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Sample records for hemodynamically tolerated vt

  1. Hemodynamic mechanisms underlying the incomplete tolerance to caffeine's pressor effects.

    Farag, Noha H; Vincent, Andrea S; McKey, Barbara S; Whitsett, Thomas L; Lovallo, William R

    2005-06-01

    Blood pressure (BP) and cardiovascular hemodynamics were assessed at baseline and after caffeine administration in a 4-week, placebo-controlled, double-blind, randomized, crossover trial of caffeine tolerance formation. Half of the subjects developed tolerance to the pressor effect of caffeine, whereas the other half continued to show increases in BP after caffeine ingestion (F = 16.7, p <0.0001). In the subjects who did not develop tolerance, peripheral resistance increased incrementally as the daily dose of caffeine increased (F = 2.8, p = 0.05).

  2. DEC VT220

    1983-01-01

    The DEC (Digital Equipment Corporation) VT220 is a text terminal which uses an redesigned keyboard(LK201). The VT220 improved on the earlier VT100 series of terminals with much smaller physical packaging and and a much faster microprocessor.

  3. Hemodynamic and metabolic basis of impaired exercise tolerance in patients with severe left ventricular dysfunction

    Roubin, G.S.; Anderson, S.D.; Shen, W.F.; Choong, C.Y.; Alwyn, M.; Hillery, S.; Harris, P.J.; Kelly, D.T.

    1990-01-01

    Hemodynamic and metabolic changes were measured at rest and during exercise in 23 patients with chronic heart failure and in 6 control subjects. Exercise was limited by leg fatigue in both groups and capacity was 40% lower in the patients with failure. At rest, comparing patients with control subjects, heart rate and right atrial and pulmonary wedge pressure were higher; cardiac output, stroke volume and work indexes and ejection fraction were lower; mean arterial and right atrial pressure and systemic resistance were similar. During all phases of exercise in patients with heart failure, pulmonary wedge pressure and systemic vascular resistance were higher and pulmonary vascular resistance remained markedly elevated compared with values in control subjects. Cardiac output was lower in the patients with failure, but appeared to have the same physiologic distribution in both groups during exercise. Although arterial-femoral venous oxygen content difference was higher in patients with heart failure, this increase did not compensate for the reduced blood flow. Even though the maximal oxygen consumption was significantly reduced, femoral venous lactate and pH values were higher than values in control subjects, but femoral venous pH was similar in both groups at their respective levels of maximal exercise. Ejection fraction was lower in those with heart failure at rest and did not increase with exercise. Ventilation in relation to oxygen consumption was higher in patients with failure than in control subjects

  4. The hemodynamic tolerability and feasibility of sustained low efficiency dialysis in the management of critically ill patients with acute kidney injury

    Nisenbaum Rosane

    2010-11-01

    Full Text Available Abstract Background Minimization of hemodynamic instability during renal replacement therapy (RRT in patients with acute kidney injury (AKI is often challenging. We examined the relative hemodynamic tolerability of sustained low efficiency dialysis (SLED and continuous renal replacement therapy (CRRT in critically ill patients with AKI. We also compared the feasibility of SLED administration with that of CRRT and intermittent hemodialysis (IHD. Methods This cohort study encompassed four critical care units within a single university-affiliated medical centre. 77 consecutive critically ill patients with AKI who were treated with CRRT (n = 30, SLED (n = 13 or IHD (n = 34 and completed at least two RRT sessions were included in the study. Overall, 223 RRT sessions were analyzed. Hemodynamic instability during a given session was defined as the composite of a > 20% reduction in mean arterial pressure or any escalation in pressor requirements. Treatment feasibility was evaluated based on the fraction of the prescribed therapy time that was delivered. An interrupted session was designated if Results Hemodynamic instability occurred during 22 (56.4% SLED and 43 (50.0% CRRT sessions (p = 0.51. In a multivariable analysis that accounted for clustering of multiple sessions within the same patient, the odds ratio for hemodynamic instability with SLED was 1.20 (95% CI 0.58-2.47, as compared to CRRT. Session interruption occurred in 16 (16.3, 30 (34.9 and 11 (28.2 of IHD, CRRT and SLED therapies, respectively. Conclusions In critically ill patients with AKI, the administration of SLED is feasible and provides comparable hemodynamic control to CRRT.

  5. Hemodynamic deterioration precedes onset of ventricular tachyarrhythmia after Heartmate II implantation.

    Yaksh, Ameeta; Kik, Charles; Knops, Paul; Zwiers, Korinne; van Ettinger, Maarten J B; Manintveld, Olivier C; de Wijs, Marcel C J; van der Kemp, Peter; Bogers, Ad J J C; de Groot, Natasja M S

    2016-07-08

    Early postoperative ventricular tachyarrhythmia (PoVT) after left ventricular assist device (LVAD) implantation are common and associated with higher mortality-rates. At present, there is no data on initiation of these PoVT and the role of alterations in cardiac hemodynamics. A LVAD was implanted in a patient with end-stage heart failure due to a ischemic cardiomyopathy. Alterations in cardiac rhythm and hemodynamics preceding PoVT-episodes during the first five postoperative days were examined by using continuous recordings of cardiac rhythm and various hemodynamic parameters. All PoVT (N=120) were monomorphic, most often preceded by short-long-short-sequences or regular SR and initiated by ventricular runs. Prior to PoVT, mean arterial pressure decreased; heart rate and ST-segments deviations increased. PoVT are caused by different underlying electrophysiological mechanisms. Yet, they are all monomorphic and preceded by hemodynamic deterioration due to myocardial ischemia.

  6. VT E911 ESITE geocoder - address points

    Vermont Center for Geographic Information — VT E911 ESITE geocoder - address points. VCGI, in collaboration with the VT E911 Board, has created a suite of geocoding services that can be used to batch geocode...

  7. VT Lidar-based Aspect, Symbolized, Not Cached, VT State Plane Meters

    Vermont Center for Geographic Information — ASPECT service (compass direction that a slope faces) derived from various VT Lidar datasets. A pre-defined SYMbology has been applied to the service. VT State Plane...

  8. Tolerance

    Tønder, Lars

    is linked to a different set of circumstances than the ones suggested by existing models in contemporary democratic theory. Reorienting the discussion of tolerance, the book raises the question of how to disclose new possibilities within our given context of affect and perception. Once we move away from......Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated...... by the desire to experiment and to become otherwise. The objective is to discuss what gets lost, conceptually as well as politically, when we neglect the subsistence of active tolerance within other practices of tolerance, and to develop a theory of active tolerance in which tolerance's mobilizing character...

  9. Tolerance

    Tønder, Lars

    Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated by the d...... these alternatives by returning to the notion of tolerance as the endurance of pain, linking this notion to exemplars and theories relevant to the politics of multiculturalism, religious freedom, and free speech....

  10. VT Wireless Internet Service Providers 2006

    Vermont Center for Geographic Information — (Link to Metadata) The VT Wireless Internet Service Provider (ISP) dataset (WISP2006) includes polygons depicting the extent of Vermont's WISP broadband system as of...

  11. VT Wireless Internet Service Providers 2007

    Vermont Center for Geographic Information — (Link to Metadata) The VT Wireless Internet Service Provider (ISP) dataset (WISP2007) includes polygons depicting the extent of Vermont's WISP broadband system as of...

  12. AdvanceVT Transformations: April 2009

    AdvanceVT

    2009-01-01

    This issue of Transformations will deal exclusively with the results of the 2008 Faculty Work-Life survey employed by AdvanceVT in September of 2008. We will compare/ contrast these results with those of the 2005 survey. Future issues will address: • Respondent familiarity with the AdvanceVT initiative and the implications of this data; • Breakdowns of differences in response by gender and race; and • The qualitative data elicited by the survey and how it compares to the quantitative data and...

  13. AdvanceVT Newsletter: February 2004

    AdvanceVT

    2004-01-01

    Inside this issue: Today's Leadership Seminar; Women's Month Reception; Child Care Survey National Science Foundation The AdvanceVT Team Elizabeth Creamer, Assessment Director Associate Professor of Educational Leadership and Policy Studies Catherine Eckel, ADVANCE Professor Professor of Economics Patricia Hyer, Principle Investigator Associate Provost for Academic Administration Barbara Johnson, Administrative Assistant Peggy Layne, Project Coordinator Nancy Love, Co-PI and ADVANCE Pro...

  14. VT Wireline Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  15. VT Public Locations of Broadband Data - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  16. VT Public Locations of Broadband Data - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  17. VT Public Locations of Broadband Data - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  18. VT Cable Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  19. VT Total Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  20. VT Cable Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  1. VT Detailed Broadband Availability by Census Block -12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  2. VT Detailed Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  3. VT Detailed Broadband Availability by Census Block -12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  4. VT Detailed Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  5. VT Wireline Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  6. VT Wireless Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  7. VT Total Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  8. VT Wireline Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  9. VT Wireless Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  10. VT Total Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  11. VT Cable Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  12. VT Wireless Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  13. VT Detailed Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  14. VT Total Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  15. VT DSL Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  16. VT Wireline Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  17. VT DSL Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  18. VT Wireless Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  19. VT Wireless Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  20. VT Public Locations of Broadband Data - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  1. VT DSL Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  2. VT Cable Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  3. VT Wireline Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  4. VT Cable Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  5. VT Wireless Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  6. VT DSL Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  7. VT Wireline Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  8. VT Public Locations of Broadband Data - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  9. VT Cable Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  10. VT Total Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  11. VT Detailed Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  12. VT DSL Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  13. VT DSL Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  14. VT Public Locations of Broadband Data - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  15. VT Total Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  16. VT E911 Composite geocoder - uses ESITE, RDSNAME, and RDSRANGE

    Vermont Center for Geographic Information — VT E911 Composite geocoder - uses ESITE, RDSNAME, and RDSRANGE. VCGI, in collaboration with the VT E911 Board, has created a suite of geocoding services that can be...

  17. Phase transformations at continuous cooling in VT6ch and VT23 alloys

    Lyasotskaya, V.S.; Lyasotskij, I.V.; Meshcheryakov, V.N.; Ravdonikas, N.Yu.; Nadtochij, S.I.; Faustov, N.N.

    1986-01-01

    Phase transformations at continuous cooling at β-region temperatures in VT6ch and VT23 alloys are studied. Nonequilibrium phases: α', α'', (ω), βsub(e), αsub(e), are shown to be formed in these alloys depending on cooling composition and rate. It is established that at cooling at temperatures below Ar 3 in alloys studied high-temperature α-phase is formed, and at temperatures below 650 deg C - more dispersed low-temperature α-phase precipitating from β-solution volumes mostly enriched by alloying elements according to the intermediate mechanism. Diagrams of anisothermal β-phase decomposition for VT6ch and VT23 alloys are plotted in coincidence with the results of thermal, thermodifferential, metallographic and X-ray diffraction analyses; lines of martensite transformation, lines of high- and low-temperature α-phase formation are pointed on the diagrams. Besides, for VT23 alloy a line for (ω)-phase formation is pointed

  18. Occupational exposure in hemodynamic

    Silva, Amanda J.; Fernandes, Ivani M.; Silva, Paula P. Nou; Sordi, Gian Maria A.A.; Carneiro, Janete C.G.G.

    2011-01-01

    This paper has an objective to perform a radiometric survey at a hemodynamic service. Besides, it was intended to evaluate the effective dose of health professionals and to provide data which can contribute with minimization of exposures during the realization of hemodynamic procedure. The radiometric survey was realized in the real environment of work simulating the conditions of a hemodynamic study with a ionization chamber

  19. VT Built Up Lands in Grand Isle County - 1986

    Vermont Center for Geographic Information — (Link to Metadata) NRCS mapped historical and current-day built-up lands for Grand Isle County, VT using several vintages of aerial photography: 1941, 1962, 1974,...

  20. VT Built Up Lands in Grand Isle County - 1941

    Vermont Center for Geographic Information — (Link to Metadata) NRCS mapped historical and current-day built-up lands for Grand Isle County, VT using several vintages of aerial photography: 1941, 1962, 1974,...

  1. VT Data - Zoning Ridgeline Protection Overlay 20070716, Reading

    Vermont Center for Geographic Information — Denotes the Ridgeline Protection areas referenced in the town of Reading VT town plan as adopted July 16, 2007. Based on; RidgelineProtectionOverlway_RPC_pre2009.shp

  2. Bedrock Geologic Map of the Bristol, VT Quadrangle

    Vermont Center for Geographic Information — Digital data from VG13-1 Kim, J, Weber, E, and Klepeis, K, 2013, Bedrock Geologic Map of the Bristol, VT Quadrangle: Vermont Geological Survey Open File Report...

  3. The endophyte Verticillium Vt305 protects cauliflower against Verticillium wilt.

    Tyvaert, L; França, S C; Debode, J; Höfte, M

    2014-06-01

    To investigate the interaction between cauliflower and the isolate VerticilliumVt305, obtained from a field suppressive to Verticillium wilt of cauliflower, and to evaluate the ability of VerticilliumVt305 to control Verticillium wilt of cauliflower caused by V. longisporum. Single and combined inoculations of VerticilliumVt305 and V. longisporum were performed on cauliflower seedlings. Symptom development was evaluated, and fungal colonization was measured in the roots, hypocotyl and stem with real-time PCR. No symptoms were observed after single inoculation of VerticilliumVt305, although it colonized the plant tissues. Pre-inoculation of VerticilliumVt305 reduced symptom development and colonization of plant tissues by V. longisporum. VerticilliumVt305 is an endophyte on cauliflower plants and showed effective biological control of V. longisporum in controlled conditions. This work can contribute to the development of a sustainable control measure of V. longisporum in Brassicaceae hosts, which is currently not available. Additionally, this study provides evidence for the different roles of Verticillium species present in the agro-ecosystem. © 2014 The Society for Applied Microbiology.

  4. Obesity and renal hemodynamics

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

    2006-01-01

    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile

  5. Comparative evaluation of hemodynamic and respiratory parameters during mechanical ventilation with two tidal volumes calculated by demi-span based height and measured height in normal lungs

    L Mousavi Seresht

    2014-01-01

    Full Text Available Background : Appropriate determination of tidal volume (VT is important for preventing ventilation induced lung injury. We compared hemodynamic and respiratory parameters in two conditions of receiving VTs calculated by using body weight (BW, which was estimated by measured height (HBW or demi-span based body weight (DBW. Materials and Methods : This controlled-trial was conducted in St. Alzahra Hospital in 2009 on American Society of Anesthesiologists (ASA I and II, 18-65-years-old patients. Standing height and weight were measured and then height was calculated using demi-span method. BW and VT were calculated with acute respiratory distress syndrome-net formula. Patients were randomized and then crossed to receive ventilation with both calculated VTs for 20 min. Hemodynamic and respiratory parameters were analyzed with SPSS version 20.0 using univariate and multivariate analyses. Results : Forty nine patients were studied. Demi-span based body weight and thus VT (DTV were lower than Height based body weight and VT (HTV (P = 0.028, in male patients (P = 0.005. Difference was observed in peak airway pressure (PAP and airway resistance (AR changes with higher PAP and AR at 20 min after receiving HTV compared with DTV. Conclusions : Estimated VT based on measured height is higher than that based on demi-span and this difference exists only in females, and this higher VT results higher airway pressures during mechanical ventilation.

  6. Announcing the Venus Transit 2004 (VT-2004) Programme

    2004-02-01

    Rare Celestial Event to be Observed by Millions Summary On June 8, 2004, Venus - the Earth's sister planet - will pass in front of the Sun. This event, a 'transit', is extremely rare - the last one occurred in 1882, 122 years ago. Easily observable in Europe, Asia, Africa and Australia, it is likely to attract the attention of millions of people on these continents and, indeed, all over the world. On this important occasion, the European Southern Observatory (ESO) has joined forces with the European Association for Astronomy Education (EAAE), the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) and the Observatoire de Paris in France, as well as the Astronomical Institute of the Academy of Sciences of the Czech Republic to establish the Venus Transit 2004 (VT-2004) public education programme. It is supported by the European Commission in the framework of the European Science and Technology Week and takes advantage of this extraordinary celestial event to expose the public - in a well-considered, interactive and exciting way - to a number of fundamental issues at the crucial interface between society and basic science. VT-2004 has several components, including an instructive and comprehensive website (www.vt-2004.org). It is directed towards the wide public in general and the media, school students and their teachers, as well as amateur astronomers in particular. It invites all interested persons to participate actively in the intercontinental VT-2004 Observing Campaign (that reenacts historical Venus Transit observations) and the VT-2004 Video Contest. During the VT-2004 Final Event in November, the winners of the Video Contest will be chosen by an international jury. This meeting will also serve to discuss the project and its impact. The outcome of this rare celestial event and the overall experience from this unique public education project will clearly be of very wide interest, not just in the field of astronomy.

  7. VT Fiber Optic Broadband Availability by Census Block - 12-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  8. VT Fiber Optic Broadband Availability by Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  9. VT Fiber Optic Broadband Availability by Census Block - 12-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  10. VT Fiber Optic Broadband Availability by Census Block - 12-2012

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  11. VT Fiber Optic Broadband Availability by Census Block - 06-2011

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  12. VT Fiber Optic Broadband Availability by Census Block - 06-2010

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  13. VT Current and Future Status of Broadband Availability by Sub-Census Block - 06-2013

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  14. Hemodynamic effects of a novel pharmacologic stress agent, Higemine

    Zhang, X.L.; Liu, X.J.; Tao, Z.H.; Shi, R.F.

    2002-01-01

    Objective: Higenamine (dl-demethylcodaurine) (HG), which was isolated from aconitum japonicum. This study was to evaluate the hemodynamic effects of HG in animal study. Methods: We compared the hemodynamic effects of HG (0.5-4μg/min/kg) with Dobutamine (Dob) (5-30μg/min/kg) in 6 dogs: heart rate (HR), blood pressure (BP), coronary blood flow (CBF), myocardial oxygen consumption (MOC) were measured. Tolerability and safety of HG (1-500μg/mg/min) were evaluated in 8 dogs. Results: Comparison of hemodynamic effects between Dob an HG was presented. SBP: systolic blood pressure; DP: diastolic blood pressure; P<0.01; P<0.05. Diastolic BP slightly decreased, but systolic BP did not change significantly during HG infusion. There was no significant ECG abnormalities and side effects during HG infusion. Conclusion: HG might be a safe and useful pharmacologic stress agent, especially for patients with severe hypertension

  15. High temperature soldering of the VT14 titanium alloy

    Besednyj, V.A.

    1978-01-01

    Two methods of brazing the VT14 alloys have been investigated, as well as the effect of annealing and heating during brazing and on mechanical properties of this alloy. Contact reaction brazing using a palladium layer has been shown to be applicable for simple-shape products, while capillary brazing using Cu-Ti, Ni-Ti and Fe-Ti brazing alloy systems, for complex-shape products. Brazed joints strength is similar to the strength of the VT14 alloy. Heating during brazing (960 deg - 1160 deg C) and the following annealing (900 deg C) have but a slight effect on the properties of the base metal, reducing strength by 2-5% and increasing ductility by 10-20%

  16. 2005 AdvanceVT Work/Life Survey Leadership Report

    Glass, Valerie Q.

    2005-01-01

    The AdvanceVT Faculty Work-Life Survey, distributed to all teaching and research faculty in January 2005, addressed, among other things, leadership issues at Virginia Tech. This report presents findings from tenured and tenure- track faculty members (N=816) about items on the questionnaire related to leadership including: aspirations of Virginia Tech faculty members towards leadership positions, their views about the possibility of maintaining a balance between leadership and other responsibi...

  17. Cerebrovascular Hemodynamics in Women.

    Duque, Cristina; Feske, Steven K; Sorond, Farzaneh A

    2017-12-01

    Sex and gender, as biological and social factors, significantly influence health outcomes. Among the biological factors, sex differences in vascular physiology may be one specific mechanism contributing to the observed differences in clinical presentation, response to treatment, and clinical outcomes in several vascular disorders. This review focuses on the cerebrovascular bed and summarizes the existing literature on sex differences in cerebrovascular hemodynamics to highlight the knowledge deficit that exists in this domain. The available evidence is used to generate mechanistically plausible and testable hypotheses to underscore the unmet need in understanding sex-specific mechanisms as targets for more effective therapeutic and preventive strategies. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  18. Cerebral hemodynamics in migraine

    Hachinski, V C; Olesen, Jes; Norris, J W

    1977-01-01

    Clinical and angiographic findings in migraine are briefly reviewed in relation to cerebral hemodynamic changes shown by regional cerebral blood flow (rCBF) studies. Three cases of migraine studied by the intracarotid xenon 133 method during attacks are reported. In classic migraine, with typical...... prodromal symptoms, a decrease in cerebral blood flow has been demonstrated during the aura. Occasionally, this flow decrease persists during the headache phase. In common migraine, where such prodromata are not seen, a flow decrease has not been demonstrated. During the headache phase of both types...... of migraine, rCBF has usually been found to be normal or in the high range of normal values. The high values may represent postischemic hyperemia, but are probably more frequently secondary to arousal caused by pain. Thus, during the headache phase rCBF may be subnormal, normal or high. These findings do...

  19. Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles

    2007-11-01

    Tolerant Overactuated Autonomous Vehicles Casavola, A.; Garone, E. (2007) Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous ...Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Tolerant Overactuated Autonomous Vehicles 3.2 - 2 RTO-MP-AVT-145 UNCLASSIFIED/UNLIMITED Control allocation problem (CAP) - Given a virtual input v(t

  20. Natriuretic peptides and cerebral hemodynamics

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth

    2014-01-01

    Natriuretic peptides have emerged as important diagnostic and prognostic tools for cardiovascular disease. Plasma measurement of the bioactive peptides as well as precursor-derived fragments is a sensitive tool in assessing heart failure. In heart failure, the peptides are used as treatment...... in decompensated disease. In contrast, their biological effects on the cerebral hemodynamics are poorly understood. In this mini-review, we summarize the hemodynamic effects of the natriuretic peptides with a focus on the cerebral hemodynamics. In addition, we will discuss its potential implications in diseases...... where alteration of the cerebral hemodynamics plays a role such as migraine and acute brain injury including stroke. We conclude that a possible role of the peptides is feasible as evaluated from animal and in vitro studies, but more research is needed in humans to determine the precise response...

  1. Hemodynamic imaging of cerebrovascular disease

    Grond, J. van der; Hendrikse, J.; Osch, M.J.P. van [Dept. of Radiology, University Hospital Utrecht (Netherlands)

    2001-11-01

    MR can provide data on perfusion, oxygen consumption and oxygen metabolism, which can be of great value in stroke research. This article reviews the possibilities and current status of the MR techniques with respect to intracranial hemodynamic changes. (orig.)

  2. Lagrangian postprocessing of computational hemodynamics.

    Shadden, Shawn C; Arzani, Amirhossein

    2015-01-01

    Recent advances in imaging, modeling, and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries, and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows.

  3. Duration Test Report for the Ventera VT10 Wind Turbine

    Smith, J.; Huskey, A.; Jager, D.; Hur, J.

    2013-06-01

    This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small wind turbines. Five turbines were tested at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) as a part of round one of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality. Test results will provide manufacturers with reports that can be used to fulfill part of the requirements for small wind turbine certification. The test equipment included a grid-connected Ventera Energy Corporation VT10 wind turbine mounted on an 18.3-m (60-ft) self-supporting lattice tower manufactured by Rohn.

  4. Hemodynamic Effects of Glucagon - A Literature Review

    Meidahl Petersen, Kasper; Bøgevig, Søren; Holst, Jens Juul

    2018-01-01

    Context: Glucagon's effects on hemodynamic parameters - most notably heart rate and cardiac contractility - are overlooked. The glucagon receptor is a central target in novel and anticipated type 2 diabetes therapies and hemodynamic consequences of glucagon signaling have therefore become increas...

  5. Comparison of the hemodynamic effects of etomidate between hypertensive and normotensive patients

    Hayrettin Daşkaya

    2014-06-01

    Full Text Available Objective: Comparison of the hemodynamic effect of ethomidate induction in normotensive and hypertensive patients. Methods: Forty ASA 1-2 patients were included. After informed consent were obtained, patients were divided into two group; Group H: Hypertensive patients, Group N: Normotensive patients. Fentanile and midazolam were administrated for premedication. Anesthesia induction was performed by etomidate 0.3 mg/kg and rocuronium 0.6 mg/kg. Arterial pressures and heart rates were measured at certain intervals: control, pre-intubation and 1, 3 and 5 min post-intubation. Myoclonic movements and hemodynamic parameters were noted by an anesthetist who was masked to the groups. Results: Hemodynamic parameters were higher in hypertensive patients but were in clinically tolerable limits. Conclusion: No hemodynamic instability was observed in anesthesia induction with ethomidate in neither hypertensive nor normotensive patients. J Clin Exp Invest 2014; 5 (2: 164-168

  6. Investigation of fretting corrosion of vacuum-chrome-plated vt3-1 titanium alloy in pair with unprotected vt3-1 alloy and 40khnma steel

    Rojkh, I.L.; Koltunova, L.N.; Vejtsman, M.G.; Birman, Ya.N.; Skosarev, A.V.; Kogan, I.S.

    1978-01-01

    The character of destruction of contacting surfaces in the process of fretting corrosion of titanium alloy VT3-1 chromized in vacuum in pair with unprotected alloy VT3-1 and steel 40KhNMA has been studied by scanning electron microscopy, electronography, and recording the surface profile. The specific load was 200 kg/cm 2 , vibration amplitude 50 mkm and frequency 500 Hz. It has been established that pairs unprotected with coating are subjected to intensive fretting corrosion especially when they are made of titanium alloy. For the pair chromized alloy VT3-1 - unprotected alloy VT3-1 no destruction of a chromized surface is observed. Vacuum chromium coating in the pair with steel 40KhNMA reveals similar properties as in pair with a titanium alloy. The surface of a steel sample is destroyed because of fretting corrosion, though the intensity of corrosion is lower than in the case of unprotected pairs. Vacuum chromium coating is recommended for protection of titanium alloy VT3-1 from fretting corrosion in pair with steel 40KhNMA or an alloy VT3-1 especially in those cases when various organic coatings are unsuitable

  7. Childhood moyamoya disease: hemodynamic MRI

    Tzika, A.A. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Robertson, R.L. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Barnes, P.D. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Vajapeyam, S. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Burrows, P.E. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Treves, S.T. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Scott, R.M. l [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States)

    1997-09-01

    Background. Childhood moyamoya disease is a rare progressive cerebrovascular disease. Objective. To evaluate cerebral hemodynamics using dynamic Gd-DTPA-enhanced imaging in children with moyamoya disease. Materials and methods. Eight children (2-11 years of age) with the clinical and angiographic findings typical of moyamoya disease, before and/or after surgical intervention (pial synangiosis), underwent conventional MR imaging (MRI) and hemodynamic MR imaging (HMRI). HMRI used a spoiled gradient-echo with low flip angle (10 deg) and long TE (TR/TE = 24/15 ms) to minimize T 1 effects and emphasize T 2{sup *} weighting. Raw and calculated hemodynamic images were reviewed. Three-dimensional time-of-flight MR angiography (MRA) and perfusion brain single photon emission computed tomography (SPECT) were also performed. Results. Abnormal hemodynamic maps resulting from vascular stenosis or occlusion and basal collaterals were observed in six patient studies. HMRI depicted perfusion dynamics of affected cerebrovascular territories, detected cortical perfusion deficits, and complemented conventional MRI and MRA. HMRI findings were consistent with those of catheter angiography and perfusion SPECT. Conclusion. Our preliminary experience suggests that HMRI may be of value in the preoperative and postoperative evaluation of surgical interventions in moyamoya disease. (orig.). With 4 figs., 3 tabs.

  8. Childhood moyamoya disease: hemodynamic MRI

    Tzika, A.A.; Robertson, R.L.; Barnes, P.D.; Vajapeyam, S.; Burrows, P.E.; Treves, S.T.; Scott, R.M. I

    1997-01-01

    Background. Childhood moyamoya disease is a rare progressive cerebrovascular disease. Objective. To evaluate cerebral hemodynamics using dynamic Gd-DTPA-enhanced imaging in children with moyamoya disease. Materials and methods. Eight children (2-11 years of age) with the clinical and angiographic findings typical of moyamoya disease, before and/or after surgical intervention (pial synangiosis), underwent conventional MR imaging (MRI) and hemodynamic MR imaging (HMRI). HMRI used a spoiled gradient-echo with low flip angle (10 deg) and long TE (TR/TE = 24/15 ms) to minimize T 1 effects and emphasize T 2 * weighting. Raw and calculated hemodynamic images were reviewed. Three-dimensional time-of-flight MR angiography (MRA) and perfusion brain single photon emission computed tomography (SPECT) were also performed. Results. Abnormal hemodynamic maps resulting from vascular stenosis or occlusion and basal collaterals were observed in six patient studies. HMRI depicted perfusion dynamics of affected cerebrovascular territories, detected cortical perfusion deficits, and complemented conventional MRI and MRA. HMRI findings were consistent with those of catheter angiography and perfusion SPECT. Conclusion. Our preliminary experience suggests that HMRI may be of value in the preoperative and postoperative evaluation of surgical interventions in moyamoya disease. (orig.). With 4 figs., 3 tabs

  9. [Hemodynamic changes in hypoglycemic shock].

    Gutiérrez, C; Piza, R; Chousleb, A; Hidalgo, M A; Ortigosa, J L

    1977-01-01

    Severe hypoglycemia may be present in seriously ill patients; if it is not corrected opportunely a series of neuroendocrinal mechanisms take place aimed at correcting metabolic alterations. These mechanisms can produce hemodynamic alterations as well. Nine mongrel dogs were studied with continuous registration of: blood pressure, central venous pressure, cardiac frequency, respiratory frequency, electrocardiogram and first derivative (Dp/Dt). Six dogs received crystalline (fast acting) insuline intravenously (group 1). After hemodynamic changes were registered hypoglycemia was corrected with 50 per cent glucose solution. Complementary insuline doses were administered to three dogs (group 2); in this group hypoglycemia was not corrected. In group 1 during hypoglycemia there was an increase in blood pressure, central venous pressure, cardiac frequency, respiratory frequency and Dp/Dt, and changes in QT and T wave on the EKG; these changes were partially reversible after hypoglycemia was corrected. The above mentioned alterations persisted in group 2, breathing became irregular irregular and respiratory arrest supervened. It can be inferred that the hemodynamic response to hypoglycemia is predominantly adrenergic. The role of catecolamines, glucocorticoides, glucagon, insuline, cyclic AMP in metabolic and hemodynamic alterations consecutive to hypoglycemia are discussed.

  10. 33 CFR 110.8 - Lake Champlain, N.Y. and Vt.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lake Champlain, N.Y. and Vt. 110... ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.8 Lake Champlain, N.Y. and Vt. (a) Ticonderoga, N.Y. An area shoreward of a line bearing 312° from Ticonderoga Light to the southeast corner of the...

  11. Function of VtPGIP in pathogenic fungus resistance of Vitis thunbergii

    edoja

    2014-02-19

    Feb 19, 2014 ... with pathogenic fungi and water were harvested, immediately frozen in liquid nitrogen, and stored at ... structure of the VtPGIP protein and molecular modeling were analyzed using Swiss-Pdb Viewer 3.7. Cloning of the VtPGIP ...

  12. Function of VtPGIP in pathogenic fungus resistance of Vitis thunbergii

    In plants, polygalacturonase inhibitor proteins (PGIPs) are very important to inactivate polygalacturonases secreted by pathogens. Vitis thunbergii Sieb. et Zucc. polygalacturonase inhibitor proteins (VtPGIP) was first isolated from the wild grape Vitis thunbergii Sieb. et Zucc., which exhibits high resistance to disease. VtPGIP ...

  13. VT Data - Lidar Aspect (0.7m) 2014, Chittenden Co., Lamoille Co., Orleans Co., Washington Co.

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and related ASPECT datasets. This metadata complies with the VT...

  14. Hemodynamics in Korean Hemorrhagic Fever

    Han, Ji Young; Lee, Jung Sang; Koh, Chang Soon; Lee, Mun Ho

    1974-01-01

    The author in an attempt to evaluate hemodynamic changes in the clinical stages of Korean hemorrhagic fever measured plasma volume, cardiac output and effective renal plasma flow utilizing radioisoto as during various phases of the disease. Cardiac output was measured by radiocardiography with external monitoring method using RIHSA. Effective renal plasma flow was obtained from blood clearance curve drawn by external monitoring after radiohippuran injection according to the method described by Razzak et al. The study was carried out in thirty-eight cases of Korean hemorrhagic fever and the following conclusions were obtained. 1) Plasma volume was increased in the patients during the oliguric and hypertensive-diuretic phases, while it was normal in the patients during the normotensive-diuretic phase. 2) Cardiac index was increased in the patients during the oliguric phase and was slightly increased in the patients at the hypertensive diuretic phase. It was normal in the other phases. 3) Total peripheral resistance was increased in the hypertensive patients during diuretic phase, while it was normal in the rest of phases. 4) Effective renal plasma flow was significantly reduced in the patients during the oliguric and diuretic phases as well as at one month after the oliguric onset. There was no significant difference between the oliguric and the early diuretic phases. Renal plasma flow in the group of patients at one month after the oliguric onset was about 45% of the normal, however, it returned to normal level at six months after the onset. 5) Clinical syndrome of relative hypervolemia was observed in some patients during the oliguric phase or hypertensive diuretic phase. Characteristic hemodynamic findings were high cardiac output and normal to relatively increased peripheral resistance these cases. Relatively increased circulating blood volumes due to decreased effective vascular space was suggested for the mechanism of relative hypervolemia. 6) Cardiac

  15. Effect of filler metals and heat treatment on mechanical properties of welded joints of the VT20L and VT6L titanium cast alloys

    Abramova, V.N.; Polyakov, D.A.; Vas'kin, Yu.V.; Kulikov, F.R.; Prostov, I.A.; Yasinskij, K.K.

    1979-01-01

    Developed is a technology of welding and heat treatment of the VT20L and VT6L alloys, providing the mechanical properties of welds on the base metal level. It is found, that for residual stress relieving it is quite enough to anneal the alloys at 650 deg C. Welding of the investigated alloys up to 20 mm thick using SPT-2 additional wire provides the welded joint strength on a level of 0.8 σsub(u) of base metal. Usage of additional wire of base metal provides equal strength of welds and base metal

  16. VT Lidar Hydro-flattened DEM (0.7 meter) - 2014 - Chittenden, Lamoille, Orleans, & Washington Counties

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and Digital Elevation Model (DEM) dataset of the following...

  17. VT Data - Lidar DSM (0.7m) 2016, Essex, Caledonia, Orange, and Windsor Counties

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Middle CT River subbasin 2016 0.7m; Eastern VT 2014 0.7m; Rutland/GI Counties 2013...

  18. Hemodynamics in diabetic orthostatic hypotension

    Hilsted, J; Parving, H H; Christensen, N J

    1981-01-01

    Hemodynamic variables (blood pressure, cardiac output, heart rate, plasma volume, splanchnic blood flow, and peripheral subcutaneous blood flow) and plasma concentrations of norepinephrine, epinephrine, and renin were measured in the supine position and after 30 min of quiet standing. This was done...... in normal subjects (n = 7) and in juvenile-onset diabetic patients without neuropathy (n = 8), with slight neuropathy (decreased beat-to-beat variation in heart rate during hyperventilation) (n = 8), and with severe neuropathy including orthostatic hypotension (n = 7). Blood pressure decreased precipitously...

  19. The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp.

    Kostrubiec, Viviane; Dumas, Guillaume; Zanone, Pier-Giorgio; Kelso, J A Scott

    2015-01-01

    The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities.

  20. Effect of dialysate temperature on hemodynamic stability among hemodialysis patients

    Azar, Ahmad Taher

    2009-01-01

    Cooling the dialysate below 36.5 degree C is an important factor that contributes to hemody-namic stability in patients during hemodialysis (HD). In this study, the effect of dialysate tempe-rature on hemodynamic stability, patients' perception of dialysis discomfort and post dialysis fatigue were assessed in a group of patients on HD. A total of 50 patients, all of whom were on 3-times-perweek dialysis regimen, were studied. Patients were assessed during six dialysis sessions; in three sessions, the dialysate temperature was normal (37 degree C) and in three other sessions, the dialysate temperature was low (35 degree C). Specific scale questionnaires were used in each dialysis session, to evaluate the symptoms during the dialysis procedure as well as post-dialysis fatigue, and respective scores were noted. The results showed that usage of low dialysate temperature was associated with the following: higher post dialysis systolic blood pressure (P< 0.05) and lower post dialysis heart rate (P<0.01), with similar ultrafiltration rates, better intra-dialysis symptoms score and post-dialysis fatigue scores (P< 0.001, and P<0.001, respectively), shorter post-dialysis fatigue period (P<0.001) as well as higher urea removal (P< 00001) and Kt/V (P< 0.0001). Patients' perceptions were measured by a questionnaire, which showed that 76% of them felt more energetic after dialysis with cool dialysate and requested to be always dialyzed with cool dialysate. Low temperature dialysate is particularly beneficial for highly symptomatic patients, improves tolerance to dialysis in hypotensive patients and helps increase ultrafiltration while maintaining hemodynamic stability during and after dialysis. (author)

  1. Immunologic, hemodynamic, and adrenal incompetence in cirrhosis

    Risør, Louise Madeleine; Bendtsen, Flemming; Møller, Søren

    2015-01-01

    dysfunction, but is not responsive to volume expansion. Recent research indicates that development of hepatic nephropathy represents a continuous spectrum of functional and structural dysfunction and may be precipitated by the inherent immunologic, adrenal, and hemodynamic incompetence in cirrhosis. New...... research explores several new markers of renal dysfunction that may replace serum creatinine in the future and give new insight on the hepatic nephropathy. Our understanding of the pathophysiological mechanisms causing the immunologic, adrenal, and hemodynamic incompetence, and the impact on renal...

  2. Central Hemodynamics and Microcirculation in Critical Conditions

    A. A. Kosovskikh

    2013-01-01

    Full Text Available Objective: to compare central hemodynamic and microcirculatory changes in critical conditions caused by different factors and to reveal their possible differences for a further differentiated approach to intensive therapy. Subjects and methods. The study covered 16 subjects with severe concomitant injury (mean age 41.96±2.83 years and 19 patients with general purulent peritonitis (mean age 45.34±2.16 years. Their follow-up was 7 days. The central hemodynamics was estimated by transpulmonary thermodilution using a Pulsion PiCCO Plus system (Pulsion Medical Systems, Germany. The microcirculatory bed was evaluated by cutaneous laser Doppler flowmetry using a LAKK-02 capillary blood flow laser analyzer (LAZMA Research-and-Production Association, Russian Federation. Results. The pattern of central hemodynamic and microcirculatory disorders varies with the trigger that has led to a critical condition. Central hemodynamics should be stabilized to ensure the average level of tissue perfusion in victims with severe concomitant injury. In general purulent peritonitis, microcirculatory disorders may persist even if the macrohemodynamic parameters are normal. Conclusion. The macrohemodynamic and microcirculatory differences obtained during the study suggest that a complex of intensive therapy should be differentiated and, if the latter is used, it is necessary not only to be based on the central hemodynamics, but also to take into consideration functional changes in microcirculation. Key words: severe concomitant injury, general purulent peritonitis, micro-circulation, central hemodynamics, type of circulation.

  3. Three graduate students receive Virginia Tech's first AdvanceVT Ph.D. fellowships

    Cox, Clara B.

    2004-01-01

    AdvanceVT, a comprehensive program that promotes and enhances the careers of women in science and engineering, has awarded its first three Ph.D. fellowships as part of an ongoing effort to increase the number of women electing to pursue academic careers.

  4. Virginia Tech announces AdvanceVT awards seed grants; names leadership fellows

    Cox, Clara B.

    2004-01-01

    AdvanceVT, a comprehensive program that promotes and enhances the careers of women in science and engineering at Virginia Tech, has awarded its first seed grants and named its first leadership fellows as part of an ongoing effort to increase the number of women electing to pursue or remain in academic careers.

  5. Investigation of broken symmetry of Sb/Cu(111) surface alloys by VT-STM

    Ndlovu, GF

    2011-07-01

    Full Text Available This work present an in situ Variable Temperature Scanning Tunneling Microscopy (VT-STM) study of the Sb/Cu(111) system studied at various temperatures. The experimental data support a structural model in which Sb atoms displace up to 1...

  6. VT Data - Lidar DSM (0.7m) 2015, Windham County

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Windham County 2015 0.7m; Eastern VT 2014 0.7m; Rutland/GI Counties 2013 0.7m; and...

  7. VT-NRK Toepassing bioplastics : verbeteren van de technische eigenschappen van PLA-folies

    Molenveld, K.; Schennink, G.G.J.

    2009-01-01

    Het doel van dit project, VT-NRK toepassing bioplastics, is het genereren en verspreiden van kennis met betrekking tot het verbeteren van de technische eigenschappen van PLA folies. De kennis is bedoeld voor de bedrijven die binnen de kunststofindustrie aangesloten zijn bij de MJA én folies

  8. MAGNETIC VT study: a prospective, multicenter, post-market randomized controlled trial comparing VT ablation outcomes using remote magnetic navigation-guided substrate mapping and ablation versus manual approach in a low LVEF population.

    Di Biase, Luigi; Tung, Roderick; Szili-Torok, Tamás; Burkhardt, J David; Weiss, Peter; Tavernier, Rene; Berman, Adam E; Wissner, Erik; Spear, William; Chen, Xu; Neužil, Petr; Skoda, Jan; Lakkireddy, Dhanunjaya; Schwagten, Bruno; Lock, Ken; Natale, Andrea

    2017-04-01

    Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. Clinicaltrials.gov identifier: NCT02637947.

  9. Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

    1991-01-01

    The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

  10. Hemodynamics in patients with hypertensive intracerebral hemorrhage

    Kitahara, Tetsuhiro

    1997-01-01

    Cerebral hemodynamics in 15 patients with hypertensive intracerebral hemorrhage (HICH) were evaluated by measuring cerebral blood flow (CBF) and cerebrovascular reserve capacity, using stable xenon-enhanced computed tomography. Their hematomas were removed by stereotactic aqua stream aspiration. The hemispheric and thalamic CBFs of patients with HICH were lower than those of hypertensive patients without hematomas. However, the hemispheric CBF increased according to how much of the hematoma was removed surgically. Thus, hemodynamics in patients with HICH can be improved by surgical hematoma removal, although some adjunct therapies are necessary in order to prevent secondary edema and the delayed neuronal death. (author)

  11. V-T theory for the self-intermediate scattering function in a monatomic liquid.

    Wallace, Duane C; Chisolm, Eric D; De Lorenzi-Venneri, Giulia

    2017-02-08

    In V-T theory the atomic motion is harmonic vibrations in a liquid-specific potential energy valley, plus transits, which move the system rapidly among the multitude of such valleys. In its first application to the self intermediate scattering function (SISF), V-T theory produced an accurate account of molecular dynamics (MD) data at all wave numbers q and time t. Recently, analysis of the mean square displacement (MSD) resolved a crossover behavior that was not observed in the SISF study. Our purpose here is to apply the more accurate MSD calibration to the SISF, and assess the results. We derive and discuss the theoretical equations for vibrational and transit contributions to the SISF. The time evolution is divided into three successive intervals: the vibrational interval when the vibrational contribution alone accurately accounts for the MD data; the crossover when the vibrational contribution saturates and the transit contribution becomes resolved; and the diffusive interval when the transit contribution alone accurately accounts for the MD data. The resulting theoretical error is extremely small at all q and t. V-T theory is compared to mode-coupling theories for the MSD and SISF, and to recent developments in Brownian motion experiments and theory.

  12. V-T theory for the self-intermediate scattering function in a monatomic liquid

    Wallace, Duane C; Chisolm, Eric D; De Lorenzi-Venneri, Giulia

    2017-01-01

    In V-T theory the atomic motion is harmonic vibrations in a liquid-specific potential energy valley, plus transits, which move the system rapidly among the multitude of such valleys. In its first application to the self intermediate scattering function (SISF), V-T theory produced an accurate account of molecular dynamics (MD) data at all wave numbers q and time t . Recently, analysis of the mean square displacement (MSD) resolved a crossover behavior that was not observed in the SISF study. Our purpose here is to apply the more accurate MSD calibration to the SISF, and assess the results. We derive and discuss the theoretical equations for vibrational and transit contributions to the SISF. The time evolution is divided into three successive intervals: the vibrational interval when the vibrational contribution alone accurately accounts for the MD data; the crossover when the vibrational contribution saturates and the transit contribution becomes resolved; and the diffusive interval when the transit contribution alone accurately accounts for the MD data. The resulting theoretical error is extremely small at all q and t . V-T theory is compared to mode-coupling theories for the MSD and SISF, and to recent developments in Brownian motion experiments and theory. (paper)

  13. Improvement in properties of welded joints of titanium alloy VT22 by thermocyclic treatment

    Lyasotskaya, V.S.; Kulikov, F.R.; Kirillov, Yu.G.; Ravdonikas, N.Yu.

    1983-01-01

    The results of investigations of the thermocyclic treatment (TCT) effect on the structure and properties of butt welded joints of tubes (with external diameter 180 mm and wall thickness 20-25 mm) of the VT22 alloy are presented. Welded joints have been obtained by means of multipassing automatic argon-arc (ARAW) and electron-beam (ELB) welding. It is shown that TCT of welded joints of the VT22 alloy results in formation in all zones of substructure with disperse precipitations of α-phase which is analogous to the structure of near welded seam zone metal immediately after welding. As a result of TCT and subsequent TT of welded joints poligonization and recrystallization processes of α- and #betta#-phases, changes in parameters of structural components and thin phase structure take place. TCT with strengthening TT or annealing leads to strength increase, while TCT with annealing besides that improves placticity and impact strength of the VT22 alloy welded joints

  14. Symptom-Hemodynamic Mismatch and Heart Failure Event Risk

    Lee, Christopher S.; Hiatt, Shirin O.; Denfeld, Quin E.; Mudd, James O.; Chien, Christopher; Gelow, Jill M.

    2014-01-01

    Background Heart failure (HF) is a heterogeneous condition of both symptoms and hemodynamics. Objective The goal of this study was to identify distinct profiles among integrated data on physical and psychological symptoms and hemodynamics, and quantify differences in 180-day event-risk among observed profiles. Methods A secondary analysis of data collected during two prospective cohort studies by a single group of investigators was performed. Latent class mixture modeling was used to identify distinct symptom-hemodynamic profiles. Cox proportional hazards modeling was used to quantify difference in event-risk (HF emergency visit, hospitalization or death) among profiles. Results The mean age (n=291) was 57±13 years, 38% were female, and 61% had class III/IV HF. Three distinct symptom-hemodynamic profiles were identified. 17.9% of patients had concordant symptoms and hemodynamics (i.e. moderate physical and psychological symptoms matched the comparatively hemodynamic profile), 17.9% had severe symptoms and average hemodynamics, and 64.2% had poor hemodynamics and mild symptoms. Compared to those in the concordant profile, both profiles of symptom-hemodynamic mismatch were associated with a markedly increased event-risk (severe symptoms hazards ratio = 3.38, p=0.033; poor hemodynamics hazards ratio = 3.48, p=0.016). Conclusions A minority of adults with HF have concordant symptoms and hemodynamics. Either profile of symptom-hemodynamic mismatch in HF is associated with a greater risk of healthcare utilization for HF or death. PMID:24988323

  15. Hemodynamic significance of internal carotid artery disease

    Schroeder, T

    1988-01-01

    Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure. Th...

  16. Exploration of Sub-VT and Near-VT 2T Gain-Cell Memories for Ultra-Low Power Applications under Technology Scaling

    Alexander Fish

    2013-04-01

    Full Text Available Ultra-low power applications often require several kb of embedded memory and are typically operated at the lowest possible operating voltage (VDD to minimize both dynamic and static power consumption. Embedded memories can easily dominate the overall silicon area of these systems, and their leakage currents often dominate the total power consumption. Gain-cell based embedded DRAM arrays provide a high-density, low-leakage alternative to SRAM for such systems; however, they are typically designed for operation at nominal or only slightly scaled supply voltages. This paper presents a gain-cell array which, for the first time, targets aggressively scaled supply voltages, down into the subthreshold (sub-VT domain. Minimum VDD design of gain-cell arrays is evaluated in light of technology scaling, considering both a mature 0.18 μm CMOS node, as well as a scaled 40 nm node. We first analyze the trade-offs that characterize the bitcell design in both nodes, arriving at a best-practice design methodology for both mature and scaled technologies. Following this analysis, we propose full gain-cell arrays for each of the nodes, operated at a minimum VDD. We find that an 0.18 μm gain-cell array can be robustly operated at a sub-VT supply voltage of 400mV, providing read/write availability over 99% of the time, despite refresh cycles. This is demonstrated on a 2 kb array, operated at 1 MHz, exhibiting full functionality under parametric variations. As opposed to sub-VT operation at the mature node, we find that the scaled 40 nm node requires a near-threshold 600mV supply to achieve at least 97% read/write availability due to higher leakage currents that limit the bitcell’s retention time. Monte Carlo simulations show that a 600mV 2 kb 40 nm gain-cell array is fully functional at frequencies higher than 50 MHz.

  17. Hemodynamic effects of rapid and slow infusions of manganese chloride and gadolinium-DTPA in dogs

    Slutsky, R.A.; Peterson, T.; Strich, G.; Brown, J.J.

    1985-01-01

    The acute hemodynamic effects of two paramagnetic contrast materials, manganese chloride and gadolinium-DTPA, were examined in dogs using ultrasonic dimension gauge crystals. Slow infusions (more than 15 minutes) of MnCl 2 or Gd-DTPA via an infusion pump had no significant hemodynamic effects. When given in just over 1 minute, Gd-DTPA produced elevated left ventricular (LV) end diastolic pressure and minor dilation of the ventricle and slowed diastolic filling. MnCl 2 , given rapidly, reduced systemic vascular resistance, resulting in hypotension. With both agents, these side effects waned after 5-10 minutes. It is concluded that both Gd-DTPA and MnCl 2 can be given safely in 0.1-mm/kg doses when administered as a slow, continuous infusion. Slow, intravenous infusion of Gd-DTPA or MnCl 2 is likely to be tolerated well by even severely ill individuals

  18. Crafting tolerance

    Kirchner, Antje; Freitag, Markus; Rapp, Carolin

    2011-01-01

    Ongoing changes in social structures, orientation, and value systems confront us with the growing necessity to address and understand transforming patterns of tolerance as well as specific aspects, such as social tolerance. Based on hierarchical analyses of the latest World Values Survey (2005......–08) and national statistics for 28 countries, we assess both individual and contextual aspects that influence an individual's perception of different social groupings. Using a social tolerance index that captures personal attitudes toward these groupings, we present an institutional theory of social tolerance. Our...

  19. VT Data - Lidar Hydro-enforced DEM (0.7m) 2014, Chittenden Co., Lamoille Co., Orleans Co., Washington Co.

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and Hydro Enforced Digital Elevation Model (DEMHE) dataset. This...

  20. VT Data - Lidar Slope (0.7m) 2014, Chittenden Co., Lamoille Co., Orleans Co., Washington Co.

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and related SLOPE datasets. Created using ArcGIS "SLOPE" command...

  1. VT Data - Lidar nDSM (0.7m) 2014, Chittenden Co., Lamoille Co., Orleans Co., Washington Co.

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and related 'normalized' Digital Surface Model (nDSM). Created...

  2. VT Data - Lidar Hillshade (0.7m) 2014, Chittenden Co., Lamoille Co., Orleans Co., Washington Co.

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and related "HILLSHADE" raster data. HILLSHADE data is for...

  3. Venous hemodynamic changes in lower limb venous disease

    Lee, Byung Boong; Nicolaides, Andrew N; Myers, Kenneth

    2016-01-01

    ). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various...... forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic...... changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatment by compression using different materials...

  4. Central hemodynamic responses during serial exercise tests in heart failure patients using implantable hemodynamic monitors.

    Ohlsson, A; Steinhaus, D; Kjellström, B; Ryden, L; Bennett, T

    2003-06-01

    Exercise testing is commonly used in patients with congestive heart failure for diagnostic and prognostic purposes. Such testing may be even more valuable if invasive hemodynamics are acquired. However, this will make the test more complex and expensive and only provides information from isolated moments. We studied serial exercise tests in heart failure patients with implanted hemodynamic monitors allowing recording of central hemodynamics. Twenty-one NYHA Class II-III heart failure patients underwent maximal exercise tests and submaximal bike or 6-min hall walk tests to quantify their hemodynamic responses and to study the feasibility of conducting exercise tests in patients with such devices. Patients were followed for 2-3 years with serial exercise tests. During maximal tests (n=70), heart rate increased by 52+/-19 bpm while S(v)O(2) decreased by 35+/-10% saturation units. RV systolic and diastolic pressure increased 29+/-11 and 11+/-6 mmHg, respectively, while pulmonary artery diastolic pressure increased 21+/-8 mmHg. Submaximal bike (n=196) and hall walk tests (n=172) resulted in S(v)O(2) changes of 80 and 91% of the maximal tests, while RV pressures ranged from 72 to 79% of maximal responses. An added potential value of implantable hemodynamic monitors in heart failure patients may be to quantitatively determine the true hemodynamic profile during standard non-invasive clinical exercise tests and to compare that to hemodynamic effects of regular exercise during daily living. It would be of interest to study whether such information could improve the ability to predict changes in a patient's clinical condition and to improve tailoring patient management.

  5. Hemodynamic monitoring in the critically ill.

    Voga, G

    1995-06-01

    Monitoring of vital functions is one of the most important and essential tools in the management of critically ill patients in the ICU. Today it is possible to detect and analyze a great variety of physiological signals by various noninvasive and invasive techniques. An intensivist should be able to select and perform the most appropriate monitoring method for the individual patient considering risk-benefit ratio of the particular monitoring technique and the need for immediate therapy, specific diagnosis, continuous monitoring and evaluation of morphology should be included. Despite rapid development of noninvasive monitoring techniques, invasive hemodynamic monitoring in still one of the most basic ICU procedures. It enables monitoring of pressures, flow and saturation, pressures in the systemic and pulmonary circulation, estimation of cardiac performance and judgment of the adequacy of the cardiocirculatory system. Carefully and correctly obtained information are basis for proper hemodynamic assessment which usually effects the therapeutic decisions.

  6. Biology and hemodynamics of aneurismal vasculopathies

    Pereira, Vitor Mendes; Brina, Olivier; Gonzalez, Ana Marcos; Narata, Ana Paula; Ouared, Rafik; Karl-Olof, Lovblad

    2013-01-01

    Aneurysm vasculopathies represents a group of vascular disorders that share a common morphological diagnosis: a vascular dilation, the aneurysm. They can have a same etiology and a different clinical presentation or morphology, or have different etiology and very similar anatomical geometry. The biology of the aneurysm formation is a complex process that will be a result of an endogenous predisposition and epigenetic factors later on including the intracranial hemodynamics. We describe the biology of saccular aneurysms, its growth and rupture, as well as, current concepts of hemodynamics derived from application of computational flow dynamics on patient specific vascular models. Furthermore, we describe different aneurysm phenotypes and its extremely variability on morphological and etiological presentation

  7. Hemodynamic significance of internal carotid artery disease

    Schroeder, T

    1988-01-01

    Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure...... stenosis. This is considered a result of chronic low perfusion pressure with subsequent loss of autoregulation, and autoregulatory control is first regained after some days.(ABSTRACT TRUNCATED AT 400 WORDS)...

  8. HEMODYNAMIC EFFECTS OF XENON ANESTHESIA IN CHILDREN

    M. V. Bykov

    2014-01-01

    Full Text Available The study was aimed at hemodynamic effects of xenon on operative interventions in children. Patients and methods: the study involved 30 5-17-year-old children – 10 (33.3% girls and 20 (66.7% boys with ASA score 1-3 admitted for surgical treatment. The children underwent endotracheal anesthesia with xenon-oxygen mixture (Xe:O2 = 60-65:30% and fentanyl (2.5‑3.5  mcg/kg per hour for the following operations: appendectomy – 10 (33.3% patients, herniotomy – 8 (26.7% patients, Ivanissevich procedure – 6 (20.0% patients, plastic surgery of posttraumatic defects of skin and soft tissues – 4 (13.3% patients, abdominal adhesiotomy – 2 (6.7% patients. Central hemodynamics was studied echocardiographically (Philips HD 11, the Netherlands using the Teichholz technique along the cephalocaudal axis (parasternal access. Results: the anesthesia was notable for hemodynamic stability during the operation: as a result, a statistically significant (p < 0.05 increase in systolic, diastolic and mean arterial pressure by 10, 18 and 17%, respectively, was observed. Conclusion: the analysis demonstrated that xenon anesthesia improves lusitropic myocardial function statistically significantly increasing cardiac output by 12% by way of increasing stroke volume by 30%. 

  9. Prospects of the "VT-Pro" series beef protein using in the sausages products technology

    O. P. Dvoryaninova

    2017-01-01

    Full Text Available Recently, the negative attitude of consumers towards soy protein has been formed. Therefore, to increase the mass fraction of protein in the finished product, it is advisable to use animal proteins, the main advantage of which is multipurpose designation, easy use and the ability to ensure an increase in the finished products yield and high production profitability due to their use . The application of beef proteins from collagen-containing raw materials makes it possible to enrich meat products with dietary fiber, to improve the rheological properties of food products significantly, especially their consistency. High functional properties of animal proteins are manifested in their water-retaining capacity. The company "TRUMP Food Technologies" introduced several new positions into its assortment - beef proteins of the "VT-Pro" trade mark (fibrillar fraction collagen, the manufacturer of which is JSC "Verkhnevolzhsky tannery" (Tver region. Proteins of the "VT-Pro" trademark are unique in their characteristics and are natural, environmentally friendly products. Beef protein "VT-Pro" is suitable for the production of cooked sausage and ham products, semi-smoked and boiled-smoked sausages, canned goods, chopped semi-finished products and other meat products. It is used as a full-fledged stabilizing additive for the preparation of meat products with a specified yield and certain organoleptic characteristics (hydration 1: 10-15. It is determined that it is possible to use this protein in dry form, as a protein-fat emulsion, in the form of gel and granules. According to the pilot-industrial approbation under the conditions of AIC "PROMAGRO" LLC, it is possible to underline a number of advantages of beef protein "VT-Pro" using: it possesses high water-retaining and emulsifying ability; allows to process low-grade and fired raw materials and to replace expensive meat raw materials; it reduces the risk of broth-fat swelling; it improves the structure of

  10. VHTR-fuel irradiation capsules for VT-1 hole of JRR-2

    Kikuchi, Teruo; Kikuchi, Akira; Tobita, Tsutomu; Kashimura, Satoru; Miyasaka, Yasuhiko

    1977-02-01

    Irradiations of VHTR fuels were made in the VT-1 irradiation hole of JRR-2. Three capsules, VP-1, VP-2 and VP-4, which contained fuel compacts, were irradiated for 300 hr at temperatures of 950 0 , 1370 0 and 1500 0 C up to the estimated burn-ups of 0.74, 0.87 and 0.80%FIMA, respectively. And, to study the amoeba effect of fuel particles, two capsules, VP-3 and VP-5, were irradiated for 300 hr at temperatures of 1650 0 and 1670 0 C up to the estimated burn-ups of 0.38 and 0.33%FIMA, respectively. (auth.)

  11. Surface hardening alloy VT6 of electric explosion and by electron beam

    Ivanov, Yu. F.; Kobzareva, T. Yu.; Gromov, V. E.; Soskova, N. A.; Budovskikh, E. A.; Raikov, S. V.

    2014-01-01

    The aim is to study the phase composition, structure and properties of the surface layer of the VT6 titanium alloy, subjected to combined treatment, consisting of alloying by the plasma of an electric explosion of a graphite fiber with a charge of the SiC powder and subsequent exposure by a high-intense electron beam. As a result of such treatment, a multiphase surface layer with a submicron and nanosize structure forms with the microhardness manifold exceeding its value in the sample volume are presented

  12. Om tolerance

    Huggler, Jørgen

    2007-01-01

    Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik.......Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik....

  13. Occupational exposure in hemodynamic; Exposicao ocupacional em hemodinamica

    Silva, Amanda J.; Fernandes, Ivani M.; Silva, Paula P. Nou; Sordi, Gian Maria A.A.; Carneiro, Janete C.G.G., E-mail: ajsilva@ipen.b, E-mail: imfernandes@ipen.b, E-mail: ppsilva@ipen.b, E-mail: gmsordi@ipen.b, E-mail: janetegc@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper has an objective to perform a radiometric survey at a hemodynamic service. Besides, it was intended to evaluate the effective dose of health professionals and to provide data which can contribute with minimization of exposures during the realization of hemodynamic procedure. The radiometric survey was realized in the real environment of work simulating the conditions of a hemodynamic study with a ionization chamber

  14. Whole-Genome Characterization and Strain Comparison of VT2f-Producing Escherichia coli Causing Hemolytic Uremic Syndrome

    Michelacci, Valeria; Bondì, Roslen; Gigliucci, Federica; Franz, Eelco; Badouei, Mahdi Askari; Schlager, Sabine; Minelli, Fabio; Tozzoli, Rosangela; Caprioli, Alfredo; Morabito, Stefano

    2016-01-01

    Verotoxigenic Escherichia coli infections in humans cause disease ranging from uncomplicated intestinal illnesses to bloody diarrhea and systemic sequelae, such as hemolytic uremic syndrome (HUS). Previous research indicated that pigeons may be a reservoir for a population of verotoxigenic E. coli producing the VT2f variant. We used whole-genome sequencing to characterize a set of VT2f-producing E. coli strains from human patients with diarrhea or HUS and from healthy pigeons. We describe a phage conveying the vtx2f genes and provide evidence that the strains causing milder diarrheal disease may be transmitted to humans from pigeons. The strains causing HUS could derive from VT2f phage acquisition by E. coli strains with a virulence genes asset resembling that of typical HUS-associated verotoxigenic E. coli. PMID:27584691

  15. Central and peripheral hemodynamics in exercising humans

    Calbet, J A L; González-Alonso, J; Helge, J W

    2015-01-01

    In humans, arm exercise is known to elicit larger increases in arterial blood pressure (BP) than leg exercise. However, the precise regulation of regional vascular conductances (VC) for the distribution of cardiac output with exercise intensity remains unknown. Hemodynamic responses were assessed...... perfusion pressure to increase O2 delivery, allowing a similar peak VO2 per kg of muscle mass in both extremities. In summary, despite a lower Qpeak during arm cranking the cardiovascular strain is much higher than during leg pedalling. The adjustments of regional conductances during incremental exercise...... to exhaustion depend mostly on the relative intensity of exercise and are limb-specific....

  16. Pain and hemodynamic effects in aortofemoral angiography

    Nyman, U.; Nilsson, P.; Westergren, A.

    1982-01-01

    Two new contrast media, iohexol (non-ionic monomer) and ioxaglate (monoacidic dimer), were compared with the non-ionic metrizamide during aortofemoral angiography in a single blind randomized trial in 2 groups of patients with 20 in each. The degree of heat and pain produced by iohexol and ioxaglate did not differ significantly from that produced by metrizamide, while subsequent injections of metrizoate caused significantly more heat and pain. The hemodynamic effects recorded in 10 patients in each group showed that iohexol and ioxaglate induced a decrease in vascular resistance, decrease in blood pressure and increase in heart rate not differing significantly from that induced by metrizamide. (Auth.)

  17. Structure and microhardness of alloy VT22 granules additionally doped with carbon and boron

    Sysoeva, N.V.; Polyakova, I.G.; Karpova, I.G.

    1996-01-01

    Aimed to improve heat resistance and strength of titanium base alloys due to carbon and boron additions (up to 0.3%) a study was made into regularities of phase decomposition in VT22 alloy during its rapid quenching from a liquid state on manufacturing granules 100-400 μm in size. Cooling rates on quenching were found to be sufficiently high to prevent precipitating carbides and borides. Subsequent annealing of granules promotes homogeneous precipitation of strengthening phases in the form of titanium carbides and borides, a reasonable amount of carbon and boron remaining in solid solution. An increase in microhardness of annealed granules reaches 20-25% compared to the standard alloy. 6 refs.; 2 figs.; 2 tabs

  18. Patient-Specific Modeling of Intraventricular Hemodynamics

    Vedula, Vijay; Marsden, Alison

    2017-11-01

    Heart disease is the one of the leading causes of death in the world. Apart from malfunctions in electrophysiology and myocardial mechanics, abnormal hemodynamics is a major factor attributed to heart disease across all ages. Computer simulations offer an efficient means to accurately reproduce in vivo flow conditions and also make predictions of post-operative outcomes and disease progression. We present an experimentally validated computational framework for performing patient-specific modeling of intraventricular hemodynamics. Our modeling framework employs the SimVascular open source software to build an anatomic model and employs robust image registration methods to extract ventricular motion from the image data. We then employ a stabilized finite element solver to simulate blood flow in the ventricles, solving the Navier-Stokes equations in arbitrary Lagrangian-Eulerian (ALE) coordinates by prescribing the wall motion extracted during registration. We model the fluid-structure interaction effects of the cardiac valves using an immersed boundary method and discuss the potential application of this methodology in single ventricle physiology and trans-catheter aortic valve replacement (TAVR). This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and partly through NIH NHLBI R01 Grant 5R01HL129727-02.

  19. Cerebral hemodynamics and functional prognosis in hydrocephalus

    Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime (Hamamatsu Rosai Hospital, Shizuoka (Japan))

    1989-11-01

    The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using {sup 99m}Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.).

  20. Cerebral hemodynamics and functional prognosis in hydrocephalus

    Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime

    1989-01-01

    The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using 99m Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.)

  1. Hemodynamic Simulations in Dialysis Access Fistulae

    McGah, Patrick; Leotta, Daniel; Beach, Kirk; Riley, James; Aliseda, Alberto

    2010-11-01

    Arteriovenous fistulae are created surgically to provide adequate access for dialysis in patients with End-Stage Renal Disease. It has long been hypothesized that the hemodynamic and mechanical forces (such as wall shear stress, wall stretch, or flow- induced wall vibrations) constitute the primary external influence on the remodeling process. Given that nearly 50% of fistulae fail after one year, understanding fistulae hemodynamics is an important step toward improving patency in the clinic. We perform numerical simulations of the flow in patient-specific models of AV fistulae reconstructed from 3D ultrasound scans with physiologically-realistic boundary conditions also obtained from Doppler ultrasound. Comparison of the flow features in different geometries and configurations e.g. end-to-side vs. side-to-side, with the in vivo longitudinal outcomes will allow us to hypothesize which flow conditions are conducive to fistulae success or failure. The flow inertia and pulsatility in the simulations (mean Re 700, max Re 2000, Wo 4) give rise to complex secondary flows and coherent vortices, further complicating the spatio- temporal variability of the wall pressure and shear stresses. Even in mature fistulae, the anastomotic regions are subjected to non-physiological shear stresses (>10.12pcPa) which may potentially lead to complications.

  2. Review: hemodynamic response to carbon monoxide

    Penney, D.G.

    1988-04-01

    Historically, and at present, carbon monoxide is a major gaseous poison responsible for widespread morbidity and mortality. From threshold to maximal nonlethal levels, a variety of cardiovascular changes occur, both immediately and in the long term, whose homeostatic function it is to renormalize tissue oxygen delivery. However, notwithstanding numerous studies over the past century, the literature remains equivocal regarding the hemodynamic responses in animals and humans, although CO hypoxia is clearly different in several respects from hypoxic hypoxia. Factors complicating interpretation of experimental findings include species, CO dose level and rate, route of CO delivery, duration, level of exertion, state of consciousness, and anesthetic agent used. Augmented cardiac output usually observed with moderate COHb may be compromised in more sever poisoning for the same reasons, such that regional or global ischemia result. The hypotension usually seen in most animal studies is thought to be a primary cause of CNS damage resulting from acute CO poisoning, yet the exact mechanism(s) remains unproven in both animals and humans, as does the way in which CO produces hypotension. This review briefly summarizes the literature relevant to the short- and long-term hemodynamic responses reported in animals and humans. It concludes by presenting an overview using data from a single species in which the most complete work has been done to date.

  3. Towards Tolerance

    Lisette Kuyper; Jurjen Iedema; Saskia Keuzenkamp

    2013-01-01

    Across Europe, public attitudes towards lesbian, gay and bisexual (LGB) individuals range from broad tolerance to widespread rejection. Attitudes towards homosexuality are more than mere individual opinions, but form part of the social and political structures which foster or hinder the equality

  4. Intolerant tolerance.

    Khushf, G

    1994-04-01

    The Hyde Amendment and Roman Catholic attempts to put restrictions on Title X funding have been criticized for being intolerant. However, such criticism fails to appreciate that there are two competing notions of tolerance, one focusing on the limits of state force and accepting pluralism as unavoidable, and the other focusing on the limits of knowledge and advancing pluralism as a good. These two types of tolerance, illustrated in the writings of John Locke and J.S. Mill, each involve an intolerance. In a pluralistic context where the free exercise of religion is respected, John Locke's account of tolerance is preferable. However, it (in a reconstructed form) leads to a minimal state. Positive entitlements to benefits like artificial contraception or nontherapeutic abortions can legitimately be resisted, because an intolerance has already been shown with respect to those that consider the benefit immoral, since their resources have been coopted by taxation to advance an end that is contrary to their own. There is a sliding scale from tolerance (viewed as forbearance) to the affirmation of communal integrity, and this scale maps on to the continuum from negative to positive rights.

  5. Texture and structure of VT-19 alloy thin sheets and their welded joints

    Ehgiz, I.V.; Babarehko, A.A.; Khorev, M.A.

    1986-01-01

    The phase content and texture of VT-19 alloys in all zones of welded joints (weld, a heat affected zone a base metal) after different heat treatments and the effect of the latter on mechanical properties of the welded joint are studied. It is characteristic of a 2.5 mm sheet of the VT-19 alloy rolled in the β → α phase transformation temperature range the development of β-phase plane deformation textures with (001), (112), (111) orientations in the rolling plane that compose 56% of the β-phase material volume. In this case a texture of univariant phase transformation of the above β-phase components { 1120 } - { 1122 } - { 1124 }, as well as that of α-phase plane deformation } 1014 } - { 1015 } are formed in the α-phase. Hardening with subsequent ageing of the rolled sheet leads to increasing the fraction of textured material in the β-phase up to 95% with expanding the volume with the (111) orientation, but as a whole the β-phase texture type remains the same. The α-phase texture type corresponds to the univariant β → α phase transformation, the material having the α-phase texture accounts for 70%. In the weld zone the and axes with orientation spreading to 20 deg are the β-phase crystallization axes in the trans verse direction. The textured material accounts for ∼ 70%. The same texture is observed along the normal to the sheet plane. The α-phase texture after hardening and ageing corresponds to the univariant phase transformation of the above-mentionedβ-phase orientations, the material volume with the α-phase texture is ∼80%

  6. New approach to intracardiac hemodynamic measurements in small animals

    Eskesen, Kristian; Olsen, Niels T; Dimaano, Veronica L

    2012-01-01

    Invasive measurements of intracardiac hemodynamics in animal models have allowed important advances in the understanding of cardiac disease. Currently they are performed either through a carotid arteriotomy or via a thoracotomy and apical insertion. Both of these techniques have disadvantages...... and are not conducive to repeated measurements. Therefore, the purpose of this study was to develop a new technique for measuring intracardiac hemodynamics....

  7. Development of BOLD signal hemodynamic responses in the human brain

    Arichi, T.; Varela, M.; Melendez-Calderon, A.; Allievi, A.; Merchant, N.; Tusor, N.; Counsell, S.J.; Burdet, E.; Beckmann, Christian; Edwards, A.D.

    2012-01-01

    In the rodent brain the hemodynamic response to a brief external stimulus changes significantly during development. Analogous changes in human infants would complicate the determination and use of the hemodynamic response function (HRF) for functional magnetic resonance imaging (fMRI) in developing

  8. Invasive hemodynamic characterization of heart failure with preserved ejection fraction

    Andersen, Mads Jønsson; Borlaug, Barry A

    2014-01-01

    Recent hemodynamic studies have advanced our understanding of heart failure with preserved ejection fraction (HFpEF). Despite improved pathophysiologic insight, clinical trials have failed to identify an effective treatment for HFpEF. Invasive hemodynamic assessment can diagnose or exclude HFp...

  9. Salt Tolerance

    Xiong, Liming; Zhu, Jian-Kang

    2002-01-01

    Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are sh...

  10. [Myocardial contractility and hemodynamics in hypothyroidism].

    Selivonenko, V G

    1977-01-01

    The author determined the phasic structure of the systole of the left ventricle by the method of polycardiography and hemodynamics in 20 patients suffering from hypothyrodism. Blood plasma and erythrocyte electrolytes were examined at the same time. Patients with hypothyroidism displayed a phasic syndrome of hypodynamia and a marked correlation between the phase of the synchronous contraction, the period of ejection, the strength of contraction of the left ventricle and the electrolyte content. Sodium and magnesium produced the greatest influence on the phasic structure of the systole; potassium and calcium had a lesser effect. The heart stroke volume diminished; as to the cardiac index, expenditure of the energy of cardiac contractions directed to the maintenance of movement of 1 litre of the minute blood volume; the external work, and the peripheral vascular resistance displayed no significant change.

  11. Hemodynamic stress testing using pacing tachycardia

    McKay, R.G.; Grossman, W.

    1986-01-01

    A trial pacing was first introduced in 1967 by Sowton and co-workers as a stress test which could be used in the cardiac catheterization laboratory to evaluate patients with schemic heart disease. Sowton noted that artificially increasing the heart rate by pacing the right atrium could usually induce angina in patients with symptomatic coronary artery disease. Since Sowton's original description, numerous investigators have described characteristic pacing-induced electrocardiographic changes, derangements of myocardial lactate metabolism, hemodynamic abnormalities, regional wall abnormalities, and defects in thallium scintigraphy. Although agreement on the overall usefulness of atrial pacing has not been uniform, it is clear that the technique can safely and reliably induce ischemia in most patients with coronary artery disease and that information obtained during the pacing-induced ischemic state can often be helpful in the diagnosis and treatment of the patient's underlying disease

  12. SpoVT: From Fine-Tuning Regulator in Bacillus subtilis to Essential Sporulation Protein in Bacillus cereus.

    Eijlander, Robyn T; Holsappel, Siger; de Jong, Anne; Ghosh, Abhinaba; Christie, Graham; Kuipers, Oscar P

    2016-01-01

    Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus , whereas this is not observed in Bacillus subtilis . Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus Δ spoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes.

  13. Hemodynamic characteristics of early stage hepatocellular carcinoma

    Kudo, Masatoshi; Tomita, Shusuke; Tochio, Hitoshi

    1992-01-01

    Hemodynamic characteristics were studied by using in vivo vascular imaging techniques in 17 resected early stage hepatocellular carcinoma (e-HCC) by comparing them with 49 resected advanced HCCs (ad-HCC) less than 3 cm in diameter. In this study, e-HCC was defined as the nodule being uniformly composed of well-differentiated HCC or adenomatous hyperplastic nodule containing well-differentiated HCC foci within the nodule. In vivo vascular imaging techniques are as follows; US angiography with intraarterial CO 2 microbubbles were performed to assess the tumor arterial vascularity, and CT during arterial portography (CTAP) was performed to assess the portal perfusion within the nodule. Of 17 e-HCC nodules 5 were hypervascular, 5 were isovascular, 4 were hypovascular, and 3 were vascular spot in hypovascular pattern in contrast to 49 ad-HCC nodules, 43 of which were hypervascular and 6 were isovascular. Of 14 e-HCCs, 9 nodules showed perfusion defect and 5 did not on CTAP, whereas all 37 ad-HCCs on which CTAP was performed, showed perfusion defect. Forty-one percent (7/17) of e-HCC showed fatty metamorphosis in contrast to 8% (4/49) of ad-HCC. In conclusion, hemodynamic characteristics of e-HCC are summarized as follows. (1) Arterial tumor neovascularization is relatively low. (2) Portal perfusion is present in some of e-HCC cases. (3) Hypoperfusion state both from arterial and portal supply is present in some of e-HCC cases. (4) Vascular spot in hypovascular pattern is characteristic arterial pattern in AH containing HCC foci. (5) Fatty metamorphosis may be related with hypoperfusion state of the nodule in e-HCC. (author)

  14. Hemodynamic effects of sodium bicarbonate administration.

    Katheria, A C; Brown, M K; Hassan, K; Poeltler, D M; Patel, D A; Brown, V K; Sauberan, J B

    2017-05-01

    To describe the hemodynamic changes that occur with sodium bicarbonate (NaHCO 3 ) administration in premature neonates. This retrospective study included premature neonates 23 to 31+6 weeks of gestational age who underwent continuous cardiac and cerebral monitoring as participants in prospective trials at our institution, and who received NaHCO 3 infused over 30 min in the first 24 h of life. Blood pressure (BP), heart rate, cardiac output (CO), SpO 2 and cerebral oximetry (StO 2 ) were captured every 2 s. A baseline was established for all continuous data and averaged over the 10 min before NaHCO 3 administration. Baseline was compared with measurements over 10 min epochs until 80 min after administration. Arterial blood gases before and within 1 h of administration were also compared. Significance was set at P<0.05. A total of 36 subjects received NaHCO 3 (1.3±0.3 mEq kg -1 ) in the first 24 h (14±8.5 h) of life. NaHCO 3 administration increased pH (7.23 vs 7.28, P<0.01) and decreased base deficit (-8.9 vs -6.8, P<0.01) and PaCO 2 (45 vs 43 mm Hg, P<0.05). There was a transient but significant (P<0.05) decrease in systemic BP coinciding with an increase in cerebral oxygenation without an increase in oxygen extraction. CO did not change. Early postnatal NaHCO 3 administration does not acutely improve CO but does cause transient fluctuations in cerebral and cardiovascular hemodynamics in extremely premature infants.

  15. Efficacy of the clinical agent VT-1161 against fluconazole-sensitive and -resistant Candida albicans in a murine model of vaginal candidiasis.

    Garvey, E P; Hoekstra, W J; Schotzinger, R J; Sobel, J D; Lilly, E A; Fidel, P L

    2015-09-01

    Vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC) remain major health problems for women. VT-1161, a novel fungal CYP51 inhibitor which has potent antifungal activity against fluconazole-sensitive Candida albicans, retained its in vitro potency (MIC50 of ≤0.015 and MIC90 of 0.12 μg/ml) against 10 clinical isolates from VVC or RVVC patients resistant to fluconazole (MIC50 of 8 and MIC90 of 64 μg/ml). VT-1161 pharmacokinetics in mice displayed a high volume of distribution (1.4 liters/kg), high oral absorption (73%), and a long half-life (>48 h) and showed rapid penetration into vaginal tissue. In a murine model of vaginal candidiasis using fluconazole-sensitive yeast, oral doses as low as 4 mg/kg VT-1161 significantly reduced the fungal burden 1 and 4 days posttreatment (P < 0.0001). Similar VT-1161 efficacy was measured when an isolate highly resistant to fluconazole (MIC of 64 μg/ml) but fully sensitive in vitro to VT-1161 was used. When an isolate partially sensitive to VT-1161 (MIC of 0.12 μg/ml) and moderately resistant to fluconazole (MIC of 8 μg/ml) was used, VT-1161 remained efficacious, whereas fluconazole was efficacious on day 1 but did not sustain efficacy 4 days posttreatment. Both agents were inactive in treating an infection with an isolate that demonstrated weaker potency (MICs of 2 and 64 μg/ml for VT-1161 and fluconazole, respectively). Finally, the plasma concentrations of free VT-1161 were predictive of efficacy when in excess of the in vitro MIC values. These data support the clinical development of VT-1161 as a potentially more efficacious treatment for VVC and RVVC. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Ionizing radiation occupational exposure in the hemodynamics services

    Gronchi, Claudia Carla

    2004-01-01

    The purpose of this research is to study the ionizing radiation occupational exposure in the hemodynamic services of two large scale hospitals (Hospital A and Hospital B) of the Sao Paulo city. The research looked into annual doses that 279 professionals of the hemodynamic services were exposed to between 1991 and 2002. The data analyzed was collected from the database of the Instituto de Pesquisas Energeticas e Nucleares (IPEN) for Hospital A, and from the Radiological Protection Department of Hospital B. Besides this, measures of hands and crystalline lens equivalent doses were performed during hemodynamic procedures of the physicians, assistant physicians and nursing assistants with TL dosimeters (CaSO 4 :Dy + Teflon R) produced at IPEN. The safety procedures adopted by the hospitals were verified with the aid of a specific questionnaire for the hemodynamic services. Finally, a profile of the professionals that work in cardiac catheterism laboratories of the hemodynamic services was delineated, considering the variables of individual monitoring time, age and sex. This study allowed for observation of the behavior of the professionals' annual doses of these hemodynamic services in relation to the Comissao Nacional de Energia Nuclear and the Secretaria de Vigilancia Sanitaria limits. It showed that the annual doses of the same specialized occupations would vary from one hospital to another. It further showed the need of individual monitoring of the physicians' unprotected body parts (hands and crystalline lens) during the hemodynamic procedures. (author)

  17. Congenital heart malformations induced by hemodynamic altering surgical interventions

    Madeline eMidgett

    2014-08-01

    Full Text Available Embryonic heart formation results from a dynamic interplay between genetic and environmental factors. Blood flow during early embryonic stages plays a critical role in heart development, as interactions between flow and cardiac tissues generate biomechanical forces that modulate cardiac growth and remodeling. Normal hemodynamic conditions are essential for proper cardiac development, while altered blood flow induced by surgical manipulations in animal models result in heart defects similar to those seen in humans with congenital heart disease. This review compares the altered hemodynamics, changes in tissue properties, and cardiac defects reported after common surgical interventions that alter hemodynamics in the early chick embryo, and shows that interventions produce a wide spectrum of cardiac defects. Vitelline vein ligation and left atrial ligation decrease blood pressure and flow; and outflow tract banding increases blood pressure and flow velocities. These three surgical interventions result in many of the same cardiac defects, which indicate that the altered hemodynamics interfere with common looping, septation and valve formation processes that occur after intervention and that shape the four-chambered heart. While many similar defects develop after the interventions, the varying degrees of hemodynamic load alteration among the three interventions also result in varying incidence and severity of cardiac defects, indicating that the hemodynamic modulation of cardiac developmental processes is strongly dependent on hemodynamic load.

  18. Hemodynamic Perturbations in Deep Brain Stimulation Surgery: First Detailed Description

    Tumul Chowdhury

    2017-08-01

    Full Text Available Background: Hemodynamic perturbations can be anticipated in deep brain stimulation (DBS surgery and may be attributed to multiple factors. Acute changes in hemodynamics may produce rare but severe complications such as intracranial bleeding, transient ischemic stroke and myocardium infarction. Therefore, this retrospective study attempts to determine the incidence of hemodynamic perturbances (rate and related risk factors in patients undergoing DBS surgery.Materials and Methods: After institutional approval, all patients undergoing DBS surgery for the past 10 years were recruited for this study. Demographic characteristics, procedural characteristics and intraoperative hemodynamic changes were noted. Event rate was calculated and the effect of all the variables on hemodynamic perturbations was analyzed by regression model.Results: Total hemodynamic adverse events during DBS surgery was 10.8 (0–42 and treated in 57% of cases.Conclusion: Among all the perioperative variables, the baseline blood pressure including systolic, diastolic, and mean arterial pressure was found to have highly significant effect on these intraoperative hemodynamic perturbations.

  19. Permanent education that approaches radiation protection in hemodynamic service

    Flor, Rita de Cassia; Anjos, Djeniffer Valdirene dos

    2011-01-01

    In the hemodynamic services that apply ionizing radiation yet exist the necessity of capacitation of workers for actuation in those areas. So, this qualitative study performed in a hemodynamic service at Sao Jose, Santa Catarina, Brazil, had the objective to analyse how are developed the permanent education programs and the real necessity of workers. The results have shown that the workers are longing for their qualification and formation, as generally they are admitted with not any qualification for those services. So, the workers that realize the on duty hemodynamic service praxis must do it in a conscious manner and the E P is a way for to adopt good practice in radiological protection

  20. Infectious Tolerance

    Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

    2002-01-01

    Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, ...

  1. Heat treatment effect on the texture and mechanical properties of the VT14 alloy cylinders

    Betsofen, S.Ya.; Khorev, A.I.; Babarehko, A.A.; Krasnozhon, A.I.; Kadobnova, N.V.

    1978-01-01

    The mechanical properties and the texture of cylinders made of VT14 alloy in the conditions after quenching from the temperature of 880 deg C, followed by ageing for 16 hours at the temperature of about 480 deg C, or after 20 minutes annealing at the temperature of 750 deg C, were stu--died, while taking into account the influence of intermediate preheats up to 800-1000 deg C prior to carrying into effect those kinds of heat treatment. It is shown that the texture of cylinders after heat treatment without the intermediate preheats prior to quenching is characterized by an increased density of poles in the axial and tangential directions. It is the preheating up to 1000 deg C prior to quenching that shifts the texture maxima in the axial direction and causes the appearance of component (0001). Under the effect of the intermediate preheating up to 1000 deg C, the biaxial and monoaxial strength of the cylinders decreases, whereas their tendency to brittle failure increases. The mechanical strength of all the thermally hardened cylinders, independently of the intermediate treatment, is in the tangential direction higher than in the axial direction. The proportions of the structure and texture factors have been assessed in the variation of the structural strength of the cylinders during the course of their heat treatment

  2. Infectious Tolerance

    Jonuleit, Helmut; Schmitt, Edgar; Kakirman, Hacer; Stassen, Michael; Knop, Jürgen; Enk, Alexander H.

    2002-01-01

    Regulatory CD4+CD25+ T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact–mediated suppression of conventional CD4+ T cells by human CD25+ Treg cells is fixation resistant, independent from membrane-bound TGF-β but requires activation and protein synthesis of CD25+ Treg cells. Coactivation of CD25+ Treg cells with Treg cell–depleted CD4+ T cells results in anergized CD4+ T cells that in turn inhibit the activation of conventional, freshly isolated CD4+ T helper (Th) cells. This infectious suppressive activity, transferred from CD25+ Treg cells via cell contact, is cell contact–independent and partially mediated by soluble transforming growth factor (TGF)-β. The induction of suppressive properties in conventional CD4+ Th cells represents a mechanism underlying the phenomenon of infectious tolerance. This explains previously published conflicting data on the role of TGF-β in CD25+ Treg cell–induced immunosuppression. PMID:12119350

  3. Hemodynamic changes during robotic radical prostatectomy

    Vanlal Darlong

    2012-01-01

    Full Text Available Background: Effect on hemodynamic changes and experience of robot-assisted laparoscopic radical prostatectomy (RALRP in steep Trendelenburg position (45° with high-pressure CO 2 pneumoperitoneum is very limited. Therefore, we planned this prospective clinical trial to study the effect of steep Tredelenburg position with high-pressure CO 2 pneumoperitoneum on hemodynamic parameters in a patient undergoing RALRP using FloTrac/Vigileo™1.10. Methods: After ethical approval and informed consent, 15 patients scheduled for RALRP were included in the study. In the operation room, after attaching standard monitors, the radial artery was cannulated. Anesthesia was induced with fentanyl (2 μg/kg and thiopentone (4-7 mg/kg, and tracheal intubation was facilitated by vecuronium bromide (0.1 mg/kg. The patient′s right internal jugular vein was cannulated and the Pre Sep™ central venous oximetry catheter was connected to it. Anesthesia was maintained with isoflurane in oxygen and nitrous oxide and intermittent boluses of vecuronium. Intermittent positive-pressure ventilation was provided to maintain normocapnea. After CO 2 pneumoperitoneum, position of the patient was gradually changed to 45° Trendelenburg over 5 min. The robot was then docked and the robot-assisted surgery started. Intraoperative monitoring included central venous pressure (CVP, stroke volume (SV, stroke volume variation (SVV, cardiac output (CO, cardiac index (CI and central venous oxygen saturation (ScvO 2 . Results: After induction of anesthesia, heart rate (HR, SV, CO and CI were decreased significantly from the baseline value (P>0.05. SV, CO and CI further decreased significantly after creating pneumoperitoneum (P>0.05. At the 45° Trendelenburg position, HR, SV, CO and CI were significantly decreased compared with baseline. Thereafter, CO and CI were persistently low throughout the 45° Trendelenburg position (P=0.001. HR at 20 min and 1 h, SV and mean arterial blood pressure

  4. Levosimendan for Hemodynamic Support after Cardiac Surgery.

    Landoni, Giovanni; Lomivorotov, Vladimir V; Alvaro, Gabriele; Lobreglio, Rosetta; Pisano, Antonio; Guarracino, Fabio; Calabrò, Maria G; Grigoryev, Evgeny V; Likhvantsev, Valery V; Salgado-Filho, Marcello F; Bianchi, Alessandro; Pasyuga, Vadim V; Baiocchi, Massimo; Pappalardo, Federico; Monaco, Fabrizio; Boboshko, Vladimir A; Abubakirov, Marat N; Amantea, Bruno; Lembo, Rosalba; Brazzi, Luca; Verniero, Luigi; Bertini, Pietro; Scandroglio, Anna M; Bove, Tiziana; Belletti, Alessandro; Michienzi, Maria G; Shukevich, Dmitriy L; Zabelina, Tatiana S; Bellomo, Rinaldo; Zangrillo, Alberto

    2017-05-25

    Acute left ventricular dysfunction is a major complication of cardiac surgery and is associated with increased mortality. Meta-analyses of small trials suggest that levosimendan may result in a higher rate of survival among patients undergoing cardiac surgery. We conducted a multicenter, randomized, double-blind, placebo-controlled trial involving patients in whom perioperative hemodynamic support was indicated after cardiac surgery, according to prespecified criteria. Patients were randomly assigned to receive levosimendan (in a continuous infusion at a dose of 0.025 to 0.2 μg per kilogram of body weight per minute) or placebo, for up to 48 hours or until discharge from the intensive care unit (ICU), in addition to standard care. The primary outcome was 30-day mortality. The trial was stopped for futility after 506 patients were enrolled. A total of 248 patients were assigned to receive levosimendan and 258 to receive placebo. There was no significant difference in 30-day mortality between the levosimendan group and the placebo group (32 patients [12.9%] and 33 patients [12.8%], respectively; absolute risk difference, 0.1 percentage points; 95% confidence interval [CI], -5.7 to 5.9; P=0.97). There were no significant differences between the levosimendan group and the placebo group in the durations of mechanical ventilation (median, 19 hours and 21 hours, respectively; median difference, -2 hours; 95% CI, -5 to 1; P=0.48), ICU stay (median, 72 hours and 84 hours, respectively; median difference, -12 hours; 95% CI, -21 to 2; P=0.09), and hospital stay (median, 14 days and 14 days, respectively; median difference, 0 days; 95% CI, -1 to 2; P=0.39). There was no significant difference between the levosimendan group and the placebo group in rates of hypotension or cardiac arrhythmias. In patients who required perioperative hemodynamic support after cardiac surgery, low-dose levosimendan in addition to standard care did not result in lower 30-day mortality than placebo

  5. The hemodynamic repercussions of the autonomic modulations in ...

    Igor Victorovich Lakhno

    2017-01-16

    Jan 16, 2017 ... autonomic balance, arterial and venous hemodynamic Doppler indices and CTG variables in case of nor- mal fetal ... score of decelerations. Results: The .... puter electrocardiographic system ''Cardiolab Baby Card” (Scien-.

  6. Hemodynamic changes after levothyroxine treatment in subclinical hypothyroidism

    Faber, J; Petersen, L; Wiinberg, N

    2002-01-01

    by LT(4) (p treatment in SH results in changes in hemodynamic parameters of potentially beneficial character. SH and overt hypothyroidism should......In hypothyroidism, lack of thyroid hormones results in reduced cardiac function (cardiac output [CO]), and an increase of systemic vascular resistance (SVR). We speculated whether hemodynamic regulation in subjects with subclinical hypothyroidism (SH) (defined as mildly elevated thyrotropin [TSH......) and T(3) estimates) LT(4) treatment resulted in 6% reduction in supine MAP (p treatment (p

  7. Reliability of oscillometric central hemodynamic responses to an orthostatic challenge

    Stoner, Lee; Bonner, Chantel; Credeur, Daniel; Lambrick, Danielle; Faulkner, James; Wadsworth, Daniel; Williams, Michelle A.

    2015-01-01

    BackgroundMonitoring central hemodynamic responses to an orthostatic challenge may provide important insight into autonomic nervous system function. Oscillometric pulse wave analysis devices have recently emerged, presenting clinically viable options for investigating central hemodynamic properties. The purpose of the current study was to determine whether oscillometric pulse wave analysis can be used to reliably (between-day) assess central blood pressure and central pressure augmentation (a...

  8. Postural hemodynamic changes after turning to prone position

    Микола Віталійович Лизогуб

    2015-03-01

    Full Text Available Background of study. Prone position is one of the most complex positions for anesthesiologist as it is accompanied by several physiological changes that can lead to specific complications. Hemodynamic changes are most controversial.Aim of study was to establish hemodynamic changes in non-anaesthetized patients in prone position depending on body mass index.Material and methods. We examined central hemodynamics in 40 patients the day before surgery using thoracic rheography in supine position, in prone position 5 min after turning and in prone position 20 min after turning. Patients were divided into 2 groups according to body mass index (18-25 and 26-35.Results. Patients with normal body weight did not have any hemodynamic changes after turning to prone position. Patients with increased body weight had higher cardiac index. After turning to prone position obese patients’ cardiac output and cardiac index reduced 22% comparing with supine position. After 20 min in prone position these hemodynamic parameters were found to be reduced to the same level.Conclusion. Significant hemodynamic changes after turning from supine to prone position were revealed only in patients with increased body mass index. In these patients cardiac index in prone position was reduced by 22% comparing to supine position

  9. Study of the penetration of a plate made of titanium alloy VT6 with a steel ball

    Buzyurkin, A. E.

    2018-03-01

    The purpose of this work is the development and verification of mathematical relationships, adapted to the package of finite element analysis LS-DYNA and describing the deformation and destruction of a titanium plate in a high-speed collision. Using data from experiments on the interaction of a steel ball with a titanium plate made of VT6 alloy, verification of the available constants necessary for describing the behavior of the material using the Johnson-Cook relationships was performed, as well as verification of the parameters of the fracture model used in the numerical modeling of the collision process. An analysis of experimental data on the interaction of a spherical impactor with a plate showed that the data accepted for VT6 alloy in the first approximation for deformation hardening in the Johnson-Cook model give too high results on the residual velocities of the impactor when piercing the plate.

  10. Improvement of high-temperature thermomechanical treatment of the rolled section made of VT3-1 alloy

    Gavze, A.L.; Korostelev, Yu.P.

    2002-01-01

    Changes in mechanical properties and structure are investigated in alloy VT3-1 rods produced with the use of high temperature thermomechanical treatment (HTMT) on their heating and deformation during straightening as well as during preliminary hot deformation of the billets on a helical rolling mill (HRM). It is stated that the straightening at 550-700 deg C with elongation of ∼ 2% results in some decrease of ultimate strength and in essential enhancement of plasticity and impact strength. In a similar manner, preliminary rolling on HRM affects the properties of rods after final heat treatment. It is shown that rod production according to the experimental processing procedure increases the quality of the rods and can be realized when manufacturing rolled products of alloy VT3-1 with the use of HTMT [ru

  11. CT of hemodynamically unstable abdominal trauma

    Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A.

    1999-01-01

    This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.)

  12. CT of hemodynamically unstable abdominal trauma

    Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A. [Department of Radiology, General Hospital ``G. Papanikolaou,`` Thessaloniki (Greece)

    1999-03-01

    This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.) With 6 figs., 5 tabs., 20 refs.

  13. [Hemodynamic phenomena in retrobulhar and eyeball vessels].

    Modrzejewska, Monika

    2011-01-01

    The purpose of this review was to evaluate factors connected with blood flow and indices regulating vascular diameter and some parameters influencing retrobulbar circulation such as type of vascular resistance, anatomical structure of vascular wall and vessel lumen. Neurogenic and angiogenic factors, rheological blood composition, presence of anatomical and pathological obstructions on blood flow pathway as well as degree of development of collateral circulation pathways--have influence on the volume and blood flow velocity in eyeball. There were discussed bulbar circulation hemodynamics, emphasizing the importance of perfusion pressure. The role of risk factors was underlined for pathological lesions in vessels supplying blood to eyeball and in ophthalmic artery (OA) and its collaterals, in central retinal artery (CRA) as well as posterior ciliary arteries (PCAs), and in venous system carrying away blood from eye. IN CONCLUSION--the results of many studies of retrobulbar blood flow in different types of ophthalmic diseases of the vascular etiopathogenesis indicate that registry of the mean values of blood flow parameters and vascular resistance indices parallel to measurement of blood flow spectrum in OA, CRA, PCAs arteries, might contribute much information to explain or to evaluate nature of pathological changes in retinal and choroidal circulation.

  14. Studying the compactibility of the VT22 high-strength alloy powder obtained by the PREP method

    Kryuchkov, D. I.; Berezin, I. M.; Nesterenko, A. V.; Zalazinsky, A. G.; Vichuzhanin, D. I.

    2017-12-01

    Compression curves are plotted for VT22 high-strength alloy powder under conditions of uniaxial compression at room temperature. The density of the compacted briquette at the loading and unloading stages is determined. It is demonstrated that strong interparticle bonds are formed in the area of the action of shear deformation. The results are supposed to be used to identify the flow model of the material studied and to perform the subsequent numerical modeling of the compaction process.

  15. Corrosion cracking resistance of the VT3-1 titanium alloy with initial defects in the metal

    Konradi, G.G.; Mozhaev, A.V.; Zmievskij, V.I.; Sokolov, V.S.

    1978-01-01

    Investigated is the corrosion cracking resistance of thick sheet half-finished product of the VT3-1 alloy in 3% NaCl solution during 800 hrs. It is shown that crack development occurs during the first 24 hours with stress intensities above the threshold coefficient of stress intensities. Ratios of crack sizes permissible for using the alloy in the air and NaCl solution media are obtained

  16. Welding of the VNZh7-3 alloy with the VT1-0 titanium by laser beam

    Baranov, M.S.; Voshchinskij, M.L.; Fedorov, P.M.; Shilov, I.F.; Zytner, G.D.

    1980-01-01

    Found is the principle possibility of the laser welding of dissimilar metals and the optimum welding mode as well with the testing of quality and strength indices of welded joints and with mode test on structural elements. The possibility of laser welding of the sintered VNZh 7-3 alloy with the VT1-0 titanium in argon is shown. Studied is the technique of forming of welded edge joint of the above dissimilar metals. Established is the optimum method of laser beam setting at an angle of 20 deg to the butt surface and with the shift by 1/3 of diameter of welded point in the titanium direction. Shear tests of elementary and natural samples have shown that real strength of welded joint exceeds the VT1-0 titanium strength. Macro- and microstructure of welded joints has layer-vortex alloy structure on the base of the VT1-0 titanium inclusion of tungsten grains that indicates the intensive mixing of metals during the welding

  17. Dipole controlled metal gate with hybrid low resistivity cladding for gate-last CMOS with low Vt

    Hinkle, Christopher L.; Galatage, Rohit V.; Chapman, Richard A.; Vogel, Eric M.; Alshareef, Husam N.; Freeman, Clive M.; Wimmer, Erich; Niimi, Hiroaki; Li-Fatou, Andrei V.; Shaw, Judy B.; Chambers, James J.

    2010-01-01

    In this contribution, NMOS and PMOS band edge effective work function (EWF) and correspondingly low Vt are demonstrated using standard fab materials and processes in a gate-last scheme. For NMOS, the use of an Al cladding layer results in Vt = 0.08 V consistent with NMOS EWF = 4.15 eV. Migration of the Al cladding into the TiN and a relatively low oxygen concentration near the TiN/HfO2 interface are responsible for the low EWF. For PMOS, employing a W cladding layer along with a post-TiN anneal in an oxidizing ambient results in elevated oxygen concentration near the TiN/HfO2 interface and Vt = -0.20 V consistent with a PMOS EWF = 5.05 eV. First-principles calculations indicate N atoms displaced from the TiN during the oxidizing anneal form dipoles at the TiN/HfO2 interface that play a critical role in determining the PMOS EWF. © 2010 IEEE.

  18. Dipole controlled metal gate with hybrid low resistivity cladding for gate-last CMOS with low Vt

    Hinkle, Christopher L.

    2010-06-01

    In this contribution, NMOS and PMOS band edge effective work function (EWF) and correspondingly low Vt are demonstrated using standard fab materials and processes in a gate-last scheme. For NMOS, the use of an Al cladding layer results in Vt = 0.08 V consistent with NMOS EWF = 4.15 eV. Migration of the Al cladding into the TiN and a relatively low oxygen concentration near the TiN/HfO2 interface are responsible for the low EWF. For PMOS, employing a W cladding layer along with a post-TiN anneal in an oxidizing ambient results in elevated oxygen concentration near the TiN/HfO2 interface and Vt = -0.20 V consistent with a PMOS EWF = 5.05 eV. First-principles calculations indicate N atoms displaced from the TiN during the oxidizing anneal form dipoles at the TiN/HfO2 interface that play a critical role in determining the PMOS EWF. © 2010 IEEE.

  19. Repressive Tolerance

    Pedersen, Morten Jarlbæk

    2017-01-01

    Consultation of organised interests and others when drafting laws is often seen as an important source of both input and output legitimacy. But whereas the input side of the equation stems from the very process of listening to societal actors, output legitimacy can only be strengthened if consult......Consultation of organised interests and others when drafting laws is often seen as an important source of both input and output legitimacy. But whereas the input side of the equation stems from the very process of listening to societal actors, output legitimacy can only be strengthened...... a substantial effect on the substance of laws – shows that there is a great difference in the amenability of different branches of government but that, in general, authorities do not listen much despite a very strong consultation institution and tradition. A suggestion for an explanation could be pointing...... to an administrative culture of repressive tolerance of organised interests: authorities listen but only reacts in a very limited sense. This bears in it the risk of jeopardising the knowledge transfer from societal actors to administrative ditto thus harming the consultation institutions’ potential for strengthening...

  20. Echocardiographic Evaluation of Hemodynamics in Neonates and Children

    Yogen Singh

    2017-09-01

    Full Text Available Hemodynamic instability and inadequate cardiac performance are common in critically ill children. The clinical assessment of hemodynamic status is reliant upon physical examination supported by the clinical signs such as heart rate, blood pressure, capillary refill time, and measurement of the urine output and serum lactate. Unfortunately, all of these parameters are surrogate markers of cardiovascular well-being and they provide limited direct information regarding the adequacy of blood flow and tissue perfusion. A bedside point-of-care echocardiography can provide real-time hemodynamic information by assessing cardiac function, loading conditions (preload and afterload and cardiac output. The echocardiography has the ability to provide longitudinal functional assessment in real time, which makes it an ideal tool for monitoring hemodynamic assessment in neonates and children. It is indispensable in the management of patients with shock, pulmonary hypertension, and patent ductus arteriosus. The echocardiography is the gold standard diagnostic tool to assess hemodynamic stability in patients with pericardial effusion, cardiac tamponade, and cardiac abnormalities such as congenital heart defects or valvar disorders. The information from echocardiography can be used to provide targeted treatment in intensive care settings such as need of fluid resuscitation versus inotropic support, choosing appropriate inotrope or vasopressor, and in providing specific interventions such as selective pulmonary vasodilators in pulmonary hypertension. The physiological information gathered from echocardiography may help in making timely, accurate, and appropriate diagnosis and providing specific treatment in sick patients. There is no surprise that use of bedside point-of-care echocardiography is rapidly gaining interest among neonatologists and intensivists, and it is now being used in clinical decision making for patients with hemodynamic instability. Like any

  1. Evidence for the role of horizontal transfer in generating pVT1, a large mosaic conjugative plasmid from the clam pathogen, Vibrio tapetis.

    Gaël Erauso

    Full Text Available The marine bacterium Vibrio tapetis is the causative agent of the brown ring disease, which affects the clam Ruditapes philippinarum and causes heavy economic losses in North of Europe and in Eastern Asia. Further characterization of V. tapetis isolates showed that all the investigated strains harbored at least one large plasmid. We determined the sequence of the 82,266 bp plasmid pVT1 from the CECT4600(T reference strain and analyzed its genetic content. pVT1 is a mosaic plasmid closely related to several conjugative plasmids isolated from Vibrio vulnificus strains and was shown to be itself conjugative in Vibrios. In addition, it contains DNA regions that have similarity with several other plasmids from marine bacteria (Vibrio sp., Shewanella sp., Listonella anguillarum and Photobacterium profundum. pVT1 contains a number of mobile elements, including twelve Insertion Sequences or inactivated IS genes and an RS1 phage element related to the CTXphi phage of V. cholerae. The genetic organization of pVT1 underscores an important role of horizontal gene transfer through conjugative plasmid shuffling and transposition events in the acquisition of new genetic resources and in generating the pVT1 modular organization. In addition, pVT1 presents a copy number of 9, relatively high for a conjugative plasmid, and appears to belong to a new type of replicon, which may be specific to Vibrionaceae and Shewanelleacae.

  2. Hemodynamics Modeling and Simulation of Anterior Communicating Artery Aneurysms

    Jianjun Li

    2014-07-01

    Full Text Available It is a general agreement that hemodynamics plays very important role in the initiation, growth, and rupture of cerebral aneurysms and hemodynamics in the anterior communicating artery aneurysms is considered the most complex in all cerebral aneurysms and it is difficult to find some reasonable relationship between the hemodynamics parameters and the rupture risk. In this paper, the 3D geometries of four anterior communicating artery aneurysms were generated from the CTA data and the computational models with bilateral feeding arteries for the four aneurysms were constructed. The blood flow was simulated by computational fluid dynamics software and the hemodynamics parameters such as velocity, wall shear stress, and oscillatory shear index were calculated. The following results were observed: one of the four models only needs the left feeding artery; the max normalized wall shear stress locates at the aneurysmal neck of the largest aneurysm; the max oscillatory shear index locates at the aneurysmal sac of the largest aneurysm. The conclusion was drawn that the anterior communicating artery aneurysm has higher rupture risk from the hemodynamics viewpoint if the max wall shear stress locates at the neck and the max oscillatory shear index locates at the dome.

  3. Economic valuation of flood mitigation services: A case study from the Otter Creek, VT.

    Galford, G. L.; Ricketts, T.; Bryan, K. L.; ONeil-Dunne, J.; Polasky, S.

    2014-12-01

    The ecosystem services provided by wetlands are widely recognized but difficult to quantify. In particular, estimating the effect of landcover and land use on downstream flood outcomes remains challenging, but is increasingly important in light of climate change predictions of increased precipitation in many areas. Economic valuation can help incorporate ecosystem services into decisions and enable communities to plan for climate and flood resiliency. Here we estimate the economic value of Otter Creek wetlands for Middlebury, VT in mitigating the flood that followed Tropical Storm Irene, as well as for ten historic floods. Observationally, hydrographs above and below the wetlands in the case of each storm indicated the wetlands functioned as a temporary reservoir, slowing the delivery of water to Middlebury. We compare observed floods, based on Middlebury's hydrograph, with simulated floods for scenarios without wetlands. To simulate these "without wetlands" scenarios, we assume the same volume of water was delivered to Middlebury, but in a shorter time pulse similar to a hydrograph upstream of the wetlands. For scenarios with and without wetlands, we map the spatial extent of flooding using LiDAR digital elevation data. We then estimate flood depth at each affected building, and calculate monetary losses as a function of the flood depth and house value using established depth damage relationships. For example, we expect damages equal to 20% of the houses value for a flood depth of two feet in a two-story home with a basement. We define the value of flood mitigation services as the difference in damages between the with and without wetlands scenario, and find that the Otter Creek wetlands reduced flood damage in Middlebury by 88% following Hurricane Irene. Using the 10 additional historic floods, we estimate an ongoing mean value of $400,000 in avoided damages per year. Economic impacts of this magnitude stress the importance of wetland conservation and warrant the

  4. Ocular hemodynamics and glaucoma: the role of mathematical modeling.

    Harris, Alon; Guidoboni, Giovanna; Arciero, Julia C; Amireskandari, Annahita; Tobe, Leslie A; Siesky, Brent A

    2013-01-01

    To discuss the role of mathematical modeling in studying ocular hemodynamics, with a focus on glaucoma. We reviewed recent literature on glaucoma, ocular blood flow, autoregulation, the optic nerve head, and the use of mathematical modeling in ocular circulation. Many studies suggest that alterations in ocular hemodynamics play a significant role in the development, progression, and incidence of glaucoma. Although there is currently a limited number of studies involving mathematical modeling of ocular blood flow, regulation, and diseases (such as glaucoma), preliminary modeling work shows the potential of mathematical models to elucidate the mechanisms that contribute most significantly to glaucoma progression. Mathematical modeling is a useful tool when used synergistically with clinical and laboratory data in the study of ocular blood flow and glaucoma. The development of models to investigate the relationship between ocular hemodynamic alterations and glaucoma progression will provide a unique and useful method for studying the pathophysiology of glaucoma.

  5. Invasive and noninvasive hemodynamic monitoring of patients with cerebrovascular accidents.

    Velmahos, G C; Wo, C C; Demetriades, D; Bishop, M H; Shoemaker, W C

    1998-01-01

    Seventeen patients with hemodynamic instability from acute cerebrovascular accidents were evaluated shortly after arrival at the emergency department of a university-run county hospital with both invasive Swan-Ganz pulmonary artery catheter placement and a new, noninvasive, thoracic electrical bioimpedance device. Values were recorded and temporal patterns of survivors and nonsurvivors were described. Cardiac indices obtained simultaneously by the 2 techniques were compared. Of the 17 patients, 11 (65%) died. Survivors had higher values than nonsurvivors for mean arterial pressure, cardiac index, and oxygen saturation, delivery, and consumption at comparable times. Cardiac index values, as measured by invasive and noninvasive methods, were correlated. We concluded that hemodynamic monitoring in an acute care setting may recognize temporal circulatory patterns associated with outcome. Noninvasive electrical bioimpedance technology offers a new method for early hemodynamic evaluation. Further research in this area is warranted. PMID:9682626

  6. [Unit of hemodynamics: the production of the knowledge].

    Linch, Graciele Fernanda da Costa; Guido, Laura de Azevedo; Pitthan, Luiza de Oliveira; Umann, Juliane

    2009-12-01

    This study aimed at doing an integrative review that has as objective to investigate what has been published on nursing in hemodynamic in the following data bases: Scientific Electronic Library Online (SciELO), Medical Literature Analysis and Retrieval System Online (MEDLINE), Latin American and Caribbean Health Sciences (LILACS), and Nursing Database (BDENF); with the descriptors: Enfermagem and Hemodinâmica and Nursing and Hemodynamics. The data indicate that the studies in his majority were developed by nurses, and made a list to the presence of nursing, there were still boarded aspects made a list to the reprocess of catheters and health of the professionals of nursing. Nevertheless, it is noticeable that the publication of works connected with the thematic of hemodynamic is limited. However, they demonstrate the predominance of inquiries and reports making a list to the aspects of the presence of nursing in this sector which may represent the necessities and the problems that permeate the work.

  7. The nursing perspective on monitoring hemodynamics and oxygen transport.

    Tucker, Dawn; Hazinski, Mary Fran

    2011-07-01

    Maintenance of adequate systemic oxygen delivery requires careful clinical assessment integrated with hemodynamic measurements and calculations to detect and treat conditions that may compromise oxygen delivery and lead to life-threatening shock, respiratory failure, or cardiac arrest. The bedside nurse constantly performs such assessments and measurements to detect subtle changes and trends in patient condition. The purpose of this editorial is to highlight nursing perspectives about the hemodynamic and oxygen transport monitoring systems summarized in the Pediatric Cardiac Intensive Care Society Evidence- Based Review and Consensus Statement on Monitoring of Hemodynamics and Oxygen Transport Balance. There is no substitute for the observations of a knowledgeable and experienced clinician who understands the patient's condition and potential causes of deterioration and is able to evaluate response to therapy.

  8. Adiponectin haploinsufficiency promotes mammary tumor development in MMTV-PyVT mice by modulation of phosphatase and tensin homolog activities.

    Janice B B Lam

    Full Text Available Adiponectin is an adipokine possessing beneficial effects on obesity-related medical complications. A negative association of adiponectin levels with breast cancer development has been demonstrated. However, the precise role of adiponectin deficiency in mammary carcinogenesis remains elusive.In the present study, MMTV-polyomavirus middle T antigen (MMTV-PyVT transgenic mice with reduced adiponectin expressions were established and the stromal effects of adiponectin haploinsufficiency on mammary tumor development evaluated. In mice from both FVB/N and C57BL/6J backgrounds, insufficient adiponectin production promoted mammary tumor onset and development. A distinctive basal-like subtype of tumors, with a more aggressive phenotype, was derived from adiponectin haplodeficient MMTV-PyVT mice. Comparing with those from control MMTV-PyVT mice, the isolated mammary tumor cells showed enhanced tumor progression in re-implanted nude mice, accelerated proliferation in primary cultures, and hyperactivated phosphatidylinositol-3-kinase (PI3K/Akt/beta-catenin signaling, which at least partly attributed to the decreased phosphatase and tensin homolog (PTEN activities. Further analysis revealed that PTEN was inactivated by a redox-regulated mechanism. Increased association of PTEN-thioredoxin complexes was detected in tumors derived from mice with reduced adiponectin levels. The activities of thioredoxin (Trx1 and thioredoxin reductase (TrxR1 were significantly elevated, whereas treatment with either curcumin, an irreversible inhibitor of TrxR1, or adiponectin largely attenuated their activities and resulted in the re-activation of PTEN in these tumor cells. Moreover, adiponectin could inhibit TrxR1 promoter-mediated transcription and restore the mRNA expressions of TrxR1.Adiponectin haploinsufficiency facilitated mammary tumorigenesis by down-regulation of PTEN activity and activation of PI3K/Akt signalling pathway through a mechanism involving Trx1/TrxR1

  9. Hemodynamics and vasopressor support in therapeutic hypothermia after cardiac arrest

    Bro-Jeppesen, John; Kjaergaard, Jesper; Søholm, Helle

    2014-01-01

    AIM: Inducing therapeutic hypothermia (TH) in Out-of-Hospital Cardiac Arrest (OHCA) can be challenging due to its impact on central hemodynamics and vasopressors are frequently used to maintain adequate organ perfusion. The aim of this study was to assess the association between level of vasopres......AIM: Inducing therapeutic hypothermia (TH) in Out-of-Hospital Cardiac Arrest (OHCA) can be challenging due to its impact on central hemodynamics and vasopressors are frequently used to maintain adequate organ perfusion. The aim of this study was to assess the association between level...

  10. Hemodynamic causes of exercise intolerance in Fontan patients

    Hebert, Anders; Jensen, Annette S; Mikkelsen, Ulla Ramer

    2014-01-01

    BACKGROUND: Exercise intolerance is frequent among Fontan patients and an important determinant for quality of life. This study investigated the hemodynamic causes of impaired exercise capacity in Fontan patients with particular focus on the influence of stroke volume index (SVI) and heart rate (HR...... patients and controls respectively. CONCLUSION: SVI decreased significantly in Fontan patients near the end of maximal effort exercise. The low SVI at maximal exercise was the most important hemodynamic factor limiting exercise capacity in Fontan patients, whereas chronotropic impairment had a smaller...

  11. Electron microscopy study of hardened layers structure at electrospark alloying the VT-18 titanium alloy with aluminium

    Pilyankevich, A.N.; Martynenko, A.N.; Verkhoturov, A.D.; Paderno, V.N.

    1979-01-01

    Presented are the results of metallographic, electron-microscopic, and X-ray structure analysis, of microhardness measurements and of the study of the electrode weight changes at electrospark alloying the VT-18 titanium alloy with aluminium. It is shown, that pulsating thermal and mechanical loadings in the process of electrospark alloying result in the electrode surface electroerosion, a discrete relief is being formed, which changes constantly in the process depending on the alloying time. Though with the process time the cathode weight gain increases, microareas of fracture in the hardened layer appear already at the initial stages of electrospark alloying

  12. Full Scale Earth Fault Experiments on 10 kV laboratory network with comparative Measurements on Conventional CT's and VT's

    Sørensen, Stefan; Nielsen, Hans Ove; Bak-Jensen, Birgitte

    2002-01-01

    In this paper we present a result of a full scale earth fault carried out on the 10 kV research/laboratory distribution network at Kyndbyvaerket Denmark in May 2001. The network is compensated through a Petersen-Coil and current and voltage measurements were measured on conventional current....... The necessity of high bandwidth measurement equipment for earth fault measurements on compensated distribution networks can be undermined, since it will be shown that the transient signal transfer through conventional CT?s and VT?s for further signal analysis is sufficient. Caused the inadequacy three phase...

  13. Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables

    van Liebergen, R. A.; Piek, J. J.; Koch, K. T.; de Winter, R. J.; Schotborgh, C. E.; Lie, K. I.

    1999-01-01

    Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia. There is limited information regarding the hemodynamic quantification of recruitable collateral vessels. Angiography of the donor coronary artery was performed before and during

  14. Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates

    De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen

    2016-01-01

    Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new...

  15. Methylene Blue Is Effective to Reverse Refractory Hemodynamic Instability due to Dimethoate Poisoning

    Nick Youssefi

    2015-09-01

    Conclusion:MB treatment was effective to reverse hypotension and restore hemodynamic instability caused by dimethoate poisoning. This index case may pave way to further investigation of MB therapy for OP-induced hemodynamic instabilities.

  16. Acute coronary hemodynamic effects of equihypotensive doses of nisoldipine and diltiazem

    H. Suryapranata (Harry); P.W.J.C. Serruys (Patrick); A.L. Soward; J. Planellas; G. Vanhaleweyk; P.G. Hugenholtz (Paul)

    1985-01-01

    textabstractThe hemodynamic effects of nisoldipine and diltiazem were investigated in two groups of patients undergoing investigation for suspected coronary artery disease. Emphasis was placed on the coronary hemodynamic changes. Approximately equihypotensive doses of these two calcium channel

  17. Modeling Temporal and Spatial Flows of Ecosystem Services in Chittenden County, VT

    Voigt, B. G.; Bagstad, K.; Johnson, G.; Villa, F.

    2010-12-01

    This paper documents the integration of ARIES (ARtificial Intelligence for Ecosystem Services) with the land use change model UrbanSim to explore the impacts of current and future land use patterns on flood protection and water provision services in Chittenden County, VT. ARIES, an open source modeling platform, is particularly well-suited for measuring, mapping, and modeling the temporal and spatial flows of ecosystem services across the landscape, linking the areas of provision (sources) with human beneficiaries (users) through a spatially explicit agent-based modeling approach. UrbanSim is an open source agent-based land use model designed to facilitate a wide-range of scenarios based on user-specified behavioral assumptions, zoning regulations, and demographic, economic, and infrastructure (e.g. transportation, water, sewer, etc.) parameters. Ecosystem services travel through time and space and are susceptible to disruption and destruction from both natural and anthropogenic perturbations. The conversion of forested or agricultural land to urbanizing uses is replete with a long history of hydrologic impairment, habitat fragmentation, and the degradation of sensitive landscapes. Development decisions are predicated on the presence of landscape characteristics that meet the needs of developers and satisfy the desires of consumers, with minimal consideration of access to or effect on the provision of ecosystem services. The County houses nearly 25% of the state’s population and several employment centers that draw labor from throughout the region. Additionally, the County is expected to maintain modest residential and employment growth over the next 30 years, and will continue to serve as the state’s population and employment center. Expected future growth is likely to adversely affect the remaining farm and forest land in the County in the absence of policies to support sustainable development. We demonstrate how ARIES can be used to quantify changes in

  18. Prospective evaluation of intraoperative hemodynamics in liver transplantation with whole, partial and DCD grafts

    Sainz-Barriga, M; Reyntjens, K; Costa, M G; Scudeller, L; Rogiers, X; Wouters, P; de Hemptinne, B; Troisi, R I

    The interaction of systemic hemodynamics with hepatic flows at the time of liver transplantation (LT) has not been studied in a prospective uniform way for different types of grafts. We prospectively evaluated intraoperative hemodynamics of 103 whole and partial LT. Liver graft hemodynamics were

  19. Is the antiproteinuric effect of dipyridamole hemodynamically mediated

    de Jong, P. E.; van der Meer, J.; van der Hem, G. K.; de Zeeuw, D.

    1988-01-01

    We studied the acute antiproteinuric and renal hemodynamic effect of dipyridamole 30–60 mg intravenously in 13 salt-depleted patients with the nephrotic syndrome of different etiology. Whereas mean arterial pressure did not change, a small fall in glomerular filtration rate with a concomitant fall

  20. Relationship Between Serum Uric Acid Levels and Intrarenal Hemodynamic Parameters

    Hideki Uedono

    2015-06-01

    Full Text Available Background/Aims: Hyperuricemia has been reported to affect renal hemodynamics in rat models. We evaluate the relationship between serum uric acid and intrarenal hemodynamic parameters in humans, utilizing the plasma clearance of para-aminohippurate (CPAH and inulin (Cin. Methods: Renal and glomerular hemodynamics were assessed by simultaneous measurement of CPAH and Cin in 58 subjects. Of these, 19 subjects were planned to provide a kidney for transplantation; 26 had diabetes without proteinuria; and 13 had mild proteinuria. Renal and glomerular hemodynamics were calculated using Gomez`s formulae. Results: Cin was more than 60 ml/min/1.73m2 in all subjects. Serum uric acid levels correlated significantly with vascular resistance at the afferent arteriole (Ra (r = 0.354, p = 0.006 but not with that of the efferent arteriole (Re. Serum uric acid levels (β = 0.581, p = a after adjustment for several confounders (R2 = 0.518, p = Conclusions: These findings suggest, for the first time in humans, that higher serum uric acid levels are associated significantly with Ra in subjects with Cin > 60 ml/min/1.73m2. The increase in Ra in subjects with higher uric acid levels may be related to dysfunction of glomerular perfusion.

  1. White-collar workers' hemodynamic responses during working hours.

    Liu, Xinxin; Iwakiri, Kazuyuki; Sotoyama, Midori

    2017-08-08

    In the present study, two investigations were conducted at a communication center, to examine white-collar workers' hemodynamic responses during working hours. In investigation I, hemodynamic responses were measured on a working day; and in investigation II, cardiovascular responses were verified on both working and non-working days. In investigation I, blood pressure, cardiac output, heart rate, stroke volume, and total peripheral resistance were measured in 15 workers during working hours (from 9:00 am to 18:00 pm) on one working day. Another 40 workers from the same workplace participated in investigation II, in which blood pressure and heart rate were measured between the time workers arose in the morning until they went to bed on 5 working days and 2 non-working days. The results showed that blood pressure increased and remained at the same level during working hours. The underlying hemodynamics of maintaining blood pressure, however, changed between the morning and the afternoon on working days. Cardiac responses increased in the afternoon, suggesting that cardiac burdens increase in the afternoon on working days. The present study suggested that taking underlying hemodynamic response into consideration is important for managing the work-related cardiovascular burden of white-collar workers.

  2. Monitoring Detrusor Oxygenation and Hemodynamics Noninvasively during Dysfunctional Voiding

    Macnab, Andrew J.; Stothers, Lynn S.; Shadgan, Babak

    2012-01-01

    The current literature indicates that lower urinary tract symptoms (LUTSs) related to benign prostatic hyperplasia (BPH) have a heterogeneous pathophysiology. Pressure flow studies (UDSs) remain the gold standard evaluation methodology for such patients. However, as the function of the detrusor muscle depends on its vasculature and perfusion, the underlying causes of LUTS likely include abnormalities of detrusor oxygenation and hemodynamics, and available treatment options include agents thought to act on the detrusor smooth muscle and/or vasculature. Hence, near infrared spectroscopy (NIRS), an established optical methodology for monitoring changes in tissue oxygenation and hemodynamics, has relevance as a means of expanding knowledge related to the pathophysiology of BPH and potential treatment options. This methodological report describes how to conduct simultaneous NIRS monitoring of detrusor oxygenation and hemodynamics during UDS, outlines the clinical implications and practical applications of NIRS, explains the principles of physiologic interpretation of NIRS voiding data, and proposes an exploratory hypothesis that the pathophysiological causes underlying LUTS include detrusor dysfunction due to an abnormal hemodynamic response or the onset of oxygen debt during voiding. PMID:23019422

  3. Clinical review: Update on hemodynamic monitoring - a consensus of 16.

    Vincent, J.L.; Rhodes, A.; Perel, A.; Martin, G.S.; Rocca, G.D.; Vallet, B.; Pinsky, M.R.; Hofer, C.K.; Teboul, J.L.; Boode, W.P. de; Scolletta, S.; Viellard-Baron, A.; Backer, D. de; Walley, K.R.; Maggiorini, M.; Singer, M.

    2011-01-01

    Hemodynamic monitoring plays a fundamental role in the management of acutely ill patients. With increased concerns about the use of invasive techniques, notably the pulmonary artery catheter, to measure cardiac output, recent years have seen an influx of new, less-invasive means of measuring

  4. Acute hemodynamic response to vasodilators in primary pulmonary hypertension.

    Kulkarni H

    1996-01-01

    Full Text Available Acute hemodynamic effects of high flow oxygen (O2 inhalation, sublingual isosorbide dinitrate (ISDN, intravenous aminophylline (AMN and sublingual nifedipine (NIF were studied in 32 patients with primary pulmonary hypertension (PPH. In 30 out of 32 patients the basal ratio of pulmonary to systemic vascular resistance (Rp/Rs was > 0.5 (mean = 0.77 +/- 0.20. Oxygen caused significant decrease in the mean resistance ratio to 0.68 +/- 0.20 (p = 0.005. ISDN, AMN and NIF caused increase in the resistance ratio to 0.79 +/- 0.26; 0.78 +/- 0.26; and 0.80 +/- 0.23 respectively. O2, ISDN, AMN and NIF caused a fall of Rp/Rs in 21 (65.6%, 10 (31.2%, 10(31.2% and 9(28.1% patients respectively. Thus, of the four drugs tested high flow O2 inhalation resulted in fall of Rp/Rs in two thirds of patients whereas ISDN, AMN and NIF caused a mean rise in Rp/Rs. One third of patients did respond acutely to the latter three drugs. Acute hemodynamic studies are useful before prescribing vasodilators in patients with PPH since more of the commonly used drugs like ISDN, AMN, NIF could have detrimental hemodynamic responses in some patients. However, great caution should be exercised before performing hemodynamic study as the procedure has definite mortality and morbidity.

  5. Monitoring Detrusor Oxygenation and Hemodynamics Noninvasively during Dysfunctional Voiding

    Andrew J. Macnab

    2012-01-01

    Full Text Available The current literature indicates that lower urinary tract symptoms (LUTSs related to benign prostatic hyperplasia (BPH have a heterogeneous pathophysiology. Pressure flow studies (UDSs remain the gold standard evaluation methodology for such patients. However, as the function of the detrusor muscle depends on its vasculature and perfusion, the underlying causes of LUTS likely include abnormalities of detrusor oxygenation and hemodynamics, and available treatment options include agents thought to act on the detrusor smooth muscle and/or vasculature. Hence, near infrared spectroscopy (NIRS, an established optical methodology for monitoring changes in tissue oxygenation and hemodynamics, has relevance as a means of expanding knowledge related to the pathophysiology of BPH and potential treatment options. This methodological report describes how to conduct simultaneous NIRS monitoring of detrusor oxygenation and hemodynamics during UDS, outlines the clinical implications and practical applications of NIRS, explains the principles of physiologic interpretation of NIRS voiding data, and proposes an exploratory hypothesis that the pathophysiological causes underlying LUTS include detrusor dysfunction due to an abnormal hemodynamic response or the onset of oxygen debt during voiding.

  6. Neonatal Hemodynamics: From Developmental Physiology to Comprehensive Monitoring

    Sabine L. Vrancken

    2018-04-01

    Full Text Available Maintenance of neonatal circulatory homeostasis is a real challenge, due to the complex physiology during postnatal transition and the inherent immaturity of the cardiovascular system and other relevant organs. It is known that abnormal cardiovascular function during the neonatal period is associated with increased risk of severe morbidity and mortality. Understanding the functional and structural characteristics of the neonatal circulation is, therefore, essential, as therapeutic hemodynamic interventions should be based on the assumed underlying (pathophysiology. The clinical assessment of systemic blood flow (SBF by indirect parameters, such as blood pressure, capillary refill time, heart rate, urine output, and central-peripheral temperature difference is inaccurate. As blood pressure is no surrogate for SBF, information on cardiac output and systemic vascular resistance should be obtained in combination with an evaluation of end organ perfusion. Accurate and reliable hemodynamic monitoring systems are required to detect inadequate tissue perfusion and oxygenation at an early stage before this result in irreversible damage. Also, the hemodynamic response to the initiated treatment should be re-evaluated regularly as changes in cardiovascular function can occur quickly. New insights in the understanding of neonatal cardiovascular physiology are reviewed and several methods for current and future neonatal hemodynamic monitoring are discussed.

  7. Initial approach to hypertension in the hemodynamics unit: review article

    Gustavo Teixeira Fulton Schimit

    2013-06-01

    Full Text Available Correct identification and early management of hypertensive disorders should be a part of the therapeutic repertoire of every professional working in hemodynamics units. Based on recent publications, this study aims to propose a practical approach to the identification and early management of these disorders in this type of service.

  8. Dietary melatonin alters uterine artery hemodynamics in pregnant holstein heifers

    The objective was to examine uterine artery hemodynamics and maternal serum profiles in pregnant heifers supplemented with dietary melatonin (MEL) or no supplementation (CON). In addition, melatonin receptor–mediated responses in steroid metabolism were examined using a bovine endometrial epithelial...

  9. Effects of an interatrial shunt on rest and exercise hemodynamics

    Kaye, David; Shah, Sanjiv J; Borlaug, Barry A

    2014-01-01

    BACKGROUND: A treatment based on an interatrial shunt device has been proposed for counteracting elevated pulmonary capillary wedge pressure (PCWP) in patients with heart failure and mildly reduced or preserved ejection fraction (HFpEF). We tested the theoretical hemodynamic effects of this appro...

  10. Physiological basis of clinically used coronary hemodynamic indices

    Spaan, Jos A. E.; Piek, Jan J.; Hoffman, Julien I. E.; Siebes, Maria

    2006-01-01

    In deriving clinically used hemodynamic indices such as fractional flow reserve and coronary flow velocity reserve, simplified models of the coronary circulation are used. In particular, myocardial resistance is assumed to be independent of factors such as heart contraction and driving pressure.

  11. Ruptured congenital aneurysm of the right sinus of Valsalva into the right ventricle: with special reference to pathoanatomic and hemodynamic characteristics in symptomless cases.

    Chen, J J; Lien, W P; Chang, F Z; Lee, Y S; Hung, C R; Chu, S S; Wu, T L

    1980-02-01

    Clinical features of 19 cases with congenital aneurysm of the right sinus of Valsalva rupturing into the right ventricular outflow region (Type 1) were analysed in relation to their pathoanatomic lesions and hemodynamic alterations. Sixteen cases were operated with one surgical death. All were catheterized together with ascending aortographic study. Rupture of the aneurysm in many cases was silent or symptomless and progressive heart failure was not quite common. Symptomatology of the patients did not seem to be related entirely to status of the pathoanatomical lesions or hemodynamic alterations. Time of the rupture, and inherent right ventricular characteristics, tolerating volume overload rather well, might be, in part, responsible for its better prognosis in some cases. However, all patients with ruptured aneurysm of the sinus of Valsalva should be treated surgically. Bacterial endocarditis is a serious complication leading to death.

  12. Toward Intelligent Hemodynamic Monitoring: A Functional Approach

    Pierre Squara

    2012-01-01

    Full Text Available Technology is now available to allow a complete haemodynamic analysis; however this is only used in a small proportion of patients and seems to occur when the medical staff have the time and inclination. As a result of this, significant delays occur between an event, its diagnosis and therefore, any treatment required. We can speculate that we should be able to collect enough real time information to make a complete, real time, haemodynamic diagnosis in all critically ill patients. This article advocates for “intelligent haemodynamic monitoring”. Following the steps of a functional analysis, we answered six basic questions. (1 What is the actual best theoretical model for describing haemodynamic disorders? (2 What are the needed and necessary input/output data for describing this model? (3 What are the specific quality criteria and tolerances for collecting each input variable? (4 Based on these criteria, what are the validated available technologies for monitoring each input variable, continuously, real time, and if possible non-invasively? (5 How can we integrate all the needed reliably monitored input variables into the same system for continuously describing the global haemodynamic model? (6 Is it possible to implement this global model into intelligent programs that are able to differentiate clinically relevant changes as opposed to artificial changes and to display intelligent messages and/or diagnoses?

  13. Hemodynamic and tissue oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism.

    Monachini, Maristela C; Lage, Silvia G; Ran, Miguel A N; Cardoso, Rita H A; Medeiros, Caio; Caramelli, Bruno; Sposito, Andrei C; Ramires, José A F

    2004-07-01

    Exercise-induced dyspnea is a frequent feature in patients with hyperthyroidism. Data from clinical studies to elucidate the origin of this symptom are lacking. In the current study, we examined the hemodynamic and oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism and their relationship with dyspnea. Hemodynamic studies were performed under resting conditions and after isotonic exercise in 15 patients with hyperthyroidism and 11 control subjects. Exercise was applied using a bicycle ergometer, with progressive loads. In the hyperthyroid group, measurements were repeated at rest and during supine exercise after administering 15 mg of intravenous metoprolol. End-diastolic pulmonary artery pressure and cardiac index were higher in the hyperthyroid group than in controls (18.6 +/- 5.3 vs. 11.2 +/- 4.9 mmHg; p = 0.02, and 6.0 +/- 1.7 vs. 2.8 +/- 0.5 l/min/m2; p = 0.0001, respectively). After exercise, there was an increase in end-diastolic pulmonary artery pressure in the hyperthyroid group (18.6 +/- 5.3 to 25.5 +/- 9.9 mmHg; p = 0.02), revealing impaired cardiocirculatory reserve. Pulmonary arteriolar resistance increased significantly in parallel with end-diastolic pulmonary artery pressure after drug administration, suggesting an inadequate cardiovascular response after beta blockade in patients with hyperthyroidism. We observed that functional left ventricular reserve is impaired in patients with hyperthyroidism, suggesting an explanation for the frequent symptom of dyspnea and impaired exercise tolerance. Moreover, we also suggest that beta-adrenergic blockade may adversely affect cardiovascular function in patients with hyperthyroidism.

  14. The Adverse Events and Hemodynamic Effects of Adenosine-Based Cardiac MRI

    Voigtlander, Thomas; Magedanz, Annett; Schmermund, Axel; Bramlage, Peter; Elsaesser, Amelie; Kauczor, Hans-Ulrich; Mohrs, Oliver K.

    2011-01-01

    We wanted to prospectively assess the adverse events and hemodynamic effects associated with an intravenous adenosine infusion in patients with suspected or known coronary artery disease and who were undergoing cardiac MRI. One hundred and sixty-eight patients (64 ± 9 years) received adenosine (140 μg/kg/min) during cardiac MRI. Before and during the administration, the heart rate, systemic blood pressure, and oxygen saturation were monitored using a MRI-compatible system. We documented any signs and symptoms of potential adverse events. In total, 47 out of 168 patients (28%) experienced adverse effects, which were mostly mild or moderate. In 13 patients (8%), the adenosine infusion was discontinued due to intolerable dyspnea or chest pain. No high grade atrioventricular block, bronchospasm or other life-threatening adverse events occurred. The hemodynamic measurements showed a significant increase in the heart rate during adenosine infusion (69.3 ± 11.7 versus 82.4 ± 13.0 beats/min, respectively; p < 0.001). A significant but clinically irrelevant increase in oxygen saturation occurred during adenosine infusion (96 ± 1.9% versus 97 ± 1.3%, respectively; p < 0.001). The blood pressure did not significantly change during adenosine infusion (systolic: 142.8 ± 24.0 versus 140.9 ± 25.7 mmHg; diastolic: 80.2 ± 12.5 mmHg versus 78.9 ± 15.6, respectively). This study confirms the safety of adenosine infusion during cardiac MRI. A considerable proportion of all patients will experience minor adverse effects and some patients will not tolerate adenosine infusion. However, all adverse events can be successfully managed by a radiologist. The increased heart rate during adenosine infusion highlights the need to individually adjust the settings according to the patient, e.g., the number of slices of myocardial perfusion imaging.

  15. Intraosseous anesthesia in hemodynamic studies in children with cardiopathy.

    Aliman, Ana Cristina; Piccioni, Marilde de Albuquerque; Piccioni, João Luiz; Oliva, José Luiz; Auler Júnior, José Otávio Costa

    2011-01-01

    Intraosseous (IO) access has been used with good results in emergency situations, when venous access is not available for fluids and drugs infusion. The objective of this study was to evaluate IO a useful technique for anesthesia and fluids infusion during hemodynamic studies and when peripheral intravascular access is unobtainable. The setting was an university hospital hemodynamics unit, and the subjects were twenty one infants with congenital heart disease enrolled for elective hemodynamic study diagnosis. This study compared the effectiveness of IO access in relation to IV access for infusion of anesthetics agents (ketamine, midazolam, and fentanyl) and fluids during hemodynamic studies. The anesthetic induction time, procedure duration, anesthesia recovery time, adequate hydration, and IV and IO puncture complications were compared between groups. The puncture time was significantly smaller in IO group (3.6 min) that in IV group (9.6 min). The anesthetic onset time (56.3 second) for the IV group was faster than IO group (71.3 second). No significant difference between groups were found in relation to hydration (IV group, 315.5 mL vs IO group, 293.2 mL), and anesthesia recovery time (IO group, 65.2 min vs IV group, 55.0 min). The puncture site was reevaluated after 7 and 15 days without signs of infection or other complications. Results showed superiority for IO infusion when considering the puncture time of the procedure. Due to its easy manipulation and efficiency, hydration and anesthesia by IO access was satisfactory for hemodynamic studies without the necessity of other infusion access. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  16. Reliability of oscillometric central hemodynamic responses to an orthostatic challenge.

    Stoner, Lee; Bonner, Chantel; Credeur, Daniel; Lambrick, Danielle; Faulkner, James; Wadsworth, Daniel; Williams, Michelle A

    2015-08-01

    Monitoring central hemodynamic responses to an orthostatic challenge may provide important insight into autonomic nervous system function. Oscillometric pulse wave analysis devices have recently emerged, presenting clinically viable options for investigating central hemodynamic properties. The purpose of the current study was to determine whether oscillometric pulse wave analysis can be used to reliably (between-day) assess central blood pressure and central pressure augmentation (augmentation index) responses to a 5 min orthostatic challenge (modified tilt-table). Twenty healthy adults (26.4 y (SD 5.2), 55% F, 24.7 kg/m(2) (SD 3.8)) were tested on 3 different mornings in the fasted state, separated by a maximum of 7 days. Central hemodynamic variables were assessed on the left arm using an oscillometric device. Repeated measures analysis of variance indicated a significant main effect of the modified tilt-table for all central hemodynamic variables (P response to the tilt, central diastolic pressure increased by 4.5 mmHg (CI: 2.6, 6.4), central systolic blood pressure increased by 2.3 (CI: 4.4, 0.16) mmHg, and augmentation index decreased by an absolute - 5.3%, (CI: -2.7, -7.9%). The intra-class correlation coefficient values for central diastolic pressure (0.83-0.86), central systolic blood pressure (0.80-0.87) and AIx (0.79-0.82) were above the 0.75 criterion in both the supine and tilted positions, indicating excellent between-day reliability. Central hemodynamic responses to an orthostatic challenge can be assessed with acceptable between-day reliability using oscillometric pulse wave analysis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Teaching Tolerance? Associational Diversity and Tolerance Formation

    Rapp, Carolin; Freitag, Markus

    2015-01-01

    , a closer look is taken at how associational diversity relates to the formation of tolerance and the importance of associations as schools of tolerance are evaluated. The main theoretical argument follows contact theory, wherein regular and enduring contact in diverse settings reduces prejudice and thereby...

  18. Effects of head-down-tilt bed rest on cerebral hemodynamics during orthostatic stress

    Zhang, R.; Zuckerman, J. H.; Pawelczyk, J. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    1997-01-01

    Our aim was to determine whether the adaptation to simulated microgravity (microG) impairs regulation of cerebral blood flow (CBF) during orthostatic stress and contributes to orthostatic intolerance. Twelve healthy subjects (aged 24 +/- 5 yr) underwent 2 wk of -6 degrees head-down-tilt (HDT) bed rest to simulate hemodynamic changes that occur when humans are exposed to microG. CBF velocity in the middle cerebral artery (transcranial Doppler), blood pressure, cardiac output (acetylene rebreathing), and forearm blood flow were measured at each level of a ramped protocol of lower body negative pressure (LBNP; -15, -30, and -40 mmHg x 5 min, -50 mmHg x 3 min, then -10 mmHg every 3 min to presyncope) before and after bed rest. Orthostatic tolerance was assessed by using the cumulative stress index (CSI; mmHg x minutes) for the LBNP protocol. After bed rest, each individual's orthostatic tolerance was reduced, with the group CSI decreased by 24% associated with greater decreases in cardiac output and greater increases in systemic vascular resistance at each level of LBNP. Before bed rest, mean CBF velocity decreased by 14, 10, and 45% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. After bed rest, mean velocity decreased by 16% at -30 mmHg and by 21, 35, and 39% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. Compared with pre-bed rest, post-bed-rest mean velocity was less by 11, 10, and 21% at -30, -40, and -50 mmHg, respectively. However, there was no significant difference at maximal LBNP. We conclude that cerebral autoregulation during orthostatic stress is impaired by adaptation to simulated microG as evidenced by an earlier and greater fall in CBF velocity during LBNP. We speculate that impairment of cerebral autoregulation may contribute to the reduced orthostatic tolerance after bed rest.

  19. Pulmonary hemodynamic profile in chronic obstructive pulmonary disease

    Portillo K

    2015-07-01

    Full Text Available Karina Portillo,1 Yolanda Torralba,1,2 Isabel Blanco,1,2 Felip Burgos,1,2 Roberto Rodriguez-Roisin,1,2 Jose Rios,3 Josep Roca,1,2 Joan A Barberà1,21Department of Pulmonary Medicine, Hospital Clínic-Institut d’Investigacions Biomèdiques August Pi iSunyer (IDIBAPS, University of Barcelona, Barcelona, Spain; 2Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES, Madrid, Spain; 3Biostatistics and Data Management Core Facility, Hospital Clínic-Institut d’Investigacions Biomèdiques August Pi iSunyer (IDIBAPS, Biostatistics Unit, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, SpainIntroduction: Few data are available in regards to the prevalence of pulmonary hypertension (PH in the broad spectrum of COPD. This study was aimed at assessing the prevalence of PH in a cohort of COPD patients across the severity of airflow limitation, and reporting the hemodynamic characteristics at rest and during exercise.Methods: We performed a retrospective analysis on COPD patients who underwent right-heart catheterization in our center with measurements obtained at rest (n=139 and during exercise (n=85. PH was defined as mean pulmonary artery pressure (mPAP ≥25 mmHg and pulmonary capillary wedge pressure <15 mmHg. Exercise-induced PH (EIPH was defined by a ratio of ∆mPAP/∆cardiac output >3.Results: PH was present in 25 patients (18%. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD classification, PH prevalence in GOLD 2 was 7% (3 patients; 25% (14 patients in GOLD 3; and 22% (8 patients in GOLD 4. Severe PH (mPAP ≥35 mmHg was identified in four patients (2.8%. Arterial partial oxygen pressure was the outcome most strongly associated with PH (r=-0.29, P<0.001. EIPH was observed in 60 patients (71% and had a similar prevalence in both GOLD 2 and 3, and was present in all GOLD 4 patients. Patients with PH had lower cardiac index during exercise than patients without PH (5

  20. Lactose tolerance tests

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen ...

  1. Evaluation of plain radiograph in mitral stenosis related to hemodynamics

    Choe, Ku Ok; Suh, Jung Ho; Park, Chang Yun; Choi, Byung So

    1973-01-01

    Mitral stenosis, the most frequent heart disease in adult, showed relatively characteristic pulmonary findings in plain chest X-ray. In recent years the knowledge of the altered physiology of hemodynamics could offer considerable amount of hemodynamic barrier in plain chest. But the value of several parameters was still controversial. In this study a variety of roentgen signs were related to physiologic data and those were acquired by the cardiac catheterization in total of 67 cases of mitral stenosis. 1. Correlation of DPA/DHT ratio (Diameter of pulmonary arterial segment/ Diameter of hemithorax X 100) to hemodynamic data; The pulmonary arterial segments was dilated by two factors, the one was pulmonary blood flow and the other the blood pressure within it. In mitral stenosis, the cardiac output was decreased to quite uniform level, hence measurement of pulmonary arterial segment might be valuable. The correlation coefficient of DPA/ DHT ratio to hemodynamic data were as follows: 0.54 to mean pulmonary artery pressure, 0.32 to pulmonary capillary wedge pressure, -0.37 to mitral valvular area and 0.07 to pulmonary vascular resistance. No significant difference was noted in between pure mitral stenosis and mitral stenosis associated with other valvular disease. 2. Correlation of diameter of right descending pulmonary artery to hemodynamic data: The measurement was made near the first bifurcation of right descending pulmonary artery at its widest point. Pulmonary vascular pattern was best correlated (r=0.71). Another had rough correlation: 0.05 to mean pulmonary artery pressure, 0.31 to pulmonary capillary wedge pressure, -0.44 to mitral valvular area in correlation coefficient. No pulmonary arterial hypertension was observed in the cases diameter of less than 12 mm, but all except two cases had pulmonary hypertension in which diameter exceeded 16 mm. According to increase of the mean pulmonary arterial pressure, the same increment in pressure increased change

  2. Evaluation of plain radiograph in mitral stenosis related to hemodynamics

    Choe, Ku Ok; Suh, Jung Ho; Park, Chang Yun; Choi, Byung So [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1973-04-15

    Mitral stenosis, the most frequent heart disease in adult, showed relatively characteristic pulmonary findings in plain chest X-ray. In recent years the knowledge of the altered physiology of hemodynamics could offer considerable amount of hemodynamic barrier in plain chest. But the value of several parameters was still controversial. In this study a variety of roentgen signs were related to physiologic data and those were acquired by the cardiac catheterization in total of 67 cases of mitral stenosis. 1. Correlation of DPA/DHT ratio (Diameter of pulmonary arterial segment/ Diameter of hemithorax X 100) to hemodynamic data; The pulmonary arterial segments was dilated by two factors, the one was pulmonary blood flow and the other the blood pressure within it. In mitral stenosis, the cardiac output was decreased to quite uniform level, hence measurement of pulmonary arterial segment might be valuable. The correlation coefficient of DPA/ DHT ratio to hemodynamic data were as follows: 0.54 to mean pulmonary artery pressure, 0.32 to pulmonary capillary wedge pressure, -0.37 to mitral valvular area and 0.07 to pulmonary vascular resistance. No significant difference was noted in between pure mitral stenosis and mitral stenosis associated with other valvular disease. 2. Correlation of diameter of right descending pulmonary artery to hemodynamic data: The measurement was made near the first bifurcation of right descending pulmonary artery at its widest point. Pulmonary vascular pattern was best correlated (r=0.71). Another had rough correlation: 0.05 to mean pulmonary artery pressure, 0.31 to pulmonary capillary wedge pressure, -0.44 to mitral valvular area in correlation coefficient. No pulmonary arterial hypertension was observed in the cases diameter of less than 12 mm, but all except two cases had pulmonary hypertension in which diameter exceeded 16 mm. According to increase of the mean pulmonary arterial pressure, the same increment in pressure increased change

  3. Cellular Mechanism Underlying Hypothermia-Induced VT/VF in the Setting of Early Repolarization and the Protective Effect of Quinidine, Cilostazol and Milrinone

    Gurabi, Zsolt; Koncz, István; Patocskai, Bence; Nesterenko, Vladislav V.; Antzelevitch, Charles

    2014-01-01

    Background Hypothermia has been reported to induce ventricular tachycardia and fibrillation (VT/VF) in patients with early repolarization (ER) pattern. This study examines the cellular mechanisms underlying VT/VF associated with hypothermia in an experimental model of ER syndrome (ERS) and examines the effectiveness of quinidine, cilostazol and milrinone to prevent hypothermia-induced arrhythmias. Method and Results Transmembrane action potentials (AP) were simultaneously recorded from 2 epicardial and 1 endocardial site of coronary-perfused canine left-ventricular wedge preparations, together with a pseudo-ECG. A combination of NS5806 (3–10 µM) and verapamil (1µM) was used to pharmacologically model the genetic mutations responsible for ERS. Acetylcholine (3µM) was used to simulate increased parasympathetic tone, which is known to promote ER. In control, lowering the temperature of the coronary perfusate to induce mild hypothermia (32°C-34°C) resulted in increased J wave area on the ECG and accentuated epicardial AP notch but no arrhythmic activity. In the setting of ER, hypothermia caused further accentuation of the epicardial AP notch, leading to loss of the AP dome at some sites but not others, thus creating the substrate for development of phase-2-reentry and VT/VF. Addition of the Ito antagonist quinidine (5 µM) or the phosphodiesterase III inhibitors cilostazol (10 µM) or milrinone (5 µM), diminished the ER manifestations and prevented the hypothermia-induced phase 2 reentry and VT/VF. Conclusions Hypothermia leads to VT/VF in the setting of ER by exaggerating repolarization abnormalities, leading to development of phase-2-reentry. Quinidine, cilostazol and milrinone suppress the hypothermia-induced VT/VF by reversing the repolarization abnormalities. PMID:24429494

  4. ECG Markers of Hemodynamic Improvement in Patients with Pulmonary Hypertension

    Marcin Waligóra

    2018-01-01

    Full Text Available Introduction. Several diagnostic tests have been recommended for risk assessment in pulmonary hypertension (PH, but the role of electrocardiography (ECG in monitoring of PH patients has not been yet established. Therefore the aim of the study was to evaluate which ECG patterns characteristic for pulmonary hypertension can predict hemodynamic improvement in patients treated with targeted therapies. Methods. Consecutive patients with pulmonary arterial hypertension (PAH or chronic thromboembolic pulmonary hypertension (CTEPH were eligible to be included if they had had performed two consecutive right heart catheterization (RHC procedures before and after starting of targeted therapies. Patients were followed up from June 2009 to July 2017. ECG patterns of right ventricular hypertrophy according to American College of Cardiology Foundation were assessed. Results. We enrolled 80 patients with PAH and 11 patients with inoperable CTEPH. The follow-up RHC was performed within 12.6±10.0 months after starting therapy. Based on median change of pulmonary vascular resistance, we divided our patients into two subgroups: with and without significant hemodynamic improvement. RV1, max⁡RV1,2 + max⁡SI,aVL-SV1, and PII improved along with the improvement of hemodynamic parameters including PVR. They predicted hemodynamic improvement with similarly good accuracy as shown in ROC analysis: RV1 (AUC: 0.75; 95% CI: 0.63–0.84, PII (AUC: 0.67, 95% CI: 0.56–0.77, and max⁡RV1,2+max⁡SI,aVL-SV1 (0.73; 95% CI: 0.63–0.82. In Cox regression only change in RV1 remained significant mortality predictor (HR: 1.12, 95% CI: 1.01–1.24. Conclusion. Electrocardiogram may be useful in predicting hemodynamic effects of targeted therapy in precapillary pulmonary hypertension. Decrease of RV1, max⁡RV1,2+max⁡SI,aVL-SV1, and PII corresponds with hemodynamic improvement after treatment. Of these changes a decrease of R wave amplitude in V1 is associated with better

  5. Assessing the feasibility of the Healthy Life in Suriname Study: using advanced hemodynamics to evaluate cardiovascular risk

    Jet Q. Aartman

    2017-06-01

    Full Text Available ABSTRACT Objectives To determine the feasibility of assessing population cardiovascular risk with advanced hemodynamics in the Healthy Life in Suriname (HELISUR study. Methods This was a preliminary study conducted in May – June 2012 using the Technical-Economic-Legal-Operational-Scheduling (TELOS method to assess the feasibility of the HELISUR—a large-scale, cross-sectional population study of cardiovascular risk factors and disease in Suriname. Suriname, a middle-income country in South America with a population of mostly African and Asian ethnicity, has a high risk of cardiovascular disease. A total of 135 volunteers 18 – 70 years of age participated. A health questionnaire was tested in a primary health care center, and non-invasive cardiovascular evaluations were performed in an academic health center. The cardiovascular evaluation included sitting, supine, and standing blood pressure, and intermediate endpoints, such as cardiac output, peripheral vascular resistance, pulse wave velocity, and augmentation index. Results The TELOS testing found that communicating by cellular phone was most effective for appointment adherence, and that completion of the questionnaire often required assistance from a trained interviewer; modifications to improve the clarity of the questions are recommended. Regarding the extended cardiovascular assessments of peripheral and central hemodynamics, the findings showed these to be technically and operationally feasible and well tolerated by participants, in terms of burden and duration. Conclusions Findings of this feasibility assessment indicate that large-scale, detailed evaluations of cardiovascular risk, including a questionnaire and advanced central and peripheral hemodynamics, are feasible in a high-risk population in a middle-income setting.

  6. Technological capabilities of increasing surface quality of workpieces made of titanium alloy VT22 and stability of surface grinding

    Soler, Ya I.; Salov, V. M.; Mai, D. S.

    2018-03-01

    Surface grinding of flat workpieces made of alloy VT22 was conducted by the periphery of a highly porous wheel (HPW) from cubic boron nitride CBN30 B107 100 OV K27 КF40 with three processing techniques (ij). They are 10 - cross-feed per stroke, HPW cutting into a workpiece changes alternately from up to down; 12 – cross-feed per double stroke during the up HPW cutting-in at the working stroke; 22 – cross-feed per double stroke during the down HPW cutting-in at the working stroke. With the involvement of artificial neural network models, it was revealed that to improve the quality of surfaces and stability of its formation, grinding should be conducted if ij = 12.

  7. Fatigue-induced dislocation structure of titanium alloy VT5-1ct at temperatures of 293-11 K

    Grinberg, N.M. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Aleksenko, E.N. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Moskalenko, V.A. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Smirnov, A.R.N. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Yakovenko, L.F. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Mozhaev, A.V. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine)); Arinushkin, I.A. (Inst. for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, Kharkov (Ukraine))

    1993-07-05

    The dislocation structure formed during the final stage of fatigue at high- and low-amplitude stresses at T=293 K in air and T=293, 93 and 11 K in high vacuum is studied on the Ti alloy VT5-1ct which has been prepared by two processing methods. The [sigma]-N curves are plotted for corresponding experimental conditions. It is shown that slip alone is responsible for the plastic deformation. The characteristic features of the dislocation structure formed are reported. The morphology of the a phase does not influence the character of the dislocation structure. At lower temperatures, the substructure remains practically unaltered, although the likelihood of uniformly distributed dislocations is lower. The lifetime is essentially dependent on the environment, temperature and the alloy microstructure, the latter being especially important at low temperatures in the high-amplitude region. (orig.)

  8. Effect of hydrostatic pressure application at cryogenic temperatures on the properties of VT1-0 alloy

    Khajmovich, P.A; Shulgin, N.A.; Chernyaeva, E.V.

    2015-01-01

    Attempt was made to determine the influence of hydrostatic pressure on the properties of the alloy VT1-0 at cryogenic temperatures both under straining of the alloy and without it. Hardening of the material is observed only in that part of the specimen, which experienced a deformation, while the very exposure of the alloy under hydrostatic pressure does not lead to strengthening of the material. At the same time, measurements of acoustic emission (AE) show that in the near-surface layers the forces of hydrostatic compression alone, i.e. without a deformation, cause some changes in the structure, which stipulate an increase of the energy and (to a lesser extent) of the median frequency of AE signals. An explanation of this phenomenon is suggested

  9. Recognition and Toleration

    Lægaard, Sune

    2010-01-01

    Recognition and toleration are ways of relating to the diversity characteristic of multicultural societies. The article concerns the possible meanings of toleration and recognition, and the conflict that is often claimed to exist between these two approaches to diversity. Different forms...... or interpretations of recognition and toleration are considered, confusing and problematic uses of the terms are noted, and the compatibility of toleration and recognition is discussed. The article argues that there is a range of legitimate and importantly different conceptions of both toleration and recognition...

  10. Fault Tolerant Feedback Control

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  11. Differentiation of Constriction and Restriction: Complex Cardiovascular Hemodynamics.

    Geske, Jeffrey B; Anavekar, Nandan S; Nishimura, Rick A; Oh, Jae K; Gersh, Bernard J

    2016-11-29

    Differentiation of constrictive pericarditis (CP) from restrictive cardiomyopathy (RCM) is a complex and often challenging process. Because CP is a potentially curable cause of heart failure and therapeutic options for RCM are limited, distinction of these 2 conditions is critical. Although different in regard to etiology, prognosis, and treatment, CP and RCM share a common clinical presentation of predominantly right-sided heart failure, in the absence of significant left ventricular systolic dysfunction or valve disease, due to impaired ventricular diastolic filling. Fundamental to the diagnosis of either condition is a clear understanding of the underlying hemodynamic principles and pathophysiology. We present a contemporary review of the pathophysiology, hemodynamics, diagnostic assessment, and therapeutic approach to patients presenting with CP and RCM. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  12. The hemodynamic basis of exercise intolerance in tricuspid regurgitation

    Andersen, Mads Jønsson; Nishimura, Rick a; Borlaug, Barry A

    2014-01-01

    ≥3 TR underwent high-fidelity invasive hemodynamic exercise testing with simultaneous expired gas analysis and were compared with 13 age- and sex-matched controls. At rest, TR subjects had lower pulmonary blood flow (3.6±0.4 versus 5.1±1.9 L/min; P=0.01), increased right atrial pressure (12±5 versus.......001). TR subjects displayed higher pulmonary capillary wedge pressure with exercise, but this was solely because of RA hypertension (27±9 versus 8±3 mm Hg; P......BACKGROUND:Patients with severe tricuspid regurgitation (TR) frequently present with exertional fatigue and dyspnea, but the hemodynamic basis for exercise limitation in people with TR remains unclear. METHODS AND RESULTS:Twelve subjects with normal left ventricular (LV) ejection fraction and grade...

  13. Hemodynamic effects of microgravity and their ground-based simulations

    Lobachik, V. I.; Abrosimov, S. V.; Zhidkov, V. V.; Endeka, D. K.

    Hemodynamic effects of simulated microgravity were investigated, in various experiments, using radioactive isotopes, in which 40 healthy men, aged 35 to 42 years, took part. Blood shifts were evaluated qualitatively and quantitatively. Simulation studies included bedrest, head-down tilt (-5° and -15°), and vertical water immersion, it was found that none of the methods could entirely simulate hemodynamic effects of microgravity. Subjective sensations varied in a wide range. They cannot be used to identify reliably the effects of real and simulated microgravity. Renal fluid excretion in real and simulated microgravity was different in terms of volume and time. The experiments yielded data about the general pattern of circulation with blood displaced to the upper body.

  14. Systemic and intracardiac hemodynamic disturbance in complicated forms of hepatocirrhosis

    Mjasnik, B.N.; Chodzibekov, M.C.; Achmedzanova, S.S.

    1990-01-01

    On the base of radionuclide investigation of systemic and intracardiac hemodynamics was shown that the rate of kinetic variants of hemocirculation does not depend on the stage of portal hypertension in complicated forms of hepatocirrhosis. Blood redistribution in these patients creates volumentrical overload of cardiac ventricles and pulmonary circulation, that is conditioned of additional tension of cardiac muscle and especially of right ventricle myocardium, which reserve rapidly ran out. Operations which increase blood shunt from portal system to superior vena cava raise preload of myocardium that makes the high risk in appearance of cardiac insufficiency, especially of right ventricle in early post operative period. The received data indicated on necessity to take into account the state of intracardiac hemodynamics in selection of surgical approach in patients with complicated forms of hepatocirrhosis. (orig.) [de

  15. Use of active dosemeters as a optimization tool in hemodynamics

    Nunes, Rafael; Pereira, Dirceu D.; Rodrigues, Barbara B.D.; Ferreira, Esmeralci

    2016-01-01

    Interventional cardiology procedures are, in general, associated with high doses in patients and professionals. The objective of this study is to measure the radiation levels received by professionals .The professional dosimetry was performed in a department of Hemodynamics of University Hospital in Rio de Janeiro. were followed 331 coronary angiography (CA) and 26 percutaneous transluminal coronary angioplasty (PTCA) procedures. For this, were used active dosemeters to measure the radiation levels at the chest of interventional professionals. The results show that average personal equivalent dose of doctors, per procedure was 100 e 154 μSv. On average, nursing technicians and radiologist receive 12 and 10% of doses of physicians, respectively, during CA procedures. From the results, it appears that the doses of hemodynamics exceed the annual dose limit of the standards. The use of lead shielding is presented as an effective action to reduce doses in these workers. (author)

  16. Distribution of the Vasotocin Subtype Four Receptor (VT4R) in the Anterior Pituitary Gland of the Chicken, Gallus gallus, and its Possible Role in the Avian Stress Response.

    Selvam, R; Jurkevich, A; Kang, S W; Mikhailova, M V; Cornett, L E; Kuenzel, W J

    2013-01-01

    The neurohormone arginine vasotocin (AVT) in non mammalian vertebrates is homologous to arginine vasopressin (AVP) in mammals. Its actions are mediated via G protein-coupled receptors that belong to the vasotocin/mesotocin family. Because of the known regulatory effects of nonapeptide hormones on anterior pituitary functions, receptor subtypes in that family have been proposed to be located in anterior pituitary cells. Recently, an avian vasotocin receptor subtype designated VT4R has been cloned, which shares 69% sequence homology with a human vasopressin receptor, the V1aR. In the present study, a polyclonal antibody to the VT4R was developed and validated to confirm its specificity to the VT4R. The antibody was used to test the hypothesis that the VT4R is present in the avian anterior pituitary and is specifically associated with certain cell types, where its expression is modulated by acute stress. Western blotting of membrane protein extracts from pituitary tissue, the use of HeLa cells transfected with the VT4R and peptide competition assays all confirmed the specificity of the antibody to the VT4R. Dual-labelling immunofluorescence microscopy was utilised to identify pituitary cell types that contained immunoreactive VT4R. The receptor was found to be widely distributed throughout the cephalic lobe but not in the caudal lobe of the anterior pituitary. Immunoreactive VT4R was associated with corticotrophs. Approximately 89% of immunolabelled corticotrophs were shown to contain the VT4R. The immunoreactive VT4R was not found in gonadotrophs, somatotrophs or lactotrophs. To determine a possible functional role of the VT4R and previously characterised VT2R, gene expression levels in the anterior pituitary were determined after acute immobilisation stress by quantitative reverse transcriptase-polymerase chain reaction. The results showed a significant increase in plasma corticosterone levels (three- to four-fold), a significant reduction of VT4R mRNA and an

  17. Pharmacological Modulation of Hemodynamics in Adult Zebrafish In Vivo.

    Daniel Brönnimann

    Full Text Available Hemodynamic parameters in zebrafish receive increasing attention because of their important role in cardiovascular processes such as atherosclerosis, hematopoiesis, sprouting and intussusceptive angiogenesis. To study underlying mechanisms, the precise modulation of parameters like blood flow velocity or shear stress is centrally important. Questions related to blood flow have been addressed in the past in either embryonic or ex vivo-zebrafish models but little information is available for adult animals. Here we describe a pharmacological approach to modulate cardiac and hemodynamic parameters in adult zebrafish in vivo.Adult zebrafish were paralyzed and orally perfused with salt water. The drugs isoprenaline and sodium nitroprusside were directly applied with the perfusate, thus closely resembling the preferred method for drug delivery in zebrafish, namely within the water. Drug effects on the heart and on blood flow in the submental vein were studied using electrocardiograms, in vivo-microscopy and mathematical flow simulations.Under control conditions, heart rate, blood flow velocity and shear stress varied less than ± 5%. Maximal chronotropic effects of isoprenaline were achieved at a concentration of 50 μmol/L, where it increased the heart rate by 22.6 ± 1.3% (n = 4; p < 0.0001. Blood flow velocity and shear stress in the submental vein were not significantly increased. Sodium nitroprusside at 1 mmol/L did not alter the heart rate but increased blood flow velocity by 110.46 ± 19.64% (p = 0.01 and shear stress by 117.96 ± 23.65% (n = 9; p = 0.03.In this study, we demonstrate that cardiac and hemodynamic parameters in adult zebrafish can be efficiently modulated by isoprenaline and sodium nitroprusside. Together with the suitability of the zebrafish for in vivo-microscopy and genetic modifications, the methodology described permits studying biological processes that are dependent on hemodynamic alterations.

  18. Morphological and hemodynamic analysis of mirror posterior communicating artery aneurysms.

    Jinyu Xu

    Full Text Available BACKGROUND AND PURPOSE: Hemodynamic factors are commonly believed to play an important role in the pathogenesis, progression, and rupture of cerebral aneurysms. In this study, we aimed to identify significant hemodynamic and morphological parameters that discriminate intracranial aneurysm rupture status using 3-dimensional-angiography and computational fluid dynamics technology. MATERIALS AND METHODS: 3D-DSA was performed in 8 patients with mirror posterior communicating artery aneurysms (Pcom-MANs. Each pair was divided into ruptured and unruptured groups. Five morphological and three hemodynamic parameters were evaluated for significance with respect to rupture. RESULTS: The normalized mean wall shear stress (WSS of the aneurysm sac in the ruptured group was significantly lower than that in the unruptured group (0.52±0.20 versus 0.81±0.21, P = .012. The percentage of the low WSS area in the ruptured group was higher than that in the unruptured group (4.11±4.66% versus 0.02±0.06%, P = .018. The AR was 1.04±0.21 in the ruptured group, which was significantly higher than 0.70±0.17 in the unruptured group (P = .012. By contrast, parameters that had no significant differences between the two groups were OSI (P = .674, aneurysm size (P = .327, size ratio (P = .779, vessel angle (P = 1.000 and aneurysm inclination angle (P = 1.000. CONCLUSIONS: Pcom-MANs may be a useful disease model to investigate possible causes of aneurysm rupture. The ruptured aneurysms manifested lower WSS, higher percentage of low WSS area, and higher AR, compared with the unruptured one. And hemodynamics is as important as morphology in discriminating aneurysm rupture status.

  19. Continuous Hemodynamic Monitoring in Acute Stroke: An Exploratory Analysis

    Ayan Sen

    2014-07-01

    Full Text Available Introduction: Non-invasive, continuous hemodynamic monitoring is entering the clinical arena. The primary objective of this study was to test the feasibility of such monitoring in a pilot sample of Emergency Department (ED stroke patients. Secondary objectives included analysis of hemodynamic variability and correlation of continuous blood pressure measurements with standard measurements. Methods: This study was a secondary analysis of 7 stroke patients from a prospectively collected data set of patients that received 2 hours of hemodynamic monitoring in the ED. Stroke patients were included if hemorrhagic or ischemic stroke was confirmed by neuroimaging, and symptom onset was within 24 hours. They were excluded for the presence of a stroke mimic or transient ischemic attack. Monitoring was performed using the Nexfin device (Edwards Lifesciences, Irvine CA. Results: The mean age of the cohort was 71 ± 17 years, 43% were male, and the mean National Institute of Health Stroke Scale (NIHSS was 6.9 ± 5.5. Two patients had hemorrhagic stroke. We obtained 42,456 hemodynamic data points, including beat-to-beat blood pressure measurements with variability of 18 mmHg and cardiac indices ranging from 1.8 to 3.6 l/min/m2. The correlation coefficient between continuous blood pressure measurements with the Nexfin device and standard ED readings was 0.83. Conclusion: This exploratory investigation revealed that continuous, noninvasive monitoring in the ED is feasible in acute stroke. Further research is currently underway to determine how such monitoring may impact outcomes in stroke or replace the need for invasive monitoring. [West J Emerg Med. 2014;15(4:–0.

  20. Mechanical tolerance stackup and analysis

    Fischer, Bryan R

    2004-01-01

    BackgroundDimensioning and TolerancingTolerance Format and Decimal PlacesConverting Plus/Minus Dimensions and Tolerances into Equal Bilaterally Toleranced DimensionsVariation and Sources of VariationTolerance AnalysisWorst-case Tolerance StackupsStatistical Tolerance StackupsGeometric Dimensioning and Tolerancing (GD&T)Converting Plus/Minus Tolerancing to Positional Tolerancing and Projected Tolerance ZonesDiametral and Radial Tolerance StackupsSpecifying Material Condition Modifiers and Their Effect on Tolerance Stackups The Tolerance Stackup SketchThe Tolerance Stackup Report FormTolerance S

  1. The incidence of serious hemodynamic changes in physically-limited patients following oral dipyridamole challenge before thallium-201 scintigraphy

    Kahn, D.; Argenyi, E.A.; Berbaum, K.; Rezai, K.

    1990-01-01

    Dipyridamole has liberalized referrals for stress TI-201 chloride (thallium) studies at the Iowa City Veterans Administration Medical Center. Seventy-five percent of referrals now receive dipyridamole and, unlike patients who tolerate conventional exercise testing, these patients are often quite debilitated. Therefore, the hemodynamic consequences of dipyridamole were reviewed in 120 consecutive, physically-limited patients referred for thallium scintigraphy following an average oral dose of 5.4 mg/kg. Each patient's blood pressure was measured every 5 minutes for 1 hour after dipyridamole and compared with several clinical factors to determine if blood pressure change was predictable. In all patients, blood pressure changed from 136 +/- 21/83 +/- 15 (mean +/- 1 SD) to 117 +/- 25/72 +/- 15 following dipyridamole administration. One hundred nine of the 120 patients had a blood pressure decline from 137 +/- 21/82 +/- 12 to 113 +/- 21/70 +/- 13. Of the 109, 43% (N = 47) had a systolic blood pressure decline greater than 20 mmHg, 16% (n = 18) greater than 40 mmHg, and 13% (n = 14) greater than 50 mmHg. Thirteen percent (n = 14) required emergent reversal of the dipyridamole with aminophylline. Significant hypotension is relatively common but generally unpredictable after oral dipyridamole. Therefore, patient eligibility criteria should be carefully considered; strict hemodynamic monitoring must be routine in the usual patient undergoing thallium scintigraphy after oral dipyridamole challenge

  2. Invasive hemodynamic monitoring in the postoperative period of cardiac surgery

    Desanka Dragosavac

    1999-08-01

    Full Text Available OBJETIVE: To assess the hemodynamic profile of cardiac surgery patients with circulatory instability in the early postoperative period (POP. METHODS: Over a two-year period, 306 patients underwent cardiac surgery. Thirty had hemodynamic instability in the early POP and were monitored with the Swan-Ganz catheter. The following parameters were evaluated: cardiac index (CI, systemic and pulmonary vascular resistance, pulmonary shunt, central venous pressure (CVP, pulmonary capillary wedge pressure (PCWP, oxygen delivery and consumption, use of vasoactive drugs and of circulatory support. RESULTS: Twenty patients had low cardiac index (CI, and 10 had normal or high CI. Systemic vascular resistance was decreased in 11 patients. There was no correlation between oxygen delivery (DO2 and consumption (VO2, p=0.42, and no correlation between CVP and PCWP, p=0.065. Pulmonary vascular resistance was decreased in 15 patients and the pulmonary shunt was increased in 19. Two patients with CI < 2L/min/m² received circulatory support. CONCLUSION: Patients in the POP of cardiac surgery frequently have a mixed shock due to the systemic inflammatory response syndrome (SIRS. Therefore, invasive hemodynamic monitoring is useful in handling blood volume, choice of vasoactive drugs, and indication for circulatory support.

  3. Hemodynamic response during aneurysm clipping surgery among experienced neurosurgeons.

    Bunevicius, Adomas; Bilskiene, Diana; Macas, Andrius; Tamasauskas, Arimantas

    2016-02-01

    Neurosurgery is a challenging field associated with high levels of mental stress. The goal of this study was to investigate the hemodynamic response of experienced neurosurgeons during aneurysm clipping surgery and to evaluate whether neurosurgeons' hemodynamic responses are associated with patients' clinical statuses. Four vascular neurosurgeons (all male; mean age 51 ± 10 years; post-residency experience ≥7 years) were studied during 42 aneurysm clipping procedures. Blood pressure (BP) and heart rate (HR) were assessed at rest and during seven phases of surgery: before the skin incision, after craniotomy, after dural opening, after aneurysm neck dissection, after aneurysm clipping, after dural closure and after skin closure. HR and BP were significantly greater during surgery relative to the rest situation (p ≤ 0.03). There was a statistically significant increase in neurosurgeons' HR (F [6, 41] = 10.88, p neurosurgeon experience, the difference in BP as a function of aneurysm rupture was not significant (p > 0.08). Aneurysm location, intraoperative aneurysm rupture, admission WFNS score, admission Glasgow Coma Scale scores and Fisher grade were not associated with neurosurgeons' intraoperative HR and BP (all p > 0.07). Aneurysm clipping surgery is associated with significant hemodynamic system activation among experienced neurosurgeons. The greatest HR and BP were after aneurysm neck dissection and clipping. Aneurysm location and patient clinical status were not associated with intraoperative changes of neurosurgeons' HR and BP.

  4. Hemodynamics alter arterial low-density lipoprotein metabolism

    Warty, V.S.; Calvo, W.J.; Berceli, S.A.; Pham, S.M.; Durham, S.J.; Tanksale, S.K.; Klein, E.C.; Herman, I.M.; Borovetz, H.S.

    1989-01-01

    We have investigated the role of hemodynamic factors on low-density lipoprotein transport and metabolism in the intact arterial wall. Freshly excised canine carotid blood vessels were exposed to well-defined pulsatile flow in vitro for continuous periods up to 20 hours. We chose to impose the following hemodynamic conditions on our test carotid arteries: normotension, hypertension (at physiologic flow conditions), and hypertension coupled with elevated flow of canine serum perfusate. In several experiments the effect of endothelial denudation was examined in carotid arteries exposed to normotensive pulsatile flow. A trapped ligand method was used for quantitating low-density lipoprotein uptake and metabolism in the arterial wall. The distribution of both intact and degraded low-density lipoprotein fractions was determined from measurements of radiolabelled low-density lipoprotein activity within thin radial sections of perfused arteries. Our results suggest that both hypertensive hemodynamic simulations exacerbate the uptake of low-density lipoprotein within the arterial wall (by a factor of three to nine). The percentage of low-density lipoprotein that undergoes irreversible degradation falls from 41% under normotensive conditions to below 30% when hypertensive conditions are imposed, indicating that degradative processes are not proportionally elevated with the accelerated influx. A similar pattern is observed for deendothelialized vessels

  5. Quantifying the abnormal hemodynamics of sickle cell anemia

    Lei, Huan; Karniadakis, George

    2012-02-01

    Sickle red blood cells (SS-RBC) exhibit heterogeneous morphologies and abnormal hemodynamics in deoxygenated states. A multi-scale model for SS-RBC is developed based on the Dissipative Particle Dynamics (DPD) method. Different cell morphologies (sickle, granular, elongated shapes) typically observed in deoxygenated states are constructed and quantified by the Asphericity and Elliptical shape factors. The hemodynamics of SS-RBC suspensions is studied in both shear and pipe flow systems. The flow resistance obtained from both systems exhibits a larger value than the healthy blood flow due to the abnormal cell properties. Moreover, SS-RBCs exhibit abnormal adhesive interactions with both the vessel endothelium cells and the leukocytes. The effect of the abnormal adhesive interactions on the hemodynamics of sickle blood is investigated using the current model. It is found that both the SS-RBC - endothelium and the SS-RBC - leukocytes interactions, can potentially trigger the vicious ``sickling and entrapment'' cycles, resulting in vaso-occlusion phenomena widely observed in micro-circulation experiments.

  6. Hemodynamic and tubular changes induced by contrast media.

    Caiazza, Antonella; Russo, Luigi; Sabbatini, Massimo; Russo, Domenico

    2014-01-01

    The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI.

  7. Comprehensive cognitive and cerebral hemodynamic evaluation after cranioplasty

    Coelho F

    2014-05-01

    Full Text Available Fernanda Coelho,1 Arthur Maynart Oliveira,2 Wellingson Silva Paiva,2 Fabio Rios Freire,1 Vanessa Tome Calado,1 Robson Luis Amorim,2 Iuri Santana Neville,2 Almir Ferreira de Andrade,2 Edson Bor-Seng-Shu,3 Renato Anghinah,1 Manoel Jacobsen Teixeira21Neurorehabilitation Group, Division of Neurology, 2Division of Neurosurgery, 3Neurosonology and Cerebral Hemodynamics Group, University of São Paulo Medical School, São Paulo, BrazilAbstract: Decompressive craniectomy is an established procedure to lower intracranial pressure and can save patients' lives. However, this procedure is associated with delayed cognitive decline and cerebral hemodynamics complications. Studies show the benefits of cranioplasty beyond cosmetic aspects, including brain protection, and functional and cerebrovascular aspects, but a detailed description of the concrete changes following this procedure are lacking. In this paper, the authors report a patient with trephine syndrome who underwent cranioplasty; comprehensive cognitive and cerebral hemodynamic evaluations were performed prior to and following the cranioplasty. The discussion was based on a critical literature review.Keywords: cranioplasty, decompressive craniotomy, perfusion CT, traumatic brain injury, cognition, neuropsychological test

  8. A study of the hemodynamics of anterior communicating artery aneurysms

    Cebral, Juan R.; Castro, Marcelo A.; Putman, Christopher M.

    2006-03-01

    In this study, the effects of unequal physiologic flow conditions in the internal carotid arteries on the intra-aneurysmal hemodynamics of anterior communicating artery aneurysms were investigated. Patient-specific vascular computational fluid dynamics models of five cerebral aneurysms were constructed from bilateral 3D rotational angiography images. The aneurysmal hemodynamics was analyzed under a range of physiologic flow conditions including the effects of unequal mean flows and phase shifts between the flow waveforms of the left and right internal carotid arteries. A total of five simulations were performed for each patient, and unsteady wall shear stress (WSS) maps were created for each flow condition. Time dependent curves of average WSS magnitude over selected regions on the aneurysms were constructed and used to analyze the influence of the inflow conditions. It was found that mean flow imbalances in the feeding vessels tend to shift the regions of elevated WSS (flow impingement region) towards the dominating inflow jet and to change the magnitude of the WSS peaks. However, the overall qualitative appearance of the WSS distribution and velocity simulations is not substantially affected. In contrast, phase differences tend to increase the temporal complexity of the hemodynamic patterns and to destabilize the intra-aneurysmal flow pattern. However, these effects are less important when the A1 confluence is less symmetric, i.e. dominated by one of the A1 segments. Conditions affecting the flow characteristics in the parent arteries of cerebral aneurysms with more than one avenue of inflow should be incorporated into flow models.

  9. Vascular Adaptation to Exercise in Humans: Role of Hemodynamic Stimuli

    Green, Daniel J.; Hopman, Maria T. E.; Padilla, Jaume; Laughlin, M. Harold; Thijssen, Dick H. J.

    2017-01-01

    On the 400th anniversary of Harvey's Lumleian lectures, this review focuses on “hemodynamic” forces associated with the movement of blood through arteries in humans and the functional and structural adaptations that result from repeated episodic exposure to such stimuli. The late 20th century discovery that endothelial cells modify arterial tone via paracrine transduction provoked studies exploring the direct mechanical effects of blood flow and pressure on vascular function and adaptation in vivo. In this review, we address the impact of distinct hemodynamic signals that occur in response to exercise, the interrelationships between these signals, the nature of the adaptive responses that manifest under different physiological conditions, and the implications for human health. Exercise modifies blood flow, luminal shear stress, arterial pressure, and tangential wall stress, all of which can transduce changes in arterial function, diameter, and wall thickness. There are important clinical implications of the adaptation that occurs as a consequence of repeated hemodynamic stimulation associated with exercise training in humans, including impacts on atherosclerotic risk in conduit arteries, the control of blood pressure in resistance vessels, oxygen delivery and diffusion, and microvascular health. Exercise training studies have demonstrated that direct hemodynamic impacts on the health of the artery wall contribute to the well-established decrease in cardiovascular risk attributed to physical activity. PMID:28151424

  10. Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

    2015-03-01

    Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

  11. A Novel Stretch Sensor to Measure Venous Hemodynamics

    Syrpailyne Wankhar

    2018-07-01

    Full Text Available Chronic venous insufficiency is a debilitating condition causing varicose veins and venous ulcers. The pathophysiology includes reflux and venous obstruction. The diagnosis is often made by clinical examination and confirmed by Venous Doppler studies. Plethysmography helps to quantitatively examine the reflux and diagnose the burden of deep venous pathology to better understand venous hemodynamics, which is not elicited by venous duplex examination alone. However, most of these tests are qualitative, expensive, and not easily available. In this paper, we demonstrate the potential use of a novel stretch sensor in the assessment of venous hemodynamics during different maneuvers by measuring the change in calf circumference. We designed the stretch sensor by using semiconductor strain gauges pasted onto a small metal bar to form a load cell. The elastic and Velcro material attached to the load cell form a belt. It converts the change in limb circumference to a proportional tension (force of distension when placed around the calf muscle. We recorded the change in limb circumference from arrays of stretch sensors by using an in-house data acquisition system. We calculated the venous volume (VV, venous filling index (VFI, ejection fraction (EF and residual venous volume (RVV on two normal subjects and on two patients to assess venous hemodynamics. The values (VV > 60 ml, VFI 60%, RVV 2ml/s, EF 35% in patients were comparable to those reported in the literature.

  12. Hemodynamic stroke: A rare pitfall in cranio cervical junction surgery

    Jan Frederick Cornelius

    2014-01-01

    Full Text Available Surgical C1C2-stabilization may be complicated by arterial-arterial embolism or arterial injury. Another potential complication is hemodynamic stroke. The latter might be induced in patients with poor posterior fossa collateralization (risk factor 1 when the vertebral artery (VA is compressed during reduction (risk factor 2. We report a clinical case where this rare situation occurred: A 72-year old patient was undergoing C1C2-stabilization for subluxation due to rheumatoid arthritis. Preoperative computed tomography angiography (CTA had shown poor collaterals in the posterior fossa. Furthermore, intraoperative Doppler ultrasound (US detected unilateral VA occlusion during reduction. It appeared to be a high-risk situation for hemodynamic stroke. Surgical inspection of the VA found osteofibrous compressing elements. Arterial decompression was performed resulting in the normal flow as detected by US. Subsequently, C1C2-stabilization could be realized. The clinical and radiological outcome was very favorable. In C1C2-stabilization precise analysis of preoperative CTA and intraoperative US are important to detect risk factors of hemodynamic stroke. Using these data may prevent this rare, but potentially life-threatening complication.

  13. A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.

    Anselmino, Matteo; Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2017-01-01

    Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model. The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8). Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56). The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.

  14. Non-hemodynamic effects of organic nitrates and the distinctive characteristics of pentaerithrityl tetranitrate.

    Gori, Tommaso; Daiber, Andreas

    2009-01-01

    Organic nitrates are among the oldest and yet most commonly employed drugs in the long-term therapy of coronary artery disease and congestive heart failure. While they have long been used in clinical practice, our understanding of their mechanism of action and side effects remains incomplete. For instance, recent findings provide evidence of previously unanticipated, non-hemodynamic properties that include potentially beneficial mechanisms (such as the induction of a protective phenotype that mimics ischemic preconditioning), but also toxic effects (such as endothelial and autonomic dysfunction, rebound angina, tolerance). To date, the most commonly employed organic nitrates are isosorbide mononitrate, isosorbide dinitrate, and nitroglycerin (glyceryl trinitrate). Another organic nitrate, pentaerithrityl tetranitrate (PETN), has long been employed in eastern European countries and is currently being reintroduced in Western countries. In light of their wide use, and of the (re)introduction of PETN in Western markets, the present review focuses on the novel effects of organic nitrates, describing their potential clinical implications and discussing differences among different compounds. We believe that these recent findings have important clinical implications. Since the side effects of organic nitrates such as nitroglycerin and isosorbides appear to be mediated by reactive oxygen species, care should be taken that drugs with antioxidant properties are co-administered. On the other hand, efforts should be made to clinically exploit the preconditioning effects of these drugs.

  15. Hemodynamic responses to dexmedetomidine in critically injured intubated pediatric burned patients: a preliminary study.

    Shank, Erik S; Sheridan, Robert L; Ryan, Colleen M; Keaney, Timothy J; Martyn, J A Jeevendra

    2013-01-01

    Because of ineffectiveness and tolerance to benzodiazepines and opioids developing with time, drugs acting via other receptor systems (eg, α-2 agonists) have been advocated in burn patients to improve sedation and analgesia. This study in severely burned pediatric subjects examined the hemodynamic consequences of dexmedetomidine (Dex) administration. Eight intubated patients with ≥20 to 79% TBSA burns were studied between 7 and 35 days after injury. After baseline measurements of mean arterial blood pressure and heart rhythm were taken, each patient received a 1.0 µg/kg bolus of Dex followed by an ascending dose infusion protocol (0.7-2.5 µg/kg/hr), with each dose administered for 15 minutes. There was significant hypotension (27±7.5%, average drop in mean arterial pressure [MAP] ± SD), and a decrease in heart rate (HR; 19% ± 7, average drop in HR ± SD). The average HR decreased from 146 beats per minute to 120. No bradycardia (HR patients, the MAP decreased to patients, three patients completed the study receiving the highest infusion dose of Dex (2.5 µg/kg/hr), whereas in 2 patients the infusion part of the study was begun, but the study was stopped due to persistent hypotension (MAP burn patients.

  16. Toleration out of respect?

    Lægaard, Sune

    2013-01-01

    Under conditions of pluralism different cultures, interests or values can come into conflict, which raises the problem of how to secure peaceful co-existence. The idea of toleration historically emerged as an answer to this problem. Recently Rainer Forst has argued that toleration should not just...... be based on a modus vivendi designed to secure peaceful co-existence, but should be based on moral reasons. Forst therefore advances what he calls the ‘respect conception’ of toleration as an in itself morally desirable type of relationship, which is furthermore the only conception of toleration...... that avoids various so-called ‘paradoxes of toleration’. The paper first examines whether Forst’s respect conception can be applied descriptively to distinguish between actual patterns of behaviour and classify different acts of toleration. Then the focus is shifted to toleration out of respect as a normative...

  17. Tolerance in Drosophila

    Atkinson, Nigel S.

    2009-01-01

    The set of genes that underlie ethanol tolerance (inducible resistance) are likely to overlap with the set of genes responsible for ethanol addiction. Whereas addiction is difficult to recognize in simple model systems, behavioral tolerance is readily identifiable and can be induced in large populations of animals. Thus, tolerance lends itself to analysis in model systems with powerful genetics. Drosophila melanogaster has been used by a variety of laboratories for the identification of genes...

  18. Advanced hemodynamic monitoring in intensive care medicine : A German web-based survey study.

    Saugel, B; Reese, P C; Wagner, J Y; Buerke, M; Huber, W; Kluge, S; Prondzinsky, R

    2018-04-01

    Advanced hemodynamic monitoring is recommended in patients with complex circulatory shock. To evaluate the current attitudes and beliefs among German intensivists, regarding advanced hemodynamic monitoring, the actual hemodynamic management in clinical practice, and the barriers to using it. Web-based survey among members of the German Society of Medical Intensive Care and Emergency Medicine. Of 284 respondents, 249 (87%) agreed that further hemodynamic assessment is needed to determine the type of circulatory shock if no clear clinical diagnosis can be made. In all, 281 (99%) agreed that echocardiography is helpful for this purpose (transpulmonary thermodilution: 225 [79%]; pulmonary artery catheterization: 126 [45%]). More than 70% of respondents agreed that blood flow variables (cardiac output, stroke volume) should be measured in patients with hemodynamic instability. The parameters most respondents agreed should be assessed in a patient with hemodynamic instability were mean arterial pressure, cardiac output, and serum lactate. Echocardiography is available in 99% of ICUs (transpulmonary thermodilution: 91%; pulmonary artery catheter: 63%). The respondents stated that, in clinical practice, invasive arterial pressure measurements and serum lactate measurements are performed in more than 90% of patients with hemodynamic instability (cardiac output monitoring in about 50%; transpulmonary thermodilution in about 40%). The respondents did not feel strong barriers to the use of advanced hemodynamic monitoring in clinical practice. This survey study shows that German intensivists deem advanced hemodynamic assessment necessary for the differential diagnosis of circulatory shock and to guide therapy with fluids, vasopressors, and inotropes in ICU patients.

  19. Multiparametric estimation of brain hemodynamics with MR fingerprinting ASL.

    Su, Pan; Mao, Deng; Liu, Peiying; Li, Yang; Pinho, Marco C; Welch, Babu G; Lu, Hanzhang

    2017-11-01

    Assessment of brain hemodynamics without exogenous contrast agents is of increasing importance in clinical applications. This study aims to develop an MR perfusion technique that can provide noncontrast and multiparametric estimation of hemodynamic markers. We devised an arterial spin labeling (ASL) method based on the principle of MR fingerprinting (MRF), referred to as MRF-ASL. By taking advantage of the rich information contained in MRF sequence, up to seven hemodynamic parameters can be estimated concomitantly. Feasibility demonstration, flip angle optimization, comparison with Look-Locker ASL, reproducibility test, sensitivity to hypercapnia challenge, and initial clinical application in an intracranial steno-occlusive process, Moyamoya disease, were performed to evaluate this technique. Magnetic resonance fingerprinting ASL provided estimation of up to seven parameters, including B1+, tissue T 1 , cerebral blood flow (CBF), tissue bolus arrival time (BAT), pass-through arterial BAT, pass-through blood volume, and pass-through blood travel time. Coefficients of variation of the estimated parameters ranged from 0.2 to 9.6%. Hypercapnia resulted in an increase in CBF by 57.7%, and a decrease in BAT by 13.7 and 24.8% in tissue and vessels, respectively. Patients with Moyamoya disease showed diminished CBF and lengthened BAT that could not be detected with regular ASL. Magnetic resonance fingerprinting ASL is a promising technique for noncontrast, multiparametric perfusion assessment. Magn Reson Med 78:1812-1823, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  20. Post-Treatment Hemodynamics of a Basilar Aneurysm and Bifurcation

    Ortega, J; Hartman, J; Rodriguez, J; Maitland, D

    2008-01-16

    Aneurysm re-growth and rupture can sometimes unexpectedly occur following treatment procedures that were initially considered to be successful at the time of treatment and post-operative angiography. In some cases, this can be attributed to surgical clip slippage or endovascular coil compaction. However, there are other cases in which the treatment devices function properly. In these instances, the subsequent complications are due to other factors, perhaps one of which is the post-treatment hemodynamic stress. To investigate whether or not a treatment procedure can subject the parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. The simulations demonstrate that the treatment procedure produces a substantial increase in the wall shear stress. Analysis of the post-treatment flow field indicates that the increase in wall shear stress is due to the impingement of the basilar artery flow upon the aneurysm filling material and to the close proximity of a vortex tube to the artery wall. Calculation of the time-averaged wall shear stress shows that there is a region of the artery exposed to a level of wall shear stress that can cause severe damage to endothelial cells. The results of this study demonstrate that it is possible for a treatment procedure, which successfully excludes the aneurysm from the vascular system and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the immediately adjacent vessel wall.

  1. Closure technique after carotid endarterectomy influences local hemodynamics.

    Harrison, Gareth J; How, Thien V; Poole, Robert J; Brennan, John A; Naik, Jagjeeth B; Vallabhaneni, S Rao; Fisher, Robert K

    2014-08-01

    Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection. Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared. The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width. Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8

  2. Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

    Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

    1990-01-01

    To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with 99m Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by 133 Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with 99m Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with 133 Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with 133 Xe SPECT and 99m Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author)

  3. Hemodynamic study of cervical carotid arteries using DSA

    Kumashiro, Masayuki; Araki, Osamu; Matsunaga, Morio; Shigeyasu, Makio

    1986-01-01

    Although intravenous digital subtraction angiography (IVDSA) has been widely utilized as a means of morphological examination for the detection of intracranial or extracranial vascular lesions, it has thus for contributed little to quantitative assessment in hemodynamics. In the present study, a fundamental analysis of the hemodynamics on the cervical carotid artery was performed with a relative perfusion efficiency (Rath et al., 1979). This was not related to the measurement of time, such as the mean transit time, but was based on Sapirstein's principle. After the intravenous administration of the contrast material, dynamic DSA was performed using our equipment, Shimadzu DAR-100. After setting the region of interest in common carotid arteries on DSA images by means of a microdensitometer (Sakura PDS-15) combined with a computer (NEC ACOS-460), time-density curves were obtained on both sides. Thereafter, the RPE was calculated as a ratio of two integrals from the zero time to the earlier peak time of the time-density curves with respect to the time. The flow model with the hydro-dynamic system was used to detect the relationship between the RPEs and the ratios of the actual flows in the system. The results of this experiment showed a high correlation between the RPEs and the flows (r = 0.85, p < 0.001). In normal subjects (n = 28), the mean of the RPEs was 1.07 ± 0.27 (S.D.). The RPEs showed significantly lower values in the 5 patients with severe stenosis of the internal carotid artery (0.76 ± 0.15, p < 0.02), as well as even more significantly lower values in the 9 patients with a complete occlusion of the internal carotid artery (0.64 ± 0.19, p < 0.001). The RPE measurement with IVDSA has been shown to be useful for recognizing the cervical hemodynamic changes in patients with occlusive cervicovascular disease. (author)

  4. Separating genetic and hemodynamic defects in neuropilin 1 knockout embryos.

    Jones, Elizabeth A V; Yuan, Li; Breant, Christine; Watts, Ryan J; Eichmann, Anne

    2008-08-01

    Targeted inactivation of genes involved in murine cardiovascular development frequently leads to abnormalities in blood flow. As blood fluid dynamics play a crucial role in shaping vessel morphology, the presence of flow defects generally prohibits the precise assignment of the role of the mutated gene product in the vasculature. In this study, we show how to distinguish between genetic defects caused by targeted inactivation of the neuropilin 1 (Nrp1) receptor and hemodynamic defects occurring in homozygous knockout embryos. Our analysis of a Nrp1 null allele bred onto a C57BL/6 background shows that vessel remodeling defects occur concomitantly with the onset of blood flow and cause death of homozygous mutants at E10.5. Using mouse embryo culture, we establish that hemodynamic defects are already present at E8.5 and continuous circulation is never established in homozygous mutants. The geometry of yolk sac blood vessels is altered and remodeling into yolk sac arteries and veins does not occur. To separate flow-induced deficiencies from those caused by the Nrp1 mutation, we arrested blood flow in cultured wild-type and mutant embryos and followed their vascular development. We find that loss of Nrp1 function rather than flow induces the altered geometry of the capillary plexus. Endothelial cell migration, but not replication, is altered in Nrp1 mutants. Gene expression analysis of endothelial cells isolated from freshly dissected wild-type and mutants and after culture in no-flow conditions showed down-regulation of the arterial marker genes connexin 40 and ephrin B2 related to the loss of Nrp1 function. This method allows genetic defects caused by loss-of-function of a gene important for cardiovascular development to be isolated even in the presence of hemodynamic defects.

  5. Predicting ICU hemodynamic instability using continuous multiparameter trends.

    Cao, Hanqing; Eshelman, Larry; Chbat, Nicolas; Nielsen, Larry; Gross, Brian; Saeed, Mohammed

    2008-01-01

    Identifying hemodynamically unstable patients in a timely fashion in intensive care units (ICUs) is crucial because it can lead to earlier interventions and thus to potentially better patient outcomes. Current alert algorithms are typically limited to detecting dangerous conditions only after they have occurred and suffer from high false alert rates. Our objective was to predict hemodynamic instability at least two hours before a major clinical intervention (e.g., vasopressor administration), while maintaining a low false alert rate. From the MIMIC II database, containing ICU minute-by-minute heart rate (HR) and invasive arterial blood pressure (BP) monitoring trend data collected between 2001 and 2005, we identified 132 stable and 104 unstable patients that met our stability-instability criteria and had sufficient data points. We first derived additional physiological parameters of shock index, rate pressure product, heart rate variability, and two measures of trending based on HR and BP. Then we developed 220 statistical features and systematically selected a small set to use for classification. We applied multi-variable logistic regression modeling to do classification and implemented validation via bootstrapping. Area under receiver-operating curve (ROC) 0.83+/-0.03, sensitivity 0.75+/-0.06, and specificity 0.80+/-0.07; if the specificity is targeted at 0.90, then the sensitivity is 0.57+/-0.07. Based on our preliminary results, we conclude that the algorithms we developed using HR and BP trend data may provide a promising perspective toward reliable predictive alerts for hemodynamically unstable patients.

  6. Mathematical modeling of renal hemodynamics in physiology and pathophysiology.

    Sgouralis, Ioannis; Layton, Anita T

    2015-06-01

    In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Effects of Dietary Nitrates on Systemic and Cerebrovascular Hemodynamics

    Vernon Bond

    2013-01-01

    Full Text Available Cerebral blood flow dysregulation is often associated with hypertension. We hypothesized that a beetroot juice (BRJ treatment could decrease blood pressure and cerebrovascular resistance (CVR. We subjected 12 healthy females to control and BRJ treatments. Cerebrovascular resistance index (CVRI, systolic blood pressure (SBP, total vascular resistance (TVR, and the heart rate-systolic pressure product (RPP measured at rest and at two exercise workloads were lower after the BRJ treatment. CVRI, SBP, and RPP were lower without a lower TVR at the highest exercise level. These findings suggest improved systemic and cerebral hemodynamics that could translate into a dietary treatment for hypertension.

  8. Cerebral hemodynamic and metabolic changes in fulminant hepatic failure

    Fernando Mendes Paschoal Junior

    Full Text Available ABSTRACT Intracranial hypertension and brain swelling are a major cause of morbidity and mortality of patients suffering from fulminant hepatic failure (FHF. The pathogenesis of these complications has been investigated in man, in experimental models and in isolated cell systems. Currently, the mechanism underlying cerebral edema and intracranial hypertension in the presence of FHF is multi-factorial in etiology and only partially understood. The aim of this paper is to review the pathophysiology of cerebral hemodynamic and metabolism changes in FHF in order to improve understanding of intracranial dynamics complication in FHF.

  9. Automated analysis of plethysmograms for functional studies of hemodynamics

    Zatrudina, R. Sh.; Isupov, I. B.; Gribkov, V. Yu.

    2018-04-01

    The most promising method for the quantitative determination of cardiovascular tone indicators and of cerebral hemodynamics indicators is the method of impedance plethysmography. The accurate determination of these indicators requires the correct identification of the characteristic points in the thoracic impedance plethysmogram and the cranial impedance plethysmogram respectively. An algorithm for automatic analysis of these plethysmogram is presented. The algorithm is based on the hard temporal relationships between the phases of the cardiac cycle and the characteristic points of the plethysmogram. The proposed algorithm does not require estimation of initial data and selection of processing parameters. Use of the method on healthy subjects showed a very low detection error of characteristic points.

  10. Portal hemodynamics in chronic portal-systemic encephalopathy

    Takashi, Motohide; Igarashi, Masahiko; Hino, Shinichi; Takayasu, Kenichi; Goto, Nobuaki; Musha, Hirotaka; Ohnishi, Kunihiko; Okuda, Kunio

    1985-01-01

    A portal hemodynamic study was made in 7 consecutive patients with chronic portal-systemic encephalopathy by percutaneous transhepatic catheterization of the portal vein and injecting contrast medium into the superior mesenteric vein or by superior mesenteric arterial portography in comparison with patients without encephalopathy studied by percutaneous catheterization of these veins. It is suggested that chronic portal-systemic encephalopathy is a result of a large collateral route shunting a large proportion of the superior mesenteric venous blood into systemic circulation, and that development of such collaterals precludes formation of large esophageal varices. (Auth.)

  11. A sliding mode observer for hemodynamic characterization under modeling uncertainties

    Zayane, Chadia

    2014-06-01

    This paper addresses the case of physiological states reconstruction in a small region of the brain under modeling uncertainties. The misunderstood coupling between the cerebral blood volume and the oxygen extraction fraction has lead to a partial knowledge of the so-called balloon model describing the hemodynamic behavior of the brain. To overcome this difficulty, a High Order Sliding Mode observer is applied to the balloon system, where the unknown coupling is considered as an internal perturbation. The effectiveness of the proposed method is illustrated through a set of synthetic data that mimic fMRI experiments.

  12. BRAD: Software for BRain Activity Detection from hemodynamic response

    Pidnebesna, Anna; Tomeček, David; Hlinka, Jaroslav

    2018-01-01

    Roč. 156, March (2018), s. 113-119 ISSN 0169-2607 R&D Projects: GA ČR GA13-23940S; GA ČR GA17-01251S; GA ČR GA13-23940S Grant - others:GA MŠk(CZ) LO1611 Institutional support: RVO:67985807 Keywords : deconvolution methods * functional magnetic resonance imaging * hemodynamic response * neuronal activity estimation * Wiener filtering Subject RIV: JC - Computer Hardware ; Software Impact factor: 2.503, year: 2016

  13. Compromise and Toleration

    Rostbøll, Christian F.

    Political compromise is akin to toleration, since both consist of an "agreement to disagree." Compromise and toleration also share a predicament of being regarded as ambiguous virtues that require of us to accept something we actually regard as wrong. However, we misunderstand the nature, justifi...... in compromise are more stringent than those for being tolerated. Still, the limits of compromise cannot be drawn to narrowly if it is to remain its value as a form of agreement that respects and embodies the differences of opinion in society.......Political compromise is akin to toleration, since both consist of an "agreement to disagree." Compromise and toleration also share a predicament of being regarded as ambiguous virtues that require of us to accept something we actually regard as wrong. However, we misunderstand the nature......, justification, and limits of compromise if we see it merely as a matter of toleration. While toleration is mainly a matter of accepting citizens' equal right to co-existence as subjects to law, political compromise includes the parties in making law – it makes them co-authors of law. Toleration entails...

  14. Tolerances in micro manufacturing

    Hansen, Hans Nørgaard; Zhang, Yang; Islam, Aminul

    This paper describes a method for analysis of tolerances in micro manufacturing. It proposes a mapping oftolerances to dimensions and compares this with current available international standards. The analysisdocuments that tolerances are not scaled down as the absolute dimension. In practice...

  15. Fault tolerant computing systems

    Randell, B.

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (orig.)

  16. Toleration out of respect?

    Lægaard, Sune

    2014-01-01

    be based on a modus vivendi designed to secure peaceful co-existence, but should be based on moral reasons. Forst therefore advances what he calls the ‘respect conception’ of toleration as an in itself morally desirable type of relationship, which is furthermore the only conception of toleration...

  17. Recognition and Toleration

    Lægaard, Sune

    2010-01-01

    Recognition and toleration are ways of relating to the diversity characteristic of multicultural societies. The article concerns the possible meanings of toleration and recognition, and the conflict that is often claimed to exist between these two approaches to diversity. Different forms or inter...

  18. Risk factors of HIV-1 vertical transmission (VT) and the influence of antiretroviral therapy (ART) in pregnancy outcome.

    Barral, Maria F M; de Oliveira, Gisele R; Lobato, Rubens C; Mendoza-Sassi, Raul A; Martínez, Ana M B; Gonçalves, Carla V

    2014-01-01

    In the absence of intervention, the rate of vertical transmission of HIV can range from 15-45%. With the inclusion of antiretroviral drugs during pregnancy and the choice of delivery route this amounts to less than 2%. However ARV use during pregnancy has generated several questions regarding the adverse effects of the gestational and neonatal outcome. This study aims to analyze the risk factors for vertical transmission of HIV-1 seropositive pregnant women living in Rio Grande and the influence of the use of ARVs in pregnancy outcome. Among the 262 pregnant women studied the rate of vertical transmission of HIV was found to be 3.8%. Regarding the VT, there was a lower risk of transmission when antiretroviral drugs were used and prenatal care was conducted at the referral service. However, the use of ART did not influence the outcome of pregnancy. However, initiation of prenatal care after the first trimester had an influence on low birth weight, as well as performance of less than six visits increased the risk of prematurity. Therefore, the risk factors analyzed in this study appear to be related to the realization of inadequate pre-natal and maternal behavior.

  19. RISK FACTORS OF HIV-1 VERTICAL TRANSMISSION (VT AND THE INFLUENCE OF ANTIRETROVIRAL THERAPY (ART IN PREGNANCY OUTCOME

    Maria F.M. Barral

    2014-04-01

    Full Text Available In the absence of intervention, the rate of vertical transmission of HIV can range from 15-45%. With the inclusion of antiretroviral drugs during pregnancy and the choice of delivery route this amounts to less than 2%. However ARV use during pregnancy has generated several questions regarding the adverse effects of the gestational and neonatal outcome. This study aims to analyze the risk factors for vertical transmission of HIV-1 seropositive pregnant women living in Rio Grande and the influence of the use of ARVs in pregnancy outcome. Among the 262 pregnant women studied the rate of vertical transmission of HIV was found to be 3.8%. Regarding the VT, there was a lower risk of transmission when antiretroviral drugs were used and prenatal care was conducted at the referral service. However, the use of ART did not influence the outcome of pregnancy. However, initiation of prenatal care after the first trimester had an influence on low birth weight, as well as performance of less than six visits increased the risk of prematurity. Therefore, the risk factors analyzed in this study appear to be related to the realization of inadequate pre-natal and maternal behavior.

  20. Remember Tolerance Differently

    Tønder, Lars

    2012-01-01

    This essay questions the linear conception of history which often accompanies the way contemporary democratic theory tends to disavow tolerance's discontinuities and remainders. In the spirit of Foucault's genealogy of descent, the idea is to develop a new sense of tolerance's history, not by inv......This essay questions the linear conception of history which often accompanies the way contemporary democratic theory tends to disavow tolerance's discontinuities and remainders. In the spirit of Foucault's genealogy of descent, the idea is to develop a new sense of tolerance's history......, not by invoking a critique external to contemporary democratic theory, but by witnessing the history of tolerance paraliptically, with an eye to what it obscures and yet presupposes....

  1. [Effects of captopril on hemodynamics, gas exchange and exercise capacity in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease].

    Paitl, C E; Nery, L E; Romaldini, H; Herrmann, J L; Portugal, O P; dos Santos, M L; Martinez Filho, E E

    1989-02-01

    Captopril, a potent inhibitor of angiotensin converting enzyme, was tested in patients with COPD (means forced expired volume in the first second--FEV1 = 0.73 l) and pulmonary hypertension (PAP = 41.3 mmHg). In the first phase of the experiment, patients underwent and incremental exercise test to the limit of tolerance. These were double blind, randomized, cross-over studies, where the patients received oral placebo (Pl) or captopril (Cp) 25 mg, on different days. In a second phase, the patients were submitted to hemodynamic and gasometric studies in the supine position, before placebo, the 60 min after and immediately after exercise (cycling-like leg movements). After 30 min of rest the same protocol was repeated with oral administration of 25 mg of captopril. In the metabolic evaluation (cycloergometry) captopril increased significantly exercise tolerance (means VO2-uptake at maximal exercise: CP = 0.81 vs Pl = 0.73 1/min), associated with a slower heart rate and higher O2-pulse at maximal exercise. In the hemodynamic study, when the effects of Cp and Pl were compared, the mean values of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were similar at rest, but significantly lower during exercise, after captopril (means PAP Cp = 41.3 vs Pl = 51.2 mmHg; XPVR Cp = 278 vs Pl = 392 dyn. sec. cm5). There were similar systemic hemodynamic effects after Cp, but these were more intense in the pulmonary circulation (lower PVR/SVR ratio post-Cp in relation to post-Pl, during exercise). The cardiac index, systemic O2 transport and arterial and mixed venous blood gases were similar at rest and during exercise, with Pl or Cp.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Hemodynamic measurement using four-dimensional phase-contrast MRI: Quantification of hemodynamic parameters and clinical applications

    Ha, Ho Jin; Lee, Sang Joon [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang (Korea, Republic of); Kim, Guk Bae; Kweon, Ji Hoon; Kim, Young Hak; Lee, Deok Hee; Yang, Dong Hyun; KIm, Nam Kug [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2016-07-15

    Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.

  3. Hemodynamic Measurement Using Four-Dimensional Phase-Contrast MRI: Quantification of Hemodynamic Parameters and Clinical Applications

    Ha, Hojin [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Kim, Guk Bae [Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Kweon, Jihoon [Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Lee, Sang Joon [POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Kim, Young-Hak [Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Lee, Deok Hee; Yang, Dong Hyun [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Kim, Namkug [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of); Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of)

    2016-11-01

    Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.

  4. Brain Electrodynamic and Hemodynamic Signatures Against Fatigue During Driving

    Chun-Hsiang Chuang

    2018-03-01

    Full Text Available Fatigue is likely to be gradually cumulated in a prolonged and attention-demanding task that may adversely affect task performance. To address the brain dynamics during a driving task, this study recruited 16 subjects to participate in an event-related lane-departure driving experiment. Each subject was instructed to maintain attention and task performance throughout an hour-long driving experiment. The subjects' brain electrodynamics and hemodynamics were simultaneously recorded via 32-channel electroencephalography (EEG and 8-source/16-detector functional near-infrared spectroscopy (fNIRS. The behavior performance demonstrated that all subjects were able to promptly respond to lane-deviation events, even if the sign of fatigue arose in the brain, which suggests that the subjects were fighting fatigue during the driving experiment. The EEG event-related analysis showed strengthening alpha suppression in the occipital cortex, a common brain region of fatigue. Furthermore, we noted increasing oxygenated hemoglobin (HbO of the brain to fight driving fatigue in the frontal cortex, primary motor cortex, parieto-occipital cortex and supplementary motor area. In conclusion, the increasing neural activity and cortical activations were aimed at maintaining driving performance when fatigue emerged. The electrodynamic and hemodynamic signatures of fatigue fighting contribute to our understanding of the brain dynamics of driving fatigue and address driving safety issues through the maintenance of attention and behavioral performance.

  5. HEMODYNAMIC AND LACTIC ACID RESPONSES TO PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION EXERCISE

    Zuhal Gültekin

    2006-09-01

    Full Text Available The hemodynamic and metabolic responses to proprioceptive neuromuscular facilitation (PNF exercise were examined in 32 male university students (aged 19-28 years. Ten repetitions of PNF exercises were applied to the subjects' dominant upper extremities in the following order: as an agonist pattern flexion, adduction and external rotation; and as an antagonist pattern extension, abduction and internal rotation. Heart rate (HR, systolic blood pressure (SBP, diastolic blood pressure (DBP, double product (DP, and blood lactate concentration (La were determined before, immediately after, and at 1st, 3rd, and 5th minutes after PNF exercise. A one-way ANOVA with repeated measures indicated significant differences in HR, SBP, DBP, DP and La immediately after PNF exercise. HR increased from 81 (±10 to 108 (±15 b·min-1 (p < 0.01, SBP increased from 117 (±10 to 125 (±11 mmHg (p < 0.01, DBP increased from 71 (±10 to 75 (±8 mmHg (p < 0.01, DP increased from 96 (±16 to 135 (±24 (p < 0.01, and La increased from 0.69 (±0.31 to 3.99 (±14.63 mmol·L-1 (p < 0.01. Thus PNF exercise resulted in increased hemodynamic responses and blood lactate concentration that indicate a high strain on the cardiovascular system and anaerobic metabolism in healthy subjects

  6. EVALUATION OF DEXMEDETOMIDINE ON HEMODYNAMICS IN PATIENTS UNDERGOING LAPAROSCOPIC CHOLECYSTECTOMY

    Penchalaiah

    2015-09-01

    Full Text Available BACKGROUND: Dexmedetomidine a newer generation highly selective alpha - 2 adrenergic agonist are well known to inhibit catecholamine release. The present study compares the effects of intravenously administered dexmedetomidine to attenuate hemodynamic response to pneumoperitoneum to laparoscopic cholecystectomy under general anaesthesia. METHODOLOGY: 60 patients ASA Physical status I and II, aged between 18 and 50 years of either sex, scheduled for elective laparoscopic cholecy stectomy were randomized in to 2 groups ( group D and S inn a double blind fashion to receive either Dexmedetomidine ( 1microgram/kg in 100ml of 0.9% normal saline or only 0.9%plain normal saline respectively. It is given 30 min prior to induction. Patient vitals like HR, SBP, DBP, MAP were monitored during the study at various time intervals. RESULTS: Following intubation and pneumoperitoneum there significant rise in HR, MAP, SBP, DBP in group S but no significant rise in Group D. CONCLUSION: Dexmedetomid ine given in a dose of 1microgram/kg as a premedication is e ffective in attenuating the hemodynamic responses in laparoscopic surgery

  7. The Effect of Hemodynamics on Cerebral Aneurysm Morphology

    Metcalfe, Ralph; Mantha, Aishwarya; Karmonik, Christof; Strother, Charles

    2004-11-01

    One of the difficulties in applying principles of hemodynamics to the study of blood flow in aneurysms are the drastic variations in possible shape of both the aneurysms and the parent arteries in the region of interest. We have taken data from three para-opthalmic internal carotid artery aneurysms using 3D-digital subtraction angiography (3D-DSA) and performed CFD simulations of steady and unsteady flows through the three different cases using the same pressure gradients and pulsatile flow waveforms (based on the Ku model for flow through the Carotid bifurcation). We have found that the total pressure differential within the aneurysms is consistent with the direction of flow, and that the dynamic pressure gradient within the aneurysm is very small compared with the static pressure variations. Wall shear stresses were highest near regions of sharp arterial curvature, but always remained low inside the aneurysm. These results suggest a more complex role for hemodynamics in aneurysm generation, growth and rupture.

  8. Study of retrobulbar hemodynamics in diabetes via color doppler ultrasound

    Wei Chen

    2014-09-01

    Full Text Available AIM: To explore the changes of retrobulbar hemodynamics in diabetes via color doppler ultrasound. METHODS: Totally 80 patients(160 eyeswith eye diseases in type 2 diabetes from June 2010 to May 2013 in our hospital were enrolled as research group. By fundus photography and direct ophthalmoscopy, patients were assigned to diabetes without retinopathy group(DNR subgroup, non-proliferative diabetic retinopathy group(NPDR subgroupand proliferative diabetic retinopathy group(PDR subgroup. Of 60 healthy patients(120 eyesover the same period were chosen as control group. The doppler parameters of central retinal artery(CRA, posterior ciliary artery(PCAand ophthalmic artery(OAwere measured.RESULTS: There were significant differences on circulatory parameters of CRA, PCA and OA between both groups(PPPCONCLUSION: The monitoring of retinal blood flow and analysis of blood spectrum morphology via color doppler ultrasound can effectively evaluate the degree of diabetic retinopathy lesions, especially before DR vascular disease. Early detection can reveal the hemodynamic change pattern of DR, facilitating the prevention of diabetic eye complications and improvement of the quality of life.

  9. Optimal hemodynamic response model for functional near-infrared spectroscopy

    Muhammad Ahmad Kamran

    2015-06-01

    Full Text Available Functional near-infrared spectroscopy (fNIRS is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650-950 nm wavelengths. The cortical hemodynamic response (HR differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF is modeled by using two Gamma functions with six unknown parameters. The HRF model is supposed to be linear combination of HRF, baseline and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown. An objective function is developed as a square of the residuals with constraints on twelve free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using ten real and fifteen simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis, i.e., (t-value >tcritical and p-value < 0.05.

  10. Complex Coronary Hemodynamics - Simple Analog Modelling as an Educational Tool.

    Parikh, Gaurav R; Peter, Elvis; Kakouros, Nikolaos

    2017-01-01

    Invasive coronary angiography remains the cornerstone for evaluation of coronary stenoses despite there being a poor correlation between luminal loss assessment by coronary luminography and myocardial ischemia. This is especially true for coronary lesions deemed moderate by visual assessment. Coronary pressure-derived fractional flow reserve (FFR) has emerged as the gold standard for the evaluation of hemodynamic significance of coronary artery stenosis, which is cost effective and leads to improved patient outcomes. There are, however, several limitations to the use of FFR including the evaluation of serial stenoses. In this article, we discuss the electronic-hydraulic analogy and the utility of simple electrical modelling to mimic the coronary circulation and coronary stenoses. We exemplify the effect of tandem coronary lesions on the FFR by modelling of a patient with sequential disease segments and complex anatomy. We believe that such computational modelling can serve as a powerful educational tool to help clinicians better understand the complexity of coronary hemodynamics and improve patient care.

  11. Hemodynamic transition driven by stent porosity in sidewall aneurysms.

    Bouillot, Pierre; Brina, Olivier; Ouared, Rafik; Lovblad, Karl-Olof; Farhat, Mohamed; Pereira, Vitor Mendes

    2015-05-01

    The healing process of intracranial aneurysms (IAs) treated with flow diverter stents (FDSs) depends on the IA flow modifications and on the epithelization process over the neck. In sidewall IA models with straight parent artery, two main hemodynamic regimes with different flow patterns and IA flow magnitude were broadly observed for unstented and high porosity stented IA on one side, and low porosity stented IA on the other side. The hemodynamic transition between these two regimes is potentially involved in thrombosis formation. In the present study, CFD simulations and multi-time lag (MTL) particle imaging velocimetry (PIV) measurements were combined to investigate the physical nature of this transition. Measurable velocity fields and non-measurable shear stress and pressure fields were assessed experimentally and numerically in the aneurysm volume in the presence of stents with various porosities. The two main regimes observed in both PIV and CFD showed typical flow features of shear and pressure driven regimes. In particular, the waveform of the averaged IA velocities was matching both the shear stress waveform at IA neck or the pressure gradient waveform in parent artery. Moreover, the transition between the two regimes was controlled by stent porosity: a decrease of stent porosity leads to an increase (decrease) of pressure differential (shear stress) through IA neck. Finally, a good PIV-CFD agreement was found except in transitional regimes and low motion eddies due to small mismatch of PIV-CFD running conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Life Satisfaction and Hemodynamic Reactivity to Mental Stress.

    Schwerdtfeger, Andreas; Gaisbachgrabner, Kerstin; Traunmüller, Claudia

    2017-06-01

    Satisfaction with life has been considered a health-protective variable, which could impact cardiovascular morbidity and mortality. However, few studies have examined the physiological pathways involved in the potentially salutary effect of life satisfaction. It was hypothesized that life satisfaction should be associated with a cardiovascular response profile that signals challenge (i.e., higher cardiac output, lower peripheral resistance), rather than threat during a mental stress task. A sample of 75 healthy, medication-free men without clinical signs of psychological disorders who worked full-time and occupied highly demanding positions participated in this study. They performed two mental stress tasks (n-back) with varying degrees of difficulty. The tasks were embedded between a baseline and a recovery period. Cardiovascular and hemodynamic variables (heart rate, blood pressure, cardiac output, total peripheral resistance) were recorded by means of impedance cardiography. Individuals who were more satisfied with their life displayed higher cardiac output and lower peripheral resistance levels during the stress tasks, indicating a challenge rather than a threat profile. Findings were robust when controlled for physical activity, smoking, age, and depressive symptoms. Life satisfaction could be positively correlated with beneficial hemodynamic stress reactivity, indicating that individuals with higher levels of life satisfaction can more adaptively cope with stress. Increased cardiac output and decreased peripheral resistance during stress may constitute one route through which life satisfaction can benefit health.

  13. A Multirelational Account of Toleration

    Ferretti, Maria Paola; Lægaard, Sune

    2013-01-01

    Toleration classically denotes a relation between two agents that is characterised by three components: objection, power, and acceptance overriding the objection. Against recent claims that classical toleration is not applicable in liberal democracies and that toleration must therefore either be ...

  14. Hemodynamic control of in patients with concomitant hypertensive disease during brain aneurysm clipping

    Dzyuba, D.O.; Melnik, A.F.; Yavorsky, F.A.

    2018-01-01

    The article describes the state of the problem of hemodynamic control during brain aneurysm clipping in concomitant hypertensive disease. Author studies hemodynamic control by using magnesia therapy with the addition of clonidine solution and infusion of urapidil solution. Based on the results of the study, the advantages of urapidil infusion are given.

  15. Differential hemodynamic effects of exercise and volume expansion in people with and without heart failure

    Andersen, Mads Jønsson; Olson, Thomas P; Melenovsky, Vojtech

    2015-01-01

    BACKGROUND:Invasive hemodynamic exercise testing is commonly used in the evaluation of patients with suspected heart failure with preserved ejection fraction (HFpEF) or pulmonary hypertension. Saline loading has been suggested as an alternative provocative maneuver, but the hemodynamic changes...

  16. Impact of Diversity of Morphological Characteristics and Reynolds number on Local Hemodynamics in Basilar Aneurysms

    Rafat, Marjan; Dabagh, Mahsa; Heller, Martin

    2018-01-01

    management. Existing aneurysm hemodynamics studies generally evaluate limited geometries or Reynolds numbers (Re), which are difficult to apply to a wide range of patient-specific cases. We focused on the association between hemodynamic characteristics and morphology. We assessed several two-dimensional (2D...

  17. Journal of Clinical Monitoring and Computing 2015 end of year summary : cardiovascular and hemodynamic monitoring

    Bendjelid, Karim; Rex, Steffen; Scheeren, Thomas; Saugel, Bernd

    Hemodynamic monitoring is essential in critically ill patients. In this regard, the Journal of Clinical Monitoring and Computing (JCMC) has become an ideal platform for publishing cardiovascular and hemodynamic monitoring-related research, as reflected by an increasing number of articles related to

  18. Year in review in journal of clinical monitoring and computing 2014 : cardiovascular and hemodynamic monitoring

    Bendjelid, Karim; Rex, Steffen; Scheeren, Thomas; Critchley, Lester

    Hemodynamic instability is a common sign in critically ill patients and its importance has been increasingly recognized during the last 20 years. Indeed, It is now appreciated that an adequate hemodynamic monitoring associated to reactive vigorous therapy is able to decrease the present ominous

  19. Encephalic hemodynamic phases in subarachnoid hemorrhage: how to improve the protective effect in patient prognoses

    Marcelo de Lima Oliveira

    2015-01-01

    Full Text Available Subarachnoid hemorrhage is frequently associated with poor prognoses. Three different hemodynamic phases were identified during subarachnoid hemorrhage: oligemia, hyperemia, and vasospasm. Each phase is associated with brain metabolic changes. In this review, we correlated the hemodynamic phases with brain metabolism and potential treatment options in the hopes of improving patient prognoses.

  20. Fermented ginseng, GBCK25, ameliorates hemodynamic function on experimentally induced myocardial injury

    Adithan Aravinthan

    2016-10-01

    Full Text Available In the present study, we investigated whether treatment with GBCK25 facilitated the recovery of hemodynamic parameters, left ventricle systolic pressure, left ventricular developed pressure, and electrocardiographic changes. GBCK25 significantly prevented the decrease in hemodynamic parameters and ameliorated the electrocardiographic abnormality. These results indicate that GBCK25 has distinct cardioprotective effects in rat heart.

  1. Short-term vascular hemodynamic responses to isometric exercise in young adults and in the elderly

    Hartog, R. (Renee); D. Bolignano (Davide); E.J.G. Sijbrands (Eric); Pucci, G. (Giacomo); F.U.S. Mattace Raso (Francesco)

    2018-01-01

    textabstractBackground: Vascular aging is known to induce progressive stiffening of the large elastic arteries, altering vascular hemodynamics under both rest and stress conditions. In this study, we aimed to investigate changes in vascular hemodynamics in response to isometric handgrip exercise

  2. Some hemodynamic changes in the organism following exposure to X-and gamma-radiation

    Bliznakov, V; Mikhailov, A [Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya

    1982-01-01

    The hemodynamic response to dosed exercise of 705 physicians, nurses, roentgen technicians and hospital attendants, working with X-ray diagnostic and therapeutic devices, was studied. The doses received on professional irradiation proved to be below the threshold ones. A significantly increased incidence was recorded in cases of atonic hemodynamic response, mainly in medical workers, employed in X-ray departments.

  3. Use of lignocaine or nitroglycerine for blunting of hemodynamic stress response during electroconvulsive therapy

    Muhammad Umar Zahoor

    2014-01-01

    Conclusion: NTG provided more hemodynamic stability in post-ECT period as compared to lignocaine which only prevented a surge in HR without any effect on MAP. We conclude that NTG can safely be instituted for anaesthesia in ECT patients for prevention of hemodynamic stress response.

  4. [Effect of complex sanatorium treatment including magnetotherapy on hemodynamics in patients with arterial hypertension].

    Efremushkin, G G; Duruda, N V

    2003-01-01

    Forty nine patients with arterial hypertension of stage I-II received combined sanatorium treatment. Of them, 21 had adjuvant total magnetotherapy. All the patients were examined for parameters of central, cerebral hemodynamics and microcirculation. The adjuvant magnetotherapy produced a beneficial effect on hypertension: clinical symptoms attenuated, arterial pressure became more stable, hemodynamics improved, duration of hospitalization reduced, requirement in hypotensive drugs diminished.

  5. Novel Use of a Noninvasive Hemodynamic Monitor in a Personalized, Active Learning Simulation

    Zoller, Jonathan K.; He, Jianghua; Ballew, Angela T.; Orr, Walter N.; Flynn, Brigid C.

    2017-01-01

    The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical…

  6. A Microbiomic Analysis in African Americans with Colonic Lesions Reveals Streptococcus sp.VT162 as a Marker of Neoplastic Transformation

    Hassan Brim

    2017-11-01

    Full Text Available Increasing evidence suggests a role of the gut microbiota in colorectal carcinogenesis (CRC. To detect bacterial markers of colorectal cancer in African Americans a metabolomic analysis was performed on fecal water extracts. DNA from stool samples of adenoma and healthy subjects and from colon cancer and matched normal tissues was analyzed to determine the microbiota composition (using 16S rDNA and genomic content (metagenomics. Metagenomic functions with discriminative power between healthy and neoplastic specimens were established. Quantitative Polymerase Chain Reaction (q-PCR using primers and probes specific to Streptococcus sp. VT_162 were used to validate this bacterium association with neoplastic transformation in stool samples from two independent cohorts of African Americans and Chinese patients with colorectal lesions. The metabolomic analysis of adenomas revealed low amino acids content. The microbiota in both cancer vs. normal tissues and adenoma vs. normal stool samples were different at the 16S rRNA gene level. Cross-mapping of metagenomic data led to 9 markers with significant discriminative power between normal and diseased specimens. These markers identified with Streptococcus sp. VT_162. Q-PCR data showed a statistically significant presence of this bacterium in advanced adenoma and cancer samples in an independent cohort of CRC patients. We defined metagenomic functions from Streptococcus sp. VT_162 with discriminative power among cancers vs. matched normal and adenomas vs. healthy subjects’ stools. Streptococcus sp. VT_162 specific 16S rDNA was validated in an independent cohort. These findings might facilitate non-invasive screening for colorectal cancer.

  7. State, religion and toleration

    Huggler, Jørgen

    2009-01-01

    Contribution to Religion and State - From separation to cooperation? Legal-philosophical reflections for a de-secularized world. (IVR Cracow Special Workshop). Eds. Bart. C. Labuschagne & Ari M. Solon. Abstract: Toleration is indeed a complex phenomenon. A discussion of the concept will have...... to underline not only the broadmindedness and liberty of individuals or of groups, but also the relevant distinctions and arguments in political philosophy, epistemology, philosophy of religion and philosophical anthropology and their connection with educational issues. Through a discussion of these relations......, the essay argues three theses: (1) Toleration is not reducible to an ethics of spiritual freedom. (2) Toleration is not neutral to fanatism. (3) Toleration involves esteem for the person....

  8. A Theory of Tolerance

    Corneo, Giacomo; Jeanne, Olivier

    2006-01-01

    We develop an economic theory of tolerance where styles of behaviour are invested with symbolic value. Value systems are endogenous and taught by parents to their children. In conjunction with actual behaviour, value systems determine the esteem enjoyed by individuals. Intolerant individuals have all symbolic value invested in a single style of behaviour, whereas tolerant people have diversified values. The proposed model identifies a link between the unpredictability of children's lifestyles...

  9. Studies on the Hemodynamic Change in Cirrhosis of the Liver

    Kim, Jung Il; Lee, Jung Sang; Koh, Chang Soon

    1970-01-01

    Cardiac output, plasma volume and renal plasma flow were determined to evaluate hemodynamic changes in 29 patients with cirrhosis of the liver. The results obtained were as follows. 1) The mean plasma volume was 3793±895 ml and it was significantly higher than the normal controls. The mean blood volume (5266±1222 ml) and blood volume per kg body weight (95.7±23.41 ml) were also increased significantly. The mean plasma volume per kg body weight (69.1±19.1 ml) showed increased tendency and the mean difference between blood volume and plasma volume per kg body weight (26.4±7.05 ml) was in lower limit of normal range. 2) The mean cardiac output was 7708±2652 ml/min and it was significantly increased. The mean cardiac index (4924±1998 ml/min/M 2 ), stroke volume (96.2±34.2 ml/beat), stroke index (62.3±27.34 ml/beat/M 2 ) and fractional cardiac index (1.54±0.577) were also increased significantly. The mean total peripheral resistance was 1664±753.8 dynes sec cm -5 M 2 and it was significantly lower than the normal controls. 3) The mean renal plasma flow was 537±146.8 ml/min/1.73M 2 and it was normal to decreased tendency. The mean endogenous creatinine clearance (66.7±23.0 ml/min/1.73M 2 ) was significantly decreased. Filtration fraction was variable, but it was slightly lower than normal in most cases. The mean renal fraction of cardiac output (11.4±6.27%) was relatively decreased. 4) Although renal plasma flow was normal or decreased in general, it was definitely diminished in patients with creatinine clearance less than 60 ml/min/1.73M 2 , resistant ascites, and signs of azotemia (elevated BUN and serum creatinine). 5) Diminished glomerular filtration rate with low filtration fraction and decreased renal fraction of cardiac output observed strongly supported increased renal afferent arteriolar resistance. 6) Renal circulatory impairment preceded azotemia or oroliguria in cirrhosis. 7) Clinical findings and liver function were not correlated with

  10. Diastolic pressure underestimates age-related hemodynamic impairment.

    Galarza, C R; Alfie, J; Waisman, G D; Mayorga, L M; Cámera, L A; del Río, M; Vasvari, F; Limansky, R; Farías, J; Tessler, J; Cámera, M I

    1997-10-01

    It has been hypothesized that as large arteries become more rigid with age, the pattern of hypertension changes from diastolic to systolic. Thus, diastolic blood pressure (DBP) may lose its ability to reflect the increase in vascular resistance with age. To assess this, we studied the age-related changes in blood pressure pattern and its steady-state and pulsatile determinants. We performed an epidemiological analysis based on a national survey of 10,462 subjects from Argentina. A hemodynamic analysis (impedance cardiography) was then carried out in 636 consecutive hypertensive patients (age, 25 to 74 years). Whereas the rate of increment in the prevalence of mild to moderate hypertension (MMH) reached a plateau after the sixth decade, isolated and borderline systolic forms of hypertension began a steep and sustained rise. Among patients with MMH, DBP remained stable from the third to the seventh decade, whereas SBP maintained a sustained increase. Despite similar DBP, the systemic vascular resistance index increased 47% (P<.01) and the cardiac index decreased 27% (P<.01), whereas the ratio of stroke volume to pulse pressure, an index of arterial compliance, decreased 45% (P<.01). However, there were no significant differences between older patients with MMH and those with isolated systolic hypertension in the level of SBP, vascular resistance, stroke volume, and cardiac index. Compared with age-matched normotensive control subjects, the ratio of stroke volume to pulse pressure was much more reduced in isolated systolic hypertension (48%) than in MMH (30%). In summary, the present study, carried out in a large sample of hypertensive subjects with a wide age range, showed a simultaneous impairment in vascular resistance and arterial compliance associated with aging in different patterns of hypertension. The magnitude of these changes, with opposite effects on DBP but additive effects on SBP, suggests that a hemodynamic mechanism could determine the transition in the

  11. Estimating Hemodynamic Responses to the Wingate Test Using Thoracic Impedance

    Todd A. Astorino, Curtis Bovee, Ashley DeBoe

    2015-12-01

    Full Text Available Techniques including direct Fick and Doppler echocardiography are frequently used to assess hemodynamic responses to exercise. Thoracic impedance has been shown to be a noninvasive alternative to these methods for assessing these responses during graded exercise to exhaustion, yet its feasibility during supramaximal bouts of exercise is relatively unknown. We used thoracic impedance to estimate stroke volume (SV and cardiac output (CO during the Wingate test (WAnT and compared these values to those from graded exercise testing (GXT. Active men (n = 9 and women (n = 7 (mean age = 24.8 ± 5.9 yr completed two Wingate tests and two graded exercise tests on a cycle ergometer. During exercise, heart rate (HR, SV, and CO were continuously estimated using thoracic impedance. Repeated measures analysis of variance was used to identify potential differences in hemodynamic responses across protocols. Results: Maximal SV (138.6 ± 37.4 mL vs. 135.6 ± 26.9 mL and CO (24.5 ± 6.1 L·min-1 vs. 23.7 ± 5.1 L·min-1 were similar (p > 0.05 between repeated Wingate tests. Mean maximal HR was higher (p < 0.01 for GXT (185 ± 7 b·min-1 versus WAnT (177 ± 11 b·min-1, and mean SV was higher in response to WAnT (137.1 ± 32.1 mL versus GXT (123.0 ± 32.0 mL, leading to similar maximal cardiac output between WAnT and GXT (23.9 ± 5.6 L·min-1 vs. 22.5 ± 6.0 L·min-1. Our data show no difference in hemodynamic responses in response to repeated administrations of the Wingate test. In addition, the Wingate test elicits similar cardiac output compared to progressive cycling to VO2max.

  12. VT Lake Champlain Bathymetry

    Vermont Center for Geographic Information — (Link to Metadata) The ElevationDEM_LKCHDEM data layer includes bathymetric data derived NOAA nautical charts. All points were digitized from the RF 40,000 scale...

  13. VT Boundaries - state polygon

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  14. VT Boundaries - village polygons

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  15. VT Boundaries - LEPC polygons

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  16. VT Boundaries - county polygons

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  17. VT Boundaries - all lines

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  18. VT Wildlife Linkage Habitat

    Vermont Center for Geographic Information — (Link to Metadata) The Wildlife Linkage Habitat Analysis uses landscape scale data to identify or predict the location of potentially significant wildlife linkage...

  19. VT Wildlife Crossing Value

    Vermont Center for Geographic Information — (Link to Metadata) WCV describes the value of the Wildlife Habitat Suitability as it approaches the state highway system. This analysis was designed to use the...

  20. VT Boundaries - RPC polygons

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  1. VT ZIP Code Areas

    Vermont Center for Geographic Information — (Link to Metadata) A ZIP Code Tabulation Area (ZCTA) is a statistical geographic entity that approximates the delivery area for a U.S. Postal Service five-digit...

  2. VT Hospital Site Locations

    Vermont Center for Geographic Information — (Link to Metadata) This data layer contains point locations of all major community, regional, comprehensive health, and healthcare provider hospitals in the state of...

  3. VT Boundaries - town polygons

    Vermont Center for Geographic Information — (Link to Metadata) The BNDHASH dataset depicts Vermont villages, towns, counties, Regional Planning Commissions (RPC), and LEPC (Local Emergency Planning Committee)...

  4. VT Water Classifications

    Vermont Center for Geographic Information — The Vermont Water Quality Standards (VTWQS) are rules intended to achieve the goals of the Vermont Surface Water Strategy, as well as the objective of the federal...

  5. VT Existing Hydroelectric Sites

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  6. VT Telecommunication Facilities

    Vermont Center for Geographic Information — (Link to Metadata) The UtilityTelecom_TELEFAC data layer contains points which are intended to represent the location of telecommunications facilities (towers and/or...

  7. VT Designated Downtown Boundary

    Vermont Center for Geographic Information — Downtown designation provides communities with financial incentives, training and technical assistance to support local efforts to restore historic buildings,...

  8. VT Historic Preservation Grant

    Vermont Center for Geographic Information — The State-funded Historic Preservation Grant Program helps municipalities and non-profit organizations rehabilitate the historic buildings that are a vital part of...

  9. VT Potential Hydroelectric Sites

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  10. VT Biodiversity Project - Landforms

    Vermont Center for Geographic Information — (Link to Metadata) This is a raster (cell-based) dataset depicting landforms in Vermont. Cells are 30 meters. Landforms are topographic units of landscapes that...

  11. VT Roadside Historic Markers

    Vermont Center for Geographic Information — Roadside Historic Site Marker program has proven an effective way to commemorate Vermont’s many people, events, and places of regional, statewide, or national...

  12. VT Road Centerline

    Vermont Center for Geographic Information — (Link to Metadata)(User Guide)(Symbology layer files: aotclass_only.lyr aotclass_surfacetyp.lyr)The Vermont Road Centerline data layer (TransRoad_RDS) contains all...

  13. VT Senate Districts 2012

    Vermont Center for Geographic Information — (Link to Metadata) Vermont General Assembly is periodically re-apportioned to reflect the state's changing population patterns. The current apportionment process is...

  14. Efficient hemodynamic event detection utilizing relational databases and wavelet analysis

    Saeed, M.; Mark, R. G.

    2001-01-01

    Development of a temporal query framework for time-oriented medical databases has hitherto been a challenging problem. We describe a novel method for the detection of hemodynamic events in multiparameter trends utilizing wavelet coefficients in a MySQL relational database. Storage of the wavelet coefficients allowed for a compact representation of the trends, and provided robust descriptors for the dynamics of the parameter time series. A data model was developed to allow for simplified queries along several dimensions and time scales. Of particular importance, the data model and wavelet framework allowed for queries to be processed with minimal table-join operations. A web-based search engine was developed to allow for user-defined queries. Typical queries required between 0.01 and 0.02 seconds, with at least two orders of magnitude improvement in speed over conventional queries. This powerful and innovative structure will facilitate research on large-scale time-oriented medical databases.

  15. Radioprotection in the infirmary praxis in service of hemodynamic

    Flor, Rita de Cassia; Gelbcke, Francine Lima

    2011-01-01

    Qualitative study made in a hemodynamic service at Santa Catarina, Brazil, viewing to analyse the attitude of workers in infirmary related to the use of radioprotection measurements in interventionist procedures. A methodology of Labor Psycho dynamics was used through the observations, collective interviews and the document analysis. Totally it was realized 36 encounters, completed a total of 54 observation hours. The results have shown that the workers used defense strategies for justification the not use of some radioprotection measurements. Yet, become evident that the measurements related to the distance from the radiation source and the exposure time have not used sometimes, perhaps due to negligence. Finally, it was concluded that, some attitudes adopted by the workers referred to the lack of a continued educational program

  16. Intraoperative hemodynamic monitoring during liver transplantation: goals and devices

    Nissen, Peter; Frederiksen, H J; Secher, N H

    2010-01-01

    With the introduction of orthotopic liver transplantation (OLT) almost 40 years ago, changes in the cardiovascular system that manifest during the different phases of the operation combined, sometimes with massive hemorrhage in likely critically ill patients have been a challenge. Here hemodynamic...... monitoring of the patients during OLT is addressed with focus on maintaining the patients' central blood volume (CBV) and methods and devices that can serve that purpose are listed. It is considered that a stable CBV maintains cerebral blood flow and oxygenation and thereby the well-being of the patient......, while even a small reduction in blood pressure affects cerebral blood flow and oxygenation if it reflects a reduced CBV and thereby cardiac output. In that regard it is accepted that for the patient going through OLT cardiac output (~8 L/min-1) and also venous oxygen saturation (~85%) are larger than...

  17. Milrinone use for hemodynamic instability in patent ductus arteriosus ligation.

    Halliday, Matthew; Kavarana, Minoo; Ebeling, Myla; Kiger, James

    2017-03-01

    Determine if prophylactic milrinone improves cardiovascular or long-term clinical outcomes in preterm neonates who receive surgical patent ductus arteriosus (PDA) ligation. Retrospective review of 45 infants over a 4-year period that received a PDA ligation at one institution. Data were collected on morbidity and mortality outcomes for all infants as well as milrinone therapy perioperatively. Of the 45 infants that were studied 15 received milrinone in the perioperative period of PDA ligation and the remaining 30 infants did not receive milrinone. The use of milrinone showed no statistically significant improvement in acute markers of hemodynamic stability. There was also no statistically significant difference in morbidity and mortality outcomes in milrinone group compared to the non-milrinone group. Prophylactic milrinone use for premature infants following PDA ligation does not show a significant cardiovascular or long-term clinical benefit.

  18. Hemodynamic signals of mixed messages during a social exchange.

    Zucker, Nancy L; Green, Steven; Morris, James P; Kragel, Philip; Pelphrey, Kevin A; Bulik, Cynthia M; LaBar, Kevin S

    2011-06-22

    This study used functional magnetic resonance imaging to characterize hemodynamic activation patterns recruited when the participants viewed mixed social communicative messages during a common interpersonal exchange. Mixed messages were defined as conflicting sequences of biological motion and facial affect signals that are unexpected within a particular social context (e.g. observing the reception of a gift). Across four social vignettes, valenced facial expressions were crossed with rejecting and accepting gestures in a virtual avatar responding to presentation of a gift from the participant. The results indicate that conflicting facial affect and gesture activated superior temporal sulcus, a region implicated in expectancy violations, as well as inferior frontal gyrus and putamen. Scenarios conveying rejection differentially activated the insula and putamen, regions implicated in embodied cognition, and motivated learning, as well as frontoparietal cortex. Characterizing how meaning is inferred from integration of conflicting nonverbal communicative cues is essential to understand nuances and complexities of human exchange.

  19. Ocular hemodynamics in patients with rhegmatogenous retinal detachment

    N. H. Zavgorodnya

    2014-10-01

    Full Text Available Aim. In case of retinal detachment atrophic processes lead to irreversible loss of functions within 4–6 days, it happens on underlying low ocular blood flow. In order to evaluate the degree of violation of regional hemodynamics in patients with retinal detachment two groups of patients were examined: the main group (52 patients with rhegmatogenous retinal detachment and the control group (24 myopic patients with lattice form of peripheral chorioretinal dystrophy. Methods and results. Doppler and reography results had been compared, significant decrease of blood flow in patients with retinal detachment was found. No differences between affected and fellow eye in these patients, close negative correlation between the level of ocular blood flow and the degree of myopia in the control group. Conclusion. This demonstrates the feasibility of actions to improve regional blood flow in patients operated on for retinal detachment.

  20. [Damage control in trauma patients with hemodynamic instability].

    Müller, Thorben; Doll, Dietrich; Kliebe, Frank; Ruchholtz, Steffen; Kühne, Christian

    2010-10-01

    The term "Damage-control" is borrowed from naval terminology. It means the initial control of a damaged ship. Because of the lethal triad in multiple injured patients the classical concept of definitive surgically therapy in the acute phase of the injury has a high rate of complications such as exsanguination, sepsis, heart failure and multiple organ failure. The core idea of the damage control concept was to minimize the additional trauma by surgical operations in these critical patients in the first phase. This means temporary control of a hemorrhage and measures for stopping abdominal contamination. After 24 - 48 hours in the intensive care unit and correction of physiological disturbances further interventions are performed for definitively treatment of the injuries. Summarized, the damage control strategy comprises an abbreviated operation, intensive care unit resuscitation, and a return to the operating room for the definitive operation after hemodynamic stabilisation of the patient. © Georg Thieme Verlag Stuttgart · New York.

  1. A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.

    Matteo Anselmino

    Full Text Available Clinical data indicating a heart rate (HR target during rate control therapy for permanent atrial fibrillation (AF and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model.The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running, considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations. To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8.Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77, while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56.The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.

  2. Metabolic and Hormonal Determinants of Glomerular Filtration Rate and Renal Hemodynamics in Severely Obese Individuals

    Edoardo Vitolo

    2016-10-01

    Full Text Available Objective: Renal function is often compromised in severe obesity. A true measurement of glomerular filtration rate (GFR is unusual, and how estimation formulae (EstForm perform in such individuals is unclear. We characterized renal function and hemodynamics in severely obese individuals, assessing the reliability of EstForm. Methods: We measured GFR (mGFR by iohexol plasma clearance, renal plasma flow (RPF by 123I-ortho-iodo-hippurate, basal and stimulated vascular renal indices, endothelium-dependent and -independent vasodilation using flow-mediated dilation (FMD as well as metabolic and hormonal profile in morbid, otherwise healthy, obese subjects. Results: Compared with mGFR, the better performing EstForm was CKD-EPI (5.3 ml/min/1.73 m2 bias by Bland-Altman analysis. mGFR was directly related with RPF, total and incremental glucose AUC, and inversely with PTH and h8 cortisol. Patients with mGFR below the median shown significantly higher PTH and lower vitamin D3. Basal or dynamic renal resistive index, FMD, pulse wave velocity were not related with mGFR. In an adjusted regression model, renal diameter and plasma flow remained related with mGFR (R2 = 0.67, accounting for 15% and 21% of mGFR variance, respectively. Conclusions: CKD-EPI formula should be preferred in morbid obesity; glucose increments during oral glucose tolerance test correlate with hyperfiltration; RPF and diameter are independent determinants of mGFR; slightly high PTH values, frequent in obesity, might influence mGFR.

  3. Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

    Woods, L.L.; Mizelle, H.L.; Montani, J.P.; Hall, J.E.

    1986-01-01

    Our purpose was to investigate the mechanisms by which increased plasma amino acids elevate renal blood flow (RBF) and glomerular filtration rate (GFR). Since transport of amino acids and Na + is linked in the proximal tubule, the authors hypothesized that increased amino acids might stimulate proximal tubular Na + reabsorption (PR/sub Na/) and thus increase RBF and GFR by a macula densa feedback mechanism. A solution of four amino acids (Ala, Ser, Gly, Pro) was infused intravenously into anesthetized dogs with normal kidneys (NK) and with kidneys in which the tubuloglomerular feedback mechanism was blunted by lowering renal artery pressure (LPK) or blocked by making the kidneys nonfiltering (NFK). In NK, RBF and GFR increased by 35 +/- 4% and 30 +/- 7% after 90 min of amino acid infusion, while PR/sub Na/ (estimated from lithium clearance) and O 2 consumption increased by 31 +/- 5% and 29 +/- 5% and distal Na + delivery remained relatively constant. Autoregulation of RBF and GFR in response to step deceases in renal artery pressure was impaired during amino acids in NK. The hemodynamic responses to amino acids were abolished in LPK and NFK. Infusion of the nonmetabolized α-aminoisobutyric acid into NK produced changes in renal hemodynamics that were similar to the responses observed with the four metabolizable amino acids. These data are consistent with the hypothesis that elevation of plasma amino acids increases RBF and GFR by a mechanism that requires an intact macula densa feedback. Metabolism of the amino acids does not appear to be necessary for these changes to occur

  4. Pulsatile flow effects on the hemodynamics of intracranial aneurysms.

    Le, Trung B; Borazjani, Iman; Sotiropoulos, Fotis

    2010-11-01

    High-resolution numerical simulations are carried out to systematically investigate the effect of the incoming flow waveform on the hemodynamics and wall shear stress patterns of an anatomic sidewall intracranial aneurysm model. Various wave forms are constructed by appropriately scaling a typical human waveform such that the waveform maximum and time-averaged Reynolds numbers, the Womersley number (α), and the pulsatility index (PI) are systematically varied within the human physiologic range. We show that the waveform PI is the key parameter that governs the vortex dynamics across the aneurysm neck and the flow patterns within the dome. At low PI, the flow in the dome is similar to a driven cavity flow and is characterized by a quasi-stationary shear layer that delineates the parent artery flow from the recirculating flow within the dome. At high PI, on the other hand, the flow is dominated by vortex ring formation, transport across the neck, and impingement and breakdown at the distal wall of the aneurysm dome. We further show that the spatial and temporal characteristics of the wall shear stress field on the aneurysm dome are strongly correlated with the vortex dynamics across the neck. We finally argue that the ratio between the characteristic time scale of transport by the mean flow across the neck and the time scale of vortex ring formation can be used to predict for a given sidewall aneurysm model the critical value of the waveform PI for which the hemodynamics will transition from the cavity mode to the vortex ring mode.

  5. Hemodynamic Effect of Laser Therapy in Spontaneously Hypertensive Rats

    Tomimura, Suely, E-mail: suelytomimura@uol.com.br [Programa de Pós-Graduação em Biofotônica em Ciências da Saúde da Universidade Nove de Julho (UNINOVE) (Brazil); Silva, Bianca Passos Assumpção [Programa de Graduação e Pós-Graduação em Medicina da UNINOVE (Brazil); Sanches, Iris Callado [Laboratório de Fisiologia Translacional da UNINOVE (Brazil); Canal, Marina [Programa de Graduação e Pós-Graduação em Medicina da UNINOVE (Brazil); Consolim-Colombo, Fernanda [Programa de Graduação e Pós-Graduação em Medicina da UNINOVE (Brazil); Unidade de Hipertensão e Central Médica de Laser do Instituto do Coração - Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (InCor/HC-FMUSP), São Paulo, SP (Brazil); Conti, Felipe Fernandes; Angelis, Katia De [Laboratório de Fisiologia Translacional da UNINOVE (Brazil); Chavantes, Maria Cristina [Programa de Pós-Graduação em Biofotônica em Ciências da Saúde da Universidade Nove de Julho (UNINOVE) (Brazil); Programa de Graduação e Pós-Graduação em Medicina da UNINOVE (Brazil); Unidade de Hipertensão e Central Médica de Laser do Instituto do Coração - Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (InCor/HC-FMUSP), São Paulo, SP (Brazil)

    2014-08-15

    Systemic arterial hypertension (SAH) is considered to be the greatest risk factor for the development of neuro-cardiovascular pathologies, thus constituting a severe Public Health issue in the world. The Low-Level Laser Therapy (LLLT), or laser therapy, activates components of the cellular structure, therefore converting luminous energy into photochemical energy and leading to biophysical and biochemical reactions in the mitochondrial respiratory chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes in metabolism, leading to molecular, cellular and systemic changes. The objective of this study was to analyze the action of low-level laser in the hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals (n = 16) were randomly divided into the Laser Group (n = 8), which received three weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8), which received three weekly simulations of laser for seven weeks, accounting for 21 applications in each group. After seven weeks, animals were cannulated by the implantation of a catheter in the left carotid artery. On the following day, the systemic arterial pressure was recorded. The Laser Group showed reduced levels of mean blood pressure, with statistically significant reduction (169 ± 4 mmHg* vs. 182 ± 4 mmHg from the Sham Group) and reduced levels of diastolic pressure (143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group), revealing a 13 and 14 mmHg decrease, respectively. Besides, there was a concomitant important decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham Group). Therefore, laser therapy was able to produce hemodynamic changes, thus reducing pressure levels in spontaneously hypertensive rats.

  6. Optimal hemodynamic response model for functional near-infrared spectroscopy.

    Kamran, Muhammad A; Jeong, Myung Yung; Mannan, Malik M N

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650-950 nm wavelengths. The cortical hemodynamic response (HR) differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF) is modeled by two Gamma functions with six unknown parameters (four of them to model the shape and other two to scale and baseline respectively). The HRF model is supposed to be a linear combination of HRF, baseline, and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown). An objective function is developed as a square of the residuals with constraints on 12 free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using 10 real and 15 simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis (i.e., t-value > t critical and p-value < 0.05).

  7. Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

    Woods, L.L.; Mizelle, H.L.; Montani, J.P.; Hall, J.E.

    1986-08-01

    Our purpose was to investigate the mechanisms by which increased plasma amino acids elevate renal blood flow (RBF) and glomerular filtration rate (GFR). Since transport of amino acids and Na is linked in the proximal tubule, the authors hypothesized that increased amino acids might stimulate proximal tubular Na reabsorption (PR/sub Na/) and thus increase RBF and GFR by a macula densa feedback mechanism. A solution of four amino acids (Ala, Ser, Gly, Pro) was infused intravenously into anesthetized dogs with normal kidneys (NK) and with kidneys in which the tubuloglomerular feedback mechanism was blunted by lowering renal artery pressure (LPK) or blocked by making the kidneys nonfiltering (NFK). In NK, RBF and GFR increased by 35 +/- 4% and 30 +/- 7% after 90 min of amino acid infusion, while PR/sub Na/ (estimated from lithium clearance) and O2 consumption increased by 31 +/- 5% and 29 +/- 5% and distal Na delivery remained relatively constant. Autoregulation of RBF and GFR in response to step deceases in renal artery pressure was impaired during amino acids in NK. The hemodynamic responses to amino acids were abolished in LPK and NFK. Infusion of the nonmetabolized -aminoisobutyric acid into NK produced changes in renal hemodynamics that were similar to the responses observed with the four metabolizable amino acids. These data are consistent with the hypothesis that elevation of plasma amino acids increases RBF and GFR by a mechanism that requires an intact macula densa feedback. Metabolism of the amino acids does not appear to be necessary for these changes to occur.

  8. Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

    Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

    2010-05-15

    Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  9. Hemodynamic Effect of Laser Therapy in Spontaneously Hypertensive Rats

    Suely Tomimura

    2014-08-01

    Full Text Available Systemic arterial hypertension (SAH is considered to be the greatest risk factor for the development of neuro-cardiovascular pathologies, thus constituting a severe Public Health issue in the world. The Low-Level Laser Therapy (LLLT, or laser therapy, activates components of the cellular structure, therefore converting luminous energy into photochemical energy and leading to biophysical and biochemical reactions in the mitochondrial respiratory chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes in metabolism, leading to molecular, cellular and systemic changes. The objective of this study was to analyze the action of low-level laser in the hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals (n = 16 were randomly divided into the Laser Group (n = 8, which received three weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8, which received three weekly simulations of laser for seven weeks, accounting for 21 applications in each group. After seven weeks, animals were cannulated by the implantation of a catheter in the left carotid artery. On the following day, the systemic arterial pressure was recorded. The Laser Group showed reduced levels of mean blood pressure, with statistically significant reduction (169 ± 4 mmHg* vs. 182 ± 4 mmHg from the Sham Group and reduced levels of diastolic pressure (143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group, revealing a 13 and 14 mmHg decrease, respectively. Besides, there was a concomitant important decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham Group. Therefore, laser therapy was able to produce hemodynamic changes, thus reducing pressure levels in spontaneously hypertensive rats.

  10. Arterial stiffness, central hemodynamics, and cardiovascular risk in hypertension

    Palatini, Paolo; Casiglia, Edoardo; Gąsowski, Jerzy; Głuszek, Jerzy; Jankowski, Piotr; Narkiewicz, Krzysztof; Saladini, Francesca; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Van Bortel, Luc; Wojciechowska, Wiktoria; Kawecka-Jaszcz, Kalina

    2011-01-01

    This review summarizes several scientific contributions at the recent Satellite Symposium of the European Society of Hypertension, held in Milan, Italy. Arterial stiffening and its hemodynamic consequences can be easily and reliably measured using a range of noninvasive techniques. However, like blood pressure (BP) measurements, arterial stiffness should be measured carefully under standardized patient conditions. Carotid-femoral pulse wave velocity has been proposed as the gold standard for arterial stiffness measurement and is a well recognized predictor of adverse cardiovascular outcome. Systolic BP and pulse pressure in the ascending aorta may be lower than pressures measured in the upper limb, especially in young individuals. A number of studies suggest closer correlation of end-organ damage with central BP than with peripheral BP, and central BP may provide additional prognostic information regarding cardiovascular risk. Moreover, BP-lowering drugs can have differential effects on central aortic pressures and hemodynamics compared with brachial BP. This may explain the greater beneficial effect provided by newer antihypertensive drugs beyond peripheral BP reduction. Although many methodological problems still hinder the wide clinical application of parameters of arterial stiffness, these will likely contribute to cardiovascular assessment and management in future clinical practice. Each of the abovementioned parameters reflects a different characteristic of the atherosclerotic process, involving functional and/or morphological changes in the vessel wall. Therefore, acquiring simultaneous measurements of different parameters of vascular function and structure could theoretically enhance the power to improve risk stratification. Continuous technological effort is necessary to refine our methods of investigation in order to detect early arterial abnormalities. Arterial stiffness and its consequences represent the great challenge of the twenty-first century for

  11. Leonardo da Vinci and the first hemodynamic observations.

    Martins e Silva, J

    2008-02-01

    Leonardo da Vinci was a genius whose accomplishments and ideas come down to us today, five centuries later, with the freshness of innovation and the fascination of discovery. This brief review begins with a summary of Leonardo's life and a description of the most important works of art that he bequeathed us, and then concentrates on his last great challenge. There was a point at which Leonardo's passion for art gave way to the study of human anatomy, not only to improve his drawing but to go beyond what had been simply a representation of form to understand the underlying functioning. Among his many interests, we focus on his study of the heart and blood vessels, which he observed carefully in animals and human autopsies, and reproduced in drawings of great quality with annotations of astonishing acuteness. The experience that he had acquired from observing the flow of water in currents and around obstacles, and the conclusions that he drew concerning hydrodynamics, were central to his interpretation of the mechanisms of the heart and of blood flow, to which he devoted much of his time between 1508 and 1513. From these studies, immortalized in drawings of great clarity, come what are acknowledged to be the first hemodynamic records, in which Leonardo demonstrates the characteristics of blood flow in the aorta and great vessels and the importance of blood reflux and the formation of eddies in the sinus in aortic valve his assiduous and careful observations, and his subsequent deductions, Leonardo put forward detailed findings on hemodynamic questions that advanced technology has only recently enabled us to confirm.

  12. Hemodynamic, ventilator, and ECG changes in pediatric patients undergoing extraction

    Y K Sanadhya

    2013-01-01

    Full Text Available Background: Dental treatment induces pain anxiety and fear. This study was conducted to assess the changes in hemodynamic, ventilator, and electrocardiograph changes during extraction procedure among 12-15-year-old children and compare these changes with anxiety, fear, and pain. Materials and Methods: A purposive sample of 60 patients selected based on inclusion and exclusion criteria underwent study procedure in the dental OPD of a medical college and hospital. The anxiety, fear, and pain were recorded by dental anxiety scale, dental fear scale, and visual analogue scale, respectively, before the start of the procedure. The systolic blood pressure, diastolic blood pressure, heart rate, oxygen saturation, and electrocardiogram changes were monitored during the extraction procedure. The recording was taken four times (preinjection phase, injection, extraction, and postextraction and was analyzed. Results: At the preinjection phase the mean vales were systolic blood pressure (128 ± 11.2, diastolic blood pressure (85.7 ± 6.3, heart rate (79.7 ± 9.3, and oxygen saturation (97.9 ± 5.8. These values increased in injection phases and decreased in extraction phase and the least values were found after 10 min of procedure and this relation was significant for all parameters except oxygen saturation (P = 0.48, NS. ECG abnormalities were seen among 22 patients and were significant before and after injection of Local anesthetic (P = 0.0001, S. Conclusions: Anxiety, fear, and pain have an effect on hemodynamic, ventilator, and cardiovascular parameters during the extraction procedure and hence behavioral management has to be emphasized among children in dental clinics.

  13. Hemodynamic changes by drug interaction of adrenaline with chlorpromazine.

    Higuchi, Hitoshi; Yabuki, Akiko; Ishii-Maruhama, Minako; Tomoyasu, Yumiko; Maeda, Shigeru; Miyawaki, Takuya

    2014-01-01

    Adrenaline (epinephrine) is included in dental local anesthesia for the purpose of vasoconstriction. In Japan, adrenaline is contraindicated for use in patients receiving antipsychotic therapy, because the combination of adrenaline and an antipsychotic is considered to cause severe hypotension; however, there is insufficient evidence supporting this claim. The purpose of the present study was to clarify the changes in hemodynamics caused by drug interaction between adrenaline and an antipsychotic and to evaluate the safety of the combined use of adrenaline and an antipsychotic in an animal study. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital. A catheter was inserted into the femoral artery to measure blood pressure and pulse rate. Rats were pretreated by intraperitoneal injection of chlorpromazine or chlorpromazine and propranolol, and after 20 minutes, saline or 1 of 3 different doses of adrenaline was administered by intraperitoneal injection. Changes in the ratio of mean arterial blood pressure and pulse rate were measured after the injection of adrenaline. Significant hypotension and tachycardia were observed after the injection of adrenaline in the chlorpromazine-pretreated rats. These effects were in a dose-dependent manner, and 100 μg/kg adrenaline induced significant hemodynamic changes. Furthermore, in the chlorpromazine and propranolol-pretreated rats, modest hypertension was induced by adrenaline, but hypotension and tachycardia were not significantly shown. Hypotension was caused by a drug interaction between adrenaline and chlorpromazine through the activation of the β-adrenergic receptor and showed a dose-dependent effect. Low-dose adrenaline similar to what might be used in human dental treatment did not result in a significant homodynamic change.

  14. Correlation between electrical and hemodynamic responses during visual stimulation with graded contrasts

    Si, Juanning; Zhang, Xin; Li, Yuejun; Zhang, Yujin; Zuo, Nianming; Jiang, Tianzi

    2016-09-01

    Brain functional activity involves complex cellular, metabolic, and vascular chain reactions, making it difficult to comprehend. Electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) have been combined into a multimodal neuroimaging method that captures both electrophysiological and hemodynamic information to explore the spatiotemporal characteristics of brain activity. Because of the significance of visually evoked functional activity in clinical applications, numerous studies have explored the amplitude of the visual evoked potential (VEP) to clarify its relationship with the hemodynamic response. However, relatively few studies have investigated the influence of latency, which has been frequently used to diagnose visual diseases, on the hemodynamic response. Moreover, because the latency and the amplitude of VEPs have different roles in coding visual information, investigating the relationship between latency and the hemodynamic response should be helpful. In this study, checkerboard reversal tasks with graded contrasts were used to evoke visual functional activity. Both EEG and fNIRS were employed to investigate the relationship between neuronal electrophysiological activities and the hemodynamic responses. The VEP amplitudes were linearly correlated with the hemodynamic response, but the VEP latency showed a negative linear correlation with the hemodynamic response.

  15. Resting-state hemodynamics are spatiotemporally coupled to synchronized and symmetric neural activity in excitatory neurons

    Ma, Ying; Shaik, Mohammed A.; Kozberg, Mariel G.; Portes, Jacob P.; Timerman, Dmitriy

    2016-01-01

    Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear. In this study, neural activity and hemodynamics were recorded simultaneously over the bilateral cortex of awake and anesthetized Thy1-GCaMP mice using wide-field optical mapping. Neural activity was visualized via selective expression of the calcium-sensitive fluorophore GCaMP in layer 2/3 and 5 excitatory neurons. Characteristic patterns of resting-state hemodynamics were accompanied by more rapidly changing bilateral patterns of resting-state neural activity. Spatiotemporal hemodynamics could be modeled by convolving this neural activity with hemodynamic response functions derived through both deconvolution and gamma-variate fitting. Simultaneous imaging and electrophysiology confirmed that Thy1-GCaMP signals are well-predicted by multiunit activity. Neurovascular coupling between resting-state neural activity and hemodynamics was robust and fast in awake animals, whereas coupling in urethane-anesthetized animals was slower, and in some cases included lower-frequency (resting-state hemodynamics in the awake and anesthetized brain are coupled to underlying patterns of excitatory neural activity. The patterns of bilaterally-symmetric spontaneous neural activity revealed by wide-field Thy1-GCaMP imaging may depict the neural foundation of functional connectivity networks detected in resting-state fMRI. PMID:27974609

  16. On the density scaling of pVT data and transport properties for molecular and ionic liquids.

    López, Enriqueta R; Pensado, Alfonso S; Fernández, Josefa; Harris, Kenneth R

    2012-06-07

    In this work, a general equation of state (EOS) recently derived by Grzybowski et al. [Phys. Rev. E 83, 041505 (2011)] is applied to 51 molecular and ionic liquids in order to perform density scaling of pVT data employing the scaling exponent γ(EOS). It is found that the scaling is excellent in most cases examined. γ(EOS) values range from 6.1 for ammonia to 13.3 for the ionic liquid [C(4)C(1)im][BF(4)]. These γ(EOS) values are compared with results recently reported by us [E. R. López, A. S. Pensado, M. J. P. Comuñas, A. A. H. Pádua, J. Fernández, and K. R. Harris, J. Chem. Phys. 134, 144507 (2011)] for the scaling exponent γ obtained for several different transport properties, namely, the viscosity, self-diffusion coefficient, and electrical conductivity. For the majority of the compounds examined, γ(EOS) > γ, but for hexane, heptane, octane, cyclopentane, cyclohexane, CCl(4), dimethyl carbonate, m-xylene, and decalin, γ(EOS) liquids. For viscosities and the self-diffusion coefficient-temperature ratio, we have tested the relation linking EOS and dynamic scaling parameters, proposed by Paluch et al. [J. Phys. Chem. Lett. 1, 987-992 (2010)] and Grzybowski et al. [J. Chem. Phys. 133, 161101 (2010); Phys. Rev. E 82, 013501 (2010)], that is, γ = (γ(EOS)/φ) + γ(G), where φ is the stretching parameter of the modified Avramov relation for the density scaling of a transport property, and γ(G) is the Grüneisen constant. This relationship is based on data for structural relaxation times near the glass transition temperature for seven molecular liquids, including glass formers, and a single ionic liquid. For all the compounds examined in our much larger database the ratio (γ(EOS)/φ) is actually higher than γ, with the only exceptions of propylene carbonate and 1-methylnaphthalene. Therefore, it seems the relation proposed by Paluch et al. applies only in certain cases, and is really not generally applicable to liquid transport properties such as

  17. Endovascular management of renal transplant dysfunction secondary to hemodynamic effects related to ipsilateral femoral arteriovenous graft

    Salsamendi, Jason; Pereira, Keith; Quintana, David; Bleicher, Drew; Tabbara, Marwan; Goldstein, Michael; Narayanan, Govindarajan

    2016-01-01

    Hemodialysis access options become complex in long-term treatment for patients with renal disease, while awaiting renal transplantation (RT). Once upper extremity sites are exhausted, lower extremities are used. RT is preferably in the contralateral iliac fossa, rarely ipsilateral. In current literature, RT dysfunction secondary to the hemodynamic effects of an ipsilateral femoral arteriovenous graft (AVG) has been rarely described. To our knowledge, AVG ligation is the only published technique for hemodynamic correction of an ipsilateral AVG. We present a simple, potentially reversible endovascular approach to manage the hemodynamic effects of an AVG, without potentially permanently losing future AVG access. PMID:26899147

  18. [Indicators of general, cerebral, and regional hemodynamics in myopic schoolchildren aged 13-15 years].

    Iastrebtseva, T A; Chuprov, A D; Plotnikova, Iu A

    2002-01-01

    110 schoolchildren aged 13-15 years were examined. 24 of them had pseudomyopia and 6 patients myopia of various forms. A control group consisted of 38 children. Central hemodynamics was estimated by average dynamic pressure, cerebral hemodynamics--by rheoencephalography, regional hemodynamics--by dopplerography of the internal carotid and suprapubic arteries. It was found that with myopia progression, the average dynamic pressure positively comes down with reduction of reographic waves amplitude in rheogram. The blood flow rate in internal carotid and suprapubic arteries has no substantial impact on myopia course. Predisposition to arterial hypotension is a risk factor for myopia development and progression.

  19. Novel use of a noninvasive hemodynamic monitor in a personalized, active learning simulation.

    Zoller, Jonathan K; He, Jianghua; Ballew, Angela T; Orr, Walter N; Flynn, Brigid C

    2017-06-01

    The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical knowledge concerning physiology were examined with a pre-and posttest. Simply by observation of one's own hemodynamic variables, the understanding of complex physiological concepts was significantly enhanced. Copyright © 2017 the American Physiological Society.

  20. Escaping the tolerance trap

    Hammoudeh, S.; Madan, V.

    1994-01-01

    In order to examine the implications of the weakening of OPEC's responsiveness in adjusting its production levels, this paper explicitly incorporates rigidity in the quantity adjustment mechanism, thereby extending previous research which assumed smooth quantity adjustments. The rigidity is manifested in a tolerance range for the discrepancy between the declared target price and that of the market. This environment gives rise to a 'tolerance trap' which impedes the convergence process and inevitably brings the market to a standstill before its reaches the targeted price and revenue objectives. OPEC's reaction to the standstill has important implications for the achievement of the target-based equilibrium and for the potential collapse of the market price. This paper examines OPEC's policy options in the tolerance trap and reveals that the optional policy in order to break this impasse and move closer to the equilibrium point is gradually to reduce output and not to flood the market. (Author)

  1. Fault tolerant linear actuator

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  2. Inequality, Tolerance, and Growth

    Bjørnskov, Christian

    This paper argues for the importance of individuals' tolerance of inequality for economic growth. By using the political ideology of governments as a measure of revealed tolerance of inequality, the paper shows that controlling for ideology improves the accuracy with which the effects of inequality...... are measured. Results show that inequality reduces growth but more so in societies where people perceive it as being relatively unfair. Further results indicate that legal quality and social trust are likely transmission channels for the effects of inequality....

  3. Inequality, Tolerance, and Growth

    Bjørnskov, Christian

    2004-01-01

    This paper argues for the importance of individuals' tolerance of inequality for economic growth. By using the political ideology of governments as a measure of revealed tolerance of inequality, the paper shows that controlling for ideology improves the accuracy with which the effects of inequality...... are measured. Results show that inequality reduces growth but more so in societies where people perceive it as being relatively unfair. Further results indicate that legal quality and social trust are likely transmission channels for the effects of inequality....

  4. Effects of Lignocaine Administered Intravenously or Intratracheally on Airway and Hemodynamic Responses during Emergence and Extubation in Patients Undergoing Elective Craniotomies in Supine Position.

    Shabnum, Tabasum; Ali, Zulfiqar; Naqash, Imtiaz Ahmad; Mir, Aabid Hussain; Azhar, Khan; Zahoor, Syed Amer; Mir, Abdul Waheed

    2017-01-01

    Sympathoadrenergic responses during emergence and extubation can lead to an increase in heart rate (HR) and blood pressure whereas increased airway responses may lead to coughing and laryngospasm. The aim of our study was to compare the effects of lignocaine administered intravenously (IV) or intratracheally on airway and hemodynamic responses during emergence and extubation in patients undergoing elective craniotomies. Sixty patients with physical status American Society of Anaesthesiologists Classes I and II aged 18-70 years, scheduled to undergo elective craniotomies were included. The patients were randomly divided into three groups of twenty patients; Group 1 receiving IV lignocaine and intratracheal placebo (IV group), Group 2 receiving intratracheal lignocaine and IV placebo (I/T group), and Group 3 receiving IV and intratracheal placebo (placebo group). The tolerance to the endotracheal tube was monitored, and number of episodes of cough was recorded during emergence and at the time of extubation. Hemodynamic parameters such as HR and blood pressure (systolic, diastolic, mean arterial pressure) were also recorded. There was a decrease of HR in both IV and intratracheal groups in comparison with placebo group ( P < 0.005). Rise in blood pressure (systolic blood pressure, diastolic blood pressure and mean arterial pressure) was comparable in both Groups 1 and 2 but was lower in comparison with placebo group ( P < 0.005). Cough suppression was comparable in all the three groups. Grade III cough (15%) was documented only in placebo group. Both IV and intratracheal lignocaine are effective in attenuation of hemodynamic response if given within 20 min from skull pin removal to extubation. There was comparable cough suppression through intratracheal route and IV routes than the placebo group.

  5. Hemodynamic determinants of dyspnea improvement in acute decompensated heart failure.

    Solomonica, Amir; Burger, Andrew J; Aronson, Doron

    2013-01-01

    Dyspnea relief constitutes a major treatment goal and a key measure of treatment efficacy in decompensated heart failure. However, there are no data with regard to the relationship between hemodynamic measurements during treatment and dyspnea improvement. We studied 233 patients assigned to right heart catheterization in the Vasodilation in the Management of Acute Congestive Heart Failure trial. Dyspnea (assessed using a 7-point Likert scale) and hemodynamic parameters were measured simultaneously at 15 and 30 minutes and 1, 2, 3, 6, and 24 hours. Dyspnea relief was defined as moderate or marked improvement. There was a time-dependent association between the reductions in pulmonary capillary wedge pressure (PCWP; 25.4, 24.6, 24.0, 23.5, 23.4, 21.5, and 19.9 mm Hg) and the percentage of patients achieving dyspnea relief (17.7%, 24.6%, 32.2%, 36.2%, 37.8%, 47.4%, and 66.1%, in the respective time points). Multivariable logistic generalized estimating equations modeling demonstrated that reductions of both PCWP and mean pulmonary artery pressure were independently associated with dyspnea relief. Compared with the highest PCWP quartile, the adjusted odds ratios for dyspnea relief were 0.92 (95% confidence interval [CI], 0.67-1.29), 1.07 (95% CI, 0.75-1.55), and 1.80 (95% CI, 1.22-2.65) in the third, second, and first PCWP quartiles, respectively (P(trend)=0.003). Compared with the highest mean pulmonary artery pressure quartile, the adjusted odds ratios for dyspnea relief were 2.0 (95% CI, 1.41-2.82), 2.23 (95% CI, 1.52-3.27), and 2.98 (95% CI, 1.91-4.66) in the third, second, and first mean pulmonary artery pressure quartiles, respectively (P(trend)<0.0001). A clinically significant improvement in dyspnea is associated with a reduction in both PCWP and mean pulmonary artery pressure.

  6. The Influence of Age on Hemodynamic Parameters During Rest and Exercise in Healthy Individuals

    Wolsk, Emil; Bakkestrøm, Rine; Thomsen, Jacob H

    2017-01-01

    OBJECTIVES: The authors sought to obtain hemodynamic estimates across a wide age span and in both sexes for future reference and compare these estimates with current guideline diagnostic hemodynamic thresholds for abnormal filling pressure and pulmonary hypertension. BACKGROUND: At present....... METHODS: Sixty-two healthy participants, evenly distributed with respect to age (20 to 80 years) and sex (32 women/30 men), were prospectively enrolled in the study. Participants were all deemed healthy by medical history, echocardiography, exercise test, spirometry, blood tests, and electrocardiogram....... Participants had hemodynamic parameters measured using right heart catheterization during rest, passive leg raise, and incremental exercise. RESULTS: During rest, all hemodynamic parameters were similar between age groups, apart from blood pressure. During leg raise and incremental exercise...

  7. Experts' opinion on management of hemodynamics in ARDS patients: focus on the effects of mechanical ventilation

    Vieillard-Baron, A.; Matthay, M.; Teboul, J. L.; Bein, T.; Schultz, M.; Magder, S.; Marini, J. J.

    2016-01-01

    Acute respiratory distress syndrome (ARDS) is frequently associated with hemodynamic instability which appears as the main factor associated with mortality. Shock is driven by pulmonary hypertension, deleterious effects of mechanical ventilation (MV) on right ventricular (RV) function, and

  8. Hemodynamic pattern in myocardial infarction patients at the common stages of rehabilitation

    Perepech, N.B.

    1986-01-01

    Integrated body rheography, radiocardiography and radionuclide ventriculography were used to investigate hemodynamic changes in 101 myocardial infarction patients during the hospital stage of the disease. Changes in major hemodynamic parameters were demonstrated by the end of the 1st week and when walking was resumed. At the resumed-walking stage, the mechanism of declining stroke and cardiac indices was shown to depend on physical activation rates. Hemodynamic response is mostly conditioned by myocardial insufficiency when walking is resumed rapidly during the 2nd week, and by smaller venous return due to hypovolemia where it is resumed slowly during the 4th week. Expanding motion regimens at slow rates results in persistent hemodynamic disturbances in myocardial infarction patients

  9. Hemodynamic comparison of mild and severe preeclampsia: concept of stroke systemic vascular resistance index.

    Scardo, J; Kiser, R; Dillon, A; Brost, B; Newman, R

    1996-01-01

    Our purpose was to compare baseline hemodynamic parameters of mild and severe preeclampsia. Patients admitted to the Medical University Labor and Delivery Unit with the diagnosis of preeclampsia who had not received prior antihypertensive or magnesium sulfate therapy were recruited for noninvasive hemodynamic monitoring with thoracic electrical bioimpedance. After stabilization in the lateral recumbent position, hemodynamic monitoring was begun. Baseline hemodynamic parameters, mean arterial pressure (MAP), heart rate (HR), systemic vascular resistance index (SVRI), cardiac index (CI), and stroke index (SI) were recorded. Stroke systemic vascular resistance index (SSVRI), the resistance imposed by vasculature on each beat of the heart, was calculated for each patient by multiplying SVRI by HR. For statistical analysis, unpaired Student's t-tests (two-tailed) were utilized (P preclampsia appears to be a more intensely vasoconstricted state than mild preeclampsia. Although CI is inversely proportional to SVRI, increased HR in severe preeclampsia prevents this expected decrease in cardiac output.

  10. A review of the hemodynamic effects of external leg and lower body compression.

    Helmi, M; Gommers, D; Groeneveld, A B J

    2014-03-01

    External leg and lower body compression (ELC) has been used for decades in the prevention of deep vein thrombosis and the treatment of leg ischemia. Because of systemic effects, the methods have regained interest in anesthesia, surgery and critical care. This review intends to summarize hemodynamic effects and their mechanisms. Compilation of relevant literature published in English as full paper and retrieved from Medline. By compressing veins, venous stasis is diminished and venous return and arterial blood flow are increased. ELC has been suggested to improve systemic hemodynamics, in different clinical settings, such as postural hypotension, anesthesia, surgery, shock, cardiopulmonary resuscitation and mechanical ventilation. However, the hemodynamic alterations depend upon the magnitude, extent, cycle, duration and thus the modality of ELC, when applied in a static or intermittent fashion (by pneumatic inflation), respectively. ELC may help future research and optimizing treatment of hemodynamically unstable, surgical or critically ill patients, independent of plasma volume expansion.

  11. Toleration, Groups, and Multiculturalism

    Lægaard, Sune

    2014-01-01

    have the ability to interfere with the group’s activities, an object of dislike or disapproval, an agent enjoying non-interference or a moral patient. This means that 'toleration of groups' can mean quite different things depending on the exact meaning of 'group' in relation to each component...

  12. Fault Tolerant Control Systems

    Bøgh, S. A.

    This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...

  13. Toleration and its enemies

    Jarvad, Ib Martin

    2010-01-01

    After a presentation of the development of freedom of expression in Danish constitutional law, to freedom of the press in European human rights law - the Jersild case- to a right to mock and ridicule other faiths in recent Danish practice, the essay of Locke on toleration is examined, its...

  14. A little toleration, please

    McKnight, C.

    2000-01-01

    Value pluralism does not imply relativism or subjectivism about values. What it does is allow respect for an at least limited toleration of values with which one may profoundly disagree. Thus a doctor can respect the autonomy of a patient whose values he does not share. Key Words: Pluralism • multiculturalism • relativism • subjectivism • patient autonomy PMID:11129842

  15. He lived for the sake of people. To the 180th anniversary of the Yekaterinoslav zemstvo doctor V.T. Skrylnikov (1837-1898

    Pisarenko Yu.G.

    2017-04-01

    Full Text Available For the first time the article introduces to the reader biography of one of the founders of the Yekaterinoslav Medical Society, a local doctor, author of numerous scientific papers on medicine and hygiene Vasiliy Timofeevich Skrylnikov. The first part provides previously unknown details about his origin, the work as the head of the free zemstvo clinic, highlights his proposals in the field of sanitary service of the city Yekaterinoslav, wide publishing activities. The aspects of V.T. Skrylnikov’s service on guardianship of orphans, and the initiative to create Yekaterinoslav Department of Russian society of public health are touched upon.

  16. Computational medical imaging and hemodynamics framework for functional analysis and assessment of cardiovascular structures.

    Wong, Kelvin K L; Wang, Defeng; Ko, Jacky K L; Mazumdar, Jagannath; Le, Thu-Thao; Ghista, Dhanjoo

    2017-03-21

    Cardiac dysfunction constitutes common cardiovascular health issues in the society, and has been an investigation topic of strong focus by researchers in the medical imaging community. Diagnostic modalities based on echocardiography, magnetic resonance imaging, chest radiography and computed tomography are common techniques that provide cardiovascular structural information to diagnose heart defects. However, functional information of cardiovascular flow, which can in fact be used to support the diagnosis of many cardiovascular diseases with a myriad of hemodynamics performance indicators, remains unexplored to its full potential. Some of these indicators constitute important cardiac functional parameters affecting the cardiovascular abnormalities. With the advancement of computer technology that facilitates high speed computational fluid dynamics, the realization of a support diagnostic platform of hemodynamics quantification and analysis can be achieved. This article reviews the state-of-the-art medical imaging and high fidelity multi-physics computational analyses that together enable reconstruction of cardiovascular structures and hemodynamic flow patterns within them, such as of the left ventricle (LV) and carotid bifurcations. The combined medical imaging and hemodynamic analysis enables us to study the mechanisms of cardiovascular disease-causing dysfunctions, such as how (1) cardiomyopathy causes left ventricular remodeling and loss of contractility leading to heart failure, and (2) modeling of LV construction and simulation of intra-LV hemodynamics can enable us to determine the optimum procedure of surgical ventriculation to restore its contractility and health This combined medical imaging and hemodynamics framework can potentially extend medical knowledge of cardiovascular defects and associated hemodynamic behavior and their surgical restoration, by means of an integrated medical image diagnostics and hemodynamic performance analysis framework.

  17. Radiation protection in hemodynamics work process: the look of the multidisciplinary team

    Borges, Laurete Medeiros; Klauberg, Daniela; Huhn, Andrea; Melo, Juliana Almeida Coelho de

    2014-01-01

    The study was conducted in a hemodynamics service of a public hospital in Florianopolis, SC, Brazil. Qualitative research with the participation of 13 professionals from a multidisciplinary team: doctors, technicians, technologists in radiology and nurses. The research material was extracted from the observations, semi-structured interviews and documentary analysis. The responses were grouped into three categories relating to: training of hemodynamic professionals and the perception of radiological protection in the work process; occupational exposure and safety of the professionals of Hemodynamics; and continuing education in hemodynamic service. Professionals are daily exposed to ionizing radiation, and for being long procedures, lead to high levels of exposure in workers. In hemodynamic services the risk of biological effects are cumulative, because radiodiagnostic procedures include issuing the higher doses of ionizing radiation in which the personnel exposure is critical. The workforce in the service researched mostly consists of technical professionals who reported little knowledge of radiation protection and ionizing radiation and that this issue was not addressed during their training. However, despite mention little knowledge about radiological protection, participants demonstrated understand the biological effects, especially with regard to pathologies caused by frequent exposure without protection to ionizing radiation. These professionals said they have no knowledge of the proper use of radiological protection equipment and the dosimeter, and that the institution does not provide all individual protective equipment required for the procedures performed in the hemodynamic service. Permanent education in hemodynamic service is very important part in the work process, though, cited by participants as little effectiveness in the institution, even when the professionals show interest in the area. Knowledge of the team providing hemodynamic service calls

  18. Endothelial cell impact on smooth muscle cell properties: role of hemodynamic forces

    Killeen, Maria T.

    2009-01-01

    The vascular endothelium is a dynamic cell monolayer located at the interface of the vessel wall and bloodstream, where it regulates the physiological effects of humoral and hemodynamic stimuli on vessel tone and remodelling. Hemodynamic forces are of particular interest and include shear stress, the frictional force generated by blood as it drags against the endothelium, and cyclic strain, transmural pressure due to the pulsatile nature of blood flow. Both forces can profoundly modulate vasc...

  19. The Effect of Inlet Waveforms on Computational Hemodynamics of Patient-Specific Intracranial Aneurysms

    Xiang, J.; Siddiqui, A.H.; Meng, H.

    2014-01-01

    Due to the lack of patient-specific inlet flow waveform measurements, most computational fluid dynamics (CFD) simulations of intracranial aneurysms usually employ waveforms that are not patient-specific as inlet boundary conditions for the computational model. The current study examined how this assumption affects the predicted hemodynamics in patient-specific aneurysm geometries. We examined wall shear stress (WSS) and oscillatory shear index (OSI), the two most widely studied hemodynamic qu...

  20. [Cerebral hemodynamics in patients with neurosensory hearing loss before and after magnetotherapy].

    Morenko, V M; Enin, I P

    2001-01-01

    Magnetotherapy effects on cerebral hemodynamics were studied using rheoencephalography (REG). When the treatment results and changes in cerebral hemodynamics were compared it was evident that normalization or improvement of vascular status in vertebrobasilar and carotid territories registered at REG results in better hearing. This confirms the role of vascular factor in pathogenesis of neurosensory hypoacusis of different etiology and effectiveness of magnetotherapy in such patients.

  1. Deconstructing tolerance with clobazam

    Wechsler, Robert T.; Sankar, Raman; Montouris, Georgia D.; White, H. Steve; Cloyd, James C.; Kane, Mary Clare; Peng, Guangbin; Tworek, David M.; Shen, Vivienne; Isojarvi, Jouko

    2016-01-01

    Objective: To evaluate potential development of tolerance to adjunctive clobazam in patients with Lennox-Gastaut syndrome. Methods: Eligible patients enrolled in open-label extension study OV-1004, which continued until clobazam was commercially available in the United States or for a maximum of 2 years outside the United States. Enrolled patients started at 0.5 mg·kg−1·d−1 clobazam, not to exceed 40 mg/d. After 48 hours, dosages could be adjusted up to 2.0 mg·kg−1·d−1 (maximum 80 mg/d) on the basis of efficacy and tolerability. Post hoc analyses evaluated mean dosages and drop-seizure rates for the first 2 years of the open-label extension based on responder categories and baseline seizure quartiles in OV-1012. Individual patient listings were reviewed for dosage increases ≥40% and increasing seizure rates. Results: Data from 200 patients were included. For patients free of drop seizures, there was no notable change in dosage over 24 months. For responder groups still exhibiting drop seizures, dosages were increased. Weekly drop-seizure rates for 100% and ≥75% responders demonstrated a consistent response over time. Few patients had a dosage increase ≥40% associated with an increase in seizure rates. Conclusions: Two-year findings suggest that the majority of patients do not develop tolerance to the antiseizure actions of clobazam. Observed dosage increases may reflect best efforts to achieve seizure freedom. It is possible that the clinical development of tolerance to clobazam has been overstated. ClinicalTrials.gov identifier: NCT00518713 and NCT01160770. Classification of evidence: This study provides Class III evidence that the majority of patients do not develop tolerance to clobazam over 2 years of treatment. PMID:27683846

  2. Asiatic Acid Alleviates Hemodynamic and Metabolic Alterations via Restoring eNOS/iNOS Expression, Oxidative Stress, and Inflammation in Diet-Induced Metabolic Syndrome Rats

    Poungrat Pakdeechote

    2014-01-01

    Full Text Available Asiatic acid is a triterpenoid isolated from Centella asiatica. The present study aimed to investigate whether asiatic acid could lessen the metabolic, cardiovascular complications in rats with metabolic syndrome (MS induced by a high-carbohydrate, high-fat (HCHF diet. Male Sprague-Dawley rats were fed with HCHF diet with 15% fructose in drinking water for 12 weeks to induce MS. MS rats were treated with asiatic acid (10 or 20 mg/kg/day or vehicle for a further three weeks. MS rats had an impairment of oral glucose tolerance, increases in fasting blood glucose, serum insulin, total cholesterol, triglycerides, mean arterial blood pressure, heart rate, and hindlimb vascular resistance; these were related to the augmentation of vascular superoxide anion production, plasma malondialdehyde and tumor necrosis factor-alpha (TNF-α levels (p < 0.05. Plasma nitrate and nitrite (NOx were markedly high with upregulation of inducible nitric oxide synthase (iNOS expression, but dowregulation of endothelial nitric oxide synthase (eNOS expression (p < 0.05. Asiatic acid significantly improved insulin sensitivity, lipid profiles, hemodynamic parameters, oxidative stress markers, plasma TNF-α, NOx, and recovered abnormality of eNOS/iNOS expressions in MS rats (p < 0.05. In conclusion, asiatic acid improved metabolic, hemodynamic abnormalities in MS rats that could be associated with its antioxidant, anti-inflammatory effects and recovering regulation of eNOS/iNOS expression.

  3. Relationship between systemic hemodynamics and ambulatory blood pressure level are sex dependent.

    Alfie, J; Waisman, G D; Galarza, C R; Magi, M I; Vasvari, F; Mayorga, L M; Cámera, M I

    1995-12-01

    Sex-related differences in systemic hemodynamics were analyzed by means of cardiac index and systemic vascular resistance according to the level of daytime ambulatory blood pressure. In addition, we assessed the relations between ambulatory blood pressure measurements and systemic hemodynamics in male and female patients. We prospectively included 52 women and 53 men referred to our unit for evaluation of arterial hypertension. Women and men were grouped according to the level of daytime mean arterial pressure: or = 110 mm Hg. Patients underwent noninvasive evaluation of resting hemodynamics (impedance cardiography) and 24-hour ambulatory blood pressure monitoring. Compared with women men with lower daytime blood pressure had a 12% higher systemic vascular resistance index (P = NS) and a 14% lower cardiac index (P < .02), whereas men with higher daytime blood pressure had a 25% higher vascular resistance (P < .003) and a 21% lower cardiac index (P < .0004). Furthermore, in men systemic vascular resistance correlated positively with both daytime and nighttime systolic and diastolic blood pressures, whereas cardiac index correlated negatively only with daytime diastolic blood pressure. In contrast, women did not exhibit any significant correlation between hemodynamic parameters and ambulatory blood pressure measurements. In conclusion, sex-related differences in systemic hemodynamics were more pronounced in the group with higher daytime hypertension. The relations between systemic hemodynamics and ambulatory blood pressure level depended on the sex of the patient. In men a progressive circulatory impairment underlies the increasing level of ambulatory blood pressure, but this was not observed in women.

  4. Lack of evidence for an association between hemodynamic variables and hematoma growth in spontaneous intracerebral hemorrhage.

    Jauch, Edward C; Lindsell, Christopher J; Adeoye, Opeolu; Khoury, Jane; Barsan, William; Broderick, Joseph; Pancioli, Arthur; Brott, Thomas

    2006-08-01

    Early hematoma expansion in spontaneous intracerebral hemorrhage (ICH) is associated with worse clinical outcome. We hypothesized that hemodynamic parameters are associated with the increase in hematoma volume owing to their relationship to blood vessel wall stresses. We performed a post hoc analysis of clinical and computed tomography (CT) data from patients enrolled in a prospective observational study of ICH patients presenting within 3 hours from symptom onset. Hematoma volumes were measured at hospital arrival and at 1 and 20 hours from presentation. Blood pressure and heart rate, recorded at 19 time points between presentation and 20 hours, were used to derive hemodynamic variables. Multivariable logistic-regression models were constructed to assess the relation between hemodynamic parameters and hematoma growth, adjusted for clinical covariates. From the original study, 98 patients underwent baseline and 1-hour CT scans; of these, 65 had 20-hour CT scans. Substantial hematoma growth was observed in 28% within the first hour. Of the 65 patients not undergoing surgery within 20 hours, 37% experienced hematoma growth by 20 hours. Neither baseline or peak hemodynamic parameters nor changes in hemodynamic parameters were significantly associated with hematoma growth at either 1 or 20 hours. We found no blood pressure or heart rate parameters, individually or in combination, that were associated with hematoma growth. Our data suggest the influence of hemodynamic parameters on vessel wall stress to be an unlikely target for intervention in reducing the risk of early hematoma growth in ICH.

  5. Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

    Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

    1998-01-01

    This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

  6. [System analytical approach of lung function and hemodynamics].

    Naszlady, Attila; Kiss, Lajos

    2009-02-15

    The authors critically analyse the traditional views in physiology and complete them with new statements based on computer model simulations of lung function and of hemodynamics. Conclusions are derived for the clinical practice as follows: the four-dimensional function curves are similar in both systems; there is a "waterfall" zone in the pulmonary blood perfusion; the various time constants of pulmonary regions can modify the blood gas values; pulmonary capillary pressure is equal to pulmonary arterial diastole pressure; heart is not a pressure pump, but a flow source; ventricles are loaded by the input impedance of the arterial systems and not by the total vascular (ohmlike) resistance; optimum heart rate in rest depends on the length of the aorta; this law of heart rate, based on the principle of resonance is valid along the mammalian allometric line; tachycardia decreases the input impedance; using positive end expiratory pressure respirators the blood gas of pulmonary artery should be followed; coronary circulation should be assessed in beat per milliliter, the milliliter per minute may be false. These statements are compared to related references.

  7. Hemodynamic forces regulate developmental patterning of atrial conduction.

    Michael C Bressan

    Full Text Available Anomalous action potential conduction through the atrial chambers of the heart can lead to severe cardiac arrhythmia. To date, however, little is known regarding the mechanisms that pattern proper atrial conduction during development. Here we demonstrate that atrial muscle functionally diversifies into at least two heterogeneous subtypes, thin-walled myocardium and rapidly conducting muscle bundles, during a developmental window just following cardiac looping. During this process, atrial muscle bundles become enriched for the fast conduction markers Cx40 and Nav1.5, similar to the precursors of the fast conduction Purkinje fiber network located within the trabeculae of the ventricles. In contrast to the ventricular trabeculae, however, atrial muscle bundles display an increased proliferation rate when compared to the surrounding myocardium. Interestingly, mechanical loading of the embryonic atrial muscle resulted in an induction of Cx40, Nav1.5 and the cell cycle marker Cyclin D1, while decreasing atrial pressure via in vivo ligation of the vitelline blood vessels results in decreased atrial conduction velocity. Taken together, these data establish a novel model for atrial conduction patterning, whereby hemodynamic stretch coordinately induces proliferation and fast conduction marker expression, which in turn promotes the formation of large diameter muscle bundles to serve as preferential routes of conduction.

  8. Effect of Aspirin Supplementation on Hemodynamics in Older Firefighters.

    Lane-Cordova, Abbi D; Ranadive, Sushant M; Yan, Huimin; Kappus, Rebecca M; Sun, Peng; Bunsawat, Kanokwan; Smith, Denise L; Horn, Gavin P; Ploutz-Snyder, Robert; Fernhall, B O

    2015-12-01

    Cardiovascular events are the leading cause of line-of-duty fatality for firefighters. Aspirin reduces the risk of cardiovascular events in men and may reduce fatalities in older (>40 yr) firefighters. We hypothesized that both chronic and acute aspirin supplementation would improve vascular function after live firefighting but that chronic supplementation would also improve resting hemodynamics. Twenty-four firefighters (40-60 yr) were randomly assigned to acute or chronic aspirin supplementation or placebo in a balanced, crossover design. Arterial stiffness, brachial and central blood pressures, as well as forearm vasodilatory capacity and blood flow were measured at rest and immediately after live firefighting. Total hyperemic blood flow (area under the curve (AUC)) was increased (P 0.05 for interaction). Arterial stiffness/central blood pressure increased (P < 0.04) with no effect of aspirin (from 0.0811 ± 0.001 to 0.0844 ± 0.003 m·s·mm⁻¹ Hg⁻¹ in aspirin condition versus 0.0802 ± 0.002 to 0.0858 ± 0.002 m·s⁻¹·mm Hg⁻¹ in placebo condition), whereas peripheral and central systolic and pulse pressures decreased after firefighting across conditions (P < 0.05). Live firefighting resulted in increased AUC and pressure-controlled arterial stiffness and decreased blood pressure in older firefighters, but aspirin supplementation did not affect macro- or microvascular responsiveness at rest or after firefighting.

  9. Remote Left Ventricular Hemodynamic Monitoring Using a Novel Intracardiac Sensor.

    Mondritzki, Thomas; Boehme, Philip; White, Jason; Park, Jin Woo; Hoffmann, Jessica; Vogel, Julia; Kolkhof, Peter; Walsh, Stuart; Sandner, Peter; Bischoff, Erwin; Dinh, Wilfried; Hüser, Jörg; Truebel, Hubert

    2018-05-01

    Heart failure (HF) remains the most common reason for hospital admission in patients aged >65 years. Despite modern drug therapy, mortality and readmission rates for patients hospitalized with HF remain high. This necessitates further research to identify early patients at risk for readmission to limit hospitalization by timely adjustment of medical therapy. Implantable devices can monitor left ventricular (LV) hemodynamics and remotely and continuously detect the early signs of decompensation to trigger interventions and reduce the risk of hospitalization for HF. Here, we report the first preclinical study validating a new batteryless and easy to implant LV-microelectromechanical system to assess LV performance. A miniaturized implantable wireless pressure sensor was adapted for implantation in the LV apex. The LV-microelectromechanical system sensor was tested in a canine model of HF. The wireless pressure sensor measurements were compared with invasive left heart catheter-derived measurements at several time points. During different pharmacological challenge studies with dobutamine or vasopressin, the device was equally sensitive compared with invasive standard procedures. No adverse events or any observable reaction related to the implantation and application of the device for a period of 35 days was observed. Our miniaturized wireless pressure sensor placed in the LV (LV-microelectromechanical system) has the potential to become a new telemetric tool to earlier identify patients at risk for HF decompensation and to guide the treatment of patients with HF. © 2018 American Heart Association, Inc.

  10. Oxytocin modulates hemodynamic responses to monetary incentives in humans

    Mickey, Brian J.; Heffernan, Joseph; Heisel, Curtis; Peciña, Marta; Hsu, David T.; Zubieta, Jon-Kar; Love, Tiffany M.

    2016-01-01

    Oxytocin is a neuropeptide widely recognized for its role in regulating social and reproductive behavior. Increasing evidence from animal models suggests that oxytocin also modulates reward circuitry in non-social contexts, but evidence in humans is lacking. Here we examined the effects of oxytocin administration on reward circuit function in 18 healthy men as they performed a monetary incentive task. The blood oxygenation level dependent (BOLD) signal was measured using functional magnetic resonance imaging in the context of a randomized, double-blind, placebo-controlled, crossover trial of intranasal oxytocin. We found that oxytocin increases the BOLD signal in the midbrain (substantia nigra and ventral tegmental area) during the late phase of the hemodynamic response to incentive stimuli. Oxytocin’s effects on midbrain responses correlated positively with its effects on positive emotional state. We did not detect an effect of oxytocin on responses in the nucleus accumbens. Whole-brain analyses revealed that oxytocin attenuated medial prefrontal cortical deactivation specifically during anticipation of loss. Our findings demonstrate that intranasal administration of oxytocin modulates human midbrain and medial prefrontal function during motivated behavior. These findings suggest that endogenous oxytocin is a neurochemical mediator of reward behaviors in humans – even in a non-social context – and that the oxytocinergic system is a potential target of pharmacotherapy for psychiatric disorders that involve dysfunction of reward circuitry. PMID:27614896

  11. Adrenergic Metabolic and Hemodynamic Effects of Octopamine in the Liver

    Adelar Bracht

    2013-11-01

    Full Text Available The fruit extracts of Citrus aurantium (bitter orange are traditionally used as weight-loss products and as appetite suppressants. A component of these extracts is octopamine, which is an adrenergic agent. Weight-loss and adrenergic actions are always related to metabolic changes and this work was designed to investigate a possible action of octopamine on liver metabolism. The isolated perfused rat liver was used to measure catabolic and anabolic pathways and hemodynamics. Octopamine increased glycogenolysis, glycolysis, oxygen uptake, gluconeogenesis and the portal perfusion pressure. Octopamine also accelerated the oxidation of exogenous fatty acids (octanoate and oleate, as revealed by the increase in 14CO2 production derived from 14C labeled precursors. The changes in glycogenolysis, oxygen uptake and perfusion pressure were almost completely abolished by α1-adrenergic antagonists. The same changes were partly sensitive to the β-adrenergic antagonist propranolol. It can be concluded that octopamine accelerates both catabolic and anabolic processes in the liver via adrenergic stimulation. Acceleration of oxygen uptake under substrate-free perfusion conditions also means acceleration of the oxidation of endogenous fatty acids, which are derived from lipolysis. All these effects are compatible with an overall stimulating effect of octopamine on metabolism, which is compatible with its reported weight-loss effects in experimental animals.

  12. Right Ventricular Hemodynamics in Patients with Pulmonary Hypertension

    Browning, James; Fenster, Brett; Hertzberg, Jean; Schroeder, Joyce

    2012-11-01

    Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for characterization of blood flow in the right ventricle (RV), including calculation of vorticity and circulation, and qualitative visual assessment of coherent flow patterns. In this study, we investigate qualitative and quantitative differences in right ventricular hemodynamics between subjects with pulmonary hypertension (PH) and normal controls. Fifteen (15) PH subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine right ventricular diastolic function as well as pulmonary artery systolic pressure (PASP). Velocity vectors, vorticity vectors, and streamlines in the RV were visualized in Paraview and total RV Early (E) and Atrial (A) wave diastolic vorticity was quantified. Visualizations of blood flow in the RV are presented for PH and normal subjects. The hypothesis that PH subjects exhibit different RV vorticity levels than normals during diastole is tested and the relationship between RV vorticity and PASP is explored. The mechanics of RV vortex formation are discussed within the context of pulmonary arterial pressure and right ventricular diastolic function coincident with PH.

  13. Hemodynamic Modeling of Surgically Repaired Coarctation of the Aorta.

    Olivieri, Laura J; de Zélicourt, Diane A; Haggerty, Christopher M; Ratnayaka, Kanishka; Cross, Russell R; Yoganathan, Ajit P

    2011-12-01

    PURPOSE: Late morbidity of surgically repaired coarctation of the aorta includes early cardiovascular and cerebrovascular disease, shortened life expectancy, abnormal vasomodulator response, hypertension and exercise-induced hypertension in the absence of recurrent coarctation. Observational studies have linked patterns of arch remodeling (Gothic, Crenel, and Romanesque) to late morbidity, with Gothic arches having the highest incidence. We evaluated flow in native and surgically repaired aortic arches to correlate respective hemodynamic indices with incidence of late morbidity. METHODS: Three dimensional reconstructions of each remodeled arch were created from an anatomic stack of magnetic resonance (MR) images. A structured mesh core with a boundary layer was generated. Computational fluid dynamic (CFD) analysis was performed assuming peak flow conditions with a uniform velocity profile and unsteady turbulent flow. Wall shear stress (WSS), pressure and velocity data were extracted. RESULTS: The region of maximum WSS was located in the mid-transverse arch for the Crenel, Romanesque and Native arches. Peak WSS was located in the isthmus of the Gothic model. Variations in descending aorta flow patterns were also observed among the models. CONCLUSION: The location of peak WSS is a primary difference among the models tested, and may have clinical relevance. Specifically, the Gothic arch had a unique location of peak WSS with flow disorganization in the descending aorta. Our results suggest that varied patterns and locations of WSS resulting from abnormal arch remodeling may exhibit a primary effect on clinical vascular dysfunction.

  14. Oxytocin modulates hemodynamic responses to monetary incentives in humans.

    Mickey, Brian J; Heffernan, Joseph; Heisel, Curtis; Peciña, Marta; Hsu, David T; Zubieta, Jon-Kar; Love, Tiffany M

    2016-12-01

    Oxytocin is a neuropeptide widely recognized for its role in regulating social and reproductive behavior. Increasing evidence from animal models suggests that oxytocin also modulates reward circuitry in non-social contexts, but evidence in humans is lacking. We examined the effects of oxytocin administration on reward circuit function in 18 healthy men as they performed a monetary incentive task. The blood oxygenation level-dependent (BOLD) signal was measured using functional magnetic resonance imaging in the context of a randomized, double-blind, placebo-controlled, crossover trial of intranasal oxytocin. We found that oxytocin increases the BOLD signal in the midbrain (substantia nigra and ventral tegmental area) during the late phase of the hemodynamic response to incentive stimuli. Oxytocin's effects on midbrain responses correlated positively with its effects on positive emotional state. We did not detect an effect of oxytocin on responses in the nucleus accumbens. Whole-brain analyses revealed that oxytocin attenuated medial prefrontal cortical deactivation specifically during anticipation of loss. Our findings demonstrate that intranasal administration of oxytocin modulates human midbrain and medial prefrontal function during motivated behavior. These findings suggest that endogenous oxytocin is a neurochemical mediator of reward behaviors in humans-even in a non-social context-and that the oxytocinergic system is a potential target of pharmacotherapy for psychiatric disorders that involve dysfunction of reward circuitry.

  15. Dietary melatonin alters uterine artery hemodynamics in pregnant Holstein heifers.

    Brockus, K E; Hart, C G; Gilfeather, C L; Fleming, B O; Lemley, C O

    2016-04-01

    The objective was to examine uterine artery hemodynamics and maternal serum profiles in pregnant heifers supplemented with dietary melatonin (MEL) or no supplementation (CON). In addition, melatonin receptor-mediated responses in steroid metabolism were examined using a bovine endometrial epithelial culture system. Twenty singleton pregnant Holstein heifers were supplemented with 20 mg of melatonin (n = 10) or no melatonin supplementation (control; n = 10) from days 190 to 262 of gestation. Maternal measurements were recorded on days 180 (baseline), 210, 240, and 262 of gestation. Total uterine blood flow was increased by 25% in the MEL-treated heifers compared with the CON. Concentrations of progesterone were decreased in MEL vs CON heifers. Total serum antioxidant capacity was increased by 43% in MEL-treated heifers when compared with CON. Activity of cytochrome P450 1A, 2C, and superoxide dismutase was increased in bovine endometrial epithelial cells treated with melatonin, whereas the melatonin receptor antagonist, luzindole, negated the increase in cytochrome P450 2C activity. Moreover, estradiol or progesterone treatment altered bovine uterine melatonin receptor expression, which could potentiate the melatonin-mediated responses during late gestation. The observed increase in total uterine blood flow during melatonin supplementation could be related to its antioxidant properties. Compromised pregnancies are typically accompanied by increased oxidative stress; therefore, melatonin could serve as a therapeutic supplementation strategy. This could lead to further fetal programming implications in conjunction with offspring growth and development postnatally. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Occupational doses in medical staff during hemodynamic procedures

    Alonso, Thessa C.; Silva, Teogenes A. da

    2008-01-01

    The main objective of an occupational radiation program for workers is to keep radiation exposures under control and to assure that radiation protection principles are followed. Due to different types of interventionist medical exams, usually the medical staffs are highly exposed to radiation, which it emphasizes that it is required safety procedures for dose reduction. In this work, studies were concerned with individual doses of medical staff that are directly engaged to interventionist procedures at hemodynamic services. Dose values from a data bank of the CDTN Individual Monitoring Service (IMS) were analyzed and measurements with film type and thermoluminescent (TL) dosimeters were performed for comparison purposes. Additionally, the influence of the use of a lead apron on the individual dose was investigated. Results suggested that the medical staff does not care about wearing the routine personal dosimeter and that the registered doses may not be representative to the actual annual effective doses. They also showed that effective doses are highly dependent on the characteristics and conditions of the lead apron that is worn by the medical staff. It is concluded that it is important to have personal dosimetric system up-graded for reliable measurements, to define an adequate algorithm for determining the effective dose and to train the medical staff to follow the basic radiation protection principle of optimization. (author)

  17. Prevalence and hemodynamic effects of leaning during CPR

    Niles, Dana E.; Sutton, Robert M.; Nadkarni, Vinay M.; Glatz, Andrew; Zuercher, Mathias; Maltese, Matthew R.; Eilevstjønn, Joar; Abella, Benjamin S.; Becker, Lance B.; Berg, Robert A.

    2013-01-01

    Background Cardiopulmonary resuscitation (CPR) guidelines recommend complete release between chest compressions (CC). Objective Evaluate the hemodynamic effects of leaning (incomplete chest wall release) during CPR and the prevalence of leaning during CPR. Results In piglet ventricular fibrillation cardiac arrests, 10% and 20% (1.8 kg and 3.6 kg, respectively), leaning during CPR increased right atrial pressures, decreased coronary perfusion pressures, and decreased cardiac index and left ventricular myocardial blood flow by nearly 50%. In contrast, residual leaning of a 260 g accelerometer/ force feedback device did not adversely affect cardiac index or myocardial blood flow. Among 108 adult in-hospital CPR events, leaning ≥2.5 kg was demonstrable in 91% of the events and 12% of the evaluated CC. For 12 children with in-hospital CPR, 28% of CC had residual leaning ≥2.5 kg and 89% had residual leaning ≥0.5 kg. Conclusions Leaning during CPR increases intrathoracic pressure, decreases coronary perfusion pressure, and decreases cardiac output and myocardial blood flow. Leaning is common during CPR. PMID:22208173

  18. Hemodynamics before and after bleb formation in cerebral aneurysms

    Cebral, Juan R.; Radaelli, Alessandro; Frangi, Alejandro; Putman, Christopher M.

    2007-03-01

    We investigate whether blebs in cerebral aneurysms form in regions of low or high wall shear stress (WSS), and how the intraaneurysmal hemodynamic pattern changes after bleb formation. Seven intracranial aneurysms harboring well defined blebs were selected from our database and subject-specific computational models were constructed from 3D rotational angiography. For each patient, a second anatomical model representing the aneurysm before bleb formation was constructed by smoothing out the bleb. Computational fluid dynamics simulations were performed under pulsatile flow conditions for both models of each aneurysm. In six of the seven aneurysms, the blebs formed in a region of elevated WSS associated to the inflow jet impaction zone. In one, the bleb formed in a region of low WSS associated to the outflow zone. In this case, the inflow jet maintained a fairly concentrated structure all the way to the outflow zone, while in the other six aneurysms it dispersed after impacting the aneurysm wall. In all aneurysms, once the blebs formed, new flow recirculation regions were formed inside the blebs and the blebs progressed to a state of low WSS. Assuming that blebs form due to a focally damaged arterial wall, these results seem to indicate that the localized injury of the vessel wall may be caused by elevated WSS associated with the inflow jet. However, the final shape of the aneurysm is probably also influenced by the peri-aneurysmal environment that can provide extra structural support via contact with structures such as bone or dura matter.

  19. Effects of adenosine infusion into renal interstitium on renal hemodynamics

    Pawlowska, D.; Granger, J.P.; Knox, F.G.

    1987-01-01

    This study was designed to investigate the hemodynamic effects of exogenous adenosine in the interstitium of the rat kidney. Adenosine or its analogues were infused into the renal interstitium by means of chronically implanted capsules. In fusion of adenosine decreased glomerular filtration rate (GFR) from 0.81 +/- 0.06 to 0.37 +/- 0.06 ml/min while having no effect on renal blood flow (RBF). The metabolically stable analogue, 2-chloradenosine (2-ClAdo), decreased GFR from 0.73 +/- 0.07 to 021 +/- 0.06 ml/min. Interstitial infusion of theophylline, an adenosine receptor antagonist, completely abolished the effects of adenosine and 2-ClAdo on GFR. The distribution of adenosine, when infused into the renal interstitium, was determined using radiolabeled 5'-(N-ethyl)-carboxamidoadenosine (NECA), a metabolically stable adenosine agonist. After continuous infusion, [ 3 H]NECA was distributed throughout the kidney. The effects of NECA to reduce GFR were similar to those of adenosine and 2-ClAdo. They conclude that increased levels of adenosine in the renal interstitium markedly decrease GFR without affecting RBF in steady-state conditions. The marked effects of adenosine agonists during their infusion into the renal interstitium and the complete blockade of these effects by theophylline suggest an extracellular action of adenosine

  20. A dimensionless parameter for classifying hemodynamics in intracranial

    Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the most important factors correlated to the IA rupture are hemodynamic factors such as wall shear stress (WSS) and oscillatory shear index (OSI) which are affected by the IA flows. Here, we carry out three-dimensional high resolution simulations on representative IA models with simple geometries to test a dimensionless number (first proposed by Le et al., ASME J Biomech Eng, 2010), denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports across the IA neck to the time required for vortex ring formation. Based on the definition, the flow mode is vortex if An>1 and it is cavity if AnOSI on the human subject IA. This work was supported partly by the NIH grant R03EB014860, and the computational resources were partly provided by CCR at UB. We thank Prof. Hui Meng and Dr. Jianping Xiang for providing us the database of aneurysms and helpful discussions.

  1. Evaluation of collective protection equipment in a hemodynamic room

    Casagrande, Saman; Silva, Ana Maria Marques da; Real, Jessica Villa; Luz, Renata Matos da

    2014-01-01

    Interventional radiology has high occupational dose rates. The use of personal protective equipment (PPE) and collective protection (ECP) help to reduce the dose delivered to the individuals occupationally exposed (IOE). In order to minimize the exposure of IOE's in interventionists procedures, evaluated the attenuation of the secondary radiation produced by collective protection equipment (CPE), was used a chest non-anthropomorphic phantom of polymethylmethacrylates (PMMA), with column simulator in aluminum, with variable thicknesses and kerma rate measures the air by varying the frequency tables 15 and 30 frames / s and different exposure modes. Data were acquired initially at the height of 1.25 m, using the following combinations of the ECP: (I) unshielded, (II) with plumbum display, (III) combining skirt + display. Measured at a height of 0.5 m were acquired with and without skirt. The attenuation ranged from 83.8% to 95.4% for a thickness of 25 cm. The maximum attenuation occurred with the combination of display and skirt. There was a 5 time increase in air kerma rate to be used cine display mode, when compared to the low mode. By analyzing the frequency of the frames were obtained differences up to 3 times higher for 30 frames / s, when compared with 15 frames / s. The results show the importance of using ECP in hemodynamics services, which together with the PPE, ensure adequate protection for IOEs

  2. Mining data from hemodynamic simulations via Bayesian emulation

    Nair Prasanth B

    2007-12-01

    Full Text Available Abstract Background: Arterial geometry variability is inevitable both within and across individuals. To ensure realistic prediction of cardiovascular flows, there is a need for efficient numerical methods that can systematically account for geometric uncertainty. Methods and results: A statistical framework based on Bayesian Gaussian process modeling was proposed for mining data generated from computer simulations. The proposed approach was applied to analyze the influence of geometric parameters on hemodynamics in the human carotid artery bifurcation. A parametric model in conjunction with a design of computer experiments strategy was used for generating a set of observational data that contains the maximum wall shear stress values for a range of probable arterial geometries. The dataset was mined via a Bayesian Gaussian process emulator to estimate: (a the influence of key parameters on the output via sensitivity analysis, (b uncertainty in output as a function of uncertainty in input, and (c which settings of the input parameters result in maximum and minimum values of the output. Finally, potential diagnostic indicators were proposed that can be used to aid the assessment of stroke risk for a given patient's geometry.

  3. Evaluation of the occupational dose in hemodynamic procedures

    Silva, Amanda J. da; Fernandes, Ivani M.; Sordi, Gian Maria A.A.; Carneiro, Janete C. Gaburo

    2010-01-01

    The purpose of this study was to evaluate the dose received by health professionals in a hemodynamic service. It was necessary to know the profile of these professional, to carry out a survey the occupational external doses during the years 2000 to 2009 and to evaluate the distribution of the effective dose from the special procedures guided by fluoroscopy. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account variables such as gender, age, individual monitoring time, number of jobs and tasks performed in the sector. In addition, it was performed an examination of the external individual monitoring doses from the records of the institution. The sample was composed of 35 professionals, 11 males and 24 females, with mean age of (43.0 +- 10.4) years. The average monitoring time of individuals analyzed within the institution was (11.3 +- 9.1) years, considering the period before the study. The minimum record dose level was 0.2 mSv and the maximum dose was 22.7 mSv. Doctors and nursing assistants were the professionals more exposed to radiation, due probably remaining closer to the examination table and X-ray tube during the interventional procedure. (author)

  4. Maternal hemodynamics: a method to classify hypertensive disorders of pregnancy.

    Ferrazzi, Enrico; Stampalija, Tamara; Monasta, Lorenzo; Di Martino, Daniela; Vonck, Sharona; Gyselaers, Wilfried

    2018-01-01

    The classification of hypertensive disorders of pregnancy is based on the time at the onset of hypertension, proteinuria, and other associated complications. Maternal hemodynamic interrogation in hypertensive disorders of pregnancy considers not only the peripheral blood pressure but also the entire cardiovascular system, and it might help to classify the different clinical phenotypes of this syndrome. This study aimed to examine cardiovascular parameters in a cohort of patients affected by hypertensive disorders of pregnancy according to the clinical phenotypes that prioritize fetoplacental characteristics and not the time at onset of hypertensive disorders of pregnancy. At the fetal-maternal medicine unit of Ziekenhuis Oost-Limburg (Genk, Belgium), maternal cardiovascular parameters were obtained through impedance cardiography using a noninvasive continuous cardiac output monitor with the patients placed in a standing position. The patients were classified as pregnant women with hypertensive disorders of pregnancy who delivered appropriate- and small-for-gestational-age fetuses. Normotensive pregnant women with an appropriate-for-gestational-age fetus at delivery were enrolled as the control group. The possible impact of obesity (body mass index ≥30 kg/m 2 ) on maternal hemodynamics was reassessed in the same groups. Maternal age, parity, body mass index, and blood pressure were not significantly different between the hypertensive disorders of pregnancy/appropriate-for-gestational-age and hypertensive disorders of pregnancy/small-for-gestational-age groups. The mean uterine artery pulsatility index was significantly higher in the hypertensive disorders of pregnancy/small-for-gestational-age group. The cardiac output and cardiac index were significantly lower in the hypertensive disorders of pregnancy/small-for-gestational-age group (cardiac output 6.5 L/min, cardiac index 3.6) than in the hypertensive disorders of pregnancy/appropriate-for-gestational-age group

  5. Influence of norepinephrine transporter inhibition on hemodynamic response to hypergravitation

    Strempel, Sebastian

    2011-01-01

    Background: Sympathetically-mediated tachycardia and vasoconstriction maintain blood pressure during hypergravitational stress, thereby preventing gravitation-induced loss of consciousness (g-LOC). Norepinephrine transporter (NET) inhibition prevents neurally-mediated (pre)syncope during gravitational stress imposed by head-up tilt testing. Thus, it seems reasonable that NET inhibition could increase tolerance to hypergravitational stress. Methods. We performed a double-blind, randomized...

  6. Heat tolerance in wheat

    Sharma, Dew Kumari

    As a consequence of global climate change, heat stress together with other abiotic stresses will remain an important determinant of future food security. Wheat (Triticum aestivum L.) is the third most important crop of the world feeding one third of the world population. Being a crop of temperate...... climate, wheat is sensitive to heat stress. We need to understand how our crops will perform in these changing climatic conditions and how we can develop varieties, which are more tolerant. The PhD study focussed on understanding heat tolerance in wheat with a combined approach of plant physiology...... and quantitative genetics in particular, plant phenotyping based quantitative trait loci (QTL) discovery for a physiological trait under heat stress. Chlorophyll a fluorescence trait, Fv/Fm was used as a phenotyping tool, as it reflects the effect of heat stress on maximum photochemical efficiency of photosystem...

  7. Magma replenishment and volcanic unrest inferred from the analysis of VT micro-seismicity and seismic velocity changes at Piton de la Fournaise Volcano

    Brenguier, F.; Rivemale, E.; Clarke, D. S.; Schmid, A.; Got, J.; Battaglia, J.; Taisne, B.; Staudacher, T.; Peltier, A.; Shapiro, N. M.; Tait, S.; Ferrazzini, V.; Di Muro, A.

    2011-12-01

    Piton de la Fournaise volcano (PdF) is among the most active basaltic volcanoes worldwide with more than one eruption per year on average. Also, PdF is densely instrumented with short-period and broad-band seismometers as well as with GPS receivers. Continuous seismic waveforms are available from 1999. Piton de la Fournaise volcano has a moderate inter-eruptive seismic activity with an average of five detected Volcano-Tectonic (VT) earthquakes per day with magnitudes ranging from 0.5 to 3.5. These earthquakes are shallow and located about 2.5 kilometers beneath the edifice surface. Volcanic unrest is captured on average a few weeks before eruptions by measurements of increased VT seismicity rate, inflation of the edifice summit, and decreased seismic velocities from correlations of seismic noise. Eruptions are usually preceded by seismic swarms of VT earthquakes. Recently, almost 50 % of seismic swarms were not followed by eruptions. Within this work, we aim to gather results from different groups of the UnderVolc research project in order to better understand the processes of deep magma transfer, volcanic unrest, and pre-eruptive magma transport initiation. Among our results, we show that the period 1999-2003 was characterized by a long-term increase of VT seismicity rate coupled with a long-term decrease of seismic velocities. These observations could indicate a long-term replenishment of the magma storage area. The relocation of ten years of inter-eruptive micro-seismicity shows a narrow (~300 m long) sub-vertical fault zone thus indicating a conduit rather than an extended magma reservoir as the shallow magma feeder system. Also, we focus on the processes of short-term volcanic unrest and prove that magma intrusions within the edifice leading to eruptions activate specific VT earthquakes that are distinct from magma intrusions that do not lead to eruptions. We thus propose that, among the different pathways of magma transport within the edifice, only one will

  8. Socially-Tolerable Discrimination

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

  9. Regional variation in interhemispheric coordination of intrinsic hemodynamic fluctuations.

    Stark, David E; Margulies, Daniel S; Shehzad, Zarrar E; Reiss, Philip; Kelly, A M Clare; Uddin, Lucina Q; Gee, Dylan G; Roy, Amy K; Banich, Marie T; Castellanos, F Xavier; Milham, Michael P

    2008-12-17

    Electrophysiological studies have long demonstrated a high degree of correlated activity between the left and right hemispheres, however little is known about regional variation in this interhemispheric coordination. Whereas cognitive models and neuroanatomical evidence suggest differences in coordination across primary sensory-motor cortices versus higher-order association areas, these have not been characterized. Here, we used resting-state functional magnetic resonance imaging data acquired from 62 healthy volunteers to examine interregional correlation in spontaneous low-frequency hemodynamic fluctuations. Using a probabilistic atlas, we correlated probability-weighted time series from 112 regions comprising the entire cerebrum. We then examined regional variation in correlated activity between homotopic regions, contrasting primary sensory-motor cortices, unimodal association areas, and heteromodal association areas. Consistent with previous studies, robustly correlated spontaneous activity was noted between all homotopic regions, which was significantly higher than that between nonhomotopic (heterotopic and intrahemispheric) regions. We further demonstrated substantial regional variation in homotopic interhemispheric correlations that was highly consistent across subjects. Specifically, there was a gradient of interhemispheric correlation, with highest correlations across primary sensory-motor cortices (0.758, SD=0.152), significantly lower correlations across unimodal association areas (0.597, SD=0.230) and still lower correlations across heteromodal association areas (0.517, SD=0.226). These results demonstrate functional differences in interhemispheric coordination related to the brain's hierarchical subdivisions. Synchrony across primary cortices may reflect networks engaged in bilateral sensory integration and motor coordination, whereas lower coordination across heteromodal association areas is consistent with functional lateralization of these regions

  10. Cerebral hemodynamics in patients with moyamoya disease, (2)

    Takeuchi, Shigekazu

    1983-01-01

    Regional cerebral blood flow (rCBF) was measured by the 133 Xe inhalation method in 19 patients with moyamoya disease aged 5 to 46 and compared with that in 17 healthy volunteers aged 7 to 67. In healthy volunteers, mean hemispheric flow values (mCBF) in the steady state decreased and cerebrovascular resistance (CVR) increased with advancing age. Most young patients showed low values of mCBF in both hemispheres in comparison with healthy volunteers. About half of the young patients showed higher values of CVR than young healthy volunteers. The distribution of rCBF showed a hyperfrontal pattern in healthy volunteers. However, in the patients, regional distribution of hemispheric flow showed a different pattern with low flow in the upper frontal region and mean flow in the posterotemporal and occipital regions. rCBF measurements were carried out during hyperventilation in five healthy volunteers and in one patient, and during 5% CO 2 inhalation in one healthy volunteer and two patients. CO 2 reactivity was uniformly present in the hemispheres of healthy volunteers. rCBF in both hemispheres was reduced by hyperventilation, more markedly in the patient than in healthy volunteers. On the other hand, in two patients, the flow was increased in the temporo-occipital regions and was decreased in the frontal region by 5% CO 2 inhalation, and mCBF was slightly increased. Postoperative rCBF measurements in 21 sides of 12 young patients indicated a gradual increase of mCBF in 14 sides of nine patients from 3 months after surgery. These results indicate that rCBF measurements by the 133 Xe inhalation method are useful in determining cerebral hemodynamics in patients with moyamoya disease, especially in children. (J.P.N.)

  11. Hemodynamic and permeability characteristics of acute experimental necrotizing enterocolitis

    Miller, M.J.; Adams, J.; Gu, X.A.; Zhang, X.J.; Clark, D.A.

    1990-01-01

    We examined the local hemodynamic response of intestinal loops during acute necrotizing enterocolitis (NEC) in anesthetized rabbits. NEC was induced in ileal loops by transmural injection of a solution containing casein (10 mg/ml) and calcium gluconate (50 mg/ml) acidified to pH 4.0 with propionic or acetic acid. Control loops received casein only (pH 5.0). Mucosal damage was quantified by the blood-to-lumen movement of [51Cr]EDTA, fluid shifts into the lumen, and histology. Mean arterial pressure and loop blood flow were steady over the 3-hr period, loop fluid volume decreased, and there was no evidence of necrosis or epithelial damage. In loops receiving acidified casein and calcium gluconate, there was an immediate dramatic increase in loop blood flow that returned to baseline by 50 min. In addition, loop fluid volume was dramatically increased, necrosis was noted in the form of blunting and loss of villi, and sevenfold increase in [51Cr]EDTA permeability was evident. Administration of CV 1808 (30 mg/kg/hr), a selective adenosine2 agonist, which maintained and elevated loop blood flow throughout the 3 hr protocol, failed to alter the changes in loop fluid volume or prevent necrosis. Histamine levels in loop fluid levels were significantly elevated 20-30 min after NEC induction when compared to saline controls, indicating an early activation of mucosal defenses with this luminal insult. Thus, this model of NEC is characterized by a transient, acute hyperemia, increased intestinal permeability, and histamine release. As mucosal damage was independent of ischemia and could not be prevented by vasodilatory therapy, this model supports the clinical findings that NEC is correlated with luminal factors related to feeding and independent of cardiovascular stress

  12. Ambient Temperature and Cerebrovascular Hemodynamics in the Elderly.

    Pan, Wen-Chi; Eliot, Melissa N; Koutrakis, Petros; Coull, Brent A; Sorond, Farzaneh A; Wellenius, Gregory A

    2015-01-01

    Some prior studies have linked ambient temperature with risk of cerebrovascular events. If causal, the pathophysiologic mechanisms underlying this putative association remain unknown. Temperature-related changes in cerebral vascular function may play a role, but this hypothesis has not been previously evaluated. We evaluated the association between ambient temperature and cerebral vascular function among 432 participants ≥65 years old from the MOBILIZE Boston Study with data on cerebrovascular blood flow, cerebrovascular resistance, and cerebrovascular reactivity in the middle cerebral artery. We used linear regression models to assess the association of mean ambient temperature in the previous 1 to 28 days with cerebrovascular hemodynamics adjusting for potential confounding factors. A 10°C increase in the 21-day moving average of ambient temperature was associated with a 10.1% (95% confidence interval [CI], 2.2%, 17.3%) lower blood flow velocity, a 9.0% (95% CI, 0.7%, 18.0%) higher cerebrovascular resistance, and a 15.3% (95%CI, 2.7%, 26.4%) lower cerebral vasoreactivity. Further adjustment for ozone and fine particulate matter (PM2.5) did not materially alter the results. However, we found statistically significant interactions between ambient temperature and PM2.5 such that the association between temperature and blood flow velocity was attenuated at higher levels of PM2.5. In this elderly population, we found that ambient temperature was negatively associated with cerebral blood flow velocity and cerebrovascular vasoreactivity and positively associated with cerebrovascular resistance. Changes in vascular function may partly underlie the observed associations between ambient temperature and risk of cerebrovascular events.

  13. Central Hemodynamics and Arterial Stiffness in Systemic Sclerosis.

    Bartoloni, Elena; Pucci, Giacomo; Cannarile, Francesca; Battista, Francesca; Alunno, Alessia; Giuliani, Marco; Cafaro, Giacomo; Gerli, Roberto; Schillaci, Giuseppe

    2016-12-01

    Although microvascular disease is a hallmark of systemic sclerosis (SSc), a higher prevalence of macrovascular disease and a poorer related prognosis have been reported in SSc than in the general population. The simultaneous assessment of prognostically relevant functional properties of larger and smaller arteries, and their effects on central hemodynamics, has never been performed in SSc using the state-of-the-art techniques. Thirty-four women with SSc (aged 61±15 years, disease duration 17±12 years, and blood pressure 123/70±18/11 mm Hg) and 34 healthy women individually matched by age and mean arterial pressure underwent the determination of carotid-femoral (aortic) and carotid-radial (upper limb) pulse wave velocity (a direct measure of arterial stiffness), aortic augmentation (a measure of the contribution of reflected wave to central pulse pressure), and aortobrachial pulse pressure amplification (brachial/aortic pulse pressure) through applanation tonometry (SphygmoCor). Patients and controls did not differ by carotid-femoral or carotid-radial pulse wave velocity. Aortic augmentation index corrected for a heart rate of 75 bpm (AIx@75) was higher in women with SSc (30.9±16% versus 22.2±12%; P=0.012). Patients also had a lower aortobrachial amplification of pulse pressure (1.22±0.18 versus 1.33±0.25; P=0.041). SSc was an independent predictor of AIx@75 (direct) and pulse pressure amplification (inverse). Among patients, age, mean arterial pressure, and C-reactive protein independently predicted carotid-femoral pulse wave velocity. Age and mean arterial pressure were the only predictors of AIx@75. Women with SSc have increased aortic augmentation and decreased pulse pressure amplification (both measures of the contribution of reflected wave to central waveform) but no changes in aortic or upper limb arterial stiffness. Microvascular involvement occurs earlier than large artery stiffening in SSc. © 2016 American Heart Association, Inc.

  14. Hemodynamic Characteristics Including Pulmonary Hypertension at Rest and During Exercise Before and After Heart Transplantation

    Lundgren, Jakob; Rådegran, Göran

    2015-01-01

    Background Little is known about the hemodynamic response to exercise in heart failure patients at various ages before and after heart transplantation (HT). This information is important because postoperative hemodynamics may be a predictor of survival. To investigate the hemodynamic response to HT and exercise, we grouped our patients based on preoperative age and examined their hemodynamics at rest and during exercise before and after HT. Methods and Results Ninety-four patients were evaluated at rest prior to HT with right heart catheterization at our laboratory. Of these patients, 32 were evaluated during slight supine exercise before and 1 year after HT. Postoperative evaluations were performed at rest 1 week after HT and at rest and during exercise at 4 weeks, 3 months, 6 months, and 1 year after HT. The exercise patients were divided into 2 groups based on preoperative age of ≤50 or >50 years. There were no age-dependent differences in the preoperative hemodynamic exercise responses. Hemodynamics markedly improved at rest and during exercise at 1 and 4 weeks, respectively, after HT; however, pulmonary and, in particular, ventricular filling pressures remained high during exercise at 1 year after HT, resulting in normalized pulmonary vascular resistance response but deranged total pulmonary vascular resistance response. Conclusions Our findings suggest that, (1) in patients with heart failure age ≤50 or >50 years may not affect the hemodynamic response to exercise to the same extent as in healthy persons, and (2) total pulmonary vascular resistance may be more adequate than pulmonary vascular resistance for evaluating the exercise response after HT. PMID:26199230

  15. Effects on hemodynamics and gas exchange of omega-3 fatty acid-enriched lipid emulsion in acute respiratory distress syndrome (ARDS: a prospective, randomized, double-blind, parallel group study

    Sacanell Judit

    2008-10-01

    Full Text Available Abstract Introduction We investigated the effects on hemodynamics and gas exchange of a lipid emulsion enriched with omega-3 fatty acids in patients with ARDS. Methods The design was a prospective, randomized, double-blind, parallel group study in our Intensive Medicine Department of Vall d'Hebron University Hospital (Barcelona-Spain. We studied 16 consecutive patients with ARDS and intolerance to enteral nutrition (14 men and 2 women; mean age: 58 ± 13 years; APACHE II score: 17.8 ± 2.3; Lung Injury Score: 3.1 ± 0.5; baseline PaO2/FiO2 ratio: 149 ± 40. Patients were randomized into 2 groups: Group A (n = 8 received the study emulsion Lipoplus® 20%, B.Braun Medical (50% MCT, 40% LCT, 10% ω-3; Group B (n = 8 received the control emulsion Intralipid® Fresenius Kabi (100% LCT. Lipid emulsions were administered during 12 h at a dose of 0.12 g/kg/h. Measurements of the main hemodynamic and gas exchange parameters were made at baseline (immediately before administration of the lipid emulsions, every hour during the lipid infusion, at the end of administration, and six hours after the end of administration lipid infusion. Results No statistically significant changes were observed in the different hemodynamic values analyzed. Likewise, the gas exchange parameters did not show statistically significant differences during the study. No adverse effect attributable to the lipid emulsions was seen in the patients analyzed. Conclusion The lipid emulsion enriched with omega-3 fatty acids was safe and well tolerated in short-term administration to patients with ARDS. It did not cause any significant changes in hemodynamic and gas exchange parameters. Trial registration ISRCTN63673813

  16. Impact of Intra-Extracranial Hemodynamics on Cerebral Ischemia by Arterial Hypertension (Part 2

    Alexander G. Kruglov, PhD, ScD

    2012-06-01

    Full Text Available The association between hemodynamic and biochemical parameters of cerebral blood flow have been studied in man, using mathematical methods of statistics. The values have been obtained through catheterization using a probe jammed at the level of the bulb of the superior jugular vein. Relationships with central hemodynamic parameters have been evaluated, including the right atrium, the right ventricle, and the left ventricle, as well as with pressure and biochemical values of the arterial bed. Data have been acquired in patients with stable arterial hypertension. Analysis of all relationship between hemodynamic and biochemical parameters has shown that the uniform hemodynamic zone: Sin.P. – SJV – SEV – the right atrium, normally participates in regulation of gaseous exchange in the human brain depending on the minimum pressure on the way of outflow from the brain. In stable arterial hypertension, this type of regulation is lost. On the basis of the results of this study, it has been concluded that blood viscosity is normally a primary controlled parameter of homeostasis. In stable arterial hypertension, homeostatic control of factors determining rheological and thrombogenic properties of blood, as well as participating in the development of brain ischemic conditions is lost. This increases risk of disturbances in central hemodynamics.

  17. Intraoperative brain hemodynamic response assessment with real-time hyperspectral optical imaging (Conference Presentation)

    Laurence, Audrey; Pichette, Julien; Angulo-Rodríguez, Leticia M.; Saint Pierre, Catherine; Lesage, Frédéric; Bouthillier, Alain; Nguyen, Dang Khoa; Leblond, Frédéric

    2016-03-01

    Following normal neuronal activity, there is an increase in cerebral blood flow and cerebral blood volume to provide oxygenated hemoglobin to active neurons. For abnormal activity such as epileptiform discharges, this hemodynamic response may be inadequate to meet the high metabolic demands. To verify this hypothesis, we developed a novel hyperspectral imaging system able to monitor real-time cortical hemodynamic changes during brain surgery. The imaging system is directly integrated into a surgical microscope, using the white-light source for illumination. A snapshot hyperspectral camera is used for detection (4x4 mosaic filter array detecting 16 wavelengths simultaneously). We present calibration experiments where phantoms made of intralipid and food dyes were imaged. Relative concentrations of three dyes were recovered at a video rate of 30 frames per second. We also present hyperspectral recordings during brain surgery of epileptic patients with concurrent electrocorticography recordings. Relative concentration maps of oxygenated and deoxygenated hemoglobin were extracted from the data, allowing real-time studies of hemodynamic changes with a good spatial resolution. Finally, we present preliminary results on phantoms obtained with an integrated spatial frequency domain imaging system to recover tissue optical properties. This additional module, used together with the hyperspectral imaging system, will allow quantification of hemoglobin concentrations maps. Our hyperspectral imaging system offers a new tool to analyze hemodynamic changes, especially in the case of epileptiform discharges. It also offers an opportunity to study brain connectivity by analyzing correlations between hemodynamic responses of different tissue regions.

  18. Hemodynamics in stented vertebral artery ostial stenosis based on computational fluid dynamics simulations.

    Qiao, Aike; Dai, Xuan; Niu, Jing; Jiao, Liqun

    2016-01-01

    Hemodynamic factors may affect the potential occurrence of in-stent restenosis (ISR) after intervention procedure of vertebral artery ostial stenosis (VAOS). The purpose of the present study is to investigate the influence of stent protrusion length in implantation strategy on the local hemodynamics of the VAOS. CTA images of a 58-year-old female patient with posterior circulation transient ischemic attack were used to perform a 3D reconstruction of the vertebral artery. Five models of the vertebral artery before and after the stent implantation were established. Model 1 was without stent implantation, Model 2-5 was with stent protruding into the subclavian artery for 0, 1, 2, 3 mm, respectively. Computational fluid dynamics simulations based on finite element analysis were employed to mimic the blood flow in arteries and to assess hemodynamic conditions, particularly the blood flow velocity and wall shear stress (WSS). The WSS and the blood flow velocity at the vertebral artery ostium were reduced by 85.33 and 35.36% respectively after stents implantation. The phenomenon of helical flow disappeared. Hemodynamics comparison showed that stent struts that protruded 1 mm into the subclavian artery induced the least decrease in blood speed and WSS. The results suggest that stent implantation can improve the hemodynamics of VAOS, while stent struts that had protruded 1 mm into the subclavian artery would result in less thrombogenesis and neointimal hyperplasia and most likely decrease the risk of ISR.

  19. Fault Tolerant Computer Architecture

    Sorin, Daniel

    2009-01-01

    For many years, most computer architects have pursued one primary goal: performance. Architects have translated the ever-increasing abundance of ever-faster transistors provided by Moore's law into remarkable increases in performance. Recently, however, the bounty provided by Moore's law has been accompanied by several challenges that have arisen as devices have become smaller, including a decrease in dependability due to physical faults. In this book, we focus on the dependability challenge and the fault tolerance solutions that architects are developing to overcome it. The two main purposes

  20. Toleration, Synthesis or Replacement?

    Holtermann, Jakob v. H.; Madsen, Mikael Rask

    2016-01-01

    , in order to answer is not yet another partisan suggestion, but rather an attempt at making intelligible both the oppositions and the possibilities of synthesis between normative and empirical approaches to law. Based on our assessment and rational reconstruction of current arguments and positions, we...... therefore outline a taxonomy consisting of the following three basic, ideal-types in terms of the epistemological understanding of the interface of law and empirical studies: toleration, synthesis and replacement. This tripartite model proves useful with a view to teasing out and better articulating...

  1. Renal functional reserve and renal hemodynamics in hypertensive patients.

    Gaipov, Abduzhappar; Solak, Yalcin; Zhampeissov, Nurlan; Dzholdasbekova, Aliya; Popova, Nadezhda; Molnar, Miklos Z; Tuganbekova, Saltanat; Iskandirova, Elmira

    2016-10-01

    The renal functional reserve (RFR) is the ability of the kidneys to increase renal plasma flow and glomerular filtration rate (GFR) in response to protein intake. It is a measure of functional and anatomic integrity of nephrons. It is not known what relation between RFR and kidney Doppler parameters. We aimed to study the relation between the RFR and renal hemodynamic parameters in hypertensive patients with and without nephropathy who had normal kidney function. Twenty-four hypertensive subjects with nephropathy (HTN-n, n = 10) and hypertension without nephropathy (HTN, n = 14) were included in the study. Control group included 11 healthy subjects. Baseline GFR (GFR1) and GFR after intake of egg protein 1 mg/kg of body weight were determined (GFR2). RFR was calculated by the following formula: (GFR2-GFR1)/GFR1 × 100%. Doppler ultrasonography was performed. Arterial blood pressure (BP), body mass index (BMI), and estimated GFR were also recorded. HTN and HTN-n groups had impaired levels of RFR compared with controls (p < 0.05), significantly decreased value of flow velocity parameters (Vmax, Vmin), and increased RRI compared with controls. There was significant negative correlation of RFR with blood pressure levels (sBP, r = -0.435, p = 0.009; dBP, r = -0.504, p = 0.002), RRI (r = -0.456, p = 0.008), micro albuminuria (MAU, r = -0.366, p = 0.031) and positive correlation with Vmax and Vmin (r = 0.556, p = 0.001 and r = 0.643, respectively, p < 0.001). Linear regression showed that RRI and MAU were independent predictors of decreased RFR. RFR is lower in hypertensive patients despite near-normal level of kidney function and is related to particular level of BP. RRI and MAU were independent predictors of decreased RFR.

  2. Utility of Angle Correction for Hemodynamic Measurements with Doppler Echocardiography.

    Sigurdsson, Martin I; Eoh, Eun J; Chow, Vinca W; Waldron, Nathan H; Cleve, Jayne; Nicoara, Alina; Swaminathan, Madhav

    2018-04-06

    The routine application angle correction (AnC) in hemodynamic measurements with transesophageal echocardiography currently is not recommended but potentially could be beneficial. The authors hypothesized that AnC can be applied reliably and may change grading of aortic stenosis (AS). Retrospective analysis. Single institution, university hospital. During phase I, use of AnC was assessed in 60 consecutive patients with intraoperative transesophageal echocardiography. During phase II, 129 images from a retrospective cohort of 117 cases were used to quantify AS by mean pressure gradient. A panel of observers used custom-written software in Java to measure intra-individual and inter-individual correlation in AnC application, correlation with preoperative transthoracic echocardiography gradients, and regrading of AS after AnC. For phase I, the median AnC was 21 (16-35) degrees, and 17% of patients required no AnC. For phase II, the median AnC was 7 (0-15) degrees, and 37% of assessed images required no AnC. The mean inter-individual and intra-individual correlation for AnC was 0.50 (95% confidence interval [CI] 0.49-0.52) and 0.87 (95% CI 0.82-0.92), respectively. AnC did not improve agreement with the transthoracic echocardiography mean pressure gradient. The mean inter-rater and intra-rater agreement for grading AS severity was 0.82 (95% CI 0.81-0.83) and 0.95 (95% CI 0.91-0.95), respectively. A total of 241 (7%) AS gradings were reclassified after AnC was applied, mostly when the uncorrected mean gradient was within 5 mmHg of the severity classification cutoff. AnC can be performed with a modest inter-rater and intra-rater correlation and high degree of inter-rater and intra-rater agreement for AS severity grading. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Ethnopoly promotes tolerance

    CERN Bulletin

    2010-01-01

    On Friday 23 April, 225 primary school children from the eight schools in Meyrin-Cointrin and their accompanying adults took part in a big game of Ethnopoly. Private individuals, associations, administrations, shopkeepers and CERN all opened their doors to them to talk about their countries, their customs and what they are doing to promote tolerance and integration.   The CERN stand set up at ForumMeyrin for the Ethnopoly game. Scurrying from one place to another, the 10 and 11 year olds were made aware of the rich cultural diversity of their commune, which is home to 130 different nationalities. Physicists and engineers from CERN took up residence in the Forum Meyrin for the day in order to talk to the children about the advantages of international collaboration, a subject dear to the Organization's heart. They welcomed around fifty children in the course of the day, conveying to them a message of tolerance: despite their differences, the 10,000 scientists and other members of the CERN...

  4. Hemodynamic modelling of BOLD fMRI - A machine learning approach

    Jacobsen, Danjal Jakup

    2007-01-01

    This Ph.D. thesis concerns the application of machine learning methods to hemodynamic models for BOLD fMRI data. Several such models have been proposed by different researchers, and they have in common a basis in physiological knowledge of the hemodynamic processes involved in the generation...... of the BOLD signal. The BOLD signal is modelled as a non-linear function of underlying, hidden (non-measurable) hemodynamic state variables. The focus of this thesis work has been to develop methods for learning the parameters of such models, both in their traditional formulation, and in a state space...... formulation. In the latter, noise enters at the level of the hidden states, as well as in the BOLD measurements themselves. A framework has been developed to allow approximate posterior distributions of model parameters to be learned from real fMRI data. This is accomplished with Markov chain Monte Carlo...

  5. Estimation of equivalent dose on the ends of hemodynamic physicians during neurological procedures

    Squair, Peterson L.; Souza, Luiz C. de; Oliveira, Paulo Marcio C. de

    2005-01-01

    The estimation of doses in the hands of physicists during hemodynamic procedures is important to verify the application of radiation protection related to the optimization and limit of dose, principles required by the Portaria 453/98 of Ministry of Health/ANVISA, Brazil. It was checked the levels of exposure of the hands of doctors during the use of the equipment in hemodynamic neurological procedures through dosimetric rings with thermoluminescent dosemeters detectors of LiF: Mg, Ti (TLD-100), calibrated in personal Dose equivalent HP (0.07). The average equivalent dose in the end obtained was 41.12. μSv per scan with an expanded uncertainty of 20% for k = 2. This value is relative to the hemodynamic Neurology procedure using radiological protection procedures accessible to minimize the dose

  6. Ultrasound investigation central hemodynamics as a method of assessment effective analgesia in children

    K. Y. Dmytriieva

    2016-06-01

    Vinnitsa National Medical University M.I. Pirogov   Summary: The study was include in 23 children (12,4±1,2 years operated on for tumors of the retroperitoneal space (14 children, 61%, renal tumors (6 children, 26%, ovarian cancer (3 children, 13% showed that a comprehensive study of the reactions of pain behavior and central hemodynamics by ultrasonography showed that the use of the scheme KSME bupivacaine 0.3-0.4 mg / kg and a continuous infusion of drugs (fentanyl in a dose of 10 mcg/kg/h for postoperative pain relief leads to effective analgesia after traumatic operations and comprehensive ultrasound including color and spectral Doppler studies, is the main tool by enabling timely and accurately assess the condition of the central hemodynamics at different methods of analgesia.   Key words: central hemodynamics, ultrasound, anesthesia.

  7. Hemodynamic disturbances in cerebral ischemia; Correlation between positron emission tomographic and angiographic findings

    Tenjin, Hiroshi; Ueda, Satoshi; Mizukawa, Norihiko; Imahori, Yoshio; Hino, Akihiko; Ohmori, Yoshio [Kyoto Prefectural Univ. of Medicine (Japan); Nakahashi, Hisamitsu

    1993-04-01

    Proper treatment of ischemic stroke requires better understanding of cerebral hemodynamic changes. The hemodynamic changes associated with ischemia were measured using positron emission tomography and related to angiographic findings in the subacute and chronic stages of 17 ischemia patients who showed symptoms of main trunk stenosis of the internal carotid artery system. The hemodynamic factors, cerebral blood flow, cerebral blood volume, cerebral metabolic rate for oxygen, oxygen extraction fraction, and flow/volume ratio, were measured in regions of interest determined from the angiographic stenosis (over 50%) and compared in each stage. The cerebral blood flow and flow/volume ratio in the territory downstream of the main trunk stenosis and cerebral metabolic rate for oxygen in the whole cortex were decreased in the subacute stage. In the chronic stage, cerebral blood flow and flow/volume ratio decreased mainly in borderzone areas. (author).

  8. Automatd assessment of the state of central hemodynamics using a radiocardioanalyser RCA 3-01

    Sivachenko, T.P.; Zozulya, A.A.; Sribnaya, A.F.; Ratmanskij, A.Yu.; Tishchenko, F.M.; Kurenya, A.G.; Krupka, I.N.; Kulagin, S.N.; Protsenko, A.S.

    1987-01-01

    The authors presented the results of a clinical use of a new radiocardioanalyzer RCA 3-01 (manufactured in the USSR) providing for automated measurements and computations of indices of the central hemodynamics during studies using a method of dilution of radioactive nuclides. The main technical potentialities of the device designed on the basis of microprocessor technology, were described. The authors also provided the results of automated computation of the circulating blood volume and the main hemodynamic indices in a group of patients. Values of the hemodynamic indices were shown to correspond to actual ones and comparable to control ones and clinical evidence. The comparison of automated processing with a manual method of calculation indicated a significant coincidence of index values. The clinical use of the radiocardioanalyzer RGA 3-01 for automated assessment of the indices of the cardiovascular system was shown to hold promise among various groups of patients

  9. Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

    Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

    1986-01-01

    Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation

  10. The numerical simulation study of hemodynamics of the new dense-mesh stent

    Ma, Jiali; Yuan, Zhishan; Yu, Xuebao; Feng, Zhaowei; Miao, Weidong; Xu, Xueli; Li, Juntao

    2017-09-01

    The treatment of aortic aneurysm in new dense mesh stent is based on the principle of hemodynamic changes. But the mechanism is not yet very clear. This paper analyzed and calculated the hemodynamic situation before and after the new dense mesh stent implanting by the method of numerical simulation. The results show the dense mesh stent changed and impacted the blood flow in the aortic aneurysm. The changes include significant decrement of blood velocity, pressure and shear forces, while ensuring blood can supply branches, which means the new dense mesh stent's hemodynamic mechanism in the treatment of aortic aneurysm is clearer. It has very important significance in developing new dense mesh stent in order to cure aortic aneurysm.

  11. Weak correlations between hemodynamic signals and ongoing neural activity during the resting state

    Winder, Aaron T.; Echagarruga, Christina; Zhang, Qingguang; Drew, Patrick J.

    2017-01-01

    Spontaneous fluctuations in hemodynamic signals in the absence of a task or overt stimulation are used to infer neural activity. We tested this coupling by simultaneously measuring neural activity and changes in cerebral blood volume (CBV) in the somatosensory cortex of awake, head-fixed mice during periods of true rest, and during whisker stimulation and volitional whisking. Here we show that neurovascular coupling was similar across states, and large spontaneous CBV changes in the absence of sensory input were driven by volitional whisker and body movements. Hemodynamic signals during periods of rest were weakly correlated with neural activity. Spontaneous fluctuations in CBV and vessel diameter persisted when local neural spiking and glutamatergic input was blocked, and during blockade of noradrenergic receptors, suggesting a non-neuronal origin for spontaneous CBV fluctuations. Spontaneous hemodynamic signals reflect a combination of behavior, local neural activity, and putatively non-neural processes. PMID:29184204

  12. Biomechanical and Hemodynamic Measures of Right Ventricular Diastolic Function: Translating Tissue Biomechanics to Clinical Relevance.

    Jang, Sae; Vanderpool, Rebecca R; Avazmohammadi, Reza; Lapshin, Eugene; Bachman, Timothy N; Sacks, Michael; Simon, Marc A

    2017-09-12

    Right ventricular (RV) diastolic function has been associated with outcomes for patients with pulmonary hypertension; however, the relationship between biomechanics and hemodynamics in the right ventricle has not been studied. Rat models of RV pressure overload were obtained via pulmonary artery banding (PAB; control, n=7; PAB, n=5). At 3 weeks after banding, RV hemodynamics were measured using a conductance catheter. Biaxial mechanical properties of the RV free wall myocardium were obtained to extrapolate longitudinal and circumferential elastic modulus in low and high strain regions (E 1 and E 2 , respectively). Hemodynamic analysis revealed significantly increased end-diastolic elastance (E ed ) in PAB (control: 55.1 mm Hg/mL [interquartile range: 44.7-85.4 mm Hg/mL]; PAB: 146.6 mm Hg/mL [interquartile range: 105.8-155.0 mm Hg/mL]; P =0.010). Longitudinal E 1 was increased in PAB (control: 7.2 kPa [interquartile range: 6.7-18.1 kPa]; PAB: 34.2 kPa [interquartile range: 18.1-44.6 kPa]; P =0.018), whereas there were no significant changes in longitudinal E 2 or circumferential E 1 and E 2 . Last, wall stress was calculated from hemodynamic data by modeling the right ventricle as a sphere: stress=Pressure×radius2×thickness. RV pressure overload in PAB rats resulted in an increase in diastolic myocardial stiffness reflected both hemodynamically, by an increase in E ed , and biomechanically, by an increase in longitudinal E 1 . Modest increases in tissue biomechanical stiffness are associated with large increases in E ed . Hemodynamic measurements of RV diastolic function can be used to predict biomechanical changes in the myocardium. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  13. Spontaneous hemodynamic oscillations during human sleep and sleep stage transitions characterized with near-infrared spectroscopy.

    Tiina Näsi

    Full Text Available Understanding the interaction between the nervous system and cerebral vasculature is fundamental to forming a complete picture of the neurophysiology of sleep and its role in maintaining physiological homeostasis. However, the intrinsic hemodynamics of slow-wave sleep (SWS are still poorly known. We carried out 30 all-night sleep measurements with combined near-infrared spectroscopy (NIRS and polysomnography to investigate spontaneous hemodynamic behavior in SWS compared to light (LS and rapid-eye-movement sleep (REM. In particular, we concentrated on slow oscillations (3-150 mHz in oxy- and deoxyhemoglobin concentrations, heart rate, arterial oxygen saturation, and the pulsation amplitude of the photoplethysmographic signal. We also analyzed the behavior of these variables during sleep stage transitions. The results indicate that slow spontaneous cortical and systemic hemodynamic activity is reduced in SWS compared to LS, REM, and wakefulness. This behavior may be explained by neuronal synchronization observed in electrophysiological studies of SWS and a reduction in autonomic nervous system activity. Also, sleep stage transitions are asymmetric, so that the SWS-to-LS and LS-to-REM transitions, which are associated with an increase in the complexity of cortical electrophysiological activity, are characterized by more dramatic hemodynamic changes than the opposite transitions. Thus, it appears that while the onset of SWS and termination of REM occur only as gradual processes over time, the termination of SWS and onset of REM may be triggered more abruptly by a particular physiological event or condition. The results suggest that scalp hemodynamic changes should be considered alongside cortical hemodynamic changes in NIRS sleep studies to assess the interaction between the autonomic and central nervous systems.

  14. Fault-tolerant computing systems

    Dal Cin, M.; Hohl, W.

    1991-01-01

    Tests, Diagnosis and Fault Treatment were chosen as the guiding themes of the conference. However, the scope of the conference included reliability, availability, safety and security issues in software and hardware systems as well. The sessions were organized for the conference which was completed by an industrial presentation: Keynote Address, Reconfiguration and Recover, System Level Diagnosis, Voting and Agreement, Testing, Fault-Tolerant Circuits, Array Testing, Modelling, Applied Fault Tolerance, Fault-Tolerant Arrays and Systems, Interconnection Networks, Fault-Tolerant Software. One paper has been indexed separately in the database. (orig./HP)

  15. Commercialization of radiation tolerant camera

    Lee, Yong Bum; Choi, Young Soo; Kim, Sun Ku; Lee, Jong Min; Cha, Bung Hun; Lee, Nam Ho; Byun, Eiy Gyo; Yoo, Seun Wook; Choi, Bum Ki; Yoon, Sung Up; Kim, Hyun Gun; Sin, Jeong Hun; So, Suk Il

    1999-12-01

    In this project, radiation tolerant camera which tolerates 10{sup 6} - 10{sup 8} rad total dose is developed. In order to develop radiation tolerant camera, radiation effect of camera components was examined and evaluated, and camera configuration was studied. By the result of evaluation, the components were decided and design was performed. Vidicon tube was selected to use by image sensor and non-browning optics and camera driving circuit were applied. The controller needed for CCTV camera system, lens, light, pan/tilt controller, was designed by the concept of remote control. And two type of radiation tolerant camera were fabricated consider to use in underwater environment or normal environment. (author)

  16. Commercialization of radiation tolerant camera

    Lee, Yong Bum; Choi, Young Soo; Kim, Sun Ku; Lee, Jong Min; Cha, Bung Hun; Lee, Nam Ho; Byun, Eiy Gyo; Yoo, Seun Wook; Choi, Bum Ki; Yoon, Sung Up; Kim, Hyun Gun; Sin, Jeong Hun; So, Suk Il

    1999-12-01

    In this project, radiation tolerant camera which tolerates 10 6 - 10 8 rad total dose is developed. In order to develop radiation tolerant camera, radiation effect of camera components was examined and evaluated, and camera configuration was studied. By the result of evaluation, the components were decided and design was performed. Vidicon tube was selected to use by image sensor and non-browning optics and camera driving circuit were applied. The controller needed for CCTV camera system, lens, light, pan/tilt controller, was designed by the concept of remote control. And two type of radiation tolerant camera were fabricated consider to use in underwater environment or normal environment. (author)

  17. Variability of hemodynamic parameters in young healthy subjects with and without hypertensive family history

    Palombo, C.; Michelassi, C.; Ghione, S.

    1987-01-01

    In order to assess the short-term variability of the hemodynamic pattern in healthy normal subjects, Transcutaneous Aortovelography, a continuous wave Doppler technique, was performed in 17 normotensive males, 11 with and 6 without hypertensive family history and repeated after 30'. Reproducibility of measurements in the whole sample was comparable with previous observation reported in literature, but in the group with a positive family history of hypertension the reproducibility of most parameters was lower than in the other, suggesting the existence of a greater hemodynamic variability in normotensive offspring of hypertensive parents

  18. Hemodynamic and neuroendocrine responses to changes in sodium intake in compensated heart failure

    Damgaard, Morten; Norsk, Peter; Gustafsson, Finn

    2005-01-01

    inhibitors and beta-adrenoreceptor blockers. Therefore, we determined the hemodynamic and neuroendocrine responses to 1 wk of a low-sodium diet (70 mmol/day) and 1 wk of a high-sodium diet (250 mmol/day) in 12 HF patients and 12 age-matched controls in a randomized, balanced fashion. During steady......-state conditions, hemodynamic and neuroendocrine examinations were performed at rest and during bicycle exercise. In seated HF patients, high sodium intake increased body weight (1.6 +/- 0.4%), plasma volume (9 +/- 2%), cardiac index (14 +/- 6%), and stroke volume index (21 +/- 5%), whereas mean arterial pressure...

  19. Is there a specific hemodynamic effect in reflexology? A systematic review of randomized controlled trials.

    Jones, Jenny; Thomson, Patricia; Irvine, Kathleen; Leslie, Stephen J

    2013-04-01

    Reflexology claims that the feet are representative of the body and that massage to specific points of the feet increases blood supply to "mapped" organs in the body. This review provides the first systematic evaluation of existing reflexology randomized controlled trials (RCTs) to determine whether there is any evidence to suggest the existence of a reflexology treatment-related hemodynamic effect; to examine whether reflexology researchers used study designs that systematically controlled for nonspecific effects in order to isolate this specific component; and to highlight some of the methodological challenges that need to be overcome to demonstrate specific and beneficial hemodynamic effects. Fifty-two RCTs of reflexology published from 1990 to September 2011 were initially retrieved. Cardiorespiratory Department, Highland Heartbeat Centre, Raigmore Hospital, Inverness. Adult subjects. Studies using reflexology foot massage techniques as the intervention versus sham reflexology treatment, simple foot massage, conventional treatment, or no treatment as the control were then selected. OUTCOME MEASURES included any hemodynamic parameter potentially involved in the regulation of circulating blood volume and flow, including heart rate and systolic and diastolic arterial blood pressure. Seven RCTs suggested that reflexology has an effect on selected cardiovascular parameters; however, five of these delivered the reflexology intervention as a whole complex treatment, with the data collector often delivering the intervention themselves. This systematic review found that although reflexology has been shown to have an effect on selected hemodynamic variables, the lack of methodological control for nonspecific general massage effects means that there is little convincing evidence at this time to suggest the existence of a specific treatment-related hemodynamic effect. Furthermore, the review found that few studies of reflexology controlled for nonspecific effects in order

  20. Vegetative and hemodynamic responses to stress in adolescents with constitutional-exogenous obesity and vascular dystonia of hypertensive type

    Larina, N.

    2011-01-01

    We studied the characteristics of central hemodynamics and autonomic responses to cold and psycho-emotional test in adolescents with obesity and vascular dystonia of hypertensive type. Various options for the autonomic responses accompanied by changes in central hemodynamics as a function of body weight have been identified.

  1. Comparison of gabapentin, pregabalin and placebo as premedication for attenuation of hemodynamic response to laryngoscopy and endotracheal intubation

    Alireza Mahoori

    2017-08-01

    Conclusion: Oral gabapentin premedication is effective for control of hemodynamic pressor response of laryngoscopy and tracheal intubation. The study data showed that the pregabalin have the same effect. Pregabalin and gabapentin are both useful and safe for control of hemodynamic pressor response as premedication.

  2. Norepinephrine transporter inhibition alters the hemodynamic response to hypergravitation.

    Strempel, Sebastian; Schroeder, Christoph; Hemmersbach, Ruth; Boese, Andrea; Tank, Jens; Diedrich, André; Heer, Martina; Luft, Friedrich C; Jordan, Jens

    2008-03-01

    Sympathetically mediated tachycardia and vasoconstriction maintain blood pressure during hypergravitational stress, thereby preventing gravitation-induced loss of consciousness. Norepinephrine transporter (NET) inhibition prevents neurally mediated (pre)syncope during gravitational stress imposed by head-up tilt testing. Thus it seems reasonable that NET inhibition could increase tolerance to hypergravitational stress. We performed a double-blind, randomized, placebo-controlled crossover study in 11 healthy men (26 +/- 1 yr, body mass index 24 +/- 1 kg/m2), who ingested the selective NET inhibitor reboxetine (4 mg) or matching placebo 25, 13, and 1 h before testing on separate days. We monitored heart rate, blood pressure, and thoracic impedance in three different body positions (supine, seated, standing) and during a graded centrifuge run (incremental steps of 0.5 g for 3 min each, up to a maximal vertical acceleration load of 3 g). NET inhibition increased supine blood pressure and heart rate. With placebo, blood pressure increased in the seated position and was well maintained during standing. However, with NET inhibition, blood pressure decreased in the seated and standing position. During hypergravitation, blood pressure increased in a graded fashion with placebo. With NET inhibition, the increase in blood pressure during hypergravitation was profoundly diminished. Conversely, the tachycardic responses to sitting, standing, and hypergravitation all were greatly increased with NET inhibition. In contrast to our expectation, short-term NET inhibition did not improve tolerance to hypergravitation. Redistribution of sympathetic activity to the heart or changes in baroreflex responses could explain the excessive tachycardia that we observed.

  3. Numerical reproduction of hemodynamics change by acupuncture on Taichong (LR-3 based on the lumped-parameter approximation model of the systemic arteries

    Atsushi Shirai

    2015-09-01

    Conclusion: The present model has a potential to emulate hemodynamic change by acupuncture therapy by incorporating physiological correlation of stimulation of an acupoint and regulation of parameters that affect the hemodynamics.

  4. Salt Tolerance in Soybean

    Tsui-Hung Phang; Guihua Shao; Hon-Ming Lam

    2008-01-01

    Soybean is an Important cash crop and its productivity is significantly hampered by salt stress. High salt Imposes negative impacts on growth, nodulation, agronomy traits, seed quality and quantity, and thus reduces the yield of soybean. To cope with salt stress, soybean has developed several tolerance mechanisms, including: (I) maintenance of ion homeostasis; (ii) adjustment in response to osmotic stress; (iii) restoration of osmotic balance; and (iv) other metabolic and structural adaptations. The regulatory network for abiotic stress responses in higher plants has been studied extensively in model plants such as Arabidopsis thaliana. Some homologous components involved in salt stress responses have been identified in soybean. In this review, we tried to integrate the relevant works on soybean and proposes a working model to descdbe Its salt stress responses at the molecular level.

  5. Delay tolerant networks

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  6. Characteristics of intraoperative abnormal hemodynamics during resection of an intra-fourth ventricular tumor located on the dorsal medulla oblongata.

    Ideguchi, Makoto; Kajiwara, Koji; Yoshikawa, Koichi; Sadahiro, Hirokazu; Nomura, Sadahiro; Fujii, Masami; Suzuki, Michiyasu

    2013-01-01

    Abnormal hemodynamics during extirpation of a para-medulla oblongata (MO) tumor is common and may be associated with direct vagal stimulation of the medullary circuit. However, resection of tumors on the dorsal MO may also induce hemodynamic instability without direct vagal stimulus. The objective of this study was to examine the characteristics of hemodynamic instability unrelated to vagal stimulus during dissection of an intra-fourth ventricular tumor with attachment to the dorsal MO. A retrospective analysis was performed in 13 patients. Abnormal hemodynamics were defined as a > 20% change from the means of the intraoperative mean arterial pressure (MAP) and heart rate (HR). Relationships of intraoperative hemodynamics were evaluated with various parameters, including the volume of the MO. Six patients (46.2%) had intraoperative hypertension during separation of the tumor bulk from the dorsal MO. The maximum MAP and HR in these patients were significantly greater than those in patients with normal hemodynamics (116.0 ± 18.0 mmHg versus 85.6 ± 6.5 mmHg; 124.3 ± 22.8 bpm versus 90.5 ± 14.7 bpm). All six cases with abnormal hemodynamics showed hemodynamic fluctuation during separation of the tumor bulk from the dorsal MO. The preoperative volume of the MO in these patients was 1.11 cc less than that in patients with normal hemodynamics, but the volume after tumor resection was similar in the two groups (5.23 cc and 5.12 cc). This suggests that the MO was compressed by the conglutinate tumor bulk, with resultant fluctuation of hemodynamics. Recognition of and preparation for this phenomenon are important for surgery on a tumor located on the dorsal MO.

  7. Shaping tolerant attitudes towards immigrants

    Rapp, Carolin

    2017-01-01

    This article contributes to the ongoing discussion on how tolerance may be fostered in Western European countries and to the question of how contextual factors such as welfare state expenditures may contribute to this formation. Tolerance is understood as a basic democratic principle that helps c...

  8. Legal Quality, Inequality, and Tolerance

    Bjørnskov, Christian

    Previous findings suggest that income inequality leads to lower legal quality. This paper argues that voters' tolerance of inequality exerts an additional influence. Empirical findings suggest that inequality leads to lower legal quality due to its effect on trust while the tolerance of inequality...

  9. Legal Quality, Inequality, and Tolerance

    Bjørnskov, Christian

    2004-01-01

    Previous findings suggest that income inequality leads to lower legal quality. This paper argues that voters' tolerance of inequality exerts an additional influence. Empirical findings suggest that inequality leads to lower legal quality due to its effect on trust while the tolerance of inequality...

  10. Tolerance Issue in Kazakh Culture

    Aubakirova, Saltanat S.; Ismagambetova, Zukhra N.; Karabayeva, Aliya G.; Rysbekova, Shamshiya S.; Mirzabekova, Alma Sh.

    2016-01-01

    In this article the authors reveal the basic cultural mechanisms that influence the formation of the tolerance strategy in Kazakh and Kazakhstan society, show its basic directions, as well as its importance for the modern Kazakhstan society and the formation of intercultural communication with foreign countries. Tolerance is a necessary element of…

  11. Tolerance-Based Feature Transforms

    Reniers, Dennie; Telea, Alexandru

    2007-01-01

    Tolerance-based feature transforms (TFTs) assign to each pixel in an image not only the nearest feature pixels on the boundary (origins), but all origins from the minimum distance up to a user-defined tolerance. In this paper, we compare four simple-to-implement methods for computing TFTs on binary

  12. Effects of irradiation on the pulmonary hemodynamics and the pulmonary vascular permeability

    Ohkuda, Kazuhiro; Watanabe, Shinkichi; Okada, Shinichiroh

    1982-01-01

    In 4 sheeps, base lines of hemodynamics and lymph dynamics were observed for 2 hours, and then 1,000 rad of 60 Co was irradiated to the inferior lobes of the lung. Pulmonary hemodynamics and lymph dynamics were continuously observed, and water and protein permeability of the irradiated pulmonary vessels was evaluated. In 4 control sheeps, no change in pulmonary hemodynamics and lymph dynamics was noted. In the irradiated group, there was no remarkable change in pulmonary hemodynamics for 6 to 8 hours after 60 Co irradiation. Pulmonary lymph flow began to increase 2 hours after irradiation to about 1.7 times the base line level after 4 hours. The increase in pulmonary lymph flow was accompanied by decrease in plasma protein concentration and increase in protein concentration of the lung lymph, resulting in an apparent increase in the ratio of lymph/plasma protein concentration. Water and protein leak from the pulmonary vessels increased. A photomicroscopic observation revealed dilatation of the lymphatic vessels in the lung interstice and a mild pulmonary interstitial edema. Vascular damage, especially due to increased water and protein permeability of the lung capillary vessels, occurred immediately after 60 Co irradiation. (Ueda, J.)

  13. Hemodynamic and morphological characteristics of unruptured posterior communicating artery aneurysms with oculomotor nerve palsy.

    Lv, Nan; Yu, Ying; Xu, Jinyu; Karmonik, Christof; Liu, Jianmin; Huang, Qinghai

    2016-08-01

    OBJECT Unruptured posterior communicating artery (PCoA) aneurysms with oculomotor nerve palsy (ONP) have a very high risk of rupture. This study investigated the hemodynamic and morphological characteristics of intracranial aneurysms with high rupture risk by analyzing PCoA aneurysms with ONP. METHODS Fourteen unruptured PCoA aneurysms with ONP, 33 ruptured PCoA aneurysms, and 21 asymptomatic unruptured PCoA aneurysms were included in this study. The clinical, morphological, and hemodynamic characteristics were compared among the different groups. RESULTS The clinical characteristics did not differ among the 3 groups (p > 0.05), whereas the morphological and hemodynamic analyses showed that size, aspect ratio, size ratio, undulation index, nonsphericity index, ellipticity index, normalized wall shear stress (WSS), and percentage of low WSS area differed significantly (p PCoA aneurysms with ONP demonstrated a distinctive morphological-hemodynamic pattern that was significantly different compared with asymptomatic unruptured PCoA aneurysms and was similar to ruptured PCoA aneurysms. The larger size, more irregular shape, and lower WSS might be related to the high rupture risk of PCoA aneurysms.

  14. Effects of radiation, burn and combined radiation-burn injury on hemodynamics

    Ye Benlan; Cheng Tianming; Xiao Jiasi

    1996-01-01

    Changes in hemodynamics after radiation, burn and combined radiation burn injury within eight hours post injury were studied. The results indicate: (1) Shock of rats in the combined injury group is more severe than that in the burn group. One of the reasons is that the blood volume in the combined injury group is less than that in the burn group. Radiation injury plays an important role in this effect, which enhances the increase in vascular permeability and causes the loss of plasma. (2) Decrease in cardiac output and stroke work and increase in vascular resistance in the combined radiation burn group are more drastic than those in the burn group, which may cause and enhance shock. Replenishing fluid is useful for recovery of hemodynamics. (3) Rb uptake is increased in the radiation group which indicates that compensated increase of myocardial nutritional blood flow may take place before the changes of hemodynamics and shock. Changes of Rb uptake in the combined injury group is different from that in the radiation groups and in the burn group. The results also suggest that changes of ion channel activities may occur to a different extent after injury. (4) Verapamil is helpful to the recovery of hemodynamics post injury. It is better to combine verapamil with replenishing fluid

  15. Augmentation of sensory-evoked hemodynamic response in an early Alzheimer's disease mouse model.

    Kim, Jinho; Jeong, Yong

    2013-01-01

    Based on enlarged blood oxygen level-dependent (BOLD) responses in cognitively normal subjects at risk for Alzheimer's disease (AD), compensatory neuronal hyperactivation has been proposed as an early marker for diagnosis of AD. The BOLD response results from neurovascular coupling, i.e., hemodynamic response induced by neuronal activity. However, there has been no evidence of task-induced increases in hemodynamic response in animal models of AD. Here, we observed an augmented hemodynamic response pattern in a transgenic AβPP(SWE)/PS1ΔE9 mouse model of AD using three in vivo imaging methods: intrinsic optical signal imaging, multi-photon laser scanning microscopy, and laser Doppler flowmetry. Sensory stimulation resulted in augmented and prolonged hemodynamic responses in transgenic mice evidenced by changes in total, oxygenated, and deoxygenated hemoglobin concentration. This difference between transgenic and wild-type mice was significant at 7 months of age when amyloid plaques and cerebral amyloid angiopathy had developed but not at younger or older ages. Correspondingly, sensory stimulation-induced pial arteriole diameter was also augmented and prolonged in transgenic mice at 7 months of age. Cerebral blood flow response in transgenic mice was augmented but not prolonged. These results are consistent with the existence of BOLD signal hyperactivation in non-demented AD-risk human subjects, supporting its potential use as an early diagnostic marker of AD.

  16. Alpha-adducin Gly460Trp polymorphism and renal hemodynamics in essential hypertension

    Beeks, Esther; van der Klauw, Melanie M; Kroon, Abraham A; Spiering, Wilko; Fuss-Lejeune, Monique J M J; de Leeuw, Peter W

    2004-01-01

    Previous studies have shown an association between the alpha-adducin Gly460Trp polymorphism and salt-sensitive hypertension. Not much is known about the effects of the variants of this polymorphism on renal hemodynamics and function. Therefore, we performed the present study to investigate the

  17. Comparison of hemodynamic effects of lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor in hypertensive patients

    Bahadir Ezmek

    2010-08-01

    Full Text Available OBJECTIVE: Local anesthetic solutions with vasoconstrictors are not contraindicated in hypertensive patients, but due to their hemodynamic effects, local anesthetics without vasoconstrictors are mainly preferred by the clinicians. The aim of this study was to compare hemodynamic effects of three different local anesthetics without vasoconstrictors during tooth extraction in hypertensive patients. MATERIAL AND METHODS: Sixty-five mandibular molars and premolars were extracted in 60 hypertensive patients (29 females and 31 males; mean age: 66.95 ± 10.87 years; range: 38 to 86 years old. Inferior alveolar and buccal nerve blocks were performed with 2% lidocaine hydrochloride (HCl, 2% prilocaine HCl or 3% mepivacaine HCl without vasoconstrictor. Hemodynamic parameters namely systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial pressure (MAP, heart rate (HR, saturation rate (SR, rate pressure product (RPP and pressure rate quotient (PRQ were investigated before and at different intervals after anesthetic injection. RESULTS: The hemodynamic effects of the three agents were similar to each other, although some significance was observed for DBP, MAP, RPP and PRQ values in the lidocaine, prilocaine and mepivacaine groups. CONCLUSION: Lidocaine, prilocaine and mepivacaine solutions without vasoconstrictor can be safely used in hypertensive patients. It is advisable that dental practitioners select anesthetic solutions for hypertensive patients considering their cardiovascular effects in order to provide patient comfort and safety.

  18. Echographic and hemodynamic parameters in patients with hepatic cirrhosis and portal hypertension

    Rikhsieva, L.Eh.; Akhmedzhanova, Sh.Sh.; Myasnik, B.N.; Khodzhibekov, M.Kh.

    1989-01-01

    The efficiency of combined echoradionuclide investigation for the identification of the severity of portal hypertension and the determination of clear-cut criteria for the differentiation of stages of portal hypertension with reference to functional potentials of renal hemodynamics and systemic circulation at large is demonstrated

  19. Neuronal inhibition and excitation, and the dichotomic control of brain hemodynamic and oxygen responses

    Lauritzen, Martin; Mathiesen, Claus; Schaefer, Katharina

    2012-01-01

    under most conditions correlate to excitation of inhibitory interneurons, but there are important exceptions to that rule as described in this paper. Thus, variations in the balance between synaptic excitation and inhibition contribute dynamically to the control of metabolic and hemodynamic responses...

  20. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    Mommsen, Philipp; Pfeifer, Roman; Mohr, Juliane; Ruchholtz, Steffen; Flohé, Sascha; Fröhlich, Matthias; Keibl, Claudia; Seekamp, Andreas; Witte, Ingo

    2015-01-01

    Background. The deterioration of hemodynamics instantly endangers the patients' life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C) was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals' hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia. PMID:26170533

  1. The hemodynamic response of the alpha rhythm: an EEG/fMRI study.

    de Munck, J.C.; Goncalves, S.I.; Huijboom, L.; Kuijer, J.P.; Pouwels, P.J.; Heethaar, R.M.; Lopes da Silva, F.H.

    2007-01-01

    EEG was recorded during fMRI scanning of 16 normal controls in resting condition with eyes closed. Time variations of the occipital alpha band amplitudes were correlated to the fMRI signal variations to obtain insight into the hemodynamic correlates of the EEG alpha activity. Contrary to earlier

  2. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    Matthias Weuster

    2015-01-01

    Full Text Available Background. The deterioration of hemodynamics instantly endangers the patients’ life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals’ hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia.

  3. [Role of cerebral hemodynamics in the mechanism of development of acquired myopia in schoolchildren].

    Iastrebtseva, T A; Demidova, T E; Polikarpova, V E

    2008-01-01

    Rheoencephalography was used to study cerebral venous circulation in 199 schoolchildren aged 12-15 years who had emmetropia, pseudomyopia, and myopia. Tonometry was carried out in 39 persons. Cerebral venous hemodynamic dysfunction was more frequently encountered in schoolchildren with myopia than in those with emmetropia. Intraocular pressure was significantly higher only in schoolchildren with high myopia than in the controls.

  4. A Novel Technique for Identifying Patients with ICU Needs Using Hemodynamic Features

    A. Jalali

    2012-01-01

    Full Text Available Identification of patients requiring intensive care is a critical issue in clinical treatment. The objective of this study is to develop a novel methodology using hemodynamic features for distinguishing such patients requiring intensive care from a group of healthy subjects. In this study, based on the hemodynamic features, subjects are divided into three groups: healthy, risky and patient. For each of the healthy and patient subjects, the evaluated features are based on the analysis of existing differences between hemodynamic variables: Blood Pressure and Heart Rate. Further, four criteria from the hemodynamic variables are introduced: circle criterion, estimation error criterion, Poincare plot deviation, and autonomic response delay criterion. For each of these criteria, three fuzzy membership functions are defined to distinguish patients from healthy subjects. Furthermore, based on the evaluated criteria, a scoring method is developed. In this scoring method membership degree of each subject is evaluated for the three classifying groups. Then, for each subject, the cumulative sum of membership degree of all four criteria is calculated. Finally, a given subject is classified with the group which has the largest cumulative sum. In summary, the scoring method results in 86% sensitivity, 94.8% positive predictive accuracy and 82.2% total accuracy.

  5. Journal of Clinical Monitoring and Computing 2016 end of year summary : cardiovascular and hemodynamic monitoring

    Saugel, Bernd; Bendjelid, Karim; Critchley, Lester A.; Rex, Steffen; Scheeren, Thomas W. L.

    The assessment and optimization of cardiovascular and hemodynamic variables is a mainstay of patient management in the care for critically ill patients in the intensive care unit (ICU) or the operating room (OR). It is, therefore, of outstanding importance to meticulously validate technologies for

  6. Patient-Specific Modeling of Interventricular Hemodynamics in Single Ventricle Physiology

    Vedula, Vijay; Feinstein, Jeffrey; Marsden, Alison

    2016-11-01

    Single ventricle (SV) congenital heart defects, in which babies are born with only functional ventricle, lead to significant morbidity and mortality with over 30% of patients developing heart failure prior to adulthood. Newborns with SV physiology typically undergo three palliative surgeries, in which the SV becomes the systemic pumping chamber. Depending on which ventricle performs the systemic function, patients are classified as having either a single left ventricle (SLV) or a single right ventricle (SRV), with SRV patients at higher risk of failure. As the native right ventricles are not designed to meet systemic demands, they undergo remodeling leading to abnormal hemodynamics. The hemodynamic characteristics of SLVs compared with SRVs is not well established. We present a validated computational framework for performing patient-specific modeling of ventricular flows, and apply it across 6 SV patients (3SLV + 3SRV), comparing hemodynamic conditions between the two subgroups. Simulations are performed with a stabilized finite element method coupled with an immersed boundary method for modeling heart valves. We discuss identification of hemodynamic biomarkers of ventricular remodeling for early risk assessment of failure. This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and due to U.S. National Institute of Health through NIH NHLBI R01 Grants 5R01HL129727-02 and 5R01HL121754-03.

  7. Thoracic Aorta 3D Hemodynamics in Pediatric and Young Adult Patients With Bicuspid Aortic Valve

    Allen, Bradley D.; van Ooij, Pim; Barker, Alex J.; Carr, Maria; Gabbour, Maya; Schnell, Susanne; Jarvis, Kelly B.; Carr, James C.; Markl, Michael; Rigsby, Cynthia; Robinson, Joshua D.

    2015-01-01

    Background: To evaluate the 3D hemodynamics in the thoracic aorta of pediatric and young adult bicuspid aortic valve (BAV) patients. Methods: 4D flow MRI was performed in 30 pediatric and young adult BAV patients (age: 13.9 +/- 4.4 (range: [3.4, 20.7]) years old, M:F = 17:13) as part of this

  8. Hemodynamic effects of iodixanol and iohexol during ventriculography in patients with compromised left ventricular function

    Bergstra, A; van Dijk, RB; Brekke, O; Orozco, L; den Heijer, P; Crijns, HJGM

    A crossover study was performed to compare the hemodynamic effects of the isoosmolar contrast agent iodixanol (Visipaque(R)) 320 mg I/ml to those of the low-osmolar iohexol (Omnipaque(R)) 350 mg I/ml. The main hypothesis was that iodixanol and iohexol would affect left ventricular end-diastolic

  9. The hemodynamic repercussions of the autonomic modulations in growth-restricted fetuses

    Igor Victorovich Lakhno

    2017-12-01

    Conclusion: Fetal heart rate pattern was influenced by maternal and fetal autonomic tone. Maternal cardiovascular oscillations were reflected in the umbilical circulation in healthy pregnancy Fetal distress was featured by sympathetic overactivity and the reduction of vagal tone. Such autonomic modulations was manifested by the decelerative pattern of CTG and deteriorated umbilical hemodynamics.

  10. Serial hemodynamic measurement in normal pregnancy, preeclampsia, and intrauterine growth restriction

    Rang, Saskia; van Montfrans, Gert A.; Wolf, Hans

    2008-01-01

    OBJECTIVE: The study hypothesis was that hemodynamic measurements in conjunction with uterine artery Doppler could enable selection of women at risk for the development of preeclampsia or fetal growth restriction. STUDY DESIGN: Systolic (SBP) and diastolic blood pressure, heart rate (RR), cardiac

  11. Circadian monitoring of ECG findings and central hemodynamics in cancer patients at radiotherapy planning

    Tolkachov, Yu.A.; Vasil'jev, L.Ya.; Svinarenko, A.V.

    2003-01-01

    Fifty-seven patients aged 34-67 were examined. Considerable circadian fluctuations of main hemodynamic and ECG parameters, which can suggest disorders of circadian rhythms or limit chemoradiotherapy were not noticed in different cancers. Functional criteria of biorhythm state require further investigation

  12. Impact of metabolic, hemodynamic and inflammatory factors on target organ damage in healthy subjects

    Blicher, M.; Kruger, R.; Olesen, Thomas Bastholm

    2015-01-01

    Objective: We wanted to test the impact of metabolic, hemodynamic and inflammatory factors on target organ damage (TOD) defined as cardiac hypertrophy, atherosclerosis, arterioclerosis and microvascular damage. Design and method: In a population based cohort study of 2115 healthy subjects (1049...... associated to hypertrophy, arteriosclerosis and microvascular damage in healthy subjects....

  13. Differences in postprandial hemodynamic response on a high protein versus a high carbohydrate diet

    Dopheide, J.; Geleijnse, J.M.; Bakker, S.J.L.; Brink, E.J.; Baak, van M.A.

    2011-01-01

    Objective: Several intervention trials have shown that diet composition affects blood pressure (BP). In this study we focused on postprandial hemodynamic changes on a high carbohydrate versus a high protein diet. Design and Method: In this randomized double-blind parallel group study, 53 adult

  14. The effect of metabolic control on hemodynamics in short-term insulin-dependent diabetic patients

    Mathiesen, E R; Hilsted, J; Feldt-Rasmussen, B

    1985-01-01

    Hemodynamics variables (heart rate, arterial blood pressure, cardiac output, hepato-splanchnic blood flow, forearm blood flow, and plasma catecholamines) were measured during good (median blood glucose 4.7 mmol/L) and poor (median blood glucose 16.3 mmol/L) metabolic control in eight young, short...

  15. A New Framework for the Assessment of Cerebral Hemodynamics Regulation in Neonates Using NIRS

    Caicedo, Alexander; Alderliesten, Thomas; Naulaers, Gunnar; Lemmers, Petra; van Bel, Frank; Van Huffel, Sabine

    2016-01-01

    We present a new framework for the assessment of cerebral hemodynamics regulation (CHR) in neonates using near-infrared spectroscopy (NIRS). In premature infants, NIRS measurements have been used as surrogate variables for cerebral blood flow (CBF) in the assessment of cerebral autoregulation (CA).

  16. Characterization of Hemodynamics in Patients with Idiopathic and Thromboembolic Pulmonary Hypertension

    Carmelle V. Remillard

    2008-01-01

    Full Text Available Demographic and hemodynamic data from patients with idiopathic pulmonary arterial hypertension (IPAH and chronic thromboembolic pulmonary hypertension (CTEPH have not been systematically characterized to identify differences related to gender, age, race, disease severity, and drug response. Our goal was to define the distribution and relation of IPAH and CTEPH based on these criteria. Hemodynamic and demographic data from 242 IPAH patients and 90 CTEPH patients were collected and compared. IPAH incidence was greater in women, but men had a higher basal mean pulmonary arterial pressure (mPAP. mPAP was comparable among all IPAH ethnic groups. IPAH patients with no history of fenfluramine-phentermine use had a higher mPAP than users. Exercise-induced IPAH was apparent in 14.5% of IPAH patients. Only 9% of IPAH patients responded to inhaled nitric oxide with a ≥20% decrease in mPAP. Compared to CTEPH patients, mPAP was greater but average age of diagnosis was lower in IPAH patients. mPAP negatively correlated with age of diagnosis in IPAH patients only. These results indicate that elevated CO is not the main determinant of mPAP in both IPAH and CTEPH patients. However, the two patient groups differ in terms of their demographic and hemodynamic distributions, and according to the correlation between mPAP and other clinical hemodynamics and demographics.

  17. Application of a user-friendly comprehensive circulatory model for estimation of hemodynamic and ventricular variables

    Ferrari, G.; Kozarski, M.; Gu, Y. J.; De Lazzari, C.; Di Molfetta, A.; Palko, K. J.; Zielinski, K.; Gorczynska, K.; Darowski, M.; Rakhorst, G.

    2008-01-01

    Purpose: Application of a comprehensive, user-friendly, digital computer circulatory model to estimate hemodynamic and ventricular variables. Methods: The closed-loop lumped parameter circulatory model represents the circulation at the level of large vessels. A variable elastance model reproduces

  18. Effect of breath holding on cerebrovascular hemodynamics in normal pregnancy and preeclampsia

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; Zeeman, Gerda G.; Belfort, Michael A.

    2015-01-01

    Preeclampsia (PE) is associated with endothelial dysfunction and impaired autonomic function, which is hypothesized to cause cerebral hemodynamic abnormalities. Our aim was to test this hypothesis by estimating the difference in the cerebrovascular response to breath holding (BH; known to cause

  19. Effects of midazolam and morphine on cerebral oxygenation and hemodynamics in ventilated premature infants.

    Velden, A.A.E.M. van der; Hopman, J.C.W.; Klaessens, J.H.G.M.; Feuth, A.B.; Sengers, R.C.A.; Liem, K.D.

    2006-01-01

    BACKGROUND: Midazolam sedation and morphine analgesia are commonly used in ventilated premature infants. OBJECTIVES: To evaluate the effects of midazolam versus morphine infusion on cerebral oxygenation and hemodynamics in ventilated premature infants. METHODS: 11 patients (GA 26.6-33.0 weeks, BW

  20. Concurrent OCT imaging of stimulus evoked retinal neural activation and hemodynamic responses

    Son, Taeyoon; Wang, Benquan; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2017-02-01

    It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation. These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases, which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye diseases.

  1. Laparoscopic cholecystectomy using abdominal wall retraction. Hemodynamics and gas exchange, a comparison with conventional pneumoperitoneum

    Meijer, D. W.; Rademaker, B. P.; Schlooz, S.; Bemelman, W. A.; de Wit, L. T.; Bannenberg, J. J.; Stijnen, T.; Gouma, D. F.

    1997-01-01

    BACKGROUND: Disadvantages related to CO2 pneumoperitoneum have led to development of the abdominal wall retractor (AWR), a device designed to facilitate laparoscopic surgery without conventional pneumoperitoneum (15 mmHg CO2). We investigated the effects of the AWR on hemodynamics and gas exchange

  2. Physiology of school burnout in medical students: Hemodynamic and autonomic functioning

    Ross W. May

    2016-09-01

    Full Text Available This study investigated the relationship between burnout and hemodynamic and autonomic functioning in both medical students (N = 55 and premedical undergraduate students (N = 77. Questionnaires screened for health related issues and assessed school burnout and negative affect symptomatology (anxiety and depression. Continuous beat-to-beat blood pressure (BP through finger plethysmography and electrocardiogram (ECG monitoring was conducted during conditions of baseline and cardiac stress induced via the cold pressor task to produce hemodynamic, heart rate variability, and blood pressure variability indices. Independent sample t-tests demonstrated that medical students had significantly higher school burnout scores compared to their undergraduate counterparts. Controlling for age, BMI, anxiety and depressive symptoms, multiple regression analyses indicated that school burnout was a stronger predictor of elevated hemodynamics (blood pressure, decreased heart rate variability, decreased markers of vagal activity and increased markers of sympathetic tone at baseline for medical students than for undergraduates. Analyses of physiological values collected during the cold pressor task indicated greater cardiac hyperactivity for medical students than for undergraduates. The present study supports previous research linking medical school burnout to hemodynamic and autonomic functioning, suggests biomarkers for medical school burnout, and provides evidence that burnout may be implicated as a physiological risk factor in medical students. Study limitations and potential intervention avenues are discussed.

  3. Prevention of hemodynamic and vascular albumin filtration changes in diabetic rats by aldose reductase inhibitors

    Tilton, R.G.; Chang, K.; Pugliese, G.; Eades, D.M.; Province, M.A.; Sherman, W.R.; Kilo, C.; Williamson, J.R.

    1989-01-01

    This study investigated hemodynamic changes in diabetic rats and their relationship to changes in vascular albumin permeation and increased metabolism of glucose to sorbitol. The effects of 6 wk of streptozocin-induced diabetes and three structurally different inhibitors of aldose reductase were examined on (1) regional blood flow (assessed with 15-microns 85Sr-labeled microspheres) and vascular permeation by 125I-labeled bovine serum albumin (BSA) and (2) glomerular filtration rate (assessed by plasma clearance of 57Co-labeled EDTA) and urinary albumin excretion (determined by radial immunodiffusion assay). In diabetic rats, blood flow was significantly increased in ocular tissues (anterior uvea, posterior uvea, retina, and optic nerve), sciatic nerve, kidney, new granulation tissue, cecum, and brain. 125I-BSA permeation was increased in all of these tissues except brain. Glomerular filtration rate and 24-h urinary albumin excretion were increased 2- and 29-fold, respectively, in diabetic rats. All three aldose reductase inhibitors completely prevented or markedly reduced these hemodynamic and vascular filtration changes and increases in tissue sorbitol levels in the anterior uvea, posterior uvea, retina, sciatic nerve, and granulation tissue. These observations indicate that early diabetes-induced hemodynamic changes and increased vascular albumin permeation and urinary albumin excretion are aldose reductase-linked phenomena. Discordant effects of aldose reductase inhibitors on blood flow and vascular albumin permeation in some tissues suggest that increased vascular albumin permeation is not entirely attributable to hemodynamic change

  4. Measurement of hemodynamics during postural changes using a new wearable cephalic laser blood flowmeter.

    Fujikawa, Tetsuya; Tochikubo, Osamu; Kura, Naoki; Kiyokura, Takanori; Shimada, Junichi; Umemura, Satoshi

    2009-10-01

    Patients with orthostatic hypotension have pathologic hemodynamics related to changes in body posture. A new cephalic laser blood flowmeter that can be worn on the tragus to investigate the hemodynamics upon rising from a sitting or squatting posture was developed. The relationship between cephalic hemodynamics and cerebral ischemic symptoms in 63 subjects in a sitting, squatting, and standing positions using the new device was evaluated. Transient decrease in blood pressure within 15 s after rising to an erect position possibly causes dizziness, syncope, and fall. Subjects exhibiting dizziness upon standing showed a significant decrease in the cephalic blood flow (CBF) and indirect beat-to-beat systolic blood pressure, as monitored by the Finometer, and a significant correlation was observed between the drop ratio (drop value on rising/mean value in the squatting position) of CBF and that of systolic blood pressure. This new wearable CBF-meter is potentially useful for estimating cephalic hemodynamics and objectively diagnosing cerebral ischemic symptoms of subjects in a standing posture.

  5. Modeling the hemodynamic response in fMRI using smooth FIR filters

    Goutte, Cyril; Nielsen, Finn Årup; Hansen, Lars Kai

    2000-01-01

    Modeling the hemodynamic response in functional magnetic resonance (fMRI) experiments is an important aspect of the analysis of functional neuroimages. This has been done in the past using parametric response function, from a limited family. In this contribution, the authors adopt a semi...

  6. Repeatability of fractional flow reserve despite variations in systemic and coronary hemodynamics

    Johnson, N.P.; Johnson, D.T.; Kirkeeide, R.L.; Berry, C.; de Bruyne, B.; Fearon, W.F.; Oldroyd, K.G.; Pijls, N.H.J.; Gould, K. Lance

    2015-01-01

    Objectives This study classified and quantified the variation in fractional flow reserve (FFR) due to fluctuations in systemic and coronary hemodynamics during intravenous adenosine infusion. Background Although FFR has become a key invasive tool to guide treatment, questions remain regarding its

  7. The effect of some hemodynamic factors on the behaviour of the aortic valve

    Steenhoven, van A.A.; Veenstra, P.C.; Reneman, R.S.

    1982-01-01

    To test the validity of a theoretical model of aortic valve closure, based upon the observations in a two-dimensional analogue, the effect of some hemodynamic factors on aortic valve behaviour was studied in open-chest dogs. Direct cinematography was used to record aortic valve movements. The ECG,

  8. The role of hemodynamics in the development of the outflow tract of the heart

    Loots, Erwin; Hillen, Berend; Veldman, Arthur E.P.

    The question whether, and if so to what extent, hemodynamic forces and mechanical stimuli do modulate the morphogenesis of the vascular system is a century-old problem. It is important especially in the outflow tract where a spiraling septum develops in and after a strong bend in the tube. Spiraling

  9. Tolerance and chimerism.

    Kolb, Hans-Jochem; Guenther, Wolfgang; Gyurkocza, Boglarka; Hoetzl, Florian; Simoes, Belinda; Falk, Christine; Schleuning, Michael; Ledderose, Georg

    2003-05-15

    Stem-cell transplantation from human leukocyte antigen (HLA)-haploidentical family members carries a high risk of rejection and graft-versus-host disease (GVHD) if donor and recipient differ by more than one HLA antigen. The authors have developed treatment protocols from studies in dog leukocyte antigen-haploidentical dogs that prevent rejection and modify GVHD to the extent that patients with aggressive hematologic neoplasia can be treated with success. Principal improvements have been achieved in the use of cyclophosphamide and total-body irradiation for conditioning and T-cell depletion for prevention of GVHD. More recently, the combination of marrow and CD6-depleted mobilized donor blood cells (MDBC) has been introduced for HLA-haploidentical transplantation on the basis that CD6-depleted MDBC contain immunoregulatory cells besides stem cells and natural killer cells. Clinical results are reported on 36 patients with high-risk hematologic neoplasia. The results encourage the use of HLA-haploidentical stem-cell transplantation at an earlier stage of the disease. This method could also be of use for tolerance induction in organ transplantation.

  10. Disorders of cardiac hemodynamic in attack period of bronchial asthma in children

    Kondratiev V.А.

    2016-05-01

    Full Text Available By dopplerechocardiography method there was studied functional state of cardiac ventricles and character of hemodynamic disorders in 48 patients aged 5-17 years in attack period of moderately-severe and severe bronchial asthma. Group of comparison included 40 healthy peers. Disorders of central and peripheral hemodynamic in attack period of bronchial asthma in children were accompanied both by systolic and diastolic dysfunction of the left and right heart ventricles, herewith right ventricle was functioning in the mode of hyperdynamic, and left one – in the mode of hypodynamic. Combined systolic-diastolic variant of dysfunction both of right and left ventricles was developing in 58,3% of patients with moderately-severe and in 91,6% of patients with severe bronchial asthma. In the attack period of bronchial asthma in children equal directionality of systolic and diastolic dysfunction of heart ventricles was developing; this was characterized by synchronization of their function. Assessment of functional interaction of the ventricles under conditions of severe asthma attack showed direct and high (r=0,67 correlative interaction between finding of Tei index of the left and right ventricles, which characterize their systolic function; this, under conditions of increased hemodynamic pre-loading testified to compensatory increase of systolic interaction of ventricles. Direct and high (r=0,69 correlative interaction between time indices of isovolumic relaxation of the left and right ventricles, characterizing their diastolic function, testified to compensatory increase of diastolic interaction of ventricles under conditions of increase of hemodynamic post-loading. Imbalance of central and peripheral link of hemodynamic in attack period of bronchial asthma in children testified to development of cardiac insufficiency, which was compensated predominantly at the expense of increase of heart contractions rate.

  11. Prognostic value of noninvasive hemodynamic evaluation of the acute effect of levosimendan in advanced heart failure.

    Malfatto, Gabriella; Della Rosa, Francesco; Rella, Valeria; Villani, Alessandra; Branzi, Giovanna; Blengino, Simonetta; Giglio, Alessia; Facchini, Mario; Parati, Gianfranco

    2014-04-01

    Optimization of inotropic treatment in worsening heart failure sometimes requires invasive hemodynamic assessment in selected patients. Impedance cardiography (ICG) may be useful for a noninvasive hemodynamic evaluation. ICG was performed in 40 patients (69 ± 8 years; left ventricular ejection fraction 27.5 ± 5.6%; New York Heart Association 3.18 ± 0.34; Interagency Registry for Mechanically Assisted Circulatory Support 5.48 ± 0.96, before and after infusion of Levosimendan (0.1–0.2 µg/kg per min for up to 24 h). Echocardiogram, ICG [measuring cardiac index (CI), total peripheral resistances (TPRs) and thoracic fluid content (TFC)] and plasma levels of brain natriuretic peptide (BNP) were obtained; in nine patients, right heart catheterization was also carried out. When right catheterization and ICG were performed simultaneously, a significant relationship was observed between values of CI and TPR, and between TFC and pulmonary wedge pressure. ICG detected the Levosimendan-induced recovery of the hemodynamic status, associated with improved systolic and diastolic function and reduction in BNP levels. One-year mortality was 4.4%. At multivariate analysis, independent predictors of mortality were: no improvement in the severity of mitral regurgitation, a persistent restrictive filling pattern (E/E’ > 15), a reduction of BNP levels below 30% and a change below 10% in CI, TPR and TFC. When combined, absence of hemodynamic improvement at ICG could predict 1-year mortality with better sensitivity (86%) and specificity (85%) than the combination of echocardiographic and BNP criteria only (sensitivity 80% and specificity 36%). Noninvasive hemodynamic evaluation of heart failure patients during infusion of inodilator drugs is reliable and may help in their prognostic stratification.

  12. Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms

    Dohan, Anthony; Eveno, Clarisse; Dautry, Raphael; Guerrache, Youcef; Camus, Marine; Boudiaf, Mourad; Gayat, Etienne; Dref, Olivier Le; Sirol, Marc; Soyer, Philippe

    2015-01-01

    PurposeTo assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA).Materials and MethodsSeventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed.ResultsSeventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53 %). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88 %). Technical success rate of TAE was 100 %. TAE was performed using metallic coils in all patients (100 %), in association with gelatin sponge in 5/17 patients (29 %). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94 %). In 1/17 patient (6 %), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12 %, respectively. Morbidity consisted in coil migration in 1/17 patient (6 %) and transient serum liver enzyme elevation in 1/17 patient (6 %).ConclusionTAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94 %. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA

  13. Freedom Solo Versus Trifecta Bioprotheses: Clinical and Hemodynamic Evaluation after Propensity Score Matching.

    J Cerqueira, Rui; Melo, Renata; Moreira, Soraia; A Saraiva, Francisca; Andrade, Marta; Salgueiro, Elson; Almeida, Jorge; J Amorim, Mário; Pinho, Paulo; Lourenço, André; F Leite-Moreira, Adelino

    2017-01-01

    To compare stentless Freedom Solo and stented Trifecta aortic bioprostheses regarding hemodynamic profile, left ventricular mass regression, early and late postoperative outcomes and survival. Longitudinal cohort study of consecutive patients undergoing aortic valve replacement (from 2009 to 2016) with either Freedom Solo or Trifecta at one centre. Local databases and national records were queried. Postoperative echocardiography (3-6 months) was obtained for hemodynamic profile (mean transprosthetic gradient and effective orifice area) and left ventricle mass determination. After propensity score matching (21 covariates), Kaplan-Meier analysis and cumulative incidence analysis were performed for survival and combined outcome of structural valve deterioration and endocarditis, respectively. Hemodynamics and left ventricle mass regression were assessed by a mixed- -effects model including propensity score as a covariate. From a total sample of 397 Freedom Solo and 525 Trifecta patients with a median follow-up time of 4.0 (2.2- 6.0) and 2.4 (1.4-3.7) years, respectively, a matched sample of 329 pairs was obtained. Well-balanced matched groups showed no difference in survival (hazard ratio=1.04, 95% confidence interval=0.69-1.56) or cumulative hazards of combined outcome (subhazard ratio=0.54, 95% confidence interval=0.21-1.39). Although Trifecta showed improved hemodynamic profile compared to Freedom Solo, no differences were found in left ventricle mass regression. Trifecta has a slightly improved hemodynamic profile compared to Freedom Solo but this does not translate into differences in the extent of mass regression, postoperative outcomes or survival, which were good and comparable for both bioprostheses. Long-term follow-up is needed for comparisons with older models of bioprostheses.

  14. Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms

    Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Eveno, Clarisse, E-mail: clarisse.eveno@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Dautry, Raphael, E-mail: raphael.dautry@lrb.aphp.fr; Guerrache, Youcef, E-mail: docyoucef05@yahoo.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Camus, Marine, E-mail: marine.camus@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Boudiaf, Mourad, E-mail: mourad.boudiaf@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Gayat, Etienne, E-mail: etienne.gayat@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Dref, Olivier Le, E-mail: olivier.ledref@lrb.aphp.fr; Sirol, Marc, E-mail: marc.sirol@lrb.aphp.fr; Soyer, Philippe, E-mail: philippe.soyer@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France)

    2015-08-15

    PurposeTo assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA).Materials and MethodsSeventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed.ResultsSeventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53 %). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88 %). Technical success rate of TAE was 100 %. TAE was performed using metallic coils in all patients (100 %), in association with gelatin sponge in 5/17 patients (29 %). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94 %). In 1/17 patient (6 %), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12 %, respectively. Morbidity consisted in coil migration in 1/17 patient (6 %) and transient serum liver enzyme elevation in 1/17 patient (6 %).ConclusionTAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94 %. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA.

  15. [Meta-analyses on measurement precision of non-invasive hemodynamic monitoring technologies in adults].

    Pestel, G; Fukui, K; Higashi, M; Schmidtmann, I; Werner, C

    2018-06-01

    An ideal non-invasive monitoring system should provide accurate and reproducible measurements of clinically relevant variables that enables clinicians to guide therapy accordingly. The monitor should be rapid, easy to use, readily available at the bedside, operator-independent, cost-effective and should have a minimal risk and side effect profile for patients. An example is the introduction of pulse oximetry, which has become established for non-invasive monitoring of oxygenation worldwide. A corresponding non-invasive monitoring of hemodynamics and perfusion could optimize the anesthesiological treatment to the needs in individual cases. In recent years several non-invasive technologies to monitor hemodynamics in the perioperative setting have been introduced: suprasternal Doppler ultrasound, modified windkessel function, pulse wave transit time, radial artery tonometry, thoracic bioimpedance, endotracheal bioimpedance, bioreactance, and partial CO 2 rebreathing have been tested for monitoring cardiac output or stroke volume. The photoelectric finger blood volume clamp technique and respiratory variation of the plethysmography curve have been assessed for monitoring fluid responsiveness. In this manuscript meta-analyses of non-invasive monitoring technologies were performed when non-invasive monitoring technology and reference technology were comparable. The primary evaluation criterion for all studies screened was a Bland-Altman analysis. Experimental and pediatric studies were excluded, as were all studies without a non-invasive monitoring technique or studies without evaluation of cardiac output/stroke volume or fluid responsiveness. Most studies found an acceptable bias with wide limits of agreement. Thus, most non-invasive hemodynamic monitoring technologies cannot be considered to be equivalent to the respective reference method. Studies testing the impact of non-invasive hemodynamic monitoring technologies as a trend evaluation on outcome, as well as

  16. Correction of Hemodynamic Disorders in the Complex Surgical Correction of Acquired Cardiac Valvular Defects

    A. I. Lenkin

    2011-01-01

    Full Text Available Objective: to compare the efficiency of using the values of transpulmonary (PiCCO and prepulmonary (Swan-Ganz catheter thermodilution as guides to targeted therapy for hemodynamic disorders in the surgical correction of mixed cardiac valvular defects. Subjects and methods. The study enrolled 40 patients operated on for acquired cardiac diseases who were randomized to two matched groups. Hemodynamics was monitored by means of a Swan-Ganz catheter in Group 1 and by transpulmonary thermodilution in Group 2. Anesthesia was maintained with propofol and fentanyl. Infusion therapy was performed using crystalloid and colloid solutions. Continuous intravenous infusion of inotropic agents was used when heart failure was developed. Hemodynamic, clinical, and laboratory parameters were estimated intraoperatively and within 24 hours postoperatively. Results. The groups did not differ in the degree of baseline heart failure, the duration of an operation and myocardial ischemia, and the length of extracorporeal circulation. In the PiCCO group, postoperative infusion volume was 33% higher than that in the Swan-Ganz group, which ensured increases in stroke volume and oxygen delivery in the early postoperative period (p<0.05. Respiratory support was 26% shorter in the PiCCO group (p<0.04. Conclusion. After surgical interventions for mixed cardiac defects, the targeted therapy algorithm based on transpulmonary thermodilution provided more steady-state values of hemodynamics and oxygen transport, which was followed by the increased scope of infusion therapy and the shorter length of postoperative mechanical ventilation than that based on hemodynamics being corrected from the values of prepul-monary thermodilution. Key words: transpulmonary thermodilution, targeted therapy, prepulmonary ther-modilution, acquired heart disease.

  17. Association between percutaneous hemodynamic support device and survival from cardiac arrest in the state of Michigan.

    Pressman, Andrew; Sawyer, Kelly N; Devlin, William; Swor, Robert

    2018-05-01

    The role of circulatory support in the post-cardiac arrest period remains controversial. Our objective was to investigate the association between treatment with a percutaneous hemodynamic support device and outcome after admission for cardiac arrest. We performed a retrospective study of adult patients with admission diagnosis of cardiac arrest or ventricular fibrillation (VF) from the Michigan Inpatient Database, treated between July 1, 2010, and June 30, 2013. Patient demographics, clinical characteristics, treatments, and disposition were electronically abstracted based on ICD-9 codes at the hospital level. Mixed-effects logistic regression models were fit to test the effect of percutaneous hemodynamic support device defined as either percutaneous left ventricular assist device (pLVAD) or intra-aortic balloon pump (IABP) on survival. These models controlled for age, sex, VF, myocardial infarction (MI), and cardiogenic shock with hospital modeled as a random effect. A total of 103 hospitals contributed 4393 patients for analysis, predominately male (58.8%) with a mean age of 64.1years (SD 15.5). On univariate analysis, younger age, male sex, VF as the initial rhythm, acute MI, percutaneous coronary intervention, percutaneous hemodynamic support device, and absence of cardiogenic shock were associated with survival to discharge (each p<0.001). Mixed-effects logistic regressions revealed use of percutaneous hemodynamic support device was significantly associated with survival among all patients (OR 1.8 (1.28-2.54)), and especially in those with acute MI (OR 1.95 (1.31-2.93)) or cardiogenic shock (OR 1.96 (1.29-2.98)). Treatment with percutaneous hemodynamic support device in the post-arrest period may provide left ventricular support and improve outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Acute effects of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers

    Vikas Thakran

    2015-01-01

    Full Text Available Background: Long-term adverse cardiovascular effects of smokeless tobacco are well established, however, the effect of chewing tobacco on coronary microcirculation and hemodynamic have not been studied. We intended to analyze the acute effect of chewing tobacco on coronary microcirculation and hemodynamics in habitual tobacco chewers with stable coronary artery disease undergoing elective percutaneous coronary intervention (PCI. Materials and Methods: We prospectively enrolled seven habitual tobacco chewers with stable coronary artery disease with single vessel disease or double vessel disease satisfying the criteria for elective PCI. Patients were instructed to keep 1 g of crushed dried tobacco leaves in the mouth after a successful PCI. Lesion in last stented vessels was evaluated for fractional flow reserve (FFR, coronary flow reserve (CFR, and index of microcirculatory resistance (IMR post-PCI, after 15 min and 30 min of tobacco chewing along with the measurement of serum cotinine levels. Results: Oral tobacco led to high levels of cotinine in the majority of patients. There was an insignificant rise in heart rate, systolic and diastolic blood pressure following tobacco consumption. Baseline CFR (median 1.6, range 1.1–5.5 was low in tobacco chewers after PCI even after optimum FFR (0.9 ± 0.05 in the majority of patients suggesting abnormal microvascular hemodynamics (high IMR in 3 patients, overall median 14.2, range 7–36.2. However, there was no significant change in the estimated CFR or IMR values following tobacco chewing. One patient had bradycardia and hypotension which may be related to vagal reaction or acute nicotine poisoning. Conclusion: Tobacco chewers have abnormal coronary microcirculation hemodynamics even following a successful PCI. However, the coronary micocirculation and hemodynamics do not change acutely following tobacco chewing despite high serum cotinine concentrations.

  19. Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters.

    Paliwal, Nikhil; Damiano, Robert J; Davies, Jason M; Siddiqui, Adnan H; Meng, Hui

    2017-02-11

    Treatment of intracranial aneurysms (IAs) has been revolutionized by the advent of endovascular Flow Diverters (FDs), which disrupt blood flow within the aneurysm to induce pro-thrombotic conditions, and serves as a scaffold for endothelial ingrowth and arterial remodeling. Despite good clinical success of FDs, complications like incomplete occlusion and post-treatment rupture leading to subarachnoid hemorrhage have been reported. In silico computational fluid dynamic analysis of the pre- and post-treated geometries of IA patients can shed light on the contrasting blood hemodynamics associated with different clinical outcomes. In this study, we analyzed hemodynamic modifications in 15 IA patients treated using a single FD; 10 IAs were completely occluded (successful) and 5 were partially occluded (unsuccessful) at 12-month follow-up. An in-house virtual stenting workflow was used to recapitulate the clinical intervention on these cases, followed by CFD to obtain pre- and post-treatment hemodynamics. Bulk hemodynamic parameters showed comparable reductions in both groups with average inflow rate and aneurysmal velocity reduction of 40.3% and 52.4% in successful cases, and 34.4% and 49.2% in unsuccessful cases. There was a substantial reduction in localized parameter like vortex coreline length and Energy Loss for successful cases, 38.2% and 42.9% compared to 10.1% and 10.5% for unsuccessful cases. This suggest that for successfully treated IAs, the localized complex blood flow is disrupted more prominently by the FD as compared to unsuccessful cases. These localized hemodynamic parameters can be potentially used in prediction of treatment outcome, thus aiding the clinicians in a priori assessment of different treatment strategies.

  20. Myocardial hypertrophy and intracardial hemodynamics in children with bicuspid aortic valve

    А. V. Kamenshchyk

    2017-08-01

    Full Text Available Bicuspid aortic valve is one of the most common congenital heart diseases with low manifestation in childhood and severe consequences in adults that determines the importance in early diagnostics of myocardial changes in this anomaly. According to the literature the polymorphisms in the genes of NFATC family could result both in impaired embriogenetic valves formation and development of postnatal myocardial hypertrophy. The aim of the study was to detect the early changes of intracardial hemodynamics at aortic valve in children with bicuspid aortic valve (BAV and establish their interrelations to the signs of myocardial hypertrophy in these children. Materials and methods: Dopplerograhphic study of basic intracardiac hemodynamics parameters in 38 children with BAV and in 28 children of control group was conducted. The results were processed statistically by Student’s t-test, correlation analysis and multiple regression. Results: In the result of study the moderate concentric left ventricle myocardial hypertrophy development was detected in 62 % of children with BAV which is accompanying to significant increasing of blood flow velocity and pressure gradient at aortic valve. There were not established significant correlations between the parameters of hemodynamics at valve and left ventricle’s posterior wall depth and septum depth whereas the highest inputs of these values were obtained in the left ventricle systolic dimension and volume and less in the hypertrophic signs. Conclusions: In children with BAV the moderate concentric myocardial hypertrophy with significant changes of intracardial hemodynamics at aortic valve takes place with the highest inputs in left ventricle volumetric values The obtained data serves as a substantiation for the treatment and prevention of it further development. bicuspid aortic valve; children; heart hypertrophy; dopplerechocardiography; hemodynamics; regression analysis