Sample records for maximal stroke volume

  1. Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

    Vieira, Stella S.; Lemes, Brunno; de T. C. de Carvalho, Paulo; N. de Lima, Rafael; S. Bocalini, Danilo; A. S. Junior, José; Arsa, Gisela; A. Casarin, Cezar; L. Andrade, Erinaldo; J. Serra, Andrey


    Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load. PMID:27347221

  2. Maximal expiratory flow volume curve in quarry workers.

    Subhashini, Arcot Sadagopa; Satchidhanandam, Natesa


    Maximal Expiratory Flow Volume (MEFV) curves were recorded with a computerized Spirometer (Med Spiror). Forced Vital Capacity (FVC), Forced Expiratory Volumes (FEV), mean and maximal flow rates were obtained in 25 quarry workers who were free from respiratory disorders and 20 healthy control subjects. All the functional values are lower in quarry workers than in the control subject, the largest reduction in quarry workers with a work duration of over 15 years, especially for FEF75. The effects are probably due to smoking rather than dust exposure.


    Prasantha Kumar Thankappan


    Full Text Available BACKGROUND Stroke is a major cause of long term morbidity and mortality. Several factors are known to increase the liability to stroke. Platelets play a crucial role in the pathogenesis of atherosclerotic complications, contributing to thrombus formation. Platelet size (mean platelet volume, MPV is a marker and possible determinant of platelet function, large platelets being potentially more reactive. Hence an attempt has-been made to study the association if any between mean platelet volume and thrombotic stroke. The aim of this study was to determine whether an association exists between Mean Platelet Volume (MPV and thrombotic stroke. MATERIALS AND METHODS The study is a case control study and data was collected at Government Medical College Hospital, Kottayam, Kerala a tertiary care referral centre. The study was carried out among fifty patients diagnosed with thrombotic stroke and presenting to the hospital within forty eight hours of onset of symptoms. Fifty age group and sex matched controls were also recruited. Mean platelet volume was obtained using a SYSMEX automated analyser. RESULTS This study has shown a statistically significant relation between mean platelet volume and risk of thrombotic stroke but no statistically significant correlation between clinical severity of stroke and mean platelet volume. CONCLUSION This study has shown an elevation of MPV in acute phase of thrombotic stroke. Platelet mass was found to be more or less a constant. This study did not find a statistically significant correlation between clinical severity of stroke and mean platelet volume.

  4. Impact of 8-week endurance training on qualitative and quantitative parameters of stroke volume

    Suzana Pustivšek


    Full Text Available Background: Dynamics of stroke volume during increasing progressive load varies widely among individuals. The data of current studies describing the impact of long-term endurance training on the dynamics of cardiac stroke volume are conflicting. The purpose of this study was to evaluate the impact of 8-week endurance training on the dynamics of stroke volume and some quantitative features of cardiac function in recreational female runners.Methods: Measurements were performed in the physiological laboratory at the Institute of Sport, Faculty of Sport in Ljubljana. CosmedK4b2 equipment that allows continuous “on-line”, “breath-by-breath” monitoring of oxygen consumption and gases in exhaled air was used. Cardiac output was calculated by the method described by Stringer et al.Results: The results showed a significant increase in stroke volume at rest and during the first two minutes of the test. Maximum stroke volume did not increase, but there was a decrease in heart rate during maximal stroke volume from 126.65 (± 27.14 to 120.15 (± 26.56 beats per minute. The dynamics of stroke volume in a majority of participants did not change. The most common dynamics of stroke volume before and after test was plateau dynamics. The training resulted in an increase in running endurance and the average increase in running speed during the final test by 4.41 % (± 4.62.Conclusion: The exercise resulted in minimal changes in cardiac function and a significant improvement in endurance parameters.

  5. In-treatment stroke volume predicts cardiovascular risk in hypertension

    Lønnebakken, Mai T; Gerdts, Eva; Boman, Kurt


    To evaluate whether lower stroke volume during antihypertensive treatment is a predictor of cardiovascular events independent of left ventricular geometric pattern. Methods: The association between left ventricular stroke volume and combined cardiovascular death, stroke and myocardial infarction......, the prespecified primary study endpoint, was assessed in Cox regression analysis using data from baseline and annual follow-up visits in 855 patients during 4.8 years of randomized losartan-based or atenolol-based treatment in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiography...... resistance, more concentric left ventricular geometry and impaired diastolic relaxation (all P treatment left ventricular stroke volume indexed for height2.04 was associated...


    Klemen Lavrenčak


    Full Text Available Stroke volume (SV is well known as a routine clinical cardiodynamic measure. It represents the amount of blood ejected by the left ventricle in one beat. Our aim in present study was to evaluate, both, the stroke volume dynamics in males with different fitness level and the relationship between maximal SV value measured during graded exercise testing (GXT on treadmill and VO2 max. One hundred male participants of age 43,06 ± 9.03 years, height 175 ± 8.25 cm, body mass 76.94 ± 15.42 kg, BSA 2.01 ± 0,15 m2 and peak oxygen consumption 46.55 ± 7.03 ml kg-1 min-1 volunteered to participate in this study. All tests were performed in Exercise Physiology Laboratory (University of Ljubljana, Faculty of Sport, The group of expirienced recreational runners differed from sedentary or less trained recreational runners in higher cardiac output (Q; 20.92 ± 4.57 vs 16,90 ± 4,34 l · min-1 (p ≤ 0,001, bigger SV: 136,43 ± 34,59 vs 112,04 ± 30,11 ml · beat -1 (p ≤ 0,001 and higher SI: 73,41 ± 13,42 vs 60,66 ± 11,58 ml · beat -1 · m-2 (p ≤ 0,001. Interestingly, both groups reached maximal SV at practically identical level of test (58.62 ± 17.81 % vs 59,85 ± 14,27 % VO2max. Also, the pattern of SV fall according to VO2max in both groups tested, were similar (12.08 ± 6.26 % vs 11,33 ± 6,23 %.

  7. Relationship between stroke volume and pulse pressure during blood volume perturbation: a mathematical analysis.

    Bighamian, Ramin; Hahn, Jin-Oh


    Arterial pulse pressure has been widely used as surrogate of stroke volume, for example, in the guidance of fluid therapy. However, recent experimental investigations suggest that arterial pulse pressure is not linearly proportional to stroke volume. However, mechanisms underlying the relation between the two have not been clearly understood. The goal of this study was to elucidate how arterial pulse pressure and stroke volume respond to a perturbation in the left ventricular blood volume based on a systematic mathematical analysis. Both our mathematical analysis and experimental data showed that the relative change in arterial pulse pressure due to a left ventricular blood volume perturbation was consistently smaller than the corresponding relative change in stroke volume, due to the nonlinear left ventricular pressure-volume relation during diastole that reduces the sensitivity of arterial pulse pressure to perturbations in the left ventricular blood volume. Therefore, arterial pulse pressure must be used with care when used as surrogate of stroke volume in guiding fluid therapy.

  8. Stroke phases responses around maximal lactate steady state in front crawl.

    Pelarigo, Jailton G; Denadai, Benedito S; Greco, Camila C


    The objective of this study was to analyze changes in stroke rate (SR), stroke length (SL) and stroke phases (entry and catch, pull, push and recovery) when swimming at (MLSS) and above (102.5% MLSS) the maximal lactate steady state. Twelve endurance swimmers (21±8 year, 1.77±0.10 m and 71.6±7.7 kg) performed in different days the following tests: (1) 200- and 400-m all-out tests, to determine critical speed (CS), and; (2) 2-4 30-min sub-maximal constant-speed tests, to determine the MLSS and 102.5% MLSS. There was significant difference among MLSS (1.22±0.05 ms(-1)), 102.5% MLSS (1.25±0.04 ms(-1)) and CS (1.30±0.08 ms(-1)). SR and SL were maintained between the 10th and 30th minute of the test swum at MLSS and have modified significantly at 102.5% MLSS (SR - 30.9±3.4 and 32.2±3.5 cycles min(-1) and SL - 2.47±0.2 and 2.38±0.2 m cycle(-1), respectively). All stroke phases were maintained at 10th and 30th minute at MLSS. However, the relative duration of propulsive phase B (pull) increased significantly at 102.5% MLSS (21.7±3.4% and 22.9±3.9%, respectively). Therefore, the metabolic condition may influence the stroke parameters (SR and SL) and stroke strategy to maintain the speed during swim tests lasting 30 min.

  9. A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

    Konings Maurits K


    Full Text Available Abstract Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP is presented, that measures the average stroke volume (SV for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo. These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds. The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling

  10. Optimising stroke volume and oxygen delivery in abdominal aortic surgery

    Bisgaard, J; Gilsaa, T; Rønholm, E


    group, stroke volume was optimised by 250 ml colloid boluses intraoperatively and for the first 6 h post-operatively. The optimisation aimed at an oxygen delivery of 600 ml/min/m(2) in the post-operative period. Haemodynamic data were collected at pre-defined time points, including baseline......BACKGROUND: Post-operative complications after open elective abdominal aortic surgery are common, and individualised goal-directed therapy may improve outcome in high-risk surgery. We hypothesised that individualised goal-directed therapy, targeting stroke volume and oxygen delivery, can reduce......, intraoperatively and post-operatively. Patients were followed up for 30 days. RESULTS: Stroke volume index and oxygen delivery index were both higher in the post-operative period in the intervention group. In this group, 27 of 32 achieved the post-operative oxygen delivery index target vs. 18 of 32 in the control...

  11. A simple physiologic algorithm for managing hemodynamics using stroke volume and stroke volume variation: physiologic optimization program.

    McGee, William T


    Intravascular volume status and volume responsiveness continue to be important questions for the management of critically ill or injured patients. Goal-directed hemodynamic therapy has been shown to be of benefit to patients with severe sepsis and septic shock, acute lung injury and adult respiratory distress syndrome, and for surgical patients in the operating room. Static measures of fluid status, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) are not useful in predicting volume responsiveness. Stroke volume variation and pulse pressure variation related to changes in stroke volume during positive pressure ventilation predict fluid responsiveness and represent an evolving practice for volume management in the intensive care unit (ICU) or operating room. Adoption of dynamic parameters for volume management has been inconsistent. This manuscript reviews some of the basic physiology regarding the use of stroke volume variation to predict fluid responsiveness in the ICU and operating room. A management algorithm using this physiology is proposed for the critically ill or injured in various settings.

  12. Maximizing Volume Ratios for Shadow Covering by Tetrahedra

    Chen, Christina


    Define a body A to be able to hide behind a body B if the orthogonal projection of B contains a translation of the corresponding orthogonal projection of A in every direction. In two dimensions, it is easy to observe that there exist two objects such that one can hide behind another and have a larger area than the other. It was recently shown that similar examples exist in higher dimensions as well. However, the highest possible volume ratio for such bodies is still undetermined. We investigated two three-dimensional examples, one involving a tetrahedron and a ball and the other involving a tetrahedron and an inverted tetrahedron. We calculate the highest volume ratio known up to this date, 1.16, which is generated by our second example.

  13. Noninvasively derived stroke volume variation by finger volume clamping can reliably predict fluid responsiveness

    Vos, Jaap Jan; Poterman, Marieke; Struys, Michel; Scheeren, Thomas; Kalmar, A.F.


    Background and Goal of Study:  Dynamic preload variables derived from the arterial pressure waveform have been shown to accurately predict fluid responsiveness in mechanically ventilated patients. One of these variables, stroke volume variation (SVV), can also be obtained noninvasively by the finger

  14. Stroke rates and diving air volumes of emperor penguins: implications for dive performance.

    Sato, Katsufumi; Shiomi, Kozue; Marshall, Greg; Kooyman, Gerald L; Ponganis, Paul J


    Emperor penguins (Aptenodytes forsteri), both at sea and at an experimental dive hole, often have minimal surface periods even after performance of dives far beyond their measured 5.6 min aerobic dive limit (ADL: dive duration associated with the onset of post-dive blood lactate accumulation). Accelerometer-based data loggers were attached to emperor penguins diving in these two different situations to further evaluate the capacity of these birds to perform such dives without any apparent prolonged recovery periods. Minimum surface intervals for dives as long as 10 min were less than 1 min at both sites. Stroke rates for dives at sea were significantly greater than those for dives at the isolated dive hole. Calculated diving air volumes at sea were variable, increased with maximum depth of dive to a depth of 250 m, and decreased for deeper dives. It is hypothesized that lower air volumes for the deepest dives are the result of exhalation of air underwater. Mean maximal air volumes for deep dives at sea were approximately 83% greater than those during shallow (emperor penguins, (b) stroke rate at sea is greater than at the isolated dive hole and, therefore, a reduction in muscle stroke rate does not extend the duration of aerobic metabolism during dives at sea, and (c) a larger diving air volume facilitates performance of deep dives by increasing the total body O(2) store to 68 ml O(2) kg(-1). Although increased O(2) storage and cardiovascular adjustments presumably optimize aerobic metabolism during dives, enhanced anaerobic capacity and hypoxemic tolerance are also essential for longer dives. This was exemplified by a 27.6 min dive, after which the bird required 6 min before it stood up from a prone position, another 20 min before it began to walk, and 8.4 h before it dived again.

  15. 17q25 Locus is associated with white matter hyperintensity volume in ischemic stroke, but not with lacunar stroke status.

    Adib-Samii, Poneh; Rost, Natalia; Traylor, Matthew; Devan, William; Biffi, Alessandro; Lanfranconi, Silvia; Fitzpatrick, Kaitlin; Bevan, Steve; Kanakis, Allison; Valant, Valerie; Gschwendtner, Andreas; Malik, Rainer; Richie, Alexa; Gamble, Dale; Segal, Helen; Parati, Eugenio A; Ciusani, Emilio; Holliday, Elizabeth G; Maguire, Jane; Wardlaw, Joanna; Worrall, Bradford; Bis, Joshua; Wiggins, Kerri L; Longstreth, Will; Kittner, Steve J; Cheng, Yu-Ching; Mosley, Thomas; Falcone, Guido J; Furie, Karen L; Leiva-Salinas, Carlos; Lau, Benison C; Saleem Khan, Muhammed; Sharma, Pankaj; Fornage, Myriam; Mitchell, Braxton D; Psaty, Bruce M; Sudlow, Cathie; Levi, Christopher; Boncoraglio, Giorgio B; Rothwell, Peter M; Meschia, James; Dichgans, Martin; Rosand, Jonathan; Markus, Hugh S


    Recently, a novel locus at 17q25 was associated with white matter hyperintensities (WMH) on MRI in stroke-free individuals. We aimed to replicate the association with WMH volume (WMHV) in patients with ischemic stroke. If the association acts by promoting a small vessel arteriopathy, it might be expected to also associate with lacunar stroke. We quantified WMH on MRI in the stroke-free hemisphere of 2588 ischemic stroke cases. Association between WMHV and 6 single-nucleotide polymorphisms at chromosome 17q25 was assessed by linear regression. These single-nucleotide polymorphisms were also investigated for association with lacunar stroke in 1854 cases and 51 939 stroke-free controls from METASTROKE. Meta-analyses with previous reports and a genetic risk score approach were applied to identify other novel WMHV risk variants and uncover shared genetic contributions to WMHV in community participants without stroke and ischemic stroke. Single-nucleotide polymorphisms at 17q25 were associated with WMHV in ischemic stroke, the most significant being rs9894383 (P=0.0006). In contrast, there was no association between any single-nucleotide polymorphism and lacunar stroke. A genetic risk score analysis revealed further genetic components to WMHV shared between community participants without stroke and ischemic stroke. This study provides support for an association between the 17q25 locus and WMH. In contrast, it is not associated with lacunar stroke, suggesting that the association does not act by promoting small-vessel arteriopathy or the same arteriopathy responsible for lacunar infarction.

  16. Effects of tongue position and lung volume on voluntary maximal tongue protrusion force in humans.

    Saboisky, Julian P; Luu, Billy L; Butler, Jane E; Gandevia, Simon C


    Maximal voluntary protrusion force of the human tongue has not been examined in positions beyond the incisors or at different lung volumes. Tongue force was recorded with the tongue tip at eight positions relative to the incisors (12 and 4mm protrusion, neutral and 4, 12, 16, 24 and 32mm retraction) at functional residual capacity (FRC), total lung capacity (TLC) and residual volume (RV) in 15 healthy subjects. Maximal force occurred between 12mm and 32mm retraction (median 16mm). Maximum force at FRC was reproducible at the optimal tongue position across sessions (P=0.68). Across all positions at FRC the average force was highest at 24mm retraction (28.3±5.3N, mean±95% CI) and lowest at 12mm protrusion (49.1±4.6% maximum; Ptongue positions, maximal force was on average 9.3% lower at FRC than TLC and RV (range: 4.5-12.7% maximum, P<0.05). Retracted positions produce higher-force protrusions with a small effect of lung volume.

  17. Changes in superior mesenteric artery Doppler waveform during reduction of cardiac stroke volume and hypotension

    Perko, M J; Perko, Grazyna; Just, S


    Influence of stroke volume reduction and hypotension on the superior mesenteric artery (SMA) Doppler waveform was evaluated during head-up tilt-induced central hypovolemia in 11 healthy volunteers. During normotensive reduction in stroke volume, peak systolic velocity (pV), mean velocity, pulsati......Influence of stroke volume reduction and hypotension on the superior mesenteric artery (SMA) Doppler waveform was evaluated during head-up tilt-induced central hypovolemia in 11 healthy volunteers. During normotensive reduction in stroke volume, peak systolic velocity (pV), mean velocity...... of the study indicate that alterations in stroke volume induce consequential changes in the SMA Doppler waveform. These changes originate from both direct influence of stroke volume and/or pressure on blood flow velocity, and alterations in SMA peripheral resistance that follow variations in stroke volume....... Presented interdependencies should be taken into consideration while studying mesenteric physiology with the use of Doppler technique and while interpreting the duplex results in patients suffering from diseases that may influence flow velocity and mimic or obscure Doppler effects of the SMA stenosis....

  18. Measurement properties of maximal cardiopulmonary exercise tests protocols in persons after stroke: a systematic review.

    Wittink, H.; Verschuren, O.; Terwee, C.; Groot, J. de; Kwakkel, G.; Port, I. van de


    Objective: To systematically review and critically appraise the literature on measurement properties of cardiopulmonary exercise test protocols for measuring aerobic capacity, VO2max, in persons after stroke. Data sources: PubMed, Embase and Cinahl were searched from inception up to 15 June 2016. A

  19. Red cell volume with changes in plasma osmolarity during maximal exercise.

    Van Beaumont, W.


    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  20. Red cell volume with changes in plasma osmolarity during maximal exercise.

    Van Beaumont, W.


    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  1. Exercise stroke volume and heart rate response differ in right and left heart failure.

    Groepenhoff, Herman; Westerhof, Nico; Jacobs, Wouter; Boonstra, Anco; Postmus, Piet E; Vonk-Noordegraaf, Anton


    In pulmonary arterial hypertension (PAH), the exercise-induced increase in stroke volume (SV) is limited by the increase in pulmonary artery pressure. In left heart failure (LHF), systemic arterial pressure increases little during exercise, and the SV increase is limited by the left ventricle itself. These differences might be reflected by a dissimilar SV and heart rate (HR) response to exercise, which could have important therapeutic implications, for example in beta-blocker therapy. Therefore, we tested the hypothesis that SV and HR responses during exercise are different between PAH and LHF patients. We included 28 PAH and 18 LHF patients (recruited from the heart failure unit) matched on a maximal oxygen uptake of exercise test. Only patients who had not been exposed to beta-blockers were included. Pulmonary arterial hypertension and LHF patient groups had equally impaired exercise tolerance (about 42% of predicted) with a maximal oxygen uptake of 0.80 +/- 0.29 and 0.86 +/- 0.19 L/min. The peak SV response to exercise was significantly lower in PAH patients (-14 mL, P = 0.01); this was compensated by a steeper slope of HR relating to oxygen uptake (0.03 beats/mL, P = 0.001). We conclude that PAH patients have a smaller SV response, but a larger HR response than LHF patients.

  2. Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale

    Pabst Wolfgang


    Full Text Available Abstract Background In patients with patent foramen ovale (PFO there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO. Methods The RLS volume assessed during hospitalisation for stroke (index event/T0 was compared with the RLS volume on follow-up (T1 (median time between T0 and T1 was 10 months. In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES or no evidence of RLS during ce-TCD ultrasound on follow-up. Results There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P Conclusions RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.

  3. Stroke volume of the heart and thoracic fluid content during head-up and head-down tilt in humans

    van Lieshout, J J; Harms, M P M; Pott, F


    The stroke volume (SV) of the heart depends on the diastolic volume but, for the intact organism, central pressures are applied widely to express the filling of the heart.......The stroke volume (SV) of the heart depends on the diastolic volume but, for the intact organism, central pressures are applied widely to express the filling of the heart....

  4. Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia


    Measurement of Stroke Volume Stroke volume (SV) was measured noninvasively using thoracic electrical bioimpedance (TEB). TEB was measured using four...tients who did not die. For the current study, we measured mean arterial blood pressure (MAP), pulse pressure (PP), SV, and muscle sympathetic nerve...hemorrhagic shock. The vital sign monitors placed in emergency transport vehicles provide the medic with routine measures of arterial systolic, diastolic and

  5. [The effect of cerebrolysin in dosage 50 ml on the volume of lesion in ischemic stroke].

    Shamalov, N A; Stakhovskaia, L V; Burenchev, D V; Kichuk, I V; Tvorogova, T V; Botsina, A Iu; Smychkov, A S; Kerbikov, O B; Moessler, H; Novak, P; Skvortsova, V I


    The purpose of this randomized, double-blind, placebo-controlled study was to assess safety and efficacy of cerebrolysin used in dosage 50 ml in acute ischemic stroke. Forty-seven patients with ischemic stroke, aged 45-85 years, who were admitted to a clinical unit within the first 12 h after stroke onset were included in the study. A quantitative time-related MRI analysis of the dynamics of neurological deficit revealed the more rapid decrease of stroke volume to the 28th day in the group treated with cerebrolysin (45.4% versus 43.6% in the placebo-group (p cerebrolysin was found. The results of this prospective, randomized, placebo-controlled study suggest the positive effect of cerebrolysin on the dynamics of volume lesion in patients with ischemic stroke.

  6. Maximal expiratory and inspiratory flow-volume curves in Parkinson's disease.

    Bogaard, J M; Hovestadt, A; Meerwaldt, J; vd Meché, F G; Stigt, J


    In order to investigate the type and degree of upper airway obstruction (UAO) in a group of patients with Parkinson's disease in different stages of the disease, we obtained maximal expiratory and inspiratory flow-volume (MEFV and MIFV) curves and maximal static mouth pressures. The clinical disability was indicated by a Hoehn-Yahr (H-Y) scale, ranging from III to V, and a more continuous Northwestern University Disability Scale (NUDS), ranging from zero to 50. Twelve patients were in H-Y Group III, and eleven and eight were in Groups IV and V, respectively. The pattern of the flow-volume curves was classified as either normal, or with superimposed regular or irregular oscillations (A), or with rounded-off and delayed expiratory peak appearance (B). Mean MEFV curves in Groups III and IV were not appreciably different from reference. In Group V, the mean curve showed a lower peak expiratory flow (PEF) and a more convex tail. Only the effort-dependent variables PEF, peak inspiratory flow (PIF), and maximal mouth pressures at RV and TLC (PmTLC and PmRV) appeared to be significantly correlated with the NUDS index and decreased with increasing clinical disability. The mean values of those variables were also significantly different between the H-Y groups. The number of normal curves decreased from H-Y Group III to Group V. The contribution of A and B curves was relatively equal in the groups, with only a small number of A curves.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Estimating exercise stroke volume from asymptotic oxygen pulse in humans.

    Whipp, B J; Higgenbotham, M B; Cobb, F C


    Noninvasive techniques have been devised to estimate cardiac output (Q) during exercise to obviate vascular cannulation. However, although these techniques are noninvasive, they are commonly not nonintrusive to subjects' spontaneous ventilation and gas-exchange responses. We hypothesized that the exercise stroke volume (SV) and, hence, Q might be accurately estimated simply from the response pattern of two standardly determined variables: O2 uptake (VO2) and heart rate (HR). Central to the theory is the demonstration that the product of Q and mixed venous O2 content is virtually constant (k) during steady-state exercise. Thus from the Fick equation, VO2 = Q.CaCO2-k, where CaCO2 is the arterial CO2 content, the O2 pulse (O2-P) equals SV.CaCO2-(k/HR). Because the arterial O2 content (CaO2) is usually relatively constant in normal subjects during exercise, O2-P should change hyperbolically with HR, asymptoting at SV.CaO2. In addition, because the asymptotic O2-P equals the slope (S) of the linear O2-HR relationship, exercise SV may be predicted as S/CaO2. We tested this prediction in 23 normal subjects who underwent a 3-min incremental cycle-ergometer test with direct determination of CaO2 and mixed venous O2 content from indwelling catheters. The predicted SV closely reflected the measured value (r = 0.80). We therefore conclude that, in normal subjects, exercise SV may be estimated simply as five times S of the linear VO2-HR relationship (where 5 is approximately 1/CaO2).

  8. Estimating stroke volume from oxygen pulse during exercise.

    Crisafulli, Antonio; Piras, Francesco; Chiappori, Paolo; Vitelli, Stefano; Caria, Marcello A; Lobina, Andrea; Milia, Raffaele; Tocco, Filippo; Concu, Alberto; Melis, Franco


    This investigation aimed at verifying whether it was possible to reliably assess stroke volume (SV) during exercise from oxygen pulse (OP) and from a model of arterio-venous oxygen difference (a-vO(2)D) estimation. The model was tested in 15 amateur male cyclists performing an exercise test on a cycle-ergometer consisting of a linear increase of workload up to exhaustion. Starting from the analysis of previous published data, we constructed a model of a-vO(2)D estimation (a-vO(2)D(est)) which predicted that the a-vO(2)D at rest was 30% of the total arterial O(2) content (CaO(2)) and that it increased linearly during exercise reaching a value of 80% of CaO(2) at the peak workload (W(max)) of cycle exercise. Then, the SV was calculated by applying the following equation, SV = OP/a-vO(2)D(est), where the OP was assessed as the oxygen uptake/heart rate. Data calculated by our model were compared with those obtained by impedance cardiography. The main result was that the limits of agreement between the SV assessed by impedance cardiography and the SV estimated were between 22.4 and -27.9 ml (+18.8 and -24% in terms of per cent difference between the two SV measures). It was concluded that our model for estimating SV during effort may be reasonably applicable, at least in a healthy population.

  9. Very low cerebral blood volume predicts parenchymal hematoma in acute ischemic stroke

    Hermitte, Laure; Cho, Tae-Hee; Ozenne, Brice;


    BACKGROUND AND PURPOSE: Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective was to exp...

  10. Moderate Recovery Unnecessary to Sustain High Stroke Volume during Interval Training. A Brief Report

    Jamie Stanley


    Full Text Available It has been suggested that the time spent at a high stroke volume (SV is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT session in fourteen well-trained cyclists. Oxygen consumption (VO2, heart rate (HR, SV, cardiac output (Qc, and oxygenation of vastus lateralis (TSI were measured during a HIIT (3×3-min work period, 2 min of recovery session on two occasions. VO2, HR and Qc were largely higher during moderate-intensity (60% compared with low-intensity (30% (VO2, effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2 and passive (HR, ES = +2.2; Qc, ES = +1.7 recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = −0.1; 30%, ES = −0.2. To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT.


    Kandan Muralidharan


    Full Text Available CONTEXT Stroke is the most common cause of death after cardiac disease and cancer. This study attempts to identify the significance of mean platelet volume as a risk factor as well as prognostic factor for ischemic stroke patients1 . This may help in early identification of high risk individuals who can be targeted for aggressive acute management and improved secondary prevention measures. AIM OF THE STUDY To assess whether mean platelet volume levels are elevated in ischemic stroke and to assess MPV as independent risk factor and to assess whether the severity and outcome of ischemic stroke correlates with elevated mean platelet volume. SETTINGS AND DESIGN Analytical Case Control Study. MATERIALS AND METHODS This study is conducted among 50 ischemic stroke patients who were admitted at Government Rajaji Hospital, Madurai from December 2014 to June 2015. After taking detailed history and physical examination and investigations, MPV was determined for Ischemic stroke patients and Modified Rankin scale (MRS at the time of admission was calculated. After 8 weeks of onset of stroke, all the patients were again followed up. Functional outcomes were determined by use of Modified Rankin Scale (MRS2,3. All patients were stratified using MRS2,3 Scale [0-2, 3-4 and 5-6] into three groups. MPV level was correlated with MRS score at the time of admission and again at 8 weeks. Patients with MRS score of 5 and 6 were declared as very poor outcome & MRS of 3 and 4 as poor outcome. Patients with MRS 0, and 1 were considered as good outcome. STATISTICAL ANALYSIS One way ANOVA, Pearson correlation and Chi square test. RESULTS There is no statistically significant difference among the case and control groups with regard to the age or sex composition or smoking or alcoholism. MPV did not vary with diabetes or hypertension. There was a linear relation with MPV and severity of ischemic stroke i.e. as the MPV increases the severity (MRS 2,3of stroke increases

  12. Intrinsic Volumes of the Maximal Facet Process in Higher Dimensional STIT Tessellations

    Schreiber, Tomasz


    Stationary and isotropic random tessellations in ${\\Bbb R}^d$ are considered, which are stable under the operation of iteration -- so-called STIT tessellations. These tessellations are constructed by a random process of cell division and we analyze first- and second-order properties of the intrinsic volumes of the collection of all cell-separating facets (so-called maximal or I-facets) at a fixed time $t$ in a convex window $W\\subset{\\Bbb R}^d$. We provide formulas for mean values, exact and asymptotic variances, as well as a characterization of the lower-dimensional face covariance measures. We will focus here on the case $d\\geq 3$, which is more involved than the planar case, treated separately in an earlier paper. Beside the afore mentioned results, we prove central limit theorems for the process of suitably rescaled intrinsic volumes, leading -- in sharp contrast to the situation in the plane -- to non-Gaussian limit distributions.

  13. Stroke

    ... rehabilitation helps individuals overcome disabilities that result from stroke damage. Drug therapy with blood thinners is the most common treatment for stroke. NIH: National Institute of Neurological Disorders and Stroke

  14. The bilateral movement condition facilitates maximal but not submaximal paretic-limb grip force in people with post-stroke hemiparesis

    DeJong, Stacey L.; Lang, Catherine E.


    Objectives Although healthy individuals have less force production capacity during bilateral muscle contractions compared to unilateral efforts, emerging evidence suggests that certain aspects of paretic upper limb task performance after stroke may be enhanced by moving bilaterally instead of unilaterally. We investigated whether the bilateral movement condition affects grip force differently on the paretic side of people with post-stroke hemiparesis, compared to their non-paretic side and both sides of healthy young adults. Methods Within a single session, we compared: 1) maximal grip force during unilateral vs. bilateral contractions on each side, and 2) force contributed by each side during a 30% submaximal bilateral contraction. Results Healthy controls produced less grip force in the bilateral condition, regardless of side (- 2.4% difference), and similar findings were observed on the non-paretic side of people with hemiparesis (- 4.5% difference). On the paretic side, however, maximal grip force was increased by the bilateral condition in most participants (+11.3% difference, on average). During submaximal bilateral contractions in each group, the two sides each contributed the same percentage of unilateral maximal force. Conclusions The bilateral condition facilitates paretic limb grip force at maximal, but not submaximal levels. Significance In some people with post-stroke hemiparesis, the paretic limb may benefit from bilateral training with high force requirements. PMID:22248812

  15. Estimating changes in Stroke Volume by non-invasive pulse-oximetry Pulse Transit Time Measurements

    ten Bokkel-Andela, J.; Poterman, Marieke; Scheeren, Thomas; Kalmar, A.F.


    Background and Goal of Study:  Pulse wave transit time (PTT), the interval between the R-wave peak on an electrocardiogram (ECG) and arrival of the pulse waves in the periphery (e.g. the finger), is reported to be a reliable estimate for stroke volume[1,2]. In this study, the PTT based on ECG and th

  16. Lung function in North American Indian children: reference standards for spirometry, maximal expiratory flow volume curves, and peak expiratory flow.

    Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S


    Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.

  17. Resonant frequency does not predict high-frequency chest compression settings that maximize airflow or volume.

    Luthy, Sarah K; Marinkovic, Aleksandar; Weiner, Daniel J


    High-frequency chest compression (HFCC) is a therapy for cystic fibrosis (CF). We hypothesized that the resonant frequency (f(res)), as measured by impulse oscillometry, could be used to determine what HFCC vest settings produce maximal airflow or volume in pediatric CF patients. In 45 subjects, we studied: f(res), HFCC vest frequencies that subjects used (f(used)), and the HFCC vest frequencies that generated the greatest volume (f(vol)) and airflow (f(flow)) changes as measured by pneumotachometer. Median f(used) for 32 subjects was 14 Hz (range, 6-30). The rank order of the three most common f(used) was 15 Hz (28%) and 12 Hz (21%); three frequencies tied for third: 10, 11, and 14 Hz (5% each). Median f(res) for 43 subjects was 20.30 Hz (range, 7.85-33.65). Nineteen subjects underwent vest-tuning to determine f(vol) and f(flow). Median f(vol) was 8 Hz (range, 6-30). The rank order of the three most common f(vol) was: 8 Hz (42%), 6 Hz (32%), and 10 Hz (21%). Median f(flow) was 26 Hz (range, 8-30). The rank order of the three most common f(flow) was: 30 Hz (26%) and 28 Hz (21%); three frequencies tied for third: 8, 14, and 18 Hz (11% each). There was no correlation between f(used) and f(flow) (r(2)  = -0.12) or f(vol) (r(2) = 0.031). There was no correlation between f(res) and f(flow) (r(2)  = 0.19) or f(vol) (r(2) = 0.023). Multivariable analysis showed no independent variables were predictive of f(flow) or f(vol). Vest-tuning may be required to optimize clinical utility of HFCC. Multiple HFCC frequencies may need to be used to incorporate f(flow) and f(vol).

  18. Plasma volume expansion does not increase maximal cardiac output or VO2 max in lowlanders acclimatized to altitude.

    Calbet, José A L; Rådegran, Göran; Boushel, Robert; Søndergaard, Hans; Saltin, Bengt; Wagner, Peter D


    With altitude acclimatization, blood hemoglobin concentration increases while plasma volume (PV) and maximal cardiac output (Qmax) decrease. This investigation aimed to determine whether reduction of Qmax at altitude is due to low circulating blood volume (BV). Eight Danish lowlanders (3 females, 5 males: age 24.0 +/- 0.6 yr; mean +/- SE) performed submaximal and maximal exercise on a cycle ergometer after 9 wk at 5,260 m altitude (Mt. Chacaltaya, Bolivia). This was done first with BV resulting from acclimatization (BV = 5.40 +/- 0.39 liters) and again 2-4 days later, 1 h after PV expansion with 1 liter of 6% dextran 70 (BV = 6.32 +/- 0.34 liters). PV expansion had no effect on Qmax, maximal O2 consumption (VO2), and exercise capacity. Despite maximal systemic O2 transport being reduced 19% due to hemodilution after PV expansion, whole body VO2 was maintained by greater systemic O2 extraction (P VO2 during exercise regardless of PV. Pulmonary ventilation, gas exchange, and acid-base balance were essentially unaffected by PV expansion. Sea level Qmax and exercise capacity were restored with hyperoxia at altitude independently of BV. Low BV is not a primary cause for reduction of Qmax at altitude when acclimatized. Furthermore, hemodilution caused by PV expansion at altitude is compensated for by increased systemic O2 extraction with similar peak muscular O2 delivery, such that maximal exercise capacity is unaffected.

  19. Improved cardiac filling facilitates the postprandial elevation of stroke volume in Python regius.

    Enok, Sanne; Leite, Gabriella S P C; Leite, Cléo A C; Gesser, Hans; Hedrick, Michael S; Wang, Tobias


    To accommodate the pronounced metabolic response to digestion, pythons increase heart rate and elevate stroke volume, where the latter has been ascribed to a massive and fast cardiac hypertrophy. However, numerous recent studies show that heart mass rarely increases, even upon ingestion of large meals, and we therefore explored the possibility that a rise in mean circulatory filling pressure (MCFP) serves to elevate venous pressure and cardiac filling during digestion. To this end, we measured blood flows and pressures in anaesthetized Python regius The anaesthetized snakes exhibited the archetypal tachycardia as well as a rise in both venous pressure and MCFP that fully account for the approximate doubling of stroke volume. There was no rise in blood volume and the elevated MCFP must therefore stem from increased vascular tone, possibly by means of increased sympathetic tone on the veins. Furthermore, although both venous pressure and MCFP increased during volume loading, there was no evidence that postprandial hearts were endowed with an additional capacity to elevate stroke volume. In vitro measurements of force development of paced ventricular strips also failed to reveal signs of increased contractility, but the postprandial hearts had higher activities of cytochrome oxidase and pyruvate kinase, which probably serves to sustain the rise in cardiac work during digestion. © 2016. Published by The Company of Biologists Ltd.

  20. Limitations and pitfalls in measurements of right ventricular stroke volume in an animal model of right heart failure.

    Vildbrad, Mads Dam; Andersen, Asger; Andersen, Thomas Krarup; Axelgaard, Sofie; Holmboe, Sarah; Andersen, Stine; Ringgaard, Steffen; Nielsen-Kudsk, Jens Erik


    Right heart failure occurs in various heart and pulmonary vascular diseases and may be fatal. We aimed to identify limitations in non-invasive measurements of right ventricular stroke volume in an animal model of right ventricular failure. Data from previous studies randomising rats to pulmonary trunk banding (PTB, n = 33) causing pressure-overload right ventricular failure or sham operation (n = 16) was evaluated retrospectively. We measured right ventricular stroke volume by high frequency echocardiography and magnetic resonance imaging (MRI). We found correlation between right ventricular stroke volume measured by echocardiography and MRI in the sham animals (r = 0.677, p = 0.004) but not in the PTB group. Echocardiography overestimated the stroke volume compared to MRI in both groups. Intra- and inter-observer variation did not explain the difference. Technical, physiological and anatomical issues in the pulmonary artery might explain why echocardiography over-estimates stroke volume. Flow acceleration close to the pulmonary artery banding can cause uncertainties in the PTB model and might explain the lack of correlation. In conclusion, we found a correlation in right ventricular stroke volume measured by echocardiography versus MRI in the sham group but not the PTB group. Echocardiography overestimated right ventricular stroke volume compared to MRI.

  1. Changes in Stroke Volume Induced by Lung Recruitment Maneuver Predict Fluid Responsiveness in Mechanically Ventilated Patients in the Operating Room.

    Biais, Matthieu; Lanchon, Romain; Sesay, Musa; Le Gall, Lisa; Pereira, Bruno; Futier, Emmanuel; Nouette-Gaulain, Karine


    Lung recruitment maneuver induces a decrease in stroke volume, which is more pronounced in hypovolemic patients. The authors hypothesized that the magnitude of stroke volume reduction through lung recruitment maneuver could predict preload responsiveness. Twenty-eight mechanically ventilated patients with low tidal volume during general anesthesia were included. Heart rate, mean arterial pressure, stroke volume, and pulse pressure variations were recorded before lung recruitment maneuver (application of continuous positive airway pressure of 30 cm H2O for 30 s), during lung recruitment maneuver when stroke volume reached its minimal value, and before and after volume expansion (250 ml saline, 0.9%, infused during 10 min). Patients were considered as responders to fluid administration if stroke volume increased greater than or equal to 10%. Sixteen patients were responders. Lung recruitment maneuver induced a significant decrease in mean arterial pressure and stroke volume in both responders and nonresponders. Changes in stroke volume induced by lung recruitment maneuver were correlated with those induced by volume expansion (r = 0.56; P recruitment maneuver predicted fluid responsiveness with a sensitivity of 88% (95% CI, 62 to 98) and a specificity of 92% (95% CI, 62 to 99). Pulse pressure variations more than 6% before lung recruitment maneuver discriminated responders with a sensitivity of 69% (95% CI, 41 to 89) and a specificity of 75% (95% CI, 42 to 95). The area under receiver operating curves generated for changes in stroke volume induced by lung recruitment maneuver (0.96; 95% CI, 0.81 to 0.99) was significantly higher than that for pulse pressure variations (0.72; 95% CI, 0.52 to 0.88; P recruitment maneuver could predict preload responsiveness in mechanically ventilated patients in the operating room.

  2. Infarct volume predicts critical care needs in stroke patients treated with intravenous thrombolysis

    Faigle, Roland; Marsh, Elisabeth B.; Llinas, Rafael H.; Urrutia, Victor C. [Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD (United States); Wozniak, Amy W. [Johns Hopkins University, Department of Biostatistics, Bloomberg School of Public Health, Baltimore, MD (United States)


    Patients receiving intravenous thrombolysis with recombinant tissue plasminogen activator (IVT) for ischemic stroke are monitored in an intensive care unit (ICU) or a comparable unit capable of ICU interventions due to the high frequency of standardized neurological exams and vital sign checks. The present study evaluates quantitative infarct volume on early post-IVT MRI as a predictor of critical care needs and aims to identify patients who may not require resource intense monitoring. We identified 46 patients who underwent MRI within 6 h of IVT. Infarct volume was measured using semiautomated software. Logistic regression and receiver operating characteristics (ROC) analysis were used to determine factors associated with ICU needs. Infarct volume was an independent predictor of ICU need after adjusting for age, sex, race, systolic blood pressure, NIH Stroke Scale (NIHSS), and coronary artery disease (odds ratio 1.031 per cm{sup 3} increase in volume, 95 % confidence interval [CI] 1.004-1.058, p = 0.024). The ROC curve with infarct volume alone achieved an area under the curve (AUC) of 0.766 (95 % CI 0.605-0.927), while the AUC was 0.906 (95 % CI 0.814-0.998) after adjusting for race, systolic blood pressure, and NIHSS. Maximum Youden index calculations identified an optimal infarct volume cut point of 6.8 cm{sup 3} (sensitivity 75.0 %, specificity 76.7 %). Infarct volume greater than 3 cm{sup 3} predicted need for critical care interventions with 81.3 % sensitivity and 66.7 % specificity. Infarct volume may predict needs for ICU monitoring and interventions in stroke patients treated with IVT. (orig.)

  3. Plasma volume expansion does not increase maximal cardiac output or VO2 max in lowlanders acclimatized to altitude

    Calbet, José A L; Rådegran, Göran; Boushel, Robert Christopher


    With altitude acclimatization, blood hemoglobin concentration increases while plasma volume (PV) and maximal cardiac output (Qmax) decrease. This investigation aimed to determine whether reduction of Qmax at altitude is due to low circulating blood volume (BV). Eight Danish lowlanders (3 females, 5...... males: age 24.0 +/- 0.6 yr; mean +/- SE) performed submaximal and maximal exercise on a cycle ergometer after 9 wk at 5,260 m altitude (Mt. Chacaltaya, Bolivia). This was done first with BV resulting from acclimatization (BV = 5.40 +/- 0.39 liters) and again 2-4 days later, 1 h after PV expansion with 1...... level Qmax and exercise capacity were restored with hyperoxia at altitude independently of BV. Low BV is not a primary cause for reduction of Qmax at altitude when acclimatized. Furthermore, hemodilution caused by PV expansion at altitude is compensated for by increased systemic O2 extraction...

  4. Cerebral blood volume affects blood–brain barrier integrity in an acute transient stroke model

    Huang, Shuning; Kim, Jeong Kon; Atochin, Dmitriy N; Farrar, Christian T; Huang, Paul L; Suh, Ji Yeon; Kwon, Seon Joo; Shim, Woo Hyun; Cho, Hyungjoon; Cho, Gyunggoo; Kim, Young Ro


    Insufficient vascular reserve after an ischemic stroke may induce biochemical cascades that subsequently deteriorate the blood–brain barrier (BBB) function. However, the direct relationship between poor cerebral blood volume (CBV) restoration and BBB disruption has not been examined in acute stroke. To quantify BBB integrity at acute stages of transient stroke, in particular for cases in which extravasation of the standard contrast agent (Gd-DTPA) is not observed, we adopted the water exchange index (WEI), a novel magnetic resonance image-derived parameter to estimate the water permeability across the BBB. The apparent diffusion coefficient (ADC) and R2 relaxation rate constant were also measured for outlining the tissue abnormality, while fractional CBV and WEI were quantified for assessing vascular alterations. The significantly decreased ADC and R2 in the ischemic cortices did not correlate with the changes in CBV or WEI. In contrast, a strong negative correlation between the ipsilesional WEI and CBV was found, in which stroke mice were clustered into two groups: (1) high WEI and low CBV and (2) normal WEI and CBV. The low CBV observed for mice with a disrupted BBB, characterized by a high WEI, indicates the importance of CBV restoration for maintaining BBB stability in acute stroke. PMID:23462571

  5. Gray matter volume changes in chronic subcortical stroke: A cross-sectional study

    Qingqing Diao


    Full Text Available This study aimed to investigate the effects of lesion side and degree of motor recovery on gray matter volume (GMV difference relative to healthy controls in right-handed subcortical stroke. Structural MRI data were collected in 97 patients with chronic subcortical ischemic stroke and 79 healthy controls. Voxel-wise GMV analysis was used to investigate the effects of lesion side and degree of motor recovery on GMV difference in right-handed chronic subcortical stroke patients. Compared with healthy controls, right-lesion patients demonstrated GMV increase (P < 0.05, voxel-wise false discovery rate correction in the bilateral paracentral lobule (PCL and supplementary motor area (SMA and the right middle occipital gyrus (MOG; while left-lesion patients did not exhibit GMV difference under the same threshold. Patients with complete and partial motor recovery showed similar degree of GMV increase in right-lesion patients. However, the motor recovery was correlated with the GMV increase in the bilateral SMA in right-lesion patients. These findings suggest that there exists a lesion-side effect on GMV difference relative to healthy controls in right-handed patients with chronic subcortical stroke. The GMV increase in the SMA may facilitate motor recovery in subcortical stroke patients.

  6. Know your tools - concordance of different methods for measuring brain volume change after ischemic stroke

    Yassi, Nawaf; Campbell, Bruce C.V.; Davis, Stephen M.; Bivard, Andrew [The University of Melbourne, Departments of Medicine and Neurology, Melbourne Brain Centre rate at The Royal Melbourne Hospital, Parkville, Victoria (Australia); Moffat, Bradford A.; Steward, Christopher; Desmond, Patricia M. [The University of Melbourne, Department of Radiology, The Royal Melbourne Hospital, Parkville (Australia); Churilov, Leonid [The University of Melbourne, The Florey Institute of Neurosciences and Mental Health, Parkville (Australia); Parsons, Mark W. [University of Newcastle and Hunter Medical Research Institute, Priority Research Centre for Translational Neuroscience and Mental Health, Newcastle (Australia)


    Longitudinal brain volume changes have been investigated in a number of cerebral disorders as a surrogate marker of clinical outcome. In stroke, unique methodological challenges are posed by dynamic structural changes occurring after onset, particularly those relating to the infarct lesion. We aimed to evaluate agreement between different analysis methods for the measurement of post-stroke brain volume change, and to explore technical challenges inherent to these methods. Fifteen patients with anterior circulation stroke underwent magnetic resonance imaging within 1 week of onset and at 1 and 3 months. Whole-brain as well as grey- and white-matter volume were estimated separately using both an intensity-based and a surface watershed-based algorithm. In the case of the intensity-based algorithm, the analysis was also performed with and without exclusion of the infarct lesion. Due to the effects of peri-infarct edema at the baseline scan, longitudinal volume change was measured as percentage change between the 1 and 3-month scans. Intra-class and concordance correlation coefficients were used to assess agreement between the different analysis methods. Reduced major axis regression was used to inspect the nature of bias between measurements. Overall agreement between methods was modest with strong disagreement between some techniques. Measurements were variably impacted by procedures performed to account for infarct lesions. Improvements in volumetric methods and consensus between methodologies employed in different studies are necessary in order to increase the validity of conclusions derived from post-stroke cerebral volumetric studies. Readers should be aware of the potential impact of different methods on study conclusions. (orig.)

  7. Arterial compliance in patients with cirrhosis: stroke volume-pulse pressure ratio as simplified index

    Henriksen, J H; Fuglsang, Stefan; Bendtsen, Flemming;


    Arterial function may be altered in patients with cirrhosis. We determined compliance of the arterial tree (C(1)) in relation to systemic and splanchnic hemodynamic derangement and clinical variables. C(1) and the stroke volume-pulse pressure index (SV/PP) were significantly higher (+62% and +40...... predictors of SV/PP (P index seems to reflect abnormalities in the arterial compliance of these patients....

  8. Arterial compliance in patients with cirrhosis: stroke volume-pulse pressure ratio as simplified index

    Fuglsang, S; Bendtsen, F; Christensen, E


    Arterial function may be altered in patients with cirrhosis. We determined compliance of the arterial tree (C(1)) in relation to systemic and splanchnic hemodynamic derangement and clinical variables. C(1) and the stroke volume-pulse pressure index (SV/PP) were significantly higher (+62% and +40...... predictors of SV/PP (P compliance is elevated in cirrhosis. A simplified SV/PP index seems to reflect abnormalities in the arterial compliance of these patients....

  9. Stroke Volume and Sympathetic Responses to Lower-Body Negative Pressure Reveal New Insight into Circulatory Shock in Humans


    of SBP and twice DBP by three. 2.4. Measurement of stroke volume Stroke volume was measured noninvasively using tho- racic electrical bioimpedance ...received in revised form 25 February 2004; accepted 26 February 2004 Abstract We measured various hemodynamic responses and muscle sympathetic nerve...responses to central hypovolemia. We measured heart rates, arterial blood pressures, sympathetic neural activity (MSNA; peroneal nerve microneurography), and

  10. Increased range of motion and decreased muscle activity during maximal reach with gravity compensation in stroke patients

    Prange, Grada Berendina; Stienen, Arno; Jannink, M.J.A.; van der Kooij, Herman; IJzerman, Maarten Joost; Hermens, Hermanus J.; G.J. Gelderblom Bart Driessen, Just L. Herder


    To stimulate restoration of arm function after stroke, active movement is important, which can be facilitated by supporting the weight of the hemiparetic arm, either in conventional treatment or in other approaches such as robot-aided therapy. During arm support, the active range of motion during

  11. Natural allelic variation of the IL-21 receptor modulates ischemic stroke infarct volume.

    Lee, Han Kyu; Keum, Sehoon; Sheng, Huaxin; Warner, David S; Lo, Donald C; Marchuk, Douglas A


    Risk for ischemic stroke has a strong genetic basis, but heritable factors also contribute to the extent of damage after a stroke has occurred. We previously identified a locus on distal mouse chromosome 7 that contributes over 50% of the variation in postischemic cerebral infarct volume observed between inbred strains. Here, we used ancestral haplotype analysis to fine-map this locus to 12 candidate genes. The gene encoding the IL-21 receptor (Il21r) showed a marked difference in strain-specific transcription levels and coding variants in neonatal and adult cortical tissue. Collateral vessel connections were moderately reduced in Il21r-deficient mice, and cerebral infarct volume increased 2.3-fold, suggesting that Il21r modulates both collateral vessel anatomy and innate neuroprotection. In brain slice explants, oxygen deprivation (OD) activated apoptotic pathways and increased neuronal cell death in IL-21 receptor-deficient (IL-21R-deficient) mice compared with control animals. We determined that the neuroprotective effects of IL-21R arose from signaling through JAK/STAT pathways and upregulation of caspase 3. Thus, natural genetic variation in murine Il21r influences neuronal cell viability after ischemia by modulating receptor function and downstream signal transduction. The identification of neuroprotective genes based on naturally occurring allelic variations has the potential to inform the development of drug targets for ischemic stroke treatment.

  12. Intracranial pressure pulse waveform correlates with aqueductal cerebrospinal fluid stroke volume.

    Hamilton, Robert; Baldwin, Kevin; Fuller, Jennifer; Vespa, Paul; Hu, Xiao; Bergsneider, Marvin


    This study identifies a novel relationship between cerebrospinal fluid (CSF) stroke volume through the cerebral aqueduct and the characteristic peaks of the intracranial pulse (ICP) waveform. ICP waveform analysis has become much more advanced in recent years; however, clinical practice remains restricted to mean ICP, mainly due to the lack of physiological understanding of the ICP waveform. Therefore, the present study set out to shed some light on the physiological meaning of ICP morphological metrics derived by the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm by investigating their relationships with a well defined physiological variable, i.e., the stroke volume of CSF through the cerebral aqueduct. Seven patients received both overnight ICP monitoring along with a phase-contrast MRI (PC-MRI) of the cerebral aqueduct to quantify aqueductal stroke volume (ASV). Waveform morphological analysis of the ICP signal was performed by the MOCAIP algorithm. Following extraction of morphological metrics from the ICP signal, nine temporal ICP metrics and two amplitude-based metrics were compared with the ASV via Spearman's rank correlation. Of the nine temporal metrics correlated with the ASV, only the width of the P2 region (ICP-Wi2) reached significance. Furthermore, both ICP pulse pressure amplitude and mean ICP did not reach significance. In this study, we showed the width of the second peak (ICP-Wi2) of an ICP pulse wave is positively related to the volume of CSF movement through the cerebral aqueduct. This finding is an initial step in bridging the gap between ICP waveform morphology research and clinical practice.

  13. Relationship between plasma metalloproteinase-9 levels and volume and severity of infarct in patients with acute ischemic stroke.

    Demir, Recep; Ulvi, Hızır; Özel, Lütfi; Özdemir, Gökhan; Güzelcik, Metin; Aygül, Recep


    Matrix metalloproteinases (MMP) constitute an endopeptidase family involved in various physiological and pathological processes. It was demonstrated that plasma MMP-9 level was increased in patients with acute ischemic stroke. In this study, it was investigated whether there was a relationship between the levels of plasma MMP-9 and the severity of stroke and infarct volume in patients with acute ischemic stroke. A total of 32 patients with acute ischemic stroke, (16 males and 16 females) and 30 healthy controls were included in the study. Plasma MMP-9 levels were measured using ELISA method. Computed tomography was performed at 48th hour and infarct volume was calculated using the Cavalieri method. The National Institute of Health Stroke Scale (NIHSS) was checked at baseline, 12, 24, and 48th hour. Plasma MMP-9 levels of the patient group at baseline, 12, 24, and 48th hour were found significantly higher compared to the control group (p acute period of ischemic cerebrovascular disease and correlated with the severity of the disease and infarct volume. The definition of the exact role of plasma MMP-9 after ischemic stroke will have important diagnostic implications for stroke and for the development of therapeutic strategies aimed at modulating plasma MMP-9.

  14. CT angiography and CT perfusion improve prediction of infarct volume in patients with anterior circulation stroke

    Seeters, Tom van; Schaaf, Irene C. van der; Dankbaar, Jan Willem; Horsch, Alexander D.; Niesten, Joris M.; Luitse, Merel J.A.; Mali, Willem P.T.M.; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, Geert Jan; Kappelle, L.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Majoie, Charles B.L.M. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Vos, Jan Albert [St. Antonius Hospital, Department of Radiology, Nieuwegein (Netherlands); Schonewille, Wouter J. [St. Antonius Hospital, Department of Neurology, Nieuwegein (Netherlands); Walderveen, Marianne A.A. van [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Wermer, Marieke J.H. [Leiden University Medical Center, Department of Neurology, Leiden (Netherlands); Duijm, Lucien E.M. [Catharina Hospital, Department of Radiology, Eindhoven (Netherlands); Keizer, Koos [Catharina Hospital, Department of Neurology, Eindhoven (Netherlands); Bot, Joseph C.J. [VU University Medical Center, Department of Radiology, Amsterdam (Netherlands); Visser, Marieke C. [VU University Medical Center, Department of Neurology, Amsterdam (Netherlands); Lugt, Aad van der [Erasmus MC University Medical Center, Department of Radiology, Rotterdam (Netherlands); Dippel, Diederik W.J. [Erasmus MC University Medical Center, Department of Neurology, Rotterdam (Netherlands); Kesselring, F.O.H.W. [Rijnstate Hospital, Department of Radiology, Arnhem (Netherlands); Hofmeijer, Jeannette [Rijnstate Hospital, Department of Neurology, Arnhem (Netherlands); Lycklama a Nijeholt, Geert J. [Medical Center Haaglanden, Department of Radiology, The Hague (Netherlands); Boiten, Jelis [Medical Center Haaglanden, Department of Neurology, The Hague (Netherlands); Rooij, Willem Jan van [St. Elisabeth Hospital, Department of Radiology, Tilburg (Netherlands); Kort, Paul L.M. de [St. Elisabeth Hospital, Department of Neurology, Tilburg (Netherlands); Roos, Yvo B.W.E.M. [Academic Medical Center, Department of Neurology, Amsterdam (Netherlands); Meijer, Frederick J.A. [Radboud University Medical Center, Department of Radiology, Nijmegen (Netherlands); Pleiter, C.C. [St. Franciscus Hospital, Department of Radiology, Rotterdam (Netherlands); Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Collaboration: Dutch acute stroke study (DUST) investigators


    We investigated whether baseline CT angiography (CTA) and CT perfusion (CTP) in acute ischemic stroke could improve prediction of infarct presence and infarct volume on follow-up imaging. We analyzed 906 patients with suspected anterior circulation stroke from the prospective multicenter Dutch acute stroke study (DUST). All patients underwent baseline non-contrast CT, CTA, and CTP and follow-up non-contrast CT/MRI after 3 days. Multivariable regression models were developed including patient characteristics and non-contrast CT, and subsequently, CTA and CTP measures were added. The increase in area under the curve (AUC) and R{sup 2} was assessed to determine the additional value of CTA and CTP. At follow-up, 612 patients (67.5 %) had a detectable infarct on CT/MRI; median infarct volume was 14.8 mL (interquartile range (IQR) 2.8-69.6). Regarding infarct presence, the AUC of 0.82 (95 % confidence interval (CI) 0.79-0.85) for patient characteristics and non-contrast CT was improved with addition of CTA measures (AUC 0.85 (95 % CI 0.82-0.87); p < 0.001) and was even higher after addition of CTP measures (AUC 0.89 (95 % CI 0.87-0.91); p < 0.001) and combined CTA/CTP measures (AUC 0.89 (95 % CI 0.87-0.91); p < 0.001). For infarct volume, adding combined CTA/CTP measures (R{sup 2} = 0.58) was superior to patient characteristics and non-contrast CT alone (R{sup 2} = 0.44) and to addition of CTA alone (R{sup 2} = 0.55) or CTP alone (R{sup 2} = 0.54; all p < 0.001). In the acute stage, CTA and CTP have additional value over patient characteristics and non-contrast CT for predicting infarct presence and infarct volume on follow-up imaging. These findings could be applied for patient selection in future trials on ischemic stroke treatment. (orig.)

  15. Stroke

    ... how to live with the effects of the stroke so you can be as independent as possible. It may include physical therapy, occupational therapy, speech therapy, and swallowing therapy.Your doctor will decide what kind of rehabilitation will be helpful for you. Rehabilitation can begin ...

  16. Simulation method for cardiac stroke volume estimation by intracardiac electrical impedance measurement.

    Barak, C; Leviatan, Y; Inbar, G F; Hoekstein, K N


    Using the electrical impedance measurement technique to investigate stroke volume estimation, three models of the ventricle were simulated. A four-electrode impedance catheter was used; two electrodes to set up an electric field in the model and the other two to measure the potential difference. A new approach, itself an application of the quasi-static case of a method used to solve electromagnetic field problems, was used to solve the electric field in the model. The behaviour of the estimation is examined with respect to the electrode configuration on the catheter and to catheter location with respect to the ventricle walls. Cardiac stroke volume estimation was found to be robust to catheter location generating a 10 per cent error for an offset of 40 per cent of the catheter from the chamber axis and rotation of 20 degrees with respect to the axis. The electrode configuration has a dominant effect on the sensitivity and accuracy of the estimation. Certain configurations gave high accuracy, whereas in others high sensitivity was found with lower accuracy. This led to the conclusion that the electrode configuration should be carefully chosen according to the desired criteria.

  17. Automatic extraction of forward stroke volume using dynamic PET/CT

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik;

    Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study was to vali......Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...... subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic...

  18. Limitations of stroke volume estimation by non-invasive blood pressure monitoring in hypergravity.

    Olivier Manen

    Full Text Available Altitude and gravity changes during aeromedical evacuations induce exacerbated cardiovascular responses in unstable patients. Non-invasive cardiac output monitoring is difficult to perform in this environment with limited access to the patient. We evaluated the feasibility and accuracy of stroke volume estimation by finger photoplethysmography (SVp in hypergravity.Finger arterial blood pressure (ABP waveforms were recorded continuously in ten healthy subjects before, during and after exposure to +Gz accelerations in a human centrifuge. The protocol consisted of a 2-min and 8-min exposure up to +4 Gz. SVp was computed from ABP using Liljestrand, systolic area, and Windkessel algorithms, and compared with reference values measured by echocardiography (SVe before and after the centrifuge runs.The ABP signal could be used in 83.3% of cases. After calibration with echocardiography, SVp changes did not differ from SVe and values were linearly correlated (p<0.001. The three algorithms gave comparable SVp. Reproducibility between SVp and SVe was the best with the systolic area algorithm (limits of agreement -20.5 and +38.3 ml.Non-invasive ABP photoplethysmographic monitoring is an interesting technique to estimate relative stroke volume changes in moderate and sustained hypergravity. This method may aid physicians for aeronautic patient monitoring.

  19. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output

    Smerup, Morten Holdgaard; Damkjær, Mads; Brøndum, Emil


    to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End......-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke...

  20. Effect of fluid loading with normal saline and 6% hydroxyethyl starch on stroke volume variability and left ventricular volume

    Kanda H


    Full Text Available Hirotsugu Kanda,1 Yuji Hirasaki,2 Takafumi Iida,1 Megumi Kanao,1 Yuki Toyama,1 Takayuki Kunisawa,1 Hiroshi Iwasaki,11Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Asahikawa, 2Department of Anatomy, The Jikei University Graduate School of Medicine, Tokyo, JapanPurpose: The aim of this clinical trial was to investigate changes in stroke volume variability (SVV and left ventricular end-diastolic volume (LVEDV after a fluid bolus of crystalloid or colloid using real-time three-dimensional transesophageal echocardiography (3D-TEE and the Vigileo-FloTrac™ system.Materials and methods: After obtaining Institutional Review Board approval, and informed consent from the research participants, 22 patients undergoing scheduled peripheral vascular bypass surgery were enrolled in the study. The patients were randomly assigned to receive 500 mL of hydroxyethyl starch (HES; HES group, n=11 or normal saline (Saline group, n=11 for fluid replacement therapy. SVV was measured using the Vigileo-FloTrac system. LVEDV, stroke volume, and cardiac output were measured by 3D-TEE. The measurements were performed over 30 minutes before and after the fluid bolus in both groups.Results: SVV significantly decreased after fluid bolus in both groups (HES group, 14.7%±2.6% to 6.9%±2.7%, P<0.001; Saline group, 14.3%±3.9% to 8.8%±3.1%, P<0.001. LVEDV significantly increased after fluid loading in the HES group (87.1±24.0 mL to 99.9±27.2 mL, P<0.001, whereas no significant change was detected in the Saline group (88.8±17.3 mL to 91.4±17.6 mL, P>0.05. Stroke volume significantly increased after infusion in the HES group (50.6±12.5 mL to 61.6±19.1 mL, P<0.01 but not in the Saline group (51.6±13.4 mL to 54.1±12.8 mL, P>0.05. Cardiac output measured by 3D-TEE significantly increased in the HES group (3.5±1.1 L/min to 3.9±1.3 L/min, P<0.05, whereas no significant change was seen in the Saline group (3.4±1.1 L/min to 3.3±1.0 L

  1. Stroke Volume During Concomitant Apnea and Exercise: Influence of Gravity and Venous Return

    Hoffmann, Uwe; Drager, Tobias; Steegmanns, Ansgar; Koesterer, Thomas; Linnarsson, Dag


    The responses of the cardiovascular system to intensive exercise (hiP) and combined stimuli by hiP and breath-hold (hiP-BH) for 20 s were examined during changing gravity (parabolic flight) and constant gravity (1g). The basic response to microgravity (μg) during low-intensity exercise was an increase in cardiac output (CO) and stroke volume (SV) as a result of augmented venous return. When onset of hiP was superimposed, the initial augmentation of CO and SV were increased further. In contrast, when BH was added, the increases of CO and SV were slowed. We propose that this was due to a transient increase of the pulmonary blood volume with the combination of μg and BH at large lung volume, creating a temporary imbalance between right ventricular input and left ventricular output. In addition, the BH- induced relative bradycardia may have contributed to a prolongation of the right-to- left indirect ventricular interdependence.

  2. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    Perner, A; Faber, T


    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  3. Validation of a New Method for Stroke Volume Variation Assessment: a Comparaison with the PiCCO Technique

    Laleg-Kirati, Taous-Meriem; Papelier, Yves; Cottin, François; Van De Louw, Andry


    This paper proposes a novel, simple and minimally invasive method for stroke volume variation assessment using arterial blood pressure measurements. The arterial blood pressure signal is reconstructed using a semi-classical signal analysis method allowing the computation of a parameter, called the first systolic invariant INVS1. We show that INVS1 is linearly related to stroke volume. To validate this approach, a statistical comparaison between INVS1 and stroke volume measured with the PiCCO technique was performed during a 15-mn recording in 21 mechanically ventilated patients in intensive care. In 94% of the whole recordings, a strong correlation was estimated by cross-correlation analysis (mean coefficient=0.9) and linear regression (mean coefficient=0.89). Once the linear relation had been verified, a Bland-Altman test showed the very good agreement between the two approaches and their interchangeability. For the remaining 6%, INVS1 and the PiCCO stroke volume were not correlated at all, and this discrepa...

  4. Cardiovascular consequences of bed rest: effect on maximal oxygen uptake

    Convertino, V. A.


    Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake

  5. Maximal expiratory flow-volume types in young subjects with past history of nasal allergy and bronchial asthma.



    Full Text Available Pulmonary function tests were performed on 252 healthy young subjects free from respiratory and allergic symptoms, and 80 young subjects with past history of nasal allergy (PNA and 10 subjects with past history of bronchial asthma (PBA. All the subjects were non-smokers. Maximal expiratory flow-volume (MEFV curves were visually classified into five types (A-E. The percent distribution of type A in healthy subjects was significantly higher than in the PNA group, while the total sum of percentage of types B, C, and D in the PNA group was significantly higher than in the healthy subjects. The percent distribution of type E in the PNA group was similar to that in the healthy subjects. The percent distribution of MEFV types were significantly different between healthy males and healthy females. The percent distribution of types A, B and E were the highest in healthy subjects, PNA and PBA groups, respectively. Conclusively, the difference in the percent distributions of MEFV types was recognized among healthy subjects, PNA and PBA groups.

  6. Stroke volume variation and pleth variability index to predict fluid responsiveness during resection of primary retroperitoneal tumors in Hans Chinese.

    Fu, Q; Mi, W D; Zhang, H


    Respiration variation in arterial pulse pressure (ΔPP) and pulse oximetry plethysmographic waveform amplitude (ΔPOP) are accurate predictors of fluid responsiveness in mechanically ventilated patients. We hypothesized that stroke volume variation (SVV) and pleth variability index (PVI) can predict fluid responsiveness in mechanically ventilated patients during major surgical procedures in Hans Chinese. This prospective study consisted of fifty-five Hans Chinese patients undergoing resection of primary retroperitoneal tumors (PRPT). During the surgical procedures, hemodynamic data [central venous pressure (CVP), cardiac index (CI), stroke volume index (SVI), SVV, and PVI] were recorded before and after volume expansion (VE) (8 ml•kg-1 of 6% hydroxyethyl starch 130/0.4). Fluid responsiveness was defined as an increase in SVI ≥ 10% after VE. Four patients were excluded from analysis for arrhythmia or obvious hemorrhage during VE. Baseline SVV correlated well with baseline PVI and the changes in SVV was correlated with the changes in PVI (p Chinese.

  7. Effect of baseline magnetic resonance imaging (MRI) apparent diffusion coefficient lesion volume on functional outcome in ischemic stroke.

    Ma, Li; Gao, Pei-yi; Hu, Qing-mao; Lin, Yan; Jing, Li-na; Xue, Jing; Chen, Zhi-jun; Wang, Yong-jun; Liu, Mei-li; Cai, Ye-feng


    We explored the relationship between predicted infarct core, predicted ischemic penumbras and predicted final infarct volumes obtained though apparent diffusion coefficient (ADC)-based method, as well as other clinical variables, and functional outcome. Patients with acute cerebral ischemic stroke were retrospectively recruited. The National Institutes of Health Stroke Scale score was evaluated at baseline and the modified Rankin Scale (mRS) at day 90. Favorable outcome was defined as an mRS score of 0 to 2, and unfavorable outcome as 3 to 6. Multimodal stroke magnetic resonance imaging was carried out at presentation. The volumes of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) were measured using the regions of interest (ROI) method. The volumes of predicted infarct core, predicted ischemic penumbra and predicted final infarct were obtained by an automated image analysis system based on baseline ADC maps. The association between baseline magnetic resonance imaging volumes, baseline clinical variables, and functional outcome was statistically analyzed. The study included 30 males and 20 females (mean±SD age, 56±10 years). Baseline DWI, PWI and PWI-DWI mismatch volumes were not correlated with day-90 mRS (P>0.05). Predicted infarct core, predicted ischemic penumbra and predicted final infarct through ADC-based method were all correlated with day-90 mRS (PStroke Scale and recanalization also demonstrated a trend toward a favorable outcome. Receiver operating characteristic analysis showed that the area under the curve of predicted final infarct volume and recanalization were higher with statistical significance (PStroke Scale and recanalization may have effect on functional outcome in acute ischemic stroke.

  8. Pulse pressure variation and stroke volume variation under different inhaled concentrations of isoflurane, sevoflurane and desflurane in pigs undergoing hemorrhage

    Alexandre Hideaki Oshiro


    Full Text Available OBJECTIVES: Inhalant anesthesia induces dose-dependent cardiovascular depression, but whether fluid responsiveness is differentially influenced by the inhalant agent and plasma volemia remains unknown. The aim of this study was to compare the effects of isoflurane, sevoflurane and desflurane on pulse pressure variation and stroke volume variation in pigs undergoing hemorrhage. METHODS: Twenty-five pigs were randomly anesthetized with isoflurane, sevoflurane or desflurane. Hemodynamic and echocardiographic data were registered sequentially at minimum alveolar concentrations of 1.00 (M1, 1.25 (M2, and 1.00 (M3. Then, following withdrawal of 30% of the estimated blood volume, these data were registered at a minimum alveolar concentrations of 1.00 (M4 and 1.25 (M5. RESULTS: The minimum alveolar concentration increase from 1.00 to 1.25 (M2 decreased the cardiac index and increased the central venous pressure, but only modest changes in mean arterial pressure, pulse pressure variation and stroke volume variation were observed in all groups from M1 to M2. A significant decrease in mean arterial pressure was only observed with desflurane. Following blood loss (M4, pulse pressure variation, stroke volume variation and central venous pressure increased (p <0.001 and mean arterial pressure decreased in all groups. Under hypovolemia, the cardiac index decreased with the increase of anesthesia depth in a similar manner in all groups. CONCLUSION: The effects of desflurane, sevoflurane and isoflurane on pulse pressure variation and stroke volume variation were not different during normovolemia or hypovolemia.

  9. Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

    Donald P Bernstein


    Full Text Available Impedance cardiography (ICG is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV. As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC. By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω. Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t, which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t. ΔZ(t represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t, (i.e. dZ/dtmax, with the presumed units of Ω·s-1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t, Ωcm·s-1, and it is the peak rate of change of the blood resistivity variation dρb(t/dtmax (Ωcm·s-2 that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s-2, it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s-2 and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s-2

  10. Respiratory-gated electrical impedance tomography: a potential technique for quantifying stroke volume

    Arshad, Saaid H.; Murphy, Ethan K.; Halter, Ryan J.


    Telemonitoring is becoming increasingly important as the proportion of the population living with cardiovascular disease (CVD) increases. Currently used health parameters in the suite of telemonitoring tools lack the sensitivity and specificity to accurately predict heart failure events, forcing physicians to play a reactive versus proactive role in patient care. A novel cardiac output (CO) monitoring device is proposed that leverages a custom smart phone application and a wearable electrical impedance tomography (EIT) system. The purpose of this work is to explore the potential of using respiratory-gated EIT to quantify stroke volume (SV) and assess its feasibility using real data. Simulations were carried out using the 4D XCAT model to create anatomically realistic meshes and electrical conductivity profiles representing the human thorax and the intrathoracic tissue. A single 5-second period respiration cycle with chest/lung expansion was modeled with end-diastole (ED) and end-systole (ES) heart volumes to evaluate how effective EIT-based conductivity changes represent clinically significant differences in SV. After establishing a correlation between conductivity changes and SV, the applicability of the respiratory-gated EIT was refined using data from the PhysioNet database to estimate the number of useful end-diastole (ED) and end-systole (ES) heart events attained over a 3.3 minute period. The area associated with conductivity changes was found to correlate to SV with a correlation coefficient of 0.92. A window of 12.5% around peak exhalation was found to be the optimal phase of the respiratory cycle from which to record EIT data. Within this window, ~47 useable ED and ES were found with a standard deviation of 28 using 3.3 minutes of data for 20 patients.

  11. Effects of radiation dose reduction in Volume Perfusion CT imaging of acute ischemic stroke

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikobashman, Omid; Brockmann, Marc A.; Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Yang, Zepa; Kim, Changwon [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kim, Jong Hyo [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Center for Medical-IT Convergence Technology Research, Advanced Institute of Convergence Technology, Suwon (Korea, Republic of)


    To examine the influence of radiation dose reduction on image quality and sensitivity of Volume Perfusion CT (VPCT) maps regarding the detection of ischemic brain lesions. VPCT data of 20 patients with suspected ischemic stroke acquired at 80 kV and 180 mAs were included. Using realistic reduced-dose simulation, low-dose VPCT datasets with 144 mAs, 108 mAs, 72 mAs and 36 mAs (80 %, 60 %, 40 % and 20 % of the original levels) were generated, resulting in a total of 100 datasets. Perfusion maps were created and signal-to-noise-ratio (SNR) measurements were performed. Qualitative analyses were conducted by two blinded readers, who also assessed the presence/absence of ischemic lesions and scored CBV and CBF maps using a modified ASPECTS-score. SNR of all low-dose datasets were significantly lower than those of the original datasets (p <.05). All datasets down to 72 mAs (40 %) yielded sufficient image quality and high sensitivity with excellent inter-observer-agreements, whereas 36 mAs datasets (20 %) yielded poor image quality in 15 % of the cases with lower sensitivity and inter-observer-agreements. Low-dose VPCT using decreased tube currents down to 72 mAs (40 % of original radiation dose) produces sufficient perfusion maps for the detection of ischemic brain lesions. (orig.)

  12. Rowing increases stroke volume and cardiac output to a greater extent than cycling.

    Horn, P; Ostadal, P; Ostadal, B


    Exercise stimulates increases in heart rate (HR), stroke volume (SV) and cardiac output (CO). These adaptive mechanisms are strongly dependent on the type of exercise. Both rowing and cycling are widely used for physical training worldwide; however, evidence regarding the differences in major hemodynamic parameters during rowing and cycling remains insufficient. Ten healthy male volunteers were randomly assigned to perform either a rowing or cycling exercise. After 20 min rest, the group who had rowed first performed the cycling exercise and vice versa. Exercise was performed at a power-to-weight ratio of 2 W/kg for 2 min. HR, SV, CO and blood pressure (BP) were measured noninvasively using pulse-wave analysis at baseline and immediately after each exercise. HR, SV and CO were significantly higher after exercise than at rest. Whereas HR was comparable between rowing and cycling, SV and CO were significantly higher after rowing than after cycling. BP was comparable among all three measurements. Rowing increased SV and CO to a greater extent than cycling, whereas HR and BP were not influenced by the type of exercise. Our data suggest that rowing leads to more extensive stimulation of cardiac contractility and/or decreases in peripheral vascular resistance compared with cycling.

  13. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Randa Aly Soliman


    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  14. The evolution of the cerebral blood volume abnormality in patients with ischemic stroke: a CT perfusion study

    D' Esterre, Christopher D.; Lee, Ting Yim (Lawson Health Research Inst., London (Canada); Robarts Research Inst., London (Canada)), email:; Aviv, Richard I. (Sunnybrook Health Sciences Centre, Toronto (Canada))


    Background: Accurate identification of the acute infarct core abnormality is important for guiding acute stroke treatment. Abnormality volumes from diffusion-weighted MRI (DWI) and CT perfusion (CTP)-cerebral blood volume (CBV) are highly correlated. DWI lesions have been shown to be reversible at 24 h. Purpose: To examine the temporal profile of the CT perfusion (CTP)-derived CBV abnormality out to 7 days post ischemic stroke. Material and Methods: Twenty-six patients were included. Group A (n = 13) underwent a noncontrast CT (NCCT), CTP/CT angiography (CTA) within 6 h of stroke onset, CTP/CTA at 24 h, and CTP/NCCT at 5-7 days post stroke. Group B (n = 13) underwent a NCCT, CTP/CTA within 6 h of stroke onset, and NCCT at 5-7 days. Recanalization status was established in all patients. For both groups, infarct volumes were traced on 5-7 day NCCT images and superimposed onto all CTP-CBV functional maps to determine CBV. Group B (n = 13) admission images were used to define CBV infarct thresholds for gray and white matter. CBV-lesion overestimation was determined for Group A using the thresholds from Group B. Results: CBV (ml x 100g- 1; mean +- stdev) for gray/white matter, within confirmed infarcted regions (CBVI) at admission, 24 h, and 5-7 days were 1.82 +- 0.56, 1.56 +- 0.42, 1.75 +- 0.31, and 1.38 +- 0.65, 1.13 +- 0.31, 1.32 +- 0.44, respectively, when averaged over all patients (P > 0.05). Four patients had tissue time-density curves from ischemic lesions (TDCi) with an incomplete contrast medium wash-out phase (truncation) at admission and/or 24 h. Compared to admission, gray matter CBVI was higher at 5-7 days for patients with TDCi truncation (P < 0.05). There were no significant CBVI increases for the eight patients without truncation (P > 0.05). Over-estimation of acute CBV lesion was present in 3/4 (75%) and 1/9 (11%) of patients with/without TDCi truncation, respectively. Conclusion: CTP-derived CBV lesion reversal is associated with TDCi truncation

  15. Peak plasma interleukin-6 and other peripheral markers of inflammation in the first week of ischaemic stroke correlate with brain infarct volume, stroke severity and long-term outcome

    del Zoppo Gregory J


    Full Text Available Abstract Background Cerebral ischaemia initiates an inflammatory response in the brain and periphery. We assessed the relationship between peak values of plasma interleukin-6 (IL-6 in the first week after ischaemic stroke, with measures of stroke severity and outcome. Methods Thirty-seven patients with ischaemic stroke were prospectively recruited. Plasma IL-6, and other markers of peripheral inflammation, were measured at pre-determined timepoints in the first week after stroke onset. Primary analyses were the association between peak plasma IL-6 concentration with both modified Rankin score (mRS at 3 months and computed tomography (CT brain infarct volume. Results Peak plasma IL-6 concentration correlated significantly (p Conclusions These data provide evidence that the magnitude of the peripheral inflammatory response is related to the severity of acute ischaemic stroke, and clinical outcome.

  16. Pilot Study: Estimation of Stroke Volume and Cardiac Output from Pulse Wave Velocity.

    Obata, Yurie; Mizogami, Maki; Nyhan, Daniel; Berkowitz, Dan E; Steppan, Jochen; Barodka, Viachaslau


    Transesophageal echocardiography (TEE) is increasingly replacing thermodilution pulmonary artery catheters to assess hemodynamics in patients at high risk for cardiovascular morbidity. However, one of the drawbacks of TEE compared to pulmonary artery catheters is the inability to measure real time stroke volume (SV) and cardiac output (CO) continuously. The aim of the present proof of concept study was to validate a novel method of SV estimation, based on pulse wave velocity (PWV) in patients undergoing cardiac surgery. This is a retrospective observational study. We measured pulse transit time by superimposing the radial arterial waveform onto the continuous wave Doppler waveform of the left ventricular outflow tract, and calculated SV (SVPWV) using the transformed Bramwell-Hill equation. The SV measured by TEE (SVTEE) was used as a reference. A total of 190 paired SV were measured from 28 patients. A strong correlation was observed between SVPWV and SVTEE with the coefficient of determination (R2) of 0.71. A mean difference between the two (bias) was 3.70 ml with the limits of agreement ranging from -20.33 to 27.73 ml and a percentage error of 27.4% based on a Bland-Altman analysis. The concordance rate of two methods was 85.0% based on a four-quadrant plot. The angular concordance rate was 85.9% with radial limits of agreement (the radial sector that contained 95% of the data points) of ± 41.5 degrees based on a polar plot. PWV based SV estimation yields reasonable agreement with SV measured by TEE. Further studies are required to assess its utility in different clinical situations.

  17. Three-dimensional whole-brain perfused blood volume imaging with multimodal CT for evaluation of acute ischaemic stroke

    Lu, J.; Zhang, M.; Cao, Y. [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing (China); Ma, Q. [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing (China); Chen, J. [Healthcare, Siemens Ltd. China, Beijing (China); Ji, X. [Department of Neurosurgery Xuanwu Hospital, Capital Medical University, Beijing (China); Li, K., E-mail: [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing (China)


    Aim: To determine the diagnostic value of integrating three-dimensional perfused blood volume (3D PBV) with multimodal computed tomography (CT) [non-enhanced CT (NECT), CT perfusion (CTP), and CT angiography (CTA)] in acute ischaemic stroke. Materials and methods: NECT, CTP, and CTA were performed in 25 acute ischaemic stroke patients. The ischaemia detection rate of 3D PBV was compared with the results of baseline NECT and CTP. The correlation of ischaemic lesion volume between 3D PBV, CTP images, and follow-up NECT were analysed. Results: NECT demonstrated ischaemic signs in 12 of 25 patients with proven infarction. CTP maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) all demonstrated perfusion deficits in 21 of 25 patients. However, 3D PBV demonstrated perfusion deficits in all of the 25 patients. Among the 25 patients, a strong correlation was found between PBV and the follow-up NECT infarct (r = 0.858). The correlation between CTP and the follow-up NECT infarct as following: CBF (r = 0.718), CBV (r = 0.785), and TTP (r = 0.569). In 14 thrombolytic patients, strong correlation was found between the ischaemic volume on 3D PBV and follow-up NECT (r = 0.798). Conclusion: In acute stroke patients, the combination of 3D PBV and multimodal CT (NECT, CTP, and CTA) can improve the detection rate of ischaemia and enable assessment of the full extent of ischaemia, which correlates well with follow-up NECT.

  18. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias


    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  19. Fullerenols and glucosamine fullerenes reduce infarct volume and cerebral inflammation after ischemic stroke in normotensive and hypertensive rats.

    Fluri, Felix; Grünstein, Dan; Cam, Ertugrul; Ungethuem, Udo; Hatz, Florian; Schäfer, Juliane; Samnick, Samuel; Israel, Ina; Kleinschnitz, Christoph; Orts-Gil, Guillermo; Moch, Holger; Zeis, Thomas; Schaeren-Wiemers, Nicole; Seeberger, Peter


    Cerebral inflammation plays a crucial role in the pathophysiology of ischemic stroke and is involved in all stages of the ischemic cascade. Fullerene derivatives, such as fullerenol (OH-F) are radical scavengers acting as neuroprotective agents while glucosamine (GlcN) attenuates cerebral inflammation after stroke. We created novel glucosamine-fullerene conjugates (GlcN-F) to combine their protective effects and compared them to OH-F regarding stroke-induced cerebral inflammation and cellular damage. Fullerene derivatives or vehicle was administered intravenously in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) immediately after transient middle cerebral artery occlusion (tMCAO). Infarct size was determined at day 5 and neurological outcome at days 1 and 5 after tMCAO. CD68- and NeuN-staining were performed to determine immunoreactivity and neuronal survival respectively. Cytokine and toll like receptor 4 (TLR-4) expression was assessed using quantitative real-time PCR. Magnetic resonance imaging revealed a significant reduction of infarct volume in both, WKY and SHR that were treated with fullerene derivatives. Treated rats showed an amelioration of neurological symptoms as both OH-F and GlcN-F prevented neuronal loss in the perilesional area. Cerebral immunoreactivity was reduced in treated WKY and SHR. Expression of IL-1β and TLR-4 was attenuated in OH-F-treated WKY rats. In conclusion, OH-F and GlcN-F lead to a reduction of cellular damage and inflammation after stroke, rendering these compounds attractive therapeutics for stroke.

  20. Formerly preeclamptic women with a subnormal plasma volume are unable to maintain a rise in stroke volume during moderate exercise.

    Aardenburg, R.; Spaanderman, M.E.A.; Eijndhoven, H.W. van; Leeuw, P.W. de; Peeters, L.L.


    INTRODUCTION: In formerly preeclamptic women with a low plasma volume, the recurrence rate of preeclampsia is higher than in women with a normal prepregnant plasma volume. In a recent study, we demonstrated that the low plasma volume subgroup also had a subnormal venous capacitance. In the present

  1. Formerly preeclamptic women with a subnormal plasma volume are unable to maintain a rise in stroke volume during moderate exercise.

    Aardenburg, R.; Spaanderman, M.E.A.; Eijndhoven, H.W. van; Leeuw, P.W. de; Peeters, L.L.


    INTRODUCTION: In formerly preeclamptic women with a low plasma volume, the recurrence rate of preeclampsia is higher than in women with a normal prepregnant plasma volume. In a recent study, we demonstrated that the low plasma volume subgroup also had a subnormal venous capacitance. In the present s

  2. Left ventricular atrioventricular plane displacement is preserved with lifelong endurance training and is the main determinant of maximal cardiac output

    Steding-Ehrenborg, Katarina; Boushel, Robert C; Calbet, José A


    BACKGROUND: Age-related decline in cardiac function can be prevented or postponed by lifelong endurance training. However, effects of normal ageing as well as of lifelong endurance exercise on longitudinal and radial contribution to stroke volume are unknown. The aim of this study was to determine...... subjects (29 ± 4 years) underwent cardiac MR. All subjects underwent maximal exercise testing and for elderly subjects maximal cardiac output during cycling was determined using dye dilution technique. RESULTS: Longitudinal and radial contribution to stroke volume did not differ between groups...... and exercise capacity. This article is protected by copyright. All rights reserved....

  3. The effects of long-term aerobic exercise on cardiac structure, stroke volume of the left ventricle, and cardiac output.

    Lee, Bo-Ae; Oh, Deuk-Ja


    The purpose of this study is to investigate the effect of the long-term aerobic exercises on cardiac structure, left ventricular stroke volume, and cardiac output. To achieve the purpose of the study, a total of 22 volunteers-including 10 people who have continued regular exercises and 12 people as the control group-were selected as subjects. With regard to data processing, the IBM SPSS Statistics ver. 21.0 was used to calculate the mean and standard deviation, and the difference of the means between the groups was verified through an independent t-test. As a result, there were significant differences between groups in the left ventricular end-diastolic internal dimension, left ventricular end-systolic internal dimension, left ventricular end-diastolic septum thickness. There were significant differences between groups in left ventricular end-diastolic volume, left ventricular mass, and left ventricular mass index per body surface area. However, in cardiac function, only left ventricular stroke volume showed a significant difference between groups.

  4. The GPVI-Fc fusion protein Revacept improves cerebral infarct volume and functional outcome in stroke.

    Silvia Goebel

    Full Text Available OBJECTIVES: We examined the effect of Revacept, an Fc fusion protein which is specifically linked to the extracellular domain of glycoprotein VI (GPVI, on thrombus formation after vessel wall injury and on experimental stroke in mice. BACKGROUND: Several antiplatelet drugs for the treatment of myocardial infarction or ischemic stroke with potent anti-ischemic effects have been developed, but all incur a significant risk of bleeding. METHODS: Platelet adhesion and thrombus formation after endothelial injury was monitored in the carotid artery by intra-vital fluorescence microscopy. The morphological and clinical consequences of stroke were investigated in a mouse model with a one hour-occlusion of the middle cerebral artery. RESULTS: Thrombus formation was significantly decreased after endothelial injury by 1 mg/kg Revacept i.v., compared to Fc only. 1 mg/kg Revacept i.v. applied in mice with ischemic stroke immediately before reperfusion significantly improved functional outcome, cerebral infarct size and edema compared to Fc only. Also treatment with 10 mg/kg rtPA was effective, and functional outcome was similar in both treatment groups. The combination of Revacept with rtPA leads to increased reperfusion compared to treatment with either agent alone. In contrast to rtPA, however, there were no signs of increased intracranial bleeding with Revacept. Both rtPA and Revacept improved survival after stroke compared to placebo treatment. Revacept and vWF bind to collagen and Revacept competitively prevented the binding of vWF to collagen. CONCLUSIONS: Revacept reduces arterial thrombus formation, reduces cerebral infarct size and edema after ischemic stroke, improves functional and prognostic outcome without intracranial bleeding. Revacept not only prevents GPVI-mediated, but probably also vWF-mediated platelet adhesion and aggregate formation. Therefore Revacept might be a potent and safe tool to treat ischemic complications of stroke.

  5. High-volume plasma exchange in a patient with acute liver failure due to non-exertional heat stroke in a sauna.

    Chen, Kuan-Jung; Chen, Tso-Hsiao; Sue, Yuh-Mou; Chen, Tzay-Jinn; Cheng, Chung-Yi


    Heat stroke is a life-threatening condition characterized by an increased core body temperature (over 40°C) and a systemic inflammatory response, which may lead to a syndrome of multiple organ dysfunction. Heat stroke may be due to either strenuous exercise or non-exercise-induced exposure to a high environmental temperature. Current management of heat stroke is mostly supportive, with an emphasis on cooling the core body temperature and preventing the development of multiple organ dysfunction. Prognosis of heat stroke depends on the severity of organ involvement. Here, we report a rare case of non-exercise-induced heat stroke in a 73-year-old male patient who was suffering from acute liver failure after prolonged exposure in a hot sauna room. We successfully managed this patient by administering high-volume plasma exchange, and the patient recovered completely after treatment.

  6. Non-invasive measurement of stroke volume and left ventricular ejection fraction. Radionuclide cardiography compared with left ventricular cardioangiography

    Kelbaek, H; Svendsen, Jesper Hastrup; Aldershvile, J;


    The stroke volume (SV) was determined by first passage radionuclide cardiography and the left ventricular ejection fraction (LVEF) by multigated radionuclide cardiography in 20 patients with ischemic heart disease. The results were evaluated against those obtained by the invasive dye dilution...... or thermodilution and left ventricular cardioangiographic techniques. In a paired comparison the mean difference between the invasive and radionuclide SV was -1 ml (SED 3.1) with a correlation coefficient of 0.83 (p less than 0.01). Radionuclide LVEF values also correlated well with cardioangiographic measurements...

  7. Prediction of subacute infarct lesion volumes by processing apparent diffusion coefficient maps based on apparent diffusion coefficient cut-off values in patients with acute stroke



    Objective To explore the feasibility of prediction of subacute infarct lesion volumes by processing ADC maps based on ADC cut-off values in patients with acute stroke.Methods MRI was performed in 20 patients with clinically diagnosed acute infarct less than 6 h after stroke onset.The MRI included a DWI and conventional MRI.The follow-up MR examinations of all the patients

  8. Hubungan Kadar High Sensitivity- C Reactive Protein (Hs-Crp) Dengan Volume Infark Dan Outcome Fungsional Pada Pasien Stroke Iskemik Akut

    Aritonang, Minar


    Introduction : C-reactive protein is the acute phase protein and a well known marker of inflamation. The high-sensitivity C-Reactive Protein assay is being increasingly used as a marker for stroke risk assessment, and as a marker for prognostication of ischemic stroke. The aim of this study is to evaluate the correlation between hs-CRP level with infarct volume and functional outcome in acute ishemic stroke patients. Methods : We conducted a cross-sectional study of 35-acute ischemic ...

  9. The pathophysiology of the aqueduct stroke volume in normal pressure hydrocephalus: can co-morbidity with other forms of dementia be excluded?

    Bateman, Grant A. [John Hunter Hospital, Department of Medical Imaging, Newcastle (Australia); Levi, Christopher R.; Wang, Yang; Lovett, Elizabeth C. [Hunter Medical Research Institute, Clinical Neurosciences Program, Newcastle (Australia); Schofield, Peter [James Fletcher Hospital, Neuropsychiatry Unit, Newcastle (Australia)


    Variable results are obtained from the treatment of normal pressure hydrocephalus (NPH) by shunt insertion. There is a high correlation between NPH and the pathology of Alzheimer's disease (AD) on brain biopsy. There is an overlap between AD and vascular dementia (VaD), suggesting that a correlation exists between NPH and other forms of dementia. This study seeks to (1) understand the physiological factors behind, and (2) define the ability of, the aqueduct stroke volume to exclude dementia co-morbidity. Twenty-four patients from a dementia clinic were classified as having either early AD or VaD on the basis of clinical features, Hachinski score and neuropsychological testing. They were compared with 16 subjects with classical clinical findings of NPH and 12 aged-matched non-cognitively impaired subjects. MRI flow quantification was used to measure aqueduct stroke volume and arterial pulse volume. An arterio-cerebral compliance ratio was calculated from the two volumes in each patient. The aqueduct stroke volume was elevated in all three forms of dementia, with no significant difference noted between the groups. The arterial pulse volume was elevated by 24% in VaD and reduced by 35% in NPH, compared to normal (P=0.05 and P=0.002, respectively), and was normal in AD. There was a spectrum of relative compliance with normal compliance in VaD and reduced compliance in AD and NPH. The aqueduct stroke volume depends on the arterial pulse volume and the relative compliance between the arterial tree and brain. The aqueduct stroke volume cannot exclude significant co-morbidity in NPH. (orig.)

  10. Angiosperms evolved a higher mesophyll surface area per volume to maximize exchange surface under a low CO2 world

    Théroux-Rancourt, Guillaume; Mason Earles, J.; Gilbert, Matthew E.; Zwieniecki, Maciej A.; Boyce, C. Kevin; McElrone, Andrew; Brodersen, Craig


    Variation in leaf mesophyll structure strongly affects CO2 diffusion and photosynthetic rates. One key trait is the surface of mesophyll cells exposed to intercellular airspace (Sm) which increases mesophyll conductance. Consequently, Sm is a key control of CO2 diffusion among species and genotypes. Using Sm values from the literature (> 200 species with 500 data points) and from our high-resolution X-ray computed tomography (μCT) dataset (currently 117 species), Sm shows little variation from pteridophytes to early angiosperms, while eudicots show the greatest structural diversity. However, Sm increases with total thickness of the mesophyll. By considering the exposed surface of the mesophyll to the intercellular air space (IAS) on a leaf or mesophyll volume (Ames/V mes) rather than leaf area basis (Sm), we demonstrate that angiosperms, and most specifically commelinids and non-basal eudicots, have constructed leaves with more surface per volume, while gymnosperms keep a constant Ames/V mes ratio. Thus, this strong phylogenetic signal suggests that angiosperms have developed IAS properties favoring leaves with higher surface to volume ratio, trait that allowed for the potential of high productivity even as atmospheric CO2 declined over the Cenozoic.

  11. CTA collateral score predicts infarct volume and clinical outcome after endovascular therapy for acute ischemic stroke: a retrospective chart review.

    Elijovich, Lucas; Goyal, Nitin; Mainali, Shraddha; Hoit, Dan; Arthur, Adam S; Whitehead, Matthew; Choudhri, Asim F


    Acute ischemic stroke (AIS) due to emergent large-vessel occlusion (ELVO) has a poor prognosis. To examine the hypothesis that a better collateral score on pretreatment CT angiography (CTA) would correlate with a smaller final infarct volume and a more favorable clinical outcome after endovascular therapy (EVT). A retrospective chart review of the University of Tennessee AIS database from February 2011 to February 2013 was conducted. All patients with CTA-proven LVO treated with EVT were included. Recanalization after EVT was defined by Thrombolysis in Cerebral Infarction (TICI) score ≥2. Favorable outcome was assessed as a modified Rankin Score ≤3. Fifty patients with ELVO were studied. The mean National Institutes of Health Stroke Scale score was 17 (2-27) and 38 of the patients (76%) received intravenous tissue plasminogen activator. The recanalization rate for EVT was 86.6%. Good clinical outcome was achieved in 32% of patients. Univariate predictors of good outcome included good collateral scores (CS) on presenting CTA (p=0.043) and successful recanalization (p=0.02). Multivariate analysis confirmed both good CS (p=0.024) and successful recanalization (p=0.009) as predictors of favorable outcome. Applying results of the multivariate analysis to our cohort we were able to determine the likelihood of good clinical outcome as well as predictors of smaller final infarct volume after successful recanalization. Good CS predict smaller infarct volumes and better clinical outcome in patients recanalized with EVT. These data support the use of this technique in selecting patients for EVT. Poor CS should be considered as an exclusion criterion for EVT as patients with poor CS have poor clinical outcomes despite recanalization. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  12. Effects of positive expiratory pressure on chest wall volumes in subjects with stroke compared to healthy controls: a case-control study.

    Cabral, Elis E A; Resqueti, Vanessa R; Lima, Illia N D F; Gualdi, Lucien P; Aliverti, Andrea; Fregonezi, Guilherme A F


    Alterations in respiratory system kinematics in stroke lead to restrictive pattern associated with decreased lung volumes. Chest physical therapy, such as positive expiratory pressure, may be useful in the treatment of these patients; however, the optimum intensity to promote volume and motion changes of the chest wall remains unclear. To assess the effect of different intensities of positive expiratory pressure on chest wall kinematics in subjects with stroke compared to healthy controls. 16 subjects with chronic stroke and 16 healthy controls matched for age, gender, and body mass index were recruited. Chest wall volumes were assessed using optoelectronic plethysmography during quiet breathing, 5 minutes, and recovery. Three different intensities of positive expiratory pressure (10, 15, and 20cmH2O) were administered in a random order with a 30 minutes rest interval between intensities. During positive expiratory pressure, tidal chest wall expansion increased in both groups compared to quiet breathing; however, this increase was not significant in the subjects with stroke (0.41 vs. 1.32L, 0.56 vs. 1.54L, 0.52 vs. 1.8L, at 10, 15, 20cmH2O positive expiratory pressure, for stroke and control groups; pFisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  13. Low- and high-volume of intensive endurance training significantly improves maximal oxygen uptake after 10-weeks of training in healthy men.

    Arnt Erik Tjønna

    Full Text Available UNLABELLED: Regular exercise training improves maximal oxygen uptake (VO2max, but the optimal intensity and volume necessary to obtain maximal benefit remains to be defined. A growing body of evidence suggests that exercise training with low-volume but high-intensity may be a time-efficient means to achieve health benefits. In the present study, we measured changes in VO2max and traditional cardiovascular risk factors after a 10 wk. training protocol that involved three weekly high-intensity interval sessions. One group followed a protocol which consisted of 4×4 min at 90% of maximal heart rate (HRmax interspersed with 3 min active recovery at 70% HRmax (4-AIT, the other group performed a single bout protocol that consisted of 1×4 min at 90% HRmax (1-AIT. Twenty-six inactive but otherwise healthy overweight men (BMI: 25-30, age: 35-45 y were randomized to either 1-AIT (n = 11 or 4-AIT (n = 13. After training, VO2max increased by 10% (∼5.0 mL⋅kg(-1⋅min(-1 and 13% (∼6.5 mL⋅kg(-1⋅min(-1 after 1-AIT and 4-AIT, respectively (group difference, p = 0.08. Oxygen cost during running at a sub-maximal workload was reduced by 14% and 13% after 1-AIT and 4-AIT, respectively. Systolic blood pressure decreased by 7.1 and 2.6 mmHg after 1-AIT and 4-AIT respectively, while diastolic pressure decreased by 7.7 and 6.1 mmHg (group difference, p = 0.84. Both groups had a similar ∼5% decrease in fasting glucose. Body fat, total cholesterol, LDL-cholesterol, and ox-LDL cholesterol only were significantly reduced after 4-AIT. Our data suggest that a single bout of AIT performed three times per week may be a time-efficient strategy to improve VO2max and reduce blood pressure and fasting glucose in previously inactive but otherwise healthy middle-aged individuals. The 1-AIT type of exercise training may be readily implemented as part of activities of daily living and could easily be translated into programs designed to improve public

  14. Relationship between stroke volume, cardiac output and filling of the heart during tilt

    Bundgaard-Nielsen, M.; Sorensen, H.; Dalsgaard, M.;


    %) in LVEDV because HR increased 3 bpm and CO decreased 0.5 l/min (ns). CONCLUSION: This study confirmed that SV and CO are maximal in resting, supine, healthy humans and decrease during HUT. However, 90 degrees HDT was associated with increased LVEDV and induced a reduction in SV Udgivelsesdato: 2009/11...

  15. Goal-directed intraoperative fluid therapy guided by stroke volume and its variation in high-risk surgical patients : a prospective randomized multicentre study

    Scheeren, Thomas W. L.; Wiesenack, Christoph; Gerlach, Herwig; Marx, Gernot


    Perioperative hemodynamic optimisation improves postoperative outcome for patients undergoing high-risk surgery (HRS). In this prospective randomized multicentre study we studied the effects of an individualized, goal-directed fluid management based on continuous stroke volume variation (SVV) and st

  16. Maximal trees

    Brendle, Joerg


    We show that, consistently, there can be maximal subtrees of P (omega) and P (omega) / fin of arbitrary regular uncountable size below the size of the continuum. We also show that there are no maximal subtrees of P (omega) / fin with countable levels. Our results answer several questions of Campero, Cancino, Hrusak, and Miranda.

  17. Intravenous administration of human umbilical cord blood-derived AC133+ endothelial progenitor cells in rat stroke model reduces infarct volume: magnetic resonance imaging and histological findings.

    Iskander, Asm; Knight, Robert A; Zhang, Zheng Gang; Ewing, James R; Shankar, Adarsh; Varma, Nadimpalli Ravi S; Bagher-Ebadian, Hassan; Ali, Meser M; Arbab, Ali S; Janic, Branislava


    Endothelial progenitor cells (EPCs) hold enormous therapeutic potential for ischemic vascular diseases. Previous studies have indicated that stem/progenitor cells derived from human umbilical cord blood (hUCB) improve functional recovery in stroke models. Here, we examined the effect of hUCB AC133+ EPCs on stroke development and resolution in a middle cerebral artery occlusion (MCAo) rat model. Since the success of cell therapies strongly depends on the ability to monitor in vivo the migration of transplanted cells, we also assessed the capacity of magnetic resonance imaging (MRI) to track in vivo the magnetically labeled cells that were administered. Animals were subjected to transient MCAo and 24 hours later injected intravenously with 10(7) hUCB AC133+ EPCs. MRI performed at days 1, 7, and 14 after the insult showed accumulation of transplanted cells in stroke-affected hemispheres and revealed that stroke volume decreased at a significantly higher rate in cell-treated animals. Immunohistochemistry analysis of brain tissues localized the administered cells in the stroke-affected hemispheres only and indicated that these cells may have significantly affected the magnitude of endogenous proliferation, angiogenesis, and neurogenesis. We conclude that transplanted cells selectively migrated to the ischemic brain parenchyma, where they exerted a therapeutic effect on the extent of tissue damage, regeneration, and time course of stroke resolution.

  18. Use of the Frank-Starling mechanism during submaximal versus maximal upright exercise.

    Plotnick, G D; Becker, L C; Fisher, M L; Gerstenblith, G; Renlund, D G; Fleg, J L; Weisfeldt, M L; Lakatta, E G


    To evaluate the extent to which the Frank-Starling mechanism is utilized during successive stages of vigorous upright exercise, absolute left ventricular end-diastolic volume and ejection fraction were determined by gated blood pool scintigraphy at rest and during multilevel maximal upright bicycle exercise in 30 normal males aged 26-50 yr, who were able to exercise to 125 W or greater. Left ventricular end-systolic volume, stroke volume, and cardiac output were calculated at rest and during each successive 3-min stage of exercise [25, 50, 75, 100, and 125-225 W (peak)]. During early exercise (25 W), end-diastolic and stroke volumes increased (+17 +/- 1 and +31 +/- 4%, respectively), with no change in end-systolic volume. With further exercise (50-75 W) end-diastolic volume remained unchanged as end-systolic volume decreased (-12 +/- 4 and -24 + 5%, respectively). At peak exercise end-diastolic volume decreased to resting level, stroke volume remained at a plateau, and end-systolic volume further decreased (-48 +/- 7%). Thus the Frank-Starling mechanism is used early in exercise, perhaps because of a delay in sympathetic mobilization, and does not appear to play a role in the later stages of vigorous exercise.

  19. Associations of Ischemic Lesion Volume With Functional Outcome in Patients With Acute Ischemic Stroke: 24-Hour Versus 1-Week Imaging.

    Bucker, Amber; Boers, Anna M; Bot, Joseph C J; Berkhemer, Olvert A; Lingsma, Hester F; Yoo, Albert J; van Zwam, Wim H; van Oostenbrugge, Robert J; van der Lugt, Aad; Dippel, Diederik W J; Roos, Yvo B W E M; Majoie, Charles B L M; Marquering, Henk A


    Ischemic lesion volume (ILV) on noncontrast computed tomography at 1 week can be used as a secondary outcome measure in patients with acute ischemic stroke. Twenty-four-hour ILV on noncontrast computed tomography has greater availability and potentially allows earlier estimation of functional outcome. We aimed to assess lesion growth 24 hours after stroke onset and compare the associations of 24-hour and 1-week ILV with functional outcome. We included 228 patients from MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), who received noncontrast computed tomography at 24-hour and 1-week follow-up on which ILV was measured. Relative and absolute lesion growth was determined. Logistic regression models were constructed either including the 24-hour or including the 1-week ILV. Ordinal and dichotomous (0-2 and 3-6) modified Rankin scale scores were, respectively, used as primary and secondary outcome measures. Median ILV was 42 mL (interquartile range, 21-95 mL) and 64 mL (interquartile range: 30-120 mL) at 24 hours and 1 week, respectively. Relative lesion growth exceeding 30% occurred in 121 patients (53%) and absolute lesion growth exceeding 20 mL occurred in 83 patients (36%). Both the 24-hour and 1-week ILVs were similarly significantly associated with functional outcome (both P<0.001). In the logistic analyses, the areas under the curve of the receiver-operator characteristic curves were similar: 0.85 (95% confidence interval, 0.80-0.90) and 0.87 (95% confidence interval, 0.82-0.91) for including the 24-hour and 1-week ILV, respectively. Growth of ILV is common 24-hour poststroke onset. Nevertheless, the 24-hour ILV proved to be a valuable secondary outcome measure as it is equally strongly associated with functional outcome as the 1-week ILV. URL: Unique identifier: ISRCTN10888758. © 2017 American Heart Association, Inc.

  20. Normovolemia defined according to cardiac stroke volume in healthy supine humans

    Bundgaard-Nielsen, Morten; Jørgensen, Christoffer C; Kehlet, Henrik


    BACKGROUND: Both hypovolemia and a fluid overload are detrimental for outcome in surgical patients but the effort to establish normovolemia is hampered by the lack of an operational clinical definition. Manipulating the central blood volume on a tilt table demonstrates that the flat part...

  1. The Effect of Pre-Nutrition of Hydroalcoholic Extracts of Origanum vulgare on Infarct Volume and Neurologic Deficits in a Rat Stroke Model

    meysam Foroozandeh


    Full Text Available Background & objectives: Basic and clinical studies have shown that the production of free radicals was one of the main factors leading to the injury after stroke. In this study we investigated the effect of hydroalcoholic extracts of Origanum vulgare on infarct volume and neurological deficits in a rat stroke model. Methods: In this experimental study 35 male Wistar rats were randomly divided into 5 groups, each containing 7 animals. First group (control received distilled water, while other three treatment groups received oral Origanum vulgare extract by gavage for 30 days (50, 75 and 100 mg/kg/day, respectively. These groups were subjected to 60 min middle cerebral artery occlusion 2 hours after the last dose of Origanum extracts and followed by 24 hrs reperfusion. After 24 hrs, the infarct volume and neurologic deficits were evaluated in the groups. Sham operated groups (n=7 did not receive Marjoram and brain ischemia. Results: The hydroalcoholic extract of Origanum reduced the infarct volume and neurologic deficits in all treatment groups compared to control group. Conclusion: It seems that Origanum vulgare extract can exert the neuroprotective effect against stroke damage by reducing infarct volume and neurological disorders.

  2. Entropy Maximization

    K B Athreya


    It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf that satisfy $\\int fh_id_=_i$ for $i=1,2,\\ldots,\\ldots k$ the maximizer of entropy is an $f_0$ that is proportional to $\\exp(\\sum c_i h_i)$ for some choice of $c_i$. An extension of this to a continuum of constraints and many examples are presented.

  3. Evolution of Volume and Signal Intensity on Fluid-attenuated Inversion Recovery MR Images after Endovascular Stroke Therapy.

    Federau, Christian; Mlynash, Michael; Christensen, Soren; Zaharchuk, Greg; Cha, Brannon; Lansberg, Maarten G; Wintermark, Max; Albers, Gregory W


    Purpose To analyze both volume and signal evolution on magnetic resonance (MR) fluid-attenuated inversion recovery (FLAIR) images between the images after endovascular therapy and day 5 (which was the prespecified end point for infarct volume in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution [DEFUSE 2] trial) in a subset of patients enrolled in the DEFUSE 2 study. Materials and Methods This study was approved by the local ethics committee at all participating sites. Informed written consent was obtained from all patients. In this post hoc analysis of the DEFUSE 2 study, 35 patients with FLAIR images acquired both after endovascular therapy (median time after symptom onset, 12 hours) and at day 5 were identified. Patients were separated into two groups based on the degree of reperfusion achieved on time to maximum greater than 6-second perfusion imaging (≥90% vs <90%). After coregistration and signal normalization, lesion volumes and signal intensity were assessed by using FLAIR imaging for the initial lesion (ie, visible after endovascular therapy) and the recruited lesion (the additional lesion visible on day 5, but not visible after endovascular therapy). Statistical significance was assessed by using Wilcoxon signed-rank, Mann-Whitney U, and Fisher exact tests. Results All 35 patients had FLAIR lesion growth between the after-revascularization examination and day 5. Median lesion growth was significantly larger in patients with <90% reperfusion (27.85 mL) compared with ≥90% (8.12 mL; P = .003). In the initial lesion, normalized signal did not change between after endovascular therapy (median, 1.60) and day 5 (median, 1.58) in the ≥90% reperfusion group (P = .97), but increased in the <90% reperfusion group (from 1.60 to 1.73; P = .01). In the recruited lesion, median normalized signal increased significantly in both groups between after endovascular therapy and day 5 (after endovascular therapy, from 1.19 to 1.56, P

  4. Determinants of maximal oxygen uptake in severe acute hypoxia

    Calbet, J A L; Boushel, Robert Christopher; Rådegran, G


    To unravel the mechanisms by which maximal oxygen uptake (VO2 max) is reduced with severe acute hypoxia in humans, nine Danish lowlanders performed incremental cycle ergometer exercise to exhaustion, while breathing room air (normoxia) or 10.5% O2 in N2 (hypoxia, approximately 5,300 m above sea...... level). With hypoxia, exercise PaO2 dropped to 31-34 mmHg and arterial O2 content (CaO2) was reduced by 35% (P ..., as reflected by the higher alveolar-arterial O2 difference in hypoxia (P stroke VOlume (P

  5. Continuous stroke volume estimation from aortic pressure using zero dimensional cardiovascular model: proof of concept study from porcine experiments.

    Shun Kamoi

    Full Text Available Accurate, continuous, left ventricular stroke volume (SV measurements can convey large amounts of information about patient hemodynamic status and response to therapy. However, direct measurements are highly invasive in clinical practice, and current procedures for estimating SV require specialized devices and significant approximation.This study investigates the accuracy of a three element Windkessel model combined with an aortic pressure waveform to estimate SV. Aortic pressure is separated into two components capturing; 1 resistance and compliance, 2 characteristic impedance. This separation provides model-element relationships enabling SV to be estimated while requiring only one of the three element values to be known or estimated. Beat-to-beat SV estimation was performed using population-representative optimal values for each model element. This method was validated using measured SV data from porcine experiments (N = 3 female Pietrain pigs, 29-37 kg in which both ventricular volume and aortic pressure waveforms were measured simultaneously.The median difference between measured SV from left ventricle (LV output and estimated SV was 0.6 ml with a 90% range (5th-95th percentile -12.4 ml-14.3 ml. During periods when changes in SV were induced, cross correlations in between estimated and measured SV were above R = 0.65 for all cases.The method presented demonstrates that the magnitude and trends of SV can be accurately estimated from pressure waveforms alone, without the need for identification of complex physiological metrics where strength of correlations may vary significantly from patient to patient.

  6. Pediatric Stroke

    ... News About Neurology Image Library Search The Internet Stroke Center Patients & Families About Stroke Stroke Diagnosis Stroke ... communicate with your child’s doctor. Symptoms of a Stroke Stroke is an injury to part of the ...

  7. Diagnostic and predictive value of voiding diary data versus prostate volume, maximal free urinary flow rate, and Abrams-Griffiths number in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia

    van Venrooij, Ger E. P. M.; van Melick, Harm H. E.; Eckhardt, Mardy D.; Boon, Tom A.


    OBJECTIVES To investigate the information of voiding data in relation to symptoms and well-being in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) and to compare this information with that of prostate volume (Vprostate), maximal free urinary flow rate (

  8. Lowering bronchoaspiration rate in an acute stroke unit by means of a 2 volume/3 texture dysphagia screening test with pulsioximetry.

    Cocho, D; Sagales, M; Cobo, M; Homs, I; Serra, J; Pou, M; Perez, G; Pujol, G; Tantinya, S; Bao, P; Aloy, A; Sabater, R; Gendre, J; Otermin, P

    During acute stroke, 30% of all patients present dysphagia and 50% of that subgroup will experience bronchoaspiration. Our aim was to compare mortality and bronchoaspiration rates associated with the water test compared to those associated with a 2 volume/3 texture test controlled with pulse oximetry (2v/3t-P test) in our stroke unit. Over a 5-year period, we performed a prospective analysis of all consecutive acute ischaemic stroke patients hospitalised in the Stroke Unit. Dysphagia was evaluated using the water test between 2008 and 2010 (group 0 or G0), and the 2v/3t-P test (group 1 or G1) between 2011 and 2012. We analysed demographic data, vascular risk factors, neurological deficit on the NIHSS, aetiological subtype according to TOAST criteria, clinical subtype according to the Oxfordshire classification, prevalence of dysphagia, percentage of patients with bronchoaspiration, and mortality. We examined 418 patients with acute stroke (G0=275, G1=143). There were significant differences between the 2 groups regarding the percentage of patients with TACI (17% in G0 vs. 29% in G1, P=.005) and median NIHSS score (4 points in G0 vs. 7 points in G1, P=.003). Since adopting the new swallowing test, we detected a non-significant increase in the percentage of dysphagia (22% in G0 vs. 25% in G1, P=.4), lower mortality (1.7% in G0 vs. 0.7% in G1, P=.3) and a significant decrease in the bronchoaspiration rate (6.2% in G0 vs. 2.1% in G1, P=.05). Compared to the water test used for dysphagia screening, the new 2v/3t-P test lowered bronchoaspiration rates in acute stroke patients. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Improvement of Repeated-Sprint Ability and Horizontal-Jumping Performance in Elite Young Basketball Players With Low-Volume Repeated-Maximal-Power Training.

    Gonzalo-Skok, Oliver; Tous-Fajardo, Julio; Arjol-Serrano, José Luis; Suarez-Arrones, Luis; Casajús, José Antonio; Mendez-Villanueva, Alberto


    To examine the effects of a low-volume repeated-power-ability (RPA) training program on repeated-sprint and change-of- direction (COD) ability and functional jumping performance. Twenty-two male elite young basketball players (age 16.2 ± 1.2 y, height 190.0 ± 10.0 cm, body mass 82.9 ± 10.1 kg) were randomly assigned either to an RPA-training group (n = 11) or a control group (n = 11). RPA training consisted of leg-press exercise, twice a week for 6 wk, of 1 or 2 blocks of 5 sets × 5 repetitions with 20 s of passive recovery between sets and 3 min between blocks with the load that maximized power output. Before and after training, performance was assessed by a repeated-sprint-ability (RSA) test, a repeated-COD-ability test, a hop for distance, and a drop jump followed by tests of a double unilateral hop with the right and left legs. Within-group and between-groups differences showed substantial improvements in slowest (RSAs) and mean time (RSAm) on RSA; best, slowest and mean time on repeated-COD ability; and unilateral right and left hop in the RPA group in comparison with control. While best time on RSA showed no improvement in any group, there was a large relationship (r = .68, 90% CI .43;.84) between the relative decrement in RSAm and RSAs, suggesting better sprint maintenance with RPA training. The relative improvements in best and mean repeated-COD ability were very largely correlated (r = .89, 90% CI .77;.94). Six weeks of lowvolume (4-14 min/wk) RPA training improved several physical-fitness tests in basketball players.

  10. Stability of ischemic core volume during the initial hours of acute large vessel ischemic stroke in a subgroup of mechanically revascularized patients

    Finitsis, Stephanos [Universitaetsklinikum Hamburg-Eppendorf, Neuroradiologie, Hamburg (Germany); Aristotle University of Thessaloniki, Neuroradiology Department, Ahepa Hospital, Thessaloniki (Greece); Kemmling, Andrea; Fiehler, Jens; Brekenfeld, Caspar [Universitaetsklinikum Hamburg-Eppendorf, Neuroradiologie, Hamburg (Germany); Havemeister, Stephanie; Thomalla, Goetz [Universitaetsklinikum Hamburg-Eppendorf, Klinik und Poliklinik fuer Neurologie, Kopf- und Neurozentrum, Hamburg (Germany)


    This study aimed to relate growth of the infarct core with time to recanalization in patients receiving mechanical recanalization in whom the time of recanalization is known. We analyzed data from patients with anterior circulation acute ischemic stroke who underwent mechanical recanalization. Demographic and angiographic characteristics, initial apparent diffusion coefficient (ADC) infarct volume, time-to-peak defect volume, revascularization grade, 24-48 h nonenhanced computed tomography (CT) infarct volume, symptom onset to recanalization time, diffusion-weighted imaging to recanalization time, and discharge National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores were compared between minimal and substantial infarct growth groups. Substantial infarct growth was defined as an increase of infarct volume >10 cm{sup 3} assessed by subtracting initial ADC infarct core volume from infarct volume at 24-48 h CT. Of 25 patients, 9 had minimal infarct growth (median 0 cm{sup 3}, interquartile range (IQR) -3 to 5 cm{sup 3}) and 16 had substantial infarct growth (median 103 cm{sup 3}, IQR 48-132 cm{sup 3}). Patients with minimal infarct growth had a median time from symptom onset to recanalization of 329 min (IQR 314-412 min) and a median time from imaging to recanalization of 231 min (IQR 198-309 min). On univariate analysis, minimal infarct growth was related to male gender (p = 0.04), smaller initial ADC volume (p = 0.04), higher recanalization grade (p < 0.001), and lower discharge NIHSS (p = 0.04) and mRS grades (p = 0.04). There was no or minimal infarct core growth in at least one third of patients despite an exceptionally long median time from magnetic resonance imaging to recanalization of almost 4 h. (orig.)

  11. Maximal heart rate does not limit cardiovascular capacity in healthy humans

    Munch, G D W; Svendsen, J H; Damsgaard, R


    In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function...... and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax...... and RAP (P exercise, suggesting that HRmax and myocardial work capacity do not limit VO2 max in healthy...

  12. The clot burden score, the Boston Acute Stroke Imaging Scale, the cerebral blood volume ASPECTS, and two novel imaging parameters in the prediction of clinical outcome of ischemic stroke patients receiving intravenous thrombolytic therapy

    Sillanpaa, Niko; Hakomaki, Jari; Lahteela, Arto; Dastidar, Prasun; Soimakallio, Seppo [Tampere University Hospital, Medical Imaging Center, Tampere (Finland); Saarinen, Jukka T.; Numminen, Heikki; Elovaara, Irina [Tampere University Hospital, Department of Neurology, Tampere (Finland); Rusanen, Harri [Oulu University Hospital, Department of Neurology, Oulu (Finland)


    Recently two classification methods based on the location and the extent of thrombosis detected with CT angiography have been introduced: the Boston Acute Stroke Imaging Scale (BASIS) and the clot burden score (CBS). We studied the performance of BASIS and CBS in predicting good clinical outcome (mRS {<=}2 at 90 days) in an acute (<3 h) stroke cohort treated with intravenous thrombolytic therapy. Eighty-three consecutive patients who underwent multimodal CT were analyzed. Binary logistic regression model was used to assess how BASIS, CBS, and cerebral blood volume (CBV) ASPECTS predict favorable clinical outcome. Diagnostic sensitivities and specificities were calculated and compared. Patients with low CBS and CBV ASPECTS scores and major strokes according to BASIS had significantly higher admission NIHSS scores, larger perfusion defects, and more often poor clinical outcome. In logistic regression analysis, CBV ASPECTS, CBS and BASIS were significantly associated with the clinical outcome. The performance of BASIS improved when patients with thrombosis of the M2 segment of the middle cerebral artery were classified as having minor stroke (M1-BASIS). In the anterior circulation, the sum of CBS and CBV ASPECTS (CBSV) proved to be the most robust predictor of favorable outcome. CBV ASPECTS and CBS had high sensitivity but moderate to poor specificity while BASIS was only moderately sensitive and specific. CBS, BASIS, and CBV ASPECTS are statistically robust and sensitive but unspecific predictors of good clinical outcome. Two new derived imaging parameters, CBSV and M1-BASIS, share these properties and may have increased prognostic value. (orig.)

  13. Stroke Treatments

    ... T. Quiz 5 Things to Know About Stroke Stroke Treatment Stroke used to rank fourth in leading causes of ... type of treatment depends on the type of stroke. Ischemic stroke happens when a clot blocks a ...

  14. Maximal heart rate does not limit cardiovascular capacity in healthy humans: insight from right atrial pacing during maximal exercise.

    Munch, G D W; Svendsen, J H; Damsgaard, R; Secher, N H; González-Alonso, J; Mortensen, S P


    In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax) and remained unchanged until exhaustion. SV initially increased, plateaued and then decreased before exhaustion (P rate pressure product and RAP (P heart can be paced to a higher HR than observed during maximal exercise, suggesting that HRmax and myocardial work capacity do not limit VO2 max in healthy individuals. A limited left ventricular filling and possibly altered contractility reduce SV during atrial pacing, whereas a plateau in LVFP appears to restrict Q close to VO2 max .

  15. Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study

    Jian Zhang


    Full Text Available OBJECTIVES: This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. METHODS: Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. RESULTS: The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. CONCLUSION: The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting in thoracic surgery patients requiring one-lung ventilation.

  16. Automatic extraction of forward stroke volume using dynamic PET/CT: a dual-tracer and dual-scanner validation in patients with heart valve disease

    Harms, Hendrik Johannes; Tolbod, Lars Poulsen; Hansson, Nils Henrik Stubkjær; Kero, Tanja; Örndahl, Lovisa Holm; Kim, Won Yong; Bjerner, Tomas; Bouchelouche, Kirsten; Wiggers, Henrik; Frøkiær, Jørgen; Sörensen, Jens


    BACKGROUND: The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners. METHODS: 35 subjects underwent a dynamic (11)C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic (15)O-water PET and (11)C-acetate PET scans on a GE Discovery-ST PET...

  17. Ischemic Stroke

    ... fit. Learn more Survivors Just Experienced a Stroke Stroke Recovery Caregivers and Family Careliving Guide Careliving Community Stroke Support Groups Online Education Healthcare Professionals Join Us ...

  18. Assessment of cardiac stroke volume in patients with implanted cardiac pacemaker using parametric electrical impedance tomography: a theoretical 2D study.

    Mhajna, Muhammad; Abboud, Shimon


    The present theoretical study examines the ability to estimate cardiac stroke volume (CSV) in patients with implanted cardiac pacemaker using parametric electrical impedance tomography (pEIT) in a 2D computerized model of the thorax. CSV is a direct indicator of the cardiac pumping efficiency. The commonly used methods for measuring CSV require the invasive procedure of right heart catheterization or use expensive imaging techniques (i.e., MRI). Hence, experience with these techniques for diagnosis and monitoring has been limited to hospitalized patients. In the present study, pEIT scheme was applied in a computerized 2D model of the human thorax with implanted cardiac device to determine the left ventricular (LV) volume at different cardiac cycle phases. The LV was simulated as a prolate ellipse with its axes' lengths as the reconstruction parameters while all other geometries and conductivity values remained constant. An optimization was carried out in order to ensure that the ellipse is the appropriate model for the LV at each cardiac cycle phase. LV volumes calculated by both the pEIT algorithm and the ellipsoid model are consistent. A high correlation (ρ = 0.99) between the true and reconstructed volumes was found. The SV calculation error was ∼1%. The results suggest that the LV volume can be estimated using the pEIT method in a 2D computerized model, and that the method has the potential to be used for monitoring patients with implanted cardiac pacemaker.

  19. Correlation between stroke volume variation and blood volume during hypovolemia%低血容量状态下患者每搏量变异度与血容量的相关性

    李文静; 李健; 彭科


    Objective To investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.Methods Twenty ASA Ⅰ or Ⅱ patients,aged 20-64 years,with body mass index (BMI) of 20-30 kg/m2,scheduled for elective orthopedic operation were enrolled in this study.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium,and maintained with sevoflurane,fentanyl and cisatracurium.Then the patients received endotracheal intubation and mechanical ventilation.Heart rate (HR),mean arterial blood pressure (MAP),central venous pressure (CVP),arterial pressure-based cardiac output (APCO),SW,systemic vascular resistance (SVR) and cardiac index (Cl) were recorded 5 minutes after endotracheal intubation.Blood was taken from the central vein at a rate of 30-50 ml/min and the volume was 5% of the whole blood volume,and then haemodynamic parameters mentioned above were recorded after the haemodynamics were kept stable for 5 minutes.Blood was taken again with the method mentioned above and the haemodynamic parameters were recorded.Then 6% hydroxyethyl starch (HES) 130/0.4 was infused at 50-70 ml/min via the right internal jugular vein,and the volume was equal to 5% of the whole blood volume,and then haemodynamic parameters were recorded after the haemodynamics was kept stable for 5 minutes.Fluid replacement was performed again using the method mentioned above and the haemodynamic parameters were recorded.Linear correlation of the changes in blood volume (difference between the blood volume at each time point and the baseline value) with dSVV (difference between the value monitored at each time point and the baseline value) was analyzed.Results Significant changes were found in SW,APCO and Cl after each change in blood volume (P < 0.05 or 0.01),while no significant changes were found in HR,MAP,CVP and SVR after each change in blood volume.The change in blood volume was negatively correlated with dSVV (r =-0.875,P < 0

  20. In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?

    William A Copen

    Full Text Available In the treatment of patients with suspected acute ischemic stroke, increasing evidence suggests the importance of measuring the volume of the irreversibly injured "ischemic core." The gold standard method for doing this in the clinical setting is diffusion-weighted magnetic resonance imaging (DWI, but many authors suggest that maps of regional cerebral blood volume (CBV derived from computed tomography perfusion imaging (CTP can substitute for DWI. We sought to determine whether DWI and CTP-derived CBV maps are equivalent in measuring core volume.58 patients with suspected stroke underwent CTP and DWI within 6 hours of symptom onset. We measured low-CBV lesion volumes using three methods: "objective absolute," i.e. the volume of tissue with CBV below each of six published absolute thresholds (0.9-2.5 mL/100 g, "objective relative," whose six thresholds (51%-60% were fractions of mean contralateral CBV, and "subjective," in which two radiologists (R1, R2 outlined lesions subjectively. We assessed the sensitivity and specificity of each method, threshold, and radiologist in detecting infarction, and the degree to which each over- or underestimated the DWI core volume. Additionally, in the subset of 32 patients for whom follow-up CT or MRI was available, we measured the proportion of CBV- or DWI-defined core lesions that exceeded the follow-up infarct volume, and the maximum amount by which this occurred.DWI was positive in 72% (42/58 of patients. CBV maps' sensitivity/specificity in identifying DWI-positive patients were 100%/0% for both objective methods with all thresholds, 43%/94% for R1, and 83%/44% for R2. Mean core overestimation was 156-699 mL for objective absolute thresholds, and 127-200 mL for objective relative thresholds. For R1 and R2, respectively, mean±SD subjective overestimation were -11±26 mL and -11±23 mL, but subjective volumes differed from DWI volumes by up to 117 and 124 mL in individual patients. Inter-rater agreement

  1. Ischemic Stroke

    A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Ischemic stroke is the most common type. It is usually ... are at risk for having a more serious stroke. Symptoms of stroke are Sudden numbness or weakness ...

  2. Stroke - discharge

    ... Know Stroke. Post-Stroke Rehabilitation. Updated September 2014. . Accessed July 22, 2016. The American Occupational Therapy Association. Recovering From Stroke. 2013. www. ...

  3. Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment.

    Marina Padroni

    Full Text Available The capability of CT perfusion (CTP Alberta Stroke Program Early CT Score (ASPECTS to predict outcome and identify ischemia severity in acute ischemic stroke (AIS patients is still questioned.62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF, cerebral blood volume (CBV and mean transit time (MTT maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT, recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS at 3 months after onset were recorded.Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001. CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS ≤ 2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001. CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02 only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome.Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size.

  4. Impact of 5-Hz rTMS over the primary sensory cortex is related to white matter volume in individuals with chronic stroke.

    Brodie, Sonia M; Borich, Michael R; Boyd, Lara A


    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that may facilitate mechanisms of motor learning. In a recent single-blind, pseudo-randomized study, we showed that 5-Hz rTMS over ipsilesional primary somatosensory cortex followed by practice of a skilled motor task enhanced motor learning compared with sham rTMS + practice in individuals with chronic stroke. However, the beneficial effect of stimulation was inconsistent. The current study examined how differences in sensorimotor cortex morphology might predict rTMS-related improvements in motor learning in these individuals. High-resolution T1-weighted magnetic resonance images were acquired and processed in FreeSurfer using a newly developed automated, whole brain parcellation technique. Gray matter and white matter volumes of the ipsilesional primary somatosensory and motor cortices were extracted. A significant positive association was observed between the volume of white matter in the primary somatosensory cortex and motor learning-related change, exclusively in the group that received active 5-Hz rTMS. A regression model with age, gray matter and white matter volumes as predictors was significant for predicting motor learning-related change in individuals who received active TMS. White matter volume predicted the greatest amount of variance (47.6%). The same model was non-significant when volumes of the primary motor cortex were considered. We conclude that white matter volume in the cortex underlying the TMS coil may be a novel predictor for behavioral response to 5-Hz rTMS over the ipsilesional primary somatosensory followed by motor practice.

  5. Beyond Volume: Hospital-Based Healthcare Technology for Better Outcomes in Cerebrovascular Surgical Patients Diagnosed With Ischemic Stroke: A Population-Based Nationwide Cohort Study From 2002 to 2013.

    Kim, Jae-Hyun; Park, Eun-Cheol; Lee, Sang Gyu; Lee, Tae-Hyun; Jang, Sung-In


    We examined whether the level of hospital-based healthcare technology was related to the 30-day postoperative mortality rates, after adjusting for hospital volume, of ischemic stroke patients who underwent a cerebrovascular surgical procedure. Using the National Health Insurance Service-Cohort Sample Database, we reviewed records from 2002 to 2013 for data on patients with ischemic stroke who underwent cerebrovascular surgical procedures. Statistical analysis was performed using Cox proportional hazard models to test our hypothesis. A total of 798 subjects were included in our study. After adjusting for hospital volume of cerebrovascular surgical procedures as well as all for other potential confounders, the hazard ratio (HR) of 30-day mortality in low healthcare technology hospitals as compared to high healthcare technology hospitals was 2.583 (P technology hospitals with high volume as compared to high healthcare technology hospitals with high volume was the highest (10.014, P technology hospitals had the highest 30-day mortality rate, irrespective of hospital volume. Although results of our study provide scientific evidence for a hospital volume/30-day mortality rate relationship in ischemic stroke patients who underwent cerebrovascular surgical procedures, our results also suggest that the level of hospital-based healthcare technology is associated with mortality rates independent of hospital volume. Given these results, further research into what components of hospital-based healthcare technology significantly impact mortality is warranted.

  6. Association between acute statin therapy, survival, and improved functional outcome after ischemic stroke: the North Dublin Population Stroke Study.


    Statins improve infarct volume and neurological outcome in animal stroke models. We investigated the relationship between statin therapy and ischemic stroke outcome in the North Dublin Population Stroke Study.

  7. Role of heart rate and stroke volume during muscle metaboreflex-induced cardiac output increase: differences between activation during and after exercise.

    Crisafulli, Antonio; Piras, Francesco; Filippi, Michele; Piredda, Carlo; Chiappori, Paolo; Melis, Franco; Milia, Raffaele; Tocco, Filippo; Concu, Alberto


    We hypothesized that the role of stroke volume (SV) in the metaboreflex-induced cardiac output (CO) increase was blunted when the metaboreflex was stimulated by exercise muscle ischemia (EMI) compared with post-exercise muscle ischemia (PEMI), because during EMI heart rate (HR) increases and limits diastolic filling. Twelve healthy volunteers were recruited and their hemodynamic responses to the metaboreflex evoked by EMI, PEMI, and by a control dynamic exercise were assessed. The main finding was that the blood pressure increment was very similar in the EMI and PEMI settings. In both conditions the main mechanism used to raise blood pressure was a CO elevation. However, during the EMI test CO was increased as a result of HR elevation whereas during the PEMI test CO was increased as a result of an increase in SV. These results were explainable on the basis of the different HR behavior between the two settings, which in turn led to different diastolic time and myocardial performance.

  8. Estimation of beat-to-beat changes in stroke volume from arterial pressure: A comparison of two pressure wave analysis techniques during head- up tilt testing in young, healthy men

    Jellema, W.T.; Imholz, B.P.M.; Oosting, H.; Wesseling, K.H.; Lieshout, J.J. van


    Objective: The aim of this study was to compare beat-to-beat changes in stroke volume (SV) estimated by two different pressure wave analysis techniques during orthostatic stress testing: pulse contour analysis and Modelflow, ie, simulation of a three-element model of aortic input impedance. Methods:

  9. Comparison of quantitative estimation of intracerebral hemorrhage and infarct volumes after thromboembolism in an embolic stroke model

    Eriksen, Nina; Rasmussen, Rune Skovgaard; Overgaard, Karsten


    . AIMS: We evaluated different methods for estimating the volume of infarcts, hemorrhages, after embolic middle cerebral artery occlusion with or without thrombolysis. METHODS: An experimental thromboembolytic rat model was used in this study. The rats underwent surgery and were placed in two groups...... of the infarct and intracerebral hemorrhage. RESULTS: No differences were observed in the infarct volume or amount of bleeding when comparing the three methods of volume estimation. Although semiautomated computer estimation and manual erythrocyte counting provided similar results as the stereological...... measurements, the stereological method was the most efficient and advantageous. CONCLUSIONS: We found that stereology was the superior method for quantification of hemorrhagic volume, especially for rodent petechial bleeding, which is otherwise difficult to measure. Our results suggest the possibility...

  10. Preventing stroke

    Stroke - prevention; CVA - prevention; cerebral vascular accident - prevention; TIA - prevention, transient ischemic attack - prevention ... something that increases your chance of having a stroke. You cannot change some risk factors for stroke. ...

  11. Stroke Rehabilitation

    A stroke can cause lasting brain damage. People who survive a stroke need to relearn skills they lost because of ... them relearn those skills. The effects of a stroke depend on which area of the brain was ...

  12. Hemorrhagic Stroke

    A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Hemorrhagic stroke is the less common type. It happens when ... an artery wall that breaks open. Symptoms of stroke are Sudden numbness or weakness of the face, ...

  13. Left ventricular atrioventricular plane displacement is preserved with lifelong endurance training and is the main determinant of maximal cardiac output.

    Steding-Ehrenborg, Katarina; Boushel, Robert C; Calbet, José A; Åkeson, Per; Mortensen, Stefan P


    Age-related decline in cardiac function can be prevented or postponed by lifelong endurance training. However, effects of normal ageing as well as of lifelong endurance exercise on longitudinal and radial contribution to stroke volume are unknown. The aim of this study was to determine resting longitudinal and radial pumping in elderly athletes, sedentary elderly and young sedentary subjects. Furthermore, we aimed to investigate determinants of maximal cardiac output in elderly. Eight elderly athletes (63 ± 4 years), seven elderly sedentary (66 ± 4 years) and ten young sedentary subjects (29 ± 4 years) underwent cardiac magnetic resonance imaging. All subjects underwent maximal exercise testing and for elderly subjects maximal cardiac output during cycling was determined using a dye dilution technique. Longitudinal and radial contribution to stroke volume did not differ between groups (longitudinal left ventricle (LV) 52-65%, P = 0.12, right ventricle (RV) 77-87%, P = 0.16, radial 7.9-8.6%, P = 1.0). Left ventricular atrioventricular plane displacement (LVAVPD) was higher in elderly athletes and young sedentary compared with elderly sedentary subjects (14 ± 3, 15 ± 2 and 11 ± 1 mm, respectively, P cardiac output (R(2) = 0.61, P Longitudinal and radial contributions to stroke volume did not differ between groups. However, how longitudinal pumping was achieved differed; elderly athletes and young sedentary subjects showed similar AVPD whereas this was significantly lower in elderly sedentary subjects. Elderly sedentary subjects achieved longitudinal pumping through increased short-axis area of the ventricle. Large AVPD was a determinant of maximal cardiac output and exercise capacity.

  14. Profit maximization mitigates competition

    Dierker, Egbert; Grodal, Birgit


    We consider oligopolistic markets in which the notion of shareholders' utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price...... competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution...... of profits among consumers fully into account and partial equilibrium analysis suffices...

  15. Kinesthetic taping improves walking function in patients with stroke

    Boeskov, Birgitte; Carver, Line Tornehøj; von Essen-Leise, Anders


    walking speed and clinical indices of spasticity in patients with stroke. METHODS: Thirty-two patients (9 women) receiving rehabilitation after stroke (average, 50 days since stroke) who had impaired walking ability were recruited. Primary outcome was maximal walking speed measured by the 10-meter walk...... be a valuable adjunct in physical therapy and rehabilitation of patients with stroke.......BACKGROUND: Stroke is an important cause of severe disability and impaired motor function. Treatment modalities that improve motor function in patients with stroke are needed. The objective of this study was to investigate the effect of kinesthetic taping of the anterior thigh and knee on maximal...

  16. Stroke Rehabilitation

    ... or other long-term facility 15% die shortly after the stroke Approximately 14% of stroke survivors experience a second stroke in the first year following a stroke. Successful rehabilitation depends on: Amount of damage to the brain Skill on the part of ...

  17. Impact of low-volume, high-intensity interval training on maximal aerobic capacity, health-related quality of life and motivation to exercise in ageing men.

    Knowles, Ann-Marie; Herbert, Peter; Easton, Chris; Sculthorpe, Nicholas; Grace, Fergal M


    There is a demand for effective training methods that encourage exercise adherence during advancing age, particularly in sedentary populations. This study examined the effects of high-intensity interval training (HIIT) exercise on health-related quality of life (HRQL), aerobic fitness and motivation to exercise in ageing men. Participants consisted of males who were either lifelong sedentary (SED; N = 25; age 63 ± 5 years) or lifelong exercisers (LEX; N = 19; aged 61 ± 5 years). [Formula: see text] and HRQL were measured at three phases: baseline (Phase A), week seven (Phase B) and week 13 (Phase C). Motivation to exercise was measured at baseline and week 13. [Formula: see text] was significantly higher in LEX (39.2 ± 5.6 ml kg min(-1)) compared to SED (27.2 ± 5.2 ml kg min(-1)) and increased in both groups from Phase A to C (SED 4.6 ± 3.2 ml kg min(-1), 95 % CI 3.1 - 6.0; LEX 4.9 ± 3.4 ml kg min(-1), 95 % CI 3.1-6.6) Physical functioning (97 ± 4 LEX; 93 ± 7 SED) and general health (70 ± 11 LEX; 78 ± 11 SED) were significantly higher in LEX but increased only in the SED group from Phase A to C (physical functioning 17 ± 18, 95 % CI 9-26, general health 14 ± 14, 95 % CI 8-21). Exercise motives related to social recognition (2.4 ± 1.2 LEX; 1.5 ± 1.0 SED), affiliation (2.7 ± 1.0 LEX; 1.6 ± 1.2 SED) and competition (3.3 ± 1.3 LEX; 2.2 ± 1.1) were significantly higher in LEX yet weight management motives were significantly higher in SED (2.9 ± 1.1 LEX; 4.3 ± 0.5 SED). The study provides preliminary evidence that low-volume HIIT increases perceptions of HRQL, exercise motives and aerobic capacity in older adults, to varying degrees, in both SED and LEX groups.

  18. Brain perfusion CT for acute stroke using a 256-slice CT: improvement of diagnostic information by large volume coverage

    Dorn, F. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Institut fuer Radiologie, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Muenchen (Germany); Muenzel, D.; Meier, R.; Rummeny, E.J.; Huber, A. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Poppert, H. [Technical University, Department of Neurology, Klinikum rechts der Isar, Munich (Germany)


    To compare a 256-slice CT with a simulated standard CT for brain CT perfusion (CTP). CTP was obtained in 51 patients using a 256-slice CT (128 detector rows, flying z-focus, 8-cm detector width, 80 kV, 120mAs, 20 measurements, 1 CT image/2.5 s). Signal-to-noise ratios (SNR) were compared in grey and white matter. Perfusion maps were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in hypoperfused areas and corresponding contralateral regions. Two reconstructed 10-mm slices for simulation of a standard CT (SDCT) were compared with the complete data sets (large-volume CT, LVCT). Adequate image quality was achieved in 50/51 cases. SNR were significantly different in grey and white matter. A perfusion deficit was present in 27 data sets. Differences between the hypoperfusions and the control regions were significant for MTT and CBF, but not for CBV. Three lesions were missed by SDCT but detected by LVCT; 24 lesions were covered incompletely by SDCT, and 6 by LVCT. 21 lesions were detected completely by LVCT, but none by SDCT. CTP imaging of the brain using an increased detector width can detect additional ischaemic lesions and cover most ischaemic lesions completely. (orig.)

  19. Goal-Directed Fluid Therapy Using Stroke Volume Variation Does Not Result in Pulmonary Fluid Overload in Thoracic Surgery Requiring One-Lung Ventilation

    Sebastian Haas


    Full Text Available Background. Goal-directed fluid therapy (GDT guided by functional parameters of preload, such as stroke volume variation (SVV, seems to optimize hemodynamics and possibly improves clinical outcome. However, this strategy is believed to be rather fluid aggressive, and, furthermore, during surgery requiring thoracotomy, the ability of SVV to predict volume responsiveness has raised some controversy. So far it is not known whether GDT is associated with pulmonary fluid overload and a deleterious reduction in pulmonary function in thoracic surgery requiring one-lung-ventilation (OLV. Therefore, we assessed the perioperative course of extravascular lung water index (EVLWI and paO2/FiO2-ratio during and after thoracic surgery requiring lateral thoracotomy and OLV to evaluate the hypothesis that fluid therapy guided by SVV results in pulmonary fluid overload. Methods. A total of 27 patients (group T were enrolled in this prospective study with 11 patients undergoing lung surgery (group L and 16 patients undergoing esophagectomy (group E. Goal-directed fluid management was guided by SVV (SVV 0.05 in EVLWI during the observation period (BL: 7.8 ± 2.5, 24postop: 8.1 ± 2.4 mL/kg. A subgroup analysis for group L and group E also did not reveal significant changes of EVLWI. The paO2/FiO2-ratio decreased significantly during the observation period (group L: BL: 462 ± 140, OLVterm15: 338 ± 112 mmHg; group E: BL: 389 ± 101, 24postop: 303 ± 74 mmHg but remained >300 mmHg except during OLV. Conclusions. SVV-guided fluid management in thoracic surgery requiring lateral thoracotomy and one-lung ventilation does not result in pulmonary fluid overload. Although oxygenation was reduced, pulmonary function remained within a clinically acceptable range.

  20. In connection with the publication in Bali Med J 2016, Volume 5, Number 2: 25-29, entitled "Intra-Arterial Heparin Flushing Increases Manual Muscle Test – Medical Research Councils (MMT-MRC Score in Chronic Ischemic Stroke Patient "

    Moh Hasan Machfoed


    Full Text Available  In connection with the publication in Bali Med J 2016, Volume 5, Number 2: 25-29, entitled "Intra-Arterial Heparin Flushing Increases Manual Muscle Test – Medical Research Councils (MMT-MRC Score in Chronic Ischemic Stroke Patient ", herewith, please allow us to do reviews of the study discussion. By assessing the discussion, it can be proved whether there are references that support the results of study.

  1. Maximally incompatible quantum observables

    Heinosaari, Teiko, E-mail: [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)


    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  2. (55)Cobalt (Co) as a PET-tracer in stroke, compared with blood flow, oxygen metabolism, blood volume and gadolinium-MRI

    Stevens, H; Jansen, HML; De Reuck, J; Lemmerling, M; Strijckmans, K; Goethals, P; Lemahieu, [No Value; de Jong, BM; Willemsen, ATM; Korf, J


    Several studies have shown the feasibility of divalent cobalt (Co)-isotopes (Co-55 and Co-57) in imaging of neuronal damage in stroke, multiple sclerosis, cerebral tumors and traumatic brain injury. Little is known how regional Co uptake relates to other pathophysiological changes after stroke.

  3. Know Stroke

    ... Home Current Issue Past Issues Special Section Know Stroke Past Issues / Summer 2007 Table of Contents For ... D. Director, National Institute of Neurological Disorders and Stroke Photo courtesy of NIH/NINDS Welcome to this ...

  4. Stroke - slideshow

    ... this page: // Stroke - series—Part 1 To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Ischemic Stroke A.D.A.M., Inc. is accredited by ...

  5. Stroke: Overview

    ... NICHD Research Information Clinical Trials Resources and Publications Stroke: Overview Skip sharing on social media links Share this: Page Content Stroke is a leading cause of disability and death ...

  6. Recovering after stroke

    Stroke rehabilitation; Cerebrovascular accident - rehabilitation; Recovery from stroke; Stroke - recovery; CVA - recovery ... WHERE TO LIVE AFTER A STROKE Most people will need stroke ... after they leave the hospital. Stroke rehab will help you ...

  7. Maximizers versus satisficers

    Parker, Andrew M.; Wandi Bruine de Bruin; Baruch Fischhoff


    Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions...

  8. Cryptogenic Stroke

    Mohammad Saadatnia


    Full Text Available Cryptogenic stroke is defined as brain infarction that is not attributable to a source of definite embolism, large artery atherosclerosis, or small artery disease despite a thorough vascular, cardiac, and serologic evaluation. Despite many advances in our understanding of ischemic stroke, cryptogenic strokes remain a diagnostic and therapeutic challenge. The pathophysiology of cryptogenic stroke is likely various. Probable mechanisms include cardiac embolism secondary to occult paroxysmal atrial fibrillation, aortic atheromatous disease or other cardiac sources, paradoxical embolism from atrial septal abnormalities such as patent foramen ovale, hypercoagulable states, and preclinical or subclinical cerebrovascular disease.  Cryptogenic stroke is one-fourth among cerebral infarction, but most of them could be ascribed to embolic stroke. A significant proportion of cryptogenic strokes adhere to embolic infarct topography on brain imaging and improvement in our ability to detect paroxysmal atrial fibrillation in patients with cryptogenic stroke has strengthened the idea that these strokes are embolic in nature. a significant proportion of cryptogenic strokes adhere to embolic infarct topography on brain imaging.embolic stroke of undetermined sources(ESUS was planned for unifying embolic stroke of undetermined source.  The etiologies underlying ESUS included minor-risk potential cardioembolic sources, covert paroxysmal atrial fibrillation, cancer-associated coagulopathy and embolism, arteriogenic emboli, and paroxysmal embolism. Extensive evaluation including transesophageal echocardiography and cardiac monitoring for long time could identify the etiology of these patients. Therefore cryptogenic stroke is a diagnosis of exclusion. Compared with other stroke subtypes, cryptogenic stroke tends to have a better prognosis and lower long-term risk of recurrence.

  9. A Novel "Maximizing Kappa" Approach for Assessing the Ability of a Diagnostic Marker and Its Optimal Cutoff Value.

    Chang, Chia-Hao; Yang, Jen-Tsung; Lee, Ming-Hsueh


    Threshold-dependent accuracy measures such as true classification rates in ordered multiple-class (k > 3) receiver operating characteristic (ROC) hyper-surfaces have recently been used to assist with medical decision making. However, based on low power performance in some circumstances, we construct a new method that relies on the kappa coefficient to solve such diagnostic problems. Under the approach proposed in the present article, the statistics depend strongly on the [Formula: see text] cutoff threshold, which can be chosen to maximize the kappa statistics of true disease status and of the new biomarker. The Monte Carlo simulation results confirm the effectiveness of the proposed method in terms of its predictive power. The proposed design is then compared with the volume under the ROC hyper-surface by applying it to intracerebral hemorrhagic patients classified into five stroke classes using the National Institutes of Health Stroke Scale.

  10. 每搏输出量变异度在脓毒症休克液体复苏治疗中的指导作用%Value of Stroke Volume Variation in Guiding Resuscitation of Septic Shock

    李权; 陈琦; 郭俊; 李鲲; 王夜明


    Objective: To review the recent research on the application of stroke volume variation in re-suscitation of septic shock. Methods: The characteristics, mechanism, advances, application, limitations, etc. , were reviewed in this paper about stroke volume variation. Results: Early fluid resuscitation is an important procedure in anti-septic shock therapy, while during this process, hemodynamics and blood volume changes should be monitored. As an effective and real-time technique, stroke volume variation is a superior indicator to central venous pressure (CVP) in reflecting the changes of circulation during resuscitation. Conclusion; Stroke volume variation has better guiding value and application prospect in the early fluid resuscitation in septic shock therapy%目的:探讨每搏输出量变异度在脓毒症休克液体复苏治疗中的指导作用.方法:对每搏输出量变异度的特点、机理、研究进展、应用范围、局限性等方面进行综述.结果:早期液体复苏在脓毒症休克治疗中占据重要的地位,可维持最佳前负荷,改善容量管理,防止由于低血容量导致的低灌注和过度复苏,可能进一步防止发生多器官功能障碍.因而治疗中监测血流动力学和容量的变化极为重要.脉搏波指示连续心排血量技术是新近出现的一种简便、有效的临床实时监测手段,测定每搏输出量变异度比传统的测定中心静脉压更准确地指导快速液体复苏.结论:每搏输出量变异对预测脓毒症体克早期液体复苏的效果具有良好的指导意义和应用前景.

  11. On Maximal Injectivity

    Ming Yi WANG; Guo ZHAO


    A right R-module E over a ring R is said to be maximally injective in case for any maximal right ideal m of R, every R-homomorphism f : m → E can be extended to an R-homomorphism f' : R → E. In this paper, we first construct an example to show that maximal injectivity is a proper generalization of injectivity. Then we prove that any right R-module over a left perfect ring R is maximally injective if and only if it is injective. We also give a partial affirmative answer to Faith's conjecture by further investigating the property of maximally injective rings. Finally, we get an approximation to Faith's conjecture, which asserts that every injective right R-module over any left perfect right self-injective ring R is the injective hull of a projective submodule.

  12. Maximizers versus satisficers

    Andrew M. Parker


    Full Text Available Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007. Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002, we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions, more avoidance of decision making, and greater tendency to experience regret. Contrary to predictions, self-reported maximizers were more likely to report spontaneous decision making. However, the relationship between self-reported maximizing and worse life outcomes is largely unaffected by controls for measures of other decision-making styles, decision-making competence, and demographic variables.

  13. On Maximal Green Sequences

    Brüstle, Thomas; Pérotin, Matthieu


    Maximal green sequences are particular sequences of quiver mutations which were introduced by Keller in the context of quantum dilogarithm identities and independently by Cecotti-Cordova-Vafa in the context of supersymmetric gauge theory. Our aim is to initiate a systematic study of these sequences from a combinatorial point of view. Interpreting maximal green sequences as paths in various natural posets arising in representation theory, we prove the finiteness of the number of maximal green sequences for cluster finite quivers, affine quivers and acyclic quivers with at most three vertices. We also give results concerning the possible numbers and lengths of these maximal green sequences. Finally we describe an algorithm for computing maximal green sequences for arbitrary valued quivers which we used to obtain numerous explicit examples that we present.

  14. Effect of patent ductus arteriosus and patent foramen ovale on left ventricular stroke volume measurement by electrical velocimetry in comparison to transthoracic echocardiography in neonates.

    Blohm, Martin Ernst; Hartwich, Jana; Obrecht, Denise; Kersten, Jan Felix; Singer, Dominique


    This prospective single-center observational study compared impedance cardiography [electrical velocimetry (EV)] with transthoracic echocardiography (TTE, based on trans-aortic flow) and analyzed the influence of physiological shunts, such as patent ductus arteriosus (PDA) or patent foramen ovale (PFO), on measurement accuracy. Two hundred and ninety-one triplicate simultaneous paired left ventricular stroke volume (LVSV) measurements by EV (LVSVEV) and TTE (LVSVTTE) in 99 spontaneously breathing neonates (mean weight 3270 g; range 1227-4600 g) were included. For the whole cohort, the mean absolute LVSVEV was 5.5 mL, mean LVSVTTE was 4.9 mL, resulting in an absolute Bland-Altman bias of -0.7 mL (limits of agreement LOA -3.0 to 1.7 mL), relative bias -12.8 %; mean percentage error MPE 44.9 %; true precision TPEV 33.4 % (n = 99 aggregated data points). In neonates without shunts (n = 32): mean LVSVEV 5.0 mL, mean LVSVTTE 4.6 mL, Bland-Altman bias -0.4 mL (LOA -2.8 to 2.0 mL), relative bias -8.2 %; MPE 50.7 %; TPEV 40.9 %. In neonates with shunts (PDA and/or PFO; n = 67): mean LVSVEV 5.8 mL, mean LVSVTTE 5.0 mL, bias -0.8 mL (LOA -3.1 to 1.5 mL), relative bias -14.8 %, MPE 41.9 %, TPEV 29.3 %. Accuracy was affected by PDA and/or PFO, with a significant increase in the relative difference in LVSVEV versus LVSVTTE: Subjects without shunts -2.9 % (n = 91), PFO alone -9.6 % (n = 125), PDA alone -14.0 % (n = 12), and PDA and PFO -18.5 % (n = 63). Physiological shunts (PDA and/or PFO) in neonates affect measurement accuracy and cause overestimation of LVSVEV compared with LVSVTTE.

  15. With age a lower individual breathing reserve is associated with a higher maximal heart rate.

    Burtscher, Martin; Gatterer, Hannes; Faulhaber, Martin; Burtscher, Johannes


    Maximal heart rate (HRmax) is linearly declining with increasing age. Regular exercise training is supposed to partly prevent this decline, whereas sex and habitual physical activity do not. High exercise capacity is associated with a high cardiac output (HR x stroke volume) and high ventilatory requirements. Due to the close cardiorespiratory coupling, we hypothesized that the individual ventilatory response to maximal exercise might be associated with the age-related HRmax. Retrospective analyses have been conducted on the results of 129 consecutively performed routine cardiopulmonary exercise tests. The study sample comprised healthy subjects of both sexes of a broad range of age (20-86 years). Maximal values of power output, minute ventilation, oxygen uptake and heart rate were assessed by the use of incremental cycle spiroergometry. Linear multivariate regression analysis revealed that in addition to age the individual breathing reserve at maximal exercise was independently predictive for HRmax. A lower breathing reserve due to a high ventilatory demand and/or a low ventilatory capacity, which is more pronounced at a higher age, was associated with higher HRmax. Age explained the observed variance in HRmax by 72% and was improved to 83% when the variable "breathing reserve" was entered. The presented findings indicate an independent association between the breathing reserve at maximal exercise and maximal heart rate, i.e. a low individual breathing reserve is associated with a higher age-related HRmax. A deeper understanding of this association has to be investigated in a more physiological scenario. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Study and Analysis of Six Stroke Engine

    B. Ramya


    Full Text Available Six Stroke engine, the name itself indicates a cycle of six strokes out of which two are useful power strokes. According to its mechanical design, the six-stroke engine with external and internal combustion and double flow is similar to the actual internal reciprocating combustion engine. However, it differentiates itself entirely, due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: combustion and an air heating chamber, both independent from the cylinder. In this the cylinder and the combustion chamber are separated which gives more freedom for design analysis. In addition to the two valves in the four stroke engine two more valves are incorporated which are operated by a piston arrangement. The Six Stroke is thermodynamically more efficient because the change in volume of the power stroke is greater than the intake stroke and the compression stroke. The main advantages of six stroke engine includes reduction in fuel consumption by 40%, two power strokes in the six stroke cycle, dramatic reduction in pollution, adaptability to multi fuel operation. Six stroke engine’s adoption by the automobile industry would have a tremendous impact on the environment and world economy .

  17. Once Again, Maxims

    Rudiger Bubner


    Full Text Available Even though the maxims' theory is not at thecenter of Kant's ethics, it is the unavoidable basis of the categoric imperative's formulation. Kant leanson the transmitted representations of modem moral theory. During the last decades, the notion of maxims has deserved more attention, due to the philosophy of language's debates on rules, and due to action theory's interest in this notion. I here by brietly expound my views in these discussions.

  18. Does treadmill running performance, heart rate and breathing rate response during maximal graded exercise improve after volitional respiratory muscle training?

    Radhakrishnan, K; Sharma, V K; Subramanian, S K


    Maximal physical exertion in sports usually causes fatigue in the exercising muscles, but not in the respiratory muscles due to triggering of the Respiratory muscle metabo-reflex, a sympathetic vasoconstrictor response leading to preferential increment in blood flow to respiratory muscles.(1) We planned to investigate whether a six week yogic pranayama based Volitional Respiratory Muscle Training (VRMT) can improve maximal Graded Exercise Treadmill Test (GXTT) performance in healthy adult recreational sportspersons. Consecutive, consenting healthy adult recreational sportspersons aged 20.56±2.49 years (n=30), volunteered to 'baseline recording' of resting heart rate (HR), blood pressure (BP), respiratory rate (RR), and Bruce ramp protocol maximal GXTT until volitional exhaustion providing total test time (TTT), derived VO2max, Metabolic Equivalent of Task (METs), HR and BP response during maximal GXTT and drop in recovery HR data. After six weeks of observation, they underwent 'pre-intervention recording' followed by supervised VRMT intervention for 6 weeks (30 minutes a day; 5 days a week) and then 'post-intervention recording'. Repeated measures ANOVA with pairwise t statistical comparison was used to analyse the data. After supervised VRMT, we observed significant decrease in their resting supine RR (pincrease in TTT (pincrease in cardiac stroke volume and autonomic resetting towards parasympatho-dominance. Yogic Pranayama based VRMT can be used in sports conditioning programme of athletes to further improve their maximal exercise performance, and as part of rehabilitation training during return from injury.

  19. Atherosclerosis and Stroke

    ... After Stroke Inspirational Stories Stroke Heroes Among Us Atherosclerosis and Stroke Updated:Oct 24,2016 Excerpted and ... cause difficulty walking and eventually gangrene. Stroke and atherosclerosis There are two types of ischemic stroke caused ...

  20. The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players

    Raphael Rodrigues Perim


    Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

  1. Ipsilateral hippocampal atrophy is associated with long-term memory dysfunction after ischemic stroke in young adults

    Schaapsmeerders, P.; Uden, I.W.M. van; Tuladhar, A.M.; Maaijwee, N.A.M.M.; Dijk, E.J. van; Rutten-Jacobs, L.C.A.; Arntz, R.M.; Schoonderwaldt, H.C.; Dorresteijn, L.D.A.; Leeuw, H.F. de; Kessels, R.P.C.


    Memory impairment after stroke in young adults is poorly understood. In elderly stroke survivors memory impairments and the concomitant loss of hippocampal volume are usually explained by coexisting neurodegenerative disease (e.g., amyloid pathology) in interaction with stroke. However,

  2. Danger signals in stroke.

    Gelderblom, Mathias; Sobey, Christopher G; Kleinschnitz, Christoph; Magnus, Tim


    Danger molecules are the first signals released from dying tissue after stroke. These danger signals bind to receptors on immune cells that will result in their activation and the release of inflammatory and neurotoxic mediators, resulting in amplification of the immune response and subsequent enlargement of the damaged brain volume. The release of danger signals is a central event that leads to a multitude of signals and cascades in the affected and neighbouring tissue, therefore providing a potential target for therapy.

  3. The correlation of respiratory muscle strength and cough capacity in stroke patients.

    Jo, Myeong-Rae; Kim, Nan-Soo


    [Purpose] The purpose of this study was to investigate the correlation between respiratory muscle strength and cough capacity in stroke patients. [Subjects and Methods] Forty-two stroke patients were assigned to 2 different groups (intervention group=21, control group=21). Both groups participated in a conventional stroke rehabilitation program, with the intervention group also receiving respiratory muscle training for 20 to 30 minutes a day, 3 times a week for 8 weeks. Respiratory muscle strength (maximal inspiratory pressure, maximal expiratory pressure), forced vital capacity, and cough capacity were measured. [Results] The intervention group showed significant increases in maximal inspiratory pressure, maximal expiratory pressure, forced vital capacity, and cough capacity. The change in maximal inspiratory pressure, maximal expiratory pressure, and forced vital capacity showed a significant correlation with cough capacity, with maximal expiratory pressure showing the highest correlation. [Conclusion] The present study showed that the increase in maximal expiratory pressure plays an important role in improving the cough capacity of stroke patients.

  4. How a Stroke Is Diagnosed

    ... News About Neurology Image Library Search The Internet Stroke Center Patients & Families About Stroke Stroke Diagnosis Stroke ... Diagnosis » How a Stroke is Diagnosed How a Stroke is Diagnosed How a Stroke is Diagnosed Lab ...

  5. Stability of relative oxygen pulse curve during repeated maximal cardiopulmonary testing in professional soccer players

    R.R. Perim


    Full Text Available During cardiopulmonary exercise testing (CPET, stroke volume can be indirectly assessed by O2 pulse profile. However, for a valid interpretation, the stability of this variable over time should be known. The objective was to analyze the stability of the O2 pulse curve relative to body mass in elite athletes. VO2, heart rate (HR, and relative O2 pulse were compared at every 10% of the running time in two maximal CPETs, from 2005 to 2010, of 49 soccer players. Maximal values of VO2 (63.4 ± 0.9 vs 63.5 ± 0.9 mL O2•kg-1•min-1, HR (190 ± 1 vs188 ± 1 bpm and relative O2 pulse (32.9 ± 0.6 vs 32.6 ± 0.6 mL O2•beat-1•kg-1 were similar for the two CPETs (P > 0.05, while the final treadmill velocity increased from 18.5 ± 0.9 to 18.9 ± 1.0 km/h (P < 0.01. Relative O2 pulse increased linearly and similarly in both evaluations (r² = 0.64 and 0.63 up to 90% of the running time. Between 90 and 100% of the running time, the values were less stable, with up to 50% of the players showing a tendency to a plateau in the relative O2 pulse. In young healthy men in good to excellent aerobic condition, the morphology of the relative O2 pulse curve is consistent up to close to the peak effort for a CPET repeated within a 1-year period. No increase in relative O2pulse at peak effort could represent a physiologic stroke volume limitation in these athletes.

  6. Nursing application of Bobath principles in stroke care.

    Passarella, P M; Lewis, N


    The nursing approach in the care of stroke patients has a direct impact on functional outcome. Nursing application of Bobath principles in stroke care offers a nursing focus on involvement of the affected side; facilitation of normal tone, posture, and movement; and development of more normal function. A research study evaluating the functional gains of stroke patients demonstrated a significant level of functional improvement in those treated with Bobath principles over stroke patients treated with the traditional nursing approach. Practical methods for applying Bobath principles in patient care activities are described. These therapeutic methods provide nurses with the means to maximize stroke patients' potential and further influence their functional recovery.

  7. Do stroke models model stroke?

    Philipp Mergenthaler


    Full Text Available Stroke is one of the leading causes of death worldwide and the biggest reason for long-term disability. Basic research has formed the modern understanding of stroke pathophysiology, and has revealed important molecular, cellular and systemic mechanisms. However, despite decades of research, most translational stroke trials that aim to introduce basic research findings into clinical treatment strategies – most notably in the field of neuroprotection – have failed. Among other obstacles, poor methodological and statistical standards, negative publication bias, and incomplete preclinical testing have been proposed as ‘translational roadblocks’. In this article, we introduce the models commonly used in preclinical stroke research, discuss some of the causes of failed translational success and review potential remedies. We further introduce the concept of modeling ‘care’ of stroke patients, because current preclinical research models the disorder but does not model care or state-of-the-art clinical testing. Stringent statistical methods and controlled preclinical trials have been suggested to counteract weaknesses in preclinical research. We conclude that preclinical stroke research requires (1 appropriate modeling of the disorder, (2 appropriate modeling of the care of stroke patients and (3 an approach to preclinical testing that is similar to clinical testing, including Phase 3 randomized controlled preclinical trials as necessary additional steps before new therapies enter clinical testing.

  8. Maximally Atomic Languages

    Janusz Brzozowski


    Full Text Available The atoms of a regular language are non-empty intersections of complemented and uncomplemented quotients of the language. Tight upper bounds on the number of atoms of a language and on the quotient complexities of atoms are known. We introduce a new class of regular languages, called the maximally atomic languages, consisting of all languages meeting these bounds. We prove the following result: If L is a regular language of quotient complexity n and G is the subgroup of permutations in the transition semigroup T of the minimal DFA of L, then L is maximally atomic if and only if G is transitive on k-subsets of 1,...,n for 0 <= k <= n and T contains a transformation of rank n-1.

  9. Guinea pig maximization test

    Andersen, Klaus Ejner


    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline with...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....

  10. Quantum-Inspired Maximizer

    Zak, Michail


    A report discusses an algorithm for a new kind of dynamics based on a quantum- classical hybrid-quantum-inspired maximizer. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen 'computational' potential. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables, using classical methods. Such optimal combination of characteristics is a perfect match for quantum-inspired computing. As an application, an algorithm for global maximum of an arbitrary integrable function is proposed. The idea of the proposed algorithm is very simple: based upon the Quantum-inspired Maximizer (QIM), introduce a positive function to be maximized as the probability density to which the solution is attracted. Then the larger value of this function will have the higher probability to appear. Special attention is paid to simulation of integer programming and NP-complete problems. It is demonstrated that the problem of global maximum of an integrable function can be found in polynomial time by using the proposed quantum- classical hybrid. The result is extended to a constrained maximum with applications to integer programming and TSP (Traveling Salesman Problem).

  11. Driving After a Stroke

    ... Inspirational Stories Stroke Heroes Among Us Driving After Stroke Updated:Jul 23,2015 Can I drive after ... more tips for daily living . Let's Talk About Stroke Fact Sheets Our stroke fact sheets cover treatments, ...

  12. Stroke (For Kids)

    ... de los dientes Video: Getting an X-ray Stroke KidsHealth > For Kids > Stroke Print A A A ... get help quickly. continue What Happens During a Stroke? A stroke usually happens suddenly, and a person ...

  13. Stroke (For Kids)

    ... Emergency Room? What Happens in the Operating Room? Stroke KidsHealth > For Kids > Stroke A A A What's ... get help quickly. continue What Happens During a Stroke? A stroke usually happens suddenly, and a person ...

  14. Picturing the Size and Site of Stroke With an Expanded National Institutes of Health Stroke Scale.

    Agis, Daniel; Goggins, Maria B; Oishi, Kumiko; Oishi, Kenichi; Davis, Cameron; Wright, Amy; Kim, Eun Hye; Sebastian, Rajani; Tippett, Donna C; Faria, Andreia; Hillis, Argye E


    The National Institutes of Health Stroke Scale (NIHSS) includes minimal assessment of cognitive function, particularly in right hemisphere (RH) stroke. Descriptions of the Cookie Theft picture from the NIHSS allow analyses that (1) correlate with aphasia severity and (2) identify communication deficits in RH stroke. We hypothesized that analysis of the picture description contributes valuable information about volume and location of acute stroke. We evaluated 67 patients with acute ischemic stroke (34 left hemisphere [LH]; 33 RH) with the NIHSS, analysis of the Cookie Theft picture, and magnetic resonance imaging, compared with 35 sex- and age-matched controls. We evaluated descriptions for total content units (CU), syllables, ratio of left:right CU, CU/minute, and percent interpretive CU, based on previous studies. Lesion volume and percent damage to regions of interest were measured on diffusion-weighted imaging. Multivariable linear regression identified variables associated with infarct volume, independently of NIHSS score, age and sex. Patients with RH and LH stroke differed from controls, but not from each other, on CU, syllables/CU, and CU/minute. Left:right CU was lower in RH compared with LH stroke. CU, syllables/CU, and NIHSS each correlated with lesion volume in LH and RH stroke. Lesion volume was best accounted by a model that included CU, syllables/CU, NIHSS, left:right CU, percent interpretive CU, and age, in LH and RH stroke. Each discourse variable and NIHSS score were associated with percent damage to different regions of interest, independently of lesion volume and age. Brief picture description analysis complements NIHSS scores in predicting stroke volume and location. © 2016 The Authors.

  15. The use of LiDCO based fluid management in patients undergoing hip fracture surgery under spinal anaesthesia: Neck of femur optimisation therapy - targeted stroke volume (NOTTS: study protocol for a randomized controlled trial

    Moran Chris G


    Full Text Available Abstract Background Approximately 70,000 patients/year undergo surgery for repair of a fractured hip in the United Kingdom. This is associated with 30-day mortality of 9% and survivors have a considerable length of acute hospital stay postoperatively (median 26 days. Use of oesophageal Doppler monitoring to guide intra-operative fluid administration in hip fracture repair has previously been associated with a reduction in hospital stay of 4-5 days. Most hip fracture surgery is now performed under spinal anaesthesia. Oesophageal Doppler monitoring may be unreliable in the presence of spinal anaesthesia and most patients would not tolerate the probes. An alternative method of guiding fluid administration (minimally-invasive arterial pulse contour analysis has been shown to reduce length of stay in high-risk surgical patients but has never been studied in hip fracture surgery. Methods Single-centre randomised controlled parallel group trial. Randomisation by website using computer generated concealed tables. Setting: University hospital in UK. Participants: 128 patients with acute primary hip fracture listed for operative repair under spinal anaesthesia and aged > 65 years. Intervention: Stroke volume guided intra-operative fluid management. Continuous measurement of SV recorded by a calibrated cardiac output monitor (LiDCOplus. Maintenance fluid and 250 ml colloid boluses given to achieve sustained 10% increases in stroke volume. Control group: fluid administration at the responsible (blinded anaesthetist's discretion. The intervention terminates at the end of the surgical procedure and post-operative fluid management is at the responsible anaesthetist's discretion. Primary outcome: length of acute hospital stay is determined by a blinded team of clinicians. Secondary outcomes include number of complications and total cost of care. Funding NIHR/RfPB: PB-PG-0407-13073. Trial registration number Trial registration: Current Controlled Trials ISRCTN

  16. Social group utility maximization

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan


    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  17. Maximizing Modularity is hard

    Brandes, U; Gaertler, M; Goerke, R; Hoefer, M; Nikoloski, Z; Wagner, D


    Several algorithms have been proposed to compute partitions of networks into communities that score high on a graph clustering index called modularity. While publications on these algorithms typically contain experimental evaluations to emphasize the plausibility of results, none of these algorithms has been shown to actually compute optimal partitions. We here settle the unknown complexity status of modularity maximization by showing that the corresponding decision version is NP-complete in the strong sense. As a consequence, any efficient, i.e. polynomial-time, algorithm is only heuristic and yields suboptimal partitions on many instances.

  18. Chloride channels in stroke

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN


    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  19. Maximizing without difficulty: A modified maximizing scale and its correlates

    Linda Lai


    This article presents several studies that replicate and extend previous research on maximizing. A modified scale for measuring individual maximizing tendency is introduced. The scale has adequate psychometric properties and reflects maximizers' aspirations for high standards and their preference for extensive alternative search, but not the decision difficulty aspect included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cogniti...

  20. Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease

    Höllmer, M.; Willesen, J. L.; Tolver, A.


    of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. ANIMALS: This prospective study included 205 client-owned dogs of different breeds, 114...... healthy dogs, and 91 dogs with MMVD of different disease severities. METHODS: Using two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function. RESULTS: Left atrial volume and LA...... stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100...

  1. Stroke Location Is an Independent Predictor of Cognitive Outcome.

    Munsch, Fanny; Sagnier, Sharmila; Asselineau, Julien; Bigourdan, Antoine; Guttmann, Charles R; Debruxelles, Sabrina; Poli, Mathilde; Renou, Pauline; Perez, Paul; Dousset, Vincent; Sibon, Igor; Tourdias, Thomas


    On top of functional outcome, accurate prediction of cognitive outcome for stroke patients is an unmet need with major implications for clinical management. We investigated whether stroke location may contribute independent prognostic value to multifactorial predictive models of functional and cognitive outcomes. Four hundred twenty-eight consecutive patients with ischemic stroke were prospectively assessed with magnetic resonance imaging at 24 to 72 hours and at 3 months for functional outcome using the modified Rankin Scale and cognitive outcome using the Montreal Cognitive Assessment (MoCA). Statistical maps of functional and cognitive eloquent regions were derived from the first 215 patients (development sample) using voxel-based lesion-symptom mapping. We used multivariate logistic regression models to study the influence of stroke location (number of eloquent voxels from voxel-based lesion-symptom mapping maps), age, initial National Institutes of Health Stroke Scale and stroke volume on modified Rankin Scale and MoCA. The second part of our cohort was used as an independent replication sample. In univariate analyses, stroke location, age, initial National Institutes of Health Stroke Scale, and stroke volume were all predictive of poor modified Rankin Scale and MoCA. In multivariable analyses, stroke location remained the strongest independent predictor of MoCA and significantly improved the prediction compared with using only age, initial National Institutes of Health Stroke Scale, and stroke volume (area under the curve increased from 0.697-0.771; difference=0.073; 95% confidence interval, 0.008-0.155). In contrast, stroke location did not persist as independent predictor of modified Rankin Scale that was mainly driven by initial National Institutes of Health Stroke Scale (area under the curve going from 0.840 to 0.835). Similar results were obtained in the replication sample. Stroke location is an independent predictor of cognitive outcome (MoCA) at 3

  2. Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

    F.J. Neves


    Full Text Available To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11 underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96 and control (P = 0.24 experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P 0.05. In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

  3. HEMI: Hyperedge Majority Influence Maximization

    Gangal, Varun; Narayanam, Ramasuri


    In this work, we consider the problem of influence maximization on a hypergraph. We first extend the Independent Cascade (IC) model to hypergraphs, and prove that the traditional influence maximization problem remains submodular. We then present a variant of the influence maximization problem (HEMI) where one seeks to maximize the number of hyperedges, a majority of whose nodes are influenced. We prove that HEMI is non-submodular under the diffusion model proposed.

  4. Guinea pig maximization test

    Andersen, Klaus Ejner


    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...... with 30% (v/v) ethanol or saline, respectively. Relative viscosity was used as one measure of physical properties of the emulsion. Higher degrees of sensitization (but not rates) were obtained at the 48 h challenge reading with the oil/propylene glycol and oil/saline + ethanol emulsions compared...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....


    Widya Hanum Sari Pertiwi


    Full Text Available This study was qualitative research action that focuses to find out the flouting of Gricean maxims and the functions of the flouting in the tales which are included in collection of children literature entitled My Giant Treasury of Stories and Rhymes. The objective of the study is generally to identify the violation of maxims of quantity, quality, relevance, and manner in the data sources and also to analyze the use of the flouting in the tales which are included in the book. Qualitative design using categorizing strategies, specifically coding strategy, was applied. Thus, the researcher as the instrument in this investigation was selecting the tales, reading them, and gathering every item which reflects the violation of Gricean maxims based on some conditions of flouting maxims. On the basis of the data analysis, it was found that the some utterances in the tales, both narration and conversation, flouting the four maxims of conversation, namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner. The researcher has also found that the flouting of maxims has one basic function that is to encourage the readers’ imagination toward the tales. This one basic function is developed by six others functions: (1 generating specific situation, (2 developing the plot, (3 enlivening the characters’ utterance, (4 implicating message, (5 indirectly characterizing characters, and (6 creating ambiguous setting. Keywords: children literature, tales, flouting maxims

  6. Mixed Stroke

    HuangRuxun(黄如训); Zeng Jinsheng(曾进胜)


    Purpose To summarize the chnical, autoptic and animal experimental dala of stroke, propose the concept of mixed stroke (MS) and demonstrate the enoiogy, pathogenesis, clinical mainfestations, prophylaxis and treatment of MS Background At present. stroke still is classified in the national and international academic fields as two main groups: hemorrhage and ischema In fact, thc cerebral vascular disease with hemorrhage forus and ischema focus at the same time is not rare moreover, this type of stroke has special etiology, pathogenesis and clinical manifestations. But it is always made a main dagnosis and neglected the other nature of coexistent focus on either clinical or pathological diagnosis according to traditional classification of stroke Data sources and methods Mort of pablished originsl articles about MS in our department and laboralory wcre reviewed. Resulta The clinical autoptic and animal experimental dats all prcved that hemorrhage and infarction could occur in the course of a stroke simultaneously or in suecession during a short time, which demonstrated the existence of MS It was found clinically that MS patients all had the hustory of hypcrtension and in the autoptic data the MS patients dying of stroke all had typical hypertensive changes in the heart and kidney. and had hypertensive arteriosclerosis in the cerebral arteriole and small artery. MS was cas lily thdueed in stroke-prone renovascular hypertensivc rats This kind of rats are free from genetic deficiency and arc not affected by senile factor, so their cerebral vascular foci are mainly induced by the single factor -hypertension. TThese indicate definitely that hypertensive cerebral vascular lesion is the basis inducing MS. The main lesions of hypertensive cerebral arteriole and small artery were hyalinosis and fibrinoid of the walls, and the formation of microaneurysms or hyperplasla of iniernal and external layers The math lcsions of hypertensive cerebral capillaries were increasing vascular

  7. Recovery After Stroke: Recurrent Stroke

    ... cholesterol or are overweight. If you are at risk for high blood pressure, ask your doctor how to manage it more ... feel fine. Medicines Medicine may help reduce stroke risk. In addition to those that treat high blood pressure, drugs are also available to control high cholesterol ...

  8. Stroke awareness in Denmark

    Truelsen, Thomas; Krarup, Lars-Henrik


    This is the first study to examine the awareness of major stroke symptoms and stroke risk factors among the general population in Denmark. Early recognition of stroke warning signs and means of reducing stroke occurrence could improve the treatment and prevention of stroke....

  9. Stroke awareness in Denmark

    Truelsen, Thomas; Krarup, Lars-Henrik


    This is the first study to examine the awareness of major stroke symptoms and stroke risk factors among the general population in Denmark. Early recognition of stroke warning signs and means of reducing stroke occurrence could improve the treatment and prevention of stroke....

  10. Maximal equilateral sets

    Swanepoel, Konrad J


    A subset of a normed space X is called equilateral if the distance between any two points is the same. Let m(X) be the smallest possible size of an equilateral subset of X maximal with respect to inclusion. We first observe that Petty's construction of a d-dimensional X of any finite dimension d >= 4 with m(X)=4 can be generalised to show that m(X\\oplus_1\\R)=4 for any X of dimension at least 2 which has a smooth point on its unit sphere. By a construction involving Hadamard matrices we then show that both m(\\ell_p) and m(\\ell_p^d) are finite and bounded above by a function of p, for all 1 1 such that m(X) <= d+1 for all d-dimensional X with Banach-Mazur distance less than c from \\ell_p^d. Using Brouwer's fixed-point theorem we show that m(X) <= d+1 for all d-\\dimensional X with Banach-Mazur distance less than 3/2 from \\ell_\\infty^d. A graph-theoretical argument furthermore shows that m(\\ell_\\infty^d)=d+1. The above results lead us to conjecture that m(X) <= 1+\\dim X.

  11. Unified Maximally Natural Supersymmetry

    Huang, Junwu


    Maximally Natural Supersymmetry, an unusual weak-scale supersymmetric extension of the Standard Model based upon the inherently higher-dimensional mechanism of Scherk-Schwarz supersymmetry breaking (SSSB), possesses remarkably good fine tuning given present LHC limits. Here we construct a version with precision $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ unification: $\\sin^2 \\theta_W(M_Z) \\simeq 0.231$ is predicted to $\\pm 2\\%$ by unifying $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ into a 5D $SU(3)_{\\rm EW}$ theory at a Kaluza-Klein scale of $1/R_5 \\sim 4.4\\,{\\rm TeV}$, where SSSB is simultaneously realised. Full unification with $SU(3)_{\\rm C}$ is accommodated by extending the 5D theory to a $N=4$ supersymmetric $SU(6)$ gauge theory on a 6D rectangular orbifold at $1/R_6 \\sim 40 \\,{\\rm TeV}$. TeV-scale states beyond the SM include exotic charged fermions implied by $SU(3)_{\\rm EW}$ with masses lighter than $\\sim 1.2\\,{\\rm TeV}$, and squarks in the mass range $1.4\\,{\\rm TeV} - 2.3\\,{\\rm TeV}$, providing distinct signature...

  12. Cardiovascular determinants of maximal oxygen consumption in upright and supine posture at the end of prolonged bed rest in humans.

    Bringard, Aurélien; Pogliaghi, Silvia; Adami, Alessandra; De Roia, Gabriela; Lador, Frédéric; Lucini, Daniela; Pizzinelli, Paolo; Capelli, Carlo; Ferretti, Guido


    We tested the hypothesis that, after bed rest, maximal oxygen consumption ( VO₂max ) decreases more upright than supine, because of adequate cardiovascular response supine, but not upright. On 9 subjects, we determined VO₂max and maximal cardiac output (Q ) upright and supine, before and after (reambulation day upright, the following day supine) 35-day bed rest, by classical steady state protocol. Oxygen consumption, heart rate (f(H)) and stroke volume (Q(st)) were measured by a metabolic cart, electrocardiography and Modelflow from pulse pressure profiles, respectively. We computed Q as f(H) times Q(st), and systemic oxygen flow ( QaO₂) as Q. times arterial oxygen concentration, obtained after haemoglobin and arterial oxygen saturation measurements. Before bed rest, all parameters at maximal exercise were similar upright and supine. After bed rest, VO₂max was lower (pcardiovascular response (i) did not affect VO₂max supine, (ii) partially explained the VO₂max decrease upright, and (iii) caused the VO₂max differences between postures. We speculate that impaired peripheral oxygen transfer and/or utilisation may explain the VO₂max decrease supine and the fraction of VO₂max decrease upright unexplained by cardiovascular responses.

  13. [Hippocampal stroke].

    Rollnik, J D; Traitel, B; Dietrich, B; Lenz, O


    Unilateral cerebral ischemia of the hippocampus is very rare. This paper reviews the literature and presents the case of a 59-year-old woman with an amnestic syndrome due to a left hippocampal stroke. The patient suffered from retrograde amnesia which was most severe over the 2 days prior to presenting and a slight anterograde amnesia. In addition, a verbal memory disorder was confirmed 1 week after admission by neurological tests. As risk factors, arterial hypertension and a relative hyper-beta lipoproteinemia were found. This case shows that unilateral amnestic stroke, e.g. in the hippocampus region, may be the cause of an amnestic syndrome and should be included in the differential diagnostics.

  14. The role of stroke volume variation in predicting the volume responsiveness of patients with severe sepsis and septic shock%每搏量变异度预测严重感染和感染性休克患者容量反应性的价值

    黄磊; 张卫星; 蔡文训; 罗华; 陈映群; 张声


    目的 研究每搏量变异度(stroke volume variation,SW)预测严重感染和感染性休克机械通气患者容量反应性的价值.方法 前瞻观察性研究,对2009年1月至2010年3月北京大学深圳医院ICU严重感染和感染性休克机械通气患者28例进行容量负荷试验.超声心输出量监测仪无创监测心脏指数(cardiac index,CI)、每搏输出量指数(stroke volume index,SVI)、外周血管阻力(systemic vascular resistance,SVR)、SVV等血流动力学指标.根据容量负荷试验前后CI增加值是否大于12%分为有反应组和无反应组,组间比较应用两独立样本t检验;容量负荷试验前后比较应用配对t检验;受试者工作特征曲线评价SVV、中心静脉压(central venous pressure,CVP)以及容量负荷试验前后CVP变化值(△CVP)预测容量反应性的价值.结果 容量负荷试验前,有反应组SW高于无反应组[(18.2±4.7)%和(12.7±4.2)%,P=0.003];而CVP两组差异无统计学意义[(10.2±4.0)cmH2O和(10.8±4.8)cmH2O,P>0.05].容量负荷试验后,有反应组△CVP低于无反应组[(2.9±3.1)cmH2O和(5.3±2.7)cmH2O,P=0.037].SVV、CVP和△CVP的曲线下面积(AUC)分别是0.836(95%CI:0.680~0.992,P=0.003)、0.549(95%CI:0.329~0.768,P=0.662)和0.762(95%CI:0.570~0.953,P=0.019).SVV为15.5%时预测容量反应性的敏感度和特异度分别是84.6%和80%.结论 SVV预测严重感染和感染性休克机械通气患者的容量反应性具有良好价值,明显优于CVP、△CVP等传统指标.%Objective To assess the role of stroke volume variation (SVV) in predicting the volume responsiveness of mechanically ventilated patients with severe sepsis and septic shock. Method A total of 28 mechanically ventilated patients with severe sepsis and septic shock were admitted from January 2009 to March 2010. Every patient was treated with volume loading test. Cardiac index (CI), stroke volume index (SVI), systemic vascular resistance (SVR) and SVV were measured non-invasively by

  15. Evaluation of right ventricular volumes measured by magnetic resonance imaging

    Møgelvang, J; Stubgaard, M; Thomsen, C


    Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular...... stroke volume was calculated as the difference between end-diastolic and end-systolic volume and compared to left ventricular stroke volume and to stroke volume determined simultaneously by a classical indicator dilution technique. There was good agreement between right ventricular stroke volume...... determined by MRI and by the indicator dilution method and between right and left ventricular stroke volume determined by MRI. Thus, MRI gives reliable values not only for left ventricular volumes, but also for right ventricular volumes. By MRI it is possible to obtain volumes from both ventricles...

  16. Multiple Strokes

    Obododimma Oha


    Full Text Available This poem playfully addresses the slippery nature of linguistic signification, employing humour and sarcasm in presenting a wide range of human experience. It ironical twists -- and "strokes" (read ambiguously as both a giving a punishment and erotic pleasuring -- move from the naming of location through international discourse of capital to the crumbling relationships between nation states. It reading of the signs of language is tied to the unease and fracture in cultural and political experience.

  17. National Stroke Association

    ... Virginia Washington West Virginia Wisconsin Wyoming Go National Stroke Association Our mission is to reduce the incidence ... and support for all impacted by stroke. Understanding stroke and the recovery journey can be overwhelming, but ...

  18. Two Kinds of Stroke

    ... Issue Past Issues Special Section Two Kinds of Stroke Past Issues / Summer 2007 Table of Contents For ... are often a warning sign for future strokes. Stroke Can Affect Anyone Award-winning actress Julie Harris ...

  19. Healthy Living after Stroke

    ... Stories Stroke Heroes Among Us Healthy Living After Stroke Nutrition Good nutrition is one way to reduce ... look to maintain health and wellness. Subscribe to Stroke Connection Get quarterly digital issues plus our monthly ...

  20. The "Know Stroke" Campaign

    ... Current Issue Past Issues Special Section The "Know Stroke" Campaign Past Issues / Summer 2007 Table of Contents ... campaign for the U.S. Hispanic community. 1 Know Stroke A stroke occurs when the blood supply to ...

  1. Stroke - risk factors

    ... Association Stroke Council; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Functional Genomics and Translational Biology; Council on Hypertension. Guidelines for the primary prevention of stroke: a ...

  2. Maximal subgroups of finite groups

    S. Srinivasan


    Full Text Available In finite groups maximal subgroups play a very important role. Results in the literature show that if the maximal subgroup has a very small index in the whole group then it influences the structure of the group itself. In this paper we study the case when the index of the maximal subgroups of the groups have a special type of relation with the Fitting subgroup of the group.

  3. Finding Maximal Quasiperiodicities in Strings

    Brodal, Gerth Stølting; Pedersen, Christian N. S.


    of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...

  4. Maximizing Entropy over Markov Processes

    Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis


    computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of an system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...

  5. Maximizing entropy over Markov processes

    Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis


    computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of a system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...

  6. Rehabilitation of a patient with stroke

    Apurba Barman


    Full Text Available Stroke is a significant cause of long-term disability world-wide. The post-stroke disabilities are due to loss of locomotion, activity of daily living, cognition and communication skills. Rehabilitation is an integral part of medical management and continues longitudinally through acute care, post-acute care and community reintegration. The objectives of stroke rehabilitation are to maximize the functional independence, minimize the disabilities, reintegrate back into the home and community and improve the self-esteem of patient. A comprehensive stroke rehabilitation service should provide early assessment of impairments and disabilities, management and prevention of complications and well-organized rehabilitation program in both in-patient and out-patient settings. A multidisciplinary or interdisciplinary team approach is necessary to reduce the post-stroke disabilities. It has many members, including physicians, physical therapists, occupational therapists, speech and language pathologists, orthotist, psychotherapists, social workers, vocational rehabilitation therapists, rehabilitation nurse, patients, families and other caregivers. Physicians caring for patients with stroke during rehabilitation must be aware of potential medical complications, as well as a number of special problems that may complicate recovery, including cognitive deficits, aphasia, dysphagia, urinary incontinence, shoulder pain, spasticity, falls and depression. Involvement of patient and caregivers in the rehabilitation process is essential. This article outlines the salient features of the early comprehensive rehabilitation after stroke.

  7. Positron CT imaging of an impending stroke

    Itoh, M.; Hatazawa, J.; Watanuki, S.; Pozzilli, C.; Matsuzawa, T.; Abe, Y.; Fujiwara, T.; Satoh, T.; Fukuda, H.; Wada, T.


    We present PET findings of a case of a transient ischemic attack which later progressed to cerebral infarction. Cerebral blood flow at the stroke focus in the right parietal cortex measured after a TIA attack and before stroke was as low as 24 ml/100 g/min with some increase in oxygen extraction fraction and blood volume. The condition was compatible with 'misery perfusion'. This case may be an example suggestive that the 'misery perfusion sign' is a warning of impending stroke and its poor prognosis if left without appropriate treatments.

  8. Clinical comparison between HeartMate VE auto-mode and HeartMate XVE auto-mode with Opti-Fill and the effect of stroke volume on blood chamber and inflow valve peak pressures.

    Rodermans, Ben F M; Lahpor, Jaap R; van Schelven, Leonard J; Nieuwenhuis, Esther; Sukkel, Eveline Y; van Schouwen-van Kranen, Else


    We determined the difference between HeartMate (HM) VE auto mode, average filling 76 mL, and HM XVE Opti-Fill, average filling 79 mL, regarding blood chamber and inflow valve peak pressure pulses (BCPP and IVPP). The relation between stroke volume (SV) and peak pressures was investigated by using a circulatory mock loop. At high SVs, 79 to 83 mL, BCPP and IVPP never exceeded 400 mm Hg. For lower SVs, down to 50 mL, the peak pressures increased to 788 mm Hg for BCPP and 416 mm Hg for IVPP. Distribution of SV was measured in 2 VE and 6 XVE patients during rest and activities of daily living (ADL). For clinical comparison, percentages of SV >78 mL were determined. At rest, 2190 (VE) and 5772 (XVE) pump beats were registered and 4511 (VE) and 8713 (XVE) during ADL. Percentages of "SV >78 mL" at rest, respectively, were 42.5 +/- 3.5 and 78.2 +/- 4.7 (p 78 mL and makes an important contribution to reducing the incidence of high peak pressures in the clinical setting.

  9. Sex Disparities in Stroke

    Dehlendorff, Christian; Andersen, Klaus Kaae; Olsen, Tom Skyhøj


    BACKGROUND: Uncertainty remains about whether stroke affects men and women similarly. We studied differences between men and women with regard to stroke severity and survival. METHODS AND RESULTS: We used the Danish Stroke Registry, with information on all hospital admissions for stroke in Denmark...... between 2003 and 2012 (N=79 617), and the Danish Register of Causes of Death. Information was available on age, sex, marital status, stroke severity, stroke subtype, socioeconomic status, and cardiovascular risk profile. We studied only deaths due to the index stroke, with the assumption that death...... reported on death certificates as due to stroke was related to the index stroke if death occurred within the first week or month after stroke. Multivariate Cox regression analysis and multiple imputation were applied. Stroke was the cause of death for 4373 and 5512 of the 79 617 patients within 1 week (5...

  10. Prevention Of Stroke

    Nagaraja D


    Full Text Available Stroke is an important cause for neurological morbidity and mortality. Prevention of ischemic stroke involves identification and prevention of risk factors and optimal use of pharmacotherapy. Risk factors have been classified as modifiable and non-modifiable; control of modifiable factors should prevent stroke occurrence. Stroke prevention has been described at three levels: primary, secondary and tertiary. Prolonged hypertension increases an individual′s risk for developing fatal or nonfatal stroke by three times and its control has been shown to prevent stroke. Diabetes mellitus is an important cause for microangiopathy and predisposes to stroke. Statin trials have shown significant reduction in stroke in those who were treated with statins. Stroke risk can be reduced by avoiding tobacco use, control of obesity and avoiding sedentary life style. Anti platelet medications are effective for secondary prevention of stroke. Educating society regarding modifiable risk factors and optimal use of pharmacotherapy form the cornerstone for the prevention of stroke.

  11. On w-maximal groups

    Gonzalez-Sanchez, Jon


    Let $w = w(x_1,..., x_n)$ be a word, i.e. an element of the free group $F =$ on $n$ generators $x_1,..., x_n$. The verbal subgroup $w(G)$ of a group $G$ is the subgroup generated by the set $\\{w (g_1,...,g_n)^{\\pm 1} | g_i \\in G, 1\\leq i\\leq n \\}$ of all $w$-values in $G$. We say that a (finite) group $G$ is $w$-maximal if $|G:w(G)|> |H:w(H)|$ for all proper subgroups $H$ of $G$ and that $G$ is hereditarily $w$-maximal if every subgroup of $G$ is $w$-maximal. In this text we study $w$-maximal and hereditarily $w$-maximal (finite) groups.

  12. Maximizing without difficulty: A modified maximizing scale and its correlates

    Lai, Linda


    ... included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cognition, desire for consistency, risk aversion, intrinsic motivation, self-efficacy and perceived workload, whereas...

  13. Maximizing and customer loyalty: Are maximizers less loyal?

    Linda Lai


    Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.

  14. Are maximizers really unhappy? The measurement of maximizing tendency,

    Dalia L. Diab


    Full Text Available Recent research suggesting that people who maximize are less happy than those who satisfice has received considerable fanfare. The current study investigates whether this conclusion reflects the construct itself or rather how it is measured. We developed an alternative measure of maximizing tendency that is theory-based, has good psychometric properties, and predicts behavioral outcomes. In contrast to the existing maximization measure, our new measure did not correlate with life (dissatisfaction, nor with most maladaptive personality and decision-making traits. We conclude that the interpretation of maximizers as unhappy may be due to poor measurement of the construct. We present a more reliable and valid measure for future researchers to use.

  15. Principles of maximally classical and maximally realistic quantum mechanics

    S M Roy


    Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2-dimensional phase space, a maximally realistic quantum mechanics can have quantum probabilities of no more than + 1 complete commuting cets (CCS) of observables coexisting as marginals of one positive phase space density. Here I formulate a stationary principle which gives a nonperturbative definition of a maximally classical as well as maximally realistic phase space density. I show that the maximally classical trajectories are in fact exactly classical in the simple examples of coherent states and bound states of an oscillator and Gaussian free particle states. In contrast, it is known that the de Broglie–Bohm realistic theory gives highly nonclassical trajectories.

  16. Epilepsy after stroke

    Olsen, T S; Høgenhaven, H; Thage, O


    Development of epilepsy was studied prospectively in a group of 77 consecutive stroke patients. Included were stroke patients less than 75 years old admitted within the first 3 days after the stroke. Excluded were patients with subarachnoid hemorrhage, vertebrobasilar stroke, and patients...

  17. Stroke: First Aid

    First aid Stroke: First aid Stroke: First aid By Mayo Clinic Staff A stroke occurs when there's bleeding into your brain or when normal blood flow to ... next several hours. Seek immediate medical assistance. A stroke is a true emergency. The sooner treatment is ...

  18. Leukocytosis in acute stroke

    Kammersgaard, L P; Jørgensen, H S; Nakayama, H


    Leukocytosis is a common finding in the acute phase of stroke. A detrimental effect of leukocytosis on stroke outcome has been suggested, and trials aiming at reducing the leukocyte response in acute stroke are currently being conducted. However, the influence of leukocytosis on stroke outcome has...

  19. Adapting the Home After a Stroke

    ... News About Neurology Image Library Search The Internet Stroke Center Patients & Families About Stroke Stroke Diagnosis Stroke ... after a Stroke Adapting the Home after a Stroke Caregiver Introduction What is Aphasia? Stroke Recovery Guides ...

  20. Has the Brain Maximized its Information Storage Capacity?

    Stepanyants, A L


    Learning and memory may rely on the ability of neuronal circuits to reorganize by dendritic spine remodeling. We have looked for geometrical parameters of cortical circuits, which maximize information storage capacity associated with this mechanism. In particular, we calculated optimal volume fractions of various neuropil components. The optimal axonal and dendritic volume fractions are not significantly different from anatomical measurements in the mouse and rat neocortex, and the rat hippocampus. This has led us to propose that the maximization of information storage capacity associated with dendritic spine remodeling may have been an important driving force in the evolution of the cortex.

  1. Effect of pre-stroke use of ACE inhibitors on ischemic stroke severity

    Caplan Louis


    Full Text Available Abstract Background Recent trials suggest that angiotensin-converting enzyme inhibitors (ACEI are effective in prevention of ischemic stroke, as measured by reduced stroke incidence. We aimed to compare stroke severity between stroke patients who were taking ACEI before their stroke onset and those who were not, to examine the effects of pretreatment with ACEI on ischemic stroke severity. Methods We retrospectively studied 126 consecutive patients presenting within 24 hours of ischemic stroke onset, as confirmed by diffusion-weighted magnetic resonance imaging (DWI. We calculated the NIHSS score at presentation, as the primary measure of clinical stroke severity, and categorized stroke severity as mild (NIHSS [less than or equal to] 7, moderate (NIHSS 8–13 or severe (NIHSS [greater than or equal to] 14. We analyzed demographic data, risk-factor profile, blood pressure (BP and medications on admissions, and determined stroke mechanism according to TOAST criteria. We also measured the volumes of admission diffusion- and perfusion-weighted (DWI /PWI magnetic resonance imaging lesions, as a secondary measure of ischemic tissue volume. We compared these variables among patients on ACEI and those who were not. Results Thirty- three patients (26% were on ACE-inhibitors. The overall median baseline NIHSS score was 5.5 (range 2–21 among ACEI-treated patients vs. 9 (range 1–36 in non-ACEI patients (p = 0.036. Patients on ACEI prior to their stroke had more mild and less severe strokes, and smaller DWI and PWI lesion volumes compared to non-ACEI treated patients. However, none of these differences were significant. Predictably, a higher percentage of patients on ACEI had a history of heart failure (p = 0.03. Age, time-to-imaging or neurological evaluation, risk-factor profile, concomitant therapy with lipid lowering, other antihypertensives or antithrombotic agents, or admission BP were comparable between the two groups. Conclusion Our results


    Rebecca M. Sealey


    Full Text Available This study aimed to identify the effect of different stroke rates on various kinematic parameters during 1000 m outrigger canoeing. Sixteen, experienced female outrigger canoeists completed three 1000 m outrigger ergometer time trials, one trial each using a self-selected, a Hawaiian ( 65 strokes·min-1 stroke rate. Stroke rate, stroke length, stroke time, proportion of time spent in propulsion and recovery, torso flexion angle and 'twist' were measured and compared with repeated measures ANOVAs. Stroke rate, stroke length and stroke time were significantly different across all interventions (p < 0.05 despite no difference in the percentage of time spent in the propulsive and recovery phases of the stroke. Stroke length and stroke time were negatively correlated to stroke rate for all interventions (r = -0.79 and -0.99, respectively. Female outrigger canoeists maintain consistent stroke kinematics throughout a 1000 m time trial, most likely as a learned skill to maximize crew paddling synchrony when paddling on-water. While the Hawaiian stroke rate resulted in the greatest trunk flexion movement and 'twist' action, this potential increased back injury risk may be offset by the slow stroke rate and long stroke length and hence slow rate of force development.

  3. Maximizing ROI with yield management

    Neil Snyder


    .... the technology is based on the concept of yield management, which aims to sell the right product to the right customer at the right price and the right time therefore maximizing revenue, or yield...

  4. Stroke Genetics Network (SiGN) study: design and rationale for a genome-wide association study of ischemic stroke subtypes.

    Meschia, James F; Arnett, Donna K; Ay, Hakan; Brown, Robert D; Benavente, Oscar R; Cole, John W; de Bakker, Paul I W; Dichgans, Martin; Doheny, Kimberly F; Fornage, Myriam; Grewal, Raji P; Gwinn, Katrina; Jern, Christina; Conde, Jordi Jimenez; Johnson, Julie A; Jood, Katarina; Laurie, Cathy C; Lee, Jin-Moo; Lindgren, Arne; Markus, Hugh S; McArdle, Patrick F; McClure, Leslie A; Mitchell, Braxton D; Schmidt, Reinhold; Rexrode, Kathryn M; Rich, Stephen S; Rosand, Jonathan; Rothwell, Peter M; Rundek, Tatjana; Sacco, Ralph L; Sharma, Pankaj; Shuldiner, Alan R; Slowik, Agnieszka; Wassertheil-Smoller, Sylvia; Sudlow, Cathie; Thijs, Vincent N S; Woo, Daniel; Worrall, Bradford B; Wu, Ona; Kittner, Steven J


    Meta-analyses of extant genome-wide data illustrate the need to focus on subtypes of ischemic stroke for gene discovery. The National Institute of Neurological Disorders and Stroke SiGN (Stroke Genetics Network) contributes substantially to meta-analyses that focus on specific subtypes of stroke. The National Institute of Neurological Disorders and Stroke SiGN includes ischemic stroke cases from 24 genetic research centers: 13 from the United States and 11 from Europe. Investigators harmonize ischemic stroke phenotyping using the Web-based causative classification of stroke system, with data entered by trained and certified adjudicators at participating genetic research centers. Through the Center for Inherited Diseases Research, the Network plans to genotype 10,296 carefully phenotyped stroke cases using genome-wide single nucleotide polymorphism arrays and adds to these another 4253 previously genotyped cases, for a total of 14,549 cases. To maximize power for subtype analyses, the study allocates genotyping resources almost exclusively to cases. Publicly available studies provide most of the control genotypes. Center for Inherited Diseases Research-generated genotypes and corresponding phenotypes will be shared with the scientific community through the US National Center for Biotechnology Information database of Genotypes and Phenotypes, and brain MRI studies will be centrally archived. The Stroke Genetics Network, with its emphasis on careful and standardized phenotyping of ischemic stroke and stroke subtypes, provides an unprecedented opportunity to uncover genetic determinants of ischemic stroke.

  5. Are CEOs Expected Utility Maximizers?

    John List; Charles Mason


    Are individuals expected utility maximizers? This question represents much more than academic curiosity. In a normative sense, at stake are the fundamental underpinnings of the bulk of the last half-century's models of choice under uncertainty. From a positive perspective, the ubiquitous use of benefit-cost analysis across government agencies renders the expected utility maximization paradigm literally the only game in town. In this study, we advance the literature by exploring CEO's preferen...

  6. Gaussian maximally multipartite entangled states

    Facchi, Paolo; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio


    We introduce the notion of maximally multipartite entangled states (MMES) in the context of Gaussian continuous variable quantum systems. These are bosonic multipartite states that are maximally entangled over all possible bipartitions of the system. By considering multimode Gaussian states with constrained energy, we show that perfect MMESs, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of MMESs and their frustration for n <= 7.

  7. All maximally entangling unitary operators

    Cohen, Scott M. [Department of Physics, Duquesne University, Pittsburgh, Pennsylvania 15282 (United States); Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States)


    We characterize all maximally entangling bipartite unitary operators, acting on systems A and B of arbitrary finite dimensions d{sub A}{<=}d{sub B}, when ancillary systems are available to both parties. Several useful and interesting consequences of this characterization are discussed, including an understanding of why the entangling and disentangling capacities of a given (maximally entangling) unitary can differ and a proof that these capacities must be equal when d{sub A}=d{sub B}.

  8. On the maximal diphoton width

    Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo


    Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

  9. Effects of Mesenchymal Stem Cell Treatment on the Expression of Matrix Metalloproteinases and Angiogenesis during Ischemic Stroke Recovery.

    Nam, Hyo Suk; Kwon, Il; Lee, Bo Hyung; Kim, Haejin; Kim, Jayoung; An, Sunho; Lee, Ok-Hee; Lee, Phil Hyu; Kim, Hyun Ok; Namgoong, Hyun; Kim, Young Dae; Heo, Ji Hoe


    The efficacy of mesenchymal stem cell (MSC) transplantation in ischemic stroke might depend on the timing of administration. We investigated the optimal time point of MSC transplantation. After MSC treatment, we also investigated the expression of matrix metalloproteinases (MMPs), which play a role in vascular and tissue remodeling. Human bone marrow-derived MSCs (2 × 10(6), passage 5) were administrated intravenously after permanent middle cerebral artery occlusion (MCAO) was induced in male Sprague-Dawley rats. First, we determined the time point of MSC transplantation that led to maximal neurological recovery at 1 h, 1 day, and 3 days after MCAO. Next, we measured activity of MMP-2 and MMP-9, neurological recovery, infarction volume, and vascular density after transplanting MSCs at the time that led to maximal neurological recovery. Among the MSC-transplanted rats, those of the MSC 1-hour group showed maximal recovery in the rotarod test (P = 0.023) and the Longa score (P = 0.018). MMP-2 activity at 1 day after MCAO in the MSC 1-hour group was significantly higher than that in the control group (P = 0.002), but MMP-9 activity was not distinct. The MSC 1-hour group also showed smaller infarction volume and higher vascular density than did the control group. In a permanent model of rodent MCAO, very early transplantation of human MSCs (1 h after MCAO) produced greater neurological recovery and decreased infraction volume. The elevation of MMP-2 activity and the increase in vascular density after MSC treatment suggest that MSCs might help promote angiogenesis and lead to neurological improvement during the recovery phase after ischemic stroke.

  10. Neurogenesis in Stroke Recovery.

    Koh, Seong-Ho; Park, Hyun-Hee


    Stroke, resulting from limited blood flow to the brain, is one of the most important causes of morbidity and mortality worldwide. Stroke is classified as ischemic, due to lack of blood flow, or hemorrhagic, due to bleeding. Because 87 % of strokes are classified as ischemic, this type will be the predominant focus of this review. Except for thrombolytic therapy, there is no established treatment to reduce the neurological deficits caused by ischemic stroke. Therefore, it is necessary to develop new therapeutic strategies designed to improve neurological functions after ischemic stroke. Recently, therapies to enhance neurogenesis after ischemic stroke have been investigated. However, these approaches have not led to successful clinical outcomes. This review addresses the pathophysiology of stroke, neurogenesis after stroke, and how to stimulate these processes based on the current literature. Finally, ongoing clinical trials to improve neurological functions after stroke by enhancing neurogenesis are discussed in this review.

  11. General Anesthesia Versus Conscious Sedation for Endovascular Treatment of Acute Ischemic Stroke: The AnStroke Trial (Anesthesia During Stroke).

    Löwhagen Hendén, Pia; Rentzos, Alexandros; Karlsson, Jan-Erik; Rosengren, Lars; Leiram, Birgitta; Sundeman, Henrik; Dunker, Dennis; Schnabel, Kunigunde; Wikholm, Gunnar; Hellström, Mikael; Ricksten, Sven-Erik


    Retrospective studies have found that patients receiving general anesthesia for endovascular treatment in acute ischemic stroke have worse neurological outcome compared with patients receiving conscious sedation. In this prospective randomized single-center study, we investigated the impact of anesthesia technique on neurological outcome in acute ischemic stroke patients. Ninety patients receiving endovascular treatment for acute ischemic stroke in 2013 to 2016 were included and randomized to general anesthesia or conscious sedation. Difference in neurological outcome at 3 months, measured as modified Rankin Scale score, was analyzed (primary outcome) and early neurological improvement of National Institutes of Health Stroke Scale and cerebral infarction volume. Age, sex, comorbidities, admission National Institutes of Health Stroke Scale score, intraprocedural blood pressure, blood glucose, Paco2 and Pco2 modified Thrombolysis in Cerebral Ischemia score, and relevant time intervals were recorded. In the general anesthesia group 19 of 45 patients (42.2%) and in the conscious sedation group 18 of 45 patients (40.0%) achieved a modified Rankin Scale score ≤2 (P=1.00) at 3 months, with no differences in intraoperative blood pressure decline from baseline (P=0.57); blood glucose (P=0.94); PaCO2 (P=0.68); time intervals (P=0.78); degree of successful recanalization, 91.1% versus 88.9% (P=1.00); National Institutes of Health Stroke Scale score at 24 hours 8 (3-5) versus 9 (2-15; P=0.60); infarction volume, 20 (10-100) versus 20(10-54) mL (P=0.53); and hospital mortality (13.3% in both groups; P=1.00). In endovascular treatment for acute ischemic stroke, no difference was found between general anesthesia and conscious sedation in neurological outcome 3 months after stroke. URL: Unique identifier: NCT01872884. © 2017 American Heart Association, Inc.

  12. The value of volume reaction evaluation through stroke volume variation combined with passive leg test for septic shock patients with autonomous breathing%每搏量变异结合被动抬腿试验在自主呼吸感染性休克患者容量反应评估中的价值研究

    林冰; 蒋丽芳; 孟繁甦; 郭应军


    Objective To evaluate the value of PLR-△SVV for the septic shock patients with autonomous breathing. Methods 60 patients were included in the study. Hemodynamic data of PICCO were collected before and after treatment. After rehydration, the group (△SV≥10%) was defined volume responder group, and then the predictive value of PLR-△SVV was analyzed. Results Compared with the nonresponders group, PLR-△SVV was increased significantly in response group[(10 ± 4)mL vs (14 ± 6)mL,P<0.05]. The ROC curve for PLR-△SVV were 0.881, and the sensitivity was 85.7%, the specificity was 92.0%. Conclusion PLR-△SVV can be used to predict fluid responsiveness for septic shock patients with spontaneously breathing.%目的:评估被动抬腿试验(passive leg raising,PLR)后每搏量变异(stroke volume variation,SVV),即PLR-△SVV在自主呼吸感染性休克患者中容量反应的预测价值。方法:患者60例,用 PiCCO 监测 PLR和补液试验前后的血流动力学,补液试验后△SV(stroke volume)≥10%为容量反应组,评价PLR-△SVV预测容量反应的价值。结果:反应组PLR-△SVV明显变化[(10±4)mL vs (14±6)mL,P<0.05],无反应组无明显变化(P>0.05)。 PLR-△SVV预测容量反应的ROC曲线下面积为0.881。以PLR-△SVV≥11.2%评价容量反应性,灵敏度为85.7%,特异度为92.0%。结论:PLR-△SVV可预测自主呼吸感染性休克患者的容量反应。

  13. Stroke and High Blood Pressure

    ... More How High Blood Pressure Can Lead to Stroke Updated:Dec 2,2016 Stroke and high blood ... Changes That Matter • Find Tools & Resources Show Your Stroke Support! Show your stroke support with our new ...

  14. Difficulty Swallowing After Stroke (Dysphagia)

    ... Stroke Heroes Among Us Difficulty Swallowing After Stroke (Dysphagia) Updated:Nov 15,2016 Excerpted and adapted from "Swallowing Disorders After a Stroke," Stroke Connection Magazine July/August ...

  15. Maximization

    A. Garmroodi Asil


    To further reduce the sulfur dioxide emission of the entire refining process, two scenarios of acid gas or air preheats are investigated when either of them is used simultaneously with the third enrichment scheme. The maximum overall sulfur recovery efficiency and highest combustion chamber temperature is slightly higher for acid gas preheats but air preheat is more favorable because it is more benign. To the best of our knowledge, optimization of the entire GTU + enrichment section and SRU processes has not been addressed previously.

  16. [Stroke and aging].

    Ly, J; Maquet, P


    Stroke risk increases with aging and one third of ischemic strokes occurs in very elderly (> or = 80 years). These are responsible of two thirds of the overall stroke-related morbi-mortality. Stroke in very elderly differs from younger individuals by sex ratio (more women), risk factors (more atrial fibrillation and hypertension) and usually a worse functional outcome. Very elderly are likely to benefit from stroke unit care and early revascularisation treatments although they have historically been excluded from this urgent management. These issues are likely to worsen in the future with the increasing impact of stroke on our aging societies.

  17. Neuroimaging in stroke and non-stroke pusher patients

    Taiza Elaine Grespan Santos-Pontelli


    Full Text Available Pusher behavior (PB is a disorder of postural control affecting patients with encephalic lesions. This study has aimed to identify the brain substrates that are critical for the occurrence of PB, to analyze the influence of the midline shift (MS and hemorrhagic stroke volume (HSV on the severity and prognosis of the PB. We identified 31 pusher patients of a neurological unit, mean age 67.4±11.89, 61.3% male. Additional neurological and functional examinations were assessed. Neuroimaging workup included measurement of the MS, the HSV in patients with hemorrhagic stroke, the analysis of the vascular territory, etiology and side of the lesion. Lesions in the parietal region (p=0.041 and thalamus (p=0.001 were significantly more frequent in PB patients. Neither the MS nor the HSV were correlated with the PB severity or recovery time.

  18. The neuroanatomy of pure apraxia of speech in stroke.

    Graff-Radford, Jonathan; Jones, David T; Strand, Edythe A; Rabinstein, Alejandro A; Duffy, Joseph R; Josephs, Keith A


    The left insula or Broca's area have been proposed as the neuroanatomical correlate for apraxia of speech (AOS) based on studies of patients with both AOS and aphasia due to stroke. Studies of neurodegenerative AOS suggest the premotor area and the supplementary motor areas as the anatomical correlates. The study objective was to determine the common infarction area in patients with pure AOS due to stroke. Patients with AOS and no or equivocal aphasia due to ischemic stroke were identified through a pre-existing database. Seven subjects were identified. Five had pure AOS, and two had equivocal aphasia. MRI lesion analysis revealed maximal overlap spanning the left premotor and motor cortices. While both neurodegenerative AOS and stroke induced pure AOS involve the premotor cortex, further studies are needed to establish whether stroke-induced AOS and neurodegenerative AOS share a common anatomic substrate.

  19. Increased oxygen pulse after lung volume reduction surgery is associated with reduced dynamic hyperinflation.

    Lammi, Matthew R; Ciccolella, David; Marchetti, Nathaniel; Kohler, Malcolm; Criner, Gerard J


    Stroke volume augmentation during exercise is limited in chronic obstructive pulmonary disease patients because of decreased preload from dynamic hyperinflation (DH). We hypothesised that oxygen pulse and pulse pressure (PP) improve following lung volume reduction surgery (LVRS), and the magnitude of improvement correlates with reduction in DH. We compared 16 emphysema patients undergoing LVRS with six emphysema patients not undergoing LVRS. Oxygen pulse and PP were calculated from maximal cardiopulmonary exercise tests at baseline and 6 months. End-expiratory lung volume (EELV)/total lung capacity (TLC) represented DH. Comparisons were made between baseline and 6 months at metabolic isotimes (per cent maximal carbon dioxide production (V'(CO(2),max))). At baseline, the LVRS group was older with higher forced expiratory volume in 1 s, but had similar hyperinflation to the non-LVRS group. At 6 months, oxygen pulse (50%, 75%, and 100% V'(CO(2),max)) and PP (50% and 75% V'(CO(2),max)) increased in the LVRS, but not in the non-LVRS group. Baseline functional residual capacity/TLC inversely correlated with resting oxygen pulse (r= -0.449, p=0.04). Decreased EELV/TLC correlated with increased oxygen pulse at 75% (r= -0.487, p=0.02) and 100% V'(CO(2),max) (r= -0.548, p=0.008). LVRS led to increased oxygen pulse and PP during exercise at metabolic isotimes 6 months following surgery. Reductions in DH correlated with increases in oxygen pulse during exercise. Reducing lung volume may improve stroke volume response to exercise by decreasing DH.

  20. Algebraic curves of maximal cyclicity

    Caubergh, Magdalena; Dumortier, Freddy


    The paper deals with analytic families of planar vector fields, studying methods to detect the cyclicity of a non-isolated closed orbit, i.e. the maximum number of limit cycles that can locally bifurcate from it. It is known that this multi-parameter problem can be reduced to a single-parameter one, in the sense that there exist analytic curves in parameter space along which the maximal cyclicity can be attained. In that case one speaks about a maximal cyclicity curve (mcc) in case only the number is considered and of a maximal multiplicity curve (mmc) in case the multiplicity is also taken into account. In view of obtaining efficient algorithms for detecting the cyclicity, we investigate whether such mcc or mmc can be algebraic or even linear depending on certain general properties of the families or of their associated Bautin ideal. In any case by well chosen examples we show that prudence is appropriate.




    The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L2 to itseff, it is proved that the maximal singu lar integral is bounded from L∞ to RBMO except that it is infinite μ-a.e. on Rd. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L2 to itself are also obtained. There is a small gap between the two conditions.

  2. An International Standard Set of Patient-Centered Outcome Measures After Stroke

    Salinas, J. (Joel); Sprinkhuizen, S.M. (Sara M.); Ackerson, T. (Teri); Bernhardt, J. (Julie); Davie, C. (Charlie); George, M.G. (Mary G.); Gething, S. (Stephanie); Kelly, A.G. (Adam G.); Lindsay, P. (Patrice); Liu, L. (Liping); Martins, S.C.O. (Sheila C.O.); Morgan, L. (Louise); B. Norrving (Bo); Ribbers, G.M. (Gerard M.); Silver, F.L. (Frank L.); Smith, E.E. (Eric E.); Williams, L.S. (Linda S.); Schwamm, L.H. (Lee H.)


    markdownabstract__BACKGROUND AND PURPOSE:__ Value-based health care aims to bring together patients and health systems to maximize the ratio of quality over cost. To enable assessment of healthcare value in stroke management, an international standard set of patient-centered stroke outcome measures

  3. Heart rate recovery after maximal exercise is blunted in hypertensive seniors.

    Best, Stuart A; Bivens, Tiffany B; Dean Palmer, M; Boyd, Kara N; Melyn Galbreath, M; Okada, Yoshiyuki; Carrick-Ranson, Graeme; Fujimoto, Naoki; Shibata, Shigeki; Hastings, Jeffrey L; Spencer, Matthew D; Tarumi, Takashi; Levine, Benjamin D; Fu, Qi


    Abnormal heart rate recovery (HRR) after maximal exercise may indicate autonomic dysfunction and is a predictor for cardiovascular mortality. HRR is attenuated with aging and in middle-age hypertensive patients, but it is unknown whether HRR is attenuated in older-age adults with hypertension. This study compared HRR among 16 unmedicated stage 1 hypertensive (HTN) participants [nine men/seven women; 68 ± 5 (SD) yr; awake ambulatory blood pressure (BP) 149 ± 10/87 ± 7 mmHg] and 16 normotensive [control (CON)] participants (nine men/seven women; 67 ± 5 yr; 122 ± 4/72 ± 5 mmHg). HR, BP, oxygen uptake (V̇o2), cardiac output (Qc), and stroke volume (SV) were measured at rest, at two steady-state work rates, and graded exercise to peak during maximal treadmill exercise. During 6 min of seated recovery, the change in HR (ΔHR) was obtained every minute and BP every 2 min. In addition, HRR and R-R interval (RRI) recovery kinetics were analyzed using a monoexponential function, and the indexes (HRRI and RRII) were calculated. Maximum V̇o2, HR, Qc, and SV responses during exercise were not different between groups. ΔHR was significantly different (P < 0.001) between the HTN group (26 ± 8) and the CON group (36 ± 12 beats/min) after 1 min of recovery but less convincing at 2 min (P = 0.055). BP recovery was similar between groups. HRRI was significantly lower (P = 0.016), and there was a trend of lower RRII (P = 0.066) in the HTN group compared with the CON group. These results show that in older-age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. Copyright © 2014 the American Physiological Society.

  4. Heart and Stroke Encyclopedia

    ... Venous Thromboembolism Aortic Aneurysm More The Heart and Stroke Encyclopedia Click a letter below to get a ... dozens of cardiovascular terms from our Heart and Stroke Encyclopedia and get links to in-depth information. ...

  5. Stroke Trials Registry

    ... News About Neurology Image Library Search The Internet Stroke Center Trials Registry Clinical Trials Interventions Conditions Sponsors ... a clinical trial near you Welcome to the Stroke Trials Registry Our registry of clinical trials in ...

  6. Stroke Fact Sheet

    ... tells you to. Return to top Does taking birth control pills increase my risk for stroke? Taking birth ... your vagina Return to top Does using the birth control patch increase my risk for stroke? The patch ...

  7. Stroke Connection Magazine

    ... reason to live a longer, healthier life. These stroke survivors, caregivers and others share their 'whys'. We'd love ... let us know! Main Menu Survival Journeys For Caregivers Tips and ... Stroke Association. All rights reserved. | Privacy Policy

  8. Perinatal and Childhood Stroke

    J Gordon Millichap


    Full Text Available The epidemiology, risk factors, outcome and prognosis of perinatal and childhood stroke were reviewed at a workshop sponsored by the National Institute of Neurological Disorders and Stroke in Bethesda, MD, on Sept 18 and 19, 2000.

  9. Dizziness in stroke

    M V Zamergrad


    Differential diagnosis of new-onset acute vestibular vertigo is chiefly made between vestibular neuronitis and stroke. Dizziness in stroke is usually accompanied by other focal neurological symptoms of brainstem and cerebellar involvement. However, stroke may appear as isolated vestibular vertigo in some cases. An analysis of history data and the results of neurovestibular examination and brain magnetic resonance imaging allows stroke to be diagnosed in patients with acute isolated dizziness....

  10. Genetics of stroke

    Guo, Jin-Min; Liu, Ai-Jun; Su, Ding-Feng


    Stroke is the second most common cause of death and the most common cause of disability in developed countries. Stroke is a multi-factorial disease caused by a combination of environmental and genetic factors. Numerous epidemiologic studies have documented a significant genetic component in the occurrence of strokes. Genes encoding products involved in lipid metabolism, thrombosis, and inflammation are believed to be potential genetic factors for stroke. Although a large group of candidate ge...

  11. Understanding maximal repetitions in strings

    Crochemore, Maxime


    The cornerstone of any algorithm computing all repetitions in a string of length n in O(n) time is the fact that the number of runs (or maximal repetitions) is O(n). We give a simple proof of this result. As a consequence of our approach, the stronger result concerning the linearity of the sum of exponents of all runs follows easily.

  12. Arterial hypertension aggravates innate immune responses after experimental stroke

    Karoline eMöller


    Full Text Available Arterial hypertension is not only the leading risk factor for stroke, but also attribute to impaired recovery and poor outcome. The latter could be explained by hypertensive vascular remodeling that aggravates perfusion deficits and blood brain barrier disruption. However, besides vascular changes, one could hypothesize that activation of the immune system due to pre-existing hypertension may negatively influence post-stroke inflammation and thus stroke outcome. To test this hypothesis, male adult spontaneously hypertensive rats (SHR and normotensive Wistar Kyoto rats (WKY were subjected to photothrombotic stroke. One and three days after stroke, infarct volume and functional deficits were evaluated by magnetic resonance imaging and behavioral tests. Expression levels of adhesion molecules and chemokines, along with the post-stroke inflammatory response was analyzed by flow cytometry, quantitative real-time PCR and immunohistochemistry in rat brains four days after stroke. Although comparable at day one, lesion volumes were significantly larger in SHR at day three. The infarct volume showed a strong correlation with the amount of CD45 highly positive leukocytes present in the ischemic hemispheres. Functional deficits were comparable between SHR and WKY. Brain endothelial expression of intercellular adhesion molecule 1 (ICAM-1, vascular cell adhesion molecule 1 (VCAM-1 and P-selectin (CD62P was neither increased by hypertension nor by stroke. However, in SHR, brain infiltrating myeloid leukocytes showed significantly higher surface expression of ICAM-1 which may augment leukocyte transmigration by leukocyte-leukocyte interactions. The expression of chemokines that primarily attract monocytes and granulocytes was significantly increased by stroke and, furthermore, by hypertension. Accordingly, ischemic hemispheres of SHR contain considerably higher numbers of monocytes, macrophages and granulocytes. Exacerbated brain inflammation in SHR may

  13. Post-Stroke Rehabilitation

    ... PDF (704 kb) » Spanish Version » Order Materials » Post-Stroke Rehabilitation In the United States more than 700,000 ... best possible long-term outcome. What is post-stroke rehabilitation? Rehabilitation helps stroke survivors relearn skills that are ...

  14. Analysis of the influential factors of maximal-effort expiratory capacity of elderly women.

    Lee, Bomjin; Park, Soyun; Han, Dongwook


    [Purpose] The purpose of this study was to find the influential factors of maximal-effort expiratory capacity of elderly women. [Subjects and Methods] The subjects of this study were 83 healthy elderly women. The study's methods and purpose were explained and these women agreed to participate. The maximal-effort expiratory capacity was measured using spirometry (Pony FX, COSMED Inc., Italy). We measured forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%. [Results] Regarding forced vital capacity and forced expiratory volume in 1 second, it was found that height and age were influential factors. Regarding forced expiratory volume in 1 second/forced vital capacity %, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%, it was found that only age was an influential factor. [Conclusion] This study demonstrated that the most influential factors of maximal-effort expiratory capacity of elderly women were age, and the second influential factor was height. We noticed that weight was the least influential factor among them.

  15. Kinematical Analysis along Maximal Lactate Steady State Swimming Intensity

    Pedro Figueiredo, Rafael Nazario, Marisa Sousa, Jailton Gregório Pelarigo, João Paulo Vilas-Boas, Ricardo Fernandes


    Full Text Available The purpose of this study was to conduct a kinematical analysis during swimming at the intensity corresponding to maximal lactate steady state (MLSS. Thirteen long distance swimmers performed, in different days, an intermittent incremental protocol of n x 200 m until exhaustion and two to four 30-min submaximal constant speed bouts to determine the MLSS. The video analysis, using APAS System (Ariel Dynamics Inc., USA, allowed determining the following relevant swimming determinants (in five moments of the 30-min test: 0, 25, 50, 75, and 100%: stroke rate, stroke length, trunk incline, intracyclic velocity variation, propelling efficiency, index of coordination and the time allotted to propulsion per distance unit. An ANOVA for repeated measures was used to compare the parameters mean values along each moment of analysis. Stoke rate tended to increase and stroke length to decrease along the test; a tendency to decrease was also found for intracyclic velocity variation and propelling efficiency whereas the index of coordination and the propulsive impulse remained stable during the MLSS test. It can be concluded that the MLSS is not only an intensity to maintain without a significant increase of blood lactate concentration, but a concomitant stability for some biomechanical parameters exists (after an initial adaptation. However, efficiency indicators seem to be more sensitive to changes occurring during swimming at this threshold intensity.

  16. Epigenetics in Stroke Recovery

    Kassis, Haifa; Shehadah, Amjad; Chopp, Michael; Zhang, Zheng Gang


    Abstract: While the death rate from stroke has continually decreased due to interventions in the hyperacute stage of the disease, long-term disability and institutionalization have become common sequelae in the aftermath of stroke. Therefore, identification of new molecular pathways that could be targeted to improve neurological recovery among survivors of stroke is crucial. Epigenetic mechanisms such as post-translational modifications of histone proteins and microRNAs have recently emerged as key regulators of the enhanced plasticity observed during repair processes after stroke. In this review, we highlight the recent advancements in the evolving field of epigenetics in stroke recovery. PMID:28264471

  17. Psychoneuroimmunology of stroke.

    Skinner, Robert; Georgiou, Rachel; Thornton, Peter; Rothwell, Nancy


    Stroke is the major cause of disability in the Western world and is the third greatest cause of death, but there are no widely effective treatments to prevent the devastating effects of stroke. Extensive and growing evidence implicates inflammatory and immune processes in the occurrence of stroke and particularly in the subsequent injury. Several inflammatory mediators have been identified in the pathogenesis of stroke including specific cytokines, adhesion molecules, matrix metalloproteinases, and eicosanoids. An early clinical trial suggests that inhibiting interleukin-1 may be of benefit in the treatment of acute stroke.

  18. Clinical Epidemiology Of Stroke

    Nagaraja D


    Full Text Available Stroke is a huge public health problem because of its high morbidity and disability. The epidemiology of stroke is of relevance to construct practical paradigms to tackle this major health issue in the community. Recent data have shown that about 72-86% of strokes are ischemic, 9-18% are due to hemorrhage (intracerebral of subarachnoid and the rest are undefined. The risk factors for stroke are multiple and combined. At present, stroke is no more considered as unavoidable and untreatable. It is an emergency and specialized units and teams improve outcome and lower costs. Death related to stroke is declining in many countries and in both sexes. This decrease in multifactorial. The detection and more effective treatment of hypertension may play an important factor, as well as the improved medical care and improvement in diagnostic procedures. While stroke incidence appears stable and stroke mortality is slowly declining, the absolute magnitude of stroke is likely to grow over the next 30 years. as the population ages, the absolute number of stroke victims and demands on healthcare and other support systems is likely to increase substantially in the future. Keeping this in perspective, this chapter shall focus on the epidemiology of stroke in the world and in Indian, in particular.

  19. Registration of acute stroke

    Wildenschild, Cathrine; Mehnert, Frank; Thomsen, Reimar Wernich


    BACKGROUND: The validity of the registration of patients in stroke-specific registries has seldom been investigated, nor compared with administrative hospital discharge registries. The objective of this study was to examine the validity of the registration of patients in a stroke-specific registry...... (The Danish Stroke Registry [DSR]) and a hospital discharge registry (The Danish National Patient Registry [DNRP]). METHODS: Assuming that all patients with stroke were registered in either the DSR, DNRP or both, we first identified a sample of 75 patients registered with stroke in 2009; 25 patients...... in the DSR, 25 patients in the DNRP, and 25 patients registered in both data sources. Using the medical record as a gold standard, we then estimated the sensitivity and positive predictive value of a stroke diagnosis in the DSR and the DNRP. Secondly, we reviewed 160 medical records for all potential stroke...

  20. Sleep and Stroke

    M V Padma Srivastav


    Full Text Available Circadian variations in conjunction with sleep-related heart rhythm changes and sleepdisordered breathing (SDB are contributing risk factors for stroke. Strong scientificevidence now exists indicating that SDB contributes to systemic hypertension, aprominent risk factor for stroke, and compelling circumstantial evidence is presentsuggesting that SDB raises the risk for development of stroke through other circulatorymechanisms as well. Preliminary evidence indicates that post-stroke patients have ahigher prevalence of SDB, which is likely to compromise their rehabilitation outcomes.Since SDB is modifiable with the application of CPAP and other treatment modalities,there is practical value in investigating patients at risk of stroke or post stroke forpresence of SDB. Successful application of CPAP or BiPAP therapy may improve theoutcome in both instances.Key words : Sleep, Stroke, SDB, CPAP

  1. Note on maximal distance separable codes

    YANG Jian-sheng; WANG De-xiu; JIN Qing-fang


    In this paper, the maximal length of maximal distance separable(MDS)codes is studied, and a new upper bound formula of the maximal length of MDS codes is obtained. Especially, the exact values of the maximal length of MDS codes in some parameters are given.

  2. Maximization, learning, and economic behavior.

    Erev, Ido; Roth, Alvin E


    The rationality assumption that underlies mainstream economic theory has proved to be a useful approximation, despite the fact that systematic violations to its predictions can be found. That is, the assumption of rational behavior is useful in understanding the ways in which many successful economic institutions function, although it is also true that actual human behavior falls systematically short of perfect rationality. We consider a possible explanation of this apparent inconsistency, suggesting that mechanisms that rest on the rationality assumption are likely to be successful when they create an environment in which the behavior they try to facilitate leads to the best payoff for all agents on average, and most of the time. Review of basic learning research suggests that, under these conditions, people quickly learn to maximize expected return. This review also shows that there are many situations in which experience does not increase maximization. In many cases, experience leads people to underweight rare events. In addition, the current paper suggests that it is convenient to distinguish between two behavioral approaches to improve economic analyses. The first, and more conventional approach among behavioral economists and psychologists interested in judgment and decision making, highlights violations of the rational model and proposes descriptive models that capture these violations. The second approach studies human learning to clarify the conditions under which people quickly learn to maximize expected return. The current review highlights one set of conditions of this type and shows how the understanding of these conditions can facilitate market design.

  3. [Maximal exercise in spinal cord injured subjects: effects of an antigravity suit].

    Bazzi-Grossin, C; Bonnin, P; Bailliart, O; Bazzi, H; Kedra, A W; Martineaud, J P


    Paraplegics have low aerobic capacity because of the spinal cord injury. Their functional muscle mass is reduced and usually untrained. They have to use upperbody muscles for displacements and daily activities. Sympathic nervous system injury is responsible of vasomotricity disturbances in leg vessels and possible abdominal vessels, proportionally to level injury. If cord injury level is higher than T5, then sympathic cardiac efferences may be damaged. Underbody muscles atrophy and vasomotricity disturbances contribute to phlebostasis. This stasis may decrease venous return, preload and stroke volume (Starling). To maintain appropriate cardiac output, tachycardia is necessary, especially during exercise. Low stroke volume, all the more since it is associated with cardio-acceleration disturbances, may reduce cardiac output reserve, and so constitutes a limiting factor for adaptation to exercise. The aim of this study was to verify if use of an underlesional pressure suit may increase cardiac output reserve because of lower venous stasis, and increase performance. We studied 10 able-bodied and 14 traumatic paraplegic subjects. Able-bodied subjects were 37 +/- 6 years old, wellbeing, not especially trained with upperbody muscles: there were 2 women and 8 men. Paraplegics were 27 +/- 7 years old, wellbeing except paraplegia, five of them practiced sport regularly (athletism or basket for disabled), and the others just daily propelled their wheelchair; there were 5 women and 9 men. For 8 of them, cord injury levels were located below T7, between T1 and T6 for the others. The age disability varied from 6 months to 2 years for 9 of them, it was approximately five years for 4 of them, and 20 years for one. We used a maximal triangular arm crank exercise with an electro-magnetic ergocycle Gauthier frame. After five minutes warm up, it was proceeded in one minute successive stages until maximal oxygen consumption is raised. VO2, VCO2, RER were measured by direct method with

  4. Flow Augmentation in Acute Ischemic Stroke.

    Yadollahikhales, Golnaz; Borhani-Haghighi, Afshin; Torabi-Nami, Mohammad; Edgell, Randall; Cruz-Flores, Salvador


    There is an urgent need for additional therapeutic options for acute ischemic stroke considering the major pitfalls of the options available. Herein, we briefly review the role of cerebral blood flow, collaterals, vasoreactivity, and reperfusion injury in acute ischemic stroke. Then, we reviewed pharmacological and interventional measures such as volume expansion and induced hypertension, intra-aortic balloon counterpulsation, partial aortic occlusion, extracranial-intracranial carotid bypass surgery, sphenopalatine ganglion stimulation, and transcranial laser therapy with regard to their effects on flow augmentation and neuroprotection. © The Author(s) 2014.

  5. Application of stroke volume variation in directing management of elderly septic shock patients%每搏量变异度在老年脓毒性休克患者中的应用

    王志; 汤卫兵; 刘野


    目的:探讨每搏量变异度(SVV)在老年脓毒性休克患者中的应用。方法将进行机械通气的老年脓毒性休克患者28例分为常规组13例和SVV指导组15例,常规组根据中心静脉压(CVP)指导容量复苏,SVV指导组根据SVV、心输出量(CO)指导容量复苏。观察2组患者复苏时间、复苏后血乳酸、氧合指数、CVP、平均动脉压(MAP)、N端尿钠肽前体(NT-proB⁃NP)等变化,机械通气时间、24 h内左心功能不全发生率,28 d发生多器官功能障碍综合征(MODS)和死亡情况,记录SVV指导组复苏前后血流动力学参数SVV、CO、外周血管阻力(SVR)的变化。结果 SVV指导组复苏时间短于常规组(t=3.83),乳酸、NT-proBNP较常规组下降(t分别为3.20和12.32,P<0.05),氧合指数较常规组升高(t=3.01,P<0.05)。2组左心功能不全、MODS及病死率差异无统计学意义(P分别为0.198、0.410和0.372)。SVV指导组复苏后CO、SVV较复苏前改善(P<0.05)。结论 SVV能更好地指导老年脓毒性休克患者的容量复苏。%Objective To investigate the application of stroke volume variation (SVV) in directing management of elderly septic shock patients. Methods Patients who were diagnosed with elderly septic shock and supported with mechanical ventilation were in⁃cluded (n=28). They were divided into control group (n=13) and SVV group (n=15). Volume recovery was directed by CVP (central ve⁃nous pressure ) in control group and by SVV and CO (cardiac output) in SVV guoup respectively. Blood lactate, oxidation index, CVP , MVP, NT-proBNP, time of recovery, the length relying on mechanical ventilation and Vigileo parameters were compared after volume resuscition. During the period of treatment, the incidence of acute left ventricle dysfunction within 24 hours, MODS within 28 days and mortality rates of all causes were compared between these two groups. Changes in SVV, cardiac output (CO) and

  6. Oral antiplatelet therapy for acute ischaemic stroke.

    Sandercock, Peter A G; Counsell, Carl; Tseng, Mei-Chiun; Cecconi, Emanuela


    In people with acute ischaemic stroke, platelets become activated and can cause blood clots to form and block an artery in the brain, resulting in damage to part of the brain. Such damage gives rise to the symptoms of stroke. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and also reduce the risk of early recurrent ischaemic stroke, thereby reducing the risk of early death and improving long-term outcomes in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage. To assess the efficacy and safety of immediate oral antiplatelet therapy (that is started as soon as possible and no later than two weeks after stroke onset) in people with acute presumed ischaemic stroke. We searched the Cochrane Stroke Group Trials Register (last searched 16 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2013), MEDLINE (June 1998 to May 2013), and EMBASE (June 1998 to May 2013). In 1998, for a previous version of this review, we searched the register of the Antiplatelet Trialists' Collaboration, MedStrategy and contacted relevant drug companies. Randomised trials comparing oral antiplatelet therapy (started within 14 days of the stroke) with control in people with definite or presumed ischaemic stroke. Two review authors independently applied the inclusion criteria and assessed trial quality. For the included trials, they extracted and cross-checked the data. We included eight trials involving 41,483 participants. No new trials have been added since the last update.Two trials testing aspirin 160 mg to 300 mg once daily, started within 48 hours of onset, contributed 98% of the data. The risk of bias was low. The maximum follow-up was six months. With treatment, there was a significant decrease in death or dependency at the end of follow-up (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91 to 0.99). For every 1000 people treated with

  7. Sequential strokes in a hyperacute stroke unit.

    Ganesalingam, Jeban; Buddha, Sandeep; Carlton-Jones, Anoma L; Nicholas, Richard


    Vasculitis is a rare, but treatable condition that can present to hyperacute stroke units. Thrombolysis does not treat the underlying pathology, and a rapidly evolving clinical picture drives clinical decision often before all the investigation results are available.

  8. Viscosity and density dependence during maximal flow in man.

    Staats, B A; Wilson, T A; Lai-Fook, S J; Rodarte, J R; Hyatt, R E


    Maximal expiratory flow curves were obtained from ten healthy subjects white breathing air and three other gas mixtures with different densities and viscosities. From these data, the magnitudes of the dependence of maximal flow on gas density and viscosity were obtained. The scaling laws of fluid mechanics, together with a model for the flow-limiting mechanism, were used to obtain a prediction of the relationship between the density dependence and the viscosity dependence of maximal flow. Although the data for individual subjects were too variable to allow a precise comparison with this prediction, the relationship between the mean density dependence and the mean viscosity dependence of all usbjects agreed with the theoretic prediction. This agreement supports the assumption, which is frequently made, that flow resistance rather than tissue visoelasticity is the dominant contributor to peripheral resistance. Information on the relationships between the pressure drop to the flow-limiting segment and flow, gas density and viscosity, and lung volume were also obtained.

  9. Paradoxical centrally increased diffusivity in perinatal arterial ischemic stroke

    Stence, Nicholas V.; Mirsky, David M.; Deoni, Sean C.L. [University of Colorado Anschutz School of Medicine, Department of Radiology, Aurora, CO (United States); Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States); Armstrong-Wells, Jennifer [University of Colorado Anschutz School of Medicine, Department of Pediatrics (Neurology) and OB/GYN, Aurora, CO (United States); University of Colorado Hemophilia and Thrombosis Center, Aurora, CO (United States)


    Restricted diffusion on acute MRI is the diagnostic standard for perinatal arterial ischemic stroke. In a subset of children with perinatal arterial ischemic stroke, primarily those with large infarct volumes, we noted a core of centrally increased diffusivity with a periphery of restricted diffusion. Given the paradoxical diffusion-weighted imaging (DWI) appearance observed in some children with perinatal arterial ischemic stroke, we sought to determine its significance and hypothesized that: (1) centrally increased diffusivity is associated with larger infarcts in perinatal arterial ischemic stroke and (2) this tissue is irreversibly injured (infarcted). We reviewed all perinatal arterial ischemic stroke cases in a prospective cohort study from Aug. 1, 2000, to Jan. 1, 2012. Infarct volumes were measured by drawing regions of interest around the periphery of the area of restricted diffusion on DWI. The Mann-Whitney U test was used to compare means between groups. Of 25 eligible cases, centrally increased diffusivity was seen in 4 (16%). Cases with centrally increased diffusivity had larger average infarct volumes (mean 117,182 mm{sup 3} vs. 36,995 mm{sup 3}; P = 0.008), higher average apparent diffusion coefficient (ADC) values in the infarct core (1,679 x 10{sup -6} mm{sup 2}/s vs. 611 x 10{sup -6} mm{sup 2}/s, P < 0.0001), and higher ADC ratio (1.2 vs. 0.5, P < 0.0001). At last clinical follow-up, children with perinatal arterial ischemic stroke and centrally increased diffusivity were more often treated for ongoing seizures (75% vs. 0%; P < 0.001) than those without. Centrally increased diffusivity was associated with larger stroke volume and the involved tissue was confirmed to be infarcted on follow-up imaging. Radiologists should be aware of this unusual appearance of perinatal arterial ischemic stroke in order to avoid underestimating infarct volume or making an incorrect early diagnosis. (orig.)

  10. Asymptotics of robust utility maximization

    Knispel, Thomas


    For a stochastic factor model we maximize the long-term growth rate of robust expected power utility with parameter $\\lambda\\in(0,1)$. Using duality methods the problem is reformulated as an infinite time horizon, risk-sensitive control problem. Our results characterize the optimal growth rate, an optimal long-term trading strategy and an asymptotic worst-case model in terms of an ergodic Bellman equation. With these results we propose a duality approach to a "robust large deviations" criterion for optimal long-term investment.

  11. Multivariate residues and maximal unitarity

    Søgaard, Mads; Zhang, Yang


    We extend the maximal unitarity method to amplitude contributions whose cuts define multidimensional algebraic varieties. The technique is valid to all orders and is explicitly demonstrated at three loops in gauge theories with any number of fermions and scalars in the adjoint representation. Deca-cuts realized by replacement of real slice integration contours by higher-dimensional tori encircling the global poles are used to factorize the planar triple box onto a product of trees. We apply computational algebraic geometry and multivariate complex analysis to derive unique projectors for all master integral coefficients and obtain compact analytic formulae in terms of tree-level data.

  12. Beeping a Maximal Independent Set

    Afek, Yehuda; Alon, Noga; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian


    We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot...

  13. Maximal Congruences on Some Semigroups

    Jintana Sanwong; R.P. Sullivan


    In 1976 Howie proved that a finite congruence-free semigroup is a simple group if it has at least three elements but no zero elementInfinite congruence-free semigroups are far more complicated to describe, but some have been constructed using semigroups of transformations (for example, by Howie in 1981 and by Marques in 1983)Here, forcertain semigroups S of numbers and of transformations, we determine all congruences p on S such that S/p is congruence-free, that is, we describe all maximal congruences on such semigroups S.

  14. Blood Pressure Control: Stroke and Stroke Prevention

    Hans-Christoph Diener


    Full Text Available Hypertension is the most important modifiable risk factor for primary and secondary stroke prevention.All antihypertensive drugs are effective in primary prevention: the risk reduction for stroke is 30—42%. However, not all classes of drugs have the same effects: there is some indication that angiotensin receptor blockers may be superior to other classes of antihypertensive drugs in stroke prevention.Seventy-five percent of patients who present to hospital with acute stroke have elevated blood pressure within the first 24—48 hours. Extremes of systolic blood pressure (SBP increase the risk of death or dependency. The aim of treatment should be to achieve and maintain the SBP in the range 140—160 mmHg. However, fast and drastic blood pressure lowering can have adverse consequences.The PROGRESS trial of secondary prevention with perindopril + indapamide versus placebo + placebo showed a decrease in numbers of stroke recurrences in patients given both active antihypertensive agents, more impressive for cerebral haemorrhage.There were also indications that active treatment might decrease the development of post-stroke dementia.

  15. Value of measuring serum vascular endothelial growth factor levels in diagnosing acute ischemic stroke.

    Dassan, Pooja; Keir, Geoffrey; Jäger, Hans Rolf; Brown, Martin M


    It has previously been reported that serum levels of vascular endothelial growth factor are raised after acute ischemic stroke compared to healthy controls. The aim of this prospective study was to ascertain whether serum vascular endothelial growth factor measurements could be used to distinguish between acute ischemic stroke and common stroke mimics in the emergency room. Blood samples were taken on arrival to hospital and daily for six-days, in 44 patients with suspected ischemic stroke (29 acute infarcts and 15 stroke mimics), arriving within 24 h of symptom onset. Vascular endothelial growth factor levels were measured by enzyme-linked immunoassay. The neurological deficit was recorded daily using the National Institute of Health Stroke Scale. Evaluation of infarct volumes was based on diffusion-weighted magnetic resonance imaging. Serum vascular endothelial growth factor levels were significantly raised in acute ischemic stroke patients on the day of symptom onset and at all other time points, compared to healthy controls (P acute ischemic stroke on admission to hospital were only 69% and 73%, respectively. Vascular endothelial growth factor levels were also elevated in four out of 15 stroke mimics, including three patients presenting with postictal paresis. Vascular endothelial growth factor has limited clinical utility in the diagnosis of acute ischemic stroke in the emergency room because levels are also raised in common stroke mimics. Further studies are required to establish the mechanism of vascular endothelial growth factor elevation in postictal paresis. © 2011 The Authors. International Journal of Stroke © 2011 World Stroke Organization.

  16. Genetics of ischaemic stroke.

    Sharma, Pankaj; Yadav, Sunaina; Meschia, James F


    Recent advances in genomics and statistical computation have allowed us to begin addressing the genetic basis of stroke at a molecular level. These advances are at the cusp of making important changes to clinical practice of some monogenic forms of stroke and, in the future, are likely to revolutionise the care provided to these patients. In this review we summarise the state of knowledge in ischaemic stroke genetics particularly in the context of how a practicing clinician can best use this knowledge.

  17. Knowledge discovery by accuracy maximization.

    Cacciatore, Stefano; Luchinat, Claudio; Tenori, Leonardo


    Here we describe KODAMA (knowledge discovery by accuracy maximization), an unsupervised and semisupervised learning algorithm that performs feature extraction from noisy and high-dimensional data. Unlike other data mining methods, the peculiarity of KODAMA is that it is driven by an integrated procedure of cross-validation of the results. The discovery of a local manifold's topology is led by a classifier through a Monte Carlo procedure of maximization of cross-validated predictive accuracy. Briefly, our approach differs from previous methods in that it has an integrated procedure of validation of the results. In this way, the method ensures the highest robustness of the obtained solution. This robustness is demonstrated on experimental datasets of gene expression and metabolomics, where KODAMA compares favorably with other existing feature extraction methods. KODAMA is then applied to an astronomical dataset, revealing unexpected features. Interesting and not easily predictable features are also found in the analysis of the State of the Union speeches by American presidents: KODAMA reveals an abrupt linguistic transition sharply separating all post-Reagan from all pre-Reagan speeches. The transition occurs during Reagan's presidency and not from its beginning.

  18. Inapproximability of maximal strip recovery

    Jiang, Minghui


    In comparative genomic, the first step of sequence analysis is usually to decompose two or more genomes into syntenic blocks that are segments of homologous chromosomes. For the reliable recovery of syntenic blocks, noise and ambiguities in the genomic maps need to be removed first. Maximal Strip Recovery (MSR) is an optimization problem proposed by Zheng, Zhu, and Sankoff for reliably recovering syntenic blocks from genomic maps in the midst of noise and ambiguities. Given $d$ genomic maps as sequences of gene markers, the objective of \\msr{d} is to find $d$ subsequences, one subsequence of each genomic map, such that the total length of syntenic blocks in these subsequences is maximized. For any constant $d \\ge 2$, a polynomial-time 2d-approximation for \\msr{d} was previously known. In this paper, we show that for any $d \\ge 2$, \\msr{d} is APX-hard, even for the most basic version of the problem in which all gene markers are distinct and appear in positive orientation in each genomic map. Moreover, we provi...

  19. Maximal right smooth extension chains

    Huang, Yun Bao


    If $w=u\\alpha$ for $\\alpha\\in \\Sigma=\\{1,2\\}$ and $u\\in \\Sigma^*$, then $w$ is said to be a \\textit{simple right extension}of $u$ and denoted by $u\\prec w$. Let $k$ be a positive integer and $P^k(\\epsilon)$ denote the set of all $C^\\infty$-words of height $k$. Set $u_{1},\\,u_{2},..., u_{m}\\in P^{k}(\\epsilon)$, if $u_{1}\\prec u_{2}\\prec ...\\prec u_{m}$ and there is no element $v$ of $P^{k}(\\epsilon)$ such that $v\\prec u_{1}\\text{or} u_{m}\\prec v$, then $u_{1}\\prec u_{2}\\prec...\\prec u_{m}$ is said to be a \\textit{maximal right smooth extension (MRSE) chains}of height $k$. In this paper, we show that \\textit{MRSE} chains of height $k$ constitutes a partition of smooth words of height $k$ and give the formula of the number of \\textit{MRSE} chains of height $k$ for each positive integer $k$. Moreover, since there exist the minimal height $h_1$ and maximal height $h_2$ of smooth words of length $n$ for each positive integer $n$, we find that \\textit{MRSE} chains of heights $h_1-1$ and $h_2+1$ are good candidates t...

  20. Acute stroke imaging research roadmap

    Wintermark, Max; Albers, Gregory W.; Alexandrov, Andrei V.; Alger, Jeffry R.; Bammer, Roland; Baron, Jean-Claude; Davis, Stephen; Demaerschalk, Bart M.; Derdeyn, Colin P.; Donnan, Geoffrey A.; Eastwood, James D.; Fiebach, Jochen B.; Fisher, Marc; Furie, Karen L.; Goldmakher, Gregory V.; Hacke, Werner; Kidwell, Chelsea S.; Kloska, Stephan P.; Koehrmann, Martin; Koroshetz, Walter; Lee, Ting-Yim; Lees, Kennedy R.; Lev, Michael H.; Liebeskind, David S.; Ostergaard, Leif; Powers, William J.; Provenzale, James; Schellinger, Peter; Silbergleit, Robert; Sorensen, Alma Gregory; Wardlaw, Joanna; Warach, Steven


    The recent "Advanced Neuroimaging for Acute Stroke Treatment" meeting on September 7 and 8, 2007 in Washington DC, brought together stroke neurologists, neuroradiologists, emergency physicians, neuroimaging research scientists, members of the National Institute of Neurological Disorders and Stroke (

  1. Heart Disease and Stroke Prevention

    ... Heart Health and Stroke Heart disease and stroke prevention Related information Learn more about healthy eating and ... top More information on Heart disease and stroke prevention Read more from A Lifetime of ...


    S. Y. Martsevich


    Full Text Available Importance of the stroke as one of the main reason of population mortality and invalidity is considered. Stroke risk factors including arterial hypertension are described. The main pharmacotherapy ways of primary and secondary stroke prevention are discussed.

  3. Nutrition and stroke

    Huang, Chen Ya


    ..., Homocysteinemia, and alcohol are the most significant modifiable risk factors of stroke. Of these, hypertension, diabetes, smoking, hyperlipidemia, homocysteinemia and alcoholism are obviously affected by lifestyle and nutrition...

  4. Ischemic Stroke Treatment Trials: Neuroimaging Advancements and Implications.

    Patel, Vivek P; Heit, Jeremy J


    There have been significant advancements in the treatment of acute ischemic stroke in the last 2 decades. Recent trials have placed a significant emphasis on minimizing the time from symptom onset to stroke treatment by reperfusion therapies, which decreases the cerebral infarct volume and improves clinical outcomes. These clinical advances have paralleled and been aided by advances in neuroimaging. However, controversy remains regarding how much time should be spent on neuroimaging evaluation versus expediting patient treatment. In this review article, we examine the key endovascular stroke trials published in the past 25 years, and we briefly highlight the failures and successes of endovascular stroke trials performed in the past 4 years. We also discuss the advantages and disadvantages of using time from symptom onset versus neuroimaging in determining endovascular stroke therapy candidacy.

  5. Body Mass Index and Stroke

    Andersen, Klaus Kaae; Olsen, Tom Skyhøj


    Although obesity is associated with excess mortality and morbidity, mortality is lower in obese than in normal weight stroke patients (the obesity paradox). Studies now indicate that obesity is not associated with increased risk of recurrent stroke in the years after first stroke. We studied...... the association between body mass index (BMI) and stroke patient's risk of having a history of previous stroke (recurrent stroke)....

  6. Spontaneous ischaemic stroke in dogs

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.


    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  7. Relatedl factors of cognitive impairment after stroke

    Xiaofang Chen; Yueji Sun; Haiyan Liu; Yunqiao Ding; Shujuan Liu; Jinghua Chen; Xueying Wang; Zhenpeng Han; Fang Qu


    BACKGROUND: Cognitive impairment after stroke associates with various factors, such as age, educational years, etc. Besides concerning about the recovery of limb function after stroke, we should also focus on the rehabilitation of cognition. Moreover, we'd better pay attention to the control of all the risk factors of stroke, and improve the quality of life in stroke patients.OBJECTIVE: To analyze the factors that affect cognitive impairment after stroke.DESIGN: A related factors analysis.SET-FINGS: Department of Neurology of Dalian Port Hospital and Dalian Second People's Hospital.PARTICIPANTS: Totally 148 stroke inpatients were selected from Department of Neurology, Dalian Port Hospital and Dalian Second People's Hospital from April 2004 to December 2005, including 100 males and 48females, aging 45-75 years with an average age of (67±8) years; Their educational years ranged 2-10 years with an average of (6.1 ±3.7) years; The disease course ranged 15-30 days; All were right-handed. Inclusive criteria: All were accorded with the diagnostic standard set by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by CT or MRI; Informed consents were obtained from all the subjects.METHODS: After the disease conditions were stable, the patients were assessed with Wechsler memory scale (WMS) and Wisconsin card sorting test (WCST). WMS included forward and backward recitation of numbers and short-term memory (verbal memory, visual recognition). The number of times for correct and wrong classifications in WCST and the time to complete the trail making tests A and B were recorded. The focal volume, area and layer were recorded at 24 hours after admission. The general data of the patients were recorded, including name, sex, age, educational years, history of hypertension, history of diabetes mellitus.Electroencepalograph (EEC) was examined to record the wave shape, blood lipids were detected, and the cognition related indexes were analyzed with the

  8. On entire f-maximal graphs in the Lorentzian product Gn ×R1

    An, H. V. Q.; Cuong, D. V.; Duyen, N. T. M.; Hieu, D. T.; Nam, T. L.


    In the Lorentzian product Gn ×R1, we give a comparison theorem between the f-volume of an entire f-maximal graph and the f-volume of the hyperbolic Hr+ under the condition that the gradient of the function defining the graph is bounded away from 1. This condition comes from an example of non-planar entire f-maximal graph in Gn ×R1 and is equivalent to the hyperbolic angle function of the graph being bounded. As a consequence, we obtain a Calabi-Bernstein type theorem for f-maximal graphs in Gn ×R1.

  9. Preventable Pediatric Stroke via Vaccination?

    Press, Craig A.; Wainwright, Mark S


    Investigators from the Vascular Effects of Infection in Pediatric Stroke (VIPS) group studied the risk of arterial ischemic stroke (AIS) associated with minor infection and routine childhood vaccinations.

  10. Dysphagia in acute stroke: Correlation with stroke subtype, vascular territory and in-hospital respiratory morbidity and mortality

    Sundar Uma


    Full Text Available Aims: The study aimed at correlation of post-stroke dysphagia with area and volume of infarct/ bleed, and with subsequent in-hospital respiratory morbidity and mortality. Materials and Methods: 50 patients of acute stroke were serially recruited. Standard Staff swallowing assessment was performed within 24 hours of admission along with pulse oximetry. Ischemic strokes were classified as per OCPS registry. In-hospital respiratory morbidity and mortality, mode of nutrition and disability status at discharge were noted. Results: 21/50 (42% patients had post-stroke dysphagia during their hospital course. Among infarcts, Total Anterior Circulation Infarcts (TACI had 100% incidence of dysphagia, followed by Partial Anterior Circulation Infarcts (PACI-36%, Posterior Circulation infarcts (POCI-33%, and Lacunar infarcts (LACI-18%. 67% of hemorrhages had post-stroke dysphagia. Staff swallowing assessment had a sensitivity and specificity of 75% and 73% respy., for predicting respiratory morbidity. The corresponding figures for Pulse oximetry were 79% and 91%.

  11. Secondary Stroke Prevention in Cryptogenic Stroke and Embolic Stroke of Undetermined Source (ESUS).

    Diener, Hans-Christoph; Bernstein, Richard; Hart, Robert


    The purpose of the study was to review the literature on cryptogenic stroke and embolic stroke of undetermined stroke (ESUS). Cryptogenic stroke according to TOAST criteria is a stroke which is not due to cardiogenic embolism, small vessel disease with lacunes or large vessel disease of brain supplying arteries. In the context of secondary stroke prevention studies, cryptogenic stroke is not operationally defined. The new concept of "embolic stroke of undetermined source" (ESUS) provides an operational definition. ESUS is diagnosed as a non-lacunar stroke on cerebral imaging and exclusion of large vessel atherosclerosis by CTA, MRA or ultrasound. Cardiogenic embolism is made less likely by ECG monitoring and echocardiography. At present, aspirin is used for secondary stroke prevention in patients with cryptogenic stroke. Based on the construct that ESUS might be caused by undetected atrial fibrillation or other embolic mechanisms, ongoing randomised secondary stroke prevention trials are comparing non-vitamin K oral anticoagulants (NOACs) with aspirin.

  12. Real-time optoacoustic monitoring of stroke

    Kneipp, Moritz; Turner, Jake; Hambauer, Sebastian; Krieg, Sandro M.; Lehmberg, Jens; Lindauer, Ute; Razansky, Daniel


    Characterizing disease progression and identifying possible therapeutic interventions in stroke is greatly aided by the use of longitudinal function imaging studies. In this study, we investigate the applicability of real-time multispectral optoacoustic tomography (MSOT) as a tool for non-invasive monitoring of the progression of stroke in the whole brain. The middle cerebral artery occlusion (MCAO) method was used to induce stroke. Mice were imaged under isoflurane anesthesia preoperatively and at several time points during and after the 60-minute occlusion. The animals were sacrificed after 24 hours and their excised brains frozen at -80°C for sectioning. The cryosection were stained using H&E staining to identify the ischemic lesion. Major vessels are readily identifiable in the whole mouse head in the in vivo optoacoustic scans. During ischemia, a reduction in cerebral blood volume is detectable in the cortex. Post ischemia, spectral unmixing of the optoacoustic signals shows an asymmetry of the deoxygenated hemoglobin in the hemisphere affected by MCAO. This hypoxic area was mainly located around the boundary of the ischemic lesion and was therefore identified as the ischemic penumbra. Non-invasive functional MSOT imaging is able to visualize the hypoxic penumbra in brains affected by stroke. Stopping the spread of the infarct area and revitalizing the penumbra is central in stroke research, this new imaging technique may therefore prove to be a valuable tool in the monitoring and developing new treatments.

  13. The maximal D = 4 supergravities

    Wit, Bernard de [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Postbus 80.195, NL-3508 TD Utrecht (Netherlands); Samtleben, Henning [Laboratoire de Physique, ENS Lyon, 46 allee d' Italie, F-69364 Lyon CEDEX 07 (France); Trigiante, Mario [Dept. of Physics, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)


    All maximal supergravities in four space-time dimensions are presented. The ungauged Lagrangians can be encoded in an E{sub 7(7)}-Sp(56; R)/GL(28) matrix associated with the freedom of performing electric/magnetic duality transformations. The gauging is defined in terms of an embedding tensor {theta} which encodes the subgroup of E{sub 7(7)} that is realized as a local invariance. This embedding tensor may imply the presence of magnetic charges which require corresponding dual gauge fields. The latter can be incorporated by using a recently proposed formulation that involves tensor gauge fields in the adjoint representation of E{sub 7(7)}. In this formulation the results take a universal form irrespective of the electric/magnetic duality basis. We present the general class of supersymmetric and gauge invariant Lagrangians and discuss a number of applications.

  14. Maximizing profit using recommender systems

    Das, Aparna; Ricketts, Daniel


    Traditional recommendation systems make recommendations based solely on the customer's past purchases, product ratings and demographic data without considering the profitability the items being recommended. In this work we study the question of how a vendor can directly incorporate the profitability of items into its recommender so as to maximize its expected profit while still providing accurate recommendations. Our approach uses the output of any traditional recommender system and adjust them according to item profitabilities. Our approach is parameterized so the vendor can control how much the recommendation incorporating profits can deviate from the traditional recommendation. We study our approach under two settings and show that it achieves approximately 22% more profit than traditional recommendations.

  15. The maximal D=5 supergravities

    de Wit, Bernard; Trigiante, M; Wit, Bernard de; Samtleben, Henning; Trigiante, Mario


    The general Lagrangian for maximal supergravity in five spacetime dimensions is presented with vector potentials in the \\bar{27} and tensor fields in the 27 representation of E_6. This novel tensor-vector system is subject to an intricate set of gauge transformations, describing 3(27-t) massless helicity degrees of freedom for the vector fields and 3t massive spin degrees of freedom for the tensor fields, where the (even) value of t depends on the gauging. The kinetic term of the tensor fields is accompanied by a unique Chern-Simons coupling which involves both vector and tensor fields. The Lagrangians are completely encoded in terms of the embedding tensor which defines the E_6 subgroup that is gauged by the vectors. The embedding tensor is subject to two constraints which ensure the consistency of the combined vector-tensor gauge transformations and the supersymmetry of the full Lagrangian. This new formulation encompasses all possible gaugings.

  16. Constraint Propagation as Information Maximization

    Abdallah, A Nait


    Dana Scott used the partial order among partial functions for his mathematical model of recursively defined functions. He interpreted the partial order as one of information content. In this paper we elaborate on Scott's suggestion of regarding computation as a process of information maximization by applying it to the solution of constraint satisfaction problems. Here the method of constraint propagation can be interpreted as decreasing uncertainty about the solution -- that is, as gain in information about the solution. As illustrative example we choose numerical constraint satisfaction problems to be solved by interval constraints. To facilitate this approach to constraint solving we formulate constraint satisfaction problems as formulas in predicate logic. This necessitates extending the usual semantics for predicate logic so that meaning is assigned not only to sentences but also to formulas with free variables.

  17. The Optimal Golf Stroke

    Buchinger, Mikael; Durigen, Susan; Dahl, Johan Rambech


    The paper presents a preliminary investigation into aspects of the game of golf. A series of models is proposed for the golf stroke, the momentum transfer between club and ball and the flight of the ball.Numerical and asymptotic solutions are presented reproducing many of the features observed...... in the golf stroke of a professional golfer....

  18. Relational Processing Following Stroke

    Andrews, Glenda; Halford, Graeme S.; Shum, David; Maujean, Annick; Chappell, Mark; Birney, Damian


    The research examined relational processing following stroke. Stroke patients (14 with frontal, 30 with non-frontal lesions) and 41 matched controls completed four relational processing tasks: sentence comprehension, Latin square matrix completion, modified Dimensional Change Card Sorting, and n-back. Each task included items at two or three…

  19. Strokes (For Parents)

    ... the brain that's affected and the amount of damage the stroke causes. More likely, a parent first notices changes ... rehabilitation and therapy. previous continue Complications The brain damage that occurs during a stroke can cause a number of other problems that ...


    Gabriella Tantular


    Full Text Available Stroke adalah salah satu sindrom neurologi yang dapat menimbulkan kecacatan dalam kehidupanmanusia. Salah  satu gejala yang dapat  timbul  setelah  seseorang  terkena  stroke adalah gangguanmood. Gangguan mood berhubungan dengan disabilitas fisik, beratnya stroke dan gangguan kognitif.Gangguan mood yang ditemukan pada stroke adalah depresi, gangguan afektif bipolar dan mania.Gambaran  gejala  berhubungan dengan  lesi  anatomis  stroke. Terapi  yang diberikan dapat  berupafarmakologis, psikoterapi, dan rehabilitasi. [MEDICINA 2015;46:33-36].Stroke is one of neurology syndrome that cause disability in human life. One of the symptoms thatappear after stroke was mood disorder. Mood disorder were related to physical disability, severity ofstroke  and  cognitive  dysfunction. Mood  disorder  found  in  stroke was  depression,  affective  bipolardisorder, and mania. Symptoms were associated with anatomical lesion. Treatment for this disorderare pharmacologic treatment, psychotherapy, and rehabilitation. [MEDICINA 2015;46:33-36].

  1. The Danish Stroke Registry

    Johnsen, Søren Paaske; Ingeman, Annette; Hundborg, Heidi Holmager


    AIM OF DATABASE: The aim of the Danish Stroke Registry is to monitor and improve the quality of care among all patients with acute stroke and transient ischemic attack (TIA) treated at Danish hospitals. STUDY POPULATION: All patients with acute stroke (from 2003) or TIA (from 2013) treated...... at Danish hospitals. Reporting is mandatory by law for all hospital departments treating these patients. The registry included >130,000 events by the end of 2014, including 10,822 strokes and 4,227 TIAs registered in 2014. MAIN VARIABLES: The registry holds prospectively collected data on key processes...... of care, mainly covering the early phase after stroke, including data on time of delivery of the processes and the eligibility of the individual patients for each process. The data are used for assessing 18 process indicators reflecting recommendations in the national clinical guidelines for patients...

  2. Stroke risk factors among participants of a world stroke day ...


    Apr 20, 2015 ... stroke day awareness program in an urban area of Nigeria. Community ... of ischemic stroke was 1.64 in obese versus healthy subjects and 1.22 in .... Acute stroke mortality at Lagos University Teaching Hospital‑A five ... A review of stroke admissions at a tertiary hospital in rural Southwestern. Nigeria.

  3. Kinesthetic taping improves walking function in patients with stroke: a pilot cohort study.

    Boeskov, Birgitte; Carver, Line Tornehøj; von Essen-Leise, Anders; Henriksen, Marius


    Stroke is an important cause of severe disability and impaired motor function. Treatment modalities that improve motor function in patients with stroke are needed. The objective of this study was to investigate the effect of kinesthetic taping of the anterior thigh and knee on maximal walking speed and clinical indices of spasticity in patients with stroke. Thirty-two patients (9 women) receiving rehabilitation after stroke (average, 50 days since stroke) who had impaired walking ability were recruited. Primary outcome was maximal walking speed measured by the 10-meter walk test. Secondary outcomes were number of steps taken during the test and clinical signs of spasticity measured by the Tardieu Scale. Tests were conducted before and immediately after application of kinesthetic tape to the anterior thigh and knee of the paretic lower limb. After application of the tape, the maximal walking speed increased, on average, by 0.08 m/s (95% CI, 0.04 to 0.12; P stroke. Such a positive effect on motor function could be a valuable adjunct in physical therapy and rehabilitation of patients with stroke.

  4. Kinetic measurements of hand motor impairments after mild to moderate stroke using grip control tasks.

    Ye, Yu; Ma, Le; Yan, Tiebin; Liu, Huihua; Wei, Xijun; Song, Rong


    The aim of this study is to investigate quantitative outcome measurements of hand motor performance for subjects after mild to moderate stroke using grip control tasks and characterize abnormal flexion synergy of upper extremities after stroke. A customized dynamometer with force sensors was used to measure grip force and calculate rotation torque during the sub-maximal grip control tasks. The paretic and nonpartic sides of eleven subjects after stroke and the dominant sides of ten healthy persons were tested. Their maximal voluntary grip force was measured and used to set sub-maximal grip control tasks at three different target force levels. Force control ability was characterized by the maximal grip force, mean force percentage, coefficient of variation (CV), target deviation ratio (TDR), and rotation torque ratio (RTR). The motor impairments of subjects after stroke were also evaluated using the Fugl-Meyer assessment for upper extremity (FMA-UE) and Wolf Motor Function Test (WMFT). Maximal grip force of the paretic side was significantly reduced as compared to the nonparetic side and the healthy group, while the difference of maximal grip force between the nonparetic side and the healthy group was not significant. TDR and RTR increased for all three groups with increasing target force level. There were significant differences of CV, TDR and RTR between the paretic side and the healthy group at all the force levels. CV, TDR and RTR showed significant negative correlations with FMA-UE and WMFT at 50% of maximum grip force. This study designed a customized dynamometer together with an innovative measurement, RTR, to investigate the hand motor performance of subjects after mild to moderate stroke during force control tasks. And stroke-induced abnormal flexion synergy of wrist and finger muscles could be characterized by RTR. This study also identified a set of kinetic parameters which can be applied to quantitatively assess the hand motor function of subjects after

  5. Stroke and Women

    Gülçin Benbir


    Full Text Available OBJECTIVE: We aimed to investigate the differences in vascular risk factor and etiology of stroke in two sexes. METHODS: We reviewed the medical files of 2798 patients being followed-up in our Stroke Clinic between the years 1996-2011. The stroke subtypes and risk factors were recorded on the basis of clinical data, physical and neurological examinations, and neuroimaging findings. Data were collected in SPSS 11.5 system and Pearson chi-square and Mann-Whitney U tests were used for statistical analysis. RESULTS: Of a total of 2798 patients, 2564 patients (91,6% had ischemic stroke, and 234 of them (8,4% had hemorrhagic stroke. The mean follow-up duration was 50.2+42.7 months. Of whole study population, 1289 patients were women (46%, 1509 of them were men (54%. The analysis of stroke subtypes showed that the most common subtype was stroke of unknown etiology in both sexes. Following this, the most common subtype was atherothrombotic stroke in men, and cardioembolic stroke in women. Coronary heart disease was more common in men, while atrial fibrillation and other rhythm anomalies were more common in women. Smoking and alcohol consumption were more common in men. CONCLUSION: Our study showed that there are major differences in stroke subtypes and vascular risk factors. Better knowledge of these differences, as well as influencing factors, is of crucial value – in addition to the need of hormonal changes, pregnancy and depression to be better identified in women – for both primary and secondary prevention.

  6. Hospital Variation in Home-Time After Acute Ischemic Stroke: Insights From the PROSPER Study (Patient-Centered Research Into Outcomes Stroke Patients Prefer and Effectiveness Research).

    O'Brien, Emily C; Xian, Ying; Xu, Haolin; Wu, Jingjing; Saver, Jeffrey L; Smith, Eric E; Schwamm, Lee H; Peterson, Eric D; Reeves, Mathew J; Bhatt, Deepak L; Maisch, Lesley; Hannah, Deidre; Lindholm, Brianna; Olson, DaiWai; Prvu Bettger, Janet; Pencina, Michael; Hernandez, Adrian F; Fonarow, Gregg C


    Stroke survivors identify home-time as a high-priority outcome; there are limited data on factors influencing home-time and home-time variability among discharging hospitals. We ascertained home-time (ie, time alive out of a hospital, inpatient rehabilitation facility, or skilled nursing facility) at 90 days and 1-year post discharge by linking data from Get With The Guidelines-Stroke Registry patients (≥65 years) to Medicare claims. Using generalized linear mixed models, we estimated adjusted mean home-time for each hospital. Using linear regression, we examined associations between hospital characteristics and risk-adjusted home-time. We linked 156 887 patients with ischemic stroke at 989 hospitals to Medicare claims (2007-2011). Hospital mean home-time varied with an overall unadjusted median of 59.5 days over the first 90 days and 270.2 days over the first year. Hospital factors associated with more home-time over 90 days included higher annual stroke admission volume (number of ischemic stroke admissions per year); South, West, or Midwest geographic regions (versus Northeast); and rural location; 1-year patterns were similar. Lowest home-time quartile patients (versus highest) were more likely to be older, black, women, and have more comorbidities and severe strokes. Home-time variation decreased after risk adjustment (interquartile range, 57.4-61.4 days over 90 days; 266.3-274.2 days over 1 year). In adjusted analyses, increasing annual stroke volume and rural location were associated with significantly more home-time. In older ischemic stroke survivors, home-time post discharge varies by hospital annual stroke volume, severity of case-mix, and region. In adjusted analyses, annual ischemic stroke admission volume and rural location were associated with more home-time post stroke. © 2016 American Heart Association, Inc.

  7. Association of MTHFR C677T Genotype With Ischemic Stroke Is Confined to Cerebral Small Vessel Disease Subtype.

    Rutten-Jacobs, Loes C A; Traylor, Matthew; Adib-Samii, Poneh; Thijs, Vincent; Sudlow, Cathie; Rothwell, Peter M; Boncoraglio, Giorgio; Dichgans, Martin; Meschia, James; Maguire, Jane; Levi, Christopher; Rost, Natalia S; Rosand, Jonathan; Hassan, Ahamad; Bevan, Steve; Markus, Hugh S


    Elevated plasma homocysteine levels are associated with stroke. However, this might be a reflection of bias or confounding because trials have failed to demonstrate an effect from homocysteine lowering in stroke patients, although a possible benefit has been suggested in lacunar stroke. Genetic studies could potentially overcome these issues because genetic variants are inherited randomly and are fixed at conception. Therefore, we tested the homocysteine levels-associated genetic variant MTHFR C677T for association with magnetic resonance imaging-confirmed lacunar stroke and compared this with associations with large artery and cardioembolic stroke subtypes. We included 1359 magnetic resonance imaging-confirmed lacunar stroke cases, 1824 large artery stroke cases, 1970 cardioembolic stroke cases, and 14 448 controls, all of European ancestry. Furthermore, we studied 3670 ischemic stroke patients in whom white matter hyperintensities volume was measured. We tested MTHFR C677T for association with stroke subtypes and white matter hyperintensities volume. Because of the established association of homocysteine with hypertension, we additionally stratified for hypertension status. MTHFR C677T was associated with lacunar stroke (P=0.0003) and white matter hyperintensity volume (P=0.04), but not with the other stroke subtypes. Stratifying the lacunar stroke cases for hypertension status confirmed this association in hypertensive individuals (P=0.0002), but not in normotensive individuals (P=0.30). MTHFR C677T was associated with magnetic resonance imaging-confirmed lacunar stroke, but not large artery or cardioembolic stroke. The association may act through increased susceptibility to, or interaction with, high blood pressure. This heterogeneity of association might explain the lack of effect of lowering homocysteine in secondary prevention trials which included all strokes. © 2016 The Authors.

  8. Ipsilateral hippocampal atrophy is associated with long-term memory dysfunction after ischemic stroke in young adults.

    Schaapsmeerders, Pauline; van Uden, Inge W M; Tuladhar, Anil M; Maaijwee, Noortje A M; van Dijk, Ewoud J; Rutten-Jacobs, Loes C A; Arntz, Renate M; Schoonderwaldt, Hennie C; Dorresteijn, Lucille D A; de Leeuw, Frank-Erik; Kessels, Roy P C


    Memory impairment after stroke in young adults is poorly understood. In elderly stroke survivors memory impairments and the concomitant loss of hippocampal volume are usually explained by coexisting neurodegenerative disease (e.g., amyloid pathology) in interaction with stroke. However, neurodegenerative disease, such as amyloid pathology, is generally absent at young age. Accumulating evidence suggests that infarction itself may cause secondary neurodegeneration in remote areas. Therefore, we investigated the relation between long-term memory performance and hippocampal volume in young patients with first-ever ischemic stroke. We studied all consecutive first-ever ischemic stroke patients, aged 18-50 years, admitted to our academic hospital center between 1980 and 2010. Episodic memory of 173 patients was assessed using the Rey Auditory Verbal Learning Test and the Rey Complex Figure and compared with 87 stroke-free controls. Hippocampal volume was determined using FSL-FIRST, with manual correction. On average 10 years after stroke, patients had smaller ipsilateral hippocampal volumes compared with controls after left-hemispheric stroke (5.4%) and right-hemispheric stroke (7.7%), with most apparent memory dysfunctioning after left-hemispheric stroke. A larger hemispheric stroke was associated with a smaller ipsilateral hippocampal volume (b=-0.003, P<0.0001). Longer follow-up duration was associated with smaller ipsilateral hippocampal volume after left-hemispheric stroke (b=-0.028 ml, P=0.002) and right-hemispheric stroke (b=-0.015 ml, P=0.03). Our results suggest that infarction is associated with remote injury to the hippocampus, which may lower or expedite the threshold for cognitive impairment or even dementia later in life. © 2015 Wiley Periodicals, Inc.

  9. A CAD System for Hemorrhagic Stroke.

    Nowinski, Wieslaw L; Qian, Guoyu; Hanley, Daniel F


    Computer-aided detection/diagnosis (CAD) is a key component of routine clinical practice, increasingly used for detection, interpretation, quantification and decision support. Despite a critical need, there is no clinically accepted CAD system for stroke yet. Here we introduce a CAD system for hemorrhagic stroke. This CAD system segments, quantifies, and displays hematoma in 2D/3D, and supports evacuation of hemorrhage by thrombolytic treatment monitoring progression and quantifying clot removal. It supports seven-step workflow: select patient, add a new study, process patient's scans, show segmentation results, plot hematoma volumes, show 3D synchronized time series hematomas, and generate report. The system architecture contains four components: library, tools, application with user interface, and hematoma segmentation algorithm. The tools include a contour editor, 3D surface modeler, 3D volume measure, histogramming, hematoma volume plot, and 3D synchronized time-series hematoma display. The CAD system has been designed and implemented in C++. It has also been employed in the CLEAR and MISTIE phase-III, multicenter clinical trials. This stroke CAD system is potentially useful in research and clinical applications, particularly for clinical trials.

  10. Beeping a Maximal Independent Set

    Afek, Yehuda; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian


    We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot, beeping nodes receive no feedback, while silent nodes can only differentiate between none of its neighbors beeping, or at least one of its neighbors beeping. We start by proving a lower bound that shows that in this model, it is not possible to locally converge to an MIS in sub-polynomial time. We then study four different relaxations of the model which allow us to circumvent the lower bound and find an MIS in polylogarithmic time. First, we show that if a polynomial upper bound on the network size is known, it is possi...

  11. Maximal switchability of centralized networks

    Vakulenko, Sergei; Morozov, Ivan; Radulescu, Ovidiu


    We consider continuous time Hopfield-like recurrent networks as dynamical models for gene regulation and neural networks. We are interested in networks that contain n high-degree nodes preferably connected to a large number of N s weakly connected satellites, a property that we call n/N s -centrality. If the hub dynamics is slow, we obtain that the large time network dynamics is completely defined by the hub dynamics. Moreover, such networks are maximally flexible and switchable, in the sense that they can switch from a globally attractive rest state to any structurally stable dynamics when the response time of a special controller hub is changed. In particular, we show that a decrease of the controller hub response time can lead to a sharp variation in the network attractor structure: we can obtain a set of new local attractors, whose number can increase exponentially with N, the total number of nodes of the nework. These new attractors can be periodic or even chaotic. We provide an algorithm, which allows us to design networks with the desired switching properties, or to learn them from time series, by adjusting the interactions between hubs and satellites. Such switchable networks could be used as models for context dependent adaptation in functional genetics or as models for cognitive functions in neuroscience.

  12. A Maximally Supersymmetric Kondo Model

    Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; /Stanford U., Phys. Dept. /SLAC


    We study the maximally supersymmetric Kondo model obtained by adding a fermionic impurity to N = 4 supersymmetric Yang-Mills theory. While the original Kondo problem describes a defect interacting with a free Fermi liquid of itinerant electrons, here the ambient theory is an interacting CFT, and this introduces qualitatively new features into the system. The model arises in string theory by considering the intersection of a stack of M D5-branes with a stack of N D3-branes, at a point in the D3 worldvolume. We analyze the theory holographically, and propose a dictionary between the Kondo problem and antisymmetric Wilson loops in N = 4 SYM. We perform an explicit calculation of the D5 fluctuations in the D3 geometry and determine the spectrum of defect operators. This establishes the stability of the Kondo fixed point together with its basic thermodynamic properties. Known supergravity solutions for Wilson loops allow us to go beyond the probe approximation: the D5s disappear and are replaced by three-form flux piercing a new topologically non-trivial S3 in the corrected geometry. This describes the Kondo model in terms of a geometric transition. A dual matrix model reflects the basic properties of the corrected gravity solution in its eigenvalue distribution.

  13. Maximal exercise performance-impairing effects of simulated blast overpressure in sheep.

    Januszkiewicz, A J; Mundie, T G; Dodd, K T


    Lung contusion has been identified as a primary blast injury. These experiments addressed a fundamental and overt endpoint of primary blast injury, incapacitation (performance decrement). Respiration, hemodynamics, and blood gases were measured in sheep undergoing incremental exercise challenge before and 1 h after simulated blast exposure of the thorax. Pathologic examination of lung tissue was performed after exposure and exercise testing. Blast overpressure was simulated in the laboratory using a compressed air-driven shock tube. Three levels of lung injury (Levels 1-3, 'Trivial', 'Slight', and 'Moderate' injury, respectively) were examined for effects on maximal oxygen consumption (VO[2max]), an index of cardiorespiratory fitness. Resting hemodynamics and blood gases were relatively normal an hour after exposure, immediately before exercise. However, Levels 1-3 lung injury were associated with average 4.8, 29.9 and 49.3% VO(2max). decreases, respectively. These performance decrements for Levels 2 and 3 were significantly different from respective controls (non-exposed). Exercise caused significant hemoconcentration in sheep under control conditions, before exposure (resting 9.5 +/- 0.9, end-exercise 11.8 +/- 0.9 g/100 ml). Blast exposure resulted in average decreases of 4.9 +/- 3.4, 12.8 +/- 4.0, and 12.6 +/- 3.3% in exercise-induced hemoconcentration for Levels 1-3 injury, respectively. Normal exercise-induced hemodynamic increases were also attenuated after exposure. Levels 2 and 3 injury resulted in average 22.6 +/- 2.9 and 18.5 +/- 11.2% stroke volume decreases, and also 22.3 +/- 8.4 and 29.0 +/- 14.2% cardiac output decreases, respectively, during exercise. While blast lung pathology and pulmonary function changes could account for post-blast performance decrements, these experiments suggest that in sheep, early after exposure, diminished hemoconcentration and cardiac disfunction may also contribute to decreased exercise performance.

  14. Risks for Heart Disease & Stroke

    ... for Heart Disease & Stroke Risks for Heart Disease & Stroke About 1.5 million heart attacks and strokes happen every year in the United States. You ... some of your risks for heart disease and stroke, but you can manage many of your risks ...

  15. Third European Stroke Science Workshop

    Dichgans, Martin; Planas, Anna M.; Biessels, Geert Jan; van der Worp, Bart; Sudlow, Cathie; Norrving, B.; Lees, Kennedy; Mattle, Heinrich P.


    Lake Eibsee, Garmisch-Partenkirchen, November 19 to 21, 2015: The European Stroke Organization convened >120 stroke experts from 27 countries to discuss latest results and hot topics in clinical, translational, and basic stroke research. Since its inception in 2011, the European Stroke Science

  16. Volume inside old black holes

    Christodoulou, Marios; De Lorenzo, Tommaso


    Black holes that have nearly evaporated are often thought of as small objects, due to their tiny exterior area. However, the horizon bounds large spacelike hypersurfaces. A compelling geometric perspective on the evolution of the interior geometry was recently shown to be provided by a generally covariant definition of the volume inside a black hole using maximal surfaces. In this article, we expand on previous results and show that finding the maximal surfaces in an arbitrary spherically symmetric spacetime is equivalent to a 1 +1 geodesic problem. We then study the effect of Hawking radiation on the volume by computing the volume of maximal surfaces inside the apparent horizon of an evaporating black hole as a function of time at infinity: while the area is shrinking, the volume of these surfaces grows monotonically with advanced time, up to when the horizon has reached Planckian dimensions. The physical relevance of these results for the information paradox and the remnant scenarios are discussed.

  17. Dizziness in stroke

    M. V. Zamergrad


    Full Text Available Differential diagnosis of new-onset acute vestibular vertigo is chiefly made between vestibular neuronitis and stroke. Dizziness in stroke is usually accompanied by other focal neurological symptoms of brainstem and cerebellar involvement. However, stroke may appear as isolated vestibular vertigo in some cases. An analysis of history data and the results of neurovestibular examination and brain magnetic resonance imaging allows stroke to be diagnosed in patients with acute isolated dizziness. The treatment of patients with stroke-induced dizziness involves a wide range of medications for the reduction of the degree of dizziness and unsteadiness and for the secondary prevention of stroke. Vestibular rehabilitation is an important component of treatment. The paper describes an observation of a patient with poorly controlled hypertension, who developed new-onset acute systemic dizziness. Vestibular neuronitis might be presumed to be a peripheral cause of vestibular disorders, by taking into account the absence of additional obvious neurological symptoms (such as pareses, defective sensation, diplopia, etc. and the nature of nystagmus. However, intention tremor in fingernose and heel-knee tests on the left side, a negative Halmagyi test, and results of Romberg’s test could suggest that stroke was a cause ofdizziness.

  18. Imaging acute ischemic stroke.

    González, R Gilberto; Schwamm, Lee H


    Acute ischemic stroke is common and often treatable, but treatment requires reliable information on the state of the brain that may be provided by modern neuroimaging. Critical information includes: the presence of hemorrhage; the site of arterial occlusion; the size of the early infarct "core"; and the size of underperfused, potentially threatened brain parenchyma, commonly referred to as the "penumbra." In this chapter we review the major determinants of outcomes in ischemic stroke patients, and the clinical value of various advanced computed tomography and magnetic resonance imaging methods that may provide key physiologic information in these patients. The focus is on major strokes due to occlusions of large arteries of the anterior circulation, the most common cause of a severe stroke syndrome. The current evidence-based approach to imaging the acute stroke patient at the Massachusetts General Hospital is presented, which is applicable for all stroke types. We conclude with new information on time and stroke evolution that imaging has revealed, and how it may open the possibilities of treating many more patients. © 2016 Elsevier B.V. All rights reserved.

  19. Hyponatremia in stroke

    Sheikh Saleem


    Full Text Available Introduction: Hyponatremia is a common electrolyte disorder encountered in patients of neurological disorders which is usually either due to inappropriate secretion of Antidiuretic hormone (SIADH or cerebral salt wasting syndrome (CSWS. We conducted this study in a tertiary care hospital to determine the incidence and etiology of hyponatremia in patients of stroke admitted in the hospital. Materials and Methods: It was a prospective study done over a period of two years that included established cases of stroke diagnosed on the basis of clinical history, examination and neuroimaging. 1000 stoke patients were evaluated for hyponatremia (serum sodium <130 meq/l. The data was analysed using Chi-square test using SPSS (Statistical package for social science software. Results: Out of 1000 patients, 353 patients had hyponatremia. Out of this 353 patients, 238 (67% had SIADH and 115 (33% had CSWS. SIADH was seen in 83 patients who had ischemic stroke and 155 patients of hemorrhagic stroke. CSWS was found in 38 patients with ischemic stroke and 77 patients with hemorrhagic stroke. Statistical analysis revealed that hyponatremia significantly affects the outcome of stroke especially when it is due to CSWS rather than SIADH. Conclusion: Incidence of hyponatremia in our study population was 35%. In patients of hyponatremia 67% were having SIADH and 33% were having CSWS. Overall hyponatremia affected the outcome of stroke especially when caused by CSWS. Therefore close monitoring of serum sodium must be done in all patients who are admitted with stroke and efforts must be made to determine the cause of hyponatremia, in order to properly manage such patients thereby decreasing the mortality rate.

  20. Hyponatremia in stroke

    Saleem, Sheikh; Yousuf, Irfan; Gul, Azhara; Gupta, Satish; Verma, Sawan


    Introduction: Hyponatremia is a common electrolyte disorder encountered in patients of neurological disorders which is usually either due to inappropriate secretion of Antidiuretic hormone (SIADH) or cerebral salt wasting syndrome (CSWS). We conducted this study in a tertiary care hospital to determine the incidence and etiology of hyponatremia in patients of stroke admitted in the hospital. Materials and Methods: It was a prospective study done over a period of two years that included established cases of stroke diagnosed on the basis of clinical history, examination and neuroimaging. 1000 stoke patients were evaluated for hyponatremia (serum sodium <130 meq/l). The data was analysed using Chi-square test using SPSS (Statistical package for social science) software. Results: Out of 1000 patients, 353 patients had hyponatremia. Out of this 353 patients, 238 (67%) had SIADH and 115 (33%) had CSWS. SIADH was seen in 83 patients who had ischemic stroke and 155 patients of hemorrhagic stroke. CSWS was found in 38 patients with ischemic stroke and 77 patients with hemorrhagic stroke. Statistical analysis revealed that hyponatremia significantly affects the outcome of stroke especially when it is due to CSWS rather than SIADH. Conclusion: Incidence of hyponatremia in our study population was 35%. In patients of hyponatremia 67% were having SIADH and 33% were having CSWS. Overall hyponatremia affected the outcome of stroke especially when caused by CSWS. Therefore close monitoring of serum sodium must be done in all patients who are admitted with stroke and efforts must be made to determine the cause of hyponatremia, in order to properly manage such patients thereby decreasing the mortality rate. PMID:24753660

  1. [Obesity Paradox and Stroke].

    Baumgartner, Ralf; Oesch, Lisa; Sarikaya, Hakan


    The obesity paradox suggests that overweight and obese patients of older age may have higher survival rates after stroke as compared to normalweight patients. However, the results need a cautious interpretation due to selection bias, treatment bias and different patients’ characteristics. Moreover, randomized studies that prove a benefit of weight reduction are still lacking. As obesity is an independet risk factor for stroke, weight reduction should still be recommended in overweight patients. Randomized-controlled studies are needed to prove the effect of weight reduction on morbidity and mortality after stroke.

  2. Sleep and Stroke.

    Mims, Kimberly Nicole; Kirsch, Douglas


    Evidence increasingly suggests sleep disorders are associated with higher risk of cardiovascular events, including stroke. Strong data correlate untreated sleep apnea with poorer stroke outcomes and more recent evidence implicates sleep disruption as a possible etiology for increased cerebrovascular events. Also, sleep duration may affect incidence of cardiovascular events. In addition, sleep-disordered breathing, insomnia, restless legs syndrome, and parasomnias can occur as a result of cerebrovascular events. Treatment of sleep disorders improve sleep-related symptoms and may also improve stroke recovery and risk of future events.

  3. Strokes in mitochondrial diseases

    N V Pizova


    Full Text Available It is suggested that mitochondrial diseases might be identified in 22—33% of cryptogenic stroke cases in young subjects. The incidence of mitochondrial disorders in patients with stroke is unknown; it is 0.8 to 7.2% according to the data of some authors. The paper gives data on the prevalence, pathogenesis, and clinical manifestations of mitochondrial diseases, such as mitochondrial encephalopathy, lactic acidosis, and stroke-like syndrome (MELAS and insulin-like episodes; myoclonic epilepsy and ragged-red fibers (MERRF syndrome, and Kearns-Sayre syndrome (sporadic multisystem mitochondrial pathology.

  4. Neuromuscular fatigue after maximal exercise in patients with cystic fibrosis.

    Vallier, J M; Gruet, M; Mely, L; Pensini, M; Brisswalter, J


    The aim of this study was to determine whether patients with cystic fibrosis (CF), despite their ventilatory limitation, would develop neuromuscular fatigue of quadriceps muscles following a maximal cycling exercise. Eleven adults with CF (age=26.8±6.9years; forced expiratory volume in 1s=54.1±12.8% predicted) and 11 age-matched healthy subjects performed a maximal incremental cycle test with respiratory gas exchange measurements. Maximal voluntary contraction (MVC) and electromyographic (EMG) activity of the vastus medialis muscle were recorded before and after exercise. Neural and contractile properties of the quadriceps were also investigated using femoral nerve electrical stimulation. Patients had lower exercise capacity, peak oxygen uptake and MVC than controls. MVC fell significantly postexercise in both groups (CF: -20±10%, controls: -19±6%; ppattern (-38.4±14.4%, -42.1±14.7% and -15±20.4%) but the statistical significance was not reached for the maximal rate of twitch torque relaxation. In conclusion, CF patients demonstrated lower limb fatigue following symptom-limited cycle exercise, which was comparable to that exhibited by healthy controls. This fatigue may be due to contractile impairments and not to transmission failure. Further studies should be conducted in a larger sample to confirm these preliminary results.

  5. Optoelectronic plethysmography compared to spirometry during maximal exercise.

    Layton, Aimee M; Moran, Sienna L; Garber, Carol Ewing; Armstrong, Hilary F; Basner, Robert C; Thomashow, Byron M; Bartels, Matthew N


    The purpose of this study was to compare simultaneous measurements of tidal volume (Vt) by optoelectronic plethysmography (OEP) and spirometry during a maximal cycling exercise test to quantify possible differences between methods. Vt measured simultaneously by OEP and spirometry was collected during a maximal exercise test in thirty healthy participants. The two methods were compared by linear regression and Bland-Altman analysis at submaximal and maximal exercise. The average difference between the two methods and the mean percentage discrepancy were calculated. Submaximal exercise (SM) and maximal exercise (M) Vt measured by OEP and spirometry had very good correlation, SM R=0.963 (pspirometry. OEP could measure exercise Vt as much as 0.188 L above and -0.017 L below that of spirometry. The discrepancy between measurements was -2.0 ± 7.2% at SM and -2.4 ± 3.9% at M. In conclusion, Vt measurements at during exercise by OEP and spirometry are closely correlated and the difference between measurements was insignificant.

  6. Society of Vascular and Interventional Neurology (SVIN) Stroke Interventional Laboratory Consensus (SILC) Criteria: A 7M Management Approach to Developing a Stroke Interventional Laboratory in the Era of Stroke Thrombectomy for Large Vessel Occlusions.

    Shams, Tanzila; Zaidat, Osama; Yavagal, Dileep; Xavier, Andrew; Jovin, Tudor; Janardhan, Vallabh


    Brain attack care is rapidly evolving with cutting-edge stroke interventions similar to the growth of heart attack care with cardiac interventions in the last two decades. As the field of stroke intervention is growing exponentially globally, there is clearly an unmet need to standardize stroke interventional laboratories for safe, effective, and timely stroke care. Towards this goal, the Society of Vascular and Interventional Neurology (SVIN) Writing Committee has developed the Stroke Interventional Laboratory Consensus (SILC) criteria using a 7M management approach for the development and standardization of each stroke interventional laboratory within stroke centers. The SILC criteria include: (1) manpower: personnel including roles of medical and administrative directors, attending physicians, fellows, physician extenders, and all the key stakeholders in the stroke chain of survival; (2) machines: resources needed in terms of physical facilities, and angiography equipment; (3) materials: medical device inventory, medications, and angiography supplies; (4) methods: standardized protocols for stroke workflow optimization; (5) metrics (volume): existing credentialing criteria for facilities and stroke interventionalists; (6) metrics (quality): benchmarks for quality assurance; (7) metrics (safety): radiation and procedural safety practices.

  7. Efecto de la maniobra inspiratoria y de la hiperinsuflación pulmonar en los flujos espiratorios máximos en pacientes con fibrosis quística EFFECT OF INSPIRATORY MANEUVER AND LUNG HYPERINFLATION ON MAXIMAL EXPIRATORY FLOW-VOLUME CURVES IN CYSTIC FIBROSIS PATIENTS



    Full Text Available El tiempo inspiratorio previo a la realización de una maniobra espiratoria forzada máxima (FEM es una variable que no ha sido completamente estudiada en Fibrosis Quística (FQ. El objetivo de este estudio fue evaluar la hipótesis que niños con FQ tendrían mayores volúmenes y flujos espiratorios forzados al disminuir la duración del tiempo inspiratorio. Se estudiaron 16 niños con FQ, en etapa estable, sin haber presentado una exacerbación respiratoria en los últimos dos meses, (10 hombres, de edad 11,9 ± 0,7 años (promedio ± ES, con un FEV1 de 62,8 ± 6,4% predicho. Las pruebas de función pulmonar consistieron en la medición de volúmenes pulmonares estáticos y resistencia de la vía aérea, seguido de evaluación dinámica de la función pulmonar. Esta última medición fue precedida de 3 maniobras inspiratorias diferentes en forma aleatoria [inspiración y detención de 0 segundos (M0, 2 segundos (M2 o 5 segundos (M5]. El grupo se dividió en pacientes con hiperinsuflación pulmonar detectada por VR/CPT > 30%, (n = 9 y sin hiperinsuflación pulmonar RV/CPT The time course of the inspiration preceding the maximal forced expiratory maneuver (MFEM has not been studied in cystic fibrosis (CF. We tested the hypothesis that CF children would have significantly higher forced expiratory volumes (FVC and flows with decreasing duration of the inspiratory breathhold. We studied 16 stable CF patients (10 males with no pulmonary exacerbation 2 months prior to the study, aged 11.9 ± 0.7 years (mean ± SEM with a FEV1 of 62.8 ± 6.4% predicted. Pulmonary function tests included static lung volume and airway resistance measurements, followed by dynamic lung function measurements. The latter were preceded by 3 different inspiratory maneuvers in a random order [breathhold of 0 (M0, 2 (M2 or 5 seconds (M5]. Patients were divided by the presence of lung hyperinflation (RV/TLC > 30%, with 9 children with hyperinflation and 7 no

  8. Branes in the GL(1 vertical stroke 1) WZNW-Model

    Creutzig, T.; Schomerus, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Quella, T. [Amsterdam Univ. (Netherlands). KdV Inst. for Mathematics


    We initiate a systematic study of boundary conditions in conformal field theories with target space supersymmetry. The WZNW model on GL(1 vertical stroke 1) is used as a prototypical example for which we find the complete set of maximally symmetric branes. This includes a unique brane of maximal super-dimension 2 vertical stroke 2, a 2-parameter family of branes with super-dimension 0 vertical stroke 2 and an infinite set of fully localized branes possessing a single modulus. Members of the latter family can only exist along certain lines on the bosonic base, much like fractional branes at orbifold singularities. Our results establish that all essential algebraic features of Cardy-type boundary theories carry over to the non-rational logarithmic WZNW model on GL(1 vertical stroke 1). (orig.)

  9. World Stroke Organization global stroke services guidelines and action plan.

    Lindsay, Patrice; Furie, Karen L; Davis, Stephen M; Donnan, Geoffrey A; Norrving, Bo


    Every two seconds, someone across the globe suffers a symptomatic stroke. 'Silent' cerebrovascular disease insidiously contributes to worldwide disability by causing cognitive impairment in the elderly. The risk of cerebrovascular disease is disproportionately higher in low to middle income countries where there may be barriers to stroke care. The last two decades have seen a major transformation in the stroke field with the emergence of evidence-based approaches to stroke prevention, acute stroke management, and stroke recovery. The current challenge lies in implementing these interventions, particularly in regions with high incidences of stroke and limited healthcare resources. The Global Stroke Services Action Plan was conceived as a tool to identifying key elements in stroke care across a continuum of health models. At the minimal level of resource availability, stroke care delivery is based at a local clinic staffed predominantly by non-physicians. In this environment, laboratory tests and diagnostic studies are scarce, and much of the emphasis is placed on bedside clinical skills, teaching, and prevention. The essential services level offers access to a CT scan, physicians, and the potential for acute thrombolytic therapy, however stroke expertise may still be difficult to access. At the advanced stroke services level, multidisciplinary stroke expertise, multimodal imaging, and comprehensive therapies are available. A national plan for stroke care should incorporate local and regional strengths and build upon them. This clinical practice guideline is a synopsis of the core recommendations and quality indicators adapted from ten high quality multinational stroke guidelines. It can be used to establish the current level of stroke services, target goals for expanding stroke resources, and ensuring that all stages of stroke care are being adequately addressed, even at the advanced stroke services level. This document is a start, but there is more to be done

  10. Maximal inequalities for demimartingales and their applications

    WANG XueJun; HU ShuHe


    In this paper,we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides.The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob's type maximal inequality for demimartingales,strong laws of large numbers and growth rate for demimartingales and associated random variables.At last,we give an equivalent condition of uniform integrability for demisubmartingales.

  11. Maximal inequalities for demimartingales and their applications


    In this paper, we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides. The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob’s type maximal inequality for demimartingales, strong laws of large numbers and growth rate for demimartingales and associated random variables. At last, we give an equivalent condition of uniform integrability for demisubmartingales.

  12. Task-oriented maximally entangled states

    Agrawal, Pankaj; Pradhan, B, E-mail: agrawal@iopb.res.i, E-mail: bpradhan@iopb.res.i [Institute of Physics, Sachivalaya Marg, Bhubaneswar, Orissa 751 005 (India)


    We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.

  13. Cost of stroke

    Jennum, Poul; Iversen, Helle K; Ibsen, Rikke


    BACKGROUND: To estimate the direct and indirect costs of stroke in patients and their partners. DESCRIPTION: Direct and indirect costs were calculated using records from the Danish National Patient Registry from 93,047 ischemic, 26,012 hemorrhagic and 128,824 unspecified stroke patients...... and compared with 364,433, 103,741 and 500,490 matched controls, respectively. RESULTS: Independent of age and gender, stroke patients had significantly higher rates of mortality, health-related contacts, medication use and lower employment, lower income and higher social-transfer payments than controls....... The attributable cost of direct net health care costs after the stroke (general practitioner services, hospital services, and medication) and indirect costs (loss of labor market income) were €10,720, €8,205 and €7,377 for patients, and €989, €1,544 and €1.645 for their partners, over and above that of controls...

  14. A Stroke of Language

    Blaisdell, Bob


    The author reflects on foreign-language learning by his EFL students as well as his own foreign-language learning. He concludes by musing on the possible and fantastical devastation on language-ability wrought by strokes.

  15. Inflation in maximal gauged supergravities

    Kodama, Hideo [Theory Center, KEK,Tsukuba 305-0801 (Japan); Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801 (Japan); Nozawa, Masato [Dipartimento di Fisica, Università di Milano, and INFN, Sezione di Milano,Via Celoria 16, 20133 Milano (Italy)


    We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of SO(4,4) and SO(5,3) dyonic gaugings, for which the base point of the scalar manifold corresponds to an unstable de Sitter critical point. In the gauge-field frame where the embedding tensor takes the value in the sum of the 36 and 36’ representations of SL(8), we present a scheme that allows us to derive an analytic expression for the scalar potential. With the help of this formalism, we derive the full potential and gauge coupling functions in analytic forms for the SO(3)×SO(3)-invariant subsectors of SO(4,4) and SO(5,3) gaugings, and argue that there exist no new critical points in addition to those discovered so far. For the SO(4,4) gauging, we also study the behavior of 6-dimensional scalar fields in this sector near the Dall’Agata-Inverso de Sitter critical point at which the negative eigenvalue of the scalar mass square with the largest modulus goes to zero as the deformation parameter s approaches a critical value s{sub c}. We find that when the deformation parameter s is taken sufficiently close to the critical value, inflation lasts more than 60 e-folds even if the initial point of the inflaton allows an O(0.1) deviation in Planck units from the Dall’Agata-Inverso critical point. It turns out that the spectral index n{sub s} of the curvature perturbation at the time of the 60 e-folding number is always about 0.96 and within the 1σ range n{sub s}=0.9639±0.0047 obtained by Planck, irrespective of the value of the η parameter at the critical saddle point. The tensor-scalar ratio predicted by this model is around 10{sup −3} and is close to the value in the Starobinsky model.

  16. Tetrafluoroethane (R134a) hydrate formation within variable volume reactor accompanied by evaporation and condensation

    Jeong, K.; Choo, Y. S.; Hong, H. J.; Yoon, Y. S.; Song, M. H., E-mail: [Department of Mechanical, Robotics, and Energy Engineering, Dongguk University, Seoul 100-715 (Korea, Republic of)


    Vast size hydrate formation reactors with fast conversion rate are required for the economic implementation of seawater desalination utilizing gas hydrate technology. The commercial target production rate is order of thousand tons of potable water per day per train. Various heat and mass transfer enhancement schemes including agitation, spraying, and bubbling have been examined to maximize the production capacities in scaled up design of hydrate formation reactors. The present experimental study focused on acquiring basic knowledge needed to design variable volume reactors to produce tetrafluoroethane hydrate slurry. Test vessel was composed of main cavity with fixed volume of 140 ml and auxiliary cavity with variable volume of 0 ∼ 64 ml. Temperatures at multiple locations within vessel and pressure were monitored while visual access was made through front window. Alternating evaporation and condensation induced by cyclic volume change provided agitation due to density differences among water and vapor, liquid and hydrate R134a as well as extended interface area, which improved hydrate formation kinetics coupled with latent heat release and absorption. Influences of coolant temperature, piston stroke/speed, and volume change period on hydrate formation kinetics were investigated. Suggestions of reactor design improvement for future experimental study are also made.

  17. Endocarditis and stroke.

    Grecu, Nicolae; Tiu, Cristina; Terecoasa, Elena; Bajenaru, Ovidiu


    Endocarditis is an important, although less common, cause of cerebral embolism. All forms of endocarditis share an initial common pathophysiologic pathway, best illustrated by the non-bacterial thrombotic form, but also a final potential for embolization. Stroke associated with endocarditis has signifficant mortality and morbidity rates, especially due to the frequent concomitant multiple sites of brain embolization. In this article we aim to briefly review endocarditis with a focus on stroke as a complication, while also presenting case correlates from our department.

  18. Effect of lung protection strategy on stroke volume variation in patients undergoing open-chest operation%肺保护策略对胸外科手术患者每搏量变异度的影响

    陆珠凤; 葛圣金; 薛张纲; 邓小明


    目的 探讨肺保护策略对择期行胸外科手术患者每搏量变异度(SVV)的影响.方法 选择20例择期行开胸手术的患者,ASA分级Ⅰ~Ⅱ级,均无术前用药.研究患者清醒平卧位自主呼吸(T1)、清醒侧卧位自主呼吸(T2)、单纯全麻平卧位双肺通气(T3)、单纯全麻平卧位肺保护策略下单肺通气(T4)、单纯全麻侧卧位双肺通气(T5)、单纯全麻侧卧位肺保护策略下单肺通气(T6)、联合麻醉肺保护策略下单肺通气切皮时(T7)以及联合麻醉肺保护策略下单肺通气切开胸膜时(T8)的心率(HR)、平均动脉压(MAP)、SVV、心脏指数(CI)4个血流动力学指标的变化,以及SVV变化与HR、MAP、CI的相关性.4个指标数据组内采用单因素方差分析,根据方差齐性检验结果决定进一步统计学检验方案,4个数据组间采用Pearson相关分析.结果 单因素方差分析结果显示,T1~T8时间点SVV、HR变化差异无统计学意义(P>0.05),MAP、CI的变化差异有统计学意义(P<0.05);方差齐性LSD多重比较结果显示,SVV在T2时间点与T5时间点之间,CI在T1时间点与T3~T8时间点之间,CI在T2时间点与T4时间点、T6~T8时间点之间,MAP在T1时间点与T3~T4时间点、T6~T8时间点之间,MAP在T2时间点与T3~T4时间点、T6~T8时间点之间,MAP在T4时间点与T5时间点之间差异有统计学意义(P<0.05).相关分析结果显示SVV与CI呈负相关(r=-0.267,P=0.018).结论 术前无容量不足的患者体位改变(从仰卧位到侧卧位)对SVV和HR无显著影响;肺保护策略下单肺通气对SVV、HR、MAP和CI均无显著影响;麻醉因素可引起MAP和CI明显下降,且麻醉状态下被动翻身动作可引起MAP和CI升高,SVV变化与CI呈负相关,但相关性较弱.%Objective To investigate the effect of lung-protective ventilation mode on stroke volume variation (SVV) in patients receiving selected thoracotomy. Methods Twenty patients of the American

  19. Nursing care for stroke patients

    Tulek, Zeliha; Poulsen, Ingrid; Gillis, Katrin


    AIMS AND OBJECTIVES: To conduct a survey of the clinical nursing practice in European countries in accordance with the European Stroke Strategies (ESS) 2006, and to examine to what extent the ESS have been implemented in stroke care nursing in Europe. BACKGROUND: Stroke is a leading cause of death...... comprising 61 questions based on the ESS and scientific evidence in nursing practice was distributed to representatives of the European Association of Neuroscience Nurses, who sent the questionnaire to nurses active in stroke care. The questionnaire covered the following areas of stroke care: Organization...... of stroke services, Management of acute stroke and prevention including basic care and nursing, and Secondary prevention. RESULTS: Ninety-two nurses in stroke care in 11 European countries participated in the survey. Within the first 48 hours after stroke onset, 95% monitor patients regularly, 94% start...

  20. Possible Anandamide and Palmitoylethanolamide involvement in human stroke

    Pizzolato Gilberto


    Full Text Available Abstract Background Endocannabinoids (eCBs are ubiquitous lipid mediators that act on specific (CB1, CB2 and non-specific (TRPV1, PPAR receptors. Despite many experimental animal studies proved eCB involvement in the pathogenesis of stroke, such evidence is still lacking in human patients. Our aim was to determine eCB peripheral levels in acute stroke patients and evaluate their relationship with clinical disability and stroke volume. Methods A cohort of ten patients with a first acute (within six hours since symptoms onset ischemic stroke and a group of eight age- and sex-matched normal subjects were included. Groups were also matched for metabolic profile. All subjects underwent a blood sample collection for anandamide (AEA, 2-arachidonoylglycerol (2-AG and palmitoylethanolamide (PEA measurement; blood sampling was repeated in patients on admission (T0, at 6 (T1 and 18 hours (T2 thereafter. Patients neurological impairment was assessed using NIHSS and Fugl-Meyer Scale arm subitem (FMSa; stroke volume was determined on 48 h follow-up brain CT scans. Blood samples were analyzed by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry. Results 1T0 AEA levels were significantly higher in stroke patients compared to controls. 2A significant inverse correlation between T0 AEA levels and FMSa score was found. Moreover a positive correlation between T0 AEA levels and stroke volume were found in stroke patients. T0 PEA levels in stroke patients were not significantly different from the control group, but showed a significant correlation with the NIHSS scores. T0 2-AG levels were lower in stroke patients compared to controls, but such difference did not reach the significance threshold. Conclusions This is the first demonstration of elevated peripheral AEA levels in acute stroke patients. In agreement with previous murine studies, we found a significant relationship between AEA or PEA levels and neurological involvement, such

  1. Can fully automated detection of corticospinal tract damage be used in stroke patients?

    Leff, Alexander P.; Seghier, Mohamed L.; Kou, Nancy; Park, Chang-hyun; Ward, Nick S.


    We compared manual infarct definition, which is time-consuming and open to bias, with an automated abnormal tissue detection method in measuring corticospinal tract-infarct overlap volumes in chronic stroke patients to help predict motor outcome.

  2. Finite Element Modeling of scattered electromagnetic waves for stroke analysis.

    Priyadarshini, N; Rajkumar, E R


    Stroke has become one of the leading causes of mortality worldwide and about 800 in every 100,000 people suffer from stroke each year. The occurrence of stroke is ranked third among the causes of acute death and first among the causes for neurological dysfunction. Currently, Neurological examinations followed by medical imaging with CT, MRI or Angiography are used to provide better identification of the location and the type of the stroke, however they are neither fast, cost-effective nor portable. Microwave technology has emerged to complement these modalities to diagnose stroke as it is sensitive to the differences between the distinct dielectric properties of the brain tissues and blood. This paper investigates the possibility of diagnosing the type of stroke using Finite Element Analysis (FEA). The object of interest is a simulated head phantom with stroke, created with its specifying material characteristics like electrical conductivity and relative permittivity. The phantom is then placed in an electromagnetic field generated by a dipole antenna radiating at 1 GHz. The FEM forward model solver computes the scattered electromagnetic field by finding the solution for the Maxwell's wave equation in the head volume. Subsequently the inverse scattering problem is solved using the Contrast Source Inversion (CSI) method to reconstruct the dielectric profile of the head phantom.

  3. Volume control device for digital signals

    Schinkel, Daniel; van Tuijl, Adrianus Johannes Maria; Nuijten, Petrus A.C.M.


    A digital volume control device comprises a logic unit for volume control of digital input signals. Successively supplied m-bits words with maximally k bits active, derived from the output signals of or supplied by a volume control (4) with a quantizer (5) element the filtered m-bits workds are

  4. Computing Maximally Supersymmetric Scattering Amplitudes

    Stankowicz, James Michael, Jr.

    This dissertation reviews work in computing N = 4 super-Yang--Mills (sYM) and N = 8 maximally supersymmetric gravity (mSUGRA) scattering amplitudes in D = 4 spacetime dimensions in novel ways. After a brief introduction and overview in Ch. 1, the various techniques used to construct amplitudes in the remainder of the dissertation are discussed in Ch. 2. This includes several new concepts such as d log and pure integrand bases, as well as how to construct the amplitude using exactly one kinematic point where it vanishes. Also included in this chapter is an outline of the Mathematica package on shell diagrams and numerics.m (osdn) that was developed for the computations herein. The rest of the dissertation is devoted to explicit examples. In Ch. 3, the starting point is tree-level sYM amplitudes that have integral representations with residues that obey amplitude relations. These residues are shown to have corresponding residue numerators that allow a double copy prescription that results in mSUGRA residues. In Ch. 4, the two-loop four-point sYM amplitude is constructed in several ways, showcasing many of the techniques of Ch. 2; this includes an example of how to use osdn. The two-loop five-point amplitude is also presented in a pure integrand representation with comments on how it was constructed from one homogeneous cut of the amplitude. On-going work on the two-loop n-point amplitude is presented at the end of Ch. 4. In Ch. 5, the three-loop four-point amplitude is presented in the d log representation and in the pure integrand representation. In Ch. 6, there are several examples of four- through seven-loop planar diagrams that illustrate how considerations of the singularity structure of the amplitude underpin dual-conformal invariance. Taken with the previous examples, this is additional evidence that the structure known to exist in the planar sector extends to the full theory. At the end of this chapter is a proof that all mSUGRA amplitudes have a pole at

  5. 对脑卒中偏瘫患者阶段康复护理的体会%Rehabilitation nursing experiences of patients with paralysis after stroke



    @@ BACKGROUND:Because disease course of stroke was long,directed nursing was undertaken to different mental and physiological manifestations to restore function at maximal degree and reduce incidence of disability.

  6. Stroke risk perception among participants of a stroke awareness campaign

    Heuschmann Peter U


    Full Text Available Abstract Background Subjective risk factor perception is an important component of the motivation to change unhealthy life styles. While prior studies assessed cardiovascular risk factor knowledge, little is known about determinants of the individual perception of stroke risk. Methods Survey by mailed questionnaire among 1483 participants of a prior public stroke campaign in Germany. Participants had been informed about their individual stroke risk based on the Framingham stroke risk score. Stroke risk factor knowledge, perception of lifetime stroke risk and risk factor status were included in the questionnaire, and the determinants of good risk factor knowledge and high stroke risk perception were identified using logistic regression models. Results Overall stroke risk factor knowledge was good with 67–96% of the participants recognizing established risk factors. The two exceptions were diabetes (recognized by 49% and myocardial infarction (57%. Knowledge of a specific factor was superior among those affected by it. 13% of all participants considered themselves of having a high stroke risk, 55% indicated a moderate risk. All major risk factors contributed significantly to the perception of being at high stroke risk, but the effects of age, sex and education were non-significant. Poor self-rated health was additionally associated with high individual stroke risk perception. Conclusion Stroke risk factor knowledge was high in this study. The self perception of an increased stroke risk was associated with established risk factors as well as low perception of general health.

  7. Relearning the Basics: Rehabilitation after a Stroke

    ... of this page please turn Javascript on. Feature: Stroke Rehabilitation Relearning the Basics: Rehabilitation After a Stroke Past ... to help them recover successfully. What is post-stroke rehabilitation? Rehab helps stroke survivors relearn skills lost to ...

  8. The multilevel four-stroke swap engine and its environment

    Uzdin, Raam; Kosloff, Ronnie


    A multilevel four-stroke engine where the thermalization strokes are generated by unitary collisions with thermal bath particles is analyzed. Our model is solvable even when the engine operates far from thermal equilibrium and in the strong system-bath coupling. Necessary operation conditions for the heat machine to perform as an engine or a refrigerator are derived. We relate the work and efficiency of the device to local and non-local statistical properties of the baths (purity, index of coincidence, etc) and put upper bounds on these quantities. Finally, in the ultra-hot regime, we analytically optimize the work and find a striking similarity to results obtained for efficiency at maximal power of classical engines. The complete swap limit of our results holds for any four-stroke quantum Otto engine that is coupled to the baths for periods that are significantly longer than the thermal relaxation time.

  9. Preliminary investigation of cardiopulmonary function in stroke patients with stable heart failure and exertional dyspnea

    Liaw, Mei-Yun; Wang, Lin-Yi; Pong, Ya-Ping; Tsai, Yu-Chin; Huang, Yu-Chi; Yang, Tsung-Hsun; Lin, Meng-Chih


    Abstract The aim of this study was to investigate the relationships between pulmonary function, respiratory muscle strength, perceived dyspnea, degree of fatigue, and activity of daily living with motor function and neurological status in stroke patients with stable congestive heart failure (CHF). This was a cohort study in a tertiary care medical center. Stroke patients with CHF and exertional dyspnea (New York Heart Association class I–III) were recruited. The baseline characteristics included duration of disease, Brunnstrom stage, spirometry, resting heart rate, resting oxyhemoglobin saturation (SpO2), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), Borg scale, fatigue scale, and Barthel index. A total of 47 stroke patients (24 males, 23 females, mean age 65.9 ± 11.5 years) were included. The average Brunnstrom stages of affected limbs were 3.6 ± 1.3 over the proximal parts and 3.5 ± 1.4 over the distal parts of upper limbs, and 3.9 ± 0.9 over lower limbs. The average forced vital capacity (FVC) was 2.0 ± 0.8 L, with a predicted FVC% of 67.9 ± 18.8%, forced expiratory volume in the first second (FEV1) of 1.6 ± 0.7 L, predicted FEV1% of 70.6 ± 20.1%, FEV1/FVC of 84.2 ± 10.5%, and maximum mid-expiratory flow of 65.4 ± 29.5%. The average MIP and MEP were −52.9 ± 33.3 cmH2O and 60.8 ± 29.0 cmH2O, respectively. The Borg scale was 1.5 ± 0.8. MIP was negatively associated with the average Brunnstrom stage of the proximal (r = −0.318, P lower extremities (r = −0.288, P lower extremities (r = −0.311, P limbs. FVC was more strongly associated with MIP and MEP than predicted FVC%. FEV1/FVC may be used as a reference for the pulmonary dysfunction. PMID:27749577

  10. Are all maximally entangled states pure?

    Cavalcanti, D; Terra-Cunha, M O


    In this Letter we study if all maximally entangled states are pure through several entanglement monotones. Our conclusions allow us to generalize the idea of monogamy of entanglement. Then we propose a polygamy of entanglement, which express that if a general multipartite state is maximally entangled it is necessarily factorized by any other system.

  11. Sampling and Representation Complexity of Revenue Maximization

    Dughmi, Shaddin; Han, Li; Nisan, Noam


    We consider (approximate) revenue maximization in auctions where the distribution on input valuations is given via "black box" access to samples from the distribution. We observe that the number of samples required -- the sample complexity -- is tightly related to the representation complexity of an approximately revenue-maximizing auction. Our main results are upper bounds and an exponential lower bound on these complexities.

  12. New Maximal Two-distance Sets

    Lisonek, Petr


    our classifications confirmthe maximality of previously known sets, the results in E^7 and E^8are new. Their counterpart in dimension larger than 10is a set of unit vectors with only two values of inner products in the Lorentz space R^{d,1}.The maximality of this set again follows from a bound due...

  13. An ethical justification of profit maximization

    Koch, Carsten Allan


    In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing b...

  14. Alternative trailer configurations for maximizing payloads

    Jason D. Thompson; Dana Mitchell; John Klepac


    In order for harvesting contractors to stay ahead of increasing costs, it is imperative that they employ all options to maximize productivity and efficiency. Transportation can account for half the cost to deliver wood to a mill. Contractors seek to maximize truck payload to increase productivity. The Forest Operations Research Unit, Southern Research Station, USDA...

  15. Cohomology of Weakly Reducible Maximal Triangular Algebras

    董浙; 鲁世杰


    In this paper, we introduce the concept of weakly reducible maximal triangular algebras φwhich form a large class of maximal triangular algebras. Let B be a weakly closed algebra containing 5φ, we prove that the cohomology spaces Hn(φ, B) (n≥1) are trivial.

  16. Stroke prevention in atrial fibrillation

    Freedman, Ben; Potpara, Tatjana S; Lip, Gregory Y H


    Atrial fibrillation is found in a third of all ischaemic strokes, even more after post-stroke atrial fibrillation monitoring. Data from stroke registries show that both unknown and untreated or under treated atrial fibrillation is responsible for most of these strokes, which are often fatal...... or debilitating. Most could be prevented if efforts were directed towards detection of atrial fibrillation before stroke occurs, through screening or case finding, and treatment of all patients with atrial fibrillation at increased risk of stroke with well-controlled vitamin K antagonists or non-vitamin K...

  17. Multimodal MR examination in acute ischemic stroke

    Mezzapesa, D.M.; Petruzzellis, M.; Lucivero, V.; Prontera, M.; Tinelli, A.; Sancilio, M.; Carella, A.; Federico, F. [University of Bari, Department of Neurological and Psychiatric Sciences, Bari (Italy)


    In recent years, combined diffusion-weighted imaging (DWI) with perfusion imaging (PI) has become an important investigational tool in the acute phase of ischemic stroke, as it may differentiate reversible from irreversible brain tissue damage. We consecutively examined 20 subjects within 12 h of stroke onset using a multiparametric magnetic resonance (MR) examination consisting of DWI, mean transit time (MTT) as PI parameter, and MR angiography (MRA). T2-weighted and fluid-attenuated inversion recovery (FLAIR) on day 7 were also acquired in order to obtain final infarct volume. The following MR parameters were considered: volumetric measures of lesion growth and MTT abnormalities, quantification of regional apparent diffusion coefficient (ADC) and visual inspection of MRA findings. Our results showed: (1) an acute DWI lesion was not predictive of lesion growth and the DWI abnormality did not represent the irreversibly infarcted tissue; (2) ADC values in the ischemic penumbra could not predict tissue at risk; (3) the DWI-PI mismatch did not predict lesion growth, and the PI abnormality overestimated the amount of tissue at risk; and (4) patients with proximal middle cerebral artery occlusion had greater initial and final infarct volumes. This study did not demonstrate the prognostic value of a multimodal MR approach in early ischemic stroke; MRA alone provided predictive information about the volumetric evolution of the lesion. (orig.)

  18. 最大用力呼气流量-容积曲线法检测学龄期儿童肺功能的质量控制分析%Quality control for maximal expiratory lfow-volume curve as a pulmonary function test in school-age children

    王群; 任亦欣; 刘永革; 皇惠杰; 向莉


    目的:了解最大用力呼气流量-容积曲线法(MEFV)测定学龄期儿童肺功能的质控符合情况。方法将行MEFV次数≥2的862例患儿按年龄分为6岁~组(n=379)、8岁~组(n=210)、10岁~组(n=164)和12~17岁组(n=109),比较MEFV测定各组患儿肺功能质控参数和质控标准符合率。将诊断为哮喘的417例患儿分为肺功能异常组(n=262)与肺功能正常组(n=155),比较两组间肺功能质控参数的差异性。结果862例患儿共行2367次肺功能检测用于质控分析;符合起始标准外推容积(VBE)<0.15 L百分率为97.8%,其中6岁~组符合率最高,12~17岁组符合率最低;符合结束标准呼气时间(FET)百分率为44.2%,其中10岁以上患儿符合率低于10岁以下患儿(P<0.05);符合可重复标准最佳两次第一秒用力呼气容积差(⊿FEV1)<0.15 L与最佳两次用力肺活量差(⊿FVC)<0.15 L的百分率分别为91.9%和84.8%。肺功能异常的哮喘患儿肺功能质控参数均优于肺功能正常组(P<0.05)。结论 MEFV检测肺功能起始标准与可重复性标准符合率较高,结束标准符合率较低,建议进一步优化提高FET标准符合率。%Objective To assess the quality control for the maximal expiratory flow-volume (MEFV) curve in school-age children. Methods Eight hundred and sixty-two children who had two or more MEFV manoeuvres were classiifed into≥6-year-old (n=379),≥8-year-old (n=210),≥10-year-old (n=64), and 12-17-year-old groups (n=109). The parameters of quality control and concordance with quality control criteria for MEFV were compared between the two groups. In addition, patients who were diagnosed with asthma were classiifed into two groups, one with normal pulmonary function (n=155) and the other with abnormal pulmonary function (n=62), based on the results of spirometry. Differences in the parameters of quality control for spirometry were compared between the

  19. Inclusive fitness maximization: An axiomatic approach.

    Okasha, Samir; Weymark, John A; Bossert, Walter


    Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of quasi-inclusive fitness maximization can be derived from axioms on an individual׳s 'as if preferences' (binary choices) for the case in which phenotypic effects are additive. Our results help integrate evolutionary theory and rational choice theory, help draw out the behavioural implications of inclusive fitness maximization, and point to a possible way in which evolution could lead organisms to implement it. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Maximal Hypersurfaces in Spacetimes with Translational Symmetry

    Bulawa, Andrew


    We consider four-dimensional vacuum spacetimes which admit a free isometric spacelike R-action. Taking a quotient with respect to the R-action produces a three-dimensional quotient spacetime. We establish several results regarding maximal hypersurfaces (spacelike hypersurfaces of zero mean curvature) in quotient spacetimes. First, we show that complete noncompact maximal hypersurfaces must either be flat cylinders S^1 x R or conformal to the Euclidean plane. Second, we establish a positive mass theorem for certain maximal hypersurfaces. Finally, while it is meaningful to use a bounded lapse when adopting the maximal hypersurface gauge condition in the four-dimensional (asymptotically flat) setting, it is shown here that nontrivial quotient spacetimes admit the maximal hypersurface gauge only with an unbounded lapse.

  1. Sex Differences in Neuromuscular Fatigability of the Knee Extensors Post-Stroke

    Kirking, Meghan; Berrios Barillas, Reivian; Nelson, Philip Andrew; Hunter, Sandra Kay; Hyngstrom, Allison


    Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women) with chronic stroke (≥6 months) and 23 (12 men, 11 women) nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest) at 30% of maximal voluntary contraction (MVC) torque until failure to maintain the target torque. Electromyography was used to determine muscle activation and contractile properties were assessed with electrical stimulation of the quadriceps muscles. Results: Individuals with stroke had a briefer task duration (greater fatigability) than nonstroke individuals (24.1 ± 17 min vs. 34.9 ± 16 min). Men were more fatigable than women for both nonstroke controls and individuals with stroke (17.9 ± 9 min vs. 41.6 ± 15 min). Individuals with stroke had less fatigue-related changes in muscle contractile properties and women with stroke differed in their muscle activation strategy during the fatiguing contractions. Conclusions: Men and women fatigue differently post-stroke and this may be due to the way they neurally activate muscle groups. PMID:28085089

  2. Is time limit at the minimum swimming velocity of VO2 max influenced by stroking parameters?

    Fernandes, Ricardo J; Marinho, Daniel A; Barbosa, Tiago M; Vilas-Boas, J Paulo


    The aim of this study was to observe the relationship between time limit at the minimum velocity that elicits maximal oxygen consumption (TLim-v VO2 max) and stroke rate, stroke length, and stroke index. 13 men and 10 women, highly trained swimmers, performed an intermittent incremental test for v VO2 max assessment and an all-out swim to estimate TLim-v VO2 max. The mean +/- SD TLim-v VO2 max, v VO2 max, stroke rate, stroke length, and stroke index values were 233.36 +/- 53.92 sec., 1.40 +/- .06 meter/sec., 35.58 +/- 2.89 cycles/min., 2.39 +/- .22 meter/cycle, and 3.36 +/- .41 meter2/(cycle x sec.), respectively. The correlation between TLim-v VO2 max and stroke rate was -.51 (p VO2 max with stroke length (r = .52, p < .01) and stroke index (r = .45, p < .05). These results seem to suggest that technical skill is a key factor in typical efforts requiring prolonged aerobic power.

  3. Sex Differences in Neuromuscular Fatigability of the Knee Extensors Post-Stroke

    Meghan Kirking


    Full Text Available Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women with chronic stroke (≥6 months and 23 (12 men, 11 women nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest at 30% of maximal voluntary contraction (MVC torque until failure to maintain the target torque. Electromyography was used to determine muscle activation and contractile properties were assessed with electrical stimulation of the quadriceps muscles. Results: Individuals with stroke had a briefer task duration (greater fatigability than nonstroke individuals (24.1 ± 17 min vs. 34.9 ± 16 min. Men were more fatigable than women for both nonstroke controls and individuals with stroke (17.9 ± 9 min vs. 41.6 ± 15 min. Individuals with stroke had less fatigue-related changes in muscle contractile properties and women with stroke differed in their muscle activation strategy during the fatiguing contractions. Conclusions: Men and women fatigue differently post-stroke and this may be due to the way they neurally activate muscle groups.

  4. Variation of Linear and Nonlinear Parameters in the Swim Strokes According to the Level of Expertise.

    Barbosa, Tiago M; Goh, Wan Xiu; Morais, Jorge E; Costa, Mário J


    The aim was to examine the variation of linear and nonlinear proprieties of the behaviour in participants with different levels of swimming expertise among the four swim strokes. Seventy-five swimmers were split into three groups (highly qualified experts, experts and non-experts) and performed a maximal 25m trial for each of the four competitive swim strokes. A speed-meter cable was attached to the swimmer's hip to measure hip speed; from which speed fluctuation (dv), approximate entropy (ApEn) and fractal dimension (D) variables were derived. Although simple main effects of expertise and swim stroke were obtained for dv and D, no significant interaction of expertise and stroke were found except in ApEn. The ApEn and D were prone to decrease with increasing expertise. As a conclusion, swimming does exhibit nonlinear properties but its magnitude differs according to the swim stroke and level of expertise of the performer.

  5. Mini-Stroke vs. Regular Stroke: What's the Difference?

    ... How is a ministroke different from a regular stroke? Answers from Jerry W. Swanson, M.D. When ... brain, spinal cord or retina, which may cause stroke-like symptoms but does not damage brain cells ...

  6. Code stroke in Asturias.

    Benavente, L; Villanueva, M J; Vega, P; Casado, I; Vidal, J A; Castaño, B; Amorín, M; de la Vega, V; Santos, H; Trigo, A; Gómez, M B; Larrosa, D; Temprano, T; González, M; Murias, E; Calleja, S


    Intravenous thrombolysis with alteplase is an effective treatment for ischaemic stroke when applied during the first 4.5 hours, but less than 15% of patients have access to this technique. Mechanical thrombectomy is more frequently able to recanalise proximal occlusions in large vessels, but the infrastructure it requires makes it even less available. We describe the implementation of code stroke in Asturias, as well as the process of adapting various existing resources for urgent stroke care in the region. By considering these resources, and the demographic and geographic circumstances of our region, we examine ways of reorganising the code stroke protocol that would optimise treatment times and provide the most appropriate treatment for each patient. We distributed the 8 health districts in Asturias so as to permit referral of candidates for reperfusion therapies to either of the 2 hospitals with 24-hour stroke units and on-call neurologists and providing IV fibrinolysis. Hospitals were assigned according to proximity and stroke severity; the most severe cases were immediately referred to the hospital with on-call interventional neurology care. Patient triage was provided by pre-hospital emergency services according to the NIHSS score. Modifications to code stroke in Asturias have allowed us to apply reperfusion therapies with good results, while emphasising equitable care and managing the severity-time ratio to offer the best and safest treatment for each patient as soon as possible. Copyright © 2015 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  7. Maximal hypersurfaces and foliations of constant mean curvature in general relativity

    Marsden, Jerrold E.; Tipler, Frank J.


    We prove theorems on existence, uniqueness and smoothness of maximal and constant mean curvature compact spacelike hypersurfaces in globally hyperbolic spacetimes. The uniqueness theorem for maximal hypersurfaces of Brill and Flaherty, which assumed matter everywhere, is extended to spacetimes that are vacuum and non-flat or that satisfy a generic-type condition. In this connection we show that under general hypotheses, a spatially closed universe with a maximal hypersurface must be Wheeler universe; i.e. be closed in time as well. The existence of Lipschitz achronal maximal volume hypersurfaces under the hypothesis that candidate hypersurfaces are bounded away from the singularity is proved. This hypothesis is shown to be valid in two cases of interest: when the singularities are of strong curvature type, and when the singularity is a single ideal point. Some properties of these maximal volume hypersurfaces and difficulties with Avez' original arguments are discussed. The difficulties involve the possibility that the maximal volume hypersurface can be null on certain portions; we present an incomplete argument which suggests that these hypersurfaces are always smooth, but prove that an a priori bound on the second fundamental form does imply smoothness. An extension of the perturbation theorem of Choquet-Bruhat, Fischer and Marsden is given and conditions under which local foliations by constant mean curvature hypersurfaces can be extended to global ones is obtained.

  8. Stroke risk perception among participants of a stroke awareness campaign

    Heuschmann Peter U; Heidrich Jan; Kraywinkel Klaus; Wagner Markus; Berger Klaus


    Abstract Background Subjective risk factor perception is an important component of the motivation to change unhealthy life styles. While prior studies assessed cardiovascular risk factor knowledge, little is known about determinants of the individual perception of stroke risk. Methods Survey by mailed questionnaire among 1483 participants of a prior public stroke campaign in Germany. Participants had been informed about their individual stroke risk based on the Framingham stroke risk score. S...

  9. S-100AND#946; protein as a biomarker in acute hemorrhagic stroke

    Omkar Prasad Baidya


    Full Text Available Acute hemorrhagic stroke, a subtype of acute stroke is one of the leading causes of death and disability throughout the world. At present, the diagnosis of acute hemorrhagic stroke is mainly based on Computer Tomography (CT or Magnetic Resonance Imaging (MRI but till now no biomarkers are routinely used in acute hemorrhagic stroke management. This article is a critical and descriptive review on the role of S100β protein as a biomarker in acute hemorrhagic stroke. Plasma S-100β level increases significantly in acute hemorrhagic stroke patients when compared to the normal subjects. Beside, the plasma S-100β can be correlated to the volume of hemorrhage in brain measured by plane CT scan. Plasma S-100β is an useful biomarker in acute hemorrhagic stroke and can be used for estimation of volume of hemorrhage in brain in acute hemorrhagic stroke patients. Thus, S-100β can be useful as an alternative to CT scan/MRI in diagnosis and in taking therapeutic decision in acute hemorrhagic stroke management. [Int J Res Med Sci 2014; 2(1.000: 13-15

  10. The units of measurement of the ventricular stroke work: a review study.

    Schramm, Wolfgang


    The ventricular stroke work refers to the work done by the left or right ventricle to eject the volume of blood during one cardiac cycle, called stroke volume. Sarnoff and Berglund were one of the first to calculate the stroke work from the pressure volume diagram in 1954. However, they published a wrong unit of measurement for the stroke work, namely gram meter. The present work reviewed 779 scientific publications between May 1954 and January 2010 which used the left or right ventricular stroke work as a variable. Interestingly, the majority (87.2%) of scientific papers since 1954 have either copied this (or a similar) wrong unit of measurement or have invented another one. Only 12.8% of the publications gave a correct unit. The present search in scientific literature demonstrates that the haemodynamic variable ventricular stroke work, which is used daily by thousands of medical doctors and scientists, was specified in an incorrect manner for 56 years in the majority of scientific papers. A correct unit of measurement, of course, is an imperative condition when comparing scientific papers. The aim of this publication is the elimination of incorrect units of measurement of the ventricular stroke work variable in all future scientific papers. Moreover, the present work facilitates the interpretation of at least some of the studies containing the ventricular stroke work variable published up to now.

  11. Promoting Neuroplasticity for Motor Rehabilitation After Stroke: Considering the Effects of Aerobic Exercise and Genetic Variation on Brain-Derived Neurotrophic Factor

    Mang, Cameron S.; Campbell, Kristin L.; Ross, Colin J.D.; Boyd, Lara A.


    Recovery of motor function after stroke involves relearning motor skills and is mediated by neuroplasticity. Recent research has focused on developing rehabilitation strategies that facilitate such neuroplasticity to maximize functional outcome poststroke. Although many molecular signaling pathways are involved, brain-derived neurotrophic factor (BDNF) has emerged as a key facilitator of neuroplasticity involved in motor learning and rehabilitation after stroke. Thus, rehabilitation strategie...

  12. [Neuroimaging and Blood Biomarkers in Functional Prognosis after Stroke].

    Branco, João Paulo; Costa, Joana Santos; Sargento-Freitas, João; Oliveira, Sandra; Mendes, Bruno; Laíns, Jorge; Pinheiro, João


    Stroke remains one of the leading causes of morbidity and mortality around the world and it is associated with an important long-term functional disability. Some neuroimaging resources and certain peripheral blood or cerebrospinal fluid proteins can give important information about etiology, therapeutic approach, follow-up and functional prognosis in acute ischemic stroke patients. However, among the scientific community, there is currently more interest in the stroke vital prognosis over the functional prognosis. Predicting the functional prognosis during acute phase would allow more objective rehabilitation programs and better management of the available resources. The aim of this work is to review the potential role of acute phase neuroimaging and blood biomarkers as functional recovery predictors after ischemic stroke. Review of the literature published between 2005 and 2015, in English, using the terms "ischemic stroke", "neuroimaging" e "blood biomarkers". We included nine studies, based on abstract reading. Computerized tomography, transcranial doppler ultrasound and diffuse magnetic resonance imaging show potential predictive value, based on the blood flow study and the evaluation of stroke's volume and localization, especially when combined with the National Institutes of Health Stroke Scale. Several biomarkers have been studied as diagnostic, risk stratification and prognostic tools, namely the S100 calcium binding protein B, C-reactive protein, matrix metalloproteinases and cerebral natriuretic peptide. Although some biomarkers and neuroimaging techniques have potential predictive value, none of the studies were able to support its use, alone or in association, as a clinically useful functionality predictor model. All the evaluated markers were considered insufficient to predict functional prognosis at three months, when applied in the first hours after stroke. Additional studies are necessary to identify reliable predictive markers for functional

  13. Acute MRI Changes in Progressive Ischemic Stroke

    Kalowska, Elizabeth; Rostrup, Egill; Rosenbaum, S


    as a permanent decrease of >/=3 Scandinavian Stroke Scale (SSS) points for speech or >/=2 SSS points for consciousness or >/=2 SSS points for limb strength, when assessed at baseline compared to the day after admission and daily during the following week. Patients were followed up on day 90 and assessed using......-weighted imaging (DWI), perfusion-weighted imaging and magnetic resonance angiography were performed 3 times, immediately after clinical evaluation, on day 7 and after 3 months. Clinical neurological assessments were performed every 2 h during the first 24 h and once daily from day 2 to 7. SIP was defined...... the modified Rankin Scale, Barthel Index and SSS score. Patients with and without SIP were compared using both clinical and MRI data obtained on admission, on day 7 and after 3 months. Results: Fifteen patients (37%) developed SIP. Increased DWI lesion volume on day 7 in all strokes was associated with SIP...

  14. Acute MRI changes in progressive ischemic stroke

    Kalowska, E.; Rostrup, E.; Rosenbaum, S.


    as a permanent decrease of >or=3 Scandinavian Stroke Scale (SSS) points for speech or >or=2 SSS points for consciousness or >or=2 SSS points for limb strength, when assessed at baseline compared to the day after admission and daily during the following week. Patients were followed up on day 90 and assessed using......-weighted imaging (DWI), perfusion-weighted imaging and magnetic resonance angiography were performed 3 times, immediately after clinical evaluation, on day 7 and after 3 months. Clinical neurological assessments were performed every 2 h during the first 24 h and once daily from day 2 to 7. SIP was defined...... the modified Rankin Scale, Barthel Index and SSS score. Patients with and without SIP were compared using both clinical and MRI data obtained on admission, on day 7 and after 3 months. RESULTS: Fifteen patients (37%) developed SIP. Increased DWI lesion volume on day 7 in all strokes was associated with SIP...

  15. From stroke unit care to stroke care unit

    De Keyser, J; Sulter, G.


    In some stroke units continuous monitoring of blood pressure, electrocardiogram, body temperature, and oxygen saturation has become an integral part of the management of acute stroke. In addition, regular measurements of blood glucose are performed. Stroke units equipped with such monitoring facilit

  16. An Economic Evaluation Comparing Stroke Telemedicine to Conventional Stroke Medicine

    Budhram, Stanley Chandra


    Stroke is not only a serious medical problem, but it also poses an enormous economic burden on society. Stroke ranks the third as the leading cause of death in the United States behind heart disease and cancer. The survivors of stroke suffer from various degrees of long-term disability which create a severe financial burden on society. University…

  17. From stroke unit care to stroke care unit

    De Keyser, J; Sulter, G.


    In some stroke units continuous monitoring of blood pressure, electrocardiogram, body temperature, and oxygen saturation has become an integral part of the management of acute stroke. In addition, regular measurements of blood glucose are performed. Stroke units equipped with such monitoring

  18. Diabetes, Heart Disease, and Stroke

    ... busting” drug. The drug must be given soon after a stroke to be effective. Subsequent treatment for stroke includes medications and physical therapy, as well as surgery to repair the damage. Meal planning and physical activity may be part ...

  19. Hispanics and Heart Disease, Stroke

    ... Thromboembolism Aortic Aneurysm More Hispanics and Heart Disease, Stroke Updated:Aug 30,2016 Heart disease is the No. 1 killer for all Americans and stroke is the fifth leading cause of death. Hispanics ...

  20. Diabetes, Heart Disease, and Stroke

    ... Disease, & Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetes, Heart Disease, and Stroke Having diabetes means that ... help to stop. What is the link between diabetes, heart disease, and stroke? Over time, high blood ...

  1. Preventable Pediatric Stroke via Vaccination?

    Craig A. Press


    Full Text Available Investigators from the Vascular Effects of Infection in Pediatric Stroke (VIPS group studied the risk of arterial ischemic stroke (AIS associated with minor infection and routine childhood vaccinations.

  2. Let's Talk about Ischemic Stroke

    ... Thromboembolism Aortic Aneurysm More Let's Talk About Ischemic Stroke Updated:Dec 9,2015 The majority of strokes ... Should I Limit Sodium? How Do I Understand "Nutrition Facts" Labels? How Can I Quit Smoking? How ...

  3. Heart Disease and Stroke Statistics

    ... Media for Heart and Stroke Association Statistics Banner 1 - Stats white banner Each year, the ... health and disease in the population. Heart & Stroke Statistics FAQs What is Prevalence? Prevalence is an estimate ...

  4. Stroke rehabilitation and discharge planning.

    Kerr, Peter

    Nurses play a pivotal role in the rehabilitation and discharge planning process of patients who have had a stroke. The nurse's role in the wider stroke multidisciplinary team is complex and diverse and, as such, stroke nurses may find it hard to describe their role and how it fits into the rehabilitation and discharge planning process. A definition of the stroke nurse role in prominent publications such as those of the Scottish Intercollegiate Guidelines Network and the Royal College of Physicians is lacking. This article emphasises the role of the stroke nurse in the rehabilitation and discharge planning process in the stroke unit, while highlighting the complexity, diversity and importance of this role in providing holistic care and support for patients who have survived a stroke. The author draws on his clinical experience of stroke nursing practice in primary, secondary and tertiary care in west central Scotland.

  5. Educational approach on stroke training in Europe.

    Corea, F; Gunther, A; Kwan, J; Petzold, A; Debette, S; Sessa, M; Silvestrelli, G; Parnetti, L; Tambasco, N


    According to the European Stroke Initiative (EUSI), stroke care is best delivered within a stroke unit by a specialized multidisciplinary stroke team led by stroke specialists. At present, there is no guideline or consensus regarding training requirements or clinical standards that stroke specialists should achieve. It is envisaged that stroke specialists in training would need to acquire adequate knowledge and competency across three major areas of stroke care: acute stroke, stroke rehabilitation, and stroke prevention. With an EUSI document, the European Association of Young Neurologists and Trainees Stroke Subspeciality Group aims to promote discussion on the many aspects of stroke training and the requirements to be a stroke specialist in the European community. The ultimate purpose is to agree on common standards to promote good clinical care and effective stroke prevention across Europe. In the future, this may be translated into better patient outcome and a reduction in the global burden of this condition.

  6. Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study

    Steding-Ehrenborg, Katarina; Jablonowski, Robert; Arvidsson, Per M;


    The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study...

  7. Are all maximally entangled states pure?

    Cavalcanti, D.; Brandão, F. G. S. L.; Terra Cunha, M. O.


    We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.

  8. An ethical justification of profit maximization

    Koch, Carsten Allan


    In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing...... behaviour. It is argued that some form of consequential ethics must be applied, and that both profit seeking and profit maximization can be defended from a rule-consequential point of view. It is noted, however, that the result does not apply unconditionally, but requires that certain form of profit (and...

  9. Robust utility maximization in a discontinuous filtration

    Jeanblanc, Monique; Ngoupeyou, Armand


    We study a problem of utility maximization under model uncertainty with information including jumps. We prove first that the value process of the robust stochastic control problem is described by the solution of a quadratic-exponential backward stochastic differential equation with jumps. Then, we establish a dynamic maximum principle for the optimal control of the maximization problem. The characterization of the optimal model and the optimal control (consumption-investment) is given via a forward-backward system which generalizes the result of Duffie and Skiadas (1994) and El Karoui, Peng and Quenez (2001) in the case of maximization of recursive utilities including model with jumps.

  10. Improving the Post-Stroke Therapeutic Potency of Mesenchymal Multipotent Stromal Cells by Cocultivation With Cortical Neurons: The Role of Crosstalk Between Cells.

    Babenko, Valentina A; Silachev, Denis N; Zorova, Ljubava D; Pevzner, Irina B; Khutornenko, Anastasia A; Plotnikov, Egor Y; Sukhikh, Gennady T; Zorov, Dmitry B


    The goal of the present study was to maximally alleviate the negative impact of stroke by increasing the therapeutic potency of injected mesenchymal multipotent stromal cells (MMSCs). To pursue this goal, the intercellular communications of MMSCs and neuronal cells were studied in vitro. As a result of cocultivation of MMSCs and rat cortical neurons, we proved the existence of intercellular contacts providing transfer of cellular contents from one cell to another. We present evidence of intercellular exchange with fluorescent probes specifically occupied by cytosol with preferential transfer from neurons toward MMSCs. In contrast, we observed a reversed transfer of mitochondria (from MMSCs to neural cells). Intravenous injection of MMSCs in a postischemic period alleviated the pathological indexes of a stroke, expressed as a lower infarct volume in the brain and partial restoration of neurological status. Also, MMSCs after cocultivation with neurons demonstrated more profound neuroprotective effects than did unprimed MMSCs. The production of the brain-derived neurotrophic factor was slightly increased in MMSCs, and the factor itself was redistributed in these cells after cocultivation. The level of Miro1 responsible for intercellular traffic of mitochondria was increased in MMSCs after cocultivation. We conclude that the exchange by cellular compartments between neural and stem cells improves MMSCs' protective abilities for better rehabilitation after stroke. This could be used as an approach to enhance the therapeutic benefits of stem cell therapy to the damaged brain. The idea of priming stem cells before practical use for clinical purposes was applied. Thus, cells were preconditioned by coculturing them with the targeted cells (i.e., neurons for the treatment of brain pathological features) before the transfusion of stem cells to the organism. Such priming improved the capacity of stem cells to treat stroke. Some additional minimal study will be required to

  11. SAR: Stroke Authorship Recognition

    Shaheen, Sara


    Are simple strokes unique to the artist or designer who renders them? If so, can this idea be used to identify authorship or to classify artistic drawings? Also, could training methods be devised to develop particular styles? To answer these questions, we propose the Stroke Authorship Recognition (SAR) approach, a novel method that distinguishes the authorship of 2D digitized drawings. SAR converts a drawing into a histogram of stroke attributes that is discriminative of authorship. We provide extensive classification experiments on a large variety of data sets, which validate SAR\\'s ability to distinguish unique authorship of artists and designers. We also demonstrate the usefulness of SAR in several applications including the detection of fraudulent sketches, the training and monitoring of artists in learning a particular new style and the first quantitative way to measure the quality of automatic sketch synthesis tools. © 2015 The Eurographics Association and John Wiley & Sons Ltd.

  12. Stroke and Episodic Memory Disorders

    Lim, Chun; Alexander, Michael P.


    Memory impairments are common after stroke, and the anatomical basis for impairments may be quite variable. To determine the range of stroke-related memory impairment, we identified all case reports and group studies through the Medline database and the Science Citation Index. There is no hypothesis about memory that is unique to stroke, but there…

  13. Recovery of gait after stroke

    Kollen, B.J.


    In the Netherlands annually about 30,000 people suffer a stroke for the first time. One third of these stroke patients die within the first year, while 41% experience long term disabilities. This makes stroke a major disease in medical and in socio-economic terms. Not just on society but also, and f

  14. Recovery of gait after stroke

    Kollen, B.J.


    Revised edition of the digital PhD thesis, 14-03-2006 In the Netherlands annually about 30,000 people suffer a stroke for the first time. One third of these stroke patients die within the first year, while 41% experience long term disabilities. This makes stroke a major disease in medical and in soc

  15. Personal accounts of stroke experiences

    Wachters-Kaufmann, CSM


    As there appeared to be a need for personal accounts of stroke experiences, a book called "Speaking about Stroke" was written for stroke patients and their caregivers. For the past two years, a questionnaire was sent to the people who had ordered the book, to gain an insight into the characteristics

  16. Personal accounts of stroke experiences

    Wachters-Kaufmann, CSM


    As there appeared to be a need for personal accounts of stroke experiences, a book called "Speaking about Stroke" was written for stroke patients and their caregivers. For the past two years, a questionnaire was sent to the people who had ordered the book, to gain an insight into the characteristics

  17. Recovery of gait after stroke

    Kollen, B.J.

    Revised edition of the digital PhD thesis, 14-03-2006 In the Netherlands annually about 30,000 people suffer a stroke for the first time. One third of these stroke patients die within the first year, while 41% experience long term disabilities. This makes stroke a major disease in medical and in

  18. Recovery of gait after stroke

    Kollen, B.J.


    In the Netherlands annually about 30,000 people suffer a stroke for the first time. One third of these stroke patients die within the first year, while 41% experience long term disabilities. This makes stroke a major disease in medical and in socio-economic terms. Not just on society but also, and

  19. The Therapeutic Potential of Induced Pluripotent Stem Cells After Stroke: Evidence from Rodent Models.

    Zents, Karlijn; Copray, Sjef


    Stroke is the second most common cause of death and the leading cause of disability in the world. About 30% of the people that are affected by stroke die within a year; 25% of the patients that survive stroke remain in need of care after a year. Therefore, stroke is a major burden for health care costs. The most common subtype is ischemic stroke. This type is characterized by a reduced and insufficient blood supply to a certain part of the brain. Despite the high prevalence of stroke, the currently used therapeutic interventions are limited. No therapies that aim to restore damaged neuronal tissue or to promote recovery are available nowadays. Transplantation of stem cell-derived cells has been investigated as a potential regenerative and protective treatment. Embryonic stem cell (ESC)-based cell therapy in rodent models of stroke has been shown to improve functional outcome. However, the clinical use of ESCs still raises ethical questions and implantation of ESC-derived cells requires continuous immunosuppression. The groundbreaking detection of induced pluripotent stem cells (iPSCs) has provided a most promising alternative. This mini-review summarizes current literature in which the potential use of iPSC-derived cells has been tested in rodent models of stroke. iPSC-based cell therapy has been demonstrated to improve motor function, decrease stroke volume, promote neurogenesis and angiogenesis and to exert immunomodulatory, anti-inflammatory effects in the brain of stroke-affected rodents.

  20. Endocarditis and Stroke

    GRECU, Nicolae; TIU, Cristina; TERECOASA, Elena; BAJENARU, Ovidiu


    Endocarditis is an important, although less common, cause of cerebral embolism. All forms of endocarditis share an initial common pathophysiologic pathway, best illustrated by the non-bacterial thrombotic form, but also a final potential for embolization. Stroke associated with endocarditis has signifficant mortality and morbidity rates, especially due to the frequent concomitant multiple sites of brain embolization. In this article we aim to briefly review endocarditis with a focus on stroke as a complication, while also presenting case correlates from our department. PMID:25705308


    HR Division


    Affected by both the salary adjustment index on 1.1.2000 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maximal, has changed significantly. An adjustment of the amounts of the reimbursement maximal and the fixed contributions is therefore necessary, as from 1 January 2000.Reimbursement maximalThe revised reimbursement maximal will appear on the leaflet summarising the benefits for the year 2000, which will soon be available from the divisional secretariats and from the AUSTRIA office at CERN.Fixed contributionsThe fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions):voluntarily insured member of the personnel, with complete coverage:815,- (was 803,- in 1999)voluntarily insured member of the personnel, with reduced coverage:407,- (was 402,- in 1999)voluntarily insured no longer dependent child:326,- (was 321...

  2. Maximizing throughput by evaluating critical utilization paths

    Weeda, P.J.


    Recently the relationship between batch structure, bottleneck machine and maximum throughput has been explored for serial, convergent and divergent process configurations consisting of two machines and three processes. In three of the seven possible configurations a multiple batch structure maximize

  3. Relationship between maximal exercise parameters and individual ...

    Relationship between maximal exercise parameters and individual time trial ... It is widely accepted that the ventilatory threshold (VT) is an important ... This study investigated whether the physiological responses during a 20km time trial (TT) ...

  4. Simple technique for maximal thoracic muscle harvest.

    Marshall, M Blair; Kaiser, Larry R; Kucharczuk, John C


    We present a modification of technique for standard muscle flap harvest, the placement of cutaneous traction sutures. This technique allows for maximal dissection of the thoracic muscles even through minimal incisions. Through improved exposure and traction, complete dissection of the muscle bed can be performed and the tissue obtained maximized. Because more muscle bulk is obtained with this technique, the need for a second muscle may be prevented.


    Every canonical linearly separable truth function is a regular function, but not every regular truth function is linearly separable. The most...promising method of determining which of the regular truth functions are linearly separable r quires finding their maximal and minimal points. In is developed a quick, systematic method of finding the maximal points of any regular truth function in terms of its arithmetic invariants. (Author)

  6. Maximal Subgroups of Skew Linear Groups

    M. Mahdavi-Hezavehi


    Let D be an infinite division algebra of finite dimension over its centre Z(D) = F, and n a positive integer. The structure of maximal subgroups of skew linear groups are investigated. In particular, assume N is a normal subgroup of GLn(D) and M is a maximal subgroup of N containing Z(N). It is shown that if M/Z(N) is finite, then N is central.

  7. Additive Approximation Algorithms for Modularity Maximization

    Kawase, Yasushi; Matsui, Tomomi; Miyauchi, Atsushi


    The modularity is a quality function in community detection, which was introduced by Newman and Girvan (2004). Community detection in graphs is now often conducted through modularity maximization: given an undirected graph $G=(V,E)$, we are asked to find a partition $\\mathcal{C}$ of $V$ that maximizes the modularity. Although numerous algorithms have been developed to date, most of them have no theoretical approximation guarantee. Recently, to overcome this issue, the design of modularity max...

  8. Family History in Young Patients With Stroke.

    Thijs, Vincent; Grittner, Ulrike; Dichgans, Martin; Enzinger, Christian; Fazekas, Franz; Giese, Anne-Katrin; Kessler, Christof; Kolodny, Edwin; Kropp, Peter; Martus, Peter; Norrving, Bo; Ringelstein, Erich Bernd; Rothwell, Peter M; Schmidt, Reinhold; Tanislav, Christian; Tatlisumak, Turgut; von Sarnowski, Bettina; Rolfs, Arndt


    Family history of stroke is an established risk factor for stroke. We evaluated whether family history of stroke predisposed to certain stroke subtypes and whether it differed by sex in young patients with stroke. We used data from the Stroke in Fabry Patients study, a large prospective, hospital-based, screening study for Fabry disease in young patients (aged stroke in whom cardiovascular risk factors and family history of stroke were obtained and detailed stroke subtyping was performed. A family history of stroke was present in 1578 of 4232 transient ischemic attack and ischemic stroke patients (37.3%). Female patients more often had a history of stroke in the maternal lineage (P=0.027) than in the paternal lineage. There was no association with stroke subtype according to Trial of Org 10172 in Acute Stroke Treatment nor with the presence of white matter disease on brain imaging. Patients with dissection less frequently reported a family history of stroke (30.4% versus 36.3%; P=0.018). Patients with a parental history of stroke more commonly had siblings with stroke (3.6% versus 2.6%; P=0.047). Although present in about a third of patients, a family history of stroke is not specifically related to stroke pathogenic subtypes in patients with young stroke. Young women with stroke more often report stroke in the maternal lineage. URL: Unique identifier: NCT00414583. © 2015 American Heart Association, Inc.

  9. Maximal Frequent Itemset Generation Using Segmentation Apporach



    Full Text Available Finding frequent itemsets in a data source is a fundamental operation behind Association Rule Mining.Generally, many algorithms use either the bottom-up or top-down approaches for finding these frequentitemsets. When the length of frequent itemsets to be found is large, the traditional algorithms find all thefrequent itemsets from 1-length to n-length, which is a difficult process. This problem can be solved bymining only the Maximal Frequent Itemsets (MFS. Maximal Frequent Itemsets are frequent itemsets whichhave no proper frequent superset. Thus, the generation of only maximal frequent itemsets reduces thenumber of itemsets and also time needed for the generation of all frequent itemsets as each maximal itemsetof length m implies the presence of 2m-2 frequent itemsets. Furthermore, mining only maximal frequentitemset is sufficient in many data mining applications like minimal key discovery and theory extraction. Inthis paper, we suggest a novel method for finding the maximal frequent itemset from huge data sourcesusing the concept of segmentation of data source and prioritization of segments. Empirical evaluationshows that this method outperforms various other known methods.

  10. Natural selection and the maximization of fitness.

    Birch, Jonathan


    The notion that natural selection is a process of fitness maximization gets a bad press in population genetics, yet in other areas of biology the view that organisms behave as if attempting to maximize their fitness remains widespread. Here I critically appraise the prospects for reconciliation. I first distinguish four varieties of fitness maximization. I then examine two recent developments that may appear to vindicate at least one of these varieties. The first is the 'new' interpretation of Fisher's fundamental theorem of natural selection, on which the theorem is exactly true for any evolving population that satisfies some minimal assumptions. The second is the Formal Darwinism project, which forges links between gene frequency change and optimal strategy choice. In both cases, I argue that the results fail to establish a biologically significant maximization principle. I conclude that it may be a mistake to look for universal maximization principles justified by theory alone. A more promising approach may be to find maximization principles that apply conditionally and to show that the conditions were satisfied in the evolution of particular traits.

  11. Navigating stroke care: the experiences of younger stroke survivors.

    Sadler, Euan; Daniel, Katie; Wolfe, Charles D A; McKevitt, Christopher


    Although stroke is associated with ageing, a significant proportion of strokes occur in younger people. Younger stroke survivors have experienced care available as inappropriate to their needs. However, insufficient attention has been paid to how the social context shapes their experiences of care. We investigated this question with younger stroke survivors in Greater London, UK. We conducted in-depth interviews with individuals aged between 24 and 62 years. Interviews were analysed thematically, with interpretation informed by Bourdieu's concepts of field, capital and habitus. In the acute care setting it was implicit for participants that expertise and guidance was to be prioritised and largely this was reported as what was received. Individuals' cultural capital shaped expectations to access information, but health care professionals' symbolic capital meant they controlled its provision. After discharge, professional guidance was still looked for, but many felt it was limited or unavailable. It was here that participants' social, cultural and economic capital became more important in experiences of care. The field of stroke shaped younger stroke survivors' experiences of care. Navigating stroke care was contingent on accessing different forms of capital. Differences in access to these resources influenced longer term adjustment after stroke. Stroke care can be conceptualised as a temporal field of social activity and relationships which shapes variations in experiences of care among younger stroke survivors, and differences in expectations of support at different time points after stroke. On entering the field of stroke participants reported needing health care professional guidance and expertise to manage the acute event, yet difficulties accessing information in hospital limited the agency of some individuals wanting to take an active role in their recovery. After discharge from hospital variations in experiences of care among participants were more evident

  12. Citicoline enhances neuroregenerative processes after experimental stroke in rats.

    Diederich, Kai; Frauenknecht, Katrin; Minnerup, Jens; Schneider, Barbara K; Schmidt, Antje; Altach, Elena; Eggert, Verena; Sommer, Clemens J; Schäbitz, Wolf-Rüdiger


    The neuroprotective potential of citicoline in acute ischemic stroke has been shown in many experimental studies and, although the exact mechanisms are still unknown, a clinical Phase III trial is currently underway. Our present study was designed to check whether citicoline also enhances neuroregeneration after experimental stroke. Forty Wistar rats were subjected to photothrombotic stroke and treated either with daily injections of citicoline (100 mg/kg) or vehicle for 10 consecutive days starting 24 hours after ischemia induction. Sensorimotor tests were performed after an adequate training period at Days 1, 10, 21, and 28 after stroke. Then brains were removed and analyzed for infarct size, glial scar formation, neurogenesis, and ligand binding densities of excitatory and inhibitory neurotransmitter receptors. Animals treated with citicoline showed a significantly better neurological outcome at Days 10, 21, and 28 after ischemia, which could not be attributed to differences in infarct volumes or glial scar formation. However, neurogenesis in the dentate gyrus, subventricular zone, and peri-infarct area was significantly increased by citicoline. Furthermore, enhanced neurological outcome after citicoline treatment was associated with a shift toward excitation in the perilesional cortex. Our present data demonstrate that, apart from the well-known neuroprotective effects in acute ischemic stroke, citicoline also possesses a substantial neuroregenerative potential. Thanks to its multimodal effects, easy applicability, and history as a well-tolerated drug, promising possibilities of neurological treatment including chronic stroke open up.

  13. Sex and acute stroke presentation.

    Labiche, Lise A; Chan, Wenyaw; Saldin, Kamaldeen R; Morgenstern, Lewis B


    We determine whether a sex difference exists for acute stroke emergency department presentation. The TLL Temple Foundation Stroke Project is a prospective observational study of acute stroke management that identified 1,189 validated strokes in nonurban community EDs from February 1998 to March 2000. Structured interview of the patient and the person with the patient at symptom onset identified the symptom or symptoms that prompted the patient to seek medical attention. Interview data were available for 1,124 (94%) patients. A physician blinded to sex classified the reported symptoms into 14 categories. Nontraditional stroke symptoms were reported by 28% of women and 19% of men (odds ratio 1.62; 95% confidence interval 1.2 to 2.2). Nontraditional stroke symptoms, pain (men 8%, women 12%) and change in level of consciousness (men 12%, women 17%), were more often reported by women. Traditional stroke symptoms, imbalance (men 20%, women 15%) and hemiparesis (men 24%, women 19%), were reported more frequently by men. Trends were also found for women to present with nonneurologic symptoms (men 17%, women 21%) and men to present with gait abnormalities (men 11%, women 8%). There was no sex difference in the mean number of symptoms reported by an individual patient. This study suggests that a sex difference exists in reporting of acute stroke symptoms. Women with validated strokes present more frequently with nontraditional stroke symptoms than men. Recognition of this difference might yield faster evaluation and management of female patients with acute stroke eligible for acute therapies.

  14. Rehabilitation of motor function after stroke: a multiple systematic review focused on techniques to stimulate upper extremity recovery

    Samar M Hatem


    Full Text Available Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients’ mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed.At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation.

  15. Rehabilitation of Motor Function after Stroke: A Multiple Systematic Review Focused on Techniques to Stimulate Upper Extremity Recovery

    Hatem, Samar M.; Saussez, Geoffroy; della Faille, Margaux; Prist, Vincent; Zhang, Xue; Dispa, Delphine; Bleyenheuft, Yannick


    Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients' mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training, and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed. At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning, and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation. PMID:27679565

  16. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E


    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  17. Stroke while jogging.

    Kelly, W F; Roussak, J.


    Jogging is a form of physical exercise that has stimulated the imagination of the public as shown by recent appearance of its own journal (Jogging Magazine, Editor J. Bryant). We wish to report the unusual complication of an acute stroke sustained during jogging.

  18. Ischemic strokes and migraine

    Bousser, M.G.; Baron, J.C.; Chiras, J.


    Lasting neurological deficits, though most infrequent, do occur in migrainous subjects and are well documented by clinical angiographic computed tomographic (CT scan) and even pathological studies. However the mechanism of cerebral ischemia in migraine remains widely unknown and the precise role of migraine in the pathogenesis of ischemic strokes is still debated. (orig./MG).

  19. Heart Disease and Stroke


    In this podcast, Dr. Tom Frieden, CDC Director, discusses the number one killer in the United States - heart disease and stroke.  Created: 9/3/2013 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 3/6/2014.

  20. Stroke? Localized, otogenic meningitis!

    Ingolfsdottir, Harpa Maria; Thomasen, Per Caye


    We report the case of a patient admitted with aphasia, treated for a stroke. Subsequently, it was revealed that the symptoms were caused by complicated otitis media with localized meningitis. This case draws attention to the possible intracranial spread of infection when neurological symptoms occur...

  1. Neurorehabilitation after Stroke

    Rüdiger J. Seitz


    Full Text Available Recovery from ischaemic stroke is determined in the acute phase by the lesion impact of ischaemia and subsequently, by functional and structural network changes in the spared brain tissue. Neurorehabilitation supports the restitution of function using repetitive, learning-based and, more recently, technology-based training strategies.

  2. Burden of stroke in Malaysia.

    Loo, Keat Wei; Gan, Siew Hua


    Stroke is one of the top five leading causes of death and one of the top 10 causes for hospitalization in Malaysia. Stroke is also in the top five diseases with the greatest burden of disease, based on disability-adjusted life years. However, prospective studies on stroke in Malaysia are limited. To date, neither the prevalence of stroke nor its incidence nationally has been recorded. Hypertension is the major risk factor for stroke. The mean age of stroke patients in Malaysia is between 54.5 and 62.6 years. Traditional medicine is commonly practiced. With the increasing number of stroke cases annually, more government and nongovernment organizations should be involved in primary and secondary prevention strategies.

  3. Therapeutic hypothermia for acute stroke

    Olsen, Tom Skyhøj; Weber, Uno Jakob; Kammersgaard, Lars Peter


    Experimental evidence and clinical experience show that hypothermia protects the brain from damage during ischaemia. There is a growing hope that the prevention of fever in stroke will improve outcome and that hypothermia may be a therapeutic option for the treatment of stroke. Body temperature...... is directly related to stroke severity and outcome, and fever after stroke is associated with substantial increases in morbidity and mortality. Normalisation of temperature in acute stroke by antipyretics is generally recommended, although there is no direct evidence to support this treatment. Despite its...... obvious therapeutic potential, hypothermia as a form of neuroprotection for stroke has been investigated in only a few very small studies. Therapeutic hypothermia is feasible in acute stroke but owing to serious side-effects--such as hypotension, cardiac arrhythmia, and pneumonia--it is still thought...

  4. Community reintegration of stroke survivors: the effect of a community navigation intervention.

    Montgomery, Phyllis; Jermyn, Darren; Bailey, Patricia; Nangia, Parveen; Egan, Mary; Mossey, Sharolyn


    The overall aim of the proposed study is to examine a newly implemented navigation intervention intended to support stroke survivors' community integration during the first year following hospital discharge in four regions of Ontario, Canada. Stroke is a leading cause of disability worldwide. Stroke survivors living in the community require regular, ongoing follow-up to assess recovery, prevent deterioration and maximize health outcomes. Internationally published evidence, often conducted in large urban centres, suggests that community reintegration services are an important component of the continuum of care for stroke survivors. This evidence, however, often does not address the particular challenges inherent in smaller urban and rural contexts. The design of this 2-year mixed-method study will use cohort and focused ethnography. The three stages of this study include: (1) collection of quantitative data to profile the health status, support and extent of community reintegration of stroke survivors; (2) collection of qualitative data from stroke survivors and their care partners about community reintegration and navigation; and following triangulation of findings (3) knowledge translation activities. This study was ethically approved by the academic Research Ethics Board and clinical Research Ethics Board (Sudbury, Ontario) and funded by the Ontario Stroke Network (Canada). Results will describe experiences and outcomes of a community navigation intervention. Engagement of multiple stakeholders has the potential to develop a shared understanding of community reintegration and generate evidence informed recommendations for service enhancement at critical points in stroke recovery to support survivor and community well-being. © 2014 John Wiley & Sons Ltd.

  5. Physical activity and exercise recommendations for stroke survivors: a statement for healthcare professionals from the American Heart Association/American Stroke Association.

    Billinger, Sandra A; Arena, Ross; Bernhardt, Julie; Eng, Janice J; Franklin, Barry A; Johnson, Cheryl Mortag; MacKay-Lyons, Marilyn; Macko, Richard F; Mead, Gillian E; Roth, Elliot J; Shaughnessy, Marianne; Tang, Ada


    This scientific statement provides an overview of the evidence on physical activity and exercise recommendations for stroke survivors. Evidence suggests that stroke survivors experience physical deconditioning and lead sedentary lifestyles. Therefore, this updated scientific statement serves as an overall guide for practitioners to gain a better understanding of the benefits of physical activity and recommendations for prescribing exercise for stroke survivors across all stages of recovery. Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association's Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and indicate gaps in current knowledge. Physical inactivity after stroke is highly prevalent. The assessed body of evidence clearly supports the use of exercise training (both aerobic and strength training) for stroke survivors. Exercise training improves functional capacity, the ability to perform activities of daily living, and quality of life, and it reduces the risk for subsequent cardiovascular events. Physical activity goals and exercise prescription for stroke survivors need to be customized for the individual to maximize long-term adherence. The recommendation from this writing group is that physical activity and exercise prescription should be incorporated into the management of stroke survivors. The promotion of physical activity in stroke survivors should emphasize low- to moderate-intensity aerobic activity, muscle-strengthening activity, reduction of sedentary behavior, and risk management for secondary prevention of stroke. © 2014 American Heart Association, Inc.

  6. Postoperative volume balance

    Frost, H; Mortensen, C.R.; Secher, Niels H.


    In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determined...... non-invasively by Modelflow. In Trendelenburg's position, SV (83 ± 19 versus 89 ± 20 ml) and CO (6·2 ± 1·8 versus 6·8 ± 1·8 l/min; both Pheart rate (75 ± 15 versus 76 ± 14 b min(-1) ) and mean arterial pressure were unaffected (84 ± 15 versus 84 ± 16 mmHg). For the 33 patients......, determination of SV and/or CO in Trendelenburg's position can be used to evaluate whether a patient is in need of IV fluid as here exemplified after surgery....

  7. Physiological and stroke parameters to assess aerobic capacity in swimming.

    Oliveira, Mariana F M; Caputo, Fabrizio; Lucas, Ricardo D; Denadai, Benedito S; Greco, Camila C


    To identify the speed corresponding to anaerobic threshold using the D-max method for both blood lactate and biomechanical stroke parameters determined in an incremental swimming test and to compare this information with the speed corresponding to the maximal lactate steady state (SMLSS). Five male long-distance swimmers and 8 triathletes (N=13; age 23.8±9.5 y, height 1.76±0.1 m, weight 71.3±9.8 kg) performed the following protocols: maximal 400-m test to determine maximal aerobic speed (S400); 7×200-m incremental test to determine the speed corresponding to the D-max point on the blood lactate (SLa), stroke-rate (SSR), stroke-length (SSL), and stroke-index (SSI) responses; and two to four 30-min submaximal tests to determine the SMLSS. SLA (1.18±0.08 m/s), SSI (1.18±0.08 m/s), SSR (1.17±0.1 m/s), and SSL (1.16±0.09 m/s) were not significantly different from each other or from SMLSS (1.13±0.08 m/s). There were high correlations between SLA, SSI, SSR, SSL, and SMLSS (r=.91, .89, .85, and .80, respectively). The typical errors of estimate for SLA (3.2%), SSI (3.7%), SSR (4.1%), and SSL (4.7%) suggest good validity of these variables to predict SMLSS. Furthermore, all physiological and biomechanical variables were moderately to highly correlated with S400 (r=.73-.95). It is possible to obtain a physiological index of aerobic capacity and performance using simple biomechanical measurements during an incremental test without performing blood lactate analyses.

  8. Rehabilitating the Stroke Collection

    Mary Grimmond


    Full Text Available Objective The aim of this project was to complete an analysis of monograph and audiovisual items held in the Central Coast Health Service (CCHS Libraries and containing information relevant to the treatment of acute stroke. Acute stroke is treated by multidisciplinary teams of clinicians based at two hospitals within the CCHS. The adequacy of the library collection was measured by subject coverage and age. Methods The methodology used consisted of three main steps: a literature review; design, administration, and analysis of a questionnaire to members of the CCHS Acute Stroke Team; and an analysis of the libraries’ collections. The research project utilised project management methodology and an evidence based librarianship framework. Results The questionnaire revealed that electronic resources were by far the most frequently used by participants, followed in order by print journals, books, interlibrary loan articles, and audiovisual items. Collection analysis demonstrated that the monograph and audiovisual collections were adequate in both scope and currency to support the information needs of Acute Stroke Team members, with the exception of resources to support patient education. Conclusion The researchers developed recommendations for future collection development in the area of acute stroke resources. Conducting this project within the evidence based librarianship framework helped to develop library staff members’ confidence in their ability to make future collection development decisions, informed by the target group’s information needs and preferences. The collection analysis methodology was designed to be replicated, and new specialist groups within the client base of the library will be targeted to repeat the collection analysis process.

  9. Knowledge of Stroke Risk Factors among Stroke Survivors in Nigeria

    Grace Vincent-Onabajo


    Full Text Available Background. Knowledge of stroke risk factors is expected to reduce the incidence of stroke—whether first-ever or recurrent. This study examined knowledge of stroke risk factors and its determinants among stroke survivors. Methods. A cross-sectional survey of consenting stroke survivors at two physiotherapy facilities in Nigeria was carried out. Sociodemographic and clinical data were obtained and knowledge of stroke risk factors (defined as the ability to mention at least one correct risk factor was assessed using open-ended questionnaire. Data were treated with descriptive statistics and logistic regression analysis. Results. Sixty-nine stroke survivors (male = 72.5%; mean ± SD age = 49.7±10.6 years participated in the study. Thirty-four (49.4% participants had knowledge of stroke risk factors. Only educational level was significantly associated with knowledge and participants with tertiary educational qualification were about 48 times (odds ratio = 48.5; CI = 7.6–309.8; P<0.0001 more likely to be knowledgeable than those with no education. Conclusion. Less than half of the participants had knowledge of stroke risk factors. Participants with tertiary education were significantly more knowledgeable than those with lower educational qualifications. Effective means of educating stroke survivors on stroke risk factors should be identified and adopted.

  10. Outcome Determinants of Stroke in a Brazilian Primary Stroke Center

    Gustavo W. Kuster


    Full Text Available Background. Stroke mortality in Brazil is one of the highest among Western countries. Nonetheless, stroke outcome determinants are still poorly known in this country. In this study we evaluate outcome determinants of stroke in a primary stroke center in São Paulo, Brazil. Methods. We evaluated demographic, clinical, and outcome data of patients with ischemic stroke (IS, transient ischemic attack (TIA, and intracerebral hemorrhage (ICH admitted at “Hospital Paulistano,” São Paulo, Brazil. In-hospital mortality and functional outcome determinants were assessed. Univariate and binary logistic regression analysis were performed. Results. Three hundred forty-one patients were included in the study, 52.2% being male with 66.8±15.7 years. The stroke type distribution was IS: 59.2%, TIA: 29.6%, and ICH: 11.1%. ICH was associated with greater severity and poorer functional outcome. The determinants of poorer functional outcome were higher NIHSS, lower Glasgow score, and lower oxygen saturation level. The most important mortality determinant was the presence of visual symptoms. Conclusions. The stroke mortality and stroke outcome determinants found in the present study do not remarkably differ from studies carried out in developed countries. Stroke prognosis studies are crucial to better understand the high burden of stroke in Brazil.

  11. Periodic Limb Movements and White Matter Hyperintensities in First-Ever Minor Stroke or High-Risk Transient Ischemic Attack.

    Boulos, Mark I; Murray, Brian J; Muir, Ryan T; Gao, Fuqiang; Szilagyi, Gregory M; Huroy, Menal; Kiss, Alexander; Walters, Arthur S; Black, Sandra E; Lim, Andrew S; Swartz, Richard H


    Emerging evidence suggests that periodic limb movements (PLMs) may contribute to the development of cerebrovascular disease. White matter hyperintensities (WMHs), a widely accepted biomarker for cerebral small vessel disease, are associated with incident stroke and death. We evaluated the association between increased PLM indices and WMH burden in patients presenting with stroke or transient ischemic attack (TIA), while controlling for vascular risk factors and stroke severity. Thirty patients presenting within 2 weeks of a first-ever minor stroke or high-risk TIA were prospectively recruited. PLM severity was measured with polysomnography. WMH burden was quantified using the Age Related White Matter Changes (ARWMC) scale based on neuroimaging. Partial Spearman's rank-order correlations and multiple linear regression models tested the association between WMH burden and PLM severity. Greater WMH burden was correlated with elevated PLM index and stroke volume. Partial Spearman's rank-order correlations demonstrated that the relationship between WMH burden and PLM index persisted despite controlling for vascular risk factors. Multivariate linear regression models revealed that PLM index was a significant predictor of an elevated ARWMC score while controlling for age, stroke volume, stroke severity, hypertension, and apnea-hypopnea index. The quantity of PLMs was associated with WMH burden in patients with first-ever minor stroke or TIA. PLMs may be a risk factor for or marker of WMH burden, even after considering vascular risk factors and stroke severity. These results invite further investigation of PLMs as a potentially useful target to reduce WMH and stroke burden.

  12. Understanding Stroke - Know Stroke • Know the Signs • Act in Time

    ... Home Current Issue Past Issues Special Section Understanding Stroke Know Stroke • Know the Signs • Act in Time Past Issues / ... Julie Harris, and motivational speaker David Layton. Preventing Stroke "Until I had my stroke, I didn't ...

  13. Morphological and Metabolic Alteration of Cerebellum in Patients with Post-Stroke Depression

    Ling Zhang


    Full Text Available Background: To study morphological and metabolic changes of cerebellum with multimodality magnetic resonance imaging (MRI and proton magnetic resonance spectroscopy (1H-MRS, respective, to explore correlation between cerebellum alteration and severity of depression in patients with post-stroke depression. Methods: 60 subjects, including 40 stroke patients and 20 healthy volunteers were enrolled. Depression of stroke patients was tested by Self-rating Depression Scale (SDS and Hamilton Depression Scale (HAMD, based on which stroke-patients were grouped into post-stroke depression (PSD group and without post-stroke depression (CONT group. Results: Volume of cerebellum decreased in PSD group and CONT group compared with healthy volunteer (NORM group. White matter of cerebellum in PSD group and CONT group was disrupted; such disruption was significantly in PSD group. In addition, there was correlation between cerebellum volume and FA and HDRS scores (PConclusion: Morphologic and metabolic alterations are evident in patients with post-stroke depression, indicating possible involvement of cerebellum in post-stroke-depression occurrence.

  14. Welfare-maximizing and revenue-maximizing tariffs with a few domestic firms

    Bruno Larue; Jean-Philippe Gervais


    In this paper we compare the orthodox optimal tariff formula with the appropriate welfare-maximizing tariff when there are a few producing or importing firms. The welfare-maximizing tariff can be very low, voire negative in some cases, while in others it can even exceed the maximum-revenue tariff. The relationship between the welfare-maximizing tariff and the number of firms need not be monotonically increasing, because the tariff is not strictly used to internalize terms of trade externality...

  15. Cell Treatment for Stroke in Type Two Diabetic Rats Improves Vascular Permeability Measured by MRI.

    Guangliang Ding

    Full Text Available Treatment of stroke with bone marrow stromal cells (BMSC significantly enhances brain remodeling and improves neurological function in non-diabetic stroke rats. Diabetes is a major risk factor for stroke and induces neurovascular changes which may impact stroke therapy. Thus, it is necessary to test our hypothesis that the treatment of stroke with BMSC has therapeutic efficacy in the most common form of diabetes, type 2 diabetes mellitus (T2DM. T2DM was induced in adult male Wistar rats by administration of a high fat diet in combination with a single intraperitoneal injection (35mg/kg of streptozotocin. These rats were then subjected to 2h of middle cerebral artery occlusion (MCAo. T2DM rats received BMSC (5x106, n = 8 or an equal volume of phosphate-buffered saline (PBS (n = 8 via tail-vein injection at 3 days after MCAo. MRI was performed one day and then weekly for 5 weeks post MCAo for all rats. Compared with vehicle treated control T2DM rats, BMSC treatment of stroke in T2DM rats significantly (p<0.05 decreased blood-brain barrier disruption starting at 1 week post stroke measured using contrast enhanced T1-weighted imaging with gadopentetate, and reduced cerebral hemorrhagic spots starting at 3 weeks post stroke measured using susceptibility weighted imaging, although BMSC treatment did not reduce the ischemic lesion volumes as demarcated by T2 maps. These MRI measurements were consistent with histological data. Thus, BMSC treatment of stroke in T2DM rats initiated at 3 days after stroke significantly reduced ischemic vascular damage, although BMSC treatment did not change infarction volume in T2DM rats, measured by MRI.

  16. Role of Acute Lesion Topography in Initial Ischemic Stroke Severity and Long-Term Functional Outcomes.

    Wu, Ona; Cloonan, Lisa; Mocking, Steven J T; Bouts, Mark J R J; Copen, William A; Cougo-Pinto, Pedro T; Fitzpatrick, Kaitlin; Kanakis, Allison; Schaefer, Pamela W; Rosand, Jonathan; Furie, Karen L; Rost, Natalia S


    Acute infarct volume, often proposed as a biomarker for evaluating novel interventions for acute ischemic stroke, correlates only moderately with traditional clinical end points, such as the modified Rankin Scale. We hypothesized that the topography of acute stroke lesions on diffusion-weighted magnetic resonance imaging may provide further information with regard to presenting stroke severity and long-term functional outcomes. Data from a prospective stroke repository were limited to acute ischemic stroke subjects with magnetic resonance imaging completed within 48 hours from last known well, admission NIH Stroke Scale (NIHSS), and 3-to-6 months modified Rankin Scale scores. Using voxel-based lesion symptom mapping techniques, including age, sex, and diffusion-weighted magnetic resonance imaging lesion volume as covariates, statistical maps were calculated to determine the significance of lesion location for clinical outcome and admission stroke severity. Four hundred ninety subjects were analyzed. Acute stroke lesions in the left hemisphere were associated with more severe NIHSS at admission and poor modified Rankin Scale at 3 to 6 months. Specifically, injury to white matter (corona radiata, internal and external capsules, superior longitudinal fasciculus, and uncinate fasciculus), postcentral gyrus, putamen, and operculum were implicated in poor modified Rankin Scale. More severe NIHSS involved these regions, as well as the amygdala, caudate, pallidum, inferior frontal gyrus, insula, and precentral gyrus. Acute lesion topography provides important insights into anatomic correlates of admission stroke severity and poststroke outcomes. Future models that account for infarct location in addition to diffusion-weighted magnetic resonance imaging volume may improve stroke outcome prediction and identify patients likely to benefit from aggressive acute intervention and personalized rehabilitation strategies. © 2015 American Heart Association, Inc.

  17. Left atrial appendage morphology in patients with suspected cardiogenic stroke without known atrial fibrillation.

    Miika Korhonen

    Full Text Available The left atrial appendage (LAA is the typical origin for intracardiac thrombus formation. Whether LAA morphology is associated with increased stroke/TIA risk is controversial and, if it does, which morphological type most predisposes to thrombus formation. We assessed LAA morphology in stroke patients with cryptogenic or suspected cardiogenic etiology and in age- and gender-matched healthy controls. LAA morphology and volume were analyzed by cardiac computed tomography in 111 patients (74 males; mean age 60 ± 11 years with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology other than known atrial fibrillation (AF. A subgroup of 40 patients was compared to an age- and gender-matched control group of 40 healthy individuals (21 males in each; mean age 54 ± 9 years. LAA was classified into four morphology types (Cactus, ChickenWing, WindSock, CauliFlower modified with a quantitative qualifier. The proportions of LAA morphology types in the main stroke group, matched stroke subgroup, and control group were as follows: Cactus (9.0%, 5.0%, 20.0%, ChickenWing (23.4%, 37.5%, 10.0%, WindSock (47.7%, 35.0%, 67.5%, and CauliFlower (19.8%, 22.5%, 2.5%. The distribution of morphology types differed significantly (P<0.001 between the matched stroke subgroup and control group. The proportion of single-lobed LAA was significantly higher (P<0.001 in the matched stroke subgroup (55% than the control group (6%. LAA volumes were significantly larger (P<0.001 in both stroke study groups compared to controls patients. To conclude, LAA morphology differed significantly between stroke patients and controls, and single-lobed LAAs were overrepresented and LAA volume was larger in patients with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology.

  18. Saline volume expansion and cardiovascular physiology: novel observations, old explanations, and new questions.

    Robotham, James L


    In a clinical investigation, Kumar and coworkers reported the hemodynamic events that accompany plasma volume expansion over 3 hours in healthy adult volunteers, and found that increases in stroke volume (SV) may be related to increases in left ventricular (LV)/right ventricular (RV) end-diastolic volume, as they expected, but also to decreases in LV/RV end-systolic volume. The latter finding suggests increased contractility and/or decreased afterload, which do not fit with their perception that clinicians ascribe increases in SV to increases in end-diastolic volume based on Starling's work. Increased ejection fraction and decreased vascular resistances were also observed. The same authors recently reported novel data suggesting that reduced blood viscosity may account for the observed reduction in vascular resistances with saline volume expansion. However, the variances in preload and afterload, along with uncertainty in estimates of contractility, substantially limit their ability to define a primary mechanism to explain decreases in LV end-systolic volume. A focus on using ejection fraction to evaluate the integrated performance of the cardiovascular system is provided to broaden this analytic perspective. Sagawa and colleagues described an approach to estimate the relationship, under clinical conditions, between ventricular and arterial bed elastances (i.e. maximal ventricular systolic elastance [Emax] and maximal arterial systolic elastance [Ea]), reflecting ventricular-arterial coupling. I used the mean data provided in one of the reports from Kumar and coworkers to calculate that LV Emax decreased from 1.09 to 0.96 mmHg/ml with saline volume expansion, while Ea decreased from 1.1 to 0.97 mmHg/ml and the SV increased (i.e. the increase in mean SV was associated with a decrease in mean afterload while the mean contractility decreased). The results reported by Kumar and coworkers invite further studies in normal and critically ill patients during acute saline

  19. Efficiency of a Care Coordination Model: A Randomized Study with Stroke Patients

    Claiborne, Nancy


    Objectives: This study investigated the efficiency of a social work care coordination model for stroke patients. Care coordination addresses patient care and treatment resources across the health care system to reduce risk, improve clinical outcomes, and maximize efficiency. Method: A randomly assigned, pre-post experimental design measured…

  20. Objective evaluation of the quality of movement in daily life after stroke

    van Meulen, Fokke; Klaassen, Bart; Held, Jeremia; Reenalda, Jasper; Buurke, Jaap; van Beijnum, Bernhard J.F.; Luft, Andreas; Veltink, Petrus H.


    Stroke survivors are commonly left with disabilities that impair activities of daily living. The main objective of their rehabilitation program is to maximize the functional performance at home. However, the actual performance of patients in their home environment is unknown. Therefore, objective

  1. Analysis of the XRCC1 gene as a modifier of the cerebral response in ischemic stroke

    Juo Suh-Hang H


    Full Text Available Abstract Background Although there have been studies of the genetic risk factors in the development of stroke, there have been few investigations of role of genes in the cerebral response to ischemia. The brain responds to ischemia in a series of reactions that ultimately influence the volume of a stroke that, in general, correlates with disability. We hypothesize that polymorphisms in genes encoding proteins involved in these reactions could act as modifiers of this response and impact stroke volume. One of the pathways participating in the cerebral ischemic response involves reactive oxygen species which can cause oxidative damage to nucleic acids. DNA repair mechanisms are in place to protect against such damage and imply a role for DNA repair genes in the response of the brain to ischemia and are potential candidate genes for further investigation. Methods We studied two common polymorphisms in the DNA repair gene, XRCC1, C26304T and G28152A, in 134 well characterized patients with non lacunar ischemic strokes. We also performed a case control association study with 113 control patients to assess whether these variants represent risk factors in the development of ischemic stroke. Results Independent of etiology, the "T" allele of the C26304T polymorphism is significantly associated with larger stroke volumes (T-test analysis, p Conclusion Our study suggests a major gene effect of the "T" allele of the C26304T polymorphism modulating the cerebral response to ischemia in non lacunar ischemic stroke.

  2. Maximizing Complementary Quantities by Projective Measurements

    M. Souza, Leonardo A.; Bernardes, Nadja K.; Rossi, Romeu


    In this work, we study the so-called quantitative complementarity quantities. We focus in the following physical situation: two qubits ( q A and q B ) are initially in a maximally entangled state. One of them ( q B ) interacts with a N-qubit system ( R). After the interaction, projective measurements are performed on each of the qubits of R, in a basis that is chosen after independent optimization procedures: maximization of the visibility, the concurrence, and the predictability. For a specific maximization procedure, we study in detail how each of the complementary quantities behave, conditioned on the intensity of the coupling between q B and the N qubits. We show that, if the coupling is sufficiently "strong," independent of the maximization procedure, the concurrence tends to decay quickly. Interestingly enough, the behavior of the concurrence in this model is similar to the entanglement dynamics of a two qubit system subjected to a thermal reservoir, despite that we consider finite N. However, the visibility shows a different behavior: its maximization is more efficient for stronger coupling constants. Moreover, we investigate how the distinguishability, or the information stored in different parts of the system, is distributed for different couplings.

  3. Cardiac Function in Patients with Early Cirrhosis during Maximal Beta-Adrenergic Drive

    Krag, Aleksander; Bendtsen, Flemming; Dahl, Emilie Kristine


    with cirrhosis and controls had an equal stress response, the heart rate and ejection fraction increased similarly and maximal heart rate was reached in all. At rest CO was higher in Child B patients than controls. During maximal stress, Child B patients had higher CO (10.6±2.7 vs. 8.0±1.8 L/min), left ventricle...... A and B cirrhosis (9 with non-alcoholic cirrhosis) and 7 matched controls were included. We used cardiac magnetic resonance imaging to assess left ventricular volumes and cardiac output (CO) at rest and during maximal heart rate induced by increasing dosages of dobutamine and atropine. RESULTS: Patients...... stress induced by dobutamine is normal. With progression of the disease, the mass of the heart increases along with increase in cardiac volumes....

  4. A practical algorithm for finding maximal exact matches in large sequence datasets using sparse suffix arrays

    Khan, Zia; Bloom, Joshua S.; Kruglyak, Leonid; Singh, Mona


    Motivation: High-throughput sequencing technologies place ever increasing demands on existing algorithms for sequence analysis. Algorithms for computing maximal exact matches (MEMs) between sequences appear in two contexts where high-throughput sequencing will vastly increase the volume of sequence data: (i) seeding alignments of high-throughput reads for genome assembly and (ii) designating anchor points for genome–genome comparisons.

  5. Scaling and chiral extrapolation of pion mass and decay constant with maximally twisted mass QCD

    Dimopoulos, P; Herdoiza, G; Jansen, K; Michael, C; Urbach, C


    We present an update of the results for pion mass and pion decay constant as obtained by the ETM collaboration in large scale simulations with maximally twisted mass fermions and two mass degenerate flavours of light quarks. We discuss the continuum, chiral and infinite volume extrapolation of these quantities as well as the extraction of low energy constants, and investigate possible systematic uncertainties.

  6. Ischemia-modified albumin and heart fatty acid-binding protein: could early ischemic cardiac biomarkers be used in acute stroke management?

    Herisson, Fanny; Delaroche, Odile; Auffray-Calvier, Elisabeth; Duport, Benjamin Daumas; Guillon, Benoit


    The detection of biomarkers such as ischemia-modified albumin (IMA) and heart fatty acid-binding protein (HFABP) is used in the early diagnosis of acute myocardial infarction. As these biomarkers are not organ specific, we tested them in the neurovascular field. A total of 41 patients with acute stroke were enrolled (31 ischemic strokes and 10 intracerebral hemorrhages). IMA and HFABP levels were measured in serum samples collected within 4.5 hours of stroke onset. Clinical, imaging, and outcome data were recorded. No difference in baseline IMA or HFABP was found between patients with ischemic and hemorrhagic stroke. There was no correlation among biomarker levels at admission, National Institutes of Health Stroke Scale score, or stroke volume. Neither of the biomarkers could predict short-term prognosis. IMA and HFABP do not appear to be relevant in acute stroke management. Copyright (c) 2010 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Clinical Study on Evolutionary Stroke Treated by Defibrase

    YANG Zhi; JIANG Xiandi


    Objective Evolutionary stroke is one common and important subgroup of acute ischemic stroke with nerve damage symptoms evolutionarily heaving. There is not effective methods clinically to stop its development. This article aims to study the feasibility and effectiveness of Defibrase therapy on evolutionary stroke through observing curative effect of evolutionary stroke treated by defibrase therapy and analyze and compare with that of treated by routine medicine. Methods Select 52 evolutionary stroke cases 8 hours to 5 days after stroke and divide them into treatment group(28 cases):treated by 250ml saline intravenous transfusion with 10u Defibrase,once per day,after 3 successive days switch to routine treatmcnt, and control group(24 cases):receive routine treatment. Both groups have not found significant difference in age and severity through X2 inspection,and are comparable both in case history and complication accumulation.The curative effect is evaluated 10 days and 20 days after treatment respectively.Results 10 days after treatment, in treatment group total efficiency is 63%,in control group that is 36%;20 days after treatment,in treatment group total efficiency is 82% and that in control group is 53%.Both have significant difference(P<0.01).No untoward effect such as hemorrhage occurs to both groups.Discussion and Conclutions In general speaking.within 6 hours after ischmic stroke is the optimum time to conduct thrombus-dissolution,but for evolutionary stroke the situation is still developing within several hours and even several days after stroke,that is to say thrombus is still developing or ischemia half dark band is changing to irreversible .Therefore evolutionary stroke itself is the indication of needing thrombus dissolution.Volume urokinase thrombus-dissolving therapy is easy to superven serious complication such as intracrainial hemorrhage. Insertion treatment is not matured enough limited to equipment,infarct position and curative effect. Defibrase

  8. Organizational issues in stroke treatment: The Swiss paradigm - Stroke units

    Georgios K Matis


    Full Text Available Stroke represents the leading cause of acquired disability in adults and poses a tremendous socioeconomic burden both on patients and the society. In this sense, prompt diagnosis and urgent treatment are needed in order to radically reduce the devastating consequences of this disease. Herein the authors present the new guidelines recently adopted by the Swiss Stroke Society concerning the establishment of stroke units. Standardized treatment and allocation protocols along with an acute rehabilitation concept seem to be the core of the Swiss stroke management system. Coordinated multidisciplinary care provided by specialized medical, nursing and therapy staff is of utmost importance for achieving a significant dependency and death reduction. It is believed that the implementation of these guidelines in the stroke care system would be beneficial not only for the stroke patients, but also for the health system.

  9. Polyploidy Induction of Pteroceltis tatarinowii Maxim

    Lin ZHANG; Feng WANG; Zhongkui SUN; Cuicui ZHU; Rongwei CHEN


    3%Objective] This study was conducted to obtain tetraploid Pteroceltis tatari-nowi Maxim. with excel ent ornamental traits. [Method] The stem apex growing points of Pteroceltis tatarinowi Maxim. were treated with different concentrations of colchicine solution for different hours to figure out a proper method and obtain poly-ploids. [Result] The most effective induction was obtained by treatment with 0.6%-0.8% colchicine for 72 h with 34.2% mutation rate. Flow cytometry and chromosome observation of the stem apex growing point of P. tatarinowi Maxim. proved that the tetraploid plants were successful y obtained with chromosome number 2n=4x=36. [Conclusion] The result not only fil s the blank of polyploid breeding of P. tatarinowi , but also provides an effective way to broaden the methods of cultivation of fast-growing, high-quality, disease-resilience, new varieties of Pteroceltis.

  10. Quantum theory allows for absolute maximal contextuality

    Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán


    Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.

  11. The maximal process of nonlinear shot noise

    Eliazar, Iddo; Klafter, Joseph


    In the nonlinear shot noise system-model shots’ statistics are governed by general Poisson processes, and shots’ decay-dynamics are governed by general nonlinear differential equations. In this research we consider a nonlinear shot noise system and explore the process tracking, along time, the system’s maximal shot magnitude. This ‘maximal process’ is a stationary Markov process following a decay-surge evolution; it is highly robust, and it is capable of displaying both a wide spectrum of statistical behaviors and a rich variety of random decay-surge sample-path trajectories. A comprehensive analysis of the maximal process is conducted, including its Markovian structure, its decay-surge structure, and its correlation structure. All results are obtained analytically and in closed-form.

  12. Energy Band Calculations for Maximally Even Superlattices

    Krantz, Richard; Byrd, Jason


    Superlattices are multiple-well, semiconductor heterostructures that can be described by one-dimensional potential wells separated by potential barriers. We refer to a distribution of wells and barriers based on the theory of maximally even sets as a maximally even superlattice. The prototypical example of a maximally even set is the distribution of white and black keys on a piano keyboard. Black keys may represent wells and the white keys represent barriers. As the number of wells and barriers increase, efficient and stable methods of calculation are necessary to study these structures. We have implemented a finite-element method using the discrete variable representation (FE-DVR) to calculate E versus k for these superlattices. Use of the FE-DVR method greatly reduces the amount of calculation necessary for the eigenvalue problem.

  13. Green and black tea consumption and risk of stroke: a meta-analysis.

    Arab, Lenore; Liu, Weiqing; Elashoff, David


    Experimental models of stroke provide consistent evidence of smaller stroke volumes in animals ingesting tea components or tea extracts. To assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational data on tea and stroke. We searched PubMed and Web of Science for all studies on stroke and tea consumption in humans with original data, including estimation or measurement of tea consumption and outcomes of fatal or nonfatal stroke. Data from 9 studies involving 4378 strokes among 194 965 individuals were pooled. The main outcome was the occurrence of fatal or nonfatal stroke. We tested for heterogeneity and calculated the summary effect estimate associated with consumption of >or=3 cups of tea (green or black) per day using random-effects and fixed-effects models for the homogeneous studies. Publication bias was also evaluated. Regardless of their country of origin, individuals consuming >or=3 cups of tea per day had a 21% lower risk of stroke than those consuming risk reduction, 0.79; CI, 0.73 to 0.85). The proportion of heterogeneity not explained by chance alone was 23.8%. Although a randomized clinical trial would be necessary to confirm the effect, this meta-analysis suggests that daily consumption of either green or black tea equaling 3 cups per day could prevent the onset of ischemic stroke.

  14. Stroke risk interacts with Alzheimer's disease biomarkers on brain aging outcomes.

    Hohman, Timothy J; Samuels, Lauren R; Liu, Dandan; Gifford, Katherine A; Mukherjee, Shubhabrata; Benson, Elleena M; Abel, Ty; Ruberg, Frederick L; Jefferson, Angela L


    Alzheimer's disease (AD) biomarkers and stroke risk factors independently predict cognitive impairment, likely through independent disease pathways. However, limited work has sought to describe the dynamic interplay between these important risk factors. This article evaluated the interaction between stroke risk and AD biomarkers on hippocampal volume and cognitive performance. We first evaluated the interaction between stroke risk factors and AD biomarkers using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI, n = 1202). We then extended our findings to an independent autopsy data set from the National Alzheimer's Coordinating Center (NACC, n = 1122) using measures of AD pathology. Stroke risk was quantified using the Framingham Stroke Risk Profile. In ADNI, stroke risk interacted with tau and amyloid levels in relation to baseline and longitudinal cognitive performance. Similarly, in NACC, stroke risk interacted with amyloid and tau positivity on cognitive performance. The effect of stroke risk factors on cognition was strongest in the absence of AD biomarkers or neuropathology, providing additional evidence that AD biomarkers and stroke risk factors relate to cognition through independent pathways.

  15. Absence of parasympathetic reactivation after maximal exercise.

    de Oliveira, Tiago Peçanha; de Alvarenga Mattos, Raphael; da Silva, Rhenan Bartels Ferreira; Rezende, Rafael Andrade; de Lima, Jorge Roberto Perrout


    The ability of the human organism to recover its autonomic balance soon after physical exercise cessation has an important impact on the individual's health status. Although the dynamics of heart rate recovery after maximal exercise has been studied, little is known about heart rate variability after this type of exercise. The aim of this study is to analyse the dynamics of heart rate and heart rate variability recovery after maximal exercise in healthy young men. Fifteen healthy male subjects (21·7 ± 3·4 years; 24·0 ± 2·1 kg m(-2) ) participated in the study. The experimental protocol consisted of an incremental maximal exercise test on a cycle ergometer, until maximal voluntary exhaustion. After the test, recovery R-R intervals were recorded for 5 min. From the absolute differences between peak heart rate values and the heart rate values at 1 and 5 min of the recovery, the heart rate recovery was calculated. Postexercise heart rate variability was analysed from calculations of the SDNN and RMSSD indexes, in 30-s windows (SDNN(30s) and RMSSD(30s) ) throughout recovery. One and 5 min after maximal exercise cessation, the heart rate recovered 34·7 (±6·6) and 75·5 (±6·1) bpm, respectively. With regard to HRV recovery, while the SDNN(30s) index had a slight increase, RMSSD(30s) index remained totally suppressed throughout the recovery, suggesting an absence of vagal modulation reactivation and, possibly, a discrete sympathetic withdrawal. Therefore, it is possible that the main mechanism associated with the fall of HR after maximal exercise is sympathetic withdrawal or a vagal tone restoration without vagal modulation recovery. © 2012 The Authors Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  16. Brain repair: cell therapy in stroke

    Kalladka D


    Full Text Available Dheeraj Kalladka, Keith W Muir Institute of Neuroscience and Psychology, University of Glasgow, Southern General Hospital, Glasgow, United Kingdom Abstract: Stroke affects one in every six people worldwide, and is the leading cause of adult disability. Some spontaneous recovery is usual but of limited extent, and the mechanisms of late recovery are not completely understood. Endogenous neurogenesis in humans is thought to contribute to repair, but its extent is unknown. Exogenous cell therapy is promising as a means of augmenting brain repair, with evidence in animal stroke models of cell migration, survival, and differentiation, enhanced endogenous angiogenesis and neurogenesis, immunomodulation, and the secretion of trophic factors by stem cells from a variety of sources, but the potential mechanisms of action are incompletely understood. In the animal models of stroke, both mesenchymal stem cells (MSCs and neural stem cells (NSCs improve functional recovery, and MSCs reduce the infarct volume when administered acutely, but the heterogeneity in the choice of assessment scales, publication bias, and the possible confounding effects of immunosuppressants make the comparison of effects across cell types difficult. The use of adult-derived cells avoids the ethical issues around embryonic cells but may have more restricted differentiation potential. The use of autologous cells avoids rejection risk, but the sources are restricted, and culture expansion may be necessary, delaying treatment. Allogeneic cells offer controlled cell numbers and immediate availability, which may have advantages for acute treatment. Early clinical trials of both NSCs and MSCs are ongoing, and clinical safety data are emerging from limited numbers of selected patients. Ongoing research to identify prognostic imaging markers may help to improve patient selection, and the novel imaging techniques may identify biomarkers of recovery and the mechanism of action for cell

  17. Etiologic Ischemic Stroke Phenotypes in the NINDS Stroke Genetics Network

    Ay, Hakan; Arsava, Ethem Murat; Andsberg, Gunnar; Benner, Thomas; Brown, Robert D.; Chapman, Sherita N.; Cole, John W.; Delavaran, Hossein; Dichgans, Martin; Engström, Gunnar; Giralt-Steinhauer, Eva; Grewal, Raji P.; Gwinn, Katrina; Jern, Christina; Jimenez-Conde, Jordi; Jood, Katarina; Katsnelson, Michael; Kissela, Brett; Kittner, Steven J.; Kleindorfer, Dawn O.; Labovitz, Daniel L.; Lanfranconi, Silvia; Lee, Jin-Moo; Lehm, Manuel; Lemmens, Robin; Levi, Chris; Li, Linxin; Lindgren, Arne; Markus, Hugh S.; McArdle, Patrick F.; Melander, Olle; Norrving, Bo; Peddareddygari, Leema Reddy; Pedersén, Annie; Pera, Joanna; Rannikmäe, Kristiina; Rexrode, Kathryn M.; Rhodes, David; Rich, Stephen S.; Roquer, Jaume; Rosand, Jonathan; Rothwell, Peter M.; Rundek, Tatjana; Sacco, Ralph L.; Schmidt, Reinhold; Schürks, Markus; Seiler, Stephan; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie; Thijs, Vincent; Woodfield, Rebecca; Worrall, Bradford B.; Meschia, James F.


    Background and Purpose NINDS Stroke Genetics Network (SiGN) is an international consortium of ischemic stroke studies that aims to generate high quality phenotype data to identify the genetic basis of etiologic stroke subtypes. This analysis characterizes the etiopathogenetic basis of ischemic stroke and reliability of stroke classification in the consortium. Methods Fifty-two trained and certified adjudicators determined both phenotypic (abnormal test findings categorized in major etiologic groups without weighting towards the most likely cause) and causative ischemic stroke subtypes in 16,954 subjects with imaging-confirmed ischemic stroke from 12 US studies and 11 studies from 8 European countries using the web-based Causative Classification of Stroke System. Classification reliability was assessed with blinded re-adjudication of 1509 randomly selected cases. Results The distribution of etiologic categories varied by study, age, sex, and race (pstroke etiology (phenotypic subtype) were classified into the same final causative category with high confidence. There was good agreement for both causative (kappa 0.72, 95%CI:0.69-0.75) and phenotypic classifications (kappa 0.73, 95%CI:0.70-0.75). Conclusions This study demonstrates that etiologic subtypes can be determined with good reliability in studies that include investigators with different expertise and background, institutions with different stroke evaluation protocols and geographic location, and patient populations with different epidemiological characteristics. The discordance between phenotypic and causative stroke subtypes highlights the fact that the presence of an abnormality in a stroke patient does not necessarily mean that it is the cause of stroke. PMID:25378430

  18. Guidelines for acute ischemic stroke treatment: part II: stroke treatment

    Sheila Cristina Ouriques Martins


    Full Text Available The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (

  19. A single bout of high-intensity interval training improves motor skill retention in individuals with stroke

    Nepveu, Jean-Francois; Thiel, Alexander; Tang, Ada


    intensity is sufficient to induce neuroplastic changes and improve motor skill retention in patients with chronic stroke. METHODS: Twenty-two patients with different levels of motor impairment were recruited. On the first session, the effects of a maximal graded exercise test on corticospinal...... exercise test triggers only modest neuroplastic changes in patients with chronic stroke. However, a single bout of high-intensity interval training performed immediately after motor practice improves skill retention, which could potentially accelerate motor recovery in these individuals....

  20. Maximizing band gaps in plate structures

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard


    Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...... periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated...

  1. Maximal and Minimal Congruences on Some Semigroups



    In 2006,Sanwong and Sullivan described the maximal congruences on the semigroup N consisting of all non-negative integers under standard multiplication,and on the semigroup T(X) consisting of all total transformations of an infinite set X under composition. Here,we determine all maximal congruences on the semigroup Zn under multiplication modulo n. And,when Y X,we do the same for the semigroup T(X,Y) consisting of all elements of T(X) whose range is contained in Y. We also characterise the minimal congruences on T(X,Y).

  2. Maximizing oil yields may not optimize economics


    The Los Alamos National Laboratory has used the ASPEN computer code to calculate the economics of different hydroretorting conditions. When the oil yield was maximized and a oil shale plant designed around this process, the costs turned out much higher than expected. However, calculations based on runs of less than maximum yields showed lower cost estimates. It is recommended that future efforts should be concentrated on minimizing production costs rather than maximizing yields. An oil shale plant has been designed around minimum production cost, but has not been able to be tested experimentally.

  3. Maximal Inequalities for Dependent Random Variables

    Hoffmann-Jorgensen, Jorgen


    Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X...

  4. Singularity Structure of Maximally Supersymmetric Scattering Amplitudes

    Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy


    We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....

  5. Hemichorea after ischemic stroke

    Sadullah Saglam


    Full Text Available The deterioration of the balance between direct and indirect ways in the basal ganglia causes chorea. The lesions of contralateral basal ganglia, thalamus or the connection of them all together are responsible for this. Chorea can be observed during the course of metabolic and vascular diseases, neurodegenerative or hereditary diseases. Hyperkinetic movement disorders after acute ischemic stroke are reported as rare; however, hemichorea is the most frequent developing disorder of hyperkinetic movement as a result of cerebrovascular disease. In this case report, we presented two case who applied us with choreiform movements in his left half of the body after acute thalamic stroke. [Cukurova Med J 2016; 41(0.100: 29-32

  6. Plasma cytokines in acute stroke

    Christensen, Hanne Krarup; Boysen, Gudrun; Christensen, Erik


    GOALS: The aim of this study was to test the relations between plasma cytokines and the clinical characteristics, course, and risk factors in acute stroke. PATIENTS AND METHODS: The analysis was based on 179 patients with acute stroke included within 24 hours of stroke onset. On inclusion and 3...... measured by enzyme-linked immunoassay (ELISA). FINDINGS: The levels of most cytokines were significantly different in acute stroke from the levels 3 months later; but only IL-10 was positively associated with stroke severity. C-reactive protein and white blood cell count were positively associated...... with the cytokine response. CONCLUSIONS: We found a substantial overall cytokine reaction that reflected the stroke incident. However, these results do not, at present, suggest a potential for clinical use, as they do not seem to add to the information obtained from the clinical workup of the individual patient....

  7. Pathogenic mechanisms following ischemic stroke.

    Khoshnam, Seyed Esmaeil; Winlow, William; Farzaneh, Maryam; Farbood, Yaghoob; Moghaddam, Hadi Fathi


    Stroke is the second most common cause of death and the leading cause of disability worldwide. Brain injury following stroke results from a complex series of pathophysiological events including excitotoxicity, oxidative and nitrative stress, inflammation, and apoptosis. Moreover, there is a mechanistic link between brain ischemia, innate and adaptive immune cells, intracranial atherosclerosis, and also the gut microbiota in modifying the cerebral responses to ischemic insult. There are very few treatments for stroke injuries, partly owing to an incomplete understanding of the diverse cellular and molecular changes that occur following ischemic stroke and that are responsible for neuronal death. Experimental discoveries have begun to define the cellular and molecular mechanisms involved in stroke injury, leading to the development of numerous agents that target various injury pathways. In the present article, we review the underlying pathophysiology of ischemic stroke and reveal the intertwined pathways that are promising therapeutic targets.

  8. [Mitochondrial diseases and stroke].

    Irimia, P; Oliveros-Cid, A; Martínez-Vila, E


    We review the mitochondrial diseases in which cerebrovascular changes are seen, such as the MERRF syndrome (myoclonic epilepsy and ragged red fibers) or the Kearns-Sayre syndrome (progressive external ophthalmoplegia, retinitis pigmentaria, cerebellar disorders and disorders of cardiac conduction), focusing on the syndrome involving mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). We consider the different clinical aspects, diagnostic methods, pathophysiological mechanisms of the cerebrovascular involvement as well as therapeutic approaches.

  9. Local depletion of glycogen with supra-maximal exercise in human skeletal muscle fibres

    Gejl, K D; Ørtenblad, N; Andersson, E


    four ∼4-minute supra-maximal sprint time trials (STT 1-4) with 45 min recovery. The sub-cellular glycogen volumes in m. triceps brachii were quantified from electron microscopy images before and after both STT 1 and STT 4. During STT 1, the depletion of intramyofibrillar glycogen was higher in type I...... glycogen volume was significantly reduced during STT 4, in both fibre types (main effect: -31% [-50:-11%], P = 0.002). Furthermore, for each of the sub-cellular compartments, the depletion of glycogen during STT 1 was associated with the volumes of glycogen before STT 1. In conclusion, the depletion...

  10. Post-stroke cognitive dysfunctions: A clinical and neuroimaging study

    Andrei Yuryevich Emelin


    Full Text Available Clinical, neuropsychological, and neuroimaging examinations were made in 65 patients (52 men and 13 women aged 65.6±10.1 years who had experienced ischemic stroke. Cognitive impairments (CI were heterogeneous; regulatory functions, attention, and counting were most significantly affected in moderate CI. In mild dementia, mainly poor attention and regulatory dysfunctions were added by clearly-cut impairments of memory, orientation, and visual-spatial function. Brain atrophy, white matter changes, and small focal gray matter damages along with focal post-stroke changes were revealed by neuroimaging in most patients. It was found that besides the volume and location of a damage focus, the signs of impaired integrated mental activity of the brain, regulatory dysfunctions in particular, should be a necessary condition for the verification of post-stroke CI.

  11. The origins of neuromuscular fatigue post-stroke.

    Knorr, S; Ivanova, T D; Doherty, T J; Campbell, J A; Garland, S J


    Fatigue post-stroke is a disabling and persistent symptom affecting many stroke survivors. Despite its high prevalence, the pathophysiology underlying this phenomenon remains obscure. The aim of the present study was to investigate the origins of neuromuscular fatigue post-stroke. Ten chronic stroke survivors and 10 controls sustained an isometric contraction at 30% of maximal voluntary contraction (MVC) with the ankle dorsiflexors. Motor evoked potential (MEP), cortical silent period (SP), voluntary activation, M wave and contractile properties were evaluated before, during and after fatigue among the paretic, non-paretic and control limbs. The pattern of response to fatigue in the non-paretic and control limbs was comparable; therefore, results are presented between the paretic and non-paretic limbs. Before fatigue, reduced MVC peak torque and MEP amplitude were observed on the paretic side in comparison with the non-paretic side. During fatigue, the cortical SP duration increased significantly in both limbs, whereas the MEP amplitude significantly increased only in the non-paretic limb. After fatigue, MVC peak torque decreased significantly in both limbs. Significant reductions in M wave and twitch peak torque were observed in both limbs, pointing to the development of peripheral fatigue. However, central fatigue, evident by a significant reduction in voluntary activation, was greater in the paretic than in the non-paretic limb. After stroke, an inability to increase central excitability in response to an increased cortical inhibition associated with the fatiguing contraction may contribute to central fatigue observed in the paretic limb, which may also be linked to increased self-reported fatigue during activities of daily living. These findings advance our understanding of the neuromuscular basis of fatigue post-stroke.

  12. Optimizing muscle power after stroke: a cross-sectional study

    Stavric Verna A


    Full Text Available Abstract Background Stroke remains a leading cause of disability worldwide and results in muscle performance deficits and limitations in activity performance. Rehabilitation aims to address muscle dysfunction in an effort to improve activity and participation. While muscle strength has an impact on activity performance, muscle power has recently been acknowledged as contributing significantly to activity performance in this population. Therefore, rehabilitation efforts should include training of muscle power. However, little is known about what training parameters, or load, optimize muscle power performance in people with stroke. The purpose of this study was to investigate lower limb muscle power performance at differing loads in people with and without stroke. Methods A cross-sectional study design investigated muscle power performance in 58 hemiplegic and age matched control participants. Lower limb muscle power was measured using a modified leg press machine at 30, 50 and 70% of one repetition maximum (1-RM strength. Results There were significant differences in peak power between involved and uninvolved limbs of stroke participants and between uninvolved and control limbs. Peak power was greatest when pushing against a load of 30% of 1RM for involved, uninvolved and control limbs. Involved limb peak power irrespective of load (Mean:220 ± SD:134 W was significantly lower (p  Conclusions Significant power deficits were seen in both the involved and uninvolved limbs after stroke. Maximal muscle power was produced when pushing against lighter loads. Further intervention studies are needed to determine whether training of both limbs at lighter loads (and higher velocities are preferable to improve both power and activity performance after stroke.

  13. Khat and stroke

    Sanjay V Kulkarni


    Full Text Available Khat chewing, though a tradition followed majorly in African countries, has of late spread widely across the globe due to faster transport systems and advanced preservation techniques. Many complications such as psychosis, arterial hypertension, angina pectoris, and myocardial infarction have been reported in connection to khat abuse. We present a case of a young man who presented with acute onset left-sided weakness. He was a known khat addict for over three decades. A diagnosis of left hemiplegia due to right middle cerebral artery infarction was established. Detailed evaluation revealed no significant underlying cause for stroke. Since the main central nervous system effects of khat are comparable with those of amphetamines and there are established reports of stroke in amphetamine abuse, the former was assumed to be the etiological factor. The patient was discontinued from taking khat and was managed conservatively. The subject showed significant recovery with no further complications or similar episodes during follow-up. To the best of our knowledge, this is the second case of stroke associated with khat. Since the management is essentially conservative, a vigilant history eliciting of khat abuse in prevalent countries would cut down unnecessary healthcare costs.

  14. Calorie restriction and stroke

    Manzanero Silvia


    Full Text Available Abstract Stroke, a major cause of disability and mortality in the elderly, occurs when a cerebral blood vessel is occluded or ruptured, resulting in ischemic damage and death of brain cells. The injury mechanism involves metabolic and oxidative stress, excitotoxicity, apoptosis and inflammatory processes, including activation of glial cells and infiltration of leukocytes. In animal models, dietary energy restriction, by daily calorie reduction (CR or intermittent fasting (IF, extends lifespan and decreases the development of age-related diseases. Dietary energy restriction may also benefit neurons, as suggested by experimental evidence showing that CR and IF protect neurons against degeneration in animal models. Recent findings by our group and others suggest the possibility that dietary energy restriction may protect against stroke induced brain injury, in part by inducing the expression of neurotrophic factors, such as brain-derived neurotrophic factor (BDNF and basic fibroblast growth factor (bFGF; protein chaperones, including heat shock protein 70 (Hsp70 and glucose regulated protein 78 (GRP78; antioxidant enzymes, such as superoxide dismutases (SOD and heme oxygenase-1 (HO-1, silent information regulator T1 (SIRT1, uncoupling proteins and anti-inflammatory cytokines. This article discusses the protective mechanisms activated by dietary energy restriction in ischemic stroke.

  15. Neuroprotection In Acute Stroke

    Ali Amini Harandi


    Full Text Available Stroke is the leading cause of adult disability and remains the third most common cause of death in industrialized nations. The concept of neuroprotection mainly came from the studies of the pathology and pathophysiology of ischemic brain injury. Greater understanding of the pathophysiology of neuronal damage in ischemic stroke has generated interest in neuroprotection as a management strategy. Neuroprotective agents in stroke treatment, have generated long-term interest that have the potential to preserve brain tissue and improve overall outcome. One arm of neuroprotective agents limits acute injury to neurons in the ischemic penumbra. Many of these agents modulate neuronal receptors to reduce release of excitatory neurotransmitters, which contribute to early neuronal injury. Other neuroprotective agents prevent potentially detrimental events associated with return of blood flow. Returning blood contains leukocytes that may occlude small vessels and release toxic products. In fact they should act targeting excitotoxicity, oxidative and nitrosative stress, and inflammation. The past few decades have produced a plethora of negative neuroprotective trial results. The questions of feasibility and practicability cannot be resolved simultaneously. In the future, optimal therapy may be achieved by combining neuroprotective agents with complementary mechanisms. Relevant areas of interest include the search for safe and effective treatment strategies that combine neuroprotection reperfusion, better use of advanced brain imaging for patient selection, and wider implementation of prehospital conducted clinical trials.

  16. Multi-Volume High Resolution RGB-D Mapping with Dynamic Volume Placement

    Salvato, Michael; Finman, Ross; Leonard, John


    We present a novel RGB-D mapping system for generating 3D maps over spatially extended regions with higher resolution than current methods using multiple, dynamically placed mapping volumes. Our method takes in RGB-D frames and dynamically assigns multiple mapping volumes to the environment, exchanging mapping volumes between the CPU and GPU. Mapping volumes are added or removed as needed to allow for spatially extended, high resolution mapping. Our system is designed to maximize the resoluti...

  17. Cycle-maximal triangle-free graphs

    Durocher, Stephane; Gunderson, David S.; Li, Pak Ching;


    Abstract We conjecture that the balanced complete bipartite graph K ⌊ n / 2 ⌋ , ⌈ n / 2 ⌉ contains more cycles than any other n -vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds...

  18. Gradient dynamics and entropy production maximization

    Janečka, Adam


    Gradient dynamics describes irreversible evolution by means of a dissipation potential, which leads to several advantageous features like Maxwell--Onsager relations, distinguishing between thermodynamic forces and fluxes or geometrical interpretation of the dynamics. Entropy production maximization is a powerful tool for predicting constitutive relations in engineering. In this paper, both approaches are compared and their shortcomings and advantages are discussed.

  19. Robust Utility Maximization Under Convex Portfolio Constraints

    Matoussi, Anis, E-mail: [Université du Maine, Risk and Insurance institut of Le Mans Laboratoire Manceau de Mathématiques (France); Mezghani, Hanen, E-mail:; Mnif, Mohamed, E-mail: [University of Tunis El Manar, Laboratoire de Modélisation Mathématique et Numérique dans les Sciences de l’Ingénieur, ENIT (Tunisia)


    We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle.

  20. Maximizing the Motivated Mind for Emergent Giftedness.

    Rea, Dan


    This article explains how the theory of the motivated mind conceptualizes the productive interaction of intelligence, creativity, and achievement motivation and how this theory can help educators to maximize students' emergent potential for giftedness. It discusses the integration of cold-order thinking and hot-chaotic thinking into fluid-adaptive…

  1. The Winning Edge: Maximizing Success in College.

    Schmitt, David E.

    This book offers college students ideas on how to maximize their success in college by examining the personal management techniques a student needs to succeed. Chapters are as follows: "Getting and Staying Motivated"; "Setting Goals and Tapping Your Resources"; "Conquering Time"; "Think Yourself to College Success"; "Understanding and Remembering…


    刘心歌; 蔡海涛


    An existence theorem of maximal elements for a new type of preference correspondences which are Qθ-majorized is given. Then some existence theorems of equilibrium for abstract economy and qualitative game in which the constraint or preference correspondences are Qθ-majorized are obtained in locally convex topological vector spaces.

  3. DNA solution of the maximal clique problem.

    Ouyang, Q; Kaplan, P D; Liu, S; Libchaber, A


    The maximal clique problem has been solved by means of molecular biology techniques. A pool of DNA molecules corresponding to the total ensemble of six-vertex cliques was built, followed by a series of selection processes. The algorithm is highly parallel and has satisfactory fidelity. This work represents further evidence for the ability of DNA computing to solve NP-complete search problems.

  4. Maximal workload capacity on moving platforms

    Heus, R.; Wertheim, A.H.


    Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main

  5. Maximal workload capacity on moving platforms

    Heus, R.; Wertheim, A.H.


    Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main qu

  6. Maximizing Resource Utilization in Video Streaming Systems

    Alsmirat, Mohammad Abdullah


    Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…

  7. Maximizing throughput in an automated test system



    @@ Overview This guide is collection of whitepapers designed to help you develop test systems that lower your cost, increase your test throughput, and can scale with future requirements. This whitepaper provides strategies for maximizing system throughput. To download the complete developers guide (120 pages), visit ni. com/automatedtest.

  8. The gaugings of maximal D=6 supergravity

    Bergshoeff, E.; Samtleben, H.; Sezgin, E.


    We construct the most general gaugings of the maximal D = 6 supergravity. The theory is ( 2, 2) supersymmetric, and possesses an on-shell SO( 5, 5) duality symmetry which plays a key role in determining its couplings. The field content includes 16 vector fields that carry a chiral spinor representat



    In this note the authors give the weighted Lp-boundedness fora class of maximal singular integral operators with rough kernel.The result in this note is an improvement and extension ofthe result obtained by Chen and Lin in 1990.

  10. Maximizing the Range of a Projectile.

    Brown, Ronald A.


    Discusses solutions to the problem of maximizing the range of a projectile. Presents three references that solve the problem with and without the use of calculus. Offers a fourth solution suitable for introductory physics courses that relies more on trigonometry and the geometry of the problem. (MDH)

  11. Ehrenfest's Lottery--Time and Entropy Maximization

    Ashbaugh, Henry S.


    Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…

  12. Testing maximality in muon neutrino flavor mixing

    Choubey, S; Choubey, Sandhya; Roy, Probir


    The small difference between the survival probabilities of muon neutrino and antineutrino beams, traveling through earth matter in a long baseline experiment such as MINOS, is shown to be an important measure of any possible deviation from maximality in the flavor mixing of those states.

  13. Average utility maximization: A preference foundation

    A.V. Kothiyal (Amit); V. Spinu (Vitalie); P.P. Wakker (Peter)


    textabstractThis paper provides necessary and sufficient preference conditions for average utility maximization over sequences of variable length. We obtain full generality by using a new algebraic technique that exploits the richness structure naturally provided by the variable length of the sequen

  14. On the Hardy-Littlewood maximal theorem

    Shinji Yamashita


    Full Text Available The Hardy-Littlewood maximal theorem is extended to functions of class PL in the sense of E. F. Beckenbach and T. Radó, with a more precise expression of the absolute constant in the inequality. As applications we deduce some results on hyperbolic Hardy classes in terms of the non-Euclidean hyperbolic distance in the unit disk.

  15. Maximal Cartel Pricing and Leniency Programs

    Houba, H.E.D.; Motchenkova, E.; Wen, Q.


    For a general class of oligopoly models with price competition, we analyze the impact of ex-ante leniency programs in antitrust regulation on the endogenous maximal-sustainable cartel price. This impact depends upon industry characteristics including its cartel culture. Our analysis disentangles the

  16. How to Generate Good Profit Maximization Problems

    Davis, Lewis


    In this article, the author considers the merits of two classes of profit maximization problems: those involving perfectly competitive firms with quadratic and cubic cost functions. While relatively easy to develop and solve, problems based on quadratic cost functions are too simple to address a number of important issues, such as the use of…

  17. Ehrenfest's Lottery--Time and Entropy Maximization

    Ashbaugh, Henry S.


    Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…

  18. Maximally entangled mixed states made easy

    Aiello, A; Voigt, D; Woerdman, J P


    We show that, contrarily to a recent claim [M. Ziman and V. Bu\\v{z}ek, Phys. Rev. A. \\textbf{72}, 052325 (2005)], it is possible to achieve maximally entangled mixed states of two qubits from the singlet state via the action of local nonunital quantum channels. Moreover, we present a simple, feasible linear optical implementation of one of such channels.

  19. Maximizing Resource Utilization in Video Streaming Systems

    Alsmirat, Mohammad Abdullah


    Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…

  20. Maximizing scientific knowledge from randomized clinical trials

    Gustafsson, Finn; Atar, Dan; Pitt, Bertram


    Trialists have an ethical and financial responsibility to plan and conduct clinical trials in a manner that will maximize the scientific knowledge gained from the trial. However, the amount of scientific information generated by randomized clinical trials in cardiovascular medicine is highly...