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Sample records for artificial arterial blood

  1. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  2. Pulmonary blood flow and pressure as well as arterial blood oxygenation simulations in ventilated artificial patient supported by continuous rotary blood pump.

    OpenAIRE

    ZielińSki, Krzysztof; Golczewski, Tomasz; Fresiello, Libera; Di Molfetta, Arianna; Ferrari, Gianfranco; Kozarski, Maciej; Darowski, Marek

    2011-01-01

    Objectives: Our previous study suggested insignificant impairment of pulmonary circulation during artificial ventilation if the inspiration time is smaller than the duration of 2-3 heart cycles. This was due to pulmonary blood volume periodic changes. The aim of this study is to analyze the influence of left ventricular assistance by continuous rotary blood pump (RBP) on hemodynamic in ventilated, virtual patient. Methods: Virtual RBP was added to a previously elaborated hybrid (pneumonumeric...

  3. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  4. Mechanics of Cellular Adhesion to Artificial Artery Templates

    OpenAIRE

    Knöner, Gregor; Rolfe, Barbara E.; Campbell, Julie H.; Parkin, Simon J.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2006-01-01

    We are using polymer templates to grow artificial artery grafts in vivo for the replacement of diseased blood vessels. We have previously shown that adhesion of macrophages to the template starts the graft formation. We present a study of the mechanics of macrophage adhesion to these templates on a single cell and single bond level with optical tweezers. For whole cells, in vitro cell adhesion densities decreased significantly from polymer templates polyethylene to silicone to Tygon (167, 135...

  5. Structured Tree Outflow Condition for Blood Flow in Arteries

    Science.gov (United States)

    Olufsen, Mette

    1998-11-01

    Modeling blood flow and especially propagation of the pulse wave in the systemic arteries is of interests to the medical society because of the significance of the dicrotic wave. The pulse wave propagating along the larger arteries is reflected because of tapering and branching of the vessels, as well as the peripheral resistance, which is mainly stemming from the smaller arteries and arterioles. In order to avoid artificial reflections it is important to determine a boundary condition, representing the smaller arteries and arterioles, which is physiologically correct. In this work we have proposed a boundary condition based on a structured tree model. The result will be compared both with other modeling approaches as well as with results from measurements of flow and pressure at a number of locations along the larger arteries. The model for the larger arteries is based on the axisymmetrical Navier Stokes equations where the blood is assumed Newtonian and incompressible and the vessels are tapering. In the structured tree the model is based on a linearization of the axisymmetrical Navier-Stokes equations. The reason for setting up a structured tree is that the smaller arteries consist of an almost binary tree. Furthermore, the role of the smaller arteries is to allow blood perfusion of specific tissues. This is done in a structured and optimal way such that the smaller arteries cover the tissue evenly using a minimization principle.

  6. Continuous blood gas monitoring in femoral arteries

    Science.gov (United States)

    Schlain, Les A.; Spar, Steven M.; Dellinger, Bart

    1995-05-01

    Continuous intra-arterial blood gas monitoring is a potentially valuable tool in the surgical and intensive care arenas. Patient oxygenation and acid base status can change rapidly and without warning. The ability to monitor pHa, PaCO2 and PaO2 in arterial blood will be a major medical advance for the anesthesiologist and intensivist. Intra-arterial blood gas sensors are typically placed in radial arteries. In certain patient populations accurate monitoring is not possible in radial arteries due to arterial environmental factors such as hypotension, vasoconstriction and atherosclerotic disease. These same factors can make radial cannulation difficult resulting in traumatic catheter insertion, thereby further compromising flow conditions. In situations where radial artery flow is expected to be compromised, selecting a large vessel for sensor placement is desirable. We report an initial feasibility study of our blood gas monitoring system using the femoral artery as the sensing site. Clinical results are presented as well as potential advantages and disadvantages associated with monitoring in the femoral artery.

  7. Modeling of blood flow in arterial trees.

    Science.gov (United States)

    Anor, Tomer; Grinberg, Leopold; Baek, Hyoungsu; Madsen, Joseph R; Jayaraman, Mahesh V; Karniadakis, George E

    2010-01-01

    Advances in computational methods and medical imaging techniques have enabled accurate simulations of subject-specific blood flows at the level of individual blood cell and in complex arterial networks. While in the past, we were limited to simulations with one arterial bifurcation, the current state-of-the-art is simulations of arterial networks consisting of hundreds of arteries. In this paper, we review the advances in methods for vascular flow simulations in large arterial trees. We discuss alternative approaches and validity of various assumptions often made to simplify the modeling. To highlight the similarities and discrepancies of data computed with different models, computationally intensive three-dimensional (3D) and inexpensive one-dimensional (1D) flow simulations in very large arterial networks are employed. Finally, we discuss the possibilities, challenges, and limitations of the computational methods for predicting outcomes of therapeutic interventions for individual patients. PMID:20836052

  8. Middle cerebral artery blood velocity during running

    DEFF Research Database (Denmark)

    Lyngeraa, Tobias; Pedersen, Lars Møller; Mantoni, T;

    2013-01-01

    Running induces characteristic fluctuations in blood pressure (BP) of unknown consequence for organ blood flow. We hypothesized that running-induced BP oscillations are transferred to the cerebral vasculature. In 15 healthy volunteers, transcranial Doppler-determined middle cerebral artery (MCA...

  9. Water hammer experiment in artificial blood vessel

    Czech Academy of Sciences Publication Activity Database

    Hromádka, D.; Horný, L.; Žitný, R.; Chlup, Hynek

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 127-132 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : water hammer * artificial blood vessel * reinforced latex tube Subject RIV: JJ - Other Materials

  10. Geomagnetic field modulates artificial static magnetic field effect on arterial baroreflex and on microcirculation

    Science.gov (United States)

    Gmitrov, Juraj

    2007-03-01

    Spreading evidence suggests that geomagnetic field (GMF) modulates artificial magnetic fields biological effect and associated with increased cardiovascular morbidity. To explore the underlying physiological mechanism we studied 350 mT static magnetic field (SMF) effect on arterial baroreflex-mediated skin microcirculatory response in conjunction with actual geomagnetic activity, reflected by K and K p indices. Fourteen experiments were performed in rabbits sedated by pentobarbital infusion (5 mg/kg/h). Mean femoral artery blood pressure, heart rate, and the ear lobe skin microcirculatory blood flow, measured by microphotoelectric plethysmogram (MPPG), were simultaneously recorded before and after 40 min of NdFeB magnets local exposure to sinocarotid baroreceptors. Arterial baroreflex sensitivity (BRS) was estimated from heart rate/blood pressure response to intravenous bolus injections of nitroprusside and phenylephrine. We found a significant positive correlation between SMF-induced increase in BRS and increment in microvascular blood flow (ΔBRS with ΔMPPG, r=0.7, p<0.009) indicated the participation of the arterial baroreflex in the regulation of the microcirculation and its enhancement after SMF exposure. Geomagnetic disturbance, as opposed to SMF, decreased both microcirculation and BRS, and counteracted SMF-induced increment in microcirculatory blood flow ( K-index with ΔMPPG; r s=-0.55, p<0.041). GMF probably affected central baroreflex pathways, diminishing SMF direct stimulatory effect on sinocarotid baroreceptors and on baroreflex-mediated vasodilatatory response. The results herein may thus point to arterial baroreflex as a possible physiological mechanism for magnetic-field cardiovascular effect. It seems that geomagnetic disturbance modifies artificial magnetic fields biological effect and should be taken into consideration in the assessment of the final effect.

  11. Arterial Blood, Rather Than Venous Blood, is a Better Source for Circulating Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Mizue Terai

    2015-11-01

    Interpretation: Our data indicate that arterial blood specimens might be a better source of circulating uveal melanoma cells. Although less conveniently processed, perhaps arterial blood should be evaluated as sample source for measurement of CTCs.

  12. Blood serum atherogenicity and coronary artery calcification.

    Science.gov (United States)

    Sobenin, Igor A; Myasoedova, Veronica A; Anisimova, Elena V; Pavlova, Xenia N; Möhlenkamp, Stefan; Schmermund, Axel; Seibel, Rainer; Berenbein, Sina; Lehmann, Nils; Moebus, Susanne; Jöckel, KarlHeinz; Orekhov, Alexander N; Erbel, Raimund

    2014-01-01

    The phenomenon of blood serum atherogenicity was described as the ability of human serum to induce lipid accumulation in cultured cells. The results of recent two-year prospective study in asymptomatic men provided the evidence for association between the changes in serum atherogenicity and dynamics of carotid intima-media thickness progression. The present study was undertaken to test the hypothesis that blood serum atherogenicity and its changes in dynamics may be associated with accumulation of coronary calcium in subclinical atherosclerosis. It was performed in 782 CHD-free participants of The Heinz Nixdorf RECALL (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) Study, in whom blood samples have been taken at the baseline and at the end of 5-year follow-up. Opposite to the previous findings, the changes in serum atherogenicity did not correlate neither with the extent of coronary artery calcification, nor with the changes in Agatston CAC score. There was a moderate but significant rise in serum atherogenicity after 5-year followup period, and the same dynamics was observed for Agatston CAC score, but not for convenient lipid-related risk factors. The absence of association of the changes in serum atherogenicity with the changes in Agatston CAC score, along with previous findings, provides a point of view that serum-induced intracellular cholesterol accumulation is not related to the processes of calcium deposition in arterial wall, since the last one reflects the progression of already existing subclinical atherosclerotic lesions. PMID:24533940

  13. DETERMINATION OF AMMONIA IN EAR-LOBE CAPILLARY BLOOD IS AN ALTERNATIVE TO ARTERIAL BLOOD AMMONIA

    NARCIS (Netherlands)

    HUIZENGA, [No Value; GIPS, CH; CONN, HO; JANSEN, PLM

    1995-01-01

    Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

  14. The "artificial artery" as in vitro perfusion model.

    Directory of Open Access Journals (Sweden)

    Doreen Janke

    Full Text Available Metabolic stimuli, pressure, and fluid shear stress (FSS are major mediators of vascular plasticity. The exposure of the vessel wall to increased laminar FSS is the main trigger of arteriogenesis, the remodelling of pre-existent arterio-arteriolar anastomoses to functional conductance arteries. In this study, we have used an in vitro bioreactor to investigate cell-specific interactions, molecular mechanisms as well as time-dependent effects under laminar FSS conditions. This bioreactor termed "artificial artery" can be used for screening potential arterio-protective substances, pro-arteriogenic factors, and for investigating biomarkers of cardiovascular diseases such as cardiac diseases. The bioreactor is built up out of 14 hollow fiber membranes colonized with endothelial cells (HUVECs on the inside and smooth muscle cells (HUASMCs on the outside. By means of Hoechst 33342 staining as well as immunocytochemistry of ß-catenin and α-smooth-muscle-actin, a microporous polypropylene membrane was characterized as being the appropriate polymer for co-colonization. Defined arterial flow conditions (0.1 N/m2 and 3 N/m2, metabolic exchange, and cross-talk of HUVECs and HUASMCs through hollow fibers mimic physiological in vivo conditions of the vasculature. Analysing mono- and co-culture secretomes by MALDI-TOF-TOF mass spectrometry, we could show that HUVECs secreted Up4A upon 3 N/m2. A constant cellular secretion of randomly chosen peptides verified viability of the "artificial artery" for a cultivation period up to five days. qRT-PCR analyses revealed an up-regulation of KLF2 and TIMP1 as mechano-regulated genes and demonstrated arterio-protective, homeostatic FSS conditions by a down-regulation of EDN1. Expression analyses of VWF and EDN1 furthermore confirmed that RNA of both cell types could separately be isolated without cross-contamination. CCND1 mRNA expression in HUVECs did not change upon FSS indicating a quiescent endothelial phenotype

  15. Influence of Artificial Sweetener on Human Blood Glucose Concentration

    OpenAIRE

    Ilse Skokan; P. Christian Endler; Beatrix Wulkersdorfer; Dieter Magometschnigg; Heinz Spranger

    2007-01-01

    Artificial sweeteners, such as saccharin or cyclamic acid are synthetically manufactured sweetenings. Known for their low energetic value they serve especially diabetic and adipose patients as sugar substitutes. It has been hypothesized that the substitution of sugar with artificial sweeteners may induce a decrease of the blood glucose. The aim of this study was to determine the reliability of this hypothesis by comparing the influence of regular table sugar and artificial sweeteners on the b...

  16. Blood transfusion requirement in surgery for femoral artery aneurysms

    DEFF Research Database (Denmark)

    Levi, N; Schroeder, T V

    1997-01-01

    Audit of blood usage in various surgical specialities have shown that over-ordering of blood is widespread, causing unnecessary pressure on the transfusion facilities and giving growing concern over the expense of cross-matching blood. The aim of this study was to assess the blood transfusion req...... requirement in patients undergoing surgery for femoral artery aneurysms....

  17. Penetration of an artificial arterial thromboembolism in a live animal using an intravascular therapeutic microrobot system.

    Science.gov (United States)

    Jeong, Semi; Choi, Hyunchul; Go, Gwangjun; Lee, Cheong; Lim, Kyung Seob; Sim, Doo Sun; Jeong, Myung Ho; Ko, Seong Young; Park, Jong-Oh; Park, Sukho

    2016-04-01

    The biomedical applications of wireless robots are an active area of study. In addition to moving to a target lesion, wireless locomotive robots can deliver a therapeutic drug for a specific disease. Thus, they hold great potential as therapeutic devices in blood vessel diseases, such as thrombi and occlusions, and in other diseases, such as cancer and inflammation. During a percutaneous coronary intervention (PCI), surgeons wear a heavy shielding cloth. However, they cannot escape severe radiation exposure owing to unstable shielding. They may also suffer from joint pains because of the weight of the shielding cloth. In addition, the catheters in PCIs are controlled by the surgeon's hand. Thus, they lack steering ability. A new intravascular therapeutic system is needed to address these problems in conventional PCIs. We developed an intravascular therapeutic microrobot system (ITMS) using an electromagnetic actuation (EMA) system with bi-plane X-ray devices that can remotely control a robot in blood vessels. Using this proposed ITMS, we demonstrated the locomotion of the robot in abdominal and iliac arteries of a live pig by the master-slave method. After producing an arterial thromboembolism in a live pig in a partial iliac artery, the robot moved to the target lesion and penetrated by specific motions (twisting and hammering) of the robot using the proposed ITMS. The results reveal that the proposed ITMS can realize stable locomotion (alignment and propulsion) of a robot in abdominal and iliac arteries of a live pig. This can be considered the first preclinical trial of the treatment of an artificial arterial thromboembolism by penetration of a blood clot. PMID:26857290

  18. Influence on fluid dynamics of coronary artery outlet angle variation in artificial aortic root prosthesis

    Directory of Open Access Journals (Sweden)

    Verhey Janko F

    2008-02-01

    Full Text Available Abstract Background Because of higher life expectancy, the number of elderly patients today with degenerative aortic diseases is on the increase. Often artificial aortic roots are needed to replace the native tissue. This surgical procedure requires re-implantation of the previous separated coronary arteries into the wall of the prosthesis. Regardless of the prosthesis type, changes in the reinsertion technique, e.g., the variation of the outlet angle of the coronary arteries, could influence the coronary blood flow. Whether the prosthesis type or the outlet angle variation significantly improves the blood circulation and lowers the risk of coronary insufficiency is still an open question. The numerical calculations presented can help to clear up these disputable questions. Methods Two simplified base geometries are used for simulating the blood flow in order to determine velocity and pressure distributions. One model uses a straight cylindrical tube to approximate the aortic root geometry; the other uses a sinus design with pseudosinuses of Valsalva. The coronary outlet angle of the right coronary artery was discretely modified in both models in the range from 60° to 120°. The pressure and velocity distributions of both models are compared in the ascending aorta as well as in the right and the left coronary artery. Results The potentially allowed and anatomic limited variation of the outlet angle influences the pressure only a little bit and shows a very slight relative maximum between 70° and 90°. The sinus design and variations of the outlet angle of the coronary arteries were able to minimally optimize the perfusion pressure and the velocities in the coronary circulation, although the degree of such changes is rather low and would probably not achieve any clinical influence. Conclusion Our results show that surgeons should feel relatively free to vary the outlet angle within the anatomic structural conditions when employing the technique

  19. Heart and Artery Damage and High Blood Pressure

    Science.gov (United States)

    ... Stroke More Heart and Artery Damage and High Blood Pressure Updated:Oct 22,2015 There are several harmful ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  20. Differences in superior thyroid artery and inferior thyroid artery blood flow spectrum parameters in subacute thyroiditis

    Institute of Scientific and Technical Information of China (English)

    Jin-Bo Li

    2016-01-01

    Objective:To study the differences in superior thyroid artery and inferior thyroid artery blood flow spectrum parameters in subacute thyroiditis. Methods:A Total of 40 cases of patients with subacute thyroiditis and 40 cases of healthy volunteers were selected for study and enrolled in pathology group and control group respectively, color Doppler ultrasonography was conducted to detect peak blood flow velocities (Vmax) of superior thyroid artery and inferior thyroid artery as well as resistance index (RI), and serum was collected to detect thyroid hormone contents, infection indexes and oxidative stress indexes. Results:Peak blood flow velocities Vmax of superior thyroid artery and inferior thyroid artery of pathology group were significantly higher than those of control group, and resistance index RI was not different from that of control group;FT3, FT4, TT3, TT4, ESR, CRP, PCT and MDA of pathology group were significantly higher than those of control group, and SOD and TAOC were significantly lower than those of control group;Vmax of superior thyroid artery and inferior thyroid artery were positively correlated with FT3, FT4, TT3, TT4, ESR, CRP, PCT and MDA, and negatively correlated with SOD and TAOC. Conclusion:Peak blood flow velocities (Vmax) of superior thyroid artery and inferior thyroid artery in subacute thyroiditis are significantly accelerated, Vmax has good consistency with thyroid hormone contents, infection indexes and oxidative stress indexes, and it can accurately assess the severity of the disease.

  1. Blood flow modeling for patient-specific bypass surgery in lower-limb arteries

    OpenAIRE

    Willemet, Marie

    2012-01-01

    Every day in Belgium, at least one or two people will undergo a bypass surgery in the lower-limb arteries. This medical procedure consists of replacing an occluded section of the leg arteries with an artificial vessel, in order to allow blood to flow downwards of this blockage. Even though this intervention is very common, failure of this treatment within five years reaches up to 60%. In order to improve our understanding of the causes of bypass failure, one approach is to study the local hem...

  2. MEASUREMENTS OF THE BLOOD CAPILLARY PRESSURE AND ARTERIAL ELASTICITY

    Institute of Scientific and Technical Information of China (English)

    HuangMengcai; GuZhong; HangWenjing; ZhongQuan; TangFuyong

    1990-01-01

    Describe some new fully automatic instruments for the measurements of the blood capillary pressure (Pcap) and arterial elastic properties in human fingers using a photoelectric plethysmographic technique, With these instruments, the value of Pcap was in good agreement with those reported by other investigators, the arterial elastic properties in human fingers have been successfully measured. The measurements of Pcap and arterial elasticity are now required in clinics because they provide useful and important information for evaluating vascular haemodynamics.

  3. Management of high blood pressure in peripheral arterial disease

    OpenAIRE

    Krzesinski, Jean-Marie

    2005-01-01

    Arterial hypertension (HTA) is a promoter of peripheral arterial disease (PAD) in association with other atherosclerotic risk factors factors. Systolic HTA is the most frequently noted form in such disease, secondary to marked increase in large artery siffness. The existence of PAD confers on the hypertensive patient a very high cardiovascular (CV) risk, requiring an intensive global therapeutical approach. Treating HTA is one of such beneficial actions. The optimal blood pressure (BP) to...

  4. Arterial blood gas levels in high altitude Kashmiri population, India

    Directory of Open Access Journals (Sweden)

    Sheikh Imran Sayeed

    2015-11-01

    Conclusions: The present study might provide useful base line normal values of Arterial Blood Gases for the local population and will be beneficial to the clinicians. [Int J Res Med Sci 2015; 3(11.000: 3283-3287

  5. Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids

    OpenAIRE

    Aiken, Christopher Geoffrey Alexander

    2013-01-01

    Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium.

  6. Rarefaction and blood pressure in systemic and pulmonary arteries.

    Science.gov (United States)

    Olufsen, Mette S; Hill, N A; Vaughan, Gareth D A; Sainsbury, Christopher; Johnson, Martin

    2012-08-01

    The effects of vascular rarefaction (the loss of small arteries) on the circulation of blood are studied using a multiscale mathematical model that can predict blood flow and pressure in the systemic and pulmonary arteries. We augmented a model originally developed for the systemic arteries (Olufsen et al. 1998, 1999, 2000, 2004) to (a) predict flow and pressure in the pulmonary arteries, and (b) predict pressure propagation along the small arteries in the vascular beds. The systemic and pulmonary arteries are modelled as separate, bifurcating trees of compliant and tapering vessels. Each tree is divided into two parts representing the `large' and `small' arteries. Blood flow and pressure in the large arteries are predicted using a nonlinear cross-sectional area-averaged model for a Newtonian fluid in an elastic tube with inflow obtained from magnetic resonance measurements. Each terminal vessel within the network of the large arteries is coupled to a vascular bed of small `resistance' arteries, which are modelled as asymmetric structured trees with specified area and asymmetry ratios between the parent and daughter arteries. For the systemic circulation, each structured tree represents a specific vascular bed corresponding to major organs and limbs. For the pulmonary circulation, there are four vascular beds supplied by the interlobar arteries. This manuscript presents the first theoretical calculations of the propagation of the pressure and flow waves along systemic and pulmonary large and small arteries. Results for all networks were in agreement with published observations. Two studies were done with this model. First, we showed how rarefaction can be modelled by pruning the tree of arteries in the microvascular system. This was done by modulating parameters used for designing the structured trees. Results showed that rarefaction leads to increased mean and decreased pulse pressure in the large arteries. Second, we investigated the impact of decreasing vessel

  7. Prediction of arterial blood gas values from arterialized earlobe blood gas values in patients treated with mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Honarmand Azim

    2008-01-01

    Full Text Available Background/Objective: Arterial blood gas (ABG analysis is useful in evaluation of the clinical condition of critically ill patients; however, arterial puncture or insertion of an arterial catheter may sometimes be difficult and cause many complications. Arterialized ear lobe blood samples have been described as adequate to gauge gas exchange in acute and chronically ill pediatric patients. Purpose: This study evaluates whether pH, partial pressure of oxygen (PO 2 , partial pressure of carbon dioxide (PCO 2 , base excess (BE, and bicarbonate (HCO 3 values of arterialized earlobe blood samples could accurately predict their arterial blood gas analogs for adult patients treated by mechanical ventilation in an intensive care unit (ICU. Setting: A prospective descriptive study Methods: Sixty-seven patients who were admitted to ICU and treated with mechanical ventilation were included in this study. Blood samples were drawn simultaneously from the radial artery and arterialized earlobe of each patient. Results: Regression equations and mean percentage-difference equations were derived to predict arterial pH, PCO 2 , PO 2 , BE, and HCO 3 -values from their earlobe analogs. pH, PCO 2 , BE, and HCO 3 all significantly correlated in ABG and earlobe values. In spite of a highly significant correlation, the limits of agreement between the two methods were wide for PO 2 . Regression equations for prediction of pH, PCO 2 , BE, and HCO3- values were: arterial pH (pHa = 1.81+ 0.76 x earlobe pH (pHe [r = 0.791, P < 0.001]; PaCO 2 = 1.224+ 1.058 x earlobePCO 2 (PeCO 2 [r = 0.956, P < 0.001]; arterial BE (BEa = 1.14+ 0.95 x earlobe BE (BEe [r= 0.894, P < 0.001], and arterial HCO 3 - (HCO 3 -a = 1.41+ earlobe HCO 3 (HCO 3 -e [r = 0.874, P < 0.001]. The predicted ABG values from the mean percentage-difference equations were derived as follows: pHa = pHe x 1.001; PaCO 2 = PeCO 2 x 0.33; BEa = BEe x 0.57; and HCO 3 -a = HCO 3 -e x 1.06. Conclusions: Arterialized

  8. Changing blood flow in peripheral artery disease

    OpenAIRE

    Borne, P. van den

    2014-01-01

    Cardiovascular disease (CVD) is the leading cause of death globally and it is predicted this will remain to increase throughout 2030 to an estimated 23,3 million patients per year. This trend is accompanied by a steep increase in healthcare costs, making it a great health and socio-economic burden. The underlying pathology of CVD is often atherosclerosis, characterized by the development of atherosclerotic plaques in middle- and larger-sized arteries. Peripheral artery disease (PAD) is a dise...

  9. 20 CFR 718.105 - Arterial blood-gas studies.

    Science.gov (United States)

    2010-04-01

    ... DEATH DUE TO PNEUMOCONIOSIS Criteria for the Development of Medical Evidence § 718.105 Arterial blood... test shall be offered to the miner unless medically contraindicated. If an exercise blood-gas test is... Appendix C is administered during a hospitalization which ends in the miner's death, then any such...

  10. PERFORMANCE MODELING AND ANALYSIS OF BLOOD FLOW IN ELASTIC ARTERIES

    Institute of Scientific and Technical Information of China (English)

    Anil Kumar; C.L. Varshney; G.C. Sharma

    2005-01-01

    Two different non-Newtonian models for blood flow are considered, first a simple power law model displaying shear thinning viscosity, and second a generalized Maxwell model displaying both shear thinning viscosity and oscillating flow viscous-elasticity. These models are used along with a Newtonian model to study sinusoidal flow of blood in rigid and elastic straight arteries in the presence of magnetic field. The elasticity of blood does not appear to influence its flow behavior under physiological conditions in the large arteries,purely viscous shear thinning model should be quite realistic for simulating blood flow under these conditions. On using the power law model with high shear rate for sinusoidal flow simulation in elastic arteries, the mean and amplitude of the flow rate were found to be lower for a power law fluid compared to Newtonian fluid for the same pressure gradient. The governing equations have been solved by Crank-Niclson scheme. The results are interpreted in the context of blood in the elastic arteries keeping the magnetic effects in view. For physiological flow simulation in the aorta, an increase in mean wall shear stress, but a reduction in peak wall shear stress were observed for power law model compared to a Newtonian fluid model for matched flow rate wave form. Blood flow in the presence of transverse magnetic field in an elastic artery is investigated and the influence of factors such as morphology and surface irregularity is evaluated.

  11. Giant coronary artery aneurysm seen on blood-pool study.

    Science.gov (United States)

    Trujillo, Alexander; Soontrapa, Suthipong; Singh, Preeti; Sehli, Sharmila; Harris, Jennifer; Suarez, Jose A; Arvandi, Aliakbar; Paone, Ralph F; Meyerrose, Gary E

    2013-01-01

    An 81-year-old man was incidentally found to have a large pericardial cyst on a chest computed tomography. Before surgical removal, an echocardiogram demonstrated that the cyst was more likely a large (7.5 cm) right coronary arterial aneurysm. A cardiac blood-pool study demonstrated a blood-filled structure adjacent to the heart, roughly the same size as the combined size of both the right and left ventricles. Coronary angiography confirmed the presence of a large right coronary artery aneurysm. A coronary aneurysm should be considered when a blood-filled structure is seen adjacent to the heart on a multigated acquisition scan. PMID:23242065

  12. Influence of Artificial Sweetener on Human Blood Glucose Concentration

    Directory of Open Access Journals (Sweden)

    Ilse Skokan

    2007-01-01

    Full Text Available Artificial sweeteners, such as saccharin or cyclamic acid are synthetically manufactured sweetenings. Known for their low energetic value they serve especially diabetic and adipose patients as sugar substitutes. It has been hypothesized that the substitution of sugar with artificial sweeteners may induce a decrease of the blood glucose. The aim of this study was to determine the reliability of this hypothesis by comparing the influence of regular table sugar and artificial sweeteners on the blood glucose concentration. In this pilot-study 16 patients were included suffering from adiposity, pre-diabetes and hypertension. In the sense of a cross-over design, three test trials were performed at intervals of several weeks. Each trial was followed by a test free interval. Within one test trial each patient consumed 150 ml test solution (water that contained either 6 g of table sugar (“Kandisin” with sweetener free serving as control group. Tests were performed within 1 hr after lunch to ensure conditions comparable to patients having a desert. Every participant had to determine their blood glucose concentration immediately before and 5, 15, 30 and 60 minutes after the intake of the test solution. For statistics an analysis of variance was performed. The data showed no significant changes in the blood glucose concentration. Neither the application of sugar (F4;60 = 1.645; p = .175 nor the consumption of an artificial sweetener (F2.068;31.023 = 1.551; p > .05 caused significant fluctuations in the blood sugar levels. Over a time frame of 60 minutes in the control group a significant decrease of the blood sugar concentration was found (F2.457;36.849 = 4.005; p = .020 as a physiological reaction during lunch digestion.

  13. Noninvasive 24-hour ambulatory arterial blood pressure monitoring in cirrhosis

    DEFF Research Database (Denmark)

    Møller, Søren; Wiinberg, N; Henriksen, Jens Henrik

    1995-01-01

    Cirrhotic patients have disturbed systemic hemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulant...... device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the daytime, SBP, DBP, and MAP were significantly lower in the patients than in the controls (median 118 vs. 127; 70 vs. 78; 86 vs. 94 mm Hg, P < .0001 to P < .05). The nighttime blood pressures...... were almost similar in the two groups (108 vs. 110; 65 vs. 67; 78 vs. 82 mm Hg, NS). Conversely, HR was significantly higher in the patients both in the daytime (86 vs. 72/min, P < .0001) and at night (80 vs. 64/min, P < .0001). Consequently, the reduction in blood pressure and HR from daytime to...

  14. Blood flow and arterial endothelial dysfunction: Mechanisms and implications

    Science.gov (United States)

    Barakat, Abdul I.

    2013-06-01

    The arterial endothelium exquisitely regulates vascular function, and endothelial dysfunction plays a critical role in the development of atherosclerosis. Atherosclerotic lesions develop preferentially at arterial branches and bifurcations where the blood flow is disturbed. Understanding the basis for this observation requires elucidating the effects of blood flow on the endothelial cell (EC) function. The goal of this review is: (1) to describe our current understanding of the relationships between arterial blood flow and atherosclerosis, (2) to present the wide array of flow-induced biological responses in ECs, and (3) to discuss the mechanisms by which ECs sense, transmit, and transduce flow-derived mechanical forces. We conclude by presenting some future perspectives in the highly interdisciplinary field of EC mechanotransduction.

  15. Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells

    International Nuclear Information System (INIS)

    Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation

  16. Investigation on artificial blood vessels prepared from bacterial cellulose.

    Science.gov (United States)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai; Chang, Xiao; Qiu, Guixing; Wu, Zhihong; Yang, Guang

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1mm and an outer diameter of 4 or 6mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. PMID:25491966

  17. Nocturnal foot blood flow in patients with arterial insufficiency

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Tønnesen, K H

    1984-01-01

    Twenty-four hour continuous recording of xenon (133Xe) wash-out from the forefoot was performed on patients with normal circulations (n = 10) and on patients with different degrees of arterial insufficiency (n = 36). During day hours the calculated subcutaneous blood flow in the forefoot was on a...

  18. Uterine artery blood flow, fetal hypoxia and fetal growth

    OpenAIRE

    Browne, Vaughn A.; Julian, Colleen G.; Toledo-Jaldin, Lillian; Cioffi-Ragan, Darleen; Vargas, Enrique; Moore, Lorna G.

    2015-01-01

    Evolutionary trade-offs required for bipedalism and brain expansion influence the pregnancy rise in uterine artery (UtA) blood flow and, in turn, reproductive success. We consider the importance of UtA blood flow by reviewing its determinants and presenting data from 191 normotensive (normal, n = 125) or hypertensive (preeclampsia (PE) or gestational hypertension (GH), n = 29) Andean residents of very high (4100–4300 m) or low altitude (400 m, n = 37). Prior studies show that UtA blood flow i...

  19. Venous flow velocity, venous volume and arterial blood flow

    International Nuclear Information System (INIS)

    The relationship of arterial blood flow and venous volume to venous flow velocity was studied in normal subjects. The effects of current modes of treatment in venous thrombosis and of a vasodilator drug on venous flow velocity were also investigated. Total calf flow and venous volume were measured by venous occlusion plethysmography while venous flow axial velocity was determined by the transit time of 131I albumin from calf to inguinal region. Local intravenous epinephrine administration induced venoconstriction and increased venous flow velocity. Intra-arterial isoproterenol and angiotensin increased and decreased arterial flow, respectively, with no change in venous flow velocity or volume, but local heat increased arterial flow and venous flow velocity with no change in venous volume. Local cold, despite venoconstriction, decreased venous flow velocity accompanied by decreased arterial flow. Intravenous heparin did not affect venous flow velocity. Intravenous but not oral nylidrin increased venous flow velocity. Therefore venous flow velocity can be significantly increased by venoconstriction, by large increases in arterial flow (local heat), and by a parenteral vasodilator drug. These experiments indicate that there is a basis for applying heat but not cold in the prevention and treatment of venous thrombosis

  20. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  1. Direct in vivo study of flowing blood-artificial surface interactions - an original application of dynamic isotopic techniques

    International Nuclear Information System (INIS)

    A Ge(Li) detector, associated with a data acquisition and storage unit, and a data analysis facility, was used to record sequentially the activity, related to several radioisotopes, inside an extracorporeal shunt, settled between the femoral artery and the colateral vein of an anaesthetized dog. The shunt was made of a material, the haemocompatibility of which needed to be evaluated. Before the blood was allowed to flow through the shunt, the circulation of the dog was fed with technetium- or indium-labelled biological species thought to be concerned with blood-artificial surface interactions. The method described here offers the possibility of computing kinetic parameters for these interactions. (author)

  2. The measurement of blood speed in the pulmonary artery trunk

    International Nuclear Information System (INIS)

    The paper describes a non invasive methodology for the measurement of blood speed in the pulmonary artery trunk. The methodology has been tested with a moving radioactive tracer (nuclear medicine). An image processing technique is proposed, for detection and analysis of a moving object with variable shape and intensity over time (radioactive bolus). Experiments on the application of the technique in nuclear medicine are critically analysed. (authors)

  3. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Kyriacou, P A [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Shafqat, K [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Pal, S K [St Andrew' s Centre for Plastic Surgery and Burns, Broomfield Hospital, Chelmsford, CM1 7ET (United Kingdom)

    2007-10-15

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures

  4. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    Science.gov (United States)

    Kyriacou, P. A.; Shafqat, K.; Pal, S. K.

    2007-10-01

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

  5. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    International Nuclear Information System (INIS)

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

  6. Investigation on artificial blood vessels prepared from bacterial cellulose

    International Nuclear Information System (INIS)

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel

  7. Investigation on artificial blood vessels prepared from bacterial cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chang, Xiao; Qiu, Guixing; Wu, Zhihong [Department of Orthopaedics, Peking Union Medical College Hospital, Beijing 100730 (China); Yang, Guang, E-mail: yang_sunny@yahoo.com [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel.

  8. In vivo quantification of hyperoxic arterial blood water T1.

    Science.gov (United States)

    Siero, Jeroen C W; Strother, Megan K; Faraco, Carlos C; Hoogduin, Hans; Hendrikse, Jeroen; Donahue, Manus J

    2015-11-01

    Normocapnic hyperoxic and hypercapnic hyperoxic gas challenges are increasingly being used in cerebrovascular reactivity (CVR) and calibrated functional MRI experiments. The longitudinal arterial blood water relaxation time (T1a) change with hyperoxia will influence signal quantification through mechanisms relating to elevated partial pressure of plasma-dissolved O2 (pO2) and increased oxygen bound to hemoglobin in arteries (Ya) and veins (Yv). The dependence of T1a on Ya and Yv has been elegantly characterized ex vivo; however, the combined influence of pO2, Ya and Yv on T1a in vivo under normal ventilation has not been reported. Here, T1a is calculated during hyperoxia in vivo by a heuristic approach that evaluates T1 -dependent arterial spin labeling (ASL) signal changes to varying gas stimuli. Healthy volunteers (n = 14; age, 31.5 ± 7.2 years) were scanned using pseudo-continuous ASL in combination with room air (RA; 21% O2/79% N2), hypercapnic normoxic (HN; 5% CO2/21% O2/74% N2) and hypercapnic hyperoxic (HH; 5% CO2/95% O2) gas administration. HH T1a was calculated by requiring that the HN and HH cerebral blood flow (CBF) change be identical. The HH protocol was then repeated in patients (n = 10; age, 61.4 ± 13.3 years) with intracranial stenosis to assess whether an HH T1a decrease prohibited ASL from being performed in subjects with known delayed blood arrival times. Arterial blood T1a decreased from 1.65 s at baseline to 1.49 ± 0.07 s during HH. In patients, CBF values in the affected flow territory for the HH condition were increased relative to baseline CBF values and were within the physiological range (RA CBF = 36.6 ± 8.2 mL/100 g/min; HH CBF = 45.2 ± 13.9 mL/100 g/min). It can be concluded that hyperoxic (95% O2) 3-T arterial blood T1aHH = 1.49 ± 0.07 s relative to a normoxic T1a of 1.65 s. PMID:26419505

  9. Arterial secondary blood flow patterns visualized with vector flow ultrasound

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Pihl, Michael Johannes; Hansen, Jens Munk;

    2011-01-01

    This study presents the first quantification and visualisation of secondary flow patterns with vector flow ultrasound. The first commercial implementation of the vector flow method Transverse Oscillation was used to obtain in-vivo, 2D vector fields in real-time. The hypothesis of this study...... was that the rotational direction is constant within each artery. Three data sets of 10 seconds were obtained from three main arteries in healthy volunteers. For each data set the rotational flow patterns were identified during the diastole. Each data set contains a 2D vector field over time and with the vector angles...... and velocity magnitudes the blood flow patterns were visualised with streamlines in Matlab (Mathworks, Natick, MA, USA). The rotational flow was quantified by the angular frequency for each cardiac cycle, and the mean rotational frequencies and standard deviations were calculated for the abdominal aorta f-1...

  10. Pulmonary blood flow distribution in transposition of the great arteries

    International Nuclear Information System (INIS)

    Pulmonary blood flow distribution was studied by scintillation scanning of the lungs after the infusion of iodine-131-labeled macroaggregates of human albumin before and after the Mustard operation in 53 patients with transposition of the great arteries. The patients were classified as follows: Group 1 (24 infants with uncomplicated transposition of the great arteries); Group II (18 patients with transposition and ventricular septal defect); and Group III (11 patients with transposition, ventricular septal defect and pulmonary obstruction). Before operation, 21 patients had a normal distribution of pulmonary blood flow, 10 had preferential flow to the right lung and 2 had preferential flow to the left lung. After operation, 19 had a normal pattern of pulmonary blood flow, 21 had preferential flow to the right lung and 3 had preferential flow to the left lung. The scanning studies have proved helpful in follow-up of patients to rule out recurrence of the shunt, pulmonary or systemic venous obstruction, development of pulmonary hypertension and occlusion of a palliative systemic-pulmonary shunt

  11. Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

    LENUS (Irish Health Repository)

    Flynn, Michael J

    2012-02-03

    OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg\\/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg\\/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+\\/-14.2 ml\\/min, placebo group LIMA flow at 26.1+\\/-16.3 ml\\/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+\\/-9.6 beats\\/min and placebo group at 71.1+\\/-7.6 beats\\/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg\\/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may

  12. Straight versus tortuous retinal arteries in relation to blood pressure and genetics

    DEFF Research Database (Denmark)

    Taarnhøj, N C B B; Munch, I C; Sander, B;

    2008-01-01

    dizygotic same-sex healthy twin pairs, aged 20 to 46 years, who were characterised by determination of retinal vessel diameters, arterial blood pressure, blood glucose, body mass index, smoking habits and retinal arterial tortuosity, using a three-level grading scale (straight, wavy, tortuous). Heritability...... factors accounting for the remaining 18% (CI(95 )8, 36%). Increasing values of mean arterial blood pressure and body mass index were both associated with decreasing levels of retinal arterial tortuosity. CONCLUSION: There was a large variation in tortuosity of retinal arteries in these healthy subjects...

  13. Middle cerebral artery blood velocity and plasma catecholamines during exercise

    DEFF Research Database (Denmark)

    Pott, F; Jensen, K; Hansen, H;

    1996-01-01

    . Vmean increased by 31 +/- 3% and 48 +/- 4%, respectively, and this was significantly higher compared to handgrip (P < 0.05). During maximal cycling, plasma adrenaline increased from 0.21 +/- 0.04 nmol L-1 at rest to 4.18 +/- 1.46 nmol L-1, and noradrenaline increased from 0.79 +/- 0.08 to 12.70 +/- 1......During dynamic exercise, mean blood velocity (Vmean) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional cerebral blood flow. At a high work rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction of the MCA and...... thereby elevate Vmean at a given volume flow. To evaluate transcranial Doppler-determined Vmean at high plasma catecholamine levels, seven elite cyclists performed a maximal performance test on a bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts and during...

  14. Freeze dried blood and development of an artificial diet for blood feeding arthropods

    International Nuclear Information System (INIS)

    The goals of the research were to determine the biochemical differences between freeze dried bovine and porcine blood relative to their nutritional value to Glossina palpalis palpalis and Stomoxys calcitrans and to develop an artificial diet for mass rearing these flies. Freeze dried bovine and porcine blood were found to differ in their amino acid content; total dietary lipids did not significantly differ, but some notable exceptions were found in fatty acid content. Both sonication and addition of foetal bovine serum to freeze dried bovine blood improved its nutritional value for G. p. palpalis. A two component, semi-defined artificial diet was developed for G. p. palpalis and S. calcitrans. The College Station diet consisted of lipid contaminated bovine haemoglobin (BHb) and bovine serum albumin (BSA). To conduct dietary deletion tests, a process was developed for preparing large quantities of ultrapure lipid free bovine haemoglobin. S. calcitrans fed on lipid free BHb plus BSA had zero fecundity. Lipids were re-added to the protein diet in three forms: (1) lipid contaminated BHb, (2) pure erythrocyte ghosts, and (3) pure lipids. It was found that membrane lipid from the erythrocyte is required by S. calcitrans. A defined artificial diet consisting of lipid free BHb, BSA, sphingomyelin, phosphatidyl ethanolamine, phosphatidyl serine and cholesterol gave normal adult survival, as well as near normal fecundity and percentage egg hatch for S. calcitrans. Knowing the identity of the lipids, it is now possible to prepare dietary formulations to alleviate dependency on the blood proteins BHb and BSA. (author). 34 refs, 1 fig., 15 tabs

  15. Relationship of daily arterial blood pressure monitoring readings and arterial stiffness profile in male patients with chronic obstructive pulmonary disease combined with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Karoli N.A.

    2013-06-01

    Full Text Available The aim of the study was to determine correlation between arterial blood pressure daily rhythm and daily profile of arterial stiffness in male patients with chronic obstructive pulmonary disease (COPD and arterial hypertension. Materials et methods: Prospective investigation comprised 45 male patients with COPD and arterial hypertension. Individuals of 40 years younger and 80 years elder, patients with diabetes, stroke, angina pectoris, or heart infarction, vascular diseases, and exacerbation of chronic disease, bronchial and pulmonary diseases of other etiology were excluded from the analyses. Comparison group included 47 patients with essential arterial hypertension and without chronic respiratory diseases closely similar on general parameters with patients from main clinical series. Twenty-four-hour arterial blood pressure monitoring (ABPM and daily arterial stiffness monitoring were performed using BPLab® MnSDP-2 apparatus (Petr Telegin, Russian Federation. Results: Patients with COPD combined with arterial hypertension with raised arterial stiffness measures prevail over individuals in essential hypertension group. There is pathological alteration of the ABPM circadian rhythm and raised «Pressure load» values in raised arterial stiffness group. Conclusion: We found ABPM raised parameters in patients with COPD and arterial hypertension. It confirms necessity of ABPM in daily arterial stiffness assessment in patients with COPD.

  16. Noninvasive alternatives to arterial blood sampling in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography is commonly employed for the quantitative assessment of regional biochemistry. The determination of glucose and oxygen utilization rates using [F-18] 2FDG and [0-15] 0/sub 2/ demand accurate measurement of the driving function producing the observed tissue response. Conventional techniques consist of an arterial or venous puncture with either discrete or continuous sampling of blood label concentrations. A time-of-flight (TOF) probe and expired gas detector have been developed as alternatives to these invasive techniques. The acquisition of serial spectra with the TOF pair (4 x 4cm BaF/sub 2/;XP2020Q;380 psec FWHM), sampling a line through the cardiac chambers, reveals the spatial distribution of activity in the heart and surrounding tissue as a function of time. Region-of-interest analysis of the temporally resolved spectra produce the activity time courses required for analysis of tissue response data. Multigated TOF acquisition using a pulsewatch (LED-phototransistor pair which detects finger-tip blood volume changes) as the gating mechanism promises to provide an easy and accurate method for positioning the TOF probe. Dynamic techniques for the measurement of oxygen utilization rates require both the arterial [0-15] 0/sub 2/ and [0-15] H/sub 2/O concentrations. A heated flow-through plastic (NE 102) beta detector was developed to measure the concentration of label in the alveolar gas which was equilibrated with the blood in the pulmonary capillaries. Combining the TOF probe and expired gas data allows the separation of the oxygen and water components of the input function

  17. Deoxygenation Reduces Sickle Cell Blood Flow at Arterial Oxygen Tension.

    Science.gov (United States)

    Lu, Xinran; Wood, David K; Higgins, John M

    2016-06-21

    The majority of morbidity and mortality in sickle cell disease is caused by vaso-occlusion: circulatory obstruction leading to tissue ischemia and infarction. The consequences of vaso-occlusion are seen clinically throughout the vascular tree, from the relatively high-oxygen and high-velocity cerebral arteries to the relatively low-oxygen and low-velocity postcapillary venules. Prevailing models of vaso-occlusion propose mechanisms that are relevant only to regions of low oxygen and low velocity, leaving a wide gap in our understanding of the most important pathologic process in sickle cell disease. Progress toward understanding vaso-occlusion is further challenged by the complexity of the multiple processes thought to be involved, including, but not limited to 1) deoxygenation-dependent hemoglobin polymerization leading to impaired rheology, 2) endothelial and leukocyte activation, and 3) altered cellular adhesion. Here, we chose to focus exclusively on deoxygenation-dependent rheologic processes in an effort to quantify their contribution independent of the other processes that are likely involved in vivo. We take advantage of an experimental system that, to our knowledge, uniquely enables the study of pressure-driven blood flow in physiologic-sized tubes at physiologic hematocrit under controlled oxygenation conditions, while excluding the effects of endothelium, leukocyte activation, adhesion, inflammation, and coagulation. We find that deoxygenation-dependent rheologic processes are sufficient to increase apparent viscosity significantly, slowing blood flow velocity at arterial oxygen tension even without additional contributions from inflammation, adhesion, and endothelial and leukocyte activation. We quantify the changes in apparent viscosity and define a set of functional regimes of sickle cell blood flow personalized for each patient that may be important in further dissecting mechanisms of in vivo vaso-occlusion as well as in assessing risk of patient

  18. Relationship between leptin levels in maternal blood,amniotic fluid,arterial and venous cord blood and fetal growth

    Institute of Scientific and Technical Information of China (English)

    林丽莎; 薛昭卿; 宋岩峰; 何晓宇

    2003-01-01

    Objective:To study the relationship between leptin concentration and fetal growth.Methods: Levels of leptin in maternal serum, amniotic fluid, arterial and venouscord blood of 65 normal parturients (gestational age 37-42weeks) were measured by ra-dioimmunoassay (RIA) method. At the same time, maternal blood lipids were detected.Neonates were divided into three groups: small for gestational age (SGA) group (n=10), appropriate for gestational age (AGA) group (n=45), large for gestational age(LGA) group (n= 10). Statistical analysis was performed by t test, variance analysisand correlation analysis.Results: (1) There was no obvious correlation between leptin concentrations in ma-ternal serum and arterial/ venous cord blood, amniotic fluid, and also no correlationwith birth weight and placental weight (P>0.05). Maternal body mass index signifi-cantly correlated with birth weight and neonatal length and leptin levels in arterial andvenous cord blood (P<0.01). Leptin levels in arterial and venous cord blood positivelycorrelated significantly with placental and neonatal weight and body length (P<0.01)and negatively correlated with high density lipoprotein (P<0. 01). There was no obvi-ous correlation between fetal gender and leptin concentrations in maternal serum, arteri-al and venous cord blood and amniotic fluid; (2) Leptin levels in arterial and venouscord blood , placental weight in LGA group were significantly higher than those in SGAand AGA group (P<0.05). Among three groups, leptin concentrations in maternalblood were significantly higher than those in arterial and venous cord blood (P<0.05).Conclusions: (1)Fetal leptin is synthesized in uterus, born of itself and placenta.Leptin levels in arterial and venous cord blood are related to the intrauterine growthpattern. It might positively regulate birth weight and body fat content. (2)Either mater-nal or fetal leptin was not correlated with fetal gender. There is no gender difference infetal leptin

  19. A new noninvasive device for continuous arterial blood pressure monitoring in the superficial temporal artery

    International Nuclear Information System (INIS)

    Continuous recording of arterial blood pressure (ABP) has many applications in cardiovascular physiology, but existing alternatives rely on measurements performed in the fingers or radial artery. Peripheral recordings have significant differences from central ABP regarding the pattern of the waveform and corresponding systolic and diastolic values. To address the need for noninvasive measurements closer to the ascending aorta, a new device was constructed to measure ABP in the superficial temporal artery (STA) using photoplethysmography and the arterial volume clamping technique. The optoelectronic circuitry to generate the photoplethysmogram is contained in a specially designed probe placed over the STA and kept in place with a head frame. The prototype (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature regularly updates the photoplethysmogram operating point to improve accuracy. The performance of the STAbp was compared against the Finapres in 19 healthy subjects. At rest, the bias (SDd) was −23.1 (15.05), −10.8 (13.83) and −12.4 (12.93) mmHg for systolic, mean and diastolic pressures respectively, without significant differences in drift between the two devices. The 99% bandwidth (SD) for the spectral distribution of ABP waveforms was 5.3 (1.46) Hz for STAbp and 6.8 (0.73) Hz for the Finapres (p < 0.01). Handgrip manoeuvre showed a very similar response to the Finapres, including the rapid return to baseline on release. The new STAbp device has considerable potential as a new tool for clinical and research applications where continuous recording of more central ABP is advantageous compared to peripheral alternatives. (paper)

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

    OpenAIRE

    Komine Hidehiko; Asai Yoshiyuki; Yokoi Takashi; Yoshizawa Mutsuko

    2012-01-01

    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 ...

  1. Non-arterial assessment of blood gas status in patients with chronic pulmonary disease.

    OpenAIRE

    Elborn, J. S.; Finch, M B; Stanford, C. F.

    1991-01-01

    Assessment of blood gas status is important in the management of patients with chronic pulmonary disease. Arterial puncture is often painful and may damage the arterial wall. Measurement of oxygen saturation by transcutaneous oximetry offers a non-invasive alternative to arterial methods but does not allow assessment of partial pressure of carbon dioxide. We have examined the value of oximetry and dorsal hand venous carbon dioxide as an alternative to arterial puncture. Transcutaneous oxygen ...

  2. [Synchonization of the blood flow rate in arterial with the changing rate of space of blood pressure with time].

    Science.gov (United States)

    Zhang, Shenghua; Qin, Renjia

    2012-10-01

    In physiology-related books, there are many relationship curves about blood flow rate in arteries and blood pressure changes with time, but there are not much explanation about such relationship. This is the very the question that the present article tries to answer. We clarified the relations between blood flow rate and blood pressure gradient using the experimental curves as the basis, using Poiseuille Law and relative knowledge of phisics and mathematics, and using analysis and reasoning. Based on the study, it can be concluded that in every course of cardiac cycle, the blood flow rate of any section in artery blood vessel is roughly synchronized with changing rate of space and time of the blood pressure, but blood flow rate is not synchronized with blood pressure. PMID:23198422

  3. Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise

    DEFF Research Database (Denmark)

    Madsen, P L; Sperling, B K; Warming, T; Schmidt, J F; Secher, N H; Wildschiødtz, Gordon; Holm, S; Lassen, N A

    1993-01-01

    Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions....... To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow...... velocity in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise...

  4. Analysis of Arterial and Venous Blood Gases in Healthy Gyr Falcons ( Falco rusticolus ) Under Anesthesia.

    Science.gov (United States)

    Raghav, Raj; Middleton, Rachael; BSc, Rinshiya Ahamed; Arjunan, Raji; Caliendo, Valentina

    2015-12-01

    Arterial and venous blood gas analysis is useful in the assessment of tissue oxygenation and ventilation and in diagnosis of metabolic and respiratory derangements. It can be performed with a relatively small volume of blood in avian patients under emergency situations. Arterial and venous blood gas analysis was performed in 30 healthy gyr falcons ( Falco rusticolus ) under anaesthesia to establish temperature-corrected reference intervals for arterial blood gas values and to compare them to temperature-corrected venous blood gas values with a portable point-of-care blood gas analyzer (i-STAT 1, Abbott Laboratories, Abbott Park, IL, USA). Statistically significant differences were observed between the temperature-corrected values of pH, partial pressure of carbon dioxide (Pco2), and partial pressure of oxygen (Po2) and the corresponding nontemperature-corrected values of these parameters in both arterial and venous blood. Values of temperature-corrected pH, temperature-corrected Pco2, bicarbonate concentrations, and base excess of extra cellular fluid did not differ significantly between arterial and venous blood, suggesting that, in anesthetized gyr falcons, venous blood gas analysis can be used in place of arterial blood gas analysis in clinical situations. Values for hematocrit, measured by the point-of-care analyzer, were significantly lower compared with those obtained by the microhematocrit method. PMID:26771318

  5. Treating hepatic carcinoma with internal mammary artery blood supply through transcatheter arterial chemoembolization

    International Nuclear Information System (INIS)

    Objective: To study blood supply by the internal mammary artery (IMA)for hepatic carcinoma and evaluate the efficacy and safety of transcatheter arterial chemoembolization (TACE)via IMA. Methods: 86 cases of hepatic cancer(HCC) fed by the IMA underwent TACE of the IMA. All of the patients had previously undergone several TACE for HCC. 16 patients had undertaken percutaneous microwave coagulation therapy in addition to TAE. 4 patients had a history of surgery for upper abdomen. Plain and enhanced CT and MRI scannings were performed before operation. Internal mammary arteriography was carried out during the interventional procedure to clarify the feeding range and then the superselected catheterization of the feeding branch was done with TACE. The IMA angiographic features, tumor location, clinical observation, laboratory tests, imageology were evaluated, and finally were correlated with the angiographic findings of the IMA. Results: All lesions were massive type and located at the ventral aspect and subcapsular region of the liver: 57 cases in segment 4, 5, 8, and 29 cases in segment 5, 7, 8. Recurrent HCCs were supplied by the right IMA in 80 cases, from the left IMA in 5 cases and with the bilateral IMA in 1 case. Lipiodol-TACE of the IMA for HCC can be performed without skin complications in cases of subselective catheterization. Conclusion Tumors located ventrally and superficially in the liver may recruit blood supply through IMA collaterals, often occurring in massive type of HCC after several times of TACE. TACE of IMA is safe and has become technically feasible in almost all patients, although cutaneous damage should be cautious during the interventional procedure. (authors)

  6. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  7. ADRC or adaptive controller--A simulation study on artificial blood pump.

    Science.gov (United States)

    Wu, Yi; Zheng, Qing

    2015-11-01

    Active disturbance rejection control (ADRC) has gained popularity because it requires little knowledge about the system to be controlled, has the inherent disturbance rejection ability, and is easy to tune and implement in practical systems. In this paper, the authors compared the performance of an ADRC and an adaptive controller for an artificial blood pump for end-stage congestive heart failure patients using only the feedback signal of pump differential pressure. The purpose of the control system was to provide sufficient perfusion when the patients' circulation system goes through different pathological and activity variations. Because the mean arterial pressure is equal to the total peripheral flow times the total peripheral resistance, this goal was converted to an expression of making the mean aortic pressure track a reference signal. The simulation results demonstrated that the performance of the ADRC is comparable to that of the adaptive controller with the saving of modeling and computational effort and fewer design parameters: total peripheral flow and mean aortic pressure with ADRC fall within the normal physiological ranges in activity variation (rest to exercise) and in pathological variation (left ventricular strength variation), similar to those values of adaptive controller. PMID:26409226

  8. Transvaginal color Doppler ultrasound of ovarian artery blood flow in healthy women of reproductive age

    International Nuclear Information System (INIS)

    Objective: To provide reference standard for physiological and pathological changes of ovarian blood flow. Methods: Color Doppler ultrasound of ovarian artery blood flow was performed on 50 healthy women of reproductive age. Ovarian artery peak systolic velocity (PSV), end-diastolic velocity (EDV), blood flow resistant index (RI), pulsatility index (PI), and systolic end diastolic ratio (S/D) were studied in the follicular, ovulation, luteal and luteal atrophy phases. Results: There was a significant difference (P<0.05) among the ovarian artery EDV, RI, PI, S/D of different groups except for the highest (P<0.05). Conclusion: There are cyclical ovarian artery blood flow changes in healthy women of reproductive age. There is close relation between the blood supply and the functional status of the ovaries. (authors)

  9. 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.

  10. Assessment of Normal Vertebral Arteries Vs. Normal Internal Carotid and Common Carotid Arteries Blood Flow Spectral Doppler Indices

    Directory of Open Access Journals (Sweden)

    Sh. Sharif Kashani

    2005-08-01

    Full Text Available Introduction & Background: Vertebrobasilar insufficiency is the main cause of cerebrovascular accidents (CVAs in 20% of cases. There are few reports regarding spectral Doppler indices (SDIs of vertebral arteries (VAs normal blood flow. The objective of this study is to provide basic reference data about SDIs of VAs nor-mal blood flow separately, and in comparison with internal and common carotid arteries (ICAs and CCAs normal blood flows SDIs, for better and earlier detection of disordered SDIs of these arteries blood flow. Patients & Methods: This cross-sectional study was performed in Amir Alam hospital by three radiologists ex-perienced in vascular color Doppler sonography (CDS and spectral Doppler sonography (SDS from February 2002 till March 2004, on 70 normal patients. CDS and SDS of right and left vertebral arteries (RVA and LVA, right and left common carotid arteries (RCCA and LCCA, and right and left internal carotid arteries (RICA and LICA were performed. SDIs consisted of peak systolic velocity (PSV, end- diastolic velocity (EDV, and resistive index (RI values of these arteries blood flows and were assessed and compared with one another. Fi-nally all data was collected in SPSS version 12 software, and analyzed with the Student's T-test. Results: In this study, the mean PSV, EDV, and RI values of RVA blood flow were respectively 41.60 ± 9.6 cm/s, 14.60 ± 3.7 cm/s and 0.65 ± 0.06; the mean PSV, EDV and RI values of LVA blood flow were respectively 42.20 ± 10.2 cm/s, 15.20 ± 4.2 cm/s, and 0.64 ± 0.05. There was not statistically significant difference between the mean PSV, EDV, and RI values of RVA and LVA blood flows (P value > 0.1. The mean PSV and EDV val-ues of VAs blood flows were significantly lower than the mean PSV and EDV values of CCAs and ICCAs blood flows respectively (p-value 0.05.

  11. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P; Seifert, Thomas; Overgaard, Morten; Secher, Niels H

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V(mean......(mean) ), suggesting α-adrenergic-mediated cerebral vasoconstriction, this remains unconfirmed by evaluation of arterial and venous cerebral blood flow.......Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  12. Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia.

    Science.gov (United States)

    González-Alonso, J; Mora-Rodríguez, R; Coyle, E F

    1999-08-01

    We determined whether the deleterious effects of dehydration and hyperthermia on cardiovascular function during upright exercise were attenuated by elevating central blood volume with supine exercise. Seven trained men [maximal oxygen consumption (VO(2 max)) 4.7 +/- 0. 4 l/min (mean +/- SE)] cycled for 30 min in the heat (35 degrees C) in the upright and in the supine positions (VO(2) 2.93 +/- 0.27 l/min) while maintaining euhydration by fluid ingestion or while being dehydrated by 5% of body weight after 2 h of upright exercise. When subjects were euhydrated, esophageal temperature (T(es)) was 37. 8-38.0 degrees C in both body postures. Dehydration caused equal hyperthermia during both upright and supine exercise (T(es) = 38. 7-38.8 degrees C). During upright exercise, dehydration lowered stroke volume (SV), cardiac output, mean arterial pressure (MAP), and cutaneous vascular conductance and increased heart rate and plasma catecholamines [30 +/- 6 ml, 3.0 +/- 0.7 l/min, 6 +/- 2 mmHg, 22 +/- 8%, 14 +/- 2 beats/min, and 50-96%, respectively; all P < 0. 05]. In contrast, during supine exercise, dehydration did not cause significant alterations in MAP, cutaneous vascular conductance, or plasma catecholamines. Furthermore, supine versus upright exercise attenuated the increases in heart rate (7 +/- 2 vs. 9 +/- 1%) and the reductions in SV (13 +/- 4 vs. 21 +/- 3%) and cardiac output (8 +/- 3 vs. 14 +/- 3%) (all P < 0.05). These results suggest that the decline in cutaneous vascular conductance and the increase in plasma norepinephrine concentration, independent of hyperthermia, are associated with a reduction in central blood volume and a lower arterial blood pressure. PMID:10444482

  13. A Review of Genetics, Arterial Stiffness, and Blood Pressure in African Americans

    OpenAIRE

    Hall, Jennifer L.; Duprez, Daniel A; Barac, Ana; Rich, Stephen S.

    2012-01-01

    The prevalence of hypertension in African Americans in the United States is amongst the highest in the world and increasing. The identification of genes and pathways regulating blood pressure in African Americans has been challenging. An early predictor of hypertension is arterial stiffness. The prevalence of arterial stiffness is significantly higher in African Americans compared to Caucasians. Approximately 20% of the variance in arterial stiffness is estimated to be heritable. Identifying ...

  14. 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; Sager, P

    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....

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

    OpenAIRE

    Jong-Gu Choi; Keun-Ho Kim; Woo-Beom Lee; Dong-Hyun Nam; Il-Ho Son; You-Sik Hong; Sang-Suk Lee

    2011-01-01

    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...

  16. Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    1995-01-01

    BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...... and in controls. METHODS: Thirty-nine patients with cirrhosis (12 patients with Child-Turcotte class A, 14 with class B, and 13 with class C) and 6 controls were studied. During hepatic vein catheterization, cardiac output, systemic vascular resistance, central and arterial blood volume, noncentral...... change was found in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not...

  17. Phantom with Pulsatile Arteries to Investigate the Influence of Blood Vessel Depth on Pulse Oximeter Signal Strength

    Directory of Open Access Journals (Sweden)

    Hunor Santha

    2012-01-01

    Full Text Available This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm. The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm, 0.55 nW (0.31 ppm, and 0.18 nW (0.10 ppm for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin, 5.0 mm (skull, and > 50 mm (brain.

  18. ASSESSMENT OF VERTEBRAL ARTERIES BLOOD FLOW SPECTRAL DOPPLER INDICES IN COMPARISON WITH INTERNAL AND COMMON CAROTID ARTERIES BLOOD FLOW SPECTRAL DOPPLER INDICES

    Directory of Open Access Journals (Sweden)

    H. Mazaher

    2007-05-01

    Full Text Available Vertebrobasilar insufficiency is the cause of cerebrovascular accidents in 20% of cases. There are few reports regarding spectral Doppler indices (SDIs of vertebral arteries (VAs normal blood flow. The objective of this study was to provide basic reference data about SDIs of VAs normal blood flow separately and in comparison with internal carotid arteries (ICAs and common carotid arteries (CCAs normal blood flows SDIs. This cross-sectional study performed on 70 normal patients. Color Doppler sonography (CDS and spectral Doppler sonography (SDS of right and left VAs (RVA and LVA, right and left CCAs (RCCA and LCCA, right and left ICAs (RICA and LICA, were performed. The mean PSV, EDV, and RI values of RVA blood flow were as 41.60 ± 9.6 cm/s, 14.60 ± 3.7 cm/s and 0.65 ± 0.06, and the mean PSV, EDV and RI values of LVA blood flow were as 42.20 ± 10.2 cm/s, 15.20 ± 4.2 cm/s, and 0.64 ± 0.05, respectively. There was not statistically significant difference between the mean PSV, EDV and RI values of RVA and LVA blood flows. The mean PSV and EDV values of VAs blood flows were significantly lower than the values of CCAs and ICCAs blood flows, respectively. The mean RI value of VAs blood flows was significantly lower than the mean RI Value of CCAs blood flows, but there was not statistically significant difference between the mean RI value of VAs blood flows and the mean RI value of ICAs blood flows.

  19. Association between arterial stiffness and the deformability of red blood cells (RBCs)

    NARCIS (Netherlands)

    S.S. Lee; N.J. Kim; K. Sun; J.G. Dobbe; M.R. Hardeman; J.F. Antaki; K.H. Ahn; S.J. Lee

    2006-01-01

    The relationship between the flexibility of atherosclerotic vessels and RBC deformability has been investigated. A significant difference of RBC deformability was found among the arterial stiffness groups classified by oscillometric measurement of blood pressure. The deformability was determined by

  20. Multidetector CT in evaluating blood supply of hepatocellular carcinoma after transcatheter arterial chemoembolization

    OpenAIRE

    Guan, Yong-Song; Zheng, Xiao-Hua; Zhou, Xiang-Ping; Huang, Juan; Sun, Long; Chen, Xian; Li, Xiao; He, Qing

    2004-01-01

    AIM: To assess the value of multidetector-row computed tomography (MDCT) in choosing retreatment methods of hepatocellular carcinoma (HCC) through evaluating the blood supply of low-density area of HCC after transcatheter arterial chemoembolization (TACE).

  1. Blood Pressure Regulation VIII: Resistance Vessel Tone and Implications for a Pro-Atherogenic Conduit Artery Endothelial Cell Phenotype

    OpenAIRE

    Padilla, Jaume; Jenkins, Nathan T.; Laughlin, M. Harold; Fadel, Paul J.

    2013-01-01

    Dysfunction of the endothelium is proposed as the primary initiator of atherosclerotic peripheral artery disease, which occurs mainly in medium to large-sized conduit arteries of the lower extremities (e.g., iliac, femoral, popliteal arteries). In this review article, we propose the novel concept that conduit artery endothelial cell phenotype is determined, in part, by microvascular tone in skeletal muscle resistance arteries through both changes in arterial blood pressure as well as upstream...

  2. Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension

    OpenAIRE

    Farha Samar; Laskowski Daniel; George Deepa; Park Margaret M; Tang WH Wilson; Dweik Raed A; Erzurum Serpil C

    2013-01-01

    Abstract Background Reduced gas transfer in patients with pulmonary arterial hypertension (PAH) is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange. Methods We tested this hypothesis by determination of lung diffusing capacity (DL) and its components, the alveolar capillary membrane diffusing capacity (Dm) and lung capillary blood volume (Vc) in 28 individuals with PAH in c...

  3. Slip Effects on Pulsatile Flow of Blood through a Stenosed Arterial Segment under Periodic Body Acceleration

    OpenAIRE

    Sinha, A; Shit, G. C.; Kundu, P.K.

    2013-01-01

    A theoretical investigation concerning the influence of externally imposed periodic body acceleration on the flow of blood through a time-dependent stenosed arterial segment by taking into account the slip velocity at the wall of the artery has been carried out. A mathematical model is developed by treating blood as a non-Newtonian fluid obeying the Casson fluid model. The pulsatile flow is analyzed by considering a periodic pressure gradient and the inertial effects as negligibly small. A su...

  4. Arterial blood gas analysis or oxygen saturation in the assessment of acute asthma?

    OpenAIRE

    Carruthers, D M; Harrison, B. D.

    1995-01-01

    BACKGROUND--A study was undertaken to determine if arterial blood gas estimation is always necessary in the assessment of patients presenting to hospital with acute severe asthma, or whether oxygen saturation as measured by pulse oximetry is a reliable screening test for predicting those in respiratory failure. METHODS--A prospective study was conducted in a specialist respiratory medical unit. Arterial blood gas tensions and pulse oximetry were measured in 89 consecutive patients admitted wi...

  5. Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures

    OpenAIRE

    Fong, Allan; Mittu, Ranjeev; Ratwani, Raj; Reggia, James

    2014-01-01

    Alarm fatigue caused by false alarms and alerts is an extremely important issue for the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the staff and hospital systems better classify a patient’s waveforms and subsequent alarms. This paper explores the use of Echo State Networks, a specific type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure wave...

  6. Gene Expression Patterns in Peripheral Blood Correlate with the Extent of Coronary Artery Disease

    OpenAIRE

    Sinnaeve, Peter R; Donahue, Mark P.; Grass, Peter; Seo, David; Vonderscher, Jacky; Chibout, Salah-Dine; Kraus, William E.; Sketch, Michael; Nelson, Charlotte; Ginsburg, Geoffrey S.; Goldschmidt-Clermont, Pascal J.; Granger, Christopher B.

    2009-01-01

    Systemic and local inflammation plays a prominent role in the pathogenesis of atherosclerotic coronary artery disease, but the relationship of whole blood gene expression changes with coronary disease remains unclear. We have investigated whether gene expression patterns in peripheral blood correlate with the severity of coronary disease and whether these patterns correlate with the extent of atherosclerosis in the vascular wall. Patients were selected according to their coronary artery disea...

  7. Intrauterine blood transfusion in immune hydrops fetalis, corrects middle cerebral artery Doppler velocimetry very quickly

    OpenAIRE

    Yalinkaya, Ahmet; Evsen, Mehmet Sıddık; Celik, Yusuf; Sak, Muhammet Erdal; Soydinc, Hatice Ender; Taner, Mehmet Zeki

    2012-01-01

    The aim of our study was to evaluate the middle cerebral artery velocimetry before and after intrauterine blood transfusion in immune hydrops fetalis. The current study was conducted in a tertiary research hospital, from February 2009 to January 2011. Nineteen intrauterine blood transfusions performed during the study period. The factors recorded were age of the mothers, gestational weeks, pre-transfusion fetal hematocrit and post-transfusion fetal hematocrit, and also middle cerebral artery ...

  8. Prospect for vaginal delivery of growth restricted fetuses with abnormal umbilical artery blood flow.

    OpenAIRE

    Li, Hui; Gudmundsson, Saemundur; Olofsson, Per

    2003-01-01

    Background. The best mode of delivery in cases of intrauterine growth restriction (IUGR) with umbilical artery blood flow changes is not well elucidated. Objective. To evaluate outcome in IUGR with umbilical artery blood flow changes planned for vaginal delivery after a negative oxytocin challenge test (OCT). Methods. In 84 term singleton pregnancies with suspected IUGR and no unanimous indication for abdominal delivery, Doppler velocimetry and OCT were performed. Positive OCT c...

  9. Blood flow changes after unilateral carotid artery ligation monitored by optical coherence tomography

    Science.gov (United States)

    Ma, Yushu; Liang, Chengbo; Suo, Yanyan; Zhao, Yuqian; Wang, Yi; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

    2016-03-01

    Unilateral carotid artery ligation which could induce adaptive improvement is a classic model that has been widely used to study pathology of ischemic disease. In those studies, blood flow is an important parameter to characterize the ischemia. Optical coherence tomography (OCT) is a powerful imaging modality which can provide depth resolved images in biological tissue with high spatial and temporal resolution. SPF rats was anesthetized with isoflurane and divided into two groups. In first group, bilateral carotid artery was surgically exposed, and then left carotid artery was ligated. Blood flow changes of the contralateral carotid artery was monitored using high speed spectral domain optical coherence tomography, including the absolute flow velocity and the flow volume. In the other group, skull window was opened at the ipsilateral cerebral cortex of ligation and blood supply of small artery was measured before and after the ligation. The measured results demonstrate the blood supply compensation process after unilateral carotid artery ligation. With the superiority of high resolution, OCT is an effective technology in monitoring results of carotid artery after ligation.

  10. Modeling of human colonic blood flow for a novel artificial anal sphincter system

    Institute of Scientific and Technical Information of China (English)

    Peng ZAN; Guo-zheng YAN; Hua LIU

    2008-01-01

    A novel artificial anal sphincter system has been developed to simulate the normal physiology of the human anorectum. With the goal of engineering a safe and reliable device, the model of human colonic blood flow has been built and the relationship between the colonic blood flow rate and the operating occlusion pressure of the anorectum is achieved. The tissue ischemia is analyzed based on constitutive relations for human anorectum. The results suggest that at the planned operating occlusion pressure of less than 4 kPa the artificial anal sphincter should not risk the vaseularity of the human colon.

  11. Use of phase-contrast magnetic resonance angiography to measure blood flow in the ophthalmic artery

    International Nuclear Information System (INIS)

    The aim of this study was to examine the usefulness of phase-contrast magnetic resonance (MR) angiography (PC-MRA) to measure blood flow in the ophthalmic artery. PC-MRA was performed in 16 volunteers with no ophthalmic abnormalities and measurement of blood flow based on the results was attempted. It was possible to measure blood flow in the ophthalmic artery using PC-MRA in all 16 volunteers. The mean (±1 standard deviation) velocity was 9.17±2.28 cm/second, peak systolic velocity was 16.69±3.33 cm/second, and end diastolic velocity was 3.69±2.44 cm/second. The resistivity index was 0.79±0.12, the pulsatility index was 1.49±0.41, and flow was 6.25±2.33 ml/minute. It was possible to identify the ophthalmic artery and a portion of the artery in which blood flow could be measured using MR imaging, a preliminary step to blood flow measurement using MR angiography. In addition to the velocity of blood flow in the ophthalmic artery, measurement of the amount of flow was possible with PC-MRA, which is one advantage of this method. (author)

  12. The pulmonary artery does not participate in the blood supply of lung cancer: experimental and DSA study

    International Nuclear Information System (INIS)

    Objective: To investigate whether or not the pulmonary artery participates in the blood supply of lung cancer and its change of morphology and blood flow in lung cancer. Methods: Two different colors of silicone were injected separately into the bronchial and pulmonary arteries of 33 rat models with squamous cell carcinoma of lung. The origin of blood supply of lung cancer and the morphologic change of pulmonary artery were observed under a stereo-microscope. The DSA of bronchial and pulmonary artery were performed simultaneously in 28 patients with lung cancer. Results: The pulmonary branch of rat and patients were reduced,thinned and occluded in the affected lung. The pulmonary artery did not form tumor vessel,and pulmonary blood flow and perfusion were reduced or absent in the affected area. Conclusion: The pulmonary artery did not participate in the blood supply of lung cancer. It is unreasonable to perform transcatheter chemo-embolization for lung cancer via pulmonary artery

  13. Relaxin mediates uterine artery compliance during pregnancy and increases uterine blood flow.

    Science.gov (United States)

    Vodstrcil, Lenka A; Tare, Marianne; Novak, Jacqueline; Dragomir, Nicoleta; Ramirez, Rolando J; Wlodek, Mary E; Conrad, Kirk P; Parry, Laura J

    2012-10-01

    Normal pregnancy involves dramatic remodeling of the uterine vasculature, with abnormal vascular adaptations contributing to pregnancy diseases such as preeclampsia. The peptide hormone relaxin is important for the renal and systemic hemodynamic adaptations to pregnancy, and has been shown to increase arterial compliance and outward hypertrophic remodeling. Therefore, we investigated the possibility that relaxin acts on its receptor, RXFP1, to mediate uterine artery compliance in late pregnancy and increase uterine blood flow velocity in rats. RXFP1 was predominantly localized to the tunica media vascular smooth muscle cells in the uterine artery, although receptors were also detected in endothelial cells. Highest expression of Rxfp1 in the uterine artery occurred in estrus and early pregnancy. Isolated uterine arteries from late pregnant rats treated with a monoclonal antibody against circulating relaxin (MCA1) had significantly increased vessel wall stiffness compared with controls, with no reduction in wall thickness. Chronic infusion of relaxin (4 μg/h, osmotic minipump) for 5 d in nonpregnant rats significantly increased uterine artery blood flow velocity. Overall, these data demonstrate a functional role for relaxin in mediating uterine artery compliance in pregnant rats, which may be necessary to maintain adequate uterine blood flow to the uterus and placenta. PMID:22744867

  14. Arterial blood pressure measurement and pulse wave analysis—their role in enhancing cardiovascular assessment

    International Nuclear Information System (INIS)

    The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. (topical review)

  15. Arterial blood pressure measurement and pulse wave analysis--their role in enhancing cardiovascular assessment.

    Science.gov (United States)

    Avolio, Alberto P; Butlin, Mark; Walsh, Andrew

    2010-01-01

    The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. PMID:19940350

  16. Mathematical Modelling of Blood Flow through a Tapered Overlapping Stenosed Artery with Variable Viscosity

    OpenAIRE

    Shit, G. C.; Roy, M.; Sinha, A

    2014-01-01

    This paper presents a theoretical study of blood flow through a tapered and overlapping stenosed artery under the action of an externally applied magnetic field. The fluid (blood) medium is assumed to be porous in nature. The variable viscosity of blood depending on hematocrit (percentage volume of erythrocytes) is taken into account in order to improve resemblance to the real situation. The governing equation for laminar, incompressible and Newtonian fluid subject to the boundary conditions ...

  17. Mathematical modelling of blood flow through a tapered overlapping stenosed artery with variable viscosity

    OpenAIRE

    Shit, G. C.; Roy, M.; Sinha, A

    2012-01-01

    This paper presents a theoretical study of blood flow through a tapered and overlapping stenosed artery under the action of an externally applied magnetic field. The fluid (blood) medium is assumed to be porous in nature. The variable viscosity of blood depending on hematocrit (percentage volume of erythrocytes) is taken into account in order to improve resemblance to the real situation. The governing equation for laminar, incompressible and Newtonian fluid subject to the boundary conditions ...

  18. Results of ambulatory arterial blood pressure monitoring in children with obesity

    OpenAIRE

    Faruk Öktem

    2010-01-01

    Objectives: The relationship between obesity and essential hypertension is well known. In this study, we aimed to evaluate ambulatory arterial blood pressure monitoring of obese and non-obese children who had similar demographic characteristics.Materials and methods: Seventy one children and adolescents (n=39 obesity, n=32 controls) were studied. Blood pressure of the children were measured by 24 hour ambulatory blood pressure monitoring device.Results: Obese children had significantly higher...

  19. EFFECT OF ACUPUNCTURE ON BLOOD FLOW OF VERTEBRAL AND BASILAR ARTERIES IN STROKE PATIENTS

    Institute of Scientific and Technical Information of China (English)

    吕建明; 王伟志

    2004-01-01

    Objective: To observe the short-term effect and long-term effect of acupuncture on blood flow of vertebral and basilar arteries in stroke patients.Methods: A total of 58 stroke patients (34 males and 24 females) were agreed to participate in this study, and changes of blood flow of the vertebral and basilar arteries were detected after one week's and 45 days' continuous acupuncture treatment by using a Doppler's ultrasonic diagnosis apparatus.Bilateral Fengchi (GB 20), Wangu (GB 12), Tianzhu (BL 10), etc.were punctured and stimulated with small amplitude, high frequency and twirling-reinforcing method for 3 min.The treatment was conducted once daily.Results: Following one week's and 45 days' acupuncture treatment, diastolic velocity (DV), systolic velocity (SV) and mean velocity (MV) of the basilar artery increased significantly in comparison with pre-treatment (P0.05).Results indicated that acupuncture treatment could effectively improve blood supply of the basilar artery and regulate the uneven blood flow of the bilateral vertebral arteries.Conclusion: Acupuncture treatment can raise blood flow of the brain in stroke patients.

  20. The effect of captopril on the superior mesenteric artery and portal venous blood flow in normal man.

    OpenAIRE

    Ray-Chaudhuri, K; Thomaides, T; Maule, S; Watson, L.; Lowe, S; Mathias, C J

    1993-01-01

    1. Measurements of superior mesenteric artery and portal venous blood flow were made non-invasively along with systemic and other regional (cardiac index, forearm and cutaneous blood flow) vascular responses to acute ingestion of the ACE inhibitor captopril (50 mg) or placebo (50 mg vitamin C), in 12 healthy subjects while supine and during head-up tilt. 2. After captopril, superior mesenteric artery and portal blood flow rose markedly with a reduction in superior mesenteric artery vascular r...

  1. Sensory Nerves Determine the Pattern of Arterial Differentiation and Blood Vessel Branching in the Skin

    OpenAIRE

    Mukouyama, Yoh-suke; Shin, Donghun; Britsch, Stefan; Taniguchi, Masahiko; Anderson, David J.

    2002-01-01

    Nerves and blood vessels are branched structures, but whether their branching patterns are established independently or coordinately is not clear. Here we show that arteries, but not veins, are specifically aligned with peripheral nerves in embryonic mouse limb skin. Mutations that eliminate peripheral sensory nerves or Schwann cells prevent proper arteriogenesis, while those that disorganize the nerves maintain the alignment of arteries with misrouted axons. In vitro, sensory neurons or Schw...

  2. EFFECT OF MAGNETIC FIELD ON BLOOD FLOW THROUGH AN ARTERY: A NUMERICAL MODEL

    OpenAIRE

    J Misra; Shit, G.

    2007-01-01

    In this paper we have investigated the unsteady flow of blood by treating it as an incompressible, Newtonian, electrically conducting fluid in a straight segment of an elastic artery subject to a uniform transverse magnetic field. The problem is solved numerically with the theoretical assumption of 'local flow' model [?]. A sinusoidal variation of the arterial wall motion and a pulsatile pressure gradient have been studied. An implicit finite difference technique is used to analyze the flow. ...

  3. 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.

  4. Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness

    DEFF Research Database (Denmark)

    Hvidt, Kristian N; Olsen, Michael H; Holm, Jens-Christian;

    2014-01-01

    BACKGROUND: Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness...... in obese children and adolescents. METHODS: Ninety-two obese patients aged 10-18 years were compared with 49 healthy control individuals. Insulin resistance was measured as the homeostatic assessment model (HOMA), and arterial stiffness was measured as carotid-femoral pulse wave velocity (cfPWV). RESULTS...... analyses, the higher nighttime BP in the obese group was independent of logHOMA and cfPWV. CONCLUSIONS: Obese children had a higher nighttime BP when compared with the control group independently of insulin resistance and arterial stiffness. No relationship was found between insulin resistance and arterial...

  5. Surgical Relevance of Liver Arterial Blood Supply Reconstruction by CT Scan before a Whipple Procedure

    Directory of Open Access Journals (Sweden)

    Offir Ben-Ishay

    2009-11-01

    Full Text Available Dear Sir: Anatomical arterial vascular supply to the liver is varied [1]. Establishing the exact variant of this blood supply is important before pancreatic surgery. Identifying the exact vascular anatomy may help in decision-making during surgery. In 1955, Michels [2] published a study on hepatic arterial anatomy which was based on 200 autopsies. The classification was revised in 1966 by Michels and then modified by Hiatt et al. in 1996 [3]. According to Michels’ findings, 10 anatomical variations of the hepatic arteries were identified and classified.

  6. Carotid arterial blood pressure waveform monitoring using a portable ultrasound system.

    Science.gov (United States)

    Joohyun Seo; Pietrangelo, Sabino J; Hae-Seung Lee; Sodini, Charles G

    2015-08-01

    This work presents a non-invasive arterial blood pressure (ABP) waveform monitoring technique using ultrasound. A portable ultrasound system to excite ultrasound transducers and acquire data is designed with off-the-shelf components. The insonation angles are identified using a vector Doppler technique based on the cosine dependency of the Doppler signals. The pulse pressure of an estimated waveform at the left common carotid artery is compared to the standard sphygmomanometer measurement in a clinical test. The estimated carotid ABP waveform shows excellent agreement to the finger ABP waveform with expected discrepancy of the systolic peak shape due to different measurement sites. The proposed method also tracks slow blood pressure fluctuations. This validation on human subjects shows potential for a noninvasive blood pressure waveform monitoring device at central arterial sites. PMID:26737584

  7. Slip effects on unsteady non-Newtonian blood flow through an inclined catheterized overlapping stenotic artery

    Science.gov (United States)

    Zaman, Akbar; Ali, Nasir; Sajid, M.

    2016-01-01

    Slip effects on unsteady non-Newtonian blood hydro-magnetic flow through an inclined catheterized overlapping stenotic artery are analyzed. The constitutive equation of power law model is employed to simulate the rheological characteristics of the blood. The governing equations giving the flow derived by assuming the flow to be unsteady and two-dimensional. Mild stenosis approximation is employed to obtain the reduced form of the governing equations. Finite difference method is employed to obtain the solution of the non-linear partial differential equation in the presence of slip at the surface. An extensive quantitative analysis is performed for the effects of slip parameter, Hartmann number, cathetered parameter and arterial geometrical parameters of stenosis on the quantities of interest such as axial velocity, flow rate, resistance impedance and wall shear stress. The streamlines for the blood flow through the artery are also included.

  8. Slip effects on unsteady non-Newtonian blood flow through an inclined catheterized overlapping stenotic artery

    Directory of Open Access Journals (Sweden)

    Akbar Zaman

    2016-01-01

    Full Text Available Slip effects on unsteady non-Newtonian blood hydro-magnetic flow through an inclined catheterized overlapping stenotic artery are analyzed. The constitutive equation of power law model is employed to simulate the rheological characteristics of the blood. The governing equations giving the flow derived by assuming the flow to be unsteady and two-dimensional. Mild stenosis approximation is employed to obtain the reduced form of the governing equations. Finite difference method is employed to obtain the solution of the non-linear partial differential equation in the presence of slip at the surface. An extensive quantitative analysis is performed for the effects of slip parameter, Hartmann number, cathetered parameter and arterial geometrical parameters of stenosis on the quantities of interest such as axial velocity, flow rate, resistance impedance and wall shear stress. The streamlines for the blood flow through the artery are also included.

  9. Multidetector CT in evaluating blood supply of hepatocellular carcinoma after transcatheter arterial chemoembolization

    Institute of Scientific and Technical Information of China (English)

    Yong-Song Guan; Xiao-Hua Zheng; Xiang-Ping Zhou; Juan Huang; Long Sun; Xian Chen; Xiao Li; Qing He

    2004-01-01

    AIM: To assess the value of multidetector-row computed tomography (MDCT) in choosing retreatment methods of hepatocellular carcinoma (HCC) through evaluating the blood supply of low-density area of HCC after transcatheter arterial chemoembolization (TACE).METHODS: Thirty-two patients with HCC after TACE treatment were examined by plain scanning and hepatic multidetector-row CT. The location of low-density area on plain scanning and the enhancement patterns on dynamic contrast-enhanced scanning were observed. At the same time, three-dimensional CT (3D CT) models of the volume rendering, curved multiplanar reformations, surface shaded display and maximum intensity projection reconstruction of the hepatic artery and portal vein were performed in 6 cases.RESULTS: In CT plain scanning data, low density areas of 32 cases of HCC after TACE treatment were divided into three types: peripheral, one-side-located and mixed types.In contrast-enhanced CT scans, the blood supply of lowdensity area was classified into four types: arterial blood supply (20 cases), portal blood supply (5 cases), arterial combined with portal blood supply (5 cases) and poor blood supply (2 cases). In 6 cases, the relationship between the low-density area and branches of hepatic artery as well as portal vein was shown by 3D CT.CONCLUSION: Hepatic MDCT is an effective method for evaluating the blood supply of low-density area and therapeutic effect of HCC after TACE treatment. Types of blood supply is helpful for the selection of retreatment.

  10. [Arterial blood supply of the digestive tract in badgers].

    Science.gov (United States)

    Rahm, S; Frewein, J

    1982-01-01

    In 5 dendrohyraxes, 6 heterohyraxes, and 7 procaviae the three main visceral arteries have been studied. In all hyracoidea the Arteria coeliaca divides into the Arteria lienalis, Arteria hepatica communis, and Arteria gastrica sinistra. Occasionally the latter two arteries run together for 7-15 mm before they separate. The Arteria mesenterica cranialis gives rise to the Arteriae pancreaticoduodenales caudales, Arteriae jejunales, Arteria colica media, and Arteria colica dextra and continues as Arteria ileocolica. Some animals had an Arteria colica media accessoria which supplied the first half of the colon descendens. In all other animals the entire colon descendens was supplied by the Arteria colica sinistra which originates in the Arteria mesenterica caudalis. Branches of the Arteria rectalis cranialis extend close to the anus. PMID:7124335

  11. Arterial blood architecture of the maxillary sinus in dentate specimens

    OpenAIRE

    Kqiku, Lumnije; Biblekaj, Robert; Weiglein, Andreas H.; Kqiku, Xhylsime; Städtler, Peter

    2013-01-01

    Aim To describe vascular anatomy of the maxillary sinus in dentate specimens dissected from human cadavers. Methods Twenty dentate maxillary specimens were dissected, anatomically prepared, and injected with liquid latex for a better visualization of the maxillary sinus artery. Results We found an intraosseous anastomosis in 100% and an extraosseous anastomosis in 90% of the cases. The anterior lateral wall of the maxillary sinus was transversed by two anastomoses between the posterior superi...

  12. Mathematical Analysis of Casson Fluid Model for Blood Rheology in Stenosed Narrow Arteries

    OpenAIRE

    Venkatesan, J.; D. S. Sankar; Hemalatha, K.; Yazariah Yatim

    2013-01-01

    The flow of blood through a narrow artery with bell-shaped stenosis is investigated, treating blood as Casson fluid. Present results are compared with the results of the Herschel-Bulkley fluid model obtained by Misra and Shit (2006) for the same geometry. Resistance to flow and skin friction are normalized in two different ways such as (i) with respect to the same non-Newtonian fluid in a normal artery which gives the effect of a stenosis and (ii) with respect to the Newtonian fluid in the st...

  13. Scintigraphic study of blood perfusion of the pulmonary artery in pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Blood perfusion in the pulmonary artery is studied by pulmonary scintigraphy with macroaggregated albumin 131I, in 74 cases of pulmonary tuberculosis. Results shown by scintigraphy are compared to those observed in roentgenography and also correlated with the extension and degree of the lesions, and with the presence of associated tuberculosis, considered capable of changing the scintigraphic picture. The reduction of blood flow in the pulmonary artery are observed in cases of infiltrative, fibrotic of caseous lesions, as well as in cases of minor lesions

  14. Flow Structures in a Healthy and Plaqued Artificial Artery using Fully Index Matched Vascular Flow Facility

    Science.gov (United States)

    Mehdi, Faraz; Jain, Akash; Sheng, Jian

    2014-11-01

    Particle Image Velocimetry measurements are made in a closed loop fully index matched flow facility to study the flow structures and flow wall interactions in healthy and diseased model arteries. The test section is 0.63 m long and the facility is capable of emulating both steady and pulsatile flows under physiologically relevant conditions. The model arteries are in-house developed compliant polymer (PDMS) tubes with 1 cm diameter and 1 mm wall thickness. The Reynolds numbers of flows vary up to 20,000. The plaque is simulated by introducing a radially asymmetric bump that can be varied in shape, size and compliancy. The overall compliancy of the model can be also controlled by varying ratio between the elastomer and the curing agent. The tubes are doped with particles allowing the simultaneous measurements of wall deformation and flows over it. The working fluid in the facility is NaI and is refractive index matched to the PDMS model. This allows flow measurement very close to the wall and measurement of wall shear stress. The aim of this study is to characterize the changes in flow as the compliancy and geometry of blood vessels change due to age or disease. These differences can be used to develop a diagnostic tool to detect early onset of vascular diseases.

  15. Patient-specific coronary artery blood flow simulation using myocardial volume partitioning

    Science.gov (United States)

    Kim, Kyung Hwan; Kang, Dongwoo; Kang, Nahyup; Kim, Ji-Yeon; Lee, Hyong-Euk; Kim, James D. K.

    2013-03-01

    Using computational simulation, we can analyze cardiovascular disease in non-invasive and quantitative manners. More specifically, computational modeling and simulation technology has enabled us to analyze functional aspect such as blood flow, as well as anatomical aspect such as stenosis, from medical images without invasive measurements. Note that the simplest ways to perform blood flow simulation is to apply patient-specific coronary anatomy with other average-valued properties; in this case, however, such conditions cannot fully reflect accurate physiological properties of patients. To resolve this limitation, we present a new patient-specific coronary blood flow simulation method by myocardial volume partitioning considering artery/myocardium structural correspondence. We focus on that blood supply is closely related to the mass of each myocardial segment corresponding to the artery. Therefore, we applied this concept for setting-up simulation conditions in the way to consider many patient-specific features as possible from medical image: First, we segmented coronary arteries and myocardium separately from cardiac CT; then the myocardium is partitioned into multiple regions based on coronary vasculature. The myocardial mass and required blood mass for each artery are estimated by converting myocardial volume fraction. Finally, the required blood mass is used as boundary conditions for each artery outlet, with given average aortic blood flow rate and pressure. To show effectiveness of the proposed method, fractional flow reserve (FFR) by simulation using CT image has been compared with invasive FFR measurement of real patient data, and as a result, 77% of accuracy has been obtained.

  16. Gene expression patterns in peripheral blood correlate with the extent of coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Peter R Sinnaeve

    Full Text Available Systemic and local inflammation plays a prominent role in the pathogenesis of atherosclerotic coronary artery disease, but the relationship of whole blood gene expression changes with coronary disease remains unclear. We have investigated whether gene expression patterns in peripheral blood correlate with the severity of coronary disease and whether these patterns correlate with the extent of atherosclerosis in the vascular wall. Patients were selected according to their coronary artery disease index (CADi, a validated angiographical measure of the extent of coronary atherosclerosis that correlates with outcome. RNA was extracted from blood of 120 patients with at least a stenosis greater than 50% (CADi > or = 23 and from 121 controls without evidence of coronary stenosis (CADi = 0. 160 individual genes were found to correlate with CADi (rho > 0.2, P<0.003. Prominent differential expression was observed especially in genes involved in cell growth, apoptosis and inflammation. Using these 160 genes, a partial least squares multivariate regression model resulted in a highly predictive model (r(2 = 0.776, P<0.0001. The expression pattern of these 160 genes in aortic tissue also predicted the severity of atherosclerosis in human aortas, showing that peripheral blood gene expression associated with coronary atherosclerosis mirrors gene expression changes in atherosclerotic arteries. In conclusion, the simultaneous expression pattern of 160 genes in whole blood correlates with the severity of coronary artery disease and mirrors expression changes in the atherosclerotic vascular wall.

  17. Variability of arterial blood pressure in normal and hypertensive pregnancy.

    Science.gov (United States)

    Oney, T; Meyer-Sabellek, W

    1990-12-01

    In normal pregnancy the circadian blood pressure rhythm is similar to that in the non-pregnant state, with the highest blood pressure values in the morning and the lowest at midnight. This rhythm is lost in patients with pre-eclampsia. Women with severe pre-eclampsia show a reversed circadian rhythm, with a nocturnal increase in blood pressure during the sleeping phase. Although the reasons for this nocturnal hypertension in severe pre-eclampsia are poorly understood, the results suggest that pre-eclamptic women are endangered by hypertensive emergencies, mostly at night. Therefore blood pressure measurement should be extended to the night, and antihypertensive treatment must be adapted to the demands of a reversed circadian rhythm in relevant subgroups of patients. PMID:2082002

  18. 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.

  19. Vasoactive enzymes and blood flow responses to passive and active exercise in peripheral arterial disease

    DEFF Research Database (Denmark)

    Walker, Meegan A.; Høier, Birgitte; Walker, Philip J.;

    2016-01-01

    than CON (1.04 ± 0.19 vs 0.50 ± 0.06 AU, P = 0.02), with no differences for other enzymes. Leg blood flow during exercise was correlated with prostacyclin synthase (P = 0.001). Conclusion: Elevated NADPH oxidase indicates that oxidative stress may be a primary cause of low nitric oxide availability......Background: Peripheral arterial disease (PAD) is characterised by impaired leg blood flow, which contributes to claudication and reduced exercise capacity. This study investigated to what extent vasoactive enzymes might contribute to altered blood flow in PAD (Fontaine stage II). Methods: We...... compared femoral artery blood flow during reactive hyperaemia, leg-extension exercise and passive leg movement, and determined the level of vasoactive enzymes in skeletal muscle samples from the vastus lateralis in PAD (n = 10, 68.5 ± 6.5 years) and healthy controls (CON, n = 9, 62.1 ± 12.3 years). Leg...

  20. [Intralobar pulmonary sequestration with multiple arterial blood supply].

    Science.gov (United States)

    Uroz Tristán, J; Mogueya, S A; Poenaru, D; Martínez Lagares, F; Arteaga García, R; Sanchís Solera, L; López-Pinto Ruiz, J

    1994-04-01

    We report the case of a 4 years old boy, who presented at our institution with reiterative neumonia affecting left basal lobe. Anomalous vascular appearance was detected in the chest x-ray. With the suspicion of pulmonary sequestration we carried on Digital Intravenous Angiography by Substraction (DIVAS) and aortogram. The anomalous systemic arterial supply was formed by 6 vessels coming from the thoracic aorta and going into the left lower lobe basal segment. Lobectomy was performed and previous diagnosis was confirmed pathologically. PMID:8086288

  1. Elementary theory of synchronous arterio-arterial blood pumps

    Science.gov (United States)

    Jones, R. T.; Petscheck, H. E.; Kantrowitz, A. R.

    1976-01-01

    In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by a formula that considers stroke output of the unaided heart and the increment caused by the pump with a stroke. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological mechanical impedance of the heart. The total effect is, however, independent of the impedance.

  2. Blood flow redistribution and ventilation-perfusion mismatch during embolic pulmonary arterial occlusion

    OpenAIRE

    Burrowes, K. S.; Clark, A. R.; Tawhai, M.H

    2011-01-01

    Acute pulmonary embolism causes redistribution of blood in the lung, which impairs ventilation/perfusion matching and gas exchange and can elevate pulmonary arterial pressure (PAP) by increasing pulmonary vascular resistance (PVR). An anatomically-based multi-scale model of the human pulmonary circulation was used to simulate pre- and post-occlusion flow, to study blood flow redistribution in the presence of an embolus, and to evaluate whether reduction in perfused vascular bed is sufficient ...

  3. Validation of the pulse decomposition analysis algorithm using central arterial blood pressure

    OpenAIRE

    Baruch, Martin C; Kalantari, Kambiz; Gerdt, David W; Adkins, Charles M

    2014-01-01

    Background There is a significant need for continuous noninvasive blood pressure (cNIBP) monitoring, especially for anesthetized surgery and ICU recovery. cNIBP systems could lower costs and expand the use of continuous blood pressure monitoring, lowering risk and improving outcomes. The test system examined here is the CareTaker® and a pulse contour analysis algorithm, Pulse Decomposition Analysis (PDA). PDA’s premise is that the peripheral arterial pressure pulse is a superposition of five ...

  4. Effect on intra-arterial blood pressure of slow release metoprolol combined with placebo or chlorthalidone.

    OpenAIRE

    Kieso, H A; Gould, B A; Mann, S; Hornung, R S; Altman, D G; Raftery, E. B.

    1983-01-01

    Thirty patients with essential hypertension participated in a double blind crossover trial in which they were randomly allocated to treatment with either once daily slow release metoprolol (200 mg) with placebo or once daily slow release metoprolol (200 mg) with chlorthalidone (25 mg). Ambulatory intra-arterial blood pressure was recorded continuously for 24-48 hours before treatment and two months after each change in regimen. The response of blood pressure and pulse rate to a standard exerc...

  5. Changes in cerebral artery blood flow velocity after intermittent cerebrospinal fluid drainage.

    OpenAIRE

    Kempley, S T; Gamsu, H R

    1994-01-01

    Doppler ultrasound was used to measure blood flow velocity in the anterior cerebral artery of six premature infants with posthaemorrhagic hydrocephalus, before and after intermittent cerebrospinal fluid (CSF) drainage, on 23 occasions. There was a significant increase in mean blood flow velocity after the drainage procedures (+5.6 cm/s, 95% confidence interval +2.9 to +8.3 cm/s), which was accompanied by a decrease in velocity waveform pulsatility. CSF pressure also fell significantly. In pat...

  6. Hemoglobin, hematocrit, and changes in cerebral blood flow : The Second Manifestations of ARTerial disease-Magnetic Resonance study

    NARCIS (Netherlands)

    van der Veen, Pieternella H.; Muller, Majon; Vincken, Koen L.; Westerink, Jan; Mali, Willem P. T. M.; van der Graaf, Yolanda; Geerlings, Mirjam I.; Doevendans, PAFM

    2015-01-01

    Hemoglobin and hematocrit are important determinants of blood viscosity and arterial oxygen content and may therefore influence cerebral blood flow (CBF). We examined cross-sectional and prospective associations of hemoglobin and hematocrit with CBF in 569 patients with manifest arterial disease (me

  7. The postural reduction in middle cerebral artery blood velocity is not explained by PaCO2

    DEFF Research Database (Denmark)

    Immink, R V; Secher, N H; Roos, C M; Pott, F; Madsen, P L; van Lieshout, J J

    2006-01-01

    In the normocapnic range, middle cerebral artery mean velocity (MCA Vmean) changes approximately 3.5% per mmHg carbon-dioxide tension in arterial blood (PaCO2) and a decrease in PaCO2 will reduce the cerebral blood flow by vasoconstriction (the CO2 reactivity of the brain). When standing up MCA...

  8. 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

    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...

  9. Blood Flow Imaging in Maternal and Fetal Arteries and Veins

    Science.gov (United States)

    Ricci, S.; Urban, G.; Vergani, P.; Paidas, M. J.; Tortoli, P.

    Maternal and fetal blood circulation has been investigated for nearly a decade through ultrasound (US) techniques. Evaluation of the spectrogram related to a single sample volume has been proven valuable for the assessment of fetal well-being and for prediction of pregnancy complications. In this work, an alternative technique, called Multigate Spectral Doppler Analysis (MSDA), is proposed. In this approach, 128 sample volumes aligned along the same scan line are simultaneously investigated to detect the blood velocity profile with high resolution. Profiles obtained through MSDA reveal features not detectable with the standard US technique, thus representing a more accurate flow signature. Some preliminary illustrative results are reported here.

  10. Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN).

    Science.gov (United States)

    Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

    2016-01-01

    Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4-2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

  11. Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN)

    Science.gov (United States)

    Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

    2016-01-01

    Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4–2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

  12. Modeling blood flow circulation in intracranial arterial networks: a comparative 3D/1D simulation study.

    Science.gov (United States)

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

    2011-01-01

    We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models with rigid walls show good agreement in massflow distribution at tens of arterial junctions and also in pressure drop along the arteries. The 3D simulations with the rigid walls predict higher amplitude of the flowrate and pressure temporal oscillations than the 1D simulations with compliant walls at various segments even for small time-variations in the arterial cross-sectional areas. Sensitivity of the flow and pressure with respect to variation in the elasticity parameters is investigated with the 1D model. PMID:20661645

  13. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P;

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  14. Ambulatory Blood Pressure and Arterial Stiffness in Obese Children and Adolescents

    OpenAIRE

    Carmen Duicu; Oana Mărginean Cristina; Maria Pitea Ana; Elena Melit Lorena

    2015-01-01

    The aim of the present study was to investigate differences regarding 24-hour blood pressure and arterial stiffness in a cohort of office normotensive obese and non-obese children and adolescents, and to evaluate correlations of these parameters with some anthropometric indices. We retrospectively evaluated ABPM records in 71 children (42 boys); 31 obese compared with 40 normal-weight children.

  15. Non-Newtonian effects of blood on LDL transport inside the arterial lumen and across multi-layered arterial wall with and without stenosis

    Science.gov (United States)

    Deyranlou, Amin; Niazmand, Hamid; Sadeghi, Mahmood-Reza; Mesri, Yaser

    2016-06-01

    Blood non-Newtonian behavior on low-density lipoproteins (LDL) accumulation is analyzed numerically, while fluid-multilayered arteries are adopted for nonstenotic and 30%-60% symmetrical stenosed models. Present model considers non-Newtonian effects inside the lumen and within arterial layers simultaneously, which has not been examined in previous studies. Navier-Stokes equations are solved along with the mass transport convection-diffusion equations and Darcy’s model for species transport inside the luminal flow and across wall layers, respectively. Carreau model for the luminal flow and the modified Darcy equation for the power-law fluid within arterial layers are employed to model blood rheological characteristics, appropriately. Results indicate that in large arteries with relatively high Reynolds number Newtonian model estimates LDL concentration patterns well enough, however, this model seriously incompetent for regions with low WSS. Moreover, Newtonian model for plasma underestimates LDL concentration especially on luminal surface and across arterial wall. Therefore, applying non-Newtonian model seems essential for reaching to a more accurate estimation of LDL distribution in the artery. Finally, blood flow inside constricted arteries demonstrates that LDL concentration patterns along the stenoses inside the luminal flow and across arterial layers are strongly influenced as compared to the nonstenotic arteries. Additionally, among four stenosis severity grades, 40% stenosis is prone to more LDL accumulation along the post-stenotic regions.

  16. Measurements of cerebral blood flow in vertebrobasilar artery territory determined by direct injection of 133Xe

    International Nuclear Information System (INIS)

    Direct injection of 133Xe has been used for measurements of cerebral blood flow (CBF) in internal carotid arterial territory, but little is known as to whether this technique can be utilized for measurements of CBF within the vertebrobasilar artery system. This study investigated a validity of 133Xe injection into the vertebral artery for CBF measurement of infratentorium. A catheter was inserted into either left or right vertebral artery through the femoral artery under florescopic control to directly inject 1 - 2 mCi of 133Xe. Similar catheter procedures were used for CBF measurement for the internal carotid artery. Four probes as well as seven probes fitted with colimaters of 40 mm length and 17 mm diameter were placed respectively over posterior fossa and cerebral hemisphere. Cerebral blood flow values for vertebrobasilar arterial system (V-CBF) and for internal carotid arterial system (I-CBF) were calculated from the initial part of clearrance curves. Measurements were made in 7 patients with infra-tentorial stroke. The patients' clinical severities were of different degrees. The results obtained could be summarized as follows: (1) The more severe the grade of disturbed consciousness, the more apparent the decrease of V-CBF. (2) In patients with mild disturbance of consciousness, the decrease of V-CBF was more prominent compared to I-CBF. (3) In comatose or semicomatose patients. I-CBF and V-CBF were markedly reduced showing indentical values. These results indicate the possibility and clinical usefulness of V-CBF measurement in stroke patients. (author)

  17. Surface modification of cellulose materials : from wood pulps to artificial blood vessels

    OpenAIRE

    Ahrenstedt, Lage

    2007-01-01

    This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable a...

  18. Instability of the middle cerebral artery blood flow in response to CO2.

    Directory of Open Access Journals (Sweden)

    Rosemary E Regan

    Full Text Available BACKGROUND: The middle cerebral artery supplies long end-artery branches to perfuse the deep white matter and shorter peripheral branches to perfuse cortical and subcortical tissues. A generalized vasodilatory stimulus such as carbon dioxide not only results in an increase in flow to these various tissue beds but also redistribution among them. We employed a fast step increase in carbon dioxide to detect the dynamics of the cerebral blood flow response. METHODOLOGY/PRINCIPAL FINDINGS: The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. We used transcranial ultrasound to measure the time course of middle cerebral artery blood flow velocity in 28 healthy adults. Normoxic, isoxic step increases in arterial carbon dioxide tension of 10 mmHg from both hypocapnic and normocapnic baselines were produced using a new prospective targeting system that enabled a more rapid step change than has been previously achievable. In most of the 28 subjects the responses at both carbon dioxide ranges were characterised by more complex responses than a single exponential rise. Most responses were characterised by a fast initial response which then declined rapidly to a nadir, followed by a slower secondary response, with some showing oscillations before stabilising. CONCLUSIONS/SIGNIFICANCE: A rapid step increase in carbon dioxide tension is capable of inducing instability in the cerebral blood flow control system. These dynamic aspects of the cerebral blood flow responses to rapid changes in carbon dioxide must be taken into account when using transcranial blood flow velocity in a single artery segment to measure cerebrovascular reactivity.

  19. Dependence of renal blood flow on renal artery stenosis measured using CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Luedemann, Lutz [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiotherapy; Nafz, B.; Persson, P. [Charite - Universitaetsmedizin Berlin (Germany). Inst. for Vegetative Physiology; Elsner, F. [Krankenhaus am Urban, Berlin (Germany). Dept. of Anesthesiology; Grosse-Siestrup, C.; Meissler, M. [Charite - Universitaetsmedizin Berlin (Germany). Experimental Animal Unit; Gutberlet, M. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Univ. Leipzig/ Leipzig Heart Center (Germany). Dept. of Diagnostic and Interventional Radiology; Lengsfeld, P.; Voth, M. [Bayer-Schering Pharma AG, Berlin (Germany). Global Medical Affairs Diagnostic Imaging

    2011-03-15

    The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

  20. Mathematical modelling of blood flow through a tapered overlapping stenosed artery with variable viscosity

    CERN Document Server

    Shit, G C; Sinha, A

    2012-01-01

    This paper presents a theoretical study of blood flow through a tapered and overlapping stenosed artery under the action of an externally applied magnetic field. The fluid (blood) medium is assumed to be porous in nature. The variable viscosity of blood depending on hematocrit (percentage volume of erythrocytes) is taken into account in order to improve resemblance to the real situation. The governing equation for laminar, incompressible and Newtonian fluid subject to the boundary conditions is solved by using a well known Frobenius method. The analytical expressions for velocity component, volumetric flow rate, wall shear stress and pressure gradient are obtained. The numerical values are extracted from these analytical expressions and are presented graphically. It is observed that the influence of hematocrit, magnetic field and the shape of artery have important impact on the velocity profile, pressure gradient and wall shear stress. Moreover, the effect of primary stenosis on the secondary one has been sig...

  1. Mathematical Modelling of Blood Flow through a Tapered Overlapping Stenosed Artery with Variable Viscosity

    Directory of Open Access Journals (Sweden)

    G. C. Shit

    2014-01-01

    Full Text Available This paper presents a theoretical study of blood flow through a tapered and overlapping stenosed artery under the action of an externally applied magnetic field. The fluid (blood medium is assumed to be porous in nature. The variable viscosity of blood depending on hematocrit (percentage volume of erythrocytes is taken into account in order to improve resemblance to the real situation. The governing equation for laminar, incompressible and Newtonian fluid subject to the boundary conditions is solved by using a well known Frobenius method. The analytical expressions for velocity component, volumetric flow rate, wall shear stress and pressure gradient are obtained. The numerical values are extracted from these analytical expressions and are presented graphically. It is observed that the influence of hematocrit, magnetic field and the shape of artery have important impact on the velocity profile, pressure gradient and wall shear stress. Moreover, the effect of primary stenosis on the secondary one has been significantly observed.

  2. Phytoestrogen genistein decreases contractile response of aortic artery in vitro and arterial blood pressure in vivo

    Institute of Scientific and Technical Information of China (English)

    Hong-fang LI; Long-de WANG; Song-yi QU

    2004-01-01

    AIM: To determine the mechanisms of effects of phytoestrogen genistein on the contracted rabbit aortic arteries in vitro, and observe the effect of genistein and 17-β estradiol on mean arterial pressure (MAP) in ovariectomized (OVX) rats. METHODS: (1) Strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb's solution, and then isometric tension was measured. (2) Female mature Wistar rats underwent a bilateral ovariectomy (OVX). Sham-operated rats (SHAM) were used as controls. After administration of genistein (0.4(1) Similar to 17-β estradiol, genistein could dose-dependently relax 40 mmol/L KCl-precontracted arterial strips.Incubation with Nω-L-nitro-arginine (L-NNA), methylene blue (MB), indomethacin, propranolol or endothelium removal did not affect relaxation induced by genistein. In calcium-free solution containing 0.01mmol/L egtazic acid (EGTA), genistein inhibited not only the first phase contraction induced by noradrenaline (NA), but also the second contraction induced by CaCl2. In addition, genistein could reduce the contractile responses of NA, KCl and CaCl2,and shift their cumulative concentration-response curves rightward. (2) MAP in OVX rats was significantly higher compared with that of SHAM rats. However, after chronically treatment with genistein or 17-β estradiol for 21 d the baseline MAP in OVX rats was reduced significantly. CONCLUSIONS: (1) The vasodilator effect of genistein in vitro is endothelium independent and not related to the nitric oxide, its mechanisms being probably due to inhibition of Ca2+ influx through calcium channels in a noncompetitive manner and Ca2+ release from intracellular store induced by NA. (2) Administration of genistein or 17-β estradiol can chronically decrease MAP in OVX rats.

  3. Relationship of blood folate, vitamin B12 levels with coronary artery disease

    International Nuclear Information System (INIS)

    To investigate the relationship of blood folate, vitamin B12 (Vit. B12) with coronary artery disease and the mechanism, whole blood folate, plasma folate and Vit. B12 in 94 patients with coronary heart disease (CHD) were measured and compared with normal controls. The relationship of folate, Vit. B12 levels with the number of coronary vessel stenosis was also studied. Homocysteine(Hcy) and lipid levels in 57 subjects randomly selected were measured and the correlation of whole blood folate, plasma folate and Vit. B12 with Hcy and lipid levels was analyzed. The results showed that whole blood folate, plasma folate and Vit. B12 concentrations in CHD patients were significantly lower than those in normal controls. There were no significant differences in whole blood folate, plasma folate and Vit. B12 levels between patients with different number of coronary vessel stenosis. There was negative correlation of whole blood folate, plasma folate and Vit. B12 with Hcy, but no significant correlation was found with lipid. The results demonstrated that low blood folate and Vit. B12 levels were associated with the coronary heart disease, and that high plasma Hcy caused by deficiency of folate and Vit. B12 may be an independent risk factor for coronary artery disease. (authors)

  4. The effects of fenoldopam on coronary conduit blood flow after coronary artery bypass graft surgery.

    LENUS (Irish Health Repository)

    Halpenny, M

    2012-02-03

    OBJECTIVE: To quantify the effects of fenoldopam, 0.1 microg\\/kg\\/min, on left internal mammary artery (LIMA) and saphenous vein blood flow after coronary anastomosis. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial. SETTING: University teaching hospital, single institution. PARTICIPANTS: Thirty-one American Society of Anesthesiologists III patients undergoing elective coronary revascularization. INTERVENTIONS: A perivascular ultrasonic flow probe (Linton Instrumentation, Norfolk, UK) was placed around the LIMA and saphenous vein graft after coronary anastomosis. MEASUREMENTS AND MAIN RESULTS: Immediately before and at 5-minute intervals for 15 minutes after starting the infusion, blood flow was measured in the LIMA and one saphenous vein graft using a transit time ultrasonic flow probe. Heart rate, blood pressure, and central venous pressure were documented at these time points. Administration of fenoldopam, 0.1 microg\\/kg\\/min, did not alter heart rate or blood pressure. A small, nonsignificant increase in LIMA blood flow occurred during the 15-minute study period (30 +\\/- 12 to 35 +\\/- 10 mL\\/min) in patients who received fenoldopam. No significant changes occurred in the placebo group. CONCLUSIONS: The findings indicate that fenoldopam, 0.1 microg\\/kg\\/min, did not influence coronary conduit blood flow to a clinically significant extent. The small increase in LIMA blood flow may be of greater importance in high-risk patients or in the prevention of coronary arterial spasm.

  5. The accuracy of blood pressure measured by arterial line and non-invasive cuff in critically ill children

    OpenAIRE

    Joffe, Rachel; Duff, Jonathan; Garcia Guerra, Gonzalo; Pugh, Jodie; Ari R. Joffe

    2016-01-01

    Background The accuracy of arterial lines (AL) using the flush test or stopcock test has not been described in children, nor has the difference between invasive arterial blood pressure (IABP) versus non-invasive cuff (NIBP) blood pressure. Methods After ethics approval and consent, we performed the flush test and stopcock test on AL (to determine over damping, under damping, and optimal damping), and determined the difference (NIBP–IABP) in systolic, diastolic, and mean blood pressure (ΔSBP, ...

  6. Correlation between arterial and venous blood gas analysis parameters in patients with acute exacerbation of chronic obstructive pulmonary disease

    OpenAIRE

    Novović Miloš; Topić Vesna

    2012-01-01

    Introduction. Arterial blood gas (ABG) analyses have an important role in the assessment and monitoring of the metabolic and oxygen status of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). Arterial puncture could have a lot of adverse effects, while sampling of venous blood is simpler and is not so invasive. Objective. The aim of this study was to evaluate whether venous blood gas (VBG) values of pH, partial pressure of carbon dioxide (PCO2), partial o...

  7. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery

    OpenAIRE

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H.; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to...

  8. Energy harvesting from arterial blood pressure for powering embedded brain sensors

    Science.gov (United States)

    Nanda, Aditya; Karami, M. Amin

    2016-04-01

    This paper investigates energy harvesting from arterial blood pressure via the piezoelectric effect by using a novel streaked cylinder geometry for the purpose of powering embedded micro-sensors in the brain. Initially, we look at the energy harvested by a piezoelectric cylinder placed inside an artery acted upon by blood pressure. Such an arrangement would be tantamount to constructing a stent out of piezoelectric materials. A stent is a cylinder placed in veins and arteries to prevent obstruction in blood flow. The governing equations of a conductor coated piezoelectric cylinder are obtained using Hamilton's principle. Pressure acting in arteries is radially directed and this is used to simplify the modal analysis and obtain the transfer function relating pressure to the induced voltage across the surface of the harvester. The power harvested by the cylindrical harvester is obtained for different shunt resistances. Radially directed pressure occurs elsewhere and we also look at harvesting energy from oil flow in pipelines. Although the energy harvested by the cylindrical energy harvester is significant at resonance, the natural frequency of the system is found to be very high. To decrease the natural frequency, we propose a novel streaked stent design by cutting it along the length, transforming it to a curved plate and decreasing the natural frequency. The governing equations corresponding to the new geometry are derived using Hamilton's principle and modal analysis is used to obtain the transfer function.

  9. Use of paravascular admittance waveforms to monitor relative change in arterial blood pressure

    Science.gov (United States)

    Zielinski, Todd M.; Hettrick, Doug; Cho, Yong

    2010-04-01

    Non-invasive methods to monitor ambulatory blood pressure often have limitations that can affect measurement accuracy and patient adherence [1]. Minimally invasive measurement of a relative blood pressure surrogate with an implantable device may provide a useful chronic diagnostic and monitoring tool. We assessed a technique that uses electrocardiogram and paravascular admittance waveform morphology analysis to one, measure a time duration (vascular tone index, VTI in milliseconds) change from the electrocardiogram R-wave to admittance waveform peak and two, measure the admittance waveform minimum, maximum and magnitude as indicators of change in arterial compliance/distensibility or pulse pressure secondary to change in afterload. Methods: Five anesthetized domestic pigs (32 ± 4.2 kg) were used to study the effects of phenylephrine (1-5 ug/kg/min) on femoral artery pressure and admittance waveform morphology measured with a quadrapolar electrode array catheter placed next to the femoral artery to assess the relative change in arterial compliance due to change in peripheral vascular tone. Results: Statistical difference was observed (p measurement techniques that monitor relative change in blood pressure may be suitable for implantable devices to detect progression of cardiovascular disease such as hypertension.

  10. A strategy for determining arterial blood gases on the summit of Mt. Everest

    Directory of Open Access Journals (Sweden)

    Powell Frank L

    2006-03-01

    Full Text Available Abstract Background Climbers on the summit of Mt. Everest are exposed to extreme hypoxia, and the physiological implications are of great interest. Inferences have been made from alveolar gas samples collected on the summit, but arterial blood samples would give critical information. We propose a plan to insert an arterial catheter at an altitude of 8000 m, take blood samples above this using an automatic sampler, store the samples in glass syringes in an ice-water slurry, and analyze them lower on the mountain 4 to 6 hours later. Results A preliminary design of the automatic sampler was successfully tested at the White Mountain Research Station (altitude 3800 m – 4300 m. To determine how much the blood gases changed over a long period, rabbit blood was tonometered to give a gas composition close to that expected on the summit (PO2 4.0 kPa (30 mmHg, PCO2 1.3 kPa (10 mmHg, pH 7.7 and the blood gases were measured every 2 hours for 8 hours both at sea level and 3800 m. The mean changes were PO2 +0.3 to +0.4 kPa (+2 to +3 mmHg, PCO2 0 to +0.13 kPa (+1 mmHg, pH -0.02 to -0.04, base excess -0.7 to -1.2 mM. In practice the delay before analysis should not exceed 4 to 6 hours. The small paradoxical rise in PO2 is presumably caused mainly by contamination of the blood with air. Conclusion We conclude that automatic arterial blood sampling at high altitude is technically feasible and that the changes in the blood gases over a period of several hours are acceptably small.

  11. Active Path Selection of Fluid Microcapsules in Artificial Blood Vessel by Acoustic Radiation Force

    Science.gov (United States)

    Masuda, Kohji; Muramatsu, Yusuke; Ueda, Sawami; Nakamoto, Ryusuke; Nakayashiki, Yusuke; Ishihara, Ken

    2009-07-01

    Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled. To control the behavior of microcapsules, acoustic radiation force was introduced. We detected local changes in microcapsule density by producing acoustic radiation force in an artificial blood vessel. Furthermore, we theoretically estimated the conditions required for active path selection of capsules at a bifurcation point in the artificial blood vessel. We observed the difference in capsule density at both in the bifurcation point and in alternative paths downstream of the bifurcation point for different acoustic radiation forces. Comparing the experimental results with those obtained theoretically, the conditions for active path selection were calculated from the acoustic radiation force and fluid resistance of the capsules. The possibility of controlling capsule flow towards a specific point in a blood vessel was demonstrated.

  12. 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. PMID:25429784

  13. Volumetric liquid flow measurement through thermography to simulate blood flow in an artery

    Science.gov (United States)

    Villaseñor-Mora, Carlos; Rabell-Montiel, Adela; González-Vega, Arturo; Gutierrez-Juarez, Gerardo

    2015-09-01

    Encouraged to improve the procedure to measure the blood flow in cases with peripheral artery disease using thermography, that allows to evaluate several arteries simultaneously, it was developed an alternative to measure the volumetric flow through a conduit, it was studied the variation of the thermal energy computed from thermal images due to changes in flow at different temperatures, and it was observed that the measurement is not strongly influenced by the emissivity of the conduit, the ambient temperature and humidity, but that is necessary to establish an adequate calibration of the camera to can use it as measurement instrument.

  14. The usefulness of the arterial blood gas in pure carbon monoxide poisoning.

    Science.gov (United States)

    Lebby, T I; Zalenski, R; Hryhorczuk, D O; Leikin, J B

    1989-04-01

    In a retrospective study of 49 cases of carbon monoxide (CO) intoxication presented to the University of Illinois Hospital (UIH) Emergency Department between November 1986 and April 1988, we looked for a correlation between carboxyhemoglobin (COHb) as determined by a venous sample and the pH as determined by arterial blood gas analysis. The range of COHb levels in our study was 10-64% (mean 21.8% +/- 10.2%). Smoke inhalation cases (n = 3) were excluded from our study because they did not represent pure CO intoxication. Of the remaining 46 cases, 18 had arterial blood gases drawn. In none of these 18 cases (mean COHb 24.5% +/- 12.6%) did we find a correlation between COHb levels and the pH as determined by linear regression analysis. Also, in none of the 18 cases were there any therapeutic interventions associated with the arterial blood gas result. Additionally, in none of the remaining 28 cases were any therapeutic interventions performed with regards to patients' acidosis or ventilatory status (except 100% oxygen administration. We also retrospectively reviewed records of 104 cases who presented to Cook County Hospital Emergency Department with COHb levels over 10% during the period between March 1986 and May 1988. In these cases, we found no significant correlation between COHb level and arterial pH. We therefore conclude that arterial blood gases drawn in order to determine the degree of acidosis in mild CO intoxication without respiratory distress may not be useful in guiding therapeutic intervention and need not be routinely drawn. PMID:2929122

  15. Transcutaneous monitoring of blood gases: is it comparable with arterialized earlobe sampling?

    Science.gov (United States)

    Dawson, S; Cave, C; Pavord, I; Potter, J F

    1998-03-01

    Researchers are increasingly looking for reliable non-invasive methods of assessing blood gas concentrations, and several new techniques have recently become available. Values derived using arterialized earlobe samples have been found to be comparable with conventional arterial samples, and recent studies have compared transcutaneous blood gas analysis with the traditional arterial samples and found a reasonable level of agreement in particular for the partial pressure of carbon dioxide. There are no data comparing oxygen and carbon dioxide partial pressures (pO2, pCO2) derived from arterialized samples with one of the newer transcutaneous techniques. We therefore simultaneously studied arterialized earlobe blood gas samples and values for pO2 and pCO2 obtained by a transcutaneous monitor (TINA, Radiometer, Copenhagen) in 26 subjects with varying blood gas values. There was a close agreement between the two methods for assessment of pCO2 [mean difference (95% C.I.) between transcutaneous and earlobe values 0.25 kPa (-0.004, 0.5 kPa)], but not for pO2 [1.71 kPa (0.35, 3.07 kPa)]. Similarly, the limits of agreement were narrow for pCO2 compared to those for pO2 (-0.98, 1.47 kPa and -6.44, 3.02 kPa respectively). We conclude that transcutaneous measurement of pCO2 using the TINA is acceptable in the research setting, whereas assessment of pO2 cannot reliably be made using this technique. PMID:9692127

  16. Computational modeling of non-Newtonian blood flow through stenosed arteries in the presence of magnetic field.

    Science.gov (United States)

    Alshare, Aiman; Tashtoush, Bourhan; El-Khalil, Hossam H

    2013-11-01

    Steady flow simulations of blood flow in an axisymmetric stenosed artery, subjected to a static magnetic field, are performed to investigate the influence of artery size, magnetic field strength, and non-Newtonian behavior on artery wall shear stress and pressure drop in the stenosed section. It is found that wall shear stress and pressure drop increase by decreasing artery size, assuming non-Newtonian fluid, and increasing magnetic field strength. In the computations, the shear thinning behavior of blood is accounted for by the Carreau-Yasuda model. Computational results are compared and found to be inline with available experimental data. PMID:24061603

  17. Artificial reproduction of magnetic fields produced by a natural geomagnetic storm increases systolic blood pressure in rats

    Science.gov (United States)

    Martínez-Bretón, J. L.; Mendoza, B.; Miranda-Anaya, M.; Durán, P.; Flores-Chávez, P. L.

    2016-04-01

    The incidence of geomagnetic storms may be associated with changes in circulatory physiology. The way in which the natural variations of the geomagnetic field due to solar activity affects the blood pressure are poorly understood and require further study in controlled experimental designs in animal models. In the present study, we tested whether the systolic arterial pressure (AP) in adult rats is affected by simulated magnetic fields resembling the natural changes of a geomagnetic storm. We exposed adult rats to a linear magnetic profile that simulates the average changes associated to some well-known geomagnetic storm phases: the sudden commencement and principal phase. Magnetic stimulus was provided by a coil inductor and regulated by a microcontroller. The experiments were conducted in the electromagnetically isolated environment of a semi-anechoic chamber. After exposure, AP was determined with a non-invasive method through the pulse on the rat's tail. Animals were used as their own control. Our results indicate that there was no statistically significant effect in AP when the artificial profile was applied, neither in the sudden commencement nor in the principal phases. However, during the experimental period, a natural geomagnetic storm occurred, and we did observe statistically significant AP increase during the sudden commencement phase. Furthermore, when this storm phase was artificially replicated with a non-linear profile, we noticed a 7 to 9 % increase of the rats' AP in relation to a reference value. We suggested that the changes in the geomagnetic field associated with a geomagnetic storm in its first day could produce a measurable and reproducible physiological response in AP.

  18. The physiological basis of pulmonary gas exchange: implications for clinical interpretation of arterial blood gases.

    Science.gov (United States)

    Wagner, Peter D

    2015-01-01

    The field of pulmonary gas exchange is mature, with the basic principles developed more than 60 years ago. Arterial blood gas measurements (tensions and concentrations of O₂ and CO₂) constitute a mainstay of clinical care to assess the degree of pulmonary gas exchange abnormality. However, the factors that dictate arterial blood gas values are often multifactorial and complex, with six different causes of hypoxaemia (inspiratory hypoxia, hypoventilation, ventilation/perfusion inequality, diffusion limitation, shunting and reduced mixed venous oxygenation) contributing variably to the arterial O₂ and CO₂ tension in any given patient. Blood gas values are then usually further affected by the body's abilities to compensate for gas exchange disturbances by three tactics (greater O₂ extraction, increasing ventilation and increasing cardiac output). This article explains the basic principles of gas exchange in health, mechanisms of altered gas exchange in disease, how the body compensates for abnormal gas exchange, and based on these principles, the tools available to interpret blood gas data and, quantitatively, to best understand the physiological state of each patient. This understanding is important because therapeutic intervention to improve abnormal gas exchange in any given patient needs to be based on the particular physiological mechanisms affecting gas exchange in that patient. PMID:25323225

  19. An effective fractal-tree closure model for simulating blood flow in large arterial networks.

    Science.gov (United States)

    Perdikaris, Paris; Grinberg, Leopold; Karniadakis, George Em

    2015-06-01

    The aim of the present work is to address the closure problem for hemodynamic simulations by developing a flexible and effective model that accurately distributes flow in the downstream vasculature and can stably provide a physiological pressure outflow boundary condition. To achieve this goal, we model blood flow in the sub-pixel vasculature by using a non-linear 1D model in self-similar networks of compliant arteries that mimic the structure and hierarchy of vessels in the meso-vascular regime (radii [Formula: see text]). We introduce a variable vessel length-to-radius ratio for small arteries and arterioles, while also addressing non-Newtonian blood rheology and arterial wall viscoelasticity effects in small arteries and arterioles. This methodology aims to overcome substantial cut-off radius sensitivities, typically arising in structured tree and linearized impedance models. The proposed model is not sensitive to outflow boundary conditions applied at the end points of the fractal network, and thus does not require calibration of resistance/capacitance parameters typically required for outflow conditions. The proposed model convergences to a periodic state in two cardiac cycles even when started from zero-flow initial conditions. The resulting fractal-trees typically consist of thousands to millions of arteries, posing the need for efficient parallel algorithms. To this end, we have scaled up a Discontinuous Galerkin solver that utilizes the MPI/OpenMP hybrid programming paradigm to thousands of computer cores, and can simulate blood flow in networks of millions of arterial segments at the rate of one cycle per 5 min. The proposed model has been extensively tested on a large and complex cranial network with 50 parent, patient-specific arteries and 21 outlets to which fractal trees where attached, resulting to a network of up to 4,392,484 vessels in total, and a detailed network of the arm with 276 parent arteries and 103 outlets (a total of 702,188 vessels

  20. Microalbuminuria associated with systolic blood pressure and arterial compliance in Chinese metabolic syndrome patients

    Institute of Scientific and Technical Information of China (English)

    LI Xin-li; XU Qiong; TONG Min; LU Xin-zheng; ZHANG Hai-feng; ZHOU Yan-li; CAO Ke-jiang; HUANG Jun

    2007-01-01

    Background There is significant evidence showing that microalbuminuria and arterial compliance are sensitive markers for early cardiovascular diseases. However, whether microalbuminuria is associated with reduced arterial compliance in Chinese metabolic syndrome (MS) patients remains unknown.Methods According to the definition of MS proposed by ATPⅢ in 2001, USA, subjects (n=362) were divided into three groups according to the number of risk factors: group 1 (control), group 2 (medium, < 3 risk factors) and group 3 (MS, ≥ 3 risk factors). Both large artery compliance (C1) and small artery compliance (C2) were measured with the CVProfilor DO-2020 Cardiovascular Profiling System, and microalbuminuria was evaluated with the ratio of albumin to urine creatinine.Results (1) As C1 and C2 levels elasticity decreased, albumin creatinine ratio (ACR) and the prevalence of microalbuminuria increased within those groups with MS risk factors. C1 and C2 were negatively correlated with the ranking of MS risk factors, ACR was positively correlated with the ranking of MS risk factors (all P<0.05). (2) Subjects were also categorized into a microalbuminuria group and a normal group, C1 and C2 in the microalbuminuria group were lower than in the normal group. (3) Multivariate regression analysis showed that increased systolic blood pressure (SBP) and reduced arterial compliance were the main risk factors for microalbuminuria in the MS group.Conclusions The risk of developing microalbuminuria was higher in the subjects with multiple metabolic abnormalities.Increased systolic blood pressure and reduced arterial compliance may be the main predictors for microalbuminuria in MS.

  1. Assessment of tissue blood flow following small artery welding with an intraluminal dissolvable stent.

    Science.gov (United States)

    He, F C; Wei, L P; Lanzetta, M; Owen, E R

    1999-01-01

    Using the technique of radioactive 51Cr-labeled biological microspheres, this study evaluated arterial blood flow following small vessel anastomosis by CO2 laser welding and a dissolvable stent in the lumen. A total of 30 Sprague-Dawley rats were divided into two groups. Group A: 11 rats had their femoral arteries ligated on one side. The contralateral side served as a control, with the artery transected and repaired using conventional microsuturing. Group B: 19 rats had their femoral arteries transected and repaired using CO2 laser welding and an intraluminal dissolvable stent technique. The contralateral side was again used as a control using conventional microsuturing. At 1 hr postoperatively, 51Cr-labeled biological microspheres were injected centripetally into the left common carotid artery and the legs and thighs immediately harvested for measurement of radioactivity. All repaired arteries were patent (30/30 in the microsuturing group and 19/19 in the stented welding group), with no detectable stenosis or dilation at the repaired site. Statistical analysis showed that tissue radioactivity (cpm/g) in the ligated group (3,972 +/- 384 in thighs and 3,142 +/- 742 in legs) was significantly lower than in the microsuturing group (7,132 +/- 1,723 in thighs and 6,557 +/- 1,469 in legs) (P welding group, in both thighs (7,064 +/- 2,599 and 7,006 +/- 2,406, respectively; P > 0.05) and legs (6,386 +/- 1,703 and 6,288 +/- 1,757, respectively; P > 0.05). This study provided evidence that the dissolvable stent placed intraluminally does not impair blood circulation and that when coupled with CO2 laser welding offers a high-quality alternative to conventional small vessel anastomosis. PMID:10231124

  2. Evaluation of blood flow in Allograft Renal Arteries anastomosed with two different techniques

    International Nuclear Information System (INIS)

    Renal artery stenosis in renal transplantation (TRAS) is an avoidable short or long term surgical complication. The etiology is multifactorial, but faulty anastomosis is a major factor. In our transplant center, we evaluated the incidence of TRAS with the use of two different suturing techniques of the anastomosis site between allograft renal and renal and iliac arteries in two groups of renal transplant recipients, group A: 14 patients (6 males and 8 females with age 16 to 59 and mean age of 38 years) in whom allograft arteries were anastomosed with a continuous suture technique and group B: 14 patients (7 males and 7 females with age 32 to 61 and mean age of 46.6 years) in whom the allograft arteries were anastomosed with a combined suture technique (continuous and uninterrupted. Post transplantation, the velocity of blood flow in the renal and iliac arteries at the site of anastomosis was measured by color Doppler ultrasound. The ultrasonographer was blinded to the surgical technique in both study groups. The ratio of the maximum velocity of blood at the site of anastomosis to that in the iliac artery of less than 2.5 was considered as non-significant stenosis, while a ratio of more than 2.5 was considered significant stenosis. In group A there were 9 cases of non-significant stenosis in comparison to 3 cases in group B, while there were no cases of significant stenosis in group A in comparison to 3 cases in group B; the difference was not statistically significant. We conclude that there was no difference in the compared surgical techniques of anastomosis in our study groups. This suggests that other factors such as gentle handling of tissue, enough spatula, margin reversion and comparable diameter of the anastomosed vessels may be more important in the prevention of renal allograft stenosis than the type of suture technique. (author)

  3. No benefit of intraoperative whole blood sequestration and autotransfusion during coronary artery bypass grafting : results of a randomized clinical trial

    NARCIS (Netherlands)

    Ramnath, A N; Naber, H R; de Boer, A; Leusink, J A

    2003-01-01

    OBJECTIVES: In a randomized clinical trial of patients undergoing elective coronary artery bypass grafting, we evaluated the effect of intraoperative whole blood sequestration and autotransfusion on postoperative blood loss and the use of allogeneic blood products. METHODS: Male patients were includ

  4. Heat stress redistributes blood flow in arteries of the brain during dynamic exercise.

    Science.gov (United States)

    Sato, Kohei; Oue, Anna; Yoneya, Marina; Sadamoto, Tomoko; Ogoh, Shigehiko

    2016-04-01

    We hypothesized that heat stress would decrease anterior and posterior cerebral blood flow (CBF) during exercise, and the reduction in anterior CBF would be partly associated with large increase in extracranial blood flow (BF). Nine subjects performed 40 min of semirecumbent cycling at 60% of the peak oxygen uptake in hot (35°C; Heat) and thermoneutral environments (25°C; Control). We evaluated BF and conductance (COND) in the external carotid artery (ECA), internal carotid artery (ICA), and vertebral artery (VA) using ultrasonography. During the Heat condition, ICA and VA BF were significantly increased 10 min after the start of exercise (PECA BF and COND at the end of Heat were both higher than levels in the Control condition (PECA BF during Heat was negatively correlated with a change in ICA BF (r= -0.75). Heat stress resulted in modification of the vascular response of head and brain arteries to exercise, which resulted in an alteration in the distribution of cardiac output. Moreover, a hyperthermia-induced increase in extracranial BF might compromise anterior CBF during exercise with heat stress. PMID:26846548

  5. Correlation between penile cavernosal artery blood flow and retinal vascular findings in arteriogenic erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Ahmed M Emarah

    2010-09-01

    Full Text Available Ahmed M Emarah1, Shawky M El-Haggar2, Ihab A Osman2, Abdel Wahab S Khafagy21Departments of Ophthalmology, 2Andrology and Sexology, Cairo University Hospital, EgyptObjectives: Arteriogenic erectile dysfunction (ED is a target organ disease of atherosclerosis, and therefore might be a predictor of systemic atherosclerosis. Being systemic, it might be possible to evaluate the extent of atherosclerosis from retinal vascular findings. We investigated the possible correlation between penile cavernosal artery blood flow and retinal vascular findings in patients with arteriogenic ED.Patients and methods: Sixty patients with ED were divided according to the peak systolic velocity (PSV in their penile cavernosal arteries into two groups; Group A included 30 patients with PSV less than 25 cm/sec, and Group B included 30 patients with PSV more than 35 cm/sec. Blood flow in the penile cavernosal artery was measured with color Doppler ultrasonography. All patients were assessed by ocular fundus examination under amydriatic conditions to evaluate retinal vascular atherosclerotic changes using Hyman’s classification.Results: Evidence of retinal vascular atherosclerotic changes was found in 19 patients (63.3% in Group A and in 10 patients (33.3% in Group B.Conclusions: Our study confirms the possibility of predicting penile arterial vascular status in patients with ED from their retinal vascular findings by using amydriatic simple, practical funduscopy.Keywords: erectile dysfunction, atherosclerosis, retinal vascular atherosclerosis

  6. Comparison of oscillometric and intra-arterial blood pressure and pulse measurement.

    Science.gov (United States)

    Rithalia, S V; Edwards, D

    1994-01-01

    Non-invasive oscillometric blood pressure and pulse measured by an Omron HEM-703CP monitor were compared with arterial values obtained from direct measurements of the radial artery. An excellent correlation and agreement was found between the two methods (systolic r = 0.99; diastolic r = 0.97; pulse r = 0.99), although there was some variability among individual subjects. The range of difference between them was 0 to 10 mmHg for systolic and -6 to +5 mmHg for diastolic pressures. When tested on the bench using the Metron QA-1280 non-invasive blood pressure analyser the HEM-703CP monitor rarely exhibited errors exceeding 2-3 mmHg over a measurement range of 50-200 mmHg. PMID:7776359

  7. Recent trends on the stent research for blood arteries by bibliometric analysis

    OpenAIRE

    Ahn, Sejung; Sung, Jung-Suk; Choi, Brad; Kim, Hackjoo; Sung, Yong Kiel

    2014-01-01

    The research trends on stent for blood arteries are reviewed by bibliometric analysis using 7,790 journal articles published from 1986 to 2013 of the Web of Science database. The bibliometric indicators are applied to analyze the journal article data, which are simple number of publications for selecting key players, citation indicators for measuring qualitative research performance, collaboration indicators for figuring out the degree of international collaboration and keyword mapping for id...

  8. Aspects of the continuous clinical measurement of arterial blood pressure and cardiac output

    International Nuclear Information System (INIS)

    In this paper the authors try to classify circulatory measurements as to certain characteristics such as ''activeness'', ''invasivenesss'', etc. Next they turn to defining some fundamental measurements in the blood circulation and focus attention on the continuous measurement of systemic arterial pressure and flow to finally emphasize the inaccuracy of clinical cardiac output methods. The conclusion is that clinical circulatory measurement methods have accuracies at least an order of magnitude worse than common physical methods used in electrical or mechanical engineering. (Auth.)

  9. Measurement of brachial artery endothelial function using a standard blood pressure cuff

    OpenAIRE

    Maltz, Jonathan S.; Tison, Geoffrey H; Alley, Hugh F.; Budinger, Thomas F; Owens, Christopher D.; Olgin, Jeffrey

    2015-01-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, lab-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arg...

  10. Numerical simulation of blood flow and pressure drop in the pulmonary arterial and venous circulation.

    Science.gov (United States)

    Qureshi, M Umar; Vaughan, Gareth D A; Sainsbury, Christopher; Johnson, Martin; Peskin, Charles S; Olufsen, Mette S; Hill, N A

    2014-10-01

    A novel multiscale mathematical and computational model of the pulmonary circulation is presented and used to analyse both arterial and venous pressure and flow. This work is a major advance over previous studies by Olufsen et al. (Ann Biomed Eng 28:1281-1299, 2012) which only considered the arterial circulation. For the first three generations of vessels within the pulmonary circulation, geometry is specified from patient-specific measurements obtained using magnetic resonance imaging (MRI). Blood flow and pressure in the larger arteries and veins are predicted using a nonlinear, cross-sectional-area-averaged system of equations for a Newtonian fluid in an elastic tube. Inflow into the main pulmonary artery is obtained from MRI measurements, while pressure entering the left atrium from the main pulmonary vein is kept constant at the normal mean value of 2 mmHg. Each terminal vessel in the network of 'large' arteries is connected to its corresponding terminal vein via a network of vessels representing the vascular bed of smaller arteries and veins. We develop and implement an algorithm to calculate the admittance of each vascular bed, using bifurcating structured trees and recursion. The structured-tree models take into account the geometry and material properties of the 'smaller' arteries and veins of radii ≥ 50 μm. We study the effects on flow and pressure associated with three classes of pulmonary hypertension expressed via stiffening of larger and smaller vessels, and vascular rarefaction. The results of simulating these pathological conditions are in agreement with clinical observations, showing that the model has potential for assisting with diagnosis and treatment for circulatory diseases within the lung. PMID:24610385

  11. 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...... PAD was sufficiently high in subjects over the age of 60 years to warrant screening. The ankle brachial index based on measurements with an oscillometric device was shown reliable in the exclusion of PAD, thereby fulfilling an important criterion for the use in screening....

  12. Exercise intensity modulates brachial artery retrograde blood flow and shear rate during leg cycling in hypoxia.

    Science.gov (United States)

    Iwamoto, Erika; Katayama, Keisho; Ishida, Koji

    2015-06-01

    The purpose of this study was to elucidate the effect of exercise intensity on retrograde blood flow and shear rate (SR) in an inactive limb during exercise under normoxic and hypoxic conditions. The subjects performed two maximal exercise tests on a semi-recumbent cycle ergometer to estimate peak oxygen uptake (V˙O2peak) while breathing normoxic (inspired oxygen fraction [FIO2 = 0.21]) and hypoxic (FIO2 = 0.12 or 0.13) gas mixtures. Subjects then performed four exercise bouts at the same relative intensities (30 and 60% V˙O2peak) for 30 min under normoxic or hypoxic conditions. Brachial artery diameter and blood velocity were simultaneously recorded, using Doppler ultrasonography. Retrograde SR was enhanced with increasing exercise intensity under both conditions at 10 min of exercise. Thereafter, retrograde blood flow and SR in normoxia returned to pre-exercise levels, with no significant differences between the two exercise intensities. In contrast, retrograde blood flow and SR in hypoxia remained significantly elevated above baseline and was significantly greater at 60% than at 30% V˙O2peak. We conclude that differences in exercise intensity affect brachial artery retrograde blood flow and SR during prolonged exercise under hypoxic conditions. PMID:26038470

  13. Two-Fluid Mathematical Models for Blood Flow in Stenosed Arteries: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Sankar DS

    2009-01-01

    Full Text Available The pulsatile flow of blood through stenosed arteries is analyzed by assuming the blood as a two-fluid model with the suspension of all the erythrocytes in the core region as a non-Newtonian fluid and the plasma in the peripheral layer as a Newtonian fluid. The non-Newtonian fluid in the core region of the artery is assumed as a (i Herschel-Bulkley fluid and (ii Casson fluid. Perturbation method is used to solve the resulting system of non-linear partial differential equations. Expressions for various flow quantities are obtained for the two-fluid Casson model. Expressions of the flow quantities obtained by Sankar and Lee (2006 for the two-fluid Herschel-Bulkley model are used to get the data for comparison. It is found that the plug flow velocity and velocity distribution of the two-fluid Casson model are considerably higher than those of the two-fluid Herschel-Bulkley model. It is also observed that the pressure drop, plug core radius, wall shear stress and the resistance to flow are significantly very low for the two-fluid Casson model than those of the two-fluid Herschel-Bulkley model. Hence, the two-fluid Casson model would be more useful than the two-fluid Herschel-Bulkley model to analyze the blood flow through stenosed arteries.

  14. Blood compatibility of artificial blood vessels probed by infrared spectroscopic imaging

    Science.gov (United States)

    Steiner, Gerald; Maitz, Manfred; Tunc, Sibel; Salzer, Reiner

    2006-02-01

    The determination of protein structure and function plays an important role in biomedical and biochemical research. Common techniques that give full structural information do not permit in-vivo measurements. Infrared spectroscopy has a sufficient sensitivity to examine the structure of proteins solution under in-situ conditions and even on surfaces. However, measurements at few spots on the surface are not suitable to find out the blood compatibility of the protein layer, because the changes in conformation occur often in small domains. Here we report on the investigations of adsorbed fibrinogen with FTIR imaging. FTIR imaging permits an identification of coagulation spots in the micrometer range and the identification of coagulation spots on the implant material.

  15. Percutaneous renal artery stenting reduces arterial blood pressure, but what about renal function? A single-center experience

    Directory of Open Access Journals (Sweden)

    Erkan Dervişoğlu

    2010-02-01

    Full Text Available Objective: To assess the effects of percutaneous transluminal angioplasty and stenting (PTRA/S on arterial blood pressure and renal function.Methods: A retrospective chart review of patients undergoing PTRA/S at our institution between December 2003 and September 2006 was done. Follow-up data were derived from hospital records. Estimated glomerular filtration rate (EGFR was used as the marker of renal function. To evaluate the pre- and post-procedure values in individual patients the paired t test and Wilcoxon signed-rank tests were used.Results: Thirty-six patients (16 women, 30 men; mean age 59±15 years, range: 25-83 years underwent 43 PTRA/S interventions at our institution. The mean duration of follow-up was 9.3±8.6 (range 2-28 months. We observed no significant change in EGFR from pre-procedure to that obtained at follow-up (71.4±40.2 mL/min vs.73.3±39.0 mL/min; p=0.483. Mean arterial blood pressure (MABP, however, was reduced significantly: pre-procedure MABP-123±22 mmHg; post-procedure follow-up value of 101±14 mmHg (p <0.001. The mean number of antihypertensive medications used at the time of intervention was 2.1±1.0 (range: 0-4, whereas at follow-up, this number had decreased to 1.3±1.0 (range: 0-4; p<0.001. In patients with renal impairment (EGFR ≤59 mL/min, 41% showed improvement, 29% showed no change and 29% demonstrated deterioration in EGFR. Conclusion: PTRA/S may preserve renal function, especially in patients with pre-procedural impaired renal function.

  16. Twenty-four-hour exposure to altered blood flow modifies endothelial Ca2+-activated K+ channels in rat mesenteric arteries

    DEFF Research Database (Denmark)

    Hilgers, Rob H P; Janssen, Ger M J; Fazzi, Gregorio E;

    2010-01-01

    We tested the hypothesis that changes in arterial blood flow modify the function of endothelial Ca2+-activated K+ channels [calcium-activated K+ channel (K(Ca)), small-conductance calcium-activated K+ channel (SK3), and intermediate calcium-activated K+ channel (IK1)] before arterial structural...

  17. Comparison of obstructing blood flow interventional embolectomy and simple interventional embolectomy for acute lower limb arterial embolism

    International Nuclear Information System (INIS)

    Objective: To evaluate the effects (mortality, amputation rate, the length and expense of hospital stay, etc)of the obstructing blood flow interventional embolectomy and simple interventional embolectomy for acute lower limb arterial embolism. Methods: 79 cases of acute lower limb arterial embolism including 23 cases of two sites puncturing and obstructing blood flow interventional embolectomy and 56 cases treated by simple interventional embolectomy were retrospectively analyzed and compared. Results: Embolisms were removed in all 79 cases and arteries were reopened successfully. The mortality and the amputation rates of the simple and the obstructing blood flow embolectomies were 5.36%, 19.6%, and 4.35%, 8.70% respectively. Conclusion: Two sites puncturing and obstructing blood flow interventional embolectomy for acute lower limb arterial embolism is simple, safe and effective, comparing with the simple interventional embolectomy, with lower amputation rate, quicker recovery and lower expense, however with no statistical significance in mortalities. (authors)

  18. Determining the Arterial Blood Pressure of People Living in Yesilyurt Local Healthcare Office

    Directory of Open Access Journals (Sweden)

    Feyza Dereli

    2009-02-01

    Full Text Available AIM: Whereas the prevalance of arterial blood pressure which was a chronical health problem was 20%-25% among 30 year-old people, them showing an increase in aging, the percentage went as high as 50% in 60’s and later ages. What was that worrisome was that despite the high prevalance, only half of these received treathment. This is study was descriptively and cross-sectionally planned to determine whether the people asking their tensions to be measured in and around the Yesilyurt local healthcare office region. METHODS: The environment of the research consisted of 1400 people over 35 age and registered Yesilyurt Local healthcare Office and the whole of the environment were included in this sample. The study was conducted over 340 voluntaries. The data was collected by a questionnaire of 14 questions containing socio-demografic features and by measuring the arterial blood pressure, height and weight of the individuals. In the evaluation of the data, chi-square test was used and the level of significantly was accepted as 0.05. RESULTS: In this study, the rate of high sistolic blood pressure was found to be 21.47% and the rate of high diastolic blood pressure to be 8.23%. It was determined that age and body mass index varrieties were effective on sistolic hipertension. It was also found that in their behaviors of the use of hypertensive medicine, of regular arterial pressure controls and of having the hypertesion diagnosis significant differnces varied statistically on both sistolic and diastolic blood pressure people having. CONCLUSION: In order to improve the health, informative information abouth hypertension was provided for the participants for too days consisting of 4 sessions. [TAF Prev Med Bull 2009; 8(1.000: 53-58

  19. Regional blood flow distribution in dog during induced hypotension and low cardiac output. Spontaneous breathing versus artificial ventilation.

    OpenAIRE

    Viires, N; Sillye, G; Aubier, M.; Rassidakis, A; Roussos, C

    1983-01-01

    Respiratory muscle blood flow and organ blood flow was studied in two groups of dogs with radioactively labeled microspheres to assess the influence of the working respiratory muscles on the regional distribution of blood flow when arterial pressure and cardiac output were lowered by pericardial tamponade. In one group (n = 6), the dogs were paralyzed and mechanically ventilated (Mv), while in the other (n = 6), they were left to breathe spontaneously (Sb). Cardiac output fell to 30% of contr...

  20. Radiosensitization by oxygen in ehrlich tumor receiving artificial blood substitute (FOB 20%)

    International Nuclear Information System (INIS)

    To enhance tissue PO2 of radioresistant hypoxic cells of tumor, artificial blood substitute (FOB) was applied, because it is excellent solvent for oxygen and allows the blood circulation system to recover and consequently increase the oxygen supply from blood to the tissue. When transplanted Ehrlich tumor of mice on thigh grew about 1,000 mm3 in volume, those were divided into three groups, group 1: 60Co γ-ray irradiation alone, group 2: irradiation under breathing oxygen, and group 3: irradiation under breathing oxygen after exchange transfusion with FOB. The radiosensitization of FOB was studied by compairing with the OER values of three groups for 50% TGD time, 50% SD time, and 50% and 75% TCP. The OER values of 50% TGD time, 5, 10 and 50% SD time 10 of oxygen group were 1.46, 1.29, and 1.22, respectively, and oxygen effect was observed in this group. Those values of FOB group were 2.02, 1.56, and 1.56, respectively and oxygen effect of FOB group was greater than those of oxygen group. Animals receiving FOB were apparently radiosensitized by oxygen against animals breathing oxygen at small doses irradiation effect (50% TGD time, and 50% SD time). The OER values of 50% and 75% TCP at 30 days and 90 days after irradiation of oxygen group were about 1.5 (1.46-1.61) and these of FOB group about 1.3 (1.15-1.38). Radiosensitization by oxygen of animals receiving FOB was not clearly recognized a gainst animals breathing oxygen in TCP effect at high dose irradiation. These results indicate that radioresistant hypoxic cells of tumor receiving artificial blood substitute (FOB) increase the sensitivity of 60Co γ-ray irradiation, especially at small dose irradiation. (author)

  1. Artificial heart system thermal converter and blood pump component research and development

    International Nuclear Information System (INIS)

    A bench model version of a nuclear-powered artificial heart system to be used as a replacement for the natural heart was constructed and tested as a part of a broader U. S. ERDA program. The objective of the broader program has been to develop a prototype of a fully implantable nuclear-powered total artificial heart system powered by the thermal energy of plutonium-238 and having minimum weight and volume and a minimum life of ten years. As a forward step in this broader program, component research and development has been carried out directed towards a fully implantable and advanced version of the bench model (IVBM). Some of the results of the component research and development effort on a Stirling engine, blood pump drive mechanisms, and coupling mechanisms are presented. The Stirling-mechanical system under development is shown. There are three major subassemblies: the thermal converter, the coupling mechanism, and the blood pump drive mechanism. The thermal converter uses a Stirling cycle to convert the heat of the plutonium-238 fueled heat source to a rotary shaft power output. The coupling mechanism changes the orientation of the output shaft by 90 degrees and transmits the pumping power by wire-wound core flexible shafting to the pumping mechanism. The coupling mechanism also provides routing of the coolant lines which carry the cycle waste heat from the thermal converter to the blood pump. The change in orientation of the thermal converter output shaft is for convenience in implanting in a calf. This orientation of thermal converter to blood pump seemed to give the best overall system fit in a calf based on fit trials with wooden models in a calf cadaver

  2. Fourier Analysis of Peripheral Blood Pressure and Flow in Intraoperative Assessment of Infrainguinal Arterial Reconstructions

    Directory of Open Access Journals (Sweden)

    Cheshmedzhiev Mihail V.

    2014-08-01

    Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9≈2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

  3. Uterine artery blood flow in the periimplantation period in embryo transfer cycles

    Institute of Scientific and Technical Information of China (English)

    Ursula Zollner; Marie-Theres Specketer; Klaus-Peter Zollner; Johannse Dietl

    2012-01-01

    Objective:To assess the role of the uterine artery blood flow in the prediction of implantation in women undergoing embryo transfer during the periimplantation period.Methods:A total of 233 couples were included in this prospective study.All patients had embryo transfer,125 were performed inin-vitro fertilization/intracytoplasmic sperm injection(IVF/ICSI) and108 in cryo cycles.Ultrasound measurements were performed immediately before transfer.The pulsatility index(PI),Resistance index(RI) and the peak systolic velocity(PSV) were measured in both uterine arteries using endovaginal ultrasound.Results:InIVF/ICSI cycles the doppler parameters PI(2.48vs.2.15),RI(0.78vs.1.30) andPSV(60 vs.63) did not differ significantly between the pregnant and non-pregnant group.The pregnancy rate per transfer was similar in women showing an unilateral(24%), bilateral(33%) or no(27%) notch in the uterine blood flow.In cryo cycles the uterine artery blood flow parametersPI(3.2vs.3.0),RI(0.9vs.0.9) andPSV(53.2vs.51.2) did not differ either between pregnant and not pregnant patients.Conclusions:Previous studies were aiming at the measurement of arterial doppler parameters during the follicular phase which may not be adequate for the prediction of implantation.However, our results show that doppler studies during the early luteal phase of assisted reproductive technology cycles are not indicative for the likelihood of pregnancy, too.

  4. Intrapericardial denervation - Radial artery blood flow and heart rate responses to LBNP

    Science.gov (United States)

    Mckeever, Kenneth H.; Skidmore, Michael G.; Keil, Lanny C.; Sandler, Harold

    1990-01-01

    The effects of intrapericardial denervation on the radial artery blood flow velocity (RABFV) and heart rate (HR) responses to LBNP in rhesus monkeys were investigated by measuring the RABFV transcutaneously by a continuous-wave Doppler ultrasonic flowmeter in order to derive an index of forearm blood flow response to low (0 to -20 mm Hg) and high (0 to -60 mm Hg) ramp exposures during supine LBNP. Four of the eight subjects were subjected to efferent and afferent cardiac denervation. It was found that, during low levels of LBNP, monkeys with cardiac denervation exhibited no cardiopulmonary baroreceptor-mediated change in the RABFV or HR, unlike the intact animals, which showed steady decreases in RABFV during both high- and low-pressure protocols. It is suggested that forearm blood flow and HR responses to low-level LBNP, along with pharmacological challenge, are viable physiological tests for verifying the completeness of atrial and cardiopulmonary baroreceptor denervation.

  5. Wall morphology, blood flow and wall shear stress: MR findings in patients with peripheral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Galizia, Mauricio S.; Barker, Alex; Collins, Jeremy; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Liao, Yihua [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); McDermott, Mary M. [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); Northwestern University' s Feinberg School of Medicine, Department of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States)

    2014-04-15

    To investigate the influence of atherosclerotic plaques on femoral haemodynamics assessed by two-dimensional (2D) phase-contrast (PC) magnetic resonance imaging (MRI) with three-directional velocity encoding. During 1 year, patients with peripheral artery disease and an ankle brachial index <1.00 were enrolled. After institutional review board approval and written informed consent, 44 patients (age, 70 ± 12 years) underwent common femoral artery MRI. Patients with contra-indications for MRI were excluded. Sequences included 2D time-of-flight, proton-density, T1-weighted and T2-weighted MRI. Electrocardiogram (ECG)-gated 2D PC-MRI with 3D velocity encoding was acquired. A radiologist classified images in five categories. Blood flow, velocity and wall shear stress (WSS) along the vessel circumference were quantified from the PC-MRI data. The acquired images were of good quality for interpretation. There were no image quality problems related to poor ECG-gating or slice positioning. Velocities, oscillatory shear stress and total flow were similar between patients with normal arteries and wall thickening/plaque. Patients with plaques demonstrated regionally increased peak systolic WSS and enhanced WSS eccentricity. Combined multi-contrast morphological imaging of the peripheral arterial wall with PC-MRI with three-directional velocity encoding is a feasible technique. Further study is needed to determine whether flow is an appropriate marker for altered endothelial cell function, vascular remodelling and plaque progression. (orig.)

  6. Effect of TIPS placement on portal and splanchnic arterial blood flow in 4-dimensional flow MRI

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Zoran [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); University Medical Center Freiburg, Department of Diagnostic Radiology and Medical Physics, Freiburg (Germany); Roessle, Martin; Schultheiss, Michael [University Medical Center Freiburg, Department of Gastroenterology, Freiburg (Germany); Euringer, Wulf; Langer, Mathias [University Medical Center Freiburg, Department of Diagnostic Radiology and Medical Physics, Freiburg (Germany); Salem, Riad; Barker, Alex; Carr, James; Collins, Jeremy D. [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States)

    2015-09-15

    To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique. Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement. Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision. Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies. (orig.)

  7. Effect of TIPS placement on portal and splanchnic arterial blood flow in 4-dimensional flow MRI

    International Nuclear Information System (INIS)

    To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique. Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement. Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision. Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies. (orig.)

  8. Wall morphology, blood flow and wall shear stress: MR findings in patients with peripheral artery disease

    International Nuclear Information System (INIS)

    To investigate the influence of atherosclerotic plaques on femoral haemodynamics assessed by two-dimensional (2D) phase-contrast (PC) magnetic resonance imaging (MRI) with three-directional velocity encoding. During 1 year, patients with peripheral artery disease and an ankle brachial index <1.00 were enrolled. After institutional review board approval and written informed consent, 44 patients (age, 70 ± 12 years) underwent common femoral artery MRI. Patients with contra-indications for MRI were excluded. Sequences included 2D time-of-flight, proton-density, T1-weighted and T2-weighted MRI. Electrocardiogram (ECG)-gated 2D PC-MRI with 3D velocity encoding was acquired. A radiologist classified images in five categories. Blood flow, velocity and wall shear stress (WSS) along the vessel circumference were quantified from the PC-MRI data. The acquired images were of good quality for interpretation. There were no image quality problems related to poor ECG-gating or slice positioning. Velocities, oscillatory shear stress and total flow were similar between patients with normal arteries and wall thickening/plaque. Patients with plaques demonstrated regionally increased peak systolic WSS and enhanced WSS eccentricity. Combined multi-contrast morphological imaging of the peripheral arterial wall with PC-MRI with three-directional velocity encoding is a feasible technique. Further study is needed to determine whether flow is an appropriate marker for altered endothelial cell function, vascular remodelling and plaque progression. (orig.)

  9. 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 of...... the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the...... lower extremity cannot be determined non-invasively by elevation of the extremity, probably due to collapse of segments of the vascular bed increasing the vascular resistance considerably....

  10. The blood flow in the posterior communicant artery. Angiographic study by using magnetic resonance

    CERN Document Server

    Portela, L A P

    1995-01-01

    did not change the direction of flow present, in the circumstances of this study. The arterial circle of Willis is the most important collateral pathway for the cerebral vessels when one the afferents is occluded. Its normal function, without vascular compromise, has been considered in conflicting ways in the literature. For centuries after its description by Thomas Willis in 1664 it was considered a flow equalizer, with free admixture of blood within it. Since the beginning of this century the dominant view is one of a potential value only, with null effective flow in the communicating arteries. The premise is included in different experimental models. Alternatively, it was considered that the normal direction of flow is antero-posterior, from carotid to posterior cerebral, since carotid flow is greater. Using phase-contrast magnetic resonance angiography, a non-invasive qualitative method, it was found in 40 patients without morphological brain abnormality and in 10 healthy volunteers that flow can be seen ...

  11. Correlation of arterial blood pressure and compliance with left ventricular structure and function in the very elderly.

    Science.gov (United States)

    Rosendorff, Clive; Go, Orson; Schmeidler, James; Silverman, Jeremy M; Beeri, Michal S

    2012-01-01

    There are very few data on the relationship between systolic blood pressure (SBP), diastolic blood pressure (DBP), arterial compliance, and left ventricular structure and function, particularly left ventricular hypertrophy (LVH), in the very elderly (>75 years). SBP and arterial stiffness increase with age, and the question is: which of the two is the main stimulus to LVH? This is a cross-sectional study to compare blood pressure and arterial stiffness measures with regard to their correlations with echocardiographic parameters of LV structure and function, controlling for age and cardiovascular risk factors, in a very elderly population. Arterial stiffness was determined by radial pulse waveform using pulse contour analysis. LV dimensions were measured by transthoracic M-mode echocardiography, and diastolic function by tissue Doppler measurements of diastolic mitral annular velocities. There were 179 subjects, all male, with a mean age of 81.8 years. Using age-adjusted partial correlations, SBP, DBP, and mean arterial pressure (MAP) were correlated with parameters of LV structure and function. Correlation coefficients were: SBP versus left ventricular mass index (LVMI), r = 0.246; SBP versus early diastolic mitral annular velocity (MAV), r = -0.179; DBP versus LVMI, r = 0.199; DBP versus MAV, r = -0.199; MAP versus LVMI, r = 0.276; and MAP versus MAV, r = -0.206, all with P < .05. However, neither capacitative nor reflective arterial compliance was significantly correlated with any parameter of LV structure and function. After controlling for age and 10 cardiovascular and metabolic risk factors, the correlation between blood pressure and the measured LV parameters was substantially unchanged, as was the lack of correlation between indices of arterial compliance and the LV indices. Arterial blood pressure is correlated with LV structure and function in the very elderly, but arterial stiffness, as measured by diastolic pulse contour analysis, is not. PMID:22243840

  12. Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

    International Nuclear Information System (INIS)

    Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 °C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 °C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

  13. Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

    Energy Technology Data Exchange (ETDEWEB)

    Cao Wei, E-mail: cawe-001@163.com [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Li Jing, E-mail: lijing02@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Burn and Plastic Surgery (China); Wu Zhiqun, E-mail: zhiqunwu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Zhou Changxi, E-mail: changxizhou@163.com [Chinese PLA General Hospital, Department of Respiratory Disease (China); Liu Xi, E-mail: xiliu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China); Wan Yi, E-mail: yiwan@163.com [The Fourth Military Medical University, Department of Health Statistics, Institute for Health Informatics (China); Duan Yunyou, E-mail: yunyouduan@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China)

    2013-06-15

    Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 Degree-Sign C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 Degree-Sign C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

  14. Flow of non-Newtonian blood analog fluids in rigid curved and straight artery models.

    Science.gov (United States)

    Mann, D E; Tarbell, J M

    1990-01-01

    The influence of non-Newtonian rheology on wall shear rate in steady and oscillatory flow through rigid curved and straight artery models was studied experimentally. Wall shear rates measured by flush mounted hot film anemometry under nearly identical flow conditions are reported for the following four fluids: aqueous glycerin (Newtonian), aqueous polyacrylamide (shear thinning, highly elastic), aqueous Xanthan gum (shear thinning, moderately elastic), and bovine blood. For steady flow conditions there was little difference at any measurement site in the wall shear rate levels measured for the four fluids. However, large differences were apparent for oscillatory flows, particularly at the inner curvature 180 degrees from the entrance of the curved artery model. At that position the peak wall shear rate for polyacrylamide was 5-6 times higher than for glycerin and 2-3 times higher than for bovine blood. It is concluded that polyacylamide is too elastic to provide a good model of blood flow under oscillatory conditions, particularly when there is wall shear reversal. Xanthan gum and glycerin are better analog fluids, but neither is entirely satisfactory. PMID:2271763

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

    International Nuclear Information System (INIS)

    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)

  16. 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)

  17. Simulation of the Second Grade Fluid Model for Blood Flow through a Tapered Artery with a Stenosis

    Science.gov (United States)

    Nadeem, S.; Noreen Sher, Akbar

    2010-06-01

    We analyze the blood flow through a tapered artery, assuming the blood to be a second order fluid model. The resulting nonlinear implicit system of partial differential equations is solved by the perturbation method. The expressions for shear stress, velocity, flow rate, wall shear stress and longitudinal impedance are obtained. The physical behavior of different parameters is also discussed, as are trapping phenomena.

  18. Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

    International Nuclear Information System (INIS)

    Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures

  19. Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Cao Tan, E-mail: bstanhatinh@gmail.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Karam, Ibrahim Michel [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); Department of Anatomy, Faculty of Medicine Nancy, 9 Avenue de la Foret de haye BP, 54505 Vandoeuvre Lès Nancy Cedex (France); Nguyen-Thi, Phi Linh [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); INSERM, CIC-EC CIE6, 92 Avenue du Maréchal de Lattre de Tassigny, 54000 Nancy (France); Lefèvre, Frédéric [Department of Radiology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); Hubert, Jacques [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Felblinger, Jacques [IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Eschwège, Pascal [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France)

    2015-05-15

    Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures.

  20. Numerical simulation of blood pulsatile flow in a stenosed carotid artery using different rheological models.

    Science.gov (United States)

    Razavi, A; Shirani, E; Sadeghi, M R

    2011-07-28

    Symmetrical 30-60% stenosis in a common carotid artery under unsteady flow condition for Newtonian and six non-Newtonian viscosity models are investigated numerically. Results show power-law model produces higher deviations, in terms of velocity and wall shear stress in comparison with other models while generalized power-law and modified-Casson models are more prone to Newtonian state. Comparing separation length of recirculation region at different critical points of cardiac cycle confirms the necessity of considering blood flow in unsteady mode. Increasing stenosis intensity causes flow patterns more disturbed downstream of the stenosis and WSS appear to develop remarkably at the stenosis throat. PMID:21696742

  1. Dual stack black blood carotid artery CMR at 3T: Application to wall thickness visualization

    Directory of Open Access Journals (Sweden)

    Marx Nikolaus

    2009-11-01

    Full Text Available Abstract Background The increasing understanding of atherosclerosis as an important risk factor for the development of acute ischemic events like ischemic stroke has stimulated increasing interest in non-invasive assessment of the structure, composition and burden of plaque depositions in the carotid artery wall. Vessel wall imaging by means of cardiovascular magnetic resonance (CMR is conventionally done by 2D dual inversion recovery (DIR techniques, which often fail in covering large volumes of interest as required in plaque burden assessment. Although the technique has been extended to 2D multislice imaging, its straight extension to 3D protocols is still limited by the prolonged acquisition times and incomplete blood suppression. A novel approach for rapid overview imaging of large sections of the carotid artery wall at isotropic spatial resolutions is presented, which omits excitation of the epiglottis. By the interleaved acquisition of two 3D stacks with the proposed motion sensitized segmented steady-state black-blood gradient echo technique (MSDS the coverage of the carotid artery trees on both sides in reasonable scan times is enabled. Results 10 patients were investigated with the proposed technique and compared to conventional transversal DIR turbo spin and gradient echo approaches centered at the height of the carotid bifurcation. In all MSDS experiments sufficient black-blood contrast could be obtained over the entire covered volumes. The contrast to noise ratio between vessel and suppressed blood was improved by 73% applying the motion sensitizing technique. In all patients the suspicious areas of vessel wall thickening could be clearly identified and validated by the conventional local imaging approach. The average assessable vessel wall segment length was evaluated to be 18 cm. While in 50% of the cases motion artifacts could be appreciated in the conventional images, none were detected for the MSDS technique. Conclusion The

  2. Changes of arterial blood flow patterns by patients' posture during hepatic arterial infusion chemotherapy assessed by 99mTc-MAA perfusion scintigraphy

    International Nuclear Information System (INIS)

    Hepatic arterial perfusion scintigraphy (HAPS) with 99mTc-macroaggregated albumin (MAA) was performed to reveal the effect of patients' posture for the arterial blood flow patterns in hepatic arterial infusion (HAI) chemotherapy. Twenty patients with liver metastases having the percutaneously implanted catheter into the hepatic artery underwent HAPS following administration of 99mTc-MAA at the supine and the upright position under one week interval. Ten ml of the saline with radionuclide was injected at a rate of one ml per minute. Acquired two images at the different position of each patient were compared and grouped into three classes: similar, slightly different and different. Of 20 patients, 6 (30%) were judged as similar, 8 (40%) as slightly different, and 6 (30%) as different. These results suggest that the drug distribution can change by patients' posture in case of the slow rate HAI performed with continuous infusion pump. (author)

  3. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

    International Nuclear Information System (INIS)

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s−1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

  4. The analysis of MHD blood flows through porous arteries using a locally modified homogenous nanofluids model.

    Science.gov (United States)

    Akbarzadeh, Pooria

    2016-05-12

    In this paper, magneto-hydrodynamic blood flows through porous arteries are numerically simulated using a locally modified homogenous nanofluids model. Blood is taken into account as the third-grade non-Newtonian fluid containing nanoparticles. In the modified nanofluids model, the viscosity, density, and thermal conductivity of the solid-liquid mixture (nanofluids) which are commonly utilized as an effective value, are locally combined with the prevalent single-phase model. The modified governing equations are solved numerically using Newton's method and a block tridiagonal matrix solver. The results are compared to the prevalent nanofluids single-phase model. In addition, the efficacies of important physical parameters such as pressure gradient, Brownian motion parameter, thermophoresis parameter, magnetic-field parameter, porosity parameter, and etc. on temperature, velocity and nanoparticles concentration profiles are examined. PMID:27175464

  5. Effect of blood flow parameters on flow patterns at arterial bifurcations--studies in models.

    Science.gov (United States)

    Liepsch, D W

    1990-01-01

    Atherosclerotic lesions are found primarily at arterial bends and bifurcations. Flow disturbances at these anatomic sites play a major role in atherogenesis. How hemodynamic factors such as vessel geometry, the pulsatile nature of blood flow, vessel wall elasticity and the non-Newtonian flow behavior of blood influence the flow field at these sites must be clarified. We have performed fundamental studies using a birefringent solution in a simplified rigid 90 degree T-bifurcation and pulsatile flow. The velocity distribution was measured with a laser Doppler anemometer. Flow in an elastic abdominal aorta model has been visualized using magnetic resonance imaging. In both flow studies, zones with negative velocity were found. These model measurements demonstrate that no flow parameter can be neglected. Further detailed studies are necessary to examine the interaction between fluid dynamic and cellular surface properties. PMID:2404201

  6. Small artery structure adapts to vasodilatation rather than to blood pressure during antihypertensive treatment

    DEFF Research Database (Denmark)

    Mathiassen, Ole N; Buus, Niels H; Larsen, Mogens L; Mulvany, Michael J; Christensen, Kent L

    2007-01-01

    OBJECTIVE: Correction of the abnormal structure of resistance arteries in essential hypertension may be an important treatment goal in addition to blood pressure (BP) reduction. We investigated how this may be achieved in a prospective clinical study. METHODS: Plethysmography was used to measure....... RESULTS: In group A, mean ambulatory blood pressure (ABP) fell from 119 +/- 2 (SE) to 103 +/- 2 mmHg (P < 0.01), whereas mean ABP was unchanged in group B (100 +/- 1 to 99 +/- 1 mmHg, P = NS). Both groups showed similar reductions in Rrest (-33.4 and -28.5%, respectively) and in Rmin (-15.4 and -15...... forearm resting vascular resistance (Rrest) and minimum vascular resistance (Rmin) as a measure of vascular structure. Two different groups of patients with essential hypertension were examined at baseline and after 6 months of antihypertensive treatment. In group A, 21 patients with never...

  7. 20-HETE induces remodeling of renal resistance arteries independent of blood pressure elevation in hypertension.

    Science.gov (United States)

    Ding, Yan; Wu, Cheng-Chia; Garcia, Victor; Dimitrova, Irina; Weidenhammer, Adam; Joseph, Gregory; Zhang, Frank; Manthati, Vijay L; Falck, John R; Capdevila, Jorge H; Schwartzman, Michal L

    2013-09-01

    20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P-450 (Cyp)-derived arachidonic acid metabolite that has been shown to increase smooth muscle contractions and proliferation, stimulate endothelial dysfunction and activation, and promote hypertension. We examined if 20-HETE contributes to microvascular remodeling in hypertension. In Sprague-Dawley rats, administration of the 20-HETE biosynthesis inhibitor HET0016 or the 20-HETE antagonist N-20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) prevented 5α-dihydrotestosterone (DHT)-induced increases in blood pressure as well as abrogated DHT-induced increases in the media-to-lumen ratio (M/L), media thickness, and collagen IV deposition in renal interlobar arteries. Reserpine prevented blood pressure elevation in DHT-treated rats but did not affect microvascular remodeling (M/L, media thickness, and collagen deposition); under these conditions, treatment with the 20-HETE antagonist attenuated microvascular remodeling, suggesting that 20-HETE contributes to DHT-induced vascular remodeling independent of blood pressure elevation. In Cyp4a14(-/-) mice, which display androgen-driven and 20-HETE-dependent hypertension, treatment with the 20-HETE antagonist abolished remodeling of renal resistance arteries measured as media thickness (24 ± 1 vs. 15 ± 1 μm) and M/L (0.29 ± 0.03 vs. 0.17 ± 0.01). Moreover, in Cyp4a12 transgenic mice in which the expression of Cyp4a12-20-HETE synthase is driven by a tetracycline-sensitive promoter, treatment with doxycycline resulted in blood pressure elevation (140 ± 4 vs. 92 ± 5 mmHg) and a significant increase in remodeling of renal resistance arteries (media thickness: 23 ± 1 vs. 16 ± 1 μm; M/L: 0.39 ± 0.04 vs. 0.23 ± 0.02); these increases were abrogated by cotreatment with 20-HEDE. This study demonstrated that 20-HETE is a key regulator of microvascular remodeling in hypertension; its effect is independent of blood pressure elevation and androgen levels. PMID

  8. Ratio between carotid artery stiffness and blood flow – a new ultrasound index of ischemic leukoaraiosis

    Directory of Open Access Journals (Sweden)

    Turk M

    2016-01-01

    Full Text Available Monika Turk, Marjan Zaletel, Janja Pretnar-OblakDepartment of Vascular Neurology and Intensive Neurological Therapy, University Medical Centre Ljubljana, Ljubljana, SloveniaBackground: Ischemic leukoaraiosis (ILA is associated with cognitive decline and aging. Its pathophysiology is believed to be ischemic in origin due to its association with cerebrovascular risk factors and similarity in location to lacunar infarctions. ILA diagnosis is still based on magnetic resonance imaging (MRI as well as exclusion of other causes of white matter hyperintensities. So far, there are no known confirming diagnostic tests of ILA. Ultrasound studies have recently shown increased large artery stiffness, increased cerebrovascular resistance, and lower cerebral blood flow in patients with ILA. Increased arterial stiffness and decreased blood flow could have a synergistic effect, and their ratio could be a useful diagnostic index of ILA.Methods: In this post hoc analysis, we introduced new ILA indices (ILAi that are ratios of the carotid stiffness parameters (pulse wave velocity beta [PWVβ], pressure–strain elasticity modulus [Ep], β index, and diastolic and mean blood flows in the internal carotid artery: Q-ICAd and Q-ICAm. We compared the ILAi of 52 patients with ILA and 44 sex- and risk factor-matched controls with normal MRI of the head. ILA diagnosis was based on MRI and exclusion of other causes of white matter hyperintensities. The diagnostic significance of ILAi for the prediction of ILA was analyzed.Results: All ILAi significantly differed between the groups; the most significant were PWVβ/Q-ICAd (ILA group: 1.96±0.64 vs control group: 1.56±0.40, P=0.001 and PWVβ/Q-ICAm (ILA group: 1.13±0.32 vs control group: 0.94±0.25, P=0.003. All ILAi were significantly associated with ILA (P<0.01 and were significant independent predictors of ILA. All ILAi were also sensitive and specific for predicting ILA (area under the curve: 0.632–0.683, P<0

  9. Theoretical analysis of metallic nanoparticles on blood flow through stenosed artery with permeable walls

    International Nuclear Information System (INIS)

    The present analysis deals with the study of physical characteristics of blood flow in the presence of stenosis and nanoparticles through a curved channel with permeable walls. Taking mild stenosis case, the governing equations for anticipated model are solved using the corresponding boundary conditions and close-form solutions have been obtained for temperature, velocity and slip velocity by using Cauchy Euler's method. The expressions for the resistance impedance and pressure gradient in the stenotic region have also been obtained and the existence of various pertinent flow parameters, mainly Darcy number, slip parameter and nanoparticles volume fraction, has been discussed through graphs. - Highlights: • Nanoparticles analysis is discussed for diverging converging and non-tapered arteries. • Resistance impedance decreases with an increase in the nanoparticles volume fraction. • Combination of curvature and stenosis shows stenosis dominant the curvature of artery. • Pressure possesses an inverse variation to the resistance with respect to tapering. • Trapping shows that the symmetry destroys due to increase in curvature of curved artery

  10. Quantitative evaluation of cerebral blood flow by XeCT in stenting angioplasty for carotid artery

    International Nuclear Information System (INIS)

    Objective: To evaluate the hemodynamic characteristics of severe carotid artery stenosis and curative effect of stent angioplasty through XeCT. Methods: From April 2006 to November 2006, 13 patients with severe carotid artery stenoses underwent stent angioplasty in our hospital, including 11 male and 2 females, in an average age of 57.31 ± 6.12. All patients underwent XeCT examination to evaluate the quantitative cerebral blood flow (CBF). The ischemic cortex is categorized into 4 kinds, the normal region, oligemia area, reversible ischemic site and ischemic core center. Measurement and comparison of the changes were taken before and after the therapy. Results: Preoperative XeCT revealed different decrease of CBF in the ipsilateral cortex, especially in MCA distributing territory. Ischemic areas reduced significantly after the stenting angioplasty. Oligemia area reduced from 32.63% to 14.22%. Reversible ischemic area reduced from 13.54% to 8.38%. Normal area increased from 47.51% to 71.13%. But ischemic core center showed no significant changes. Conclusions: XeCT is beneficial for evaluation of the hemodynamic characteristics of carotid artery stenoses and also for accurately demonstrating the curative effects of the stent angioplasty. (authors)

  11. Theoretical analysis of metallic nanoparticles on blood flow through stenosed artery with permeable walls

    Energy Technology Data Exchange (ETDEWEB)

    Nadeem, S.; Ijaz, S., E-mail: shaguftaijaz11@yahoo.com

    2015-03-06

    The present analysis deals with the study of physical characteristics of blood flow in the presence of stenosis and nanoparticles through a curved channel with permeable walls. Taking mild stenosis case, the governing equations for anticipated model are solved using the corresponding boundary conditions and close-form solutions have been obtained for temperature, velocity and slip velocity by using Cauchy Euler's method. The expressions for the resistance impedance and pressure gradient in the stenotic region have also been obtained and the existence of various pertinent flow parameters, mainly Darcy number, slip parameter and nanoparticles volume fraction, has been discussed through graphs. - Highlights: • Nanoparticles analysis is discussed for diverging converging and non-tapered arteries. • Resistance impedance decreases with an increase in the nanoparticles volume fraction. • Combination of curvature and stenosis shows stenosis dominant the curvature of artery. • Pressure possesses an inverse variation to the resistance with respect to tapering. • Trapping shows that the symmetry destroys due to increase in curvature of curved artery.

  12. Arterial blood gas analysis and electrolyte determination in neonates with asphyxia

    Institute of Scientific and Technical Information of China (English)

    Zi-Mei Sun

    2015-01-01

    Objective:To explore the value of arterial blood gas analysis and electrolyte determination in the diagnosis of neonatal asphyxia.Methods: A total of 100 neonates with asphyxia who were admitted in our department from March, 2013 to March, 2014 were included in the study and divided into the mild asphyxia group and the severe asphyxia group according to Apgar scoring. Moreover, 50 normal neonates were served as the control group and used for comparative analysis. AVL blood-gas analyzer was used to detect the levels of pH, PaO2, HCO3-, BE, PaCO2, K+, Na+, Cl-, and Ca2+.Results:The concentrations of pH, PaO2, HCO3-, and BE in the severe asphyxia group were significantly lower than those in the mild asphyxia group and the control group, while PaCO2 level was significantly higher than that in the mild asphyxia group and the control group. The comparison of the various indicators between the control group and the mild asphyxia group was not statistically significant. The comparison of serum K+, Na+,and Cl- levels among the control group, the mild asphyxia group, and the severe asphyxia group was not statistically significant. The serum Ca2+ level in the severe asphyxia group was significantly lower than that in the mild asphyxia group and the control group, while the comparison between the mild asphyxia group and the control group was also statistically significant.Conclusions:Blood gas analysis and electrolyte determination to the arterial blood in neonates can compensate for the insufficiency of Apgar scoring and provide an objective evidence for the diagnosis of neonatal asphyxia and the estimation of severity degree. Clinical combination with Apgar scoring is of great significance in enhancing the diagnosis of neonatal asphyxia and the accuracy of severity evaluation.

  13. Development of skin surface radiation detector system to monitor radioactivity in arterial blood with positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a unique method to determine quantitatively and localize precisely human physiological functions. The measurement of regional cerebral blood flow (rCBF) is one of the most commonly used clinical PET studies. Two conventional methods are commonly used to measure the time course of activity concentration (TCC) in arterial blood. A new type detector system for measuring the TCC in the arterial blood of a subject in PET study without taking the arterial blood have been developed. The system measures the radioactivity in arterial blood through the skin of a subject. A detector is placed on the skin over a wrist. The block diagram of the detector system is shown. It was tried to measure 15O activity (half life: 122s). The nuclei emit the positrons of maximum energy 1.73 MeV, which has about 9 mm range in tissues, and can penetrate through a skin from an artery. The phantom experiment to examine the performance of the detector system and the clinical PET study and their results are reported. (K.I.)

  14. A Computational Fluid Dynamic Study of Blood Flow Within the Coiled Umbilical Arteries

    Science.gov (United States)

    Wilke, David; Denier, James; Mattner, Trent; Khong, Yee

    2013-11-01

    The umbilical cord is the lifeline of the fetus throughout gestation. In a normal pregnancy it facilitates the supply of oxygen and nutrients from the placenta via a single vein, in addition to the return of deoxygenated blood from the developing embryo or fetus via two umbilical arteries. Despite the major role it plays in the growth of the fetus, pathologies of the umbilical cord are poorly understood. In particular, variations in the cord geometry, which typically forms a helical arrangement, have been correlated with adverse outcomes in pregnancy. Cords exhibiting either abnormally low or high levels of coiling have been associated with pathological results including growth-restriction and fetal demise. Despite this, the methodology currently employed by clinicians to characterize umbilical pathologies can misdiagnose cords and is prone to error. In this talk a computational model of blood flow within rigid three-dimensional structures representative of the umbilical arteries will be presented. This study determined that the current characterization was unable to differentiate between cords which exhibited clinically distinguishable flow properties, including the cord pressure drop, which provides a measure of the loading on the fetal heart.

  15. A model for investigating the control of muscle blood flow: the masseteric artery in conscious rabbits

    International Nuclear Information System (INIS)

    The complex interplay of neural, metabolic, myogenic and mechanical mechanisms that regulate blood flow in skeletal muscle (MBF) is still incompletely understood. For the first time, a method is presented for high time-resolution recording of MBF from a purely muscular artery in physiological conditions. Ultrasound perivascular flow probes were implanted (n = 15) mono- or bilaterally around the masseteric branch of the facial artery in nine rabbits and tested up to 16 days after implant. Reliable and stable recordings were achieved in 50% of implants. Blood flow was observed to increase from a resting level of 0.2–0.3 ml min−1 up to 4.0–6.0 ml min−1 during spontaneous masticatory activity. In addition, within single masticatory cycles marked back flow transients could be observed (peak flow = −10 ml min−1) during powerful masticatory strokes but not during mild mastication. The possibility of (1) surgically removing the sympathetic supply to the relevant vascular bed and of (2) bilaterally monitoring the perfusion of masseter muscles thus allowing to use one side as control side for different types of interventions makes this model a useful tool for disentangling the different mechanisms involved in the control of MBF. (note)

  16. The effect of time from last food intake on arterial blood gases: Implication on reference values

    Directory of Open Access Journals (Sweden)

    Zahedpour Anaraki M

    2000-08-01

    Full Text Available Arterial blood gas parameters were analyzed in forty-nine healthy persons (31 males, 18 females to detemine reference values fo these parameters and their relation to the time from last food intake to arterial puncture (T. The mean ± standard deviation of arterial oxygen pressure, arterial carbon dioxide pressure and pH at core body temperature were 84.4±7.0 mmHg (Male: 83.0±6.5, Female: 86.7±73, 37.7±2.8 mmHg (Male: 38.5±2.7, Female: 36.2±2.4 respectively 7.41±0.02 (Male: 7.41±0.02 Female: 7.42±0.03. the mean PCO2 was lower in comparison with most of the studies at sea level. The difference between males and females was significant in PCO2 and PH (P=0.004, P=0.02 respectively but in was not significant in PO2 (P=0.07. The PCO2 and pH had no statistically significant relatioship with age (P=0.42, P=0.25 respectively. The relationship between Po2 with age, PCO2 and T was significant (P=0.02, P=0.017, and P=0.019 respectively. The best linear predictive equation was: Po2= 1.28 AO2-29.4 for T10hours Þ AO2 = 0.21(Baro-47 – (1.2PCO2

  17. Time course and recovery of arterial blood gases during exacerbations in adults with Cystic Fibrosis.

    LENUS (Irish Health Repository)

    Waterhouse, D F

    2012-02-01

    INTRODUCTION: Hypoxia and hypercapnia are closely linked to morbidity and mortality in patients with Cystic Fibrosis (CF). The aims of this study were to describe the changes in blood gases during and following an acute pulmonary exacerbation in adults with CF. METHODS: We performed a prospective observational study of patients with CF admitted for management of an acute exacerbation. Blood gas and spirometric analysis was performed on admission, throughout the treatment period, and 31 days after discharge (day 45). RESULTS: At presentation, eight of nineteen patients had evidence of either hypoxia (PaO(2)<8 kPa) and\\/or hypercapnia (PaCO(2)>6.6 kPa). Blood gas parameters stabilized following two weeks of intravenous antibiotic therapy, with little difference evident in between treatment completion and subsequent review following discharge. Hypercapnia reversed in three patients, with persistent hypercapnia evident in two patients. CONCLUSION: In our study group, hypoxemia and hypercapnia were frequently observed at presentation of the acute exacerbation. Blood gases stabilized following two weeks of intravenous antibiotic therapy, with arterial PCO(2) one month following hospital discharge generally similar to that at time of discharge.

  18. Usual blood pressure, peripheral arterial disease, and vascular risk: cohort study of 4.2 million adults

    OpenAIRE

    Emdin, Connor A; Anderson, Simon G.; Callender, Thomas; Conrad, Nathalie; Salimi-Khorshidi, Gholamreza; Mohseni, Hamid; Woodward, Mark; Rahimi, Kazem

    2015-01-01

    Objectives To determine the subgroup specific associations between usual blood pressure and risk of peripheral arterial disease, and to examine the relation between peripheral arterial disease and a range of other types of vascular disease in a large contemporary cohort. Design Cohort study. Setting Linked electronic health records from 1990 to 2013 in the United Kingdom. Participants 4 222 459 people aged 30-90 years, registered at a primary care practice for at least one year and with a blo...

  19. Magnetic resonance imaging-based computational modelling of blood flow and nanomedicine deposition in patients with peripheral arterial disease

    OpenAIRE

    Hossain, Shaolie S.; Zhang, Yongjie; Fu, Xiaoyi; Brunner, Gerd; Singh, Jaykrishna; Hughes, Thomas J.R.; Shah, Dipan; Decuzzi, Paolo

    2015-01-01

    Peripheral arterial disease (PAD) is generally attributed to the progressive vascular accumulation of lipoproteins and circulating monocytes in the vessel walls leading to the formation of atherosclerotic plaques. This is known to be regulated by the local vascular geometry, haemodynamics and biophysical conditions. Here, an isogeometric analysis framework is proposed to analyse the blood flow and vascular deposition of circulating nanoparticles (NPs) into the superficial femoral artery (SFA)...

  20. Correlation between arterial and venous blood gas analysis parameters in patients with acute exacerbation of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Novović Miloš

    2012-01-01

    Full Text Available Introduction. Arterial blood gas (ABG analyses have an important role in the assessment and monitoring of the metabolic and oxygen status of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD. Arterial puncture could have a lot of adverse effects, while sampling of venous blood is simpler and is not so invasive. Objective. The aim of this study was to evaluate whether venous blood gas (VBG values of pH, partial pressure of carbon dioxide (PCO2, partial oxygen pressure (PO2, bicarbonate (HCO3, and venous and arterial blood oxygen saturation (SO2 can reliably predict ABG levels in patients with acute exacerbation of COPD. Methods. Forty-seven patients with a prior diagnosis of COPD were included in this prospective study. The patients with acute exacerbation of this disease were examined at the General Hospital EMS Department in Prijepolje. ABG samples were taken immediately after venous sampling, and both were analyzed. Results. The Pearson correlation coefficients between arterial and venous parameters were 0.828, 0.877, 0.599, 0.896 and 0.312 for pH, PCO2, PO2, HCO3 and SO2, respectively. The statistically significant correlation between arterial and venous pH, PCO2 and HCO3, values was found in patients with acute exacerbation of COPD (p<0.001. Conclusion. When we cannot provide arterial blood for analysis, venous values of the pH, Pv,CO2 and HCO3 parameters can be an alternative to their arterial equivalents in the interpretation of the metabolic status in patients with acute exacerbation of COPD, while the values of venous Pv,O2 and Sv,O2 cannot be used as predictors in the assessment of oxygen status of such patients.

  1. Effect of different dosages of nitroglycerin infusion on arterial blood gas tensions in patients undergoing on- pump coronary artery bypass graft surgery

    OpenAIRE

    Gholamreza Masoumi; Evaz Hidar Pour; Ali Sadeghpour; Mohsen Ziayeefard; Mostapha Alavi; Sanam Javid Anbardan; Shahin shirani

    2012-01-01

    Background: On-pump coronary artery bypass graft (CABG) surgery impairs gas exchange in the early postoperative period. The main object on this study was evaluation of changes in arterial blood gas values in patients underwent on pump CABG surgery receiving different dose of intravenous nitroglycerin (NTG). Materials and Methods: sixty-seven consecutive patients undergoing elective on-pump CABG randomly enrolled into three groups receiving NTG 50 μg/min (Group N1, n =67), 100 μg/min (Group N2...

  2. Amylin: Localization, Effects on Cerebral Arteries and on Local Cerebral Blood Flow in the Cat

    Directory of Open Access Journals (Sweden)

    Lars Edvinsson

    2001-01-01

    Full Text Available Amylin and adrenomedullin are two peptides structurally related to calcitonin gene-related peptide (CGRP. We studied the occurrence of amylin in trigeminal ganglia and cerebral blood vessels of the cat with immunocytochemistry and evaluated the role of amylin and adrenomedullin in the cerebral circulation by in vitro and in vivo pharmacology. Immunocytochemistry revealed that numerous nerve cell bodies in the trigeminal ganglion contained CGRP immunoreactivity (-ir; some of these also expressed amylin-ir but none adrenomedullin-ir. There were numerous nerve fibres surrounding cerebral blood vessels that contained CGRP-ir. Occasional fibres contained amylin-ir while we observed no adrenomedullin-ir in the vessel walls. With RT-PCR and Real-Time�PCR we revealed the presence of mRNA for calcitonin receptor-like receptor (CLRL and receptor-activity-modifying proteins (RAMPs in cat cerebral arteries. In vitro studies revealed that amylin, adrenomedullin, and CGRP relaxed ring segments of the cat middle cerebral artery. CGRP and amylin caused concentration-dependent relaxations at low concentrations of PGF2a-precontracted segment (with or without endothelium whereas only at high concentration did adrenomedullin cause relaxation. CGRP8-37 blocked the CGRP and amylin induced relaxations in a parallel fashion. In vivo studies of amylin, adrenomedullin, and CGRP showed a brisk reproducible increase in local cerebral blood flow as examined using laser Doppler flowmetry applied to the cerebral cortex of the a-chloralose�anesthetized cat. The responses to amylin and CGRP were blocked by CGRP8-37. The studies suggest that there is a functional sub-set of amylin-containing trigeminal neurons which probably act via CGRP receptors.

  3. Related research of blood glucose, blood lipid and serum cystatin C and lower-extremity arterial disease in type 2 diabetic mellitus

    Institute of Scientific and Technical Information of China (English)

    Juan Zeng; Jie Ou; Yun-Mei He; Chun-Yu Cai

    2016-01-01

    Objective:To explore the relationship between levels of blood glucose, blood lipid and serum cystatin C and lower-extremity arterial disease in type 2 diabetic mellitus so as to provide the basis for the prevention and treatment of the disease.Methods:A total of 240 cases of patients with type 2 diabetic mellitus receiving physical examinations in our hospital from March 2014 to March 2015 were selected and divided into three groups. The control group was consisted of type 2 diabetes patients without lower-extremity arterial disease, the observation group 1 included type 2 diabetes patients with mild or moderate lower-extremity arterial disease, and the observation group 2 was formed by type 2 diabetes patients with severe lower-extremity arterial disease. Each group contained 80 cases. Then, the heights, weights, waist and hip circumferences of patients in the three groups were determined and the body mass index (BMI) and waist to hip ratio (WHR) were calculated; the fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR), 2 h postprandial blood glucose (2 h PG) and glycosylated hemoglobin (HBA1c) in two groups were detected; and the levels of serum total cholesterol(TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apoA1), apolipoprotein B (apoB) and cystatin C (CysC) in two groups were also tested.Results:Compared with the control group, the WHR, FBG, HOMA-IR, 2 h PG, HBA1c, LDL-C, apoB and CysC all increased significantly, and the differences were statistically significant. Besides, there were statistically significances existing between the observation groups 1 and 2. What’s more, the serum levels of TC, HDL-C, TG and apoA1 in the observation groups were not significantly different from those of the control group.Conclusions: There is a close relationship between blood glucose, blood lipid, serum cystatin C level and lower-extremity arterial

  4. Following-up changes in red blood cell deformability and membrane stability in the presence of PTFE graft implanted into the femoral artery in a canine model

    Science.gov (United States)

    Toth, Csaba; Kiss, Ferenc; Klarik, Zoltan; Gergely, Eszter; Toth, Eniko; Peto, Katalin; Vanyolos, Erzsebet; Miko, Iren; Nemeth, Norbert

    2014-05-01

    It is known that a moderate mechanical stress can even improve the red blood cells' (RBC) micro-rheological characteristics, however, a more significant stress causes deterioration in the deformability. In this study, we aimed to investigate the effect of the presence of artificial graft on the RBC deformability and membrane stability in beagles. In the Control group only anesthesia was induced and in the postoperative (p.o.) period blood samplings were carried out. In the Grafted group under general anesthesia, the left femoral artery was isolated, from which a 3.5 cm segment was resected and a PTFE graft (O.D.: 3 mm) of equal in length was implanted into the gap. On the 1st, 3rd, 5th, 7th and 14th p.o. days blood was collected the cephalic veins and RBC deformability was determined ektacytometry (LoRRca MaxSis Osmoscan). Membrane stability test consisted of two deformability measurements before and after the cells were being exposed to mechanical stress (60 or 100 Pa for 300 seconds). Compared to the Control group and the baseline values the red blood cell deformability showed significant deterioration on the 3rd, 5th and mainly on the 7th postoperative day after the graft implantation. The membrane stability of erythrocyte revealed marked inter-group difference on the 3rd, 5th and 7th day: in the Grafted group the deformability decreased and during the membrane stability test smaller difference was observed between the states before and after shearing. We concluded that the presence of a PTFE graft in the femoral artery may cause changes in RBC deformability in the first p.o. week. RBC membrane stability investigation shows a lower elongation index profile for the grafted group and a narrowed alteration in the deformability curves due to mechanical stress.

  5. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model, but

  6. Results of ambulatory arterial blood pressure monitoring in children with obesity

    Directory of Open Access Journals (Sweden)

    Faruk Öktem

    2010-12-01

    Full Text Available Objectives: The relationship between obesity and essential hypertension is well known. In this study, we aimed to evaluate ambulatory arterial blood pressure monitoring of obese and non-obese children who had similar demographic characteristics.Materials and methods: Seventy one children and adolescents (n=39 obesity, n=32 controls were studied. Blood pressure of the children were measured by 24 hour ambulatory blood pressure monitoring device.Results: Obese children had significantly higher mean blood pressure values (systolic 121.9±11.7 mmHg, diastolic 70.2±5.3 mmHg than control subjects (systolic 109.3±6.7 mmHg, diastolic 65.1±4.6 mmHg, p0.05. Blood pressure load was found to be increased in obese children compared to the controls (%13.6±12.9 and %2.6±3.4, respectively; p<0.05. Serum total cholesterol and LDL-cholesterol levels of obese children (181.1±33.4 and 131.1±23.1mg/dl were significantly higher than those of the controls (134.3±11.1 and 103.3±14.2 mg/dl, p<0.05.Conclusions: Obesity in children and adolescents should not be regarded as variations of normality, but as abnormality with an extremely high risk for the development of hypertension and hyperlipidemia in adulthood.

  7. Association of sleep duration with arterial blood pressure profile of Gujarati Indian adolescents

    Directory of Open Access Journals (Sweden)

    Shaikh Wasim

    2010-01-01

    Full Text Available Background and Aim: Recently, National Health and Nutritional Examination Survey-1 data analysis found short sleep duration as a risk factor for hypertension in the U.S. population. However, since ethnic differences exist in the aetiopathogenesis of diseases, the current study was undertaken to study the effect of sleep duration on the blood pressure profile of Gujarati Indian adolescents. Materials and Methods: A cross-sectional study was conducted on 489 Gujarati Indian adolescents of age group 16-19 years studying in school and colleges in the local population. The participants were assessed for their sleep duration, physical activity status, body composition, blood pressure profile and cardiovascular reactivity. The sleep duration was reported by the subjects as the number of hours they slept on most of the nights in a week over the last one year. The observations of the study were then analyzed after grouping them into: 1 Adequate Sleep Duration at Night, ASDN (≥ 7 hrs and 2 Inadequate Sleep Duration at Night, ISDN (< 7 hrs groups. Student′s unpaired t-test was used to study if any significant difference (P< 0.05 existed between the groups. Results: No significant difference was found in Systolic blood pressure, Diastolic blood pressure, Pulse pressure and Mean arterial pressure between the ASDN group and the ISDN group. Physical activity status also did not differ between the two groups. However, adolescents of ISDN group showed a significantly higher level of adiposity and cardiovascular reactivity as compared to adolescents of ASDN group. Conclusion: Although short sleep duration is associated with a higher level of adiposity and cardiovascular reactivity in Gujarati Indian adolescents, it does not affect the resting blood pressure profile of these adolescents. However, longitudinal studies would be required to observe if the changes in adiposity and cardiovascular reactivity affect these adolescents in later life.

  8. Dynamic CT imaging of intrahepatic arterial blood flow in patients with chronic liver disease

    International Nuclear Information System (INIS)

    Using dynamic CT, the parenchymal hemodynamics of the livers was studied in patients with chronic liver disease. Dynamic CT was performed on 34 patients: 8 cases of chronic inactive hepatitis (CIH), 15 cases of chronic active hepatitis (CAH) and 11 cases of liver cirrhosis (LC). After rapid intravenous administration of contrast medium (61.2% iopamidol, 20 ml), 25 consecutive scans of the liver and spleen were performed and imaged on a single slice. The single scan time was one sec. Then, the following program was performed: 15 scans at 2 sec intervals, 7 scans at 15 sec intervals and 3 scans at 20 sec intervals. The fit curve for a single pass of the medium was obtained from the analysis of time-density curves in the right and left lobes of the liver and the spleen using a gamma variate function and the least square method. Three parameters were measured on the fit curve: the peak time (PT) was defined as the time to peak enhancement, the total volume component (TVC) was defined as the area beneath the curve between the rise point and the PT point for each lobe of the liver, and the arterial flow volume component (AVC) was defined as the area beneath the curve between the rise point and the PT point of the spleen. AVC in the right liver lobe did not significantly differ between groups, but significantly differed in the manner of CIH< CAH< LC (p<0.05) in the left lobe of the liver. The ratio of intrahepatic arterial blood flow to total hepatic blood flow (AVC/TVC) did not significantly differ between groups in the right lobe. In the left liver lobe, however, AVC/TVC significantly differed in the manner of CIH≤CAH< LC (p<0.01), and was significantly higher in LC patients than in CIH or CAH patients. These results suggest that the ratio of intrahepatic arterial blood flow in the left liver lobe increases as chronic liver disease progresses. (author)

  9. Effects of renal artery stenting on renal function and blood pressure in patients with atherosclerotic renovascular disease

    Institute of Scientific and Technical Information of China (English)

    张奇; 沈卫峰; 张瑞岩; 张建盛; 胡健; 张宪

    2003-01-01

    Objective To study the effects of percutaneous renal artery intervention on renal function and blood pressure in patients with renal artery stenosis. Methods Eighty-seven patients with severe uni- or bi-lateral renal artery stenosis (luminal diameter narrowing ≥70%) and clinical hypertension received renal artery stenting between January 2002 and December 2002. The changes in blood pressure and serum creatinine level and creatinine clearance (CCr) 48 hours after intervention and during 6 months of follow-up were assessed.Results Renal stenting was performed in 98 stenotic arteries of 87 patients, and the procedural success rate was 100%. Serum creatinine level was slightly elevated from (176±21) μmol/L to (179±11) μmol/L (P=0.15) 48 hours after the procedure, but significantly decreased to (149±15) μmol/L at 6 months (P<0.001). CCr was also greatly improved [(37±11) ml/min before versus (51±8) ml/min at 6 months, P<0.001]. During follow-up, 61% of the patients experienced a normal renal function. Despite conventional medical treatment, systolic and diastolic blood pressures were also significantly decreased after stenting [(163±23)/(96±13) mm Hg before versus (148±12)/(79±15) mm Hg at 6 months, all P<0.001], and hypertension was well controlled in 67% of the patients at 6 months ' follow-up.Conclusion Renal artery stenting has a high success rate and is effective in improving renal function and blood pressure for patients with severe renal artery stenosis.

  10. Association of vitamin D status with arterial blood pressure and hypertension risk

    DEFF Research Database (Denmark)

    Vimaleswaran, Karani S; Cavadino, Alana; Berry, Diane J;

    2014-01-01

    BACKGROUND: Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated with...... blood pressure and hypertension risk. METHODS: In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta......% increase, -0·12 mm Hg, 95% CI -0·20 to -0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97-0·99; p=0·0003), but not with decreased diastolic blood pressure (β per 10% increase, -0·02 mm Hg, -0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D-CarDia and...

  11. LES of non-Newtonian physiological blood flow in a model of arterial stenosis.

    Science.gov (United States)

    Molla, M M; Paul, M C

    2012-10-01

    Large Eddy Simulation (LES) is performed to study the physiological pulsatile transition-to-turbulent non-Newtonian blood flow through a 3D model of arterial stenosis by using five different blood viscosity models: (i) Power-law, (ii) Carreau, (iii) Quemada, (iv) Cross and (v) modified-Casson. The computational domain has been chosen is a simple channel with a biological type stenosis formed eccentrically on the top wall. The physiological pulsation is generated at the inlet of the model using the first four harmonic series of the physiological pressure pulse (Loudon and Tordesillas [1]). The effects of the various viscosity models are investigated in terms of the global maximum shear rate, post-stenotic re-circulation zone, mean shear stress, mean pressure, and turbulent kinetic energy. We find that the non-Newtonian viscosity models enlarge the length of the post-stenotic re-circulation region by moving the reattachment point of the shear layer separating from the upper wall further downstream. But the turbulent kinetic energy at the immediate post-lip of the stenosis drops due to the effects of the non-Newtonian viscosity. The importance of using LES in modelling the non-Newtonian physiological pulsatile blood flow is also assessed for the different viscosity models in terms of the results of the dynamic subgrid-scale (SGS) stress Smagorinsky model constant, C(s), and the corresponding SGS normalised viscosity. PMID:22153320

  12. The impact of capillary dilation on the distribution of red blood cells in artificial networks.

    Science.gov (United States)

    Schmid, Franca; Reichold, Johannes; Weber, Bruno; Jenny, Patrick

    2015-04-01

    Recent studies suggest that pericytes around capillaries are contractile and able to alter the diameter of capillaries. To investigate the effects of capillary dilation on network dynamics, we performed simulations in artificial capillary networks of different sizes and complexities. The unequal partition of hematocrit at diverging bifurcations was modeled by assuming that each red blood cell (RBC) enters the branch with the faster instantaneous flow. Network simulations with and without RBCs were performed to investigate the effect of local dilations. The results showed that the increase in flow rate due to capillary dilation was less when the effects of RBCs are included. For bifurcations with sufficient RBCs in the parent vessel and nearly equal flows in the branches, the flow rate in the dilated branch did not increase. Instead, a self-regulation of flow was observed due to accumulation of RBCs in the dilated capillary. A parametric study was performed to examine the dependence on initial capillary diameter, dilation factor, and tube hematocrit. Furthermore, the conditions needed for an efficient self-regulation mechanism are discussed. The results support the hypothesis that RBCs play a significant role for the fluid dynamics in capillary networks and that it is crucial to consider the blood flow rate and the distribution of RBCs to understand the supply of oxygen in the vasculature. Furthermore, our results suggest that capillary dilation/constriction offers the potential of being an efficient mechanism to alter the distribution of RBCs locally and hence could be important for the local regulation of oxygen delivery. PMID:25617356

  13. Measurement of brachial artery endothelial function using a standard blood pressure cuff.

    Science.gov (United States)

    Maltz, Jonathan S; Tison, Geoffrey H; Alley, Hugh F; Budinger, Thomas F; Owens, Christopher D; Olgin, Jeffrey

    2015-11-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, laboratory-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arguably, comparable (but complementary) value in the assessment of cardiovascular health. Widespread deployment of EFMA assessment is thus a desirable clinical goal. To this end, we propose a device based on modifying the measurement protocol of a standard electronic sphygmomanometer. The protocol involves inflating the cuff to sub-diastolic levels to enable recording of the pulse waveform before and after vasodilatory stimulus. The mechanical unloading of the arterial wall provided by the cuff amplifies the distension that occurs with each pulse, which is measured as a pressure variation in the cuff. We show that the height of the rising edge of each pulse is proportional to the change in lumen area between diastole and systole. This allows the effect of vasodilatory stimuli on the artery to be measured with high sensitivity. We compare the proposed cuff flow-mediated dilation (cFMD) method to ultrasound flow-mediated dilation (uFMD). We find significant correlation (r = 0.55, p = 0.003, N = 27) between cFMD- and uFMD-based metrics obtained when the release of a 5 min cuff occlusion is employed to induce endothelial stimulus via reactive hyperemia. cFMD is approximately proportional to the square of uFMD, representing a typical increase in sensitivity to vasodilation of 300-600%. This study illustrates the potential for an individual to conveniently measure his/her EFMA by using a low-cost reprogrammed home sphygmomanometer. PMID:26393958

  14. Gas exchange as monitored in mixed venous and arterial blood during experimental cardiopulmonary resuscitation.

    Science.gov (United States)

    Wiklund, L; Jorfeldt, L; Stjernström, H; Rubertsson, S

    1992-07-01

    Nineteen anaesthetized piglets were investigated. After catheterization and a stabilization period, ventricular fibrillation was induced with a transthoracic DC shock, after which a 10-min period of cardiopulmonary resuscitation (CPR) took place. CPR included manual chest compression and mechanical ventilation with pure oxygen. After 1 min of CPR, an infusion of alkaline buffer was begun and completed within 5 min. A total of 50 mmol of either sodium bicarbonate (n = 6) or tris buffer mixture (n = 7) were given. These two groups were compared with a third control group (n = 6) receiving the same volume of normal saline. After 8 min of CPR all animals were given 0.5 mg adrenaline i.v., and after 10 min DC shocks were used to revert the heart back to normal sinus rhythm. Our results demonstrate that blood flow and not ventilation is the limiting factor for the efficient disposal of CO2 during CPR. This also applied when the demand for CO2 transport was increased by administration of sodium bicarbonate. The respiratory exchange ratio increased 1.9-fold, indicating that the transport of carbon dioxide was less affected than that of oxygen. The estimated alveolo-arterial oxygen tension difference, shunt, and overall ventilation/perfusion ratio increased, creating an inverse hyperbolic relationship between arterial PCO2 and PO2. The difference between mixed venous and arterial PCO2 correlated well to the mixed venous PCO2, implying more efficient pulmonary elimination of PCO2 when the mixed venous PCO2 was high. Pulmonary gas exchange during CPR appears to be independent of alkaline buffer therapy in the form of sodium bicarbonate or tris buffer mixture.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1632165

  15. Continuous blood pressure measurement using the pulse transit time: Comparison to intra-arterial measurement.

    Science.gov (United States)

    Patzak, Andreas; Mendoza, Yuri; Gesche, Heiko; Konermann, Martin

    2015-01-01

    Continuous blood pressure (BP) measurement allows the investigation of transient changes in BP and thus may give insights into mechanisms of BP control. We validated a continuous, non-invasive BP measurement based on the pulse transit time (PTT), i.e., BP(PTT), by comparing it with the intra-arterial BP (BP(i.a.)) measurement. Twelve subjects (five females and seven males) were included. BP(i.a.) was obtained from the radial artery using a system from ReCor Medical. Systolic and diastolic BP were calculated using the PTT (BP(PTT), SOMNOscreen). (PTT) was determined from the electrocardiogram and the peripheral pulse wave. The BP was modulated by application of increasing doses of dobutamine (5, 10, 20 μg/kg body mass). Systolic BP(PTT) and systolic BP(i.a.) correlated significantly (R = 0.94). The limits of agreement in the Bland-Altman plot were ± 19 mmHg; the mean values differed by 1 mmHg. The correlation coefficient for the diastolic BP measurements was R = 0.42. The limits of agreement in the Bland-Altman plot were ± 18 mmHg, with a mean difference of 5 mmHg in favour of the BP(PTT). The study demonstrates a significant correlation between the measurement methods for systolic BP. The results encourage the application of PTT-based BP measurement for the evaluation of BP dynamics and pathological BP changes. PMID:25857601

  16. Changes of arterial blood ketone body ratio following hypoperfusion in old and adult rats

    Institute of Scientific and Technical Information of China (English)

    Ling YE; Shiwen WANG; Songtao YU; Wei CHEN

    2004-01-01

    Objective To evaluate the sensitivity of arterial ketone body ratio as an indicator for multiple organ failure.Materials and methods The experimental model of multiple organ failure was made in adult and old rats by hypoperfusion-induced hemorrhagic shock. After blood sampling, the arterial acetoacetate, β-hydroxybutyrate, total ketone body, ALT, AST, BUN, creatinine at 2, 4, 8 hr in hypoperfusion were examined to compare the differences of ketone body ratio and organ failure between adult and old rats. Hepatic and mitochondrial metabolism were assessed by comparing ketone body ratios (AcAc/β-OHB) and free NAD+/NADH ratios. Results Ketone body ratio in old rats at 2, 4, 8 hr after the induction of hemorrhagic shock decreased from 0.68 to 0.31, 0.27 and 0.22, respectively. In adult rats, it decreased from 1.12 to 0.17, 0.12 and 0.09, respectively. Changes of ketone body ratio in the adult group were larger than in the elderly group ( P < 0.001). The development of multiple organ failure is associated with the time of hemorrhagic shock development. Conclusions There was a different ketone body ratio between multiple organ failure in the elderly (MOFE) and multiple organ failure (MOF) in general adults. Ketone body ratio is a better indicator than ALT and AST in reflecting hepatic function in the early status of MOF. (J Geriatr Cardiol 2004;1(2) :125-128. )

  17. Dependency of cerebral blood flow upon mean arterial pressure in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Larsen, Fin Stolze; Qvist, Jesper;

    2000-01-01

    Diseases, Copenhagen University Hospital, Denmark. PATIENTS: Sixteen adult patients with acute bacterial meningitis. INTERVENTION: Infusion of norepinephrine to increase MAP. MEASUREMENTS: During a rise in MAP induced by norepinephrine infusion, we measured relative changes in CBF by transcranial Doppler......OBJECTIVE: Patients with acute bacterial meningitis are often treated with sympathomimetics to maintain an adequate mean arterial pressure (MAP). We studied the influence of such therapy on cerebral blood flow (CBF). DESIGN: Prospective physiologic trial. SETTING: The Department of Infectious....... Autoregulation was classified as impaired if Vmean increased by >10% per 30 mm Hg increase in MAP and if no lower limit of autoregulation was identified by the computer program; otherwise, autoregulation was classified as preserved. MAIN RESULTS: Initially, Vmean increased from a median value of 46 cm/sec (range...

  18. Arterial pressure and cerebral blood flow variability: friend or foe? A review

    Directory of Open Access Journals (Sweden)

    CarolineAliceRickards

    2014-04-01

    Full Text Available Variability in arterial pressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension (including hemorrhage, and during cardiac bypass surgery. This review presents the dichotomous views on the role of hemodynamic variability on clinical outcome, including the physiological mechanisms underlying these patterns, and the potential impact of increased and decreased variability on cerebral perfusion and oxygenation. We suggest that reconciliation of these two apparently discrepant views may lie in the time scale of hemodynamic variability; short time scale variability appears to be cerebroprotective, while mid to longer term fluctuations are associated with primary and secondary end-organ dysfunction.

  19. [Functional assessment of the hepatic arterial blood flow by pharmacoradiography (author's transl)].

    Science.gov (United States)

    Stellamor, K; Hruby, W; Peschl, L

    1981-12-01

    By means of celiacography it was possible to demonstrate that parenteral medication with parathormone creates a selective dilatation of the liver vessels in man, provided that they are dilatable. This hemodynamic hormone effect could not be traced in the other mesenteric vessels. The increase of portal hypertension resulting from cirrhosis leads to a loss of the dilating ability of liver vessels. This regressive reaction is well demonstrated on the parathormon-celiaco-gram. Thus a functional assessment of the hepatic blood flow is possible. The extent of the dilatability of the liver artery seems to be of great importance for the prognosis and indication of the porto-systemic shunt-operation. Moreover we could show that an increase in the liver perfusion demonstrates pathologic liver processes in a better way. PMID:7323629

  20. Reducing risk of closed loop control of blood glucose in artificial pancreas using fractional calculus.

    Science.gov (United States)

    Ghorbani, Mahboobeh; Bogdan, Paul

    2014-01-01

    Healthcare costs in the US are among the highest in the world. Chronic diseases such as diabetes significantly contribute to these extensive costs. Despite technological advances to improve sensing and actuation devices, we still lack a coherent theory that facilitates the design and optimization of efficient and robust medical cyber-physical systems for managing chronic diseases. In this paper, we propose a mathematical model for capturing the complex dynamics of blood glucose time series (e.g., time dependent and fractal behavior) observed in real world measurements via fractional calculus concepts. Building upon our time dependent fractal model, we propose a novel model predictive controller for an artificial pancreas that regulates insulin injection. We verify the accuracy of our controller by comparing it to conventional non-fractal models using real world measurements and show how the nonlinear optimal controller based on fractal calculus concepts is superior to non-fractal controllers in terms of average risk index and prediction accuracy. PMID:25571075

  1. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    International Nuclear Information System (INIS)

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  2. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    Science.gov (United States)

    Nakamoto, Ryusuke; Masuda, Kohji; Watarai, Nobuyuki; Taguchi, Yuto; Kato, Toshikazu; Yoshinaga, Takashi; Miyamoto, Yoshitaka; Chiba, Toshio

    2011-09-01

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  3. Maternal and fetal arterial blood gas data during general anaesthesia for caesarean delivery of preterm twin lambs.

    Science.gov (United States)

    Musk, G C; Kemp, M W

    2016-06-01

    Much remains to be understood with regards the effects of prolonged anaesthesia on maternal and fetal haemodynamics and oxygenation. With the aim of improving anaesthetic management of pregnant sheep undergoing recovery surgery under anaesthesia, paired maternal and fetal arterial blood samples were collected during caesarean delivery of twin preterm lambs to document the blood gas status of the ewe and fetus. Twenty-one Merino twin pregnant ewes at 126 (±1) days of gestation were anaesthetized for caesarean delivery of their fetuses. Arterial blood samples were collected from the radial artery of the ewe and umbilical artery of the fetus at the point of delivery. There was a significant difference between maternal PaCO2 and end-tidal CO2 and alveolar and arterial PaO2, indicating ventilation perfusion mismatch. Interestingly, the ewes were anaemic but the fetuses were not. These data underscore the need to undertake further work to determine the optimal anaesthetic regimen for twin pregnant ewes at different gestational ages in a biomedical research setting. PMID:26219550

  4. Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Farha Samar

    2013-01-01

    Full Text Available Abstract Background Reduced gas transfer in patients with pulmonary arterial hypertension (PAH is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange. Methods We tested this hypothesis by determination of lung diffusing capacity (DL and its components, the alveolar capillary membrane diffusing capacity (Dm and lung capillary blood volume (Vc in 28 individuals with PAH in comparison to 41 healthy individuals, and in 19 PAH patients over time. Using single breath simultaneous measure of diffusion of carbon monoxide (DLCO and nitric oxide (DLNO, DL and Dm were respectively determined, and Vc calculated. Dm and Vc were evaluated over time in relation to standard clinical indicators of disease severity, including brain natriuretic peptide (BNP, 6-minute walk distance (6MWD and right ventricular systolic pressure (RVSP by echocardiography. Results Both DLCO and DLNO were reduced in PAH as compared to controls and the lower DL in PAH was due to loss of both Dm and Vc (all p CO of PAH patients did not change over time, DLNO decreased by 24 ml/min/mmHg/year (p = 0.01. Consequently, Dm decreased and Vc tended to increase over time, which led to deterioration of the Dm/Vc ratio, a measure of alveolar-capillary membrane functional efficiency without changes in clinical markers. Conclusions The findings indicate that lower than normal gas transfer in PAH is due to loss of both Dm and Vc, but that deterioration of Dm/Vc over time is related to worsening membrane diffusion.

  5. Simulation of the Second Grade Fluid Model for Blood Flow through a Tapered Artery with a Stenosis

    International Nuclear Information System (INIS)

    We analyze the blood flow through a tapered artery, assuming the blood to be a second order fluid model. The resulting nonlinear implicit system of partial differential equations is solved by the perturbation method. The expressions for shear stress, velocity, flow rate, wall shear stress and longitudinal impedance are obtained. The physical behavior of different parameters is also discussed, as are trapping phenomena. (cross-disciplinary physics and related areas of science and technology)

  6. Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

    International Nuclear Information System (INIS)

    In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven

  7. Impaired blood pressure response to exercise in patients with coronary artery disease: possible contribution of attenuated reflex vasoconstriction in non-exercising muscles.

    OpenAIRE

    Okamatsu, S; Takeshita, A; Nakamura, M.

    1989-01-01

    Eighteen patients with coronary artery disease were divided into two groups according to whether their blood pressure decreased (eight, group 1) or increased (10, group 2) in response to treadmill exercise testing. Age and the extent and distribution of coronary artery disease were similar in the two groups. At rest, blood pressure, pulmonary artery wedge pressure, cardiac index, forearm vascular resistance, and oxygen consumption were similar in the two groups. During supine leg exercise on ...

  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 with...

  9. Indirect arterial blood pressure measurement in healthy anesthetized cats using a device that combines oscillometry with photoplethysmography.

    Science.gov (United States)

    Heishima, Yasuhiro; Hori, Yasutomo; Chikazawa, Seishiro; Kanai, Kazutaka; Hoshi, Fumio; Itoh, Naoyuki

    2016-08-01

    We investigated the basic characteristics of indirect arterial blood pressure (ABP) measurement using a device that combines oscillometry and photoplethysmography in cats. Dobutamine was infused intravenously in four anesthetized cats. Direct ABP was measured by a catheter. Indirect ABP was measured from the left forelimb. Dobutamine significantly elevated both systolic arterial pressure (SAP) and mean arterial pressure (MAP) in a dose-dependent manner. The indirect SAP, MAP and diastolic arterial pressure (DAP) values were closely correlated with the direct ABP values (r=0.88, 0.89 and 0.83, respectively). The mean bias for SAP, MAP and DAP was 3.4, 0.2 and -2.4 mmHg, respectively. The indirect ABP measured by this device may be used to reliably monitor ABP changes in anesthetized cats. PMID:27003226

  10. Flavonoid metabolite 3-(3-hydroxyphenyl)propionic acid formed by human microflora decreases arterial blood pressure in rats.

    Science.gov (United States)

    Najmanová, Iveta; Pourová, Jana; Vopršalová, Marie; Pilařová, Veronika; Semecký, Vladimír; Nováková, Lucie; Mladěnka, Přemysl

    2016-05-01

    There are reports of positive effects of quercetin on cardiovascular pathologies, however, mainly due to its low biovailability, the mechanism remains elusive. Here, we report that one metabolite formed by human microflora (3-(3-hydroxyphenyl)propionic acid)relaxed isolated rat aorta and decreased arterial blood pressure in rats. PMID:26790841

  11. Angiography of renal artery with special reference to the blood supply of the kidney in camel

    International Nuclear Information System (INIS)

    The vascular system of kidney of the camel is strikingly different from that of other domestic animals. The right and left renal arteries emanated independently from the ventrolateral aspect of abdominal aorta behind cranial mesenteric artery at the level of cranial border of third and fourth lumbar vertebra respectively. The renal artery after short lateral course divided into medial and lateral lobar arteries before reaching the hilus. The lobar artery after entering into the hilus gave 9-11 interlobar arteries. These interlobar arteries at the corticomedullary junction formed 2 - 7 arcuate arteries. The arcuate arteries detached numerous straight branches from their convex surfaces and then ended by dividing into 2 - 4 terminal branches. The straight branches and the terminal branches were present in a radiating manner as interlobular arteries

  12. Pressão arterial entre trabalhadores de curtume Blood pressure among tannery workers

    Directory of Open Access Journals (Sweden)

    Ricardo Cordeiro

    1998-10-01

    Full Text Available INTRODUÇÃO: O grupo das doenças cardiovasculares tem sido apontado como a principal causa de óbito no Brasil desde os anos 70, sendo a hipertensão arterial sistêmica (HAS o fator de risco mais importante para esse grupo. Entre os trabalhadores observa-se correlação negativa entre o status ocupacional e a pressão arterial. Tais fatos ressaltam a importância do conhecimento da distribuição da pressão arterial sistêmica entre os distintos grupos profissionais. Assim, foi realizado estudo para descrever o status pressórico de uma população homogênea e estável de trabalhadores do setor secundário da economia, pouco especializados e que ganham baixos salários, estabelecendo a prevalência da HAS nesse grupo específico, relacionando-a com algumas covariáveis biológicas e socioeconômicas, e comparando-a com a prevalência de HAS em outros grupos profissionais no Brasil. MÉTODO: Foram estudados 73 trabalhadores regularmente empregados em julho de 1993 em um curtume situado no Município de Botucatu, cidade de médio porte da região Centro-Oeste do Estado de São Paulo, os quais foram submetidos a exame antropométrico, aferição de pressão arterial, anamnese e exame clínico. Os resultados foram comparados com os obtidos em estudos semelhantes, controlando-se o confundimento da idade por intermédio de diferentes técnicas. RESULTADOS: A prevalência bruta da HAS encontrada foi de 56,1%, sendo 15,8% a prevalência de hipertensão sistólica isolada. Ambas se associaram ao etilismo e ao tabagismo na população estudada. DISCUSSÃO: A prevalência da hipertensão foi consideravelmente alta e significativamente maior do que a encontrada em outros grupos de trabalhadores estudados no Brasil. Tal achado ressalta a necessidade da continuidade da investigação, objetivando o isolamento dos fatores implicados na elevação pressórica do grupo estudado.INTRODUCTION: Cardiovascular diseases have been shown to be the leading cause of

  13. Duplex Color Doppler Evaluation of Retinal Arterial Blood Flow in Type 2 Diabetic Subjects without Retinopathy

    Directory of Open Access Journals (Sweden)

    Mashah Binte Amin

    2014-09-01

    Full Text Available Background: Diabetic retinopathy is a vascular disorder affecting the microvasculature of retina. It is caused by changes in the blood vessels of retina. If untreated, it may lead to blindness which is usually preventable if retinopathy is diagnosed early and treated promptly. In ophthalmology, color Doppler imaging is a new method that enables us to assess the orbital vasculature. It allows for simultaneous two dimensional anatomical and Doppler evaluations of hemodynamic characteristics of retinal artery. Objective: To observe the difference between Doppler flow velocity indices (peak systolic velocity, end diastolic velocity and resistive index of retinal artery in type 2 diabetic subjects without retinopathy and those of normal controls. Materials and Methods: This case-control study was carried out in the department of Radiology and Imaging, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM in collaboration with Ophthalmology Outpatient Department, BIRDEM, Dhaka from July 2011 to June 2013. Eighty diabetic patients without retinopathy aged 27–68 years were enrolled as cases and age and sex matched 80 healthy subjects were selected as controls. Type 1 diabetic patients, type 2 diabetics with retinopathy, hypertensive and dyslipidemic subjects were excluded from the study. All the selected subjects underwent duplex Doppler ultrasonography of both eyes using 5 to 7.5 MHZ linear phase transducer. Duplex color Doppler findings including spectral analysis (PSV, EDV and RI were recorded. Unpaired t test was done to compare blood flow velocity indices of retinal artery in type 2 diabetic patients without retinopathy and that of healthy control subjects. p value <0.05 was considered as significant. Results: Majority (42.5% and 47.5% of subjects were in 4th decade of life in both groups with predominance of males. The mean duration of diabetes was 4.56 ± 2.1 years. Mean peak systolic

  14. Effect of selective occlusion of the umbilical arteries and/or veins on uterine blood flow in sheep.

    Science.gov (United States)

    Hasaart, T H; de Haan, J; Horiguchi, T

    1986-01-01

    Maternal uterine blood flow was depressed during total umbilical cord occlusion, probably based on an increased fetal cotyledonary tissue pressure (Hasaart and de Haan (1985) Eur. J. Obstet. Gynec. Reprod. Biol., 19, 125-131). This supposed mechanism was further analysed by performing selective occlusions of the umbilical arteries and/or veins (mean occlusion time 35 s). An occluding device which allowed separate occlusion of umbilical veins and arteries was applied to the umbilical cord in 7 chronically prepared fetal lambs between 106 and 135 days gestation. Median uterine artery blood flow (UBF) was measured with an electromagnetic flow meter. During occlusion of both umbilical veins (VV, n = 22) in 6 animals a maximal decrease in UBF to 87.5% of control value (P less than 0.001) was found at the end occlusion, followed by a gradual return to control value in the post occlusion period. Occlusion of both umbilical arteries (AA, n = 29) in 5 animals was accompanied by a slight increase in UBF to 103% of control value (P less than 0.01). Total occlusion of the umbilical arteries and veins simultaneously (n = 17) in 4 animals did not result in any change in UBF. The changes in volume and turgor in the fetal cotyledonary tissue associated with the arterial and venous occlusions should lead to respectively a decrease (AA) and increase (VV) in resistance to maternal flow, causing the changes in uterine blood flow. It is concluded that volume changes in the fetal compartment of the sheep placenta affect maternal uterine blood flow. PMID:3956829

  15. How Do Antihypertensive Drugs Work? Insights from Studies of the Renal Regulation of Arterial Blood Pressure.

    Science.gov (United States)

    Digne-Malcolm, Holly; Frise, Matthew C; Dorrington, Keith L

    2016-01-01

    Though antihypertensive drugs have been in use for many decades, the mechanisms by which they act chronically to reduce blood pressure remain unclear. Over long periods, mean arterial blood pressure must match the perfusion pressure necessary for the kidney to achieve its role in eliminating the daily intake of salt and water. It follows that the kidney is the most likely target for the action of most effective antihypertensive agents used chronically in clinical practice today. Here we review the long-term renal actions of antihypertensive agents in human studies and find three different mechanisms of action for the drugs investigated. (i) Selective vasodilatation of the renal afferent arteriole (prazosin, indoramin, clonidine, moxonidine, α-methyldopa, some Ca(++)-channel blockers, angiotensin-receptor blockers, atenolol, metoprolol, bisoprolol, labetolol, hydrochlorothiazide, and furosemide). (ii) Inhibition of tubular solute reabsorption (propranolol, nadolol, oxprenolol, and indapamide). (iii) A combination of these first two mechanisms (amlodipine, nifedipine and ACE-inhibitors). These findings provide insights into the actions of antihypertensive drugs, and challenge misconceptions about the mechanisms underlying the therapeutic efficacy of many of the agents. PMID:27524972

  16. Random perturbations of arterial blood pressure for the assessment of dynamic cerebral autoregulation

    International Nuclear Information System (INIS)

    The assessment of cerebral autoregulation (CA) relies mostly on methods that modulate arterial blood pressure (ABP). Despite advances, the gold standard of assessment remains elusive and clinical practicality is limited. We investigate a novel approach of assessing CA, consisting of the intermittent application of thigh cuffs using square wave sequences. Our aim was to increase ABP variability whilst minimizing volunteer discomfort, thus improving assessment acceptability. Two random square wave sequences and two maximum pressure settings (80 and 150 mmHg) were used, corresponding to four manoeuvres that were conducted in random order after a baseline recording. The intermittent application of thigh cuffs resulted in an amplitude dependent increase in ABP (p = 0.001) and cerebral blood flow velocity (CBFV) variability (p = 0.026) compared to baseline. No statistically significant differences in mean heart rate or heart rate variability were observed (p = 0.108 and p = 0.350, respectively), suggesting that no significant sympathetic response was elicited. No significant differences in the CBFV step response were observed, suggesting no distortion of autoregulatory parameters resulted from the use of thigh cuffs. We conclude that pseudorandom binary sequences are an effective and safe alternative for increasing ABP variability. This new approach shows great promise as a tool for the robust assessment of CA. (paper)

  17. Augmented blood pressure measurement through the noninvasive estimation of physiological arterial pressure variability

    International Nuclear Information System (INIS)

    Current noninvasive blood pressure (BP) measurement methods, such as the oscillometric method, estimate the systolic and diastolic blood pressure (SBP and DBP) at two random instants in time and do not take into account the natural variability in BP. The standard for automated BP devices sets a maximum allowable system error of ±5 mmHg, even though natural BP variability often exceeds these limits. This paper proposes a new approach using simultaneous recordings of the oscillometric and continuous arterial pulse waveforms to augment the conventional noninvasive measurement by providing (1) the mean SBP and DBP over the measurement interval and the associated confidence intervals of the mean, (2) the standard deviation of SBP and DBP over the measurement interval, which indicates the degree of fluctuation in BP and (3) an indicator as to whether or not the oscillometric reading is an outlier. Recordings with healthy subjects demonstrate the potential utility of this approach to characterize BP, to detect outlier measurements, and that it does not suffer from bias relative to the conventional oscillometric method. (paper)

  18. Differentiation between pulmonary thrombi and slow blood flow in the pulmonary artery by MR imaging

    International Nuclear Information System (INIS)

    On electrocardiogram (ECG)-gated spin-echo magnetic resonance (MR) images, differentiation of thrombi from slow blood flow in the pulmonary arteries (PA) is sometimes difficult in such cases with prominent pulmonary hypertension (PH) as they show high signal intensity of intraluminal slow flow in not only diastole but also systole. ECG-gated, double spin-echo MR images were obtained in eight patients with PH accompanied by the high signal intensity of blood flow in the right main PA in both diastole and systole. These images were compared with those of five patients with chronic pulmonary thromboembolism (CPTE). Slow flow, but not thrombi, significantly increased signal intensity relative to other tissues from the first-echo to the second-echo image. In two patients with both CPTE and PH discrimination between slow flow and central thrombi was established by this imaging technique. This study suggests that ECG-gated, double spin-echo technique is useful for differentiating central thrombi from slow flow. MR imaging can play an important role in detection and repeated noninvasive examination of proximal pulmonary thromboemboli. (author)

  19. A pressão arterial está sendo medida? Is the blood pressure being measured?

    Directory of Open Access Journals (Sweden)

    Débora C. Alavarce

    2000-03-01

    Full Text Available A medida da pressão arterial faz parte do exame físico e deve ser realizada em toda consulta médica. Para avaliar se a pressão arterial é medida nas consultas médicas, foram consultados 500 prontuários de pacientes de primeira consulta ambulatorial, sendo 335 (67% provenientes de clínicas médicas e cirúrgicas e 165 (33% das clínicas ginecológica e obstétrica. A pressão arterial foi anotada em 39% das consultas realizadas (135±32/85±19 mm Hg, sendo que em 11% destas anotações a pressão diastólica estava acima de 90 mm Hg. Em relação ao diagnóstico prévio de hipertensão arterial verificou-se que: a em 62% dos prontuários não havia esta informação; b 20% referiram ter hipertensão, e em 79% destes a pressão arterial foi anotada; e c 18% referiram não ter hipertensão e 46% destes tiveram registro da pressão arterial. Portanto, a maior parte dos pacientes não teve sua pressão arterial anotada.The blood pressure measure is part of the physical exam and it should be accomplished in every medical consultation. To verify the blood pressure measured in the accomplished medical consultations record of first they were consulted it consults 500 patient's ambulatorial being 335 (67% coming of medical and surgical clinics and 165 (33% of the gynecological and obstetric clinics. The blood pressure was written down in 39% of the accomplished consultations (135+32 mm Hg 85+19 mm Hg, and 11% of this annotations the pressure diastólica was above 90 mm Hg. In relation to the previous diagnosis of hypertension it was verified that: a in 62% of the records there was not this information; b 20% referred to have hypertension, and in 79% of these the arterial pressure was scored; and c 18% referred not to have hypertension and 46% of these had registration of the arterial pressure. Therefore, most of the patients didn't have its logged arterial pressure.

  20. An artificial pancreas for automated blood glucose control in patients with Type 1 diabetes

    DEFF Research Database (Denmark)

    Schmidt, Signe; Boiroux, Dimitri; Ranjan, Ajenthen;

    2015-01-01

    Automated glucose control in patients with Type 1 diabetes is much-coveted by patients, relatives and healthcare professionals. It is the expectation that a system for automated control, also know as an artificial pancreas, will improve glucose control, reduce the risk of diabetes complications...... and markedly improve patient quality of life. An artificial pancreas consists of portable devices for glucose sensing and insulin delivery which are controlled by an algorithm residing on a computer. The technology is still under development and currently no artificial pancreas is commercially available....... This review gives an introduction to recent progress, challenges and future prospects within the field of artificial pancreas research....

  1. The arterial blood supply of the temporomandibular joint: an anatomical study and clinical implications

    International Nuclear Information System (INIS)

    The aim of this study was to analyze three-dimensional images of the arterial supply to the temporomandibular joint. Ten patients (five men and five women, mean age 36 years) without signs or symptoms of temporomandibular disorders, who underwent contrast-enhanced computed tomographic (CT) scanning with intravenous contrast, were studied. The direct volume rendering technique of CT images was used, and a data set of images to visualize the vasculature of the human temporomandibular joint in three dimensions was created. After elaboration of the data through post-processing, the arterial supply of the temporomandibular joint was studied. The analysis revealed the superficial temporal artery, the anterior tympanic artery, the deep temporal artery, the auricular posterior artery, the transverse facial artery, the middle meningeal artery, and the maxillary artery with their branches as the main arterial sources for the lateral and medial temporomandibular joint. The direct volume rendering technique was found to be successful in the assessment of the arterial supply to the temporomandibular joint. The superficial temporal artery and maxillary artery ran along the lateral and medial sides of the condylar neck, suggesting that these arteries are at increased risk during soft-tissue procedures such as an elective arthroplasty of the temporomandibular joint.

  2. The arterial blood supply of the temporomandibular joint: an anatomical study and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Cuccia, Antonino Marco; Caradonna, Carola; Caradonna, Domenico [Dept. of Surgical and Oncological Disciplines, University of Palermo, Palermo (Italy); Anastasi, Giuseppe; Milardi, Demetrio; Favaloro, Angelo; Caradonna, Luigi; Cutroneo, Giuseppina [Biomorphology and Biotechnologies, University of Messina, Messina (Italy); De Pietro, Anita; Angileri, Tommaso Maurizio [Villa Santa Teresa, Diagnostica per Immagini, Palermo (Italy)

    2013-03-15

    The aim of this study was to analyze three-dimensional images of the arterial supply to the temporomandibular joint. Ten patients (five men and five women, mean age 36 years) without signs or symptoms of temporomandibular disorders, who underwent contrast-enhanced computed tomographic (CT) scanning with intravenous contrast, were studied. The direct volume rendering technique of CT images was used, and a data set of images to visualize the vasculature of the human temporomandibular joint in three dimensions was created. After elaboration of the data through post-processing, the arterial supply of the temporomandibular joint was studied. The analysis revealed the superficial temporal artery, the anterior tympanic artery, the deep temporal artery, the auricular posterior artery, the transverse facial artery, the middle meningeal artery, and the maxillary artery with their branches as the main arterial sources for the lateral and medial temporomandibular joint. The direct volume rendering technique was found to be successful in the assessment of the arterial supply to the temporomandibular joint. The superficial temporal artery and maxillary artery ran along the lateral and medial sides of the condylar neck, suggesting that these arteries are at increased risk during soft-tissue procedures such as an elective arthroplasty of the temporomandibular joint.

  3. Associations of blood pressure and arterial compliance with occupational noise exposure in female workers of textile mill

    Institute of Scientific and Technical Information of China (English)

    NI Chun-hui; ZHANG Yu-jun; CHEN Zhi-yong; ZHOU Yin; ZHOU Jian-wei; Pan Jing-jing; LIU Nian; WANG Jun; LIANG Chen-ke; ZHANG Zhi-zhong

    2007-01-01

    Background There are few studies on the arterial compliance of noise exposure. The purpose of this study was to understand the relationship between hearing loss, blood pressure and arterial compliance of female workers who exposed to occupational noise in a textile mill.Methods The noise levels in the workplace were measured with a HS6288 sound level meter. Cumulated noise exposure (CNE) was calculated according to the noise intensity and the exposure period. Hearing ability and arterial compliance were measured in 618 noise exposed workers. The database was set up with EpiData and the statistical analysis was performed with SAS software 9.1.3.Results The noise levels were 80.1dB(A) to 113.5dB(A), of which the levels at 92.5% of the noise monitoring sites were over the national standard. The incidence of high frequency hearing loss (HFHL) was 24.43% and language frequency hearing impairment (LFHI) was 0.81%. The incidence of hypertension was 7.93%. Both systolic blood pressure (SBP)and diastolic blood pressure (DBP) in the high frequency hearing loss group were significantly higher than those in the normal hearing group (P<0.05), while C1 (large artery compliance) and C2 (small artery compliance) were significantly lower (P<0.05). The high frequency hearing threshold (HFHT) of the hypertension group was significantly higher than in the normal blood pressure group (P<0.05), while C1 and C2 were significantly lower (P<0.05). C1 and C2 had a negative correlation with HFHT, SBP, DBP, mean of arterial pressure (MAP), pulse pressure (PP) and pulse rate (PR) (P<0.05).The multiple regression analyses showed that blood pressure and PR were the main influencing factors on C1 and C2.LFHT was an influence on C2 and HFHT on C1.Conclusions Textile mill noise pollution is very serious and has an obvious influence on worker's auditory function. The female workers with Iow artery compliance or with high blood pressure might be suffering from hearing loss; those with noise

  4. Evidence that blood pressure remains under the control of arterial baroreceptors in renal hypertensive rats

    Directory of Open Access Journals (Sweden)

    A.S. Trindade Jr.

    2009-10-01

    Full Text Available The purpose of the present study was to determine the range of the influence of the baroreflex on blood pressure in chronic renal hypertensive rats. Supramaximal electrical stimulation of the aortic depressor nerve and section of the baroreceptor nerves (sinoaortic denervation were used to obtain a global analysis of the baroreceptor-sympathetic reflex in normotensive control and in chronic (2 months 1-kidney, 1-clip hypertensive rats. The fall in blood pressure produced by electrical baroreceptor stimulation was greater in renal hypertensive rats than in normotensive controls (right nerve: -47 ± 8 vs -23 ± 4 mmHg; left nerve: -51 ± 7 vs -30 ± 4 mmHg; and both right and left nerves: -50 ± 8 vs -30 ± 4 mmHg; P < 0.05. Furthermore, the increase in blood pressure level produced by baroreceptor denervation in chronic renal hypertensive rats was similar to that observed in control animals 2-5 h (control: 163 ± 5 vs 121 ± 1 mmHg; 1K-1C: 203 ± 7 vs 170 ± 5 mmHg; P < 0.05 and 24 h (control: 149 ± 3 vs 121 ± 1 mmHg; 1K-1C: 198 ± 8 vs 170 ± 5 mmHg; P < 0.05 after sinoaortic denervation. Taken together, these data indicate that the central and peripheral components of the baroreflex are acting efficiently at higher arterial pressure in renal hypertensive rats when the aortic nerve is maximally stimulated or the activity is abolished.

  5. Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans

    DEFF Research Database (Denmark)

    Calbet, J A L; Boushel, Robert Christopher; Robach, P;

    2014-01-01

    altitude than at sea level (P < 0.05). At altitude, the high doses of adenosine and ATP reduced mean arterial blood pressure by 9-12%, independently of FI O2 . The change in vascular conductance in response to ATP was lower at altitude than at sea level by 24 and 38%, during the low and high ATP doses...... protein expression was determined in muscle biopsies after 4 weeks at 3454 m by Western blot. RESULTS: At altitude, mean arterial blood pressure was 13% higher (91 ± 2 vs. 102 ± 3 mmHg, P < 0.05) than at sea level and was unaltered by hyperoxic breathing. Baseline leg vascular conductance was 25% lower at...... blood pressure and reduces the vasodilatory responses to adenosine and ATP....

  6. A prospective study of glomerular filtration rate and arterial blood pressure in insulin-dependent diabetics with diabetic nephropathy

    DEFF Research Database (Denmark)

    Parving, H H; Smidt, U M; Friisberg, B; Bonnevie-Nielsen, V; Andersen, A R

    1981-01-01

    Glomerular filtration rate (GFR, single bolus 51Cr-EDTA technique), serum creatinine, proteinuria and arterial blood pressure have been measured prospectively in 14 young onset insulin-dependent diabetics selected by of persistent proteinuria (greater than 0.5 g/day) secondary to diabetic...... nephropathy. Twelve of the 14 patients had normal serum creatinine levels. None of the patients received antihypertensive treatment. During the mean observation period of 26 months (range 23 to 33 months) GFR decreased from 107 to 87 ml/min/1.73 m2 (p less than 0.001), serum creatinine remained unchanged: 107....../min/month (range 0.1 to 1.5 ml/min/month). The decrease in GFR did not correlate wih sex, age at onset, duration of diabetes, arterial blood pressure, proteinuria, insulin requirement, postprandial blood glucose or the initial GFR in each individual was constant, but varied considerably between patients. Increase...

  7. Mesenteric artery ischemia

    Science.gov (United States)

    Mesenteric artery ischemia occurs when there is a narrowing or blockage of one or more of the three major arteries that ... that supply blood to the intestine causes mesenteric ischemia. The arteries that supply blood to the intestines ...

  8. Angiography of testicular artery with special reference to the blood supply of the testis in camel

    International Nuclear Information System (INIS)

    The right and left testicular arteries in camel arose independently from the ventrolateral aspect of abdominal aorta at the level of fourth of fifth lumbar vertebra. Both arteries although had different relations and course inside the abdominal cavity had similar inguinal and post inguinal course. The artery described a great number of convolutions in close apposition to each other, thus formed an elongated vascular cone with its apex at the superficial inguinal ring and the base on the caputal extremity of the testis. As testicular artery reached caputal extremity of testis it showed 2 patterns in its course. The intratesticular arborization of testicular artery consideted of centripetal and centrifugal arteries

  9. Continuous arterial blood gas monitoring in rabbits: an efficient method for evaluation of ratio-based optrodes

    Science.gov (United States)

    Martin, Roy C.; Olstein, Alan D.; Malin, Stephen F.; Perkovich, Anne

    1992-04-01

    Laboratory bench testing of optical blood gas sensors is insufficient to completely predict capabilities. Sensor testing in animals offers advantages of known physiologic and regulatory mechanisms of hemodynamics to better predict sensor performance. The domestic rabbit, Oryctalogis Cuniculus, a lagomorph of the family Leporidae was used for sensor evaluation. The rabbits are ventilated and blood gases modulated by variations in FIO2 and rate adjustments. Twenty gauge catheters are placed in the dorsal aorta, cartoid, and femoral arteries. Pressures are monitored via transducers on the arterial lines. The optical blood gas sensors are fitted within the catheters and blood samples are collected over them for bench analysis. Sensors are on 125 micrometers glass optic fibers. Proprietary prepolymers are applied on the fiber tips through in fiber photopolymerization. These sensors are then calibrated in tonometered water and blood. Sensor monitoring is accomplished through OSR microfluorimetry systems. We have used this model in 26 studies over the past six months evaluating over fifty blood gas sensors. These studies have lasted from six to twenty-four hours. Our correlation of sensor readings to assayed blood samples is r2 equals .97 for pH values of 6.80 - 7.70, r2 equals .94 for PCO2 values of 10 - 175 mmHg and r2 equals .94 for PO2 values of 10 - 350 mmHg.

  10. Asymptotic analysis of blood flow in stented arteries: time dependency and direct simulations***

    Directory of Open Access Journals (Sweden)

    Pichon Gostaf Kirill

    2010-12-01

    Full Text Available This work aims to extend in two distinct directions results recently obtained in [10]. In a first step we focus on the possible extension of our results to the time dependent case. Whereas in the second part some preliminary numerical simulations aim to give orders of magnitudes in terms of numerical costs of direct 3D simulations. We consider, in the first part, the time dependent rough problem for a simplified heat equation in a straight channel that mimics the axial velocity under an oscillating pressure gradient. We derive first order approximations with respect to ϵ, the size of the roughness. In order to understand the problem and set up correct boundary layer approximations, we perform a time periodic fourier analysis and check that no frequency can interact with the roughness. We show rigorously on this toy problem that the boundary layers remain stationary in time (independent on the frequency number. Finally we perform numerical tests validating our theoretical approach. In the second part, we determine actual limits, when running three-dimensional blood flow simulations of the non-homogenized stented arteries. We solve the stationary Stokes equations for an artery containing a saccular aneurysm. Consecutive levels of uniform mesh refinement, serve to relate spatial resolution, problem scale, and required computation time. Test computations are presented for femoral side aneurysm, where a simplified ten-wire stent model was placed across the aneurysm throat. We advocate the proposed stent homogenization model, by concluding that an actual computation power is not sufficient to run accurate, direct simulations of a pulsatile flow in stented vessels.

  11. On the shape of the common carotid artery with implications for blood velocity profiles

    International Nuclear Information System (INIS)

    Clinical and engineering studies typically assume that the common carotid artery (CCA) is straight enough to assume fully developed flow, yet recent studies have demonstrated the presence of skewed velocity profiles. Toward elucidating the influence of mild vascular curvatures on blood flow patterns and atherosclerosis, this study aimed to characterize the three-dimensional shape of the human CCA. The left and right carotid arteries of 28 participants (63 ± 12 years) in the VALIDATE (Vascular Aging-–The Link that Bridges Age to Atherosclerosis) study were digitally segmented from 3D contrast-enhanced magnetic resonance angiograms, from the aortic arch to the carotid bifurcation. Each CCA was divided into nominal cervical and thoracic segments, for which curvatures were estimated by least-squares fitting of the respective centerlines to planar arcs. The cervical CCA had a mean radius of curvature of 127 mm, corresponding to a mean lumen:curvature radius ratio of 1:50. The thoracic CCA was significantly more curved at 1:16, with the plane of curvature tilted by a mean angle of 25° and rotated close to 90° with respect to that of the cervical CCA. The left CCA was significantly longer and slightly more curved than the right CCA, and there was a weak but significant increase in CCA curvature with age. Computational fluid dynamic simulations carried out for idealized CCA geometries derived from these and other measured geometric parameters demonstrated that mild cervical curvature is sufficient to prevent flow from fully-developing to axisymmetry, independent of the degree of thoracic curvature. These findings reinforce the idea that fully developed flow may be the exception rather than the rule for the CCA, and perhaps other nominally long and straight vessels

  12. Selective Heart Rate Reduction With Ivabradine Increases Central Blood Pressure in Stable Coronary Artery Disease.

    Science.gov (United States)

    Rimoldi, Stefano F; Messerli, Franz H; Cerny, David; Gloekler, Steffen; Traupe, Tobias; Laurent, Stéphane; Seiler, Christian

    2016-06-01

    Heart rate (HR) lowering by β-blockade was shown to be beneficial after myocardial infarction. In contrast, HR lowering with ivabradine was found to confer no benefits in 2 prospective randomized trials in patients with coronary artery disease. We hypothesized that this inefficacy could be in part related to ivabradine's effect on central (aortic) pressure. Our study included 46 patients with chronic stable coronary artery disease who were randomly allocated to placebo (n=23) or ivabradine (n=23) in a single-blinded fashion for 6 months. Concomitant baseline medication was continued unchanged throughout the study except for β-blockers, which were stopped during the study period. Central blood pressure and stroke volume were measured directly by left heart catheterization at baseline and after 6 months. For the determination of resting HR at baseline and at follow-up, 24-hour ECG monitoring was performed. Patients on ivabradine showed an increase of 11 mm Hg in central systolic pressure from 129±22 mm Hg to 140±26 mm Hg (P=0.02) and in stroke volume by 86±21.8 to 107.2±30.0 mL (P=0.002). In the placebo group, central systolic pressure and stroke volume remained unchanged. Estimates of myocardial oxygen consumption (HR×systolic pressure and time-tension index) remained unchanged with ivabradine.The decrease in HR from baseline to follow-up correlated with the concomitant increase in central systolic pressure (r=-0.41, P=0.009) and in stroke volume (r=-0.61, Phttp://www.clinicaltrials.gov. Unique identifier NCT01039389. PMID:27091900

  13. Effects of Weather and Heliophysical Conditions on Emergency Ambulance Calls for Elevated Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Jone Vencloviene

    2015-02-01

    Full Text Available We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009–2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs, in which the conditions for the emergency calls were made coded I.10–I.15. The Kaunas Weather Station provided daily records of air temperature (T, wind speed (WS, relative humidity, and barometric pressure (BP. We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS > 600 km/s increased the daily number of elevated arterial blood pressure (EABP by 12% (RR = 1.12; 95% confidence interval (CI 1.04–1.21; and WS ≥ 3.5 knots during days of T < 1.5 °C and T ≥ 12.5 °C by 8% (RR = 1.08; CI 1.04–1.12. An increase of T by 10 °C and an elevation of BP two days after by 10 hPa were associated with a decrease in RR by 3%. An additional effect of T was detected during days of T ≥ 17.5 °C only in females. Women and patients with grade III arterial hypertension at the time of the ambulance call were more sensitive to weather conditions. These results may help in the understanding of the population’s sensitivity to different weather conditions.

  14. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

    2014-12-15

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

  15. Contribution of spiral artery blood flow changes assessed by transvaginal color Doppler sonography for predicting endometrial pathologies

    Directory of Open Access Journals (Sweden)

    Suna Kabil Kucur

    2013-01-01

    Full Text Available ive: To investigate the diagnostic value of blood flow measurements in spiral artery by transvaginal color Doppler sonography (CDS in predicting endometrial pathologies.Methods: Ninety-seven patients presenting with abnormal uterine bleeding and requiring endometrial assessment were included in this prospective observational study. Endometrial thickness, structure and echogenicity were recorded. Pulsatility index (PI and resistive index (RI of the spiral artery were measured by transvaginal CDS. Endometrial sampling was performed for all subjects. Sonographic and hystopathologic findings were compared.Results: The histopathological diagnoses were as follows; 39 cases (40.2% endometrial polyp, 9 cases (9.3% endometrial hyperplasia, 10 cases (10.3 submucous myoma, 7 cases (7.2% endometrium cancer, and 32 cases (33% nonspecific findings. The spiral artery PI in endometrium cancer group was highly significantly lower than other groups (p<0.01. The spiral artery RI was also significantly lower in the patients with malignant histology (p<0.05. Conclusion: Endometrial pathologies are associated significantly with endometrial spiral artery Doppler changes.Key words: Spiral artery, Doppler ultrasonography, endometrium

  16. Examination of nanoparticles as a drug carrier on blood flow through catheterized composite stenosed artery with permeable walls.

    Science.gov (United States)

    Ijaz, S; Nadeem, S

    2016-09-01

    In this paper, we have discussed the influence of copper nanoparticles on a blood flow through composite stenosed artery with permeable walls. The nature of blood is discussed mathematically by considering it as viscous nanofluid. The study is carried out for a blood vessel under mild stenosis approximations and expressions of the temperature, velocity, resistance impedance to flow, wall shear stress and the pressure gradient is obtained by using corresponding boundary conditions. Results for the effects of permeability on blood flow through composite stenosis have been discussed graphically. The considered analysis also summarizes that the drug copper nanoparticles are efficient to reduce hemodynamics of stenosis and could be helpful to predict important uses for biomedical applications. Results indicate that nanoparticles are helpful as drug carriers to minimize the effects of resistance impedance to blood flow or coagulation factors due to stenosis. PMID:27393802

  17. A lumped-parameter model to investigate the effect of plantar pressure on arterial blood flow in a diabetic foot.

    Science.gov (United States)

    Hahn, C; Mahajan, A; Chu, T; Schoen, M

    2007-08-01

    This paper presents a lumped-parameter model for the big-toe region that investigates the effect of plantar pressure on the diameter of the blood vessels, specifically the arteries, in the presence of arterial and/or tissue changes. The model developed in this paper uses a multi-domain energy system approach to develop the lumped-parameter differential equations. Blood flow is modelled as fluidic flow through compliant pipes that have inertia, stiffness, and damping. The tissue material is treated as a soft compliant material that transmits the external force to the blood vessels. Conclusions have been drawn to show the effect of plantar pressure, tissue damage, and their combination on the diameter of the blood vessels. The principles used here can be used to model the entire foot and the model used to investigate the effect of plantar pressure, tissue damage, and arterial changes on different parts of the foot. The work presented here may also have applications in other vascular diseases. PMID:17937206

  18. Effects of various combinations of benzodiazepines with buprenorphine on arterial blood gases in rats.

    Science.gov (United States)

    Pirnay, Stéphane O; Mégarbane, Bruno; Borron, Stephen W; Risède, Patricia; Monier, Claire; Ricordel, Ivan; Baud, Frédéric J

    2008-09-01

    Fatalities have been attributed to combinations of high-dose buprenorphine with benzodiazepines. In rats, high-dose buprenorphine combined with midazolam was shown to induce sustained respiratory acidosis, while buprenorphine alone did not. However, the effects of buprenorphine combined with pharmacological doses of benzodiazepines remain unknown. Our objective was to compare the acute effects of four selected benzodiazepines used intravenously at equi-efficacious doses in rats, alone and in combination with buprenorphine on sedation, respiratory rate and arterial blood gases. Buprenorphine (30 mg/kg) did not significantly modify sedation level or respiratory rate, but induced mild and transient effects on pH and PaCO(2) (P < 0.05). Similarly, despite having no effects on respiratory rate, nordiazepam (10 mg/kg), bromazepam (1 mg/kg) and oxazepam (12 mg/kg) mildly and transiently altered pH and PaCO(2) (P < 0.05), whereas clonazepam (5 mg/kg) did not. Buprenorphine combined with each benzodiazepine induced no significant effects on respiratory rate or blood gases, in comparison with buprenorphine alone. However, combinations of oxazepam or nordiazepam with buprenorphine significantly deepened sedation. While both combinations reduced respiratory rate, buprenorphine + 30 mg/kg clonazepam significantly increased PaCO(2) and buprenorphine + 30 mg/kg nordiazepam decreased PaO(2). In conclusion, not all benzodiazepines induce significant respiratory depression at therapeutic doses. We were unable to demonstrate significant effects on rat ventilatory parameters of buprenorphine combined with equi-efficacious pharmacological doses of benzodiazepines in comparison with buprenorphine alone. Our results may suggest that effects of these combinations are rather mild. Respiratory failure may, however, result from the association of buprenorphine with elevated doses of benzodiazepines. PMID:18684226

  19. Endothelial Injury Associated with Cold or Warm Blood Cardioplegia during Coronary Artery Bypass Graft Surgery

    Directory of Open Access Journals (Sweden)

    Elmar W. Kuhn

    2015-01-01

    Full Text Available The aim of this investigation was to analyze the impact of intermittent cold blood cardioplegia (ICC and intermittent warm blood cardioplegia (IWC on endothelial injury in patients referred to elective on-pump coronary artery bypass graft (CABG surgery. Patients undergoing CABG procedures were randomized to either ICC or IWC. Myocardial injury was assessed by CK-MB and cardiac troponin T (cTnT. Endothelial injury was quantified by circulating endothelial cells (CECs, von Willebrand factor (vWF, and soluble thrombomodulin (sTM. Perioperative myocardial injury (PMI and major adverse cardiac events (MACE were recorded. Demographic data and preoperative risk profile of included patients (ICC: n=32, IWC: n=36 were comparable. No deaths, PMI, or MACE were observed. Levels of CK-MB and cTnT did not show intergroup differences. Concentrations of CECs peaked at 6 h postoperatively with significantly higher values for IWC-patients at 1 h (ICC: 10.1 ± 3.9/mL; IWC: 18.4 ± 4.1/mL; P=0.012 and 6 h (ICC: 19.3 ± 6.2/mL; IWC: 29.2 ± 6.7/mL; P<0.001. Concentrations of vWF (ICC: 178.4 ± 73.2 U/dL; IWC: 258.2 ± 89.7 U/dL; P<0.001 and sTM (ICC: 3.2 ± 2.1 ng/mL; IWC: 5.2 ± 2.4 ng/mL; P=0.011 were significantly elevated in IWC-group at 1 h postoperatively. This study shows that the use of IWC is associated with a higher extent of endothelial injury compared to ICC without differences in clinical endpoints.

  20. Peripheral Blood Lymphocyte Depletion After Hepatic Arterial {sup 90}Yttrium Microsphere Therapy for Hepatocellular Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Brian I., E-mail: brianicarr@hotmail.com [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA and Department of Nutrition and Exptl Biology, Saverio De Bellis Medical Research Institute, Castellana Grotte, Bari (Italy); Metes, Diana M. [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA and Department of Nutrition and Exptl Biology, Saverio De Bellis Medical Research Institute, Castellana Grotte, Bari (Italy)

    2012-03-01

    Purpose: The short- and long-term effects of {sup 90}Yttrium microspheres therapy for hepatocellular carcinoma (HCC) on peripheral blood lymphocytes are unknown and were therefore examined. Methods and Materials: Ninety-two HCC patients were enrolled in a {sup 90}Yttrium therapy study and routine blood counts were examined as part of standard clinical monitoring. Results: We found an early, profound, and prolonged lymphopenia. In a subsequent cohort of 25 additional HCC patients, prospective flow cytometric immune-monitoring analysis was performed to identify specific changes on distinct lymphocyte subsets (i.e., CD3, CD4, CD8 T, and CD19 B lymphocytes) and NK cells absolute numbers, in addition to the granulocytes and platelets subsets. We found that the pretreatment lymphocyte subset absolute numbers (with the exception of NK cells) had a tendency to be lower compared with healthy control values, but no significant differences were detected between groups. Posttherapy follow-up revealed that overall, all lymphocyte subsets, except for NK cells, were significantly (>50% from pretherapy values), promptly (as early as 24 h) and persistently (up to 30 months) depleted post-{sup 90}Yttrium microspheres therapy. In contrast, granulocytes increased rapidly (24 h) to compensate for lymphocyte depletion, and remained increased at 1-year after therapy. We further stratified patients into two groups, according to survival at 1 year. We found that lack of recovery of CD19, CD3, CD8, and especially CD4 T cells was linked to poor patient survival. No fungal or bacterial infections were noted during the 30-month follow-up period. Conclusions: The results show that lymphocytes (and not granulocytes, platelets, or NK cells) are sensitive to hepatic arterial {sup 90}Yttrium without associated clinical toxicity, and lack of lymphocyte recovery (possibly leading to dysregulation of adaptive cellular immunity) posttherapy indicates poor survival.

  1. Peripheral Blood Lymphocyte Depletion After Hepatic Arterial 90Yttrium Microsphere Therapy for Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Purpose: The short- and long-term effects of 90Yttrium microspheres therapy for hepatocellular carcinoma (HCC) on peripheral blood lymphocytes are unknown and were therefore examined. Methods and Materials: Ninety-two HCC patients were enrolled in a 90Yttrium therapy study and routine blood counts were examined as part of standard clinical monitoring. Results: We found an early, profound, and prolonged lymphopenia. In a subsequent cohort of 25 additional HCC patients, prospective flow cytometric immune-monitoring analysis was performed to identify specific changes on distinct lymphocyte subsets (i.e., CD3, CD4, CD8 T, and CD19 B lymphocytes) and NK cells absolute numbers, in addition to the granulocytes and platelets subsets. We found that the pretreatment lymphocyte subset absolute numbers (with the exception of NK cells) had a tendency to be lower compared with healthy control values, but no significant differences were detected between groups. Posttherapy follow-up revealed that overall, all lymphocyte subsets, except for NK cells, were significantly (>50% from pretherapy values), promptly (as early as 24 h) and persistently (up to 30 months) depleted post-90Yttrium microspheres therapy. In contrast, granulocytes increased rapidly (24 h) to compensate for lymphocyte depletion, and remained increased at 1-year after therapy. We further stratified patients into two groups, according to survival at 1 year. We found that lack of recovery of CD19, CD3, CD8, and especially CD4 T cells was linked to poor patient survival. No fungal or bacterial infections were noted during the 30-month follow-up period. Conclusions: The results show that lymphocytes (and not granulocytes, platelets, or NK cells) are sensitive to hepatic arterial 90Yttrium without associated clinical toxicity, and lack of lymphocyte recovery (possibly leading to dysregulation of adaptive cellular immunity) posttherapy indicates poor survival.

  2. The in vitro effects of artificial and natural sweeteners on the immune system using whole blood culture assays.

    Science.gov (United States)

    Rahiman, F; Pool, E J

    2014-01-01

    This article investigates the effects of commercially available artificial (aspartame, saccharin, sucralose) and natural sweeteners (brown sugar, white sugar, molasses) on the immune system. Human whole blood cultures were incubated with various sweeteners and stimulated in vitro with either phytohemagglutinin or endotoxin. Harvested supernatants were screened for cytotoxicity and cytokine release. Results showed that none of the artificial or natural sweeteners proved to be cytotoxic, indicating that no cell death was induced in vitro. The natural sweetener, sugar cane molasses (10 ug/mL), enhanced levels of the inflammatory biomarker IL-6 while all artificial sweeteners (10 ug/mL) revealed a suppressive effect on IL-6 secretion (P < 0.001). Exposure of blood cells to sucralose-containing sweeteners under stimulatory conditions reduced levels of the biomarker of humoral immunity, Interleukin-10 (P < 0.001). The cumulative suppression of Interleukin-6 and Interleukin-10 levels induced by sucralose may contribute to the inability in mounting an effective humoral response when posed with an exogenous threat. PMID:24063614

  3. Evaluation of the cerebrovascular pressure reactivity index using non-invasive finapres arterial blood pressure

    International Nuclear Information System (INIS)

    A pressure reactivity index (PRx) can be assessed in patients with continuous monitoring of arterial blood pressure (ABP) and intracranial pressure (ICP) as a moving correlation coefficient between slow fluctuations of these two signals within a low frequency bandwidth. The study aimed to investigate whether the invasive ABP monitoring can be replaced with non-invasive measurement of ABP using a Finapres plethysmograph (fABP) to calculate the fPRx. There is a well-defined group of patients, suffering from hydrocephalus and undergoing CSF pressure monitoring, which may benefit from such a measurement. 41 simultaneous day-by-day monitoring of ICP, ABP and fABP were performed for about 30 min in 10 head injury patients. A Bland–Altman assessment for agreement was used to compare PRx and fPRx calculations. Performance metrics and the McNemary test were used to determine whether fPRx is sensitive enough to distinguish between functioning and disturbed cerebrovascular pressure reactivity. The fPRx correlated with PRx (RSpearman = 0.92, p < 0.001; bias = −0.04; lower and upper limits of agreement: −0.26 and 0.17, respectively). The fPRx distinguished between active and passive reactivity in more than 89% cases. The fPRx can be used with care for assessment of cerebrovascular reactivity in patients for whom invasive ABP measurement is not feasible. The fPRx is sensitive enough to distinguish between functional and deranged reactivity

  4. Evaluation of the cerebrovascular pressure reactivity index using non-invasive finapres arterial blood pressure.

    Science.gov (United States)

    Kasprowicz, M; Schmidt, E; Kim, D J; Haubrich, C; Czosnyka, Z; Smielewski, P; Czosnyka, M

    2010-09-01

    A pressure reactivity index (PRx) can be assessed in patients with continuous monitoring of arterial blood pressure (ABP) and intracranial pressure (ICP) as a moving correlation coefficient between slow fluctuations of these two signals within a low frequency bandwidth. The study aimed to investigate whether the invasive ABP monitoring can be replaced with non-invasive measurement of ABP using a Finapres plethysmograph (fABP) to calculate the fPRx. There is a well-defined group of patients, suffering from hydrocephalus and undergoing CSF pressure monitoring, which may benefit from such a measurement. 41 simultaneous day-by-day monitoring of ICP, ABP and fABP were performed for about 30 min in 10 head injury patients. A Bland-Altman assessment for agreement was used to compare PRx and fPRx calculations. Performance metrics and the McNemary test were used to determine whether fPRx is sensitive enough to distinguish between functioning and disturbed cerebrovascular pressure reactivity. The fPRx correlated with PRx (R(Spearman) = 0.92, p agreement: -0.26 and 0.17, respectively). The fPRx distinguished between active and passive reactivity in more than 89% cases. The fPRx can be used with care for assessment of cerebrovascular reactivity in patients for whom invasive ABP measurement is not feasible. The fPRx is sensitive enough to distinguish between functional and deranged reactivity. PMID:20664157

  5. Influence of magnetic field and Hall currents on blood flow through a stenotic artery

    Institute of Scientific and Technical Information of China (English)

    Kh. S. Mekheimer; M.A. El Kot

    2008-01-01

    A micropolar model for blood simulating magnetohydrodynamic flow through a horizontally nonsymmetric but vertically symmetric artery with a mild stenosis is pre- sented. To estimate the effect of the stenosis shape, a suitable geometry has been consid- ered such that the horizontal shape of the stenosis can easily be changed just by varying a parameter referred to as the shape parameter. Flow parameters, such as velocity, the resistance to flow (the resistance impedance), the wall shear stress distribution in the stenotic region, and its magnitude at the maximum height of the stenosis (stenosis throat), have been computed for different shape parameters, the Hartmann number and the Hall parameter. This shows that the resistance to flow decreases with the increasing values of the parameter determining the stenosis shape and the Hall parameter, while it increases with the increasing Hartmann number. The wall shear stress and the shearing stress on the wall at the maximum height of the stenosis possess an inverse characteristic to the resistance to flow with respect to any given value of the Hartmann number and the Hall parameter. Finally, the effect of the Hartmann number and the Hall parameter on the horizontal velocity is examined.

  6. Alterations in Arterial Blood Parameters in Patients with Liver Cirrhosis and Ascites

    Directory of Open Access Journals (Sweden)

    Konstantinos Charalabopoulos, Dimitrios Peschos, Leonidas Zoganas, George Bablekos, Christos Golias, Alexander Charalabopoulos, Dimitrios Stagikas, Angi Karakosta, Athanasios Papathanasopoulos, George Karachalios, Anna Batistatou

    2007-01-01

    Full Text Available In cirrhotic patients, in addition to hepatocytes and Kuppfer cells dysfunction circulatory anatomic shunt and ventilation/perfusion (VA/ Q ratio abnormalities can induce decrease in partial pressure of oxygen in arterial blood (PaO2, in oxygen saturation of hemoglobin (SaO2 as well as various acid-base disturbances. We studied 49 cases of liver cirrhosis (LC with ascites compared to 50 normal controls. Causes were: posthepatic 37 (75.51%, alcoholic 7 (14.24%, cardiac 2 (4.08%, and cryptogenic 3 (6.12%. Complications were: upper gastrointestinal bleeding 24 (48.97, hepatic encephalopathy 20 (40.81%, gastritis 28 (57.14%, hepatoma 5 (10.2%, renal hepatic syndrome 2 (4.01%, HbsAg (+ 24 (48.97%, and hepatic pleural effusions 7 (14.28%. Average PaO2 and SaO2 were 75.2 mmHg and 94.5 mmHg, respectively, compared to 94.2 mmHg and 97.1 mmHg of the control group, respectively (p value in both PaO2 and SaO2 was pA/Q inequality can induce a decrease in PaO2 and SaO2 as well as various acid-base disturbances. As a result, pulmonary resistance is impaired and patients more likely succumb to infections and adult respiratory distress syndrome.

  7. Optical Transcutaneous pCO2 Sensor using Soft Lithography Method for Arterial Blood Gas Analysis

    Science.gov (United States)

    Kang, Byoung-Ho; Kim, Do-Eok; Leem, Myoung-Kun; Kwon, Dae-Hyuk; Lee, Kwang-Man; Kang, Shin-Won

    2008-10-01

    In this study, we carried out development of non-invasive optical transcutaneous partial pressure of carbon dioxide, pCO2, monitoring system. The purpose of this system is to detect CO2 from outer skin, not from the arterial blood-gathering method. There are advantages about a reduction of analysis time and real-time monitoring that this system might be available. The measurement system is composed of the IR lamp, the pyroelectric sensor including a 4.26 μm optical filter, the optical gas reaction chamber and the signal processing circuit. The optical reaction length of chamber was reduced by 1 mm using the soft-lithography method which CO2 is exhausted in human body as we considered. The fabricated pCO2 monitoring system showed linear result of 6.50×10-6 absorbance/ppm sensitivity for CO2 concentration from 0 ˜5,000 ppm by MFC and about 2 seconds of fast response time. The proposed system can be used in the optical biosensor field for the medical diagnosis such as pCO2 monitoring system and environment monitoring systems.

  8. Transplantation of mobilized peripheral blood mononuclear cells for peripheral arterial occlusive disease of the lower extremity

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng YANG; Yanxiang WU; Hongmei WANG; Yifeng XU; Bo XU; Xin LU; Yibin ZANG; Fa WANG; Yue ZHANG

    2006-01-01

    Objectives To assess the clinical efficacy, safety, and feasibility of autologous transplantation of mobilized peripheral blood mononuclear cells (PBMNCs) for patients with peripheral arterial occlusive disease (PAOD) of the lower extremity. Methods A total of 152 patients with PAOD of the lower extremity were enrolled into this non-controlled observational study from November 2003 to March 2006. All patients received subcutaneous injections of recombinant human granulocyte colony-stimulating factor (G-CSF, 450600 μg/day) for 5 days in order to mobilize stem/progenitor cells; their PBMNCs were collected and transplanted by multiple intramuscular injections into ischemic limbs. Patients were followed up for at least 12 weeks. Results At 12 weeks, primarymanifestations,including lower limb pain and coldness, were significantly improved in 137 (90.1%) of the patients; limb ulcers improved or healed in 46 (86.8%) of the 53 patients, while 25 of the 48 (47.9%) patients with limb gangrene remained steady or improved. Ankle-brachial index (ABI) improved in 33 (22%) of the cases, and TcPO2 increased in 45 (30%) of the cases. Angiography before treatment, and at 12 weeks after treatment, was performed in 10 of the patients and showed formation of new collateral vessels. No severe adverse effects or complications specifically related to cell transplantation were observed. Conclusion Autologous transplantation of G-CSF-mobilized PBMNCs might be a safe and effective treatment for lower limb ischemic disorder.(J Geriatr Cardiol 2006; 3:178-80.)

  9. Correlation analysis of the changes in arterial blood pressure in people with acute mountain sickness when exposed to high altitude

    Directory of Open Access Journals (Sweden)

    Yang LIU

    2014-03-01

    Full Text Available Objectives  To investigate the changes in arterial blood pressure in the healthy lowlanders when they were exposed to different altitudes and duration, and the relationship of the exposure with the prevalence and susceptibility of acute mountain sickness (AMS, in order to evaluate the significance of arterial blood pressure changes in the diagnosis of AMS and its clinical risk. Methods  Demographic data and blood pressure parameters [systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial BP (MABP] of healthy lowlanders (inhabitants in ≤500m were collected after being exposed to 3700m on day 1, 3, 5 and 7, and also after being exposed to 4400m on day 5, while healthy young men living at low altitude were randomly selected as the control group. Simultaneously the AMS symptoms Questionnaire was filled. The Lake Louise acute mountain sickness scoring system (LLS was used to diagnose AMS. The changes in arterial blood pressure in people above and its correlation with AMS were analyzed. Results  After acute exposure to 3700m (day 1, SBP, DBP and MABP rose obviously, and then descended moderately after adaptation for about a week, but still higher than that of LA level (P<0.05. And then SBP, DBP and MABP rose again at high-altitude of 4400m, but lower than the levels of day 1 at 3700m. MABP at 3700m and 4400m were related to LLS (r=0.138, P=0.048; r=0.145, P=0.045, respectively. MABP levels for diagnosis of AMS at 3700m showed an cut-off point of 98.5mmHg with sensitivity of 32.8% and specificity of 73.7% (P<0.05, and MABP levels for diagnosis of AMS at 4400m showed an cut-off point of 97.8mmHg with sensitivity of 42.4% and specificity of 75.5% (P<0.05. Conclusions  After exposure to acute hypoxia, MABP may serve as a predictive parameter for diagnosis of AMS. However, the clinical application of MABP as a diagnostic criterion is limited because of its poor specificity or sensitivity. The use of MABP as a diagnostic

  10. Classification of hypervascular liver lesions based on hepatic artery and portal vein blood supply coefficients calculated from triphasic CT scans.

    Science.gov (United States)

    Boas, F Edward; Kamaya, Aya; Do, Bao; Desser, Terry S; Beaulieu, Christopher F; Vasanawala, Shreyas S; Hwang, Gloria L; Sze, Daniel Y

    2015-04-01

    Perfusion CT of the liver typically involves scanning the liver at least 20 times, resulting in a large radiation dose. We developed and validated a simplified model of tumor blood supply that can be applied to standard triphasic scans and evaluated whether this can be used to distinguish benign and malignant liver lesions. Triphasic CTs of 46 malignant and 32 benign liver lesions were analyzed. For each phase, regions of interest were drawn in the arterially enhancing portion of each lesion, as well as the background liver, aorta, and portal vein. Hepatic artery and portal vein blood supply coefficients for each lesion were then calculated by expressing the enhancement curve of the lesion as a linear combination of the enhancement curves of the aorta and portal vein. Hepatocellular carcinoma (HCC) and hypervascular metastases, on average, both had increased hepatic artery coefficients compared to the background liver. Compared to HCC, benign lesions, on average, had either a greater hepatic artery coefficient (hemangioma) or a greater portal vein coefficient (focal nodular hyperplasia or transient hepatic attenuation difference). Hypervascularity with washout is a key diagnostic criterion for HCC, but it had a sensitivity of 72 % and specificity of 81 % for diagnosing malignancy in our diverse set of liver lesions. The sensitivity for malignancy was increased to 89 % by including enhancing lesions that were hypodense on all phases. The specificity for malignancy was increased to 97 % (p = 0.039) by also examining hepatic artery and portal vein blood supply coefficients, while maintaining a sensitivity of 76 %. PMID:25183580

  11. An efficient approach to study the pulsatile blood flow in femoral and coronary arteries by Differential Quadrature Method

    Science.gov (United States)

    Ghasemi, Seiyed E.; Hatami, M.; Hatami, J.; Sahebi, S. A. R.; Ganji, D. D.

    2016-02-01

    In this paper, flow analysis for a non-Newtonian third grade blood in coronary and femoral arteries is simulated numerically. Blood is considered as the third grade non-Newtonian fluid under periodic body acceleration motion and pulsatile pressure gradient. Differential Quadrature Method (DQM) and Crank Nicholson Method (CNM) are used to solve the Partial Differential Equation (PDE) governing equation by which a good agreement between them was observed in the results. The influences of some physical parameters such as amplitude, lead angle and body acceleration frequency on non-dimensional velocity and profiles are considered. For instance, the results show that increasing the amplitude, Ag, and reducing the lead angle of body acceleration, ϕ, make higher velocity profiles in the center line of both arteries.

  12. Effects of unsteadiness and non-Newtonian rheology on blood flow through a tapered time-variant stenotic artery

    Directory of Open Access Journals (Sweden)

    A. Zaman

    2015-03-01

    Full Text Available A two-dimensional model is used to analyze the unsteady pulsatile flow of blood through a tapered artery with stenosis. The rheology of the flowing blood is captured by the constitutive equation of Carreau model. The geometry of the time-variant stenosis has been used to carry out the present analysis. The flow equations are set up under the assumption that the lumen radius is sufficiently smaller than the wavelength of the pulsatile pressure wave. A radial coordinate transformation is employed to immobilize the effect of the vessel wall. The resulting partial differential equations along with the boundary and initial conditions are solved using finite difference method. The dimensionless radial and axial velocity, volumetric flow rate, resistance impedance and wall shear stress are analyzed for normal and diseased artery with particular focus on variation of these quantities with non-Newtonian parameters.

  13. The postural reduction in middle cerebral artery blood velocity is not explained by PaCO2

    DEFF Research Database (Denmark)

    Immink, R V; Secher, N H; Roos, C M;

    2006-01-01

    In the normocapnic range, middle cerebral artery mean velocity (MCA Vmean) changes approximately 3.5% per mmHg carbon-dioxide tension in arterial blood (PaCO2) and a decrease in PaCO2 will reduce the cerebral blood flow by vasoconstriction (the CO2 reactivity of the brain). When standing up MCA...... Vmean and the end-tidal carbon-dioxide tension (PETCO2) decrease, suggesting that PaCO2 contributes to the reduction in MCA Vmean. In a fixed body position, PETCO2 tracks changes in the PaCO2 but when assuming the upright position, cardiac output (Q) decreases and its distribution over the lung changes...

  14. Synthetic reconstruction of dynamic blood flow in cortical arteries using optical coherence tomography for the evaluation of vessel compliance

    Science.gov (United States)

    Baraghis, Edward; Bolduc, Virginie; Gillis, Marc-Antoine; Srinivasan, Vivek J.; Thorin, Éric; Boudoux, Caroline; Lesage, Frédéric

    2011-03-01

    Optical Coherence Tomography (OCT) has recently been used to produce 3D angiography of microvasculature in the rodent brain in-vivo and blood flow maps of large vessels. Key enabling developments were novel algorithms for detecting Doppler shifts produced by moving scatterers and new scanning protocols tailored to increase sensitivity to small flow speeds. These progresses were pushed by the need for a non invasive imaging modality to monitor quantitative blood flow at a higher resolution and a greater depth than could be achieved by other means. The rationale for this work originates from new hypotheses regarding the role of blood regulation in neurodegenerative diseases and from current investigations of animal models of vascular degeneration. In this work we demonstrate the synthetic reconstruction of dynamic blood flow in mice over the course of a single cardiac cycle in an 800μm wide by ~ 3mm deep B-Frame slice with a lateral resolution of 10μm and a depth resolution of 7μm. Images were taken using a cranial window over the exposed parietal bone of mice skull. Electrocardiography (ECG) recordings were co registered with the OCT A lines at high temporal resolution. QRS peak detection was then used to locate the time value of each A-line in the cardiac cycle and to reconstruct a synthetic temporal frame over one cardiac cycle. Doppler speed in this cardiac cycle was used to measure temporal variations of flow inside arteries and of their area. Three dimensional volume scans yielded measurements of quantitative blood flow on the same arteries. Using these informations a measure of compliance could be established. Comparing measures between atherosclerotic (ATX) and wild type (WT) mice revealed higher blood flow in WT mice, suggested lower systemic compliance in the ATX group but higher compliance of cerebral vasculature on these mice. These results are consistent with expectations showing that OCT is a potential tool for in-vivo arterial compliance evaluation.

  15. Stratification of Ambulatory Blood Pressure Monitoring Findings by Cluster Analysis in Patients with Arterial Hypertension, Obesity and Albuminuria

    OpenAIRE

    Samoyavcheva S.V.; Shkarin Vl.V.

    2013-01-01

    The aim of the investigation was to study the characteristics of ambulatory blood pressure monitoring (ABPM) indices in the combination of arterial hypertension (AH) with obesity and albuminuria using cluster analysis. Material and Methods. The study involved 70 AH patients randomly chosen, aged from 23 to 71 years (mean age — 47.9 years). ABPM was performed before antihypertensive therapy administration. We estimated body mass index and albuminuria level. ABPM indices were stratified int...

  16. Improving Cerebral Blood Flow Quantification for Arterial Spin Labeled Perfusion MRI by Removing Residual Motion Artifacts and Global Signal Fluctuations

    OpenAIRE

    Wang, Ze

    2012-01-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion MRI due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whol...

  17. Comparison of Neonatal Arterial Blood Oxygen Saturation Rate Immediately After Birth in Normal and Elective Cesarean Delivery

    OpenAIRE

    Mahmoodi Fatemeh; Mobaraki Asieh; Mahmoodi Zainab; Najar Shahnaz; Haghighi Mohammad hosein; Borzoueisileh Sajad; Ebrahimpour Soheil

    2016-01-01

    Objective: Ninety percent of neonates pass the transition from fetal life to outside uterus successfully, and only 1% needs intensive support for survival. The quantity of oxygen saturation immediately after birth shows the need for resuscitation immediately after birth. The present research was carried out with the objective of comparing saturation rate of arterial blood hypoxia in neonates born with normal vaginal delivery and cesarean method. Materials and Methods: 220 neonates bo...

  18. The effect of intra-arterial endothelin on resting blood flow and sympathetically mediated vasoconstriction in the forearm of man.

    OpenAIRE

    Cockcroft, J R; Clarke, J G; Webb, D. J.

    1991-01-01

    1. The hypothesis that endothelin (ET) influences sympathetically mediated vasoconstriction was investigated in 13 healthy, male subjects. 2. ET (1 pmol min-1) was infused for 60 min into the left brachial arteries of seven healthy male subjects. Resting forearm blood flow, and sympathetic vasoconstriction produced by lower body negative pressure (LBNP; 15 mm Hg), was measured in both arms by strain gauge plethysmography. In a further six subjects, noradrenaline (NA) was infused intra-arteria...

  19. Dynamic Contrast-Enhanced MRI Assessment of Hyperemic Fractional Microvascular Blood Plasma Volume in Peripheral Arterial Disease: Initial Findings

    OpenAIRE

    Bas Versluis; Marjolein H G Dremmen; Nelemans, Patty J; Wildberger, Joachim E.; Geert-Willem Schurink; Tim Leiner; Walter H Backes

    2012-01-01

    OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) to assess the microvascular status in patients with peripheral arterial disease (PAD) and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METH...

  20. Management of initial orthostatic hypotension: lower body muscle tensing attenuates the transient arterial blood pressure decrease upon standing from squatting

    OpenAIRE

    Go-Schön, Ingeborg K.; Kim, Yu-Sok; Linzer, Mark; van Lieshout, Johannes J.; Wieling, Wouter; Krediet, C. T. Paul

    2007-01-01

    Abstract Initial orthostatic hypotension (IOH) comprises symptoms of cerebral hypoperfusion caused by an abnormally large transient mean arterial blood pressure (MAP) decrease 5-15 s after arising from a supine, sitting or squatting position. Few treatment options are available. We set out to test the hypothesis that lower body muscle tensing (LBMT) attenuates IOH after rising from squatting and its symptoms in daily life. Thirteen IOH patients (9 males, 27 years) rose twice from s...

  1. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Bronzwaer, Anne-Sophie G. T.; Stok, Wim J.; Westerhof, Berend E.; Johannes J. van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI a...

  2. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Anne-SophieG.T.Bronzwaer; WimJ.Stok; BerendE.Westerhof; JohannesJ.Van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI ...

  3. Measurement of cerebral blood flow the blood sampling method using {sup 99m}Tc-ECD. Simultaneous scintigram scanning of arterial blood samples and the brain with a gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Hachiya, Takenori; Inugami, Atsushi [Rehabilitation Center for Physically Disabled Persons and Medical Center for Mental Health-Akita, Kyowa (Japan); Iida, Hidehiro; Mizuta, Yoshihiko; Kawakami, Takeshi; Inoue, Minoru

    1999-01-01

    To measure regional cerebral blood flow (rCBF) by blood sampling using {sup 99m}Tc-ECD we devised a method of measuring the radioactive concentration in arterial blood sample with a gamma camera. In this method the head and a blood sample are placed within the same visual field to record the SPECT data of both specimens simultaneously. The results of an evaluation of the counting rate performance, applying the 30 hours decaying method using {sup 99m}Tc solution showed that this method is not comparable to the well-type scintillation counter and in clinical cases the active concentration in arterial blood sample remained well within the dynamic range. In addition, examination of the influence of scattered radiation from the brain by the dilution method showed that it was negligible at a distance of more than 7.5 cm between the brain and the arterial blood sample. In the present study we placed a head-shaped phantom next to the sample. The results of the examinations suggested that this method is suitable for clinical application, and because it does not require a well-type scintillation counter, it is expected to find wide application. (author)

  4. A RETROSPECTIVE STUDY OF THE IMPACT OF MEAN ARTERIAL PRESSURE ON ESTIMATED BLOOD LOSS DURING ENDOSCOPIC SINUS SURGERY

    Directory of Open Access Journals (Sweden)

    George W Williams

    2014-10-01

    Full Text Available The current practice of lowering mean arterial pressure (MAP during endoscopic sinus surgery (ESS is common, but unproven with regard to peer reviewed literature. The controlled hypotension induced is aimed for improved surgical field and lower the blood loss. Lower mean arterial pressures especially for prolonged surgeries may result in end organ hypoperfusion. The authors reviewed all patients who underwent outpatient endoscopic sinus surgery for the diagnosis of chronic sinusitis from January 1, 2012 to December 31, 2012 at Memorial Hermann Hospital – Texas Medical Centre. We individually reviewed case sheets of every patient and documented blood loss as recorded on the anaesthesia record or in the surgical procedure note, among other variables. A total of 326 patients were included in this study. The median estimated blood loss (EBL was found to be 50 ml. The multivariate regression analysis between these three groups showed that EBL was higher in MAP 75 group. The average of EBL in MAP75 group and the average of EBL in MAP 65-70 group is 42% higher than that in MAP>75 group when other variables were fixed. Hence we found the trend toward higher blood loss with lower MAP. The authors conclude that lower MAP does not result in lower EBL in endoscopic sinus surgery. Furthermore, increases in BMI and crystalloid administered during an aesthetic management of these cases correlates with increased estimate blood loss.

  5. Evaluation of accuracy of invasive and non-invasive blood pressure monitoring in relation to carotid artery pressure in anaesthetised ponies

    OpenAIRE

    Gent, Thomas C; Schwarz, Andrea; Hatz, Lea-Annina; Gozalo-Marcilla, Miguel; Stijn, Schauvliege; Gasthuys, Frank; Bettschart-Wolfensberger, Regula

    2015-01-01

    Invasive blood pressure measurement (IBP) using peripheral arteries is a commonly used technique in equine anaesthesia, although the accuracy has not been demonstrated. Non-invasive blood pressure monitoring (NIBP) may be indicated for field anesthesia, short procedures and foal anaesthesia. In the present report, the agreement of various IBP and NIBP measuring sites compared to carotid artery pressure was tested in anaesthetised experimental ponies. Six ponies were anaesthetised in lateral r...

  6. Cerebral blood flow volume measurements of the carotid artery and ipsilateral branches using two-dimensional phase-contrast magnetic resonance angiography

    Institute of Scientific and Technical Information of China (English)

    Gang Guo; Yonggui Yang; Weiqun Yang

    2011-01-01

    The optimal velocity encoding of phase-contrast magnetic resonance angiography (PC MRA) in measuring cerebral blood flow volume (BFV) ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional (2D) PC MRA, the present study localized the region of interest at blood vessels of the neck using PC MRA based on three-dimensional time-of-flight sequences, and the velocity encodingwas set to 80 cm/s. Results of the measurements showed that the error rate was 7.0 ± 6.0%in the estimation of BFV in the internal carotid artery, the external carotid artery and the ipsilateralcommon carotid artery. There was no significant difference, and a significant correlation in BFV between internal carotid artery + external carotid artery and ipsilateral common carotid artery. Inaddition, the BFV of the common carotid artery was correlated with that of the ipsilateral internal carotid artery. The main error was attributed to the external carotid artery and its branches. Therefore,after selecting the appropriate scanning parameters and protocols, 2D PC MRA is more accuratein the determination of BFV in the carotid arteries.

  7. Hepatocellular Carcinoma with Blood Supply from Parasitized Omental Artery: Angiographic Appearance And Chemoembolization

    Institute of Scientific and Technical Information of China (English)

    Song Gao; Ren-jie Yang; Jia-hong Dong

    2012-01-01

    Objective:To analyze angiographic appearance of hepatocellular carcinoma (HCC) with blood supply from parasitized omental artery (POA),and evaluate the technical feasibility,safety and therapeutic efficacy of chemoembolization via the POAs.Methods:A total of 1,221 HCC patients who had undergone chemoembolization procedures were evaluated retrospectively.The evaluated indexes included the incidence rate of POAs,success rate of superselective catheterization,post-reaction after chemoembolization,and the cumulative survival rates.Results:Totally 1,221 HCC patients had undergone 3,639 chemoembolization procedures,and 32 patients with POAs were enrolled,with 97 POAs found in 76 angiography procedures,giving an incidence rate of 2.09%.POA was observed mostly at the right lobe and left medial lobe except the segment Ⅱ,and 62 POAs underwent superselective catheterization with microcatheter,giving a success rate of 63.9%.The angiographic appearance was:(1) hypertrophic POAs participating in tumor staining (n=28); (2) stiff and distorted POA (n=11),displaced due to tumor's oppression (n=8); and (3) defective tumor staining close to either gastrocolic omentum distribution or liver capsule (n=7).In 19 patients,chemoembolization via POAs was performed successfully (A group),while the remaining 13 patients failed (B group).Except 1 acute edema pancreatitis case,no serious complication was recorded.The cumulative survival rates of 6-,12-,18-and 24-month were 78.9%,47.4%,31.6% and 21.1% respectively for A group; correspondingly,61.5%,30.g%,15.4% and 7.7%% for B group,in which 2 patients died of ruptured HCC.Conclusion:Chemoembolization with microcatheter via POAs is a relatively safe,feasible and valuable method.

  8. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Directory of Open Access Journals (Sweden)

    Jared C Weddell

    Full Text Available Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model.

  9. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Science.gov (United States)

    Weddell, Jared C; Kwack, JaeHyuk; Imoukhuede, P I; Masud, Arif

    2015-01-01

    Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF) constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS) is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model. PMID:25897758

  10. Failure of controlling massive hemoptysis in bronchiectasis through BAE due to aberration blood supply from inferior phrenic arteries

    International Nuclear Information System (INIS)

    Objective: To describe the manifestations of the inferior phrenic arterial (IPA) blood supply in hemoptysis of bronchiectasis and to evaluate the safety and efficacy of transcatheter arterial embolization (TAE)of the IPA. Methods: During the past 5 years, 62 patients with hemoptysis due to bronchiectasis underwent BAE including 10 with additional blood supply from IPA. Mean patient age was 42.5 years (range, 26-58 years). Supplemental TAE using gelatin sponge particles and microcoils was undertaken in IPA supplying cases. The imaging findings of the IPA angiography, the predictive factors, the technique and clinical significance including safety of IPA embolization, were evaluated. Results: Selective arteriogram demonstrated enlargement of IPA, with numerous branches and neovasculature in all 10 cases, including contrast material extravasation in 4, and non-specific staining in 6 cases. In addition, there were IPA-to- pulmonary shunting in 8 cases, adjacent to the pleurae involving diaphragmatic and mediastinal pleura in 6 and only mediastinal pleura in 4. Technical success of IPA embolization was achieved in all 10 cases. Embolization of other nonbronchial systemic arteries (the internal thoracic artery in 4 and intercostal artery in 2)were performed at the same session. All bleedings ceased immediately after supplemental IPA embolization. Follow- up ranged from 8 months to 3 years, including mild recurrent hemoptysis in 2 patients at 2, 3 months respectively, but responsible to conservative management and no recurrent bleeding in 8 patients. Conclusion: Bronchiectatic hemoptysis may be further supplied by IPA, resulting in clinical failure of BAE and supplemental TAE of IPA is a safe and effective adjunct to BAE in the management. (authors)

  11. MR blood velocity measurements in the pulmonary arteries with magnetic resonance imaging. Messung der Blutflussgeschwindigkeit in den Pulmonalarterien mit Hilfe der Magnetresonanztechnik

    Energy Technology Data Exchange (ETDEWEB)

    Gamroth, A.H.; Wacker, C.M.; Knopp, M.V.; Betsch, B.; Clorius, J.H.; Kaick, G. van (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. fuer Onkologische Diagnostik und Therapie); Schad, L.R. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. fuer Biophysik und Medizinische Strahlenphysik); Gehling, U. (Thoraxklinik Heidelberg (Germany). Innere Medizin-Pneumologie)

    1992-04-01

    MR blood velocity measurements were performed by the RACE technique in a plane perpendicular to the flow of the pulmonary arteries. MR findings were correlated with those of perfusion scintigraphy, Doppler US and right heart catheter (thermodilution). The ratio of MR blood flow measurements of right and left pulmonary arteries correlated well with the results of perfusion scintigraphy (RPA to LPA) and Doppler. Poor correlation was found when comparing MR blood flow measurements with right heart catheter since absolute flow measurements can be superimposed by neighboring blood vessels in complex anatomic situations. (orig.).

  12. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus: auto-downregulation of pulmonary arterial blood supply.

    Science.gov (United States)

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V/Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially documented case of hypoxia-induced pulmonary vasoconstriction and flow shift in a main pulmonary artery due to a complete intrinsic obstruction of the ipsilateral main bronchus. The condition is reversible, contingent on being relieved within a few days. PMID:26374773

  13. Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

    Science.gov (United States)

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

    In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. PMID:27245647

  14. Body Weight and Not Exercise Capacity Determines Central Systolic Blood Pressure, a Surrogate for Arterial Stiffness, in Children and Adolescents.

    Science.gov (United States)

    Müller, Jan; Meyer, Joanna; Elmenhorst, Julia; Oberhoffer, Renate

    2016-08-01

    Cardiopulmonary fitness benefits cardiovascular health. Various studies have shown a strong negative correlation between exercise capacity and arterial stiffness in adults. However, evidence for this connection in children and adolescents is scarce. About 320 healthy children and adolescents (252 male, 14.0±2.1 years) were evaluated with regard to their demographic, anthropometric and hemodynamic parameters, and their peak oxygen uptake. Peripheral and central systolic blood pressures were measured with patients in a supine position using an oscillometric device. Peak oxygen uptake was assessed by cardiopulmonary exercise testing. In multivariate regression, only peripheral systolic blood pressure (β=0.653, P<.001) and body weight (β=0.284, P<.001) emerged as independent determinants for central systolic blood pressure. Body weight therefore determines central systolic blood pressure in children and adolescents rather than measures of cardiorespiratory fitness. The prevention of overweight in childhood is necessary to reduce stiffening of the arteries and delay the onset of cardiovascular disease. PMID:26689169

  15. Blood flow parameters of the superior mesenteric artery as an early predictor of intestinal dysmotility in preterm infants

    Energy Technology Data Exchange (ETDEWEB)

    Robel-Tillig, Eva; Knuepfer, Matthias; Pulzer, Ferdinand; Vogtmann, Christoph [University of Leipzig, Department of Neonatology, Children' s Hospital, Leipzig (Germany)

    2004-12-01

    Blood flow parameters in the superior mesenteric artery (SMA) change with vasoconstriction or vasodilatation of the intestinal vascular bed. In cases of severe growth retardation as a result of haemodynamic disturbances, the blood flow changes persist into postnatal life. To assess early changes of Doppler sonographic blood flow parameters in the SMA for prediction of later intestinal motility disturbances in preterm infants and tolerance of enteral feeding during the first week of life. Doppler sonographic blood flow parameters in the SMA were measured on the first day of life and the following 5 days in 478 neonates with a birth weight below 1,500 g. According to the Doppler results, the neonates were divided into two groups - those with pathological parameters and those with normal blood flow parameters. Correlations between blood flow parameters, the development of intestinal dysmotility and the tolerated amount of enteral feeding were calculated. Pathological blood flow parameters were observed in 148 neonates (group 1) and normal blood flow parameters in 330 neonates (group 2). Intestinal motility disturbance occurred in 125 neonates (83%) of group 1 and 47 neonates (15%) of group 2. Neonates in group 2 tolerated significantly more feed by the fifth day of life than neonates in group 1. Postnatal adaptation did not differ between the two groups, although the majority of neonates with intestinal dysmotility were small for gestational age. The predictive value of blood flow parameters for prediction of intestinal motility revealed high sensitivity and specificity by the first postnatal day, 2 or 3 days before development of clinical signs of intestinal dysmotility. There was a strong negative correlation between pathological pulsatility index on day 1 and the quantity of tolerated enteral feeding on day 5. Pathological blood flow parameters in the SMA can predict problems of intestinal motility and tolerance of enteral feeding. With the early detection of these

  16. Blood flow parameters of the superior mesenteric artery as an early predictor of intestinal dysmotility in preterm infants

    International Nuclear Information System (INIS)

    Blood flow parameters in the superior mesenteric artery (SMA) change with vasoconstriction or vasodilatation of the intestinal vascular bed. In cases of severe growth retardation as a result of haemodynamic disturbances, the blood flow changes persist into postnatal life. To assess early changes of Doppler sonographic blood flow parameters in the SMA for prediction of later intestinal motility disturbances in preterm infants and tolerance of enteral feeding during the first week of life. Doppler sonographic blood flow parameters in the SMA were measured on the first day of life and the following 5 days in 478 neonates with a birth weight below 1,500 g. According to the Doppler results, the neonates were divided into two groups - those with pathological parameters and those with normal blood flow parameters. Correlations between blood flow parameters, the development of intestinal dysmotility and the tolerated amount of enteral feeding were calculated. Pathological blood flow parameters were observed in 148 neonates (group 1) and normal blood flow parameters in 330 neonates (group 2). Intestinal motility disturbance occurred in 125 neonates (83%) of group 1 and 47 neonates (15%) of group 2. Neonates in group 2 tolerated significantly more feed by the fifth day of life than neonates in group 1. Postnatal adaptation did not differ between the two groups, although the majority of neonates with intestinal dysmotility were small for gestational age. The predictive value of blood flow parameters for prediction of intestinal motility revealed high sensitivity and specificity by the first postnatal day, 2 or 3 days before development of clinical signs of intestinal dysmotility. There was a strong negative correlation between pathological pulsatility index on day 1 and the quantity of tolerated enteral feeding on day 5. Pathological blood flow parameters in the SMA can predict problems of intestinal motility and tolerance of enteral feeding. With the early detection of these

  17. Evaluation of adjusted central venous blood gases versus arterial blood gases of patients in post-operative paediatric cardiac surgical intensive care unit

    Directory of Open Access Journals (Sweden)

    Naveen G Singh

    2015-01-01

    Full Text Available Background and Aims: Central venous catheters are in situ in most of the intensive care unit (ICU patients, which may be an alternative for determining acid-base status and can reduce complications from prolonged arterial cannulation. The aim of this study was to examine the reliability between adjusted central venous blood gas (aVBG and arterial blood gas (ABG samples for pH, partial pressure of carbon-di-oxide (pCO2, bicarbonate (HCO3−, base excess (BE and lactates in paediatric cardiac surgical ICU. Methods: We applied blood gas adjustment rule, that is aVBG pH = venous blood gas (VBG pH +0.05, aVBG CO2 = VBG pCO2 - 5 mm Hg from the prior studies. In this study, we validated this relationship with simultaneous arterial and central venous blood obtained from 30 patients with four blood sample pairs each in paediatric cardiac surgical ICU patients. Results: There was a strong correlation (R i.e., Pearson's correlation between ABG and aVBG for pH = 0.9544, pCO2 = 0.8738, lactate = 0.9741, HCO3− = 0.9650 and BE = 0.9778. Intraclass correlation co-efficients (ICCs for agreement improved after applying the adjustment rule to venous pH (0.7505 to 0.9454 and pCO2 (0.4354 to 0.741. Bland Altman showed bias (and limits of agreement for pH: 0.008 (−0.04 to + 0.057, pCO2: −3.52 (–9.68 to +2.65, lactate: −0.10 (−0.51 to +0.30, HCO3−: −2.3 (–5.11 to +0.50 and BE: −0.80 (−3.09 to +1.49. Conclusion: ABG and aVBG samples showed strong correlation, acceptable mean differences and improved agreement (high ICC after adjusting the VBG. Hence, it can be promising to use trend values of VBG instead of ABG in conjunction with a correction factor under stable haemodynamic conditions.

  18. Diets rich in conjugated linoleic acid and vaccenic acid have no effect on blood pressure and isobaric arterial elasticity in healthy young men

    DEFF Research Database (Denmark)

    Raff, M.; Tholstrup, T.; Sejrsen, K.;

    2006-01-01

    The objective of this study was to examine the effect on blood pressure (BP) and isobaric arterial elasticity (AE), as a measure of arterial health, of a commercial mixture of conjugated linoleic acids (CLA) and of milk fat produced through livestock feeding to have a high content of vaccenic acid...... test diets did not differ on any outcome variable: e.g., systolic- and diastolic blood pressure (SBP and DBP), pulse pressure (PP), isobaric arterial compliance (AC), distensibility (AD), or volume (AV). In conclusion, diets rich in milk fat and either CLA or VA have no effect on BP or AE indices in...

  19. Noninvasive tracking of systolic arterial blood pressure using pulse transit time measured with ECG and carotid doppler signals with intermittent calibration

    OpenAIRE

    Fujita, Yoshihisa

    2016-01-01

    We have developed a non-invasive blood pressure measurement system using pulse transit time (PTT) from the heart to the common carotid artery, measured by using an electrocardiogram (ECG) R-wave and carotid arterial Doppler signals at the anterior neck. In this study, we examined the validity of our system by comparing PTT derived systolic blood pressure (Dopp_SBP) with invasive radial systolic arterial pressure (Inv_SBP) with calibration every 15 min in the ICU setting.Methods: 17 patients u...

  20. NUMERICAL ANALYSIS OF THE NON-NEWTONIAN BLOOD FLOW IN THE NON-PLANAR ARTERY WITH BIFURCATION

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie; LU Xi-yun; ZHUANG Li-xian; WANG Wen

    2004-01-01

    A numerical analysis of non-Newtonian fluid flow in non-planar artery with bifurcation was performed by using a finite element method to solve the three-dimensional Navier-Stokes equations coupled with the non-Newtonian constitutive models, including Carreau,Cross and Bingham models. The objective of this study is to investigate the effects of the non-Newtonian properties of blood as well as curvature and out-of-plane geometry in the non-planar daughter vessels on the velocity distribution and wall shear stress. The results of this study support the view that the non-planarity of blood vessels and the non-Newtonian properties of blood are of important in hemodynamics and play a significant role in vascular biology and pathophysiology.

  1. Modeling of the blood flow in the lower extremities for dynamic diffuse optical tomography of peripheral artery disease

    Science.gov (United States)

    Marone, A.; Hoi, J. W.; Khalil, M. A.; Kim, H. K.; Shrikhande, G.; Dayal, R.; Hielscher, A. H.

    2015-07-01

    Peripheral Arterial Disease (PAD) is caused by a reduction of the internal diameters of the arteries in the upper or lower extremities mainly due to atherosclerosis. If not treated, its worsening may led to a complete occlusion, causing the death of the cells lacking proper blood supply, followed by gangrene that may require chirurgical amputation. We have recently performed a clinical study in which good sensitivities and specificities were achieved with dynamic diffuse optical tomography. To gain a better understanding of the physiological foundations of many of the observed effects, we started to develop a mathematical model for PAD. The model presented in this work is based on a multi-compartment Windkessel model, where the vasculature in the leg and foot is represented by resistors and capacitors, the blood pressure with a voltage drop, and the blood flow with a current. Unlike existing models, the dynamics induced by a thigh-pressure-cuff inflation and deflation during the measurements are taken into consideration. This is achieved by dynamically varying the resistances of the large veins and arteries. By including the effects of the thigh-pressure cuff, we were able to explain many of the effects observed during our dynamic DOT measurements, including the hemodynamics of oxy- and deoxy-hemoglobin concentration changes. The model was implemented in MATLAB and the simulations were normalized and compared with the blood perfusion obtained from healthy, PAD and diabetic patients. Our preliminary results show that in unhealthy patients the total system resistance is sensibly higher than in healthy patients.

  2. Suspension model for blood flow through a catheterized arterial stenosis with peripheral layer of plasma free from cells

    Science.gov (United States)

    Ponalagusamy, R.

    2016-06-01

    The present article describes the blood flow in a catheterized artery with radially symmetric and axially asymmetric stenosis. To understand the effects of red cell concentration, plasma layer thickness and catheter size simultaneously, blood is considered by a two-layered model comprising a core region of suspension of all the erythrocytes (particles) supposed to be a particle-fluid mixture and a peripheral zone of cell-free plasma. The analytical expressions for flow features, such as fluid phase and particle phase velocities, flow rate, wall shear stress and resistive force are obtained. It is witnessed that the presence of the catheter causes a substantial increase in the frictional forces on the walls of arterial stenosis and catheter, shear stress and flow resistance, in addition to that, have occurred due to the presence of red cells concentration (volume fraction density of the particles) and the absence of peripheral plasma layer near the wall of the stenosed artery. The introduction of an axially asymmetric nature of stenosis and plasma layer thickness causes significant reduction in flow resistance. One can notice that the two-phase fluid (suspension model) is more profound to the thickness of peripheral plasma layer and catheter than the single-phase fluid.

  3. A novel photoplethysmography technique to derive normalized arterial stiffness as a blood pressure independent measure in the finger vascular bed

    International Nuclear Information System (INIS)

    Stiffening of the small artery may be the earliest sign of arteriosclerosis. However, there is no adequate method for directly assessing small arterial stiffness. In this study, the finger arterial elasticity index (FEI) was defined as the parameter n which denotes the curvilinearity of an exponential model of pressure (P)–volume (Va) relationship (Va = a − b exp (−nP)). For the original estimation, the FEI was calculated from a compliance index from the finger photoplethysmogram whilst occluding the finger. A simple estimation of the FEI was devised by utilizing normalized pulse volume instead of the compliance index. Both estimations yielded close agreement with the exponential model in healthy young participants (study 1: n = 19). Since the FEI was dependent on finger mean blood pressure, normalized finger arterial stiffness index (FSI) was defined as standardized residual from their relationship: mean and standard deviation (SD) of the FSI were 50 ± 10 (study 2: n = 174). The mean coefficient of variation of the FSI for four measurements was 5.72% (study 3: n = 6). The mean and SD of the FSI in seven arteriosclerotic patients were 100.0 ± 13.5. In conclusion, the FEI and FSI by simple estimation are valid and useful for arteriosclerosis research

  4. Evaluation of the Effects of Sildenafil Citrate (Viagra) on Vertebral Artery Blood Flow in Patients with Vertebro-Basilar Insufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Bozgeyik, Zulkif; Berilgen, Sait; Ozdemir, Huseyin; Ogur, Erkin [Firat University School of Medicine, Elazig(Turkmenistan); Tekatas, Aslan [Elazig Government Hospital, Elazig (Turkmenistan)

    2008-12-15

    To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 +- 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm{sup 2} to 10.80 cm{sup 2} at 45 minutes and 10.81 cm{sup 2} at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs

  5. Evaluation of the Effects of Sildenafil Citrate (Viagra) on Vertebral Artery Blood Flow in Patients with Vertebro-Basilar Insufficiency

    International Nuclear Information System (INIS)

    To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 ± 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm2 to 10.80 cm2 at 45 minutes and 10.81 cm2 at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs

  6. Muscle size and arterial stiffness after blood flow-restricted low-intensity resistance training in older adults.

    Science.gov (United States)

    Yasuda, T; Fukumura, K; Fukuda, T; Uchida, Y; Iida, H; Meguro, M; Sato, Y; Yamasoba, T; Nakajima, T

    2014-10-01

    Previous studies have shown that blood flow-restricted low-intensity resistance training (BFR-RT) causes muscle hypertrophy while maintaining arterial function in young adults. We examined the effects of BFR-RT on muscle size and arterial stiffness in older adults. Healthy subjects (ages 61-84 years) were divided into BFR-RT (n = 9) or non-training control (CON; n = 10) groups. The BFR-RT group performed 20% and 30%, respectively, of one-repetition maximal (1-RM) knee extension and leg press exercises, 2 days/wk for 12 weeks. The BFR-RT group wore elastic cuffs (120-270 mmHg) on both legs during training. Magnetic resonance imaging-measured muscle cross-sectional area (CSA), 1-RM strength, chair stand (CS) test, and cardio-ankle vascular index testing (CAVI), an index of arterial stiffness, were measured before and 3-5 days after the final training session. Muscle CSA of the quadriceps (8.0%), adductors (6.5%), and gluteus maximus (4.4%), leg extension and leg press 1-RM strength (26.1% and 33.4%), and CS performance (18.3%) improved (P testing, there were no changes in both two groups. In conclusion, BFR-RT improves muscle CSA as well as maximal muscle strength, but does not negatively affect arterial stiffness or humeral coagulation factors in older adults. PMID:23730848

  7. Features of cerebral blood flow, cardiac arrhythmias and conduction disturbances in patients with essential hypertension stage II associated with occlusive and stenotic lesions of brachiocephalic arteries

    Directory of Open Access Journals (Sweden)

    Vizir V.A.

    2015-09-01

    Full Text Available Arterial hypertension is the most common disease of the cardiovascular system in industrially advanced countries. With the aim to determine the characteristics of cerebral blood flow, disorders of cardiac rhythm and conduction in patients with stage 2 hypertension associated with stenotic and occlusive lesions of brachiocephalic arteries, cerebral blood flow indicators were studied in 87 patients using duplex scanning of extracranial arteries and Holter ECG monitoring. It was established that linear blood flow velocity was considerably decreased in the basins of the internal and common carotid artery; cerebral blood flow asymmetry was present in the course of the internal carotid artery. Evidence-based differences in structure of arrhythmias were revealed by single and paired ventricular extrasystoles, as well as episodes of unstable ventricular tachycardia. All this indicates the progressive decrease of elasticity and tonicity of vessel walls, intensified rigidity and sinuosity of carotid arteries, more severe disorders of cardiac rhythm and conduction in case of simultaneous hypertension and atherosclerotic lesion of brachiocephalic arteries.

  8. Outflow boundary conditions for 3D simulations of non-periodic blood flow and pressure fields in deformable arteries

    CERN Document Server

    Vignon-Clementel, Irene; Jansen, K E; Taylor, C A; 10.1080/10255840903413565

    2010-01-01

    The simulation of blood flow and pressure in arteries requires outflow boundary conditions that incorporate models of downstream domains. We previously described a coupled multidomain method to couple analytical models of the downstream domains with 3D numerical models of the upstream vasculature. This prior work either included pure resistance boundary conditions or impedance boundary conditions based on assumed periodicity of the solution. However, flow and pressure in arteries are not necessarily periodic in time due to heart rate variability, respiration, complex transitional flow or acute physiological changes. We present herein an approach for prescribing lumped parameter outflow boundary conditions that accommodate transient phenomena. We have applied this method to compute haemodynamic quantities in different physiologically relevant cardiovascular models, including patient-specific examples, to study non-periodic flow phenomena often observed in normal subjects and in patients with acquired or congen...

  9. Mathematical Analysis of Casson Fluid Model for Blood Rheology in Stenosed Narrow Arteries

    Directory of Open Access Journals (Sweden)

    J. Venkatesan

    2013-01-01

    stress, as obtained by Misra and Shit (2006. It is also noticed that the resistance to flow and skin friction increase (when normalized with Newtonian fluid in stenosed artery with the increase of the yield stress.

  10. [PULMONARY COMPLICATIONS IN CHILDREN, OPERATED ON FOR INBORN HEART FAILURES IN THE ARTIFICIAL BLOOD CIRCULATION ENVIRONMENT].

    Science.gov (United States)

    Moshkivska, L V; Nastenko, E A; Golovenko, O S; Lazoryshynets, V V

    2015-11-01

    The risk factors of pulmonary complications occurrence were analyzed in children, operated on for inborn heart failures in atrificial blood circulation environment. Pulmonary complications rate and the risk factors of their occurrence were analyzed. PMID:26939427

  11. Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

    Directory of Open Access Journals (Sweden)

    Shamshad M

    2010-01-01

    Full Text Available Context: Retinal perfusion variability impacts ocular disease and physiology. Aim: To evaluate the response of central retinal artery (CRA blood flow to temperature alterations in 20 healthy volunteers. Setting and Design: Non-interventional experimental human study. Materials and Methods: Baseline data recorded: Ocular surface temperature (OST in °C (thermo-anemometer, CRA peak systolic velocity (PSV and end diastolic velocity (EDV in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling. Statistical Analysis: Repeated measures ANOVA. Results: (n = 20; μ±SD: Pre-warming values were; OST: 34.5±1.02°C, CRA-PSV: 9.3±2.33cm/s, CRA-EDV: 4.6±1.27cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37 after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21cm/s (95% CI: 0.51to1.91. Pre-cooling values were: OST: 34.5±0.96°C, CRA-PSV: 9.7±2.45 cm/s, CRA-EDV: 4.7±1.12cm/s. OST significantly decreased by 2.81°C (95% CI: -2.30 to -3.37 after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: -2.05 to -0.15 and CRA-EDV by 0.81 (95% CI: -1.47 to -0.14 at three minutes. At six minutes both PSV (95% CI: -1.38 to -0.03 and EDV (95% CI: -1.26 to -0.02 were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: -0.17 to 1.57mmHg, but was significantly lower after cooling (95% CI: -2.95 to -4.30mmHg. After ten minutes, IOP had returned to baseline. Conclusion : This study confirms that CRA flow significantly increases on warming and decreases on cooling

  12. Relaxin mediates uterine artery compliance during pregnancy and increases uterine blood flow

    OpenAIRE

    Vodstrcil, Lenka A.; Tare, Marianne; Novak, Jacqueline; Dragomir, Nicoleta; Ramirez, Rolando J.; Wlodek, Mary E.; Conrad, Kirk P.; Parry, Laura J.

    2012-01-01

    Normal pregnancy involves dramatic remodeling of the uterine vasculature, with abnormal vascular adaptations contributing to pregnancy diseases such as preeclampsia. The peptide hormone relaxin is important for the renal and systemic hemodynamic adaptations to pregnancy, and has been shown to increase arterial compliance and outward hypertrophic remodeling. Therefore, we investigated the possibility that relaxin acts on its receptor, RXFP1, to mediate uterine artery compliance in late pregnan...

  13. Benidipine has effects similar to losartan on the central blood pressure and arterial stiffness in mild to moderate essential hypertension

    Institute of Scientific and Technical Information of China (English)

    Sang-Hyun Ihm; Hui-Kyung Jeon; Shung Chull Chae; Do-Sun Lim; Kee-Sik Kim; Dong-Ju Choi; Jong-Won Ha

    2013-01-01

    Background Central blood pressure (BP) is pathophysiologically more important than peripheral BP for the pathogenesis of cardiovascular disease.Arterial stiffness is also a good predictor of cardiovascular morbidity and mortality.The effects of benidipine,a unique dual L-/T-type calcium channel blocker,on central BP have not been reported.This study aimed to compare the effect of benidipine and losartan on the central BP and arterial stiffness in mild to moderate essential hypertensives.Methods This 24 weeks,multi-center,open label,randomized,active drug comparative,parallel group study was designed as a non-inferiority study.The eligible patients (n=200) were randomly assigned to receive benidipine (n=101)or losartan (n=99).Radial artery applanation tonometry and pulse wave analysis were used to measure the central BP,pulse wave velocity (PWV) and augmentation index (Alx).We also measured the metabolic and inflammatory markers.Results After 24 weeks,the central BP decreased significantly from baseline by (16.8+14.0/10.5+9.2) mmHg (1mmHg =0.133 kPa) (systolic/diastolic BP; P <0.001) in benidipine group and (18.9+14.7/12.1+10.2) mmHg (P <0.001)in losartan group respectively.Both benidipine and losartan groups significantly lowered peripheral BP (P <0.001) and Alx (P <0.05),but there were no significant differences between the two groups.The mean aortic,brachial and femoral PWV did not change in both groups after 24-week treatment.There were no significant changes of the blood metabolic and inflammatory biomarkers in each group.Conclusion Benidipine is as effective as losartan in lowering the central and peripheral BP,and improving arterial stiffness.

  14. 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.

  15. Reduced peripheral arterial blood flow with preserved cardiac output during submaximal bicycle exercise in elderly heart failure

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2009-11-01

    Full Text Available Abstract Background Older heart failure (HF patients exhibit exercise intolerance during activities of daily living. We hypothesized that reduced lower extremity blood flow (LBF due to reduced forward cardiac output would contribute to submaximal exercise intolerance in older HF patients. Methods and Results Twelve HF patients both with preserved and reduced left ventricular ejection fraction (LVEF (aged 68 ± 10 years without large (aorta or medium sized (iliac or femoral artery vessel atherosclerosis, and 13 age and gender matched healthy volunteers underwent a sophisticated battery of assessments including a peak exercise oxygen consumption (peak VO2, b physical function, c cardiovascular magnetic resonance (CMR submaximal exercise measures of aortic and femoral arterial blood flow, and d determination of thigh muscle area. Peak VO2 was reduced in HF subjects (14 ± 3 ml/kg/min compared to healthy elderly subjects (20 ± 6 ml/kg/min (p = 0.01. Four-meter walk speed was 1.35 ± 0.24 m/sec in healthy elderly verses 0.98 ± 0.15 m/sec in HF subjects (p p ≤ 0.03. Conclusion During CMR submaximal bike exercise in the elderly with heart failure, mechanisms other than low cardiac output are responsible for reduced lower extremity blood flow.

  16. Magnetic resonance imaging-based computational modelling of blood flow and nanomedicine deposition in patients with peripheral arterial disease.

    Science.gov (United States)

    Hossain, Shaolie S; Zhang, Yongjie; Fu, Xiaoyi; Brunner, Gerd; Singh, Jaykrishna; Hughes, Thomas J R; Shah, Dipan; Decuzzi, Paolo

    2015-05-01

    Peripheral arterial disease (PAD) is generally attributed to the progressive vascular accumulation of lipoproteins and circulating monocytes in the vessel walls leading to the formation of atherosclerotic plaques. This is known to be regulated by the local vascular geometry, haemodynamics and biophysical conditions. Here, an isogeometric analysis framework is proposed to analyse the blood flow and vascular deposition of circulating nanoparticles (NPs) into the superficial femoral artery (SFA) of a PAD patient. The local geometry of the blood vessel and the haemodynamic conditions are derived from magnetic resonance imaging (MRI), performed at baseline and at 24 months post intervention. A dramatic improvement in blood flow dynamics is observed post intervention. A 500% increase in peak flow rate is measured in vivo as a consequence of luminal enlargement. Furthermore, blood flow simulations reveal a 32% drop in the mean oscillatory shear index, indicating reduced disturbed flow post intervention. The same patient information (vascular geometry and blood flow) is used to predict in silico in a simulation of the vascular deposition of systemically injected nanomedicines. NPs, targeted to inflammatory vascular molecules including VCAM-1, E-selectin and ICAM-1, are predicted to preferentially accumulate near the stenosis in the baseline configuration, with VCAM-1 providing the highest accumulation (approx. 1.33 and 1.50 times higher concentration than that of ICAM-1 and E-selectin, respectively). Such selective deposition of NPs within the stenosis could be effectively used for the detection and treatment of plaques forming in the SFA. The presented MRI-based computational protocol can be used to analyse data from clinical trials to explore possible correlations between haemodynamics and disease progression in PAD patients, and potentially predict disease occurrence as well as the outcome of an intervention. PMID:25878124

  17. Blood pressure

    Science.gov (United States)

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  18. Regional changes in cerebral blood flow oxygenation can indicate global changes in cerebral blood flow during coronary artery occlusion in juvenile pigs

    International Nuclear Information System (INIS)

    Near infrared spectroscopy (NIRS) is a widely employed method for assessment of regional cerebral oxygenation (RcStO2). RcStO2 values are expected to vary with changes in the relative amount of oxyhaemoglobin. The present experimental study aimed to assess the response of RcStO2 to controlled alterations of carotid blood flow (CQ). Landrace pigs were anesthetized followed by surgical preparation. Cyclic variations in cardiac output were accomplished by intermittently occluding the main stem of the left coronary artery. A flow measurement probe for assessing CQ was placed around the left carotid artery. One NIRS probe was placed on the left ipsilateral forehead to assess regional cerebral oximetry. Simultaneous registration of CQ and RcStO2 was conducted. There was a strong correlation for variation in CQ and RcStO2 signal values. Based on coherence analysis the fraction of power of the RcStO2 that was coherent with the CQ signal reached 0.84 ± 0.12 (P < 0.05) for frequencies lower than 0.1 Hz. The agreement of the sample-to-sample co-variation, as assessed by the Pearson correlation coefficient, was 0.83 ± 0.08 (P < 0.05). One explanatory component for variations in cerebral oxygenation verified by NIRS should be attributed to variations in the cerebral blood flow. (paper)

  19. Carotid Artery Disease

    Science.gov (United States)

    ... brain with blood. If you have carotid artery disease, the arteries become narrow, usually because of atherosclerosis. ... one of the causes of stroke. Carotid artery disease often does not cause symptoms, but there are ...

  20. The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate

    DEFF Research Database (Denmark)

    Damkjaer, M; Wang, T; Brøndum, E;

    2015-01-01

    adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS: Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective......BACKGROUND: The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary...

  1. Heat stress exacerbates the reduction in middle cerebral artery blood velocity during prolonged self-paced exercise.

    Science.gov (United States)

    Périard, J D; Racinais, S

    2015-06-01

    This study examined the influence of hyperthermia on middle cerebral artery mean blood velocity (MCA Vmean). Eleven cyclists undertook a 750 kJ self-paced time trial in HOT (35 °C) and COOL (20 °C) conditions. Exercise time was longer in HOT (56 min) compared with COOL (49 min; P partial pressure of CO2 (PETCO2 ; P pressure and oxygen uptake were lower from 50% of work completed onward in HOT compared with COOL (P pressure. PMID:25943664

  2. Quantitative measurement of regional myocardial blood flow in patients with coronary artery disease by intravenous injection of 13N-ammonia in positron emission tomography

    International Nuclear Information System (INIS)

    Measurement of myocardial blood flow with 13N-ammonia, a technique previously employed successfully in animal experiments, was introduced into clinical use to study patients with coronary artery disease. This advance has become possible by the development of a high resolution gated scan positron emission tomographic (PET) scanner equipped with a real time decay correction mechanism, HEADTOME-IV. The information obtainable includes myocardial size and wall motion as well as the absolute quantity of blood flow in various myocardial regions. The technique is simple but requires continuous arterial blood withdrawal for calculation of the arterial input function time integral. The alternative to this technique, i.e. the computation of intra left ventricular blood pool activity by PET is also discussed. (orig.)

  3. Blood pressure changes induced by arterial blood withdrawal influence bold signal in anesthesized rats at 7 Tesla: implications for pharmacologic mri.

    Science.gov (United States)

    Kalisch, R; Elbel, G K; Gössl, C; Czisch, M; Auer, D P

    2001-10-01

    Functional magnetic resonance imaging (fMRI) using the blood oxygenation level-dependent (BOLD) contrast is now increasingly applied for measuring drug effects on brain activity. A possible confound in pharmacologic fMRI (phMRI) is that the BOLD signal may be sensitive to systemic cardiovascular or respiratory parameters, which can themselves be modulated by a drug. To assess whether abrupt changes in arterial blood pressure (BP) as may be observed in phMRI experiments influence the BOLD signal, a hemorrhage model was studied in anesthesized rats at 7 T using spin-echo EPI. BP and BOLD signal time courses were found to be significantly correlated (P < 0.01). This effect was detected under the three different anesthetic regimens employed (isoflurane, halothane, and propofol). The regional pattern of BP-BOLD correlations was heterogeneous and may reflect vascular density. In physiological terms, a BOLD decrease during a decrease in BP may result from an increase in mostly venous cerebral blood volume (CBV) as an autoregulatory response to maintain cerebral blood flow (CBF) during decreased perfusion pressure. The observed influence of BP on BOLD may complicate qualitative and quantitative description of drug effects. PMID:11554808

  4. Nanostructural haemocompatible coatings for the internal side of artificial blood vessels

    Science.gov (United States)

    Trembecka-Wojciga, K.; Major, R.; Lackner, J. M.; Butruk-Raszeja, B.; Sanak, M.; Major, B.

    2016-03-01

    The main goal of the work was to elaborate low thrombogenicity of surface inside tube-like elements for cardiovascular system support by combination of low-temperature glow discharge and hydrogel coatings to inhibit blood-clotting cascade activation. A large share of amorphous phase silicon was observed in the microstructure analysis. The crystalline elements were uniformly distributed in the amorphous structure. Combination of low thickness, the proper microstructure and density of the coatings provided a highly flexible nature of the whole system. The blood-material interaction was analyzed in vitro in dynamic conditions by using a designed and fabricated novel blood flow simulator. Coatings deposited by the glow discharge expressed good hemocopatibile properties. The use of hydrogel coatings did not reduce coagulation parameter. Hydrogel coatings did not improve the hemocompatibility of the surface modified with carbon based coatings. Modification of surface with hydrogel resulted in further increased risk of hemolysis.

  5. The Prognostic Role of Red Blood Cell Distribution Width in Coronary Artery Disease: A Review of the Pathophysiology

    Directory of Open Access Journals (Sweden)

    Kamil Bujak

    2015-01-01

    Full Text Available Red blood cell distribution width (RDW is a measure of red blood cell volume variations (anisocytosis and is reported as part of a standard complete blood count. In recent years, numerous studies have noted the importance of RDW as a predictor of poor clinical outcomes in the settings of various diseases, including coronary artery disease (CAD. In this paper, we discuss the prognostic value of RDW in CAD and describe the pathophysiological connection between RDW and acute coronary syndrome. In our opinion, the negative prognostic effects of elevated RDW levels may be attributed to the adverse effects of independent risk factors such as inflammation, oxidative stress, and vitamin D3 and iron deficiency on bone marrow function (erythropoiesis. Elevated RDW values may reflect the intensity of these phenomena and their unfavorable impacts on bone marrow erythropoiesis. Furthermore, decreased red blood cell deformability among patients with higher RDW values impairs blood flow through the microcirculation, resulting in the diminution of oxygen supply at the tissue level, particularly among patients suffering from myocardial infarction treated with urgent revascularization.

  6. Fractals and fractal dimension of systems of blood vessels: An analogy between artery trees, river networks, and urban hierarchies

    CERN Document Server

    Chen, Yanguang

    2015-01-01

    An analogy between the fractal nature of networks of arteries and that of systems of rivers has been drawn in the previous works. However, the deep structure of the hierarchy of blood vessels has not yet been revealed. This paper is devoted to researching the fractals, allometric scaling, and hierarchy of blood vessels. By analogy with Horton-Strahler's laws of river composition, three exponential laws have been put forward. These exponential laws can be reconstructed and transformed into three linear scaling laws, which can be named composition laws of blood vessels network. From these linear scaling laws it follows a set of power laws, including the three-parameter Zipf's law on the rank-size distribution of blood vessel length and the allometric scaling law on the length-diameter relationship of blood vessels in different orders. The models are applied to the observed data on human beings and animals early given by other researchers, and an interesting finding is that human bodies more conform to natural r...

  7. Effect of pregnancy on regional cerebral blood flow

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by 133Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of r-CBF in each region except occipital lobe was significantly higher than that of the post abortion. Arterial blood gas was analyzed after SPECT procedure. Pco2 concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author)

  8. The Effects of Nitric Oxide Donors on Uterine Artery and Sub-endometrial Blood Flow in Patients with Unexplained Recurrent Abortion

    OpenAIRE

    Abdel-Razik, Mohamed; El-Berry, Seham; Mostafa, Ahmed

    2014-01-01

    Background Nitric oxide plays a major role in increasing uterine blood flow during the luteal phase and early pregnancy. This study was done to compare uterine artery and sub-endometrial blood flow indices during the luteal phase between patients with unexplained recurrent abortion and fertile women and also to evaluate the effects of nitric oxide donors on blood flow indices in the abortion group. Methods The study included a control group of 30 primiparae who had normal vaginal delivery and...

  9. C-14-activity incorporation into the protein of fetal organs of guinea pigs with different maternal placental blood flow and fetal arterial O2-saturation

    International Nuclear Information System (INIS)

    In anaesthesised gravid guinea-pigs the dilate, end section of a placental radial artery was connected to the A.carotis via a flow meter and a throttle in order to measure and widely alter the maternal placental blood flow. Blood samples are taken from the fetal A.carotis, the fetal arterial O2-saturation and the Hb-content were determined. By altering the maternal placental blood circulation the fetal arterial O2-concentration can stabilised at various levels. In order to study the protein synthesis, under these conditions one infused 185 kBq C-14-leucine over a period of 3 hours into the jugular vein of the fetus. During infusion the radioactive concentrations in whole plasma and plasma water were measured. After the infusion the radioactive concentrations in the tissue fluid, the intracellular fluid and the acid-insoluble tissue fraction (protein) of the heart, kidenys, liver, the muscles of the upper end lower part of the body, the brain and the placenta were measured. The following deductions were drawn from the findings: The maternal placental blood flow vitally influences the activity incorporation per activity concentration in the plasma water. These findings agree with the hypotheses that the maternal blood circulation has an essential influence on the fetal proteins synthesis and that this influence can be attributed to the connection between placenta connection blood flow and oxygen saturation of fetal arterial blood. (orig.)

  10. Study on blood flow containing nanoparticles through porous arteries in presence of magnetic field using analytical methods

    Science.gov (United States)

    Ghasemi, Seiyed E.; Hatami, M.; Sarokolaie, A. Kalani; Ganji, D. D.

    2015-06-01

    In this paper, flow analysis for a third grade non-Newtonian blood in porous arteries in presence of magnetic field is simulated analytically and numerically. Blood is considered as the third grade non-Newtonian fluid containing nanoparticles. Collocation Method (CM) and Optimal Homotopy Asymptotic Method (OHAM) are used to solve the Partial Differential Equation (PDE) governing equation which a good agreement between them was observed in the results. The influences of the some physical parameters such as Brownian motion parameter, pressure gradient and thermophoresis parameter, etc. on temperature, velocity and nanoparticles concentration profiles are considered. For instance, increasing the thermophoresis parameter (Nt) caused an increase in temperature values in whole domain and an increase in nanoparticles concentration near the inner wall.

  11. Investigating Sodium Nitrite Effect on Blood Nitric Oxide and Histopathologic Changes on Pulmonary Artery in Adult Male Rats

    Directory of Open Access Journals (Sweden)

    F Joibar

    2013-12-01

    Results: The outcome of nitric oxide plasmatic density measurement showed that nitric oxide level in animal ’s blood in 175 mg/kg/day dose recipient group and 350 mg/kg/day dose recipient group increased significantly compared with the control group at the level of P ≤ 0.05. Also thickness of media layer decreased in maximum dose group (350 mg/kg/day dose compared to the control group. Conclusion: Based on the results of different doses of sodium nitrite, the nitric oxide levels in the blood were increased, and the thickness of middle layer of the lung arteries at dose 350 mg of sodium nitrite was reduced.

  12. Soybean oil increases SERCA2a expression and left ventricular contractility in rats without change in arterial blood pressure

    Directory of Open Access Journals (Sweden)

    Vassallo Dalton

    2010-05-01

    Full Text Available Abstract Background Our aim was to evaluate the effects of soybean oil treatment for 15 days on arterial and ventricular pressure, myocardial mechanics and proteins involved in calcium handling. Methods Wistar rats were divided in two groups receiving 100 μL of soybean oil (SB or saline (CT i.m. for 15 days. Ventricular performance was analyzed in male 12-weeks old Wistar rats by measuring left ventricle diastolic and systolic pressure in isolated perfused hearts according to the Langendorff technique. Protein expression was measured by Western blot analysis. Results Systolic and diastolic arterial pressures did not differ between CT and SB rats. However, heart rate was reduced in the SB group. In the perfused hearts, left ventricular isovolumetric systolic pressure was higher in the SB hearts. The inotropic response to extracellular Ca2+ and isoproterenol was higher in the soybean-treated animals than in the control group. Myosin ATPase and Na+-K+ATPase activities, the expression of sarcoplasmic reticulum calcium pump (SERCA2a and sodium calcium exchanger (NCX were increased in the SB group. Although the phosfolamban (PLB expression did not change, its phosphorylation at Ser16 was reduced while the SERCA2a/PLB ratio was increased. Conclusions In summary, soybean treatment for 15 days in rats increases the left ventricular performance without affecting arterial blood pressure. These changes might be associated with an increase in the myosin ATPase activity and SERCA2a expression.

  13. Endovascular internal carotid artery trapping for ruptured blood blister-like aneurysms: long-term results from a single centre

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byong-Cheol [Dongguk University Ilsan Hospital, Department of Neurosurgery, Goyang (Korea, Republic of); Kwon, O-Ki; Oh, Chang Wan; Bang, Jae Seung; Hwang, Gyojun [Seoul National University Bundang Hospital, Department of Neurosurgery, Seongnam, Gyeonggi (Korea, Republic of); Jin, Sung-Chul [Inje University Haeundae Paik Hospital, Department of Neurosurgery, Busan (Korea, Republic of); Park, Hyun [Gyeongsang National University Hospital, Department of Neurosurgery, Gyeongsangnam-do (Korea, Republic of)

    2014-03-15

    Endovascular internal carotid artery (ICA) trapping was performed to treat ruptured blood blister-like aneurysms (BBAs). The aim of this study was to evaluate the procedural risks and long-term follow-up results. The records of 11 consecutive patients with BBAs who underwent endovascular ICA trapping between 2005 and 2010 were reviewed. Clinical outcomes were assessed with modified Rankin Scale (mRS) scores. Endovascular ICA trapping was performed in 11 patients as either the primary treatment (7 patients) or the secondary treatment (4 patients) after the patient underwent other treatments. Three patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass when balloon test occlusion (BTO) revealed inadequate collateral circulation. In the primary ICA trapping group (seven patients), six patients had good outcomes (mRS 0 in five, mRS 1 in one), and one patient had a poor outcome (mRS 6: dead). In the secondary ICA trapping group (four patients), two patients had good outcomes (mRS 0), and two patients had poor outcomes (mRS 4, 5). All ten of the surviving patients were clinically stable during the follow-up period (mean 39 months). A radiological follow-up of nine patients (mean 22 months) demonstrated stable occlusion, with the exception of one reopening of the ICA because of coil migration. Perfusion studies of nine patients (mean: 23 months) demonstrated no perfusion decrease. Endovascular ICA trapping is an effective and durable treatment for BBAs. (orig.)

  14. Endovascular internal carotid artery trapping for ruptured blood blister-like aneurysms: long-term results from a single centre

    International Nuclear Information System (INIS)

    Endovascular internal carotid artery (ICA) trapping was performed to treat ruptured blood blister-like aneurysms (BBAs). The aim of this study was to evaluate the procedural risks and long-term follow-up results. The records of 11 consecutive patients with BBAs who underwent endovascular ICA trapping between 2005 and 2010 were reviewed. Clinical outcomes were assessed with modified Rankin Scale (mRS) scores. Endovascular ICA trapping was performed in 11 patients as either the primary treatment (7 patients) or the secondary treatment (4 patients) after the patient underwent other treatments. Three patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass when balloon test occlusion (BTO) revealed inadequate collateral circulation. In the primary ICA trapping group (seven patients), six patients had good outcomes (mRS 0 in five, mRS 1 in one), and one patient had a poor outcome (mRS 6: dead). In the secondary ICA trapping group (four patients), two patients had good outcomes (mRS 0), and two patients had poor outcomes (mRS 4, 5). All ten of the surviving patients were clinically stable during the follow-up period (mean 39 months). A radiological follow-up of nine patients (mean 22 months) demonstrated stable occlusion, with the exception of one reopening of the ICA because of coil migration. Perfusion studies of nine patients (mean: 23 months) demonstrated no perfusion decrease. Endovascular ICA trapping is an effective and durable treatment for BBAs. (orig.)

  15. Intra-arterial blood pressure response in hypertensive subjects during low- and high-intensity resistance exercise

    Directory of Open Access Journals (Sweden)

    Sandra de Souza Nery

    2010-01-01

    Full Text Available OBJECTIVE: The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses. INTRODUCTION: Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure. METHODS: Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40% of the 1-repetition maximum (1RM with a 45-s rest between sets, and 80% of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol. RESULTS: Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80% (+80±3 vs. +62±2 mmHg, P<0.05 and at 40% of 1RM (+75±3 vs. +67±3 mmHg, P<0.05. In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40% of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives. CONCLUSION: Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.

  16. DOES TRANEXAMIC ACID REDUCE BLOOD LOSS IN OFF-PUMP CORONARY ARTERY BYPASS?

    OpenAIRE

    A. Mehr-Aein; M. Sadeghi M. Madani-Civi

    2006-01-01

    Tranexamic acid is now used on a routine basis for on-pump coronary artery bypass grafting (CABG). We assessed the hemostatic effects of tranexamic acid to decrease bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery (OPCAB). A total of 66 patients were enrolled to elective OPCAB in a double-blind, prospective randomized study. Of these, 33 patients received tranexamic acid (15 mg/kg before the infusion of heparin and 15 mg/kg after pr...

  17. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery.

    Science.gov (United States)

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to the stenotic site in the MCA was measured in 15 patients scheduled for intervention. The relationships between these local measurements and pre-intervention and intra-intervention non-invasive arm measurements were assessed. The impact of luminal stenosis on the local blood pressure was quantified. Compared with the pre-intervention arm measurement, the intra-intervention arm pressure decreased significantly by 23.9 ± 11.8 and 9.3 ± 14.7 % at diastole and systole, respectively. The pressure proximal to the stenosis was much lower than the pre-intervention arm measurement (diastole: 65.3 ± 15.7 vs 82.0 ± 9.7, p pressure in the MCA in patients with stenosis pressure (22.8 ± 6.4 vs 11.1 ± 8.3, p = 0.01; unit: mmHg). However, diastolic pressure remained unaffected (69.2 ± 9.3 vs 62.8 ± 19.0, p = 0.58; unit: mmHg). In conclusion, the obtained results are helpful in understanding the local hemodynamic environment modulated by the presence of atherosclerosis. The local pressure measurements can be used for computational analysis to quantify the critical mechanical condition within an MCA lesion. PMID:27349223

  18. Antenatal hypoxia induces programming of reduced arterial blood pressure response in female rat offspring: role of ovarian function.

    Directory of Open Access Journals (Sweden)

    DaLiao Xiao

    Full Text Available In utero exposure to adverse environmental factors increases the risk of cardiovascular disease in adulthood. The present study tested the hypothesis that antenatal hypoxia causes a gender-dependent programming of altered arterial blood pressure response (BP in adult offspring. Time-dated pregnant rats were divided into normoxic and hypoxic (10.5% O2 from days 15 to 21 of gestation groups. The experiments were conducted in adult offspring. Antenatal hypoxia caused intrauterine growth restriction, and resulted in a gender-dependent increase Angiotensin II (Ang II-induced BP response in male offspring, but significant decrease in BP response in female offspring. The baroreflex sensitivity was not significantly altered. Consistent with the reduced blood pressure response, antenatal hypoxia significantly decreased Ang II-induced arterial vasoconstriction in female offspring. Ovariectomy had no significant effect in control animals, but significantly increased Ang II-induced maximal BP response in prenatally hypoxic animals and eliminated the difference of BP response between the two groups. Estrogen replacement in ovariectomized animals significantly decreased the BP response to angiotensin II I only in control, but not in hypoxic animals. The result suggests complex programming mechanisms of antenatal hypoxia in regulation of ovary function. Hypoxia-mediated ovary dysfunction results in the phenotype of reduced vascular contractility and BP response in female adult offspring.

  19. Effects of artificial surfactant on lung function and blood gases in idiopathic respiratory distress syndrome.

    OpenAIRE

    Milner, A D; Vyas, H.; Hopkin, I E

    1983-01-01

    We have investigated the effect of giving two 25 mg doses of dry surfactant powder to the airways of 10 preterm babies with severe idiopathic respiratory distress syndrome requiring intermittent positive pressure ventilation. No useful change in static total compliance or blood gases was seen. We conclude that dry surfactant powder does not have a role in the management of severe idiopathic respiratory distress syndrome.

  20. Synergy between shear-induced migration and secondary flows on red blood cells transport in arteries: considerations on oxygen transport.

    Science.gov (United States)

    Biasetti, Jacopo; Spazzini, Pier Giorgio; Hedin, Ulf; Gasser, T Christian

    2014-08-01

    Shear-induced migration of red blood cells (RBCs) is a well-known phenomenon characterizing blood flow in the small vessels (micrometre to millimetre size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (millimetre to centimetre size), the extent of this migration and its interaction with secondary flows has not been fully elucidated. RBC migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface, which could influence vessel wall disease processes in and adjacent to the intima. Phillips' shear-induced particle migration model, coupled to the Quemada viscosity model, was employed to simulate the macroscopic behaviour of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near-wall region with a lowering of wall haematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and on the lateral-external side of the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, along the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall haematocrit are correlated with the near-wall shear layer and with the secondary flows induced by the vessel curvature. In particular, secondary flows accentuate the initial lowering in RBC near-wall concentration by convecting RBCs from the inner curvature side to the outer curvature side. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus induced by the presence of secondary flows. The lowering of wall haematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of

  1. 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...

  2. Heat stress attenuates the increase in arterial blood pressure during the cold pressor test

    OpenAIRE

    Cui, Jian; Shibasaki, Manabu; Low, David A.; Keller, David M.; Davis, Scott L.; Crandall, Craig G.

    2010-01-01

    The mechanisms by which heat stress impairs the control of blood pressure leading to compromised orthostatic tolerance are not thoroughly understood. A possible mechanism may be an attenuated blood pressure response to a given increase in sympathetic activity. This study tested the hypothesis that whole body heating attenuates the blood pressure response to a non-baroreflex-mediated sympathoexcitatory stimulus. Ten healthy subjects were instrumented for the measurement of integrated muscle sy...

  3. Evaluation of changes of intracranial blood flow after carotid artery stenting using digital subtraction angiography flow assessment

    Institute of Scientific and Technical Information of China (English)

    Hajime; Wada; Masato; Saito; Kyousuke; Kamada

    2015-01-01

    AIM: To evaluate the changes of intracranial blood flow after carotid artery stenting(CAS), using the flow assessment application "Flow-Insight", which was developed in our department.METHODS: Twenty patients treated by CAS participated in this study. We analyzed the change in concentration of the contrast media at the anterior-posterior and profile view image with the flow assessment application "Flow-Insight". And we compared the results with N-isopropyl-p-[123I] iodoamphetamine-single-photon emission computed tomography(IMP SPECT) performed before and after the treatment. RESULTS: From this study, 200% of the parameter "blood flow" change in the post/pre-treatment is suggested as the critical line of the hyperperfusion syndrome arise. Although the observed blood flow increase in the digital subtraction angiography system did not strongly correlate with the rate of increase of SPECT, the "Flow-Insight" reflected the rate of change of the vessels well. However, for patients with reduced reserve blood flow before CAS, a highly elevated site was in agreement with the site analysis results. CONCLUSION: We concluded that the cerebral angiography flow assessment application was able to more finely reveal hyperperfusion regions in the brain after CAS compared to SPECT.

  4. Effect of Combined Treatment with Alpha Lipoic Acid and Acetyl-L-Carnitine on Vascular Function and Blood Pressure in Coronary Artery Disease Patients

    OpenAIRE

    McMackin, Craig J.; Widlansky, Michael E.; Hamburg, Naomi M.; Huang, Alex L.; Weller, Susan; Holbrook, Monika; Gokce, Noyan; Hagen, Tory M.; Keaney, John F.; Vita, Joseph A.

    2007-01-01

    Mitochondria produce reactive oxygen species that may contribute to vascular dysfunction. Alpha-lipoic acid and acetyl-L-carnitine reduce oxidative stress and improve mitochondrial function. In a double blind, crossover study, we examined the effects of combined alpha-lipoic acid /acetyl-L-carnitine treatment and placebo (eight weeks per treatment) on vasodilator function and blood pressure in 36 subjects with coronary artery disease. Active treatment increased brachial artery diameter by 2.3...

  5. Influence of Rho Kinase Inhibitor Fasudil on Late Endothelial Progenitor Cells in Peripheral Blood of COPD Patients with Pulmonary Artery Hypertension

    OpenAIRE

    Liu, Pei; Zhang, Hongmei; Tang, Yijun; Sheng, Chunfeng; Liu, Jianxin; Zeng, Yanjun

    2014-01-01

    The objective of our work was to investigate the influence of Fasudil, a Rho inhibitor on the number and function of the late endothelial progenitor cells in peripheral blood of chronic obstructive pulmonary diseases (COPD) patients with pulmonary artery hypertension. Eighty COPD patients with pulmonary artery hypertension were selected and divided into two groups: the treatment group and the control group, which had 40 patients respectively. The control group received routine treatment, incl...

  6. Intrathecal injection of human umbilical cord blood-derived mesenchymal stem cells for the treatment of basilar artery dissection: a case report

    Directory of Open Access Journals (Sweden)

    Han Hoon

    2011-12-01

    Full Text Available Abstract Introduction Basilar artery dissection is a rare occurrence, and is significantly associated with morbidity and mortality. To the best of our knowledge, we report the first case of basilar artery dissection treated with mesenchymal stem cells. Case presentation We present the case of a 17-year-old Korean man who was diagnosed with basilar artery dissection. Infarction of the bilateral pons, midbrain and right superior cerebellum due to his basilar artery dissection was partially recanalized by intrathecal injection of human umbilical cord blood-derived mesenchymal stem cells. No immunosuppressants were given to our patient, and human leukocyte antigen alloantibodies were not detected after cell therapy. Conclusions This case indicates that intrathecal injections of mesenchymal stem cells can be used in the treatment of basilar artery dissection.

  7. SU-D-18C-05: Variable Bolus Arterial Spin Labeling MRI for Accurate Cerebral Blood Flow and Arterial Transit Time Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, M; Jung, Y [Wake Forest School of Medicine, Winston-Salem, NC (United States)

    2014-06-01

    Purpose: Arterial spin labeling (ASL) is an MRI perfusion imaging method from which quantitative cerebral blood flow (CBF) maps can be calculated. Acquisition with variable post-labeling delays (PLD) and variable TRs allows for arterial transit time (ATT) mapping and leads to more accurate CBF quantification with a scan time saving of 48%. In addition, T1 and M0 maps can be obtained without a separate scan. In order to accurately estimate ATT and T1 of brain tissue from the ASL data, variable labeling durations were invented, entitled variable-bolus ASL. Methods: All images were collected on a healthy subject with a 3T Siemens Skyra scanner. Variable-bolus Psuedo-continuous ASL (PCASL) images were collected with 7 TI times ranging 100-4300ms in increments of 700ms with TR ranging 1000-5200ms. All boluses were 1600ms when the TI allowed, otherwise the bolus duration was 100ms shorter than the TI. All TI times were interleaved to reduce sensitivity to motion. Voxel-wise T1 and M0 maps were estimated using a linear least squares fitting routine from the average singal from each TI time. Then pairwise subtraction of each label/control pair and averaging for each TI time was performed. CBF and ATT maps were created using the standard model by Buxton et al. with a nonlinear fitting routine using the T1 tissue map. Results: CBF maps insensitive to ATT were produced along with ATT maps. Both maps show patterns and averages consistent with literature. The T1 map also shows typical T1 contrast. Conclusion: It has been demonstrated that variablebolus ASL produces CBF maps free from the errors due to ATT and tissue T1 variations and provides M0, T1, and ATT maps which have potential utility. This is accomplished with a single scan in a feasible scan time (under 6 minutes) with low sensivity to motion.

  8. SU-D-18C-05: Variable Bolus Arterial Spin Labeling MRI for Accurate Cerebral Blood Flow and Arterial Transit Time Mapping

    International Nuclear Information System (INIS)

    Purpose: Arterial spin labeling (ASL) is an MRI perfusion imaging method from which quantitative cerebral blood flow (CBF) maps can be calculated. Acquisition with variable post-labeling delays (PLD) and variable TRs allows for arterial transit time (ATT) mapping and leads to more accurate CBF quantification with a scan time saving of 48%. In addition, T1 and M0 maps can be obtained without a separate scan. In order to accurately estimate ATT and T1 of brain tissue from the ASL data, variable labeling durations were invented, entitled variable-bolus ASL. Methods: All images were collected on a healthy subject with a 3T Siemens Skyra scanner. Variable-bolus Psuedo-continuous ASL (PCASL) images were collected with 7 TI times ranging 100-4300ms in increments of 700ms with TR ranging 1000-5200ms. All boluses were 1600ms when the TI allowed, otherwise the bolus duration was 100ms shorter than the TI. All TI times were interleaved to reduce sensitivity to motion. Voxel-wise T1 and M0 maps were estimated using a linear least squares fitting routine from the average singal from each TI time. Then pairwise subtraction of each label/control pair and averaging for each TI time was performed. CBF and ATT maps were created using the standard model by Buxton et al. with a nonlinear fitting routine using the T1 tissue map. Results: CBF maps insensitive to ATT were produced along with ATT maps. Both maps show patterns and averages consistent with literature. The T1 map also shows typical T1 contrast. Conclusion: It has been demonstrated that variablebolus ASL produces CBF maps free from the errors due to ATT and tissue T1 variations and provides M0, T1, and ATT maps which have potential utility. This is accomplished with a single scan in a feasible scan time (under 6 minutes) with low sensivity to motion

  9. THE EFFECT OF FLUOROCARBON ARTIFICIAL BLOOD (FC-34 IN ACUTE VASOGENIC BRAIN EDEMA

    Directory of Open Access Journals (Sweden)

    M NEEMATBAKHSH

    2000-03-01

    Full Text Available Background. Oxygen transport to tissue after an acute ischemia is strongly important. Fluorocarbon liquids are able to facilitated the oxygen transport. An animal experiment was designed to study the effect of FC-34 in acute brain ischemia. Methods. The left common carotid arteries were ligated in three groups of anesthetized animals for 30 minutes to obtain acute brain edema. The animals were subjected to received 15 ml/kg saline (group 1, 10% monitol (group 2 or FC-43 (group 3. All animals were recovered, and they monitored for two weeks. The electrolytes, BUN, and creatinine were measured before (all animals and after two weeks (survived animals. Pathological investigation was obtained by light and electron microscope via pathological process. Findings. The group 1 animals were died during first five days, but one and four animals were survived by two weeks in groups 2 & 3 respectively (P < 0.05. The pathological determinations indicate less cellular damages in group 3. No significant differences were detected in potassium, calcium, BUN, and creatinine before and after the experiment. Conclusion. The particle size and oxygen solubility in FC-43 is the major factors for better oxygen transport in ischem

  10. Adjustment of lipiodol dose according to tumor blood supply during transcatheter arterial chemoembolization for large hepatocellular carcinoma by multidetector helical CT

    Institute of Scientific and Technical Information of China (English)

    Hong-Yan Cheng; Yi Shou; Xiang Wang; Ai-Min Xu; Dong Chen; Yu-Chen Jia

    2004-01-01

    AIM: To work out an individualized lipiodol dose in transcatheter arterial chemoembolization (TACE) for large hepatocellularcarcinoma (HCC) according to its blood supply evaluated by CT.METHODS: One hundred patients with large HCC (more than 8 cm in diameter) were studied by multidetector helical CT. Patterns of blood supply of HCC were divided into sufficient blood supply, poor blood supply, mixed blood supply and arteriovenous (A-V) shunt. The dose of ultra fluid lipiodol was determined by diameter and blood supply type of HCC. Patients were divided into two groups (50 cases each): lipiodol perfusion group and iodized oil perfusion group according to tumor diameter and the blood supply type of tumor.RESULTS: The confirmation and effective rates were 82%, 84% in the first group and 36%, 46% in the second group (P<0.01).CONCLUSION: A relatively individualized lipiodol dose may be determined according to the blood supply pattern and the tumor diameter by CT imaging.

  11. Effects of Breath Training Pattern "End-Inspiratory Pause" on Respiratory Mechanics and Arterial Blood Gas of Patients with COPD

    Institute of Scientific and Technical Information of China (English)

    梁永杰; 蔡映云

    2002-01-01

    Objective:In order to explore the mechanism of Chinese traditional breath training, theeffects of end-inspiratory pause breathing (EIPB) on the respiratory mechanics and arterial blood gas werestudied in patients with chronic obstructive pulmonary disease (COPD). Methods: Ten patients in steadystage participating in the study had a breath training of regulating the respiration rhythm as to having apause between the deep and slow inspiration and the slow expiration. Effect of the training was observed byvisual feedback from the screen of the respiratory inductive plethysmograph. The dynamic change of par-tial pressure of oxygen saturation in blood (SpO2) was recorded with sphygmo-oximeter, the pulmonarymechanics and EIPB were determined with spirometer, and the data of arterial blood gases in tranquilizedbreathing and EIPB were analysed. Results: After EIPB training, SpO2 increased progressively, PaO2 in-creased and PaCO2 decreased, and the PaO2 increment was greater than the PaCO2 decrement. Further-more, the tidal volume increased and the frequency of respiration decreased significantly, both inspirationtime and expiration time were prolonged. There was no significant change in both mean inspiration flowrate (VT/Ti) and expiration flow rate (VT/Te). The baselines in spirogram during EIPB training had noraise. Conclusion: EIPB could decrease the ratio of the dead space and tidal volume (VD/VT), cause in-crease of PaO2 more than the decrease of PaCO2, suggesting that this training could improve both the func-tion of ventilation and gaseous exchange in the lung. EIPB training might be a breathing training patternfor rehabilitation of patients with COPD.

  12. Different Bleeding Patterns with the Use of Levonorgestrel Intrauterine System: Are They Associated with Changes in Uterine Artery Blood Flow?

    Directory of Open Access Journals (Sweden)

    Carlo Bastianelli

    2014-01-01

    Full Text Available Objective. Evaluate if different bleeding patterns associated with the use of the levonorgestrel intrauterine system (LNG-IUS are associated with different uterine and endometrial vascularization patterns, as evidenced by ultrasound power Doppler analysis. Methodology. A longitudinal study, with each subject acting as its own control was conducted between January 2010 and December 2012. Healthy volunteers with a history of heavy but cyclic and regular menstrual cycles were enrolled in the study. Ultrasonographic examination was performed before and after six months of LNG-IUS placement: uterine volume, endometrial thickness, and subendometrial and myometrial Doppler blood flow patterns have been evaluated. Results. A total of 32 women were enrolled out of 186 initially screened. At six months of follow-up, all subjects showed a reduction in menstrual blood loss; for analysis, they were retrospectively divided into 3 groups: normal cycling women (Group I, amenorrheic women (Group II, and women with prolonged bleedings (Group III. Intergroup analysis documented a statistically significant difference in endometrial thickness among the three groups; in addition, mean pulsatility index (PI and resistance index (RI in the spiral arteries were significantly lower in Group I and Group III compared to Group II. This difference persisted also when comparing—within subjects of Group III—mean PI and RI mean values before and after insertion. Conclusions. The LNG-IUS not only altered endometrial thickness, but—in women with prolonged bleedings—also significantly changed uterine artery blood flow. Further studies are needed to confirm these results and enable gynecologists to properly counsel women, improving initial continuation rates.

  13. 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; Schroeder, T V; Secher, N H

    1992-01-01

    Changes in middle cerebral artery flow velocity (Vmean), measured by transcranial Doppler ultrasound, were used to determine whether increases in mean arterial pressure (MAP) or brain activation enhance cerebral perfusion during exercise. We also evaluated the role of "central command......," 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...

  14. Effects of soy supplementation on blood lipids and arterial function in hypercholesterolaemic subjects

    DEFF Research Database (Denmark)

    Hermansen, K; Hansen, B; Jacobsen, R;

    2005-01-01

    BACKGROUND: Studies on soy supplementation suggest a cardioprotective potential. OBJECTIVE: To examine the effects on LDL cholesterol and arterial function as a result of dietary enrichment with soy supplementation. DESIGN: A Randomized, double blind, parallel intervention trial. SETTING......: Subjects were randomly assigned to 24 weeks of daily intake of either a soy supplement, Abalon (30 g soy protein, 9 g cotyledon fibre and 100 mg isoflavones) or placebo (30 g of casein). The soy supplement and placebo were provided in two sachets daily that were stirred in water. Fasting plasma lipids, TNF...... in 32 subjects, arterial dilatory capacity, compliance, and distensibility were recorded before and after the intervention. RESULTS: In the main study, no difference in fasting plasma lipid levels or insulin sensitivity was found between soy-based supplement and placebo. A significant postprandial...

  15. Effect of Algerian Varieties Dates on Glycemic, Arterial Blood Pressure and Satiety Responses

    OpenAIRE

    Gourchala Freha, Mihoub Fatma, Derradj Meriem, Henchiri Cherifa

    2016-01-01

    The purpose of our study is to determine the Glycemic Indexes (GIs)of three Algerians varieties of dates in healthy subjects, evaluate the satiety and effect on arterial pressure after their consumption. We have first documented the chemical composition of the dates. 10 healthy subjects consumed the dates (carbohydrates content of 50 g) in order to determine the GIs. The responses of glycaemia were monitored during two hours after the dates taking and compared to the reference glucose. In a r...

  16. Possibility of non-invasive blood pressure estimation by measurements of force and arteries diameter

    OpenAIRE

    Veye, Florent; Mestre, Sandrine; Perez-Martin, Antonia; Triboulet, Jean

    2014-01-01

    International audience Ultrasound examination is the first line procedure for the diagnosis and follow-up of cardiovascular diseases. Instrumenting an ultrasound probe with a force sensor may improve the non-invasive measurement of arterial biomechanical parameters (diameter, pulsatility, intima-media thickness and flow-dependent dilation) by measuring and controlling the force exerted by the sonographer. We present here the results obtained with this approach coupled with image processing...

  17. Peripheral and Central Venous Blood Glucose Concentrations in Dogs and Cats with Acute Arterial Thromboembolism

    OpenAIRE

    S. Klainbart; Kelmer, E.; Vidmayer, B.; Bdolah‐Abram, T.; Segev, G.; Aroch, I.

    2014-01-01

    Background Acute limb paralysis because of arterial thromboembolism (ATE) occurs in cats and less commonly in dogs. ATE is diagnosed based on physical examination findings and, occasionally, advanced imaging. Hypothesis/Objectives Peripheral, affected limb venous glucose concentration is decreased in ATE, whereas its systemic concentration is within or above reference interval. Animals Client‐owned cats and dogs were divided into 3 respective groups: acute limb paralysis because of ATE (22 ca...

  18. Carotid artery disease: Novel pathophysiological mechanisms identified by gene-expression profiling of peripheral blood

    OpenAIRE

    Rossi L, Lapini I, Magi A, Pratesi G, Lavitrano M, Biasi GM, Pulli R, Pratesi C, Abbate R, Giusti B

    2010-01-01

    The pathogenesis of carotid artery stenosis (CAS) as well as the mechanisms underlying the different localisation of the atherosclerotic lesions remains poorly understood. We used microarray technology to identify novel systemic mediators that could contribute to CAS pathogenesis. Moreover, we compared gene-expression profile of CAS with that of patients affected by abdominal aortic aneurysm (AAA), previously published by our group. METHODS AND RESULTS: By global gene-expression profil...

  19. Vital Signs – Presión arterial alta (High Blood Pressure)

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    En los EE. UU. casi un tercio de la población adulta tiene presión arterial alta, el principal factor de riesgo de enfermedades cardiacas y accidentes cerebrovasculares, dos de las principales causas de muerte en el país.  Created: 10/2/2012 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/17/2012.

  20. Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

    LENUS (Irish Health Repository)

    O'Connor, T M

    2012-01-31

    BACKGROUND: Arterial blood gases (ABGs) are often sampled incorrectly, leading to a \\'mixed\\' or venous sample. Delays in analysis and air contamination are common. OBJECTIVES: We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. METHODS: Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. RESULTS: Mean venous pH was 7.371 and arterial pH was 7.407 (p < 0.0001). There was a correlation between venous and arterial pH (r = 0.5347, p < 0.0001). The regression equation to predict arterial pH was: arterial pH = 4.2289 + 0.43113 . venous pH. There were no clinically significant differences in arterial PO associated with analysis delay. A statistically significant decline in pH was detected at 30 min in patients with COPD exacerbation (p = 0.0042) and 90 min in controls (p < 0.0001). A clinically significant decline in pH emerged at 73 min in patients with COPD exacerbation and 87 min in controls. Air contamination was associated with a clinically significant increase in PO in all samples, including those that were immediately analyzed. CONCLUSIONS: Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO, indicating that air-contaminated ABGs should be discarded.

  1. Quantitative cerebral H215O perfusion PET without arterial blood sampling, a method based on washout rate

    International Nuclear Information System (INIS)

    The quantitative determination of regional cerebral blood flow (rCBF) is important in certain clinical and research applications. The disadvantage of most quantitative methods using H215O positron emission tomography (PET) is the need for arterial blood sampling. In this study a new non-invasive method for rCBF quantification was evaluated. The method is based on the washout rate of H215O following intravenous injection. All results were obtained with Alpert's method, which yields maps of the washin parameter K1 (rCBFK1) and the washout parameter k2 (rCBFk2). Maps of rCBFK1 were computed with measured arterial input curves. Maps of rCBFk2* were calculated with a standard input curve which was the mean of eight individual input curves. The mean of grey matter rCBFk2* (CBFk2*) was then compared with the mean of rCBFK1 (CBFK1) in ten healthy volunteer smokers who underwent two PET sessions on day 1 and day 3. Each session consisted of three serial H215O scans. Reproducibility was analysed using the rCBF difference scan 3-scan 2 in each session. The perfusion reserve (PR = rCBFacetazolamide-rCBFbaseline) following acetazolamide challenge was calculated with rCBFk2* (PRk2*) and rCBFK1 (PRK1) in ten patients with cerebrovascular disease. The difference CBFk2*-CBFK1 was 5.90±8.12 ml/min/100 ml (mean±SD, n=55). The SD of the scan 3-scan 1 difference was 6.1% for rCBFk2* and rCBFK1, demonstrating a high reproducibility. Perfusion reserve values determined with rCBFK1 and rCBFk2* were in high agreement (difference PRk2*-PRK1=-6.5±10.4%, PR expressed in percentage increase from baseline). In conclusion, a new non-invasive method for the quantitative determination of rCBF is presented. The method is in good agreement with Alpert's original method and the reproducibility is high. It does not require arterial blood sampling, yields quantitative voxel-by-voxel maps of rCBF, and is computationally efficient and easy to implement. (orig.)

  2. Plasmodium falciparum parasitaemia in the first half of pregnancy, uterine and umbilical artery blood flow, and foetal growth: a longitudinal Doppler ultrasound study

    Directory of Open Access Journals (Sweden)

    Griffin Jennifer B

    2012-09-01

    Full Text Available Abstract Background During early pregnancy, the placenta develops to meet the metabolic demands of the foetus. The objective of this analysis was to examine the effect of malaria parasitaemia prior to 20 weeks’ gestation on subsequent changes in uterine and umbilical artery blood flow and intrauterine growth restriction. Methods Data were analysed from 548 antenatal visits after 20 weeks’ gestation of 128 women, which included foetal biometric measures and interrogation of uterine and umbilical artery blood flow. Linear mixed effect models estimated the effect of early pregnancy malaria parasitaemia on uterine and umbilical artery resistance indices. Log-binomial models with generalized estimating equations estimated the effect of early pregnancy malaria parasitaemia on the risk of intrauterine growth restriction. Results There were differential effects of early pregnancy malaria parasitaemia on uterine artery resistance by nutritional status, with decreased uterine artery resistance among nourished women with early pregnancy malaria and increased uterine artery resistance among undernourished women with early pregnancy malaria. Among primigravidae, early pregnancy malaria parasitaemia decreased umbilical artery resistance in the late third trimester, likely reflecting adaptive villous angiogenesis. In fully adjusted models, primigravidae with early pregnancy malaria parasitaemia had 3.6 times the risk of subsequent intrauterine growth restriction (95% CI: 2.1, 6.2 compared to the referent group of multigravidae with no early pregnancy malaria parasitaemia. Conclusions Early pregnancy malaria parasitaemia affects uterine and umbilical artery blood flow, possibly due to alterations in placentation and angiogenesis, respectively. Among primigravidae, early pregnancy malaria parasitaemia increases the risk of intrauterine growth restriction. The findings support the initiation of malaria parasitaemia prevention and control efforts earlier in

  3. Biochemical characterization of blood plasma of coronary artery disease patients by in vitro high-resolution proton NMR spectroscopy

    Indian Academy of Sciences (India)

    Anu Malik; Uma Sharma; R Lakshmy; Rajiv Narang; Naranamanglam R Jagannathan

    2015-03-01

    This study aimed to investigate the biochemical profile of blood plasma of patients with coronary artery disease (CAD) and angiographically normal subjects (controls) to determine biomarkers for their differentiation. In this double blind study, 5 mL venous blood was drawn before angiography from CAD patients (n=60) and controls (n=13) comprising angiography normal individuals. In vitro high-resolution NMR spectroscopy of these blood plasma samples was carried out at 400 MHz, and intensity data were analysed with partial least square discriminant analysis. Categorization of subjects as controls or CAD patients and the patients further as single vessel disease (SVD), double vessel disease (DVD) and triple vessel disease (TVD) was done at the end of the study based on their angiography reports. Raised levels of lipids, alanine (Ala) and isoleucine/leucine/valine (Ile/Leu/Val) were observed in CAD patients compared with controls. Partial least square discriminant analysis showed separation between controls vs CAD patients. TVD patients showed increased levels of Ile/Leu/Val and Ala compared with controls and SVD. Alanine, Ile/Leu/Val, and LDL/VLDL appear as possible biomarkers for distinguishing between controls and patients with SVD and TVD. A metabolic adaptation of myocardium may play a role in raising the Ala level.

  4. Standardized Peridialytic Blood Pressures for Diagnosing Arterial Hypertension in Patients on Chronic Hemodialysis

    OpenAIRE

    Raluca Moldovan; Mirela Gherman-Căprioară

    2014-01-01

    Background. The relevance of peridialytic blood pressures for diagnosing hypertension is controversial. Standardized peridialytic BPs have not yet been evaluated for the positive diagnosis and evaluation of hypertension severity in chronic hemodialysis patients.Aim. To evaluate the utility of standardized peridialytic BP for diagnosing hypertension, defined according to the results of 24-hour ambulatory blood pressure monitoring(ABPM).Methods. Thirty-five chronic hemodialysis patients with a ...

  5. Evaluation of arterial and jugular bulb venous blood gase differences during neurosurgical procedures

    OpenAIRE

    Küçük, Dr. Nergiz; Gökmen, Dr. Gökhan; Uslu, Dr. Sebahattin

    1997-01-01

    Retrograde catheterization of the internal jugular venous bulb is a useful technique which is becoming more widespread as it enables monitoring of cerebral blood flow and cerebral metabolism. In this study, we aimed to determine our neuroanaesthesia as an objective technique. After Ethic Committee approval, 10 patients with head trauma were included in this study. Radial arter and jugular venous cannulation were performed in operating room. Blood gases, Hb, osmolality, BUN, Na, and K were ana...

  6. Formation of an artificial blood vessel: adhesion force measurements with optical tweezers

    Science.gov (United States)

    Knoener, Gregor; Campbell, Julie H.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2004-10-01

    We are investigating the formation of a tissue capsule around a foreign body. This tissue capsule can be used as an autologous graft for the replacement of diseased blood vessels or for bypass surgery. The graft is grown in the peritoneal cavity of the recipient and the formation starts with the adhesion of cells to the foreign body. We identify the cell type and measure the adhesion of these cells to foreign materials using optical tweezers. Cell adhesion to macroscopic samples and microspheres is investigated. No difference in the adhesion force was measurable for polyethylene, silicon and Tygon on a scale accessible to optical tweezers. The density of adherent cells was found to vary strongly, being highest on polyethylene. The mean rupture forces for cell-microsphere adhesion ranged from 24 to 39 pN and changed upon preadsorption of bovine serum albumin. For plain microspheres, the highest mean rupture force was found for PMMA, which also showed the highest adhesion probability for the cell-microsphere interaction.

  7. Influence of a history of arterial hypertension and pretreatment blood pressure on the effect of angiotensin converting enzyme inhibition after acute myocardial infarction. Trandolapril Cardiac Evaluation Study

    DEFF Research Database (Denmark)

    Gustafsson, F; Køber, L; Torp-Pedersen, C;

    1998-01-01

    inhibition after AMI complicated by left ventricular dysfunction may be of particular importance in patients with a history of arterial hypertension or a relatively high pretreatment blood pressure. However, further investigations are necessary to establish the clinical impact of these results.......OBJECTIVE: To evaluate the influence of a history of arterial hypertension and the level of pretreatment blood pressure on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril on mortality and morbidity in patients with acute myocardial infarction (AMI) and left...... broad spectrum of potential confounders. Also, benefit from ACE inhibition increased with increasing blood pressure at the time of randomization. Significant interactions between benefit from ACE inhibition and hypertension history, and systolic and diastolic blood pressure were found. CONCLUSION: ACE...

  8. Arterial blood supply to the basal ganglionic region on CT sections, (1)

    International Nuclear Information System (INIS)

    The selective injection of dyestuff to the perforators from the anterior and middle cerebral arteries, using six normal post-mortem brains, was performed. After fixation, sections parallel with the orbitomeatal line were obtained. The area supplied by perforators of ACA, including the recurrent artery of Heubner, was visualized in the anterior commissure, the inferior and anterior parts of the caudate nucleus and putamen, the anterior part of the globus pallidus, and the anterior limb of the internal capsule below the slice which showed the anterior horn. The area supplied by the so-called lateral lenticulostriate arteries, which originates from the horizontal segment of MCA, was visualized in the lateral part of the anterior perforated substance, the posterior part of the putamen and the globus pallidus, the genu and posterior limb of the internal capsule, and the external capsule and claustrum below the slice which showed the anterior horn. The border between areas was considered as the anterior limb of the internal capsule and the lateral part of the head of the caudate nucleus on the slice which showed the anterior horn. On slices showing the anterior horn and upward, the area supplied by perforators derived from MCA demonstrated a distribution that was visualized in the lateral part of the caudate nucleus, most of the putamen, the internal and external capsules, the claustrum, and the white matter above the putamen. The identification of the area supplied by perforators in the basal ganglionic region on CT sections will be useful in the CT diagnosis of cerebrovascular disorders which involve the basal ganglion. (author)

  9. Preliminary study of abnormal increase of postexercise systolic blood pressure in the diagnosis of coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    于宗良; 杨向军; 王国强; 高美雯; 李勋; 惠杰; 蒋廷波; 宋建平; 刘志华; 蒋文平

    2003-01-01

    Objectives This study sought to evaluate the diagnostic value of abnormal increase of postexercise systolic blood pressure (SBP) for detecting coronary artery disease (CAD) in patients with or without hypertension. Methods Treadmill exercise testing (TET) was conducted in 88 patients (40 CAD patients, 48 control subjects)with or without hypertension, each of whom underwent selective coronary angiography (CAG). The abnormal increase of postexercise SBP was defined as 10mmHg higher than earlier periods during the recovery phase (6 minutes)of exercise testing. Results The abnormal increase of postexercise SBP had higher sensitivity, specificity,and accuracy for detecting CAD than those of ST - segment depression in patients with or without hypertension. Its accuracy increased with the severity of CAD while decreased in patients with hypertension, and the increase value of SBP had a positive correlation with the extent of coronary artery lesion. The combination of ST - segment depression and abnormal increase of postexercise SBP diagnosed CAD most accurately in patients with hypertension. Conclusions Abnormal increase of postexercise SBP may be a useful index for diagnosing CAD.

  10. Comparison of Neonatal Arterial Blood Oxygen Saturation Rate Immediately After Birth in Normal and Elective Cesarean Delivery

    Directory of Open Access Journals (Sweden)

    Mahmoodi Fatemeh

    2016-01-01

    Full Text Available Objective: Ninety percent of neonates pass the transition from fetal life to outside uterus successfully, and only 1% needs intensive support for survival. The quantity of oxygen saturation immediately after birth shows the need for resuscitation immediately after birth. The present research was carried out with the objective of comparing saturation rate of arterial blood hypoxia in neonates born with normal vaginal delivery and cesarean method. Materials and Methods: 220 neonates born with elective cesarean section and normal delivery were studied in an analytical-descriptive study. Demographic questionnaire was completed. Then a pulse oxymeter with its sensor fixed on the right wrist of the neonates was used. Heart rate was recorded and the level of oxygen saturation (SaO2 under 90% was considered as hypoxia. To compare the quantitative and qualitative variable between the two groups, paired t test and chi-square test was used, respectively. Pearson correlation test was used to study the correlation between the variables. Results: The age range of mothers was 16-38 years. The mothers’ average age, gestational age and neonates’ weight were not significantly different between groups. The average SaO2 in minutes 1, 3 and 5 was 72%, 81% and 89%, respectively in vaginal delivery, which showed a significant difference compared to cesarean neonates with average of 65%, 75% and 83%, respectively. No significant difference was observed after10 minutes. Also there were not significant statistical correlation between mothers age, number of pregnancies, sex and weight of neonate with SaO2 of arterial blood after 1, 3, 5 and 10 minutes after birth. Conclusion: With respect to the results of the present research SaO2 was higher in neonates of vaginal delivery in comparison to cesarean neonates. Encouraging mothers to delivery vaginally and also using aid-oxygen is proposed for the cesarean neonates at birth.

  11. The effects of venous cannulation technique and cardioplegia type on plasma potassium concentration and arterial blood pressure during cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Coleman, E T

    2012-02-03

    The cannulation method and cardioplegia solution used during cardiopulmonary bypass (CPB) may both influence plasma potassium concentrations ([K+]) and mean arterial blood pressure (MAP). Bi-caval or right atrial cannulation methods are routinely used in conjunction with crystalloid or blood cardioplegia. We investigated the influence of cannulation method and cardioplegia solutions on plasma [K+] and MAP during cardiopulmonary bypass. Sixty consecutive patients undergoing elective coronary artery bypass grafting (CABG) using CPB were studied. They were randomly divided into three groups of 20 patients. Patients in Group A underwent bi-caval venous cannulation and received crystalloid cardioplegia. Group B patients underwent right atrial cannulation and received crystalloid cardioplegia. Group C patients underwent right atrial cannulation and received blood cardioplegia. In each case. cardioplegia was administered antegrade via the aortic root. Plasma [K+], MAP. and hemoglobin concentration (Hb) were measured over an 8-min period following cardioplegia administration (pilot studies indicated pressure changes occuring post cardioplegia administration up to this time). The combination of bi-caval cannulation and crystalloid cardioplegia (Group A) was associated with the least increase in plasma [K+] and no decrease in MAP. The maximum [K+] for this Group was 4.2 mmol\\/L (4.6% increase). The minimum mean pressure was 57 mmHg (13.6% increase). Both right atrial cannulation groups (B and C) showed a large rise in plasma [K+] and a decrease in MAP. Group B maximum [K+] was 5.2 mmol\\/L (27.5% increase). Group C was also 5.2 mmol\\/L (26.0% increase). Group C showed the largest pressure decrease, the minimum mean pressure was 45 mmHg (21.3% decrease). The Group B minimum mean pressure was 45 mmHg (8.7% decrease). Our results show that patients undergoing CPB operations who are deemed to be at increased risk of suffering adverse effects from hypotensive episodes may

  12. Blood and urine levels of heavy metal pollutants in female and male patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Sponder M

    2014-05-01

    Full Text Available Michael Sponder,1 Monika Fritzer-Szekeres,2 Rodrig Marculescu,2 Martina Mittlböck,3 Maria Uhl,4 Birgit Köhler-Vallant,5 Jeanette Strametz-Juranek1 1Department of Cardiology, Medical University of Vienna, Vienna, Austria; 2Department of Medical-Chemical Laboratory Analysis, Medical University of Vienna, Vienna, Austria; 3Department of Medical Statistics, Informatics and Intelligent Systems, Section for Clinical Biometrics, Medical University of Vienna, Vienna, Austria; 4Department of Pollutants and Human, Environment Agency Austria, Vienna, Austria; 5Department of Inorganic Analysis, Environment Agency Austria, Vienna, Austria Background: Heavy metal pollutants such as cadmium (Cd, lead (Pb, and mercury (Hg are rarely the subjects of cardiovascular research although they have been suspected for decades to negatively impact the circulatory system. Methods: Apart from detailed anamnestic data, urinary levels of Cd and full blood levels of Pb and Hg were measured in 53 female (mean age: 68.04±7.03 years and 111 male (mean age: 60.68±11.43 years nonsmoking or never-smoking patients with angiographically verified and precisely quantified coronary artery disease (CAD. Results: Although Cd was quantifiable in 68.3% of subjects, only 34.1% of these patients exceeded the critical 1 µg/L Human Biomonitoring (HBM-I level. Median Pb (20 µg/L and Hg (0.55 µg/L levels were lower than the HBM-I, as well as reference levels of Pb. Wine consumption was the main source for Pb, fish and wine consumption for Hg, and previous nicotine abuse for Cd. There was no correlation between Cd, Pb, or Hg and severity of CAD although severity correlated positively with atherosclerosis parameters (uric acid, creatinine, triglycerides, blood urea nitrogen, C-reactive protein and negatively with high density lipoprotein cholesterol. Conclusion: Cd levels detected in CAD patients were high compared to German and European reference levels but it could not be proven that urine

  13. Differential Telomere Shortening in Blood versus Arteries in an Animal Model of Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Samira Tajbakhsh

    2015-01-01

    Full Text Available Vascular dysfunction is an early feature of diabetic vascular disease, due to increased oxidative stress and reduced nitric oxide (NO bioavailability. This can lead to endothelial cell senescence and clinical complications such as stroke. Cells can become senescent by shortened telomeres and oxidative stress is known to accelerate telomere attrition. Sirtuin 1 (SIRT1 has been linked to vascular health by upregulating endothelial nitric oxide synthase (eNOS, suppressing oxidative stress, and attenuating telomere shortening. Accelerated leukocyte telomere attrition appears to be a feature of clinical type 2 diabetes (T2D and therefore the telomere system may be a potential therapeutic target in preventing vascular complications of T2D. However the effect of T2D on vascular telomere length is currently unknown. We hypothesized that T2D gives rise to shortened leukocyte and vascular telomeres alongside reduced vascular SIRT1 expression and increased oxidative stress. Accelerated telomere attrition was observed in circulating leukocytes, but not arteries, in T2D compared to control rats. T2D rats had blunted arterial SIRT1 and eNOS protein expression levels which were associated with reduced antioxidant defense capacity. Our findings suggest that hyperglycemia and a deficit in vascular SIRT1 per se are not sufficient to prematurely shorten vascular telomeres.

  14. Numerical and Analytical Study of Two-Layered Unsteady Blood Flow through Catheterized Artery.

    Science.gov (United States)

    Zaman, Akbar; Ali, Nasir; Sajid, M; Hayat, Tasawar

    2016-01-01

    The pulsatile flow of blood in a catheterized blood vessel is analyzed. The flow of blood in vessel is modeled as the flow of two immiscible fluids. The fluid in the core region is characterized as a non-Newtonian viscoelastic fluid satisfying the constitutive equation of an Oldroyd-B fluid. The fluid in the peripheral region is treated as a Newtonian fluid. The catheter inside the vessel is modeled as a rigid tube of very small radius. The resulting differential system for velocity in each region is computed numerically by finite-difference scheme and analytically by Laplace transform. A comparison of numerical solution with Laplace transform solution is carried out. Various physical quantities of interest through the computed velocity are also analyzed. PMID:27548476

  15. Computational Dynamics of Arterial Blood Flow in the Presence of Magnetic Field and Thermal Radiation Therapy

    Directory of Open Access Journals (Sweden)

    T. Chinyoka

    2014-01-01

    Full Text Available We conduct a numerical study to determine the influence of magnetic field and thermal radiation on both velocity and temperature distributions in a single blood vessel. The model here assumes that blood is a Newtonian incompressible conducting fluid with radially varying viscosity due to hematocrit variation. The transient equations of momentum and energy transport governing the flow in an axisymmetric configuration are solved numerically using a semi-implicit finite difference method. Results are presented graphically and discussed both qualitatively and quantitatively from the physiological point of view. The results of this work may enhance current understanding of the factors that determine the effects of hyperthermia treatment on tumor tissues.

  16. COMPUTER SIMULATION OF BLOOD FLOW IN ARTERIES AFFECTED BY MULTIPLE ANEURYSM

    Directory of Open Access Journals (Sweden)

    H. GIRIJA BAI

    2012-12-01

    Full Text Available The aim of this study is a numerical simulation of hemodynamics in blood vessels with multiple fusiform aneurysms. Dilation of 0.25 is considered. Using computational fluid dynamics, hemodynamic factors such as velocity and pressure are investigated. The problem is solved by finite volume method. Numerical simulation is prescribed using the CFD softwares Fluent and Gambit. High pressure and low velocity is observed in the region of aneurysm. This is an indication to the interruption of blood flow. These techniques based on computer flow study are important for understanding the relationship between hemodynamic parameters and risk of rupture.

  17. Xenon CT measurements of intrahepatic blood flow divided from portal veins and arteries in healthy control and patients with chronic hepatitis and liver cirrhosis

    International Nuclear Information System (INIS)

    Using Xenon computed tomography (Xe-CT), we measured intrahepatic blood flow volume divided from portal veins and arteries in 6 healthy volunteers (HV), 22 patients with biopsy-proven chronic hepatitis (CH), and 16 patients with pathologically or clinically diagnosed as liver cirrhosis (LC). Intrahepatic blood flow volume on computed CT image were indicated of color scale and calculated by each region of interest (ROI) in reliability map. Portal veins blood flows in the liver lobes decreased with progression of chronic liver disease such as 68±7 (HV), 46±18 (CH), 37±12 (LC) ml/min/100 g in the right liver lobe, and 71±9 (HV), 45±19 (CH), 35±15 (LC) ml/min/100 g in the left liver lobe, respectively. Arterial blood flow measured by Xe-CT in the left liver lobe increased with Child-Pugh classification and portal blood flow in the liver lobes decreased with Child-Pugh classification in patients with LC. Our results suggest Xe-CT is expected as the non-invasive and easy method for evaluating intrahepatic blood flow divided from portal veins and arteries in patients with chronic liver diseases. (author)

  18. Blood Glucose Prediction Using Artificial Neural Networks Trained with the AIDA Diabetes Simulator: A Proof-of-Concept Pilot Study

    Directory of Open Access Journals (Sweden)

    Gavin Robertson

    2011-01-01

    Full Text Available Diabetes mellitus is a major, and increasing, global problem. However, it has been shown that, through good management of blood glucose levels (BGLs, the associated and costly complications can be reduced significantly. In this pilot study, Elman recurrent artificial neural networks (ANNs were used to make BGL predictions based on a history of BGLs, meal intake, and insulin injections. Twenty-eight datasets (from a single case scenario were compiled from the freeware mathematical diabetes simulator, AIDA. It was found that the most accurate predictions were made during the nocturnal period of the 24 hour daily cycle. The accuracy of the nocturnal predictions was measured as the root mean square error over five test days (RMSE5 day not used during ANN training. For BGL predictions of up to 1 hour a RMSE5 day of (±SD 0.15±0.04 mmol/L was observed. For BGL predictions up to 10 hours, a RMSE5  day of (±SD 0.14±0.16 mmol/L was observed. Future research will investigate a wider range of AIDA case scenarios, real-patient data, and data relating to other factors influencing BGLs. ANN paradigms based on real-time recurrent learning will also be explored to accommodate dynamic physiology in diabetes.

  19. Glytube: a conical tube and parafilm M-based method as a simplified device to artificially blood-feed the dengue vector mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    André Luis Costa-da-Silva

    Full Text Available Aedes aegypti, the main vector of dengue virus, requires a blood meal to produce eggs. Although live animals are still the main blood source for laboratory colonies, many artificial feeders are available. These feeders are also the best method for experimental oral infection of Ae. aegypti with Dengue viruses. However, most of them are expensive or laborious to construct. Based on principle of Rutledge-type feeder, a conventional conical tube, glycerol and Parafilm-M were used to develop a simple in-house feeder device. The blood feeding efficiency of this apparatus was compared to a live blood source, mice, and no significant differences (p = 0.1189 were observed between artificial-fed (51.3% of engorgement and mice-fed groups (40.6%. Thus, an easy to assemble and cost-effective artificial feeder, designated "Glytube" was developed in this report. This simple and efficient feeding device can be built with common laboratory materials for research on Ae. aegypti.

  20. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    Directory of Open Access Journals (Sweden)

    Anne-SophieG.T.Bronzwaer

    2014-04-01

    Full Text Available Rationale:\tA critical reduction in central blood volume (CBV is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV. Stroke volume index (SVI serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI and regional brain perfusion during CBV depletion and repletion in spontaneously breathing volunteers. Methods: This study quantified in 14 healthy subjects (11 male the effects of CBV depletion (by 30 and 70 degrees passive head-up tilt (HUT and a fluid challenge (by tilt back on CBV (thoracic admittance, mean middle cerebral artery (MCA blood flow velocity (Vmean, SVI, cardiac index (CI , PPV and SPV. Results: PPV (103±89%, p< 0.05 and SPV (136±117%, p< 0.05 increased with progression of central hypovolemia manifested by a reduction in thoracic admittance (11±5%, p< 0.001, SVI (28±6%, p< 0.001, CI (6±8%, p< 0.001 and MCAVmean (17±7%, p< 0.05 but not in arterial pressure. The reduction in MCAVmean correlated to the fall in SVI (R2=0.52, p< 0.0001 and inversely to PPV and SPV (R2=0.46 (p< 0.0001 and R2=0.45 (p< 0.0001, respectively. PPV and SPV predicted a ≥15% reduction in MCAVmean and SVI with comparable sensitivity (67%/ 67% vs. 63%/ 68% respectively and specificity (89%/94% vs. 89%/94%, respectively. A rapid fluid challenge by tilt-back restored all parameters to baseline values within one minute. Conclusion: In spontaneously breathing subjects, a reduction in MCAVmean was related to an increase in PPV and SPV during graded CBV depletion and repletion. Specifically, PPV and SPV predicted changes in both SVI and MCAVmean with comparable sensitivity and specificity, however the predictive value is limited in spontaneously breathing subjects.

  1. 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...

  2. Quality of the blood pressure phenotype in the GEnotipo, Fenotipo y Ambiente de la hipertensión arterial en UruguaY (GEFA-HT-UY) study

    OpenAIRE

    Luzardo, Leonella; Sottolano, Mariana; Lujambio, Inés; Robaina, Sebastián; Thijs, Lutgarde; da Rosa, Alicia; Krul, Nadia; Carusso, Florencia; Ríos, Ana C; Olascoaga, Alicia; Noboa, Oscar; Staessen, Jan A.; Boggia, José

    2014-01-01

    In the ongoing GEnotipo, Fenotipo y Ambiente de la HiperTensión Arterial en UruguaY (GEFA-HT-UY) study, we applied standardized epidemiological methods to determine complex phenotypes including blood pressure (BP). In this report, we present the quality control of the conventionally measured BP.

  3. Distinct alterations in sublingual microcirculatory blood flow and hemoglobin oxygenation in on-pump and off-pump coronary artery bypass graft surgery

    NARCIS (Netherlands)

    B. Atasever; C. Boer; P. Goedhart; J. Biervliet; J. Seyffert; R. Speekenbrink; L. Schwarte; B. de Mol; C. Ince

    2011-01-01

    The authors hypothesized that cardiopulmonary bypass (CPB) (on-pump) is associated with more severe changes in the microcirculatory blood flow and tissue oxygenation as compared with off-pump coronary artery bypass surgery. An observational study. A university hospital and teaching hospital. Patient

  4. Angioplasty and stenting for severe vertebral artery oriifce stenosis:effects on cerebellar function remodeling veriifed by blood oxygen level-dependent functional magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Bo Liu; Zhiwei Li; Peng Xie

    2014-01-01

    Vertebral artery oriifce stenting may improve blood supply of the posterior circulation of the brain to regions such as the cerebellum and brainstem. However, previous studies have mainly focused on recovery of cerebral blood lfow and perfusion in the posterior circulation after inter-ventional therapy. This study examined the effects of functional recovery of local brain tissue on cerebellar function remodeling using blood oxygen level-dependent functional magnetic reso-nance imaging before and after interventional therapy. A total of 40 Chinese patients with severe unilateral vertebral artery oriifce stenosis were enrolled in this study. Patients were equally and randomly assigned to intervention and control groups. The control group received drug treat-ment only. The intervention group received vertebral artery oriifce angioplasty and stenting+identical drug treatment to the control group. At 13 days after treatment, the Dizziness Handicap Inventory score was compared between the intervention and control groups. Cerebellar function remodeling was observed between the two groups using blood oxygen level-dependent function-al magnetic resonance imaging. The improvement in dizziness handicap and cerebellar function was more obvious in the intervention group than in the control group. Interventional therapy for severe vertebral artery oriifce stenosis may effectively promote cerebellar function remodeling and exert neuroprotective effects.

  5. The Effect of Diaphragmatic Plication on Pulmonary Function Test, Dyspnea Score and Arterial Blood Gases: Analysis 11 Patients with Diaphragmatic Elevation

    Directory of Open Access Journals (Sweden)

    Osman Toktas

    2011-05-01

    Full Text Available Aim: Diaphragmatic evantration or paralysis in adults is associated with respiratory distress. In this study, we aimed to compare preoperative and postoperative pulmonary function tests, arterial blood gas analyses and dyspnea scores of the cases in whom plication had been performed for diaphragmatic elevation. Material and Methods: Between January 2004 and March 2010 eleven adult patients who had undergone diaphragmatic plication due to diaphragmatic paralysis and eventration were analyzed. There were 7 (63.63% men and 4 (36.37% women aged 28-65 (mean 38 ± 2.9. Diaphragmatic plication was performed. Pulmonary function test, dyspnea scores, and arterial blood gases in the preoperative and postoperative period were studied. Results: Dyspnea was present in all of the cases and a decrease in both FVC, FEV1, FEV1/FVC values of pulmonary function test and partial pressure of oxygen in the arterial blood were observed. In chest x-ray and thorax computed tomography, it was detected that right or left diaphragm was elevated. Diaphragmatic paralysis was detected by fluoroscopy in 6 patients. Transthoracally, diaphragmatic plication was performed to the cases. There were no postoperative complications or deaths. In postoperative six and twelve months, significant improvements in the symptoms, the values of pulmonary function tests, partial pressure of oxygen in the arterial blood and dyspnea scores of the patients were observed. Conclusions: Diaphragmatic plication is a safe and effective procedure for adult patients with dyspnea due to unilateral diaphragmatic elevation. Lung expansion is easily achieved by performing diaphragm plication.

  6. Blood pressure telemonitoring is useful to achieve blood pressure control in inadequately treated patients with arterial hypertension.

    Science.gov (United States)

    Neumann, C L; Menne, J; Rieken, E M; Fischer, N; Weber, M H; Haller, H; Schulz, E G

    2011-12-01

    Failing to reach blood pressure (BP) goals is one of the main problems in hypertension management. Especially in high-risk patients, intensive monitoring including frequently office visits or new techniques to monitor home BP is required. A total of 60 patients with uncontrolled hypertension were included and randomized into a group with telemetric BP monitoring (TBPM) (n=30) and a control group receiving standard care (n=30). During the 3-month study period, patients received in addition to their antihypertensive pre-treatment up to 2 × 300 mg irbesartan to achieve the required target BP. All patients were instructed to measure their BP once daily in the morning. In the TBPM group automatic alerts were generated by the central database server using pre-defined algorithms and patients were subsequently contacted by the physician. At baseline mean 24-h ambulant BP monitoring (ABPM) was 143.3±11.1/82.6±9.9 mm Hg in the TBPM group and 141.4±12.6/82.1±6.5 mm Hg in the standard care group. During treatment mean systolic BP showed a more intensive decrease in the TBPM vs control group (-17.0±11.1 mm Hg vs -9.8±13.7 mm Hg; P=0.032). Patients in the TBPM group had a more pronounced night dipping and a higher reduction of mean pulse pressure than controls (-8.1±5.9 mm Hg vs -2.8±7.4 mm Hg, P=0.004). After 3 months, TBPM-treated patients were given a higher mean daily dose of irbesartan (375±187 mg vs 222±147 mg in controls; P=titration of the antihypertensive agent is possible. The alarm criteria chosen were useful to improve BP control. PMID:21228822

  7. Collagen-based scaffolds for tissue engineering of small-diameter blood vessels

    OpenAIRE

    Buttafoco, Laura

    2005-01-01

    Atherosclerotic vascular disease, including peripheral and coronary artery disease, is the main cause of morbidity and mortality in the Western society. Although synthetic blood vessel prostheses are successfully being used for large-diameter vascular reconstructions, until now no functional small-diameter (< 6 mm) artificial vascular graft is available. Autologous veins and arteries are currently being used as vessel substitutes, but limitations in arteries supply and compliance mismatch are...

  8. 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.

  9. Low frequency arterial wall movements for indirect blood pressure measurement in man. Validation of a method for non-invasive assessment of blood pressure under the influence of isoprenaline and angiotensin.

    Science.gov (United States)

    Dietz, U; Belz, G G

    1991-05-01

    In order to measure blood pressure noninvasively, the second derivative of the low frequency wall movements of the brachial artery were registered with a piezo-electric pressure probe during deflation of a Riva-Rocci cuff along with the actual cuff pressure. Two characteristic phenomena of this signal have been suggested to reflect systolic and diastolic blood pressure. Appearance of a positive spike phenomenon (S) was suggested to indicate systolic blood pressure and disappearance of a negative preanacrotic notch (D) to indicate diastolic blood pressure. To prove the validity of these suggestions, these phenomena were assessed in 10 young healthy males during isoprenaline and angiotensin induced changes of blood pressure. Intraarterial (A. radialis) and auscultatory (A. brachialis) blood pressures were recorded simultaneously. Determination of systolic blood pressure with the S phenomenon agreed well with invasive and auscultatory results. Invasive diastolic values agreed well with the cuff pressure at the last signal before disappearance of the preanacrotic notch (D1). Data from auscultation agreed less well with the D1 phenomenon. With increasing doses of isoprenaline, the diastolic measurements (D1) tended to be lower than the invasive ones. However, this discrepancy was far discreeter than that seen with ordinary auscultatory blood pressure measurement. We therefore conclude that registrations of low frequency arterial wall movements yield distinct characteristic spike phenomena useful for measurement of blood pressure in good agreement with the invasive method. In addition, the method provides clearly documented records and should be useful in situations which rely on a valid indirect method. PMID:1898428

  10. Epworth's sleepiness scale in outpatients with different values of arterial blood pressure

    Directory of Open Access Journals (Sweden)

    Gus Miguel

    2002-01-01

    Full Text Available OBJECTIVE: To compare sleepiness scores of the Epworth scale in patients with different levels of arterial pressure when undergoing outpatient monitoring within the context of clinical evaluation. METHODS: A total of 157 patients selected for outpatient monitoring of arterial pressure during hypertension evaluation were divided into 3 groups: group 1 - normotensive; group 2 - hypertensive; group 3 - resistant hypertensive. For analysis, values > or = 11 were considered as associated with respiratory disturbances during sleep. RESULTS: Seventeen (10.8% patients in group 1, 112 (71.3% in group 2, and 28 (17.8% in group 3, which was composed of aged, more severely hypertensive individuals, were analyzed. Groups were similar relative to sex and body mass index, but different in relation to systolic and diastolic pressure levels and age. Despite an absolute difference, no statistically significant difference occurred between Epworth scores and in the proportion of patients with values > or = 11 (5.9% vs. 18.8% vs. 212.4%; P=0.37. Despite the positive association between degree of sleepiness measured with the scale and the severity of the hypertension, no statistical significance occurred following control by age (p=0.18. CONCLUSION: A positive correlation exists between degree of sleepiness and hypertension severity. The absence of a statistical significance shown in the present study could be due to a beta type of error. Instruments that render this complaint into an objective finding could help in the pursuit of an investigation of respiratory disturbances during sleep in more severely hypertensive patients, and should therefore be studied better.

  11. Changes in celebral blood flow induced by balloon test occlusion of the internal carotid artery under hypotension

    International Nuclear Information System (INIS)

    Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study has proved to be a sensitive test for prediction of the outcome of permanent vessel occlusion. In this study, we evaluated the acute changes in regional CBF during BTO under hypotension in order to examine the possible risk of cerebral ischaemia after surgical treatment. Eleven patients in whom surgical carotid sacrifice was planned underwent BTO combined with CBF studies using technetium-99m hexamethyl-propylene amine oxime single-photon emission tomography under hypotension by decreasing the systematic blood pressure by about 50 mm Hg using a ganglion blocking agent. All patients showed a mild to severe decrease in CBF in the ipsilateral ICA territory relative to the contralateral side. A decrease in CBF of greater than 20% was observed in nine patients (82%), and two of them showed a decrease exceeding 40%. However, no ischaemic symptoms were demonstrated during scanning with hypotensive BTO. Our results suggest that in many patients with negative normotensive BTO, a considerable reduction in CBF would occur during hypotension. This procedure may predict a possible risk of hypotensive accident during and/or after surgery. (orig.)

  12. Dried Blood Spot Technique for the Monitoring of Ambrisentan, Bosentan, Sildenafil, and Tadalafil in Patients with Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Enderle, Yeliz; Meid, Andreas D; Friedrich, Jörg; Grünig, Ekkehard; Wilkens, Heinrike; Haefeli, Walter E; Burhenne, Jürgen

    2015-12-15

    Endothelin receptor antagonists (ERA) and phosphodiesterase 5 inhibitors (PDE5I) are long-term therapeutics for the treatment of pulmonary arterial hypertension (PAH). Their interindividual pharmacokinetic variability is remarkably large, and despite the seriousness of the disease, nonadherence is occurring. Therefore, methods to monitor sufficient circulating drug levels are essential. The objectives of this study were to develop and validate dried blood spot (DBS) assays for the quantification of ambrisentan, bosentan, sildenafil, tadalafil, and their main metabolites. We also quantified the influence of different hematocrit levels and assessed the correlation of simultaneously taken capillary whole blood (DBS) and venous plasma samples. The aliquot punches were extracted by liquid/liquid extraction followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) quantification methods. All assays fulfilled the requirements of the FDA and EMA guidelines for assay validation with a lower limit of quantification of 2.5 ng/mL for the ERAs, 5 ng/mL for sildenafil, and 10 ng/mL for tadalafil. All analytes were stable for at least 147 days when stored on DBS filter paper cards at room temperature in the dark. Due to poor distribution into erythrocytes, drug concentrations in DBS were always lower than in plasma, resulting in conversion factors of 1.58 for ambrisentan and sildenafil and 1.52 for bosentan and tadalafil. PMID:26583764

  13. Acute effect of oral sensation of sweetness on celiac artery blood flow and gastric myoelectrical activity in humans.

    Science.gov (United States)

    Eguchi, Kohei; Kashima, Hideaki; Yokota, Akiko; Miura, Kohei; Yamaoka Endo, Masako; Hirano, Harutoyo; Tsuji, Toshio; Fukuba, Yoshiyuki

    2016-05-01

    Little is known about the effect of sweet taste stimulus on gastrointestinal motility and splanchnic blood flow. We examined whether gastric myoelectrical activity and/or celiac artery blood flow (CABF), which perfuses the stomach, are increased following an oral sensation of sweetness. After overnight fasting, 11 subjects rested for 5min and sipped, but not swallowed, one of four solutions for 1min. The fluid was then spat out, and subjects remained at rest for a further 10min. Fluids were approximately 15ml of three glucose solutions (4, 16, or 48%) or distilled water. Subjects completed trials with all four solutions in a randomized order. During each trial, gastric myoelectrical activity and CABF were continuously measured using electrogastrography and pulsed Doppler ultrasonography, respectively. None of the four solutions affected gastric myoelectrical activity. CABF was significantly increased after oral stimuli by all three glucose solutions, but not by water. There were no significant differences in the increments in CABF among the three glucose solutions. These results suggest that a sweet taste stimulus above a certain level of intensity acutely increases CABF during cephalic phase, without augmentation of gastric myoelectrical activity. PMID:26987409

  14. Dynamic contrast-enhanced MRI assessment of hyperemic fractional microvascular blood plasma volume in peripheral arterial disease: initial findings.

    Directory of Open Access Journals (Sweden)

    Bas Versluis

    Full Text Available OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI to assess the microvascular status in patients with peripheral arterial disease (PAD and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METHODS: Ten PAD patients with intermittent claudication and 10 healthy control subjects were included. Patients underwent contrast-enhanced MR angiography of the peripheral arteries, followed by one DCE MRI examination of the musculature of the calf. Healthy control subjects were examined twice on different days to determine normative values and the interreader and interscan reproducibility of the technique. The MRI protocol comprised dynamic imaging of contrast agent wash-in under reactive hyperemia conditions of the calf musculature. Using pharmacokinetic modeling the hyperemic fractional microvascular blood plasma volume (V(p, unit: % of the anterior tibial, gastrocnemius and soleus muscles was calculated. RESULTS: V(p was significantly lower for all muscle groups in PAD patients (4.3±1.6%, 5.0±3.3% and 6.1±3.6% for anterior tibial, gastrocnemius and soleus muscles, respectively compared to healthy control subjects (9.1±2.0%, 8.9±1.9% and 9.3±2.1%. Differences in V(p between muscle groups were not significant. The coefficient of variation of V(p varied from 10-14% and 11-16% at interscan and interreader level, respectively. CONCLUSIONS: Using DCE MRI after contrast-enhanced MR angiography with gadofosveset enables reproducible assessment of hyperemic fractional microvascular blood plasma volume of the calf musculature. V(p was lower in PAD patients than in healthy controls, which reflects a promising functional (hemodynamic biomarker for the

  15. Changes of Umbilical Artery Blood Flow Due to Pregnancy Induced Hypertension in the Third Trimester of Pregnancy

    Directory of Open Access Journals (Sweden)

    Sarah Hashemi

    2010-05-01

    Full Text Available Background/Objective: Doppler ultrasound of umbilical vessels is a method of evaluating fetoplacental blood flow which is very important in high risk pregnancies including pregnancy induced hypertension and may predict both the duration of maternal hospitalization and fetal mortality rates in IUGR. In this study, Doppler indices of blood flow through the umbilical artery were measured in patients with pregnancy induced hypertension."nPatients and Methods: This study was a cross-sectional study which was carried out on 101 preg-nant women: 35 patients with pregnancy induced hypertension were in the case group that had no symptoms or signs of pre-eclampsia, eclampsia or diabetes melitus. 61 normal pregnant women were as the control group. All the patients were studied in their third trimester of pregnancy. Doppler ultrasound of the umbilical artery was performed for both the case and the control groups. Peak Systolic Velocity (PSV, End Diastolic Velocity (EDV and mean velocity were measured. The Resistive Index (RI, Pulsatility Index (PI and Systolic to diastolic ratio (S/D ratio were calculated. The statistical analysis was performed on the obtained recorded data, using SPSS software."nResults: The calculated mean values of spectral Doppler indices in the case group were: 0.77 for RI; 1.39 for PI and 4.88 for S/D ratio while in the control group they were calculated as 0.64, 1.08 and 2.97, respectively. Altogether, comparison of the mean values of the mentioned indices revealed a significant difference between the two groups (P<0.01. The case group was significantly rated higher in terms of the above mentioned indices."nConclusion: In patients with pregnancy induced hypertension without any complications (such as pre-eclampsia or eclampsia or without any other risk factors (such as diabetes mellitus and IUGR, Doppler ultrasound should be used for evaluating the degree of fetoplacental blood flow in order to decrease the risk of pregnancy

  16. Patients. comprehension of arterial hypertension and its management versus blood pressure control

    Directory of Open Access Journals (Sweden)

    Marciele V Guimarães

    2010-11-01

    Full Text Available This paper aims to evaluate the comprehension of hypertensive patients of their condition and its management through health practices recognized by the Health Secretariat of the city of Curitiba and adopted in the Basic Health Unit .Vista Alegre.. The methodology used included collection of data about health actions promoted by the Unit, informal interviews with health professionals about how Hypertension Programs work and interviews based on a questionnaire with 50 patients participating in the Hypertension Program, selected and approached in the Health Unit or in household visits, who had their blood pressure taken after the interview. Thirty eight percent could not define hypertension, 72% assumed that nervousness or preoccupation were causes of hypertension, 84% mentioned stroke as consequence of high blood pressure, most of patients knew their medication and how to take it, 41% admitted forgetting to take their medication occasionally or often, 8% revealed not to take it correctly, 10% felt that not taking it sometimes does not make difference. Great part of those not taking their medication declared that this happens because they do not remember to take it, not for lacking it. Two thirds had unfavorable dietary habits and 52% did not engage in physical exercise but most believed that diet and exercise help controlling high blood pressure. Ninety six percent agreed that loosing weight also helps, but 72% were overweight. Only 13 (26% had normal blood pressure; 18% presented with severe hypertension and 20% with moderate hypertension. Analysis of the collected data showed that many patients are unable to define hypertension but know how to control it and are aware of its consequences. The excuses offered for not adapting to changes in their life stile were lack of time, stimulation and proof of benefits.

  17. Pulsatile Non-Newtonian Laminar Blood Flows through Arterial Double Stenoses

    OpenAIRE

    Mir Golam Rabby; Sumaia Parveen Shupti; Md. Mamun Molla

    2014-01-01

    The paper presents a numerical investigation of non-Newtonian modeling effects on unsteady periodic flows in a two-dimensional (2D) pipe with two idealized stenoses of 75% and 50% degrees, respectively. The governing Navier-Stokes equations have been modified using the Cartesian curvilinear coordinates to handle complex geometries. The investigation has been carried out to characterize four different non-Newtonian constitutive equations of blood, namely, the (i) Carreau, (ii) Cross, (iii) Mod...

  18. Impact of sudarshan kriya yoga on mean arterial blood pressure and biochemical parameters in medical students

    Directory of Open Access Journals (Sweden)

    Nisar Ahmad

    2016-06-01

    Conclusions: Living a happy and healthy life on all planes is possible through the unified practice of sudarshan kriya yoga (SKY along with asana and pranayam. The practice of SKY seems to be beneficial on mean blood pressure and biochemical parameters in normal healthy individuals. This unique breathing practice is a potent energizer. [Int J Res Med Sci 2016; 4(6.000: 2150-2152

  19. Aortic and carotid arterial stiffness and epigenetic regulator gene expression changes precede blood pressure rise in stroke-prone Dahl salt-sensitive hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Victoria L Herrera

    Full Text Available Multiple clinical studies show that arterial stiffness, measured as pulse wave velocity (PWV, precedes hypertension and is an independent predictor of hypertension end organ diseases including stroke, cardiovascular disease and chronic kidney disease. Risk factor studies for arterial stiffness implicate age, hypertension and sodium. However, causal mechanisms linking risk factor to arterial stiffness remain to be elucidated. Here, we studied the causal relationship of arterial stiffness and hypertension in the Na-induced, stroke-prone Dahl salt-sensitive (S hypertensive rat model, and analyzed putative molecular mechanisms. Stroke-prone and non-stroke-prone male and female rats were studied at 3- and 6-weeks of age for arterial stiffness (PWV, strain, blood pressure, vessel wall histology, and gene expression changes. Studies showed that increased left carotid and aortic arterial stiffness preceded hypertension, pulse pressure widening, and structural wall changes at the 6-week time-point. Instead, differential gene induction was detected implicating molecular-functional changes in extracellular matrix (ECM structural constituents, modifiers, cell adhesion, and matricellular proteins, as well as in endothelial function, apoptosis balance, and epigenetic regulators. Immunostaining testing histone modifiers Ep300, HDAC3, and PRMT5 levels confirmed carotid artery-upregulation in all three layers: endothelial, smooth muscle and adventitial cells. Our study recapitulates observations in humans that given salt-sensitivity, increased Na-intake induced arterial stiffness before hypertension, increased pulse pressure, and structural vessel wall changes. Differential gene expression changes associated with arterial stiffness suggest a molecular mechanism linking sodium to full-vessel wall response affecting gene-networks involved in vascular ECM structure-function, apoptosis balance, and epigenetic regulation.

  20. Simultaneous mapping of temporally-resolved blood flow velocity and oxygenation in femoral artery and vein during reactive hyperemia

    Directory of Open Access Journals (Sweden)

    Langham Michael C

    2011-10-01

    Full Text Available Abstract Background Post-occlusive hyperemia is often used as a paradigm to evaluate vascular reactivity, for example by measuring post-ischemic flow-mediated dilation, arterial blood flow or temporally resolved venous blood oxygenation (HbO2. Here we demonstrate the feasibility of a simultaneous measurement of blood flow and HbO2 in the femoral circulation as part of a single procedure. Methods A multi-echo GRE pulse sequence was designed and implemented to collect velocity-encoded projections in addition to full-image echoes for field mapping as a means to quantify intravascular magnetic susceptibility. The method's feasibility was evaluated at 3T in a small pilot study involving two groups of healthy subjects (mean ages 26 ± 1.6 and 59 ± 7.3 years, N = 7 and 5, respectively in terms of six parameters characterizing the time-course of reactive hyperemia and their sensitivity to differentiate age effects. The reproducibility was assessed on two of the seven young healthy subjects with three repeated measurements. Results The physiological parameters agree with those obtained with current methods that quantify either velocity or HbO2 alone. Of the six measures of vascular reactivity, one from each group was significantly different in the two subject groups (p Conclusion The proposed method is able quantify multiple parameters that may lead to more detailed assessment of peripheral vascular reactivity in a single cuff paradigm rather than in separate procedures as required previously, thereby improving measurement efficiency and patient comfort.

  1. Peripheral Arterial Disease

    Science.gov (United States)

    Peripheral arterial disease (PAD) happens when there is a narrowing of the blood vessels outside of your heart. The cause of ... smoking. Other risk factors include older age and diseases like diabetes, high blood cholesterol, high blood pressure, ...

  2. Peripheral Artery Disease

    Science.gov (United States)

    ... or atherectomy may be used to help improve blood flow. What is peripheral artery disease (PAD)? How is peripheral artery disease evaluated? How ... PAD are diabetes, smoking, high cholesterol and high blood pressure. Most cases occur in ... is peripheral artery disease evaluated? Several imaging tests can be used to ...

  3. Quadruple-component superficial circumflex iliac artery perforator (SCIP) flap: A chimeric SCIP flap for complex ankle reconstruction of an exposed artificial joint after total ankle arthroplasty.

    Science.gov (United States)

    Yamamoto, Takumi; Saito, Takafumi; Ishiura, Ryohei; Iida, Takuya

    2016-09-01

    Total ankle arthroplasty (TAA) is becoming popular in patients with rheumatoid arthritis (RA)-associated ankle joint degeneration. However, ankle wound complications can occur after TAA, which sometimes requires challenging reconstruction due to anatomical complexity of the ankle. Superficial circumflex iliac artery (SCIA) perforator (SCIP) flap has been reported to be useful for various reconstructions, but no case has been reported regarding a chimeric SCIP flap for complex ankle reconstruction. We report a case of complex ankle defect successfully reconstructed with a free quadruple-component chimeric SCIP flap. A 73-year-old female patient with RA underwent TAA, and suffered from an extensive ankle soft tissue defect (13 × 5 cm) with exposure of the implanted artificial joint and the extensor tendons. A chimeric SCIP flap was raised based on the deep branch and the superficial branch of the SCIA, which included chimeric portions of the sartorius muscle, the deep fascia, the inguinal lymph node (ILN), and the skin/fat. The flap was transferred to the recipient ankle. The sartorius muscle was used to cover the artificial joint, the deep fascia to reconstruct the extensor retinaculum, the ILN to prevent postoperative lymphedema, and the adiposal tissue to put around the extensor tendons for prevention of postoperative adhesion. Postoperatively, the patient could walk by herself without persistent leg edema or bowstringing of the extensor tendons, and was satisfied with the concealable donor scar. Although further studies are required to confirm efficacy, multicomponent chimeric SCIP has a potential to be a useful option for complex defects of the ankle. PMID:27423250

  4. Trans-abdominal monitoring of fetal arterial blood oxygenation using pulse oximetry

    Science.gov (United States)

    Zourabian, Anna; Siegel, Andrew M.; Chance, Britton; Ramanujam, Nirmala; Rode, Martha; Boas, David A.

    2000-10-01

    Pulse oximetry (oxygen saturation monitoring) has markedly improved medical care in many fields, including anesthesiology, intensive care, and newborn intensive care. In obstetrics, fetal heart rate monitoring remains the standard for intrapartum assessment of fetal well being. Fetal oxygen saturation monitoring is a new technique currently under development. It is potentially superior to electronic fetal heart rate monitoring (cardiotocography) because it allows direct assessment of both the fetal oxygen status and fetal tissue perfusion. Here we present the analysis for determining the most optimal wavelength selection for pulse oximetry. The wavelengths we chose as the most optimal are the first in the range of 670 - 720 nm and the second in the range of 825 - 925 nm. Further, we discuss the possible systematic errors during our measurements and their contribution to the obtained saturation results. We present feasibility studies for fetal pulse oximetry, monitored noninvasively through the maternal abdomen. Our preliminary experiments show that the fetal pulse can be discriminated from the maternal pulse and thus, in principle, the fetal arterial oxygen saturation can be obtained. We present the methodology for obtaining these data, and discuss the dependence of our measurements on the fetal position with respect to the optode assembly.

  5. The imidazoline receptors and the central regulation of the arterial blood pressure: a minireview

    Directory of Open Access Journals (Sweden)

    Eduardo Tibiriça

    1993-06-01

    Full Text Available Recently, we proposed the hypothesis according to wich the central hypotensive effect of clonidine and related substances could be related to an action upon specific receptors, requiring the imidazoline or imidazoline-like structures, rather than alpha2-adrenoceptors. Since then, direct evidences have been accumulated to confirm the existence of a population of imidazoline specific binding sites in the brainstem of animals and man, more precisely in the Nucleus Reticularis Lateralis (NRL region of the ventrolateral medulla (VLM, site of the antihypertensive action of clonidine. The purification of the putative endogenous ligand of the imidazoline receptors - named endazoline - is currently being attempted from human brain extracts. This new concept might at last lead to the expected dissociation of the pharmacological mechanisms involved, on the one hand, in the therapeutic antihypertensive effect, and on the other, in their major side-effect, which is sedation. In fact, it has been recently confirmed that hypotension is mediated by the activation of imidazoline preferring receptors (IPR within the NRL region, while sedation is attributed to the inhibition of alpha2-adrenergic mechanisms in the locus coeruleus, which is involved in the control of the sleep-waking cycle. The IPRmay constitute on interesting target for new drugs in the treatment of arterial hypertension. Finally, dysfunctions of this modulatory system which could be involved in the pathophysiologyof some forms of the hypertensive disease are under investigation.

  6. [Effect of the type of diabetes on the prognosis over 4 years of arterial blood pressure].

    Science.gov (United States)

    Mayaudon, H; Dupuy, O; Belmejdoub, G; Bredin, C; Rivetta, F; Avaro, J F; Bauduceau, B

    2000-08-01

    The aim of this study was to analyse over a four years period the blood pressure rise according to the type of diabetes. The study population was composed of 79 diabetic patients (type 1: 36; type 2: 43). An evaluation of diabetes mellitus is undertaken at a four years interval (A0, A4). In the same time, blood pressure level is assessed using clinic BP and 24 h-ambulatory blood pressure monitoring (ABPM). Type 2 diabetic patients were older than type 1 (60.9 +/- 9.5 vs 43.5 +/- 12.5 years, p < 0.001). The two groups did not differ in body mass index, tobacco consumption, diabetes duration, glycemic control and serum creatinine. Hypertension was more frequent in type 2 diabetes (46.5 vs 11.1%, p < 0.01) and baseline systolic but not diastolic casual BP was significantly higher in type 2 diabetes compared with type 1 (142 +/- 14 vs 132 +/- 15 mmHg, p < 0.01). Between A0 and A4 the increase in type 1 and type 2 diabetics casual BP was not significant. Type 1 diabetic patients 24 h-ABPM did not differ from significant manner at A0 and at A4. Type 2 diabetic subjects had an increase in 24 h and night time SBP (24 h: 123 +/- 14 at A0 vs 130 +/- 16 mmHg at A4, p < 0.05; night time: 116 +/- 15 at A0 vs 125 +/- 17 mmHg at A4, p < 0.02). This reduction in nocturnal BP fall was not associated with an increase in diabetes complications frequency. BP evolution seems to be closely linked to the type of diabetes and to patients age. In this study, frequency of diabetes complications does not increase when BP level is lower than references values for ABPM. PMID:10989751

  7. T2 and T2* measurements of fetal brain oxygenation during hypoxia with MRI at 3T: correlation with fetal arterial blood oxygen saturation

    International Nuclear Information System (INIS)

    The purpose of this prospective study was to determine the oxygen saturation of blood in the fetal brain based on T2 and T2* measurements in a fetal sheep model. Five sheep fetuses were investigated during normoxia and hypoxia by 3T MRI. Multi-echo gradient-echo and turbo-spin-echo sequences were performed on the fetal brain. MR-determined oxygen saturation (MR-sO2) of blood in the fetal brain was calculated based on T2 and T2* values. Fetal arterial blood oxygen saturation (blood-sO2) was measured during the two experimental phases. The slope of MR-sO2 as a function of blood-sO2 was estimated and tested for compatibility using the one-sample t-test. During normoxia, mean values for carotid blood oxygen saturation were 67%, 83 ms for T2*, 202 ms for T2 and 96% for MR-sO2. During hypoxia, arterial blood oxygen saturation, T2* and calculated MR-sO2 decreased to 22%, 64 ms, and 68% respectively. The one-sample t-test revealed the slope to be significantly different from 0(T=5.023, df=4, P=0.007). It is feasible to perform quantitative T2 and T2* measurements in the fetal brain. MR-sO2 and fetal arterial blood oxygen saturation correlated significantly. However, based on these data a reliable quantification of fetal brain tissue oxygenation is not possible. (orig.)

  8. T2 and T2* measurements of fetal brain oxygenation during hypoxia with MRI at 3T: correlation with fetal arterial blood oxygen saturation

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, Ulrike; Adam, Gerhard [Universitaetsklinikum Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Kooijman, Hendrik [Philips Medical Systems, Best (Netherlands); Andreas, Thomas; Beindorff, Nicola; Hecher, Kurt [University Hospital Hamburg-Eppendorf, Department of Obstetrics and Prenatal Medicine, Hamburg (Germany)

    2010-01-15

    The purpose of this prospective study was to determine the oxygen saturation of blood in the fetal brain based on T2 and T2* measurements in a fetal sheep model. Five sheep fetuses were investigated during normoxia and hypoxia by 3T MRI. Multi-echo gradient-echo and turbo-spin-echo sequences were performed on the fetal brain. MR-determined oxygen saturation (MR-sO{sub 2}) of blood in the fetal brain was calculated based on T2 and T2* values. Fetal arterial blood oxygen saturation (blood-sO{sub 2}) was measured during the two experimental phases. The slope of MR-sO{sub 2} as a function of blood-sO{sub 2} was estimated and tested for compatibility using the one-sample t-test. During normoxia, mean values for carotid blood oxygen saturation were 67%, 83 ms for T2*, 202 ms for T2 and 96% for MR-sO{sub 2}. During hypoxia, arterial blood oxygen saturation, T2* and calculated MR-sO{sub 2} decreased to 22%, 64 ms, and 68% respectively. The one-sample t-test revealed the slope to be significantly different from 0(T=5.023, df=4, P=0.007). It is feasible to perform quantitative T2 and T2* measurements in the fetal brain. MR-sO{sub 2} and fetal arterial blood oxygen saturation correlated significantly. However, based on these data a reliable quantification of fetal brain tissue oxygenation is not possible. (orig.)

  9. Optimal blood pressure in patients with peripheral artery disease following endovascular therapy.

    Science.gov (United States)

    Sasaki, Haruki; Ura, Nobuyuki; Hata, Shinya; Moniwa, Norihito; Hasegawa, Koichi; Takizawa, Hideki; Tanaka, Shigemichi

    2016-01-01

    This study examined the associations between blood pressure (BP) and event incidence to define optimal BP after endovascular therapy (EVT) in patients who underwent EVT. BP was monitored every 6 months for 5 years, and the patients were divided into two groups by average BP: ≥ 140/90 mmHg and  7.0% was significantly higher among those who did not achieve target BP in the restenosis group (42.9%) than in the other group (10.8%) (p EVT. PMID:26440772

  10. Effects of Restoration of Blood Flow on the Development of Aortic Atherosclerosis in ApoE−/− Mice With Unilateral Renal Artery Stenosis

    OpenAIRE

    Pathak, Alokkumar S.; Huang, Jianhua; Rojas, Mauricio; Bazemore, Taylor C.; Zhou, Ruihai; Stouffer, George A.

    2016-01-01

    Background Chronic unilateral renal artery stenosis (RAS) causes accelerated atherosclerosis in apolipoprotein E–deficient (ApoE−/−) mice, but effects of restoration of renal blood flow on aortic atherosclerosis are unknown. Methods and Results Male ApoE−/− mice underwent sham surgery (n=16) or had partial ligation of the right renal artery (n=41) with the ligature being removed 4 days later (D4LR; n=6), 8 days later (D8LR; n=11), or left in place for 90 days (chronic RAS; n=24). Ligature rem...

  11. Predicting extraction and uptake of arterial energy metabolites by the mammary glands of lactating cows when blood flow is perturbed.

    Science.gov (United States)

    Cant, J P; Madsen, T G; Cieslar, S R L

    2016-01-01

    Previous work shows that mammary uptake of milk precursors from blood can be affected by the rate of blood flow (F) to the glands. The purpose of the current work was to test the ability of compartmental and cylindrical capillary models to account for the variation in mammary extraction and net uptake of plasma metabolites produced by perturbation of mammary F. The data for model fitting were obtained from a previous experiment in which mammary arteriovenous differences of acetate + β-hydroxybutyrate (2C), glucose, triacylglycerol (TAG), and long-chain fatty acids (LCFA) were measured in 4 cows before, during, and after intraarterial infusion of inhibitors of endothelial nitric oxide synthase and cyclooxygenase, which are 2 major systems of F control in the mammary glands. The 4 models tested were (1) constant extraction within each cow, (2) clearance from an extracellular compartment is a linear function of F with an intercept, (3) total capillary volume in a cylindrical representation is a linear function of F with an intercept, and (4) uptake from an extracellular compartment obeys Henri-Michaelis-Menten kinetics, where maximum velocity (Vmax) is a linear function of F with an intercept. According to prediction errors, model 4 fitted 2C extraction data best, accounting for 82% of the observed variation. The estimated Km (Henri-Michaelis-Menten constant) for venous 2C was 0.4 mM. For glucose clearance, a variant of model 2 with a positive effect of 2C uptake on clearance was identified as best, producing a coefficient of determination (R(2)) of 0.31. For TAG, model 2 with a positive effect of arterial TAG concentration on TAG clearance was best, with an R(2) of 0.22. For LCFA, model 2 with a positive effect of arterial LCFA on LCFA clearance was best, with an R(2) of 0.29. Models 2 and 3 fitted the extraction data with the same R(2)-values and prediction errors, so both compartmental and cylindrical approaches to describing the vascular bed were equally capable

  12. [Outcomes of using autologous peripheral-blood stem cells in patients with chronic lower arterial insufficiency].

    Science.gov (United States)

    Maksimov, A V; Kiiasov, A P; Plotnikov, M V; Maianskaia, S D; Shamsutdinova, I I; Gazizov, I M; Mavlikeev, M O

    2011-01-01

    Presented herein are the outcomes of using autologous peripheral blood stem cells (SCs) in patients with stage II В lower limb chronic obliterating diseases (according to A.V. Pokrovsky's classification). Autologous SCs had previously been stimulated by means of the recombinant granulocytic colony stimulating factor (G-CSF) for five days. On day six, we performed mobilization of the peripheral blood stem cells on the MSC+ unit by means of leukopheresis followed by intramuscular administration of half of the obtained dose into the affected extremity. The mean number of the transplanted mononuclears amounted to 6.73 ± 2.2 x 10(9) cells, with the number of CD34+ cells averaging 2.94 ± 2.312 x 10(7). Assessing the therapeutic outcomes at 3 and 6 months of follow-up showed a statistically significant increase in the ankle-brachial pressure index (ABPI) [being at baseline 0.59 ± 0.04, at 3 months - 0.66 ± 0.04 (P=0.001), and after 6 months - 0.73 ± .08 (P=0.035)], accompanied and followed by improved measures of the treadmill test, with the pain-free walking distance at baseline equalling 102.2 ± 11.55 m, after 3 months - 129 ± 11.13 m (P<0.001), and after 6 months - 140 ± 13.11 m=0.021 vs baseline). The findings of the immunohistochemical study confirmed the development of neoangiogenesis in the skeletal muscle and a 25 percent increase in the capillary-network density following administration of autologous stem cells into the muscle. The method of transplanting peripheral-blood autologous stem cells for treatment of patients presenting with distal forms of chronic obliterating insufficiency of the lower limbs proved safe and efficient. The findings obtained during this study made it possible to recommend extending the indications for its application at the expense of patients with critical ischaemia. PMID:21983456

  13. 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

    (SPPH) as measured with a photocell. Thirty-two patients (35 feet with ulcerations) had diabetes mellitus. The treatment was conservative. In 42 feet the ulcers healed after an average period of 5.8 months; in 24 feet major amputation became necessary after an average of 4.3 months. The frequency of...... cases (9%) healed. Of the 11 cases with SDBP of 20 to 29 mmHg seven cases (64%) healed and of the 33 cases with SDBP of30 mmHg or above all cases (100%) healed. There was no significant difference between the 35 diabetic feet and the 31 non-diabetic feet as regards the healing rates, although infection...... and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter....

  14. The Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN) database and analysis pipeline for arterial spin labeling MRI data.

    Science.gov (United States)

    Shin, David D; Ozyurt, I Burak; Liu, Thomas T

    2013-01-01

    Arterial spin labeling (ASL) is a magnetic resonance imaging technique that provides a non-invasive and quantitative measure of cerebral blood flow (CBF). After more than a decade of active research, ASL is now emerging as a robust and reliable CBF measurement technique with increased availability and ease of use. There is a growing number of research and clinical sites using ASL for neuroscience research and clinical care. In this paper, we present an online CBF Database and Analysis Pipeline, collectively called the Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN) that allows researchers to upload and share ASL and clinical data. In addition to serving the role as a central data repository, the CBFBIRN provides a streamlined data processing infrastructure for CBF quantification and group analysis, which has the potential to accelerate the discovery of new scientific and clinical knowledge. All capabilities and features built into the CBFBIRN are accessed online using a web browser through a secure login. In this work, we begin with a general description of the CBFBIRN system data model and its architecture, then devote the remainder of the paper to the CBFBIRN capabilities. The latter part of our work is divided into two processing modules: (1) Data Upload and CBF Quantification Module; (2) Group Analysis Module that supports three types of analysis commonly used in neuroscience research. To date, the CBFBIRN hosts CBF maps and associated clinical data from more than 1,300 individual subjects. The data have been contributed by more than 20 different research studies, investigating the effect of various conditions on CBF including Alzheimer's, schizophrenia, bipolar disorder, depression, traumatic brain injury, HIV, caffeine usage, and methamphetamine abuse. Several example results, generated by the CBFBIRN processing modules, are presented. We conclude with the lessons learned during implementation and deployment of the CBFBIRN and our

  15. Renal Arteriovenous Fistula with Rapid Blood Flow Successfully Treated by Transcatheter Arterial Embolization: Application of Interlocking Detachable Coil as Coil Anchor

    International Nuclear Information System (INIS)

    A 70-year-old woman presented to our outpatient clinic with a large idiopathic renal arteriovenous fistula (AVF). Transcatheter arterial embolization (TAE) using interlocking detachable coils (IDC) as an anchor was planned. However, because of markedly rapid blood flow and excessive coil flexibility, detaching an IDC carried a high risk of migration. Therefore, we first coiled multiple loops of a microcatheter and then loaded it with an IDC. In this way, the coil was well fitted to the arterial wall and could be detached by withdrawing the microcatheter during balloon occlusion ('pre-framing technique'). Complete occlusion of the afferent artery was achieved by additional coiling and absolute ethanol. This technique contributed to a safe embolization of a high-flow AVF, avoiding migration of the IDC

  16. Intra-arterial digital subtraction portography with a blood-isotonic, non-ionic, dimeric contrast medium

    International Nuclear Information System (INIS)

    Intra-arterial digital subtraction portography (IA-DSP) with a blood-isotonic, non-ionic, dimeric contrast medium was carried out in 27 patients with hepatocellular carcinoma. It was possible to obtain images of excellent or good quality of the portal vein and its bilateral main branches in all patients. The third-order branches of the portal vein in the right lobe could be identified in all patients, and images of excellent or good quality were obtained in a mean of 80.2% of patients. Images of third-order branches in the left lobe were of lower quality than those of third-order branches in the right lobe; in particular, images obtained were of poor quality for 27.3% of the medial branches of the left lobe. It was impossible to identify the caudal branches in almost all patients. The side effects of IA-DSP, pain and sensations of heat were very mild; only one patient complained of mild pain, while 18 patients (69.2%) complained of no sensations of heat whatsoever. (author)

  17. Improving cerebral blood flow quantification for arterial spin labeled perfusion MRI by removing residual motion artifacts and global signal fluctuations.

    Science.gov (United States)

    Wang, Ze

    2012-12-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion magnetic resonance imaging (MRI) due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whole brain, removing them in advance should enhance the CBF quantification quality for ASL MRI. The purpose of this paper was to assess this potential benefit. Three methods were proposed to suppress each or both of the two global nuisances. Their performances for CBF quantification were validated using ASL data acquired from 13 subjects. Evaluation results showed that covarying out both global nuisances significantly improved temporal SNR and test-retest stability of CBF measurement. Although the concept of removing both nuisances is not technically novel per se, this paper clearly showed the benefits for ASL CBF quantification. Dissemination of the proposed methods in a free ASL data processing toolbox should be of interest to a broad range of ASL users. PMID:22789842

  18. Blood oxygenation level-dependent MRI of the skeletal muscle during ischemia in patients with peripheral arterial occlusive disease

    International Nuclear Information System (INIS)

    Purpose: to compare calf muscle Blood Oxygenation Level-Dependent (BOLD) response during ischemia in patients suffering from peripheral arterial occlusive disease (PAOD) and age-matched non-PAOD subjects. Materials and methods: PAOD patients with symptoms of intermittent calf claudication and an age-matched control group underwent T2*-weighted single-shot multi-echo planar imaging on a whole-body MR scanner at 1.5 T. The muscle BOLD signal in the calf was acquired during 60 sec of baseline and 240 sec of ischemia induced by cuff compression. T2* time courses in four calf muscles were evaluated. Results: significant differences in the mean T2* values were noted after 150 sec of measurement (p < 0.05). Patients with PAOD revealed a significantly reduced BOLD signal decrease compared to an age-matched control group. Conclusion: potential cause for this observation may be changes in the structure and/or the metabolic turnover of the muscle in PAOD patients. (orig.)

  19. Statistical mapping of effects of middle cerebral artery occlusion (MCAO) on blood flow and oxygen consumption in porcine brain.

    Science.gov (United States)

    Watanabe, Hideaki; Sakoh, Masaharu; Andersen, Flemming; Rodell, Anders; Sørensen, Jens Christian; Østergaard, Leif; Mouridsen, Kim; Cumming, Paul

    2007-02-15

    The volume of cerebral tissue perturbed in experimental models of middle cerebral artery occlusion (MCAO) can be highly variable. Thus, the territories of reduced cerebral blood flow (CBF) or oxygen consumption (CMRO(2)) following MCAO might properly be defined using statistical parametric mapping within a population. In order to establish such a method, we mapped CBF and CMRO(2) in 18 pigs with acute MCAO. Parametric maps were flipped about the axis of symmetry, and CBF and CMRO(2) in the infarcted hemisphere were calculated as percentages of the magnitudes in mirror-image pixels. There were log-linear relationships between the volumes of affected tissue and the percentages of normal CFB or CMRO(2). This graphical analysis showed that the volume of the core deficit was smaller for CBF that for CMRO(2), but expanded more rapidly with decreasing CBF deficit than did the corresponding volumes of reduced CMRO(2). Thus, acute changes in CBF and CMRO(2) following MCAO in the pig can be defined as probabilistic volumes. PMID:17129609

  20. Blood oxygenation level-dependent MRI of the skeletal muscle during ischemia in patients with peripheral arterial occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Potthast, Silke [Unispital Basel, Inst. fuer Radiologie (Switzerland); Schulte, A. [Univ. Hospital Ulm (Germany). Clinic for Radiation Therapy and Radiooncology; Kos, S.; Bilecen, D. [Unispital Basel, Interventional Radiology (Switzerland); Aschwanden, M. [Unispital Basel (Switzerland). Angiologie

    2009-12-15

    Purpose: to compare calf muscle Blood Oxygenation Level-Dependent (BOLD) response during ischemia in patients suffering from peripheral arterial occlusive disease (PAOD) and age-matched non-PAOD subjects. Materials and methods: PAOD patients with symptoms of intermittent calf claudication and an age-matched control group underwent T2*-weighted single-shot multi-echo planar imaging on a whole-body MR scanner at 1.5 T. The muscle BOLD signal in the calf was acquired during 60 sec of baseline and 240 sec of ischemia induced by cuff compression. T2* time courses in four calf muscles were evaluated. Results: significant differences in the mean T2* values were noted after 150 sec of measurement (p < 0.05). Patients with PAOD revealed a significantly reduced BOLD signal decrease compared to an age-matched control group. Conclusion: potential cause for this observation may be changes in the structure and/or the metabolic turnover of the muscle in PAOD patients. (orig.)

  1. Color Doppler analysis of uterine, spiral, and intraovarian artery blood flow before and after treatment with cabergoline in hyperprolactinemic patients.

    Science.gov (United States)

    Temizkan, Osman; Temizkan, Sule; Asicioglu, Osman; Aydin, Kadriye; Kucur, Suna

    2015-01-01

    Prolactin (PRL) may have stimulatory effects on vascular resistance. We aimed to analyze uterine, spiral, and intraovarian artery blood flow by Doppler ultrasonography in hyperprolactinemic patients prior to and after treatment with cabergoline. The study was conducted in Sisli Etfal Training and Research Hospital gynecology outpatient clinic between 1 March 2010 and 30 September 2011. Twenty-four women with symptomatic hyperprolactinemia in reproduction age were included in the study. All hyperprolactinemic patients were studied prior to and following the suppression of circulating PRL levels by cabergoline. Patients were examined by standard B-mod and color transvaginal ultrasonography. Pulsality index (PI), resistance index (RI), and systolic/diastolic ratio (S/D) were recorded. The median PRL value was 86 (62-120) ng/ml before treatment and 4.0 (2.5-6.4) ng/ml after the treatment (p cabergoline treatment. In conclusion, this is a pilot study which shows for the first time that PRL increases the uterine, endometrial, and intraovarian vascular resistance and cabergoline reverses this effect. PMID:25222841

  2. Reconciling paradigms of abnormal pulmonary blood flow and quasi-malignant cellular alterations in pulmonary arterial hypertension.

    Science.gov (United States)

    Happé, C M; Szulcek, R; Voelkel, N F; Bogaard, H J

    2016-08-01

    In pulmonary arterial hypertension (PAH) structural and functional abnormalities of the small lung vessels interact and lead to a progressive increase in pulmonary vascular resistance and right heart failure. A current pathobiological concept characterizes PAH as a 'quasi-malignant' disease focusing on cancer-like alterations in endothelial cells (EC) and the importance of their acquired apoptosis-resistant, hyper-proliferative phenotype in the process of vascular remodeling. While changes in pulmonary blood flow (PBF) have been long-since recognized and linked to the development of PAH, little is known about a possible relationship between an altered PBF and the quasi-malignant cell phenotype in the pulmonary vascular wall. This review summarizes recognized and hypothetical effects of an abnormal PBF on the pulmonary vascular bed and links these to quasi-malignant changes found in the pulmonary endothelium. Here we describe that abnormal PBF does not only trigger a pulmonary vascular cell growth program, but may also maintain the cancer-like phenotype of the endothelium. Consequently, normalization of PBF and EC response to abnormal PBF may represent a treatment strategy in patients with established PAH. PMID:26804008

  3. Acute occlusion of the left subclavian artery with artery dissection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Subclavian steal syndrome is cerebral or brain stem ischemia resulting from diversion of blood flow from the basilar artery to the subclavian artery, which is caused by occlusive disease of either the subclavian artery or the innominate artery before they branch off at the vertebral artery. In the patients with subclavian steal syndrome the subclavian artery is fed by retrograde flow from the vertebral artery via the carotids and the circle of Willis.

  4. Management of femoral artery pseudoaneurysm due to addictive drug injection

    Institute of Scientific and Technical Information of China (English)

    李建文; 王三明; 陈小东

    2004-01-01

    Objective: To study surgical management for patients with femoral pseudoaneurysm resulting from addictive druginjection.Methods: Clinical data of 34 patients with femoral pseudoaneurysm resulting from addictive drug injection were retrospectively reviewed.Results: Thirteen patients underwent bypass graft ( end to side) of external iliac artery and superficial femoral artery using expanded polytetrafluoroethylene (ePTFE).Three patients who had an autogenous saphenous vein graft in situs, one of whom was then performed an ePTFE graft when rupture and bleeding occurred at the anastomotic site. Color Doppler image showed patent grafted blood vessels in all the patients after operation. Eighteen patients had their femoral arteries ligated. Limbs of all the 34 patients were saved.Conclusions: Ligating femoral artery is an effective way to treat femoral artery pseudoaneurysm if autogenous saphenous vein graft or artificial vessel graft is notapplicable.

  5. Treinamento resistido controla a pressão arterial de ratos hipertensos induzidos por l-NAME Resistance training controls arterial blood pressure in rats with L-NAME- induced hypertension

    Directory of Open Access Journals (Sweden)

    Ayslan Jorge Santos de Araujo

    2013-04-01

    -NAME (40 mg/Kg to the drinking water for four weeks. Arterial pressure was evaluated before and after RT. RT was performed using 50% of 1RM, 3 sets of 10 repetitions, 3 times per week for four weeks. Vascular reactivity was measured in rat mesenteric artery rings by concentration-response curves to sodium nitroprusside (SNP; phenylephrine (PHE was also used for histological and stereological analysis. RESULTS: Resistance training inhibited the increase in mean and diastolic arterial pressures. Significant reduction was observed in Rmax (maximal response and pD2 (potency of PHE between SH and TH groups. Arteries demonstrated normal intima, media and adventitia layers in all groups. Stereological analysis demonstrated no significant difference in luminal, tunica media, and total areas of arteries in the SH and TH groups when compared to the SN group. Wall-to-lumen ratio of SH arteries was significantly different compared to SN arteries (p<0.05 but there was no difference when compared to TH arteries. CONCLUSIONS: RT was able to prevent an increase in blood pressure under the conditions in this study. This appears to involve a vasoconstrictor regulation mechanism and maintenance of luminal diameter in L-NAME induced hypertensive rats.

  6. Effect of continuous positive airway pressure on blood pressure in hypertensive patients with coronary artery bypass grafting and obstructive sleep apnea

    OpenAIRE

    Dong, Yumei; Dai, Yingnan; Wei, Guoqian; Cha, Li; Li, Xueqi

    2014-01-01

    Background: Previous studies have documented that obstructive sleep apnea (OSA) increases the incidence of hypertension, respiratory failure and unexpected post-operative deaths during night in coronary artery bypass grafting (CABG) patients. We hypothesized that continuous positive airway pressure (CPAP) reduces blood pressure in these patients. Methods: We conducted a prospective, controlled study in 51 patients. The subjects received CPAP treatment were defined as CPAP group, whereas those...

  7. Decreased numbers of peripheral blood dendritic cells in patients with coronary artery disease are associated with diminished plasma Flt3 ligand levels and impaired plasmacytoid dendritic cell function

    OpenAIRE

    Van Brussel, Ilse; Van Vré, Emily A; De Meyer, Guido RY; Vrints, Christiaan J.; Bosmans, Johan M; Bult, Hidde

    2011-01-01

    Abstract Background: We investigate whether activation of circulating DCs or levels of FMS-like tyrosine kinase 3 ligand (Flt3L) and granulocyte-macrophage colony stimulating factor (GM-CSF), haematopoietic growth factors important for dendritic cell (DC) differentiation, could account for reduced blood DC numbers in coronary artery disease (CAD) patients. Methods: Concentrations of Flt3L and GM-CSF were measured in plasma from CAD patients (n=15) and controls (n=12). Frequenc...

  8. The Effect of Diaphragmatic Plication on Pulmonary Function Test, Dyspnea Score and Arterial Blood Gases: Analysis 11 Patients with Diaphragmatic Elevation

    OpenAIRE

    Osman Toktas; Duygu Mergan; Ufuk Çobanoğlu; Fuat Sayir

    2011-01-01

    Aim: Diaphragmatic evantration or paralysis in adults is associated with respiratory distress. In this study, we aimed to compare preoperative and postoperative pulmonary function tests, arterial blood gas analyses and dyspnea scores of the cases in whom plication had been performed for diaphragmatic elevation. Material and Methods: Between January 2004 and March 2010 eleven adult patients who had undergone diaphragmatic plication due to diaphragmatic paralysis and eventration were analyzed. ...

  9. Comparison of Topical Hemostatic Agents in a Swine Model of Extremity Arterial Hemorrhage: BloodSTOP iX Battle Matrix vs. QuikClot Combat Gauze

    Science.gov (United States)

    Li, Huixi; Wang, Lin; Alwaal, Amjad; Lee, Yung-Chin; Reed-Maldonado, Amanda; Spangler, Taylor A.; Banie, Lia; O’Hara, Reginald B.; Lin, Guiting

    2016-01-01

    BloodSTOP iX Battle Matrix (BM) and QuikClot Combat Gauze (CG) have both been used to treat traumatic bleeding. The purpose of this study was to examine the efficacy and initial safety of both products in a swine extremity arterial hemorrhage model, which mimics combat injury. Swine (37.13 ± 0.56 kg, NBM = 11, NCG = 9) were anesthetized and splenectomized. We then isolated the femoral arteries and performed a 6 mm arteriotomy. After 45 s of free bleeding, either BM or CG was applied. Fluid resuscitation was provided to maintain a mean arterial pressure of 65 mmHg. Animals were observed for three hours or until death. Fluoroscopic angiography and wound stability challenge tests were performed on survivors. Tissue samples were collected for histologic examination. Stable hemostasis was achieved in 11/11 BM and 5/9 CG subjects, with recovery of mean arterial pressure and animal survival for three hours (p Histologic evidence indicated no wound site, distal limb or major organ damage in either group. BM is more effective and portable in treating arterial hemorrhage compared to CG. There was no histologic evidence of further damage in either group. PMID:27077848

  10. Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls

    OpenAIRE

    Namdar, M; Schepis, T; Koepfli, P; Gaemperli, O; Siegrist, P T; Grathwohl, R; Valenta, I; R. Delaloye; Klainguti, M; Wyss, C A; Lüscher, T F; Kaufmann, P A

    2009-01-01

    BACKGROUND: Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD). METHODOLOGY/PRINCIPAL FINDINGS: MBF was measured with (15)O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean a...

  11. Caffeine Impairs Myocardial Blood Flow Response to Physical Exercise in Patients with Coronary Artery Disease as well as in Age-Matched Controls

    OpenAIRE

    Mehdi Namdar; Tiziano Schepis; Pascal Koepfli; Oliver Gaemperli; Siegrist, Patrick T.; Renate Grathwohl; Ines Valenta; Raphael Delaloye; Michael Klainguti; Wyss, Christophe A.; Lüscher, Thomas F.; Kaufmann, Philipp A.

    2009-01-01

    BACKGROUND: Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD). METHODOLOGY/PRINCIPAL FINDINGS: MBF was measured with (15)O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean a...

  12. CORRELATION OF VOLUME BLOOD CIRCULATION IN THE HEPATIC ARTERY AND THE STATE OF MICROCIRCULATORY BLOODSTREAM OF THE TRANSPLANTED LIVER AFTER ITS REVASCULIZATION

    Directory of Open Access Journals (Sweden)

    D. A. Granov

    2014-01-01

    Full Text Available Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30 comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30 had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC in the hepatic artery (HA was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01.Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.

  13. Segmental abnormal perfusion in the liver: Relation between hepatic arterial and portal vein blood flow in the fast contrast CT

    International Nuclear Information System (INIS)

    Sixty seven cases of segmental arterial hyperperfusion and thirty one cases of segmental portal hypoperfusion detected among 803 cases of arterial and portal dominant CT were studied for the evaluation of etiology and mechanism casuing intrahepatic segmental abnormal perfusion in normal portion of the liver around hepatic mass. Hepatic masses casuing segmental abnormal perfusion were hepatocellular carcinoma, peripheral cholangiocarcinoma, metastasis, abscess, and cavernous hemangioma. Segmental portal hypoperfusion was seen on the area of segmental arterial hyperperfusion in all the cases and segmental arterial hyperperfusion was seen on the area of segmental portal hypoperfusion in 77% of cases. In conclusion, there are intrahepatic segmental portal and arterial abnormal perfusions in normal portion around hepatic mass, and these phenomena may be developed with close reciprocal alteration between both portal and hepatic arterial flows

  14. Peripheral artery disease - legs

    Science.gov (United States)

    ... if they have a history of: Abnormal cholesterol Diabetes Heart disease (coronary artery disease) High blood pressure ( hypertension ) Kidney disease involving hemodialysis Smoking Stroke ( cerebrovascular disease )

  15. Computer Simulations of Pulsatile Human Blood Flow Through 3D-Models of the Human Aortic Arch, Vessels of Simple Geometry and a Bifurcated Artery: Investigation of Blood Viscosity and Turbulent Effects

    CERN Document Server

    Sultanov, Renat A

    2008-01-01

    We report computational results of blood flow through a model of the human aortic arch and a vessel of actual diameter and length. On the top of the aortic arch the branching of the %%three arteries are included: the subclavian and jugular. A realistic pulsatile flow is used in all simulations. Calculations for bifurcation type vessels are also carried out and presented. Different mathematical methods for numerical solution of the fluid dynamics equations have been considered. The non-Newtonian behaviour of the human blood is investigated together with turbulence effects. A detailed time-dependent mathematical convergence test has been carried out. The results of computer simulations of the blood flow in vessels of three different geometries are presented: for pressure, strain rate and velocity component distributions we found significant disagreements between our results obtained with realistic non-Newtonian treatment of human blood and the widely used method in the literature: a simple Newtonian approximati...

  16. The influence of hyperoxia on regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and cerebral blood flow velocity in the middle cerebral artery (CBFVMCA) in human volunteers.

    Science.gov (United States)

    Kolbitsch, Christian; Lorenz, Ingo H; Hörmann, Christoph; Hinteregger, Martin; Löckinger, Alexander; Moser, Patrizia L; Kremser, Christian; Schocke, Michael; Felber, Stephan; Pfeiffer, Karl P; Benzer, Arnulf

    2002-09-01

    Conflicting results reported on the effects of hyperoxia on cerebral hemodynamics have been attributed mainly to methodical and species differences. In the present study contrast-enhanced magnetic resonance imaging (MRI) perfusion measurement was used to analyze the influence of hyperoxia (fraction of inspired oxygen (FiO2) = 1.0) on regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) in awake, normoventilating volunteers (n = 19). Furthermore, the experiment was repeated in 20 volunteers for transcranial Doppler sonography (TCD) measurement of cerebral blood flow velocity in the middle cerebral artery (CBFV(MCA)). When compared to normoxia (FiO2 = 0.21), hyperoxia heterogeneously influenced rCBV (4.95 +/- 0.02 to 12.87 +/- 0.08 mL/100g (FiO2 = 0.21) vs. 4.50 +/- 0.02 to 13.09 +/- 0.09 mL/100g (FiO2 = 1.0). In contrast, hyperoxia diminished rCBF in all regions (68.08 +/- 0.38 to 199.58 +/- 1.58 mL/100g/min (FiO2 = 0.21) vs. 58.63 +/- 0.32 to 175.16 +/- 1.51 mL/100g/min (FiO2 = 1.0)) except in parietal and left frontal gray matter. CBFV(MCA) remained unchanged regardless of the inspired oxygen fraction (62 +/- 9 cm/s (FiO2 = 0.21) vs. 64 +/- 8 cm/s (FiO2 = 1.0)). Finding CBFV(MCA) unchanged during hyperoxia is consistent with the present study's unchanged rCBF in parietal and left frontal gray matter. In these fronto-parietal regions predominantly fed by the middle cerebral artery, the vasoconstrictor effect of oxygen was probably counteracted by increased perfusion of foci of neuronal activity controlling general behavior and arousal. PMID:12413599

  17. [Comparative analysis of action of beta-phenyl derivatives of glutamic and gamma-aminobutyric acid on cerebral blood flow and cerebrovascular endothelium after irreversible occlusion of the common carotid artery].

    Science.gov (United States)

    Volotova, E V; Kurkin, D V; Mazina, N V; Berestovitskaia, V M; Vasil'eva, O S

    2013-01-01

    A comparative analysis of the effect of phenyl derivatives of glutamic (RGPU-135) and gamma-aminobutyric acid (Phenibut) on cerebral blood flow, vasodilatory endothelial function and the number of circulating endothelial cells desquamated in animals after irreversible occlusion of the common carotid arteries. It was found that animals treated prophylactically by RGPU-135, after occlusion of the common carotid arteries have higher cerebral blood flow and lower the severity of endothelial dysfunction than in animals treated with Phenibut. PMID:24003482

  18. Effects of Cardiopulmonary Bypass on Mediastinal Drainage and the Use of Blood Products in the Intensive Care Unit in 60- to 80-Year-Old Patients Who Have Undergone Coronary Artery Bypass Grafting

    OpenAIRE

    Fatih Aygün; Mehmet Özülkü; Murat Günday

    2015-01-01

    ABSTRACT OBJECTIVE: The present study consisted of patients who underwent on-pump coronary artery bypass grafting (CABG) and off-pump CABG and investigated effect of using cardiopulmonary bypass (CPB) on the amount of postoperative drainage and blood products, red blood cell (RBC), free frozen plasma (FFP) given in the intensive care unit in 60-80-year-old patients who underwent CABG. METHODS: The present study comprises a total of 174 patients who have undergone coronary artery bypass graf...

  19. Determinants of exercise peak arterial blood pressure, circulatory power, and exercise cardiac power in a population based sample of Finnish male and female aged 30 to 47 years: the Cardiovascular Risk in Young Finns Study

    OpenAIRE

    Hulkkonen, Janne; Aatola, Heikki; Pälve, Kristiina; Lehtimäki, Terho; Hutri-Kähönen, Nina; Viikari, Jorma SA; Raitakari, Olli T.; Kähönen, Mika

    2014-01-01

    Background Novel parameters derived from peak maximal oxygen uptake (VO2) and exercise arterial blood pressure, such as peak circulatory power (CP) and exercise cardiac power (ECP), can be used in the risk assessment of cardiovascular disease and stroke. However, the determinants of these factors are poorly characterized in the general population. Methods We assessed peak arterial blood pressure, CP and ECP with standardized cardiopulmonary exercise test (CPET) on 281 female and 257 male part...

  20. Stratification of Ambulatory Blood Pressure Monitoring Findings by Cluster Analysis in Patients with Arterial Hypertension, Obesity and Albuminuria

    Directory of Open Access Journals (Sweden)

    Samoyavcheva S.V.

    2013-12-01

    Full Text Available The aim of the investigation was to study the characteristics of ambulatory blood pressure monitoring (ABPM indices in the combination of arterial hypertension (AH with obesity and albuminuria using cluster analysis. Material and Methods. The study involved 70 AH patients randomly chosen, aged from 23 to 71 years (mean age — 47.9 years. ABPM was performed before antihypertensive therapy administration. We estimated body mass index and albuminuria level. ABPM indices were stratified into clusters. Results. Clusters with normal heart rate prevailed in patients with normal weight and overweight, I degree obesity in all AH varuants. Hypertensive clusters with tachycardia were found to prevail in patients with II–III degree obesity. AH structure changed with body mass increase. In overweight and I degree obesity there grows the occurrence of systolic-diastolic AH clusters. In II–III degree obesity the clusters of systolic-diastolic and isolated diastolic AH were revealed less frequently than in normal body weight, while isolated systolic AH clusters were found more frequently. Their occurrence increased in patients with a high albuminuria level as well. Conclusion. ABPM data can be grouped into clusters, and their own pathogenic mechanisms of AH maintenance and regulation seem to prevail in each cluster. In overweight and I degree obesity patients the occurrence of systolic-diastolic AH increases. With obesity degree increase there is the tendency for heart rate rise, and hemodynamic AH variants are redistributed towards the increase of isolated systolic AH, which is likely to be due to the increase in AH severity with vascular wall remodeling progression. Isolated systolic AH prevalence is increasing not only in II–III degree obesity, but also in high albuminuria supporting the significance of systolic AH in albuminuria development. No interaction between albuminuria and heart rate was revealed.

  1. Acute post-exercise change in blood pressure and exercise training response in patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Antti M Kiviniemi

    2015-01-01

    Full Text Available We tested the hypothesis that acute post-exercise change in blood pressure (BP may predict exercise training responses in BP in patients with coronary artery disease (CAD. Patients with CAD (n=116, age 62±5 years, 85 men underwent BP assessments at rest and during 10-min recovery following a symptom-limited exercise test before and after the 6-month training intervention (one strength and 3-4 aerobic moderate-intensity exercises weekly. Post-exercise change in systolic BP (SBP was calculated by subtracting resting SBP from lowest post-exercise SBP. The training-induced change in resting SBP was -2±13 mmHg (p=0.064, ranging from -42 to 35 mmHg. Larger post-exercise decrease in SBP and baseline resting SBP predicted a larger training-induced decrement in SBP (β=0.46 and β=-0.44, respectively, p<0.001 for both. Acute post-exercise decrease in SBP provided additive value to baseline resting SBP in the prediction of training-induced change in resting SBP (R squared from 0.20 to 0.26, p=0.002. After further adjustments for other potential confounders (sex, age, baseline body mass index, realized training load, post-exercise decrease in SBP still predicted the training response in resting SBP (β=0.26, p=0.015. Acute post-exercise change in SBP was associated with training-induced change in resting SBP in patients with CAD, providing significant predictive information beyond baseline resting SBP.

  2. The Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN Database and Analysis Pipeline for Arterial Spin Labeling MRI Data

    Directory of Open Access Journals (Sweden)

    David D. Shin

    2013-10-01

    Full Text Available Arterial spin labeling (ASL is a MRI technique that provides a noninvasive and quantitative measure of cerebral blood flow (CBF. After more than a decade of active research, ASL is now emerging as a robust and reliable CBF measurement technique with increased availability and ease of use. There is a growing number of research and clinical sites using ASL for neuroscience research and clinical care. In this paper, we present an online CBF Database and Analysis Pipeline, collectively called the CBFBIRN that allows researchers to upload and share ASL and clinical data. In addition to serving the role as a central data repository, the CBFBIRN provides a streamlined data processing infrastructure for CBF quantification and group analysis, which has the potential to accelerate the discovery of new scientific and clinical knowledge. All capabilities and features built into the CBFBIRN are accessed online using a web browser through a secure login. In this work, we begin with a general description of the CBFBIRN system data model and its architecture, then devote the remainder of the paper to the CBFBIRN capabilities. The latter part of our work is divided into two processing modules: 1 Data Upload and CBF Quantification Module; 2 Group Analysis Module that supports three types of analysis commonly used in neuroscience research. To date, the CBFBIRN hosts CBF maps and associated clinical data from more than 1300 individual subjects. The data have been contributed by more than 20 different research studies, investigating the effect of various conditions on CBF including Alzheimer’s, schizophrenia, bipolar disorder, depression, traumatic brain injury, HIV, caffeine usage and Methamphetamine abuse. Several example results, generated by the CBFBIRN processing modules, are presented. We conclude with the lessons learned during implementation and deployment of the CBFBIRN and our experience in promoting data sharing.

  3. Comparison of myocardial blood flow induced by adenosine triphosphate and dipyridamole in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Myocardial perfusion imaging with adenosine triphosphate (ATP) has been used increasingly to diagnose coronary artery disease (CAD) and assess risk for this disease. This study compared absolute myocardial blood flow (MBF) and myocardial flow reserve index (MFR) with ATP and dipyridamole (DIP) in patients with CAD. MBF was quantified by 15O-H2O PET in 21 patients with CAD (17 male, 4 female), aged 55 to 81 years. MBF was measured at rest, during intravenous injection of ATP (0.16 mg/kg/min), and again after DIP infusion (0.56 mg/kg). Regions of interest were drawn in nonischemic and ischemic segments based on findings from thallium-201 (201Tl) scintigraphy and coronary angiography (CAG). Absolute MBF values and indexes of MFR were calculated in nonischemic and ischemic segments. Intravenous injection of ATP and DIP significantly increased MBF in nonischemic (2.4±0.9 and 2.1±0.8 ml/g/min, respectively; p<0.01, for both) and in ischemic segments (1.3±0.4 and 1.5±0.4 ml/g/min, respectively; p<0.01, for both). There was a significant difference in MBF values between ATP and DIP in nonischemic segments (p<0.05), which was not observed in ischemic segments. In nonischemic segments, ATP produced higher MFR than DIP (2.1±0.8 and 1.8±0.7, respectively; p<0.05), while no significant difference was observed in ischemic segments (1.5±0.6 and 1.7±0.3, respectively). ATP produced a greater hyperemia than DIP between the ischemic and nonischemic myocardium in patients with CAD. ATP is as effective as DIP for the diagnosis of CAD. (author)

  4. Cerebral blood flow changes in hemodialysis and peritoneal dialysis patients: an arterial-spin labeling MR imaging.

    Science.gov (United States)

    Jiang, Xiao Lu; Wen, Ji Qiu; Zhang, Long Jiang; Zheng, Gang; Li, Xue; Zhang, Zhe; Liu, Ya; Zheng, Li Juan; Wu, Long; Chen, Hui Juan; Kong, Xiang; Luo, Song; Lu, Guang Ming; Ji, Xue Man; Zhang, Zong Jun

    2016-08-01

    We used arterial-spin labeling (ASL) MR imaging, a non-invasive technique to evaluate cerebral blood flow (CBF) changes in patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) and hemodialysis (HD), and nondialysis ESRD patients compared with healthy cohort. Ninety seven ESRD patients including 32 PD patients (20 male, 12 female; mean age 33 ± 8 years), 33 HD patients (22 male, 11 female; mean age 33 ± 8 years) and 32 nondialysis patients (20 male, 12 female; mean age 35 ± 7 years) and 31 age- and gender-matched healthy controls (20 male, 11 female; mean age 32 ± 8 years) were included in this study. All subjects underwent ASL MR imaging, neuropsychologic tests, and ESRD patients underwent laboratory testing. CBF values were compared among PD, HD, nondialysis patients and control groups. Correlation analysis and multiple regression analysis were performed to investigate the association between CBF values and hemoglobin, neuropsychologic test results, serum creatinine, urea levels, disease duration, and dialysis duration. Elevated CBFs of whole brain region, gray matter, and white matter were found in all ESRD patient groups compared with healthy controls (all P differences for CBF between PD and HD patient groups. Negative correlations were observed between mean CBFs of whole brain region, gray matter, and white matter and the hemoglobin level in all ESRD patients. Multiple linear regression showed elevated CBF of multiple brain areas correlated with some neuropsychological tests in ESRD patients (all P differences of CBF change and cognitive function between PD and HD ESRD patients with long-term treatment. The degree of anemia may be a predominant risk factor for cognitive impairment in these ESRD patients. PMID:27167984

  5. Anatomy of the blood supply [by the circumflexa ilium profunda artery] to the flank of the sheep

    International Nuclear Information System (INIS)

    The anatomy of the circumflexa ilium profunda artery supplying the flank of the sheep was investigated in 25 sheep. Two constant branches were identified by dissection and angiography, and the cutaneous areas they supply identified. The arterial system was used successfully in 2 separate experiments

  6. Anatomical Variations of the Blood Vascular System in Veterinary Medicine. The Internal Iliac Artery of the Dog. Part Two.

    Science.gov (United States)

    Avedillo, L; Martín-Alguacil, N; Salazar, I

    2016-04-01

    The aim of this study was to investigate the variability of the internal pudendal artery. Two hundred and thirty-two pelvic halves from 116 adult dogs were examined. Twenty-six anatomical variations were found, thirteen occurring in more than 5% of the dogs. Anatomical variations were grouped in relation to the origin of the prostatic/vaginal arteries, middle rectal artery, urethral artery, ventral perineal and caudal rectal arteries. The chi-squared test was used to analyse differences in sex, side of the body, profile and size, and the results were considered statistically significant when P ≤ 0.05. An identical vascular pattern in both hemipelvises was found for most of the anatomical variations described. PMID:25702925

  7. In-vitro validation of a novel model-based approach to the measurement of arterial blood flow waveforms from dynamic digital x-ray images

    Science.gov (United States)

    Rhode, Kawal; Lambrou, Tryphon; Seifalian, Alexander M.; Hawkes, David J.

    2002-04-01

    We have developed a waveform shape model-based algorithm for the extraction of blood flow from dynamic arterial x-ray angiographic images. We have carried out in-vitro validation of this technique. A pulsatile physiological blood flow circuit was constructed using an anthropomorphic cerebral vascular phantom to simulate the cerebral arterial circulation with whole blood as the fluid. Instantaneous recording of flow from an electromagnetic flow meter (EMF) provided the gold standard measurement. Biplane dynamic digital x-ray images of the vascular phantom with injection of contrast medium were acquired at 25 fps using a PC frame capture card with calibration using a Perspex cube. Principal component analysis was used to construct a shape model by collecting 434 flow waveforms from the EMF under varying flow conditions. Blood flow waveforms were calculated from the angiographic data by using our previous concentration-distance curve matching (ORG) algorithm and by using the new model-based (MB) algorithm. Both instantaneous and mean flow values calculated using the MB algorithm showed greater correlation, less bias, and lower variability than those calculated using the ORG algorithm when compared to the EMF values. We have successfully demonstrated that use of a priori waveform shape information can improve flow measurements from dynamic x-ray angiograms.

  8. Blood flow/pump rotation ratio as an artificial lung performance monitoring tool during extracorporeal respiratory support using centrifugal pumps

    OpenAIRE

    Park, Marcelo; Mendes, Pedro Vitale; Hirota, Adriana Sayuri; dos Santos, Edzangela Vasconcelos; Costa, Eduardo Leite Vieira; Azevedo, Luciano Cesar Pontes

    2015-01-01

    Objective To analyze the correlations of the blood flow/pump rotation ratio and the transmembrane pressure, CO2 and O2 transfer during the extracorporeal respiratory support. Methods Five animals were instrumented and submitted to extracorporeal membrane oxygenation in a five-step protocol, including abdominal sepsis and lung injury. Results This study showed that blood flow/pump rotations ratio variations are dependent on extracorporeal membrane oxygenation blood flow in a positive logarithm...

  9. The prevalence of Chlamydia pneumoniae in the aortic wall and in peripheral blood of patients scheduled for coronary artery bypass grafting.

    Science.gov (United States)

    Kuczaj, A; Stryjewski, P J; Fudal, M; Domal-Kwiatkowska, D; Ryfiński, B; Sliupkas-Dyrda, E; Smolik, S; Węglarz, L; Mazurek, U; Nowalany-Kozielska, E

    2016-01-01

    Some reports confirm a potential role of Chlamydia pneumoniae (ChP) in atherogenesis. In order to explore possible association between ChP and atherosclerosis, investigations were carried out in which the frequency of ChP in the arterial wall and peripheral blood was assessed in a group of patients with chronic coronary artery disease (CAD). Fifty-seven patients were enrolled in the study, 13 women and 44 men aged 61.8±6.5 (47-74), with previously diagnosed CAD, scheduled for planned coronary artery bypass grafting due to clinical indications. Vessel specimens retrieved from the ascending aorta (as a part of routine proximal venous graft development procedure) and peripheral blood mononuclear cells (PBMCs) from venous blood were evaluated for the presence of ChP DNA. Genomic DNA was extracted from PBMCs and vessel specimens. Quantitative real-time polymerase chain reaction (qPCR) was performed to detect ChP DNA. A statistically more frequent occurrence of ChP was observed in aortic tissues compared to blood samples (70.2% vs 56.1%, respectively). Similarly, the number of ChP DNA genomic copies [n/1μg genomic DNA] was significantly higher in tissue specimens compared to blood samples (89±91 vs 41±77, respectively; p=0.0046). In patients without ChP in blood specimens, we observed significantly higher amounts of ChP in tissue specimens compared to patients with ChP in blood specimens (156±71 vs 107±88, respectively; p=0.0453). No correlation was found between the number of ChP DNA copies [n/1μg genomic DNA] in blood and in aortic specimens. The infection of ChP in the aortic wall was connected with hypercholesterolemia (p=0.029) and diabetes (p=0.03). We conclude that Chlamydia pneumoniae is a pathogen frequently occurring in the aortic wall of patients with CAD. The occurrence of ChP DNA in the aortic tissue is related to classic CAD risk factors such as diabetes and dyslipidemia. PMID:27358129

  10. Investigation of the composition of arterial plaques based on arterial waveforms and material properties.

    Science.gov (United States)

    Feng, J; Rajeswaran, T; He, S; Wilkinson, F L; Serracino-Inglott, F; Azzawi, M; Parikh, V; Miraftab, M; Alexander, M Y

    2015-08-01

    Stroke is mainly caused by a narrowing of the carotid artery from a build-up of plaque. The risk of plaque rupture and subsequent stroke is dependent on plaque composition. Advances in imaging modalities offer a non-invasive means to assess the health of blood vessels and detect damage. However, the current diagnosis fails to identify patients with soft lipid plaque that are more susceptible to fissure, resulting in stroke. The aim of this study was to use waveform analysis to identify plaque composition and the risk of rupture. We have investigated pressure and flow by combining an artificial blood flow circuit with tubing containing different materials, to simulate plaques in a blood vessel. We used fat and bone to model lipid and calcification respectively to determine if the composition of plaques can be identified by arterial waveforms. We demonstrate that the arterial plaque models with different percentages of calcification and fat, results in significantly different arterial waveforms. These findings imply that arterial waveform analysis has the potential for further development to identify the vulnerable plaques prone to rupture. These findings could have implications for improved patient prognosis by speed of detection and a more appropriate treatment strategy. PMID:26736431

  11. Carotid artery disease

    Science.gov (United States)

    ... you have had a stroke or TIA, a nervous system (neurological) exam will show other problems. You may also have the following tests: Blood cholesterol and triglycerides test Blood sugar (glucose) test Ultrasound of the carotid arteries ( carotid ...

  12. Left anterior descending coronary artery blood flow and left ventricular unloading during extracorporeal membrane oxygenation support in a swine model of acute cardiogenic shock.

    Science.gov (United States)

    Brehm, Christoph; Schubert, Sarah; Carney, Elizabeth; Ghodsizad, Ali; Koerner, Michael; McCoach, Robert; El-Banayosy, Aly

    2015-02-01

    The impact of extracorporeal membrane oxygenation (ECMO) support on coronary blood flow and left ventricular unloading is still debated. This study aimed to further characterize the influence of ECMO on coronary artery blood flow and its ability to unload the left ventricle in a short-term model of acute cardiogenic shock. Seven anesthetized pigs were intubated and then underwent median sternotomy and cannulation for venoarterial (VA) ECMO. Flow in the left anterior descending (LAD) artery, left atrial pressure (LAP), left ventricular end-diastolic pressure (LVEDP), and mean arterial pressure (MAP) were measured before and after esmolol-induced cardiac dysfunction and after initiating VA-ECMO support. Induction of acute cardiogenic shock was associated with short-term increases in LAP from 8 ± 4 mm Hg to 18 ± 14 mm Hg (P = 0.9) and LVEDP from 5 ± 2 mm Hg to 13 ± 17 mm Hg (P = 0.9), and a decrease in MAP from 63 ± 16 mm Hg to 50 ± 24 mm Hg (P = 0.3). With VA-ECMO support, blood flow in the LAD increased from 28 ± 25 mL/min during acute unsupported cardiogenic shock to 67 ± 50 mL/min (P = 0.003), and LAP and LVEDP decreased to 8 + 5 mm Hg (P = 0.7) and 5 ± 3 mm Hg (P = 0.5), respectively. In this swine model of acute cardiogenic shock, VA-ECMO improved coronary blood flow and provided some degree of left ventricular unloading for the short duration of the study. PMID:24935151

  13. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Marlies, E-mail: marlies.wagner@kgu.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com [Siemens AG, Health Care Sector (Germany); Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Singer, Oliver C., E-mail: o.singer@em.uni-frankfurt.de [Hospital of Goethe University, Department of Neurology (Germany); Berkefeld, Joachim, E-mail: berkefeld@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany)

    2013-08-01

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

  14. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    International Nuclear Information System (INIS)

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy

  15. Diets rich in conjugated linoleic acid and vaccenic acid have no effect on blood pressure and isobaric arterial elasticity in healthy young men

    DEFF Research Database (Denmark)

    Raff, M.; Tholstrup, T.; Sejrsen, K.; Straarup, Ellen Marie; Wiinberg, N.

    2006-01-01

    The objective of this study was to examine the effect on blood pressure (BP) and isobaric arterial elasticity (AE), as a measure of arterial health, of a commercial mixture of conjugated linoleic acids (CLA) and of milk fat produced through livestock feeding to have a high content of vaccenic acid......- and t10, c12-CLA isomers in equal amounts); 2) VA-diet rich in VA (3.6 g/d); or 3) C-diet, a control diet with a low content of VA and CLA. All test diets were based on milk fat. BP and AE (measured by an oscillometric method) were measured before and after the intervention period. The effects of the...... test diets did not differ on any outcome variable: e.g., systolic- and diastolic blood pressure (SBP and DBP), pulse pressure (PP), isobaric arterial compliance (AC), distensibility (AD), or volume (AV). In conclusion, diets rich in milk fat and either CLA or VA have no effect on BP or AE indices in...

  16. Deletion of Cyclooxygenase-2 in the mouse increases arterial blood pressure with no impairment in renal NO production in response to chronic high salt intake

    DEFF Research Database (Denmark)

    Staehr, Mette; Hansen, Pernille B L; Madsen, Kirsten;

    2013-01-01

    Experiments were designed to test the hypothesis that COX-2 activity attenuates the blood pressure increase during high NaCl intake by stimulation of eNOS-mediated NO synthesis in the kidney medulla. COX-2(-/-) (C57BL6) and (+/+) mice were fed a diet with 0.004% (LS) or 4% (HS) NaCl for 18 days....... Arterial blood pressure was recorded continuously using indwelling catheters. Food and water intake and diuresis were measured in metabolic cages. Urine osmolality and excretion of electrolytes, cGMP, cAMP and NOx were determined, as well as plasma NOx and cGMP. There was a significant dependence of blood...... pressure on salt intake and genotype: COX-2(-/-) exhibited higher blood pressure than COX-2(+/+) both on HS and LS intake. COX-2(+/+) littermates displayed an increase in blood pressure on HS vs. LS (102.3±1.1 mmHg vs. 91.9±0.9 mmHg) day and night. The mice exhibited significant blood pressure increases...

  17. Enhancing hippocampal blood flow after cerebral ischemia and vasodilating basilar arteries: in vivo and in vitro neuroprotective effect of antihypertensive DDPH

    Directory of Open Access Journals (Sweden)

    Li Sun

    2015-01-01

    Full Text Available 1-(2,6-Dimethylphenoxy-2-(3,4-dimethoxyphenylethylamino-propane hydrochloride (DDPH is a novel antihypertensive agent based on structural characteristics of mexiletine and verapamine. We investigated the effect of DDPH on vasodilatation and neuroprotection in a rat model of cerebral ischemia in vivo, and a rabbit model of isolated basilar arteries in vitro. Our results show that DDPH (10 mg/kg significantly increased hippocampal blood flow in vivo in cerebral ischemic rats, and exerted dose-dependent relaxation of isolated basilar arteries contracted by histamine or KCl in the in vitro rabbit model. DDPH (3 × 10 -5 M also inhibited histamine-stimulated extracellular calcium influx and intracellular calcium release. Our findings suggest that DDPH has a vasodilative effect both in vivo and in vitro, which mediates a neuroprotective effect on ischemic nerve tissue.

  18. Immediate responses of arterial blood pressure and heart rate to sudden inhalation of high concentrations of isoflurane in normotensive and hypertensive patients.

    Science.gov (United States)

    Ishikawa, T; Nishino, T; Hiraga, K

    1993-11-01

    Inhalation of pungent volatile anesthetics elicits respiratory reflex responses. To clarify whether an upper airway irritation produced by pungent anesthetics can also induce circulatory reflex responses that are clinically significant, a sudden administration of 5% isoflurane by mask was performed during continuous measurement of arterial blood pressure (BP) and heart rate (HR) in eight normotensive and eight hypertensive patients anesthetized with thiamylal and paralyzed with vecuronium. The sudden administration of 5% isoflurane caused immediate increases in BP, HR, and rate pressure products (RPP) in both normotensive and hypertensive patients. The responses observed were more pronounced in hypertensive than in normotensive patients. The circulatory changes in hypertensive patients were sufficient to be clinically significant. Our findings suggest that sudden administration of a high concentration of pungent volatile anesthetics may be associated with transient hypertensive responses in hypertensive patients with coronary artery disease. PMID:8214702

  19. ROLE OF COLOUR DOPPLER: CEREBRAL AND UMBILICAL ARTERIAL BLOOD FLOW VELOCITY IN NORMAL AND GROWTH RESTRICTED PREGNANCY

    OpenAIRE

    Patange; Neha

    2014-01-01

    INTRODUCTION: Doppler velocimetry is a rapid noninvasive test that provides valuable information about haemodynamic situation of the foetus and is an efficient diagnostic test of foetal jeopardy which helps in timely intervention and management of high risk pregnancy for better perinatal outcome. OBJECTIVES: To evaluate middle cerebral artery and umbilical arterial velocity waveforms and their various indices during third trimester of pregnancy. METHODOLOGY: Prospective st...

  20. Reduced blood flow response to acetazolamide reflects pre-existing vasodilation and decreased oxygen metabolism in major cerebral arterial occlusive disease

    International Nuclear Information System (INIS)

    A decrease in the cerebral blood flow (CBF) response to acetazolamide may indicate an increase in cerebral blood volume (CBV) caused by reduced perfusion pressure in patients with major cerebral artery steno-occlusive lesions. However, a decrease in cerebral metabolic rate of oxygen (CMRO2) caused by ischemic changes may also decrease the CBF response to acetazolamide by decreasing the production of carbon dioxide. The purpose of this study was to determine whether the values of CBV and CMRO2 are independent predictors of the CBF response to acetazolamide in major cerebral arterial occlusive disease. We used positron emission tomography to study 30 patients with major cerebral artery steno-occlusive lesions. The CBF response to acetazolamide was assessed by measuring baseline CBF and CBF 10 min after an intravenous injection of 1 g of acetazolamide. Multivariate analysis was used to test the independent predictive value of the CBV and CMRO2 at baseline with respect to the percent change in CBF during acetazolamide administration. Both increased CBV and decreased CMRO2 were significant and independent predictors of the reduced CBF response to acetazolamide. CBV accounted for 25% of the variance in the absolute change in CBF during acetazolamide administration and 42% of the variance in the percent change in CBF, whereas CMRO2 accounted for 19% and 4% of the variance, respectively. In patients with major cerebral arterial occlusive disease, a decrease in CMRO2 may contribute to the reduced CBF response to acetazolamide, although an increase in CBV appears to be the major contributing factor. (orig.)

  1. The Effect of Varied Support Models of BJUT-IIVAD on Coronary Arterial blood flow and wall shear stress: A Primary CFD Study.

    Science.gov (United States)

    Zhang, Qi; Gao, Bin; Gu, Kaiyun; Chang, Yu; Xu, Jinchao; Deuflhard, Peter

    2014-09-17

    BJUT-II VAD is a novel left ventricular assist devices. Because of the special connection between the pump and native heart, the hemodynamic effects of BJTU-II VAD on coronary artery are still unclear. Hence, numerical simulations have conducted to clarify changes in hemodynamic effects of different support modes. A patient specific left coronary arterial geometric model is reconstructed based on the CT data. And 3 support modes, "constant speed mode", "co-pulse modes" and "counter pulse mode" are used in this study. The wall shear stress (WSS), wall shear stress gradient (WSSG), cycle averaged wall shear stress (avWSS), oscillatory shear index (OSI) and the flow pattern are calculated to evaluate the hemodynamic states of coronary artery. The computational results demonstrate that the hemodynamic states of coronary artery are directly affected by the support modes. The co-pulse modes could achieve the highest blood perfusion (constant speed: 153ml/min vs. co-pulse: 775ml/min vs. counter pulse: 140ml/min) and the highest avWSS (constant speed: 18.1Pa vs. co-pulse: 42.6Pa vs. counter pulse: 22.6Pa). In addition, the WSS and WSSG at the time of peak blood velocity under the constant speed mode are both lower than those under other two support modes. In contrast, the counter pulse mode generates the highest OSI value (constant speed: 0.365 vs. co-pulse: 0.379 vs. counter pulse: 0.426). In brief, BJUT-II VAD under co-pulse mode may have benefits for improving coronary perfusion and preventing the development of atherosclerosis, however, the constant speed mode may have benefit for preventing the development of plaque vulnerability. PMID:25232766

  2. Analysis of Flow Characteristics of the Blood Flowing through an Inclined Tapered Porous Artery with Mild Stenosis under the Influence of an Inclined Magnetic Field

    Directory of Open Access Journals (Sweden)

    Neetu Srivastava

    2014-01-01

    Full Text Available Analytical investigation of MHD blood flow in a porous inclined stenotic artery under the influence of the inclined magnetic field has been done. Blood is considered as an electrically conducting Newtonian fluid. The physics of the problem is described by the usual MHD equations along with appropriate boundary conditions. The flow governing equations are finally transformed to nonhomogeneous second-order ordinary differential equations. This model is consistent with the principles of magnetohydrodynamics. Analytical expressions for the velocity profile, volumetric flow rate, wall shear stress, and pressure gradient have been derived. Blood flow characteristics are computed for a specific set of values of the different parameters involved in the model analysis and are presented graphically. Some of the obtained results show that the flow patterns in converging region (ξ0, and nontapered region (ξ=0 are effectively influenced by the presence of magnetic field and change in inclination of artery as well as magnetic field. There is also a significant effect of permeability on the wall shear stress as well as volumetric flow rate.

  3. Analysis of Flow Characteristics of the Blood Flowing through an Inclined Tapered Porous Artery with Mild Stenosis under the Influence of an Inclined Magnetic Field.

    Science.gov (United States)

    Srivastava, Neetu

    2014-01-01

    Analytical investigation of MHD blood flow in a porous inclined stenotic artery under the influence of the inclined magnetic field has been done. Blood is considered as an electrically conducting Newtonian fluid. The physics of the problem is described by the usual MHD equations along with appropriate boundary conditions. The flow governing equations are finally transformed to nonhomogeneous second-order ordinary differential equations. This model is consistent with the principles of magnetohydrodynamics. Analytical expressions for the velocity profile, volumetric flow rate, wall shear stress, and pressure gradient have been derived. Blood flow characteristics are computed for a specific set of values of the different parameters involved in the model analysis and are presented graphically. Some of the obtained results show that the flow patterns in converging region (ξ 0), and nontapered region (ξ = 0) are effectively influenced by the presence of magnetic field and change in inclination of artery as well as magnetic field. There is also a significant effect of permeability on the wall shear stress as well as volumetric flow rate. PMID:24719614

  4. Adenosine elicits an eNOS-independent reduction in arterial blood pressure in conscious mice that involves adenosine A(2A) receptors

    DEFF Research Database (Denmark)

    Andersen, Henrik; Jaff, Mohammad G; Høgh, Ditte;

    2011-01-01

    Aims:  Adenosine plays an important role in the regulation of heart rate and vascular reactivity. However, the mechanisms underlying the acute effect of adenosine on arterial blood pressure in conscious mice are unclear. Therefore, the present study investigated the effect of the nucleoside on mean...... arterial blood pressure (MAP) and heart rate (HR) in conscious mice. Methods:  Chronic indwelling catheters were placed in C57Bl/6J (WT) and endothelial nitric oxide synthase knock-out (eNOS(-/-) ) mice for continuous measurements of MAP and HR. Using PCR and myograph analysis involment of adenosine...... receptors was investigated in human and mouse renal blood vessels Results:  Bolus infusion of 0.5 mg/kg adenosine elicited significant transient decreases in MAP (99.3±2.3 to 70.4±4.5 mmHg) and HR (603.2±18.3 to 364.3±49.2 min(-1) ) which were inhibited by the A(2A) receptor antagonist ZM 241385. Activation...

  5. Blood Glucose Control Using a Novel Continuous Blood Glucose Monitor and Repetitive Intravenous Insulin Boluses: Exploiting Natural Insulin Pulsatility as a Principle for a Future Artificial Pancreas

    Directory of Open Access Journals (Sweden)

    Nils K. Skjaervold

    2013-01-01

    Full Text Available The aim of this study was to construct a glucose regulatory algorithm by employing the natural pulsatile pattern of insulin secretion and the oscillatory pattern of resting blood glucose levels and further to regulate the blood glucose level in diabetic pigs by this method. We developed a control algorithm based on repetitive intravenous bolus injections of insulin and combined this with an intravascular blood glucose monitor. Four anesthetized pigs were used in the study. The animals developed a mildly diabetic state from streptozotocin pretreatment. They were steadily brought within the blood glucose target range of 4.5–6.0 mmol/L in 21 to 121 min and kept within that range for 128 to 238 min (hypoglycemic values varied from 2.9 to 51.1 min. The study confirmed our hypotheses regarding the feasibility of this new principle for blood glucose control, and the algorithm was constantly improved during the study to produce the best results in the last animals. The main obstacles were the drift of the IvS-1 sensor and problems with the calibration procedure, which calls for an improvement in the sensor stability before this method can be applied fully in new studies in animals and humans.

  6. Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

    Directory of Open Access Journals (Sweden)

    E.G.M. Mogoa

    2000-07-01

    Full Text Available The effects of acute exposure to 3 different temperature and humidity conditions on arterial blood-gas and acid-base balance in goats were investigated after intravenous bolus administration of xylazine at a dose of 0.1 mg/kg. Significant (P < 0.05 changes in the variables occurred under all 3 environmental conditions. Decreases in pH, partial pressure of oxygen and oxyhaemoglobin saturation were observed, and the minimum values for oxygen tension and oxyhaemoglobin saturation were observed within 5 min of xylazine administration. The pH decreased to its minimum values between 5 and 15 min. Thereafter, the variables started to return towards baseline, but did not reach baseline values at the end of the 60 min observation period. Increases in the partial pressure of carbon dioxide, total carbon dioxide content, bicarbonate ion concentration, and the actual base excess were observed. The maximum increase in the carbon dioxide tension occurred within 5 min of xylazine administration. The increase in the actual base excess only became significant after 30 min in all 3 environments, and maximal increases were observed at 60 min. There were no significant differences between the variables in the 3 different environments. It was concluded that intravenous xylazine administration in goats resulted in significant changes in arterial blood-gas and acid-base balance that were associated with hypoxaemia and respiratory acidosis, followed by metabolic alkalosis that continued for the duration of the observation period. Acute exposure to different environmental temperature and humidity conditions after xylazine administration did not influence the changes in arterial blood-gas and acid-base balance.

  7. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.

    Science.gov (United States)

    Figueroa, Arturo; Alvarez-Alvarado, Stacey; Jaime, Salvador J; Kalfon, Roy

    2016-07-01

    Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress. PMID:27160957

  8. Exercício físico e o controle da pressão arterial Ejercício físico y el control de la presion arterial Physical exercise and blood pressure control

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Monteiro

    2004-12-01

    Full Text Available O exercício físico provoca uma série de respostas fisiológicas, resultantes de adaptações autonômicas e hemodinâmicas que vão influenciar o sistema cardiovascular. Diversos estudos demonstraram o seu efeito benéfico sobre a pressão arterial. Sendo a hipertensão arterial sistêmica uma entidade de alta prevalência e elevada morbimortalidade na população, o exercício físico tem importante papel como elemento não medicamentoso para o seu controle ou como adjuvante ao tratamento farmacológico.El ejercicio físico provoca una serie de respuesta fisiológicas, resultantes de adaptaciones autonómicas y hemodinámicas que van a influenciar en el sistema cardiovascular. Diversos estudios demonstraron el efecto benéfico sobre la presión arterial. Siendo así, la hipertensión arterial sistémica una entidad de alta prevalencia y elevada morbi-mortalidad en la población, el ejercicio físico tiene un papel muy importante como elemento no medicamentoso para su control y como adyuvante al tratamiento farmacológico tambien.Physical exercise causes a series of physiological responses resulting from autonomic and hemodynamic adaptation that affect the cardiovascular system. Many studies have demonstrated its beneficial effect on blood pressure. Bearing in mind that hypertension is a very prevalent condition causing high morbidity and mortality rate, the physical exercise plays an important role as a non-drug measure for its control or as an adjuvant to drug treatment.

  9. On Renal Artery Stenosis

    OpenAIRE

    Eklöf, Hampus

    2005-01-01

    Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. To visualize renal arteries with x-ray technique...

  10. Prediction of left ventricular ejection fraction in patients with coronary artery disease based on an analysis of perfusion patterns at rest. Assessment by an artificial neural network

    International Nuclear Information System (INIS)

    In CAD, left ventricular function depends on the condition of myocardial perfusion, hence it may be presumed that blood flow abnormalities may enable the LVEF to be predicted. The aim of the study was to apply an Artificial Neural Network (ANN) to investigate the relationships between myocardial perfusion and LVEF, measured simultaneously. gSPECT examinations were performed in 95 patients with CAD, divided into training (n = 50) and testing (n = 45) groups. using the acquired data, in each subject the LVEF was calculated and a perfusion polar map was constructed and divided into 25 segments. Based on results obtained in the training group, a characteristic configuration of segments was defined, with features enabling differentiation between the individual subjects of that group. The set of those segments, as well as the corresponding LVEF values enabled the optimum network architecture to be constructed and trained. The trained ANN was verified by application to the testing group. Using the above-described procedure, 15 polar map segments were defined which enabled the patients of the training group to be differentiated sufficiently enough to make their further recognition possible. The optimal network structure consisting 25 neurons was obtained by comparing the activity in those segments in individual subjects with corresponding LVEF values. Based on the above model, the obtained network was able to reproduce learning data (r = 0.832; learning error 4.84%) and to apply the gained knowledge to the testing cases (r = 0.786; testing error = 4.99%). The obtained network can generalise learned information. To predict LVEF, some polar map segments should be excluded from the analysis. Erroneous LVEF prediction may occur resulting mainly from conditions independent from perfusion abnormalities. (author)

  11. Evidence for a GABAB receptor component in the spinal action of Substance P (SP) on arterial blood pressure in the awake rat

    OpenAIRE

    Brouillette, Jonathan; Couture, Réjean

    2002-01-01

    The activation of tachykinin NK1 receptors in the rat spinal cord produced a transient drop in arterial blood pressure followed by a more prolonged pressor effect which is mediated by the stimulation of the sympatho-adrenal system. This study aims at characterizing the spinal mechanism of that initial hypotension occurring in awake unrestrained rats.The initial hypotension (−18±2.0 mmHg at 1 min) and the tachycardia (110±10 b.p.m.) produced by the intrathecal (i.t.) injection of the stable NK...

  12. Increases in platelet and red cell counts, blood viscosity, and arterial pressure during mild surface cooling: factors in mortality from coronary and cerebral thrombosis in winter.

    OpenAIRE

    Keatinge, W R; Coleshaw, S R; Cotter, F.; Mattock, M; Murphy, M; Chelliah, R

    1984-01-01

    Six hours of mild surface cooling in moving air at 24 degrees C with little fall in core temperature (0.4 degree C) increased the packed cell volume by 7% and increased the platelet count and usually the mean platelet volume to produce a 15% increase in the fraction of plasma volume occupied by platelets. Little of these increases occurred in the first hour. Whole blood viscosity increased by 21%; plasma viscosity usually increased, and arterial pressure rose on average from 126/69 to 138/87 ...

  13. Effects of detraining after blood flow-restricted low-load elastic band training on muscle size and arterial stiffness in older women

    OpenAIRE

    Yasuda, Tomohiro; Fukumura, Kazuya; Iida, Haruko; Nakajima, Toshiaki

    2015-01-01

    Background We examined the effects of detraining after blood flow-restricted (BFR) low-load elastic band training on muscle size and arterial stiffness in older women. Findings Fourteen women were divided into BFR training (BFR-T) or non-BFR training (CON-T). Each group participated in 12 weeks of arm curl and press down training using an elastic band either with (BFR-T) or without BFR (CON-T). Muscle cross-sectional area (CSA) and maximum voluntary isometric contraction (MVIC) for upper arms...

  14. Use of Caval Subtraction 2D Phase-Contrast MR Imaging to Measure Total Liver and Hepatic Arterial Blood Flow: Preclinical Validation and Initial Clinical Translation.

    Science.gov (United States)

    Chouhan, Manil D; Mookerjee, Rajeshwar P; Bainbridge, Alan; Walker-Samuel, Simon; Davies, Nathan; Halligan, Steve; Lythgoe, Mark F; Taylor, Stuart A

    2016-09-01

    Purpose To validate caval subtraction two-dimensional (2D) phase-contrast magnetic resonance (MR) imaging measurements of total liver blood flow (TLBF) and hepatic arterial fraction in an animal model and evaluate consistency and reproducibility in humans. Materials and Methods Approval from the institutional ethical committee for animal care and research ethics was obtained. Fifteen Sprague-Dawley rats underwent 2D phase-contrast MR imaging of the portal vein (PV) and infrahepatic and suprahepatic inferior vena cava (IVC). TLBF and hepatic arterial flow were estimated by subtracting infrahepatic from suprahepatic IVC flow and PV flow from estimated TLBF, respectively. Direct PV transit-time ultrasonography (US) and fluorescent microsphere measurements of hepatic arterial fraction were the standards of reference. Thereafter, consistency of caval subtraction phase-contrast MR imaging-derived TLBF and hepatic arterial flow was assessed in 13 volunteers (mean age, 28.3 years ± 1.4) against directly measured phase-contrast MR imaging PV and proper hepatic arterial inflow; reproducibility was measured after 7 days. Bland-Altman analysis of agreement and coefficient of variation comparisons were undertaken. Results There was good agreement between PV flow measured with phase-contrast MR imaging and that measured with transit-time US (mean difference, -3.5 mL/min/100 g; 95% limits of agreement [LOA], ±61.3 mL/min/100 g). Hepatic arterial fraction obtained with caval subtraction agreed well with those with fluorescent microspheres (mean difference, 4.2%; 95% LOA, ±20.5%). Good consistency was demonstrated between TLBF in humans measured with caval subtraction and direct inflow phase-contrast MR imaging (mean difference, -1.3 mL/min/100 g; 95% LOA, ±23.1 mL/min/100 g). TLBF reproducibility at 7 days was similar between the two methods (95% LOA, ±31.6 mL/min/100 g vs ±29.6 mL/min/100 g). Conclusion Caval subtraction phase-contrast MR imaging is a simple and clinically

  15. Novel chemoradiotherapy for locally advanced pancreatic cancer using arterial infusion chemotherapy following the alteration of peripancreatic blood flow

    International Nuclear Information System (INIS)

    Radiotherapy employing intraoperative radiation therapy (IORT) in combination with postoperative external beam radiation therapy (EBRT) is an effective treatment for unresectable pancreatic cancer. To achieve an even greater therapeutic outcome, 13 patients with unresectable pancreatic cancer were treated by IORT in combination with EBRT plus locally intensive arterial infusion chemotherapy. In order to increase drug delivery to the primary tumor, the splenic and major pancreatic arteries, except for the gastroduodenal artery (GDA), were embolized by radiological intervention prior to the arterial infusion chemotherapy, and the administration of gemcitabine, cisplatin, and 5-fluorouracil to the primary tumors via GDA was followed during EBRT. The values of serum tumor markers were decreased in all patients, and tumor regression was detected on CT scans in 6 patients. The evaluation of survival benefit of this treatment modality is ongoing, but it did not prolong the survival time of patients with second stage lymph node metastases. One of the advantages of this method was able to perform also in charge of hepatic arterial infusion chemotherapy concurrently, but we experienced liver abscess in 2 patients. (author)

  16. Oxygenation to Bovine Blood in Artificial Heart and Lung Using Vibrating Flow Pump: Experiment and Numerical Analysis Based on Non-Newtonian Model

    Science.gov (United States)

    Shintaku, Hirofumi; Yonemura, Tsubasa; Tsuru, Kazuaki; Isoyama, Takashi; Yambe, Tomoyuki; Kawano, Satoyuki

    In this study, we construct an experimental apparatus for a prototype artificial heart and lung (AHL) by installing hollow fibers into the cylindrical tube of the vibrating flow pump (VFP). The oxygenation characteristics are investigated both by experiments using bovine blood and by numerical analyses based on the computational fluid dynamics. The analyses are carried out at the Reynolds numbers Re ranged from O(1) to O(103), which are determined based on the experimental conditions. The blood flow and the diffusion of oxygen gas are analyzed based on the Newtonian/non-Newtonian, unsteady, incompressible and axisymmetric Navier-Stokes equations, and the advection-diffusion equation. The results show that the oxygenation rate increases in proportion to Re1/3, where the phenomenon corresponds to the decreasing thickness of the concentration boundary layer with Re. Although the effects of the vibrating flow and the rheology of the blood are clearly appeared on the velocity field, their effects on the gas exchange are relatively small at the ranges of prescribed Reynolds numbers. Furthermore, the numerical results in terms of the oxygenation rate are compared with the experimental ones. The basic design data of VFP were accumulated for the development of AHL in the clinical applications.

  17. Non invasive tomographic imaging of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) in superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis

    International Nuclear Information System (INIS)

    Clinical indications for extra-intracranial arterial bypass (EIAB) surgery are still rather ill-defined and are the matter of a randomized trial in progress currently. However, 'hemodynamic' transient ischemic attacks (TIAs) are considered at present the clinical entity that should benefit most from this surgical procedure. The contribution of conventional CBF techniques in assessing both the physiological indications and the usefulness of EIAB has been only moderate, though substantial. Clearly, both CBF and regional metabolic data should be obtained, ideally in tomographic representation. We have attempted such study using the 15O continuous inhalation technique in a small number of instructive patients. Two different patterns of the CBF-OEF relationship have been defined that could be of some importance in respect to both the underlying mechanisms of 'hemodynamic' TIAs and to the rational bases for EIAB procedures

  18. Validation of an optical flow algorithm to measure blood flow waveforms in arteries using dynamic digital x-ray images

    Science.gov (United States)

    Rhode, Kawal; Lambrou, Tryphon; Hawkes, David J.; Hamilton, George; Seifalian, Alexander M.

    2000-06-01

    We have developed a weighted optical flow algorithm for the extraction of instantaneous blood velocity from dynamic digital x-ray images of blood vessels. We have carried out in- vitro validation of this technique. A pulsatile physiological blood flow circuit was constructed using sections of silicone tubing to simulate blood vessels with whole blood as the fluid. Instantaneous recording of flow from an electromagnetic flow meter (EMF) provided the gold standard measurement. Biplanar dynamic digital x-ray images of the blood vessel with injection of contrast medium were acquired at 25 fps using a PC frame capture card. Imaging of a Perspex calibration cube allowed 3D reconstruction of the vessel and determination of true dimensions. Blood flow waveforms were calculated off-line on a Sun workstation using the new algorithm. The correlation coefficient between instantaneous blood flow values obtained from the EMF and the x-ray method was r equals 0.871, n equals 1184, p less than 0.0001. The correlation coefficient for average blood flow was r equals 0.898, n equals 16, p less than 0.001. We have successfully demonstrated that our new algorithm can measure pulsatile blood flow in a vessel phantom. We aim to use this algorithm to measure blood flow clinically in patients undergoing vascular interventional procedures.

  19. Effects of Bolus and Continuous Nasogastric Feeding on Gastric Emptying, Small Bowel Water Content, Superior Mesenteric Artery Blood Flow, and Plasma Hormone Concentrations in Healthy Adults

    Science.gov (United States)

    Chowdhury, Abeed H.; Murray, Kathryn; Hoad, Caroline L.; Costigan, Carolyn; Marciani, Luca; Macdonald, Ian A.; Bowling, Timothy E.; Lobo, Dileep N.

    2016-01-01

    Objective: We aimed to demonstrate the effect of continuous or bolus nasogastric feeding on gastric emptying, small bowel water content, and splanchnic blood flow measured by magnetic resonance imaging (MRI) in the context of changes in plasma gastrointestinal hormone secretion. Background: Nasogastric/nasoenteral tube feeding is often complicated by diarrhea but the contribution of feeding strategy to the etiology is unclear. Methods: Twelve healthy adult male participants who underwent nasogastric intubation before a baseline MRI scan, received 400 mL of Resource Energy (Nestle) as a bolus over 5 minutes or continuously over 4 hours via pump in this randomized crossover study. Changes in gastric volume, small bowel water content, and superior mesenteric artery blood flow and velocity were measured over 4 hours using MRI and blood glucose and plasma concentrations of insulin, peptide YY, and ghrelin were assayed every 30 minutes. Results: Bolus nasogastric feeding led to significant elevations in gastric volume (P < 0.0001), superior mesenteric artery blood flow (P < 0.0001), and velocity (P = 0.0011) compared with continuous feeding. Both types of feeding reduced small bowel water content, although there was an increase in small bowel water content with bolus feeding after 90 minutes (P < 0.0068). Similarly, both types of feeding led to a fall in plasma ghrelin concentration although this fall was greater with bolus feeding (P < 0.0001). Bolus feeding also led to an increase in concentrations of insulin (P = 0.0024) and peptide YY (P < 0.0001), not seen with continuous feeding. Conclusion: Continuous nasogastric feeding does not increase small bowel water content, thus fluid flux within the small bowel is not a major contributor to the etiology of tube feeding-related diarrhea. PMID:25549202

  20. Ultrafine Fibrous Membranes by Coaxial Electrospinning for Artificial Blood Vessel%同轴电纺超细纤维膜构建人工血管材料

    Institute of Scientific and Technical Information of China (English)

    曹文轩; 张红; 袁晓燕

    2011-01-01

    以右旋糖酐(DEX)为芯、聚乙二醇-b-聚(L-丙交酯-co-ε-己内酯)(PELCL)为壳,采用同轴电纺技术制备DEX/PELCL超细纤维膜.在该电纺纤维内芯分别负载血管内皮生长因子(VEGF)和血小板衍生生长因子(PDGF-bb),并以此构建双层超细纤维膜人工血管支架.28 d的释放结果表明,VEGF和PDGF-bb 均表现出突释现象,含有肝素的VEGF样品释放量有所下降.大鼠腹主动脉移植实验结果表明,载有VEGF和PDGFbb的超细纤维膜可以用于构建双层人工血管.%Core/shell ultrafine fibers, with dextran(DEX) and poly(ethylene glycol)-b-poly(L-lactide-co-εcaprolactone) (PELCL) as the core and shell, respectively, were prepared by coaxial electrospinning.Double-layered ultraline fibrous tubes of the coaxial-electrospun DEX/PELCL fiberswere constructed for application as artificial blood vessel by loading vascular endothelial growth factor (VEGF) and platelet derived growth factor-bb( PDGF-bb), respectively in the fiber core. The in vitro releasing results of 28 d indicated that initial burst release occurred for both VEGF and PDGF-bb. The in vivo implantation in abdomen aorta of a rat model showed that the double-layered fibrous tubes loading VEGF and PDGF-bb could be potential used as artificial blood vessels.