loads, varying from 0 to 9.90N. For the description of the load-deformation behavior we employed five "two-dimensional" orthotropic strain-energy functions frequently used in arterial wall mechanics. The associated constitutive models were compared in regard to their ability of representing the experimental data. Histology showed that the arteries were of the muscular type. In contrast to animal arteries they exhibited intimal layers of considerable thickness. The average ratio of wall thickness to outer diameter was 7.7, which is much less than observed for common animal arteries. We found a clear correlation between age and the axial in situ stretch lambda is (r = -0.72, P = 0.03), and between age and distensibility of specimens, i.e. aged specimens are less distensible. Axial in situ stretches were clearly smaller (1.07 +/- 0.09, mean +/- SD) than in animal arteries. For one specimen lambda is was even smaller than 1.0, i.e. the vessel elongated axially upon excision. The nonlinear and anisotropic load-deformation behavior showed small hystereses. For the majority of specimens we observed axial stretches smaller than 1.3 and circumferential stretches smaller than 1.1 for the investigated loading range. Data from in situ inflation tests showed a significant

  15. Effect of SR manipulation on conduit artery dilation in humans.

    Science.gov (United States)

    Carter, Howard H; Dawson, Ellen A; Birk, Gurpreet K; Spence, Angela L; Naylor, Louise H; Cable, N Timothy; Thijssen, Dick H J; Green, Daniel J

    2013-01-01

    The impact of manipulating shear stress on conduit artery vasodilation has not been comprehensively described in vivo. We hypothesized that manipulation of SR through the brachial and radial arteries would be associated with corresponding changes in diameter. We performed a series of studies involving the following: (1) leg cycle exercise at increasing intensities (≈70 and 85% maximum heart rate [HRmax]) with simultaneous bilateral measurement of SR in the radial arteries; (2) leg cycle exercise for 30 minutes at 80% HRmax with simultaneous bilateral measurement of velocity and diameter in the brachial arteries; and (3) bilateral forearm heating for 30 minutes with simultaneous bilateral measurement of brachial artery diameter and blood velocity. Cycling and forearm heating interventions were performed in the presence of unilateral cuff inflation throughout the experiment, or starting during the intervention (15 minutes), to manipulate SR responses. Cuff placement was associated with lower radial artery SR responses (cuffed versus uncuffed, 248±49 versus 349±105 L/s 85% HRmax; P<0.01), and diameter responses were similarly attenuated (2.45±0.30 versus 2.78±0.20 mm 85% HRmax; P<0.05). Exercise performed at 80% HRmax in the presence of unilateral cuff inflation also reduced brachial artery SR (cuffed versus uncuffed; 258±107 versus 454±157 L/s; P<0.01) and diameter (3.96±0.39 versus 4.20±0.45 mm). Finally, cuff inflation decreased the impact of forearm heating on brachial SR (cuffed versus uncuffed; 262±97 versus 440±106 L/s; P<0.01) and diameter (4.35±0.54 versus 4.87±0.47 mm; P<0.05). Similar significant differences between the cuffed and uncuffed limbs in SR and diameter were observed when cuff inflation occurred during exercise or heating. Our findings strongly implicate SR as an important stimulus to increase conduit artery diameter in humans.

  16. Heterogeneity in conduit artery function in humans: impact of arterial size.

    Science.gov (United States)

    Thijssen, Dick H J; Dawson, Ellen A; Black, Mark A; Hopman, Maria T E; Cable, N Timothy; Green, Daniel J

    2008-11-01

    To determine whether conduit artery size affects functional responses, we compared the magnitude, time course, and eliciting shear rate stimulus for flow-mediated dilation (FMD) in healthy men (n = 20; 31 +/- 7 yr). Upper limb (brachial and radial) and lower limb (common and superficial femoral) FMD responses were simultaneously assessed, whereas popliteal responses were measured in the same subjects during a separate visit. Glyceryl trinitrate (GTN)-mediated responses were similarly examined. Edge detection and wall tracking of high-resolution B-mode arterial ultrasound images, combined with synchronized Doppler waveform envelope analysis, were used to calculate conduit artery diameter, blood flow, and shear rate continuously across the cardiac cycle. Baseline artery size correlated inversely with the FMD response (r = -0.57, P < 0.001). Within-artery comparisons revealed a significant inverse correlation between artery size and FMD% for the radial (r = -0.66, P = 0.001), brachial (r = -0.55, P = 0.01), and popliteal artery (r = -0.48, P = 0.03), but not for the superficial and common femoral artery. Normalization of FMD responses for differences in eliciting shear rate did not abolish the between-artery relationship for artery function and size (r = -0.48, P < 0.001), suggesting that differences between artery function responses were not entirely due to size-related differences in shear rate. This was reinforced by a significant between-artery correlation for GTN responses and baseline artery size (r = -0.74, P < 0.001). In summary, systematic differences exist in vascular function responses of conduit arteries that differ in size. This raises the possibility that differences in artery size within or between individuals may influence functional responses.

  17. Relationship between upper and lower limb conduit artery vasodilator function in humans.

    Science.gov (United States)

    Thijssen, Dick H J; Rowley, Nicola; Padilla, Jaume; Simmons, Grant H; Laughlin, M Harold; Whyte, Greg; Cable, N Timothy; Green, Daniel J

    2011-07-01

    Brachial artery flow-mediated dilation (FMD) is a strong predictor of future cardiovascular disease and is believed to represent a "barometer" of systemic endothelial health. Although a recent study [Padilla et al. Exp Biol Med (Maywood) 235: 1287-1291, 2010] in pigs confirmed a strong correlation between brachial and femoral artery endothelial function, it is unclear to what extent brachial artery FMD represents a systemic index of endothelial function in humans. We conducted a retrospective analysis of data from our laboratory to evaluate relationships between the upper (i.e., brachial artery) vs. lower limb (superficial femoral n = 75; popliteal artery n = 32) endothelium-dependent FMD and endothelium-independent glyceryl trinitrate (GTN)-mediated dilation in young, healthy individuals. We also examined the relationship between FMD assessed in both brachial arteries (n = 42). There was no correlation between brachial and superficial femoral artery FMD (r(2) = 0.008; P = 0.46) or between brachial and popliteal artery FMD (r(2) = 0.003; P = 0.78). However, a correlation was observed in FMD between both brachial arteries (r(2) = 0.34; P < 0.001). Brachial and superficial femoral artery GTN were modestly correlated (r(2) = 0.13; P = 0.007), but brachial and popliteal artery GTN responses were not (r(2) = 0.08; P = 0.11). Collectively, these data indicate that conduit artery vasodilator function in the upper limbs (of healthy humans) is not predictive of that in the lower limbs, whereas measurement of FMD in one arm appears to be predictive of FMD in the other. These data do not support the hypothesis that brachial artery FMD in healthy humans represents a systemic index of endothelial function.

  18. Morphologic expression of the left coronary artery in pigs. An approach in relation to human heart

    Directory of Open Access Journals (Sweden)

    Fabian Alejandro Gómez

    2014-04-01

    Full Text Available Introduction: In spite of its importance as an experimental model, the information on the left coronary artery in pigs is sparse. Objective: To determine the morphologic features of the left coronary artery in pigs. Methods: We evaluated 158 pig hearts. The left coronary artery was perfused with synthetic resin after their ostia had been catheterized. Diameters and courses of the vascular beds were measured with an electronic caliper (Mitutoyo(r. Results: The diameter of left coronary artery was 6.98 ± 1.56 mm and its length was 3.51±0.99 mm. It was found to end up by bifurcating itself into the anterior interventricular artery and the circumflex artery in 79% of the cases, and by trifurcating in 21% of the cases, with the presence of the diagonal artery. The anterior interventricular artery ended up at the apex in 79.7% of the cases, and the circumflex artery at the posterior aspect of the left ventricle in 64% of the case, this artery never reached the posterior interventricular sulcus. An anastomosis between the terminal branches of the anterior interventricular artery and the posterior interventricular artery was found in 7.6% of the specimens. The antero-superior branch of the anterior interventricular artery occurred in 89.9% of the hearts. A left marginal branch was observed in 87.9% of the cases with a diameter of 2.25±0.55 mm. Conclusion: Compared with humans, pigs have shorter left coronary artery trunks and branches; even the circumflex artery never reaches the posterior interventricular sulcus. Our findings are useful for the design of experimental hemodynamic and procedural models.

  19. Multiresolution Approach for Noncontact Measurements of Arterial Pulse Using Thermal Imaging

    Science.gov (United States)

    Chekmenev, Sergey Y.; Farag, Aly A.; Miller, William M.; Essock, Edward A.; Bhatnagar, Aruni

    This chapter presents a novel computer vision methodology for noncontact and nonintrusive measurements of arterial pulse. This is the only investigation that links the knowledge of human physiology and anatomy, advances in thermal infrared (IR) imaging and computer vision to produce noncontact and nonintrusive measurements of the arterial pulse in both time and frequency domains. The proposed approach has a physical and physiological basis and as such is of a fundamental nature. A thermal IR camera was used to capture the heat pattern from superficial arteries, and a blood vessel model was proposed to describe the pulsatile nature of the blood flow. A multiresolution wavelet-based signal analysis approach was applied to extract the arterial pulse waveform, which lends itself to various physiological measurements. We validated our results using a traditional contact vital signs monitor as a ground truth. Eight people of different age, race and gender have been tested in our study consistent with Health Insurance Portability and Accountability Act (HIPAA) regulations and internal review board approval. The resultant arterial pulse waveforms exactly matched the ground truth oximetry readings. The essence of our approach is the automatic detection of region of measurement (ROM) of the arterial pulse, from which the arterial pulse waveform is extracted. To the best of our knowledge, the correspondence between noncontact thermal IR imaging-based measurements of the arterial pulse in the time domain and traditional contact approaches has never been reported in the literature.

  20. Experience With Intravascular Ultrasound Imaging Of Human Atherosclerotic Arteries

    Science.gov (United States)

    Mallery, John A.; Gessert, James M.; Maciel, Mario; Tobis, John M.; Griffith, James M.; Berns, Michael W.; Henry, Walter L.

    1989-08-01

    Normal human arteries have a well-defined structure on intravascular images. The intima appears very thin and is most likely represented by a bright reflection arising from the internal elastic lamina. The smooth muscle tunica media is echo-lucent on the ultrasound image and appears as a dark band separating the intima from the adventitia. The adventitia is a brightly reflective layer of variable thickness. The thickness of the intima, and therefore of the atherosclerotic plaque can be accurately measured from the ultrasound images and correlates well with histology. Calcification within the wall of arteries is seen as bright echo reflection with shadowing of the peripheral wall. Fibrotic regions are highly reflective but do not shadow. Necrotic liquid regions within advanced atherosclerotic plaques are seen on ultrasound images as large lucent zones surrounded by echogenic tissue. Imaging can be performed before and after interventional procedures, such as laser angioplasty, balloon angioplasty and atherectomy. Intravascular ultrasound appears to provide an imaging modality for identifying the histologic characteristics of diseased arteries and for quantifying plaque thickness. It might be possible to perform such quantification to evaluate the results of interventional procedures.

  1. Harmonic skeleton guided evaluation of stenoses in human coronary arteries.

    Science.gov (United States)

    Yang, Yan; Zhu, Lei; Haker, Steven; Tannenbaum, Allen R; Giddens, Don P

    2005-01-01

    This paper presents a novel approach that three-dimensionally visualizes and evaluates stenoses in human coronary arteries by using harmonic skeletons. A harmonic skeleton is the center line of a multi-branched tubular surface extracted based on a harmonic function, which is the solution of the Laplace equation. This skeletonization method guarantees smoothness and connectivity and provides a fast and straightforward way to calculate local cross-sectional areas of the arteries, and thus provides the possibility to localize and evaluate coronary artery stenosis, which is a commonly seen pathology in coronary artery disease.

  2. Computational modeling of hypertensive growth in the human carotid artery

    Science.gov (United States)

    Sáez, Pablo; Peña, Estefania; Martínez, Miguel Angel; Kuhl, Ellen

    2014-06-01

    Arterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively.

  3. Temperature measurement methods during direct heat arterial tissue fusion.

    Science.gov (United States)

    Cezo, James D; Kramer, Eric; Taylor, Kenneth D; Ferguson, Virginia; Rentschler, Mark E

    2013-09-01

    Fusion of biological tissues through direct and indirect heating is a growing area of medical research, yet there are still major gaps in understanding this procedure. Several companies have developed devices which fuse blood vessels, but little is known about the tissue's response to the stimuli. The need for accurate measurements of tissue behavior during tissue fusion is essential for the continued development and improvement of energy delivery devices. An experimental study was performed to measure the temperatures experienced during tissue fusion and the resulting burst pressure of the fused arteries. An array of thermocouples was placed in the lumen of a porcine splenic artery segment and sealed using a ConMed Altrus thermal fusion device. The temperatures within the tissue, in the device, and at the tissue-device interface were recorded. These measurements were then analyzed to calculate the temperature profile in the lumen of the artery. The temperature in the artery at the site of tissue fusion was measured to range from 142 to 163 °C using the ConMed Altrus. The corresponding burst pressure for arteries fused at this temperature was measured as 416 ± 79 mmHg. This study represents the first known experimental measurement of temperature at the site of vessel sealing found in the literature.

  4. Reduced arterial diameter during static exercise in humans

    DEFF Research Database (Denmark)

    Olesen, H L; Mitchell, J H; Friedman, D B

    1995-01-01

    exertion was approximately 15 units after both types of exercise. The dorsalis pedis arterial diameter was 1.50 +/- 0.20 mm (mean and SE) and the radial AD 2.45 +/- 0.12 mm. During both types of contractions the luminal diameters decreased approximately 3.5% within the first 30 s (P ...In eight subjects luminal diameter of the resting limb radial and dorsalis pedis arteries was determined by high-resolution ultrasound (20 MHz). This measurement was followed during rest and during 2 min of static handgrip or of one-leg knee extension at 30% of maximal voluntary contraction...... of another limb. Static exercise increased heart rate and mean arterial pressure, which were largest during one-leg knee extension. After exercise heart rate and mean arterial pressure returned to the resting level. No changes were recorded in arterial carbon dioxide tension, and the rate of perceived...

  5. Femoral artery pressure measurement to predict the outcome of arterial surgery in patients with multilevel disease

    DEFF Research Database (Denmark)

    Faris, I; Tønnesen, K H; Agerskov, K

    1982-01-01

    Direct measurement of the femoral artery pressure before operation has been used to predict the postoperative change in ankle and toe pressure in 102 limbs (83 patients) that underwent aortoiliac surgery for the treatment of atherosclerotic occlusion or stenosis affecting both the aortoiliac...... 25 mm Hg was associated with a high probability that amputation would be required. The chances of an amputation were less than 3% if a toe pressure higher than 40 mm Hg was predicted. If the predicted ankle pressure index was lower than 0.56, there was a 90% chance that intermittent claudication...... would persist. Measurement of the femoral artery pressure allows prediction of the toe and ankle pressure response to surgery to be made with sufficient accuracy to permit a preoperative decision to be made between the need for a single-level or a two-level arterial reconstruction: no patients who had...

  6. Hemorheological abnormalities in human arterial hypertension

    Science.gov (United States)

    Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

    2014-05-01

    Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

  7. Impact of age and sex on carotid and peripheral arterial wall thickness in humans.

    Science.gov (United States)

    van den Munckhof, I; Scholten, R; Cable, N T; Hopman, M T E; Green, D J; Thijssen, D H J

    2012-12-01

    Although previous studies have reported age-related wall thickening in carotid arteries, it is not clear whether this is a systemic phenomenon which is also apparent in peripheral conduit arteries or whether conduit wall thickness (WT) changes occur to a similar degree in men and women. To determine whether sex modifies the impact of ageing on WT or wall-to-lumen ratio (W:L) in atherosclerosis-prone (i.e. carotid artery, femoral, superficial femoral, popliteal artery) and atherosclerosis-resistant (i.e. brachial artery) conduit arteries. We included 30 young (23 ± 2 year; 15M : 15F) and 31 older (70 ± 5 year; 18M : 13F) healthy subjects. High-resolution ultrasound was used to measure diameter, WT and wall-to-lumen ratio (W/L) in all arteries. Older subjects had increased WT and W/L in the carotid, femoral, superficial femoral, popliteal and brachial arteries (all P < 0.05). Compared with women, men demonstrated larger diameter and WT (both P < 0.01) across all arteries. Sex did not impact upon age-related changes in WT or W/L (P = 0.39 and 0.43 respectively). Our data suggest that age-related wall thickening, evident in the carotid artery, is also apparent in the arteries of the upper and lower limbs. The impact of age on wall thickening did not differ between men and women. These data support the presence of systemic increases in WT and W/L with age in apparently healthy humans, independent of sex. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society.

  8. Arterial pressure measurement: Is the envelope curve of the oscillometric method influenced by arterial stiffness?

    Energy Technology Data Exchange (ETDEWEB)

    Gelido, G [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Angiletta, S [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Pujalte, A [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Quiroga, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Cornes, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Craiem, D [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina)

    2007-11-15

    Measurement of peripheral arterial pressure using the oscillometric method is commonly used by professionals as well as by patients in their homes. This non invasive automatic method is fast, efficient and the required equipment is affordable with a low cost. The measurement method consists of obtaining parameters from a calibrated decreasing curve that is modulated by heart beats witch appear when arterial pressure reaches the cuff pressure. Diastolic, mean and systolic pressures are obtained calculating particular instants from the heart beats envelope curve. In this article we analyze the envelope of this amplified curve to find out if its morphology is related to arterial stiffness in patients. We found, in 33 volunteers, that the envelope waveform width correlates to systolic pressure (r=0.4, p<0.05), to pulse pressure (r=0.6, p<0.05) and to pulse pressure normalized to systolic pressure (r=0.6, p<0.05). We believe that the morphology of the heart beats envelope curve obtained with the oscillometric method for peripheral pressure measurement depends on arterial stiffness and can be used to enhance pressure measurements.

  9. Haemodynamic assessment of human coronary arteries is affected by degree of freedom of artery movement.

    Science.gov (United States)

    Javadzadegan, Ashkan; Yong, Andy S C; Chang, Michael; Ng, Martin K C; Behnia, Masud; Kritharides, Leonard

    2017-02-01

    Abnormal haemodynamic parameters are associated with atheroma plaque progression and instability in coronary arteries. Flow recirculation, shear stress and pressure gradient are understood to be important pathogenic mediators in coronary disease. The effect of freedom of coronary artery movement on these parameters is still unknown. Fluid-structure interaction (FSI) simulations were carried out in 25 coronary artery models derived from authentic human coronaries in order to investigate the effect of degree of freedom of movement of the coronary arteries on flow recirculation, wall shear stress (WSS) and wall pressure gradient (WPG). Each FSI model had distinctive supports placed upon it. The quantitative and qualitative differences in flow recirculation, maximum wall shear stress (MWSS), areas of low wall shear stress (ALWSS) and maximum wall pressure gradient (MWPG) for each model were determined. The results showed that greater freedom of movement was associated with lower MWSS, smaller ALWSS, smaller flow recirculation zones and lower MWPG. With increasing percentage diameter stenosis (%DS), the effect of degree of freedom on flow recirculation and WSS diminished. Freedom of movement is an important variable to be considered for computational modelling of human coronary arteries, especially in the setting of mild to moderate stenosis. 3D: Three-dimensional; 3DR: Three-dimensional Reconstruction; 3D-QCA: Three-dimensional quantitative coronary angiography; ALWSS: Areas of low wall shear stress; CAD: Coronary artery disease; CFD: Computational fluid dynamics; %DS: Diameter stenosis percentage; EPCS: End point of counter-rotating streamlines; FSI: Fluid-structure interaction; IVUS: Intravascular ultrasound; LAD: Left anterior descending; MWSS: Maximum wall shear stress; SST: Shear stress transport; TAWSS: Time-averaged wall shear stress; WSS: wall shear stress; WPG: Wall pressure gradient; MWPG: Maximum wall pressure gradient; FFR: Fractional flow reserve; i

  10. Reconstruction of brachial artery pressure from noninvasive finger pressure measurements

    NARCIS (Netherlands)

    Bos, W. J.; van Goudoever, J.; van Montfrans, G. A.; van den Meiracker, A. H.; Wesseling, K. H.

    1996-01-01

    Pulse wave distortions, mainly caused by reflections, and pressure gradients, caused by flow in the resistive vascular tree, may cause differences between finger and brachial artery pressures. These differences may limit the use of finger pressure measurements. We investigated whether brachial

  11. Constitutive modelling of an arterial wall supported by microscopic measurements

    Directory of Open Access Journals (Sweden)

    Vychytil J.

    2012-06-01

    Full Text Available An idealized model of an arterial wall is proposed as a two-layer system. Distinct mechanical response of each layer is taken into account considering two types of strain energy functions in the hyperelasticity framework. The outer layer, considered as a fibre-reinforced composite, is modelled using the structural model of Holzapfel. The inner layer, on the other hand, is represented by a two-scale model mimicing smooth muscle tissue. For this model, material parameters such as shape, volume fraction and orientation of smooth muscle cells are determined using the microscopic measurements. The resulting model of an arterial ring is stretched axially and loaded with inner pressure to simulate the mechanical response of a porcine arterial segment during inflation and axial stretching. Good agreement of the model prediction with experimental data is promising for further progress.

  12. In vivo transfer of lipoprotein(a) into human atherosclerotic carotid arterial intima

    DEFF Research Database (Denmark)

    Nielsen, Lars Bo; Grønholdt, Marie-Louise; Schroeder, T V

    1997-01-01

    The aim of this study was to compare the atherogenic potential of lipoprotein(a) [Lp(a)] and LDL by measuring the intimal clearance of these two plasma lipoproteins in the atherosclerotic intima of the human carotid artery in vivo. Autologous 131I-Lp(a) and 125I-LDL were mixed and reinjected intr...

  13. Developing Human Performance Measures

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Joe; Bruce Hallbert; Larry Blackwood; Donald Dudehoeffer; Kent Hansen

    2006-05-01

    Through the reactor oversight process (ROP), the U.S. Nuclear Regulatory Commission (NRC) monitors the performance of utilities licensed to operate nuclear power plants. The process is designed to assure public health and safety by providing reasonable assurance that licensees are meeting the cornerstones of safety and designated crosscutting elements. The reactor inspection program, together with performance indicators (PIs), and enforcement activities form the basis for the NRC’s risk-informed, performance based regulatory framework. While human performance is a key component in the safe operation of nuclear power plants and is a designated cross-cutting element of the ROP, there is currently no direct inspection or performance indicator for assessing human performance. Rather, when human performance is identified as a substantive cross cutting element in any 1 of 3 categories (resources, organizational or personnel), it is then evaluated for common themes to determine if follow-up actions are warranted. However, variability in human performance occurs from day to day, across activities that vary in complexity, and workgroups, contributing to the uncertainty in the outcomes of performance. While some variability in human performance may be random, much of the variability may be attributed to factors that are not currently assessed. There is a need to identify and assess aspects of human performance that relate to plant safety and to develop measures that can be used to successfully assure licensee performance and indicate when additional investigation may be required. This paper presents research that establishes a technical basis for developing human performance measures. In particular, we discuss: 1) how historical data already gives some indication of connection between human performance and overall plant performance, 2) how industry led efforts to measure and model human performance and organizational factors could serve as a data source and basis for a

  14. Radial artery cannulation decreases the distal arterial blood flow measured by power Doppler ultrasound.

    Science.gov (United States)

    Numaguchi, Atsushi; Adachi, Yushi U; Aoki, Yoshitaka; Ishii, Yasuhiro; Suzuki, Katsumi; Obata, Yukako; Sato, Shigehito; Nishiwaki, Kimitoshi; Matsuda, Naoyuki

    2015-10-01

    Radial arterial cannulation is a popular technique for continuous hemodynamic monitoring in an area of anesthesia and intensive care. Although the risk for invasive monitoring is considerable, there is scarce information about the change in blood flow of cannulated vessel after the catheterization. In the current investigation, we evaluated the change in the cannulated arterial blood flow. Six volunteers (study 1) and eight post-surgical patients (study 2) were enrolled into the studies. In the study 1, the both side of diameter of radial artery (RA), ulnar artery (UA) and dorsal branch of radial artery (DBRA) of participants were measured using power Doppler ultrasound (PDU) with or without proximal oppression. In the study 2, the diameter of RA, UA and DBRA of the both intact and cannulated side were compared. Study 1: The diameter of RA was 3.4 (0.52) [mean (SD)] mm and the proximal oppression significantly decreased the diameter to 1.8 (0.59) mm. The diameter of DBRA measured by PDU also decreased 2.0 (0.60)-1.3 (0.59) mm. Study 2: There was no difference between the diameters of right and left RA, however, the UA was larger [3.4 (0.60) vs. 2.8 (0.83) mm] and the DBRA was narrower [1.4 (0.43) vs. 2.0 (0.47) mm] in the cannulated side. The diameters of DBRA were different between the intact and cannulated side in the patients. Although there is no information of relationships between cause of severe complication and decreased flow, significant reduction of blood flow should be concerned.

  15. Continuous cardiac output measurement: arterial pressure analysis versus thermodilution technique during cardiac surgery with cardiopulmonary bypass

    NARCIS (Netherlands)

    Lorsomradee, S.; Lorsomradee, S. R.; Cromheecke, S.; de Hert, S. G.

    2007-01-01

    This study compared cardiac output measured with an arterial pressure-based cardiac output measurement system and a thermodilution cardiac output measurement system. We studied 36 patients undergoing cardiac surgery with cardiopulmonary bypass. Simultaneous arterial pressure-based and thermodilution

  16. Application of 1D blood flow models of the human arterial network to differential pressure predictions.

    Science.gov (United States)

    Johnson, David A; Rose, William C; Edwards, Jonathan W; Naik, Ulhas P; Beris, Antony N

    2011-03-15

    A new application of 1D models of the human arterial network is proposed. We take advantage of the sensitivity of the models predictions for the pressure profiles within the main aorta to key model parameter values. We propose to use the patterns in the predicted differences from a base case as a way to infer to the most probable changes in the parameter values. We demonstrate this application using an impedance model that we have recently developed (Johnson, 2010). The input model parameters are all physiologically related, such as the geometric dimensions of large arteries, various blood properties, vessel elasticity, etc. and can therefore be patient specific. As a base case, nominal values from the literature are used. The necessary information to characterize the smaller arteries, arterioles, and capillaries is taken from a physical scaling model (West, 1999). Model predictions for the effective impedance of the human arterial system closely agree with experimental data available in the literature. The predictions for the pressure wave development along the main arteries are also found in qualitative agreement with previous published results. The model has been further validated against our own measured pressure data in the carotid and radial arteries, obtained from healthy individuals. Upon changes in the value of key model parameters, we show that the differences seen in the pressure profiles correspond to qualitatively different patterns for different parameters. This suggests the possibility of using the model in interpreting multiple pressure data of healthy/diseased individuals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Potassium currents in cultured human pulmonary arterial smooth muscle cells.

    Science.gov (United States)

    Peng, W; Karwande, S V; Hoidal, J R; Farrukh, I S

    1996-04-01

    In this study, using whole cell and single-channel configurations of the patch-clamp technique, we characterized K+ currents (IK) in cultured human pulmonary arterial smooth muscle cells. The net whole cell outward membrane current (IKo) was activated at potentials positive to -60 mV. One component of IKo, IK(dr), was inhibited by 4-aminopyridine (4-AP) and high concentrations of tetraethylammonium (TEA) but was Ca2+ and charybdotoxin (CTX) insensitive. The other component of IKo, IK(Ca), was voltage and Ca2+ dependent and was inhibited by CTX and low concentrations of TEA. Activation of IKo in single-channel recordings was voltage dependent and demonstrated a high-conductance channel (245 +/- 2 pS) that was Ca2+ and CTX sensitive [IK(Ca)] and a low-conductance channel (109 +/- 2 pS) that was inhibited by 4-AP [IK(dr)] but was insensitive to low concentrations of TEA or to an increase in intracellular [Ca2+]. In isolated pulmonary arterial rings, TEA and 4-AP caused an additive increase in arterial tension. To our knowledge these data provide the first characterization of the IK in human pulmonary arterial smooth muscle cells and indicate that IK(Ca) and IK(dr) play an important role in maintaining pulmonary vascular tone. The data confirm previous observations in pulmonary smooth muscle cells of animal models.

  18. K ATP channels in pig and human intracranial arteries

    DEFF Research Database (Denmark)

    Ploug, Kenneth Beri; Sørensen, Mette Aaskov; Strøbech, Lotte

    2008-01-01

    Clinical trials suggest that synthetic ATP-sensitive K(+) (K(ATP)) channel openers may cause headache and migraine by dilating cerebral and meningeal arteries. We studied the mRNA expression profile of K(ATP) channel subunits in the pig and human middle meningeal artery (MMA) and in the pig middle...... cerebral artery (MCA). We determined the order of potency of four K(ATP) channel openers when applied to isolated pig MMA and MCA, and we examined the potential inhibitory effects of the Kir6.1 subunit specific K(ATP) channel blocker PNU-37883A on K(ATP) channel opener-induced relaxation of the isolated...... pig MMA and MCA. Using conventional RT-PCR, we detected the mRNA transcripts of the K(ATP) channel subunits Kir6.1 and SUR2B in all the examined pig and human intracranial arteries. Application of K(ATP) channel openers to isolated pig MMA and MCA in myographs caused a concentration...

  19. Monitoring Personalized Trait Using Oscillometric Arterial Blood Pressure Measurements

    OpenAIRE

    Young-Suk Shin

    2012-01-01

    The blood pressure patterns obtained from a linearly or stepwise deflating cuff exhibit personalized traits, such as fairly uniform peak patterns and regular beat geometry; it can support the diagnosis and monitoring of hypertensive patients with reduced sensitivity to fluctuations in Blood Pressure (BP) over time. Monitoring of personalized trait in Oscillometric Arterial Blood Pressure Measurements (OABPM) uses the Linear Discriminant Analysis (LDA) algorithm. The representation of personal...

  20. Arterial Disease in Patients With Human Immunodeficiency Virus Infection

    OpenAIRE

    Stein, James H.; Currier, Judith S.; HSUE, Priscilla Y

    2014-01-01

    With advances in antiretroviral therapy, individuals with human immunodeficiency virus (HIV) infection are living longer and increasingly die of non-HIV related diseases such as cardiovascular disease (CVD). Several observational studies suggest that HIV-infected patients on ART are at increased CVD risk; however, the precise mechanisms underlying the association between HIV infection and CVD risk are uncertain. Atherosclerosis and arterial disease in HIV-infected individuals is a multifactor...

  1. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  2. Large-scale simulation of the human arterial tree.

    Science.gov (United States)

    Grinberg, L; Anor, T; Madsen, J R; Yakhot, A; Karniadakis, G E

    2009-02-01

    1. Full-scale simulations of the virtual physiological human (VPH) will require significant advances in modelling, multiscale mathematics, scientific computing and further advances in medical imaging. Herein, we review some of the main issues that need to be resolved in order to make three-dimensional (3D) simulations of blood flow in the human arterial tree feasible in the near future. 2. A straightforward approach is computationally prohibitive even on the emerging petaflop supercomputers, so a three-level hierarchical approach based on vessel size is required, consisting of: (i) a macrovascular network (MaN); (ii) a mesovascular network (MeN); and (iii) a microvascular network (MiN). We present recent simulations of MaN obtained by solving the 3D Navier-Stokes equations on arterial networks with tens of arteries and bifurcations and accounting for the neglected dynamics through proper boundary conditions. 3. A multiscale simulation coupling MaN-MeN-MiN and running on hundreds of thousands of processors on petaflop computers will require no more than a few CPU hours per cardiac cycle within the next 5 years. The rapidly growing capacity of supercomputing centres opens up the possibility of simulation studies of cardiovascular diseases, drug delivery, perfusion in the brain and other pathologies.

  3. Energy harvesting from arterial blood pressure for powering embedded micro sensors in human brain

    Science.gov (United States)

    Nanda, Aditya; Karami, M. Amin

    2017-03-01

    This manuscript investigates energy harvesting from arterial blood pressure via the piezoelectric effect for the purpose of powering embedded micro-sensors in the human brain. One of the major hurdles in recording and measuring electrical data in the human nervous system is the lack of implantable and long term interfaces that record neural activity for extended periods of time. Recently, some authors have proposed micro sensors implanted deep in the brain that measure local electrical and physiological data which are then communicated to an external interrogator. This paper proposes a way of powering such interfaces. The geometry of the proposed harvester consists of a piezoelectric, circular, curved bimorph that fits into the blood vessel (specifically, the Carotid artery) and undergoes bending motion because of blood pressure variation. In addition, the harvester thickness is constrained such that it does not modify arterial wall dynamics. This transforms the problem into a known strain problem and the integral form of Gauss's law is used to obtain an equation relating arterial wall motion to the induced voltage. The theoretical model is validated by means of a Multiphysics 3D-FEA simulation comparing the harvested power at different load resistances. The peak harvested power achieved for the Carotid artery (proximal to Brain), with PZT-5H, was 11.7 μW. The peak power for the Aorta was 203.4 μW. Further, the variation of harvested power with variation in the harvester width and thickness, arterial contractility, and pulse rate is investigated. Moreover, potential application of the harvester as a chronic, implantable and real-time Blood pressure sensor is considered. Energy harvested via this mechanism will also have applications in long-term, implantable Brain Micro-stimulation.

  4. Pial artery and subarachnoid width response to apnoea in normal humans.

    Science.gov (United States)

    Wszedybyl-Winklewska, Magdalena; Wolf, Jacek; Swierblewska, Ewa; Kunicka, Katarzyna; Gruszecki, Marcin; Guminski, Wojciech; Winklewski, Pawel J; Frydrychowski, Andrzej F; Bieniaszewski, Leszek; Narkiewicz, Krzysztof

    2015-09-01

    Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. We tested the complex response of the pial artery and subarachnoid width to apnoea using this method. The pial artery and subarachnoid width response to consecutive apnoeas lasting 30, 60 s and maximal breath-hold (91.1 ± 23.1 s) were studied in 20 healthy volunteers. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV), pulsatility index and resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR) and beat-to-beat SBP and DBP blood pressure were recorded using a Finometer; end-tidal CO2 (EtCO2) was measured using a medical gas analyser. Apnoea evoked a multiphasic response in blood pressure, pial artery compliance and ICP. First, SBP declined, which was accompanied by an increase in cc-TQ and sas-TQ. Directly after these changes, SBP exceeded baseline values, which was followed by a decline in cc-TQ and the return of sas-TQ to baseline. During these initial changes, CBFV remained stable. Towards the end of the apnoea, BP, cc-TQ and CBFV increased, whereas pulsatility index, resistive index and sas-TQ declined. Changes in sas-TQ were linked to changes in EtCO2, HR and SBP. Apnoea is associated with ICP swings, closely reflecting changes in EtCO2, HR and peripheral BP. The baroreflex influences the pial artery response.

  5. Monitoring Personalized Trait Using Oscillometric Arterial Blood Pressure Measurements

    Directory of Open Access Journals (Sweden)

    Young-Suk Shin

    2012-01-01

    Full Text Available The blood pressure patterns obtained from a linearly or stepwise deflating cuff exhibit personalized traits, such as fairly uniform peak patterns and regular beat geometry; it can support the diagnosis and monitoring of hypertensive patients with reduced sensitivity to fluctuations in Blood Pressure (BP over time. Monitoring of personalized trait in Oscillometric Arterial Blood Pressure Measurements (OABPM uses the Linear Discriminant Analysis (LDA algorithm. The representation of personalized traits with features from the oscillometric waveforms using LDA algorithm includes four phases. Data collection consists of blood pressure data using auscultatory measurements and pressure oscillations data obtained from the oscillometric method. Preprocessing involves the normalization of various sized oscillometric waveforms to a uniform size. Feature extraction involves the use of features from oscillometric amplitudes, and trait identification involves the use of the LDA algorithm. In this paper, it presents a novel OABPM-based blood pressure monitoring system that can monitor personalized blood pressure pattern. Our approach can reduce sensitivity to fluctuations in blood pressure with the features extracted from the whole area in oscillometric arterial blood pressure measurement. Therefore this technique offers reliable blood pressure patterns. This study provides a cornerstone for the diagnosis and management of hypertension in the foreseeable future.

  6. Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses.

    Science.gov (United States)

    Dias, Deborah Penteado Martins; Teixeira, Luisa Gouvêa; Canola, Paulo Aléscio; Albernaz, Raquel Mincarelli; Marques, José Antônio; Neto, José Corrêa de Lacerda

    2012-06-01

    The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the facial artery can be kept patent by filling with a heparin/ascorbic acid solution and provide convenient invasive arterial access in horses which is suitable for use for serial blood sampling and blood pressure recordings, even during exercise on treadmill. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans.

    Science.gov (United States)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G; Stiekema, Lotte C A; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J; Nordestgaard, Børge G; Stroes, Erik S G; Kroon, Jeffrey

    2017-05-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). Arterial wall inflammation and bone marrow activity were measured using 18 F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels and hematopoietic activity was validated in the CGPS (Copenhagen General Population Study). We found a 1.2-fold increase of 18 F-FDG uptake in the arterial wall in patients with FD (n=17, age 60±8 years, remnant cholesterol: 3.26 [2.07-5.71]) compared with controls (n=17, age 61±8 years, remnant cholesterol 0.29 [0.27-0.40]; P cholesterol accumulates in human hematopoietic stem and progenitor cells coinciding with myeloid skewing. Patients with FD have increased arterial wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing to the increased cardiovascular disease risk in patients with FD. © 2017 American Heart Association, Inc.

  8. Relaxation of human isolated mesenteric arteries by vasopressin and desmopressin.

    Science.gov (United States)

    Martínez, M C; Vila, J M; Aldasoro, M; Medina, P; Flor, B; Lluch, S

    1994-01-01

    1. The effects of vasopressin and deamino-8-D-arginine vasopressin (DDAVP, desmopressin) were studied in artery rings (0.8-1 mm in external diameter) obtained from portions of human omentum during the course of abdominal operations (27 patients). 2. In arterial rings under resting tension, vasopressin produced concentration-dependent, endothelium-independent contractions with an EC50 of 0.59 +/- 0.12 nM. The V1 antagonist d(CH2)5Tyr(Me)AVP (1 microM) and the mixed V1-V2 antagonist desGly-d(CH2)5D-Tyr(Et)ValAVP (0.01 microM) displaced the control curve to vasopressin to the right in a parallel manner without differences in the maximal responses. In the presence of indomethacin (1 microM) the contractile response to vasopressin was significantly increased (P < 0.01). 3. In precontracted arterial rings, previously treated with the V1 antagonist, d(CH2)5Tyr(Me)AVP (1 microM), vasopressin produced endothelium-dependent relaxation. This relaxation was reduced significantly (P < 0.05) by indomethacin (1 microM) and unaffected by the V1-V2 receptor antagonist desGly-d(CH2)5D-Tyr(Et)ValAVP (1 microM) or by NG-nitro-L-arginine methyl ester (L-NAME, 0.1 mM). 4. The selective V2 receptor agonist, DDAVP, caused endothelium-independent, concentration-dependent relaxations in precontracted arterial rings that were inhibited by the mixed V1-V2 receptor antagonist, but not by the V1 receptor antagonist or by pretreatment with indomethacin or L-NAME. 5. Results from this study suggest that vasopressin is primarily a constrictor of human mesenteric arteries by V1 receptor stimulation; vasopressin causes dilatation only during V1 receptor blockade. The relaxation appears to be mediated by the release of vasodilator prostaglandins from the endothelial cell layer and is independent of V2 receptor stimulation or release of nitric oxide.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7834191

  9. Oscillometric blood pressure measurements: differences between measured and calculated mean arterial pressure.

    NARCIS (Netherlands)

    Kiers, H.D.; Hofstra, J.M.; Wetzels, J.F.M.

    2008-01-01

    Mean arterial pressure (MAP) is often used as an index of overall blood pressure. In recent years, the use of automated oscillometric blood pressure measurement devices is increasing. These devices directly measure and display MAP; however, MAP is often calculated from systolic blood pressure (SBP)

  10. Development of a tonometric sensor for measurement and recording of arterial pressure waveform

    Science.gov (United States)

    Tomczuk, K.; Werszko, M.; Sasiadek, J. Z.; Kosek, J.; Berny, W.; Weiser, A.; Feder-Kubis, J.

    2013-09-01

    There are many techniques and devices for measurement and recording of arterial blood pressure. Some of them allow (enable) additionally to observe the shape of a wave of arterial pressure, which can be regarded as one of the most important diagnostic parameters of human cardiovascular system. This paper presents a novel design and prototype of a new, non-invasive blood waveform measuring device. It expounds theoretical and experimental (including latest preliminary clinical) results obtained during several years of extensive investigations into blood pressure waveform measuring and monitoring problem. According to investigations performed in the laboratory and preliminary clinical evaluation, the sensor has linear steady-state characteristics and satisfactory dynamic properties. It is an efficient and accurate tool for blood pressure waveform monitoring and assessing the cardiovascular condition of the patients. The novelty of this solution is that the device is equipped with a pneumatic pressure sensor based on the pneumatic nozzle flapper amplifier principle with negative feedback. Due to such a technical solution, the device does not require any cuff, which remains an essential component of the majority of contemporary non-invasive blood pressure measurement devices; therefore, it can be used on the artery where the application of a cuff would be impossible (e.g., carotid artery). This advantage makes possible to obtain an accurate shape of blood pressure waveform with high fidelity, comparable to a direct measurement method. Moreover, during the measurement the device converts directly "pressure into pressure." Such a principle of operation makes possible to eliminate additional calibration (at the current stage of research we have eliminated the necessity of calibration in laboratory conditions).

  11. Constitutive modeling of human femoropopliteal artery biaxial stiffening due to aging and diabetes.

    Science.gov (United States)

    Desyatova, Anastasia; MacTaggart, Jason; Kamenskiy, Alexey

    2017-12-01

    Atherosclerotic obstructive disease of the femoropopliteal artery (Peripheral Arterial Disease, PAD) is notorious for high treatment failure rates. Older age and diabetes mellitus (DM) are among the major risk factors for PAD, and both are associated with increased arterial stiffness. Our goal was to develop a constitutive model describing multiaxial arterial stiffening, and use it to portray aging of normal and diabetic human femoropopliteal arteries (FPA). Fresh human FPAs (n=744) were obtained from 13-82-year-old donors. Arteries were tested using planar biaxial extension, and their behavior was modeled with a constitutive relation that included stiffening functions of age. FPA diameter, wall thickness, circumferential, and longitudinal opening angles increased with age, while longitudinal pre-stretch decreased. Diameter and circumferential opening angle did not change with age in subjects with DM. Younger FPAs were more compliant longitudinally but became more isotropic with age. Arteries with DM stiffened significantly faster in the circumferential direction than arteries without DM. Constitutive model accurately portrayed orthotropic stiffening with age of both normal and diabetic arteries. Constitutive description of FPA aging contributes to understanding of arterial pathophysiology and can help improve fidelity of computational models investigating device-artery interaction in PAD repair by providing more personalized arterial properties. We have analyzed n=744 human femoropopliteal artery (FPA) specimens using biaxial tensile testing to derive constitutive description of FPA aging in diabetic and non-diabetic subjects. The proposed model allows determination of FPA mechanical properties for subjects of any given age in the range of 13-82years. These results contribute to understanding of FPA pathophysiology and can help improve fidelity of computational models investigating device-artery interaction in peripheral arterial disease repair by providing more

  12. Sphingosine-1-Phosphate Signaling Regulates Myogenic Responsiveness in Human Resistance Arteries.

    Directory of Open Access Journals (Sweden)

    Sonya Hui

    Full Text Available We recently identified sphingosine-1-phosphate (S1P signaling and the cystic fibrosis transmembrane conductance regulator (CFTR as prominent regulators of myogenic responsiveness in rodent resistance arteries. However, since rodent models frequently exhibit limitations with respect to human applicability, translation is necessary to validate the relevance of this signaling network for clinical application. We therefore investigated the significance of these regulatory elements in human mesenteric and skeletal muscle resistance arteries. Mesenteric and skeletal muscle resistance arteries were isolated from patient tissue specimens collected during colonic or cardiac bypass surgery. Pressure myography assessments confirmed endothelial integrity, as well as stable phenylephrine and myogenic responses. Both human mesenteric and skeletal muscle resistance arteries (i express critical S1P signaling elements, (ii constrict in response to S1P and (iii lose myogenic responsiveness following S1P receptor antagonism (JTE013. However, while human mesenteric arteries express CFTR, human skeletal muscle resistance arteries do not express detectable levels of CFTR protein. Consequently, modulating CFTR activity enhances myogenic responsiveness only in human mesenteric resistance arteries. We conclude that human mesenteric and skeletal muscle resistance arteries are a reliable and consistent model for translational studies. We demonstrate that the core elements of an S1P-dependent signaling network translate to human mesenteric resistance arteries. Clear species and vascular bed variations are evident, reinforcing the critical need for further translational study.

  13. Comparison of ultrasonic Doppler flow monitor, oscillometric, and direct arterial blood pressure measurements in ill dogs.

    Science.gov (United States)

    Bosiack, Ann P; Mann, F A; Dodam, John R; Wagner-Mann, Colette C; Branson, Keith R

    2010-04-01

    To compare blood pressure measurements obtained via ultrasonic Doppler flow monitor (DOP) and 2 oscillometric noninvasive blood pressure monitors (CAR and PAS) to invasive blood pressure (IBP) in hospitalized, conscious dogs with a range of blood pressures. Prospective clinical study. University teaching hospital. Eleven client-owned dogs aged between 4 months and 11.5 years (median 6 y), and weighing between 5.8 and 37.5 kg (median 30.2 kg). Blood pressure measurement. Three consecutive measurements of systolic, diastolic, and mean arterial pressure (MAP) were recorded for each of the 3 indirect devices (only systolic for DOP), along with concurrent IBP measurements. The data were categorized into 3 groups: hypotensive (direct MAPor=100 mm Hg), and hypertensive (direct MAP>100 mm Hg). Each indirect method was compared with the corresponding direct arterial pressure using the Bland-Altman method. Within the hypotensive group, each indirect method overestimated the corresponding IBP. Within the normotensive group all indirect systolic measurements and the PAS diastolic measurements underestimated the corresponding IBP. The remaining indirect measurements overestimated the corresponding IBP. Within the hypertensive group, DOP and CAR systolic measurements underestimated the corresponding IBP, and the remaining indirect measurements overestimated the corresponding IBP. In hypertensive dogs oscillometric systolic measurements were more accurate than MAP. In hypotensive dogs MAP measurements were more accurate than systolic measurements. All indirect measurements were most accurate in hypertensive dogs. The noninvasive blood pressure monitors in our study did not meet the validation standards set in human medicine. However, CAR diastolic and MAP measurements within the normotensive group, CAR MAP measurements within the hypertensive group, and PAS diastolic measurements in all groups were close to these standards. All indirect measurements showed greater bias during

  14. Evaluation of vascular wall elasticity of human digital arteries using alternating current-signal photoplethysmography

    Directory of Open Access Journals (Sweden)

    Uangpairoj P

    2013-06-01

    Full Text Available Pichitra Uangpairoj, Masahiro Shibata Department of Bioscience and Engineering, Shibaura Institute of Technology, Saitama, Japan Purpose: A simple method of estimating arterial elasticity in the human finger using a volume-oscillometric technique with photoplethysmography was principally studied under the various effects of age, sex, and cold-stress stimulation for testing the capability of using this technique in arterial elasticity analysis. Methods: Amplitude variations in the alternating current signal of the photoplethysmograph during a continuous change in transmural pressure were analyzed to obtain the blood pressure and the transmural pressure–relative volume difference relationship of the arteries. We first tested the effect of the occluding cuff size on the arterial elasticity analysis in eight subjects (ages 20–45 years to obtain a suitable cuff size, resulting in the selection of a middle cuff with a 22 mm diameter. Blood pressure and arterial elasticity were measured in six groups of subjects separated into three age-groups of women and men (ages 20–25, 32–45, and over 50 years for testing the effect of age and sex. Twelve subjects (ages 20–25 years also had their blood pressure and arterial elasticity measured in three conditions under the influence of the cold-stress stimulation. Results: Age, sex, and cold-stress stimulation had an impact on mean blood pressure (P < 0.0005, 0.025, whereas pulse pressure and heart rate were statistically unchanged by those factors. Furthermore, an advanced age (over 50 years was found to induce an increase in relative volume difference values (P <0.025 and upward shifting of the transmural pressure–relative volume difference relationships, whereas sex, level of mean blood pressure, and cold-stress stimulation had no influence on these forms of the index. Conclusion: This study showed the usefulness of the relative volume difference as being a mean blood pressure-independent indicator

  15. Human Galectin-3 Promotes Trypanosoma cruzi Adhesion to Human Coronary Artery Smooth Muscle Cells

    OpenAIRE

    Kleshchenko, Yuliya Y.; Moody, Tapria N.; Furtak, Vyacheslav A.; Ochieng, Josiah; Lima, Maria F.; Villalta, Fernando

    2004-01-01

    Human galectin-3 binds to the surface of Trypanosoma cruzi trypomastigotes and human coronary artery smooth muscle (CASM) cells. CASM cells express galectin-3 on their surface and secrete it. Exogenous galectin-3 increased the binding of T. cruzi to CASM cells. Trypanosome binding to CASM cells was enhanced when either T. cruzi or CASM cells were preincubated with galectin-3. Cells stably transfected with galectin-3 antisense show a dramatic decrease in galectin-3 expression and very little T...

  16. Exercise-mediated changes in conduit artery wall thickness in humans: role of shear stress

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Dawson, E.A.; Munckhof, I.C. van den; Tinken, T.M.; Drijver, E. den; Hopkins, N.; Cable, N.T.; Green, D.J.

    2011-01-01

    Episodic increases in shear stress have been proposed as a mechanism that induces training-induced adaptation in arterial wall remodeling in humans. To address this hypothesis in humans, we examined bilateral brachial artery wall thickness using high-resolution ultrasound in healthy men across an

  17. MAPK signaling pathway regulates cerebrovascular receptor expression in human cerebral arteries

    DEFF Research Database (Denmark)

    Ansar, Saema; Eftekhari, Sajedeh; Waldsee, Roya

    2013-01-01

    if the upregulation of contractile cerebrovascular receptors after 48 h of organ culture of human cerebral arteries involves MAPK pathways and if it can be prevented by a MEK1/2 inhibitor. Human cerebral arteries were obtained from patients undergoing intracranial tumor surgery. The vessels were divided into ring...

  18. In vivo noninvasive method for measuring local wave velocity in femoral arteries of pig

    Science.gov (United States)

    Zhang, Xiaoming; Kinnick, Randall; Pislaru, Cristina; Fatemi, Mostafa; Greenleaf, James

    2005-09-01

    We have proposed generating a bending wave in the arterial wall using ultrasound radiation force and measuring the wave velocity along the arterial wall [Zhang et al., IEEE Trans. Ultrason. Ferroelectr. Freq. Control 52, 642-652 (2005)]. Here, we report the results of in vivo studies on pigs. The pig was anesthetized, and a micromanometer tip catheter was inserted into the femoral artery to measure luminal pressure. A water bath was created on the animal's groin to allow unimpeded access of the ultrasound beams to the femoral artery. The femoral artery was first located using a 13-MHz linear-array transducer. Then, a vibro-acoustography image was obtained to ensure precise positioning of the excitation force relative to the artery. The artery was excited by the force transducer and the resulting vibration of the arterial wall was measured by a sensing Doppler transceiver. Measured wave velocity was 3.1 m/s at 300 Hz. With this new method wave velocity over a distance of 5 mm, and therefore stiffness of arteries, can be measured locally and non-invasively. Measurement time is short in a few tens of milliseconds, which allows pressure dependence and pharmacological effect on the wall properties to be measured at different cardiac times.

  19. Activation of calpain-1 in human carotid artery atherosclerotic lesions

    Directory of Open Access Journals (Sweden)

    Pedro Luis M

    2009-06-01

    Full Text Available Abstract Background In a previous study, we observed that oxidized low-density lipoprotein-induced death of endothelial cells was calpain-1-dependent. The purpose of the present paper was to study the possible activation of calpain in human carotid plaques, and to compare calpain activity in the plaques from symptomatic patients with those obtained from patients without symptoms. Methods Human atherosclerotic carotid plaques (n = 29, 12 associated with symptoms were removed by endarterectomy. Calpain activity and apoptosis were detected by performing immunohistochemical analysis and TUNEL assay on human carotid plaque sections. An antibody specific for calpain-proteolyzed α-fodrin was used on western blots. Results We found that calpain was activated in all the plaques and calpain activity colocalized with apoptotic cell death. Our observation of autoproteolytic cleavage of the 80 kDa subunit of calpain-1 provided further evidence for enzyme activity in the plaque samples. When calpain activity was quantified, we found that plaques from symptomatic patients displayed significantly lower calpain activity compared with asymptomatic plaques. Conclusion These novel results suggest that calpain-1 is commonly active in carotid artery atherosclerotic plaques, and that calpain activity is colocalized with cell death and inversely associated with symptoms.

  20. Characterizing Methods of Measuring Flow-Mediated Dilation in the Brachial Artery

    Science.gov (United States)

    Callender, Ariane R.

    2010-01-01

    Regulation of vascular tone is one of the many important functions of the vascular endothelium. Endothelial dysfunction is a critical early event in the pathogenesis of atherosclerosis and occurs in the absence of angiographic disease. Flow-Mediated Dilation (FMD) is a noninvasive technique commonly used to evaluate endothelium-dependent vasodilation in humans and gauge the health of the cardiovascular system. Reductions in brachial artery FMD have been strongly correlated with disease progression and are predictive of future cardiac events. The flow stimulus for brachial artery FMD occurs as a result of the increased shear stress following deflation of an occlusion cuff around the upper arm. Using 2-dimensional ultrasound, changes in arterial diameter up to 5-minutes following cuff deflation are calculated from baseline image measurements. Along with pulsed Doppler measures of flow velocity through the artery, flow-mediated, endothelium-dependent vasodilation can be assessed. There is debate among investigators, however, about the proper positioning of the occlusion cuff during FMD testing. It is thought that placement of the cuff around the upper arm may not accurately reflect the impact of nitric oxide, a critically important molecule released as a result of the increased shear stress created by the FMD technique. Data suggest that the production of other endogenous metabolites may also contribute to FMD-related changes when positioning the cuff around the upper arm. To overcome the potential influence of such molecules, researchers now suggest that the occlusion cuff be placed below the elbow allowing a more precise estimate of nitric oxide mediated dilation. The purpose of this study is to compare the differences in FMD between the two methodologies of occlusion cuff placement. In addition, this study will determine the method that is easier for ultrasound technicians to perform and will produce a low coefficient of variance between technicians. Ultimately

  1. Endothelial shear stress: a critical determinant of arterial remodeling and arterial stiffness in humans--a carotid 3.0-T MRI study.

    NARCIS (Netherlands)

    Duivenvoorden, R.; Bavel, E. van; Groot, E. de; Stroes, E.S.; Disselhorst, J.A.; Hutten, B.A.; Lameris, J.S.; Kastelein, J.J.; Nederveen, A.J.

    2010-01-01

    BACKGROUND: Low endothelial shear stress (ESS) elicits endothelial dysfunction. However, the relationship between ESS and arterial remodeling and arterial stiffness is unknown in humans. We developed a 3.0-T MRI protocol to evaluate the contribution of ESS to arterial remodeling and stiffness.

  2. Evidence for a Role of Vascular Endothelium in the Control of Arterial Wall Viscosity in Humans.

    Science.gov (United States)

    Roca, Frederic; Iacob, Michele; Remy-Jouet, Isabelle; Bellien, Jeremy; Joannides, Robinson

    2018-01-01

    Arterial wall viscosity (AWV) is a major cause of energy dissipation along the arterial tree. Its determinants remain controversial but an active endothelial regulation has been suggested. Our objective was to assess in humans the physiological role of endothelium-derived nitric oxide (NO), epoxyeicosatrienoic acids and the effect of modulating smooth muscle tone in the regulation of AWV. We simultaneously measured radial artery diameter, wall thickness, and arterial pressure in healthy volunteers during the local infusion of inhibitors of NO-synthase ( N G -monomethyl-l-arginine), epoxyeicosatrienoic acids synthesis by cytochrome P450 (fluconazole), the epoxyeicosatrienoic acids cellular targets calcium-activated potassium channels (tetraethylammonium), alone and in combination. AWV was estimated from the relative viscosity expressed as the ratio of the area of the hysteresis loop of the pressure-diameter relationship to the area under the loading phase. Arterial tone was assessed by measuring change in wall stiffness and midwall stress. N G -monomethyl-l-arginine paradoxically reduced relative viscosity (34.9±8.9%-28.9±8.6%). Conversely, relative viscosity was not modified by fluconazole (33.5±15.5%-32.0±13.6%) but increased by tetraethylammonium (31.7±6.6%-35.7±8.0%). This increase was more marked with N G -monomethyl-l-arginine+fluconazole (31.1±10.7%-43.3±13.2%) and N G -monomethyl-l-arginine+tetraethylammonium (29.5±2.3%-41.5±11.1%) compared with inhibitors alone. Sodium nitroprusside decreased AWV (35.4±2.9%-28.7±2.0%). These effects were associated with parallel change in tone but of different magnitude for similar variations in viscosity, suggesting tone-dependent and independent mechanisms. In conclusion, this is the first demonstration that the endothelial factors, NO and epoxyeicosatrienoic acids, regulate AWV in humans and support the role of arterial tone in this regulation. URL: https://eudract.ema.europa.eu. Unique identifier: RCB2007-A

  3. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    Directory of Open Access Journals (Sweden)

    Komine Hidehiko

    2012-02-01

    Full Text Available Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API. We also measured brachial-ankle (baPWV PWV and carotid-femoral (cfPWV PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. Results The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV than stiff (high baPWV or cfPWV arteries. API was related to baPWV (r = -0.53, P r = -0.49, P r = 0.32, P Conclusions These results suggest that our method can simply and simultaneously evaluate arterial stiffness and blood pressure based on oscillometric measurements of blood pressure.

  4. Comparison of non-invasive blood pressure monitoring using modified arterial applanation tonometry with intra-arterial measurement.

    Science.gov (United States)

    Harju, Jarkko; Vehkaoja, Antti; Kumpulainen, Pekka; Campadello, Stefano; Lindroos, Ville; Yli-Hankala, Arvi; Oksala, Niku

    2018-02-01

    Intermittent non-invasive blood pressure measurement with tourniquets is slow, can cause nerve and skin damage, and interferes with other measurements. Invasive measurement cannot be safely used in all conditions. Modified arterial tonometry may be an alternative for fast and continuous measurement. Our aim was to compare arterial tonometry sensor (BPro®) with invasive blood pressure measurement to clarify whether it could be utilized in the postoperative setting. 28 patients who underwent elective surgery requiring arterial cannulation were analyzed. Patients were monitored post-operatively for 2 h with standard invasive monitoring and with a study device comprising an arterial tonometry sensor (BPro®) added with a three-dimensional accelerometer to investigate the potential impact of movement. Recordings were collected electronically. The results revealed inaccurate readings in method comparison between the devices based on recommendations by Association for the Advancement of Medical Instrumentation (AAMI). On a Bland-Altman plot, the bias and precision between these two methods was 19.8 ± 16.7 (Limits of agreement - 20.1 to 59.6) mmHg, Spearman correlation coefficient r = 0.61. For diastolic pressure, the difference was 4.8 ± 7.7 (LoA - 14.1 to 23.6) mmHg (r = 0.72), and for mean arterial pressure it was 11.18 ± 11.1 (LoA - 12.1 to 34.2) mmHg (r = 0.642). Our study revealed inaccurate agreement (AAMI) between the two methods when measuring systolic and mean blood pressures during post-operative care. The readings for diastolic pressures were inside the limits recommended by AAMI. Movement increased the failure rate significantly (p invasive blood pressure measurement in these patients.

  5. [The stimulation of human pulmonary artery endothelial cells by cigarette smoke extract contributed to cell senescence and induced human pulmonary artery smooth cell migration].

    Science.gov (United States)

    Cai, L; Zhu, P C; Wang, Y E; Gao, Y T; Ao, Q L

    2017-06-12

    Objective: To observe the senescent effect of human pulmonary arterial endothelial cells (HPAEC) stimulated by cigarette smoke extract (CSE) and the effect of secretion of senescent cells on human pulmonary arterial smooth muscles cell (HPASMC) proliferation and migration. Methods: HPAEC was treated with different concentrations of CSE in vitro and cell proliferation was determined by CCK8, senescence cells analyzed by detecting the β-gal activity, and the senescent proteins of cells measured by Western blot. The concentration of senescence-associated secretory phenotype (SASP) was detected by ELISA and the expression of MCP-1 and TGF-β1 was measured by Real-time PCR. The number of the proliferated cells was measured by Transwell assay and immunoflurescence. Results: The HPAEC was aging with the stimulation concentration of CSE increasing and the stimulation time prolonging (Pcells increased as the exposure time prolonged. Compared with the control group, cell viability of 48 h group(1.8±0.1) and 72 h group (1.8±0.1) decreased significantly. The flow cytometry showed a significant difference between the CSE group(14.1±1.2) and the control group(28.5±1.8) in S phase(Pcell cycle arrest. The SASP was increasing as the CSE-exposure prolonged. Compared with the control group(177±39), the 48 h group(460±43) and the 72 h group(609±64) showed a marked increase in MCP-1(Pcells could secrete SASP which induced HPASMC proliferation. After different times of conditioned medium stimulation, HPASMC proliferated especially at 72 h(P<0.05) . The immnoflorescence and Transwell assay confirmed this finding. Conclusion: CSE could induce senescence of HPAEC and SASP production which improved HPASMC proliferation and migration.

  6. Classification of peripheral occlusive arterial diseases based on symptoms, signs and distal blood pressure measurements

    DEFF Research Database (Denmark)

    Tønnesen, K H; Noer, Ivan; Paaske, William

    1980-01-01

    Systolic blood pressures at toe and ankle were measured in 459 consecutive patients with occlusive arterial disease. Fifty-eight per cent had intermittent claudication with arterial disease of all degrees of severity. Seventeen per cent complained of rest pain having toe systolic pressures below 30...... occlusive arterial disease which was located distally on the legs. A classification in three groups is suggested: (1) ischemia only during exercise; (2) ischemia at rest with or without ulcerations: and (3) diabetics with chronic ulcerations....

  7. Polyphenols modulate calcium-independent mechanisms in human arterial tissue-engineered vascular media.

    Science.gov (United States)

    Diebolt, Myriam; Laflamme, Karina; Labbé, Raymond; Auger, François A; Germain, Lucie; Andriantsitohaina, Ramaroson

    2007-10-01

    In the present study, an arterial tissue-engineered vascular media (TEVM) was produced from cultured human smooth muscle cells of the umbilical artery and we took advantage of this model to evaluate the regulation of contraction and the signalling pathways of polyphenols in arteries. Cultured human smooth muscle cells of the umbilical artery were used to produce arterial TEVMs. Contraction experiments were performed to determine intracellular targets involved in the modulation of contraction by polyphenols extract from red wine, Provinols (SEPPIC Groupe Air Liquide, Paris, France). Smooth muscle cells in arterial TEVM displayed a differentiated phenotype as demonstrated by the expression of alpha-smooth muscle actin, a vascular smooth muscle-specific marker, and tissue contraction in response to vasoconstrictor and vasodilator agents. Contractions caused by histamine were associated with an increase in [Ca(2+)](i) and a Ca(2+)-independent signalling pathway. The latter pathway involved mechanisms sensitive to protein kinase C, myosin light chain kinase, and Rho-associated protein kinase inhibitors. The regulation of contraction induced by Provinols shows that treatment of arterial TEVM with this compound significantly decreased histamine-induced contraction. This effect was associated with the inhibition of the Rho-associated protein kinase pathway and the decrease in alpha-smooth muscle actin expression. The use of arterial TEVM, brings new insights into the mechanisms by which polyphenols regulate vascular contraction in the human artery.

  8. Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

    Directory of Open Access Journals (Sweden)

    Jong-Gu Choi

    2011-01-01

    Full Text Available To measure precise blood pressure (BP and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

  9. Effect of SR manipulation on conduit artery dilation in humans

    NARCIS (Netherlands)

    Carter, H.H.; Dawson, E.A.; Birk, G.K.; Spence, A.L.; Naylor, L.H.; Cable, N.T.; Thijssen, D.H.J.; Green, D.J.

    2013-01-01

    The impact of manipulating shear stress on conduit artery vasodilation has not been comprehensively described in vivo. We hypothesized that manipulation of SR through the brachial and radial arteries would be associated with corresponding changes in diameter. We performed a series of studies

  10. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    Science.gov (United States)

    2012-01-01

    Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API). We also measured brachial-ankle (baPWV) PWV and carotid-femoral (cfPWV) PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. Results The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV) than stiff (high baPWV or cfPWV) arteries. API was related to baPWV (r = -0.53, P blood pressure based on oscillometric measurements of blood pressure. PMID:22325084

  11. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement.

    Science.gov (United States)

    Komine, Hidehiko; Asai, Yoshiyuki; Yokoi, Takashi; Yoshizawa, Mutsuko

    2012-02-10

    Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API). We also measured brachial-ankle (baPWV) PWV and carotid-femoral (cfPWV) PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV) than stiff (high baPWV or cfPWV) arteries. API was related to baPWV (r = -0.53, P blood pressure based on oscillometric measurements of blood pressure.

  12. Impact of exercise training on arterial wall thickness in humans.

    Science.gov (United States)

    Thijssen, Dick H J; Cable, N Timothy; Green, Daniel J

    2012-04-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been consistently reported in asymptomatic subjects and those with cardiovascular risk factors and diseases. In the present review, we summarize evidence pertaining to the impact of exercise and physical activity on arterial wall remodelling of the carotid artery and peripheral arteries in the upper and lower limbs. We consider the potential role of exercise intensity, duration and modality in the context of putative mechanisms involved in wall remodelling, including haemodynamic forces. Finally, we discuss the impact of exercise training in terms of primary prevention of wall thickening in healthy subjects and remodelling of arteries in subjects with existing cardiovascular disease and risk factors.

  13. Measuring senescence in human populations

    NARCIS (Netherlands)

    Koopman, Jacob Jan Egbert

    2015-01-01

    In this thesis, senescence is measured in human populations according to its definition of an increase in the risks of dysfunction, disease, and death with chronological age. Part I of this thesis investigates how a population’s senescence rate can be measured through the increase in mortality rate

  14. In-depth characterization of CGRP receptors in human intracranial arteries

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Jørgensen, Linda; Engel, Ulla

    2003-01-01

    meningeal arteries. Removal of the endothelium neither changed the maximum relaxant response nor the pIC(50) values for alpha- and beta-CGRP as compared to the responses in arteries with an intact endothelium. Human alpha-CGRP-(8-37) caused a shift of h alpha- and h beta-CGRP-induced relaxations in cerebral...

  15. Comparison of ambulatory blood pressure measurement with home, office and pharmacy measurements: is arterial blood pressure measured at pharmacy reliable?

    Science.gov (United States)

    Mutlu, Sinan; Sari, Oktay; Arslan, Erol; Aydogan, Umit; Doganer, Yusuf C; Koc, Bayram

    2016-02-01

    Standardizing arterial blood pressure (BP) measurement is difficult because of different performers like doctor or pharmacy employee. We investigated the reliability between different BP measurement methods. The study was conducted in an internal medicine service with 160 patients in Ankara, Turkey. First, the subjects' BP was measured by doctor. Then, 24-hour BP monitoring devices were placed. Participants were then instructed to measure their BPs both at home and in pharmacy. The next day, arterial BP was measured by the doctor for the second time. The prevalence rates of masked and white coat hypertension were 8.8% (n = 14) and 8.1% (n = 13), respectively. There was no statistically significant differences between ambulatory measurement and home, office and pharmacy measurements (P > 0.05). The consistency rate between ambulatory and home measurements was 97.5% (kappa = 0.947, P home measurement. There was a moderate positive correlation between ambulatory and other measurements in both systolic and diastolic values. There was a positive and very strong correlation between ambulatory and home measurements of systolic and diastolic ABP values (respectively; r = 0.926 and r = 0.968) and there was a statistically significant relation between these measurements (P home measurement when compared with ambulatory measurement. But both office and pharmacy measurements had also high sensitivity and specificity. © 2015 John Wiley & Sons, Ltd.

  16. Recombinant human activated protein C improves endotoxemia-induced endothelial dysfunction: a blood-free model in isolated mouse arteries.

    Science.gov (United States)

    Sennoun, Nacira; Baron-Menguy, Celine; Burban, Mélanie; Lecompte, Thomas; Andriantsitohaina, Ramaroson; Henrion, Daniel; Mercat, Alain; Asfar, Pierre; Levy, Bruno; Meziani, Ferhat

    2009-07-01

    Recombinant human activated protein C (rhAPC) is one of the treatment panels for improving vascular dysfunction in septic patients. In a previous study, we reported that rhAPC treatment in rat endotoxemia improved vascular reactivity, although the mechanisms involved are still under debate. In the present study, we hypothesized that rhAPC may improve arterial dysfunction through its nonanticoagulant properties. Ten hours after injection of LPS in mice (50 mg/kg ip), aortic rings and mesenteric arteries were isolated and incubated with or without rhAPC for 12 h. Aortic rings were mounted in a myograph, after which arterial contractility and endothelium-dependent relaxation were measured in the presence or absence of nitric oxide synthase or cyclooxygenase inhibitors. Flow (shear stress)-mediated dilation with or without the above inhibitors was also measured in mesenteric resistance arteries. Protein expression was assessed by Western blotting. Lipopolysaccharide (LPS) reduced aortic contractility to KCl and phenylephrine as well as dilation to acetylcholine. LPS also reduced flow-mediated dilation in mesenteric arteries. In rhAPC-treated aorta and mesenteric arteries, contractility and endothelial responsiveness to vasodilator drug and shear stress were improved. rhAPC treatment also improved LPS-induced endothelial dysfunction; this effect was associated with an increase in the phosphorylated form of endothelial nitric oxide synthase and protein kinase B as well as cyclooxygenase vasodilatory pathways, thus suggesting that these pathways, together with the decrease in nuclear factor-kappaB activation and inducible nitric oxide synthase expression in the vascular wall, are implicated in the endothelial effect of rhAPC. In conclusion, ex vivo application of rhAPC improves arterial contractility and endothelial dysfunction resulting from endotoxemia in mice. This finding provides important insights into the mechanism underlying rhAPC-induced improvements on arterial

  17. Human urotensin II in internal mammary and radial arteries of patients undergoing coronary surgery

    DEFF Research Database (Denmark)

    Chen, Zhi-Wu; Yang, Qin; Huang, Yu

    2009-01-01

    and by indomethacin, oxadiazoloquinoxalinone or N(omega)-nitro-L-arginine, oxyhemoglobin, and Ca2+-activated K+ channel (K(Ca)) blockers. Urotensin receptor mRNA was detected in both arteries. CONCLUSIONS: hU-II is an important spasmogen in arterial grafts with receptors expressed in IMA and RA. hU-II elicits......AIMS: Internal mammary (IMA) and radial artery (RA) have different incidence of vasospasm and long-term patency rates in arterial grafting. We compared the vasoreactivity of human urotensin II (hU-II) and its receptor with mechanism investigations in IMA and RA. METHODS: IMA and RA taken from...

  18. Identification of differential gene expression patterns in human arteries from patients with chronic kidney disease

    DEFF Research Database (Denmark)

    Stubbe, Jane; Skov, Vibe; Thiesson, Helle Charlotte

    2018-01-01

    BACKGROUND: Uremia accelerates atherosclerosis but little is known about affected pathways in human vasculature. This study aimed to identify differentially expressed arterial transcripts in patients with chronic kidney disease (CKD) Methods: Global mRNA expression was estimated by microarray...... hybridization in iliac arteries (n=14) from renal transplant recipients and compared with renal arteries from healthy living kidney donors (n=19) in study 1. Study 2 compared non-atherosclerotic internal mammary arteries (IMA) from five patients with elevated plasma creatinine levels and age and gender matched...

  19. Human Investigations into the Arterial and Cardiopulmonary Baroreflexes during Exercise

    Science.gov (United States)

    Fadel, Paul J.; Raven, Peter B.

    2011-01-01

    After considerable debate and key experimental evidence, the importance of the arterial baroreflex in contributing to and maintaining the appropriate neural cardiovascular adjustments to exercise is now well accepted. Indeed, the arterial baroreflex resets during exercise in an intensity-dependent manner to continue to regulate blood pressure as effectively as at rest. Studies have indicated that the exercise resetting of the arterial baroreflex is mediated by both the feed-forward mechanism of central command and the feed-back mechanism associated with skeletal muscle afferents (the exercise pressor reflex). Another perhaps less appreciated neural mechanism involved in evoking and maintaining neural cardiovascular responses to exercise is the cardiopulmonary baroreflex. The limited information available regarding the cardiopulmonary baroreflex during exercise provides evidence for a role in mediating sympathetic nerve activity and blood pressure responses. In addition, recent investigations have demonstrated an interaction between cardiopulmonary baroreceptors and the arterial baroreflex during dynamic exercise, which contributes to the magnitude of exercise-induced increases in blood pressure as well as the resetting of the arterial baroreflex. Furthermore, neural inputs from the cardiopulmonary baroreceptors appear to play an important role in establishing the operating point of the arterial baroreflex. This symposium review will highlight recent studies in these important areas indicating that the interactions of four neural mechanisms (central command, the exercise pressor reflex, the arterial baroreflex and cardiopulmonary baroreflex) are integral in mediating the neural cardiovascular adjustments to exercise. PMID:22002871

  20. Modulation of human muscle spindle discharge by arterial pulsations - functional effects and consequences

    NARCIS (Netherlands)

    Birznieks, I.; Boonstra, T.W.; Macefield, V.G.

    2012-01-01

    Arterial pulsations are known to modulate muscle spindle firing; however, the physiological significance of such synchronised modulation has not been investigated. Unitary recordings were made from 75 human muscle spindle afferents innervating the pretibial muscles. The modulation of muscle spindle

  1. Heterogeneity in conduit artery function in humans: impact of arterial size.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Dawson, E.A.; Black, M.A.; Hopman, M.T.E.; Cable, N.T.; Green, D.J.

    2008-01-01

    To determine whether conduit artery size affects functional responses, we compared the magnitude, time course, and eliciting shear rate stimulus for flow-mediated dilation (FMD) in healthy men (n = 20; 31 +/- 7 yr). Upper limb (brachial and radial) and lower limb (common and superficial femoral) FMD

  2. Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography

    NARCIS (Netherlands)

    Bleeker, Leslie; Marquering, Henk A.; van den Berg, René; Nederkoorn, Paul J.; Majoie, Charles B.

    2012-01-01

    Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure

  3. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  4. A quantitative method for studying human arterial baroreflexes

    Science.gov (United States)

    Eckberg, Dwain L.; Fritsch, Janice M.; Goble, Ross L.

    1991-01-01

    A new system is described that delivers precise, stereotyped pressure changes to the human neck and elicits neurally-mediated heart rate changes. The centerpiece of this system is a Silastic chamber that is strapped to the anterior neck. This chamber is connected to a stepping-motor-controlled bellows assembly. A strain-gauge transducer measures the intensity of pressure changes. The entire system is controlled by microprocessors, and both stimuli and responses are displayed on a digital oscilloscope. The end-product of this system is a reproducible baroreceptor stimulus-cardiac response relation that can be recorded rapidly and safely in astronauts in space.

  5. Impact of exercise training on arterial wall thickness in humans.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Cable, N.T.; Green, D.J.

    2012-01-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been

  6. Arterial supply of the human fetal testis during its migration

    NARCIS (Netherlands)

    Sampaio, FJB; Favorito, LA; Freitas, MA; Damiao, R; Gouveia, E

    Purpose: Irrespective of the surgical technique chosen to treat high undescended testis, preservation of an adequate arterial supply for the testis is crucial for successful orchiopexy with maintenance of normal testicular size and texture. To provide an anatomical background for such a procedure,

  7. Bicarbonate attenuates arterial desaturation during maximal exercise in humans

    DEFF Research Database (Denmark)

    Nielsen, Henning B; Bredmose, Per P; Strømstad, Morten

    2002-01-01

    in the difference between the end-tidal O2 pressure and arterial PO2 was similar in the two trials. Also, pulmonary O2 uptake and changes in muscle oxygenation as determined by near-infrared spectrophotometry during exercise were similar. The enlarged blood-buffering capacity after infusion of Bic attenuated...

  8. The impact of splenectomy on human coronary artery atherosclerosis and vascular macrophage distribution.

    Science.gov (United States)

    Li, Yu; Stone, James R

    Splenectomy can potentially impact atherosclerosis through multiple mechanisms including altered lipid homeostasis, increased coagulation, and altered macrophage recruitment to the plaque. In patients, splenectomy has been associated with increased rates of coronary artery events, while in experimental mice, splenectomy causes increased atherosclerosis but reduces systemic monocyte supply. In this study, the direct impact of splenectomy on human coronary artery atherosclerotic plaque severity and macrophage content was investigated. Coronary artery atherosclerotic plaque severity was determined at autopsy in 18 long-term (≥10 years) splenectomy patients and 90 matched control patients. Coronary artery macrophage content was evaluated in mild atherosclerotic plaques of 11 mid- to long-term (≥1 year) splenectomy patients and 11 matched control patients. Splenectomy was associated with reduced coronary artery atherosclerosis (P=.03). The association was most pronounced for the subgroup of patients who had undergone splenectomy 20 years or more prior to death (P=.02). There was no difference in the density of macrophages in the plaque, media, or adventitia upon comparing splenectomy and control patients. In the control group, there was no correlation between the macrophage densities in the three arterial layers. However, in the splenectomy patients, there was a strong correlation in the macrophage densities across the plaque, media, and adventitia (P≤.0002), with resulting slopes that were significantly greater than seen in the control patients (P=.0007-.011). These findings indicate that, in humans, splenectomy is associated with lower coronary artery atherosclerotic plaque severity and altered coronary artery macrophage distribution. These results suggest that the spleen can modulate the recruitment of macrophages into human coronary arteries and the progression of atherosclerosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Anterior temporal artery tap to identify systemic interference using short-separation NIRS measurements

    DEFF Research Database (Denmark)

    Sood, Mehak; Jindal, Utkarsh; Chowdhury, Shubhajit Roy

    2015-01-01

    that are also affected by tDCS. An approach may be to use short optode separations to measure systemic hemodynamic fluctuations occurring in the superficial layers which can then be used as regressors to remove the systemic contamination. Here, we demonstrate that temporal artery tap may be used to better...... change in the mean rSO2 better correlated with the corresponding percent change in log-transformed mean-power of EEG within 0.5 Hz-11.25 Hz frequency band after removing the systemic contamination using the temporal artery tap method. Based on our findings, we propose that anterior temporal artery tap...

  10. Novel formula to measure mean pulmonary artery pressure

    Directory of Open Access Journals (Sweden)

    Francisco Jose Chacon-Lozsan

    2016-11-01

    Full Text Available Mean Pulmonary Arterial Pressure (MPAP is an important parameter in evaluation of patients with pulmonary hypertension. The aim of this study is to correlate a new formula using non-invasive blood pressure and Bernoulli’s right ventricle systolic pressure (RVSP with invasive method. To archive the objectives, we enrolled 143 patients with suspected pulmonary hypertension from January 2015 till January 2016; all patients underwent right heart catheter evaluation and simultaneously RVSP by transthoracic echocardiography and non-invasive blood pressure to calculate MPAP by the formula MPAP = Pulse Pressure / (Mean Arterial Pressure/RVSP; and the results were compared using the Pearson’s simple-linear correlation method. We found a significant association between invasive and equation results with a Pearson’s correlation of 0,872 with a confidence interval from 0,795 to 0,921; sensitivity was 1,538% with a 95% confidence of interval (CI from 0,038% to 8,276%, and Specificity was 100% with 95% CI from 94,48% to 100%. Our results suggest that the new formula have a good correlation estimating MPAP compared with invasive right heart catheterization method.

  11. SIMULATION ANALYSIS OF BLOOD FLOW IN ARTERIES OF THE HUMAN ARM.

    Science.gov (United States)

    Quanyu, Wu; Xiaojie, Liu; Lingjiao, Pan; Weige, Tao; Chunqi, Qian

    2017-08-01

    Arteries in the upper limb play important roles in the circulation system of the human body. In particular, the radial artery has received considerable attention in traditional Chinese medicine for thousands of years. Here, a 3D model for the arm arteries has been created uncomplicated, in a Chinese adult's left hand, from the magnetic resonance imaging data, using professional modeling software to restore the basic structure of the arm artery in human body, before being imported to Ansys software for simulation. Blood model has been only simulated, and using the blood density of constant parameter and viscosity using the Carreau fluid model, and using viscous-laminar model of Fluent to obtain the velocity profile, static pressure and shear stress in the brachial, interosseous, ulnar, radial and palmar arch arteries. In particular, the brachial and bifurcations have the high pressure and velocity profiles. The simulation results obtained here are also validated by those published in the literature and proved the ulnar artery prevails over the radial artery as a blood supplier to the vessels in the wrist and hand.

  12. Uterine arteriovenous malformation with positive serum beta-human chorionic gonadotropin: Embolization of both uterine arteries and extra-uterine feeding arteries.

    Science.gov (United States)

    Kim, Su Mi; Ahn, Hee Young; Choi, Min Jeong; Kang, Yun Dan; Park, Jin Wan; Park, Choong Hak; Kim, Jong Soo

    2016-11-01

    The incidence of uterine arteriovenous malformation (AVM) is rare. However, it is clinically significant in that it can cause life-threatening vaginal bleeding. We report a case of a large uterine AVM with positive serum beta-human chorionic gonadotropin. A presumptive diagnosis was made; a uterine AVM accompanied by, early pregnancy or retained product of conception. Because this uterine AVM was extensive, transcatheter arterial embolization of both uterine arteries and extra-uterine feeding arteries was performed. Three months after undergoing transcatheter arterial embolization, complete resolution of the uterine AVM was confirmed without major complication.

  13. How Korotkoff, the surgeon, discovered the auscultatory method of measuring arterial pressure.

    Science.gov (United States)

    Segall, H N

    1975-10-01

    The Korotkoff sounds that measure systolic and diastolic arterial pressure levels were described in a brief communication by N.C. Korotkoff in 1905. He did not state how it happened that he discovered this auscultatory method of measuring "blood" pressure. The search for information on this matter led to studying the thesis for his doctorate published in 1910 on Experiments for Determining the Efficiency of Arterial Collaterals. It seems that when he wanted to be sure that pressureonan artery (digital, or with an Esmarch ligature or a Riva-Rocci cuff) had completely obliterated its lumen, he listened over the artery below the area of pressure. The absence of any sounds meant complete obliteration; a sound appeared with each beat when some flow did occur during partial obliteration of the lumen and when no pulsation could be detected because of the small volume of flow.

  14. Muscle contraction induced arterial shear stress increases endothelial nitric oxide synthase phosphorylation in humans.

    Science.gov (United States)

    Casey, Darren P; Ueda, Kenichi; Wegman-Points, Lauren; Pierce, Gary L

    2017-10-01

    We determined if local increases in brachial artery shear during repetitive muscle contractions induce changes in protein expression of endothelial nitric oxide synthase (eNOS) and/or phosphorylated (p-)eNOS at Ser1177, the primary activation site on eNOS, in endothelial cells (ECs) of humans. Seven young male subjects (25 ± 1 yr) performed 20 separate bouts (3 min each) of rhythmic forearm exercise at 20% of maximum over a 2-h period. Each bout of exercise was separated by 3 min of rest. An additional six male subjects (24 ± 1 yr) served as time controls (no exercise). ECs were freshly isolated from the brachial artery using sterile J-wires through an arterial catheter at baseline and again after the 2-h exercise or time control period. Expression of eNOS or p-eNOS Ser1177 in ECs was determined via immunofluorescence. Brachial artery mean shear rate was elevated compared with baseline and the time control group throughout the 2-h exercise protocol (P 0.05 for both). Our novel results suggest that elevations in brachial artery shear increase eNOS Ser1177 phosphorylation in the absence of changes in total eNOS in ECs of young healthy male subjects, suggesting that this model is sufficient to alter posttranslational modification of eNOS activity in vivo in humans.NEW & NOTEWORTHY Elevations in brachial artery shear in response to forearm exercise increased endothelial nitric oxide synthase Ser1177 phosphorylation in brachial artery endothelial cells of healthy humans. Our present study provides the first evidence in humans that muscle contraction-induced increases in conduit arterial shear lead to in vivo posttranslational modification of endothelial nitric oxide synthase activity in endothelial cells. Copyright © 2017 the American Physiological Society.

  15. Exercise-mediated changes in conduit artery wall thickness in humans: role of shear stress.

    Science.gov (United States)

    Thijssen, Dick H J; Dawson, Ellen A; van den Munckhof, Inge C L; Tinken, Toni M; den Drijver, Evert; Hopkins, Nicola; Cable, N Timothy; Green, Daniel J

    2011-07-01

    Episodic increases in shear stress have been proposed as a mechanism that induces training-induced adaptation in arterial wall remodeling in humans. To address this hypothesis in humans, we examined bilateral brachial artery wall thickness using high-resolution ultrasound in healthy men across an 8-wk period of bilateral handgrip training. Unilaterally, shear rate was attenuated by cuff inflation around the forearm to 60 mmHg. Grip strength, forearm volume, and girth improved similarly between the limbs. Acute bouts of handgrip exercise increased shear rate (P < 0.005) in the noncuffed limb, whereas cuff inflation successfully decreased exercise-induced increases in shear. Brachial blood pressure responses similarly increased during exercise in both the cuffed and noncuffed limbs. Handgrip training had no effect on baseline brachial artery diameter, blood flow, or shear rate but significantly decreased brachial artery wall thickness after 6 and 8 wk (ANOVA, P < 0.001) and wall-to-lumen ratio after week 8 (ANOVA, P = 0.005). The magnitude of decrease in brachial artery wall thickness and wall-to-lumen ratio after exercise training was similar in the noncuffed and cuffed arms. These results suggest that exercise-induced changes in shear rate are not obligatory for arterial wall remodeling during a period of 8 wk of exercise training in healthy humans.

  16. Functional antagonism of different angiotensin II type I receptor blockers in human arteries

    NARCIS (Netherlands)

    Voors, AA; Buikema, H; van Buiten, A; Lubeck, RH; Boonstra, PW; van Veldhuisen, DJ; van Gilst, WH

    Objectives. To evaluate and compare the functional type and the degree of antagonism of the selective angiotensin II type I receptor blockers (ARB) losartan, EXP 3174 (the active metabolite of losartan), valsartan and candesartan in human internal mammary arteries. Methods. Human internal mammary

  17. Association between human cartilage glycoprotein 39 (YKL-40 and arterial stiffness in essential hypertension

    Directory of Open Access Journals (Sweden)

    Ma Wei-hong

    2012-05-01

    Full Text Available Abstract Background YKL-40, a proposed marker of inflammation and endothelial dysfunction, is associated with atherosclerosis and an increased cardiovascular mortality in the general population. However, the relationship between YKL-40 and arterial stiffness in hypertensive patients has not been adequately assessed. Methods The relationship between serum levels of YKL-40 and arterial stiffness was evaluated in 93 essential hypertensive subjects and 80 normal subjects. Essential hypertensive subjects were divided into two groups based upon urinary albumin-to-creatinine ratio (ACR: nonmicroalbuminuric group, (ACR n = 50 and microalbuminuric group (ACR ≥30 mg/g, n = 43. Large artery wall stiffness was assessed by measuring femoral arterial stiffness and carotid-femoral pulse wave velocity (cf-PWV. Serum levels of YKL-40 were determined by enzyme-linked immunosorbent assay (ELISA. Results The study demonstrated that YKL-40,cf-PWV and femoral arterial stiffness were increased significantly (PPr = 0.44, P = 0.000 and femoral arterial stiffness ( r = 0.42, P =0.001. Multiple linear stepwise regression analysis showed that YKL-40 was the impact factor of arterial stiffness ( P Conclusion YKL-40 levels are elevated in essential hypertension subjects with an independent association between increasing YKL-40 levels and increasing arterial stiffness. The study suggests it played a positive role of YKL-40 in the progressing vascular complications in patients with essential hypertension.

  18. Parametric uncertainty analysis of pulse wave propagation in a model of a human arterial network

    Science.gov (United States)

    Xiu, Dongbin; Sherwin, Spencer J.

    2007-10-01

    Reduced models of human arterial networks are an efficient approach to analyze quantitative macroscopic features of human arterial flows. The justification for such models typically arise due to the significantly long wavelength associated with the system in comparison to the lengths of arteries in the networks. Although these types of models have been employed extensively and many issues associated with their implementations have been widely researched, the issue of data uncertainty has received comparatively little attention. Similar to many biological systems, a large amount of uncertainty exists in the value of the parameters associated with the models. Clearly reliable assessment of the system behaviour cannot be made unless the effect of such data uncertainty is quantified. In this paper we present a study of parametric data uncertainty in reduced modelling of human arterial networks which is governed by a hyperbolic system. The uncertain parameters are modelled as random variables and the governing equations for the arterial network therefore become stochastic. This type stochastic hyperbolic systems have not been previously systematically studied due to the difficulties introduced by the uncertainty such as a potential change in the mathematical character of the system and imposing boundary conditions. We demonstrate how the application of a high-order stochastic collocation method based on the generalized polynomial chaos expansion, combined with a discontinuous Galerkin spectral/hp element discretization in physical space, can successfully simulate this type of hyperbolic system subject to uncertain inputs with bounds. Building upon a numerical study of propagation of uncertainty and sensitivity in a simplified model with a single bifurcation, a systematical parameter sensitivity analysis is conducted on the wave dynamics in a multiple bifurcating human arterial network. Using the physical understanding of the dynamics of pulse waves in these types of

  19. Single sweep three-dimensional carotid ultrasound: reproducibility in plaque and artery volume measurements.

    Science.gov (United States)

    Kalashyan, Hayrapet; Shuaib, Ashfaq; Gibson, Patrick H; Romanchuk, Helen; Saqqur, Maher; Khan, Khurshid; Osborne, Jonathon; Becher, Harald

    2014-02-01

    There is a need for non-invasive and accurate techniques for assessment of severity of atherosclerotic disease in the carotid arteries. Recently an automated single sweep three-dimensional ultrasound (3D US) technique became available. The aims of this study were to evaluate the feasibility and reproducibility of the automated single sweep method in a cohort of patients undergoing clinically indicated carotid ultrasound. Consecutive patients with a history of stroke or transient ischemic attack (TIA) and having a plaque in the internal carotid artery (ICA) were recruited for this study. Imaging was performed using a Philips iU 22 ultrasound system equipped with the single sweep volumetric transducer vL 13-5. Analysis was performed offline with software provided by the manufacturer. Two independent observers performed all measurements. Of 137 arteries studied (from 79 patients), plaque and artery volumes could be measured in 106 (77%). Reproducibility of plaque volume measurements was assessed in 82 arteries. Bland-Altman analysis demonstrated good inter-observer reproducibility with limits of agreement -0.06 to +0.07 ml. The mean percentage difference between two observers was 5.6% ± 6.0%. Reproducibility of artery volume measurement was assessed in 31 cases. Bland-Altman analysis demonstrated limits of agreement from -0.15 to +0.15 ml. The mean percentage difference was 6.4 ± 5.9%. The new automated single sweep 3D ultrasound is feasible in the majority of patients. Good reproducibility in plaque and artery volume measurements makes this technique suitable for serial assessment of carotid plaques. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  20. Use of a wireless system to measure invasive arterial blood pressure in ponies - preliminary study.

    Science.gov (United States)

    Ricco, Carolina H; Quandt, Jane E; Novo, Roberto E; Killos, Maria; Graham, Lynelle

    2009-01-01

    To evaluate the feasibility and functionality of intra-carotid wireless device implantation in ponies, and to investigate its short-term complications. Prospective preliminary study. Five mixed breed, adult, intact male ponies weighing 104 +/- 28.8 kg (mean +/- SD) underwent surgery. Arterial blood pressure data were continuously collected from four animals. General anesthesia was induced on two consecutive days. On the first day, an intra-arterial wireless device was implanted in the right carotid artery. On the next day, a transcutaneous intra-arterial catheter was placed in the left facial artery. Data from both sources were collected. Post-mortem examination was performed. Surgical time was 27.1 +/- 11.85 minutes. All catheters remained in place with some extra vascular migration. Complications included mild seroma and hematoma. The wireless system allowed continuous monitoring in ponies throughout anesthesia and at rest and may allow for the recording of arterial blood pressure and heart rate when it would be difficult to achieve with a conventional system (e.g. during recovery from anesthesia). The wireless invasive blood pressure monitor may allow continuous measurements when only intermittent measurements would be feasible with a wired system.

  1. Methodology to study intimal failure mechanics in human internal carotid arteries.

    Science.gov (United States)

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A

    2005-12-01

    While the incidence of blunt carotid artery injuries is low, the mortality rate is extremely high (40%). Clinical evidence indicates that the intimal region of the artery often sustains failure, while maintaining the integrity of the outer layers. This condition may lead to delayed ischemic symptoms, commonly reported in clinical literature. To date, the mechanical properties of the intima relative to the outer vessel layers have not been quantified in the human carotid artery. The purpose of the present study was to develop a methodology to determine the longitudinal mechanical properties of the human internal carotid artery in tension, with an emphasis on intimal failure. This was accomplished by opening the vessel at the mid-diameter level, creating an 'I'-shaped testing specimen, subjecting the specimen to failure loading, documenting the stretch characteristics of the intimal and adventitial sides in the temporal domain, and correlating the synchronized videography with mechanical loading. Intimal failure data were quantified using stress and strain parameters in conjunction with digital videography of the intimal and adventitial sides. The present methodology can be used to determine the mechanical properties of the intima relative to ultimate carotid artery failure. These data will assist in the understanding of blunt carotid artery injuries, its diagnosis and treatment.

  2. Morphological Analysis of the Human Internal Iliac Artery in South Indian Population

    Directory of Open Access Journals (Sweden)

    Naveen NS

    2011-04-01

    Full Text Available Objectives: The accidental hemorrhage is common due to erroneous interpretation of the variant arteries during surgical procedures, hence the present study has been undertaken with reference to its morphological significance. The objectives were to examine the level of origin, length and the branching pattern of the human internal iliac artery in South Indian population. Methods: The study included 60 human bisected pelvises irrespective of their side and sex. The specimens were collected from the anatomy laboratory and were fixed with the formalin. The branching patterns were studied and demonstrated as per the guidelines of Adachi. Results: The origin of internal iliac artery was at the level of S1 vertebra in majority (58.3% of the cases. The average length of internal iliac artery was 37 ± 4.62 mm (range, 13-54 mm. The type I pattern of the internal iliac artery was most common (83.5% followed by types III and II. The type IV and V pattern of adachi were not observed. Conclusions: The results of this study were different from those reported by others and may be because of racial and geographical variations. Prior knowledge of the anatomical variations is beneficial for the vascular surgeons ligating the internal iliac artery or its branches and the radiologists interpreting angiograms of the pelvic region.

  3. Copper Dependence of Angioproliferation in Pulmonary Arterial Hypertension in Rats and Humans

    Science.gov (United States)

    Mizuno, Shiro; Guignabert, Christophe; Al Hussaini, Aysar A.; Farkas, Daniela; Ruiter, Gerrina; Kraskauskas, Donatas; Fadel, Elie; Allegood, Jeremy C.; Humbert, Marc; Noordegraaf, Anton Vonk; Spiegel, Sarah; Farkas, Laszlo; Voelkel, Norbert F.

    2012-01-01

    Obliteration of the vascular lumen by endothelial cell growth is a hallmark of many forms of severe pulmonary arterial hypertension. Copper plays a significant role in the control of endothelial cell proliferation in cancer and wound-healing. We sought to determine whether angioproliferation in rats with experimental pulmonary arterial hypertension and pulmonary microvascular endothelial cell proliferation in humans depend on the proangiogenic action of copper. A copper-depleted diet prevented, and copper chelation with tetrathiomolybdate reversed, the development of severe experimental pulmonary arterial hypertension. The copper chelation–induced reopening of obliterated vessels was caused by caspase-independent apoptosis, reduced vessel wall cell proliferation, and a normalization of vessel wall structure. No evidence was found for a role of super oxide–1 inhibition or lysyl–oxidase–1 inhibition in the reversal of angioproliferation. Tetrathiomolybdate inhibited the proliferation of human pulmonary microvascular endothelial cells, isolated from explanted lungs from control subjects and patients with pulmonary arterial hypertension. These data suggest that the inhibition of endothelial cell proliferation by a copper-restricting strategy could be explored as a new therapeutic approach in pulmonary arterial hypertension. It remains to be determined, however, whether potential toxicity to the right ventricle is offset by the beneficial pulmonary vascular effects of antiangiogenic treatment in patients with pulmonary arterial hypertension. PMID:22162909

  4. Simultaneous comparison of thoracic bioimpedance and arterial pulse waveform-derived cardiac output with thermodilution measurement.

    Science.gov (United States)

    Hirschl, M M; Kittler, H; Woisetschläger, C; Siostrzonek, P; Staudinger, T; Kofler, J; Oschatz, E; Bur, A; Gwechenberger, M; Laggner, A N

    2000-06-01

    To compare the accuracy and reliability of thoracic electrical bioimpedance (TEB) and the arterial pulse waveform analysis with simultaneous measurement of thermodilution cardiac output (TD-CO) in critically ill patients. Prospective data collection. Emergency department and critical care unit in a 2,000-bed inner-city hospital. A total of 29 critically ill patients requiring invasive hemodynamic monitoring for clinical management were prospectively studied. Noninvasive cardiac output was simultaneously measured by a TEB device and by analysis of the arterial pulse waveform derived from the finger artery. Invasive cardiac output was determined by the thermodilution technique. A total of 175 corresponding TD-CO and noninvasive hemodynamic measurements were collected in 30-min intervals. They revealed an overall bias of 0.34 L/min/m2 (95% confidence interval, 0.24-0.44 L/min/m2; p 0.50 L/min/m2. The discrepancies of the arterial pulse waveform analysis correlated positively with the magnitude of the cardiac index (r2 = 0.29; p 0.50 L/min/m2. The magnitude of the discrepancies of the TEB was significantly correlated with age (r2 = 0.17; p = .02). Measurements were in phase in 93.2% of all arterial pulse waveform analysis and in 84.9% of all TEB readings (p < .001). The arterial pulse waveform analysis exhibits a greater accuracy and reliability as compared with the TEB with regard to overall bias, number of inaccurate readings, and phase lags. The arterial pulse waveform analysis may be useful for the monitoring of hemodynamic changes. However, both methods fail to be a substitute for the TD-CO because of a substantial percentage of inaccurate readings.

  5. Male-female differences in upregulation of vasoconstrictor responses in human cerebral arteries.

    Directory of Open Access Journals (Sweden)

    Hilda Ahnstedt

    Full Text Available BACKGROUND AND PURPOSE: Male-female differences may significantly impact stroke prevention and treatment in men and women, however underlying mechanisms for sexual dimorphism in stroke are not understood. We previously found in males that cerebral ischemia upregulates contractile receptors in cerebral arteries, which is associated with lower blood flow. The present study investigates if cerebral arteries from men and women differ in cerebrovascular receptor upregulation. EXPERIMENTAL APPROACH: Freshly obtained human cerebral arteries were placed in organ culture, an established model for studying receptor upregulation. 5-hydroxtryptamine type 1B (5-HT1B, angiotensin II type 1 (AT1 and endothelin-1 type A and B (ETA and ETB receptors were evaluated using wire myograph for contractile responses, real-time PCR for mRNA and immunohistochemistry for receptor expression. KEY RESULTS: Vascular sensitivity to angiotensin II and endothelin-1 was markedly lower in cultured cerebral arteries from women as compared to men. ETB receptor-mediated contraction occurred in male but not female arteries. Interestingly, there were similar upregulation in mRNA and expression of 5-HT1B, AT1, and ETB receptors and in local expression of Ang II after organ culture. CONCLUSIONS AND IMPLICATIONS: In spite of receptor upregulation after organ culture in both sexes, cerebral arteries from women were significantly less responsive to vasoconstrictors angiotensin II and endothelin-1 as compared to arteries from men. This suggests receptor coupling and/or signal transduction mechanisms involved in cerebrovascular contractility may be suppressed in females. This is the first study to demonstrate sex differences in the vascular function of human brain arteries.

  6. Comparison of noninvasive oscillometric and intra-arterial blood pressure measurements in hyperacute stroke.

    Science.gov (United States)

    Manios, Efstathios; Vemmos, Konstantinos; Tsivgoulis, Georgios; Barlas, Gerasimos; Koroboki, Eleni; Eleni, Koroboki; Spengos, Konstantinos; Zakopoulos, Nikolaos

    2007-06-01

    This study aims to compare automatic oscillometric blood pressure recordings with simultaneous direct intra-arterial blood pressure measurements in hyperacute stroke patients to test the accuracy of oscillometric readings. A total of 51 first-ever stroke patients underwent simultaneous noninvasive automatic oscillometric and intra-arterial blood pressure monitoring within 3 h of ictus. Casual blood pressure was measured in both arms using a standard mercury sphygmomanometer on hospital admission. Patients who received antihypertensive medication during the blood pressure monitoring were excluded. The estimation of systolic blood pressure (SBP) using oscillometric recordings underestimated direct radial artery SBP by 9.7 mmHg (95% confidence interval: 6.5-13.0, Pblood pressure (DBP) recordings were compared with intra-arterial DBP recordings. For SBP and DBP, the Pearson correlation coefficients between noninvasive and intra-arterial recordings were 0.854 and 0.832, respectively. When the study population was stratified according to SBP bands (group A: SBP160 mmHg and SBP180 mmHg), higher mean DeltaSBP (intra-arterial SBP-oscillometric SBP) levels were documented in group C (+19.8 mmHg, 95% confidence intervals: 12.2-27.4) when compared with groups B (+8.5 mmHg, 95% confidence intervals: 2.7-14.5; P=0.025) and A (+5.9 mmHg, 95% confidence intervals: 1.8-9.9; P=0.002). Noninvasive automatic oscillometric BP measurements underestimate direct SBP recordings and overestimate direct DBP readings in acute stroke. The magnitude of the discrepancy between intra-arterial and oscillometric SBP recordings is even more prominent in patients with critically elevated SBP levels.

  7. Relating external compressing pressure to mean arterial pressure in non-invasive blood pressure measurements.

    Science.gov (United States)

    Chin, K Y; Panerai, R B

    2015-01-01

    Arterial volume clamping uses external compression of an artery to provide continuous non-invasive measurement of arterial blood pressure. It has been assumed that mean arterial pressure (MAP) corresponds to the point where unloading leads to the maximum oscillation of the arterial wall as reflected by photoplethysmogram (PPG), an assumption that has been challenged. Five subjects were recruited for the study (three males, mean age (SD) = 32 (15) years). The PPG waveform was analysed to identify the relationship between the external compressing pressure, PPG pulse amplitude and MAP. Two separate tests were carried out at compression step intervals of 10 mmHg and 2 mmHg, respectively. No significant differences were found between the two tests. The bias between the compressing pressure and the MAP was -4.7 ± 5.63 mmHg (p < 0.001) showing a normal distribution. Further research is needed to identify optimal algorithms for estimation of MAP using PPG associated with arterial compression.

  8. A New Method to Measure Portal Venous and Hepatic Arterial Blood Flow Patients Intraoperatively

    Science.gov (United States)

    Jakab, F.; Ráth, Z.; Schmal, F.; Nagy, P.; Faller, J.

    1996-01-01

    The intraoperative measurement of the afferent circulation of the liver, namely the hepatic artery flow and portal venous flow was carried out upon 14 anesthetized patients having carcinoma in the splanchnic area, mainly in the head of the pancreas by means of transit time ultrasonic volume flowmeter. The hepatic artery flow, portal venous flow and total hepatic flow were 0.377±0.10; 0.614±0.21; 0.992±0.276 l/min respectively. The ratio of hepatic arterical flow to portal venous flow was 0.66±0.259 There was a sharp, significant increase in hepatic arterial flow (29.8±6.1%, p<0,01) after the temporary occlusion of the portal vein, while the temporary occlusion of hepatic artery did not have any significant effect on portal venous circulation. The interaction between hepatic arterial flow and portal venous flow is a much disputed question, but according to the presented data here, it is unquestionable, that the decrease of portal venous flow immediately results a significant increase in hepatic artery circulation. PMID:8809586

  9. Impact of volunteer-related and methodology-related factors on the reproducibility of brachial artery flow-mediated vasodilation: analysis of 672 individual repeated measurements.

    NARCIS (Netherlands)

    Mil, A.C.C.M. van; Greyling, A.; Zock, P.L.; Geleijnse, J.M.; Hopman, M.T.E.; Mensink, R.P.; Reesink, K.D.; Green, D.J.; Ghiadoni, L.; Thijssen, D.H.J.

    2016-01-01

    OBJECTIVES: Brachial artery flow-mediated dilation (FMD) is a popular technique to examine endothelial function in humans. Identifying volunteer and methodological factors related to variation in FMD is important to improve measurement accuracy and applicability. METHODS: Volunteer-related and

  10. MR velocity mapping measurement of renal artery blood flow in patients with impaired kidney function

    DEFF Research Database (Denmark)

    Cortsen, M; Petersen, L.J.; Stahlberg, F

    1996-01-01

    . MR velocity mapping was performed in both renal arteries using an ECG-triggered gradient echo pulse sequence previously validated in normal volunteers. Effective renal plasma flow was calculated from the clearance rate of PAH during constant infusion and the split of renal function was evaluated......Renal blood flow (RBF) was measured in 9 patients with chronic impaired kidney function using MR velocity mapping and compared to PAH clearance and 99mTc-DTPA scintigraphy. An image plane suitable for flow measurement perpendicular to the renal arteries was chosen from 2-dimensional MR angiography...

  11. Oscillometric measurement of brachial artery cross-sectional area and its relationship with cardiovascular risk factors and arterial stiffness in a middle-aged male population.

    Science.gov (United States)

    Otsuka, Toshiaki; Munakata, Ryo; Kato, Katsuhito; Kodani, Eitaro; Ibuki, Chikao; Kusama, Yoshiki; Seino, Yoshihiko; Kawada, Tomoyuki

    2013-10-01

    An enlarged arterial diameter is associated with an increased risk for cardiovascular disease. This study examined the relationship of noninvasively measured brachial artery cross-sectional area with cardiovascular risk factors and arterial stiffness in a middle-aged male population. Absolute volumetric changes of the brachial artery were measured with a newly developed oscillometric method during a general health examination in 387 men (mean age: 38±9 years) without known cardiovascular disease. Based on the measurement, the estimated area (eA) of the brachial artery at end-diastole was obtained. Brachial artery volume elastic modulus (VE) and brachial-ankle pulse wave velocity (baPWV) were simultaneously measured as indices of arterial stiffness by the same device. The relationships of eA with cardiovascular risk factors, including age, obesity, hypertension, dyslipidemia, impaired fasting glucose/diabetes mellitus (IFG/DM), hyperuricemia, smoking and their associated continuous variables, as well as VE and baPWV, were examined. Overall, the mean eA was 12.9 ± 2.9 mm². The eA was significantly higher in subjects with obesity, hypertension or IFG/DM than in those without each of these risk factors. In a multiple linear regression analysis, body mass index (β=0.31, P<0.001), age (β=0.25, P<0.001), systolic blood pressure (β=0.16, P=0.004) and pulse rate (β=-0.13, P=0.005) were independent determinants of eA. In contrast, neither VE nor baPWV were selected as independent determinants of eA. In conclusion, enlarged brachial artery cross-sectional area was significantly associated with cardiovascular risk factors such as age, body mass index and systolic blood pressure, but it was not associated with increased arterial stiffness.

  12. Reference values for fluorine-18-fluorodeoxyglucose and fluorine-18-sodium fluoride uptake in human arteries

    DEFF Research Database (Denmark)

    Blomberg, Björn A; Thomassen, Anders; de Jong, Pim A

    2017-01-01

    OBJECTIVE: Reference values of fluorine-18-fluorodeoxyglucose (F-FDG) and fluorine-18-sodium fluoride (F-NaF) uptake in human arteries are unknown. The aim of this study was to determine age-specific and sex-specific reference values of arterial F-FDG and F-NaF uptake. PARTICIPANTS AND METHODS......: Uptake of F-FDG and F-NaF was determined in the ascending aorta, aortic arch, and descending thoracic aorta. In addition, F-FDG uptake was determined in the carotid arteries and F-NaF uptake was determined in the coronary arteries. Arterial F-FDG and F-NaF uptake were quantified as the blood pool...... subtracted maximum activity concentration in kBq/ml (BSF-FDGmax and BSF-NaFmax, respectively). In addition to determining reference values, we evaluated the influence of age and sex on BSF-FDGmax and BSF-NaFmax. RESULTS: Arterial F-FDG and F-NaF uptake was assessed in 89 healthy adults aged 21-75 years (mean...

  13. Rho kinase (ROK)-related proteins in human cavernous arteries: an immunohistochemical and functional approach.

    Science.gov (United States)

    Waldkirch, Eginhard S; Ückert, Stefan; Sohn, Michael; Kuczyk, Markus A; Hedlund, Petter

    2012-05-01

    Rho kinases (ROKs) cause calcium-independent modulation of smooth muscle contraction. A significant role for the RhoA/ROK pathway in mediating the contraction of the penile erectile tissue has been suggested. Moreover, it has been postulated that ROK activity might represent a key factor in the pathophysiology of erectile dysfunction. Up until today, little is known on the significance of ROK and related proteins in the control of blood flow in the corpus cavernosum. To investigate by means of immunohistochemistry and organ bath studies the significance of the Rho pathway in human cavernous arteries. The expression of ROK1, ROK2, RhoA, and RhoGDI in human cavernous arteries was investigated by means of immunohistochemistry; myographic studies were conducted in order to characterize the effects of the ROK inhibitor Y27632 on isolated cavernous arteries. Specimens of human cavernous arteries were processed for immunohistochemistry for ROK1, ROK2, RhoA, and RhoGDI. Circular penile vascular segments were mounted in a tissue bath and the effects of increasing concentrations of the ROK inhibitor Y27632 on the tension induced by norepinephrine (NE, 1 µM) were investigated. Alpha-actin immunoreactive cavernous arterioles also presented abundant staining specific for ROK1, ROK2, RhoA, and RhoGDI in the smooth musculature of the vascular wall. Cumulative addition of Y27632 dose-dependently reversed the tension induced by NE of isolated arterial segments. Y27632 produced relaxant responses with a reversion of tension of 34.3 ± 11.8% at a concentration of 1 µM. The findings are in support for a role of the Rho/ROK-mediated signaling in the regulation of muscle tone of human cavernous arteries. © 2012 International Society for Sexual Medicine.

  14. Impact of age, sex and exercise on brachial and popliteal artery remodelling in humans.

    Science.gov (United States)

    Green, Daniel J; Swart, Anne; Exterkate, Anne; Naylor, Louise H; Black, Mark A; Cable, N Timothy; Thijssen, Dick H J

    2010-06-01

    To examine the impact of age, sex and exercise on wall thickness and remodelling in the popliteal and brachial arteries. We compared wall thickness, lumen diameter and wall:lumen ratios in the brachial and popliteal arteries of 15 young (Y, 25.4+/-0.8 yr; 7M 8W) and 16 older sedentary (OS, 58.8+/-1.1 yr; 8M 8W) subjects, with 12 of the OS group also studied following 12 and 24 weeks exercise training. Wall thickness and lumen diameter were higher in the popliteal than the brachial artery for both groups (P<0.05); wall:lumen ratio was similar between arteries. Comparison of the Y and OS groups revealed no impact on wall thickness, whereas diameter values were higher in OS subjects (P<0.05). Whilst there were no significant differences in wall thickness between men and women in the Y or OS groups, diameter was larger in men than in women for both arteries (P<0.05). After 24 weeks of training the wall thickness of both arteries decreased (P<0.01) and the wall:lumen ratio of the brachial (P<0.01) and the popliteal (P<0.05) decreased. The cross-sectional results suggest that ageing was associated with increased lumen diameter, although wall:lumen ratio remained unchanged. Wall:lumen ratio was higher in women than men, irrespective of subject age or the artery studied. This related primarily to differences in lumen diameter between the sexes, as wall thickness did not significantly differ between men and women. Our longitudinal data strongly suggest that exercise training is associated with beneficial effects on conduit artery wall thickness and wall:lumen ratio in both upper and lower limbs in humans. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Indirect measurement of arterial blood pressure: physiotherapists’ theoretical knowledge

    Directory of Open Access Journals (Sweden)

    Marcelle Morgana Vieira de Assis

    2003-12-01

    Full Text Available Blood pressure checking and its theoretical knowledge are crucial to obtain reliable data in clinical examination. Although it is considered a simple technique to be learned and applied, it is not fully dealt with at physiotherapy university courses. Therefore, a wide range of mistakes and misinterpretations are likely to threaten treatment quality. This work aims to evaluate the theory background of physiotherapists for blood pressure measurement. From June to October 2002, 55 physiotherapists answered a 20- question multiple-choice questionnaire on general knowledge related to concepts, anatomy and physiology, suitable equipment, indirect measurement, blood pressure values, mistakes and misinterpretation factors related to blood pressure measurement. The results disclose faulty theory concepts in the sample studied, indicating the need of deeper approach to this complex theme during course and ongoing updating of professionals.

  16. X-ray micro computed tomography for the visualization of an atherosclerotic human coronary artery

    Science.gov (United States)

    Matviykiv, Sofiya; Buscema, Marzia; Deyhle, Hans; Pfohl, Thomas; Zumbuehl, Andreas; Saxer, Till; Müller, Bert

    2017-06-01

    Atherosclerosis refers to narrowing or blocking of blood vessels that can lead to a heart attack, chest pain or stroke. Constricted segments of diseased arteries exhibit considerably increased wall shear stress, compared to the healthy ones. One of the possibilities to improve patient’s treatment is the application of nano-therapeutic approaches, based on shear stress sensitive nano-containers. In order to tailor the chemical composition and subsequent physical properties of such liposomes, one has to know precisely the morphology of critically stenosed arteries at micrometre resolution. It is often obtained by means of histology, which has the drawback of offering only two-dimensional information. Additionally, it requires the artery to be decalcified before sectioning, which might lead to deformations within the tissue. Micro computed tomography (μCT) enables the three-dimensional (3D) visualization of soft and hard tissues at micrometre level. μCT allows lumen segmentation that is crucial for subsequent flow simulation analysis. In this communication, tomographic images of a human coronary artery before and after decalcification are qualitatively and quantitatively compared. We analyse the cross section of the diseased human coronary artery before and after decalcification, and calculate the lumen area of both samples.

  17. Role of Hypoxia-Induced Brain Derived Neurotrophic Factor in Human Pulmonary Artery Smooth Muscle.

    Directory of Open Access Journals (Sweden)

    William Hartman

    Full Text Available Hypoxia effects on pulmonary artery structure and function are key to diseases such as pulmonary hypertension. Recent studies suggest that growth factors called neurotrophins, particularly brain-derived neurotrophic factor (BDNF, can influence lung structure and function, and their role in the pulmonary artery warrants further investigation. In this study, we examined the effect of hypoxia on BDNF in humans, and the influence of hypoxia-enhanced BDNF expression and signaling in human pulmonary artery smooth muscle cells (PASMCs.48h of 1% hypoxia enhanced BDNF and TrkB expression, as well as release of BDNF. In arteries of patients with pulmonary hypertension, BDNF expression and release was higher at baseline. In isolated PASMCs, hypoxia-induced BDNF increased intracellular Ca2+ responses to serotonin: an effect altered by HIF1α inhibition or by neutralization of extracellular BDNF via chimeric TrkB-Fc. Enhanced BDNF/TrkB signaling increased PASMC survival and proliferation, and decreased apoptosis following hypoxia.Enhanced expression and signaling of the BDNF-TrkB system in PASMCs is a potential mechanism by which hypoxia can promote changes in pulmonary artery structure and function. Accordingly, the BDNF-TrkB system could be a key player in the pathogenesis of hypoxia-induced pulmonary vascular diseases, and thus a potential target for therapy.

  18. Pleiotropic effects of statins in distal human pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Butrous Ghazwan S

    2011-10-01

    Full Text Available Abstract Background Recent clinical data suggest statins have transient but significant effects in patients with pulmonary arterial hypertension. In this study we explored the molecular effects of statins on distal human pulmonary artery smooth muscle cells (PASMCs and their relevance to proliferation and apoptosis in pulmonary arterial hypertension. Methods Primary distal human PASMCs from patients and controls were treated with lipophilic (simvastatin, atorvastatin, mevastatin and fluvastatin, lipophobic (pravastatin and nitric-oxide releasing statins and studied in terms of their DNA synthesis, proliferation, apoptosis, matrix metalloproteinase-9 and endothelin-1 release. Results Treatment of human PASMCs with selected statins inhibited DNA synthesis, proliferation and matrix metalloproteinase-9 production in a concentration-dependent manner. Statins differed in their effectiveness, the rank order of anti-mitogenic potency being simvastatin > atorvastatin > > pravastatin. Nevertheless, a novel nitric oxide-releasing derivative of pravastatin (NCX 6550 was effective. Lipophilic statins, such as simvastatin, also enhanced the anti-proliferative effects of iloprost and sildenafil, promoted apoptosis and inhibited the release of the mitogen and survival factor endothelin-1. These effects were reversed by mevalonate and the isoprenoid intermediate geranylgeranylpyrophosphate and were mimicked by inhibitors of the Rho and Rho-kinase. Conclusions Lipophilic statins exert direct effects on distal human PASMCs and are likely to involve inhibition of Rho GTPase signalling. These findings compliment some of the recently documented effects in patients with pulmonary arterial hypertension.

  19. The Effect of Creatine Kinase Inhibition on Contractile Properties of Human Resistance Arteries

    NARCIS (Netherlands)

    Taherzadeh, Zhila; Karamat, Fares A.; Ankum, Willem M.; Clark, Joseph F.; van Montfrans, Gert A.; van Bavel, Ed; Brewster, Lizzy M.

    2016-01-01

    Creatine kinase (CK) is a main predictor of blood pressure, and this is thought to largely depend on high resistance artery contractility. We previously reported an association between vascular contractility and CK in normotensive pregnancy, but pregnancy is a strong CK inducer, and data on human

  20. Fundamental relations between short-term RR interval and arterial pressure oscillations in humans

    Science.gov (United States)

    Taylor, J. A.; Eckberg, D. L.

    1996-01-01

    BACKGROUND: One of the principal explanations for respiratory sinus arrhythmia is that it reflects arterial baroreflex buffering of respiration-induced arterial pressure fluctuations. If this explanation is correct, then elimination of RR interval fluctuations should increase respiratory arterial pressure fluctuations. METHODS AND RESULTS: We measured RR interval and arterial pressure fluctuations during normal sinus rhythm and fixed-rate atrial pacing at 17.2+/-1.8 (SEM) beats per minute greater than the sinus rate in 16 healthy men and 4 healthy women, 20 to 34 years of age. Measurements were made during controlled-frequency breathing (15 breaths per minute or 0.25 Hz) with subjects in the supine and 40 degree head-up tilt positions. We characterized RR interval and arterial pressure variabilities in low-frequency (0.05 to 0.15 Hz) and respiratory-frequency (0.20 to 0.30 Hz) ranges with fast Fourier transform power spectra and used cross-spectral analysis to determine the phase relation between the two signals. As expected, cardiac pacing eliminated beat-to-beat RR interval variability. Against expectations, however, cardiac pacing in the supine position significantly reduced arterial pressure oscillations in the respiratory frequency (systolic, 6.8+/-1.8 to 2.9 +/-0.6 mm Hg2/Hz, P=.017). In contrast, cardiac pacing in the 40 degree tilt position increased arterial pressure variability (systolic, 8.0+/-1.8 to 10.8 +/-2.6, P=.027). Cross-spectral analysis showed that 40 degree tilt shifted the phase relation between systolic pressure and RR interval at the respiratory frequency from positive to negative (9 +/-7 degrees versus -17+/-11 degrees, P=.04); that is, in the supine position, RR interval changes appeared to lead arterial pressure changes, and in the upright position, RR interval changes appeared to follow arterial pressure changes. CONCLUSIONS: These results demonstrate that respiratory sinus arrhythmia can actually contribute to respiratory arterial

  1. The effect of thickness measurement on numerical arterial models.

    Science.gov (United States)

    de Gelidi, Serena; Tozzi, Gianluca; Bucchi, Andrea

    2017-07-01

    Several optical-based techniques for measuring the sample thickness (ST) of soft tissues have been proposed in the literature to overcome the limits of hand-operated procedures. However, ST measurement still remains arbitrary. The stress calculated during an experimental procedure, usually based on a constant thickness value for all samples, cannot be considered representative of the actual stress experienced by the tissue. Therefore, a new optical methodology to measure ST is proposed and compared to four different thickness estimations. A simplified aortic geometry, under physiologic pulsatile conditions, is used to assess the impact of ST measurement on stress predictions. An additional computational model investigates the effect of such thickness values on critical pressure levels that may instigate aneurysm formation in a homogeneous or artificially modified geometry. Comparing the results obtained for the application of a pulsatile load, wall stress values associated to minimum ST are at least 24kPa inferior to maximum ST. Critical pressure values appear to be inversely proportional to ST estimation: simulations, associated to maximum ST, predict aneurysm formation for pressure levels at least 7kPa inferior to minimum ST outcomes. Finally, the role of the strain-energy function used to fit the experimental data is demonstrated to be fundamental for predictions of aneurysm formation. Copyright © 2017. Published by Elsevier B.V.

  2. Characterization of 5-HT receptors on human pulmonary artery and vein: functional and binding studies

    Science.gov (United States)

    Cortijo, Julio; Martí-Cabrera, Miguel; Bernabeu, Eva; Domènech, Teresa; Bou, Josep; Fernández, Andrés G; Beleta, Jorge; Palacios, José M; Morcillo, Esteban J

    1997-01-01

    This study aimed to investigate the 5-hydroxytryptamine (5-HT) receptors mediating contraction of ring preparations isolated from human pulmonary arteries and veins. In functional studies, the responses to 5-HT, sumatriptan, ergotamine, serotonin-O-carboxymethyl-glycyl-tyrosinamide (SCMGT), α-methyl 5-HT (α-Me) and 2-methyl 5-HT (2-Me) were studied with WAY100635, GR127935, ritanserin, zacopride and SB204070 as antagonists.All agonists produced concentration-dependent contractions of human pulmonary artery and vein preparations. The order of potency (−log EC50 values) was ergotamine (6.88)>5-HT (6.41)⩾SCMGT (6.20)=sumatriptan (6.19) ⩾α-Me (6.04) in the artery, and ergotamine (7.84)>5-HT (6.96)>sumatriptan (6.60)=α-Me (6.56)>SCMGT (6.09) in the vein. The potency of each agonist, except for SCMGT, was greater in vein than in artery preparations. Contractile responses to 5-HT were similar in intact and endothelium-denuded preparations but responses to sumatriptan were enhanced in artery rings without endothelium.GR127935 (1 nM to 0.5 μM) produced an unsurmountable antagonism of the response to 5-HT, sumatriptan, ergotamine and SCMGT. Ritanserin (1 nM to 1 μM) also reduced the maximum contractile responses to 5-HT, ergotamine and α-Me in artery and vein preparations without affecting those to sumatriptan and SCMGT. In endothelium-denuded preparations, surmountable antagonism of sumatriptan by GR127935 (in the presence of ritanserin) and of α-Me by ritanserin (in the presence of GR127935) allowed for the calculation of the apparent pKB values of GR127935 (9.17±0.11 in artery and 9.11±0.05 in vein) and ritanserin (8.82±0.09 in artery and 8.98±0.12 in vein).WAY100635 (1 nM to 1 μM), zacopride (1 nM to 1 μM), or SB204070 (1 nM) did not significantly alter the concentration-response curves for 5-HT, sumatriptan, ergotamine, SCMGT or 2-Me in human pulmonary artery or vein thus indicating that 5-HT1A, 5-HT3 and 5-HT4 receptors are

  3. Uterine arteriovenous malformation with positive serum beta-human chorionic gonadotropin: Embolization of both uterine arteries and extra-uterine feeding arteries

    OpenAIRE

    Kim, Su Mi; Ahn, Hee Young; Choi, Min Jeong; Kang, Yun Dan; Park, Jin Wan; Park, Choong Hak; Kim, Jong Soo

    2016-01-01

    The incidence of uterine arteriovenous malformation (AVM) is rare. However, it is clinically significant in that it can cause life-threatening vaginal bleeding. We report a case of a large uterine AVM with positive serum beta-human chorionic gonadotropin. A presumptive diagnosis was made; a uterine AVM accompanied by, early pregnancy or retained product of conception. Because this uterine AVM was extensive, transcatheter arterial embolization of both uterine arteries and extra-uterine feeding...

  4. Computer-Aided Diagnostics of Human Arterial System

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2003-01-01

    Full Text Available The paper deals with the modelling and the simulation of physiological fluid systems laying emphasise on the human vascular system. The presented simulation method has been developed as a helpful tool for the computer-aided non-invasive diagnostics of living bodies. Using the electromechanical analogy between physiological and electrical values the introduced method makes possible the description and 3D representation of the non-linear characteristics of the human haemodynamics as well. The simulation procedure and the obtained results verified by the experiment enable to visualize all physiological and pathophysiological states of the human vascular system.

  5. Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

    DEFF Research Database (Denmark)

    Holstein, P; Lassen, N A

    1980-01-01

    The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel ...

  6. A pitfall in the measurement of arterial blood pressure in the ischaemic limb during elevation

    DEFF Research Database (Denmark)

    Bülow, J; Jelnes, Rolf

    1987-01-01

    In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal artery pressures were measured directly in eight patients with occlusion...... arterial pressure decreased only by 20% of the value expected from the degree of elevation of the calf above the level of the heart. Thus, it could be calculated that calf vascular resistance increased two- to three-fold on average during elevation. Four patients were reexamined with the venous pressure...... kept at 10 mmHg during elevation. In these patients, the increase in vascular resistance was significantly less compared with the situation in which venous pressure was 0 mmHg during elevation. The arterial pressure still did not decrease. It is concluded that perfusion pressure in the ischaemic lower...

  7. Measuring FMD in the brachial artery: how important is QRS gating?

    Science.gov (United States)

    Kizhakekuttu, Tinoy J; Gutterman, David D; Phillips, Shane A; Jurva, Jason W; Arthur, Emily I L; Das, Emon; Widlansky, Michael E

    2010-10-01

    Recommendations for the measurement of brachial flow-mediated dilation (FMD) typically suggest images be obtained at identical times in the cardiac cycle, usually end diastole (QRS complex onset). This recommendation presumes that inter-individual differences in arterial compliance are minimized. However, published evidence is conflicting. Furthermore, ECG gating is not available on many ultrasound systems; it requires an expensive software upgrade or increased image processing time. We tested whether analysis of images acquired with QRS gating or with the more simplified method of image averaging would yield similar results. We analyzed FMD and nitroglycerin-mediated dilation (NMD) in 29 adults with type 2 diabetes mellitus and in 31 older adults and 12 young adults without diabetes, yielding a range of brachial artery distensibility. FMD and NMD were measured using recommended QRS-gated brachial artery diameter measurements and, alternatively, the average brachial diameters over the entire R-R interval. We found strong agreement between both methods for FMD and NMD (intraclass correlation coefficients = 0.88-0.99). Measuring FMD and NMD using average diameter measurements significantly reduced post-image-processing time (658.9 ± 71.6 vs. 1,024.1 ± 167.6 s for QRS-gated analysis, P FMD and NMD measurements based on average diameter measurements can be performed without reducing accuracy. This finding may allow for simplification of FMD measurement and aid in the development of FMD as a potentially useful clinical tool.

  8. Development of a Tonometric Sensor with a Decoupled Circular Array for Precisely Measuring Radial Artery Pulse

    Directory of Open Access Journals (Sweden)

    Min-Ho Jun

    2016-05-01

    Full Text Available The radial artery pulse is one of the major diagnostic indices used clinically in both Eastern and Western medicine. One of the prominent methods for measuring the radial artery pulse is the piezoresistive sensor array. Independence among channels and an appropriate sensor arrangement are important for effectively assessing the spatial-temporal information of the pulse. This study developed a circular-type seven-channel piezoresistive sensor array using face-down bonding (FDB as one of the sensor combination methods. The three-layered housing structure that included independent pressure sensor units using the FDB method not only enabled elimination of the crosstalk among channels, but also allowed various array patterns to be created for effective pulse measurement. The sensors were arranged in a circular-type arrangement such that they could estimate the direction of the radial artery and precisely measure the pulse wave. The performance of the fabricated sensor array was validated by evaluating the sensor sensitivity per channel, and the possibility of estimating the blood vessel direction was demonstrated through a radial artery pulse simulator. We expect the proposed sensor to allow accurate extraction of the pulse indices for pulse diagnosis.

  9. Magnetic Resonance Signal Intensity Ratio Measurement Before Uterine Artery Embolization

    DEFF Research Database (Denmark)

    Duvnjak, Stevo; Ravn, Pernille; Green, Anders

    2017-01-01

    PURPOSE: To evaluate whether the magnetic resonance imaging (MRI) signal intensity (SI) ratio between the dominant fibroid and the periphery striated muscle can predict fibroid volume reduction >50% after uterine fibroid embolization (UFE). MATERIALS AND METHODS: From October 2013 until May 2016......, 52 patients were included in this prospective study. The SI ratio before UFE was calculated using circular region of interests placed on the dominant fibroid and the iliac muscle. The SI fibroid-to-iliac muscle ratio was calculated as SI of the dominant fibroid/SI of the iliac muscle on T1-, T2......-, and T1 post-contrast-weighted sequences. The dominant fibroid volume was measured and analyzed before and after UFE. RESULTS: In all, 46 patients who completed the three-month follow-up MRI were available for analysis. The correlation between SI fibroid-to-muscle ratio at the T2-weighted sequence...

  10. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart

    2017-01-01

    The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared to frequen......The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared...... to frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as model system, integrating vital imaging, pressure myography and mathematical modeling. Collagenase and elastase...

  11. Impact of wall thickness on conduit artery function in humans: is there a "Folkow" effect?

    Science.gov (United States)

    Thijssen, Dick H J; Willems, Laura; van den Munckhof, Inge; Scholten, Ralph; Hopman, Maria T E; Dawson, Ellen A; Atkinson, Greg; Cable, N Timothy; Green, Daniel J

    2011-08-01

    Regional heterogeneity in wall architecture and thickness may be present between conduit arteries in the upper and lower limbs in humans. These differences in wall architecture may, in turn, influence vascular responsiveness. Folkow proposed in the 1950s that heterogeneity in wall-to-lumen ratio (W:L) could contribute to differences in vascular responsiveness, but this hypothesis has never been directly confirmed in vivo. Our first aim was to examine wall thickness and W:L across arteries in the lower (common and superficial femoral) and upper limbs (brachial and radial) of healthy men (n=35) using high resolution ultrasound. In a subgroup (n=20) we examined the relationship between W:L of these arteries, physiological (flow-mediated dilation, FMD) and pharmacological vasodilation (glyceryl trinitrate, GTN). Diameter and wall thickness differed significantly across all arteries (ANOVA P<0.001), with smaller arteries having a relatively larger wall thickness. Moreover, we found a significant correlation between W:L and the FMD-response (r=0.55, P<0.001), which remained significant after correcting for the eliciting shear stress (r=0.47, P<0.001), indicating that W:L/FMD relationship was not primarily related to the impact of diameter on the shear rate stimulus to FMD. W:L also correlated strongly with the GTN-response (r=0.56, P<0.001) across all arteries studied. These results indicate that regional heterogeneity exists in W:L within, but also between, limbs. More importantly, differences in W:L contribute to differences in vascular functional responses, reinforcing the conceptual proposal of Folkow, who suggested that arteries with larger W:L exhibit exaggerated responses to vasoactive stimuli. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Bleeker, Leslie; Berg, Rene van den; Majoie, Charles B. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Marquering, Henk A. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Nederkoorn, Paul J. [Academic Medical Center, Department of Neurology, Amsterdam (Netherlands)

    2012-09-15

    Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure intracranial internal carotid artery (ICA) degree of stenosis and calcium volume in CT angiography (CTA) images. In this retrospective study involving CTA images of 88 consecutive patients, intracranial ICA stenosis was quantitatively measured by two independent observers. Stenoses were categorized with cutoff values of 30% and 50%. The calcification in the intracranial ICA was qualitatively categorized as absent, mild, moderate, or severe and quantitatively measured using the semi-automatic application. Linear weighted kappa values were calculated to assess the interobserver agreement of the stenosis and calcium categorization. The average and the standard deviation of the quantitative calcium volume were calculated for the calcium categories. For the stenosis measurements, the CTA images of 162 arteries yielded an interobserver correlation of 0.78 (P < 0.001). Kappa values of the categorized stenosis measurements were moderate: 0.45 and 0.58 for cutoff values of 30% and 50%, respectively. The kappa value for the calcium categorization was 0.62, with a good agreement between the qualitative and quantitative calcium assessment. Quantitative degree of stenosis measurement of the intracranial ICA on CTA is feasible with a good interobserver agreement ICA. Qualitative calcium categorization agrees well with quantitative measurements. (orig.)

  13. Model of human cardiovascular system with a loop of autonomic regulation of the mean arterial pressure.

    Science.gov (United States)

    Karavaev, Anatoly S; Ishbulatov, Yurii M; Ponomarenko, Vladimir I; Prokhorov, Mikhail D; Gridnev, Vladimir I; Bezruchko, Boris P; Kiselev, Anton R

    2016-03-01

    A model of human cardiovascular system is proposed which describes the main heart rhythm, the regulation of heart function and blood vessels by the autonomic nervous system, baroreflex, and the formation of arterial blood pressure. The model takes into account the impact of respiration on these processes. It is shown that taking into account nonlinearity and introducing the autonomous loop of mean arterial blood pressure in the form of self-oscillating time-delay system allow to obtain the model signals whose statistical and spectral characteristics are qualitatively and quantitatively similar to those for experimental signals. The proposed model demonstrates the phenomenon of synchronization of mean arterial pressure regulatory system by the signal of respiration with the basic period close to 10 seconds, which is observed in the physiological experiments. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  14. Serial measurements of high-sensitivity cardiac troponin T after exercise stress test in stable coronary artery disease

    DEFF Research Database (Denmark)

    Axelsson, Anna; Ruwald, Martin Huth; Dalsgaard, Morten

    2013-01-01

    The aim was to assess serial measurements of high-sensitivity cardiac troponin T (hs-cTNT) post-exercise in patients with stable coronary artery disease (CAD).......The aim was to assess serial measurements of high-sensitivity cardiac troponin T (hs-cTNT) post-exercise in patients with stable coronary artery disease (CAD)....

  15. Mortality risk in hemodialysis patients with increased arterial stiffness is reduced by attainment of classical clinical performance measures

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Thies, Christina; Cheikhalfraj, Mohamed

    2009-01-01

    We determined whether attainment of classical clinical performance measures for hemodialysis care improves survival in hemodialysis patients with increased arterial stiffness.......We determined whether attainment of classical clinical performance measures for hemodialysis care improves survival in hemodialysis patients with increased arterial stiffness....

  16. An Ultra Miniature MEMS Capacitor for Arterial Pressure Measurement

    Science.gov (United States)

    Monga, A.; Vig, R.

    2012-12-01

    In biomedical field, there is a need for improving medical technologies to provide accurate diagnosis to patients. The objective is to develop a minimally invasive, implantable, pressure sensing system that continuously monitors physiological changes in real-time. For implementing, three different shapes of MEMS capacitive pressure sensor having same area of diaphragm 0.126 mm² is designed and simulated for blood pressure measurement. The various shapes which are taken are circular, square and rectangular. COMSOL multiphysics tool is used for simulation. For these shapes capacitance and deflection variation of membrane with applied pressure is studied. Result shows a sensitivity of 0.255 aF/kPa, 0.125 aF/kPa and 0.09 aF/kPa for circular, square and rectangular shape, respectively. So, circular MEMS capacitor provides the greater sensitivity than all other shapes and also provides greater deflection of diaphragm due to applied pressure of 40 kPa. Also deflection is more in circular diaphragm capacitive pressure sensor.

  17. Endothelin-dependent vasoconstriction in human uterine artery: application to preeclampsia.

    Directory of Open Access Journals (Sweden)

    Clotilde Dechanet

    Full Text Available BACKGROUND: Reduced uteroplacental perfusion, the initiating event in preeclampsia, is associated with enhanced endothelin-1 (ET-1 production which feeds the vasoconstriction of uterine artery. Whether the treatments of preeclampsia were effective on ET-1 induced contraction and could reverse placental ischemia is the question addressed in this study. We investigated the effect of antihypertensive drugs used in preeclampsia and of ET receptor antagonists on the contractile response to ET-1 on human uterine arteries. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed, ex vivo, on human uterine artery samples obtained after hysterectomy. We studied variations in isometric tension of arterial rings in response to the vasoconstrictor ET-1 and evaluated the effects of various vasodilators and ET-receptor antagonists on this response. Among antihypertensive drugs, only dihydropyridines were effective in blocking and reversing the ET-1 contractile response. Their efficiency, independent of the concentration of ET-1, was only partial. Hydralazine, alpha-methyldopa and labetalol had no effect on ET-1 induced contraction which is mediated by both ET(A and ET(B receptors in uterine artery. ET receptors antagonists, BQ-123 and BQ-788, slightly reduced the amplitude of the response to ET-1. Combination of both antagonists was more efficient, but it was not possible to reverse the maximal ET-1-induced contraction with antagonists used alone or in combination. CONCLUSION: Pharmacological drugs currently used in the context of preeclampsia, do not reverse ET-1 induced contraction. Only dihydropyridines, which partially relax uterine artery previously contracted with ET-1, might offer interesting perspectives to improve placental perfusion.

  18. Labetalol, nebivolol, and propranolol relax human radial artery used as coronary bypass graft.

    Science.gov (United States)

    Korkmaz, Ozge; Saraç, Bülent; Göksel, Sabahattin; Yildirim, Sahin; Berkan, Ocal; Bagcivan, Ihsan

    2015-04-01

    Beta-blockers are a heterogeneous class of agents that are used in the treatment of many cardiovascular diseases, especially hypertension and atherosclerosis, and that are commonly prescribed after cardiac surgery. In the present study, the aim is to investigate the vasorelaxant effects of some common beta-adrenoceptor blockers on the human radial artery in vitro, as well as their relaxation mechanisms. Radial artery rings sourced from human patients were mounted in an organ bath and tested for changes in isometric tension in relaxation response to labetalol, nebivolol, and propranolol in the presence and absence of NG-nitro-L-arginine methyl ester (3 × 10(-5) mol/L) and tetraethyl ammonium (3 × 10(-4) mol/L). The labetalol (10(-8) to 10(-4) mol/L), nebivolol (10(-8) to 10(-4) mol/L), and propranolol (10(-8) to 10(-4) mol/L) induced concentration-dependent relaxations on the radial artery rings, which had been precontracted with phenylephrine (10(-6) mol/L). The relaxation response induced by labetalol in the isolated radial artery rings was significantly higher when compared with the nebivolol and propranolol samples (P labetalol, nebivolol, and propranolol (P labetalol, nebivolol, and propranolol was due partly to the Ca(2+)-activated K(+) channels. In addition, the relaxation induced by nebivolol was largely related with nitric oxide release. Nebivolol, and partly propranolol, may provide significant therapeutic benefit, but labetalol can be a good alternative for coronary artery bypass grafting with radial artery use. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  19. Premature birth is associated with not fully differentiated contractile smooth muscle cells in human umbilical artery.

    Science.gov (United States)

    Roffino, S; Lamy, E; Foucault-Bertaud, A; Risso, F; Reboul, R; Tellier, E; Chareyre, C; Dignat-George, F; Simeoni, U; Charpiot, P

    2012-06-01

    Smooth muscle cells (SMCs) participate to the regulation of peripheral arterial resistance and blood pressure. To assume their function, SMCs differentiate throughout the normal vascular development from a synthetic phenotype towards a fully differentiated contractile phenotype by acquiring a repertoire of proteins involved in contraction. In human fetal muscular arteries and umbilical arteries (UAs), no data are available regarding the differentiation of SMCs during the last trimester of gestation. The objective of this study was to characterize the phenotype of SMCs during this gestation period in human UAs. We investigated the phenotype of SMCs in human UAs from very preterm (28-31 weeks of gestation), late preterm (32-35 weeks) and term (37-41 weeks) newborns using biochemical and immunohistochemical detection of α-actin, smooth muscle myosin heavy chain, smoothelin, and non-muscle myosin heavy chain. We found that the number of SMCs positive for smoothelin in UAs increased with gestational age. Western blot analysis revealed a higher content of smoothelin in term compared to very preterm UAs. These results show that SMCs in human UAs gradually acquire a fully differentiated contractile phenotype during the last trimester of gestation and thus that premature birth is associated with not fully differentiated contractile SMCs in human UAs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Quantitative flow measurement after placing a flow diverter for a distal internal carotid artery aneurysm.

    Science.gov (United States)

    Chen, Chien-Wei; Wong, Ho-Fai; Ye, Yu-Ling; Chen, Yao-Liang; Chen, Wei-Liang; Ou, Chang-Hsien; Tsai, Yuan-Hsiung

    2017-12-01

    To evaluate the differences in arterial flow after flow diverter placement using quantitative flow measurements based on digital subtraction angiography (DSA). Between November 2013 and November 2015, all patients who had flow diverters placed for distal internal carotid artery (ICA) aneurysms were reviewed. Patients in whom the stent was placed across the ostia of the ophthalmic artery (OphA) and anterior choroidal artery (AChA) were enrolled. Five regions of interest were selected: the proximal ICA (as a reference), terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA), OphA, and AChA. The values of the peak, time-to-peak (TTP), and area under the curve (AUC) were analyzed using a quantitative DSA technique. The study enrolled 13 patients. The quantitative flow analysis showed improved flow in the terminal ICA (peak and AUC, p=0.036 and p=0.04, respectively), MCA (AUC, p=0.023), and ACA (AUC, p=0.006), and decreased flow in the OphA (peak and AUC, p=0.013 and p=0.005, respectively) and AChA (peak and subtracted TTP, p=0.023 and p=0.050, respectively) after flow diverter placement. Larger aneurysm volume was significantly correlated with decreased OphA flow after the procedure (peak and AUC, p=0.049 and p=0.037, respectively). Larger aneurysm volume also had a marginal correlation with increased distal ICA flow after the procedure, but this did not reach significance (peak and AUC, p=0.195 and p=0.060, respectively). Without using extra contrast medium or radiation dosages, color-coded DSA enables quantitative monitoring of the cerebral circulation after flow-diverting treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. Circle of Willis variations and artery diameter measurements in the Turkish population.

    Science.gov (United States)

    Yeniçeri, I Ö; Çullu, N; Deveer, M; Yeniçeri, E N

    2017-01-01

    The aim of this study was to evaluate the frequency of circle of Willis (COW) variations and the measurements of the COW vessel diameters in the Turkish population. The patient population for this single-centre, retrospective study was formed of patients who had brain magnetic resonance angiography (MRA). A total of 384 subjects were included in the study. The three-dimensional time-of-flight (TOF) technique was used for MRA imaging to evaluate the anatomy of the COW. Variations in the COW were recorded. The diameters of the critical arteries of the COW were measured. Adult configuration of the COW was determined in 326 (85%) cases, foetal configuration in 50 (13%) cases and transitional configuration in 8 (2%) cases. The COW was normal in 328 (85.4%). In the remaining 56 (14.6%) cases, agenesis was determined in 62 vessels. The mean calibrations of the vessels were measured as 2.85 mm in the basilar artery, 4.24 mm in the right internal carotid artery (ICA), 4.32 mm in the left ICA, 1.58 mm in the right A1, 1.64 mm in the left A1, 2.13 mm in the right M1, 2.10 mm in the left M1, 1.80 mm in the right P1, 1.88 mm in the left P1, 1.12 mm in the right posterior communicating artery, and 1.12 mm in the left posterior communicating artery. Circle of Willis variations may show geographic and ethnic differences. Knowledge of the frequency and types of variation in the population is important for neurosurgeons and in radiological interventional procedures as a guide for entry and in respect of collateral which could develop later.

  2. Oscillometric measurement of arterial pulse pressure for patients supported by a rotary blood pump.

    Science.gov (United States)

    Yu, Yih-Choung; Peterson, Anna

    2015-01-01

    A computer model has been developed to evaluate the accuracy of an oscillometric method to measure the arterial pulse pressure from a patient with a rotary ventricular assist device (VAD). This computer model consists of three major components: the cardiovascular system, the HeartMate II VAD, and the operation of an automated cuff. Simulation was performed to mimic failure, recovery, and normal cardiac functions of a patient, supported by the HeartMate II VAD at different levels from minimum to maximum. The oscillating cuff pressure, simulating the air pressure of a deflecting cuff, was obtained from simulation under different conditions to test the accuracy of an oscillometric algorithm in determining the arterial pulse pressure. The algorithm was able to detect the systolic and diastolic arterial pressure with the error within ±2 mmHg in most cases, except the cases when ventricular suction, induced by the VAD, occurred. The results from this study suggested that the oscillometric algorithm is capable to accurately detect the arterial pulse pressure for a rotary VAD patient if the algorithm is properly tuned.

  3. A cell culture model using rat coronary artery adventitial fibroblasts to measure collagen production

    Directory of Open Access Journals (Sweden)

    Meszaros Gary

    2007-05-01

    Full Text Available Abstract Background We have developed a rat cell model for studying collagen type I production in coronary artery adventitial fibroblasts. Increased deposition of adventitial collagen type I leads to stiffening of the blood vessel, increased blood pressure, arteriosclerosis and coronary heart disease. Although the source and mechanism of collagen deposition is yet unknown, the adventitia appears to play a significant role. To demonstrate the application of our cell model, cultured adventitial fibroblasts were treated with sex hormones and the effect on collagen production measured. Methods Hearts (10–12 weeks were harvested and the left anterior descending coronary artery (LAD was isolated and removed. Tissue explants were cultured and cells (passages 2–4 were confirmed as fibroblasts using immunohistochemistry. Optimal conditions were determined for cell tissue harvest, timing, proliferation and culture conditions. Fibroblasts were exposed to 10-7 M testosterone or 10-7 M estrogen for 24 hours and either immunostained for collagen type I or subjected to ELISA. Results Results showed increased collagen staining in fibroblasts treated with testosterone compared to control and decreased staining with estrogen. ELISA results showed that testosterone increased collagen I by 20% whereas estrogen decreased collagen I by 15%. Conclusion Data demonstrates the usefulness of our cell model in studying the specific role of the adventitia apart from other blood vessel tissue in rat coronary arteries. Results suggest opposite effects of testosterone and estrogen on collagen synthesis in the rat coronary artery adventitial fibroblasts.

  4. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A

    2004-01-01

    in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

  5. Coronary flow reserve and relative flow reserve measured by N-13 ammonia PET for characterization of coronary artery disease.

    Science.gov (United States)

    Cho, Sang-Geon; Park, Ki Seong; Kim, Jahae; Kang, Sae-Ryung; Song, Ho-Chun; Kim, Ju Han; Cho, Jae Yeong; Hong, Young Joon; Jabin, Zeenat; Park, Hee Jeong; Jeong, Geum-Cheol; Kwon, Seong Young; Paeng, Jin Chul; Kim, Hyeon Sik; Min, Jung-Joon; Garcia, Ernest V; Bom, Henry Hee-Seung

    2017-02-01

    We evaluated the relationships between coronary flow reserve (CFR) and relative flow reserve (RFR) measured by N-13 ammonia positron emission tomography (PET) for characterization of epicardial coronary artery disease (CAD). Sixty-nine consecutive stable angina patients underwent N-13 ammonia PET, coronary computed tomography angiography (CCTA), and if necessary, invasive coronary angiography (CAG) within 2 weeks. Myocardial blood flow (MBF), CFR, RFR, and coronary vascular resistance of the reference arterial territory (CVR ref ) were measured by N-13 ammonia PET. The presence of significant stenosis (SS) and diffuse atherosclerosis (DA) was evaluated on CCTA and CAG. Functional parameters measured by PET were compared among arteries with and without SS and DA. Arteries with SS and those with DA showed significantly lower stress MBF, as compared to those without. RFR was significantly lower in arteries with SS as compared to those without, while CFR was not. CFR was significantly lower in arteries with DA as compared to those without, while RFR was not. Among arteries without SS, CFR was significantly lower in those with DA as compared to those without. However, among arteries with SS, CFR was similar between those with and without DA. In contrast, RFR was significantly lower in arteries with SS, regardless of the presence of DA. CFR and RFR showed a weak positive correlation (r = 0.269) with discordance in 24 cases (35%). Among the arteries with CFR-RFR discordance, the prevalence of DA was significantly higher in those with low CFR but preserved RFR, as compared to those with preserved CFR but low RFR (75 vs 25%, p = 0.028). CVR ref was significantly higher in arteries with DA, implicating a correlation of DA with underlying microvascular disease. CFR and RFR measured by myocardial perfusion PET could provide a comprehensive information for characterization of epicardial CAD.

  6. Measurement of the arterial concentration of Gd-DTPA using MRI: a step toward quantitative perfusion imaging

    DEFF Research Database (Denmark)

    Fritz-Hansen, T; Rostrup, Egill; Larsson, H B

    1996-01-01

    A noninvasive method using an inversion recovery turbo-FLASH for dynamic measurement of the arterial input function represented by the bolus passage of Gd-DTPA in the descending aorta is presented, and the results are compared with the input function obtained by arterial blood samples. A good acc...

  7. A Simplified Quantitative Method to Measure Brain Shifts in Patients with Middle Cerebral Artery Stroke.

    Science.gov (United States)

    Paletta, Nina; Maali, Laith; Zahran, Abdurrehman; Sethuraman, Sankara; Figueroa, Ramon; Nichols, Fenwick T; Bruno, Askiel

    2017-11-10

    A standardized and validated method to measure brain shifts in malignant middle cerebral artery (MCA) stroke with decompressive hemicraniectomy (DHC) could facilitate clinical decision making, prognostication, and comparison of results between studies. We tested for reliability simplified methods to measure transcalvarial herniation, midline brain shift, and the contralateral cerebral ventricular atrium in malignant MCA stroke after DHC. Multiple raters measured brain shifts on post-DHC computed tomography (CT) scans with aligned and unaligned slice orientations in 25 patients. We compared the simplified measurements to previously reported more meticulous measurements. The simplified measurements correlate well with the more meticulous measurements on both aligned and unaligned CTs (intraclass correlation coefficients .72-.89). These simplified and expedient methods of measuring brain shifts in malignant MCA stroke after DHC correlate well with the more meticulous methods. Copyright © 2017 by the American Society of Neuroimaging.

  8. Exercise and arterial adaptation in humans: uncoupling localized and systemic effects.

    Science.gov (United States)

    Rowley, Nicola J; Dawson, Ellen A; Birk, Gurpreet K; Cable, N Timothy; George, Keith; Whyte, Greg; Thijssen, Dick H J; Green, Daniel J

    2011-05-01

    Previous studies have established effects of exercise training on arterial wall thickness, remodeling, and function in humans, but the extent to which these changes are locally or systemically mediated is unclear. We examined the brachial arteries of the dominant (D) and nondominant (ND) upper limbs of elite racquet sportsmen and compared them to those of matched healthy inactive controls. Carotid and superficial femoral artery responses were also assessed in both groups. High-resolution duplex ultrasound was used to examine resting diameter, wall thickness, peak diameter, and blood flow. We found larger resting arterial diameter in the preferred arm of the athletes (4.9 ± 0.5 mm) relative to their nonpreferred arm (4.3 ± 0.4 mm, P < 0.05) and both arms of control subjects (D: 4.1 ± 0.4 mm; ND: 4.0 ± 0.4, P < 0.05). Similar limb-specific differences were also evident in brachial artery dilator capacity (5.5 ± 0.5 vs. 4.8 ± 0.4, 4.8 ± 0.6, and 4.8 ± 0.6 mm, respectively; P < 0.05) following glyceryl trinitrate administration and peak blood flow (1,118 ± 326 vs. 732 ± 320, 737 ± 219, and 698 ± 174 ml/min, respectively; P < 0.05) following ischemic handgrip exercise. In contrast, athletes demonstrated consistently lower wall thickness in carotid (509 ± 55 μm), brachial (D: 239 ± 100 μm; ND: 234 ± 133 μm), and femoral (D: 479 ± 38 μm; ND: 479 ± 42 μm) arteries compared with control subjects (carotid: 618 ± 74 μm; brachial D: 516 ± 100 μm; ND: 539 ± 129 μm; femoral D: 634 ± 155 μm; ND: 589 ± 112 μm; all P < 0.05 vs. athletes), with no differences between the limbs of either group. These data suggest that localized effects of exercise are evident in the remodeling of arterial size, whereas arterial wall thickness appears to be affected by systemic factors.

  9. Testosterone and atrial natriuretic peptide share the same pathway to induce vasorelaxation of human umbilical artery.

    Science.gov (United States)

    Feiteiro, Joana; Santos-Silva, António J; Verde, Ignacio; Cairrão, Elisa

    2014-05-01

    We recently observed in human umbilical artery smooth muscle cells that testosterone activates protein kinase G and stimulates large-conductance Ca²⁺ activated (BKCa) and voltage sensitive (KV) potassium channels. In the same work, we also show that atrial natriuretic peptide (ANP), an activator of particulate guanylate cyclase (pGC), stimulates the activity of BKCa and KV channels because of protein kinase G activation. The aim of this work was to prove that the relaxant effects of testosterone are also because of the increase of cGMP because of activation of the pGC. Subsarcolemmal cGMP signals were monitored in single cells by recording the cGMP-gated current (ICNG) in human umbilical artery smooth muscle cells expressing the wild-type rat olfactory cyclic nucleotide-gated (CNG) channel. Sodium nitroprusside (10 and 100 μM), ANP (0.1 and 1 μM), or testosterone (0.1, 1, and 10 μM) induced activation of ICNG. This activation induced by testosterone and ANP is bigger than that elicited by sodium nitroprusside. In summary, our study reveals that testosterone and ANP activate the pGC and induce vasorelaxation of human umbilical artery.

  10. Exposure to wood smoke increases arterial stiffness and decreases heart rate variability in humans.

    Science.gov (United States)

    Unosson, Jon; Blomberg, Anders; Sandström, Thomas; Muala, Ala; Boman, Christoffer; Nyström, Robin; Westerholm, Roger; Mills, Nicholas L; Newby, David E; Langrish, Jeremy P; Bosson, Jenny A

    2013-06-06

    Emissions from biomass combustion are a major source of indoor and outdoor air pollution, and are estimated to cause millions of premature deaths worldwide annually. Whilst adverse respiratory health effects of biomass exposure are well established, less is known about its effects on the cardiovascular system. In this study we assessed the effect of exposure to wood smoke on heart rate, blood pressure, central arterial stiffness and heart rate variability in otherwise healthy persons. Fourteen healthy non-smoking subjects participated in a randomized, double-blind crossover study. Subjects were exposed to dilute wood smoke (mean particle concentration of 314±38 μg/m3) or filtered air for three hours during intermittent exercise. Heart rate, blood pressure, central arterial stiffness and heart rate variability were measured at baseline and for one hour post-exposure. Central arterial stiffness, measured as augmentation index, augmentation pressure and pulse wave velocity, was higher after wood smoke exposure as compared to filtered air (p smoke compared to filtered air. Acute exposure to wood smoke as a model of exposure to biomass combustion is associated with an immediate increase in central arterial stiffness and a simultaneous reduction in heart rate variability. As biomass is used for cooking and heating by a large fraction of the global population and is currently advocated as a sustainable alternative energy source, further studies are required to establish its likely impact on cardiovascular disease. ClinicalTrials.gov, NCT01488500.

  11. Bilateral carotid artery injury response in side impact using a vessel model integrated with a human body model.

    Science.gov (United States)

    Danelson, Kerry A; Gayzik, F Scott; Yu, Mao M; Martin, R Shayn; Duma, Stefan M; Stitzel, Joel D

    2009-10-01

    In a far-side crash configuration, the occupant can experience severe excursion from the seat space. Given this challenge, there are research efforts focused on alternate restraints, such as four-point belts. A potential implication of this geometry would be interaction of the belt with the occupant's neck. This study examines the response of the carotid arteries using a Finite Element Model (FEM) in a far-side crash configuration with a reversed three-point restraint. A FEM of the carotid artery and neck fascia was developed and integrated with the Total Human Model for Safety (THUMS) version 1.44. This model was subjected to four test conditions simulating far-side crashes. Load conditions included a low velocity impact of approximately 4 m/s and a higher velocity impact of approximately 10 m/s. For each velocity, the model was restrained with a belt placed low on the neck and a belt placed higher on the neck. Strain data in each element of the carotid arteries was analyzed. The overall response of the vessel was examined to determine locations of high strain values. Low belt placement resulted in more head excursion, stretching the carotid on the non-struck side. High belt placement resulted in compression of the artery on the struck side due to direct loading of the vessel from the belt. Strain values in the carotid artery elements increased with increasing speed of impact. The lower and higher speed tests with a low belt configuration resulted in a maximum principal strains, at maximal belt engagement, of 0.223 and 0.459, respectively. Corresponding values for the high belt configuration were 0.222 and 0.563. In both belt configurations, the non-struck side vessel stretched more than the struck side vessel; however, the non-struck side vessel experienced higher compressive forces. Strain values measured during the simulations can be compared to a value of 0.31 to intimal failure in previous experimental tests. These results quantitatively illustrate the two

  12. Human localization and performance measures

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2009-01-01

    Localization is for some scenarios and situations vital for the success of hearing, e. g. when listening out single sources in multi-source environments, or when navigating primarily by audible information. It is therefore of interest to know the limits of the human localization capacity, and its...... dependence on e.g. direction and distance. When addressed in laboratory experiments, the significance of other modalities are controlled in different ways, yet figures will inherently reflect properties of the test situation as well. The present paper will discuss the methodologies of localization...

  13. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

    Directory of Open Access Journals (Sweden)

    Lynch Tadhg

    2009-04-01

    Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  14. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H

    2009-01-01

    OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  15. Geometry-based pressure drop prediction in mildly diseased human coronary arteries.

    Science.gov (United States)

    Schrauwen, J T C; Wentzel, J J; van der Steen, A F W; Gijsen, F J H

    2014-06-03

    Pressure drop (△p) estimations in human coronary arteries have several important applications, including determination of appropriate boundary conditions for CFD and estimation of fractional flow reserve (FFR). In this study a △p prediction was made based on geometrical features derived from patient-specific imaging data. Twenty-two mildly diseased human coronary arteries were imaged with computed tomography and intravascular ultrasound. Each artery was modelled in three consecutive steps: from straight to tapered, to stenosed, to curved model. CFD was performed to compute the additional △p in each model under steady flow for a wide range of Reynolds numbers. The correlations between the added geometrical complexity and additional △p were used to compute a predicted △p. This predicted △p based on geometry was compared to CFD results. The mean △p calculated with CFD was 855±666Pa. Tapering and curvature added significantly to the total △p, accounting for 31.4±19.0% and 18.0±10.9% respectively at Re=250. Using tapering angle, maximum area stenosis and angularity of the centerline, we were able to generate a good estimate for the predicted △p with a low mean but high standard deviation: average error of 41.1±287.8Pa at Re=250. Furthermore, the predicted △p was used to accurately estimate FFR (r=0.93). The effect of the geometric features was determined and the pressure drop in mildly diseased human coronary arteries was predicted quickly based solely on geometry. This pressure drop estimation could serve as a boundary condition in CFD to model the impact of distal epicardial vessels. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Physiological flow analysis in significant human coronary artery stenoses.

    Science.gov (United States)

    Banerjee, Rupak K; Back, Lloyd H; Back, Martin R; Cho, Young I

    2003-01-01

    To evaluate the local hemodynamics in flow limiting coronary lesions, computational hemodynamics was applied to a group of patients previously reported by Wilson et al. (1988) with representative pre-angioplasty stenosis geometry (minimal lesion size d(m)=0.95 mm; 68% mean diameter stenosis) and with measured values of coronary flow reserve (CFR) in the abnormal range (2.3+/-0.1). The computations were at mean flow rates (Q) of 50, 75 and 100 ml/min (the limit of our converged calculations). Computed mean pressure drops Deltap were approximately 9 mmHg for basal flow (50 ml/min), approximately 27 mmHg for elevated flow (100 ml/min) and increased to an extrapolated value of approximately 34 mmHg for hyperemic flow (115 ml/min), which led to a distal mean coronary pressure p(rh) of approximately 55 mmHg, a level known to cause ischemia in the subendocardium (Brown et al., 1984), and consistent with the occurrence of angina in the patients. Relatively high levels of wall shear stress were computed in the narrow throat region and ranged from about 600 to 1500 dyn/cm(2), with periodic (phase shifted) peak systolic values of about 3500 dyn/cm(2). In the distal vessel, the interaction between the separated shear layer wave, convected downstream by the core flow, and the wall shear layer flow, led to the formation of vortical flow cells along the distal vessel wall during the systolic phase where Reynolds numbers Re(e)(t) were higher. During the phasic vortical mode observed at both basal and elevated mean flow rates, wide variations in distal wall shear stress occurred, distal transmural pressures were depressed below throat levels, and pressure recovery was larger farther along the distal vessel. Along the constriction (convergent) and throat segments of the lesion the pulsatile flow field was principally quasi-steady before flow separation occurred. The flow regimes were complex in the narrow mean flow Reynolds number range Re(e)=100-230 and a frequency parameter of

  17. Wave processes in the human cardiovascular system: The measuring complex, computing models, and diagnostic analysis

    Science.gov (United States)

    Ganiev, R. F.; Reviznikov, D. L.; Rogoza, A. N.; Slastushenskiy, Yu. V.; Ukrainskiy, L. E.

    2017-03-01

    A description of a complex approach to investigation of nonlinear wave processes in the human cardiovascular system based on a combination of high-precision methods of measuring a pulse wave, mathematical methods of processing the empirical data, and methods of direct numerical modeling of hemodynamic processes in an arterial tree is given.

  18. A comparison of basilar artery diameters measured by T2WI and TOF MR angiography.

    Science.gov (United States)

    Çelebioğlu, Emre Can; Aldur, Muhammed Mustafa; Tunali, Selcuk; Hayran, Murvet; Taşçıoğlu, Ayşe Beliz; Sargon, F Mustafa

    2017-11-01

    The purpose of our study is to compare basilar artery diameters (BAD) measured by T2WI to diameters measured by TOF MR angiography (MRA). By doing this, we hope to understand how compatible these two methodologies are with each other. We used data from 100 patients (59 females, 41 males) who underwent a session of both T2W MRI and TOF MRA at the same time (ages between 18 and 83). We measured BAD by both T2WI and TOF MRA in three different levels. We then compared these diameters measured by two different methodologies to each other. In an area between the vertebrobasilar junction and posterior cerebral artery, all data measured by T2WI and TOF MRA in three different levels were analyzed. Average diameters measured by T2WI and TOF MRA turned out to be 79.5% correlated with each other. As a result of our mathematical model that we came up with through regression analysis, we calculated that measurements taken by T2WI on mid-pontine levels could predict TOF MRA measures with 78.3% accuracy. In T2WI and TOF MRA, average diameters measured were 2.982 ± 0.4717 and 3.205 ± 0.4281 mm, respectively. Statistical analyses showed that images measured by T2W series were significantly smaller than those measured by TOF MRA (p < 0.05). Our study showed that BAD measured by T2WI were smaller than those measured by TOF MRA. We think that it will be beneficial to refer our results to avoid T2WI and TOF MRA mismatch when evaluating BAD.

  19. Pulsatility Index of Blood Echogenicity of the Human Radial and Common Carotid Arteries: Relation with Age and Stroke

    Energy Technology Data Exchange (ETDEWEB)

    Bok, Tae Hoon; Kong, Qi; Nam, Kweon Ho; Choi, Jay Chol; Paeng, Dong Guk [Department of Ocean System Engineering, Jeju National University, Jeju (Korea, Republic of)

    2012-10-15

    In the present paper, the ultrasound blood images were measured at both the human radial artery(RA) and common carotid artery(CCA), depending on the age, and the pulsatility index of blood echogenicity(PIBE) was analyzed. In addition, the ultrasound blood images were measured at both RA and CCA of both the stroke patients and the control group, and PIBE was compared. PIBE of RA for the young group was similar with that for the old group (0.13{+-}0.21 and 0.16{+-}0.03). PIBE of CCA for the young group, however, was larger than that for the old group (0.70{+-}0.21 and 0.32{+-}0.01), and was more variable depending on the subject. Similarly, the fibrinogen concentrations of the patients (336{+-}61 and 340{+-}126 mg/dl) were more than that of the control group (264{+-}38 and 43 mg/dl), for both RA and CCA. The results indicate the possibility of the ultrasonic test on the correlation between erythrocyte aggregation and stroke, and it is expected that the in-vivo EA measurement would be clinically useful.

  20. Repeated increases in blood flow, independent of exercise, enhance conduit artery vasodilator function in humans.

    Science.gov (United States)

    Naylor, Louise H; Carter, Howard; FitzSimons, Matthew G; Cable, N Timothy; Thijssen, Dick H J; Green, Daniel J

    2011-02-01

    This study aimed to determine the importance of repeated increases in blood flow to conduit artery adaptation, using an exercise-independent repeated episodic stimulus. Recent studies suggest that exercise training improves vasodilator function of conduit arteries via shear stress-mediated mechanisms. However, exercise is a complex stimulus that may induce shear-independent adaptations. Nine healthy men immersed their forearms in water at 42°C for three 30-min sessions/wk across 8 wk. During each session, a pneumatic pressure cuff was inflated around one forearm to unilaterally modulate heating-induced increases in shear. Forearm heating was associated with an increase in brachial artery blood flow (P<0.001) and shear rate (P<0.001) in the uncuffed forearm; this response was attenuated in the cuffed limb (P<0.005). Repeated episodic exposure to bilateral heating induced an increase in endothelium-dependent vasodilation in response to 5-min ischemic (P<0.05) and ischemic handgrip exercise (P<0.005) stimuli in the uncuffed forearm, whereas the 8-wk heating intervention did not influence dilation to either stimulus in the cuffed limb. Endothelium-independent glyceryl trinitrate responses were not altered in either limb. Repeated heating increases blood flow to levels that enhance endothelium-mediated vasodilator function in humans. These findings reinforce the importance of the direct impacts of shear stress on the vascular endothelium in humans.

  1. Radiological assessment of the inferior alveolar artery course in human corpse mandibles

    Energy Technology Data Exchange (ETDEWEB)

    Bertl, Kristina [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Malmoe University, Department of Periodontology, Faculty of Odontology, Malmoe (Sweden); Hirtler, Lena [Medical University of Vienna, Center for Anatomy and Cell Biology, Department of Systematic Anatomy, Vienna (Austria); Dobsak, Toni [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Medical University of Vienna, Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, Vienna (Austria); Austrian Cluster for Tissue Regeneration, Vienna (Austria); Heimel, Patrick [Medical University of Vienna, Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, Vienna (Austria); Austrian Cluster for Tissue Regeneration, Vienna (Austria); Ludwig Boltzmann Institute for Clinical and Experimental Traumatology, Vienna (Austria); Gahleitner, Andre [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Medical University of Vienna, Department of Diagnostic Radiology, Division of Osteoradiology, General Hospital, Vienna (Austria); Ulm, Christian [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Plenk, Hanns [Medical University of Vienna, Bone and Biomaterials Research, Institute for Histology and Embryology, Vienna (Austria)

    2015-04-01

    CT assessment of the entire course of the inferior alveolar artery (IAA) within the mandibular canal. After contrast medium injection (180 or 400 mg/ml iodine concentration) into the external carotid arteries of 15 fresh human cadaver heads, the main IAA's position in the canal (cranial, buccal, lingual or caudal) was assessed in dental CT images of partially edentulous mandibles. The course of the main IAA could be followed at both iodine concentrations. The higher concentration gave the expected better contrast, without creating artefacts, and improved visibility of smaller arteries, such as anastomotic sections, dental branches and the incisive branch. The main IAA changed its position in the canal more often than so far known (mean 4.3 times, SD 1.24, range 2-7), but with a similar bilateral course. A cranial position was most often detected (42 %), followed by lingual (36 %), caudal (16 %) and buccal (6 %). With this non-invasive radiologic method, the entire course of the main IAA in the mandibular canal could be followed simultaneously with other bone structures on both sides of human cadaver mandibles. This methodology allows one to amend existing anatomical and histological data, which are important for surgical interventions near the mandibular canal. (orig.)

  2. Cannabidiol causes endothelium-dependent vasorelaxation of human mesenteric arteries via CB1 activation.

    Science.gov (United States)

    Stanley, Christopher P; Hind, William H; Tufarelli, Cristina; O'Sullivan, Saoirse E

    2015-09-01

    The protective effects of cannabidiol (CBD) have been widely shown in preclinical models and have translated into medicines for the treatment of multiple sclerosis and epilepsy. However, the direct vascular effects of CBD in humans are unknown. Using wire myography, the vascular effects of CBD were assessed in human mesenteric arteries, and the mechanisms of action probed pharmacologically. CBD-induced intracellular signalling was characterized using human aortic endothelial cells (HAECs). CBD caused acute, non-recoverable vasorelaxation of human mesenteric arteries with an Rmax of ∼ 40%. This was inhibited by cannabinoid receptor 1 (CB1) receptor antagonists, desensitization of transient receptor potential channels using capsaicin, removal of the endothelium, and inhibition of potassium efflux. There was no role for cannabinoid receptor-2 (CB2) receptor, peroxisome proliferator activated receptor (PPAR)γ, the novel endothelial cannabinoid receptor (CBe), or cyclooxygenase. CBD-induced vasorelaxation was blunted in males, and in patients with type 2 diabetes or hypercholesterolemia. In HAECs, CBD significantly reduced phosphorylated JNK, NFκB, p70s6 K and STAT5, and significantly increased phosphorylated CREB, ERK1/2, and Akt levels. CBD also increased phosphorylated eNOS (ser1177), which was correlated with increased levels of ERK1/2 and Akt levels. CB1 receptor antagonism prevented the increase in eNOS phosphorylation. This study shows, for the first time, that CBD causes vasorelaxation of human mesenteric arteries via activation of CB1 and TRP channels, and is endothelium- and nitric oxide-dependent. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  3. An angiographic study of intracardiac coronary arteries from human autopsy hearts: their clinicopathologic significance and characterization during transmural myocardial infarction.

    Science.gov (United States)

    Kuwao, S; Nishiyama, Y

    1990-03-01

    In this study of human autopsy hearts, coronary arteries were divided by morphologic criteria into classes A (branching-type) and B (straight-type) arteries. Infarcted hearts and normal hearts were investigated mainly by means of coronary angiography, as well as by gross and histologic examinations. Transmural myocardial infarction originated in the inner half of the myocardial layer, which was predominantly supplied by class A arteries, followed by gradual extension to the outer layer. The early infarcted focus revealed an angiographically avascular state. This may have been the result of shrinkage of the peripheral branches of class A arteries due to increased extravascular resistance rather than to arteriolar obstruction by small thrombi and/or leukocyte plugs. By contrast, class B arteries remained patent and were almost entirely free from such phenomena. They usually penetrated the infarcted focus to drain into the papillary muscles and trabeculae carnae. As the process of myocardial infarction progressed, various patterns of vascular reactions corresponding to the healing phase were demonstrated by these branches within the infarcted foci. The passive response of class A arteries during acute ischemia characterized the early myocardial lesion. Subsequently, neovascularization from the surviving class B arteries in the infarcted focus occurred as a part of the formation of granulation tissue. Newly formed small arteries from class A arteries also participated in this reaction at the marginal area of the lesion. These well-coordinated vascular reactions revealed in greater detail the initiation and progression of the healing process and were reflective of the clinical prognosis.

  4. Impaired glucose-induced thermogenesis and arterial norepinephrine response persist after weight reduction in obese humans

    DEFF Research Database (Denmark)

    Astrup, A; Andersen, T; Christensen, N J

    1990-01-01

    in eight obese patients than in matched control subjects (1.7% vs 9.2%, p less than 0.002). The increase in arterial norepinephrine after glucose was also blunted in the obese patients. After a 30-kg weight loss their glucose and lipid profiles were markedly improved but the thermic effect of glucose......A reduced thermic response and an impaired activation of the sympathetic nervous system (SNS) has been reported after oral glucose in human obesity. It is, however, not known whether the reduced SNS activity returns to normal along with weight reduction. The thermic effect of glucose was lower...... was still lower than that of the control subjects (4.2%, p less than 0.001). The glucose-induced arterial norepinephrine response remained diminished in the reduced obese patients whereas the changes in plasma epinephrine were similar in all three groups. The results suggest that a defective SNS may...

  5. Changing domains in human capital measurement

    Directory of Open Access Journals (Sweden)

    Pharny D. Chrysler-Fox

    2014-02-01

    Full Text Available Orientation: The management context is dynamic; this is especially evident in human capital as the primary source of value creation as opposed to physical and natural resources. In response, measurement methodologies have moved from a transactional approach (strategy implementation to a transformational approach (human capital contribution paradigm, as well as diverging into different purposes. To date, there has been little overlap on recent domains to consider in managing and measuring the contribution of the human resource function and employees, and how to unlock and add value.Research purpose: The aim of the study was to explore and describe changing domains within human capital management to be managed and measured.Motivation for the study: The motivation was to advance the understanding of changing measurement domains to aid practitioners to manage and measure the contribution of the human resource function and employees, in order to unlock and add value and ultimately contribute to the success of an organisation.Research design, approach and method: Unstructured, in-depth interview data of purposively selected cases from a selected panel of human resource practitioners specialising in human capital measurement was thematically analysed in this exploratory-descriptive investigation.Main findings: Findings suggested that seven domains should be managed and measured. These domains highlight new areas of impact and levels of management. In addition, crossdomain relationships in measurement allow for an understanding of the impact and potential value on which to capitalise.Practical/managerial implications: New domains to manage and measure focus the attention of practitioners beyond the transactional performance management paradigm to a transformational approach to influence the business strategy. Higher education institutions need to develop students’ cognitive skills to facilitate systems thinking.Contribution: This study suggests a new

  6. On-chip laser Doppler vibrometer for arterial pulse wave velocity measurement.

    Science.gov (United States)

    Li, Yanlu; Segers, Patrick; Dirckx, Joris; Baets, Roel

    2013-07-01

    Pulse wave velocity (PWV) is an important marker for cardiovascular risk. The Laser Doppler vibrometry has been suggested as a potential technique to measure the local carotid PWV by measuring the transit time of the pulse wave between two locations along the common carotid artery (CCA) from skin surface vibrations. However, the present LDV setups are still bulky and difficult to handle. We present in this paper a more compact LDV system integrated on a CMOS-compatible silicon-on-insulator substrate. In this system, a chip with two homodyne LDVs is utilized to simultaneously measure the pulse wave at two different locations along the CCA. Measurement results show that the dual-LDV chip can successfully conduct the PWV measurement.

  7. Utilization of Pulsatile flow to Decellularize the Human Umbilical Arteries to Make Small-Caliber Blood Vessel Scaffolds.

    Science.gov (United States)

    Chen, Shengjie; Li, Jingxing; Dong, Peiqing

    2013-09-01

    To explore the effect of pulsatile flow in the decellularization process of small blood vessels. A total of 30 human umbilical cords were used in the current study. The umbilical cords were flushed with 0.25% trypsin/0.01% EDTA for 30 minutes, followed by treatment with 1% sodium dodecyl sulfate sodium dodecyl sulfate for 3 hours. The effectiveness of decellularization on the umbilical artery wall was analyzed by mechanical analysis. The scaffolds' biocompatibility was observed by co-culture with the human umbilical endothelial cells. The maximum stress of the arteries before and after denuding was 3.55 ± 0.42N and 3.50 ± 0.43N, respectively. Under the pressure of 300 mmHg, 28 pieces of umbilical cords remained intact before and after the flushing, while 2 pieces ruptured under 300 mmHg. There was no significant difference in mechanical properties between flushed and control arteries. Isolated human umbilical endothelial cells grow and spread well on the decellularized umbilical artery scaffolds. Decellularization by pulsatile flow in human umbilical artery is a convenient, rapid and efficient approach to increase the availability of small caliber blood vessel scaffolds. Decellularization; Human umbilical artery; Scaffolds; Small diameter blood vessel; Vascular tissue engineering.

  8. Low concentrations of lithium and cyclooxygenase inhibitors enhance endothelin-1 (ET-1)-induced contractions in human temporal artery, but not in porcine ophthalmic artery.

    Science.gov (United States)

    Bakken, I J; Vincent, M B; White, L R; Cappelen, J; Skaanes, K O; Sjaastad, O

    1992-11-01

    Endothelins are a recently discovered group of potent vasoconstrictor peptides synthesized by endothelial cells and other tissues in various species, which seem to participate in the regulation of vascular tonus. Abnormalities in vasoactivity in the head may be an important event in headache pathophysiology, although the mechanisms responsible for such constrictions and/or dilations are not known. The endothelium and its constrictor peptide, endothelin, may play a key role in such mechanisms. Of the various drugs used in the treatment of headache, lithium is an accepted treatment for cluster headache, and indomethacin is the drug of choice for the associated condition chronic paroxysmal hemicrania. The mechanism of action of these drugs in these headaches is not known. Due to the possible involvement of endothelin in headache disorders, the objective of this study was to verify the effects of lithium and cyclooxygenase inhibitors (indomethacin, acetylsalicylic acid and naproxen) on endothelin-1 (ET-1)-induced contractions in isolated human temporal arteries and porcine ophthalmic arteries. It was found that all drugs increased the (ET-1)-induced contractions in human temporal arteries. Conversely, there were no significant changes induced by the drugs in porcine ophthalmic arteries. These results are consistent with the variation of activity often seen in different vascular beds and between species. The potential importance of such reactions for the understanding of vascular changes putatively involved in headache development and treatment is discussed.

  9. Location of the internal carotid artery and ophthalmic artery segments for non-invasive intracranial pressure measurement by multi-depth TCD.

    Science.gov (United States)

    Hamarat, Yasin; Deimantavicius, Mantas; Kalvaitis, Evaldas; Siaudvytyte, Lina; Januleviciene, Ingrida; Zakelis, Rolandas; Bartusis, Laimonas

    2017-12-01

    The aim of the present study was to locate the ophthalmic artery by using the edge of the internal carotid artery (ICA) as the reference depth to perform a reliable non-invasive intracranial pressure measurement via a multi-depth transcranial Doppler device and to then determine the positions and angles of an ultrasonic transducer (UT) on the closed eyelid in the case of located segments. High tension glaucoma (HTG) patients and healthy volunteers (HVs) undergoing non-invasive intracranial pressure measurement were selected for this prospective study. The depth of the edge of the ICA was identified, followed by a selection of the depths of the IOA and EOA segments. The positions and angles of the UT on the closed eyelid were measured. The mean depth of the identified ICA edge for HTG patients was 64.3 mm and was 63.0 mm for HVs (p = 0.21). The mean depth of the selected IOA segment for HTG patients was 59.2 mm and 59.3 mm for HVs (p = 0.91). The mean depth of the selected EOA segment for HTG patients was 48.5 mm and 49.8 mm for HVs (p = 0.14). The difference in the located depths of the segments between groups was not statistically significant. The results showed a significant difference in the measured UT angles in the case of the identified edge of the ICA and selected ophthalmic artery segments (p = 0.0002). We demonstrated that locating the IOA and EOA segments can be achieved using the edge of the ICA as a reference point. OA: ophthalmic artery; IOA: intracranial segments of the ophthalmic artery; EOA: extracranial segments of the ophthalmic artery; ICA: internal carotid artery; UT: ultrasonic transducer; HTG: high tension glaucoma; SD: standard deviation; ICP: intracranial pressure; TCD: transcranial Doppler.

  10. Human Characteristics and Measures in Systems Design

    Science.gov (United States)

    2003-01-01

    rate, blood pressure, pupillary response, electrooculogram (EOG), plasma, and salivary cortisol and other hormone levels 19.2 HUMAN TRAITS...physiological measures (e.g., EEG, oculography, cardiovascular measures, and respiratory rates) Actigraphy, temperature, melatonin levels in saliva or...plasma samples Physiological measures such as cortisol levels in saliva, plasma, and urine samples, psychophysiological measures (e.g., EEG, EDA, EeG

  11. Measurements of cardiac output obtained with transesophageal echocardiography and pulmonary artery thermodilution are not interchangeable

    DEFF Research Database (Denmark)

    Møller-Sørensen, H; Graeser, K; Hansen, K L

    2014-01-01

    was placed in the following successive positions: supine, head-down tilt, head-up tilt, supine, supine with phenylephrine administration, pace heart rate 80 beats per minute (bpm), pace heart rate 110 bpm. TEE CO and PAC CO were measured simultaneously. The agreement was analysed by Bland-Altman plots......BACKGROUND: Echocardiography is increasingly becoming an integrated tool for circulatory evaluation in the intensive care unit and the operating room. Therefore, it is imperative to know the reproducibility of measurements obtained by echocardiography. In this study, a comparison of cardiac output...... (CO) measurements obtained with transesophageal echocardiography (TEE) and pulmonary artery catheter (PAC) thermodilution (TD) was carried out to test the precision, accuracy and trending ability of CO measurements obtained with TEE. METHODS: Twenty-five patients completed the study. Each patient...

  12. An Human-Computer Interactive Augmented Reality System for Coronary Artery Diagnosis Planning and Training.

    Science.gov (United States)

    Li, Qiming; Huang, Chen; Lv, Shengqing; Li, Zeyu; Chen, Yimin; Ma, Lizhuang

    2017-09-02

    In order to let the doctor carry on the coronary artery diagnosis and preoperative planning in a more intuitive and more natural way, and to improve the training effect for interns, an augmented reality system for coronary artery diagnosis planning and training (ARS-CADPT) is designed and realized in this paper. At first, a 3D reconstruction algorithm based on computed tomographic (CT) images is proposed to model the coronary artery vessels (CAV). Secondly, the algorithms of static gesture recognition and dynamic gesture spotting and recognition are presented to realize the real-time and friendly human-computer interaction (HCI), which is the characteristic of ARS-CADPT. Thirdly, a Sort-First parallel rendering and splicing display subsystem is developed, which greatly expands the capacity of student users. The experimental results show that, with the use of ARS-CADPT, the reconstruction accuracy of CAV model is high, the HCI is natural and fluent, and the visual effect is good. In a word, the system fully meets the application requirement.

  13. Cryopreserved human aortic root allografts arterial wall: Structural changes occurring during thawing.

    Directory of Open Access Journals (Sweden)

    Robert Novotny

    Full Text Available The aim of our experimental work was to assess morphological changes of arterial wall that arise during different thawing protocols of a cryopreserved human aortic root allograft (CHARA arterial wall.The experiment was performed on CHARAs. Two thawing protocols were tested: 1, CHARAs were thawed at a room temperature at +23°C; 2, CHARAs were placed directly into a water bath at +37°C.After fixation, all samples were washed in distilled water for 5 min, and dehydrated in a graded ethanol series (70, 85, 95, and 100% for 5 min at each level. The tissue samples were then immersed in 100% hexamethyldisilazane for 10 minutes and air dried in an exhaust hood at room temperature. Processed samples were mounted on stainless steel stubs, coated with gold.Thawing protocol 1: All 6 (100% samples showed loss of the endothelium and damage to the subendothelial layers with randomly dispersed circular defects and micro-fractures without smooth muscle cells contractions in the tunica media. Thawing protocol 2: All 6 (100% samples showed loss of endothelium from the luminal surface, longitudinal corrugations in the direction of blood flow caused by smooth muscle cells contractions in the tunica media with frequent fractures in the subendothelial layer.All the samples thawed at the room temperature showed smaller structural damage to the CHARA arterial wall with no smooth muscle cell contraction in tunica media when compared to the samples thawed in a water bath.

  14. Comparison of arterial blood pressure measurements and hypertension scores obtained by use of three indirect measurement devices in hospitalized dogs.

    Science.gov (United States)

    Wernick, Morena B; Höpfner, Robert M; Francey, Thierry; Howard, Judith

    2012-04-15

    To evaluate the agreement of blood pressure measurements and hypertension scores obtained by use of 3 indirect arterial blood pressure measurement devices in hospitalized dogs. Design-Diagnostic test evaluation. 29 client-owned dogs. 5 to 7 consecutive blood pressure readings were obtained from each dog on each of 3 occasions with a Doppler ultrasonic flow detector, a standard oscillometric device (STO), and a high-definition oscillometric device (HDO). When the individual sets of 5 to 7 readings were evaluated, the coefficient of variation for systolic arterial blood pressure (SAP) exceeded 20% for 0% (Doppler), 11 % (STO), and 28% (HDO) of the sets of readings. After readings that exceeded a 20% coefficient of variation were discarded, repeatability was within 25 (Doppler), 37 (STO), and 39 (HDO) mm Hg for SAP. Correlation of mean values among the devices was between 0.47 and 0.63. Compared with Doppler readings, STO underestimated and HDO overestimated SAP. Limits of agreement between mean readings of any 2 devices were wide. With the hypertension scale used to score SAP, the intraclass correlation of scores was 0.48. Linear-weighted inter-rater reliability between scores was 0.40 (Doppler vs STO), 0.38 (Doppler vs HDO), and 0.29 (STO vs HDO). Results of this study suggested that no meaningful clinical comparison can be made between blood pressure readings obtained from the same dog with different indirect blood pressure measurement devices.

  15. Noninvasive Doppler tissue measurement of pulmonary artery compliance in children with pulmonary hypertension.

    Science.gov (United States)

    Dyer, Karrie; Lanning, Craig; Das, Bibhuti; Lee, Po-Feng; Ivy, D Dunbar; Valdes-Cruz, Lilliam; Shandas, Robin

    2006-04-01

    We have shown previously that input impedance of the pulmonary vasculature provides a comprehensive characterization of right ventricular afterload by including compliance. However, impedance-based compliance assessment requires invasive measurements. Here, we develop and validate a noninvasive method to measure pulmonary artery (PA) compliance using ultrasound color M-mode (CMM) Doppler tissue imaging (DTI). Dynamic compliance (C(dyn)) of the PA was obtained from CMM DTI and continuous wave Doppler measurement of the tricuspid regurgitant velocity. C(dyn) was calculated as: [(D(s) - D(d))/(D(d) x P(s))] x 10(4); where D(s) = systolic diameter, D(d) = diastolic diameter, and P(s) = systolic pressure. The method was validated both in vitro and in 13 patients in the catheterization laboratory, and then tested on 27 pediatric patients with pulmonary hypertension, with comparison with 10 age-matched control subjects. C(dyn) was also measured in an additional 13 patients undergoing reactivity studies. Instantaneous diameter measured using CMM DTI agreed well with intravascular ultrasound measurements in the in vitro models. Clinically, C(dyn) calculated by CMM DTI agreed with C(dyn) calculated using invasive techniques (23.4 +/- 16.8 vs 29.1 +/- 20.6%/100 mm Hg; P = not significant). Patients with pulmonary hypertension had significantly lower peak wall velocity values and lower C(dyn) values than control subjects (P < .01). C(dyn) values followed an exponentially decaying relationship with PA pressure, indicating the nonlinear stress-strain behavior of these arteries. Reactivity in C(dyn) agreed with reactivity measured using impedance techniques. The C(dyn) method provides a noninvasive means of assessing PA compliance and should be useful as an additional measure of vascular reactivity subsequent to pulmonary vascular resistance in patients with pulmonary hypertension.

  16. Agreement between two oscillometric blood pressure technologies and invasively measured arterial pressure in the dog.

    Science.gov (United States)

    da Cunha, Anderson F; Ramos, Sara J; Domingues, Michelle; Beaufrère, Hugues; Shelby, Amanda; Stout, Rhett; Acierno, Mark J

    2016-03-01

    To compare two commonly used oscillometric technologies for obtaining noninvasive blood pressure (NIBP) measurements and to determine if there is a difference in agreement between these systems and invasive blood pressure (IBP) measurements. Prospective, experimental study. Twenty adult laboratory dogs. Each dog was anesthetized and its median caudal artery catheterized for IBP monitoring. An NIBP cuff was placed in the middle third of the antebrachium and attached to either monitor-1 or monitor-2. Four pairs of concurrent NIBP and IBP measurements were recorded with each monitor. Agreement between IBP and NIBP measurements was explored using Bland-Altman analysis, as well as the American College of Veterinary Internal Medicine (ACVIM) and Association for the Advancement of Medical Instrumentation (AAMI) guidelines for the validation of NIBP devices. Both NIBP technologies produced results that met the ACVIM and AAMI guidelines for the validation of NIBP devices. For monitor-1, analyses of agreement showed biases of 0.2 mmHg [95% limits of agreement (LoA) -11.8 to 12.3 mmHg] in systolic arterial pressure (SAP) values, -2.6 mmHg (95% LoA -14.4 to 9.1 mmHg) in diastolic arterial pressure (DAP) values, and -2.5 mmHg (95% LoA -12.7 to 7.3 mmHg) in mean arterial pressure (MAP) values. For monitor-2, analyses of agreement showed biases of 3.4 mmHg (95% LoA -8.7 to 15.5 mmHg) in SAP values, 2.2 mmHg (95% LoA -6.6 to 10.9 mmHg) in DAP values, and 1.6 mmHg (95% LoA -5.9 to 8.9 mmHg) in MAP values. Multi-function monitors can contain components from various manufacturers. Clinicians should consider whether these have been validated in the species to be monitored. Both of the technologies studied here seem appropriate for use in dogs. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  17. Using entropy measures to characterize human locomotion.

    Science.gov (United States)

    Leverick, Graham; Szturm, Tony; Wu, Christine Q

    2014-12-01

    Entropy measures have been widely used to quantify the complexity of theoretical and experimental dynamical systems. In this paper, the value of using entropy measures to characterize human locomotion is demonstrated based on their construct validity, predictive validity in a simple model of human walking and convergent validity in an experimental study. Results show that four of the five considered entropy measures increase meaningfully with the increased probability of falling in a simple passive bipedal walker model. The same four entropy measures also experienced statistically significant increases in response to increasing age and gait impairment caused by cognitive interference in an experimental study. Of the considered entropy measures, the proposed quantized dynamical entropy (QDE) and quantization-based approximation of sample entropy (QASE) offered the best combination of sensitivity to changes in gait dynamics and computational efficiency. Based on these results, entropy appears to be a viable candidate for assessing the stability of human locomotion.

  18. End-tidal and arterial carbon dioxide measurements correlate across all levels of physiologic dead space.

    Science.gov (United States)

    McSwain, S David; Hamel, Donna S; Smith, P Brian; Gentile, Michael A; Srinivasan, Saumini; Meliones, Jon N; Cheifetz, Ira M

    2010-03-01

    End-tidal carbon dioxide (P(ETCO(2))) is a surrogate, noninvasive measurement of arterial carbon dioxide (P(aCO(2))), but the clinical applicability of P(ETCO(2)) in the intensive care unit remains unclear. Available research on the relationship between P(ETCO(2)) and P(aCO(2)) has not taken a detailed assessment of physiologic dead space into consideration. We hypothesized that P(ETCO(2)) would reliably predict P(aCO(2)) across all levels of physiologic dead space, provided that the expected P(ETCO(2))-P(aCO(2)) difference is considered. Fifty-six mechanically ventilated pediatric patients (0-17 y old, mean weight 19.5 +/- 24.5 kg) were monitored with volumetric capnography. For every arterial blood gas measurement during routine care, we measured P(ETCO(2)) and calculated the ratio of dead space to tidal volume (V(D)/V(T)). We assessed the P(ETCO(2))-P(aCO(2)) relationship with Pearson's correlation coefficient, in 4 V(D)/V(T) ranges. V(D)/V(T) was measurements (25%), 0.41-0.55 for 160 measurements (32%), 0.56-0.70 for 154 measurements (31%), and >0.7 for 54 measurements (11%). The correlation coefficients between P(ETCO(2)) and P(aCO(2)) were 0.95 (mean difference 0.3 +/- 2.1 mm Hg) for V(D)/V(T) 0.7. There were strong correlations between P(ETCO(2)) and P(aCO(2)) in all the V(D)/V(T) ranges. The P(ETCO(2))-P(aCO(2)) difference increased predictably with increasing V(D)/V(T).

  19. Measurement of peripheral blood flow in patients with peripheral artery disease: Methods and considerations.

    Science.gov (United States)

    Salisbury, Dereck L; Brown, Rebecca Jl; Bronas, Ulf G; Kirk, Laura N; Treat-Jacobson, Diane

    2018-02-01

    Peripheral artery disease (PAD) is a manifestation of generalized atherosclerosis which results in hemodynamic compromise of oxygen and substrate delivery to the lower extremity skeletal muscles. Hemodynamic assessments are vital in PAD diagnosis and in the evaluation of strategies aimed at treating claudication (i.e. exercise training, revascularization, and pharmacological agents). Venous occlusion plethysmography (VOP) is a century-old, non-invasive technique used to quantify limb blood flow and has been used to evaluate hemodynamic compromise in patients with PAD. However, the literature suggests a wide array of methodological variability in the measurement and analysis of limb blood flow using VOP. In this manuscript, we overview the clinical application of VOP measurement, and secondly we review the methodological variation that occurs during the measurement and analysis of VOP in healthy individuals and in patients with claudication.

  20. Techniques of cardiac output measurement during liver transplantation: arterial pulse wave versus thermodilution

    DEFF Research Database (Denmark)

    Nissen, P.; Lieshout, J.J. van; Novovic, S.

    2009-01-01

    variables were measured in 39 adult patients (13 females) every 10th minute during liver transplant surgery. Paired measurements were compared during the 4 phases of surgery-dissection, anhepatic phase, early reperfusion (the first 15 minutes after reperfusion), and late reperfusion (15-60 minutes after......In this study, we compared continuous cardiac output (CO) obtained from the femoral arterial pressure by simulation of an aortic input impedance model [model-simulated cardiac output (MCO)] to thermodilution cardiac output (TDCO) determined by bolus injection during liver transplantation. Both......, and the mutual correlation coefficient was 0.812 (P surgery, MCO reflects TDCO throughout the operation. Thus, for CO, this less invasive method appears to provide a reliable uninterrupted measurement during orthotopic liver transplantation...

  1. Comparison between oscillometric and intra-arterial blood pressure measurements in ill preterm and full-term neonates.

    Science.gov (United States)

    Lalan, Shwetal; Blowey, Douglas

    2014-01-01

    Conflicting data exist regarding the accuracy of the oscillometric method of blood pressure (BP) measurement in neonates. There is limited data regarding intra-arterial BP trends in neonates. We aimed to determine the accuracy of oscillometric BP measurements and to evaluate the BP distributions in ill neonates. A total of 1492 simultaneously obtained oscillometric and intra-arterial (umbilical arterial [UAC] or radial arterial) BP measurements were used for comparisons and 125,580 intra-arterial BP readings were used to the evaluate BP distribution. There was a statistically significant difference (P oscillometric and radial mean arterial BP (MAP) 4.8 ± 9.8 mm Hg, systolic BP 8.3 ± 11.6 mm Hg, diastolic BP 4.3 ± 9.3 mm Hg and between the oscillometric and UAC systolic BP 5.2 ± 11.9 mm Hg and diastolic BP -0.8 ± 10.4 mm Hg. The MAP increased with increases in weight (35.3 ± 4.92 mm Hg/kg), post-menstrual age (-0.29 ± 1.41 mm Hg/week) and advanced gestational age at birth (13.12 ± 0.90 mm Hg/week). Oscillometric BP measurements are not equivalent to the intra-arterial (UAC or radial arterial) BP in ill neonates. The BP increases with increase in weight, gestational age at birth, and post-menstrual age in ill neonates. Copyright © 2014 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  2. Human activated protein C variants in a rat model of arterial thrombosis

    Directory of Open Access Journals (Sweden)

    Dahlbäck Björn

    2008-10-01

    Full Text Available Abstract Background Activated protein C (APC inhibits coagulation by degrading activated factor V (FVa and factor VIII (FVIIIa, protein S (PS functioning as a cofactor to APC. Methods By mutagenesis of the vitamin K-dependent Gla domain of APC, we have recently created an APC variant having enhanced anticoagulant activity due to increased affinity for negatively charged phospholipid membranes. In the present study, the potential antithrombotic effects of this APC variant, and of a variant APC that is additionally mutated in the serine protease domain, have been evaluated in a blind randomized study in a rat model of arterial thrombosis. In this model, we have previously found the combination of bovine APC and PS to be highly antithrombotic. Four treatment groups each containing 10 rats were, in a blind random fashion, given intravenous bolus injections of wild-type or mutant variants of APC (0.8 mg/kg together with human PS (0.6 mg/kg or human PS (0.6 mg/kg alone. A control group with 20 animals where given vehicle only. Results A trend to increased patency rates was noted in a group receiving one of the APC variants, but it did not reach statistical significance. Conclusion In conclusion, administration of human APC variants having enhanced anticoagulant efficacy together with human PS in a rat model of arterial thrombosis did not give an efficient antithrombotic effect. The lack of effect may be due to species-specific differences between the human protein C system and the rat hemostatic system.

  3. Evaluation of MR angiography and blood flow measurement in abdominal and peripheral arterial occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Tabuchi, Kenji [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)

    2000-03-01

    To assess the characteristics of blood flow measurement with MR Angiography (MRA) to evaluate the status of vascular stenoses, two or three dimensional time-of-flight MRA and velocity-encoded cine MR were performed in the 230 segments of 35 patients, with abdominal and peripheral arterial occlusive diseases. In 11 of these 35 patients digital subtraction angiography was additionally underwent, and the stenotic findings was compared with MRA. There were 17 segments in which the velocity could not be measured, because the blood flow exceeded the upper limit of peak-encoded velocity (VENC) which was set at 120 cm/sec. Therefore, it is necessary to set the upper limit of VENC at higher than 120 cm/sec. There were 11 stenotic findings in DSA and 20 stenotic findings in MRA. Pulsatility Index (PI=(max velocity-min. velocity)/average velocity) were used for evaluating the blood flow waveform, and there were significant difference between the 11 stenotic findings of DSA and the others'. In summery, MRA was considered as useful examination to assess the degree of the vascular stenoses in abdominal and peripheral arterial occlusive disease. (author)

  4. Optimizing the imaging protocol for vivo coronary artery wall using high-resolution MIRI: An experimental study on porcine and human

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jiang; Li, Tao; Cul, Xiaoming; Zhou, Weihua; Zhang, Xinwu [The General Hospital of Chinese People' s Armed Police Forces, Beijing (China)

    2013-08-15

    To optimize the MR imaging protocol for coronary arterial wall depiction in vitro and characterize the coronary atherosclerotic plaques. MRI examination was prospectively performed in ten porcine hearts in order to optimize the MR imaging protocol. Various surface coils were used for coronary arterial wall imaging with the same parameters. Then, the image parameters were further optimized for high-resolution coronary wall imaging. The signal-noise ratio (SNR) and contrast-noise ratio (CNR) of images were measured. Finally, 8 human cadaver hearts with coronary atherosclerotic plaques were prospectively performed with MRI examination using optimized protocol in order to characterize the coronary atherosclerotic plaques. The SNR and CNR of MR image with temporomandibular coil were the highest of various surface coils. High-resolution and high SNR and CNR for ex vivo coronary artery wall depiction can be achieved using temporomandibular coil with 512 x 512 in matrix. Compared with histopathology, the sensitivity and specificity of MRI for identifying advanced plaques were: type IV-V (lipid, necrosis, fibrosis), 94% and 95%; type VI (hemorrhage), 100% and 98%; type VII (calcification), 91% and 100%; and type VIII (fibrosis without lipid core), 100% and 98%, respectively. Temporomandibular coil appears to be dramatically superior to eight-channel head coil and knee coil for ex vivo coronary artery wall imaging, providing higher spatial resolution and improved the SNR. Ex vivo high-resolution MRI has capability to distinguish human coronary atherosclerotic plaque compositions and accurately classify advanced plaques.

  5. Facilitative interaction between angiotensin II and oxidised LDL in cultured human coronary artery endothelial cells

    Directory of Open Access Journals (Sweden)

    Jawahar L Mehta

    2001-03-01

    Full Text Available Background Several studies have shown that angiotensin II (Ang II and oxidised low-density lipoprotein (ox-LDL are critical factors in atherosclerosis. In this study, we examined the molecular basis of mutually facilitative interactions between Ang II and ox-LDL in human coronary artery endothelial cells (HCAECs.Methods and results We observed that incubation of cultured HCAECs with Ang II (10-12 to 10-6 M for 24 hours caused a concentration-dependent increase in the expression of mRNA and protein of a specialised receptor for ox-LDL (LOX-1. These effects of Ang II were completely blocked by pretreatment of HCAECs with candesartan (10-6 M, a specific AT1-receptor blocker, but not by PD 123319 (10-6 M, a specific AT2-receptor blocker. On the other hand, incubation of HCAECs with ox-LDL (10 and 40 µg/ml for 24 hours progressively upregulated AT1-, but not AT 2-, receptor mRNA and protein. Pretreatment of cells with the anti-oxidant alpha-tocopherol (1—5 x 10-6 M inhibited the upregulation of AT1-receptor expression induced by ox-LDL (p<0.05. To determine the significance of expression of AT1-receptors and LOX-1, we measured cell injury in response to Ang II and ox-LDL. Incubation of cells with both ox-LDL and Ang II synergistically increased cell injury, measured as cell viability and LDH release, compared with either ox-LDL or Ang II alone (both p<0.05. Alpha-tocopherol, as well as candesartan, attenuated cell injury in response to Ang II and ox-LDL (both p<0.05.Conclusions These observations show that Ang II upregulates a novel endothelial receptor for ox-LDL (LOX-1 gene expression and ox-LDL in turn upregulates Ang II AT 1receptor gene expression. This interaction between Ang II and ox-LDL further augments cell injury in HCAECs. These findings provide basis for the use of AT1-receptor blockers and anti-oxidants in designing therapy for atherosclerosis and myocardial ischaemia.

  6. Noninvasive measurements of regional cerebral perfusion in preterm and term neonates by magnetic resonance arterial spin labeling

    DEFF Research Database (Denmark)

    Miranda Gimenez-Ricco, Maria Jo; Olofsson, K; Sidaros, Karam

    2006-01-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term-born neon......Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term...

  7. Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors.

    Science.gov (United States)

    Green, Daniel J; Eijsvogels, Thijs; Bouts, Yvette M; Maiorana, Andrew J; Naylor, Louise H; Scholten, Ralph R; Spaanderman, Marc E A; Pugh, Christopher J A; Sprung, Victoria S; Schreuder, Tim; Jones, Helen; Cable, Tim; Hopman, Maria T E; Thijssen, Dick H J

    2014-08-15

    The objectives of our study were to examine 1) the proportion of responders and nonresponders to exercise training in terms of vascular function; 2) a priori factors related to exercise training-induced changes in conduit artery function, and 3) the contribution of traditional cardiovascular risk factors to exercise-induced changes in artery function. We pooled data from our laboratories involving 182 subjects who underwent supervised, large-muscle group, endurance-type exercise training interventions with pre-/posttraining measures of flow-mediated dilation (FMD%) to assess artery function. All studies adopted an identical FMD protocol (5-min ischemia, distal cuff inflation), contemporary echo-Doppler methodology, and observer-independent automated analysis. Linear regression analysis was used to identify factors contributing to changes in FMD%. We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P Training-induced increase in FMD% was predicted by lower body weight (β = -0.212), lower baseline FMD% (β = -0.469), lower training frequency (β = -0.256), and longer training duration (β = 0.367) (combined: P 0.05). In conclusion, we found that, while some subjects do not demonstrate increases following exercise training, improvement in FMD% is present in those with lower pretraining body weight and endothelial function. Moreover, exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors. Copyright © 2014 the American Physiological Society.

  8. Endothelial dysfunction in obstructive sleep apnea measured by peripheral arterial tone response in the finger to reactive hyperemia.

    Science.gov (United States)

    Itzhaki, Sarah; Lavie, Lena; Pillar, Giora; Tal, Galit; Lavie, Peretz

    2005-05-01

    The aim of this study was to investigate endothelial functioning in sleep apnea patients using a novel plethysmographic device that monitors peripheral arterial tone response in the finger to reactive hyperemia induced by forearm ischemia. Forty-six sleep apnea patients, 74.0% men, mean age 46.8 +/- 9.3 years, and 17 control subjects without sleep apnea, 64.7% men, mean age 47.1 +/- 6.7 years. Eight-bed Technion Sleep Medicine Center in Haifa, Israel. Endothelial functioning assessed by the reactive hyperemia peripheral arterial tone index was measured twice, before sleep and after waking from sleep monitored by polysomnography in the laboratory. The reactive hyperemia peripheral arterial tone index was calculated as the average amplitude of the peripheral arterial tone signal after the cuff deflation divided by the average amplitude before the cuff inflation. Morning index of endothelial functioning was significantly lower in patients with moderate to severe sleep apnea (apnea-hypopnea index > or = 30) than in patients with mild sleep apnea (30 disease had significantly lower morning and evening indexes of endothelial functioning than patients without such a history. Multivariate analysis revealed that apnea-hypopnea index and sleep efficiency were significant predictors of the morning index. Measurements of the response of the peripheral arterial tone in the finger to reactive hyperemia can be used as a substitute for the brachial artery ultrasound technique to measure endothelial functioning in patients with sleep apnea.

  9. Human development index as a measure of human development

    Directory of Open Access Journals (Sweden)

    Radovanović Bojana

    2011-01-01

    Full Text Available Human development is “a process of expanding the real freedoms that people enjoy” (Sen 1999: 3. Therefore, widening of people’s choices should be the goal of the public policies aiming at human development promotion. In order to assess the level of human development, to compare it with other countries’ achievements, or to evaluate different policy proposals, decision-makers have to rely on an accurate indicator of human development. Since gross national product (GNP and gross domestic product (GDP could not serve this function, the human development index (HDI has been introduced as a more adequate measure. The aim of this paper is to discuss whether human development index reflects the basic tenets of human development. The arguments presented lead to the conclusion that the HDI does not fully reflect the ideas of human development. Since human development is much broader concept than any individual indicator could capture, country’s level of development should be assessed by the combination of different indicators.

  10. Ultrasonic Measurement of Transient Change in Stress-Strain Property of Radial Arterial Wall Caused by Endothelium-Dependent Vasodilation

    Science.gov (United States)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2008-05-01

    The endothelial dysfunction is considered to be an initial step of atherosclerosis. Additionally, it was reported that the smooth muscle, which constructs the media of the artery, changes its characteristics owing to atherosclerosis. Therefore, it is essential to develop a method for assessing the regional endothelial function and mechanical property of the arterial wall. There is a conventional technique of measuring the transient change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) after the release of avascularization. For more sensitive and regional evaluation, we developed a method of measuring the change in the elasticity of the radial artery due to FMD. In this study, the transient change in the mechanical property of the arterial wall was further revealed by measuring the stress-strain relationship during each heartbeat. The minute change in the thickness (strain) of the radial arterial wall during a cardiac cycle was measured by the phased tracking method, together with the waveform of blood pressure which was continuously measured with a sphygmometer at the radial artery. The transient change in stress-strain relationship during a cardiac cycle was obtained from the measured changes in wall thickness and blood pressure to show the transient change in instantaneous viscoelasticity. From the in vivo experimental results, the stress-strain relationship shows the hysteresis loop. The slope of the loop decreased owing to FMD, which shows that the elastic modulus decreased, and the increasing area of the loop depends on the ratio of the loss modulus (depends on viscosity) to the elastic modulus when the Voigt model is assumed. These results show a potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  11. Radial artery pulse pressure variation correlates with brachial artery peak velocity variation in ventilated subjects when measured by internal medicine residents using hand-carried ultrasound devices.

    Science.gov (United States)

    Brennan, J Matthew; Blair, John E A; Hampole, Chetan; Goonewardena, Sascha; Vasaiwala, Samip; Shah, Dipak; Spencer, Kirk T; Schmidt, Gregory A

    2007-05-01

    Rapid prediction of the effect of volume expansion is crucial in unstable patients receiving mechanical ventilation. Both radial artery pulse pressure variation (DeltaPP) and change of aortic blood flow peak velocity are accurate predictors but may be impractical point-of-care tools. We sought to determine whether respiratory changes in the brachial artery blood flow velocity (DeltaVpeak-BA) as measured by internal medicine residents using a hand-carried ultrasound (HCU) device could provide an accurate corollary to DeltaPP in patients receiving mechanical ventilation. Thirty patients passively receiving volume-control ventilation with preexisting radial artery catheters were enrolled. The brachial artery Doppler signal was recorded and analyzed by blinded internal medicine residents using a HCU device. Simultaneous radial artery pulse wave and central venous pressure recordings (when available) were analyzed by a blinded critical care physician. A Doppler signal was obtained in all 30 subjects. The DeltaVpeak-BA correlated well with DeltaPP (r = 0.84) with excellent agreement (weighted kappa, 0.82) and limited intraobserver variability (2.8 +/- 2.8%) [mean +/- SD]. A DeltaVpeak-BA cutoff of 16% was highly predictive of DeltaPP > or = 13% (sensitivity, 91%; specificity, 95%). A poor correlation existed between the CVP and both DeltaVpeak-BA (r = - 0.21) and DeltaPP (r = - 0.16). The HCU Doppler assessment of the DeltaVpeak-BA as performed by internal medicine residents is a rapid, noninvasive bedside correlate to DeltaPP, and a DeltaVpeak-BA cutoff of 16% may prove useful as a point-of-care tool for the prediction of volume responsiveness in patients receiving mechanical ventilation.

  12. Reasonable classical concepts in human lower limb anatomy from the viewpoint of the primitive persistent sciatic artery and twisting human lower limb.

    Science.gov (United States)

    Kawashima, Tomokazu; Sasaki, Hiroshi

    2010-11-01

    The main aim of this review is (1) to introduce the two previous studies we published human lower limb anatomy based on the conventional macroscopic anatomical [corrected] criteria with hazardous recognition of this description, (2) to activate the discussion whether the limb homology exists, and (3) to contribute to future study filling the gap between the gross anatomy and embryology. One of the topics we discussed was the human persistent sciatic artery. To date, numerous human cases of persistent sciatic artery have been reported in which the anomalous artery was present in the posterior compartment of the thigh alongside the sciatic nerve. As one of the important criteria for assessing the human primitive sciatic artery, its ventral arterial position with respect to the sciatic nerve is reasonable based on the initial positional relationship between ventral arterial and dorsal nervous systems and comparative anatomical findings. We also discuss ways of considering the topography of muscles of the lower limb and their innervations compared to those of the upper limb. We propose a schema of the complex anatomical characteristics of the lower limb based on the vertebrate body plan. According to this reasonable schema, the twisted anatomy of the lower limb can be understood more easily. These two main ideas discussed in this paper will be useful for further understanding of the anatomy of the lower limb and as a first step for future. We hope that the future study in lower limb will be further developed by both viewpoints of the classical gross anatomy and recent embryology.

  13. Krüppel-like Factor 5 contributes to pulmonary artery smooth muscle proliferation and resistance to apoptosis in human pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Paulin Roxane

    2011-09-01

    Full Text Available Background Pulmonary arterial hypertension (PAH is a vascular remodeling disease characterized by enhanced proliferation of pulmonary artery smooth muscle cell (PASMC and suppressed apoptosis. This phenotype has been associated with the upregulation of the oncoprotein survivin promoting mitochondrial membrane potential hyperpolarization (decreasing apoptosis and the upregulation of growth factor and cytokines like PDGF, IL-6 and vasoactive agent like endothelin-1 (ET-1 promoting PASMC proliferation. Krüppel-like factor 5 (KLF5, is a zinc-finger-type transcription factor implicated in the regulation of cell differentiation, proliferation, migration and apoptosis. Recent studies have demonstrated the implication of KLF5 in tissue remodeling in cardiovascular diseases, such as atherosclerosis, restenosis, and cardiac hypertrophy. Nonetheless, the implication of KLF5 in pulmonary arterial hypertension (PAH remains unknown. We hypothesized that KLF5 up-regulation in PAH triggers PASMC proliferation and resistance to apoptosis. Methods and results We showed that KFL5 is upregulated in both human lung biopsies and cultured human PASMC isolated from distal pulmonary arteries from PAH patients compared to controls. Using stimulation experiments, we demonstrated that PDGF, ET-1 and IL-6 trigger KLF-5 activation in control PASMC to a level similar to the one seen in PAH-PASMC. Inhibition of the STAT3 pathway abrogates KLF5 activation in PAH-PASMC. Once activated, KLF5 promotes cyclin B1 upregulation and promotes PASMC proliferation and triggers survivin expression hyperpolarizing mitochondria membrane potential decreasing PASMC ability to undergo apoptosis. Conclusion We demonstrated for the first time that KLF5 is activated in human PAH and implicated in the pro-proliferative and anti-apoptotic phenotype that characterize PAH-PASMC. We believe that our findings will open new avenues of investigation on the role of KLF5 in PAH and might lead to the

  14. Quantitative Measurements of Competitive Flow in Left Internal Mammary Artery Bypass Grafts

    NARCIS (Netherlands)

    Spoor, Pien; Halfwerk, F.R.; Hagmeijer, Rob; Grandjean, J.G.

    2017-01-01

    OBJECTIVE: A low flow rate with diminished wall shear stress in arteries can cause intima hyperplasia and diameter reduction. In coronary artery bypass grafting (CABG) a low flow rate through the graft can cause graft failure (i.e. the string sign effect and occlusion). Arterial grafts bypassing an

  15. Simulated characterization of atherosclerotic lesions in the coronary arteries by measurement of bioimpedance.

    Science.gov (United States)

    Stiles, David K; Oakley, Barbara

    2003-07-01

    FEM software was used to determine the feasibility of characterizing various types of atherosclerotic lesions in vivo. This was accomplished by simulating two electrodes as being attached to an angioplasty balloon in the coronary artery. The electrodes on the "balloon" touched and measured the simulated complex impedance of type III, IV, and Va and Vb lesions, as defined by the American Heart Association (AHA). Additionally, the effect of changes in morphology on the complex impedance was determined for type Va and Vb lesions. The simulations showed that the layer closest to the electrodes had the most significant effect on the measured complex impedance. As a consequence of these simulations, it appears plausible that electrodes could be placed in vivo to determine the characteristics and type of a given atherosclerotic lesion.

  16. New principle for measuring arterial blood oxygenation, enabling motion-robust remote monitoring.

    Science.gov (United States)

    van Gastel, Mark; Stuijk, Sander; de Haan, Gerard

    2016-12-07

    Finger-oximeters are ubiquitously used for patient monitoring in hospitals worldwide. Recently, remote measurement of arterial blood oxygenation (SpO2) with a camera has been demonstrated. Both contact and remote measurements, however, require the subject to remain static for accurate SpO2 values. This is due to the use of the common ratio-of-ratios measurement principle that measures the relative pulsatility at different wavelengths. Since the amplitudes are small, they are easily corrupted by motion-induced variations. We introduce a new principle that allows accurate remote measurements even during significant subject motion. We demonstrate the main advantage of the principle, i.e. that the optimal signature remains the same even when the SNR of the PPG signal drops significantly due to motion or limited measurement area. The evaluation uses recordings with breath-holding events, which induce hypoxemia in healthy moving subjects. The events lead to clinically relevant SpO2 levels in the range 80-100%. The new principle is shown to greatly outperform current remote ratio-of-ratios based methods. The mean-absolute SpO2-error (MAE) is about 2 percentage-points during head movements, where the benchmark method shows a MAE of 24 percentage-points. Consequently, we claim ours to be the first method to reliably measure SpO2 remotely during significant subject motion.

  17. Relationship between serum levels of triglycerides and vascular inflammation, measured as COX-2, in arteries from diabetic patients: a translational study

    Science.gov (United States)

    2013-01-01

    Background Inflammation is a common feature in the majority of cardiovascular disease, including Diabetes Mellitus (DM). Levels of pro-inflammatory markers have been found in increasing levels in serum from diabetic patients (DP). Moreover, levels of Cyclooxygenase-2 (COX-2) are increased in coronary arteries from DP. Methods Through a cross-sectional design, patients who underwent CABG were recruited. Vascular smooth muscle cells (VSMC) were cultured and COX-2 was measured by western blot. Biochemical and clinical data were collected from the medical record and by blood testing. COX-2 expression was analyzed in internal mammary artery cross-sections by confocal microscopy. Eventually, PGI2 and PGE2 were assessed from VSMC conditioned media by ELISA. Results Only a high glucose concentration, but a physiological concentration of triglycerides exposure of cultured human VSMC derived from non-diabetic patients increased COX-2 expression .Diabetic patients showed increasing serum levels of glucose, Hb1ac and triglycerides. The bivariate analysis of the variables showed that triglycerides was positively correlated with the expression of COX-2 in internal mammary arteries from patients (r2 = 0.214, P < 0.04). Conclusions We conclude that is not the glucose blood levels but the triglicerydes leves what increases the expression of COX-2 in arteries from DP. PMID:23642086

  18. Variabilidad en las medidas de tensión arterial realizada por estudiantes de 5.º y 6.º de medicina Variability of arterial pressure measurements performed by advanced medical students

    Directory of Open Access Journals (Sweden)

    C. Caramelo

    2008-06-01

    Full Text Available Introducción. No se ha definido objetivamente si los estudiantes de medicina avanzados dominan destrezas básicas, como la medida de tensión arterial. Sujetos y métodos. Se determinó la variabilidad de medida de tensión arterial por estudiantes de 5.º y 6.º cursos de medicina. Resultados. Se encontraron coeficientes de variación significativamente más elevados en la tensión arterial diastólica derecha y frecuencia cardíaca, y grupos e individuos con error sistemático de medición. Conclusión. Resulta necesario un refuerzo docente en la medida de tensión arterial diastólica y su realización en los dos brazos.Introduction. No objective data are available to know whether advanced medical students are in command of basic practical skills, ie, arterial pressure measurement. Subjects and methods. Variability of arterial pressure measurements was examined in 5th- and 6th-year medical students. Results. Significantly higher variability coefficients were found in right arm diastolic arterial pressure and heart rate. A systematic measurement error was detected in some groups and individuals. Conclusion. A teaching effort will be necessary to improve arterial pressure measurement skills, with special emphasis in diastolic arterial pressure and bilateral measurements.

  19. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart

    2017-01-01

    The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared to frequen......The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared...... to frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as model system, integrating vital imaging, pressure myography and mathematical modeling. Collagenase and elastase...... digestions were applied to evaluate the loadbearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R(2)≥0.99), while there was a nonlinear relationship to the internal...

  20. Biosensor cell assay for measuring real-time aldosterone-induced release of histamine from mesenteric arteries

    DEFF Research Database (Denmark)

    Dalgaard, Emil G; Andersen, Kenneth; Svenningsen, Per

    2017-01-01

    AIMS: The aims were to develop a method for real-time detection of histamine release and to test if incubation with aldosterone induces histamine release from isolated, perfused mice mesenteric arteries. METHODS: Fura-2 loaded HEK-293 cells transfected with the histamine H1 receptor was used...... as a sensitive biosensor assay for histamine release from isolated mouse mesenteric arteries. Activation of the H1 receptor by histamine was measured as an increased number of intracellular Ca(2+) transient peaks using fluorescence imaging RESULTS: The developed biosensor was sensitive to histamine...... by the histamine H1 blocker pyrilamine. Mesenteric arteries from mast cell deficient SASH mice induced similar pyrilamine-sensitive Ca(2+) transient response in the biosensor cells. Mesenteric arteries from wild type and SASH mice expressed histamine decarboxylase mRNA, indicating that mast cells are not the only...

  1. Cardiac MRI in pulmonary artery hypertension: correlations between morphological and functional parameters and invasive measurements

    Energy Technology Data Exchange (ETDEWEB)

    Alunni, Jean-Philippe; Otal, Philippe; Rousseau, Herve; Chabbert, Valerie [CHU Rangueil, Department of Radiology, Toulouse (France); Degano, Bruno; Tetu, Laurent; Didier, Alain [CHU Larrey, Department of Pneumology, Toulouse (France); Arnaud, Catherine [CHU Rangueil, Department of Methods in Clinical Research, Toulouse (France); Blot-Souletie, Nathalie [CHU Rangueil, Department of Cardiology, Toulouse (France)

    2010-05-15

    To compare cardiac MRI with right heart catheterisation in patients with pulmonary hypertension (PH) and to evaluate its ability to assess PH severity. Forty patients were included. MRI included cine and phase-contrast sequences, study of ventricular function, cardiac cavity areas and ratios, position of the interventricular septum (IVS) in systole and diastole, and flow measurements. We defined four groups according to the severity of PH and three groups according to IVS position: A, normal position; B, abnormal in diastole; C, abnormal in diastole and systole. IVS position was correlated with pulmonary artery pressures and PVR (pulmonary vascular resistance). Median pulmonary artery pressures and resistance were significantly higher in patients with an abnormal septal position compared with those with a normal position. Correlations were good between the right ventricular ejection fraction and PVR, right ventricular end-systolic volume and PAP, percentage of right ventricular area change and PVR, and diastolic and systolic ventricular area ratio and PVR. These parameters were significantly associated with PH severity. Cardiac MRI can help to assess the severity of PH. (orig.)

  2. Fatty Acid Metabolic Defects and Right Ventricular Lipotoxicity in Human Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Brittain, Evan L; Talati, Megha; Fessel, Joshua P; Zhu, He; Penner, Niki; Calcutt, M Wade; West, James D; Funke, Mitch; Lewis, Gregory D; Gerszten, Robert E; Hamid, Rizwan; Pugh, Meredith E; Austin, Eric D; Newman, John H; Hemnes, Anna R

    2016-05-17

    The mechanisms of right ventricular (RV) failure in pulmonary arterial hypertension (PAH) are poorly understood. Abnormalities in fatty acid (FA) metabolism have been described in experimental models of PAH, but systemic and myocardial FA metabolism has not been studied in human PAH. We used human blood, RV tissue, and noninvasive imaging to characterize multiple steps in the FA metabolic pathway in PAH subjects and controls. Circulating free FAs and long-chain acylcarnitines were elevated in PAH patients versus controls. Human RV long-chain FAs were increased and long-chain acylcarnitines were markedly reduced in PAH versus controls. With the use of proton magnetic resonance spectroscopy, in vivo myocardial triglyceride content was elevated in human PAH versus controls (1.4±1.3% triglyceride versus 0.22±0.11% triglyceride, P=0.02). Ceramide, a mediator of lipotoxicity, was increased in PAH RVs versus controls. Using an animal model of heritable PAH, we demonstrated reduced FA oxidation via failure of palmitoylcarnitine to stimulate oxygen consumption in the PAH RV. Abnormalities in FA metabolism can be detected in the blood and myocardium in human PAH and are associated with in vivo cardiac steatosis and lipotoxicity. Murine data suggest that lipotoxicity may arise from reduction in FA oxidation. © 2016 American Heart Association, Inc.

  3. Three-dimensional modelling of the human carotid artery using the lattice Boltzmann method: I. Model and velocity analysis

    Science.gov (United States)

    Boyd, J.; Buick, J. M.

    2008-10-01

    Numerical modelling is a powerful tool in the investigation of human blood flow and arterial diseases such as atherosclerosis. It is known that near wall velocity and shear are important in the pathogenesis and progression of atherosclerosis. In this paper results for a simulation of blood flow in a three-dimensional carotid artery geometry using the lattice Boltzmann method are presented. The velocity fields in the body of the fluid are analysed at six times of interest during a physiologically accurate velocity waveform. It is found that the three-dimensional model agrees well with previous literature results for carotid artery flow. Regions of low near wall velocity and circulatory flow are observed near the outer wall of the bifurcation and in the lower regions of the external carotid artery, which are regions that are typically prone to atherosclerosis.

  4. Investigation of Ultrasound-Measured Flow Velocity, Flow Rate and Wall Shear Rate in Radial and Ulnar Arteries Using Simulation.

    Science.gov (United States)

    Zhou, Xiaowei; Xia, Chunming; Stephen, Gandy; Khan, Faisel; Corner, George A; Hoskins, Peter R; Huang, Zhihong

    2017-05-01

    Parameters of blood flow measured by ultrasound in radial and ulnar arteries, such as flow velocity, flow rate and wall shear rate, are widely used in clinical practice and clinical research. Investigation of these measurements is useful for evaluating accuracy and providing knowledge of error sources. A method for simulating the spectral Doppler ultrasound measurement process was developed with computational fluid dynamics providing flow-field data. Specific scanning factors were adjusted to investigate their influence on estimation of the maximum velocity waveform, and flow rate and wall shear rate were derived using the Womersley equation. The overestimation in maximum velocity increases greatly (peak systolic from about 10% to 30%, time-averaged from about 30% to 50%) when the beam-vessel angle is changed from 30° to 70°. The Womersley equation was able to estimate flow rate in both arteries with less than 3% error, but performed better in the radial artery (2.3% overestimation) than the ulnar artery (15.4% underestimation) in estimating wall shear rate. It is concluded that measurements of flow parameters in the radial and ulnar arteries with clinical ultrasound scanners are prone to clinically significant errors. Copyright © 2017. Published by Elsevier Inc.

  5. Serum can overcome contact inhibition in confluent human pulmonary artery smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Victor Solodushko

    Full Text Available Pulmonary artery endothelial cells (PAEC in an intact vessel are continually exposed to serum, but unless injured, do not proliferate, constrained by confluence. In contrast, pulmonary artery smooth muscle cells (PASMC attain, and maintain, confluence in the presence of minimal serum, protected from serum's stimulatory effects except when the endothelial barrier becomes more permeable. We hypothesized therefore, that confluent PASMC may be less constrained by contact inhibition in the presence of serum than PAEC and tested this idea by exposing confluent non-transformed human PAEC and PASMC to media containing increasing concentrations of fetal bovine serum (FBS and determining cell growth over 7 days. PAEC that had attained confluence in low serum did not proliferate even when exposed to 5% serum, the highest concentration tested. In contrast, PASMC that attained confluence in low serum did proliferate once serum levels were increased, an effect that was dose dependent. Consistent with this observation, PASMC had more BrdU incorporation and a greater percentage of cells in S phase in 5% compared to 0.2% FBS, whereas no such difference was seen in PAEC. These results suggest that confluent human PAEC are resistant to the stimulatory effects of serum, whereas confluent PASMC can proliferate when serum levels are increased, an effect mediated in part by differences in phosphoinositide 3-kinase activation. This observation may be relevant to understanding the PASMC hyperplasia observed in humans and animals with pulmonary hypertension in which changes in endothelial permeability due to hypoxia or injury expose the underlying smooth muscle to serum.

  6. Water vapour loss measurements on human skin.

    NARCIS (Netherlands)

    Valk, Petrus Gerardus Maria van der

    1984-01-01

    In this thesis, the results of a series of investigations into the barrier function of human skin are presented. In these investigations, the barrier function was assessed by water vapour loss measurements of the skin using a method based on gradient estimation.... Zie: Summary and conclusions

  7. Adaptable setups for magnetic drug targeting in human muscular arteries: Design and implementation

    Science.gov (United States)

    Hajiaghajani, Amirhossein; Hashemi, Soheil; Abdolali, Ali

    2017-09-01

    Magnetic drug targeting has been used to steer magnetic therapeutic agents and has received much attention for capillaries and human brain arteries. In this paper, we focus on noninvasive targeting of nanoparticles in muscular arteries, in where the vessel diameter and blood flow are much challengingly higher than brain capillaries. We aim to design a low intensity magnetic field which avoids potential side effects on blood cells while steers particles with high targeting rate. The setup design procedure is considerably flexible to be used in a wide variety of large vessels. Using particle tracing, a new method is proposed to connect the geometry of the vessel under the action of targeting to the required magnetic force. Specifications of the coil which is placed outside the body are derived based on this required force. Mutual effects of coil dimensions on the produced magnetic force are elaborated and summarized in a design flowchart to be used for arbitrary muscular vessel sizes. The performance of the optimized coil is validated by in vitro experiments and it is shown that particles are steered with the average efficiency of 80.2% for various conditions.

  8. The sources of calcium for noradrenaline-induced contraction in the human thoracic internal artery.

    Science.gov (United States)

    Buzun, Leszek; Modzelewska, Beata; Kostrzewska, Anna; Kleszczewska, Ewa; Kleszczewski, Tomasz

    2017-04-22

    The aim of the present study was to examine the contribution of intracellular and extracellular calcium sources in contraction caused by noradrenaline (NA) of the human internal thoracic artery (ITA) in vitro. Distal segments of ITA were obtained from 20 patients (aged 38-73, at the time of routine coronary artery surgical revascularization (CABG)). Contractile responses to 10-6 mol/L NA in the physiological salt solution and in Ca2+-free solution without and after incubation with 10-6 mol/L thapsigargin (TSG) were recorded under isometric conditions. Responses of ITA rings to 1 μM NA without incubation with TSG accounted (% of reaction to 80 mM KCl) 224.70 ± 14.06% in PSS solution, 141.30 ± 8.66% in Ca2+-free solution, and 80.03 ± 1.71% after PSS restoration and were statistically significantly different (p calcium derived not only from the SR and the extracellular matrix. The delivery of calcium to the space surrounding tissue does not immediately deliver calcium to the myofilaments.

  9. Stiffness Properties of Adventitia, Media, and Full Thickness Human Atherosclerotic Carotid Arteries in the Axial and Circumferential Directions.

    Science.gov (United States)

    Hoffman, Allen H; Teng, Zhongzhao; Zheng, Jie; Wu, Zheyang; Woodard, Pamela K; Billiar, Kristen L; Wang, Liang; Tang, Dalin

    2017-12-01

    Arteries can be considered as layered composite material. Experimental data on the stiffness of human atherosclerotic carotid arteries and their media and adventitia layers are very limited. This study used uniaxial tests to determine the stiffness (tangent modulus) of human carotid artery sections containing American Heart Association type II and III lesions. Axial and circumferential oriented adventitia, media, and full thickness specimens were prepared from six human carotid arteries (total tissue strips: 71). Each artery yielded 12 specimens with two specimens in each of the following six categories; axial full thickness, axial adventitia (AA), axial media (AM), circumferential full thickness, circumferential adventitia (CA), and circumferential media (CM). Uniaxial testing was performed using Inspec 2200 controlled by software developed using labview. The mean stiffness of the adventitia was 3570 ± 667 and 2960 ± 331 kPa in the axial and circumferential directions, respectively, while the corresponding values for the media were 1070 ± 186 and 1800 ± 384 kPa. The adventitia was significantly stiffer than the media in both the axial (p = 0.003) and circumferential (p = 0.010) directions. The stiffness of the full thickness specimens was nearly identical in the axial (1540 ± 186) and circumferential (1530 ± 389 kPa) directions. The differences in axial and circumferential stiffness of media and adventitia were not statistically significant.

  10. Inter-Relationship of Arterial Supply to Human Retina, Choroid, and Optic Nerve Head Using Micro Perfusion and Labeling.

    Science.gov (United States)

    Yu, Paula K; McAllister, Ian L; Morgan, William H; Cringle, Stephen J; Yu, Dao-Yi

    2017-07-01

    The prevailing view is that the human retina is supplied by the central retinal artery (CRA), the short posterior ciliary arteries (SPCAs) support the choroid, and both the CRA and the SPCAs are so-called "end artery" systems. In this study, we investigate whether vascular connections among the retina, choroid, and the optic nerve head (ONH) exist, using selective cannulation and microperfusion-labeling techniques. The CRA and/or one or more of the SPCAs were selected for cannulation in 18 human donor eyes. Fluorescent probes with different excitation wavelengths were perfused through different arteries on the same eye to distinguish the supply sources of different vascular beds. After labeling and fixation, the ONH region was dissected either longitudinally or transversely as thick sections for confocal microscopy. Retina, choroid, and ONH were imaged from whole-mount specimens. Probes perfused through the CRA or the SPCA alone labeled the microvessels in the retina, choroid, and ONH regions, as well as the optic nerve trunk. The vessels of the lamina cribrosa and the optic nerve trunk were labeled when probes were perfused through the SPCA. Perfusion through both the CRA and SPCA produced double labeling of vessels in the retina, the choroid, and the ONH. The results indicate an inter-relationship of arterial supply to the retina, choroid, and ONH in the human eye. This has important implications in understanding clinical observations and disease mechanisms such as that of glaucoma and ischemic optic nerve disease.

  11. Validity and reproducibility of arterial pulse wave velocity measurement using new device with oscillometric technique: A pilot study

    Directory of Open Access Journals (Sweden)

    Patnaik Amar

    2005-08-01

    Full Text Available Abstract Background Availability of a range of techniques and devices allow measurement of many variables related to the stiffness of large or medium sized arteries. There is good evidence that, pulse wave velocity is a relatively simple measurement and is a good indicator of changes in arterial properties. The pulse wave velocity calculated from pulse wave recording by other methods like doppler or tonometry is tedious, time-consuming and above all their reproducibility depends on the operator skills. It requires intensive resource involvement. For epidemiological studies these methods are not suitable. The aim of our study was to clinically evaluate the validity and reproducibility of a new automatic device for measurement of pulse wave velocity that can be used in such studies. Methods In 44 subjects including normal healthy control and patients with coronary artery disease, heart brachial, heart ankle, brachial ankle and carotid femoral pulse wave velocities were recorded by using a new oscillometric device. Lead I and II electrocardiogram and pressure curves were simultaneously recorded. Two observers recorded the pulse wave velocity for validation and one observer recorded the velocity on two occasions for reproducibility. Results and Discussion Pulse wave velocity and arterial stiffness index were recorded in 24 control and 20 coronary artery disease patients. All the velocities were significantly high in coronary artery disease patients. There was highly significant correlation between the values noted by the two observers with low standard deviation. The Pearson's correlation coefficient for various velocities ranged from (r = 0.88–0.90 with (p Conclusion The new device "PeriScope" based on oscillometric technique has been found to be a simple, non-invasive and reproducible device for the assessment of pulse wave velocity and can be used to determine arterial stiffness in large population based studies.

  12. Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

    Science.gov (United States)

    Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

    2017-05-01

    The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

  13. Evidence for shear stress-mediated dilation of the internal carotid artery in humans

    DEFF Research Database (Denmark)

    Carter, Howard Henry; Atkinson, Ceri L; Heinonen, Ilkka H A

    2016-01-01

    Increases in arterial carbon dioxide tension (hypercapnia) elicit potent vasodilation of cerebral arterioles. Recent studies have also reported vasodilation of the internal carotid artery during hypercapnia, but the mechanism(s) mediating this extracranial vasoreactivity are unknown. Hypercapnia ...

  14. A finite element model to study the effect of tissue anisotropy on ex vivo arterial shear wave elastography measurements

    Science.gov (United States)

    Shcherbakova, D. A.; Debusschere, N.; Caenen, A.; Iannaccone, F.; Pernot, M.; Swillens, A.; Segers, P.

    2017-07-01

    Shear wave elastography (SWE) is an ultrasound (US) diagnostic method for measuring the stiffness of soft tissues based on generated shear waves (SWs). SWE has been applied to bulk tissues, but in arteries it is still under investigation. Previously performed studies in arteries or arterial phantoms demonstrated the potential of SWE to measure arterial wall stiffness—a relevant marker in prediction of cardiovascular diseases. This study is focused on numerical modelling of SWs in ex vivo equine aortic tissue, yet based on experimental SWE measurements with the tissue dynamically loaded while rotating the US probe to investigate the sensitivity of SWE to the anisotropic structure. A good match with experimental shear wave group speed results was obtained. SWs were sensitive to the orthotropy and nonlinearity of the material. The model also allowed to study the nature of the SWs by performing 2D FFT-based and analytical phase analyses. A good match between numerical group velocities derived using the time-of-flight algorithm and derived from the dispersion curves was found in the cross-sectional and axial arterial views. The complexity of solving analytical equations for nonlinear orthotropic stressed plates was discussed.

  15. Technical Note: Measurement of common carotid artery lumen dynamics using black-blood MR cine imaging.

    Science.gov (United States)

    Dai, Erpeng; Dong, Li; Zhang, Zhe; Li, Lyu; Zhang, Hui; Zhao, Xihai; Wang, Jinnan; Yuan, Chun; Guo, Hua

    2017-03-01

    To demonstrate the feasibility of measuring the common carotid artery (CCA) lumen dynamics using a black-blood cine (BB-cine) imaging method. Motion-sensitized driven-equilibrium (MSDE) prepared spoiled gradient sequence was used for the BB-cine imaging. CCAs of eleven healthy volunteers were studied using this method. Lumen dynamics, including lumen area evolution waveforms and distension values, were measured and evaluated by comparing this method with bright-blood cine (BrB-cine) imaging. Compared with the BrB-cine images, flow artifacts were effectively suppressed in the BB-cine images. BrB-cine images generally show larger lumen areas than BB-cine images. The lumen area waveforms and distension measurements from BB-cine imaging showed smaller variances among different subjects than BrB-cine imaging. The proposed BB-cine imaging technique can suppress the flow artifacts effectively and reduce the partial volume effects from the vessel wall. This might allow more accurate lumen dynamics measurements than traditional BrB-cine imaging, which may further be valuable for investigating biomechanical and functional properties of the cardiovascular system. © 2017 American Association of Physicists in Medicine.

  16. Validity and reliability of Doppler ultrasonography and direct arterial blood pressure measurements in anaesthetized dogs weighing less than 5 kg.

    Science.gov (United States)

    Moll, Xavier; Aguilar, Adria; García, Felix; Ferrer, Rosa; Andaluz, Anna

    2017-09-15

    To assess the validity and reliability of Doppler ultrasonography (DOP) as compared with invasive arterial blood pressure measurements in anaesthetized dogs weighing less than 5 kg. Controlled, prospective, clinical study. A total of 41 privately owned dogs weighing less than 5 kg. The dogs were anaesthetized, and an intra-arterial catheter was placed aseptically in the dorsal pedal artery of the pelvic limb to perform invasive blood pressure (IBP) measurement. The contralateral metatarsal surface of the foot was clipped in order to perform DOP. Both techniques were used to record blood pressure measurements every 5 minutes during surgical procedures. The blood pressure measurements were categorized into two groups: hypotensive [mean arterial pressure (MAP) blood pressure (SAP) and MAP of IBP measurements. The closest agreement between the two techniques was found for SAP; the bias was 8.8, and limits of agreement (LOA) were -32.9 and 50.4. Similar results were observed when the IBP technique was categorized. The closest agreement was for SAP in animals categorized as normotensive; the bias was 8.2, and LOAs were -32.8 and 49.2. The level of agreement between DOP and IBP did not meet the ACVIM recommendations. Our results suggest there is poor agreement between DOP and IBP measurements in anaesthetized dogs weighing less than 5 kg. Hence, the use of DOP in these animals could be misleading. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

  17. Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

    Science.gov (United States)

    Majka, Marcin; Gadda, Giacomo; Taibi, Angelo; Gałązka, Mirosław; Zieliński, Piotr

    2017-03-01

    We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.

  18. Human-centred approaches in slipperiness measurement

    Science.gov (United States)

    Grönqvist, Raoul; Abeysekera, John; Gard, Gunvor; Hsiang, Simon M.; Leamon, Tom B.; Newman, Dava J.; Gielo-Perczak, Krystyna; Lockhart, Thurmon E.; Pai, Clive Y.-C.

    2010-01-01

    A number of human-centred methodologies—subjective, objective, and combined—are used for slipperiness measurement. They comprise a variety of approaches from biomechanically-oriented experiments to psychophysical tests and subjective evaluations. The objective of this paper is to review some of the research done in the field, including such topics as awareness and perception of slipperiness, postural and balance control, rating scales for balance, adaptation to slippery conditions, measurement of unexpected movements, kinematics of slipping, and protective movements during falling. The role of human factors in slips and falls will be discussed. Strengths and weaknesses of human-centred approaches in relation to mechanical slip test methodologies are considered. Current friction-based criteria and thresholds for walking without slipping are reviewed for a number of work tasks. These include activities such as walking on a level or an inclined surface, running, stopping and jumping, as well as stair ascent and descent, manual exertion (pushing and pulling, load carrying, lifting) and particular concerns of the elderly and mobility disabled persons. Some future directions for slipperiness measurement and research in the field of slips and falls are outlined. Human-centred approaches for slipperiness measurement do have many applications. First, they are utilized to develop research hypotheses and models to predict workplace risks caused by slipping. Second, they are important alternatives to apparatus-based friction measurements and are used to validate such methodologies. Third, they are used as practical tools for evaluating and monitoring slip resistance properties of foot wear, anti-skid devices and floor surfaces. PMID:11794763

  19. Medida da pressão arterial em gestante Toma de la presión arterial en embarazadas Blood pressure measurement in pregnancy

    Directory of Open Access Journals (Sweden)

    Sonia M. Junqueira V. de Oliveira

    1997-07-01

    Full Text Available Trata-se de revisão da literatura à respeito da medida indireta da pressão arterial (P A em gestante normotensa. Aborda as modificações ocorridas na pressão arterial sistólica e diastólica decorrentes da gravidez. São discutidos aspectos polêmicos no procedimento de medida da P A, como por exemplo qual a fase dos sons de Korotkoff (fase quatro ou cinco que representa melhor a pressão diastólica e o uso da Monitorização Ambulatorial da Pressão Arterial. Enfatiza as recomendações de diferentes sociedades (American Heart Association, British Hypertension Society, Australasian Society, National High Blood Pressure Education Program e World Health Organization.Se trata de una revisión de la literatura con respeto a la toma indirecta de la presión arterial (PA en embarazadas normotensas. Se describen los cámbios que ocurrer en la presión arterial sistólica y diastólica a causa del embarazo. Son discutidos aspectos polémicos en el procedimiento de la toma de la PA, como por ejemplo: cuál es la fase de los sonidos de Korotkoff (fases cuatro o cinco que representa mejor la presión sistólica. Se enfatizan las recomendaciones de diferentes sociedades (American Heart Association, British Hypertension Society, Australasian Society, National High Blood Pressure Education Program and World Health Organization.This study deals with the review of the literature regarding the indirect blood pressure measurement in normal pregnant women. It shows the changes that happened whith the blood pressure due to pregnancy. Polemical aspects in the procedure of blood pressure measurement are discussed; for example, which one of the Korotkoff phases (4 or 5 that better represent the diastolic blood pressure and the use of Ambulatory Blood Pressure Monitoring in pregnancy. The recommendations from different societies are emphasized (American Heart Association, British Hypertension Society, Australasian Society, National High Blood Pressure Education

  20. Arterial input functions (AIFs) measured directly from arteries with low and standard doses of contrast agent, and AIFs derived from reference tissues.

    Science.gov (United States)

    Wang, Shiyang; Fan, Xiaobing; Medved, Milica; Pineda, Federico D; Yousuf, Ambereen; Oto, Aytekin; Karczmar, Gregory S

    2016-02-01

    Measurements of arterial input function (AIF) can have large systematic errors at standard contrast agent doses in dynamic contrast enhanced MRI (DCE-MRI). We compared measured AIFs from low dose (AIFLD) and standard dose (AIFSD) contrast agent injections, as well as the AIF derived from a muscle reference tissue and artery (AIFref). Twenty-two prostate cancer patients underwent DCE-MRI. Data were acquired on a 3T scanner using an mDixon sequence. Gadobenate dimeglumine was injected twice, at doses of 0.015 and 0.085 mmol/kg. Directly measured AIFs were fitted with empirical mathematical models (EMMs) and compared to the AIF derived from a muscle reference tissue (AIFref). EMMs accurately fitted the AIFs. The 1st and 2nd pass peaks were visualized in AIFLD, but not in AIFSD, thus the peak and shape of AIFSD could not be accurately measured directly. The average scaling factor between AIFSD and AIFLD in the washout phase was only 56% of the contrast dose ratio (~6:1). The shape and magnitude of AIFref closely approximated that of AIFLD after empirically determined dose-dependent normalization. This suggests that AIFref may be a good approximation of the local AIF. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Age related constitutive laws and stress distribution in human main coronary arteries with reference to residual strain.

    Science.gov (United States)

    Valenta, Jaroslav; Vitek, Karel; Cihak, Radomir; Konvickova, Svatava; Sochor, Miroslav; Horny, Lukas

    2002-01-01

    An analytical model has been used to simulate the effects of tissue aging on residual strain, constitutive relations and stiffness parameter in the main right and left (ramus circumflexus) human coronary arteries, based on experimental data. The experimental opening angle theta scatters considerably with age. The optimum angle theta(op) approximately equals 70 degrees, which makes the circumferential stress uniform in the arterial wall at a normal blood pressure, is approximately constant throughout aging. Above age of the 15 years the estimated and experimental values of theta are greater than theta(op) and therefore the mechanical load of the inner layers of the media and the intima decreases and the adventitia is overloaded. On the basis of nonlinear regression analysis, age-related constitutive laws of arterial wall circumferential stiffness have been determined. Above the age of 30, arterial wall hardening increases rapidly. The left coronary artery is stiffer than the right artery for groups from 35 to 45 years of age. Hyperelasticity theory has been used to identify age-related multiaxial stress through wall thickness. A theoretical model based on the reduced Green strain provides a very good representation of the coronary artery circumferential mechanical response and predicts its nearly isotropic behavior. Bio-composite material forms non-homogeneous stresses and, in the course of aging, it increases the adventitia loading. In groups aged from 10 to 15 years, whose coronary artery residual strains are low, the circumferential stress distribution has a classic form. Stiffness parameter beta gradually increases with age and this increase is significant above the age of 60. Parameter beta tends to decrease when the opening angle theta increases.

  2. A poor correlation exists between oscillometric and radial arterial blood pressure as measured by the Philips MP90 monitor.

    Science.gov (United States)

    Mireles, Samuel A; Jaffe, Richard A; Drover, David R; Brock-Utne, John G

    2009-06-01

    In anesthesia and critical care, invasive arterial blood pressure monitoring is the gold standard against which other methods of monitoring are compared. In this assessment of the Philips MP90 monitor, the objective was to determine whether or not oscillometric measurements were within the accuracy standards set by the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS). Three hundred and one invasive and noninvasive paired measurements were obtained from eleven adult patients on the neurosurgical service at Stanford University Medical Center. Bland-Altman plots were created to assess agreement between the two measurement systems. Paired correlation analysis, bias and precision calculations were performed. Oscillometric blood pressure measurements correlated with arterial measurements yielding Pearson r values of 0.68, 0.67 and 0.62 for systolic, diastolic and mean pressures, respectively (P < 0.01.) Mean differences with 95% confidence intervals were -3.8 mmHg +/- 13.6, -2.4 mmHg +/- 10.0, and 4.0 mmHg +/- 13.1 for systolic, diastolic and mean pressures, respectively. The mean difference for these measurements was arterial pressure, and a grade "C" for diastolic pressure, with the highest possible grade level being "A." There was a poor correlation between noninvasive and invasive measurements of arterial blood pressure as measured with a cuff and radial arterial cannula using the Philips MP90 monitor. These inaccuracies could lead to unnecessary interventions, or lack of appropriate interventions in anesthetic management. Further study is needed to specify the absolute inaccuracy of the monitor, and to determine if accuracy between the two methods varies with patient co

  3. ACE-versus chymase-dependent angiotensin II generation in human coronary arteries: a matter of efficiency?

    NARCIS (Netherlands)

    B. Tom (Beril); I.M. Garrelds (Ingrid); E. Scalbert; A.P.A. Stegmann (Sander); F. Boomsma (Frans); P.R. Saxena (Pramod Ranjan); A.H.J. Danser (Jan)

    2003-01-01

    textabstractOBJECTIVE: The objective of this study was to investigate ACE- and chymase-dependent angiotensin I-to-II conversion in human coronary arteries (HCAs). METHODS AND RESULTS: HCA rings were mounted in organ baths, and concentration-response curves to angiotensin II,

  4. Ultrasonic Measurement of Change in Elasticity due to Endothelium Dependent Relaxation Response by Accurate Detection of Artery-Wall Boundary

    Science.gov (United States)

    Kaneko, Takuya; Hasegawa, Hideyuki; Kanai, Hiroshi

    2007-07-01

    Ross hypothesized that an endothelial dysfunction is considered to be an initial step in atherosclerosis. Endothelial cells, which release nitric oxide (NO) in response to shear stress from blood flow, have a function of relaxing smooth muscle in the media of the arterial wall. For the assessment of the endothelial function, there is a conventional method in which the change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) is measured with ultrasound. However, despite the fact that the collagen-rich hard adventitia does not respond to NO, the conventional method measures the change in diameter depending on the mechanical property of the entire wall including the adventitia. Therefore, we developed a method of measuring the change in the thickness and the elasticity of the brachial artery during a cardiac cycle using the phased tracking method for the evaluation of the mechanical property of only the intima-media region. In this study, the initial positions of echoes from the lumen-intima and media-adventitia boundaries are determined using complex template matching to accurately estimate the minute change in the thickness and the elasticity of the brachial and radial arteries. The ambiguity in the determination of such boundaries was eliminated using complex template matching, and the change in elasticity measured by the proposed method was larger than the change in inner diameter obtained by the conventional method.

  5. Differential Clearance of Rat and Human Bone Marrow-Derived Mesenchymal Stem Cells From the Brain After Intra-arterial Infusion in Rats.

    Science.gov (United States)

    Khabbal, Joonas; Kerkelä, Erja; Mitkari, Bhimashankar; Raki, Mari; Nystedt, Johanna; Mikkonen, Ville; Bergström, Kim; Laitinen, Saara; Korhonen, Matti; Jolkkonen, Jukka

    2015-01-01

    Intra-arterial (IA) delivery of bone marrow-derived mesenchymal stem cells (BM-MSCs) has shown potential as a minimally invasive therapeutic approach for stroke. The aim of the present study was to determine the whole-body biodistribution and clearance of technetium-99m ((99m)Tc)-labeled rat and human BM-MSCs after IA delivery in a rat model of transient middle cerebral artery occlusion (MCAO) using single-photon emission computed tomography (SPECT). Our hypothesis was that xenotransplantation has a major impact on the behavior of cells. Male RccHan:Wistar rats were subjected to sham operation or MCAO. Twenty-four hours after surgery, BM-MSCs (2 × 10(6) cells/animal) labeled with (99m)Tc were infused into the external carotid artery. Whole-body SPECT images were acquired 20 min, 3 h, and 6 h postinjection, after which rats were sacrificed, and organs were collected and weighed for measurement of radioactivity. The results showed that the majority of the cells were located in the brain and especially in the ipsilateral hemisphere immediately after cell infusion both in sham-operated and MCAO rats. This was followed by fast disappearance, particularly in the case of human cells. At the same time, the radioactivity signal increased in the spleen, kidney, and liver, the organs responsible for destroying cells. Further studies are needed to demonstrate whether differential cell behavior has any functional impact.

  6. Histology-validated x-ray tomography for imaging human coronary arteries

    Science.gov (United States)

    Buscema, Marzia; Schulz, Georg; Deyhle, Hans; Khimchenko, Anna; Matviykiv, Sofiya; Holme, Margaret N.; Hipp, Alexander; Beckmann, Felix; Saxer, Till; Michaud, Katarzyna; Müller, Bert

    2016-10-01

    Heart disease is the number one cause of death worldwide. To improve therapy and patient outcome, the knowledge of anatomical changes in terms of lumen morphology and tissue composition of constricted arteries is crucial for designing a localized drug delivery to treat atherosclerosis disease. Traditional tissue characterization by histology is a pivotal tool, although it brings disadvantages such as vessel morphology modification during decalcification and slicing. X-ray tomography in absorption and phase contrast modes yields a deep understanding in blood vessel anatomy in healthy and diseased stages: measurements in absorption mode make visible highly absorbing tissue components including cholesterol plaques, whereas phase contrast tomography gains better contrast of the soft tissue components such as vessel walls. Established synchrotron radiation-based micro-CT techniques ensure high performance in terms of 3D visualization of highly absorbing and soft tissues.

  7. Differential mechanical response and microstructural organization between non-human primate femoral and carotid arteries

    Science.gov (United States)

    Raykin, Julia; Li, Haiyan; Gleason, Rudolph L.

    2014-01-01

    Unique anatomic locations and physiologic functions predispose different arteries to varying mechanical responses and pathologies. However, the underlying causes of these mechanical differences are not well understood. The objective of this study was to first identify structural differences in the arterial matrix that would account for the mechanical differences between healthy femoral and carotid arteries and second to utilize these structural observations to perform a microstructurally motivated constitutive analysis. Femoral and carotid arteries were subjected to cylindrical biaxial loading and their microstructure was quantified using two-photon microscopy. The femoral arteries were found to be less compliant than the carotid arteries at physiologic loads, consistent with previous studies, despite similar extracellular compositions of collagen and elastin (P > 0.05). The femoral arteries exhibited significantly less circumferential dispersion of collagen fibers (P arteries. Elastin transmural distribution, in vivo axial stretch, and opening angles were also found to be distinctly different between the arteries. Lastly, we modeled the arteries’ mechanical behaviors using a microstructural-based, distributed collagen fiber constitutive model. With this approach, the material parameters of the model were solved using the experimental microstructural observations. The findings of this study support an important role for microstructural organization in arterial stiffness. PMID:24532266

  8. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A

    1977-01-01

    Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure...... also remained normal. In the high vascular tone state, a large transmural pressure difference must apparently be established before the digital arteries are forced open. The lowered opening pressure constitutes a manifestation of the closure phenomenon of the digital arteries described in patients...

  9. 3D Residual Stress Field in Arteries: Novel Inverse Method Based on Optical Full-field Measurements

    CERN Document Server

    Badel, Pierre; Avril, Stéphane; 10.1111/str.12008

    2013-01-01

    Arterial tissue consists of multiple structurally important constituents that have individual material properties and associated stress-free configurations that evolve over time. This gives rise to residual stresses contributing to the homoeostatic state of stress in vivo as well as adaptations to perturbed loads, disease or injury. The existence of residual stresses in an intact but load-free excised arterial segment suggests compressive and tensile stresses, respectively, in the inner and outer walls. Accordingly, an artery ring springs open into a sector after a radial cut. The measurement of the opening angle is commonly used to deduce the residual stresses, which are the stresses required to close back the ring. The opening angle method provides an average estimate of circumferential residual stresses but it gives no information on local distributions through the thickness and along the axial direction. To address this lack, a new method is proposed in this article to derive maps of residual stresses usi...

  10. Auscultatory versus oscillometric blood pressure measurement in patients with atrial fibrillation and arterial hypertension.

    Science.gov (United States)

    Šelmytė-Besusparė, Aistėja; Barysienė, Jūratė; Petrikonytė, Dovilė; Aidietis, Audrius; Marinskis, Germanas; Laucevičius, Aleksandras

    2017-03-23

    The aim of our study was to investigate the reliability of automated oscillometric blood pressure (BP) monitoring in the presence and absence of atrial fibrillation (AF) in hypertensive patients. BP was measured and compared in 71 randomly selected patients with AF and arterial hypertension diagnosis, 4 times each by auscultatory and oscillometric (Microlife BP A6 PC with AF detection system) methods. Study included 71 patients: 36 males (mean age 67.4 years) and 35 females (70.2 years). At the time of BP measuring procedure, 36 patients were in sinus rhythm (SR) and 35 in AF. In SR patients mean systolic blood pressure (SBP) was 132 ± 17.9 mmHg with auscultatory method (AM), 137.4 ± 19.4 mmHg with oscillometric method (OM); mean diastolic BP was 77.1 ± 10.9 mmHg (AM), 78.5 ± 12.2 mmHg (OM), in AF patients mean SBP was 127.5 ± 15.1 mmHg (AM), 133.6 ± 17.4 mmHg (OM); mean diastolic BP was 81.4 ± 9.9 mmHg (AM), 83.5 ± 11.8 mmHg (OM), p = 0.037. The averages of differences for SBP and DBP in sinus rhythm group were (-5.3 mmHg (95% limits of agreement -27.2 - 16.6)) and (-1.4 mmHg (95% limits of agreement -12.8 - 10.0)), respectively. In patients with AF the averages of differences for SBP and DBP were (-6.1 mmHg (95% limits of agreement -23.9 - 11.7)) and (-2.1 mmHg (95% limits of agreement -12.9 - 8.7)), respectively. The oscillometric device validated for patients with AF on average gives 5.3 mmHg higher systolic BP values for patients with SR and 6.3 mmHg higher BP values for patients with AF. However, the limits of agreement between two methods reveal wide range of random error rates which is a questionable topic in clinical practice, as it could possibly affect the treatment of arterial hypertension in patients with AF.

  11. Impact of volunteer-related and methodology-related factors on the reproducibility of brachial artery flow-mediated vasodilation: analysis of 672 individual repeated measurements.

    Science.gov (United States)

    van Mil, Anke C C M; Greyling, Arno; Zock, Peter L; Geleijnse, Johanna M; Hopman, Maria T; Mensink, Ronald P; Reesink, Koen D; Green, Daniel J; Ghiadoni, Lorenzo; Thijssen, Dick H

    2016-09-01

    Brachial artery flow-mediated dilation (FMD) is a popular technique to examine endothelial function in humans. Identifying volunteer and methodological factors related to variation in FMD is important to improve measurement accuracy and applicability. Volunteer-related and methodology-related parameters were collected in 672 volunteers from eight affiliated centres worldwide who underwent repeated measures of FMD. All centres adopted contemporary expert-consensus guidelines for FMD assessment. After calculating the coefficient of variation (%) of the FMD for each individual, we constructed quartiles (n = 168 per quartile). Based on two regression models (volunteer-related factors and methodology-related factors), statistically significant components of these two models were added to a final regression model (calculated as β-coefficient and R). This allowed us to identify factors that independently contributed to the variation in FMD%. Median coefficient of variation was 17.5%, with healthy volunteers demonstrating a coefficient of variation 9.3%. Regression models revealed age (β = 0.248, P measurements (β = 0.318, P measurements, hypertension, baseline FMD% and lab experience with FMD independently predicted brachial artery variability (total R = 0.202). Although FMD% showed good reproducibility, larger variation was observed in conditions with longer time between measurements, hypertension, less experience and lower baseline FMD%. Accounting for these factors may improve FMD% variability.

  12. Relaxing Responses to Hydrogen Peroxide and Nitric Oxide in Human Pericardial Resistance Arteries Stimulated with Endothelin-1

    DEFF Research Database (Denmark)

    Leurgans, Thomas M; Bloksgaard, Maria; Irmukhamedov, Akhmadjon

    2017-01-01

    In human pericardial resistance arteries, effects of the endothelium-dependent vasodilator bradykinin are mediated by NO during contraction induced by K(+) or the TxA2 analogue U46619 and by H2 O2 during contraction by endothelin-1 (ET-1), respectively. We tested the hypotheses that ET-1 reduces...... relaxing effects of NO and increases those of H2 O2 in resistance artery smooth muscle of patients with cardiovascular disease. Arterial segments, dissected from the parietal pericardium of 39 cardiothoracic surgery patients, were studied by myography during amplitude-matched contractions induced by K......(+) , the TXA2 analogue U46619 or ET-1. Effects of the NO-donor Na-nitroprusside (SNP) and of exogenous H2 O2 were recorded in absence and presence of inhibitors of cyclooxygenases, NO-synthases and small and intermediate conductance calcium-activated K(+) channels. During contractions induced by either...

  13. Comparison of Doppler, oscillometric, auricular and carotid arterial blood pressure measurements in isoflurane anesthetized New Zealand white rabbits.

    Science.gov (United States)

    Barter, Linda S; Epstein, Steven E

    2014-07-01

    To assess agreement between carotid arterial pressure and auricular arterial, thoracic limb Doppler or thoracic limb oscillometric blood pressure measurements. Prospective experimental study. Six adult New Zealand white rabbits. Rabbits were anesthetized with isoflurane in oxygen at 1, 1.5 and 2 MAC on two separate occasions. Catheters in the auricular and the contralateral external carotid artery were connected to calibrated pressure transducers via non-compliant tubing. Inflatable cuffs of width equal to approximately 40% of the limb circumference were placed above the carpus on both thoracic limbs with a Doppler transducer placed distal to the cuff on one. Systolic (SAP) and mean (MAP) arterial blood pressure measurements were obtained at each dose, on each occasion. Agreement between measurement techniques was evaluated by repeated measures Bland Altman analysis with carotid pressure as the reference. Variation in bias over the measurement range was evaluated by regression analysis. Carotid MAP and SAP ranged from 20 to 65 mmHg and 37 to 103 mmHg respectively. Bias and 95% limits of agreement for auricular and oscillometric MAP were 7 (0-14) and -5 (-21-11) mmHg, respectively, and for auricular, oscillometric and Doppler SAP were 23 (8-37), -2 (-24-20) and 13 (-14-39) mmHg, respectively. Bias varied significantly over the measurement range (p < 0.001) for all three SAP techniques but not for MAP measurements. Limits of agreement for all measurements were large but less so for MAP than SAP. Variation in bias with SAP should be considered when using these measurements clinically. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  14. Tyrosine Phosphorylation Modulates the Vascular Responses of Mesenteric Arteries from Human Colorectal Tumors

    Directory of Open Access Journals (Sweden)

    Eduardo Ferrero

    2013-01-01

    Full Text Available The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of the VEGF receptor FLT1 was similar in control and tumoral arteries, but expression of the VEGF receptor KDR was increased in tumoral compared with control arteries. This suggests that tyrosine phosphorylation may produce inhibition of the contraction in tumoral mesenteric arteries, which may increase blood flow to the tumor when tyrosine phosphorylation is increased by stimulation of VEGF receptors.

  15. QT interval derived measurements in patients with cardiac syndrome X compared to coronary artery disease

    Directory of Open Access Journals (Sweden)

    Mohamed Faisal Lutfi

    2016-09-01

    Full Text Available Previous studies assessing effect of ischemia on ventricular repolarization are mostly directed towards patients with coronary artery disease (CAD; however, similar reports on cardiac syndrome X (CSX are scarce. Whether microvascular dysfunction of CSX and ischemia induced by CAD produce comparable effect on ventricular repolarization is unclear and deserve further studies. In the present study, ECG measures of ventricular repolarization were compared between CAD and CSX patients (40 subjects in each group. Following evaluation of sociodemographic characteristics, medical and past medical history, a resting ECG was used to assess measurements of ventricular repolarization in each patient, namely, QT interval (QT, corrected QT interval (QTc, QT dispersion (QTd, corrected QT dispersion (QTcd, adjacent QT dispersion (AdQTd, QT dispersion ratio (QTdR, JT dispersion (JTd and Corrected JT dispersion (JTcd. Results showed comparable QT intervals and QTd in CAD and CSX patients even after adjustment for the possible variations in gender, age and body mass index of the studied groups. Although JTd was increased in CSX subjects (26.6±7.2 ms compared with CAD patients (22.7±6.5 ms, p = 0.019, statistical significance disappeared after correcting JT for variations in heart rate. QT and QTc were significantly below 440 ms in CAD as well as CSX patients (p < 0.001. In contrast, maximum QTd, maximum QTcd and AdQTd of CAD and CSX patients were significantly above 440 ms (p < 0.001. The means of JTd and JTcd were significantly above 22 ms and 24 ms respectively (p < 0.001, p = 0.001 in CSX but not CAD patients (p = 0.529, p = 0.281. The present findings clearly demonstrate comparable measures of ventricular repolarization in CAD and CSX patients and consequently the risk of cardiac events.

  16. Stability of MR brain-perfusion measurement using arterial spin labeling

    Energy Technology Data Exchange (ETDEWEB)

    Petr, Jan; Hofheinz, Frank; Platzek, Ivan; Schramm, Georg; Van Den Hoff, Jorg [Helmholtz-Center Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research (Germany)

    2015-05-18

    Arterial spin labeling (ASL) is an MR technique for assessment of cerebral blood flow (CBF) that does not require use of contrast agents which makes it a less invasive alternative to the 15O-H2O-PET measurement. The repeatability of ASL has been studied extensively but mainly in young healthy volunteers. We have tested repeatability of ASL under realistic clinical conditions in elderly brain tumor patients acquired with a Philips Ingenuity TF PET/MR in the context of an ongoing 11C-Methionine PET/MR study. Twenty three patients (age 54.8±13.0 y) were scanned on two or more session. The patients underwent 6 weeks of concurrent radiochemotherapy with Temozolomide between the first session and second measurement. The mean relative difference of gray matter CBF was 18.6% between the first two session and 13.0% for the second session and further on. The mean gray matter CBF was 46.6±7.2 mL/min/100 g on the first sessions and there was a significant decrease of 9.8% between first and second session (p=0.027). In summary, the ASL presents measurement of CBF with reasonable repeatability also in elderly patients under clinical conditions when it is not possible to control for all sources of variation. Significant decrease of CBF in healthy tissue was observed after the radiochemotherapy. Prospectively, the ASL data together with the also acquired 11C-Methionine PET will be evaluated regarding their separate and combined ability to predict patient outcome and effectiveness of the performed radiochemotherapy.

  17. QT Interval Derived Measurements in Patients with Cardiac Syndrome X Compared to Coronary Artery Disease.

    Science.gov (United States)

    Lutfi, Mohamed F

    2016-01-01

    Previous studies assessing effect of ischemia on ventricular repolarization are mostly directed toward patients with coronary artery disease (CAD); however, similar reports on cardiac syndrome X (CSX) are scarce. Whether microvascular dysfunction of CSX and ischemia induced by CAD produce comparable effect on ventricular repolarization is unclear and deserve further studies. In the present study, ECG measures of ventricular repolarization were compared between CAD and CSX patients (40 subjects in each group). Following evaluation of sociodemographic characteristics, medical and past medical history, a resting ECG was used to assess measurements of ventricular repolarization in each patient, namely, QT interval (QT), corrected QT interval (QTc), QT dispersion (QTd), corrected QT dispersion (QTcd), adjacent QT dispersion (AdQTd), QT dispersion ratio (QTdR), JT dispersion (JTd), and Corrected JT dispersion (JTcd). Results showed comparable QT intervals and QTd in CAD and CSX patients even after adjustment for the possible variations in gender, age and body mass index of the studied groups. Although JTd was increased in CSX subjects (26.6 ± 7.2 ms) compared with CAD patients (22.7 ± 6.5 ms, p = 0.019), statistical significance disappeared after correcting JT for variations in heart rate. QT and QTc were significantly below 440 ms in CAD as well as CSX patients (p < 0.001). In contrast, maximum QTd, maximum QTcd and AdQTd of CAD and CSX patients were significantly above 440 ms (p < 0.001). The means of JTd and JTcd were significantly above 22 ms and 24 ms respectively (p < 0.001, p = 0.001) in CSX but not CAD patients (p = 0.529, p = 0.281). The present findings clearly demonstrate comparable measures of ventricular repolarization in CAD and CSX patients and consequently an equal risk of cardiac events in both groups.

  18. Physiological and pharmacological characterization of transmembrane acid extruders in cultured human umbilical artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Gunng-Shinng Chen

    2015-01-01

    Full Text Available Background: Intracellular pH (pH i is a pivotal factor for cellular functions and homeostasis. Apart from passive intracellular buffering capacity, active transmembrane transporters responsible for kinetic changes of pH i impacts. Acid extrusion transporters such as Na + /H + exchanger (NHE and Na + /HCO3− cotransporter (NBC have been found to be activated when cells are in an acidic condition in different cell types. However, such far, the pH i regulators have not been characterized in human umbilical artery smooth muscle cells (HUASMCs. Materials and Methods: We, therefore, investigated the mechanism of pH i recovery from intracellular acidosis, induced by NH 4 Cl-prepulse, using pH-sensitive fluorescence dye: 2′,7′-bis(2-carboxethyl-5(6-carboxy-fluorescein in HUASMCs. Cultured HUASMCs were derived from the segments of the human umbilical artery that were obtained from women undergoing children delivery. Results: The resting pH i is 7.23 ± 0.03 when cells in HEPES (nominally HCO 3− -free buffered solution. The resting pH i is higher as 7.27 ± 0.03 when cells in CO 2 /HCO3− -buffered solution. In HEPES-buffered solution, a pH i recovery following induced intracellular acidosis could be inhibited completely by 30 μM HOE 694 (a specific NHE inhibitor or by removing [Na +]o . In 5% CO2/HCO3− -buffered solution, 30 μM HOE 694 slowed the pH i recovery from the induced intracellular acidosis only. On the contrary, HOE 694 adding together with 0.2 mM 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid (a specific NBC inhibitor or removal of [Na +]o entirely blocked the acid extrusion. By using Western blot technique, we demonstrated that four different isoforms of NBC, that is, SLC4A8 (NBCBE, SLC4A7 (NBCn1, SLC4A5 (NBCe2 and SLC4A4 (NBCe1, co-exist in the HUASMCs. Conclusions: We demonstrate, for the 1 st time, that apart from the housekeeping NHE1, another Na + couple HCO3− -transporter, that is, NBC, functionally coexists to

  19. Blood oxygenation measurements by multichannel reflectometry on the venous and arterial structures of the retina.

    Science.gov (United States)

    Vucea, Valentina; Bernard, Pierre-Jean; Sauvageau, Patrick; Diaconu, Vasile

    2011-09-10

    The aim of the present study was to propose a model and a method to derive the oxyhemoglobin blood content in the retinal veins and arteries by full spectrum reflectometry measurements in the spectral zone from 430 to 680 nm. We proposed a mathematical equation expressed as a linear combination of two terms S(OHb)(λ) and S(Hb)(λ) representing the normalized spectral absorption functions of the hemoglobin and the oxyhemoglobin, one term λ(-n) representing the ocular media absorption with scattering, and a family of multi-Gaussian functions, which usefully compensate for the noncompatibility of the model and the experimental data in the red spectral zone. The present paper suggests that the spectral reflection function in the area from 520 to 580 nm is optimal in calculating the oxyhemoglobin concentration of the blood contained in the endothelial structures of retinal vessels. The model calculation needs a function (1/λ)(-n) that corrects for the ocular media absorption and light scattering on the vessels' structures. For the spectral area of lights with wavelength larger than 580 nm, the reflected light represents mainly the light scattering on the red blood cells.

  20. Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension.

    Science.gov (United States)

    Navarini, Susanne; Bellsham-Revell, Hannah; Chubb, Henry; Gu, Haotian; Sinha, Manish D; Simpson, John M

    2017-12-01

    Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 ( P hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study. © 2017 American Heart Association, Inc.

  1. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

    Science.gov (United States)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart; Heusinkveld, Maarten H G; Thorsted, Bjarne; Rosenstand, Kristoffer; Nissen, Inger; Hansen, Ulla M; Brewer, Jonathan R; Bagatolli, Luis A; Rasmussen, Lars M; Irmukhamedov, Akhmadjon; Reesink, Koen D; De Mey, Jo G R

    2017-07-01

    The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies.NEW & NOTEWORTHY This is the first study to quantitatively relate pressure-induced microstructural

  2. Comparison of invasive blood pressure measurements from the caudal ventral artery and the femoral artery in male adult SD and Wistar rats.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available BACKGROUND AND PURPOSE: Studies have suggested that the caudal ventral artery is a potential site for continuous arterial blood pressure monitoring in rats. However, the agreement of mean arterial pressure values between the femoral artery and the caudal ventral artery has not been investigated. This study was performed to identify whether the caudal ventral artery could be safely used for continuous blood pressure monitoring as an alternative site to the femoral artery. METHODS: Rats were randomized into four groups: Sprague Dawley rats under normothermia; Wistar rats under normothermia; Sprague Dawley rats under hypothermia; Wistar rats under hypothermia. Each rat underwent simultaneous monitoring of blood pressure using femoral artery and caudal ventral artery catheterization during a stable hemodynamic state and three periods of acute severe hemodynamic changes. The effects of rat strain, rectal temperature, experimental time course and hemodynamic factors on pressure gradients, the concordance of mean arterial pressure values between the femoral artery and the caudal ventral artery, and the rates of distal ischemia after surgery were determined. RESULTS: There was a significant difference in the rate of distal ischemia between femoral and caudal ventral arteries after catheterization (25% vs 5%, P<0.05. The overall mean gradient and the mean gradient under a steady hemodynamic state were 4.9±3.7 mm Hg and 5.5±2.5 mm Hg, respectively. The limits of agreement (bias±1.96 SD were (-2.5 mm Hg, 12.3 mm Hg and (-0.5 mm Hg, 10.5 mm Hg, respectively. Although the concordance decreased during the first 30 sec of each period of severe hemodynamic changes, the degree of agreement was acceptable regardless of the effects of rat strain and rectal temperature. CONCLUSIONS: Based on the degree of agreement and the safety of catheterization, the caudal ventral artery may be a preferred site for continuous arterial blood pressure monitoring without acute

  3. Uterine artery embolization: the only life saving measure in some obstetric cases

    OpenAIRE

    Asha N. Gokhale; Latika J. Chawla; Shridhar Khajindar

    2015-01-01

    Uterine artery embolization is a highly specialised and efficacious method that can be used prophylactically to reduce obstetric haemorrhage. Its use in modern obstetrics is currently limited to morbidly adherent placenta and acreta. This report presents a case where uterine artery embolization has been used as the primary treatment for obstetric haemorrhage in a patient with high risk for PPH where surgical management would not have been possible. We aim at highlighting the benefits of this ...

  4. The measurement of human capital: a multivariate macro-approach

    NARCIS (Netherlands)

    Klomp, J.G.

    2013-01-01

    We examine the human capital status of 123 countries by employing factor analysis on various national human capital indicators for the period 2000–2008 to construct two new measures. The first measure is based on advanced human capital, while the second is based on basic human capital. Our measures

  5. Temporary tattoo for wireless human pulse measurement

    Science.gov (United States)

    Pepłowski, Andrzej; Janczak, Daniel; Krzemińska, Patrycja; Jakubowska, Małgorzata

    2016-09-01

    Screen-printed sensor for measuring human pulse was designed and first tests using a demonstrator device were conducted. Various materials and sensors' set ups were compared and the results are presented as the starting point for fabrication of fully functional device. As a screen printing substrate, commercially available temporary tattoo paper was used. Using previously developed nanomaterials-based pastes design of a pressure sensor was printed on the paper and attached to the epidermis. Measurements were aimed at determining sensors impedance constant component and its variability due to pressure wave caused by the human pulse. The constant component was ranging from 2kΩ to 6kΩ and the variations of the impedance were ranging from +/-200Ω to +/-2.5kΩ, depending on the materials used and the sensor's configuration. Calculated signal-to-noise ratio was 3.56:1 for the configuration yielding the highest signal level. As the device's net impedance influences the effectiveness of the wireless communication, the results presented allow for proper design of the sensor for future health-monitoring devices.

  6. Metabolic coronary-flow regulation and exogenous nitric oxide in human coronary artery disease: assessment by intravenous administration of nitroglycerin

    NARCIS (Netherlands)

    Kal, J. E.; van Wezel, H. B.; Porsius, M.; Vergroesen, I.; Spaan, J. A.

    2000-01-01

    We sought to evaluate the effect of intravenous administration of the nitric oxide--donor substance nitroglycerin (NTG) on metabolic coronary-flow regulation in patients with coronary artery disease (CAD). In 12 patients with stable CAD, we measured coronary sinus blood flow and myocardial oxygen

  7. [Concordance between 3 methods of measurement the ankle-brachial index to diagnose peripheral artery disease].

    Science.gov (United States)

    Forés, Rosa; Alzamora, Maria Teresa; Pera, Guillem; Torán, Pere; Urrea, Magalí; Heras, Antonio

    2014-10-21

    To determine the concordance of the ankle-brachial index (ABI) determined by automatic measurements (sphygmomanometer Omron and the triple cuff device) using doppler as the gold-standard, computing as well as sensitivity and specificity. ARTPER population cohort subjects, classified as peripheral arterial disease (PAD) if ABI<0.9, calcified if ABI≥1.4 and healthy otherwise. To asses concordance we used kappa index using the 3 categories and the intraclass correlation coefficient (ICC) for ABI continuous values. Eighty-eight participants, 52% women, 57-87 years. It was possible to calculate the ABI using doppler for 100%, 97% using Omron and 95% using triple. ABI means (standard deviation) were: doppler 1.089 (0.236), Omron 1.082 (0.110), triple 1.146 (0.134), with poor agreement (ICC doppler/Omron=0.27, doppler/triple=0.13, and triple/Omron=0.39). Categorizing ABI as PAD-healthy-calcified 13.6% (doppler), 6.8% (Omron) and 3.4% (triple) were PAD and 9.1% (doppler), 1.1% (Omron) and 9.1% (triple) were calcified. Kappa indexes were weak (doppler/Omron=0.22, doppler/triple=0.01, triple/Omron=0.17). Both triple and Omron were highly specific (97%) but had very low sensitivity (8 and 33%, respectively) compared to doppler. Concordance of ABI automatic measurements as Omron and triple with doppler was poor, and they do not seem suitable for screening for PAD in primary care consultations. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  8. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A

    1977-01-01

    with vasospastic arterial disease. It implies an underestimation of palmar arch systolic pressure measured indirectly on the fingers. FSP measured under these circumstances may be taken as an estimate of the vascular tone, and can be employed in diagnosis and quantification of vasospastic disorders.......Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure...

  9. Effects of Renal Denervation on Renal Artery Function in Humans: Preliminary Study.

    Directory of Open Access Journals (Sweden)

    Adelina Doltra

    Full Text Available To study the effects of RD on renal artery wall function non-invasively using magnetic resonance.32 patients undergoing RD were included. A 3.0 Tesla magnetic resonance of the renal arteries was performed before RD and after 6-month. We quantified the vessel sharpness of both renal arteries using a quantitative analysis tool (Soap-Bubble®. In 17 patients we assessed the maximal and minimal cross-sectional area of both arteries, peak velocity, mean flow, and renal artery distensibility. In a subset of patients wall shear stress was assessed with computational flow dynamics. Neither renal artery sharpness nor renal artery distensibility differed significantly. A significant increase in minimal and maximal areas (by 25.3%, p = 0.008, and 24.6%, p = 0.007, respectively, peak velocity (by 16.9%, p = 0.021, and mean flow (by 22.4%, p = 0.007 was observed after RD. Wall shear stress significantly decreased (by 25%, p = 0.029. These effects were observed in blood pressure responders and non-responders.RD is not associated with adverse effects at renal artery level, and leads to an increase in cross-sectional areas, velocity and flow and a decrease in wall shear stress.

  10. Impact of age, sex and exercise on brachial and popliteal artery remodelling in humans.

    NARCIS (Netherlands)

    Green, D.J.; Swart, A.; Exterkate, A.; Naylor, L.H.; Black, M.A.; Cable, N.T.; Thijssen, D.H.J.

    2010-01-01

    OBJECTIVE: To examine the impact of age, sex and exercise on wall thickness and remodelling in the popliteal and brachial arteries. METHODS: We compared wall thickness, lumen diameter and wall:lumen ratios in the brachial and popliteal arteries of 15 young (Y, 25.4+/-0.8 yr; 7M 8W) and 16 older

  11. A new approach for measuring human resource accounting

    National Research Council Canada - National Science Library

    Bavali, Esmat; Jokar, Iman

    2014-01-01

    Significance of identifying human resource competency in organizations and the necessity for valuating human resource in accounting persuade many researchers to design a conceptual model for measuring...

  12. Effects of various factors on Doppler ultrasonographic measurements of radial and coccygeal arterial blood pressure in privately owned, conscious cats.

    Science.gov (United States)

    Whittemore, Jacqueline C; Nystrom, Michael R; Mawby, Dianne I

    2017-04-01

    OBJECTIVE To assess the effects of age, body condition score (BCS), and muscle condition score (MCS) on radial and coccygeal systolic arterial blood pressure (SAP) in cats. DESIGN Prospective randomized trial. ANIMALS 66 privately owned cats enrolled between May and December 2010. PROCEDURES BCS and MCS of cats were assessed by 2 investigators; SAP was measured via Doppler ultrasonic flow detector, with cats positioned in right lateral or sternal recumbency for measurements at the radial or coccygeal artery, respectively, with order of site randomized. Associations among variables were assessed through correlation coefficients, partial correlation coefficients, and ANCOVA. RESULTS Interrater reliability for BCS and MCS assessment was high (correlation coefficients, 0.95 and 0.83, respectively). No significant effect was identified for order of SAP measurement sites. Coccygeal and radial SAP were positively correlated (ρ = 0.45). The median difference in coccygeal versus radial SAP was 19 mm Hg, but differences were not consistently positive or negative. Radial SAP was positively correlated with age (ρ = 0.48) and negatively correlated with MCS (ρ = -0.30). On the basis of the correlation analysis, the association between radial SAP and MCS reflected the confounding influence of age. Coccygeal SAP was not significantly correlated with age, BCS, or MCS. CONCLUSIONS AND CLINICAL RELEVANCE Use of the coccygeal artery is recommended to reduce the confounding effects of age and sarcopenia on Doppler ultrasonographic SAP measurements in cats. Additionally, monitoring for changes in MCS is recommended for cats undergoing serial SAP measurement.

  13. Biological Atomic Force Microscopy for Imaging Gold-Labeled Liposomes on Human Coronary Artery Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Ana-María Zaske

    2013-01-01

    Full Text Available Although atomic force microscopy (AFM has been used extensively to characterize cell membrane structure and cellular processes such as endocytosis and exocytosis, the corrugated surface of the cell membrane hinders the visualization of extracellular entities, such as liposomes, that may interact with the cell. To overcome this barrier, we used 90 nm nanogold particles to label FITC liposomes and monitor their endocytosis on human coronary artery endothelial cells (HCAECs in vitro. We were able to study the internalization process of gold-coupled liposomes on endothelial cells, by using AFM. We found that the gold-liposomes attached to the HCAEC cell membrane during the first 15–30 min of incubation, liposome cell internalization occurred from 30 to 60 min, and most of the gold-labeled liposomes had invaginated after 2 hr of incubation. Liposomal uptake took place most commonly at the periphery of the nuclear zone. Dynasore monohydrate, an inhibitor of endocytosis, obstructed the internalization of the gold-liposomes. This study showed the versatility of the AFM technique, combined with fluorescent microscopy, for investigating liposome uptake by endothelial cells. The 90 nm colloidal gold nanoparticles proved to be a noninvasive contrast agent that efficiently improves AFM imaging during the investigation of biological nanoprocesses.

  14. Transcriptional Remodeling of Ion Channel Subunits by Flow Adaptation in Human Coronary Artery Endothelial Cells

    Science.gov (United States)

    Kefaloyianni, Eirini; Coetzee, William A.

    2011-01-01

    Endothelial cells (ECs) are constantly exposed to blood flow-induced shear forces in the vessels and this is a major determinant of endothelial function. Ion channels have a major role in endothelial function and in the control of vascular tone. We hypothesized that shear force is a general regulator of ion channel expression, which will have profound effects on endothelial function. We examined this hypothesis using large-scale quantitative real-time RT-PCR. Human coronary artery ECs were exposed to two levels of flow-induced shear stress for 24 h, while control cells were grown under static conditions. The expression of ion channel subunits was compared between control and flow-adapted cells. We used primers against 55 ion channel and exchanger subunits and were able to detect 54 subunits. Five dyn/cm2 of shear induced downregulation of 1 (NCX1) and upregulation of 18 subunits, including KCa2.2, KCa2.3, CX37, Kv1.5 and HCN2. Fifteen dyn/cm2 of shear stress induced the expression of 30 ion channel subunits, including KCa2.3, KCa2.2, CX37, Kir2.3 and KCa3.1. Our data demonstrate that substantial remodeling of endothelial ion channel subunit expression occurs with flow adaptation and suggest that altered ion channel expression may significantly contribute to vascular pathology associated with flow-induced alterations. PMID:21389733

  15. Colocalization of serum amyloid a with microtubules in human coronary artery endothelial cells.

    Science.gov (United States)

    Lakota, Katja; Resnik, Nataša; Mrak-Poljšak, Katjuša; Sodin-Šemrl, Snežna; Veranič, Peter

    2011-01-01

    Serum amyloid A (SAA) acts as a major acute phase protein and represents a sensitive and accurate marker of inflammation. Besides its hepatic origin, as the main source of serum SAA, this protein is also produced extrahepatically. The mRNA levels of SAA become significantly elevated following proinflammatory stimuli, as well as, are induced through their own positive feedback in human primary coronary artery endothelial cells. However, the intracellular functions of SAA are so far unknown. Colocalization of SAA with cytoskeletal filaments has previously been proposed, so we analyzed the colocalization of SAA with all three cytoskeletal elements: actin filaments, vimentin filaments, and microtubules. Immunofluorescent double-labeling analyses confirmed by PLA method revealed a strict colocalization of SAA with microtubules and a very infrequent attachment to vimentin while the distribution of actin filaments appeared clearly separated from SAA staining. Also, no significant colocalization was found between SAA and endomembranes labeled with the fluorescent lipid stain DiO₆. However, SAA appears to be located also unbound in the cytosol, as well as inside the nucleus and within nanotubes extending from the cells or bridging neighboring cells. These different locations of SAA in endothelial cells strongly indicate multiple potential functions of this protein.

  16. Colocalization of Serum Amyloid A with Microtubules in Human Coronary Artery Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Katja Lakota

    2011-01-01

    Full Text Available Serum amyloid A (SAA acts as a major acute phase protein and represents a sensitive and accurate marker of inflammation. Besides its hepatic origin, as the main source of serum SAA, this protein is also produced extrahepatically. The mRNA levels of SAA become significantly elevated following proinflammatory stimuli, as well as, are induced through their own positive feedback in human primary coronary artery endothelial cells. However, the intracellular functions of SAA are so far unknown. Colocalization of SAA with cytoskeletal filaments has previously been proposed, so we analyzed the colocalization of SAA with all three cytoskeletal elements: actin filaments, vimentin filaments, and microtubules. Immunofluorescent double-labeling analyses confirmed by PLA method revealed a strict colocalization of SAA with microtubules and a very infrequent attachment to vimentin while the distribution of actin filaments appeared clearly separated from SAA staining. Also, no significant colocalization was found between SAA and endomembranes labeled with the fluorescent lipid stain DiO6. However, SAA appears to be located also unbound in the cytosol, as well as inside the nucleus and within nanotubes extending from the cells or bridging neighboring cells. These different locations of SAA in endothelial cells strongly indicate multiple potential functions of this protein.

  17. Carotid stenosis measurement on colour Doppler ultrasound: Agreement of ECST, NASCET and CCA methods applied to ultrasound with intra-arterial angiographic stenosis measurement

    Energy Technology Data Exchange (ETDEWEB)

    Wardlaw, Joanna M. [Division of Clinical Neurosciences, Western General Hospital, Crewe Road, Edinburgh EH4 2XU (United Kingdom)]. E-mail: jmw@skull.dcn.ed.ac.uk; Lewis, Steff [Division of Clinical Neurosciences, Western General Hospital, Crewe Road, Edinburgh EH4 2XU (United Kingdom)

    2005-11-01

    Purpose: Carotid stenosis is usually determined on Doppler ultrasound from velocity readings. We wondered if angiography-style stenosis measurements applied to ultrasound images improved accuracy over velocity readings alone, and if so, which measure correlated best with angiography. Materials and methods: We studied prospectively patients undergoing colour Doppler ultrasound (CDU) for TIA or minor stroke. Those with 50%+ symptomatic internal carotid artery (ICA) stenosis had intra-arterial angiography (IAA). We measured peak systolic ICA velocity, and from the ultrasound image, the minimal residual lumen, the original lumen (ECST), ICA diameter distal (NASCET) and CCA diameter proximal (CCA method) to the stenosis. The IAAs were measured by ECST, NASCET and CCA methods also, blind to CDU. Results: Amongst 164 patients (328 arteries), on CDU the ECST, NASCET and CCA stenosis measures were similarly related to each other (ECST = 0.54 NASCET + 46) as on IAA (ECST = 0.6 NASCET + 40). Agreement between CDU- and IAA-measured stenosis was similar for ECST (r = 0.51), and CCA (r = 0.48) methods, and slightly worse for NASCET (r = 0.41). Adding IAA-style stenosis to the peak systolic ICA velocity did not improve agreement with IAA over peak systolic velocity alone. Conclusion: Angiography-style stenosis measures have similar inter-relationships when applied to CDU, but do not improve accuracy of ultrasound over peak systolic ICA velocity alone.

  18. Calcium dobesilate potentiates endothelium-derived hyperpolarizing factor-mediated relaxation of human penile resistance arteries.

    Science.gov (United States)

    Angulo, Javier; Cuevas, Pedro; Fernández, Argentina; Gabancho, Sonia; Videla, Sebastián; Sáenz de Tejada, Iñigo

    2003-06-01

    1 We have evaluated the participation of endothelium-derived hyperpolarizing factor (EDHF) in the endothelium-dependent relaxation of isolated human penile resistance arteries (HPRA) and human corpus cavernosum (HCC) strips. In addition, the effect of the angioprotective agent, calcium dobesilate (DOBE), on the endothelium-dependent relaxation of these tissues was investigated. 2 Combined inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) nearly abolished the endothelium-dependent relaxation to acetylcholine (ACh) in HCC, while 60% relaxation of HPRA was observed under these conditions. Endothelium-dependent relaxation of HPRA resistant to NOS and COX inhibition was prevented by raising the extracellular concentration of K(+) (35 mM) or by blocking Ca(2)(+)-activated K(+) channels, with apamin (APA; 100 nM) and charybdotoxin (CTX; 100 nM), suggesting the involvement of EDHF in these responses. 3 Endothelium-dependent relaxation to ACh was markedly enhanced by DOBE (10 micro M) in HPRA but not in HCC. The potentiating effects of DOBE on ACh-induced responses in HPRA, remained after NOS and COX inhibition, were reduced by inhibition of cytochrome P450 oxygenase with miconazole (0.3 mM) and were abolished by high K(+) or a combination of APA and CTX. 4 In vivo, DOBE (10 mg kg(-1) i.v.) significantly potentiated the erectile responses to cavernosal nerve stimulation in male rats. 5 EDHF plays an important role in the endothelium-dependent relaxation of HPRA but not in HCC. DOBE significantly improves endothelium-dependent relaxation of HPRA mediated by EDHF and potentiates erectile responses in vivo. Thus, EDHF becomes a new therapeutic target for the treatment of erectile dysfunction (ED) and DOBE could be considered a candidate for oral therapy for ED.

  19. Calcium dobesilate potentiates endothelium-derived hyperpolarizing factor-mediated relaxation of human penile resistance arteries

    Science.gov (United States)

    Angulo, Javier; Cuevas, Pedro; Fernández, Argentina; Gabancho, Sonia; Videla, Sebastián; Tejada, Iñigo Sáenz de

    2003-01-01

    We have evaluated the participation of endothelium-derived hyperpolarizing factor (EDHF) in the endothelium-dependent relaxation of isolated human penile resistance arteries (HPRA) and human corpus cavernosum (HCC) strips. In addition, the effect of the angioprotective agent, calcium dobesilate (DOBE), on the endothelium-dependent relaxation of these tissues was investigated. Combined inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) nearly abolished the endothelium-dependent relaxation to acetylcholine (ACh) in HCC, while 60% relaxation of HPRA was observed under these conditions. Endothelium-dependent relaxation of HPRA resistant to NOS and COX inhibition was prevented by raising the extracellular concentration of K+ (35 mM) or by blocking Ca2+-activated K+ channels, with apamin (APA; 100 nM) and charybdotoxin (CTX; 100 nM), suggesting the involvement of EDHF in these responses. Endothelium-dependent relaxation to ACh was markedly enhanced by DOBE (10 μM) in HPRA but not in HCC. The potentiating effects of DOBE on ACh-induced responses in HPRA, remained after NOS and COX inhibition, were reduced by inhibition of cytochrome P450 oxygenase with miconazole (0.3 mM) and were abolished by high K+ or a combination of APA and CTX. In vivo, DOBE (10 mg kg−1 i.v.) significantly potentiated the erectile responses to cavernosal nerve stimulation in male rats. EDHF plays an important role in the endothelium-dependent relaxation of HPRA but not in HCC. DOBE significantly improves endothelium-dependent relaxation of HPRA mediated by EDHF and potentiates erectile responses in vivo. Thus, EDHF becomes a new therapeutic target for the treatment of erectile dysfunction (ED) and DOBE could be considered a candidate for oral therapy for ED. PMID:12813009

  20. RELM-β promotes human pulmonary artery smooth muscle cell proliferation via FAK-stimulated surviving

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chunlong, E-mail: lclmd@sina.com; Li, Xiaohui; Luo, Qiong; Yang, Hui; Li, Lun; Zhou, Qiong; Li, Yue; Tang, Hao; Wu, Lifu

    2017-02-01

    Resistin-like molecule-β (RELM-β), focal adhesion kinase (FAK), and survivin may be involved in the proliferation of cultured human pulmonary artery smooth muscle cells (HPAMSCs), which is involved in pulmonary hypertension. HPAMSCs were treated with human recombinant RELM-β (rhRELM-β). siRNAs against FAK and survivin were transfected into cultured HPASMCs. Expression of FAK and survivin were examined by RT-PCR and western blot. Immunofluorescence was used to localize FAK. Flow cytometry was used to examine cell cycle distribution and cell death. Compared to the control group, all rhRELM-β-treated groups demonstrated significant increases in the expression of FAK and survivin (P<0.05). rhRELM-β significantly increased the proportion of HPASMCs in the S phase and decreased the proportion in G0/G1. FAK siRNA down-regulated survivin expression while survivin siRNA did not affect FAK expression. FAK siRNA effectively inhibited FAK and survivin expression in RELM-β-treated HPASMCs and partially suppressed cell proliferation. RELM-β promoted HPASMC proliferation and upregulated FAK and survivin expression. In conclusion, results suggested that FAK is upstream of survivin in the signaling pathway mediating cell proliferation. FAK seems to be important in RELM-β-induced HPASMC proliferation, partially by upregulating survivin expression. - Highlights: • rhRELM-β increased the expression of FAK and survivin. • rhRELM-β increased the proportion of HPASMCs in the S phase. • FAK is upstream of survivin in the signaling pathway mediating cell proliferation. • FAK is important in RELM-β-induced HPASMC proliferation, partly via survivin.

  1. Change in Elasticity Caused by Flow-Mediated Dilation Measured Only for Intima-Media Region of Brachial Artery

    Science.gov (United States)

    Sugimoto, Masataka; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-08-01

    Endothelial dysfunction is considered to be an initial step of arteriosclerosis [R. Ross: N. Engl. J. Med. 340 (2004) 115]. For the assessment of the endothelium function, brachial artery flow-mediated dilation (FMD) caused by increased blood flow has been evaluated with ultrasonic diagnostic equipment. In the case of conventional methods, the change in artery diameter caused by FMD is measured [M. Hashimoto et al.: Circulation 92 (1995) 3431]. Although the arterial wall has a layered structure (intima, media, and adventitia), such a structure is not taken into account in conventional methods because the change in diameter depends on the characteristic of the entire wall. However, smooth muscle present only in the media contributes to FMD, whereas the collagen-rich hard adventitia does not contribute. In this study, we measure the change in elasticity of only the intima-media region including smooth muscle using the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791]. From the change in elasticity, FMD measured only for the intima-media region by our proposed method was found to be more sensitive than that measured for the entire wall by the conventional method.

  2. JUSTIFICATION OF MEASURES TO IMPROVE QUALITY AND ROAD SAFETY AT REGIONAL ARTERIAL STREET IN MINSK

    Directory of Open Access Journals (Sweden)

    V. N. Kuzmenko

    2017-01-01

    Full Text Available The paper presents results pertaining to investigations of traffic conditions and intensity of traffic and pedestrian flows, calculations on loading level of objects located in the Makayonka Street, Minsk. The objects constitute transport regional development which presupposes reconstruction of regional arterial street with due account of infrastructure improvement,   residential  construction and  construction  of  multi-purpose  complex  with   shopping,  entertainment,   wellness  and business centers. In addition to this it is planned to construct a two-level underground parking, a two-level interchange at intersection of the Filimonova Street and Nezavisimosty Avenue due to an increase of traffic load at adjacent neighboring street and road network. An analysis on the current traffic management and calculation for distribution of the existing and prospective traffic load levels after implementation of appropriate measures to improve quality as a whole and road safety as well has been carried out in the paper. Determination of loading levels for a street and road network has been carried out while taking into account an intensity of traffic flows in order to evaluate various options for road traffic organization. Variants for planning of road junctions, road traffic organization and traffic signalization (including coordinated passing of  transport facilities have been developed in the paper. All this will contribute to improvement of quality and road safety in the investigated street with due consideration of further development of the region and overbuilding of the existing housing system in the Makayonka Streets and increase of its transport importance in the Minsk street and road network.

  3. Localization of oxidized low-density lipoprotein and its relation to plaque morphology in human coronary artery.

    Directory of Open Access Journals (Sweden)

    Yasumi Uchida

    Full Text Available OBJECTIVES: Oxidized low-density lipoprotein (oxLDL plays a key role in the formation of atherosclerotic plaques. However, its localization in human coronary arterial wall is not well understood. The present study was performed to visualize deposition sites and patterns of native oxLDL and their relation to plaque morphology in human coronary artery. METHODS: Evans blue dye (EB elicits a violet fluorescence by excitation at 345-nm and emission at 420-nm, and a reddish-brown fluorescence by excitation at 470-nm and emission at 515-nm characteristic of oxLDL only. Therefore, native oxLDL in excised human coronary artery were investigated by color fluorescent microscopy (CFM using EB as a biomarker. RESULTS: (1 By luminal surface scan with CFM, the % incidence of oxLDL in 38 normal segments, 41 white plaques and 32 yellow plaques that were classified by conventional angioscopy, was respectively 26, 44 and 94, indicating significantly (p<0.05 higher incidence in the latter than the former two groups. Distribution pattern was classified as patchy, diffuse and web-like. Web-like pattern was observed only in yellow plaques with necrotic core. (2 By transected surface scan, oxLDL deposited within superficial layer in normal segments and diffusely within both superficial and deep layers in white and yellow plaques. In yellow plaques with necrotic core, oxLDL deposited not only in the marginal zone of the necrotic core but also in the fibrous cap. CONCLUSION: Taken into consideration of the well-known process of coronary plaque growth, the results suggest that oxLDL begins to deposit in human coronary artery wall before plaque formation and increasingly deposits with plaque growth, exhibiting different deposition sites and patterns depending on morphological changes.

  4. Effects of diagnostic guidewire catheter presence on translesional hemodynamic measurements across significant coronary artery stenoses.

    Science.gov (United States)

    Banerjee, Rupak K; Back, Lloyd H; Back, Martin R

    2003-01-01

    This study gains insight on the nature of flow blockage effects of small guidewire catheter sensors in measuring mean trans-stenotic pressure gradients Deltap across significant coronary artery stenoses. Detailed pulsatile hemodynamic computations were made in conjunction with previously reported clinical data in a group of patients with clinically significant coronary lesions before angioplasty. Results of this study ascertain changes in hemodynamic conditions due to the insertion of a guidewire catheter (di=0.46 mm) across the lesions used to directly determine the mean pressure gradient (Deltap) and fall in distal mean coronary pressure (pr). For the 32 patient group of Wilson et al. [1988] (minimal lesion diameter dm=0.95 mm; 90% mean area stenosis; proximal measured coronary flow reserve (CFR) of 2.3 in the abnormal range) the diameter ratio of guidewire catheter to minimal lesion was 0.48, causing a tighter "artifactual" mean area stenosis of 92.1%. The results of the computations indicated a significant shift in the Deltap-Q relation due to guidewire induced increases in flow resistances (R=Deltap/Q) of 110% for hyperemic flow, a 35% blockage in hyperemic flow (Qh) and a phase shift of the coronary flow waveform to systolic predominance. These alterations in flow resulted in a fall in distal mean coronary pressure (at lower mean flow rates) below the patho-physiological range of prh approximately 55 mmHg, which is known to cause ischemia in the subendocardium (Brown et al. [1984]) and coincides with symptomatic angina. Transient wall shear stress levels in the narrow throat region (with flow blockage) were of the order of levels during hyperemic conditions for patho-physiological flow. In the separated flow region along the distal vessel wall, vortical flow cells formed periodically during the systolic phase when instantaneous Reynolds numbers Ree(t) exceeded about 110. For patho-physiological flow without the presence of the guidewire these vortical flow

  5. Estimation of an image derived input function with MR-defined carotid arteries in FDG-PET human studies using a novel partial volume correction method

    DEFF Research Database (Denmark)

    Sari, Hasan; Erlandsson, Kjell; Law, Ian

    2017-01-01

    segmentation of the carotid arteries from MR images. The simulation study results showed that at least 92% of the true intensity could be recovered after the partial volume correction. Results from 19 subjects showed that the mean cerebral metabolic rate of glucose calculated using arterial samples and partial...... volume corrected image derived input function were 26.9 and 25.4 mg/min/100 g, respectively, for the grey matter and 7.2 and 6.7 mg/min/100 g for the white matter. No significant difference in the estimated cerebral metabolic rate of glucose values was observed between arterial samples and corrected......Kinetic analysis of (18)F-fluorodeoxyglucose positron emission tomography data requires an accurate knowledge the arterial input function. The gold standard method to measure the arterial input function requires collection of arterial blood samples and is an invasive method. Measuring an image...

  6. Echocardiographic measurements in normal chinese adults focusing on cardiac chambers and great arteries: a prospective, nationwide, and multicenter study.

    Science.gov (United States)

    Yao, Gui-Hua; Deng, Yan; Liu, Yan; Xu, Ming-Jun; Zhang, Cheng; Deng, You-Bin; Ren, Wei-Dong; Li, Zhi-An; Tang, Hong; Zhang, Quan-Bin; Mu, Yu-Ming; Fang, Li-Gang; Zhang, Mei; Yin, Li-Xue; Zhang, Yun

    2015-05-01

    Currently available echocardiographic reference values are derived mainly from North American and European population studies, and no echocardiographic reference values are available for the Chinese population. The aim of this study was to establish normal values of echocardiographic measurements of the cardiac chambers and great arteries in a nationwide, population-based cohort of healthy Han Chinese adults. A total of 1,586 healthy Han Chinese volunteers aged 18 to 79 years were screened at 43 collaborating laboratories throughout China. Standard M-mode and two-dimensional echocardiography was performed to obtain measurements of the cardiac chambers and great arteries. The impacts of gender and age on all echocardiographic measurements were analyzed. A total of 1,394 qualified healthy subjects (mean age, 47.3 ± 16.0 years; 678 men) were ultimately enrolled. Except for left ventricular ejection fraction, values of cardiac chamber and great arterial dimensions were significantly higher in men than in women. Most measurements of the atrial and great arterial dimensions, left ventricular wall thickness, and left ventricular mass increased with age in both men and women. Normal reference values of cardiac dimensional parameters were established for the first time in a nationwide, population-based cohort of healthy Han Chinese adults. Because most of these parameters were found to vary with gender and age, reference values stratified for gender and age should be used in clinical practice. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  7. Transcutaneous PTCCO2 measurement in combination with arterial blood gas analysis provides superior accuracy and reliability in ICU patients.

    Science.gov (United States)

    Spelten, Oliver; Fiedler, Fritz; Schier, Robert; Wetsch, Wolfgang A; Hinkelbein, Jochen

    2017-02-01

    Hyper or hypoventilation may have serious clinical consequences in critically ill patients and should be generally avoided, especially in neurosurgical patients. Therefore, monitoring of carbon dioxide partial pressure by intermittent arterial blood gas analysis (PaCO2) has become standard in intensive care units (ICUs). However, several additional methods are available to determine PCO2 including end-tidal (PETCO2) and transcutaneous (PTCCO2) measurements. The aim of this study was to compare the accuracy and reliability of different methods to determine PCO2 in mechanically ventilated patients on ICU. After approval of the local ethics committee PCO2 was determined in n = 32 ICU consecutive patients requiring mechanical ventilation: (1) arterial PaCO2 blood gas analysis with Radiometer ABL 625 (ABL; gold standard), (2) arterial PaCO2 analysis with Immediate Response Mobile Analyzer (IRMA), (3) end-tidal PETCO2 by a Propaq 106 EL monitor and (4) transcutaneous PTCCO2 determination by a Tina TCM4. Bland-Altman method was used for statistical analysis; p analysis revealed good correlation between PaCO2 by IRMA and ABL (R2 = 0.766; p analysis revealed a bias and precision of 2.0 ± 3.7 mmHg for the IRMA, 2.2 ± 5.7 mmHg for transcutaneous, and -5.5 ± 5.6 mmHg for end-tidal measurement. Arterial CO2 partial pressure by IRMA (PaCO2) and PTCCO2 provided greater accuracy compared to the reference measurement (ABL) than the end-tidal CO2 measurements in critically ill in mechanically ventilated patients patients.

  8. Comparison of non-invasive and invasive arterial blood pressure measurement for assessment of dynamic cerebral autoregulation.

    Science.gov (United States)

    Petersen, Nils H; Ortega-Gutierrez, Santiago; Reccius, Andres; Masurkar, Arjun; Huang, Amy; Marshall, Randolph S

    2014-02-01

    There is a growing interest in measuring cerebral autoregulation in patients with acute brain injury. Non-invasive finger photo-plethysmography (Finapres) is the method of choice to relate arterial blood pressure to changes in cerebral blood flow. Among acutely ill patients, however, peripheral vasoconstriction often limits the use of Finapres requiring direct intravascular blood pressure measurement. We evaluated how these two different forms of blood pressure monitoring affect the parameters of dynamic cerebral autoregulation (DCA). We performed 37 simultaneous recordings of BP and cerebral blood flow velocity in 15 patients with acute brain injury. DCA was estimated in the frequency domain using transfer function analysis to calculate phase shift, gain, and coherence. In addition the mean velocity index (Mx) was calculated for assessment of DCA in the time domain. The mean patient age was 58.1 ± 15.9 years, 80 % (n = 12) were women. We found good inter-method agreement between Finapres and direct intravascular measurement using Bland–Altman and correlation analyses. Finapres gives higher values for the efficiency of dynamic CA compared with values derived from radial artery catheter, as indicated by biases in the phase (26.3 ± 11.6° vs. 21.7 ± 10.5°, p = 0.001) and Mx (0.571 ± 0.137 vs. 0.649 ± 0.128, p blood pressure methods. The average coherence between CBFV and ABP was higher when BP was measured with arterial catheter for frequencies above 0.05 Hz (0.8 vs. 0.73, p invasive arterial blood pressure monitoring may improve accuracy and thus should be the preferred method for DCA assessment in the ICU.

  9. Middle cerebral artery flow velocity and blood flow during exercise and muscle ischemia in humans

    DEFF Research Database (Denmark)

    Jørgensen, L G; Perko, M; Hanel, B

    1992-01-01

    ," mechanoreceptors, and/or muscle "metaboreceptors" on cerebral perfusion. Ten healthy subjects performed two levels of dynamic exercise corresponding to a heart rate of 110 (range 89-134) and 148 (129-170) beats/min, respectively, and exhaustive one-legged static knee extension. Measurements were continued during 2......-2.5 min of muscle ischemia. MAP increased similarly during static [114 (102-133) mmHg] and heavy dynamic exercise [121 (104-136) mmHg] and increased during muscle ischemia after dynamic exercise. During heavy dynamic exercise, Vmean increased 24% (10-47%; P less than 0.01) over approximately 3 min despite...... constant arterial carbon dioxide tension. In contrast, static exercise with a higher rate of perceived exertion [18 (13-20) vs. 15 (12-18) units; P less than 0.01] was associated with no significant change in Vmean. Muscle ischemia after exercise was not associated with an elevation in Vmean, and it did...

  10. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro

    NARCIS (Netherlands)

    C.L. de Korte (Chris); G. Pasterkamp (Gerard); H.A. Woutman; N. Bom (Klaas); A.F.W. van der Steen (Ton)

    2000-01-01

    textabstractBACKGROUND: The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial

  11. Human pentraxin 3 (PTX3 as a novel biomarker for the diagnosis of pulmonary arterial hypertension.

    Directory of Open Access Journals (Sweden)

    Yuichi Tamura

    Full Text Available BACKGROUND: Although inflammation is an important feature of pulmonary arterial hypertension (PAH, the usefulness of local inflammatory markers as biomarkers for PAH is unknown. In this study, we tested whether plasma concentrations of human pentraxin 3 (PTX3, a local inflammatory marker, would be a useful biomarker for detecting PAH. METHODS: Plasma PTX3 concentrations were evaluated in 50 PAH patients (27 with idiopathic PAH, 17 with PAH associated with connective tissue disease (CTD-PAH, and six with congenital heart disease, 100 age and sex-matched healthy controls, and 34 disease-matched CTD patients without PAH. Plasma concentrations of B-type natriuretic peptide (BNP and C-reactive protein (CRP were also determined. RESULTS: Mean PTX3 levels were significantly higher in all PAH patients than in the healthy controls (4.40±0.37 vs. 1.94±0.09 ng/mL, respectively; P<0.001. Using a threshold level of 2.84 ng/mL, PTX3 yielded a sensitivity of 74.0% and a specificity of 84.0% for the detection of PAH. In CTD-PAH patients, mean PTX3 concentrations were significantly higher than in CTD patients without PAH (5.02±0.69 vs. 2.40±0.14 ng/mL, respectively; P<0.001. There was no significant correlation between plasma levels of PTX3 and BNP or CRP. Receiver operating characteristic (ROC curves for screening PAH in patients with CTD revealed that PTX3 (area under the ROC curve 0.866 is superior to BNP. Using a PTX3 threshold of 2.85 ng/mL maximized true-positive and false-negative results (sensitivity 94.1%, specificity 73.5%. CONCLUSION: Plasma concentrations of PTX3 may be a better biomarker of PAH than BNP, especially in patients with CTD.

  12. Double-stranded RNA attenuates the barrier function of human pulmonary artery endothelial cells.

    Directory of Open Access Journals (Sweden)

    Zoltán Bálint

    Full Text Available Circulating RNA may result from excessive cell damage or acute viral infection and can interact with vascular endothelial cells. Despite the obvious clinical implications associated with the presence of circulating RNA, its pathological effects on endothelial cells and the governing molecular mechanisms are still not fully elucidated. We analyzed the effects of double stranded RNA on primary human pulmonary artery endothelial cells (hPAECs. The effect of natural and synthetic double-stranded RNA (dsRNA on hPAECs was investigated using trans-endothelial electric resistance, molecule trafficking, calcium (Ca(2+ homeostasis, gene expression and proliferation studies. Furthermore, the morphology and mechanical changes of the cells caused by synthetic dsRNA was followed by in-situ atomic force microscopy, by vascular-endothelial cadherin and F-actin staining. Our results indicated that exposure of hPAECs to synthetic dsRNA led to functional deficits. This was reflected by morphological and mechanical changes and an increase in the permeability of the endothelial monolayer. hPAECs treated with synthetic dsRNA accumulated in the G1 phase of the cell cycle. Additionally, the proliferation rate of the cells in the presence of synthetic dsRNA was significantly decreased. Furthermore, we found that natural and synthetic dsRNA modulated Ca(2+ signaling in hPAECs by inhibiting the sarco-endoplasmic Ca(2+-ATPase (SERCA which is involved in the regulation of the intracellular Ca(2+ homeostasis and thus cell growth. Even upon synthetic dsRNA stimulation silencing of SERCA3 preserved the endothelial monolayer integrity. Our data identify novel mechanisms by which dsRNA can disrupt endothelial barrier function and these may be relevant in inflammatory processes.

  13. Arterial stiffness

    Directory of Open Access Journals (Sweden)

    Ursula Quinn

    2012-09-01

    Full Text Available Measurements of biomechanical properties of arteries have become an important surrogate outcome used in epidemiological and interventional cardiovascular research. Structural and functional differences of vessels in the arterial tree result in a dampening of pulsatility and smoothing of blood flow as it progresses to capillary level. A loss of arterial elastic properties results a range of linked pathophysiological changes within the circulation including increased pulse pressure, left ventricular hypertrophy, subendocardial ischaemia, vessel endothelial dysfunction and cardiac fibrosis. With increased arterial stiffness, the microvasculature of brain and kidneys are exposed to wider pressure fluctuations and may lead to increased risk of stroke and renal failure. Stiffening of the aorta, as measured by the gold-standard technique of aortic Pulse Wave Velocity (aPWV, is independently associated with adverse cardiovascular outcomes across many different patient groups and in the general population. Therefore, use of aPWV has been proposed for early detection of vascular damage and individual cardiovascular risk evaluation and it seems certain that measurement of arterial stiffness will become increasingly important in future clinical care. In this review we will consider some of the pathophysiological processes that result from arterial stiffening, how it is measured and factors that may drive it as well as potential avenues for therapy. In the face of an ageing population where mortality from atheromatous cardiovascular disease is falling, pathology associated with arterial stiffening will assume ever greater importance. Therefore, understanding these concepts for all clinicians involved in care of patients with cardiovascular disease will become vital.

  14. Lifelong physical activity prevents an age-related reduction in arterial and skeletal muscle nitric oxide bioavailability in humans

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Blackwell, James R; Damsgaard, Ramsus

    2012-01-01

    circulation and in the musculature of sedentary ageing humans due to increased oxidative stress. Lifelong physical activity opposes this effect within the trained musculature and in the arterial circulation. The lower blood flow response to leg exercise in ageing humans is not associated with a reduced......Ageing has been proposed to be associated with increased levels of reactive oxygen species (ROS) that scavenge nitric oxide (NO). In eight young sedentary (23±1 years; Y), eight older lifelong sedentary (66±2 years; OS) and eight older lifelong physically active subjects (62±2 years; OA), we...

  15. Cryoplasty for femoropopliteal arterial disease: late angiographic results of initial human experience.

    Science.gov (United States)

    Fava, Mario; Loyola, Soledad; Polydorou, Antonios; Papapavlou, Prodromos; Polydorou, Adamandia; Mendiz, Oscar; Joye, James D

    2004-11-01

    A new form of angioplasty, called cryoplasty, was developed to improve the late results typically associated with percutaneous transluminal angioplasty. Cryoplasty combines the dilation force of percutaneous transluminal angioplasty with the delivery of cold thermal energy to the vessel wall. This study reports the authors' early clinical experience with cryoplasty in patients with femoropopliteal disease. Fifteen patients with femoropopliteal arterial lesions were treated with cryoplasty (CryoVascular Systems, Los Gatos, CA). Cryoplasty was performed at 6 atm of pressure and delivered at -10 degrees C for 60 seconds. The ankle-brachial index (ABI) was measured at baseline, 24 hours after cryoplasty, and at 1 and 3 months during follow-up. Repeated angiography was performed at 6 and 18 months to determine short-term and late primary patency. Cryoplasty was technically successful in 93% of patients (< 30% residual stenosis and less then grade C dissection). ABIs at baseline were 0.64 +/- 0.08 and improved the day after cryoplasty to 0.95 +/- 0.09 (P < .05). ABIs were well maintained at 1 and 3 months with measurements of 0.94 +/- 0.09 and 0.92 +/- 0.10, respectively (P < .05 vs baseline). Baseline angiographic diameter stenosis improved significantly immediately following cryoplasty (86% +/- 12% to 16% +/- 3%; P < .05). Angiography at 6 months revealed 0% binary restenosis and insignificant change in residual stenosis from the acute cryoplasty results (16 +/- 3% vs 21 +/- 5%; P = NS). Late angiographic follow-up at 14 months +/- 4 demonstrated primary patency of 83.3%. Cryoplasty was able to achieve substantial dilation of femoropopliteal lesions with well-preserved late angiographic patency. Cryoplasty represents a potential advance in the field of endovascular medicine.

  16. Chronic hypoxia aggravates monocrotaline-induced pulmonary arterial hypertension: a rodent relevant model to the human severe form of the disease

    OpenAIRE

    Coste, Florence; Guibert, Christelle; Magat, Julie; Abell, Emma; Vaillant, Fanny; Dubois, Mathilde; Courtois, Arnaud; Diolez, Philippe; Quesson, Bruno; Marthan, Roger; Savineau, Jean-Pierre; Muller, Bernard; Freund-Michel, V?ronique

    2017-01-01

    Pulmonary arterial hypertension (PAH) is a severe form of pulmonary hypertension that combines multiple alterations of pulmonary arteries, including, in particular, thrombotic and plexiform lesions. Multiple-pathological-insult animal models, developed to more closely mimic this human severe PAH form, often require complex and/or long experimental procedures while not displaying the entire panel of characteristic lesions observed in the human disease. In this study, we further characterized a...

  17. Variabilities in measurement of coronary arterial dimensions resulting from variations in cineframe selection

    NARCIS (Netherlands)

    J.H.C. Reiber (Johan); P. van Eldik-Helleman; N. Visser-Akkerman; C.J. Kooijman; P.W.J.C. Serruys (Patrick)

    1988-01-01

    textabstractTo quantitatively analyze a coronary arterial segment from a cineangiogram, an end-diastolic or neighboring cineframe is usually selected, such that a possibly existing coronary lesion is visualized optimally, as judged by the cardiologist. However, different cardiologists may select

  18. Physical Activity in Pediatric Pulmonary Arterial Hypertension Measured by Accelerometry : A Candidate Clinical Endpoint

    NARCIS (Netherlands)

    Zijlstra, Willemijn M H; Ploegstra, Mark-Jan; Vissia-Kazemier, Theresia R; Roofthooft, Marcus T. R.; du Marchie Sarvaas, Gideon; Bartelds, Beatrijs; Rackowitz, Annette; van den Heuvel, Freek; Hillege, Hans L; Plasqui, Guy; Berger, Rolf M F

    2017-01-01

    Rationale: The development of evidence-based treatment guidelines for pediatric pulmonary arterial hypertension (PAH) is hampered by lack of pediatric clinical trials. Trial design is hampered by lack of a feasible clinical endpoint in this population. Objectives: To evaluate the use of

  19. An artery accompanying the sciatic nerve (arteria comitans nervi ischiadici) and the position of the hip joint: a comparative histological study using chick, mouse, and human foetal specimens.

    Science.gov (United States)

    Ishizawa, A; Hayashi, S; Nasu, H; Abe, H; Rodríguez-Vázquez, J F; Murakami, G

    2013-02-01

    Birds and reptiles always carry a long and thick artery accompanying the sciatic nerve (i.e., the sciatic artery), whereas mammals do not. We attempted to demonstrate a difference in courses of the nerve and artery in fetuses in relation with the hip joint posture. Eight mid-term human fetuses (15-18 weeks), five mouse fetuses (E18) and five chick embryos (11 days after incubation) were examined histologically. Thin feeding arteries in the sciatic nerve were consistently observed in human fetuses in spite of the long, inferiorly curved course of the nerve around the ischium. The tissue around the human sciatic nerve was not so tight because of the medial and inferior shift of the nerve away from the hip joint. The fetal hip joint position differed among the species, being highly flexed in humans and almost at right angle flexion in mice and chicks. Because of deep adduction of the hip joint in the mouse, the knee was located near the midline of the body. The mouse sciatic nerve ran through the tight tissue along the head of the femur, whereas the chick nerve ran through the loose space even in the gluteal region. In birds, evolution of the pelvis including the hip joint without adduction seemed to make the arterial development possible. In mammals, highly flexed or adducted hip joint seemed to be one of the disturbing factors against development of the long and thick artery. A slight change in posture may cause significant arterial variation.

  20. Time-resolved PIV measurements of the flow field in a stenosed, compliant arterial model

    Science.gov (United States)

    Geoghegan, P. H.; Buchmann, N. A.; Soria, J.; Jermy, M. C.

    2013-05-01

    Compliant (flexible) structures play an important role in several biological flows including the lungs, heart and arteries. Coronary heart disease is caused by a constriction in the artery due to a build-up of atherosclerotic plaque. This plaque is also of major concern in the carotid artery which supplies blood to the brain. Blood flow within these arteries is strongly influenced by the movement of the wall. To study these problems experimentally in vitro, especially using flow visualisation techniques, can be expensive due to the high-intensity and high-repetition rate light sources required. In this work, time-resolved particle image velocimetry using a relatively low-cost light-emitting diode illumination system was applied to the study of a compliant flow phantom representing a stenosed (constricted) carotid artery experiencing a physiologically realistic flow wave. Dynamic similarity between in vivo and in vitro conditions was ensured in phantom construction by matching the distensibility and the elastic wave propagation wavelength and in the fluid system through matching Reynolds ( Re) and Womersley number ( α) with a maximum, minimum and mean Re of 939, 379 and 632, respectively, and a α of 4.54. The stenosis had a symmetric constriction of 50 % by diameter (75 % by area). Once the flow rate reached a critical value, Kelvin-Helmholtz instabilities were observed to occur in the shear layer between the main jet exiting the stenosis and a reverse flow region that occurred at a radial distance of 0.34 D from the axis of symmetry in the region on interest 0-2.5 D longitudinally downstream from the stenosis exit. The instability had an axis-symmetric nature, but as peak flow rate was approached this symmetry breaks down producing instability in the flow field. The characteristics of the vortex train were sensitive not only to the instantaneous flow rate, but also to whether the flow was accelerating or decelerating globally.

  1. Does arterial shear explain the magnitude of flow-mediated dilation?: a comparison between young and older humans.

    Science.gov (United States)

    Thijssen, Dick H J; Bullens, Lauren M; van Bemmel, Marieke M; Dawson, Ellen A; Hopkins, Nicola; Tinken, Toni M; Black, Mark A; Hopman, Maria T E; Cable, N Timothy; Green, Daniel J

    2009-01-01

    Flow-mediated dilatation (FMD) has become a commonly applied approach for the assessment of vascular function and health in humans. Recent studies emphasize the importance of normalizing the magnitude of FMD to its apparent eliciting stimulus, the postdeflation arterial shear. However, the relationship between shear stress and the magnitude of FMD may differ between groups. The aim of this study was to examine the relationship between the brachial FMD and four different indexes of postdeflation shear rate (SR) in healthy children (n = 51, 10 +/- 1 yr) and young (n = 57, 27 +/- 6 yr) and older (n = 27, 58 +/- 4 yr) adults. SR was calculated from deflation (time 0) until 9 s (peak), 30 s (0-30), 60 s (0-60), or until the time-to-peak diameter in each individual (0-ttp). Edge detection and wall tracking of high resolution B-mode arterial ultrasound images were used to calculate the conduit artery diameter. In young adults, the brachial artery FMD demonstrated a significant correlation with the area under the SR curve (SR(AUC)) 0-30 s (r(2) = 0.12, P = 0.009), 0-60 s (r(2) = 0.14, P = 0.005), and 0-ttp (r(2) = 0.14, P = 0.005) but not for the peak SR(AUC) 0-9 s (r(2) = 0.04, P = 0.12). In children and older adults, the magnitude of the brachial artery FMD did not correlate with any of the four SR(AUC) stimuli. These findings suggest that in young subjects, postdeflation SR(AUC) correlates moderately with the magnitude of the FMD response. However, the relationship between FMD and postdeflation shear appears to be age dependent, with less evidence for an association in younger and older subjects. Therefore, we support presenting SR(AUC) stimuli but not normalizing FMD responses for the SR(AUC) when using this technique.

  2. Lipocalin-2 Promotes Endoplasmic Reticulum Stress and Proliferation by Augmenting Intracellular Iron in Human Pulmonary Arterial Smooth Muscle Cells.

    Science.gov (United States)

    Wang, Guoliang; Liu, Shenghua; Wang, Li; Meng, Liukun; Cui, Chuanjue; Zhang, Hao; Hu, Shengshou; Ma, Ning; Wei, Yingjie

    2017-01-01

    Endoplasmic reticulum (ER) stress, a feature of many conditions associated with pulmonary hypertension (PH), is increasingly recognized as a common response to promote proliferation in the walls of pulmonary arteries. Increased expression of Lipocalin-2 in PH led us to test the hypothesis that Lipocalin-2, a protein known to sequester iron and regulate it intracellularly, might facilitate the ER stress and proliferation in pulmonary arterial smooth muscle cells (PASMCs). In this study, we observed greatly increased Lcn2 expression accompanied with increased ATF6 cleavage in a standard rat model of pulmonary hypertension induced by monocrotaline. In cultured human PASMCs, Lcn2 significantly promoted ER stress (determined by augmented cleavage and nuclear localization of ATF6, up-regulated transcription of GRP78 and NOGO, increased expression of SOD2, and mild augmented mitochondrial membrane potential) and proliferation (assessed by Ki67 staining and BrdU incorporation). Lcn2 promoted ER stress accompanied with augmented intracellular iron levels in human PASMCs. Treatment human PASMCs with FeSO4 induced the similar ER stress and proliferation response and iron chelator (deferoxamine) abrogated the ER stress and proliferation induced by Lcn2 in cultured human PASMCs. In conclusion, Lcn2 significantly promoted human PASMC ER stress and proliferation by augmenting intracellular iron. The up-regulation of Lcn2 probably involved in the pathogenesis and progression of PH.

  3. Effects of propofol and sevoflurane on isolated human umbilical arteries pre-contracted with dopamine, adrenaline and noradrenaline.

    Science.gov (United States)

    Gunduz, Ergun; Arun, Oguzhan; Bagci, Sengal Taylan; Oc, Bahar; Salman, Alper; Yilmaz, Setenay Arzu; Celik, Cetin; Duman, Ates

    2015-05-01

    To assess the effects of propofol and sevoflurane on the contraction elicited by dopamine, adrenaline and noradrenaline on isolated human umbilical arteries. Umbilical arteries were cut into endothelium-denuded spiral strips and suspended in organ baths containing Krebs-Henseleit solution bubbled with O2 +CO2 mixture. Control contraction to phenylephrine (10(-5)  M) was recorded. Response curves were obtained to 10(-5)  M dopamine, 10(-5)  M adrenaline or 10(-5)  M noradrenaline. Afterwards, either cumulative propofol (10(-6)  M, 10(-5)  M and 10(-4)  M) or cumulative sevoflurane (1.2%, 2.4% and 3.6%) was added to the organ bath, and the responses were recorded. Responses are expressed percentage of phenylephrine-induced contraction (mean ± standard deviation) (P noradrenaline (P noradrenaline. Dopamine, adrenaline and noradrenaline elicit contractions in human umbilical arteries, and noradrenaline causes the highest contraction. Both propofol and sevoflurane inhibit these contractions in a dose-dependent manner. Propofol caused greater relaxation in the contractions elicited by dopamine and adrenaline while sevoflurane caused greater relaxation in the contraction elicited by noradrenaline. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

  4. Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Mechteld A.R., E-mail: mar.vermeulen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Ligthart-Melis, Gerdien C., E-mail: g.ligthart-melis@vumc.nl [Department of Internal Medicine, Dietetics and Nutritional Sciences, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Buijsman, René, E-mail: renebuysman@gmail.com [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Siroen, Michiel P.C., E-mail: m.siroen6@upcmail.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Poll, Marcel C.G. van de, E-mail: mcg.vandepoll@ah.unimaas.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Boelens, Petra G., E-mail: p.boelens@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Dejong, Cornelis H.C., E-mail: chc.dejong@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Schaik, Cors van, E-mail: c.vanschaik@vumc.nl [Department of Radiology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Hofman, Mark B.M., E-mail: mbm.hofman@vumc.nl [Department of Physics and Medical Technology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Leeuwen, Paul A.M. van, E-mail: pam.vleeuwen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands)

    2012-09-15

    Background: Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose. Objective: To examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach. Methods: In this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared. Results: Mean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433 ± 200/423 ± 162/507 ± 96 ml/min (portal vein); 96 ± 70/74 ± 41/108 ± 91 ml/min (hepatic artery); 248 ± 139/201 ± 118/219 ± 69 ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent. Conclusions: Surgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements. Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.

  5. Assessment of the arterial stiffness in patients with acute ischemic stroke using longitudinal elasticity modulus measurements obtained with Shear Wave Elastography.

    Science.gov (United States)

    Li, Zhaojun; Du, Lianfang; Wang, Feng; Luo, Xianghong

    2016-06-01

    Arterial wall elasticity including the circumferential and longitudinal modulus is a measure of sub-clinical cardiovascular disease; the circumferential modulus is increased in acute ischemic stroke (AIS). There are still no reports of non-invasive measurement of longitudinal elastic modulus of arterial wall and its prospect of clinical application. In this study, the longitudinal elastic modulus of the arterial wall was assessed using real-time shear wave elastography in patients with AIS. The technique's feasibility and its related factors were studied initially. In this study 179 patients with AIS and 168 age- and sex-matched controls were examined. The pulse wave velocity (PWV) of the bilateral carotid arteries was measured using radio frequency ultrasound technology. The 20 areas of superficial walls of bilateral carotid artery were analyzed by real-time shear wave elastography (SWE), and the average values of longitudinal average elastic modulus (ME-mean), maximum elastic modulus (ME-max), minimum elastic modulus (ME-min), and elastic modulus standard deviation (MESD) were measured. The PWV, ME-mean, ME-max and ME-sp of the carotid artery in patients with AIS were greater than those in the control group. Age, systolic blood pressure, PWV, and low-density lipoprotein were positively related to ME-mean and ME-max (r=0.221and r=0.248, r=0.174 and r=0.176, r=0.776 and r=0.716, r=0.173 and r=0.200, pelastic modulus of the arterial wall and evaluate the arterial stiffness. It was equivalent to the PWV which showed circular elastic modulus of arterial wall on evaluating AIS. Age, systolic blood pressure, pulse wave velocity, and low-density lipoprotein were independent risk factors for longitudinal elastic modulus. SWE may be effective in the assessment of arterial stiffness and offer a potential clinical benefit.

  6. A Computer-Aided Diagnosis System for Measuring Carotid Artery Intima-Media Thickness (IMT) Using Quaternion Vectors.

    Science.gov (United States)

    Kutbay, Uğurhan; Hardalaç, Fırat; Akbulut, Mehmet; Akaslan, Ünsal; Serhatlıoğlu, Selami

    2016-06-01

    This study aims investigating adjustable distant fuzzy c-means segmentation on carotid Doppler images, as well as quaternion-based convolution filters and saliency mapping procedures. We developed imaging software that will simplify the measurement of carotid artery intima-media thickness (IMT) on saliency mapping images. Additionally, specialists evaluated the present images and compared them with saliency mapping images. In the present research, we conducted imaging studies of 25 carotid Doppler images obtained by the Department of Cardiology at Fırat University. After implementing fuzzy c-means segmentation and quaternion-based convolution on all Doppler images, we obtained a model that can be analyzed easily by the doctors using a bottom-up saliency model. These methods were applied to 25 carotid Doppler images and then interpreted by specialists. In the present study, we used color-filtering methods to obtain carotid color images. Saliency mapping was performed on the obtained images, and the carotid artery IMT was detected and interpreted on the obtained images from both methods and the raw images are shown in Results. Also these results were investigated by using Mean Square Error (MSE) for the raw IMT images and the method which gives the best performance is the Quaternion Based Saliency Mapping (QBSM). 0,0014 and 0,000191 mm(2) MSEs were obtained for artery lumen diameters and plaque diameters in carotid arteries respectively. We found that computer-based image processing methods used on carotid Doppler could aid doctors' in their decision-making process. We developed software that could ease the process of measuring carotid IMT for cardiologists and help them to evaluate their findings.

  7. Evaluation of the oscillometric technique for intermittent non-invasive arterial blood pressure measurement in the anaesthetized pig.

    Science.gov (United States)

    Ypsilantis, P; Didilis, V; Simopoulos, C

    2013-04-01

    This study was designed to evaluate the oscillometric technique for intermittent non-invasive measurement of arterial pressure (AP) in the anaesthetized pig. In six pigs under sevoflurane anaesthesia, intermittent (every 2 minutes) oscillometric measurements of AP made at a forelimb (FL), a hindlimb (HL) and the tail base were compared with simultaneous direct AP measurements made at the aortic arch (AA) over a wide pressure range (30-140 mmHg of mean AP). All oscillometric measurements strongly correlated (Pearson correlation coefficient >0.837, P oscillometric and AA pressure readings at graded pressure levels, measurements made at the tail base provided reliable prediction of systolic AP, at the FL of diastolic AP and at both the tail base and the FL of mean AP. In conclusion, oscillometric measurements at the FL and the tail base offer reliable prediction of AP in the anaesthetized pig.

  8. Local release of ATP into the arterial inflow and venous drainage of human skeletal muscle: insight from ATP determination with the intravascular microdialysis technique

    DEFF Research Database (Denmark)

    Mortensen, Stefan; Thaning, Pia; Nyberg, Michael Permin

    2011-01-01

    is released into plasma, we measured plasma [ATP] with the intravascular microdialysis technique at rest and during dynamic exercise (normoxia and hypoxia), passive exercise, thigh compressions and arterial ATP, tyramine and ACh infusion in a total of 16 healthy young men. Femoral arterial and venous...

  9. Accuracy of Parenchymal Cerebral Blood Flow Measurements Using Pseudocontinuous Arterial Spin-Labeling in Healthy Volunteers.

    Science.gov (United States)

    Ambarki, K; Wåhlin, A; Zarrinkoob, L; Wirestam, R; Petr, J; Malm, J; Eklund, A

    2015-10-01

    The arterial spin-labeling method for CBF assessment is widely available, but its accuracy is not fully established. We investigated the accuracy of a whole-brain arterial spin-labeling technique for assessing the mean parenchymal CBF and the effect of aging in healthy volunteers. Phase-contrast MR imaging was used as the reference method. Ninety-two healthy volunteers were included: 49 young (age range, 20-30 years) and 43 elderly (age range, 65-80 years). Arterial spin-labeling parenchymal CBF values were averaged over the whole brain to quantify the mean pCBF(ASL) value. Total CBF was assessed with phase-contrast MR imaging as the sum of flows in the internal carotid and vertebral arteries, and subsequent division by brain volume returned the pCBF(PCMRI) value. Accuracy was considered as good as that of the reference method if the systematic difference was less than 5 mL/min/100 g of brain tissue and if the 95% confidence intervals were equal to or better than ±10 mL/min/100 g. pCBF(ASL) correlated to pCBF(PCMRI) (r = 0.73; P volunteers. The systematic differences (mean ± 2 standard deviations) were -4 ± 14 mL/min/100 g in the young subjects and 6 ± 12 mL/min/100 g in the elderly subjects. Young subjects showed higher values than the elderly subjects for pCBF(PCMRI) (young, 57 ± 8 mL/min/100 g; elderly, 54 ± 7 mL/min/100 g; P = .05) and pCBF(ASL) (young, 61 ± 10 mL/min/100 g; elderly, 48 ± 10 mL/min/100 g; P < .001). The limits of agreement were too wide for the arterial spin-labeling method to be considered satisfactorily accurate, whereas the systematic overestimation in the young subjects and underestimation in the elderly subjects were close to acceptable. The age-related decrease in parenchymal CBF was augmented in arterial spin-labeling compared with phase-contrast MR imaging. © 2015 by American Journal of Neuroradiology.

  10. Biomechanics of Ergometric Stress Test: regional and local effects on elastic, transitional and muscular human arteries

    Science.gov (United States)

    Valls, G.; Torrado, J.; Farro, I.; Bia, D.; Zócalo, Y.; Lluberas, S.; Craiem, D.; Armentano, Rl

    2011-09-01

    Ergometric exercise stress tests (EST) give important information about the cardiovascular (CV) response to increased demands. The expected EST-related changes in variables like blood pressure and heart rate are known, but those in the arterial biomechanics are controversial and incompletely characterized. In this context, this work aims were to characterize the regional and local arterial biomechanical behaviour in response to EST; to evaluate its temporal profile in the post-EST recovery phase; and to compare the biomechanical response of different to EST. Methods: In 16 non-trained healthy young subjects the carotid-femoral pulse wave velocity and the carotid, femoral and brachial arterial distensibility were non-invasively evaluated before (Rest) and after EST. Main results: The EST resulted in an early increase in the arterial stiffness, evidenced by both, regional and local parameters (pulse wave velocity increase and distensibility reduction). When analyzing conjunctly the different post-EST recovery stages there were quali-quantitative differences among the arterial local stiffness response to EST. The biomechanical changes could not be explained only by blood pressure variations.

  11. Middle cerebral artery diameter changes during rhythmic handgrip exercise in humans.

    Science.gov (United States)

    Verbree, J; Bronzwaer, Agt; van Buchem, M A; Daemen, Mjap; van Lieshout, J J; van Osch, Mjp

    2017-08-01

    Transcranial Doppler (TCD) sonography is a frequently employed technique for quantifying cerebral blood flow by assuming a constant arterial diameter. Given that exercise increases arterial pressure by sympathetic activation, we hypothesized that exercise might induce a change in the diameter of large cerebral arteries. Middle cerebral artery (MCA) cross-sectional area was assessed in response to handgrip exercise by direct magnetic resonance imaging (MRI) observations. Twenty healthy subjects (11 female) performed three 5 min bouts of rhythmic handgrip exercise at 60% maximum voluntary contraction, alternated with 5 min of rest. High-resolution 7 T MRI scans were acquired perpendicular to the MCA. Two blinded observers manually determined the MCA cross-sectional area. Sufficient image quality was obtained in 101 MCA-scans of 19 subjects (age-range 20-59 years). Mixed effects modelling showed that the MCA cross-sectional area decreased by 2.1 ± 0.8% (p = 0.01) during handgrip, while the heart rate increased by 11 ± 2% (p exercise. This further strengthens the current concept of sympathetic control of large cerebral arteries, showing in vivo vasoconstriction during exercise-induced sympathetic activation. Moreover, care must be taken when interpreting TCD exercise studies as diameter constancy cannot be assumed.

  12. Nonlinear Optical Measurements of the Artery Wall: Parameters Related to the Progression of Atherosclerosis

    Science.gov (United States)

    Sowa, Michael G.; Mostaco-Guidolin, Leila B.; Smith, Michael S. D.; Kohlenberg, Elica K.; Ridsdale, Andrew; Stolow, Albert; Ko, Alex C. T.

    2009-01-01

    Nonlinear optical (NLO) microscopy is used to follow key structural and biochemical changes associated with the progression of atherosclerosis. Arteries from WHHL-MI rabbits are examined using a 3 channel NLO microscope that can simultaneously monitor the coherent anti-stokes Raman scattered light (CARS), the two-photon excited fluorescence (TPEF) and the second harmonic generation (SHG) from a sample. Distinct differences in the nonlinear optical signals are observed that correlate with the age of the vessel and the presence of atherosclerotic plaque. These differences are attributed to the changing extracellular matrix and the increased lipid deposition associated with plaque development. The capability of NLO to perform 3D sectioning in thick highly scattering vessels in order to visualize structural details of the artery wall and highlight vessel pathology is demonstrated. These features make NLO a potentially valuable tool to help understand the progression of atherosclerosis.

  13. Measurement of pleural pressure swings with a fluid-filled esophageal catheter vs pulmonary artery occlusion pressure.

    Science.gov (United States)

    Verscheure, S; Massion, P B; Gottfried, S; Goldberg, P; Samy, L; Damas, P; Magder, S

    2017-02-01

    Pleural pressure measured with esophageal balloon catheters (Peso) can guide ventilator management and help with the interpretation of hemodynamic measurements, but these catheters are not readily available or easy to use. We tested the utility of an inexpensive, fluid-filled esophageal catheter (Peso) by comparing respiratory-induced changes in pulmonary artery occlusion (Ppao), central venous (CVP), and Peso pressures. We studied 30 patients undergoing elective cardiac surgery who had pulmonary artery and esophageal catheters in place. Proper placement was confirmed by chest compression with airway occlusion. Measurements were made during pressure-regulated volume control (VC) and pressure support (PS) ventilation. The fluid-filled esophageal catheter provided a high-quality signal. During VC and PS, change in Ppao (∆Ppao) was greater than ∆Peso (bias = -2 mm Hg) indicating an inspiratory increase in cardiac filling. During VC, ∆CVP bias was 0 indicating no change in right heart filling, but during PS, CVP fell less than Peso indicating an inspiratory increase in filling. Peso measurements detected activation of expiratory muscles, development of non-west zone 3 lung conditions during inspiration, and ventilator-triggered inspiratory efforts. A fluid-filled esophageal catheter provides a high-quality, easily accessible, and inexpensive measure of change in pleural pressure and provided insights into patient-ventilator interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. A cell culture model using rat coronary artery adventitial fibroblasts to measure collagen production

    OpenAIRE

    Meszaros Gary; Doane Kathleen; Milsted Amy; Jenkins Cathleen; Toot Jonathan; Ely Daniel

    2007-01-01

    Abstract Background We have developed a rat cell model for studying collagen type I production in coronary artery adventitial fibroblasts. Increased deposition of adventitial collagen type I leads to stiffening of the blood vessel, increased blood pressure, arteriosclerosis and coronary heart disease. Although the source and mechanism of collagen deposition is yet unknown, the adventitia appears to play a significant role. To demonstrate the application of our cell model, cultured adventitial...

  15. The Sonographic Stenosis Index: A New Specific Quantitative Measure of Transplant Hepatic Arterial Stenosis.

    Science.gov (United States)

    Le, Thomas X; Hippe, Daniel S; McNeeley, Michael F; Dighe, Manjiri K; Dubinsky, Theodore J; Chan, Sherwin S

    2017-04-01

    This study evaluates the sensitivity and specificity of stenosis index (SI), which accounts for the entire spectral Doppler waveform, to detect significant transplant hepatic arterial stenosis. In this institutional review board-approved, HIPAA compliant study, we retrospectively analyzed 69 patients who had catheter angiography for suspected transplant hepatic arterial stenosis (THAS) between January 2006 and December 2010; all patients had Doppler ultrasound within 30 days before angiography. Patients with angiographic stenosis requiring intervention were considered positive for THAS. Stenosis index was calculated from each patient's spectral Doppler ultrasound images by obtaining the ratio of the area under the high-frequency signal to low-frequency signal in the spectral Doppler. Resistive index (RI) and pulsatility index (PI) were also calculated. Receiver operator curve analysis was performed and the area under the curve (AUC) was compared among the three metrics. Forty-eight of 69 patients had THAS by angiography requiring intervention; 21patients had no angiographic evidence of THAS. SI was significantly different (P transplant hepatic artery stenosis. © 2016 by the American Institute of Ultrasound in Medicine.

  16. Phylloquinone (vitamin K₁) intake and pulse pressure as a measure of arterial stiffness in older adults.

    Science.gov (United States)

    Vaccaro, Joan A; Huffman, Fatma G

    2013-01-01

    This study examined the relationships among ethnicity/race, lifestyle factors, phylloquinone (vitamin K₁) intake, and arterial pulse pressure in a nationally representative sample of older adults from four ethnic/racial groups: non-Hispanic Whites, non-Hispanic Blacks, Mexican Americans, and other Hispanics. This was a cross-sectional study of U.S. representative sample with data from the National Health and Nutrition Examination Surveys, 2007-2008 and 2009-2010 of adults aged 50 years and older (N = 5296). Vitamin K intake was determined by 24-hour recall. Pulse pressure was calculated as the difference between the averages of systolic blood pressure and diastolic blood pressure. Compared to White non-Hispanics, the other ethnic/racial groups were more likely to have inadequate vitamin K₁ intake. Inadequate vitamin K₁ intake was an independent predictor of high arterial pulse pressure. This was the first study that compared vitamin K₁ inadequacy with arterial pulse pressure across ethnicities/races in U.S. older adults. These findings suggest that vitamin K screening may be a beneficial marker for the health of older adults.

  17. Quality of life in opium-addicted patients with coronary artery disease as measured with WHOQOL-BREF.

    Science.gov (United States)

    Najafi, Mahdi; Sheikhvatan, Mehrdad; Montazeri, Ali; Sheikhfathollahi, Mahmood

    2009-05-01

    Several factors can influence the quality of life in patients with coronary artery disease (CAD). The goal of this research was to measure quality of life in opium-addicted patients with CAD in order to assess the effect of CAD risk factors on their quality of life. The WHOQOL-BREF questionnaire was completed through interviews with 275 patients who underwent isolated coronary artery bypass surgery in Tehran Heart Centre between May and September 2006. No significant differences were found in the mean scores of the four domains of quality of life between the addicted and non-addicted patients. Furthermore, the evaluation of QOL in the groups with CAD risk factors showed that the mean QOL domains were statistically similar between opium addicted and non-opium addicted patients. In the addicted group, men had a higher psychological health score than women. A previous history of myocardial infarction reduced the psychological score in this group. Also, in the addicted patients with a history of diabetes mellitus, social functioning was better than that of the non-diabetics. The different domains of quality of life in our opium-addicted and non-addicted patients with CAD were similar; and among all the major risk factors for coronary artery disease, only female gender and a previous history of myocardial infarction could influence quality of life in the opium-addicted patients.

  18. The CSF and arterial to internal jugular venous hormonal differences during exercise in humans

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Ott, Peter; Dela, Flemming

    2004-01-01

    the brain (a-v diff) of hormones that could influence its carbohydrate uptake (n= 9). In addition, neuroendocrine activity and a potential uptake of hormones via the cerebrospinal fluid (CSF) were assessed by lumbar puncture postexercise and at rest (n= 6). Exercise increased the arterial concentration...... of noradrenaline and adrenaline, but there was no cerebral uptake. However, following exercise CSF noradrenaline was 1.4 (0.73-5.5) nmol l(-1), and higher than at rest, 0.3 (0.19-1.84) nmol l(-1) (P arterial concentration of NH(4...

  19. An in vitro patient-tailored model of human cerebral artery for simulating endovascular intervention.

    Science.gov (United States)

    Ikeda, Seiichi; Arai, Fumihito; Fukuda, Toshio; Negoro, Makoto; Irie, Keiko; Takahashi, Ikuo

    2005-01-01

    An in vitro patient-tailored reproduction model of cerebral artery, a hardware platform for simulating endovascular intervention for making diagnoses and surgical trainings is presented. 3-D configuration of vessel lumen is reproduced as vessel model with 13 microm modeling resolution, using CT and MRI information. Physical characteristics of cerebral artery, such as elastic modulus and friction coefficient, are also reproduced. We also propose a novel method to visualize stress condition on vessel wall using photoelastic effect. Consequently, it should be helpful for clinical applications, academic researches and other various purposes.

  20. Ultrasonic range measurements on the human body

    NARCIS (Netherlands)

    Weenk, D.; van Beijnum, Bernhard J.F.; Droog, Adriaan; Hermens, Hermanus J.; Veltink, Petrus H.

    2013-01-01

    Ambulatory range estimation on the human body is important for the assessment of the performance of upper- and lower limb tasks outside a laboratory. In this paper an ultrasound sensor for estimating ranges on the human body is presented and validated during gait. The distance between the feet is

  1. Data on consistency among different methods to assess atherosclerotic plaque echogenicity on standard ultrasound and intraplaque neovascularization on contrast-enhanced ultrasound imaging in human carotid artery

    Directory of Open Access Journals (Sweden)

    Mattia Cattaneo

    2016-12-01

    Full Text Available Here we provide the correlation among different carotid ultrasound (US variables to assess echogenicity n standard carotid US and to assess intraplaque neovascularization on contrast enhanced US. We recruited 45 consecutive subjects with an asymptomatic≥50% carotid artery stenosis. Carotid plaque echogenicity at standard US was visually graded according to Gray–Weale classification (GW and measured by the greyscale median (GSM, a semi-automated computerized measurement performed by Adobe Photoshop®. On CEUS imaging IPNV was graded according to the visual appearance of contrast within the plaque according to three different methods: CEUS_A (1=absent; 2=present; CEUS_B a three-point scale (increasing IPNV from 1 to 3; CEUS_C a four-point scale (increasing IPNV from 0 to 3. We have also implemented a new simple quantification method derived from region of interest (ROI signal intensity ratio as assessed by QLAB software. Further information is available in “Contrast-enhanced ultrasound imaging of intraplaque neovascularization and its correlation to plaque echogenicity in human carotid arteries atherosclerosis (M. Cattaneo, D. Staub, A.P. Porretta, J.M. Gallino, P. Santini, C. Limoni et al., 2016 [1].

  2. The effect of pH and ion channel modulators on human placental arteries.

    Directory of Open Access Journals (Sweden)

    Tayyba Y Ali

    Full Text Available Chorionic plate arteries (CPA are located at the maternofetal interface where they are able to respond to local metabolic changes. Unlike many other types of vasculature, the placenta lacks nervous control and requires autoregulation for controlling blood flow. The placental circulation, which is of low-resistance, may become hypoxic easily leading to fetal acidosis and fetal distress however the role of the ion channels in these circumstances is not well-understood. Active potassium channel conductances that are subject to local physicochemical modulation may serve as pathways through which such signals are transduced. The aim of this study was to investigate the modulation of CPA by pH and the channels implicated in these responses using wire myography. CPA were isolated from healthy placentae and pre-contracted with U46619 before testing the effects of extracellular pH using 1 M lactic acid over the pH range 7.4-6.4 in the presence of a variety of ion channel modulators. A change from pH 7.4 to 7.2 produced a 29±3% (n = 9 relaxation of CPA which increased to 61±4% at the lowest pH of 6.4. In vessels isolated from placentae of women with pre-eclampsia (n = 6, pH responses were attenuated. L-methionine increased the relaxation to 67±7% (n = 6; p<0.001 at pH 6.4. Similarly the TASK 1/3 blocker zinc chloride (1 mM gave a maximum relaxation of 72±5% (n = 8; p<0.01 which compared with the relaxation produced by the TREK-1 opener riluzole (75±5%; n = 6. Several other modulators induced no significant changes in vascular responses. Our study confirmed expression of several ion channel subtypes in CPA with our results indicating that extracellular pH within the physiological range has an important role in controlling vasodilatation in the human term placenta.

  3. A Novel System for Measuring Optical Properties in Arterial Blood of Man

    Directory of Open Access Journals (Sweden)

    A. Castañeda-Miranda

    2006-01-01

    Full Text Available The necessity of man–machine communication has been increasing day by day because of the great number of approaches that help to make human life agile or comfortable. Health is one of the aspects that has generated more interest in recent years. The optical technologies are new technical tools that are being implemented for medical diagnosis and for describing various processes occurring within human blood. These techniques have the virtue of being nondestructive; in addition they have the advantage of remote direction by using an in situ technique, with sensitivity capable of studying the properties of the blood through electromagnetic excitation. A device to obtain the electromagnetic spectrum in the blood has being designed and is presented in this work. This device uses a quartz lamp, emitting electromagnetic radiation between 200 nm and 2200 nm. A model for measuring the light attenuation through the blood is used. By applying a control in the frequency domain, a circuit device is designed. This device uses a database in time domain for its subsequent analysis by Fast Fourier Transformation in order to obtain absorption spectra. The acquisition time is of the order of microseconds, and the system is controlled automatically through accessible software from a personal computer.

  4. The Accuracy of the CNAP® Device Compared with Invasive Radial Artery Measurements for Providing Continuous Noninvasive Arterial Blood Pressure Readings at a Medical Intensive Care Unit: A Method-Comparison Study.

    Science.gov (United States)

    Smolle, Karl-Heinz; Schmid, Martin; Prettenthaler, Helga; Weger, Christian

    2015-12-01

    In cases of intensive care unit (ICU) patients without an arterial line, noninvasive continuous blood pressure monitoring could be very beneficial. The CNAP® monitor (CNSystems Medizintechnik AG) provides noninvasive, beat-to-beat blood pressure (BP) estimates using the volume clamp method to measure finger arterial pressure calibrated to brachial pressure values. The aim of this study was to compare noninvasive BP estimates of the CNAP monitor with invasive blood pressure (IBP) measurements obtained via a radial arterial catheter in unselected medical ICU patients under routine clinical conditions. In 40 adult patients, IBP and noninvasive CNAP blood pressure (CBP) were measured simultaneously for 30 minutes. Bland-Altman analysis accounting for repeated measurements revealed accuracy and precision of CBP toward IBP. Percentage errors were calculated using the summary measures method and tested for interchangeability. Trending analysis was assessed using 4-quadrant plots and polar plots, whereby each reported statistical calculation used the sample size of n = 40 patients. A total of 7200 measurement pairs of CBP and IBP were analyzed. For mean arterial pressure, accuracy ± precision resulted in 4.6 ± 6.7 mm Hg (limits of agreement -8.7 to 17.8 mm Hg) with a percentage error of 6.77% (95% confidence interval [CI], 6.57%-6.97%). Trending analysis of 3-minute intervals showed a concordance rate of 94.6% (95% CI, 94.0%-95.2%; exclusion zone 10%) and a polar concordance rate of 99.50% (95% CI, 99.48%-99.52%) for changes lying within 10% limits. The CNAP device provided feasible estimates of BP in unselected medical ICU patients under routine clinical conditions. Mean arterial pressure met interchangeability criteria for accuracy toward radial arterial pressure, as well as for percentage error, and showed good trending capabilities according to the Critchley predefined criteria.

  5. Pathology of Human Coronary and Carotid Artery Atherosclerosis and Vascular Calcification in Diabetes Mellitus.

    Science.gov (United States)

    Yahagi, Kazuyuki; Kolodgie, Frank D; Lutter, Christoph; Mori, Hiroyoshi; Romero, Maria E; Finn, Aloke V; Virmani, Renu

    2017-02-01

    The continuing increase in the prevalence of diabetes mellitus in the general population is predicted to result in a higher incidence of cardiovascular disease. Although the mechanisms of diabetes mellitus-associated progression of atherosclerosis are not fully understood, at clinical and pathological levels, there is an appreciation of increased disease burden and higher levels of arterial calcification in these subjects. Plaques within the coronary arteries of patients with diabetes mellitus generally exhibit larger necrotic cores and significantly greater inflammation consisting mainly of macrophages and T lymphocytes relative to patients without diabetes mellitus. Moreover, there is a higher incidence of healed plaque ruptures and positive remodeling in hearts from subjects with type 1 diabetes mellitus and type 2 diabetes mellitus, suggesting a more active atherogenic process. Lesion calcification in the coronary, carotid, and other arterial beds is also more extensive. Although the role of coronary artery calcification in identifying cardiovascular disease and predicting its outcome is undeniable, our understanding of how key hormonal and physiological alterations associated with diabetes mellitus such as insulin resistance and hyperglycemia influence the process of vascular calcification continues to grow. Important drivers of atherosclerotic calcification in diabetes mellitus include oxidative stress, endothelial dysfunction, alterations in mineral metabolism, increased inflammatory cytokine production, and release of osteoprogenitor cells from the marrow into the circulation. Our review will focus on the pathophysiology of type 1 diabetes mellitus- and type 2 diabetes mellitus-associated vascular disease with particular focus on coronary and carotid atherosclerotic calcification. © 2016 American Heart Association, Inc.

  6. Distinct Differences on Neointima Formation in Immunodeficient and Humanized Mice after Carotid or Femoral Arterial Injury

    NARCIS (Netherlands)

    Moser, Jill; van Ark, Joris; van Dijk, Marcory C.; Greiner, Dale L.; Shultz, Leonard D.; Goor, van Harry; Hillebrands, Jan-Luuk

    2016-01-01

    Percutaneous coronary intervention is widely adopted to treat patients with coronary artery disease. However, restenosis remains an unsolved clinical problem after vascular interventions. The role of the systemic and local immune response in the development of restenosis is not fully understood.

  7. Atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing in humans

    DEFF Research Database (Denmark)

    Pump, B; Damgaard, M; Gabrielsen, A

    2001-01-01

    During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing in ...

  8. Relationship between upper and lower limb conduit artery vasodilator function in humans

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Rowley, N.; Padilla, J.; Simmons, G.H.; Laughlin, M.H.; Whyte, G.; Cable, N.T.; Green, D.J.

    2011-01-01

    Brachial artery flow-mediated dilation (FMD) is a strong predictor of future cardiovascular disease and is believed to represent a "barometer" of systemic endothelial health. Although a recent study [Padilla et al. Exp Biol Med (Maywood) 235: 1287-1291, 2010] in pigs confirmed a strong correlation

  9. Egr-1 identifies neointimal remodeling and relates to progression in human pulmonary arterial hypertension

    NARCIS (Netherlands)

    van der Feen, Diederik E; Dickinson, Michael G; Bartelds, Beatrijs; Borgdorff, Marinus A J; Sietsma, Hannie; Lévy, Marilyne; Berger, Rolf M F

    BACKGROUND: Pulmonary arterial hypertension (PAH) is hallmarked by the development of neointimal lesions. The transcription factor Egr-1 seems to play a critical role in neointimal formation in experimental PAH and was identified as a putative target for intervention. In this study we investigated

  10. Evidence for a cyclic AMP-dependent pathway in angiotensin AT1-receptor activation of human omental arteries

    Directory of Open Access Journals (Sweden)

    Hoa Ytterberg

    2001-03-01

    Full Text Available Enhanced responses to vasoconstriction induced by neuropeptide Y and α2-adrenoceptor agonists have been seen following pharmacological activation of the adenylyl cyclase (AC system. Since preliminary studies revealed only minor responses to angiotensin II (Ang II in human omental arteries, we have investigated whether enhanced activity of AC may unravel further functional Ang II receptors. Human omental arteries were obtained in conjunction with elective gut surgery. After dissection of the vessel, the endothelium was removed by 10 sec of Triton X-100 treatment. Ring segments (1—2 mm long were mounted on a myograph and studied. Ang II produced small contractions, 27±5% relative to the response elicited by 60 mM K+. However, enhanced Ang II (105±10%, p<0.001 responses were seen during AC activation by forskolin (0.1—1 µM. This enhanced contractile response to Ang II was not inhibited by the angiotensin II type 2 (AT2-receptor antagonist PD 123319 (0.1 µM, but was blocked in an insurmountable way by the angiotensin II type 1 (AT1-receptor antagonist candesartan (1 nM and in a surmountable manner by losartan (0.1 µM and irbesartan (0.1 µM. Pertussis toxin (a Gi-protein blocker and the protein kinase C inhibitor, RO31—8220 (0.01, 0.1 and 1 µM, markedly reduced this response, while the protein kinase A inhibitor, H89 (1, 10 µM, had no effect. RT-PCR provided evidence for the presence of mRNA for both AT1- and AT2-receptors. The results suggest that both a cAMP-dependent and a cAMP-independent mechanism are involved in the contractile responses to Ang II in human omental arteries and that both responses are mediated via the AT1-receptor.

  11. Effect of cocoa/chocolate ingestion on brachial artery flow-mediated dilation and its relevance to cardiovascular health and disease in humans.

    Science.gov (United States)

    Monahan, Kevin D

    2012-11-15

    Prospective studies indicate that high intake of dietary flavanols, such as those contained in cocoa/chocolate, are associated with reduced rates of cardiovascular-related morbidity and mortality in humans. Numerous mechanisms may underlie these associations such as favorable effects of flavanols on blood pressure, platelet aggregation, thrombosis, inflammation, and the vascular endothelium. The brachial artery flow-mediated dilation (FMD) technique has emerged as a robust method to quantify endothelial function in humans. Collectively, the preponderance of evidence indicates that FMD is a powerful surrogate measure for firm cardiovascular endpoints, such as cardiovascular-related mortality, in humans. Thus, literally thousands of studies have utilized this technique to document group differences in FMD, as well as to assess the effects of various interventions on FMD. In regards to the latter, numerous studies indicate that both acute and chronic ingestion of cocoa/chocolate increases FMD in humans. Increases in FMD after cocoa/chocolate ingestion appear to be dose-dependent such that greater increases in FMD are observed after ingestion of larger quantities. The mechanisms underlying these responses are likely diverse, however most data suggest an effect of increased nitric oxide bioavailability. Thus, positive vascular effects of cocoa/chocolate on the endothelium may underlie (i.e., be linked mechanistically to) reductions in cardiovascular risk in humans. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Human Capital Investment: Measuring Returns to Education

    OpenAIRE

    Potelienė, Simona; Tamašauskienė, Zita

    2013-01-01

    According to human capital theory, knowledge and skills incorporated in the individual can be referred to as capital and all activities with which the present input makes future yields while the productivity of the individual grows can be interpreted as an investment. This research considers higher education as an investment decision and presents empirical evidence on the private return on this investment. We calculate the private net present value of higher education (i.e. human capital) and...

  13. Performance assessment of Pulse Wave Imaging using conventional ultrasound in canine aortas ex vivo and normal human arteries in vivo.

    Science.gov (United States)

    Li, Ronny X; Qaqish, William; Konofagou, Elisa E

    2015-09-01

    The propagation behavior of the arterial pulse wave may provide valuable diagnostic information for cardiovascular pathology. Pulse Wave Imaging (PWI) is a noninvasive, ultrasound imaging-based technique capable of mapping multiple wall motion waveforms along a short arterial segment over a single cardiac cycle, allowing for the regional pulse wave velocity (PWV) and propagation uniformity to be evaluated. The purpose of this study was to improve the clinical utility of PWI using a conventional ultrasound system. The tradeoff between PWI spatial and temporal resolution was evaluated using an ex vivo canine aorta (n = 2) setup to assess the effects of varying image acquisition and signal processing parameters on the measurement of the PWV and the pulse wave propagation uniformity r2. PWI was also performed on the carotid arteries and abdominal aortas of 10 healthy volunteers (24.8 ± 3.3 y.o.) to determine the waveform tracking feature that would yield the most precise PWV measurements and highest r2 values in vivo. The ex vivo results indicated that the highest precision for measuring PWVs ~ 2.5 - 3.5 m/s was achieved using 24-48 scan lines within a 38 mm image plane width (i.e. 0.63 - 1.26 lines/mm). The in vivo results indicated that tracking the 50% upstroke of the waveform would consistently yield the most precise PWV measurements and minimize the error in the propagation uniformity measurement. Such findings may help establish the optimal image acquisition and signal processing parameters that may improve the reliability of PWI as a clinical measurement tool.

  14. In vitro effects of sodium nitroprusside and leptin on norepinephrine-induced vasoconstriction in human internal mammary artery.

    Science.gov (United States)

    Burma, Oktay; Ozcan, Mete; Kacar, Emine; Uysal, Ayhan; Şahna, Engin; Ayar, Ahmet

    2015-01-01

    The biological and pharmacological properties of vessels used in coronary artery bypass graft (CABG) surgery are as important as their mechanical properties. The aim of this study was to investigate the possible role of protein kinase C (PKC)-dependent mechanisms in leptin-induced relaxation in the human internal mammary artery (IMA). IMA rings, obtained from patients undergoing CABG surgery, were suspended in isolated tissue baths containing Krebs-Henseleit solution, which were continuously gassed with 95% O2 and 5% CO2 at 37(°)C. The IMA rings were pre-contracted with increasing concentrations of norepinephrine (NE 10(-9)-10(-4) mol/l) and the relaxation responses to sodium nitroprusside (SNP), a nitrosovasodilator, and leptin were studied in the presence and absence of a PKC inhibitor. Leptin (1 µM) caused a dose-dependent relaxation in NE pre-contracted IMA rings. Pre-treatment with a PKC inhibitor significantly attenuated this vasorelaxatory response to leptin in human isolated IMA. It was found that SNP and leptin caused significant relaxation of the NE pre-contracted human IMA rings, and PKC was probably the sub-cellular mediator for this effect. Our findings may have clinical or pharmacological importance as it could be hypothesised that obese subjects who have a left IMA bypass graft would have better myocardial perfusion.

  15. Problems of Measurement in Human Analog Research.

    Science.gov (United States)

    1982-05-01

    side if necessom7 mid Identlify by block niomber) cinematography measuring systems, accelerometer derived kinematic variables, measurement of rigid body... Cinematography , accelerometer con- figurations, and combined photography and accelerometer measurement systems are discussed and compared. D iAM7 1473...rigid body are determined with a least squares algorithm using the target locations in the film plane as well as the measured location and orientation

  16. Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

    OpenAIRE

    Burton, G.J.; Woods, A. W.; Jauniaux, E; Kingdom, J.C.P.

    2009-01-01

    Physiological conversion of the maternal spiral arteries is key to a successful human pregnancy. It involves loss of smooth muscle and the elastic lamina from the vessel wall as far as the inner third of the myometrium, and is associated with a 5?10-fold dilation at the vessel mouth. Failure of conversion accompanies common complications of pregnancy, such as early-onset preeclampsia and fetal growth restriction. Here, we model the effects of terminal dilation on inflow of blood into the plac...

  17. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A

    1977-01-01

    Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure...

  18. Nuclear IL-33 regulates soluble ST2 receptor and IL-6 expression in primary human arterial endothelial cells and is decreased in idiopathic pulmonary arterial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Dongmin [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom); Perros, Frédéric [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Caramori, Gaetano [Dipartimento di Scienze Mediche, Sezione di Medicina Interna e Cardiorespiratoria, Centro Interdipartimentale per lo Studio delle Malattie Infiammatorie delle Vie Aeree e Patologie Fumo-Correlate, University of Ferrara, Ferrara (Italy); Meng, Chao [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom); Department of Geriatrics, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai (China); Dormuller, Peter [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Chou, Pai-Chien [Airways Disease, National Heart and Lung Institute (United Kingdom); Church, Colin [Scottish Pulmonary Vascular Unit, University of Glasgow (United Kingdom); Papi, Alberto; Casolari, Paolo [Dipartimento di Scienze Mediche, Sezione di Medicina Interna e Cardiorespiratoria, Centro Interdipartimentale per lo Studio delle Malattie Infiammatorie delle Vie Aeree e Patologie Fumo-Correlate, University of Ferrara, Ferrara (Italy); Welsh, David; Peacock, Andrew [Scottish Pulmonary Vascular Unit, University of Glasgow (United Kingdom); Humbert, Marc [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Adcock, Ian M. [Airways Disease, National Heart and Lung Institute (United Kingdom); Wort, Stephen J., E-mail: s.wort@imperial.ac.uk [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom)

    2014-08-15

    Highlights: • Nuclear IL-33 expression is reduced in vascular endothelial cells from PAH patients. • Knockdown of IL-33 leads to increased IL-6 and sST2 mRNA expression. • IL-33 binds homeobox motifs in target gene promoters and recruits repressor proteins. - Abstract: Idiopathic pulmonary arterial hypertension (IPAH) is an incurable condition leading to right ventricular failure and death and inflammation is postulated to be associated with vascular remodelling. Interleukin (IL)-33, a member of the “alarmin” family can either act on the membrane ST2 receptor or as a nuclear repressor, to regulate inflammation. We show, using immunohistochemistry, that IL-33 expression is nuclear in the vessels of healthy subjects whereas nuclear IL-33 is markedly diminished in the vessels of IPAH patients. This correlates with reduced IL-33 mRNA expression in their lung. In contrast, serum levels of IL-33 are unchanged in IPAH. However, the expression of the soluble form of ST2, sST2, is enhanced in the serum of IPAH patients. Knock-down of IL-33 in human endothelial cells (ECs) using siRNA is associated with selective modulation of inflammatory genes involved in vascular remodelling including IL-6. Additionally, IL-33 knock-down significantly increased sST2 release from ECs. Chromatin immunoprecipitation demonstrated that IL-33 bound multiple putative homeodomain protein binding motifs in the proximal and distal promoters of ST2 genes. IL-33 formed a complex with the histone methyltransferase SUV39H1, a transcriptional repressor. In conclusion, IL-33 regulates the expression of IL-6 and sST2, an endogenous IL-33 inhibitor, in primary human ECs and may play an important role in the pathogenesis of PAH through recruitment of transcriptional repressor proteins.

  19. MR velocity mapping measurement of renal artery blood flow in patients with impaired kidney function

    DEFF Research Database (Denmark)

    Cortsen, M; Petersen, L.J.; Stahlberg, F

    1996-01-01

    . MR velocity mapping was performed in both renal arteries using an ECG-triggered gradient echo pulse sequence previously validated in normal volunteers. Effective renal plasma flow was calculated from the clearance rate of PAH during constant infusion and the split of renal function was evaluated...... by 99mTc-DTPA scintigraphy. A reduction of RBF was found, and there was a significant correlation between PAH clearance multiplied by 1/(1-hematocrit) and RBF determined by MR velocity mapping. Furthermore, a significant correlation between the distribution of renal function and the percent distribution...

  20. Translating the microRNA signature of microvesicles derived from human coronary artery smooth muscle cells in patients with familial hypercholesterolemia and coronary artery disease.

    Science.gov (United States)

    de Gonzalo-Calvo, David; Cenarro, Ana; Garlaschelli, Katia; Pellegatta, Fabio; Vilades, David; Nasarre, Laura; Camino-Lopez, Sandra; Crespo, Javier; Carreras, Francesc; Leta, Rubén; Catapano, Alberico Luigi; Norata, Giuseppe Danilo; Civeira, Fernando; Llorente-Cortes, Vicenta

    2017-05-01

    To analyze the impact of atherogenic lipoproteins on the miRNA signature of microvesicles derived from human coronary artery smooth muscle cells (CASMC) and to translate these results to familial hypercholesterolemia (FH) and coronary artery disease (CAD) patients. Conditioned media was collected after exposure of CASMC to atherogenic lipoproteins. Plasma samples were collected from two independent populations of diagnosed FH patients and matched normocholesterolemic controls (Study population 1, N=50; Study population 2, N=24) and a population of patients with suspected CAD (Study population 3, N=50). Extracellular vesicles were isolated and characterized using standard techniques. A panel of 30 miRNAs related to vascular smooth muscle cell (VSMC) (patho-)physiology was analyzed using RT-qPCR. Atherogenic lipoproteins significantly reduced levels of miR-15b-5p, -24-3p, -29b-3p, -130a-3p, -143-3p, -146a-3p, -222-3p, -663a levels (P<0.050) in microvesicles (0.1μm-1μm in diameter) released by CASMC. Two of these miRNAs, miR-24-3p and miR-130a-3p, were reduced in circulating microvesicles from FH patients compared with normocholesterolemic controls in a pilot study (Study population 1) and in different validation studies (Study populations 1 and 2) (P<0.050). Supporting these results, plasma levels of miR-24-3p and miR-130a-3p were also downregulated in FH patients compared to controls (P<0.050). In addition, plasma levels of miR-130a-3p were inversely associated with coronary atherosclerosis in a cohort of suspected CAD patients (Study population 3) (P<0.050). Exposure to atherogenic lipoproteins modifies the miRNA profile of CASMC-derived microvesicles and these alterations are reflected in patients with FH. Circulating miR-130a-3p emerges as a potential biomarker for coronary atherosclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A comparison of noninvasive blood pressure measurement on the wrist with invasive arterial blood pressure monitoring in patients undergoing bariatric surgery.

    Science.gov (United States)

    Hager, Helmut; Mandadi, Goutham; Pulley, Debra; Eagon, J Chris; Mascha, Edward; Nutter, Benjamin; Kurz, Andrea

    2009-06-01

    In morbidly obese patients, oscillometric blood pressure measurements with an upper-arm cuff are often difficult to perform. The alternative method, invasive blood pressure monitoring, can be difficult to place and is associated with risks. A wrist-mounted blood pressure-monitoring device, the Vasotrac, provides accurate blood pressure measurements in lean patients. Even in the obese, wrist morphology remains relatively unchanged. We thus assessed the degree to which blood pressure measurements with the Vasotrac on the wrist and cuff measurements agree with invasive arterial blood pressure monitoring. We evaluated 22 morbidly obese patients undergoing bariatric surgery lasting 3.8+/-1.1 h. Intraoperative blood pressure was simultaneously measured using the Vasotrac mounted on one wrist; an arterial catheter was inserted in the opposite radial artery, and an oscillometric cuff was positioned on the upper arm. Preoperative patient comfort was evaluated on a scale from 1 to 10, with 10 being most uncomfortable, just after the first oscillometric cuff inflation. Values from the Vasotrac and arterial catheter were recorded at 5-s intervals. Bias, precision, and clinically acceptable agreement were calculated between the two continuous monitoring devices and between the arterial catheter and the cuff measurements, with the arterial catheter providing the reference value. The patients' age was 44.3+/-9.5 years (mean+/-SD), body mass index was 66.7+/-13.8 kg/m2, and arm circumference was 48.6+/-7.5 cm. Patients found the Vasotrac more comfortable than the oscillometric device [1.7+/-1.8 vs 5.3+/-0.5 (P=0.009)]. A total of 40,411 pairs of values from the Vasotrac and arterial catheter were recorded. Lin's concordance correlation coefficient (95% CI) for mean arterial blood pressure measured between the arterial line and the Vasotrac was 0.74 (0.67, 0.82). The bias (mean error) was -0.25 mmHg; however, the Bland-Altman limits where 95% of individual pressure differences are

  2. Uncalibrated pulse power analysis fails to reliably measure cardiac output in patients undergoing coronary artery bypass surgery.

    Science.gov (United States)

    Broch, Ole; Renner, Jochen; Höcker, Jan; Gruenewald, Matthias; Meybohm, Patrick; Schöttler, Jan; Steinfath, Markus; Bein, Berthold

    2011-01-01

    Uncalibrated arterial pulse power analysis has been recently introduced for continuous monitoring of cardiac index (CI). The aim of the present study was to compare the accuracy of arterial pulse power analysis with intermittent transpulmonary thermodilution (TPTD) before and after cardiopulmonary bypass (CPB). Forty-two patients scheduled for elective coronary surgery were studied after induction of anaesthesia, before and after CPB respectively. Each patient was monitored with the pulse contour cardiac output (PiCCO) system, a central venous line and the recently introduced LiDCO monitoring system. Haemodynamic variables included measurement of CI derived by transpulmonary thermodilution (CITPTD) or CI derived by pulse power analysis (CIPP), before and after calibration (CIPPnon-cal., CIPPcal.). Percentage changes of CI (ΔCITPTD, ΔCIPPnon-cal./PPcal.) were calculated to analyse directional changes. Before CPB there was no significant correlation between CIPPnon-cal. and CITPTD (r2 = 0.04, P = 0.08) with a percentage error (PE) of 86%. Higher mean arterial pressure (MAP) values were significantly correlated with higher CIPPnon-cal. (r2 = 0.26, P < 0.0001). After CPB, CIPPcal. revealed a significant correlation compared with CITPTD (r2 = 0.77, P < 0.0001) with PE of 28%. Changes in CIPPcal. (ΔCIPPcal.) showed a correlation with changes in CITPTD (ΔCITPTD) only after CPB (r2 = 0.52, P = 0.005). Uncalibrated pulse power analysis was significantly influenced by MAP and was not able to reliably measure CI compared with TPTD. Calibration improved accuracy, but pulse power analysis was still not consistently interchangeable with TPTD. Only calibrated pulse power analysis was able to reliably track haemodynamic changes and trends.

  3. Diffusion measurement of intraplaque hemorrhage and intramural hematoma using diffusion weighted MRI at 3T in cervical artery

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Bin [The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi (China); Yang, Li [Fudan University, Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Shanghai (China); Wang, Guangbin; Shi, Honglu; Wang, Shanshan; Li, Huihua [Shandong University, Shandong Medical Imaging Research Institute, Jinan, Shandong (China); Chen, Weibo; Chan, Queenie [Philips Healthcare, Shanghai (China)

    2016-10-15

    To assess the difference between carotid haemorrhagic plaque and non-haemorrhagic plaque by using diffusion-weighted imaging (DWI) and to evaluate carotid intraplaque haemorrhage (IPH) and intramural hematoma (IMH) of cervical artery dissection with apparent diffusion coefficient (ADC) measurement. Fifty-one symptomatic patients underwent 3.0-T carotid MR imaging, including conventional sequences, three-dimensional (3D) magnetization-prepared rapid acquisition gradient-echo (MPRAGE) sequence, and DWI. Thirty-nine patients with carotid plaque and eight patients with IMH of cervical artery dissection were finally included. The groups of hemorrhagic plaque, non-hemorrhagic plaque and IMH were divided according to 3D MPRAGE sequence. ADC values of different groups were measured, and t tests were performed. The mean ADC values of hemorrhagic plaques, non-hemorrhagic plaque and IMH were (1.284 ± 0.327) x 10{sup -3}mm{sup 2}/s, (1.766 ± 0.477) x 10{sup -3}mm{sup 2}/s, and (0.563 ± 0.119) x 10{sup -3}mm{sup 2}/s, respectively. The mean ADC values of hemorrhagic and non-hemorrhagic regions in the hemorrhagic plaque group were (0.985 ± 0.376) x 10{sup -3}mm{sup 2}/s and (1.480 ± 0.465) x 10{sup -3}mm{sup 2}/s, respectively. The differences between the hemorrhagic plaque and non-hemorrhagic plaque, hemorrhagic region and non-hemorrhagic region in hemorrhagic plaque, and the hemorrhagic region in the hemorrhagic plaque and IMH of artery dissection were significant (P < 0.05). DWI may be a useful complement to conventional MR imaging for identifying haemorrhage of carotid plaques and differentiate IMHs from IPH. (orig.)

  4. Arterial supply to the thyroid gland and the relationship between the recurrent laryngeal nerve and the inferior thyroid artery in human fetal cadavers.

    Science.gov (United States)

    Ozgüner, G; Sulak, O

    2014-11-01

    The aim of this study was to identify the arterial supply to the thyroid gland and the relationship between the inferior thyroid artery (ITA) and the recurrent laryngeal nerve (RLN) in fetal cadavers using anatomical dissection. The anterior necks of 200 fetuses were dissected. The origins of the superior thyroid artery (STA) and the ITA and location of the ITA in relation to the entrance of the thyroid lobe were examined. The relationship between the ITA and the RLN was determined. The origins of the STA were classified as: external carotid artery, common carotid artery (CCA), and the thyrolingual trunk. The origins of the ITA were the thyrocervical trunk and the CCA. The ITA was absent on the left side in two cases. The relationship of the RLN to the ITA fell into seven different types. Type 1: the RLN lay posterior to the artery; right (42.5%), left (65%). Type 2: the RLN lay anterior to the artery; right (40.5%), left (22.5%). Type 3: the RLN lay parallel to the artery; right (11.5%), left (7%). Type 4: the RLN lay between the two branches of the artery; right (1%), left (3.5%). Type 5: The extralaryngeal branch of the RLN was detected before it crossed the ITA; right (4.5%), left (0%). Type 6: the ITA lay between the two branches of the RLN; right (0%), left (0.5%). Type 7: the branches of the RLN lay among the branches of the ITA; right (0%), left (0.5%). The results from this study would be useful in future thyroid surgeries. © 2014 Wiley Periodicals, Inc.

  5. Pollutant particles enhanced H2O2 production from NAD(P)H oxidase and mitochondria in human pulmonary artery endothelial cells.

    Science.gov (United States)

    Li, Zhuowei; Hyseni, Xhevahire; Carter, Jacqueline D; Soukup, Joleen M; Dailey, Lisa A; Huang, Yuh-Chin T

    2006-08-01

    Particulate matter (PM) induces oxidative stress and cardiovascular adverse health effects, but the mechanistic link between the two is unclear. We hypothesized that PM enhanced oxidative stress in vascular endothelial cells and investigated the enzymatic sources of reactive oxygen species and their effects on mitogen-activated protein kinase (MAPK) activation and vasoconstriction. We measured the production of extracellular H2O2, activation of extracellular signal-regulated kinases1/2 (ERK1/2) and p38 MAPKs in human pulmonary artery endothelial cells (HPAEC) treated with urban particles (UP; SRM1648), and assessed the effects of H2O2 on vasoconstriction in pulmonary artery ring and isolated perfused lung. Within minutes after UP treatment, HPAEC increased H2O2 production that could be inhibited by diphenyleneiodonium (DPI), apocynin (APO), and sodium azide (NaN3). The water-soluble fraction of UP as well as its two transition metal components, Cu and V, also stimulated H2O2 production. NaN3 inhibited H2O2 production stimulated by Cu and V, whereas DPI and APO inhibited only Cu-stimulated H2O2 production. Inhibitors of other H2O2-producing enzymes, including Nomega-methyl-L-argnine, indomethacin, allopurinol, cimetidine, rotenone, and antimycin, had no effects. DPI but not NaN3 attenuated UP-induced pulmonary vasoconstriction and phosphorylation of ERK1/2 and p38 MAPKs. Knockdown of p47phox gene expression by small interfering RNA attenuated UP-induced H2O2 production and phosphorylation of ERK1/2 and p38 MAPKs. Intravascular administration of H2O2 generated by glucose oxidase increased pulmonary artery pressure. We conclude that UP induce oxidative stress in vascular endothelial cells by activating NAD(P)H oxidase and the mitochondria. The endothelial oxidative stress may be an important mechanism for PM-induced acute cardiovascular health effects.

  6. Long-lasting physiological antagonism of calcitonin gene-related peptide towards endothelin-1 in rat mesenteric arteries and human coronary arteries

    DEFF Research Database (Denmark)

    Labruijere, Sieneke; Compeer, Matthijs G; van den Bogaerdt, Antoon J

    2013-01-01

    Endothelin-1 causes long-lasting contraction via endothelin type A receptor (ETAR) in isolated rat mesenteric arteries (RMA) that cannot be readily terminated by removing the agonist, or by adding the ETAR antagonist BQ123 or the NO donor sodium nitroprusside. It could be terminated by adding......-lasting non-selective arterial smooth muscle relaxation that may add to the neuropeptide being a physiological antagonist of arterial effects of ET-1. Long-lasting, washout-resistant ET-1/ETAR interaction does not occur in HCMAs....

  7. MEASURING CHOLINESTERASE ACTIVITY IN HUMAN SALIVA.

    Science.gov (United States)

    To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 differe...

  8. First-In-Human Dual-Modality OCT and Near-Infrared Autofluorescence Imaging of Coronary Artery Disease

    Science.gov (United States)

    Ughi, Giovanni J.; Wang, Hao; Gerbaud, Edouard; Gardecki, Joseph A.; Fard, Ali M.; Hamidi, Ehsan; Vacas-Jacques, Paulino; Rosenberg, Mireille; Jaffer, Farouc A.; Tearney, Guillermo J.

    2016-01-01

    OBJECTIVES We present the first clinical imaging of human coronary arteries in vivo using a multimodality OCT and near-infrared autofluorescence (NIRAF) intravascular imaging system and catheter. BACKGROUND While intravascular OCT is capable of providing microstructural images of coronary atherosclerotic lesions, it is limited in its capability to ascertain compositional/molecular features of plaque, including the definitive presence of a necrotic core. A recent study in cadaver coronary plaque has shown that endogenous NIRAF is elevated in necrotic core lesions. The combination of these two technologies in one device may therefore provide synergistic data to aid in the diagnosis of coronary pathology in vivo. METHODS We developed a dual-modality intravascular imaging system and 2.6-F catheter that can simultaneously acquire OCT and NIRAF data from the same location on the artery wall. This technology was utilized to obtain volumetric OCT-NIRAF images from 12 patients with coronary artery disease undergoing PCI. Images were acquired during a brief, non-occlusive 3-4 ml/sec contrast purge at a speed of 100 frames per second and a pullback rate of 20 or 40 mm/sec. OCT-NIRAF data were analyzed to determine the distribution of the NIRAF signal with respect to OCT-delineated plaque morphological features. RESULTS High quality intracoronary OCT and NIRAF image data (>50 mm pullback length) were successfully acquired without complication in all patients (17 coronary arteries). The maximum NIRAF signal intensity of each plaque was compared to OCT-defined type, showing a statistically significant difference between plaque types (one-way ANOVA, pOCT fibroatheroma, plaque rupture, and fibroatheroma associated with in-stent restenosis. CONCLUSIONS This first-in-human OCT-NIRAF study demonstrates that dual-modality microstructural and fluorescence intracoronary imaging can be safely and effectively conducted in human patients. Our findings show that NIRAF is associated with a

  9. Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells.

    Science.gov (United States)

    Chuang, Christine Y; Degendorfer, Georg; Hammer, Astrid; Whitelock, John M; Malle, Ernst; Davies, Michael J

    2014-04-15

    ECM (extracellular matrix) materials, such as laminin, perlecan, type IV collagen and fibronectin, play a key role in determining the structure of the arterial wall and the properties of cells that interact with the ECM. The aim of the present study was to investigate the effect of peroxynitrous acid, an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by HCAECs (human coronary artery endothelial cells) in vitro and in vivo. We show that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations >1 μM results in a loss of antibody recognition of perlecan, collagen IV, and cell-binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real-time PCR showed up-regulation of inflammation-associated genes, including MMP7 (matrix metalloproteinase 7) and MMP13, as well as down-regulation of the laminin α2 chain, in HCAECs cultured on peroxynitrous acid-treated matrix compared with native matrix. Immunohistochemical studies provided evidence of co-localization of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II-III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. The results of the present study suggest a mechanism through which peroxynitrous acid modifies endothelial cell-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to ECM and particularly perlecan and laminin may be important in inducing cellular dysfunction and contribute to atherogenesis.

  10. Noninvasive measurement of arterial oxyhemoglobin saturation with a heated and a non-heated skin reflectance pulse oximeter sensor.

    Science.gov (United States)

    Mendelson, Y; Yocum, B L

    1991-01-01

    The feasibility of measuring arterial oxyhemoglobin saturation (SaO2) noninvasively using a skin reflectance pulse oximeter sensor attached to the scalp, neck, and thigh regions of anesthetized swine was investigated. The optical reflectance sensor used consisted of a pair of red and infrared light-emitting diodes and a concentric array of six identical photodiodes. Two prototype sensor assemblies were evaluated: one assembly housed only the optical sensor, whereas the other also included a miniature heater. Measurements made from the scalp and neck regions were obtained with the non-heated skin reflectance sensor, and measurements from the thigh were made with the heated prototype. Each sensor was interfaced to a commercial transmittance pulse oximeter adapted to perform as a reflectance pulse oximeter. SaO2 values obtained by the reflectance pulse oximeters (SpO2(r) were compared simultaneously with SaO2 values obtained from arterial blood samples and analyzed in vitro with a CO-oximeter. The equations for the best-fitted linear regression lines describing the relationships between SpO2(r) and SaO2 values in the range between 30 and 100% were: SpO2(r) = 10.7 + 0.90 (SaO2), n = 321, r = 0.97; SpO2(r) = 16.72 + 0.82 (SaO2), n = 217, r = 0.95; and SpO2(r) = 20.21 + 0.77 (SaO2), n = 37, r = 0.97 for the neck, thigh, and scalp measurements, respectively. The regression analysis revealed significant correlation and a relatively small standard error of estimate (SEE = 4.05% for the neck, 4.79% for the thigh, and 3.50% for the scalp measurements). This study demonstrated the feasibility of measuring SaO2 noninvasively over a wide range of values utilizing the principle of reflectance pulse oximetry.

  11. Long-term use of first-line highly active antiretroviral therapy is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients

    Directory of Open Access Journals (Sweden)

    Haohui Zhu

    2014-09-01

    Conclusion: The first-line highly active antiretroviral therapy currently used in China is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients with good highly active antiretroviral therapy compliance. Human immunodeficiency virus may play a role in the development of atherosclerosis.

  12. GLP-1 inhibits VEGFA-mediated signaling in isolated human endothelial cells and VEGFA-induced dilation of rat mesenteric arteries

    DEFF Research Database (Denmark)

    Rotbøl, Cecilie Egholm; Khammy, Makhala Michell; Dalsgaard, Thomas

    2016-01-01

    to PLCγ activation, Src, and endothelial NOS (eNOS) signaling, thereby controlling endothelial vessel tone. By using RT-PCR analysis, we found mRNA for the GLP-1 receptor (GLP-1R) in human dermal microvascular endothelial cells (HDMEC), human retinal microvascular endothelial cells, and rat arteries...

  13. The Adoption of Outcome Measurement in Human Service Nonprofits

    Directory of Open Access Journals (Sweden)

    Chongmyoung Lee

    2017-07-01

    Full Text Available Performance measurement has received increasing attention in the nonprofit sector. While the current scholarship has emphasized the balanced use of performance measures, only a limited number of nonprofits have adopted outcome measurement. In this study, we investigate what factors explain a variation in the adoption of outcome measurement based on survey data from 263 human service nonprofits. The results of logistic regression find that human service nonprofits are more likely to adopt outcome measures when they are more risk-taking, influenced by institutional pressures, and have higher human resource and political capacities.

  14. The normal growth of the common iliac arteries in human fetuses - an anatomical, digital and statistical study.

    Science.gov (United States)

    Szpinda, Michał; Szpinda, Anna; Woźniak, Alina; Daroszewski, Marcin; Mila-Kierzenkowska, Celestyna

    2012-03-01

    The present study was carried out to compile normative data for dimensions of the common iliac arteries at varying gestational ages. We used anatomical dissection, digital-image analysis (system of Leica QWin Pro 16) and statistical analysis (Student T test, one-way ANOVA, post-hoc RIR Tukey test, and regression analysis) to examine the increase in length (mm), proximal external diameter (mm), and volume (mm³) of the common iliac arteries in 124 (60 males, 64 females) spontaneously aborted human fetuses aged 15-34 weeks. Neither sex nor right-left significant differences were found (P>0.05). The length ranged from 4.76 ± 1.05 to 15.38 ± 1.60 mm on the right, and from 4.92 ± 1.33 to 14.91 ± 1.25 mm on the left, according to the linear functions y=-3.598+0.585 × Age ± 1.522 (R²=0.83) and y=-3.107+0.554 × Age ± 1.444 (R²=0.83). The proximal external diameter increased from 0.66 ± 0.19 to 2.30 ± 0.42 mm on the right, and from 0.66 ± 0.14 to 2.16 ± 0.42 mm on the left, according to the quadratic models y=1.392-0.110 × Age + 0.004 × Age² ± 0.285 (R²=0.77) and y=1.283-0.099 × Age + 0.004 × Age² ± 0.238 (R²=0.81). The volumes were increasing from 1.93 ± 1.74 to 66.95 ± 29.31 mm³ on the right, and from 1.91 ± 1.65 to 56.86 ± 25.17 mm³ on the left, given by the quadratic functions: y=99.69-10.60 × Age+0.28 7 × Age² ± 14.40 (R²=0.67) and y=82.62-8.86 × Age + 0.242 × Age² ± 11.60 (R²=0.71). The common iliac arteries grow linearly in length, and parabolically in both diameter and volume. The right common iliac artery constitutes a predominant vessel in relation to its length, external diameter and volume. The morphometric data on the common iliac arteries may serve as a useful reference in the prenatal diagnosis and monitoring of congenital aorto-iliac abnormalities.

  15. An investigation of the origin, location and variations of the renal arteries in human fetuses and their clinical relevance.

    Science.gov (United States)

    Ciçekcibaşi, Aynur Emine; Ziylan, Taner; Salbacak, Ahmet; Seker, Muzaffer; Büyükmumcu, Mustafa; Tuncer, Işik

    2005-09-01

    We investigated the origin, localizations and anatomic variations of the renal artery (RA) in human fetuses with the aim of determining the distribution of these variations according to lateralization and gender. In total, 90 fetuses of spontaneous abortion (45 males, 45 females) with no congenital malformations were included to the study. The abdominal aorta and its branches were dissected after latex solution colored with red ink had been injected into the vessels from the thoracic aorta. In all, 180 RA dissections were performed bilaterally in 90 cases and the anatomic variations were photographed. Right and left RAs were found to originate from the following levels according to the columna vertebralis, respectively: 3.8% and 1.9% lower T12, 67.3% and 25.0% upper L1, 9.6% and 28.8% mid L1, 15.3% and 40.3 lower L1, 3.8% and 3.8% upper 1/3 part of L2 vertebra. The right RA originated from the lateral part and anterolateral wall of the abdominal aorta in 73.0% and 26.9% of cases while the lateral and anterolateral wall origin percentages of left RA were 90.3% and 9.6%, respectively. The origin site of the right RA from the abdominal aorta was superior to, at the same level with, and inferior to that of the left RA in 53.8%, 34.6% and 11.5% of the cases, respectively. There were no variations in 75% of the cases whereas the remaining 25% had several variation patterns. The presented morphological results are as follows: A single hilar artery in 75% of the cases, double hilar arteries in 11.1%, an inferior polar artery in 10.5%, and a superior polar artery in 3.3% of specimens studied. Anatomical variations were observed more frequently among male fetuses and on the right side. Knowledge of RA variations is important for surgeons in performing many procedures and may help to avoid clinical complications, especially, during radiological examination and/or surgical approaches in the abdominal region.

  16. Effects of Antiretroviral Therapy on Immune Function and Arterial Inflammation in Treatment-Naive Patients With Human Immunodeficiency Virus Infection.

    Science.gov (United States)

    Zanni, Markella V; Toribio, Mabel; Robbins, Gregory K; Burdo, Tricia H; Lu, Michael T; Ishai, Amorina E; Feldpausch, Meghan N; Martin, Amanda; Melbourne, Kathy; Triant, Virginia A; Suchindran, Sujit; Lee, Hang; Hoffmann, Udo; Williams, Kenneth C; Tawakol, Ahmed; Grinspoon, Steven K

    2016-07-01

    Individuals with human immunodeficiency virus (HIV) infection receiving combined antiretroviral therapy (ART) have an increased risk of myocardial infarction. Effects of ART on arterial inflammation among treatment-naive individuals with HIV are unknown. To determine the effects of newly initiated ART on arterial inflammation and other immune/inflammatory indices in ART-naive patients with HIV infection. Twelve treatment-naive HIV-infected individuals underwent fludeoxyglucose F 18 ([18F]-FDG) positron emission tomographic scanning for assessment of arterial inflammation, coronary computed tomographic angiography for assessment of subclinical atherosclerosis, and systemic immune and metabolic phenotyping before and 6 months after the initiation of therapy with elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (combined ART). Systemic immune and metabolic factors were also assessed in 12 prospectively recruited individuals without HIV serving as controls. The study began July 24, 2012, and was completed May 7, 2015. Combined ART in the HIV-infected cohort. The primary outcome was change in aortic target-background ratio (TBR) on [18F]-FDG-PET with combined ART in the HIV-infected group. For the 12 participants with HIV infection (mean (SD) age, 35 [11] years), combined ART suppressed viral load (mean [SD] log viral load, from 4.3 [0.6] to 1.3 [0] copies/mL; P response to combined ART (mean [SD], 1.9 [0.2]; median [IQR], 2.0 [1.8-2.1] at baseline to 2.2 [0.4]; 2.1 [1.9-2.6], respectively, at study end; P = .04 by 2-way test, P = .98 for test of decrease by 1-way test). Changes in aortic TBR during combined ART were significantly associated with changes in lipoprotein-associated phospholipase A2 (n = 10; r = 0.67; P = .03). Coronary plaque increased among 3 participants with HIV infection with baseline plaque and developed de novo in 1 participant during combined ART. Newly initiated combined ART in treatment

  17. Measuring Multimodal Synchrony for Human-Computer Interaction

    NARCIS (Netherlands)

    England, D.; Reidsma, Dennis; Sheridan, J.; Nijholt, Antinus; Crane, B.; Tschacher, Wolfgang; Ramseyer, Fabian

    Nonverbal synchrony is an important element in human-human interaction. It can also play various roles in human-computer interaction. This paper surveys some of these uses, and presents a quantitative method for measuring the level of nonverbal synchrony in an interaction.

  18. Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Bruce, Christopher

    2008-01-01

    Blood pressure at the ankle level is a reliable indicator of peripheral arterial disease (PAD) and the ankle brachial index (ABI) is a useful non-invasive screening tool for the early detection of atherosclerosis. In the first part of the study, systolic blood pressures obtained by oscillometry...... and plethysmography were compared in 80 subjects referred for possible vascular disease. In the second part of the study, 31 general practitioners enrolled 1258 consecutive patients aged more than 60 years. ABI was estimated by oscillometry. Patients with an ABI lower than 0.9 were referred to the local hospital......, the oscillometry showed a positive predictive value of 47%. The presence of PAD was significantly correlated to exercise related leg pain, a diagnosis of hypertension and smoking, whereas no correlation could be found with a diagnosis of heart disease, stroke, or with the presence of diabetes. The prevalence...

  19. Non-pharmacological measures in preterm newborns submitted to arterial puncture

    Directory of Open Access Journals (Sweden)

    Gleicia Martins de Melo

    Full Text Available ABSTRACT Objective: to assess pain in preterm newborns and to compare the neonatal and therapeutic variables with the total scores of the Neonatal Facial Coding System of preterm newborns submitted to arterial puncture exposed to music and 25% oral glucose. Method: a comparative study with 48 recordings of preterm newborns - Group 1, music (26; Group 2, glucose 25% (22 - individually analyzed by three trained nurses, after Kappa of at least 80%. Results: the variables and the pain scores of the groups did not present statistical significance (p < 0.05 according to the Neonatal Facial Coding System. 80.8% of the preterm infants in Group 1 had a higher quantitative score ≥ 3 in the neonatal variables (gender, type of delivery, and therapeutic variables (type of oxygen therapy, place of hospitalization, type of puncture. Conclusion: There was no difference when comparing the music and glucose 25% groups and the variables studied.

  20. Repeatability of the measurement of augmentation index in the clinical assessment of arterial stiffness using radial applanation tonometry.

    Science.gov (United States)

    Crilly, M; Coch, C; Clark, H; Bruce, M; Williams, D

    2007-01-01

    Aortic augmentation index (AIx) measured using applanation tonometry is a non-invasive indicator of arterial stiffness. The objective of this study was to assess its repeatability when used by nurses with limited experience of the technique. Blood pressure/augmentation index (BP/AIx) was measured 4 times in 20 consecutive ambulant patients (16 male) after they rested supine for 15 min. Two nurses independently and alternately measured BP/AIx using the same equipment (Omron HEM-757; SphygmoCor with Millar hand-held tonometer). Nurses were blinded to patient medical records and their colleague's AIx/BP. 'Within' and 'between' observer differences were assessed using intra-class correlation coefficients (rI) and 95 % limits of agreement (95 % LoA) derived from Bland-Altman plots. Mean age was 56 (mean BP 136/79; mean pulse 64). Mean AIx was 24.1 (range 2.8 to 41.0). Both 'between' and 'within' observer repeatability was very high, with intra-class correlation coefficients ranging from 0.92 to 0.98. Mean AIx readings 'between' observers differed by only 0.68 (95 % CI -0.24 to 1.59) with a high rI (0.98; 95 % CI 0.95 to 0.99) and a narrow 95 % LoA (-3.22 to 4.57). The 95 % LoA for 'within' observer repeatability was -6.75 to 7.95. Differences in AIx measurement did not vary over time or with increasing levels of AIx. Even when undertaken by relatively inexperienced operators, both 'within' and 'between' observer repeatability of AIx measurement is very high. Such non-invasive assessment of arterial stiffness has the potential to be included in the clinical assessment of ambulant patients.

  1. International Human Trafficking: Measuring Clandestinity by the Structural Equation Approach

    Directory of Open Access Journals (Sweden)

    Alexandra Rudolph

    2017-06-01

    Full Text Available Worldwide human trafficking is the third most often registered international criminal activity, ranked only after drug and weapon trafficking. This article focusses on three questions: 1 How can human trafficking be measured? 2 What are the causes and indicators of this criminal activity which exploits individuals? 3 Which countries observe a high (or low level of human trafficking inflow? We apply the Multiple Indicators Multiple Causes structural equation model to measure human trafficking inflows in a way which includes all potential causes and indicators in one estimation model. The human trafficking measurement focusses on international human trafficking. We use freely available existing data and thus generate an objective measure of the extent of trafficking. Countries are ranked according to their potential to be a destination country based on various characteristics of the trafficking process.

  2. Evaluation of Human Prehension Using Grasp Quality Measures

    Directory of Open Access Journals (Sweden)

    Beatriz León

    2012-10-01

    Full Text Available One of the main features of the human hand is its grasping ability. Robot grasping has been studied for years and different quality measures have been proposed to evaluate the stability and manipulability of grasps. Although the human hand is obviously more complex than robot hands, the methods used in robotics might be adopted to study the human grasp. The purpose of this work is to propose a set of measures that allow the evaluation of different aspects of the human grasp. The most common robotic grasp quality measures have been adapted to the evaluation of the human hand and a new quality measure – the fatigue index – is proposed in order to incorporate the biomechanical aspect into the evaluation. The minimum set of indices that allows the evaluation of the different aspects of the grasp is obtained from the analysis of a human prehension experiment.

  3. Measurement of human potential in organizations

    Directory of Open Access Journals (Sweden)

    Rosa María Fuchs Ángeles

    2015-09-01

    Full Text Available Companies around the world are concerned about talent management in their organizations. The concern is to retain talented employees and this may not be possible if they are not properly identified. Performance and potential evaluations become then important. Performance evaluations qualify the historical record of the employee, so their measurement is provided. However, measuring the potential performance assesses potential future charges, therefore it is not a simple task. In this paper, characteristics evaluated in potential employees and tools that are commonly used are presented. Also, the case of four companies operating in Peru is shown.

  4. Magnetic characterization of human blood in the atherosclerotic process in coronary arteries

    Energy Technology Data Exchange (ETDEWEB)

    Janus, B. [Institute of Environmental Engineering PAS, ul. SkLodowskiej-Curie 34, 41-819 Zabrze (Poland); Bucko, M.S., E-mail: michal.bucko@helsinki.f [Institute of Environmental Engineering PAS, ul. SkLodowskiej-Curie 34, 41-819 Zabrze (Poland); Division of Geophysics and Astronomy, P.O. Box 64, Gustaf Haellstroemin katu 2, 00014 University of Helsinki (Finland); Chrobak, A. [University of Silesia, Institute of Physics, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Wasilewski, J. [3rd Chair and Clinical Ward of Cardiology, Medical University of Silesia, Katowice, Silesian Centre of Heart Diseases, ul. Szpitalna 2, 41-800 Zabrze (Poland); Zych, M. [Department of Pharmacognosy and Phytochemistry, Medical University of Silesia, ul. Jagiellonska 4, 41-200 Sosnowiec (Poland)

    2011-03-15

    In the last decades there has been an increasing interest in biomagnetism-a field of biophysics concerned with the magnetic properties of living organisms. Biomagnetism focuses on the measurement of magnetic properties of biological samples in the clinical environment. Progress in this field can provide new data for the understanding of the pathomechanism of atherosclerosis and support the diagnostic options for the evaluation and treatment of atherothrombotic complications. Lyophilized human blood samples from patients with atherosclerotic lesions (calcium scoring (CS) CS>0) and without atherosclerotic lesions (CS=0) were magnetically investigated. Magnetic measurements (performed in room and low temperature) indicated significant magnetic differences between these two groups of patients. Atherosclerotic blood samples are characterized by higher concentration of ferrimagnetic particles (magnetite and/or maghemite) and significant changes in the superparamagnetic behaviour. This research presents that magnetometry, in combination with medical research can lead to a better understanding of iron physiology in the atherosclerotic process. - Research Highlights: {yields}Blood samples are characterized by higher concentration of ferrimagnetic particles. {yields}Atherosclerotic blood samples consist of larger superparamagnetic clusters. {yields}Superparamagnetic particles in pathological samples are considered to be magnetite. {yields}The formation of ferrimagnetic particles is favoured in the atherosclerotic patients. {yields}Magnetite may play a role in the progression of atherosclerosis.

  5. A new approach for measuring human resource accounting

    OpenAIRE

    Esmat Bavali; Iman Jokar

    2014-01-01

    Significance of identifying human resource competency in organizations and the necessity for valuating human resource in accounting persuade many researchers to design a conceptual model for measuring human resource accounting. This study, first, examines dimensions of various valuation models of human resource and then they are compared with Goleman individual and social competency indicators. Next, individual, organizational and social competency indicators are designed through developing G...

  6. Transcriptional profiling of human liver identifies sex-biased genes associated with polygenic dyslipidemia and coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Yijing Zhang

    Full Text Available Sex-differences in human liver gene expression were characterized on a genome-wide scale using a large liver sample collection, allowing for detection of small expression differences with high statistical power. 1,249 sex-biased genes were identified, 70% showing higher expression in females. Chromosomal bias was apparent, with female-biased genes enriched on chrX and male-biased genes enriched on chrY and chr19, where 11 male-biased zinc-finger KRAB-repressor domain genes are distributed in six clusters. Top biological functions and diseases significantly enriched in sex-biased genes include transcription, chromatin organization and modification, sexual reproduction, lipid metabolism and cardiovascular disease. Notably, sex-biased genes are enriched at loci associated with polygenic dyslipidemia and coronary artery disease in genome-wide association studies. Moreover, of the 8 sex-biased genes at these loci, 4 have been directly linked to monogenic disorders of lipid metabolism and show an expression profile in females (elevated expression of ABCA1, APOA5 and LDLR; reduced expression of LIPC that is consistent with the lower female risk of coronary artery disease. Female-biased expression was also observed for CYP7A1, which is activated by drugs used to treat hypercholesterolemia. Several sex-biased drug-metabolizing enzyme genes were identified, including members of the CYP, UGT, GPX and ALDH families. Half of 879 mouse orthologs, including many genes of lipid metabolism and homeostasis, show growth hormone-regulated sex-biased expression in mouse liver, suggesting growth hormone might play a similar regulatory role in human liver. Finally, the evolutionary rate of protein coding regions for human-mouse orthologs, revealed by dN/dS ratio, is significantly higher for genes showing the same sex-bias in both species than for non-sex-biased genes. These findings establish that human hepatic sex differences are widespread and affect diverse cell

  7. Oxidized Phospholipids on Lipoprotein(a) Elicit Arterial Wall Inflammation and an Inflammatory Monocyte Response in Humans.

    Science.gov (United States)

    van der Valk, Fleur M; Bekkering, Siroon; Kroon, Jeffrey; Yeang, Calvin; Van den Bossche, Jan; van Buul, Jaap D; Ravandi, Amir; Nederveen, Aart J; Verberne, Hein J; Scipione, Corey; Nieuwdorp, Max; Joosten, Leo A B; Netea, Mihai G; Koschinsky, Marlys L; Witztum, Joseph L; Tsimikas, Sotirios; Riksen, Niels P; Stroes, Erik S G

    2016-08-23

    Elevated lipoprotein(a) [Lp(a)] is a prevalent, independent cardiovascular risk factor, but the underlying mechanisms responsible for its pathogenicity are poorly defined. Because Lp(a) is the prominent carrier of proinflammatory oxidized phospholipids (OxPLs), part of its atherothrombosis might be mediated through this pathway. In vivo imaging techniques including magnetic resonance imaging, (18)F-fluorodeoxyglucose uptake positron emission tomography/computed tomography and single-photon emission computed tomography/computed tomography were used to measure subsequently atherosclerotic burden, arterial wall inflammation, and monocyte trafficking to the arterial wall. Ex vivo analysis of monocytes was performed with fluorescence-activated cell sorter analysis, inflammatory stimulation assays, and transendothelial migration assays. In vitro studies of the pathophysiology of Lp(a) on monocytes were performed with an in vitro model for trained immunity. We show that subjects with elevated Lp(a) (108 mg/dL [50-195 mg/dL]; n=30) have increased arterial inflammation and enhanced peripheral blood mononuclear cells trafficking to the arterial wall compared with subjects with normal Lp(a) (7 mg/dL [2-28 mg/dL]; n=30). In addition, monocytes isolated from subjects with elevated Lp(a) remain in a long-lasting primed state, as evidenced by an increased capacity to transmigrate and produce proinflammatory cytokines on stimulation (n=15). In vitro studies show that Lp(a) contains OxPL and augments the proinflammatory response in monocytes derived from healthy control subjects (n=6). This effect was markedly attenuated by inactivating OxPL on Lp(a) or removing OxPL on apolipoprotein(a). These findings demonstrate that Lp(a) induces monocyte trafficking to the arterial wall and mediates proinflammatory responses through its OxPL content. These findings provide a novel mechanism by which Lp(a) mediates cardiovascular disease. URL: http://www.trialregister.nl. Unique identifier: NTR

  8. Peak velocity measurements in tortuous arteries with phase contrast magnetic resonance imaging: the effect of multidirectional velocity encoding.

    Science.gov (United States)

    Schubert, Tilman; Bieri, Oliver; Pansini, Michele; Stippich, Christoph; Santini, Francesco

    2014-04-01

    Blood flow velocity measurement with phase contrast magnetic resonance imaging (PC-MRI) is widely applied in clinical routine imaging. Usually, velocity and volumetric flow measurements are performed using unidirectional encoding of the through-plane velocity with a 2-dimensional (2D) acquisition. Single-slice acquisitions and measurements with unidirectional encoding, however, may lead to significant errors, especially in tortuous vessels, but might benefit from higher signal-to-noise ratios (SNRs). To evaluate the impact of volumetric acquisition and multidirectional velocity encoding, blood velocity measurements were performed at 3 locations in the distal internal carotid artery with a 3-dimensional, 3-directional time-resolved phase contrast (PC) sequence (4-dimensional [4D]) and a 2D acquisition with 3-directional (2D-3dir) and through-plane velocity encoding (2D-tp) derived from the same sequence. Twenty carotid arteries of 10 healthy volunteers (24-37 years) were evaluated. For each volunteer, 1 4D acquisition and 3 2D 3-directional PC measurements were placed according to a time-of-flight angiography. Unidirectionally encoded through-plane velocities were derived from the multidirectionally encoded 2D scan by discarding the in-plane components. Regions of interest were identified on the slab after postprocessing and visualization for the 4D data set as well as directly on the digital imaging and communications in medicine images for the 2D measurement. Blood flow velocity, volumetric flow, and SNRs were measured at carotid segments C4, C5, and C7 on both sides obtaining 20 values per vessel location. The quantities were tested for significant differences between each modality at all 3 locations with paired t tests. At the segments C5 and C7, the highest peak velocities (PVs) were measured with the 4D sequence, followed by 2D-3dir and 2D tp. The PV differences between the sequences were significant (P measured with 2D-tp. The mean PV value of the 4D sequence

  9. [Measurement of Rho-kinase in peripheral blood monocytes in patients with pulmonary arterial hypertension related to chronic obstructive pulmonary diseases].

    Science.gov (United States)

    Cai, Qian; Wu, Shangjie; Zhao, Xuefeng

    2012-05-01

    To determine effects of the RhoA/Rho kinase signaling pathway on patients with pulmonary arterial hypertension related to chronic obstructive pulmonary diseases by testing levels of Rho-associated coiled-coil containing protein kinase 1(ROCK1) in peripheral blood monocytes in healthy subjects, patients with chronic obstructive pulmonary diseases (COPD), and patients with pulmonary arterial hypertension related to COPD. Ten healthy subjects (Group A), 10 patients with COPD (Group B), and 10 patients with pulmonary arterial hypertension related to COPD (Group C) were enrolled, all of whom were hospitalized in the Third Hospital of Changsha between Dec. 2010 and Apr. 2011. Twenty milliliters of blood was collected from each subject. The peripheral blood mononuclear cells (PBMC) were separated by Percoll and, monocytes were incubated. Levels of ROCK1 in the three groups were measured by ELISA. The pulmonary function was measured by spirometric tests, and the pulmonary arterial systolic pressure (PASP) was detected by color Doppler echocardiogram. 1)The PASP in Group C was significantly higher than that of Groups A and B(P0.05). Rho kinase plays a key role in the pathogenesis of pulmonary arterial hypertension. The ROCK1 may be a marker of the severity of pulmonary arterial hypertension related to COPD.

  10. Associations of Objectively Measured Physical Activity and Sedentary Time With Arterial Stiffness in Pre-Pubertal Children.

    Science.gov (United States)

    Haapala, Eero A; Väistö, Juuso; Veijalainen, Aapo; Lintu, Niina; Wiklund, Petri; Westgate, Kate; Ekelund, Ulf; Lindi, Virpi; Brage, Soren; Lakka, Timo A

    2017-08-01

    To investigate the relationships of objectively measured physical activity (PA) and sedentary time (ST) to arterial stiffness in prepubertal children. Altogether 136 children (57 boys, 79 girls) aged 6-8-years participated in the study. Stiffness index (SI) was assessed by pulse contour analysis based on photoplethysmography. ST, light PA, moderate PA, and vigorous PA were assessed using combined acceleration and heart rate monitoring. We investigated the associations of ST (<1.5METs) and time spent in intensity level of PA above 2-7METs in min/d with SI using linear regression analysis. We studied the optimal duration and intensity of PA to identify children being in the highest quarter of SI using Receiver Operating Characteristics curves. Moderate PA, vigorous PA, and cumulative time spent in PA above 3 (β=-0.279, p = .002), 4 (β =-0.341, P<0.001), 5 (β =-0.349, P<0.001), 6 (β =-0.312, P<0.001), and 7 (β =-0.254, p = .005) METs were inversely associated with SI after adjustment for age, sex, and monitor wear time. The cutoffs for identifying children being in the highest quarter of SI <68 min/d for PA exceeding 5 METs and <26 min/d for PA exceeding 6 METs. Lower levels of PA exceeding 3-6 METs were related to higher arterial stiffness in children.

  11. Measuring Key Disparities in Human Development: The Gender Inequality Index

    OpenAIRE

    Amie Gaye; Jeni Klugman; Milorad Kovacevic; Sarah Twigg; Eduardo Zambrano

    2010-01-01

    Gender inequality remains a major barrier to human development. Girls and women have made major strides since 1990, but they have not yet gained gender equity. In this paper, we review ways to measure and monitor gender inequality, providing a critique of existing measures including the first global gender indices that were launched in the 1995 Human Development Report – the Gender-related Development Index and the Gender Empowerment Measure - and introduce a new index that is presented in th...

  12. Comparison of fractional flow reserve measurements using intracoronary adenosine versus intracoronary sodium nitroprusside infusions in moderately stenotic coronary artery lesions

    Energy Technology Data Exchange (ETDEWEB)

    Safi, Morteza; Namazi, Mohammad Hasan; Fooladi, Esfandiar; Vakili, Hossein; Parsa, Saeed Alipour; Khaheshi, Isa [Cardiovascular Research Center, Modarres hospital, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Abbasi, Mohammad Amin [Department of Internal Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Movahed, Mohammad Reza, E-mail: rmova@aol.com [CareMore, Arizona, Tucson, AZ (United States); University of Arizona, Sarver Heart Center, Tucson, AZ (United States)

    2016-10-15

    Introduction: The aim of this study was to investigate the efficacy and safety of intracoronary (IC) sodium nitroprusside infusion in comparison to IC adenosine for fractional flow reserve (FFR) measurement in moderately diseased coronary artery lesions for functional assessment. Methods: During a nine month period, a consecutive of 98 patients with suspected or known coronary artery disease with moderate stenosis found during angiography (40% to 70% stenosis), were enrolled in this study. Hyperemia was induced by bolus doses of IC adenosine followed by sodium nitroprusside for FFR measurement. Results: Both IC adenosine and IC sodium nitroprusside induced similar and significant reduction in FFR. There was no statistically difference in FFR values between adenosine vs sodium nitroprusside infusions (mean FFR 84.3 ± 6.3 vs 85.7 ± 6.2, p = 0.1) respectively. Furthermore, comparing different FFR cut-off points between the groups (FFR < 0.75, 0.75–0.8 and > 0.8) showed no significant differences (p value = 0.7). Conclusion: An IC bolus of sodium nitroprusside (0.6 μg/kg) infusion induces a similar degree of hyperemia to IC bolus of 100–300 μg of adenosine. Therefore, IC sodium nitroprusside could be considered as an alternative drug to adenosine for FFR measurement with lower side effect profile. - Highlights: • Intracoronary (IC) sodium nitroprusside was compared with IC adenosine for FFR test. • IC adenosine and IC sodium nitroprusside induced similar reduction in FFR. • Different FFR cut-off points between the groups showed no significant differences. • IC sodium nitroprusside could be considered as an alternative to adenosine for FFR.

  13. Study of Anthropometric Measurements of the Anterior Ethmoidal Artery using Three-dimensional Scanning on 300 Patients

    Science.gov (United States)

    Bortoli, Vinicius Tomadon; Martins, Rafael Ferri; Negri, Krystal Calmeto

    2017-01-01

    Introduction The anterior ethmoidal artery (AEA) is one of the main arteries that supply both the nasal mucosa and the ethmoid sinuses. The AEA shows variability regarding its distance from adjacent structures. Several studies have developed techniques to identify the AEA. Objective This study aimed to compare the measurements from the AEA to the ethmoid bulla and to the frontal beak by using computed tomography of the face, while identifying their intraindividual and interindividual variations. Methods We analyzed 300 CT scans of the face performed at the CT scan Center at Hospital. The average age of subjects was 36 ± 15.1 years (range 4–84). Results We found that the average distance from the AEA to the ethmoid bulla was 17.2 ± 1.8 mm and the distance from the AEA to the frontal beak was 15.1 ± 2.2 mm. Regarding the average distance from the AEA to the frontal beak (AEA-frontal beak), there was a difference between the right and left sides, with the former being 0.4 mm higher on average than the latter. Among the age groups, there was a significant difference of distances between the AEA and the ethmoid bulla (AEA-ethmoid bulla), which were shorter in the ≤ 12 years group. There was a positive and significant correlation between both measurements analyzed, with low values (high) of AEA-ethmoid bulla distance corresponding to low values (high) of AEA-frontal beak distance. Conclusion The measurements obtained adds anatomical knowledge that can serve as a parameter in frontal and ethmoid sinus surgery. PMID:28382116

  14. A new approach for measuring human resource accounting

    Directory of Open Access Journals (Sweden)

    Esmat Bavali

    2014-06-01

    Full Text Available Significance of identifying human resource competency in organizations and the necessity for valuating human resource in accounting persuade many researchers to design a conceptual model for measuring human resource accounting. This study, first, examines dimensions of various valuation models of human resource and then they are compared with Goleman individual and social competency indicators. Next, individual, organizational and social competency indicators are designed through developing Goleman model. Finally, Analytical Hierarchy Process (AHP and experts’ ideas in human resource accounting in superior universities of the world are used to classify the indicators; and the conceptual model of measuring human resource accounting is designed based on guidelines of management and human capital development vice-presidency and inspiring effort rate of return method.

  15. Vasodilatory effect of L-arginine on isolated rabbit and human posterior ciliary arteries in vitro and increased optic disc blood flow in vivo.

    Science.gov (United States)

    Chuman, Hideki; Sugimoto, Takako; Nao-I, Nobuhisa

    2017-12-01

    This study aimed to clarify the vasodilatory effect of L-arginine on isolated rabbit and human posterior ciliary arteries (PCAs) and to investigate changes in optic disc blood flow after an infusion of L-arginine in vivo. Vascular ring segments were mounted on a double myograph system. After obtaining maximal contraction following administration of high-K solution, L-arginine was administrated. Six volunteers received an intravenous drip infusion of 100 ml of L-arginine or saline. Changes in optic disc blood flow were measured by laser speckle flowgraphy. L-arginine relaxed high-K solution-induced contracted rabbit PCAs. Carboxy-PTIO (nitric oxide scavenger) and L-NAME (nitric oxide synthase inhibitor) inhibited L-arginine-induced relaxation in rabbit PCAs. After removal of the endothelium of the rabbit PCAs, L-arginine still relaxed rabbit PCAs. L-arginine relaxed human PCAs, despite the lack of nitric oxide production. In the L-arginine infusion group, the mean blur rate was significantly greater than that of the control group in vivo. L-arginine has both nitric oxide-dependent and independent vasodilatory effect on high K- induced contractions in isolated rabbit and human PCAs. L-arginine increased optic disc blood flow in vivo.

  16. Effect of preeclampsia serum on human uterine spiral artery smooth muscle cell apoptosis in a coculture model with cytotrophoblasts.

    Science.gov (United States)

    Jiang, Rongzhen; Yan, Shilan; Teng, Yincheng; Huang, Yajuan; Gu, Jinghong; Li, Ming

    2012-01-01

    To investigate cytotrophoblast (CTB) invasive ability and human uterine spiral artery smooth muscle cell (HUSASMC) apoptosis in a coculture model with serum from preeclamptic pregnancies. Transwell migration assay was used to detect the invasive ability of CTBs. Cocultured CTBs and HUSASMCs were incubated with normal or preeclamptic serum for 24 h. Monocultures of CTBs and HUSASMCs were treated identically to the cocultures and served as controls. HUSASMC viability and apoptosis rates were determined by MTT and annexin V-FITC assays. The expressions of Fas ligand (FasL) mRNA in CTBs and Fas mRNA in HUSASMCs were detected by RT-PCR. The expression of the Fas protein in HUSASMCs was detected by Western blotting. In a model of CTBs cocultured with HUSASMCs, preeclamptic serum effectively decreased the invasive ability and FasL mRNA expression of the CTBs. Preeclampsia serum also increased HUSASMC viability, decreased their apoptotic rate, and decreased the expression of Fas mRNA and protein. The abnormal invasive ability of CTBs and decreased expression of the Fas/FasL system may be directly involved in the defective remodeling of the uterine spiral arteries during preeclampsia. Furthermore, the decrease in HUSASMC apoptosis may be related to the abnormal expression of Fas/FasL. Copyright © 2012 S. Karger AG, Basel.

  17. Effect of Australian Propolis from Stingless Bees (Tetragonula carbonaria) on Pre-Contracted Human and Porcine Isolated Arteries

    Science.gov (United States)

    Massaro, Flavia C.; Brooks, Peter R.; Wallace, Helen M.; Nsengiyumva, Vianne; Narokai, Lorraine; Russell, Fraser D.

    2013-01-01

    Bee propolis is a mixture of plant resins and bee secretions. While bioactivity of honeybee propolis has been reported previously, information is limited on propolis from Australian stingless bees (Tetragonula carbonaria). The aim of this study was to investigate possible vasomodulatory effects of propolis in KCl-precontracted porcine coronary arteries using an ex vivo tissue bath assay. Polar extracts of propolis produced a dose-dependent relaxant response (EC50=44.7±7.0 μg/ml), which was unaffected by endothelial denudation, suggesting a direct effect on smooth muscle. Propolis markedly attenuated a contractile response to Ca2+ in vessels that were depolarised with 60 mM KCl, in Ca2+-free Krebs solution. Propolis (160 µg/ml) reduced vascular tone in KCl pre-contracted vessels to near-baseline levels over 90 min, and this effect was partially reversible with 6h washout. Some loss in membrane integrity, but no loss in mitochondrial function was detected after 90 min exposure of human cultured umbilical vein endothelial cells to 160 µg/ml propolis. We conclude that Australian stingless bee (T. carbonaria) propolis relaxes porcine coronary artery in an endothelial-independent manner that involves inhibition of voltage-gated Ca2+ channels. This effect is partially and slowly reversible upon washout. Further studies are required to determine the therapeutic potential of Australian stingless bee propolis for conditions in which vascular supply is compromised. PMID:24260567

  18. Effect of chronic stress and sleep deprivation on both flow-mediated dilation in the brachial artery and the intracellular magnesium level in humans.

    Science.gov (United States)

    Takase, Bonpei; Akima, Takashi; Uehata, Akimi; Ohsuzu, Fumitaka; Kurita, Akira

    2004-04-01

    Chronic mental and physical stress has been suggested to be a trigger for cardiovascular events. In addition, a reduction in levels of intracellular magnesium has been reported to cause vasoconstriction while enhancing platelet-dependent thrombosis. The purpose of this study was to investigate whether chronic stress affects endothelial function and intracellular magnesium levels in humans. Flow-mediated dilation (endothelium-dependent vasodilation) and sublingual nitroglycerin-induced dilation (0.3 mg, endothelium-independent vasodilation) were measured in the brachial artery in 30 healthy male college students, aged 22 +/- 1 years, using high-resolution ultrasound both before and immediately after a 4-week final term examination period. Erythrocyte magnesium concentration was measured simultaneously. All students had chronic sleep deprivation for 4 weeks, during which sleep lasted students were under great stress to pass the examination. This condition was considered to be chronic stress. Chronic stress decreased flow-mediated dilation and erythrocyte magnesium concentration (from 7.4 +/- 3.0 to 3.7 +/- 2.3%, p < 0.05; from 5.7 +/- 0.4 to 5.5 +/- 0.4 mg/ml, p < 0.05, respectively). The change in flow-mediated dilation correlated significantly with that of the erythrocyte magnesium concentration (r = 0.43, p < 0.05), but not with nitroglycerin-induced dilation. Chronic stress was found to attenuate endothelial function, which may also be associated with a reduction in the intracellular magnesium level in humans.

  19. A methodology of measuring human health

    Directory of Open Access Journals (Sweden)

    B.R.K. Sinha

    2015-09-01

    Full Text Available Health is an important measure of people’s well-being and has always been a major thrust area of geographical inquiry. Several geographers and scholars from other disciplines have made their best attempts at analyzing and mapping health data but have not paid much attention in deriving health index. Devising an index of health of the target population of a region is of great interest to geographers because health (a state of complete physical, mental and social well-being is an output of society, an asset or wealth for a community, a resource in the form of energy, ability, talents and other mental and physical capabilities of normal functioning in a given environment. Many scholars consider health as a subjective state that has several dimensions. It varies in place and time at age, gender, social class, education, income and occupation levels. Such aspects of the population vary from region to region and work as determining factors of health. This paper aims at highlighting the fundamental steps of methodology and at developing the way of constructing a logical and reasonable composite index to measure health at the individual level in a given area at a given point in time. To accomplish the objectives, several health parameters have been suggested and arranged in a logical and practical form for ranking and assigning an acceptable weight as per the nature of health variables for devising Health Index as a result or as a guiding tool to apply by the health researchers in the field of study of health at individual level.

  20. Measuring the human psychophysiological conditions without contact

    Science.gov (United States)

    Scalise, L.; Casacanditella, L.; Cosoli, G.

    2017-08-01

    Heart Rate Variability, HRV, studies the variations of cardiac rhythm caused by the autonomic regulation. HRV analysis can be applied to the study of the effects of mental or physical stressors on the psychophysiological conditions. The present work is a pilot study performed on a 23-year-old healthy subject. The measurement of HRV was performed by means of two sensors, that is an electrocardiograph and a Laser Doppler Vibrometer, which is a non-contact device able to detect the skin vibrations related to the cardiac activity. The present study aims to evaluate the effects of a physical task on HRV parameters (in both time and frequency domain), and consequently on the autonomic regulation, and the capability of Laser Doppler Vibrometry in correctly detecting the effects of stress on the Heart Variability. The results show a significant reduction of HRV parameters caused by the execution of the physical task (i.e. variations of 25-40% for parameters in time domain, also higher in frequency domain); this is consistent with the fact that stress causes a reduced capability of the organism in varying the Heart Rate (and, consequently, a limited HRV). LDV was able to correctly detect this phenomenon in the time domain, while the parameters in the frequency domain show significant deviations with respect to the gold standard technique (i.e. ECG). This may be due to the movement artefacts that have consistently modified the shape of the vibration signal measured by means of LDV, after having performed the physical task. In the future, in order to avoid this drawback, the LDV technique could be used to evaluate the effects of a mental task on HRV signals (i.e. the evaluation of mental stress).

  1. Principles in selecting human capital measurements and metrics

    Directory of Open Access Journals (Sweden)

    Pharny D. Chrysler-Fox

    2014-02-01

    Full Text Available Orientation: Physical and natural resources have been surpassed by human capital as aresource of wealth creation. As a result, senior management relies increasingly on appropriatepeople information to drive strategic change. Yet, measurement within the human resourcefunction predominantly informs decisions in support of efficiency and effectiveness. Consequently, dissimilar understanding of measurement expectations between these partieslargely continues.Research purpose: The study explored principles in selecting human capital measurements,drawing on the views and recommendations of human resource management professionals,all experts in human capital measurement.Motivation for the study: The motivation was to advance the understanding of selectingappropriate and strategic valid measurements, in order for human resource practitioners tocontribute to creating value and driving strategic change.Research design, approach and method: A qualitative approach, with purposively selectedcases from a selected panel of human capital measurement experts, generated a datasetthrough unstructured interviews, which were analysed thematically.Main findings: Nineteen themes were found. They represent a process that considers thecentrality of the business strategy and a systemic integration across multiple value chains inthe organisation through business partnering, in order to select measurements and generatemanagement level-appropriate information.Practical/managerial implications: Measurement practitioners, in partnership withmanagement from other functions, should integrate the business strategy across multiplevalue chains in order to select measurements. Analytics becomes critical in discoveringrelationships and formulating hypotheses to understand value creation. Higher educationinstitutions should produce graduates able to deal with systems thinking and to operatewithin complexity.Contribution: This study identified principles to select measurements and

  2. Comparison between Carotid Artery Wall Thickness Measured by Multidetector Row Computed Tomography Angiography and Intimae-Media Thickness Measured by Sonography

    Directory of Open Access Journals (Sweden)

    Živorad N. Savić

    2011-01-01

    Full Text Available The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA in measuring carotid artery wall thickness (CAWT and color Doppler ultrasound (CD-US in measuring intimae-media thickness (IMT. Eighty-nine patients (aged 35–81 were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data were described as the mean value ± standard deviation, and were compared using the Mann–Whitney U test. A p value <0.05 was considered significant. Bland–Altman statistics were employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.62 to 1.60 mm, with a mean value of 1.09 mm. IMT ranged from 0.60 to 1.55 mm, with a mean value of 1.06 mm. We observed an excellent agreement between CD-US and MDCTA in the evaluation of the common carotid artery thickness, with a bias between methods of 0.029 mm (which is a highly statistically important difference of absolute values [t = 43.289; p < 0.01] obtained by paired T test, and limits of agreement from 0.04 to 0.104. Pearson correlation coefficient was 0.9997 (95% CI 0.9996–0.9998; p < 0.01. We conclude that there is an excellent correlation between CAWT and IMT measurements obtained with the MDCTA and CD-US.

  3. Performance assessment and optimization of Pulse Wave Imaging (PWI) in ex vivo canine aortas and in vivo normal human arteries.

    Science.gov (United States)

    Li, Ronny X; Qaqish, William W; Shahmirzadi, Danial; Konofagou, Elisa E

    2012-01-01

    The amplitude, velocity, and morphology of the arterial pulse wave may all provide valuable diagnostic information for cardiovascular pathology. Pulse Wave Imaging (PWI) is an ultrasound-based method developed by our group to noninvasively visualize and map the spatio-temporal variations of the pulse wave-induced vessel wall motion. Because PWI is capable of acquiring multiple wall motion waveforms successively along an imaged arterial segment over a single cardiac cycle in vivo, the regional morphological changes, amplitudes, and velocity (i.e. pulse wave velocity, or PWV) of the pulse wave can all be evaluated. In this study, an ex vivo setup was used to assess the effects of varying PWI image acquisition variables (beam density/frame rate and scanning orientation) and signal processing methods (beam sweep compensation scheme and waveform feature tracking) on the PWV estimation in order to validate the optimal parameters. PWI was also performed on the carotid arteries and abdominal aortas of six healthy volunteers for identification of several salient features of the waveforms over the entire cardiac cycle that may aid in assessing the morphological changes of the pulse wave. The ex vivo results suggest that the PWI temporal resolution is more important for PWV estimation than the PWI spatial resolution, and also that the reverse scanning orientation (i.e. beam sweeping direction opposite the direction of fluid flow) is advantageous due to higher precision and less dependence on the frame rate. In the in vivo waveforms, the highest precision PWV measurements were obtained by tracking the 50% upstroke of the waveforms. Finally, the dicrotic notch, reflected wave, and several inflection points were qualitatively identified in the carotid and aortic anterior wall motion waveforms and shown in one representative subject.

  4. THE ASSAY OF HYPERTENSIN FROM THE ARTERIAL BLOOD OF NORMOTENSIVE AND HYPERTENSIVE HUMAN BEINGS

    Science.gov (United States)

    Kahn, Joseph R.; Skeggs, Leonard T.; Shumway, Norman P.; Wisenbaugh, Paul E.

    1952-01-01

    Hypertensin has been assayed in the blood of patients with normal blood pressure and in those with essential hypertension in both the benign and malignant phases. 250 ml. samples of arterial blood were obtained, chemically purified, and concentrated to a volume of 1 ml. These extracts were then assayed in anesthetized rats. The concentrations of hypertensin in the blood of patients with the malignant phase of essential hypertension were found to be greatly increased. The concentrations of hypertensin found in patients with benign hypertension had a moderate degree of overlapping with those found in the normotensive group, but the mean concentration of hypertensin in the former group was twice that of the controls. Although these results are statistically significant, the amounts of hypertensin recovered in the benign group are so small that no conclusions can be drawn as to its effectiveness in producing vasoconstriction in these patients. PMID:14946317

  5. Analysis of tasks and human factors in anesthesia for coronary-artery bypass.

    Science.gov (United States)

    Kennedy, P J; Feingold, A; Wiener, E L; Hosek, R S

    1976-01-01

    A comprehensive task analysis of the anesthetist's activities during coronary-artery bypass procedures was carried out using time-lapse cinematography. This film was analyzed frame by frame to detect types of activities and the proportion of time spent on each. Link analysis was used to reveal recurring sequences of activities. Of the 9 activity categories, the anesthetist spends the greatest portion of time observing the patient and scanning the entire operative and monitoring field. Ten to 15% of the time is spent logging data on the anesthetic record. The challenge for the anesthetist is to optimize his performance, and those under his direction, in the face of the changing workload resulting from variations in patients' conditions. Use of an automated monitoring system that charts patient vital signs would allow the anesthetist to apportion this time among other tasks.

  6. The CSF and arterial to internal jugular venous hormonal differences during exercise in humans

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Ott, Peter; Dela, Flemming

    2004-01-01

    the brain (a-v diff) of hormones that could influence its carbohydrate uptake (n= 9). In addition, neuroendocrine activity and a potential uptake of hormones via the cerebrospinal fluid (CSF) were assessed by lumbar puncture postexercise and at rest (n= 6). Exercise increased the arterial concentration...... protein (HSP72), insulin, or insulin-like growth factor (IGF)-I. The findings indicate that for maximal exercise, the concentration of noradrenaline is increased within the brain, whereas blood borne hormones and cytokines are seemingly unimportant. The results support the notion that the exercise......Strenuous exercise increases the cerebral uptake of carbohydrate out of proportion to that of oxygen, but it is unknown whether such enhanced carbohydrate uptake is influenced by the marked endocrine response to exercise. During exhaustive exercise this study evaluated the a-v differences across...

  7. Effects of lipopolysaccharide infusion on arterial levels and transcerebral exchange kinetics of glutamate and glycine in healthy humans

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Taudorf, Sarah; Bailey, Damian M

    2012-01-01

    was calculated by multiplying CBF with the arterial to jugular venous differences. LPS induced a systemic inflammatory response with fever, neutrocytosis, and elevated arterial levels of tumour necrosis factor-α. This was associated with a decrease in the arterial levels of both glutamate and glycine; however...

  8. First-in-Human Experience With the Gore Balloon-Expandable Covered Endoprosthesis in Iliac Artery Occlusive Disease.

    Science.gov (United States)

    Holden, Andrew; Merrilees, Stephen; Buckley, Brendan; Connor, Brigid; Colgan, Frances; Hill, Andrew

    2017-02-01

    To report the first-in-human iliac artery experience of a new balloon-expandable covered endoprosthesis. A prospective, single-center pilot study recruited 30 symptomatic patients (mean age 64 years; 18 men) to evaluate the safety and early efficacy of the new Gore balloon-expandable covered endoprosthesis for the treatment of de novo or restenotic common and/or external iliac artery lesions. According to protocol, up to 2 discrete lesions could be treated with a maximum total treated length ≤110 mm. Follow-up included clinical evaluation with duplex ultrasound at 1, 6, and 12 months. Data are presented through 12-month follow-up. The primary safety endpoint was a composite of device- or procedure-related death, myocardial infarction, or amputation in the treated leg within 30 days of the index procedure. Multiple performance outcomes were also evaluated. The primary 30-day safety endpoint was 0%. Per-subject estimates of primary patency, freedom from target lesion revascularization, and freedom from target vessel revascularization were 100% at 1 and 6 months and 96.6% at 12 months. Estimates of assisted primary and secondary patency were both 100% at 12 months. Freedom from major adverse events at 12 months was 100%. Most patients experienced improvements in Rutherford category, ankle-brachial index, and functional status that were sustained to 12 months. This positive first-in-human experience with the Gore balloon-expandable covered endoprosthesis suggests this device will have an important role in the management of aortoiliac occlusive disease.

  9. Estimation of an image derived input function with MR-defined carotid arteries in FDG-PET human studies using a novel partial volume correction method.

    Science.gov (United States)

    Sari, Hasan; Erlandsson, Kjell; Law, Ian; Larsson, Henrik Bw; Ourselin, Sebastien; Arridge, Simon; Atkinson, David; Hutton, Brian F

    2017-04-01

    Kinetic analysis of 18 F-fluorodeoxyglucose positron emission tomography data requires an accurate knowledge the arterial input function. The gold standard method to measure the arterial input function requires collection of arterial blood samples and is an invasive method. Measuring an image derived input function is a non-invasive alternative but is challenging due to partial volume effects caused by the limited spatial resolution of the positron emission tomography scanners. In this work, a practical image derived input function extraction method is presented, which only requires segmentation of the carotid arteries from MR images. The simulation study results showed that at least 92% of the true intensity could be recovered after the partial volume correction. Results from 19 subjects showed that the mean cerebral metabolic rate of glucose calculated using arterial samples and partial volume corrected image derived input function were 26.9 and 25.4 mg/min/100 g, respectively, for the grey matter and 7.2 and 6.7 mg/min/100 g for the white matter. No significant difference in the estimated cerebral metabolic rate of glucose values was observed between arterial samples and corrected image derived input function (p > 0.12 for grey matter and white matter). Hence, the presented image derived input function extraction method can be a practical alternative to noninvasively analyze dynamic 18 F-fluorodeoxyglucose data without the need for blood sampling.

  10. Clinical Observation of Recombinant Human Vascular Endostatin Durative Transfusion Combined with Window Period Arterial Infusion Chemotherapy in the Treatment of 
Advanced Lung Squamous Carcinoma

    Directory of Open Access Journals (Sweden)

    Yuan LV

    2015-08-01

    Full Text Available Background and objective Lung cancer is one of the most common malignant tumors in China. The aim of this study is to observe the efficacy and safety of recombinant human vascular endostatin (endostar durative transfusion combined with window period arterial infusion chemotherapy in the treatment of advanced lung squamous carcinoma. Methods From February 2014 to January 2015, 10 cases of the cytological or histological pathology diagnosed stage IIIb - stage IV lung squamous carcinoma were treated with recombinant human vascular endostatin (30 mg/d durative transfusion combined with window period arterial infusion chemotherapy. Over the same period of 10 cases stage IIIb - stage IV lung squamous carcinoma patients for pure arterial perfusion chemotherapy were compared. Recombinant human vascular endostatin was durative transfused every 24 hours for 7 days in combination group, and in the 4th day of window period, the 10 patients were received artery infusion chemotherapy, using docetaxel combined with cisplatin. Pure treatment group received the same arterial perfusion chemotherapy regimen. 4 weeks was a cycle. 4 weeks after 2 cycles, to evaluate the short-term effects and the adverse drug reactions. Results 2 groups of patients were received 2 cycles treatments. The response rate (RR was 70.0%, and the disease control rate (DCR was 90.0% in the combination group; In the pure treatment group were 50.0%, 70.0% respectively, there were no statistically significant difference (P=0.650, 0.582. The adverse reactions of the treatment were mild, including level 1-2 of gastrointestinal reaction and blood toxicity, there were no statistically significant difference (P=0.999, P=0.628. In the combination group, 1 patient occurred level 1 of cardiac toxicity. Conclusion Recombinant human vascular endostatin durative transfusion combined with window period arterial infusion chemotherapy in the treatment of advanced lung squamous carcinoma could take a

  11. Measures of chronic kidney disease and risk of incident peripheral artery disease: a collaborative meta-analysis of individual participant data.

    Science.gov (United States)

    Matsushita, Kunihiro; Ballew, Shoshana H; Coresh, Josef; Arima, Hisatomi; Ärnlöv, Johan; Cirillo, Massimo; Ebert, Natalie; Hiramoto, Jade S; Kimm, Heejin; Shlipak, Michael G; Visseren, Frank L J; Gansevoort, Ron T; Kovesdy, Csaba P; Shalev, Varda; Woodward, Mark; Kronenberg, Florian

    2017-09-01

    Some evidence suggests that chronic kidney disease is a risk factor for lower-extremity peripheral artery disease. We aimed to quantify the independent and joint associations of two measures of chronic kidney disease (estimated glomerular filtration rate [eGFR] and albuminuria) with the incidence of peripheral artery disease. In this collaborative meta-analysis of international cohorts included in the Chronic Kidney Disease Prognosis Consortium (baseline measurements obtained between 1972 and 2014) with baseline measurements of eGFR and albuminuria, at least 1000 participants (this criterion not applied to cohorts exclusively enrolling patients with chronic kidney disease), and at least 50 peripheral artery disease events, we analysed adult participants without peripheral artery disease at baseline at the individual patient level with Cox proportional hazards models to quantify associations of creatinine-based eGFR, urine albumin-to-creatinine ratio (ACR), and dipstick proteinuria with the incidence of peripheral artery disease (including hospitalisation with a diagnosis of peripheral artery disease, intermittent claudication, leg revascularisation, and leg amputation). We assessed discrimination improvement through c-statistics. We analysed 817 084 individuals without a history of peripheral artery disease at baseline from 21 cohorts. 18 261 cases of peripheral artery disease were recorded during follow-up across cohorts (median follow-up was 7·4 years [IQR 5·7-8·9], range 2·0-15·8 years across cohorts). Both chronic kidney disease measures were independently associated with the incidence of peripheral artery disease. Compared with an eGFR of 95 mL/min per 1·73 m 2 , adjusted hazard ratios (HRs) for incident study-specific peripheral artery disease was 1·22 (95% CI 1·14-1·30) at an eGFR of 45 mL/min per 1·73 m 2 and 2·06 (1·70-2·48) at an eGFR of 15 mL/min per 1·73 m 2 . Compared with an ACR of 5 mg/g, the adjusted HR for incident study

  12. Ultrasonographic Measurement of the Diameter of a Normal Bile Duct, Hepatic Artery and Portal Vein in Infants Younger Than 3 Months

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Yoon; Lee, Young Seok [Dankook University Hospital, Cheonan (Korea, Republic of)

    2009-09-15

    This study focused on measuring the diameter of the normal bile duct, hepatic artery and portal vein with high resolution US in infants younger than 3 months, and we wanted to determine the relative ratio of these diameters. Fifty US examinations were performed on infants younger than 3 months and who did not have any clinical or laboratory abnormality associated with the hepatobiliary system. We measured the diameter of the bile duct, hepatic artery and portal vein at the level of the portal vein bifurcation with using 17-5 MHz US and we determined the relative ratios of these diameters. To evaluate the statistical difference in the diameter of the bile duct, hepatic artery and portal vein, we performed one-way ANOVA and Scheffe's multiple comparison test. To determine the relative ratio of these diameters, the ratio of the bile duct to the hepatic artery was defined as the hepatic artery/bile duct, the ratio of the hepatic artery to the portal vein was defined as the portal vein/hepatic artery and the ratio of the bile duct to the portal vein was defined as the portal vein/bile duct. We calculated the averages {+-} standard deviations of this data (minimum {approx} maximum). In all fifty infants, the bile duct, hepatic artery and portal vein were detectable and measurable. The average diameter of a bile duct was 0.85 {+-} 0.19 mm (0.56 {approx} 1.47 mm), it was 1.33 {+-} 0.31 mm (0.90 {approx} 2.37 mm) for the hepatic artery and 3.32 {+-} 0.68 mm (2.06 {approx} 5.08 mm) for the portal vein. The diameter of these structures was significantly different from each other according to one-way ANOVA (p < 0.001). The average diameter of the hepatic artery was significantly larger than that of the bile duct and the average diameter of the portal vein was significantly larger than that of bile duct and hepatic artery on Scheffe's multiple comparison test. The relative ratio of the bile duct to the hepatic artery was 1.60 {+-} 0.41 (0.77 {approx} 2.66), that of

  13. Validación del índice tobillo brazo oscilométrico comparado con eco-Doppler arterial de miembros inferiores para enfermedad arterial Validation of oscillometric measurement of ankle-brachial index compared with arterial lower limb echo-doppler for arterial disease

    Directory of Open Access Journals (Sweden)

    Astrid N Páez E

    2010-08-01

    Full Text Available INTRODUCCIÓN: estudios previos reportan la validación y correspondencia, o ambas, del índice tobillo brazo oscilométrico frente al índice tobillo brazo con Doppler, pero este último no corresponde al patrón de oro. OBJETIVO: determinar la validez de criterio del índice tobillo brazo oscilométrico comparado con la ecografía dúplex arterial de miembros inferiores para detectar enfermedad arterial periférica. METODOLOGÍA: estudio de evaluación de tecnologías diagnósticas realizado por muestreo transversal. De manera consecutiva, se reclutaron 101 personas del Instituto del Corazón de Bucaramanga con mínimo un factor de riesgo cardiovascular. Se midió el índice tobillo brazo oscilométrico con equipo OMRON® M7 HEM 780 y posteriormente se hizo ecografía dúplex arterial de miembros inferiores, esta última patrón de oro; los evaluadores estaban enmascarados. RESULTADOS: las mediciones repetidas de la presión arterial en cada miembro, mostraron una reproducibilidad casi perfecta, pues sus coeficientes de correlación intraclase son superiores a 0,86 y el acuerdo del método fue adecuado ± 15 mm Hg, para la mayoría de las mediciones. Según el análisis de la curva ROC, el punto de corte 90,48%, sensibilidad regular ( 70,37%, razón de probabilidad positiva cercana o superior al ideal (7-10, moderada calidad de la sensibilidad (0,58, sustancial calidad de la especificidad (0,66-0,78 y eficiencia o capacidad discriminatoria (0,62-0,67. CONCLUSIÓN: los hallazgos permiten recomendar la medición del índice tobillo brazo oscilométrico en personas con factores de riesgo cardiovasculares, como una prueba de rutina, bien sea para tamizaje (punto de corte INTRODUCTION: previous studies reported validation and/or correspondence of ankle-brachial index measured by OMRON (ABIO versus an ABI measured by Doppler, but the latter is not the gold standard. Objective: to determine the criterion validity of ABIO versus arterial duplex

  14. Workload Measurement in Human Autonomy Teaming: How and Why?

    Science.gov (United States)

    Shively, Jay

    2016-01-01

    This is an invited talk on autonomy and workload for an AFRL Blue Sky workshop sponsored by the Florida Institute for Human Machine Studies. The presentation reviews various metrics of workload and how to move forward with measuring workload in a human-autonomy teaming environment.

  15. AN ALTERNATIVE APPROACH TO MEASURE HUMAN DEVELOPMENT IN RUSSIA

    OpenAIRE

    Gerard Rostom

    2011-01-01

    The article deals with finding optimal ways to measure the level of Human Development in Russia’s regions. In the past, it was common to measure the level of regional development by the Gross Regional Income indicator. Nowadays, we shifted to more “humanized” indicators of regional development. The Human Development index is one of them. A way to improve methods of calculating this index to reflect the closest to reality situation is suggested.

  16. AN ALTERNATIVE APPROACH TO MEASURE HUMAN DEVELOPMENT IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Gerard Rostom

    2011-01-01

    Full Text Available The article deals with finding optimal ways to measure the level of Human Development in Russia’s regions. In the past, it was common to measure the level of regional development by the Gross Regional Income indicator. Nowadays, we shifted to more “humanized” indicators of regional development. The Human Development index is one of them. A way to improve methods of calculating this index to reflect the closest to reality situation is suggested.

  17. Measuring human wellbeing in Pakistan: objective versus subjective indicators

    OpenAIRE

    Haq, Rashida

    2009-01-01

    The concern for measuring wellbeing objectively and subjectively is found in modern political philosophy. This study explores objective indicators versus subjective perceptions of human wellbeing in ranking of survey data for districts of Pakistan. Data used for the analysis is ‘The Pakistan Social and Living Standards Measurement Survey’ for the year 2006-07. The human wellbeing is examined in four domains: education, health, living conditions and economic situation. Principal component anal...

  18. Measuring Human Capital in the Economy. Applications for Bulgaria.

    OpenAIRE

    Simeonova-Ganeva, Ralitsa

    2012-01-01

    This article has two main objectives: The first one is to review the most commonly used methods of measuring human capital in the macroeconomic analysis. Here, a summary of methods considering educational characteristics of population and labour force is presented, such as usage of literacy rate, enrollment rates, educational attainment, labor income and quality of education. A challenge in front of human capital measuring is solving the problems related to its depreciation as well as those r...

  19. Distance between intramuscular nerve and artery in the extraocular muscles: a preliminary immunohistochemical study using elderly human cadavers.

    Science.gov (United States)

    Kitamura, Kei; Cho, Kwang Ho; Jang, Hyung Suk; Murakami, Gen; Yamamoto, Masahito; Abe, Shin-Ichi

    2017-01-01

    Extraocular muscles are quite different from skeletal muscles in muscle fiber type and nerve supply; the small motor unit may be the most well known. As the first step to understanding the nerve-artery relationship, in this study we measured the distance from the arteriole (25-50 μm in thickness) to the nerve terminal twigs in extraocular muscles. With the aid of immunohistochemistry for nerves and arteries, we examined the arteriole-nerve distance at 10-15 sites in each of 68 extraocular muscles obtained from ten elderly cadavers. The oblique sections were nearly tangential to the muscle plate and included both global and orbital aspects of the muscle. In all muscles, the nerve twigs usually took a course parallel to muscle fibers, in contrast to most arterioles that crossed muscles. Possibly due to polyinnervation, an intramuscular nerve plexus was evident in four rectus and two oblique muscles. The arteriole-nerve distance usually ranged from 300 to 400 μm. However, individual differences were more than two times greater in each of seven muscles. Moreover, in each muscle the difference between sites sometimes reached 1 mm or more. The distance was generally shorter in the rectus and oblique muscles than in the levator palpebrae muscle, which reached statistical significance (p muscle, between muscles, and between individuals might lead to an individual biological rhythm of fatigue in oculomotor performance.

  20. Simultaneous measurement of brain perfusion and labeling efficiency in a single pseudo-continuous arterial spin labeling scan.

    Science.gov (United States)

    Chen, Zhensen; Zhao, Xihai; Zhang, Xingxing; Guo, Rui; Teeuwisse, Wouter M; Zhang, Bida; Koken, Peter; Smink, Jouke; Yuan, Chun; van Osch, Matthias J P

    2017-07-24

    The aim of this study was to propose, optimize, and validate a pseudo-continuous arterial spin labeling (pCASL) sequence for simultaneous measurement of brain perfusion and labeling efficiency. The proposed sequence incorporates the labeling efficiency measurement into the postlabeling delay period of a conventional perfusion pCASL sequence by using the time-encoding approach. In vivo validation experiments were performed on nine young subjects by comparing it to separate perfusion and labeling efficiency sequences. Sensitivity of the proposed combined sequence for measuring labeling efficiency changes was further addressed by varying the flip angles of the pCASL labeling radiofrequency pulses. The proposed combined sequence decreased the perfusion signal by ∼4% and a lower labeling efficiency (by ∼10%) was found as compared to the separate sequences. However, the temporal signal-noise-ratio of the perfusion signal remained unchanged. When the pCASL flip angle was decreased to a suboptimal setting, a strong correlation was found between the combined and the separate sequences for the relative change in pCASL perfusion signal as well as for the relative change in labeling efficiency. High correlation was also observed between relative changes in perfusion signal and the measured labeling efficiencies. The proposed sequence allows simultaneous measurement of brain perfusion and labeling efficiency with high time-efficiency at the price of only a small compromise in measurement accuracy. The additional labeling efficiency measurement can be used to facilitate qualitative interpretation of pCASL perfusion images. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. Renal frame count: a measure of renal flow that predicts success of renal artery stenting in hypertensive patients.

    Science.gov (United States)

    Naghi, Jesse; Palakodeti, Samhita; Ang, Lawrence; Reeves, Ryan; Patel, Mitul; Mahmud, Ehtisham

    2015-08-01

    Renal artery (RA) stenting can improve control of hypertension yet predicting clinical response remains difficult. We sought to determine the role of the renal frame count (RFC) (number of angiographic frames for contrast to reach distal renal parenchyma after initial RA opacification) as a predictor of improvement in blood pressure (BP) after RA stenting. Renal flow was quantified in 68 consecutive patients (age 72.5 ± 9.1 years, 72% male) undergoing RA stenting for refractory hypertension (BP ≥ 140/90 mm Hg despite treatment with two or more antihypertensive medications) by measuring RFC pre-RA stenting. Significant renal artery stenosis (RAS) was defined as a stenosis ≥ 70% by visual estimation on angiography. Baseline and 6-month follow-up BP was recorded. Clinical response was defined by a drop in systolic blood pressure (SBP) >10 mm Hg on the same or fewer number of anti-hypertensive medications. Patients with RFC > 30 had SBP reduction (43.2 ± 25.7 mm Hg vs. 30.1 ± 31.3 mm Hg, P = 0.067), diastolic blood pressure reduction (9.1 ± 19.0 vs. -0.2 ± 13.4 mm Hg, P = 0.02), and mean arterial pressure reduction (23.8 ± 19.4 vs. 11.8 ± 16.1 mm Hg, P 30 was associated with a higher rate of clinical response to RA stenting (93.5% vs. 73%, P = 0.027). RFC can be used as a clinical predictor of response to RA stenting. RFC > 30 was associated with reduction in BP after RA stenting and was predictive of clinical response. RFC provides a useful intraprocedural tool in assessing the severity of RAS and predicts the likelihood of clinical response following RA stenting. © 2015 Wiley Periodicals, Inc.

  2. Activation of endothelial and epithelial K(Ca) 2.3 calcium-activated potassium channels by NS309 relaxes human small pulmonary arteries and bronchioles

    DEFF Research Database (Denmark)

    Kroigaard, Christel; Dalsgaard, Thomas; Nielsen, Gorm

    2012-01-01

    BACKGROUND AND PURPOSE: Small (K(Ca) 2) and intermediate (K(Ca) 3.1) conductance calcium-activated potassium channels (K(Ca) ) may contribute to both epithelium- and endothelium-dependent relaxations, but this has not been established in human pulmonary arteries and bronchioles. Therefore, we inv...

  3. Comparison of Wright's Formula and the Dunn Method for Measuring the Umbilical Arterial Catheter Insertion Length

    Directory of Open Access Journals (Sweden)

    Se-ra Min

    2015-04-01

    Conclusion: The use of Wright's formula overall results in superior correct placement of the UAC tip. It may be a more accurate and practical method than the conventional practice for measuring the UAC insertion length in newborns.

  4. Comparison of methods for measuring travel time at Florida freeways and arterials.

    Science.gov (United States)

    2014-07-01

    Travel time is an important performance measure used to assess the traffic operational quality of various types of highway : facilities. Previous research funded by the Florida Department of Transportation (FDOT) on travel time reliability developed,...

  5. Comparison of methods for measuring travel time at Florida freeways and arterials : [summary].

    Science.gov (United States)

    2014-07-01

    In this project, University of Florida researchers : collected field data along several highways to : evaluate travel time measurements from several : sources: STEWARD, BlueTOAD, INRIX, and HERE. : STEWARD (Statewide Transportation Engineering : Ware...

  6. Correlation between Echo-Tracking Parameters and In Vitro Measurements of Arterial Contraction and Relaxation in Rats Fed a High-Cholesterol Diet.

    Science.gov (United States)

    Zhang, Yi; Zhan, Wei-Wei; Wu, Yong-Jie; Zhao, Bo; Zhou, Wu-Gang; Chen, Dong-Rui; Zhou, Wei; Liu, Zhen-Hua; Jiang, Wei-Min; Zheng, Lin

    2015-09-30

    Echo-tracking (ET) is a new technique that allows the assessment of arterial function and stiffness. This study aimed to ascertain the utility of the echo-tracking (ET) technique to assess vascular stiffness in rats with hypercholesterolemia and atherosclerosis. ET was used to measure the arterial stiffness of the aorta in cholesterol-fed Sprague-Dawley rats (group T1, n=10, for 4 weeks; group T2, n=10, for 12 weeks) and normal control rats (group C1, n=10; group C2, n=10). In vitro isometric tension experiments were used to measure the maximum contractile tension (MCT) and maximum relaxation percentage (MRR%) of aortic rings. Indicators of arterial stiffness and aortic MCT and MRR% were compared between groups using linear regression analysis. Light microscopic evaluation was used to demonstrate atherosclerotic changes in the aorta. The rat models were successfully induced; pathological examination of the aortas showed significant atherosclerosis in group T2, but not in groups C1, C2, or T1. The arterial stiffness parameters obtained using ET and aortic rings in vitro showed significant impairments in T1 and T2 rats compared with C1 and C2 controls (all Pparameter b (r=-0.406, P=0.009) and one-point pulse wave β (r=-0.434, P=0.005). These results suggest that ET could be used to evaluate the changes in arterial wall elasticity associated with atherosclerosis and hypercholesterolemia.

  7. Interferometric measurement of the angular velocity of moving humans

    Science.gov (United States)

    Nanzer, Jeffrey A.

    2012-06-01

    This paper presents an analysis of the measurement of the angular velocity of walking humans using a millimeter-wave correlation interferometer. Measurement of the angular velocity of moving objects is a desirable function in remote sensing applications. Doppler radar sensors are able to measure the signature of moving humans based on micro-Doppler analysis; however, a person moving with little to no radial velocity produces negligible Doppler returns. Measurement of the angular movement of humans can be done with traditional radar techniques, however the process involves either continuous tracking with narrow beamwidth or angle-of-arrival estimation algorithms. A new method of measuring the angular velocity of moving objects using interferometry has recently been developed which measures the angular velocity of an object without tracking or complex processing. The frequency of the interferometer signal response is proportional to the angular velocity of the object as it passes through the interferometer beam pattern. In this paper, the theory of the interferometric measurement of angular velocity is covered and simulations of the response of a walking human are presented. Simulations are produced using a model of a walking human to show the significant features associated with the interferometer response, which may be used in classification algorithms.

  8. The normal growth of the common iliac arteries in human fetuses – an anatomical, digital and statistical study

    Science.gov (United States)

    Szpinda, Michał; Szpinda, Anna; WoŸniak, Alina; Daroszewski, Marcin; Mila-Kierzenkowska, Celestyna

    2012-01-01

    Summary Background The present study was carried out to compile normative data for dimensions of the common iliac arteries at varying gestational ages. Material/Methods We used anatomical dissection, digital-image analysis (system of Leica QWin Pro 16) and statistical analysis (Student T test, one-way ANOVA, post-hoc RIR Tukey test, and regression analysis) to examine the increase in length (mm), proximal external diameter (mm), and volume (mm3) of the common iliac arteries in 124 (60 males, 64 females) spontaneously aborted human fetuses aged 15–34 weeks. Results Neither sex nor right-left significant differences were found (P>0.05). The length ranged from 4.76±1.05 to 15.38±1.60 mm on the right, and from 4.92±1.33 to 14.91±1.25 mm on the left, according to the linear functions y=−3.598+0.585×Age ±1.522 (R2=0.83) and y=−3.107+0.554×Age ±1.444 (R2=0.83). The proximal external diameter increased from 0.66±0.19 to 2.30±0.42 mm on the right, and from 0.66±0.14 to 2.16±0.42 mm on the left, according to the quadratic models y=1.392−0.110×Age+0.004×Age2 ±0.285 (R2=0.77) and y=1.283−0.099×Age+0.004×Age2 ±0.238 (R2=0.81). The volumes were increasing from 1.93±1.74 to 66.95±29.31 mm3 on the right, and from 1.91±1.65 to 56.86±25.17 mm3 on the left, given by the quadratic functions: y=99.69−10.60×Age+0.287×Age2 ±14.40 (R2=0.67) and y=82.62−8.86×Age+0.242×Age2 ±11.60 (R2=0.71). Conclusions The common iliac arteries grow linearly in length, and parabolically in both diameter and volume. The right common iliac artery constitutes a predominant vessel in relation to its length, external diameter and volume. The morphometric data on the common iliac arteries may serve as a useful reference in the prenatal diagnosis and monitoring of congenital aorto-iliac abnormalities. PMID:22367120

  9. Measuring human capital cost through benchmarking in health care environment.

    Science.gov (United States)

    Kocakülâh, Mehmet C; Harris, Donna

    2002-01-01

    Each organization should seek to maximize its human capital investments, which ultimately lead to increased profits and asset efficiency. Service companies utilize less capital equipment and more human productivity, customer service, and/or delivery of service as the product. With the measurement of human capital, one can understand what is happening, exercise some degree of control, and make positive changes. Senior management lives or dies by the numbers and if Human Resources (HR) really wants to be a strategic business partner, HR must be judged by the same standards as everyone else in the health care organization.

  10. A rare case of Cystic artery arising from Gastroduodenal artery ...

    African Journals Online (AJOL)

    An uncommon anatomical variation in the origin and course of cystic artery was found during human cadaveric dissection in our laboratory. A blood vessel was seen arising from the gastroduodenal artery about 1 cm distal to its origin from the common hepatic artery. The vessel when traced towards its termination was found ...

  11. No evidence of parvovirus B19, Chlamydia pneumoniae or human herpes virus infection in temporal artery biopsies in patients with giant cell arteritis

    DEFF Research Database (Denmark)

    Helweg-Larsen, J; Tarp, B; Obel, N

    2002-01-01

    using the polymerase chain reaction (PCR). METHODS: Thirty temporal artery biopsies from 30 patients suspected of having GCA within a period of 1 yr were examined. Thirteen patients had classical GCA, two had biopsy-negative GCA, 10 patients had polymyalgia rheumatica and five patients had other...... conditions. DNA was extracted from frozen biopsies and PCR was used to amplify genes from Chlamydia pneumoniae, parvovirus B19 and each of the eight human herpes viruses: herpes simplex viruses HSV-1 and 2, Epstein-Barr virus, cytomegalovirus, varicella zoster virus and human herpes viruses HHV-6, -7 and -8....... RESULTS: In all 30 biopsies, PCR was negative for DNAs of parvovirus B19, each of the eight human herpes viruses and C. pneumoniae. CONCLUSIONS: We found no evidence of DNA from parvovirus B19, human herpes virus or C. pneumoniae in any of the temporal arteries. These agents do not seem to play a unique...

  12. Platelet deposition at angioplasty sites and its relation to restenosis in human iliac and femoropopliteal arteries

    Energy Technology Data Exchange (ETDEWEB)

    Minar, E.; Ehringer, H.; Ahmadi, R.; Dudczak, R.; Leitha, T.; Koppensteiner, R.; Jung, M.; Stuempflen, A.

    1989-03-01

    The amount and time course of platelet accumulation at angioplasty sites and influence of these platelets on restenosis after percutaneous transluminal angioplasty (PTA) in peripheral arteries were determined in 92 patients, who received either a high or low dose of aspirin. Platelet deposition was quantitated by means of dual-radiotracer scintigraphy and calculation of a platelet accumulation index (PAI). The PAI was higher (P less than .05) 4-6 hours after PTA compared with that on subsequent days. There was a trend toward greater platelet accumulation in vessels with extensive dissection. Platelet accumulation at the PTA site occurred with both doses of aspirin, with no differences between the two dosage groups. Twenty-one of 67 patients who underwent PTA in the femoropopliteal segment developed restenosis during a median follow-up of 14 months. The median PAI at 4-6 and 22-24 hours after PTA was significantly less in these 21 patients than in the 46 without restenosis. The data suggest that use of antiplatelet agents to prevent platelet deposition after PTA may not be useful for prevention of restenosis.

  13. Cardiopulmonary changes in humans with coronary artery disease associated with exposure to ambient concentrations of ozone.

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset contains a list of cardiac and vascular biomarkers that were obtained on each day a participant visited the EPA Human Studies Facility. It also contains...

  14. [Ultrasonographic evaluation of selected parameters of the endothelial function in brachial arteries and IMT measurements in carotid arteries in children with diabetes type 1 using personal insulin pumps--preliminary report].

    Science.gov (United States)

    Tołwińska, Joanna; Głowińska-Olszewska, Barbara; Urban, Mirosława; Florys, Bozena; Peczyńska, Jadwiga

    2006-01-01

    Type 1 diabetes is a known risk factor for arterial atherosclerosis. The first symptoms can be found even in childhood. The ultrasonographic measurements of intimal plus medial thickness in carotid arteries (IMT) and flow mediated dilatation (FMD) evaluated in brachial arteries, play a known role in the detection in these cases. The diabetes treatment intensification is an important factor in delaying early atherosclerotic changes. Currently, intensive treatment of children's diabetes with use of continuous subcutaneous insulin infusion with personal insulin pumps is gaining more and more popularity. THE AIM OF THIS STUDY was the evaluation of IMT and FMD indexes in children suffering from type 1 diabetes in the context of treatment intensification (multidose insulin injections v. personal insulin pumps). We examined 64 children (29 boys and 35 girls) in the mean age 15.5 years treated with the multidose insulin injections method and 10 children using personal insulin pumps (4 girls and 6 boys) in the mean age 14.5 years. Using high resolution ultrasonography we evaluated IMT values in carotid arteries and FMD parameters in brachial arteries. In our analysis we estimated the blood concentration of lipid parameters, values of systolic and diastolic blood pressure, the age of diabetes onset, duration time of the illness and the values of HbA1c as a marker of metabolic control. We noticed significantly higher FMD values in patients treated with personal insulin pumps (13.7 vs. 5.5%, p=0.001). IMT values were similar in both groups (0.52 vs. 0.5 mm, p=0. 41). The level of HDL cholesterol was higher and triglycerides lower in the group with treatment intensification. The metabolic control was the same in both groups. In patients treated by the multidose insulin injections IMT correlated with systolic blood pressure values. We didn't notice any correlation between IMT and FMD in any group. 1. Treatment intensification (personal insulin pumps) influences better vascular

  15. Comparison of temperature measurements in bladder, rectum and pulmonary artery in patients after cardiac surgery

    NARCIS (Netherlands)

    Wollerich, H.; Ismael, Farouq; Nijsten, Maarten; Dieperink, Willem

    2012-01-01

    In many patients in the intensive care unit (ICU) con-tinuous temperature monitoring is performed with rectal probes. Currently there are more options to measure temperature in critically ill patients. Since bladder catheters are routinely used in the majority of ICU patients, using bladder

  16. Upregulation of Human Endogenous Retrovirus-K Is Linked to Immunity and Inflammation in Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Saito, Toshie; Miyagawa, Kazuya; Chen, Shih-Yu; Tamosiuniene, Rasa; Wang, Lingli; Sharpe, Orr; Samayoa, Erik; Harada, Daisuke; Moonen, Jan-Renier A J; Cao, Aiqin; Chen, Pin-I; Hennigs, Jan K; Gu, Mingxia; Li, Caiyun G; Leib, Ryan D; Li, Dan; Adams, Christopher M; Del Rosario, Patricia A; Bill, Matthew; Haddad, Francois; Montoya, Jose G; Robinson, William H; Fantl, Wendy J; Nolan, Garry P; Zamanian, Roham T; Nicolls, Mark R; Chiu, Charles Y; Ariza, Maria E; Rabinovitch, Marlene

    2017-11-14

    Immune dysregulation has been linked to occlusive vascular remodeling in pulmonary arterial hypertension (PAH) that is hereditary, idiopathic, or associated with other conditions. Circulating autoantibodies, lung perivascular lymphoid tissue, and elevated cytokines have been related to PAH pathogenesis but without a clear understanding of how these abnormalities are initiated, perpetuated, and connected in the progression of disease. We therefore set out to identify specific target antigens in PAH lung immune complexes as a starting point toward resolving these issues to better inform future application of immunomodulatory therapies. Lung immune complexes were isolated and PAH target antigens were identified by liquid chromatography tandem mass spectrometry, confirmed by enzyme-linked immunosorbent assay, and localized by confocal microscopy. One PAH antigen linked to immunity and inflammation was pursued and a link to PAH pathophysiology was investigated by next-generation sequencing, functional studies in cultured monocytes and endothelial cells, and hemodynamic and lung studies in a rat. SAM domain and HD domain-containing protein 1 (SAMHD1), an innate immune factor that suppresses HIV replication, was identified and confirmed as highly expressed in immune complexes from 16 hereditary and idiopathic PAH versus 12 control lungs. Elevated SAMHD1 was localized to endothelial cells, perivascular dendritic cells, and macrophages, and SAMHD1 antibodies were prevalent in tertiary lymphoid tissue. An unbiased screen using metagenomic sequencing related SAMHD1 to increased expression of human endogenous retrovirus K (HERV-K) in PAH versus control lungs (n=4). HERV-K envelope and deoxyuridine triphosphate nucleotidohydrolase mRNAs were elevated in PAH versus control lungs (n=10), and proteins were localized to macrophages. HERV-K deoxyuridine triphosphate nucleotidohydrolase induced SAMHD1 and proinflammatory cytokines (eg, interleukin 6, interleukin 1β, and tumor

  17. Growth hormone-releasing peptide ghrelin inhibits homocysteine-induced endothelial dysfunction in porcine coronary arteries and human endothelial cells.

    Science.gov (United States)

    Hedayati, Nasim; Annambhotla, Suman; Jiang, Jun; Wang, Xinwen; Chai, Hong; Lin, Peter H; Yao, Qizhi; Chen, Changyi

    2009-01-01

    Ghrelin, a novel growth hormone-releasing peptide, is implicated to play a protective role in cardiovascular tissues. However, it is not clear whether ghrelin protects vascular tissues from injury secondary to risk factors such as homocysteine (Hcy). This study investigated the effect and potential mechanisms of ghrelin on Hcy-induced endothelial dysfunction. Porcine coronary artery rings were incubated for 24 hours with ghrelin (100 ng/mL), Hcy (50 microM), or ghrelin plus Hcy. Endothelial vasomotor function was evaluated using the myograph tension model. The response to the thromboxane A(2)analog U46619, bradykinin, and sodium nitroprusside was analyzed. Endothelial nitric oxide synthase (eNOS) expression was determined using real-time polymerase chain reaction and immunohistochemistry staining, and superoxide anion production was documented lucigenin-enhanced chemiluminescence analysis. Human coronary artery endothelial cells (HCAECs) were treated with different concentrations of Hcy, ghrelin, or antighrelin receptor antibody for 24 hours, and eNOS protein levels were determined by Western blot analysis. Maximal contraction with U46619 and endothelium-independent vasorelaxation with sodium nitroprusside were not different among the four groups. However, endothelium-dependent vasorelaxation with bradykinin (10(-6) M) was significantly reduced by 34% with Hcy compared with controls (P ghrelin to Hcy had a protective effect, with 61.6% relaxation, which was similar to controls (64.7%). Homocysteine significantly reduced eNOS expression, whereas ghrelin cotreatment effectively restored eNOS expression to the control levels. Superoxide anion levels, which were increased by 100% with Hcy, returned to control levels with ghrelin cotreatment. Ghrelin also effectively blocked the Hcy-induced decrease of eNOS protein levels in HCAECs in a concentration-dependent manner. Antighrelin receptor antibody effectively inhibited the effect of ghrelin. Ghrelin has a protective

  18. Pulmonary artery diameters, cross sectional areas and area changes measured by cine cardiovascular magnetic resonance in healthy volunteers.

    Science.gov (United States)

    Burman, Elisabeth D; Keegan, Jennifer; Kilner, Philip J

    2016-03-03

    We measured by cine cardiovascular magnetic resonance (CMR) main and branch pulmonary artery diameters and cross sectional areas in diastole and systole in order to establish normal ranges and the effects on them of age, gender and body surface area (BSA). Documentation of normal ranges provides a reference for research and clinical investigation in the fields of congenital heart disease, pulmonary hypertension and connective tissue disorders. We recruited 120 healthy volunteers: ten males (M) and ten females (F) in each decile between 20 and 79 years, imaging them in a 1.5 Tesla CMR system. Scout acquisitions guided the placement of steady state free precession cine acquisitions transecting the main, right and left pulmonary arteries (MPA, RPA and LPA). Cross sections were rarely quite circular. From all subjects, the means of the greater and lesser orthogonal diastolic diameters in mm were: MPA, 22.9 ± 2.4 (M) and 21.2 ± 2.1 (F), RPA 16.6 ± 2.8 (M) and 14.7 ± 2.2 (F), and LPA 17.3 ± 2.5 (M) and 15.9 ± 2.0 (F), p measurements of minimum diastolic and maximum systolic cross sectional areas, the % systolic distensions were: MPA 42.7 ± 17.2 (M) and 41.8 ± 15.7 (F), RPA 50.6 ± 16.9 (M) and 48.2 ± 14.5 (F), LPA 35.6 ± 10.1 (M) and 35.2 ± 10.3 (F), and there was a decrease in distension with age (p Measurements of MPA, RPA and LPA by cine CMR are provided for reference, with documentation of their changes with age and BSA.

  19. Threshold Setting for Likelihood Function for Elasticity-Based Tissue Classification of Arterial Walls by Evaluating Variance in Measurement of Radial Strain

    Science.gov (United States)

    Tsuzuki, Kentaro; Hasegawa, Hideyuki; Kanai, Hiroshi; Ichiki, Masataka; Tezuka, Fumiaki

    2008-05-01

    Pathologic changes in arterial walls significantly influence their mechanical properties. We have developed a correlation-based method, the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791], for measurement of the regional elasticity of the arterial wall. Using this method, elasticity distributions of lipids, blood clots, fibrous tissue, and calcified tissue were measured in vitro by experiments on excised arteries (mean±SD: lipids 89±47 kPa, blood clots 131 ±56 kPa, fibrous tissue 1022±1040 kPa, calcified tissue 2267 ±1228 kPa) [H. Kanai et al.: Circulation 107 (2003) 3018; J. Inagaki et al.: Jpn. J. Appl. Phys. 44 (2005) 4593]. It was found that arterial tissues can be classified into soft tissues (lipids and blood clots) and hard tissues (fibrous tissue and calcified tissue) on the basis of their elasticity. However, there are large overlaps between elasticity distributions of lipids and blood clots and those of fibrous tissue and calcified tissue. Thus, it was difficult to differentiate lipids from blood clots and fibrous tissue from calcified tissue by simply thresholding elasticity value. Therefore, we previously proposed a method by classifying the elasticity distribution in each region of interest (ROI) (not a single pixel) in an elasticity image into lipids, blood clots, fibrous tissue, or calcified tissue based on a likelihood function for each tissue [J. Inagaki et al.: Jpn. J. Appl. Phys. 44 (2006) 4732]. In our previous study, the optimum size of an ROI was determined to be 1,500 µm in the arterial radial direction and 1,500 µm in the arterial longitudinal direction [K. Tsuzuki et al.: Ultrasound Med. Biol. 34 (2008) 573]. In this study, the threshold for the likelihood function used in the tissue classification was set by evaluating the variance in the ultrasonic measurement of radial strain. The recognition rate was improved from 50 to 54% by the proposed thresholding.

  20. Role of platelet-derived growth factor-BB (PDGF-BB) in human pulmonary artery smooth muscle cell proliferation.

    Science.gov (United States)

    Zhao, Yan; Lv, Wentao; Piao, Hongying; Chu, Xiaojie; Wang, Hao

    2014-08-01

    Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by enhanced proliferation of pulmonary artery smooth muscle cells (PASMCs) and suppressed apoptosis. Platelet-derived growth factor (PDGF) is a potent mitogen involved in cell proliferation and migration. PDGF-BB induces the proliferation and migration of PASMCs and has been proposed to be a key mediator in the progression of PAH. Previous studies have shown that PDGF and its receptor are substantially elevated in lung tissues and PASMCs isolated from patients and animals with PAH, but the underlying mechanisms are still poorly manifested. MAP kinases, including extracellular signal-regulated kinase1/2 (ERK1/2), c-Jun NH2-terminal kinase1/2 (JNK1/2), and p38 are the key intracellular signals for stimuli-induced cell proliferation, survival, and apoptosis. Therefore, the purpose of this study is to determine whether PDGF-BB on cell proliferation process is mediated through the MAP kinases pathway in human PASMCs (HPASMCs). Our results showed PDGF-BB-induced proliferating cell nuclear antigen (PCNA), Cyclin A and Cyclin E expression in a concentration-dependent manner. The expression levels of phosphorylated JNK (p-JNK) was upregulated with 20 ng/ml PDGF-BB treatment, while PDGF-BB could not increase phosphorylated ERK1/2 (p-ERK1/2) and p-38 (p-p38) expression. The effects of PDGF-BB on cell proliferation and survival were weakened after the administration of antagonist of the JNK pathway or si-JNK. In addition, PDGF-BB protected against the loss of mitochondrial membrane potentials evoked by serum deprivation (SD) in a JNK-dependent manner. These results suggest that PDGF-BB promotes HPASMCs proliferation and survival, which is likely to be mediated via the JNK pathway.

  1. Rheological and physiological consequences of conversion of the maternal spiral arteries for uteroplacental blood flow during human pregnancy.

    Science.gov (United States)

    Burton, G J; Woods, A W; Jauniaux, E; Kingdom, J C P

    2009-06-01

    Physiological conversion of the maternal spiral arteries is key to a successful human pregnancy. It involves loss of smooth muscle and the elastic lamina from the vessel wall as far as the inner third of the myometrium, and is associated with a 5-10-fold dilation at the vessel mouth. Failure of conversion accompanies common complications of pregnancy, such as early-onset preeclampsia and fetal growth restriction. Here, we model the effects of terminal dilation on inflow of blood into the placental intervillous space at term, using dimensions in the literature derived from three-dimensional reconstructions. We observe that dilation slows the rate of flow from 2 to 3m/s in the non-dilated part of an artery of 0.4-0.5mm diameter to approximately 10 cm/s at the 2.5mm diameter mouth, depending on the exact radius and viscosity. This rate predicts a transit time through the intervillous space of approximately 25s, which matches observed times closely. The model shows that in the absence of conversion blood will enter the intervillous space as a turbulent jet at rates of 1-2m/s. We speculate that the high momentum will damage villous architecture, rupturing anchoring villi and creating echogenic cystic lesions as evidenced by ultrasound. The retention of smooth muscle will also increase the risk of spontaneous vasoconstriction and ischaemia-reperfusion injury, generating oxidative stress. Dilation has a surprisingly modest impact on total blood flow, and so we suggest the placental pathology associated with deficient conversion is dominated by rheological consequences rather than chronic hypoxia.

  2. Measures of chronic kidney disease and risk of incident peripheral artery disease: a collaborative meta-analysis of individual participant data

    NARCIS (Netherlands)

    Matsushita, K.; Ballew, S.H.; Coresh, J.; Arima, H.; Arnlov, J.; Cirillo, M.; Ebert, N.; Hiramoto, J.S.; Kimm, H.; Shlipak, M.G.; Visseren, F.L.; Gansevoort, R.T.; Kovesdy, C.P.; Shalev, V.; Woodward, M.; Kronenberg, F.; Wetzels, J.F.M.; Grams, M.; Sang, Y.

    2017-01-01

    BACKGROUND: Some evidence suggests that chronic kidney disease is a risk factor for lower-extremity peripheral artery disease. We aimed to quantify the independent and joint associations of two measures of chronic kidney disease (estimated glomerular filtration rate [eGFR] and albuminuria) with the

  3. Measurements of Pulmonary Artery Size for Assessment of Pulmonary Hypertension by Cardiovascular Magnetic Resonance and Clinical Application

    Directory of Open Access Journals (Sweden)

    Fan YANG

    2017-02-01

    Full Text Available Background and objective Pulmonary hypertension (PH often leads to dilatation of main pulmonary artery (MPA. MPA measurements can be used to predict PH. This aim of this study is to investigate power of MPA vessel indices, which are acquired from cardiovascular magnetic resonance, to evaluate PH. Methods Cardiovascular-magnetic-resonance-determined parameters of MPA were acquired and calculated in 83 PH patients, whose diagnosis were confirmed with right heart catheterization and 49 healthy volunteers; these parameters included MPA diameter (DPA, ratio of DPA and ascending aorta diameter (DPA/DAo, max mean diameter (MDmax, min mean diameter (MDmin, fraction transverse diameter (fTD, fraction longitudinal diameter (fLD, and distensibility. Results Compared with control group, DPA, DPA/DAo, MDmax, and MDmin were significantly higher in patients with PH (P28.4 mm, and MDmax>32.4 mm (area under the curve, AUC=0.979, 0.981 showed best performance in predicting PH, yielding highest specificity at 100%. Conclusion Noninvasive cardiovascular-magnetic-resonance-derived MPA measurements provide excellent and practical reference in clinical settings for detecting PH.

  4. Relationship between clinical, 24-hour, average day-time and night-time blood pressure and measures of arterial stiffness in essential hypertension.

    Science.gov (United States)

    Rosa, J; Strauch, B; Petrák, O; Pikus, T; Holaj, R; Zelinka, T; Wichterle, D; Widimský, J

    2008-01-01

    Arterial wall stiffness is considered an independent cardiovascular risk factor. Aim of this study was to evaluate relationship between clinical, 24-hour, average day-time and night-time blood pressure (BP) and measures of arterial stiffness assessed by pulse wave velocity (PWV) (using SphygmoCor applanation tonometer) in essential hypertension (severe-resistant (RH, n=29) and moderate hypertension (EH, n=35)) and in normotensive control subjects (n-29) (NCS) matched by age. After multiple regression analysis, PWV remains significantly correlated mainly with night-time pulse pressure and to a lesser extent with age. PWV was significantly higher in RH compared to moderate EH and NCS.

  5. Small arteries can be accurately studied in vivo, using high frequency ultrasound

    DEFF Research Database (Denmark)

    Nielsen, T H; Iversen, Helle Klingenberg; Tfelt-Hansen, P

    1993-01-01

    We have validated measurements of diameters of the superficial temporal artery and other small arteries in man with a newly developed 20 MHz ultrasound scanner with A, B and M-mode imaging. The diameter of a reference object was 1.202 mm vs. 1.205 mm as measured by stereomicroscopy (nonsignifican......-gauge plethysmography (nonsignificant). Pulsations were 4.6% in the radial artery. We conclude that high frequency ultrasound provides an accurate and reproducible measure of the diameter of small and medium sized human arteries in vivo....

  6. ET-1 modulates KCa-channel activity and arterial tension in normoxic and hypoxic human pulmonary vasculature.

    Science.gov (United States)

    Peng, W; Michael, J R; Hoidal, J R; Karwande, S V; Farrukh, I S

    1998-10-01

    The molecular mechanisms by which endothelin (ET)-1 induces pulmonary hypertension are poorly understood. We investigated the effects of ET-1 on outward K+ currents of normoxic and chronically hypoxic human pulmonary arterial (PA) smooth muscle cells (HPSMCs). In normoxic HPSMCs, ET-1 has dual effects. In intact cells, 5 nM ET-1 activates the large-conductance and Ca2+-activated K+ (KCa)-channel current [IK(Ca)] by increasing intracellular Ca2+ concentration, whereas it directly inhibits IK(Ca) in isolated membrane patches. At a higher concentration (10 nM), ET-1-induced IK(Ca) inhibition predominates. In hypoxic HPSMCs, ET-1 at 5 nM significantly reduces IK(Ca). The ETA-receptor antagonist BQ-123 reverses the ET-1-induced decrease in IK(Ca). Chronic BQ-123 treatment also prevents the hypoxia-induced decrease in IK(Ca). In PA rings obtained from human organ donors, ET-1 causes a concentration-dependent increase in tension. The ET-1-mediated increase in tension is reversed by a KCa-channel agonist. The increase in tension at the highest concentration studied (9 nM) was more pronounced in PA rings obtained from patients with chronic obstructive pulmonary disease. These results imply that an ET-1-induced decrease in IK(Ca) contributes to chronic hypoxia-induced pulmonary hypertension.

  7. Arterial bypass leg - slideshow

    Science.gov (United States)

    ... presentations/100155.htm Arterial bypass leg - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  8. [Screening for asymptomatic peripheral arterial occlusive disease of the lower limbs by measuring the ankle-brachial index in the general population (Senegal)].

    Science.gov (United States)

    Pessinaba, S; Mbaye, A; Kane, Ad; Guene, B D; Mbaye Ndour, M; Niang, K; Jobe, M; Cazaubon, M; Mathieu, J-B S; Kane, M; Sow, D Diagne; Diack, B; Kane, A

    2012-07-01

    The purpose of this study was to investigate the prevalence of peripheral arterial disease (PAOD) and cardiovascular risk factors associated with the ankle-brachial index (ABI) in Senegalese patients aged 40 years and over. We prospectively studied a random sample of Senegalese aged 40 years and older, residing in the city of St.-Louis, Senegal. The ABI was measured with a portable doppler (DIADOP 50) using 4 and 8Hz dual frequency probes. The standards were: normal ABI 0.9 to 1.3; peripheral artery obstructive disease (PAOD) ABI less than 0.9; incompressible artery ABI greater than 1.3. Cardiovascular risk factors were also studied. Seven hundred and seventy-one subjects (mean age 57 ± 11.2 years, 559 women) were examined. Cardiovascular risk factors were: sedentary lifestyle (76.4%), hypertension (68%), obesity (32.1%), elevated LDL-cholesterolemia (27.8%), diabetes (18.3%) and tobacco smoking (6.9%). Ninety-three subjects (12.1%) had PAOD and 37 subjects (4.8%) had an incompressible artery. PAOD was significantly more common in sedentary subjects (P=0.008), in the elderly (P=0.0006) and in patients with a history of coronary artery disease (P=0.04). Smoking was not strongly associated with PAOD. PAOD is common in Senegalese and is associated with high prevalence of cardiovascular risk factors. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. Atypical nature of coronary artery disease in women: a proposal for measurement and classification

    Directory of Open Access Journals (Sweden)

    Viviana Marycel Céspedes Cuevas

    2015-01-01

    Full Text Available Objective: To identify subgroups of women with Acute Coronary Syndrome according to symptom experience: perception, evaluation and response, based on the Symptom Management Conceptual Model. Methodology: Quantitative, descriptive, exploratory, cross-sectional study. The sample was made of 380 women positively diagnosed with Acute Coronary Syndrome, hospitalized in two institutions in Bogotá, Colombia. A measurement instrument was designed and validated. Results: Final instrument was made of 37 items that reported content validity, scale validity, discriminant validity, and construct validity. A Cronbach's Alpha coefficient of 0,76 was obtained, which guarantees homogeneity in the measurement according to the Maximum Validity-Maximum Reliability Model. A total of 11 subgroups of women with Acute Coronary Syndrome were identified, those were characterized by atypical coronary heart disease symptomatology, evaluation processes related to extra-cardiac causes and inadequate symptom management strategies. It was possible to demonstrate that psychosocial factors, previous coronary heart disease and delays were variables making a significant influence on the components of symptom experience. Conclusions: Women with Acute Coronary Syndrome, belonging to the 11 subgroups that were identified and studied, showed atypical symptoms. The instrument designed features a proven psychometric quality; it was valid, reliable, and useful for clinical research and practice.

  10. [Computerized processing, using a Macintosh, of ambulatory arterial pressure measurements collected on a Spacelabs monitor].

    Science.gov (United States)

    Chanudet, X; Bauduceau, B; Leguicher, A; Celton, H; Larroque, P

    1987-06-01

    The use of the Spacelabs blood pressure recorder has given rise to processing programs running on Apple II and IBM PC computers. The authors have written in M.S. BASIC (2.1) a program who take advantage of graphic abilities and easy manipulation on Macintosh. The software was designed to perform three tasks: Communicating between Macintosh and Spacelabs station using serial interface (RS 232) without requesting specific interface card. Editing a report on two pages: The first is the listing of 96 measurements (one by 15 minutes). The second provides: patient identification, height, weight, diagnosis. Graphic representation of measurements Systolic and diastolic blood pressure (BP) repartition histogram for 24 hours, day and night. Standard deviation and mean of pressure and heart rate (HR) for those periods. A third optionally gives hourly chronogram and diagrams for cumulated BP and HR. Creating a file: 550 records can be stored on a 800 K floppy disk. The file handles: data for each patient (excepted identification). Random access and revision of each parameter is possible. comparative reports for group patients and patient by patient analysing data with appropriate statistical test (ANOVA and correlation) are done.

  11. The arterial supply of the tendon of the long head of the biceps brachii in the human: a combined anatomical and radiological study.

    Science.gov (United States)

    Boesmueller, Sandra; Fialka, Christian; Pretterklieber, Michael L

    2014-12-01

    Arthroscopic repair of superior labral anterior to posterior (SLAP) lesions is often associated with a prolonged period of pain during the rehabilitation process. This might possibly be due to hypoxia in the biceps tendon anchor caused by sutures. The purpose of the study was to investigate the arterial supply of the long head of the biceps brachii tendon (LHBT) that may be impaired by surgery in the region of the biceps tendon anchor. On 20 human formalin-fixed bodies, the anterior circumflex humeral artery (ACHA) was located and followed into the intertubercular groove until it reached the LHBT. On 10 fresh-frozen anatomic specimens of the upper extremities, contrast medium was injected into the axillary artery, a 3D scan was performed, and multiplanar reconstructed (MPR) slices were generated. A set of maximum intensity projection (MIP) reconstructions from 10 computed tomography angiographies (CTA) of the upper extremities was used to confirm the findings of the 3D scan. All anatomical dissections and radiological investigations revealed that the proximal portion of the LHBT was consistently supplied by an ascending branch of the ACHA. No artery was found to supply the biceps tendon anchor from the proximal aspect. As the arterial supply of the LHBT is mainly provided by the ACHA, which enters the glenohumeral joint from the distal aspect, surgery at the bony origin of the LHBT may not interfere with this specific vessel.

  12. Implantable arterial grafts from human fibroblasts and fibrin using a multi-graft pulsed flow-stretch bioreactor with noninvasive strength monitoring

    Science.gov (United States)

    Syedain, Zeeshan H.; Meier, Lee A.; Bjork, Jason W.; Lee, Ann; Tranquillo, Robert T.

    2011-01-01

    Tissue-engineered arteries based on entrapment of human dermal fibroblasts in fibrin gel yield completely biological vascular grafts that possess circumferential alignment characteristic of native arteries and essential to their mechanical properties. A bioreactor was developed to condition six grafts in the same culture medium while being subjected to similar cyclic distension and transmural flow resulting from pulsed flow distributed among the graft lumens via a manifold. The lumenal pressure and circumferential stretch were noninvasively monitored and used to calculate stiffness in the range of 80-120 mmHg and then to successfully predict graft burst strength. The length of the graft was incrementally shortened during bioreactor culture to maintain circumferential alignment and achieve mechanical anisotropy comparable to native arteries. After 7-9 weeks of bioreactor culture, the fibrin-based grafts were extensively remodeled by the fibroblasts into circumferentially-aligned tubes of collagen and other extracellular matrix with burst pressures in the range of 1400-1600 mmHg and compliance comparable to native arteries. The tissue suture retention force was also suitable for implantation in the rat model and, with poly(lactic acid) sewing rings entrapped at both ends of the graft, also in the ovine model. The strength achieved with a biological scaffold in such a short duration is unprecedented for an engineered artery. PMID:20934214

  13. Glomerular filtration rate measured by {sup 51}Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit, E-mail: annaalice100@yahoo.com.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Neurologia

    2010-07-01

    Introduction: renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid ({sup 51}Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using {sup 51}Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. Methods: this prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis ({sup 51}Cr-EDTA) and {sup 99m}Tc-DMSA scintigraphy were performed before and after captopril administration in all patients. Results: the mean baseline glomerular filtration rate was 48.6+-21.8 ml/kg/1.73 m{sup 2} in the group with renal artery stenosis, which was significantly lower than the GFR of 65.1+-28.7 ml/kg/1.73m{sup 2} in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6+-14.8 ml/kg/1.73m{sup 2}, p=0.001) and an insignificant change in the group without RAS (to 62.2+-23.6 ml/kg/1.73m{sup 2}, p=0.68). Scintigraphy with technetium-99m dimercapto

  14. Glomerular filtration rate measured by 51Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Directory of Open Access Journals (Sweden)

    Anna Alice Rolim Chaves

    2010-01-01

    Full Text Available INTRODUCTION: Renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. METHODS: This prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21 and without renal artery stenosis, (n=20. In vitro glomerular filtration rate analysis (51Cr-EDTA and 99mTc-DMSA scintigraphy were performed before and after captopril administration in all patients. RESULTS: The mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m² in the group wuth renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m² in the group without renal artery stenosis (p=0.04. Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/kg/1.73m², p=0.001 and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m², p=0.68. Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA did not show

  15. Investigation of human body potential measured by a non-contact measuring system.

    Science.gov (United States)

    Ichikawa, Norimitsu

    2016-12-07

    A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body's voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not.

  16. Photoplethysmography and ultrasonic-measurement-integrated simulation to clarify the relation between two-dimensional unsteady blood flow field and forward and backward waves in a carotid artery.

    Science.gov (United States)

    Sone, Shusaku; Hayase, Toshiyuki; Funamoto, Kenichi; Shirai, Atsushi

    2017-05-01

    Understanding the spatiotemporal change in hemodynamics is essential for the basic research of atherosclerosis. The objective of this study was to establish a methodology to clarify the relation between a two-dimensional (2D) unsteady blood flow field and forward and backward propagating waves in a carotid artery. This study utilized photoplethysmography (PPG) for blood pressure measurement and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation for flow field analysis. The validity of the methodology was confirmed in an experiment for a carotid artery of a healthy volunteer. Synchronization between the pressure measurement and flow field analysis was achieved with an error of flow field in the carotid artery was characterized in relation to forward and backward waves. 2D-UMI simulation reproduced the flow field in which the wall shear stress takes a maximum at the time of the backward wave superiority in the systolic phase, whereas 2D ordinary simulation failed to reproduce this feature because of poor reproducibility of velocity distribution. In conclusion, the proposed methodology using PPG and 2D-UMI simulation was shown to be a potential tool to clarify the relation between 2D unsteady blood flow field and the forward and backward waves in a carotid artery.

  17. Optimization of the scan protocol in the measurements of coronary artery calcium

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, L.C.G.; Lopes, R.T. [Coordenacao do Programa de Pos-graduacao em Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear; Gottlieb, I.; Carvalho, F.M. de [Clinica de Diagnostico por Imagem, Rio de Janeiro, RJ (Brazil); Kodlulovich, S., E-mail: simone@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Mecca, F.A. [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    The aim of this study was to evaluate the influence of the tube current applied for studies of calcium score. The research was carried out in a private clinic of Rio de Janeiro, using a 64-slice MDCT scanner and an anthropomorphic cardiac CT phantom. In all images, the Agatston score, the volume and mass of the calcifications, and the noise for each current tube was determined. The average CT attenuation number obtained for all tube currents was 261.6 {+-} 3.2 HU for the CaHA density insert and -0.2 HU {+-} 2.0 for the water insert. The images obtained at lower tube currents were noisier and grainier than those obtained at higher tube currents. However no significant differences were found in the calcium measurements, which suggest a high potential of patient dose reduction, around 50%, without compromising diagnostic information. (author)

  18. In-vivo spectroscopic ellipsometry measurements of human skin

    Science.gov (United States)

    Chan, Danny; Schulz, Benjamin; Ruebhausen, Michael

    2004-03-01

    Human skin can be described as a layered biological tissue. Knowledge of the behaviour of the optical properties of skin across the layers is limited. We describe an ellipsometric setup for spectrally resolved in-vivo measurements of human skin and show measurements of the complex refractive index N=n+ik of the finger of several volunteers over a range from 330 to 780 nm. A tapestripping study of human skin reveals the profile of the complex refractive index extracted from a simple bulk model over the stratum corneum. Fits of the evolution of n and k to an exponential function show that after approximately five strips a steady state is reached. A refined model applying an effective medium approximation accounting for surface roughness describes the development of the ellipsometric parameter Ψ in terms of the skin's increased water content with deeper depth of the measured layer.

  19. Comparison of the non-invasive Nexfin® monitor with conventional methods for the measurement of arterial blood pressure in moderate risk orthopaedic surgery patients.

    Science.gov (United States)

    Balzer, Felix; Habicher, Marit; Sander, Michael; Sterr, Julian; Scholz, Stephanie; Feldheiser, Aarne; Müller, Michael; Perka, Carsten; Treskatsch, Sascha

    2016-08-01

    Continuous invasive arterial blood pressure (IBP) monitoring remains the gold standard for BP measurement, but traditional oscillometric non-invasive intermittent pressure (NIBP) measurement is used in most low-to-moderate risk procedures. This study compared non-invasive continuous arterial BP measurement using a Nexfin® monitor with NIBP and IBP monitors. This was a single-centre, prospective, pilot study in patients scheduled for elective orthopaedic surgery. Systolic BP, diastolic BP and mean arterial blood pressure (MAP) were measured by Nexfin®, IBP and NIBP at five intraoperative time-points. Pearson correlation coefficients, Bland-Altman plots and trending ability of Nexfin® measurements were used as criteria for success in the investigation of measurement reliability. A total of 20 patients were enrolled in the study. For MAP, there was a sufficient correlation between IBP/Nexfin® (Pearson = 0.75), which was better than the correlation between IBP/NIBP (Pearson = 0.70). Bland-Altman analysis of the data showed that compared with IBP, there was a higher percentage error for MAPNIBP (30%) compared with MAPNexfin® (27%). Nexfin® and NIBP underestimated systolic BP; NIBP also underestimated diastolic BP and MAP. Trending ability for MAPNexfin® and MAPNIBP were comparable to IBP. Non-invasive BP measurement with Nexfin® was comparable with IBP and tended to be more precise than NIBP. © The Author(s) 2016.

  20. Role of Myoendothelial Gap Junctions in the Regulation of Human Coronary Artery Smooth Muscle Cell Differentiation by Laminar Shear Stress

    Directory of Open Access Journals (Sweden)

    Zongqi Zhang

    2016-07-01

    Full Text Available Background/Aims: Smooth muscle cells may dedifferentiate into the synthetic phenotype and promote atherosclerosis. Here, we explored the role of myoendothelial gap junctions in phenotypic switching of human coronary artery smooth muscle cells (HCASMCs co-cultured with human coronary artery endothelial cells (HCAECs exposed to shear stress. Methods: HCASMCs and HCAECs were seeded on opposite sides of Transwell inserts, and HCAECs were exposed to laminar shear stress of 12 dyn/cm2 or 5 dyn/cm2. The myoendothelial gap junctions were evaluated by using a multi-photon microscope. Results: In co-culture with HCAECs, HCASMCs exhibited a contractile phenotype, and maintained the expression of differentiation markers MHC and H1-calponin. HCASMCs and HCAECs formed functional intercellular junctions, as evidenced by colocalization of connexin(Cx40 and Cx43 on cellular projections inside the Transwell membrane and biocytin transfer from HCAECs to HCASMCs. Cx40 siRNA and 18-α-GA attenuated protein expression of MHC and H1-calponin in HCASMCs. Shear stress of 5 dyn/cm2 increased Cx43 and decreased Cx40 expression in HCAECs, and partly inhibited biocytin transfer from HCAECs to HCASMCs, which could be completely blocked by Cx43 siRNA or restored by Cx40 DNA transfected into HCAECs. The exposure of HCAECs to shear stress of 5 dyn/cm2 promoted HCASMC phenotypic switching, manifested by morphological changes, decrease in MHC and H1-calponin expression, and increase in platelet-derived growth factor (PDGF-BB release, which was partly rescued by Cx43 siRNA or Cx40 DNA or PDGF receptor signaling inhibitor. Conclusions: The exposure of HCAECs to shear stress of 5 dyn/cm2 caused the dysfunction of Cx40/Cx43 heterotypic myoendothelial gap junctions, which may be replaced by homotypic Cx43/Cx43 channels, and induced HCASMC transition to the synthetic phenotype associated with the activation of PDGF receptor signaling, which may contribute to shear stress

  1. Modelling the layer-specific three-dimensional residual stresses in arteries, with an application to the human aorta

    Science.gov (United States)

    Holzapfel, Gerhard A.; Ogden, Ray W.

    2010-01-01

    This paper provides the first analysis of the three-dimensional state of residual stress and stretch in an artery wall consisting of three layers (intima, media and adventitia), modelled as a circular cylindrical tube. The analysis is based on experimental results on human aortas with non-atherosclerotic intimal thickening documented in a recent paper by Holzapfel et al. ( Holzapfel et al. 2007 Ann. Biomed. Eng. 35, 530–545 (doi:10.1007/s10439-006-9252-z)). The intima is included in the analysis because it has significant thickness and load-bearing capacity, unlike in a young, healthy human aorta. The mathematical model takes account of bending and stretching in both the circumferential and axial directions in each layer of the wall. Previous analysis of residual stress was essentially based on a simple application of the opening-angle method, which cannot accommodate the three-dimensional residual stretch and stress states observed in experiments. The geometry and nonlinear kinematics of the intima, media and adventitia are derived and the associated stress components determined explicitly using the nonlinear theory of elasticity. The theoretical results are then combined with the mean numerical values of the geometrical parameters and material constants from the experiments to illustrate the three-dimensional distributions of the stretches and stresses throughout the wall. The results highlight the compressive nature of the circumferential stress in the intima, which may be associated with buckling of the intima and its delamination from the media, and show that the qualitative features of the stretch and stress distributions in the media and adventitia are unaffected by the presence or absence of the intima. The circumferential residual stress in the intima increases significantly as the associated residual deformation in the intima increases while the corresponding stress in the media (which is compressive at its inner boundary and tensile at its outer

  2. Measuring the differences between human-human and human-machine dialogs

    Directory of Open Access Journals (Sweden)

    David GRIOL

    2016-05-01

    Full Text Available In this paper, we assess the applicability of user simulation techniques to generate dialogs which are similar to real human-machine spoken interactions.To do so, we present the results of the comparison between three corpora acquired by means of different techniques. The first corpus was acquired with real users.A statistical user simulation technique has been applied to the same task to acquire the second corpus. In this technique, the next user answer is selected by means of a classification process that takes into account the previous dialog history, the lexical information in the clause, and the subtask of the dialog to which it contributes. Finally, a dialog simulation technique has been developed for the acquisition of the third corpus. This technique uses a random selection of the user and system turns, defining stop conditions for automatically deciding if the simulated dialog is successful or not. We use several evaluation measures proposed in previous research to compare between our three acquired corpora, and then discuss the similarities and differences with regard to these measures.

  3. Measurement of free radicals using electron paramagnetic resonance spectroscopy during open aorto-iliac arterial reconstruction.

    Science.gov (United States)

    Majewski, Wacław; Krzyminiewski, Ryszard; Stanisić, Michał; Iskra, Maria; Krasiński, Zbigniew; Nowak, Marek; Dobosz, Bernadeta

    2014-11-27

    Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals. The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD). The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction. Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09-77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56-82.12) and 24 h after the operation (25.85 U/L, range: 14.29-49.70). HO-1 concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23-38.55), IL-6 was 141.22 pg/ml (84.3-591.03), TNF-alfa was 6.82 pg/ml (1.76-80.01) and AIOD: CRP was 18.44 mg/l (2.56-33.14), IL-6: 184.1 pg/ml (128.46-448.03), TNF-alfa was 7.74 pg/ml (1.74-74.74). EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after

  4. Association of the Fractal Dimension of Retinal Arteries and Veins with Quantitative Brain MRI Measures in HIV-Infected and Uninfected Women.

    Science.gov (United States)

    Crystal, Howard A; Holman, Susan; Lui, Yvonne W; Baird, Alison E; Yu, Hua; Klein, Ronald; Rojas-Soto, Diana Marcella; Gustafson, Deborah R; Stebbins, Glenn T

    2016-01-01

    The fractal dimension of retinal arteries and veins is a measure of the complexity of the vascular tree. We hypothesized that retinal fractal dimension would be associated with brain volume and white matter integrity in HIV-infected women. Nested case-control within longitudinal cohort study. Women were recruited from the Brooklyn site of the Women's Interagency HIV study (WIHS); 34 HIV-infected and 21 HIV-uninfected women with analyzable MRIs and retinal photographs were included. Fractal dimension was determined using the SIVA software program on skeletonized retinal images. The relationship between predictors (retinal vascular measures) and outcomes (quantitative MRI measures) were analyzed with linear regression models. All models included age, intracranial volume, and both arterial and venous fractal dimension. Some models were adjusted for blood pressure, race/ethnicity, and HIV-infection. The women were 45.6 ± 7.3 years of age. Higher arterial dimension was associated with larger cortical volumes, but higher venous dimension was associated with smaller cortical volumes. In fully adjusted models, venous dimension was significantly associated with fractional anisotropy (standardized β = -0.41, p = 0.009) and total gray matter volume (β = -0.24, p = 0.03), and arterial dimension with mean diffusivity (β = -0.33,.p = 0.04) and fractional anisotropy (β = 0.34, p = 0.03). HIV-infection was not associated with any retinal or MRI measure. Higher venous fractal dimension was associated with smaller cortical volumes and lower fractional anisotropy, whereas higher arterial fractal dimension was associated with the opposite patterns. Longitudinal studies are needed to validate this finding.

  5. Performance of recommended measures on risk factors control in patients with hypertension, coronary artery disease and chronic heart failure: the data from 2014 Russian registry

    Directory of Open Access Journals (Sweden)

    Posnenkova O.M.

    2015-03-01

    Full Text Available A report presents the results of evaluation of recommended measures on risk factors control in patients with hypertension, stable coronary artery disease (CAD and chronic heart failure (CHF. The performance of recommended measures was assessed with the help of specially developed system of clinical indicators on the basis of data of the year 2014 from patients enrolled in multicenter Russian registry of hypertension, CAD and CHF.

  6. A computer simulation approach to measurement of human control strategy

    Science.gov (United States)

    Green, J.; Davenport, E. L.; Engler, H. F.; Sears, W. E., III

    1982-01-01

    Human control strategy is measured through use of a psychologically-based computer simulation which reflects a broader theory of control behavior. The simulation is called the human operator performance emulator, or HOPE. HOPE was designed to emulate control learning in a one-dimensional preview tracking task and to measure control strategy in that setting. When given a numerical representation of a track and information about current position in relation to that track, HOPE generates positions for a stick controlling the cursor to be moved along the track. In other words, HOPE generates control stick behavior corresponding to that which might be used by a person learning preview tracking.

  7. Echocardiographic estimation of right ventricular stroke work in children with pulmonary arterial hypertension: comparison with invasive measurements.

    Science.gov (United States)

    Di Maria, Michael V; Burkett, Dale A; Younoszai, Adel K; Landeck, Bruce F; Mertens, Luc; Ivy, D Dunbar; Friedberg, Mark K; Hunter, Kendall S

    2015-11-01

    Right ventricular (RV) failure is a key determinant of mortality in children with pulmonary arterial hypertension (PAH). RV stroke work (RVSW) can be estimated as the product of RV systolic pressure and stroke volume. The authors have shown that RVSW predicts adverse outcomes in this population when derived from hemodynamic data; noninvasive assessment of RVSW may be advantageous but has not been assessed. There are few data validating noninvasive versus invasive measurements in children with PAH. The aim of this study was to compare echocardiographically derived RVSW with RVSW determined from hemodynamic data. This was a retrospective study, including subjects with idiopathic PAH and minor or repaired congenital heart disease. Forty-nine subjects were included, in whom cardiac catheterization and echocardiography were performed within 1 month. Fourteen additional patients were included in a separate cohort, in whom catheterization and echocardiography were performed simultaneously. Catheterization-derived RVSW was calculated as RV systolic pressure × (cardiac output/heart rate). Echocardiographically derived RVSW was calculated as 4 × (peak tricuspid regurgitant jet velocity)(2) × (pulmonary valve area × velocity-time integral). Statistics included the intraclass correlation coefficient and Bland-Altman analysis. Echocardiographically derived RVSW was linearly correlated with invasively derived RVSW (r = 0.74, P rights reserved.

  8. Metrology of human-based and other qualitative measurements

    Science.gov (United States)

    Pendrill, Leslie; Petersson, Niclas

    2016-09-01

    The metrology of human-based and other qualitative measurements is in its infancy—concepts such as traceability and uncertainty are as yet poorly developed. This paper reviews how a measurement system analysis approach, particularly invoking as performance metric the ability of a probe (such as a human being) acting as a measurement instrument to make a successful decision, can enable a more general metrological treatment of qualitative observations. Measures based on human observations are typically qualitative, not only in sectors, such as health care, services and safety, where the human factor is obvious, but also in customer perception of traditional products of all kinds. A principal challenge is that the usual tools of statistics normally employed for expressing measurement accuracy and uncertainty will probably not work reliably if relations between distances on different portions of scales are not fully known, as is typical of ordinal or other qualitative measurements. A key enabling insight is to connect the treatment of decision risks associated with measurement uncertainty to generalized linear modelling (GLM). Handling qualitative observations in this way unites information theory, the perceptive identification and choice paradigms of psychophysics. The Rasch invariant measure psychometric GLM approach in particular enables a proper treatment of ordinal data; a clear separation of probe and item attribute estimates; simple expressions for instrument sensitivity; etc. Examples include two aspects of the care of breast cancer patients, from diagnosis to rehabilitation. The Rasch approach leads in turn to opportunities of establishing metrological references for quality assurance of qualitative measurements. In psychometrics, one could imagine a certified reference for knowledge challenge, for example, a particular concept in understanding physics or for product quality of a certain health care service. Multivariate methods, such as Principal Component

  9. Prostaglandin I2 and Prostaglandin E2 Modulate Human Intrarenal Artery Contractility Through Prostaglandin E2-EP4, Prostacyclin-IP, and Thromboxane A2-TP Receptors

    DEFF Research Database (Denmark)

    Eskildsen, Morten P; Hansen, Pernille B L; Stubbe, Jane

    2014-01-01

    receptors. Intrarenal arteries were microdissected from human nephrectomy samples (n=53, median diameter ≈362 μm, 88% viable, 76% relaxed in response to acetylcholine). Rings were suspended in myographs to record force development. In vessels with K(+)-induced tension (EC70: -log [mol/L]=1.36±0.03), PGE2......Cyclooxygenase inhibitors decrease renal blood flow in settings with decreased effective circulating volume. The present study examined the hypothesis that prostaglandins, prostaglandin E2 (PGE2) and prostacyclin (PGI2), induce relaxation of human intrarenal arteries through PGE2-EP and PGI2-IP...... receptor antagonist (BR5064, 10(-8) mol/L). Pretreatment of quiescent arteries with PGE2 for 5 minutes (10(-6) mol/L) led to a significant right shift of the concentration-response to norepinephrine (EC50 from 6.6±0.1-5.9±0.1). In intrarenal arteries with K(+)-induced tone, PGE2 and PGI2 at 10(-5) mol...

  10. Inhibition of vasoconstriction by AJ-2615, a novel calcium antagonist with alpha(1)-adrenergic receptor blocking activity in human conduit arteries used as bypass grafts.

    Science.gov (United States)

    Liu, M H; Floten, S H; Yang, Q; He, G W

    2001-09-01

    Graft spasm may develop during coronary artery bypass grafting and reversal of spasm is still challenging. The purpose of this study was to investigate the in vitro vascular relaxant properties of AJ-2615 in human internal mammary artery (IMA). We studied 264 IMA rings taken from 65 patients undergoing coronary artery bypass grafting surgery with organ bath technique. The interaction between AJ-2615 and various vasoconstrictors was investigated in two ways. AJ-2615 caused complete relaxation in methoxamine-contracted IMA rings (100.0+/-0.0%; n = 8) and nearly full relaxation in potassium chloride-contracted IMA rings (91.4+/-5.7%; n = 8) or noradrenaline-contracted IMA rings (89.3+/-2.8%; n = 8). AJ-2615 also induced remarkable relaxation in IMA rings contracted by other vasoconstrictors. In comparison with the alpha1-adrenoceptor antagonist prazosin, AJ 2615 showed similar maximal relaxation in IMA rings contracted by methoxamine or norepinephrine. On the other hand, incubation with AJ-2615 (0.1-1 microM) significantly inhibited all the vasoconstrictor-mediated vasoconstriction except endothelin-1 in a concentration-dependent manner. The results suggested that in human IMA, AJ-2615 has an inhibitory effect on vasoconstriction mediated by a variety of vasoconstrictors and the mechanism of relaxation may be related to its calcium antagonism and alpha1-adrenergic receptor blocking activity. AJ-2615 may have important clinical implications for patients undergoing coronary artery bypass surgery for reversing and preventing graft spasm.

  11. Functional ion channels in human pulmonary artery smooth muscle cells: Voltage-dependent cation channels.

    Science.gov (United States)

    Firth, Amy L; Remillard, Carmelle V; Platoshyn, Oleksandr; Fantozzi, Ivana; Ko, Eun A; Yuan, Jason X-J

    2011-01-01

    The activity of voltage-gated ion channels is critical for the maintenance of cellular membrane potential and generation of action potentials. In turn, membrane potential regulates cellular ion homeostasis, triggering the opening and closing of ion channels in the plasma membrane and, thus, enabling ion transport across the membrane. Such transmembrane ion fluxes are important for excitation-contraction coupling in pulmonary artery smooth muscle cells (PASMC). Families of voltage-dependent cation channels known to be present in PASMC include voltage-gated K(+) (Kv) channels, voltage-dependent Ca(2+)-activated K(+) (Kca) channels, L- and T- type voltage-dependent Ca(2+) channels, voltage-gated Na(+) channels and voltage-gated proton channels. When cells are dialyzed with Ca(2+)-free K(+)- solutions, depolarization elicits four components of 4-aminopyridine (4-AP)-sensitive Kvcurrents based on the kinetics of current activation and inactivation. In cell-attached membrane patches, depolarization elicits a wide range of single-channel K(+) currents, with conductances ranging between 6 and 290 pS. Macroscopic 4-AP-sensitive Kv currents and iberiotoxin-sensitive Kca currents are also observed. Transcripts of (a) two Na(+) channel α-subunit genes (SCN5A and SCN6A), (b) six Ca(2+) channel α-subunit genes (α(1A), α(1B), α(1x), α(1D), α(1E) and α(1G)) and many regulatory subunits (α(2)δ(1), β(1-4), and γ(6)), (c) 22 Kv channel α-subunit genes (Kv1.1 - Kv1.7, Kv1.10, Kv2.1, Kv3.1, Kv3.3, Kv3.4, Kv4.1, Kv4.2, Kv5.1, Kv 6.1-Kv6.3, Kv9.1, Kv9.3, Kv10.1 and Kv11.1) and three Kv channel β-subunit genes (Kv(β1-3) and (d) four Kca channel α-subunit genes (Sloα1 and SK2-SK4) and four Kca channel (β-subunit genes (Kca(β1-4) have been detected in PASMC. Tetrodotoxin-sensitive and rapidly inactivating Na(+) currents have been recorded with properties similar to those in cardiac myocytes. In the presence of 20 mM external Ca(2+), membrane depolarization from a holding

  12. Human factors and usability engineering in the development of SMT-101 for the treatment of pulmonary arterial hypertension.

    Science.gov (United States)

    Noymer, Peter; Shaked, Assaf; Newell, Kay

    2018-01-22

    SMT-101, a novel, proprietary, water-resistant wearable infusion pump prefilled with a preset dosage of treprostinil, was designed to address many of the administration-related shortcomings of existing parenteral therapy for pulmonary arterial hypertension (PAH). The objective of the human factors (HF) program was to demonstrate that the SMT-101 system is safe and effective when used by patients with PAH, their caregivers, or healthcare providers. The HF program for SMT-101 consisted of 8 studies (148 participants): an ethnographic study, an online survey of patients with PAH, 4 formative studies, a study of the instructions for use (IFU), and a summative study for validation. The pump and IFU were iteratively modified using observational data and participant feedback to inform subsequent improvements throughout the HF program to optimize safe use of SMT-101 before the final study. The results of the summative study demonstrated that the design of the SMT-101 wearable, pre-filled infusion pump and IFU are safe and effective for use. In accordance with regulatory guidelines, the usability and HF aspects of SMT-101 were developed and refined through a rigorous HF program in patients with PAH and healthcare providers, which culminated in a summative study that validated the usability and use-safety of SMT-101.

  13. Another Approach to Measuring Human Development: The Composite Dynamic Human Development Index

    Science.gov (United States)

    Bilbao-Ubillos, Javier

    2013-01-01

    This paper seeks mainly to contribute to the debate on how the relative degree of development of a country should be measured by proposing an indicator to build on the valuable starting point provided by the Human Development Index (HDI). The indicator proposed is called the "Composite, Dynamic Human Development Index". It incorporates in a simple…

  14. Validation of brachial artery pressure reconstruction from finger arterial pressure

    NARCIS (Netherlands)

    Guelen, Ilja; Westerhof, Berend E.; van der Sar, Gertrude L.; van Montfrans, Gert A.; Kiemeneij, Ferdinand; Wesseling, Karel H.; Bos, Willem Jan W.

    2008-01-01

    Objective Measurement of finger artery pressure with Finapres offers noninvasive continuous blood pressure, which, however, differs from brachial artery pressure. Generalized waveform filtering and level correction may convert the finger artery pressure waveform to a brachial waveform. An upper-arm

  15. Elasticity changes in the large arteries of human limbs in response to cycle ergometry performed with upper and lower limbs.

    Science.gov (United States)

    Mazhbich, B I; Roifman, M D

    1989-01-01

    At rest and after cycle ergometry the elastic properties of the large arteries of limbs of healthy men were examined using an original non-invasive quantitative oscillometric method. It has been shown that in response to muscle work performed with the legs there is a decrease of the effective inner radius, and an increase of the characteristic impedance modulus and bulk modulus and of the elastic resistance of the intact and relaxed wall in the large arteries in the upper limbs. All these changes testify to an increase of vascular tension in the upper limbs. In response to work performed with the hands, there is an increase of the effective inner radius of large arteries of the upper limbs, a large increase of the pulsatile blood volume increment of the intact vessels and a decrease of the characteristic impedance modulus, of the bulk modulus and of the elastic resistance of the intact arterial wall. These changes indicate a decrease of the vascular tension of these arteries. In response to work performed either with the legs or with the hands a decrease of the effective inner radius of large arteries and an increase of the elastic resistance of the relaxed arterial wall were observed in the lower limbs, all these changes indicating relatively small changes in tone of these vessels. It is concluded that the wall tension of large arteries supplying blood to the muscles of non-working limbs is increased. Vascular tension changes in the arteries in working limbs are accounted for by the superimposition of centrally originating vasoconstriction with local vasodilatation, which also affects large arteries.

  16. Measurement of interstitial cetirizine concentrations in human skin

    DEFF Research Database (Denmark)

    Petersen, Lars Jelstrup; Church, M K; Rihoux, J P

    1999-01-01

    BACKGROUND: The purpose of the present study was to measure the concentrations of cetirizine in the extracellular water compartment in intact human skin and assess simultaneously inhibition of histamine-induced wheal and flare reactions. METHODS: Skin cetirizine levels were collected by the micro...

  17. Thyroid hormone effect on human mitochondria measured by flow cytometry

    DEFF Research Database (Denmark)

    Kvetny, Jan; Bomholt, Tobias; Pedersen, Palle

    2009-01-01

    BACKGROUND: Mitochondrial function may be impaired in a number of diseases including metabolic syndrome, cardiovascular disease and endocrine disorders. Therefore it is important to be able to measure mitochondrial function in human cells. PURPOSE: The aim of the present study was to evaluate a m...

  18. Authentication of Radial Versus Femoral Arterial Pressure Waveform-Derived Cardiac Output With Transesophageal Echocardiography-Derived Cardiac Output Measurements in Patients Undergoing On-Pump Coronary Bypass Surgery.

    Science.gov (United States)

    Maddali, Madan Mohan; Waje, Niranjan Dilip; Sathiya, Panchatcharam Murthi

    2017-08-01

    The aim of this study was to ascertain if arterial waveform-derived cardiac output measurements from radial and femoral cannulation sites were reliable as compared with transesophageal echocardiography (TEE)-derived cardiac output (CO) values, and which of the CO measurements derived from radial and the femoral arterial pressure waveforms closely tracked simultaneously measured TEE-derived CO values. This study also aimed to ascertain if cardiopulmonary bypass (CPB) would impact the accuracy of arterial pressure-derived CO values from either of the 2 sites. A prospective observational study. Tertiary care cardiac center. Cardiac surgical patients undergoing on-pump primary coronary artery bypass surgery. Waveform-derived CO monitoring through radial and femoral artery cannulation using a FloTrac/Vigileo system. Twenty-seven consecutive cardiac surgical patients undergoing on-pump primary coronary artery bypass surgery were included in the study. Cardiac output was measured sequentially by the arterial pressure waveform analysis method from radial and femoral arterial sites and compared with simultaneously measured TEE-derived CO. Cardiac output data were obtained in triplicate at 6 predefined time intervals: before and after sternotomy, 5, 15, and 30 minutes after separation from CPB and prior to shifting the patient out of the operating room. The overall bias of the study was 0.11 and 0.27, the percentage error was 19.31 and 18.45, respectively, for radial and femoral arterial waveform-derived CO values as compared with TEE-derived CO measurements. The overall precision as compared with the TEE-derived CO values was 16.94 and 15.95 for the radial and femoral cannulation sites, respectively. The bias calculated by the Bland-Altman method suggested that CO measurements from the radial arterial site were in closer agreement with TEE-derived CO values at all time periods, and the relation was not affected by CPB. However, percentage error and precision calculations

  19. Interstitial and arterial-venous [K+] in human calf muscle during dynamic exercise

    DEFF Research Database (Denmark)

    Green, Stefan Mathias; Langberg, Henning; Skovgaard, D

    2000-01-01

    Changes in the concentration of interstitial K+ surrounding skeletal muscle fibres ([K+]I) probably play some role in the regulation of cardiovascular adjustments to muscular activity, as well as in the aetiology of muscle pain and fatigue during high-intensity exercise. However, there is very...... little information on the response of [K+]I to exercise in human skeletal muscle. Five young healthy subjects performed plantar flexion exercise for four 5 min periods at increasing power outputs ( approximately 1-6 W) with 10 min intervening recovery periods, as well as for two 5 min periods......+. Calf muscle pain was assessed using a visual analogue scale. On average, [K+]I was 4.4 mmol l(-1) at rest and increased during minutes 3-5 of incremental exercise by approximately 1-7 mmol l(-1) as a positive function of power output. K+ release also increased as a function of exercise intensity...

  20. Pharmacological modulation of arterial stiffness.

    LENUS (Irish Health Repository)

    Boutouyrie, Pierre

    2011-09-10

    Arterial stiffness has emerged as an important marker of cardiovascular risk in various populations and reflects the cumulative effect of cardiovascular risk factors on large arteries, which in turn is modulated by genetic background. Arterial stiffness is determined by the composition of the arterial wall and the arrangement of these components, and can be studied in humans non-invasively. Age and distending pressure are two major factors influencing large artery stiffness. Change in arterial stiffness with drugs is an important endpoint in clinical trials, although evidence for arterial stiffness as a therapeutic target still needs to be confirmed. Drugs that independently affect arterial stiffness include antihypertensive drugs, mostly blockers of the renin-angiotensin-aldosterone system, hormone replacement therapy and some antidiabetic drugs such as glitazones. While the quest continues for \\'de-stiffening drugs\\

  1. Human Factors Research for Space Exploration: Measurement, Modeling, and Mitigation

    Science.gov (United States)

    Kaiser, Mary K.; Allen, Christopher S.; Barshi, Immanuel; Billman, Dorrit; Holden, Kritina L.

    2010-01-01

    As part of NASA's Human Research Program, the Space Human Factors Engineering Project serves as the bridge between Human Factors research and Human Spaceflight applications. Our goal is to be responsive to the operational community while addressing issues at a sufficient level of abstraction to ensure that our tools and solutions generalize beyond the point design. In this panel, representatives from four of our research domains will discuss the challenges they face in solving current problems while also enabling future capabilities. Historically, engineering-dominated organizations have tended to view good Human Factors (HF) as a desire rather than a requirement in system design and development. Our field has made significant gains in the past decade, however; the Department of Defense, for example, now recognizes Human-System Integration (HSI), of which HF is a component, as an integral part of their divisions hardware acquisition processes. And our own agency was far more accepting of HF/HSI requirements during the most recent vehicle systems definition than in any prior cycle. Nonetheless, HF subject matter experts at NASA often find themselves in catch up mode... coping with legacy systems (hardware and software) and procedures that were designed with little regard for the human element, and too often with an attitude of we can deal with any operator issues during training. Our challenge, then, is to segregate the true knowledge gaps in Space Human Factors from the prior failures to incorporate best (or even good) HF design principles. Further, we strive to extract the overarching core HF issues from the point-design-specific concerns that capture the operators (and managers) attention. Generally, our approach embraces a 3M approach to Human Factors: Measurement, Modeling, and Mitigation. Our first step is to measure human performance, to move from subjective anecdotes to objective, quantified data. Next we model the phenomenon, using appropriate methods in

  2. Application of postured human model for SAR measurements

    Science.gov (United States)

    Vuchkovikj, M.; Munteanu, I.; Weiland, T.

    2013-07-01

    In the last two decades, the increasing number of electronic devices used in day-to-day life led to a growing interest in the study of the electromagnetic field interaction with biological tissues. The design of medical devices and wireless communication devices such as mobile phones benefits a lot from the bio-electromagnetic simulations in which digital human models are used. The digital human models currently available have an upright position which limits the research activities in realistic scenarios, where postured human bodies must be considered. For this reason, a software application called "BodyFlex for CST STUDIO SUITE" was developed. In its current version, this application can deform the voxel-based human model named HUGO (Dipp GmbH, 2010) to allow the generation of common postures that people use in normal life, ensuring the continuity of tissues and conserving the mass to an acceptable level. This paper describes the enhancement of the "BodyFlex" application, which is related to the movements of the forearm and the wrist of a digital human model. One of the electromagnetic applications in which the forearm and the wrist movement of a voxel based human model has a significant meaning is the measurement of the specific absorption rate (SAR) when a model is exposed to a radio frequency electromagnetic field produced by a mobile phone. Current SAR measurements of the exposure from mobile phones are performed with the SAM (Specific Anthropomorphic Mannequin) phantom which is filled with a dispersive but homogeneous material. We are interested what happens with the SAR values if a realistic inhomogeneous human model is used. To this aim, two human models, a homogeneous and an inhomogeneous one, in two simulation scenarios are used, in order to examine and observe the differences in the results for the SAR values.

  3. 1D.09: APPLICABILITY OF MEASUREMENT OF RENAL PERFUSION USING 1.5 TESLA MRI ARTERIAL SPIN LABELLING.

    Science.gov (United States)

    Kistner, I; Ott, C; Jumar, A; Friedrich, S; Grosso, R; Siegl, C; Schmieder, R E; Janka, R

    2015-06-01

    Renal perfusion is a key parameter of kidney function and the decrement of renal perfusion is a marker of target organ damage caused by hypertension. Detecting these changes in renal perfusion could help to manage antihypertensive therapy and evaluate patients[Combining Acute Accent] prognosis. Measurement of renal perfusion by MRI arterial spin labelling (ASL) is a non-invasive and non-time-consuming method without the need to inject any contrast agent. This study examined reproducibility of renal perfusion measured by 1.5 Tesla MRI. Renal perfusion was measured by ASL technique using an 1.5 Tesla MRI scanner. Subjects were scanned 3 times at two different days in an interval of two weeks to assess the test-retest reproducibility. Renal perfusion was automatically calculated for the cortex and medulla of the kidney by dedicated software. 14 patients were included with mean age 48.9 ± 12.7 and mean office blood pressure 132 ± 16/82 ± 10mmHg and estimated glomerular filtration rate> 60 ml/min/1.73m. The change of the mean total, cortical and medullary renal perfusion from the first examination to the second examination was 0.37 ± 13/0.62 ± 18/0.00 ± 12 ml/min/100 g kidney weight (p = 0.915/p = 0.898/p = 0.998), respectively. There was also no significant difference between the three renal perfusion measurements at one time point. For clinical trials these data indicate that to detect a 5% (10%) difference of cortical renal perfusion due to an intervention (vs placebo) only 38 (14) patients are required in face of the observed standard deviation for the change in renal perfusion. The inter and intra-session reproducibility of cortical renal perfusion assessed by MRI ASL 1.5 Tesla is excellent and small study cohorts can be used for examination of renal perfusion.

  4. Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients

    Directory of Open Access Journals (Sweden)

    Sharma Vikas

    2011-01-01

    Full Text Available Transthoracic electrical bioimpedance (TEB has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India and compared it with thermodilution (TD method in patients after off-pump coronary artery bypass (OPCAB graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min, while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min. The average correlation (r was 0.548 (P = 0.0002, accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min, while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min. Their average correlation was relatively poor (r = 0.469, P= 0.002, accompanied by a bias of −0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation and 17.4% (during spontaneous breathing, respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

  5. Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients.

    Science.gov (United States)

    Sharma, Vikas; Singh, Ajmer; Kansara, Bhuvnesh; Karlekar, Anil

    2011-01-01

    Transthoracic electrical bioimpedance (TEB) has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO) measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India) and compared it with thermodilution (TD) method in patients after off-pump coronary artery bypass (OPCAB) graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous) on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min), while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min). The average correlation (r) was 0.548 (P = 0.0002), accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min), while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min). Their average correlation was relatively poor (r = 0.469, P= 0.002), accompanied by a bias of -0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation) and 17.4% (during spontaneous breathing), respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

  6. Investigation of CGRP receptors and peptide pharmacology in human coronary arteries. Characterization with a nonpeptide antagonist

    DEFF Research Database (Denmark)

    Hasbak, Philip; Saetrum Opgaard, Ole; Eskesen, Karen

    2003-01-01

    .8, and 6.3 M, respectively. Preincubation with alphaCGRP(8-37) (10(-7) -10(-5) M) and a novel nonpeptide CGRP antagonist "Compound 1" (WO98/11128) (10(-7)-10(-5) M) caused a dose-dependent rightward shift of the concentration-response curves for alphaCGRP with pA(2) values of 7.0 and 7.1, respectively....... Preincubation with alphaCGRP(8-37) (10(-6) M) and Compound 1 (10(-6) M) caused significant rightward shift of the concentration-response curves for AM and amylin as well with pK B values between 6.6 and 7.5. Preincubation with AM(22-52) had no antagonistic effect on the AM and amylin response, neither did....... Compound 1 acted as a nonpeptide antagonist at the CGRP1 receptor and could thus become a tool for the study of CGRP-mediated functional responses in human tissue....

  7. Noninvasive measurement of relative cerebral blood glow using arterial spin labeling techniques: Physical basics and clinical applications; Nichtinvasive Messung des relativen zerebralen Blutflusses mit der MR-Blutbolusmarkierungstechnik (arterial-spin-labeling): Physikalische Grundlagen und klinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Weber, M.A. [Abteilung Onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany); Abteilung Onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, Heidelberg (Germany); Kroll, A. [Abteilung Biophysik und Medizinische Strahlenphysik, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany); Deutsches Krebsforschungszentrum (dkfz), Abteilung Medizinische Physik in der Radiologie (E020), Im Neuenheimer Feld 280, 69120, Heidelberg (Germany); Guenther, M. [Abteilung Biophysik und Medizinische Strahlenphysik, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany); Advanced MRI Technologies, Sebastopol, CA (United States); Delorme, S.; Debus, J.; Giesel, F.L.; Essig, M.; Kauczor, H.U. [Abteilung Onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany); Schad, L.R. [Abteilung Biophysik und Medizinische Strahlenphysik, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany)

    2004-02-01

    Knowledge of tumor blood flow is important for diagnosis and follow-up of brain tumors after therapy, especially to discriminate necrosis from tumor recurrence after radiation or chemotherapy. Meanwhile, perfusion and diffusion MRI, besides MR-angiography, are state of the art in stroke imaging. Until now, perfusion imaging was mostly performed using the first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) MRI. The MRI-based arterial spin labeling technique (ASL) is a novel approach for measuring relative cerebral blood flow (rCBF) without using extrinsic contrast agents, by labeling spins of flowing arterial blood as intrinsic contrast agent. This article describes physical basics of ASL and shows clinical examples in neuroimaging such as in meningeoma, glioblastoma, oligodendroglioma, and cerebral ischemia, using the Q2TIPS ASL technique. Gray matter is clearly visible, while the observed white matter signal obtained by Q2TIPS is only slightly higher than background noise. Venous blood causes artefacts in the sagittal sinus and other large superficial veins in the subarachnoid space. Meningeoma and glioblastoma show elevated rCBF, whereas oligodendroglioma and cerebral ischemia have reduced rCBF values. Arterial-spin-labeling techniques are noninvasive tools for measuring rCBF within 5 min, using a standard MRI scanner. (orig.) [German] Die Bestimmung des Blutflusses innerhalb eines Tumors ist fuer den klinischen Onkologen zur Differenzialdiagnostik von Hirntumoren und zur Verlaufskontrolle nach Therapie von grossem Interesse, insbesondere zur Beurteilung von Nekrose oder Rezidiv nach Chemo- oder Strahlenbehandlung. In der Schlaganfallmedizin gehoert mittlerweile die Bestimmung des Blutflusses und des Blutvolumens neben MR-Diffusionsbildgebung und MR-Angiographie zur Standarddiagnostik. Die derzeit mit der MRT durchgefuehrten Perfusionsmessungen basieren hauptsaechlich auf der kontrastmittelverstaerkten T2{sup *}-Dynamik. Mit der

  8. Quantifying Engagement: Measuring Player Involvement in Human-Avatar Interactions.

    Science.gov (United States)

    Norris, Anne E; Weger, Harry; Bullinger, Cory; Bowers, Alyssa

    2014-05-01

    This research investigated the merits of using an established system for rating behavioral cues of involvement in human dyadic interactions (i.e., face-to-face conversation) to measure involvement in human-avatar interactions. Gameplay audio-video and self-report data from a Feasibility Trial and Free Choice study of an effective peer resistance skill building simulation game (DRAMA-RAMA™) were used to evaluate reliability and validity of the rating system when applied to human-avatar interactions. The Free Choice study used a revised game prototype that was altered to be more engaging. Both studies involved girls enrolled in a public middle school in Central Florida that served a predominately Hispanic (greater than 80%), low-income student population. Audio-video data were coded by two raters, trained in the rating system. Self-report data were generated using measures of perceived realism, predictability and flow administered immediately after game play. Hypotheses for reliability and validity were supported: Reliability values mirrored those found in the human dyadic interaction literature. Validity was supported by factor analysis, significantly higher levels of involvement in Free Choice as compared to Feasibility Trial players, and correlations between involvement dimension sub scores and self-report measures. Results have implications for the science of both skill-training intervention research and game design.

  9. Measuring quality of life in Macedonia - using human development indicators

    Directory of Open Access Journals (Sweden)

    Dimitar Eftimoski

    2006-12-01

    Full Text Available By the end of the 1980s, the central issue of development was focused on the growth of income and not on the growth of quality of life. Therefore, the development strategies were oriented towards production and left no significant space for improving the welfare of individuals.In the beginning of the 1990s, the human development concept emerged, stressing that economic development ultimately should result in growth of quality of life of individuals, while the goal of the development process was to expand the capabilities of individuals by placing them in the focus of the efforts for development.This paper if focused on the quality of life of the individuals. Moreover, in addition to the previous practice in Macedonia of calculating the human development index (HDI - as a measure of quality of life, an attempt will be made to calculate the humanpoverty index (HPI-2 - as a measure of non-income poverty, gender development index (GDI - as a measure of inequality between men and women, as well as the human development index at the level of aggregated urban and rural municipalities.We hope that it will contribute to the improvement of the quality of decisions made by the state and local authorities in Macedonia when it comes to issues concerning the human development.

  10. Measurement of human embryonic stem cell in the growing cycle

    Science.gov (United States)

    Li, X.; Zhao, L.; Oh, Steve K. W.; Chong, W. K.; Ong, J. K.; Chen, Allen K.; Choo, Andre B. H.

    2008-09-01

    A measurement and imaging system has been developed for in-line continuous measurement of live, unmodified, human embryonic stem cells (hESC). The measurement will not affect cell growth, structure, sterility and suitability for clinical use. The stem cell imaging system (SCIS) can be used to support the optimization of automated stem cell growth for invitro study and for high-volume bio-manufacture. This paper present the experimental and analysis for the optimization of system parameters. A non-linear lighting is developed to obtain a clear images. The individual cluster can be traced from day one to day two. The whole system is calibrated with measurement microscope and haemacytometer. The measurement accuracy is better than 90%.

  11. Measuring selective constraint on fertility in human life histories.

    Science.gov (United States)

    Jones, James Holland; Tuljapurkar, Shripad

    2015-07-21

    Human life histories combine late age at first reproduction, long reproductive span, relatively high fertility, and substantial postreproductive survival. However, even among the most fecund populations, human fertility falls far below its theoretical maximum. The extent of parental care required for successful offspring recruitment and widespread fertility decline under proper economic conditions suggest that selection on fertility is constrained by trade-offs with recruitment. Here we measure the trade-offs between life history traits under selection by approximating the slope of the selective constraint curve on two traits at the observed values. Using a selection of populations that span human demographic space, we find that the substitution elasticity of fertility for infant survival shows age-related patterns, with minimum substitution elasticities ranging from 14 to 22 for the four populations. The age of this minimum occurs earlier in the high-mortality populations relative to generation time than it does in the low-mortality populations. The human curves are qualitatively similar to one of two comparable nonhuman primate age-specific substitution elasticity curves. The curve for rhesus macaques has a similar shape but is shifted down, meaning that the threshold for switching from investing in survival to fertility is lower at all ages. The magnitude of the substitution elasticities is similar between chimpanzees and humans but the shape is quite different, rising more slowly for a longer fraction of the chimpanzee life cycle. The steeply rising substitution elasticities with age in humans has clear implications for the evolution of reproductive senescence.

  12. Topological changes of the human autonomic cardiac nervous system in individuals with a retroesophageal right subclavian artery: two case reports and a brief review.

    Science.gov (United States)

    Kawashima, Tomokazu; Sasaki, Hiroshi

    2005-11-01

    The topological changes of the human autonomic cardiac nervous system in two cadavers with a retroesophageal right subclavian artery (Rersa) were compared with the normal autonomic cardiac nervous system. The following new results were obtained in addition to the conventional deficient finding of the right recurrent laryngeal nerve. (1) Right superior cardiac nerves arising from the superior cervical ganglion were consistently observed in both cadavers, in addition to the right thoracic cardiac nerves along the Rersa. (2) A segmental accompanying tendency of the right cardiac nerves was recognized: the cardiac nerves arising from the sympathetic trunk cranial to the middle cervical ganglia ran along with the right common carotid artery, whereas the cardiac nerves arising from the sympathetic trunk caudal to the vertebral ganglion ran along the Rersa. (3) The right thoracic cardiac nerves, which have never been observed to accompany the normal right subclavian artery, ran along the proximal part of the Rersa. According to previous reports of individuals with the Rersa, a thick right thoracic cardiac nerve is commonly observed instead of a right superior cardiac nerve. However, all the cardiac nerves were recognized in both the individuals described in the present report. Therefore, we strongly disagree with the previous idea that the origin of the right cardiac nerves from the sympathetic trunk and ganglia is shifted caudally in individuals with the Rersa. The topological changes of the autonomic cardiac nervous system in two cases of Rersa also reflected spatial changes of great arteries.

  13. Depression and anxiety in patients with coronary artery disease, measured by means of self-report measures and clinician-rated instrument.

    Science.gov (United States)

    Moryś, Joanna M; Bellwon, Jerzy; Adamczyk, Katarzyna; Gruchała, Marcin

    2016-01-01

    The presence of depression symptomatology significantly deteriorates the prognosis for the patient. There are many instruments developed to measure depression and anxiety in clinical trials; however, the suitability of the specific scale for screening these disorders in cardiovascular patients is debatable. The aim of current study is to verify which of the major assessment instruments is the most relevant for the screening evaluation of depression and anxiety in patients with cardiovascular system diseases. The sample studied consisted of 120 patients with stable coronary artery disease (CAD). They did not display serious psychiatric or somatic disorders. To assess depressive and anxiety symptoms we used self-reporting measures (BDI-II, HADS, SSAI/STAI, and PHQ), the results of which were compared to results obtained on the basis of a clinician-rating instrument (HRSD). We found that depressive symptoms assessed on the basis of HRSD, BDI-II, and PHQ-9 were equivalent in results, while the results obtained in HADS-D were significantly lower. Anxiety symptoms were found at approximate levels in HADS, SSAI, and GAD-7. The assessment of somatic symptoms in patients with CAD indicates that 87.5% of the subjects reported somatic symptoms of various intensity. Screening assessment of depression in patients with CAD gives different results depending on the tool used. We found that HADS significantly underestimates the percentage of patients with symptoms of depression in patients with CAD. Assessing anxiety symptoms with the aid of HADS gave outcomes close to the results gained by use of other tools.

  14. Impact of Personal Characteristics and Technical Factors on Quantification of Sodium 18F-Fluoride Uptake in Human Arteries

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Thomassen, Anders; de Jong, Pim A

    2015-01-01

    Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment of atherosclerosis, but is hampered by a lack of validated quantification protocols. Both personal characteristics and technical factors can affect quantification of arterial (18)F-NaF uptake....... This study investigated if blood activity, renal function, injected dose, circulating time, and PET/CT system affect quantification of arterial (18)F-NaF uptake. METHODS: Eighty-nine healthy subjects were prospectively examined by (18)F-NaF PET/CT imaging. Arterial (18)F-NaF uptake was quantified...... at the level of the ascending aorta, aortic arch, descending thoracic aorta, and coronary arteries by calculating the maximum (18)F-NaF activity (NaFmax), the maximum target-to-background ratio (TBRmax/mean), and the maximum blood subtracted (18)F-NaF activity (bsNaFmax). Multivariable linear regression...

  15. A Case of Isolated Coronary Artery Ectasia in the Setting of Chronic Inflamation From human Immunodeficiency Virus Infection.

    Science.gov (United States)

    Heckle, Mark R; Askari, Raza; Morsy, Mohamed; Ibebuogu, Uzoma N

    2016-01-01

    Coronary artery ectasia also known as dilated coronopathy is a relatively rare finding that is most commonly associated with atherosclerosis. Several alternative reasons including congenital malformations and chronic inflammation have been identified as a cause of CAE. In this case, we discuss a 61-year-old male with postoperative chest pain who was found to have localized CAE in the absence of significant atherosclerosis. We also elucidate the recently proposed markers of chronic inflammation that might be associated with coronary artery ectasia.

  16. Use of electromyography measurement in human body modeling

    Directory of Open Access Journals (Sweden)

    Valdmanová L.

    2011-06-01

    Full Text Available The aim of this study is to test the use of the human body model for the muscle activity computation. This paper shows the comparison of measured and simulated muscle activities. Muscle active states of biceps brachia muscle are monitored by method called electromyography (EMG in a given position and for given subsequently increasing loads. The same conditions are used for simulation using a human body model (Hynčík, L., Rigid Body Based Human Model for Crash Test Purposes, EngineeringMechanics, 5 (8 (2001 1–6. This model consists of rigid body segments connected by kinematic joints and involves all major muscle bunches. Biceps brachia active states are evaluated by a special muscle balance solver. Obtained simulation results show the acceptable correlation with the experimental results. The analysis shows that the validation procedure of muscle activities determination is usable.

  17. Measuring Government Expenditure Efficiencies Towards Peace and Human Development

    Directory of Open Access Journals (Sweden)

    Ahmad Danu Prasetyo

    2014-02-01

    Full Text Available In this paper, we investigate the efficiency level of government expenditure in 82 countries towards the human development and peace index of the respective countries by using Data Envelopment Analysis (DEA approach during 2007-2011. We found that only few countries that always being positioned in the efficient frontier during the sample period, namely: Japan, Nigeria, and Norway.  By using Malmquist index approach, we also found that Cyprus has the largest government expenditure efficiency improvement.Keywords: Government Expenditure Efficiencies, Human Development Index, Global Peace Indexdoi:10.12695/ajtm.2013.6.2.3 How to cite this article:Prasetyo, A.D., and Pudjono, A.N.S. (2013. Measuring Government Expenditure Efficiencies Towards Peace and Human Development. The Asian Journal of Technology Management 6 (2: 82-91. Print ISSN: 1978-6956; Online ISSN: 2089-791X. doi:10.12695/ajtm.2013.6.2.3

  18. Multiple distinct stimuli increase measured nucleosome occupancy around human promoters.

    Directory of Open Access Journals (Sweden)

    Chuong D Pham

    Full Text Available Nucleosomes can block access to transcription factors. Thus the precise localization of nucleosomes relative to transcription start sites and other factor binding sites is expected to be a critical component of transcriptional regulation. Recently developed microarray approaches have allowed the rapid mapping of nucleosome positions over hundreds of kilobases (kb of human genomic DNA, although these approaches have not yet been widely used to measure chromatin changes associated with changes in transcription. Here, we use custom tiling microarrays to reveal changes in nucleosome positions and abundance that occur when hormone-bound glucocorticoid receptor (GR binds to sites near target gene promoters in human osteosarcoma cells. The most striking change is an increase in measured nucleosome occupancy at sites spanning ∼1 kb upstream and downstream of transcription start sites, which occurs one hour after addition of hormone, but is lost at 4 hours. Unexpectedly, this increase was seen both on GR-regulated and GR-non-regulated genes. In addition, the human SWI/SNF chromatin remodeling factor (a GR co-activator was found to be important for increased occupancy upon hormone treatment and also for low nucleosome occupancy without hormone. Most surprisingly, similar increases in nucleosome occupancy were also seen on both regulated and non-regulated promoters during differentiation of human myeloid leukemia cells and upon activation of human CD4+ T-cells. These results indicate that dramatic changes in chromatin structure over ∼2 kb of human promoters may occur genomewide and in response to a variety of stimuli, and suggest novel models for transcriptional regulation.

  19. Assays for in vitro monitoring of human airway smooth muscle (ASM) and human pulmonary arterial vascular smooth muscle (VSM) cell migration.

    Science.gov (United States)

    Goncharova, Elena A; Goncharov, Dmitry A; Krymskaya, Vera P

    2006-01-01

    Migration of human pulmonary vascular smooth muscle (VSM) cells contributes to vascular remodeling in pulmonary arterial hypertension and atherosclerosis. Evidence also indicates that, in part, migration of airway smooth muscle (ASM) cells may contribute to airway remodeling associated with asthma. Here we describe migration of VSM and ASM cells in vitro using Transwell or Boyden chamber assays. Because dissecting signaling mechanisms regulating cell migration requires molecular approaches, our protocol also describes how to assess migration of transfected VSM and ASM cells. Transwell or Boyden chamber assays can be completed in approximately 8 h and include plating of serum-deprived VSM or ASM cell suspension on membrane precoated with collagen, migration of cells toward chemotactic gradient and visual (Transwell) or digital (Boyden chamber) analysis of membrane. Although the Transwell assay is easy, the Boyden chamber assay requires hands-on experience; however, both assays are reliable cell-based approaches providing valuable information on how chemotactic and inflammatory factors modulate VSM and ASM migration.

  20. Development of a device to measure human sound localization.

    Science.gov (United States)

    Eder, Reinhard; Scheel, Norman

    2011-10-01

    Measurements of human sound discrimination and localization are important for basic empirical and clinical applications. After a short survey of other methods such as evoked potentials, the development of a new device to measure human sound localization is described and its use illustrated with some examples. Built from a polyacrylic hemisphere or--in a later version--from an orbicular aluminum frame, the apparatus uses multiple speakers to emit auditory stimuli. The patient sits in the middle of the perimeter and has to press a button when a sound is perceived. In addition, the participant has to identify the correct speaker as the source of the sound. With this method it is possible to map the auditory field.

  1. Effects of some anti-diabetic and cardioprotective agents on proliferation and apoptosis of human coronary artery endothelial cells

    Directory of Open Access Journals (Sweden)

    Eriksson Linnéa

    2012-03-01

    Full Text Available Abstract Background The leading cause of death for patients suffering from diabetes is macrovascular disease. Endothelial dysfunction is often observed in type 2 diabetic patients and it is considered to be an important early event in the pathogenesis of atherogenesis and cardiovascular disease. Many drugs are clinically applied to treat diabetic patients. However, little is known whether these agents directly interfere with endothelial cell proliferation and apoptosis. This study therefore aimed to investigate how anti-diabetic and cardioprotective agents affect human coronary artery endothelial cells (HCAECs. Methods The effect of anti-diabetic and cardioprotective agents on HCAEC viability, proliferation and apoptosis was studied. Viability was assessed using Trypan blue exclusion; proliferation in 5 mM and 11 mM of glucose was analyzed using [3H]thymidine incorporation. Lipoapoptosis of the cells was investigated by determining caspase-3 activity and the subsequent DNA fragmentation after incubation with the free fatty acid palmitate, mimicking diabetic lipotoxicity. Results Our data show that insulin, metformin, BLX-1002, and rosuvastatin improved HCAEC viability and they could also significantly increase cell proliferation in low glucose. The proliferative effect of insulin and BLX-1002 was also evident at 11 mM of glucose. In addition, insulin, metformin, BLX-1002, pioglitazone, and candesartan significantly decreased the caspase-3 activity and the subsequent DNA fragmentation evoked by palmitate, suggesting a protective effect of the drugs against lipoapoptosis. Conclusion Our results suggest that the anti-diabetic and cardioprotective agents mentioned above have direct and beneficial effects on endothelial cell viability, regeneration and apoptosis. This may add yet another valuable property to their therapeutic effect, increasing their clinical utility in type 2 diabetic patients in whom endothelial dysfunction is a prominent feature

  2. Cigarette smoke but not electronic cigarette aerosol activates a stress response in human coronary artery endothelial cells in culture.

    Science.gov (United States)

    Teasdale, Jack E; Newby, Andrew C; Timpson, Nicholas J; Munafò, Marcus R; White, Stephen J

    2016-06-01

    It is generally acknowledged that e-cigarettes are unlikely to be as harmful as conventional cigarettes, but there is little data that quantifies their relative harms. We investigated the biological response to e-cigarette aerosol exposure (versus conventional cigarette smoke exposure) at the cellular level, by exposing human coronary artery endothelial cells (HCAEC) to aqueous filtered extracts of e-cigarette aerosol or cigarette smoke and looking at gene expression changes consistent with a stress response. This included genes controlled by the oxidant-stress sensing transcription factor NFR2 (NFE2L2), and cytochrome P450 family members. Cigarette smoke extract (CSE) was created using mainstream smoke from a single cigarette drawn through 10ml of endothelial cell growth media MV2. Electronic cigarette aerosol extract (eCAE) was created using the same apparatus, using a constant power output of 10.8w (4.2V) and 18mg/ml nicotine solution. eCAE was generated using 5 cycles of 5s heat with at least 10s in between each puff to allow the coil to cool, air being drawn through the device at 70ml/minute. HCAEC responded to the noxious components in CSE, resulting in activation of NRF2 and upregulation of cytochrome p450. However, eCAE did not induce NRF2 nuclear localisation, upregulation of NRF2-activated genes, or the upregulation of cytochrome p450. The use of e-