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Sample records for maximal stroke volume

  1. Clinically significant change in stroke volume in pulmonary hypertension

    NARCIS (Netherlands)

    van Wolferen, S.A.; van de Veerdonk, M.C.; Mauritz, G.J.; Jacobs, W.; Marcus, J.T.; Marques, K.M.J.; Bronzwaer, J.G.F.; Heijmans, M.W.; Boonstra, A.; Postmus, P.E.; Westerhof, N.; Noordegraaf, A.V.

    2011-01-01

    Background: Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory

  2. Influence of Lumber Volume Maximization in Sawing Hardwood Sawlogs

    Science.gov (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman

    1993-01-01

    The Best Opening Face (BOF) technology for volume maximization during sawing has been rapidly adopted by softwood sawmills. Application of this technology in hardwood sawmills has been limited because of their emphasis on sawing for the highest possible grade of lumber. The reason for this emphasis is that there is a relatively large difference in price between the...

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    . With the supine resting position as a reference, we assessed stroke volume (SV), cardiac output (CO) and filling of the heart during graded tilt to evaluate whether SV and CO are maintained during an assumed maximal physiological filling of the heart elicited by 90 degrees HDT in healthy resting humans. METHODS...

  4. Clinically significant change in stroke volume in pulmonary hypertension.

    Science.gov (United States)

    van Wolferen, Serge A; van de Veerdonk, Marielle C; Mauritz, Gert-Jan; Jacobs, Wouter; Marcus, J Tim; Marques, Koen M J; Bronzwaer, Jean G F; Heymans, Martijn W; Boonstra, Anco; Postmus, Pieter E; Westerhof, Nico; Vonk Noordegraaf, Anton

    2011-05-01

    Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory increased heart rate as is the case for cardiac output. For this reason, stroke volume, which can be measured noninvasively, is an important hemodynamic parameter to monitor during treatment. However, the extent of change in stroke volume that constitutes a clinically significant change is unknown. The aim of this study was to determine the minimal important difference (MID) in stroke volume in PH. One hundred eleven patients were evaluated at baseline and after 1 year of follow-up with a 6-min walk test (6MWT) and cardiac MRI. Using the anchor-based method with 6MWT as the anchor, and the distribution-based method, the MID of stroke volume change could be determined. After 1 year of treatment, there was, on average, a significant increase in stroke volume and 6MWT. The change in stroke volume was related to the change in 6MWT. Using the anchor-based method, an MID of 10 mL in stroke volume was calculated. The distribution-based method resulted in an MID of 8 to 12 mL. Both methods showed that a 10-mL change in stroke volume during follow-up should be considered as clinically relevant. This value can be used to interpret changes in stroke volume during clinical follow-up in PH.

  5. MEAN PLATELET VOLUME AND RISK OF THROMBOTIC STROKE

    Directory of Open Access Journals (Sweden)

    Prasantha Kumar Thankappan

    2017-07-01

    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.

  6. Improved lower extremity pedaling mechanics in individuals with stroke under maximal workloads.

    Science.gov (United States)

    Linder, Susan M; Rosenfeldt, Anson B; Bazyk, Andrew S; Koop, Mandy Miller; Ozinga, Sarah; Alberts, Jay L

    2018-05-01

    Background Individuals with stroke present with motor control deficits resulting in the abnormal activation and timing of agonist and antagonist muscles and inefficient movement patterns. The analysis of pedaling biomechanics provides a window into understanding motor control deficits, which vary as a function of workload. Understanding the relationship between workload and motor control is critical when considering exercise prescription during stroke rehabilitation. Objectives To characterize pedaling kinematics and motor control processes under conditions in which workload was systematically increased to an eventual patient-specific maximum. Methods A cohort study was conducted in which 18 individuals with chronic stroke underwent a maximal exertion cardiopulmonary exercise test on a stationary cycle ergometer, during which pedaling torque was continuously recorded. Measures of force production, pedaling symmetry, and pedaling smoothness were obtained. Results Mean Torque increased significantly (p pedaling action, improved from 0.37(0.29) to 0.29(0.35) during downstroke (p = 0.007), and worsened during the upstroke: -0.37(0.38) to -0.62(0.46) (p pedaling improved significantly from initial to terminal workloads (p pedaling kinematics at terminal workloads indicate that individuals with stroke demonstrate improved motor control with respect to the timing, sequencing, and activation of hemiparetic lower extremity musculature compared to lower workloads. Therapeutic prescription involving higher resistance may be necessary to sufficiently engage and activate the paretic lower extremity.

  7. Stroke maximizing and high efficient hysteresis hybrid modeling for a rhombic piezoelectric actuator

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    Shao, Shubao; Xu, Minglong; Zhang, Shuwen; Xie, Shilin

    2016-06-01

    Rhombic piezoelectric actuator (RPA), which employs a rhombic mechanism to amplify the small stroke of PZT stack, has been widely used in many micro-positioning machineries due to its remarkable properties such as high displacement resolution and compact structure. In order to achieve large actuation range along with high accuracy, the stroke maximizing and compensation for the hysteresis are two concerns in the use of RPA. However, existing maximization methods based on theoretical model can hardly accurately predict the maximum stroke of RPA because of approximation errors that are caused by the simplifications that must be made in the analysis. Moreover, despite the high hysteresis modeling accuracy of Preisach model, its modeling procedure is trivial and time-consuming since a large set of experimental data is required to determine the model parameters. In our research, to improve the accuracy of theoretical model of RPA, the approximation theory is employed in which the approximation errors can be compensated by two dimensionless coefficients. To simplify the hysteresis modeling procedure, a hybrid modeling method is proposed in which the parameters of Preisach model can be identified from only a small set of experimental data by using the combination of discrete Preisach model (DPM) with particle swarm optimization (PSO) algorithm. The proposed novel hybrid modeling method can not only model the hysteresis with considerable accuracy but also significantly simplified the modeling procedure. Finally, the inversion of hysteresis is introduced to compensate for the hysteresis non-linearity of RPA, and consequently a pseudo-linear system can be obtained.

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

    Directory of Open Access Journals (Sweden)

    Konings Maurits K

    2012-08-01

    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

  9. Influence of Lumber Volume Maximization on Value in Sawing Hardwood Sawlogs

    Science.gov (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman

    1992-01-01

    Research based on applying volume-maximizing sawing solutions to idealized hardwood log forms has shown that average lumber yield can be increased by 6 percent. It is possible, however, that a lumber volume-maximizing solution may result in a decrease in lumber grade and a net reduction in total value of sawn lumber. The objective of this study was to determine the...

  10. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

    1981-11-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

  11. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    International Nuclear Information System (INIS)

    Sattler, R.; Stoll, W.

    1981-01-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

  12. Stroke infarct volume estimation in fixed tissue

    DEFF Research Database (Denmark)

    Bay, Vibeke; Kjølby, Birgitte F; Iversen, Nina K

    2018-01-01

    be investigated in fixed tissue and therefore allows a more direct comparison between lesion volumes from MRI and histology. Additionally, the larger MKT infarct lesion indicates that MKT do provide increased sensitivity to microstructural changes in the lesion area compared to MD....... and prepared. The infarct was clearly visible in both MD and MKT maps. The MKT lesion volume was roughly 31% larger than the MD lesion volume. Subsequent histological analysis (hematoxylin) revealed similar lesion volumes to MD. Our study shows that structural components underlying the MD/MKT mismatch can...

  13. Radionuclide determination of right and left ventricular stroke volumes

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wei Feng; Roubin, G S; Choong, C Y.P.; Harris, P J; Flether, P J; Kelly, D T; Uren, R F; Hutton, B F

    1985-03-01

    The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P < 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

  14. The association of insular stroke with lesion volume

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    Nishanth Kodumuri

    2016-01-01

    Full Text Available The insula has been implicated in many sequelae of stroke. It is the area most commonly infarcted in people with post-stroke arrhythmias, loss of thermal sensation, hospital acquired pneumonia, and apraxia of speech. We hypothesized that some of these results reflect the fact that: (1 ischemic strokes that involve the insula are larger than strokes that exclude the insula (and therefore are associated with more common and persistent deficits; and (2 insular involvement is a marker of middle cerebral artery (MCA occlusion. We analyzed MRI scans of 861 patients with acute ischemic hemispheric strokes unselected for functional deficits, and compared infarcts involving the insula to infarcts not involving the insula using t-tests for continuous variables and chi square tests for dichotomous variables. Mean infarct volume was larger for infarcts including the insula (n = 232 versus excluding the insula (n = 629: 65.8 ± 78.8 versus 10.2 ± 15.9 cm3 (p < 0.00001. Even when we removed lacunar infarcts, mean volume of non-lacunar infarcts that included insula (n = 775 were larger than non-lacunar infarcts (n = 227 that excluded insula: 67.0 cm3 ± 79.2 versus 11.5 cm3 ± 16.7 (p < 0.00001. Of infarcts in the 90th percentile for volume, 87% included the insula (χ2 = 181.8; p < 0.00001. Furthermore, 79.0% infarcts due to MCA occlusion included the insula; 78.5% of infarcts without MCA occlusion excluded the insula (χ2 = 93.1; p < 0.0001. The association between insular damage and acute or chronic sequelae likely often reflects the fact that insular infarct is a marker of large infarcts caused by occlusion of the MCA more than a specific role of the insula in a range of functions. Particularly in acute stroke, some deficits may also be due to ischemia of the MCA or ICA territory caused by large vessel occlusion.

  15. Lung volumes and maximal respiratory pressures in collegiate swimmers and runners.

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    Cordain, L; Tucker, A; Moon, D; Stager, J M

    1990-03-01

    To determine whether respiratory muscle strength is related to pulmonary volume differences in athletes and nonathletes, 11 intercollegiate female swimmers, 11 female cross-country runners, and two nonathletic control groups, matched to the athletes in height and age, were evaluated for pulmonary parameters including maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax). Swimmers exhibited larger (p less than .05) vital capacities (VC), residual lung volumes (RV), inspiratory capacities (IC), and functional residual capacities (FRC) than both the runners or the controls but no difference (p greater than .05) in either PImax or inspiratory flow (FIV 25%-75%). Timed expiratory volumes (FEV 0.5 and FEV 1.0) were significantly (p less than .05) lower in the swimmers than in the controls. These data suggest that an adaptational growth may be responsible, in part, for the augmented static lung volumes demonstrated in swimmers.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    , 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...... with higher risk of cardiovascular events {hazard ratio 1.69 per 1 SD (6 ml/m2.04) lower stroke volume [95% confidence interval (CI) 1.35–2.11], P secondary model also independent of stress-corrected midwall shortening......, hence, adds information on cardiovascular risk in treated hypertensive patients beyond assessment of left ventricular structure alone....

  17. Goal-directed fluid therapy: stroke volume optimisation and cardiac dimensions in supine healthy humans

    DEFF Research Database (Denmark)

    Jans, O.; Tollund, C.; Bundgaard-Nielsen, M.

    2008-01-01

    BACKGROUND: Based on maximisation of cardiac stroke volume (SV), peri-operative individualised goal-directed fluid therapy improves patient outcome. It remains, however, unknown how fluid therapy by this strategy relates to filling of the heart during supine rest as reference for the anaesthetised...... by thoracic electrical admittance, central venous oxygenation and pressure, and arterial plasma atrial natriuretic peptide. Also, muscle and brain oxygenation were assessed by near infrared spectroscopy (n=7). RESULTS: The HUT reduced the mentioned indices of CBV, the end-diastolic dimensions of the heart...... therapy is that when a maximal SV is established for patients, cardiac pre-load is comparable to that of supine healthy subjects Udgivelsesdato: 2008/4...

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

    DEFF Research Database (Denmark)

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

    1996-01-01

    the hypovolemia. Alterations in pV and pulsatility indices were closely related to changes in stroke volume, and a negative correlation was found between diastolic velocities and stroke volume. regression analysis showed no significant relation between variations in velocity parameters and blood pressure. Results...

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

    Science.gov (United States)

    Wittink, Harriet; Verschuren, Olaf; Terwee, Caroline; de Groot, Janke; Kwakkel, Gert; van de Port, Ingrid

    2017-11-21

    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. PubMed, Embase and Cinahl were searched from inception up to 15 June 2016. A total of 9 studies were identified reporting on 9 different cardiopulmonary exercise test protocols. VO2max measured with cardiopulmonary exercise test and open spirometry was the construct of interest. The target population was adult persons after stroke. We included all studies that evaluated reliability, measurement error, criterion validity, content validity, hypothesis testing and/or responsiveness of cardiopulmonary exercise test protocols. Two researchers independently screened the literature, assessed methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments checklist and extracted data on measurement properties of cardiopulmonary exercise test protocols. Most studies reported on only one measurement property. Best-evidence synthesis was derived taking into account the methodological quality of the studies, the results and the consistency of the results. No judgement could be made on which protocol is "best" for measuring VO2max in persons after stroke due to lack of high-quality studies on the measurement properties of the cardiopulmonary exercise test.

  20. Splenectomy reduces infarct volume and neuroinflammation in male but not female mice in experimental stroke

    Science.gov (United States)

    Dotson, Abby L.; Wang, Jianming; Saugstad, Julie; Murphy, Stephanie J.; Offner, Halina

    2014-01-01

    The peripheral immune response contributes to neurodegeneration after stroke yet little is known about how this process differs between males and females. The current study demonstrates that splenectomy prior to experimental stroke eliminates sex differences in infarct volume and activated brain monocytes/microglia. In the periphery of both sexes, activated T cells correlate directly with stroke outcome while monocytes are reduced by splenectomy only in males. This study provides new information about the sex specific mechanisms of the peripheral immune response in neurodegeneration after stroke and demonstrates the need for representation of both sexes in basic and clinical stroke research. PMID:25434281

  1. Radionuclide stroke count ratios for assessment of right and left ventricular volume overload in children

    International Nuclear Information System (INIS)

    Parrish, M.D.; Graham, T.P. Jr.; Born, M.L.; Jones, J.P.; Boucek, R.J. Jr.; Artman, M.; Partain, C.L.

    1983-01-01

    The ratio of left ventricular to right ventricular stroke counts measured by radionuclide angiography has been used in adults to estimate the severity of left-sided valvular regurgitation. The validation of this technique in children for assessment of right and left ventricular volume overload is reported herein. Radionuclide stroke count ratios in 60 children aged 0.5 to 19 years (mean 11) were determined. Based on their diagnoses, the patients were divided into 3 groups: (1) normal--40 patients with no shunts or valvular regurgitation, (2) left ventricular volume overload--13 patients with mitral or aortic regurgitation, or both, and (3) right ventricular volume overload--7 patients, 2 with severe tricuspid regurgitation, 3 with atrial septal defects, and 2 with total anomalous pulmonary venous drainage. The radionuclide stroke count ratio clearly differentiated these groups (p less than 0.05): normal patients had a stroke count ratio of 1.04 +/- 0.17 (mean +/- 1 standard deviation), the left ventricular volume overload group had a stroke count ratio of 2.43 +/- 0.86, and the right ventricular volume overload group had a stroke count ratio of 0.44 +/- 0.17. In 22 of our 60 patients, radionuclide stroke count ratios were compared with cineangiographic stroke volume ratios, resulting in a correlation coefficient of 0.88. It is concluded that radionuclide ventriculography is an excellent tool for qualitative and quantitative assessment of valvular regurgitation in children

  2. Case volumes of intra-arterial and intravenous treatment of ischemic stroke in the USA.

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    Hirsch, J A; Yoo, A J; Nogueira, R G; Verduzco, L A; Schwamm, L H; Pryor, J C; Rabinov, J D; González, R G

    2009-07-01

    Ischemic stroke is a major cause of disability and death in the USA. Intravenous tissue plasminogen activator (t-PA) remains underutilized. With the development of newer intra-arterial reperfusion therapies, there is increased opportunity to address the more devastating large-vessel occlusions. We seek to identify the numbers of patients with stroke treated with intravenous and intra-arterial therapies, as well as to estimate the potential number of intra-arterial cases in the foreseeable future. We performed a literature search to determine case volumes of intravenous t-PA use. We extrapolated the current case volume of intra-arterial stroke therapies from the numbers of cases in which the Merci retrieval device was used. In order to estimate the potential numbers of intra-arterial stroke cases, we characterized the percentage of patients with stroke who received intra-arterial therapy at two leading stroke centers. We applied these percentages to the numbers of patients with stroke seen at the top 100, 200 and 500 stroke centers by volume. The rate of intravenous t-PA use is 2.4-3.6%, resulting in 15 000-22 000 cases/year in the USA. The estimated case volume of intra-arterial therapies is 3500-7200 in 2006. Based on data from St. Luke's Brain and Stroke Institute and Massachusetts General Hospital, approximately 5-20% of patients with ischemic stroke can be treated with intra-arterial therapies. Extrapolating this to the top 500 stroke centers by volume, the potential number of intra-arterial cases in the USA is 10 400-41 500/year. Based on the current numbers of intra-arterial cases, our theoretical model identifies a potential for significant growth of this stroke therapy.

  3. Estimated maximal and current brain volume predict cognitive ability in old age

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    Royle, Natalie A.; Booth, Tom; Valdés Hernández, Maria C.; Penke, Lars; Murray, Catherine; Gow, Alan J.; Maniega, Susana Muñoz; Starr, John; Bastin, Mark E.; Deary, Ian J.; Wardlaw, Joanna M.

    2013-01-01

    Brain tissue deterioration is a significant contributor to lower cognitive ability in later life; however, few studies have appropriate data to establish how much influence prior brain volume and prior cognitive performance have on this association. We investigated the associations between structural brain imaging biomarkers, including an estimate of maximal brain volume, and detailed measures of cognitive ability at age 73 years in a large (N = 620), generally healthy, community-dwelling population. Cognitive ability data were available from age 11 years. We found positive associations (r) between general cognitive ability and estimated brain volume in youth (male, 0.28; females, 0.12), and in measured brain volume in later life (males, 0.27; females, 0.26). Our findings show that cognitive ability in youth is a strong predictor of estimated prior and measured current brain volume in old age but that these effects were the same for both white and gray matter. As 1 of the largest studies of associations between brain volume and cognitive ability with normal aging, this work contributes to the wider understanding of how some early-life factors influence cognitive aging. PMID:23850342

  4. Cortical Composition Hierarchy Driven by Spine Proportion Economical Maximization or Wire Volume Minimization.

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    Jan Karbowski

    2015-10-01

    Full Text Available The structure and quantitative composition of the cerebral cortex are interrelated with its computational capacity. Empirical data analyzed here indicate a certain hierarchy in local cortical composition. Specifically, neural wire, i.e., axons and dendrites take each about 1/3 of cortical space, spines and glia/astrocytes occupy each about (1/3(2, and capillaries around (1/3(4. Moreover, data analysis across species reveals that these fractions are roughly brain size independent, which suggests that they could be in some sense optimal and thus important for brain function. Is there any principle that sets them in this invariant way? This study first builds a model of local circuit in which neural wire, spines, astrocytes, and capillaries are mutually coupled elements and are treated within a single mathematical framework. Next, various forms of wire minimization rule (wire length, surface area, volume, or conduction delays are analyzed, of which, only minimization of wire volume provides realistic results that are very close to the empirical cortical fractions. As an alternative, a new principle called "spine economy maximization" is proposed and investigated, which is associated with maximization of spine proportion in the cortex per spine size that yields equally good but more robust results. Additionally, a combination of wire cost and spine economy notions is considered as a meta-principle, and it is found that this proposition gives only marginally better results than either pure wire volume minimization or pure spine economy maximization, but only if spine economy component dominates. However, such a combined meta-principle yields much better results than the constraints related solely to minimization of wire length, wire surface area, and conduction delays. Interestingly, the type of spine size distribution also plays a role, and better agreement with the data is achieved for distributions with long tails. In sum, these results suggest

  5. Very Low Cerebral Blood Volume Predicts Parenchymal Hematoma in Acute Ischemic Stroke

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......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...

  6. Intraoperative stroke volume optimization using stroke volume, arterial pressure, and heart rate: closed-loop (learning intravenous resuscitator) versus anesthesiologists.

    Science.gov (United States)

    Rinehart, Joseph; Chung, Elena; Canales, Cecilia; Cannesson, Maxime

    2012-10-01

    The authors compared the performance of a group of anesthesia providers to closed-loop (Learning Intravenous Resuscitator [LIR]) management in a simulated hemorrhage scenario using cardiac output monitoring. A prospective cohort study. In silico simulation. University hospital anesthesiologists and the LIR closed-loop fluid administration system. Using a patient simulator, a 90-minute simulated hemorrhage protocol was run, which included a 1,200-mL blood loss over 30 minutes. Twenty practicing anesthesiology providers were asked to manage this scenario by providing fluids and vasopressor medication at their discretion. The simulation program was also run 20 times with the LIR closed-loop algorithm managing fluids and an additional 20 times with no intervention. Simulated patient weight, height, heart rate, mean arterial pressure, and cardiac output (CO) were similar at baseline. The mean stroke volume, the mean arterial pressure, CO, and the final CO were higher in the closed-loop group than in the practitioners group, and the coefficient of variance was lower. The closed-loop group received slightly more fluid (2.1 v 1.9 L, p closed-loop maintained more stable hemodynamics than the practitioners primarily because the fluid was given earlier in the protocol and CO optimized before the hemorrhage began, whereas practitioners tended to resuscitate well but only after significant hemodynamic change indicated the need. Overall, these data support the potential usefulness of this closed-loop algorithm in clinical settings in which dynamic predictors are not available or applicable. Published by Elsevier Inc.

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

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    DeJong, Stacey L.; Lang, Catherine E.

    2012-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Jamie Stanley

    2014-06-01

    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.

  9. The value of serum mean platelet volume in ischaemic stroke patient

    International Nuclear Information System (INIS)

    Tamer, F.; Fevzi, Y.; Deniz, A.E.; Cemil, K.; Cihat, Y.; Muhittin, Y.; Serkan, Y.M.; Ali, C.M.; Faith, B.

    2013-01-01

    Objective: To investigate the value of serum Mean Platelet Volume in acute ischaemic stroke patients. Method: The retrospective case-control study was conducted at Ankara Numune Training and Research Hospital in Turkey and comprised record of patients of acute ischaemic stroke admitted to the Emergency Department between June 2010 and January 2012. The two groups were statistically compared using SPSS 18.0. Result: Overall, there were 482 stroke patients (Group 1) and 315 subjects as controls (Group 2). The median value in Group 1 was 9.0 (2.1) (fL), while in Group 2 it was 8.80 (2.4) (fL). The difference was statistically significant (Z=-2.80; p<0.05). Conclusion: Mean Platelet Volume increased in the stroke patients. (author)

  10. Ischemic Volume and Neurological Deficit: Correlation of Computed Tomography Perfusion with the National Institutes of Health Stroke Scale Score in Acute Ischemic Stroke.

    Science.gov (United States)

    Furlanis, Giovanni; Ajčević, Miloš; Stragapede, Lara; Lugnan, Carlo; Ridolfi, Mariana; Caruso, Paola; Naccarato, Marcello; Ukmar, Maja; Manganotti, Paolo

    2018-04-30

    The National Institutes of Health Stroke Scale (NIHSS) is the most adopted stroke patients' evaluation tool in emergency settings to assess the severity of stroke and to determine the patients' eligibility for specific treatments. Computed tomography perfusion (CTP) is crucial to identify salvageable tissue that can benefit from the reperfusion treatment. The aim of this study is to identify the relation between the NIHSS scores and the hypoperfused volumes evaluated by CTP in patients with hyperacute ischemic stroke. This retrospective study was conducted on 105 patients with ischemic stroke who underwent NIHSS assessment and CTP in the hyperacute phase. Hypoperfused volume was evaluated by CTP maps processed with semi-automatic algorithm. An analysis was conducted to determine the degree of correlation between the NIHSS scores and the ischemic lesion volumes and to investigate the relation between the anterior and the posterior circulation strokes, as well as between the right and the left hemispheric strokes. A significant correlation was found between ischemic volume and NIHSS score at baseline (r = .82; P correlation was identified in the anterior circulation stroke (r = .76; P correlated for the left and the right hemispheric strokes (r = .83 and .81; P correlation between the baseline NIHSS score and the ischemic volume estimated by CTP. We confirmed that NIHSS is a reliable predictor of perfusion deficits in acute ischemic stroke. CTP allows fast imaging assessment in the hyperacute phase. The results highlight the importance of these diagnostic tools in the assessment of stroke severity and in acute decision-making. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. Maximal oxygen consumption, respiratory volume and some related factors in fire-fighting personnel

    Directory of Open Access Journals (Sweden)

    Touraj Khazraee

    2017-01-01

    Full Text Available Background: Firefighters for difficult activities and rescue of damaged people must be in appropriate physical ability. Maximal oxygen capacity is an indicator for diagnosis of physical ability of workers. This study aimed to assess the cardiorespiratory system and its related factors in firefighters. Methods: This study was conducted on 110 firefighters from various stations. An self-administered questionnaire (respiratory disorders questionnaire, Tuxworth-Shahnavaz step test, and pulmonary function test was used to collection of required data. Average of humidity and temperature was 52% and 17°C, respectively. Background average noise levels were between 55 and 65 dB. Data were analyzed using SPSS software (version 19. Results: The mean age of the study participants was 32 ± 6.2 years. The means of forced vital capacity (FVC, forced expiratory volume in 1 s (FEV1, and FEV1/FVC were 92% ±9.4%, 87% ±9.2%, and 80% ±6.1%, respectively. The participants' mean VO2-max was 2.79 ± 0.29 L/min or 37.34 ± 4.27 ml/kg body weight per minute. The results revealed that weight has a direct association with vital capacity (VC, FVC, and peak expiratory flow. In addition, height was directly associated with VC, FVC, and VO2-max (P < 0.05. However, there was an inverse and significant association between height and FEV1/FVC (r = −0.23,P< 0.05. Height, weight, body mass index, and waist circumference were directly associated with VO2-max. Conclusions: The findings of this study showed that the amount of maximum oxygen consumption is close with the proposed range of this parameter among firefighters in other studies. Furthermore, the results of the study revealed that individuals had normal amounts of lung volume index. This issue can be attributed to the appropriate usage of respiratory masks.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    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......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...

  13. Stroke

    Science.gov (United States)

    ... doctor Preventing falls Stroke - discharge Swallowing problems Images Brain Carotid stenosis, x-ray of the left artery Carotid stenosis, x-ray of the right artery Stroke Brainstem function Cerebellum - function Circle of Willis Left cerebral hemisphere - ...

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

    Science.gov (United States)

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

    1982-02-01

    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.

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

    DEFF Research Database (Denmark)

    Fuglsang, S; Bendtsen, F; Christensen, E

    2001-01-01

    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 abnormalities in the arterial compliance of these patients....

  16. Precision of gated equilibrium radioventriculography in measuring left ventricular stroke volume

    International Nuclear Information System (INIS)

    Bourguignon, M.H.; Wise, R.A.; Ehrlich, W.E.; Douglas, K.H.; Camargo, E.E.; Harrison, K.E.; Wagner, H.N. Jr.

    1983-01-01

    We have demonstrated that relative changes of small amplitude in ventricular stroke volume can be measured accurately in dogs when a fully automated technique for delineation of end diastolic and end systolic region of interest (ROI) is used. Consequently, we expect such a technique to be very sensitive in measuring relative changes of any ventricular quantitative parameter from gated equilibrium radio ventriculography in humans

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

    Czech Academy of Sciences Publication Activity Database

    Horn, P.; Ošťádal, P.; Ošťádal, Bohuslav

    2015-01-01

    Roč. 64, č. 2 (2015), s. 203-207 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : cardiac output * cycling * heart rate * stroke volume Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.643, year: 2015

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

    Science.gov (United States)

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

    2016-10-01

    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.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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. (paper)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2014-10-26

    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.)

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

    International Nuclear Information System (INIS)

    Faigle, Roland; Marsh, Elisabeth B.; Llinas, Rafael H.; Urrutia, Victor C.; Wozniak, Amy W.

    2015-01-01

    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 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 3 (sensitivity 75.0 %, specificity 76.7 %). Infarct volume greater than 3 cm 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.)

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

    Directory of Open Access Journals (Sweden)

    Qingqing Diao

    2017-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2015-07-15

    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.)

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

    International Nuclear Information System (INIS)

    Yassi, Nawaf; Campbell, Bruce C.V.; Davis, Stephen M.; Bivard, Andrew; Moffat, Bradford A.; Steward, Christopher; Desmond, Patricia M.; Churilov, Leonid; Parsons, Mark W.

    2015-01-01

    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.)

  5. Effects of volume-based overload plyometric training on maximal-intensity exercise adaptations in young basketball players.

    Science.gov (United States)

    Asadi, Abbas; Ramirez-Campillo, Rodrigo; Meylan, Cesar; Nakamura, Fabio Y; Cañas-Jamett, Rodrigo; Izquierdo, Mikel

    2017-12-01

    The aim of the present study was to compare maximal-intensity exercise adaptations in young basketball players (who were strong individuals at baseline) participating in regular basketball training versus regular plus a volume-based plyometric training program in the pre-season period. Young basketball players were recruited and assigned either to a plyometric with regular basketball training group (experimental group [EG]; N.=8), or a basketball training only group (control group [CG]; N.=8). The athletes in EG performed periodized (i.e., from 117 to 183 jumps per session) plyometric training for eight weeks. Before and after the intervention, players were assessed in vertical and broad jump, change of direction, maximal strength and a 60-meter sprint test. No significant improvements were found in the CG, while the EG improved vertical jump (effect size [ES] 2.8), broad jump (ES=2.4), agility T test (ES=2.2), Illinois agility test (ES=1.4), maximal strength (ES=1.8), and 60-m sprint (ES=1.6) (Ptraining in addition to regular basketball practice can lead to meaningful improvements in maximal-intensity exercise adaptations among young basketball players during the pre-season.

  6. Maximizing post-stroke upper limb rehabilitation using a novel telerehabilitation interactive virtual reality system in the patient's home: study protocol of a randomized clinical trial.

    Science.gov (United States)

    Kairy, Dahlia; Veras, Mirella; Archambault, Philippe; Hernandez, Alejandro; Higgins, Johanne; Levin, Mindy F; Poissant, Lise; Raz, Amir; Kaizer, Franceen

    2016-03-01

    Telerehabilitation (TR), or the provision of rehabilitation services from a distance using telecommunication tools such as the Internet, can contribute to ensure that patients receive the best care at the right time. This study aims to assess the effect of an interactive virtual reality (VR) system that allows ongoing rehabilitation of the upper extremity (UE) following a stroke, while the person is in their own home, with offline monitoring and feedback from a therapist at a distance. A single-blind (evaluator is blind to group assignment) two-arm randomized controlled trial is proposed, with participants who have had a stroke and are no longer receiving rehabilitation services randomly allocated to: (1) 4-week written home exercise program, i.e. usual care discharge home program or (2) a 4-week home-based TR exercise program using VR in addition to usual care i.e. treatment group. Motor recovery of the UE will be assessed using the Fugl-Meyer Assessment-UE and the Box and Block tests. To determine the efficacy of the system in terms of functional recovery, the Motor Activity Log, a self-reported measure of UE use will be used. Impact on quality of life will be determined using the Stroke Impact Scale-16. Lastly, a preliminary cost-effectiveness analysis will be conducted using costs and outcomes for all groups. Findings will contribute to evidence regarding the use of TR and VR to provide stroke rehabilitation services from a distance. This approach can enhance continuity of care once patients are discharged from rehabilitation, in order to maximize their recovery beyond the current available services. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Acute effects of volume-oriented incentive spirometry on chest wall volumes in patients after a stroke.

    Science.gov (United States)

    Lima, Illia Ndf; Fregonezi, Guilherme Af; Melo, Rodrigo; Cabral, Elis Ea; Aliverti, Andrea; Campos, Tânia F; Ferreira, Gardênia Mh

    2014-07-01

    The aim of the present study was to assess how volume-oriented incentive spirometry applied to patients after a stroke modifies the total and compartmental chest wall volume variations, including both the right and left hemithoraces, compared with controls. Twenty poststroke patients and 20 age-matched healthy subjects were studied by optoelectronic plethysmography during spontaneous quiet breathing (QB), during incentive spirometry, and during the recovery period after incentive spirometry. Incentive spirometry was associated with an increased chest wall volume measured at the pulmonary rib cage, abdominal rib cage and abdominal compartment (P = .001) and under 3 conditions (P spirometry, and postincentive spirometry, respectively. Under all 3 conditions, the contribution of the abdominal compartment to VT was greater in the stroke subjects (54.1, 43.2, and 48.9%) than in the control subjects (43.7, 40.8, and 46.1%, P = .039). In the vast majority of subjects (13/20 and 18/20 during QB and incentive spirometry, respectively), abdominal expansion precedes rib cage expansion during inspiration. Greater asymmetry between the right and left hemithoracic expansions occurred in stroke subjects compared with control subjects, but it decreased during QB (62.5%, P = .002), during incentive spirometry (19.7%), and postincentive spirometry (67.6%, P = .14). Incentive spirometry promotes increased expansion in all compartments of the chest wall and reduces asymmetric expansion between the right and left parts of the pulmonary rib cage; therefore, it should be considered as a tool for rehabilitation. Copyright © 2014 by Daedalus Enterprises.

  8. Robust isotropic super-resolution by maximizing a Laplace posterior for MRI volumes

    Science.gov (United States)

    Han, Xian-Hua; Iwamoto, Yutaro; Shiino, Akihiko; Chen, Yen-Wei

    2014-03-01

    Magnetic resonance imaging can only acquire volume data with finite resolution due to various factors. In particular, the resolution in one direction (such as the slice direction) is much lower than others (such as the in-plane direction), yielding un-realistic visualizations. This study explores to reconstruct MRI isotropic resolution volumes from three orthogonal scans. This proposed super- resolution reconstruction is formulated as a maximum a posterior (MAP) problem, which relies on the generation model of the acquired scans from the unknown high-resolution volumes. Generally, the deviation ensemble of the reconstructed high-resolution (HR) volume from the available LR ones in the MAP is represented as a Gaussian distribution, which usually results in some noise and artifacts in the reconstructed HR volume. Therefore, this paper investigates a robust super-resolution by formulating the deviation set as a Laplace distribution, which assumes sparsity in the deviation ensemble based on the possible insight of the appeared large values only around some unexpected regions. In addition, in order to achieve reliable HR MRI volume, we integrates the priors such as bilateral total variation (BTV) and non-local mean (NLM) into the proposed MAP framework for suppressing artifacts and enriching visual detail. We validate the proposed robust SR strategy using MRI mouse data with high-definition resolution in two direction and low-resolution in one direction, which are imaged in three orthogonal scans: axial, coronal and sagittal planes. Experiments verifies that the proposed strategy can achieve much better HR MRI volumes than the conventional MAP method even with very high-magnification factor: 10.

  9. Maximized liquid radwaste volume reduction through a total integrated process: A new technology success story

    International Nuclear Information System (INIS)

    Rae, G.A.

    1996-01-01

    A fundamental nuclear industry goal is the minimization of the generation of radioactive waste. This goal has been dramatically reinforced over the past few years due to the spiraling increased costs of both commercial and DOE disposal. To assist in meeting these goals and reducing the industry's costs, NUKEM initiated a new technology program to maximize the reduction of liquid radwaste through the use of a systematic approach or TIPS (Total Integrated Process System). This concept evaluates the total life cycle of various technologies in a combination that results in the final waste form being minimized to the pure solids content of the waste stream. Additionally, it allows for a final waste form that maximizes the utilization of the waste package and is conditioned to be readily acceptable to additional processing to meet new waste form requirements at future disposal sites, should interim storage of the waste be required. The TIPS, although first introduced at commercial facilities, has broad applications for DOE's liquid waste streams

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    2016-04-15

    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.)

  11. Mean platelet volume as a risk stratification tool in the Emergency Department for evaluating patients with ischaemic stroke and TIA

    International Nuclear Information System (INIS)

    Dogan, N.O.; Karakurt, K.

    2013-01-01

    Objective: To investigate the variations of mean platelet volume in patients with ischaemic cerebrovascular complaints, and to find out its diagnostic utility in an acute setting to help risk stratification in patients with ischaemic stroke and transient ischaemic attacks. Methods: The prospective cross-sectional study was conducted at the Gazi University Hospital, Ankara, Turkey, from November 2009 to June 2010. It comprised 143 consecutive patients of acute ischaemic stroke, 39 patients of transient ischaemic attacks and 60 healthy volunteers. SPSS 13 was used for statistical analysis, and so were t-test, one-way analysis of variance test and correlation analysis. Statistical significance was accepted at p <0.05. Results: Mean platelet volume results were significantly higher in patients with cortical infarction and transient ischaemic attack compared to the control group (p <0.001 and p <0.002). A statistically significant increase was also noted in hospitalised patients when compared with discharged patients from the emergency department (p <0.036). A weak positive correlation was identified between the National Institute of Health Stroke Scores and mean platelet volume levels (r=0.207; p <0.001). A significant relationship was identified between mean platelet volume levels and previous stroke (p <0.005). Conclusion: The measurement of mean platelet volume levels may provide useful diagnostic and prognostic information to emergency physicians caring for patients with transient ischaemic attack and ischaemic stroke. In patients with suspected neurological ischaemic symptoms, high levels may be considered as an atherosclerotic risk factor. (author)

  12. Maximal cardiorespiratory fitness testing in individuals with chronic stroke with cognitive impairment: practice test effects and test-retest reliability.

    Science.gov (United States)

    Olivier, Charles; Doré, Jean; Blanchet, Sophie; Brooks, Dina; Richards, Carol L; Martel, Guy; Robitaille, Nancy-Michelle; Maltais, Désirée B

    2013-11-01

    To evaluate, for individuals with chronic stroke with cognitive impairment, (1) the effects of a practice test on peak cardiorespiratory fitness test results; (2) cardiorespiratory fitness test-retest reliability; and (3) the relationship between individual practice test effects and cognitive impairment. Cross-sectional. Rehabilitation center. A convenience sample of 21 persons (men [n=12] and women [n=9]; age range, 48-81y; 44.9±36.2mo poststroke) with cognitive impairments who had sufficient lower limb function to perform the test. Not applicable. Peak oxygen consumption (Vo(2)peak, ml·kg(-1)·min(-1)). Test-retest reliability of Vo(2)peak was excellent (intraclass correlation coefficient model 2,1 [ICC2,1]=.94; 95% confidence interval [CI], .86-.98). A paired t test showed that there was no significant difference for the group for Vo(2)peak obtained from 2 symptom-limited cardiorespiratory fitness tests performed 1 week apart on a semirecumbent cycle ergometer (test 2-test 1 difference, -.32ml·kg(-1)·min(-1); 95% CI, -.69 to 1.33ml·kg(-1)·min(-1); P=.512). Individual test-retest differences in Vo(2)peak were, however, positively related to general cognitive function as measured by the Mini-Mental State Examination (ρ=.485; Preliably measured in this group without a practice test. General cognitive function, however, may influence the effect of a practice test in that those with lower general cognitive function appear to respond differently to a practice test than those with higher cognitive function. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  13. Right Hemisphere Grey Matter Volume and Language Functions in Stroke Aphasia

    Directory of Open Access Journals (Sweden)

    Sladjana Lukic

    2017-01-01

    Full Text Available The role of the right hemisphere (RH in recovery from aphasia is incompletely understood. The present study quantified RH grey matter (GM volume in individuals with chronic stroke-induced aphasia and cognitively healthy people using voxel-based morphometry. We compared group differences in GM volume in the entire RH and in RH regions-of-interest. Given that lesion site is a critical source of heterogeneity associated with poststroke language ability, we used voxel-based lesion symptom mapping (VLSM to examine the relation between lesion site and language performance in the aphasic participants. Finally, using results derived from the VLSM as a covariate, we evaluated the relation between GM volume in the RH and language ability across domains, including comprehension and production processes both at the word and sentence levels and across spoken and written modalities. Between-subject comparisons showed that GM volume in the RH SMA was reduced in the aphasic group compared to the healthy controls. We also found that, for the aphasic group, increased RH volume in the MTG and the SMA was associated with better language comprehension and production scores, respectively. These data suggest that the RH may support functions previously performed by LH regions and have important implications for understanding poststroke reorganization.

  14. Echocardiography underestimates stroke volume and aortic valve area: implications for patients with small-area low-gradient aortic stenosis.

    Science.gov (United States)

    Chin, Calvin W L; Khaw, Hwan J; Luo, Elton; Tan, Shuwei; White, Audrey C; Newby, David E; Dweck, Marc R

    2014-09-01

    Discordance between small aortic valve area (AVA; area (LVOTarea) and stroke volume alongside inconsistencies in recommended thresholds. One hundred thirty-three patients with mild to severe AS and 33 control individuals underwent comprehensive echocardiography and cardiovascular magnetic resonance imaging (MRI). Stroke volume and LVOTarea were calculated using echocardiography and MRI, and the effects on AVA estimation were assessed. The relationship between AVA and MPG measurements was then modelled with nonlinear regression and consistent thresholds for these parameters calculated. Finally the effect of these modified AVA measurements and novel thresholds on the number of patients with small-area low-gradient AS was investigated. Compared with MRI, echocardiography underestimated LVOTarea (n = 40; -0.7 cm(2); 95% confidence interval [CI], -2.6 to 1.3), stroke volumes (-6.5 mL/m(2); 95% CI, -28.9 to 16.0) and consequently, AVA (-0.23 cm(2); 95% CI, -1.01 to 0.59). Moreover, an AVA of 1.0 cm(2) corresponded to MPG of 24 mm Hg based on echocardiographic measurements and 37 mm Hg after correction with MRI-derived stroke volumes. Based on conventional measures, 56 patients had discordant small-area low-gradient AS. Using MRI-derived stroke volumes and the revised thresholds, a 48% reduction in discordance was observed (n = 29). Echocardiography underestimated LVOTarea, stroke volume, and therefore AVA, compared with MRI. The thresholds based on current guidelines were also inconsistent. In combination, these factors explain > 40% of patients with discordant small-area low-gradient AS. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  15. Experimental studies for the development of a new method for stroke volume measuring using X-ray videodensitometry

    International Nuclear Information System (INIS)

    Odenthal, H.J.

    1982-01-01

    Quantitative videodensitometry was studied with a view to its possible application as a new, non-invasive method of measuring cardiac stroke volume. To begin with, the accuracy of roentgen volumetric measurements was determined. After this, blood volume variations were measured by densitometry in five animal experiments. The findings were compared with the volumes measured by a flowmeter in the pulmonary artery. The total stroke volume was found to be proportional to the difference between the maximum and mean densitometric volume. A comparison between videodensitometry and other non-invasive methods showed that, in a stable circulatory system, the results of videodensitometry are equally reliable as, or even more reliable than, those of the conventional methods. (orig./MG) [de

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

    Directory of Open Access Journals (Sweden)

    Kanda H

    2015-09-01

    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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically...... from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase...

  18. Automatic extraction of forward stroke volume using dynamic 11C-acetate PET/CT

    DEFF Research Database (Denmark)

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

    Objectives: Dynamic PET with 11C-acetate can be used to quantify myocardial blood flow and oxidative metabolism, the latter of which is used to calculate myocardial external efficiency (MEE). Calculation of MEE requires forward stroke volume (FSV) data. FSV is affected by cardiac loading conditions......, potentially introducing bias if measured with a separate modality. The aim of this study was to develop and validate methods for automatically extracting FSV directly from the dynamic PET used for measuring oxidative metabolism. Methods: 16 subjects underwent a dynamic 27 min PET scan on a Siemens Biograph...... TruePoint 64 PET/CT scanner after bolus injection of 399±27 MBq of 11C-acetate. The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was derived by automatic extrapolation of the down-slope of the TAC. FSV...

  19. Noninvasive pulse pressure variation and stroke volume variation to predict fluid responsiveness at multiple thresholds : a prospective observational study

    NARCIS (Netherlands)

    Vos, Jaap Jan; Poterman, Marieke; Papineau Salm, Pieternel; Van Amsterdam, Kai; Struys, Michel M. R. F.; Scheeren, Thomas W. L.; Kalmar, Alain F.

    2015-01-01

    Pulse pressure variation (PPV) and stroke volume variation (SVV) are dynamic preload variables that can be measured noninvasively to assess fluid responsiveness (FR) in anesthetized patients with mechanical ventilation. Few studies have examined the effectiveness of predicting FR according to the

  20. Evaluation of Accordance of Magnetic Resonance Volumetric and Flow Measurements in Determining Ventricular Stroke Volume in Cardiac Patients

    International Nuclear Information System (INIS)

    Jeltsch, M.; Ranft, S.; Klass, O.; Aschoff, A.J.; Hoffmann, M.H.K.

    2008-01-01

    Background: Cardiovascular magnetic resonance imaging (CMR) has become an established noninvasive method for evaluating ventricular function utilizing three-dimensional volumetry. Postprocessing of volumetric measurements is still tedious and time consuming. Stroke volumes obtained by flow quantification across the aortic root or pulmonary trunk could be utilized to increase both speed of workflow and accuracy. Purpose: To assess accuracy of stroke volume quantification using MR volumetric imaging compared to flow quantification in patients with various cardiac diseases. Strategies for the augmentation of accuracy in clinical routine were deduced. Material and Methods: 78 patients with various cardiac diseases -excluding intra- or extracardiac shunts, regurgitant valvular defects, or heart rhythm disturbance -underwent cardiac function analysis with flow measurements across the aortic root and cine imaging of the left ventricle. Forty-six patients additionally underwent flow measurements in the pulmonary trunk and cine imaging of the right ventricle. Results: Left ventricular stroke volume (LVSV) and stroke volume of the aortic root (SVAo) correlated with r=0.97, and Bland-Altman analysis showed a mean difference of 0.11 ml and a standard error of estimation (SEE) of 4.31 ml. Ninety-two percent of the data were within the 95% limits of agreement. Right ventricular stroke volume (RVSV) and stroke volume of the pulmonary trunk (SVP) correlated with a factor of r=0.86, and mean difference in the Bland-Altman analysis was fixed at -2.62 ml (SEE 8.47 ml). For RVSV and SVP, we calculated r=0.82, and Bland-Altman analysis revealed a mean difference of 1.27 ml (SEE 9.89 ml). LVSV and RVSV correlated closely, with r=0.91 and a mean difference of 2.79 ml (SEE 7.17 ml). SVAo and SVP correlated with r=0.95 and a mean difference of 0.50 ml (SEE 5.56 ml). Conclusion: Flow quantification can be used as a guidance tool, providing accurate and reproducible stroke volumes of both

  1. Multiphasic perfusion CT in acute middle cerebral artery ischemic stroke: prediction of final infarct volume and correlation with clinical outcome

    International Nuclear Information System (INIS)

    Yi, Chin A; Na, Dong Gyu; Ryoo, Jae Wook; Moon, Chan Hong; Byun, Hong Sik; Roh, Hong Gee; Moon, Won Jin; Lee, Kwang Ho; Lee, Soo Joo

    2002-01-01

    To assess the utility of multiphasic perfusion CT in the prediction of final infarct volume, and the relationship between lesion volume revealed by CT imaging and clinical outcome in acute ischemic stroke patients who have not undergone thrombolytic therapy. Thirty-five patients underwent multiphasic perfusion CT within six hours of stroke onset. After baseline unenhanced helical CT scanning, contrast-enhanced CT scans were obtained 20, 34, 48, and 62 secs after the injection of 90 mL contrast medium at a rate of 3 mL/sec. CT peak and total perfusion maps were obtained from serial CT images, and the initial lesion volumes revealed by CT were compared with final infarct volumes and clinical scores. Overall, the lesion volumes seen on CT peak perfusion maps correlated most strongly with final infarct volumes (R2=0.819, p<0.001, slope of regression line=1.016), but individual data showed that they were less than final infarct volume in 31.4% of patients. In those who showed early clinical improvement (n=6), final infarct volume tended to be overestimated by CT peak perfusion mapping and only on total perfusion maps was there significant correlation between lesion volume and final infarct volume (R2=0.854, p=0.008). The lesion volumes depicted by CT maps showed moderate correlation with baseline clinical scores and clinical outcomes (R=0.445-0.706, p≤0.007). CT peak perfusion maps demonstrate strong correlation between lesion volume and final infarct volume, and accurately predict final infarct volume in about two-thirds of the 35 patients. The lesion volume seen on CT maps shows moderate correlation with clinical outcome

  2. Whole-brain perfusion CT using a toggling table technique to predict final infarct volume in acute ischemic stroke.

    Science.gov (United States)

    Schrader, I; Wilk, D; Jansen, O; Riedel, C

    2013-09-01

    To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the "toggling table" technique within the first three hours after symptom onset. In patients with successful thrombolytic therapy (n = 48) and in those without effective thrombolytic therapy (n = 41), the infarct volume and the volume of the penumbra on PCT were compared to the infarct size on follow-up images (CT or MRI) performed within 8 days. The feasibility of complete infarct volume prediction by 8 cm cranio-caudal coverage was evaluated. The correlation between the volume of hypoperfusion on PCT defined by cerebral blood volume reduction and final infarct volume was strongest in patients with successful thrombolytic therapy with underestimation of the definite infarct volume by 8.5 ml on average. The CBV map had the greatest prognostic value. In patients without successful thrombolytic therapy, the final infarct volume was overestimated by 12.1 ml compared to the MTT map on PCT. All infarcts were detected completely. There were no false-positive or false-negative results. Using PCT and the "toggling table" technique in acute stroke patients is helpful for the rapid and accurate quantification of the minimal final infarct and is therefore a prognostic parameter which has to be evaluated in further studies to assess its impact on therapeutic decision. ▶ Using PCT and the “toggling table technique” allows accurate quantification of the infarct core and penumbra. ▶ It is possible to record dynamic perfusion parameters quickly and easily of almost the entire supratentorial brain volume on a 64-slice MDCT unit. ▶ The technique allows identification of those patients who could profit from thrombolytic therapy outside the established time intervals. © Georg Thieme Verlag

  3. Stroke Volume estimation using aortic pressure measurements and aortic cross sectional area: Proof of concept.

    Science.gov (United States)

    Kamoi, S; Pretty, C G; Chiew, Y S; Pironet, A; Davidson, S; Desaive, T; Shaw, G M; Chase, J G

    2015-08-01

    Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV.

  4. Limitations and challenges of EIT-based monitoring of stroke volume and pulmonary artery pressure.

    Science.gov (United States)

    Braun, Fabian; Proença, Martin; Lemay, Mathieu; Bertschi, Mattia; Adler, Andy; Thiran, Jean-Philippe; Solà, Josep

    2018-01-30

    Electrical impedance tomography (EIT) shows potential for radiation-free and noninvasive hemodynamic monitoring. However, many factors degrade the accuracy and repeatability of these measurements. Our goal is to estimate the impact of this variability on the EIT-based monitoring of two important central hemodynamic parameters: stroke volume (SV) and pulmonary artery pressure (PAP). We performed simulations on a 4D ([Formula: see text]) bioimpedance model of a human volunteer to study the influence of four potential confounding factors (electrode belt displacement, electrode detachment, changes in hematocrit and lung air volume) on the performance of EIT-based SV and PAP estimation. Results were used to estimate how these factors affect the EIT measures of either absolute values or relative changes (i.e. trending). Our findings reveal that the absolute measurement of SV via EIT is very sensitive to electrode belt displacements and lung conductivity changes. Nonetheless, the trending ability of SV EIT might be a promising alternative. The timing-based measurement of PAP is more robust to lung conductivity changes but sensitive to longitudinal belt displacements at severe hypertensive levels and to rotational displacements (independent of the PAP level). We identify and quantify the challenges of EIT-based SV and PAP monitoring. Absolute SV via EIT is challenging, but trending is feasible, while both the absolute and trending of PAP via EIT are mostly impaired by belt displacements.

  5. Relative cerebral blood volume as a marker of durable tissue-at-risk viability in hyperacute ischemic stroke.

    Science.gov (United States)

    Cortijo, Elisa; Calleja, Ana Isabel; García-Bermejo, Pablo; Mulero, Patricia; Pérez-Fernández, Santiago; Reyes, Javier; Muñoz, Ma Fe; Martínez-Galdámez, Mario; Arenillas, Juan Francisco

    2014-01-01

    Selection of best responders to reperfusion therapies could be aided by predicting the duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome. We prospectively studied patients with acute MCA ischemic stroke treated with intravenous thrombolysis who underwent PCT before treatment showing a target mismatch profile. Collateral status was assessed using a PCT source image-based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow, and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were brain hypodensity volume and modified Rankin scale score at day 90. One hundred patients with MCA ischemic stroke imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV (rCBV) >0.93 emerged as the only predictor of good collaterals (odds ratio, 12.6; 95% confidence interval, 2.9-55.9; P=0.001). Early MCA recanalization was associated with better long-term outcome and lower infarct volume in patients with rCBV<0.93, but not in patients with high rCBV. None of the patients with rCBV<0.93 achieved good outcome in absence of early recanalization. High rCBV was the strongest marker of good collaterals and may characterize durable tissue-at-risk viability in hyperacute MCA ischemic stroke.

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

    Directory of Open Access Journals (Sweden)

    Donald P Bernstein

    2010-01-01

    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

  7. Assessment of Collateral Status by Dynamic CT Angiography in Acute MCA Stroke: Timing of Acquisition and Relationship with Final Infarct Volume

    NARCIS (Netherlands)

    van den Wijngaard, I. R.; Holswilder, G.; Wermer, M. J. H.; Boiten, J.; Algra, A.; Dippel, D. W. J.; Dankbaar, J. W.; Velthuis, B. K.; Boers, A. M. M.; Majoie, C. B. L. M.; van Walderveen, M. A. A.

    2016-01-01

    Dynamic CTA is a promising technique for visualization of collateral filling in patients with acute ischemic stroke. Our aim was to describe collateral filling with dynamic CTA and assess the relationship with infarct volume at follow-up. We selected patients with acute ischemic stroke due to

  8. Impact of aortic root size on left ventricular afterload and stroke volume.

    Science.gov (United States)

    Sahlén, Anders; Hamid, Nadira; Amanullah, Mohammed Rizwan; Fam, Jiang Ming; Yeo, Khung Keong; Lau, Yee How; Lam, Carolyn S P; Ding, Zee Pin

    2016-07-01

    The left ventricle (LV) ejects blood into the proximal aorta. Age and hypertension are associated with stiffening and dilation of the aortic root, typically viewed as indicative of adverse remodeling. Based on analytical considerations, we hypothesized that a larger aortic root should be associated with lower global afterload (effective arterial elastance, EA) and larger stroke volume (SV). Moreover, as antihypertensive drugs differ in their effect on central blood pressure, we examined the role of antihypertensive drugs for the relation between aortic root size and afterload. We studied a large group of patients (n = 1250; 61 ± 12 years; 78 % males; 64 % hypertensives) from a single-center registry with known or suspected coronary artery disease. Aortic root size was measured by echocardiography as the diameter of the tubular portion of the ascending aorta. LV outflow tract Doppler was used to record SV. In the population as a whole, after adjusting for key covariates in separate regression models, aortic root size was an independent determinant of both SV and EA. This association was found to be heterogeneous and stronger in patients taking a calcium channel blocker (CCB; 10.6 % of entire population; aortic root size accounted for 8 % of the explained variance of EA). Larger aortic root size is an independent determinant of EA and SV. This association was heterogeneous and stronger in patients on CCB therapy.

  9. Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation.

    Science.gov (United States)

    Choi, Jae Moon; Lee, Yoon Kyung; Yoo, Hwanhee; Lee, Sukyung; Kim, Hee Yeong; Kim, Young-Kug

    2016-01-01

    Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients. We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality. Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes. Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

  10. Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

    Science.gov (United States)

    Lahner, D; Kabon, B; Marschalek, C; Chiari, A; Pestel, G; Kaider, A; Fleischmann, E; Hetz, H

    2009-09-01

    Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to 10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

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

    DEFF Research Database (Denmark)

    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 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...

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

    International Nuclear Information System (INIS)

    Othman, Ahmed E.; Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikobashman, Omid; Brockmann, Marc A.; Wiesmann, Martin; Yang, Zepa; Kim, Changwon; Kim, Jong Hyo

    2015-01-01

    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.)

  13. Titin is a candidate gene for stroke volume response to endurance training: the HERITAGE Family Study.

    Science.gov (United States)

    Rankinen, Tuomo; Rice, Treva; Boudreau, Anik; Leon, Arthur S; Skinner, James S; Wilmore, Jack H; Rao, D C; Bouchard, Claude

    2003-09-29

    A genome-wide linkage scan for endurance training-induced changes in submaximal exercise stroke volume (DeltaSV50) in the HERITAGE Family Study revealed two chromosomal regions (2q31-q32 and 10p11.2) with at least suggestive evidence of linkage among white families. Here we report a further characterization of the quantitative trait locus (QTL) in chromosome 2q31 and provide evidence that titin (TTN) is likely a candidate gene involved. The original linkage was detected with two markers (D2S335 and D2S1391), and the QTL covered approximately 25 million base pairs (Mb). We added 12 microsatellite markers resulting in an average marker density of one marker per 2.3 Mb. The evidence of linkage increased from P = 0.006 to P = 0.0002 and 0.00002 in the multi- and single-point analyses, respectively. The strongest evidence of linkage was seen with two markers in and near the TTN gene. Transmission/disequilibrium test (TDT) with the same marker set provided evidence for association with one of the TTN markers (D2S385; P = 0.004). TTN is a major contributor to the elasticity of cardiomyocytes and a key regulator of the Frank-Starling mechanism. Since TTN is the largest gene in the human genome, the challenge is to identify the DNA sequence variants contributing to the interindividual differences in cardiac adaptation to endurance training.

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

    DEFF Research Database (Denmark)

    Kelbaek, H; Svendsen, J H; Aldershvile, J

    1988-01-01

    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 ...... are reliable. The discrepancy between the non-invasive and invasive LVEF values raises the question, whether LVEF is overestimated by cardioangiography or underestimated by radionuclide cardiography....

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

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    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 healthy...

  17. Association between the volume of inpatient rehabilitation therapy and the risk of all-cause and cardiovascular mortality in patients with ischemic stroke.

    Science.gov (United States)

    Hu, Gwo-Chi; Hsu, Chia-Yu; Yu, Hui-Kung; Chen, Jiann-Perng; Chang, Yu-Ju; Chien, Kuo-Liong

    2014-02-01

    To investigate the relationship between the volume of inpatient rehabilitation therapy and mortality among patients with acute ischemic stroke, as well as to assess whether the association varies with respect to stroke severity. A retrospective study with a cohort of consecutive patients who had acute ischemic stroke between January 1, 2008, and June 30, 2009. Referral medical center. Adults with acute ischemic stroke (N=1277) who were admitted to a tertiary hospital. Not applicable. Stroke-related mortality. During the median follow-up period of 12.3 months (ranging from January 1, 2008, to December 31, 2009), 163 deaths occurred. Greater volume of rehabilitation therapy was associated with a reduced risk of all-cause and cardiovascular mortality (P for trend rehabilitation volume was associated with a 55% lower risk of all-cause mortality (hazard ratio [HR]=.45; 95% confidence interval [CI], .30-.65) and a 50% lower risk of cardiovascular mortality (HR=.50; 95% CI, .31-.82). The association did not vary with respect to stroke severity (P for interaction = .45 and .73 for all-cause and cardiovascular mortality, respectively). The volume of inpatient rehabilitation therapy and mortality were significantly inversely related in the patients with ischemic stroke. Thus, further programs aimed at promoting greater use of rehabilitation services are warranted. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Omega-3 fatty acid supplementation enhances stroke volume and cardiac output during dynamic exercise.

    Science.gov (United States)

    Walser, Buddy; Stebbins, Charles L

    2008-10-01

    Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have beneficial effects on cardiovascular function. We tested the hypotheses that dietary supplementation with DHA (2 g/day) + EPA (3 g/day) enhances increases in stroke volume (SV) and cardiac output (CO) and decreases in systemic vascular resistance (SVR) during dynamic exercise. Healthy subjects received DHA + EPA (eight men, four women) or safflower oil (six men, three women) for 6 weeks. Both groups performed 20 min of bicycle exercise (10 min each at a low and moderate work intensity) before and after DHA + EPA or safflower oil treatment. Mean arterial pressure (MAP), heart rate (HR), SV, CO, and SVR were assessed before exercise and during both workloads. HR was unaffected by DHA + EPA and MAP was reduced, but only at rest (88 +/- 5 vs. 83 +/- 4 mm Hg). DHA + EPA augmented increases in SV (14.1 +/- 6.3 vs. 32.3 +/- 8.7 ml) and CO (8.5 +/- 1.0 vs. 10.3 +/- 1.2 L/min) and tended to attenuate decreases in SVR (-7.0 +/- 0.6 vs. -10.1 +/- 1.6 mm Hg L(-1) min(-1)) during the moderate workload. Safflower oil treatment had no effects on MAP, HR, SV, CO or SVR at rest or during exercise. DHA + EPA-induced increases in SV and CO imply that dietary supplementation with these fatty acids can increase oxygen delivery during exercise, which may have beneficial clinical implications for individuals with cardiovascular disease and reduced exercise tolerance.

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

    Directory of Open Access Journals (Sweden)

    Yurie Obata

    Full Text Available 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.

  20. Independent Prognostic Value of Stroke Volume Index in Patients With Immunoglobulin Light Chain Amyloidosis.

    Science.gov (United States)

    2018-05-01

    Heart involvement is the most important prognostic determinant in AL amyloidosis patients. Echocardiography is a cornerstone for the diagnosis and provides important prognostic information. We studied 754 patients with AL amyloidosis who underwent echocardiographic assessment at the Mayo Clinic, including a Doppler-derived measurement of stroke volume (SV) within 30 days of their diagnosis to explore the prognostic role of echocardiographic variables in the context of a well-established soluble cardiac biomarker staging system. Reproducibility of SV, myocardial contraction fraction, and left ventricular strain was assessed in a separate, yet comparable, study cohort of 150 patients from the Pavia Amyloidosis Center. The echocardiographic measures most predictive for overall survival were SV index <33 mL/min, myocardial contraction fraction <34%, and cardiac index <2.4 L/min/m 2 with respective hazard ratios (95% confidence intervals) of 2.95 (2.37-3.66), 2.36 (1.96-2.85), and 2.32 (1.91-2.80). For the subset that had left ventricular strain performed, the prognostic cut point was -14% (hazard ratios, 2.70; 95% confidence intervals, 1.84-3.96). Each parameter was independent of systolic blood pressure, Mayo staging system (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and troponin), and ejection fraction on multivariable analysis. Simple predictive models for survival, including biomarker staging along with SV index or left ventricular strain, were generated. SV index prognostic performance was similar to left ventricular strain in predicting survival in AL amyloidosis, independently of biomarker staging. Because SV index is routinely calculated and widely available, it could serve as the preferred echocardiographic measure to predict outcomes in AL amyloidosis patients. © 2018 American Heart Association, Inc.

  1. Reperfusion is a more accurate predictor of follow-up infarct volume than recanalization: a proof of concept using CT in acute ischemic stroke patients.

    Science.gov (United States)

    Soares, Bruno P; Tong, Elizabeth; Hom, Jason; Cheng, Su-Chun; Bredno, Joerg; Boussel, Loic; Smith, Wade S; Wintermark, Max

    2010-01-01

    The purpose of this study was to compare recanalization and reperfusion in terms of their predictive value for imaging outcomes (follow-up infarct volume, infarct growth, salvaged penumbra) and clinical outcome in acute ischemic stroke patients. Twenty-two patients admitted within 6 hours of stroke onset were retrospectively included in this study. These patients underwent a first stroke CT protocol including CT-angiography (CTA) and perfusion-CT (PCT) on admission, and similar imaging after treatment, typically around 24 hours, to assess recanalization and reperfusion. Recanalization was assessed by comparing arterial patency on admission and posttreatment CTAs; reperfusion, by comparing the volumes of CBV, CBF, and MTT abnormality on admission and posttreatment PCTs. Collateral flow was graded on the admission CTA. Follow-up infarct volume was measured on the discharge noncontrast CT. The groups of patients with reperfusion, no reperfusion, recanalization, and no recanalization were compared in terms of imaging and clinical outcomes. Reperfusion (using an MTT reperfusion index >75%) was a more accurate predictor of follow-up infarct volume than recanalization. Collateral flow and recanalization were not accurate predictors of follow-up infarct volume. An interaction term was found between reperfusion and the volume of the admission penumbra >50 mL. Our study provides evidence that reperfusion is a more accurate predictor of follow-up infarct volume in acute ischemic stroke patients than recanalization. We recommend an MTT reperfusion index >75% to assess therapy efficacy in future acute ischemic stroke trials that use perfusion-CT.

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

    International Nuclear Information System (INIS)

    Lu, J.; Zhang, M.; Cao, Y.; Ma, Q.; Chen, J.; Ji, X.; Li, K.

    2011-01-01

    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.

  3. Modelflow Estimates of Stroke Volume Do Not Correlate With Doppler Ultrasound Estimates During Upright Posture

    Science.gov (United States)

    Ferguson, Connor R.; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.; Laurie, Steven S.

    2014-01-01

    Orthostatic intolerance affects 60-80% of astronauts returning from long-duration missions, representing a significant risk to completing mission-critical tasks. While likely multifactorial, a reduction in stroke volume (SV) represents one factor contributing to orthostatic intolerance during stand and head up tilt (HUT) tests. Current measures of SV during stand or HUT tests use Doppler ultrasound and require a trained operator and specialized equipment, restricting its use in the field. BeatScope (Finapres Medical Systems BV, The Netherlands) uses a modelflow algorithm to estimate SV from continuous blood pressure waveforms in supine subjects; however, evidence supporting the use of Modelflow to estimate SV in subjects completing stand or HUT tests remain scarce. Furthermore, because the blood pressure device is held extended at heart level during HUT tests, but allowed to rest at the side during stand tests, changes in the finger arterial pressure waveform resulting from arm positioning could alter modelflow estimated SV. The purpose of this project was to compare Doppler ultrasound and BeatScope estimations of SV to determine if BeatScope can be used during stand or HUT tests. Finger photoplethysmography was used to acquire arterial pressure waveforms corrected for hydrostatic finger-to-heart height using the Finometer (FM) and Portapres (PP) arterial pressure devices in 10 subjects (5 men and 5 women) during a stand test while simultaneous estimates of SV were collected using Doppler ultrasound. Measures were made after 5 minutes of supine rest and while subjects stood for 5 minutes. Next, SV estimates were reacquired while each arm was independently raised to heart level, a position similar to tilt testing. Supine SV estimates were not significantly different between all three devices (FM: 68+/-20, PP: 71+/-21, US: 73+/-21 ml/beat). Upon standing, the change in SV estimated by FM (-18+/-8 ml) was not different from PP (-21+/-12), but both were significantly

  4. Comparison of Two Methods for Noninvasive Determination of Stroke Volume During Orthostatic Challenge

    Science.gov (United States)

    Doerr, Donald F.; Ratliff, Duane A.; Sithole, Joseph; Convertino, Victor A.

    2005-01-01

    Background: The real time, beat-by-beat, non-invasive determination of stroke volume (SV) is an important parameter in many aerospace related physiologic protocols. In this study, we compared simultaneous estimates of SV calculated from peripheral pulse waveforms with a more conventional non-invasive technique. Methods: Using a prospective, randomized blinded protocol, ten males and nine females completed 12-mm tilt table protocols. The relative change (%(Delta)) in beat-to-beat SV was estimated non-invasively from changes in pulse waveforms measured by application of infrared finger photoplethysmography (IFP) with a Portapres(Registered TradeMark) blood pressure monitoring device and by thoracic impedance cardiography (TIC). The %(Delta) SV values were calculated from continuous SV measurements in the supine posture and over the first 10 s (T1), second 10 s (T2), and 3.5 minutes (T3) of 80deg head-up tilt (HUT). Results: The average %(Delta) SV measured by IFP at T1 (-11.7 +/- 3.7 %) was statistically less (P measured by TIC at T1 (-21.7 +/- 3.1 %), while the average %(Delta) SV measured by 1FF at T2 (-16.2 +/- 3.9 %) and T3 (-19.1 +/- 3.8 %) were not statistically distinguishable (P > or = 0.322) than the average %(Delta) SV measured by TIC at T2 (-21.8 +/- 2.5 %), and T3 (-22.6 +/- 2.9 %). Correlation coefficients (r(sup 2)) between IFP and TIC were 0.117 (T1), 0.387 (T2), and 0.7 18 (T3). Conclusion: IFP provides beat-to-beat (real time) assessment of %(Delta) SV after 20 sec of transition to an orthostatic challenge that is comparable to the commonly accepted TIC. Our data support the notion that IFP technology which has flown during space missions can be used to accurately assess physiological status and countermeasure effectiveness for orth static problems that may arise in astronauts after space flight. While the peripherally measured IFP response is slightly delayed, the ease of implementing this monitor in the field is advantageous.

  5. Estimation of error in maximal intensity projection-based internal target volume of lung tumors: a simulation and comparison study using dynamic magnetic resonance imaging.

    Science.gov (United States)

    Cai, Jing; Read, Paul W; Baisden, Joseph M; Larner, James M; Benedict, Stanley H; Sheng, Ke

    2007-11-01

    To evaluate the error in four-dimensional computed tomography (4D-CT) maximal intensity projection (MIP)-based lung tumor internal target volume determination using a simulation method based on dynamic magnetic resonance imaging (dMRI). Eight healthy volunteers and six lung tumor patients underwent a 5-min MRI scan in the sagittal plane to acquire dynamic images of lung motion. A MATLAB program was written to generate re-sorted dMRI using 4D-CT acquisition methods (RedCAM) by segmenting and rebinning the MRI scans. The maximal intensity projection images were generated from RedCAM and dMRI, and the errors in the MIP-based internal target area (ITA) from RedCAM (epsilon), compared with those from dMRI, were determined and correlated with the subjects' respiratory variability (nu). Maximal intensity projection-based ITAs from RedCAM were comparatively smaller than those from dMRI in both phantom studies (epsilon = -21.64% +/- 8.23%) and lung tumor patient studies (epsilon = -20.31% +/- 11.36%). The errors in MIP-based ITA from RedCAM correlated linearly (epsilon = -5.13nu - 6.71, r(2) = 0.76) with the subjects' respiratory variability. Because of the low temporal resolution and retrospective re-sorting, 4D-CT might not accurately depict the excursion of a moving tumor. Using a 4D-CT MIP image to define the internal target volume might therefore cause underdosing and an increased risk of subsequent treatment failure. Patient-specific respiratory variability might also be a useful predictor of the 4D-CT-induced error in MIP-based internal target volume determination.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2005-10-01

    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.)

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

    International Nuclear Information System (INIS)

    Bateman, Grant A.; Levi, Christopher R.; Wang, Yang; Lovett, Elizabeth C.; Schofield, Peter

    2005-01-01

    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.)

  8. Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

    Science.gov (United States)

    Ernst, M; Forkert, N D; Brehmer, L; Thomalla, G; Siemonsen, S; Fiehler, J; Kemmling, A

    2015-02-01

    In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume 50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. © 2015 by American Journal of Neuroradiology.

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

    Directory of Open Access Journals (Sweden)

    Arnt Erik Tjønna

    Full Text Available 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 health

  10. Lightweight two-stroke cycle aircraft diesel engine technology enablement program, volume 2

    Science.gov (United States)

    Freen, P. D.; Berenyi, S. G.; Brouwers, A. P.; Moynihan, M. E.

    1985-01-01

    An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit a design of a multicylinder engine for eventual flight applications.

  11. Entropy maximization

    Indian Academy of Sciences (India)

    Abstract. 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 f that satisfy. ∫ fhi dμ = λi for i = 1, 2,...,...k the maximizer of entropy is an f0 that is pro- portional to exp(. ∑ ci hi ) for some choice of ci . An extension of this to a continuum of.

  12. Entropy Maximization

    Indian Academy of Sciences (India)

    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 ∫ f h i d = i for i = 1 , 2 , … , … k the maximizer of entropy is an f 0 that is proportional to exp ⁡ ( ∑ c i h i ) for some choice of c i . An extension of this to a continuum of ...

  13. MR-based cerebral blood volume maps as a diagnostic tool of stroke: results of a clinical pilot study

    International Nuclear Information System (INIS)

    Hacklaender, T.; Hofer, M.; Binkofski, F.; Reichenbach, J.; Moedder, U.

    1996-01-01

    In this study the sensitivity of proving a stroke using regional cerebral blood volume (rCBV) maps were investigated. Another aim was to evaluate the strength of the ischaemia. Seven patients were examined during the acute phase of a stroke, eight during the subacute or chronically stage. To calculate rCBV-maps of one slice low dosed Gd-DTPA was injected as a bolus. Using the relaxation-effect the obtained signal intensity-time curves were converted pixel-wise to rCBV images. For the region of the infarction rCBV ratios were calculated relative to the corresponding area in the contralateral hemisphere. Only 63% of the investigations carried out during the acute phase were utilizable. In all those cases a decrease of rCBV was found. The infarct area could only be visually recognized if the rCBV ratio was lower than 0.7. The ratios of completely and partical necrotic areas of the infarctions were 0.481 and 1.028 respectively. With a p=0.0015 these values are even statistically different. During the acute stage the sensitivity of the rCBV measurement was not as high as that of morphological MR imaging. However, rCBV maps make it possible to estimate the strength of the ischaemia even during the first hours. (orig./MG) [de

  14. The magnitude and course of exercise-induced stroke volume changes determine the exercise tolerance in heart transplant recipients with heart failure and normal ejection fraction

    Czech Academy of Sciences Publication Activity Database

    Meluzín, J.; Hude, P.; Leinveber, P.; Jurák, Pavel; Soukup, L.; Viščor, Ivo; Špinarová, L.; Štěpánová, R.; Podroužková, H.; Vondra, Vlastimil; Langer, P.; Němec, P.

    2014-01-01

    Roč. 20, č. 1 (2014), s. 674-687 ISSN 1205-6626 R&D Projects: GA MŠk(CZ) LO1212 Keywords : heart failure * stroke volume index * exercise tolerance * bioimpedance Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 0.758, year: 2013

  15. Assessment of collateral status by dynamic ct angiography in acute mca stroke : Timing of acquisition and relationship with final infarct volume

    NARCIS (Netherlands)

    Van Den Wijngaard, I. R.; Holswilder, G.; Wermer, M. J H; Boiten, J.; Algra, A.; Dippel, D. W J; Dankbaar, J. W.; Velthuis, B. K.; Boers, A. M M; Majoie, C. B L M; Van Walderveen, M. A A

    2016-01-01

    BACKGROUND AND PURPOSE: Dynamic CTA is a promising technique for visualization of collateral filling in patients with acute ischemic stroke. Our aim was to describe collateral filling with dynamic CTA and assess the relationship with infarct volume at follow-up. MATERIALS AND METHODS: We selected

  16. Assessment of collateral status by dynamic ct angiography in acute mca stroke: Timing of acquisition and relationship with final infarct volume

    NARCIS (Netherlands)

    I.R. Van Den Wijngaard (Ido R.); G. Holswilder (Ghislaine); M.J.H. Wermer (Marieke); J. Boiten (Jelis); A. Algra (Ale); D.W.J. Dippel (Diederik); J.W. Dankbaar (Jan); B.K. Velthuis (Birgitta); A.M.M. Boers (Anna); C.B. Majoie (Charles); M.A.A. van Walderveen (Marianne)

    2016-01-01

    textabstractBACKGROUND AND PURPOSE: Dynamic CTA is a promising technique for visualization of collateral filling in patients with acute ischemic stroke. Our aim was to describe collateral filling with dynamic CTA and assess the relationship with infarct volume at follow-up. MATERIALS AND METHODS: We

  17. Lightweight two-stroke cycle aircraft diesel engine technology enablement program, volume 1

    Science.gov (United States)

    Freen, P. D.; Berenyi, S. G.; Brouwers, A. P.; Moynihan, M. E.

    1985-01-01

    An experimental Single Cylinder Test Engine Program is conducted to confirm the analytically projected performance of a two-stroke cycle diesel engine for aircraft applications. The test engine delivered 78kW indicated power from 1007cc displacement, operating at 3500 RPM on Schnuerle loop scavenged two-stroke cycle. Testing confirms the ability of a proposed 4-cylinder version of such an engine to reach the target power at altitude, in a highly turbocharged configuration. The experimental program defines all necessary parameters to permit design of a multicylinder engine for eventual flight applications; including injection system requirement, turbocharging, heat rejection, breathing, scavenging, and structural requirements. The multicylinder engine concept is configured to operate with an augmented turbocharger, but with no primary scavenge blower. The test program is oriented to provide a balanced turbocharger compressor to turbine power balance without an auxiliary scavenging system. Engine cylinder heat rejection to the ambient air has been significantly reduced and the minimum overall turbocharger efficiency required is within the range of commercially available turbochargers. Analytical studies and finite element modeling is made of insulated configurations of the engines - including both ceramic and metallic versions. A second generation test engine is designed based on current test results.

  18. Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

    Science.gov (United States)

    Kanda, Hirotsugu; Hirasaki, Yuji; Iida, Takafumi; Kanao-Kanda, Megumi; Toyama, Yuki; Kunisawa, Takayuki; Iwasaki, Hiroshi

    2015-01-01

    Purpose The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system. Patients and methods After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups. Results In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV. Conclusion Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD. PMID:26527879

  19. A method for partial volume correction of PET-imaged tumor heterogeneity using expectation maximization with a spatially varying point spread function

    International Nuclear Information System (INIS)

    Barbee, David L; Holden, James E; Nickles, Robert J; Jeraj, Robert; Flynn, Ryan T

    2010-01-01

    Tumor heterogeneities observed in positron emission tomography (PET) imaging are frequently compromised by partial volume effects which may affect treatment prognosis, assessment or future implementations such as biologically optimized treatment planning (dose painting). This paper presents a method for partial volume correction of PET-imaged heterogeneous tumors. A point source was scanned on a GE Discovery LS at positions of increasing radii from the scanner's center to obtain the spatially varying point spread function (PSF). PSF images were fit in three dimensions to Gaussian distributions using least squares optimization. Continuous expressions were devised for each Gaussian width as a function of radial distance, allowing for generation of the system PSF at any position in space. A spatially varying partial volume correction (SV-PVC) technique was developed using expectation maximization (EM) and a stopping criterion based on the method's correction matrix generated for each iteration. The SV-PVC was validated using a standard tumor phantom and a tumor heterogeneity phantom and was applied to a heterogeneous patient tumor. SV-PVC results were compared to results obtained from spatially invariant partial volume correction (SINV-PVC), which used directionally uniform three-dimensional kernels. SV-PVC of the standard tumor phantom increased the maximum observed sphere activity by 55 and 40% for 10 and 13 mm diameter spheres, respectively. Tumor heterogeneity phantom results demonstrated that as net changes in the EM correction matrix decreased below 35%, further iterations improved overall quantitative accuracy by less than 1%. SV-PVC of clinically observed tumors frequently exhibited changes of ±30% in regions of heterogeneity. The SV-PVC method implemented spatially varying kernel widths and automatically determined the number of iterations for optimal restoration, parameters which are arbitrarily chosen in SINV-PVC. Comparing SV-PVC to SINV-PVC demonstrated

  20. Relative cerebral blood volume is associated with collateral status and infarct growth in stroke patients in SWIFT PRIME.

    Science.gov (United States)

    Arenillas, Juan F; Cortijo, Elisa; García-Bermejo, Pablo; Levy, Elad I; Jahan, Reza; Goyal, Mayank; Saver, Jeffrey L; Albers, Gregory W

    2017-01-01

    We aimed to evaluate how predefined candidate cerebral perfusion parameters correlate with collateral circulation status and to assess their capacity to predict infarct growth in patients with acute ischemic stroke (AIS) eligible for endovascular therapy. Patients enrolled in the SWIFT PRIME trial with baseline computed tomography perfusion (CTP) scans were included. RAPID software was used to calculate mean relative cerebral blood volume (rCBV) in hypoperfused regions, and hypoperfusion index ratio (HIR). Blind assessments of collaterals were performed using CT angiography in the whole sample and cerebral angiogram in the endovascular group. Reperfusion was assessed on 27-h CTP; infarct volume was assessed on 27-h magnetic resonance imaging/CT scans. Logistic and rank linear regression models were conducted. We included 158 patients. High rCBV ( p = 0.03) and low HIR ( p = 0.03) were associated with good collaterals. A positive association was found between rCBV and better collateral grades on cerebral angiography ( p = 0.01). Baseline and 27-h follow-up CTP were available for 115 patients, of whom 74 (64%) achieved successful reperfusion. Lower rCBV predicted a higher infarct growth in successfully reperfused patients ( p = 0.038) and in the endovascular treatment group ( p = 0.049). Finally, rCBV and HIR may serve as markers of collateral circulation in AIS patients prior to endovascular therapy. Unique identifier: NCT0165746.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......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...... groups for RVAVPD (P = 0.2). LVAVPD was an independent predictor of maximal cardiac output (R(2 = ) 0.61, P groups. However, how longitudinal pumping...

  2. Pediatric Stroke

    Science.gov (United States)

    ... and Patient Resources Home » Patients & Families » About Stroke » Pediatric Stroke » Introduction Introduction What is a Stroke? Ischemic Stroke Intracerebral Hemorrhage Subarachnoid Hemorrhage Pediatric Stroke Introduction Types of Stroke Diagnosis and Treatment ...

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

    Science.gov (United States)

    Kamoi, Shun; Pretty, Christopher; Docherty, Paul; Squire, Dougie; Revie, James; Chiew, Yeong Shiong; Desaive, Thomas; Shaw, Geoffrey M; Chase, J Geoffrey

    2014-01-01

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-05-01

    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.

  6. Surface and volume three-dimensional displays of Tc-99m HMPAO brain SPECT images in stroke patients with three-head gamma camera

    International Nuclear Information System (INIS)

    Shih, W.J.; Slevin, J.T.; Schleenbaker, R.E.; Mills, B.J.; Magoun, S.L.; Ryo, U.Y.

    1991-01-01

    This paper evaluates volume and surface 3D displays in Tc-99m HMPAO brain SPECT imaging in stroke patients. Using a triple-head gamma camera interfaced with a 64-bit supercomputer, 20 patients with stroke were studied. Each patient was imaged 30-60 minutes after an intravenous injection of 20 mCi of Tc-99m HMPAO. SPECT images as well as planar images were routinely obtained; volume and surface 3D display then proceeded, with the process requiring 5-10 minutes. Volume and surface 3D displays show the brain from all angles; thus the location and extension of lesion(s) in the brain are much easier to appreciate. While a cerebral lesion(s) was more clearly delineated by surface 3D imaging, crossed cerebellar diaschisis in seven patients was clearly exhibited with volume 3D but not with surface 3D imaging. Volume and surface 3D displays enhance continuity of structures and understanding of spatial relationships

  7. Deteriorating ischaemic stroke. cytokines, soluble cytokine receptors, ferritin, systemic blood pressure, body temperature, blood glucose, diabetes, stroke severity, and CT infarction-volume as predictors of deteriorating ischaemic stroke

    DEFF Research Database (Denmark)

    Christensen, Hanne; Boysen, Gudrun; Johannesen, Helle Hjorth

    2002-01-01

    Although the causes of neurological deterioration in acute cerebral infarction have not yet been identified, many variables have been associated with deterioration. The aim of this study was to investigate deteriorating ischaemic stroke....

  8. Two-dimensional color Doppler echocardiography for left ventricular stroke volume assessment: a comparison study with three-dimensional echocardiography.

    Science.gov (United States)

    Silva, Cristina Da; Pedro, Fátima; Deister, Lizandra; Sahlén, Anders; Manouras, Aristomenis; Shahgaldi, Kambiz

    2012-08-01

    Whether measurement of left ventricular outflow tract diameter (LVOTd) using color Doppler (CD) in order to more accurately define LVOTd is more accurate for determination of stroke volume (SV) than gray scale and compare it with direct measurement of LVOT area (a) using three-dimensional echocardiography (3DE) for SV determination. Twenty-one volunteers were examined. LVOTa was calculated by two-dimensional echocardiography (2DE) using the following formula: π× (d/2)(2) , d = LVOT diameter by gray scale and CD, respectively. Planimetry of LVOTa was performed in parasternal long axis using 3DE. Eccentricity Index was calculated using the lateral and anterior-posterior LVOTd. SV was obtained by four different methods: (1) 2D gray scale, (2) 2D color, (3) LVOTa × LVOT velocity time integral, and (4) SV by Simpson's biplane method. Gray scale LVOTd was significantly smaller compared to LVOTd obtained with CD (P vs 3.67 ± 0.70 cm(2) , P vs 3.61 ± 0.89 cm(2) , P = 0.011). Half of the subjects had at least 17% difference between the lateral and anterior-posterior LVOTd. There were significant differences between SV by 2D gray scale and 2D CD (82.8 ± 17.1 mL vs 92.4 ± 16.8 mL, P vs 90.7 ± 19.8 mL, P = 0.025). Our study demonstrates LVOT being frequently elliptical. SV and LVOTa were found to be similar when comparing 2DE CD and 3DE planimetry and showed higher values in comparison to 2DE gray scale, which suggests 2DE CD to be an alternative approach for SV assessment. © 2012, Wiley Periodicals, Inc.

  9. Accuracy and reliability of noninvasive stroke volume monitoring via ECG-gated 3D electrical impedance tomography in healthy volunteers

    Science.gov (United States)

    Proença, Martin; Adler, Andy; Riedel, Thomas; Thiran, Jean-Philippe; Solà, Josep

    2018-01-01

    Cardiac output (CO) and stroke volume (SV) are parameters of key clinical interest. Many techniques exist to measure CO and SV, but are either invasive or insufficiently accurate in clinical settings. Electrical impedance tomography (EIT) has been suggested as a noninvasive measure of SV, but inconsistent results have been reported. Our goal is to determine the accuracy and reliability of EIT-based SV measurements, and whether advanced image reconstruction approaches can help to improve the estimates. Data were collected on ten healthy volunteers undergoing postural changes and exercise. To overcome the sensitivity to heart displacement and thorax morphology reported in previous work, we used a 3D EIT configuration with 2 planes of 16 electrodes and subject-specific reconstruction models. Various EIT-derived SV estimates were compared to reference measurements derived from the oxygen uptake. Results revealed a dramatic impact of posture on the EIT images. Therefore, the analysis was restricted to measurements in supine position under controlled conditions (low noise and stable heart and lung regions). In these measurements, amplitudes of impedance changes in the heart and lung regions could successfully be derived from EIT using ECG gating. However, despite a subject-specific calibration the heart-related estimates showed an error of 0.0 ± 15.2 mL for absolute SV estimation. For trending of relative SV changes, a concordance rate of 80.9% and an angular error of −1.0 ± 23.0° were obtained. These performances are insufficient for most clinical uses. Similar conclusions were derived from lung-related estimates. Our findings indicate that the key difficulty in EIT-based SV monitoring is that purely amplitude-based features are strongly influenced by other factors (such as posture, electrode contact impedance and lung or heart conductivity). All the data of the present study are made publicly available for further investigations. PMID:29373611

  10. Fluoxetine Maintains a State of Heightened Responsiveness to Motor Training Early After Stroke in a Mouse Model.

    Science.gov (United States)

    Ng, Kwan L; Gibson, Ellen M; Hubbard, Robert; Yang, Juemin; Caffo, Brian; O'Brien, Richard J; Krakauer, John W; Zeiler, Steven R

    2015-10-01

    Data from both humans and animal models suggest that most recovery from motor impairment after stroke occurs in a sensitive period that lasts only weeks and is mediated, in part, by an increased responsiveness to training. Here, we used a mouse model of focal cortical stroke to test 2 hypotheses. First, we investigated whether responsiveness to training decreases over time after stroke. Second, we tested whether fluoxetine, which can influence synaptic plasticity and stroke recovery, can prolong the period over which large training-related gains can be elicited after stroke. Mice were trained to perform a skilled prehension task to an asymptotic level of performance after which they underwent stroke induction in the caudal forelimb area. The mice were then retrained after a 1- or 7-day delay with and without fluoxetine. Recovery of prehension after a caudal forelimb area stroke was complete if training was initiated 1 day after stroke but incomplete if it was delayed by 7 days. In contrast, if fluoxetine was administered at 24 hours after stroke, then complete recovery of prehension was observed even with the 7-day training delay. Fluoxetine seemed to mediate its beneficial effect by reducing inhibitory interneuron expression in intact premotor cortex rather than through effects on infarct volume or cell death. There is a gradient of diminishing responsiveness to motor training over the first week after stroke. Fluoxetine can overcome this gradient and maintain maximal levels of responsiveness to training even 7 days after stroke. © 2015 American Heart Association, Inc.

  11. 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

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2013-07-01

    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.

  12. Revisiting the relationship between tumour volume and diameter in advanced NSCLC patients: An exercise to maximize the utility of each measure to assess response to therapy

    International Nuclear Information System (INIS)

    Nishino, M.; Jackman, D.M.; DiPiro, P.J.; Hatabu, H.; Jänne, P.A.; Johnson, B.E.

    2014-01-01

    Aim: To revisit the presumed relationship between tumour diameter and volume in advanced non-small-cell lung cancer (NSCLC) patients, and determine whether the measured volume using volume-analysis software and its proportional changes during therapy matches with the calculated volume obtained from the presumed relationship and results in concordant response assessment. Materials and methods: Twenty-three patients with stage IIIB/IV NSCLC with a total of 53 measurable lung lesions, treated in a phase II trial of erlotinib, were studied with institutional review board approval. Tumour volume and diameter were measured at baseline and at the first follow-up computed tomography (CT) examination using volume-analysis software. Using the measured diameter (2r) and the equation, calculated volume was obtained as (4/3)πr 3 at baseline and at the follow-up. Percent volume change was obtained by comparing to baseline for measured and calculated volumes, and response assessment was assigned. Results: The measured volume was significantly smaller than the calculated volume at baseline (median 11,488.9 mm 3 versus 17,148.6 mm 3 ; p < 0.0001), with a concordance correlation coefficient (CCC) of 0.7022. At follow-up, the measured volume was once again significantly smaller than the calculated volume (median 6573.5 mm 3 versus 9198.1 mm 3 ; p = 0.0022), with a CCC of 0.7408. Response assessment by calculated versus measured volume changes had only moderate agreement (weighted κ = 0.545), with discordant assessment results in 20% (8/40) of lesions. Conclusion: Calculated volume based on the presumed relationship significantly differed from the measured volume in advanced NSCLC patients, with only moderate concordance in response assessment, indicating the limitations of presumed relationship. - Highlights: • Response assessment by measured vs calculated values has only moderate agreement. • It is important to obtain the actual measured values for tumor response

  13. Stroke Treatments

    Science.gov (United States)

    ... Stroke Association.org Professionals for Stroke Association.org Shop for Stroke Association.org Support for Stroke Association. ... works by dissolving the clot and improving blood flow to the part of the brain being deprived ...

  14. Extravascular Lung Water Does Not Increase in Hypovolemic Patients after a Fluid-Loading Protocol Guided by the Stroke Volume Variation

    Directory of Open Access Journals (Sweden)

    Carlos Ferrando

    2012-01-01

    Full Text Available Introduction. Circulatory failure secondary to hypovolemia is a common situation in critical care patients. Volume replacement is the first option for the treatment of hypovolemia. A possible complication of volume loading is pulmonary edema, quantified at the bedside by the measurement of extravascular lung water index (ELWI. ELWI predicts progression to acute lung injury (ALI in patients with risk factors for developing it. The aim of this study was to assess whether fluid loading guided by the stroke volume variation (SVV, in patients presumed to be hypovolemic, increased ELWI or not. Methods. Prospective study of 17 consecutive postoperative, fully mechanically ventilated patients diagnosed with circulatory failure secondary to presumed hypovolemia were included. Cardiac index (CI, ELWI, SVV, and global end-diastolic volume index (GEDI were determined using the transpulmonary thermodilution technique during the first 12 hours after fluid loading. Volume replacement was done with a strict hemodynamic protocol. Results. Fluid loading produced a significant increase in CI and a decrease in SVV. ELWI did not increase. No correlation was found between the amount of fluids administered and the change in ELWI. Conclusion. Fluid loading guided by SVV in hypovolemic and fully mechanically ventilated patients in sinus rhythm does not increase ELWI.

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

    LENUS (Irish Health Repository)

    2011-04-01

    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.

  16. Non-invasive measurements of pulse pressure variation and stroke volume variation in anesthetized patients using the Nexfin blood pressure monitor.

    Science.gov (United States)

    Stens, Jurre; Oeben, Jeroen; Van Dusseldorp, Ab A; Boer, Christa

    2016-10-01

    Nexfin beat-to-beat arterial blood pressure monitoring enables continuous assessment of hemodynamic indices like cardiac index (CI), pulse pressure variation (PPV) and stroke volume variation (SVV) in the perioperative setting. In this study we investigated whether Nexfin adequately reflects alterations in these hemodynamic parameters during a provoked fluid shift in anesthetized and mechanically ventilated patients. The study included 54 patients undergoing non-thoracic surgery with positive pressure mechanical ventilation. The provoked fluid shift comprised 15° Trendelenburg positioning, and fluid responsiveness was defined as a concomitant increase in stroke volume (SV) >10 %. Nexfin blood pressure measurements were performed during supine steady state, Trendelenburg and supine repositioning. Hemodynamic parameters included arterial blood pressure (MAP), CI, PPV and SVV. Trendelenburg positioning did not affect MAP or CI, but induced a decrease in PPV and SVV by 3.3 ± 2.8 and 3.4 ± 2.7 %, respectively. PPV and SVV returned back to baseline values after repositioning of the patient to baseline. Bland-Altman analysis of SVV and PPV showed a bias of -0.3 ± 3.0 % with limits of agreement ranging from -5.6 to 6.2 %. The SVV was more superior in predicting fluid responsiveness (AUC 0.728) than the PVV (AUC 0.636), respectively. The median bias between PPV and SVV was different for patients younger [-1.5 % (-3 to 0)] or older [+2 % (0-4.75)] than 55 years (P < 0.001), while there were no gender differences in the bias between PPV and SVV. The Nexfin monitor adequately reflects alterations in PPV and SVV during a provoked fluid shift, but the level of agreement between PPV and SVV was low. The SVV tended to be superior over PPV or Eadyn in predicting fluid responsiveness in our population.

  17. Profit maximization mitigates competition

    DEFF Research Database (Denmark)

    Dierker, Egbert; Grodal, Birgit

    1996-01-01

    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...

  18. Maximally incompatible quantum observables

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [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: ziman@savba.sk [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)

    2014-05-01

    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.

  19. Maximally incompatible quantum observables

    International Nuclear Information System (INIS)

    Heinosaari, Teiko; Schultz, Jussi; Toigo, Alessandro; Ziman, Mario

    2014-01-01

    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.

  20. Left ventricular end-diastolic volume is decreased at maximal exercise in athletes with marked repolarisation abnormalities: a continuous radionuclide monitoring study

    International Nuclear Information System (INIS)

    Flotats, Albert; Camacho, Valle; Mena, Esther; Estorch, Montserrat; Tembl, Ana; Fuertes, Jordi; Carrio, Ignasi; Serra-Grima, Ricard; Borras, Xavier; Cinca, Juan

    2005-01-01

    Although marked repolarisation abnormalities (MRAs) are considered innocuous in trained athletes, their functional significance awaits clarification. The aim of this study was to further evaluate the pathophysiological implications of such MRAs. We compared left ventricular (LV) functional response to exhausting exercise in 39 male athletes with (n=22) or without (n=17) MRAs and with no structural cardiac abnormalities, by means of a portable radionuclide monitoring system (Vest, Capintec, Inc., Ramsey, NJ). MRAs were defined by the presence of negative T waves ≥2 mm in three or more rest ECG leads. The Vest data were averaged for 30 s and analysed at baseline and at different heart rate (HR) values (50%, 75%, 85%, 95% and 100% of peak HR), as well as at 2, 5 and 10 min of recovery. There were no significant differences in the effect of exhausting exercise between athletes with and athletes without MRAs. However, there was a significant difference in the trend in end-diastolic volume (EDV) during exercise depending upon the group of athletes considered (p=0.05). EDV differed significantly between the two groups of athletes at peak HR (p=0.031). EDV in athletes with MRAs was lower than that in athletes without MRAs (102%±7% vs 107%±8%, p=0.034). EDV is decreased at peak HR in athletes with MRAs. Such high HR values are infrequently achieved or maintained during sporting activities; therefore, in the absence of structural heart disease, MRAs should not preclude physical training and competitive availability. (orig.)

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

    Science.gov (United States)

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

    2015-01-01

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    . Group 1 was treated with saline, and group 2 was treated with 20 mg/kg recombinant tissue plasminogen activator to promote intracerebral hemorrhages. Stereology, semiautomated computer estimation, and manual erythrocyte counting were used to test the precision and efficiency of determining the size...... 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...

  3. Fetal cardiac stroke volume determination by four-dimensional ultrasound with spatio-temporal image correlation compared with two-dimensional and Doppler ultrasonography.

    Science.gov (United States)

    Rizzo, Giuseppe; Capponi, Alessandra; Cavicchioni, Ottavia; Vendola, Marianne; Arduini, Domenico

    2007-12-01

    To assess the agreement of stroke volume (SV) measured with two-dimensional (2D) ultrasonography with Doppler capability (vs) four-dimensional (4D) with spatiotemporal image correlation (STIC) in normal and growth restricted fetuses. 2D Doppler and 4D STIC were used to measure SV of 40 normal fetuses at 20 to 22 and 28 to 32 weeks, and 16 growth-restricted fetuses at 26 to 34 weeks of gestation. Intraclass correlation was used to evaluate the agreement between left and right SV obtained by the two techniques, and proportionate Bland-Altman plots constructed. The time necessary to obtain SV was analyzed. The intraclass correlation coefficient between 2D Doppler and 4D STIC measurements for the left ventricle were 0.977 and 0.980 for the right ventricle. The proportionate limits of agreement between the two methods were 18.7 to 23.9% for the left ventricle and - 20.9 to 21.7% for the right ventricle. The time necessary to measure SV was significantly shorter with 4D STIC (3.1 (vs) 7.9 min p < 0.0001) than with 2D Doppler. There is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice. Copyright (c) 2007 John Wiley & Sons, Ltd.

  4. SU-G-BRA-04: Simulation of Errors in Maximal Intensity Projection (MIP)-Based Lung Tumor Internal Target Volumes (ITV) Using Real-Time 2D MRI and Deformable Image Registration Based Lung Tumor Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D; Kishan, A; Santhanam, A; Min, Y; O’Connell, D; Lamb, J; Cao, M; Agazaryan, N; Yang, Y; Lee, P; Low, D [University of California, Los Angeles, Ca (United States)

    2016-06-15

    Purpose: To evaluate the effect of inter- and intra-fractional tumor motion on the error in four-dimensional computed tomography (4DCT) maximal intensity projection (MIP)–based lung tumor internal target volumes (ITV), using deformable image registration of real-time 2D-sagital cine-mode MRI acquired during lung SBRT treatments. Methods: Five lung tumor patients underwent free breathing SBRT treatment on the ViewRay, with dose prescribed to PTV (4DCT MIP-based ITV+3–6mm margin). Sagittal slice cine-MR images (3.5×3.5mm pixels) were acquired through the center of the tumor at 4 frames per second throughout the treatments (3–4 fractions of 21–32 minutes duration). Tumor GTVs were contoured on the first frame of the cine and tracked throughout the treatment using off-line optical-flow based deformable registration implemented on a GPU cluster. Pseudo-4DCT MIP-based ITVs were generated from MIPs of the deformed GTV contours limited to short segments of image data. All possible pseudo-4DCT MIP-based ITV volumes were generated with 1s resolution and compared to the ITV volume of the entire treatment course. Varying pseudo-4DCT durations from 10-50s were analyzed. Results: Tumors were covered in their entirety by PTV in the patients analysed here. However, pseudo-4DCT based ITV volumes were observed that were as small as 29% of the entire treatment-ITV, depending on breathing irregularity and the duration of pseudo-4DCT. With an increase in duration of pseudo-4DCT from 10–50s the minimum volume acquired from 95% of all pseudo-4DCTs increased from 62%–81% of the treatment ITV. Conclusion: A 4DCT MIP-based ITV offers a ‘snap-shot’ of breathing motion for the brief period of time the tumor is imaged on a specific day. Real time MRI over prolonged periods of time and over multiple treatment fractions shows that the accuracy of this snap-shot varies according to inter- and intra-fractional tumor motion. Further work is required to investigate the dosimetric

  5. SU-G-BRA-04: Simulation of Errors in Maximal Intensity Projection (MIP)-Based Lung Tumor Internal Target Volumes (ITV) Using Real-Time 2D MRI and Deformable Image Registration Based Lung Tumor Tracking

    International Nuclear Information System (INIS)

    Thomas, D; Kishan, A; Santhanam, A; Min, Y; O’Connell, D; Lamb, J; Cao, M; Agazaryan, N; Yang, Y; Lee, P; Low, D

    2016-01-01

    Purpose: To evaluate the effect of inter- and intra-fractional tumor motion on the error in four-dimensional computed tomography (4DCT) maximal intensity projection (MIP)–based lung tumor internal target volumes (ITV), using deformable image registration of real-time 2D-sagital cine-mode MRI acquired during lung SBRT treatments. Methods: Five lung tumor patients underwent free breathing SBRT treatment on the ViewRay, with dose prescribed to PTV (4DCT MIP-based ITV+3–6mm margin). Sagittal slice cine-MR images (3.5×3.5mm pixels) were acquired through the center of the tumor at 4 frames per second throughout the treatments (3–4 fractions of 21–32 minutes duration). Tumor GTVs were contoured on the first frame of the cine and tracked throughout the treatment using off-line optical-flow based deformable registration implemented on a GPU cluster. Pseudo-4DCT MIP-based ITVs were generated from MIPs of the deformed GTV contours limited to short segments of image data. All possible pseudo-4DCT MIP-based ITV volumes were generated with 1s resolution and compared to the ITV volume of the entire treatment course. Varying pseudo-4DCT durations from 10-50s were analyzed. Results: Tumors were covered in their entirety by PTV in the patients analysed here. However, pseudo-4DCT based ITV volumes were observed that were as small as 29% of the entire treatment-ITV, depending on breathing irregularity and the duration of pseudo-4DCT. With an increase in duration of pseudo-4DCT from 10–50s the minimum volume acquired from 95% of all pseudo-4DCTs increased from 62%–81% of the treatment ITV. Conclusion: A 4DCT MIP-based ITV offers a ‘snap-shot’ of breathing motion for the brief period of time the tumor is imaged on a specific day. Real time MRI over prolonged periods of time and over multiple treatment fractions shows that the accuracy of this snap-shot varies according to inter- and intra-fractional tumor motion. Further work is required to investigate the dosimetric

  6. Maximizers versus satisficers

    OpenAIRE

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

    2007-01-01

    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...

  7. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  8. Ischemic Stroke

    Science.gov (United States)

    ... Workplace Giving Fundraise Planned Giving Corporate Giving Cause Marketing Join your team, your way! The Stroke Challenge ... Your Technology Guide High Blood Pressure and Stroke Importance of Physical Activity See More Multimedia Las minorías ...

  9. Paediatric stroke

    African Journals Online (AJOL)

    2011-04-02

    Apr 2, 2011 ... Organization definition of stroke is 'a clinical syndrome of rapidly developing focal or global ..... In the case of sickle cell disease primary and secondary prevention is by ... stroke and must involve caregivers. Prognosis7,10,17.

  10. Kinesthetic taping improves walking function in patients with stroke

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...... be a valuable adjunct in physical therapy and rehabilitation of patients with stroke....

  11. Maximally multipartite entangled states

    Science.gov (United States)

    Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

    2008-06-01

    We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

  12. Maximizers versus satisficers

    Directory of Open Access Journals (Sweden)

    Andrew M. Parker

    2007-12-01

    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. Part 11: adult stroke: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

    Science.gov (United States)

    Jauch, Edward C; Cucchiara, Brett; Adeoye, Opeolu; Meurer, William; Brice, Jane; Chan, Yvonne Yu-Feng; Gentile, Nina; Hazinski, Mary Fran

    2010-11-02

    Advances in stroke care will have the greatest effect on stroke outcome if care is delivered within a regional stroke system designed to improve both efficiency and effectiveness. The ultimate goal of stroke care is to minimize ongoing injury, emergently recanalize acute vascular occlusions, and begin secondary measures to maximize functional recovery. These efforts will provide stroke patients with the greatest opportunity for a return to previous quality of life and decrease the overall societal burden of stroke.

  14. Cryptogenic Stroke

    Directory of Open Access Journals (Sweden)

    Mohammad Saadatnia

    2017-02-01

    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.

  15. Is CP violation maximal

    International Nuclear Information System (INIS)

    Gronau, M.

    1984-01-01

    Two ambiguities are noted in the definition of the concept of maximal CP violation. The phase convention ambiguity is overcome by introducing a CP violating phase in the quark mixing matrix U which is invariant under rephasing transformations. The second ambiguity, related to the parametrization of U, is resolved by finding a single empirically viable definition of maximal CP violation when assuming that U does not single out one generation. Considerable improvement in the calculation of nonleptonic weak amplitudes is required to test the conjecture of maximal CP violation. 21 references

  16. Stroke Volume Variation-Guided Versus Central Venous Pressure-Guided Low Central Venous Pressure With Milrinone During Living Donor Hepatectomy: A Randomized Double-Blinded Clinical Trial.

    Science.gov (United States)

    Lee, Jiwon; Kim, Won Ho; Ryu, Ho-Geol; Lee, Hyung-Chul; Chung, Eun-Jin; Yang, Seong-Mi; Jung, Chul-Woo

    2017-08-01

    We previously demonstrated the usefulness of milrinone for living donor hepatectomy. However, a less-invasive alternative to central venous catheterization and perioperative contributors to good surgical outcomes remain undetermined. The current study evaluated whether the stroke volume variation (SVV)-guided method can substitute central venous catheterization during milrinone-induced profound vasodilation. We randomly assigned 42 living liver donors to receive either SVV guidance or central venous pressure (CVP) guidance to obtain milrinone-induced low CVP. Target SVV of 9% was used as a substitute for CVP of 5 mm Hg. The surgical field grade evaluated by 2 attending surgeons on a 4-point scale was compared between the CVP- and SVV-guided groups (n = 19, total number of scores = 38 per group) as a primary outcome variable. Multivariable analysis was performed to identify independent factors associated with the best surgical field as a post hoc analysis. Surgical field grades, which were either 1 or 2, were not found to be different between the 2 groups via Mann-Whitney U test (P = .358). There was a very weak correlation between SVV and CVP during profound vasodilation such as CVP ≤ 5 mm Hg (R = -0.06; 95% confidence interval, -0.09 to -0.04; P milrinone infusion might be helpful in providing the best surgical field. Milrinone-induced vasodilation resulted in favorable surgical environment regardless of guidance methods of low CVP during living donor hepatectomy. However, SVV was not a useful indicator of low CVP because of very weak correlation between SVV and CVP during profound vasodilation. In addition, factors contributing to the best surgical field such as donor age, proactive fasting, and proper dosing of milrinone need to be investigated further, ideally through prospective studies.

  17. Left Ventricular Stroke Volume Quantification by Contrast Echocardiography – Comparison of Linear and Flow-Based Methods to Cardiac Magnetic Resonance

    Science.gov (United States)

    Dele-Michael, Abiola O.; Fujikura, Kana; Devereux, Richard B; Islam, Fahmida; Hriljac, Ingrid; Wilson, Sean R.; Lin, Fay; Weinsaft, Jonathan W.

    2014-01-01

    Background Echocardiography (echo) quantified LV stroke volume (SV) is widely used to assess systolic performance after acute myocardial infarction (AMI). This study compared two common echo approaches – predicated on flow (Doppler) and linear chamber dimensions (Teichholz) – to volumetric SV and global infarct parameters quantified by cardiac magnetic resonance (CMR). Methods Multimodality imaging was performed as part of a post-AMI registry. For echo, SV was measured by Doppler and Teichholz methods. Cine-CMR was used for volumetric SV and LVEF quantification, and delayed-enhancement CMR for infarct size. Results 142 patients underwent same-day echo and CMR. On echo, mean SV by Teichholz (78±17ml) was slightly higher than Doppler (75±16ml; Δ=3±13ml, p=0.02). Compared to SV on CMR (78±18ml), mean difference by Teichholz (Δ=−0.2±14; p=0.89) was slightly smaller than Doppler (Δ−3±14; p=0.02) but limits of agreement were similar between CMR and echo methods (Teichholz: −28, 27 ml, Doppler: −31, 24ml). For Teichholz, differences with CMR SV were greatest among patients with anteroseptal or lateral wall hypokinesis (p<0.05). For Doppler, differences were associated with aortic valve abnormalities or root dilation (p=0.01). SV by both echo methods decreased stepwise in relation to global LV injury as assessed by CMR-quantified LVEF and infarct size (p<0.01). Conclusions Teichholz and Doppler calculated SV yield similar magnitude of agreement with CMR. Teichholz differences with CMR increase with septal or lateral wall contractile dysfunction, whereas Doppler yields increased offsets in patients with aortic remodeling. PMID:23488864

  18. Goal-Directed Fluid Therapy Based on Stroke Volume Variation in Patients Undergoing Major Spine Surgery in the Prone Position: A Cohort Study.

    Science.gov (United States)

    Bacchin, Maria Renata; Ceria, Chiara Marta; Giannone, Sandra; Ghisi, Daniela; Stagni, Gaetano; Greggi, Tiziana; Bonarelli, Stefano

    2016-09-15

    A retrospective observational study. The aim of this study was to test whether a goal-directed fluid therapy (GDFT) protocol, based on stroke volume variation (SVV), applied in major spine surgery performed in the prone position, would be effective in reducing peri-operative red blood cells transfusions. Recent literature shows that optimizing perioperative fluid therapy is associated with lower complication rates and faster recovery. Data from 23 patients who underwent posterior spine arthrodesis surgery and whose intraoperative fluid administration were managed with the GDFT protocol were retrospectively collected and compared with data from 23 matched controls who underwent the same surgical procedure in the same timeframe, and who received a liberal intraoperative fluid therapy. Patients in the GDFT group received less units of transfused red blood cells (primary endpoint) in the intra (0 vs. 2.0, P = 0.0 4) and postoperative period (2.0 vs. 4.0, P = 0.003). They also received a lower amount of intraoperative crystalloids, had fewer blood losses, and lower intraoperative peak lactate. In the postoperative period, patients in the GDFT group had fewer pulmonary complications and blood losses from surgical drains, needed less blood product transfusions, had a shorter intensive care unit stay, and a faster return of bowel function. We found no difference in the total length of stay among the two groups. Our study shows that application of a GDFT based on SVV in major spine surgery is feasible and can lead to reduced blood losses and transfusions, better postoperative respiratory performance, shorter ICU stay, and faster return of bowel function. 3.

  19. The effect of endogenously released glucose, insulin, glucagon-like peptide 1, ghrelin on cardiac output, heart rate, stroke volume, and blood pressure.

    Science.gov (United States)

    Hlebowicz, Joanna; Lindstedt, Sandra; Björgell, Ola; Dencker, Magnus

    2011-12-29

    Ingestion of a meal increases the blood flow to the gastrointestinal organs and affects the heart rate (HR), blood pressure and cardiac output (CO), although the mechanisms are not known. The aim of this study was to evaluate the effect of endogenously released glucose, insulin, glucagon-like peptide 1 (GLP-1), ghrelin on CO, HR, stroke volume (SV), and blood pressure. Eleven healthy men and twelve healthy women ((mean ± SEM) aged: 26 ± 0.2 y; body mass index: 21.8 ± 0.1 kg/m(2))) were included in this study. The CO, HR, SV, systolic and diastolic blood pressure, antral area, gastric emptying rate, and glucose, insulin, GLP-1 and ghrelin levels were measured. The CO and SV at 30 min were significantly higher, and the diastolic blood pressure was significantly lower, than the fasting in both men and women (P blood pressure (P = 0.021, r = -0.681), and the change in SV (P = 0.008, r = -0.748) relative to the fasting in men. The insulin 0-30 min AUC was significantly correlated to the CO 0-30 min AUC (P = 0.002, r = 0.814) in men. Significant correlations were also found between the 0-120 min ghrelin and HR AUCs (P = 0.007, r = 0.966) in men. No statistically significant correlations were seen in women. Physiological changes in the levels of glucose, insulin, GLP-1 and ghrelin may influence the activity of the heart and the blood pressure. There may also be gender-related differences in the haemodynamic responses to postprandial changes in hormone levels. The results of this study show that subjects should not eat immediately prior to, or during, the evaluation of cardiovascular interventions as postprandial affects may affect the results, leading to erroneous interpretation of the cardiovascular effects of the primary intervention. NCT01027507.

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

    Science.gov (United States)

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

    2015-12-01

    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. 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/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase-contrast cardiovascular magnetic resonance (CMR). FSVPET correlated highly with FSVCMR (r = 0.87, slope = 0.90 for scanner I, r = 0.87, slope = 1.65, and r = 0.85, slope = 1.69 for scanner II for (15)O-water and (11)C-acetate, respectively) although a systematic bias was observed for both scanners (p dynamic PET/CT and cluster analysis. Results are almost identical for (11)C-acetate and (15)O-water. A scanner-dependent bias was observed, and a scanner calibration factor is required for multi-scanner studies. Generalization of the method to other tracers and scanners requires further validation.

  1. Strategies of Daily Living Rehabilitative Activities for Post Stroke Patients at Minia University Hospital

    Science.gov (United States)

    Zaky, Hend Elham Mohamed; EL-Lateef Mohammad, Zienab Abd; EL-Labban, Abdou Saad Taha; Ahmed, Gahen

    2015-01-01

    Background: Stroke is a leading cause of disability. Rehabilitation aims to hasten and maximize recovery from stroke by treating the disabilities caused by the stroke. Therefore, the aim of this study determine the post stroke patients' knowledge and practices in relation to disease and activities of daily living before the implementation of…

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

    Science.gov (United States)

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

    2018-01-01

    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.

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

    Science.gov (United States)

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

    2017-05-10

    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 (prespiratory muscle aerobic capacity, attenuation of respiratory muscle metabo-reflex, increase 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.

  4. Stroke Rehabilitation.

    Science.gov (United States)

    Belagaje, Samir R

    2017-02-01

    Rehabilitation is an important aspect of the continuum of care in stroke. With advances in the acute treatment of stroke, more patients will survive stroke with varying degrees of disability. Research in the past decade has expanded our understanding of the mechanisms underlying stroke recovery and has led to the development of new treatment modalities. This article reviews and summarizes the key concepts related to poststroke recovery. Good data now exist by which one can predict recovery, especially motor recovery, very soon after stroke onset. Recent trials have not demonstrated a clear benefit associated with very early initiation of rehabilitative therapy after stroke in terms of improvement in poststroke outcomes. However, growing evidence suggests that shorter and more frequent sessions of therapy can be safely started in the first 24 to 48 hours after a stroke. The optimal amount or dose of therapy for stroke remains undetermined, as more intensive treatments have not been associated with better outcomes compared to standard intensities of therapy. Poststroke depression adversely affects recovery across a variety of measures and is an important target for therapy. Additionally, the use of selective serotonin reuptake inhibitors (SSRIs) appears to benefit motor recovery through pleiotropic mechanisms beyond their antidepressant effect. Other pharmacologic approaches also appear to have a benefit in stroke rehabilitation. A comprehensive rehabilitation program is essential to optimize poststroke outcomes. Rehabilitation is a process that uses three major principles of recovery: adaptation, restitution, and neuroplasticity. Based on these principles, multiple different approaches, both pharmacologic and nonpharmacologic, exist to enhance rehabilitation. In addition to neurologists, a variety of health care professionals are involved in stroke rehabilitation. Successful rehabilitation involves understanding the natural history of stroke recovery and a

  5. [Neuro-rehabilitation after stroke].

    Science.gov (United States)

    Murie-Fernández, M; Irimia, P; Martínez-Vila, E; John Meyer, M; Teasell, R

    2010-04-01

    the high incidence of stroke results in significant mortality and disability leading to immense health care costs. These costs lead to socioeconomic, budgetary, and staffing repercussions in developing countries. Improvements in stroke management focus mainly on acute neurological treatment, admission to stroke units, fibrinolytic treatment for ischaemic strokes and rehabilitation processes. Among these, rehabilitation has the longest therapeutic window, can be applied in both ischaemic and haemorrhagic strokes, and can improve functional outcomes months after stroke. Neurologists, because of their knowledge in neuroanatomy, physiopathology, neuro-pharmacology, and brain plasticity, are in an ideal position to actively participate in the neurorehabilitation process. Several processes have been shown to play a role in determining the efficacy of rehabilitation; time from stroke onset to rehabilitation admission and the duration and intensity of treatment. neurorehabilitation is a sub-speciality in which neurologists should be incorporated into multidisciplinary neurorehabilitation teams. Early time to rehabilitation admission and greater intensity and duration of treatment are associated with better functional outcomes, lower mortality/institutionalisation, and shorter length of stay. In order to be efficient, a concerted effort must be made to ensure patients receive neurorehabilitation treatment in a timely manner with appropriate intensity to maximize patient outcomes during both inpatient and outpatient rehabilitation. Published by Elservier España, S.L. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Raphael Rodrigues Perim

    2011-01-01

    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.

  7. The effect of endogenously released glucose, insulin, glucagon-like peptide 1, ghrelin on cardiac output, heart rate, stroke volume, and blood pressure

    Directory of Open Access Journals (Sweden)

    Hlebowicz Joanna

    2011-12-01

    Full Text Available Abstract Background Ingestion of a meal increases the blood flow to the gastrointestinal organs and affects the heart rate (HR, blood pressure and cardiac output (CO, although the mechanisms are not known. The aim of this study was to evaluate the effect of endogenously released glucose, insulin, glucagon-like peptide 1 (GLP-1, ghrelin on CO, HR, stroke volume (SV, and blood pressure. Methods Eleven healthy men and twelve healthy women ((mean ± SEM aged: 26 ± 0.2 y; body mass index: 21.8 ± 0.1 kg/m2 were included in this study. The CO, HR, SV, systolic and diastolic blood pressure, antral area, gastric emptying rate, and glucose, insulin, GLP-1 and ghrelin levels were measured. Results The CO and SV at 30 min were significantly higher, and the diastolic blood pressure was significantly lower, than the fasting in both men and women (P P = 0.015, r = 0.946, and between ghrelin levels and HR (P = 0.013, r = 0.951 at 110 min. Significant correlations were also found between the change in glucose level at 30 min and the change in systolic blood pressure (P = 0.021, r = -0.681, and the change in SV (P = 0.008, r = -0.748 relative to the fasting in men. The insulin 0-30 min AUC was significantly correlated to the CO 0-30 min AUC (P = 0.002, r = 0.814 in men. Significant correlations were also found between the 0-120 min ghrelin and HR AUCs (P = 0.007, r = 0.966 in men. No statistically significant correlations were seen in women. Conclusions Physiological changes in the levels of glucose, insulin, GLP-1 and ghrelin may influence the activity of the heart and the blood pressure. There may also be gender-related differences in the haemodynamic responses to postprandial changes in hormone levels. The results of this study show that subjects should not eat immediately prior to, or during, the evaluation of cardiovascular interventions as postprandial affects may affect the results, leading to erroneous interpretation of the cardiovascular effects of the

  8. Guinea pig maximization test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    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...

  9. Stroke Care 2: Stroke rehabilitation

    NARCIS (Netherlands)

    Langhorne, P.; Bernhardt, J.; Kwakkel, G.

    2011-01-01

    Stroke is a common, serious, and disabling global health-care problem, and rehabilitation is a major part of patient care. There is evidence to support rehabilitation in well coordinated multidisciplinary stroke units or through provision of early supported provision of discharge teams. Potentially

  10. Tri-maximal vs. bi-maximal neutrino mixing

    International Nuclear Information System (INIS)

    Scott, W.G

    2000-01-01

    It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

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

    NARCIS (Netherlands)

    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.

    2015-01-01

    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,

  12. Lower Ipsilateral Hippocampal Integrity after Ischemic Stroke in Young Adults: A Long-Term Follow-Up Study

    NARCIS (Netherlands)

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

    2015-01-01

    Background and purpose Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first

  13. Lower Ipsilateral Hippocampal Integrity after Ischemic Stroke in Young Adults: A Long-Term Follow-Up Study

    NARCIS (Netherlands)

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

    2015-01-01

    BACKGROUND AND PURPOSE: Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first

  14. Identification of the State of Maximal Hyperemia in the Assessment of Coronary Fractional Flow Reserve Using Non-Invasive Electrical Velocimetry.

    Science.gov (United States)

    Murasawa, Takahide; Takahashi, Masao; Myojo, Masahiro; Kiyosue, Arihiro; Oguri, Atsushi; Ando, Jiro; Komuro, Issei

    2017-05-31

    Previous research revealed that, in patients with coronary pressure-derived fractional flow reserve (FFR) in the 'grey zone' (0.75-0.85), repeated FFR assessments sometimes yield conflicting results. One of the causes of the fluctuations in FFR values around the grey zone may be imprecise identification of the point where maximal hyperemia is achieved. Identification of the state of maximal hyperemia during assessment of FFR can be challenging. This study aimed to determine whether non-invasive electrical velocimetry (EV) can be used to identify the state of maximal hyperemia.Stroke volume (SV), SV variation (SVV), and systemic vascular resistance index (SVRI) were determined by EV in 15 patients who underwent FFR assessment. Time intervals from initiation of adenosine infusion to achieving maximal hyperemia (time mFRR ), as well as to achieving maximal cardiac output (CO), SV, SVV, and SVRI (time mCO , time mSV , time mSVV , and time mSVRI , respectively), were determined. Time mCO and time mSVV were closer to time mFRR than other values (time mSVV /time mFRR versus time mSVRI /time mFRR = 1.03 ± 0.2 versus 1.36 ± 0.4, P state of maximal hyperemia.

  15. Preventing stroke

    Science.gov (United States)

    ... with which you were born Changes to your lifestyle You can change some risk factors for stroke, ... sodium (salt). Read labels and stay away from unhealthy fats. Avoid foods with: Saturated fat Partially-hydrogenated ...

  16. Stroke Rehabilitation

    Science.gov (United States)

    ... of the effects of a stroke Trouble swallowing (dysphagia) Problems with bowel or bladder control Fatigue Difficulty ... NINDS Focus on Disorders Alzheimer's & Related Dementias Epilepsy Parkinson's Disease Spinal Cord Injury Traumatic Brain Injury Focus ...

  17. Pediatric stroke

    International Nuclear Information System (INIS)

    Hoermann, M.

    2008-01-01

    Stroke in childhood has gained increasingly more attention and is accepted as an important disease in childhood. The reasons for this severe event and the consequences for the rest of the life are totally different than for adults. This is also true for the diagnosis and therapy. This paper gives a comprehensive overview on the characteristics of pediatric stroke to assist radiologists in making a rapid and safe diagnosis in order to identify the underlying disease. (orig.) [de

  18. Nursing application of Bobath principles in stroke care.

    Science.gov (United States)

    Passarella, P M; Lewis, N

    1987-04-01

    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.

  19. MAXIM: The Blackhole Imager

    Science.gov (United States)

    Gendreau, Keith; Cash, Webster; Gorenstein, Paul; Windt, David; Kaaret, Phil; Reynolds, Chris

    2004-01-01

    The Beyond Einstein Program in NASA's Office of Space Science Structure and Evolution of the Universe theme spells out the top level scientific requirements for a Black Hole Imager in its strategic plan. The MAXIM mission will provide better than one tenth of a microarcsecond imaging in the X-ray band in order to satisfy these requirements. We will overview the driving requirements to achieve these goals and ultimately resolve the event horizon of a supermassive black hole. We will present the current status of this effort that includes a study of a baseline design as well as two alternative approaches.

  20. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    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

  1. Atherosclerosis and Stroke

    Science.gov (United States)

    ... Stroke Association.org Professionals for Stroke Association.org Shop for Stroke Association.org Support for Stroke Association. ... endothelium significantly. The artery’s diameter shrinks and blood flow decreases, reducing oxygen supply. How atherosclerotic plaque causes ...

  2. Stroke etiology and collaterals: atheroembolic strokes have greater collateral recruitment than cardioembolic strokes.

    Science.gov (United States)

    Rebello, L C; Bouslama, M; Haussen, D C; Grossberg, J A; Dehkharghani, S; Anderson, A; Belagaje, S R; Bianchi, N A; Grigoryan, M; Frankel, M R; Nogueira, R G

    2017-06-01

    Chronic hypoperfusion from athero-stenotic lesions is thought to lead to better collateral recruitment compared to cardioembolic strokes. It was sought to compare collateral flow in stroke patients with atrial fibrillation (AF) versus stroke patients with cervical atherosclerotic steno-occlusive disease (CASOD). This was a retrospective review of a prospectively collected endovascular database. Patients with (i) anterior circulation large vessel occlusion stroke, (ii) pre-treatment computed tomography angiography (CTA) and (iii) intracranial embolism from AF or CASOD were included. CTA collateral patterns were evaluated and categorized into two groups: absent/poor collaterals (CTA collateral score 0-1) versus moderate/good collaterals (CTA collateral score 2-4). CT perfusion was also utilized for baseline core volume and evaluation of infarct growth. A total of 122 patients fitted the inclusion criteria, of whom 88 (72%) had AF and 34 (27%) CASOD. Patients with AF were older (P Collateral scores were lower in the AF group (P = 0.01) with patients having poor collaterals in 28% of cases versus 9% in the CASOD group (P = 0.03). Mortality rates (20% vs. 0%; P = 0.02) were higher in the AF patients whilst rates of any parenchymal hemorrhage (6% vs. 26%; P collaterals (odds ratio 4.70; 95% confidence interval 1.17-18.79; P = 0.03). Atheroembolic strokes seem to be associated with better collateral flow compared to cardioembolic strokes. This may in part explain the worse outcomes of AF-related stroke. © 2017 EAN.

  3. OPTIMUM LEVEL OF POSITIVE END-EXPIRATORY PRESSURE IN ACUTE RESPIRATORY DISTRESS SYNDROME CAUSED BY INFLUENZA A(H1NI)PDM09: BALANCE BETWEEN MAXIMAL END-EXPIRATORY VOLUME AND MINIMAL ALVEOLAR OVERDISTENSION.

    Science.gov (United States)

    Yaroshetskiym A I; Protsenko, D N; Boytsov, P V; Chentsov, V B; Nistratov, S L; Kudlyakov, O N; Solov'ev, V V; Banova, Zh I; Shkuratova, N V; Rezenov, N A; Gel'fand, B R

    2016-11-01

    to determine optimum level ofpositive end-expiratory pressure (PEEP) according to balance between maxi- mal end-expiratory lung volume (EEL V)(more than predicted) and minimal decrease in exhaled carbon dioxide volume (VCO) and then to develop the algorithm of gas exchange correction based on prognostic values of EEL K; alveolar recruitability, PA/FiO2, static compliance (C,,,) and VCO2. 27 mechanically ventilatedpatients with acute respiratory distress syndrome (ARDS) caused by influenza A (HINJ)pdm09 in Moscow Municipal Clinics ICU's from January to March 2016 were included in the trial. At the beginning of the study patients had the following characteristic: duration offlu symptoms 5 (3-10) days, p.0/FiO2 120 (70-50) mmHg. SOFA 7 (5-9), body mass index 30.1 (26.4-33.8) kg/m², static compliance of respiratory system 35 (30-40) ml/mbar: Under sedation and paralysis we measured EELV, C VCO and end-tidal carbon dioxide concentration (EtCO) (for CO₂ measurements we fixed short-term values after 2 min after PEEP level change) at PEEP 8, 11,13,15,18, 20 mbar consequently, and incase of good recruitability, at 22 and 24 mbar. After analyses of obtained data we determined PEEP value in which increase in EELV was maximal (more than predicted) and depression of VCO₂ was less than 20%, change in mean blood pressure and heart rate were both less than 20% (measured at PEEP 8 mbar). After that we set thus determined level of PEEP and didn't change it for 5 days. Comparision of predicted and measured EELV revealed two typical points of alveloar recruiment: the first at PEEP 11-15 mbar, the second at PEEP 20-22 mbar. EELV measured at PEEP 18 mbar appeared to be higher than predicted at PEEP 8 mbar by 400 ml (approx.), which was the sign of alveolar recruitment-1536 (1020-1845) ml vs 1955 (1360-2320) ml, p=0,001, Friedman test). we didn't found significant changes of VCO₂ when increased PEEP in the range from 8 to 15 mbar (p>0.05, Friedman test). PEEP increase from 15 to

  4. Heat Stroke

    DEFF Research Database (Denmark)

    Mørch, Sofie Søndergaard; Andersen, Johnny Dohn Holmgren; Bestle, Morten Heiberg

    2017-01-01

    not diagnosed until several days after admittance; hence treatment with cooling was delayed. Both patients were admitted to the intensive care unit, where they were treated with an external cooling device and received treatment for complications. Both cases ended fatally. As global warming continues, more heat......Heat stroke is an acute, life-threatening emergency characterized clinically by elevated body temperature and central nervous system dysfunction. Early recognition and treatment including aggressive cooling and management of life-threatening systemic complications are essential to reduce morbidity...... and mortality. This case report describes two Danish patients diagnosed with heat stroke syndrome during a heat wave in the summer of 2014. Both patients were morbidly obese and had several predisposing illnesses. However since heat stroke is a rare condition in areas with temperate climate, they were...

  5. Stroke from systemic vascular disorders in Saudi children: The devastating role of hypernatremic dehydration

    International Nuclear Information System (INIS)

    Salih, Mustafa A.; Al-Jarallah, Ahmed A.; Zahraa, Jihad N.; Alorainy, Ibrahim A.; Hassan, Hamdy H.

    2006-01-01

    Systemic vascular disorders, leading to childhood stroke, include volume depletion or systemic hypotension and hypernatremic dehydration. We describe 3 cases of stroke following systemic vascular disorders. These were diagnosed during a prospective and retrospective study on childhood stroke, which included 104 patients. Post-gastroenteritis hypernatremic dehydration is an important, potentially preventable, cause of stroke in Saudi children. (author)

  6. 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

    Directory of Open Access Journals (Sweden)

    Moran Chris G

    2011-09-01

    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

  7. Maximizing the optical network capacity.

    Science.gov (United States)

    Bayvel, Polina; Maher, Robert; Xu, Tianhua; Liga, Gabriele; Shevchenko, Nikita A; Lavery, Domaniç; Alvarado, Alex; Killey, Robert I

    2016-03-06

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. © 2016 The Authors.

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

    Directory of Open Access Journals (Sweden)

    F.J. Neves

    2012-07-01

    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.

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

    Science.gov (United States)

    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

    2016-01-01

    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

  10. Maximal Bell's inequality violation for non-maximal entanglement

    International Nuclear Information System (INIS)

    Kobayashi, M.; Khanna, F.; Mann, A.; Revzen, M.; Santana, A.

    2004-01-01

    Bell's inequality violation (BIQV) for correlations of polarization is studied for a product state of two two-mode squeezed vacuum (TMSV) states. The violation allowed is shown to attain its maximal limit for all values of the squeezing parameter, ζ. We show via an explicit example that a state whose entanglement is not maximal allow maximal BIQV. The Wigner function of the state is non-negative and the average value of either polarization is nil

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

    Science.gov (United States)

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

    2014-01-01

    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 age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. PMID:25301897

  12. Maximally Symmetric Composite Higgs Models.

    Science.gov (United States)

    Csáki, Csaba; Ma, Teng; Shu, Jing

    2017-09-29

    Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

  13. Structural MRI markers of brain aging early after ischemic stroke.

    Science.gov (United States)

    Werden, Emilio; Cumming, Toby; Li, Qi; Bird, Laura; Veldsman, Michele; Pardoe, Heath R; Jackson, Graeme; Donnan, Geoffrey A; Brodtmann, Amy

    2017-07-11

    To examine associations between ischemic stroke, vascular risk factors, and MRI markers of brain aging. Eighty-one patients (mean age 67.5 ± 13.1 years, 31 left-sided, 61 men) with confirmed first-ever (n = 66) or recurrent (n = 15) ischemic stroke underwent 3T MRI scanning within 6 weeks of symptom onset (mean 26 ± 9 days). Age-matched controls (n = 40) completed identical testing. Multivariate regression analyses examined associations between group membership and MRI markers of brain aging (cortical thickness, total brain volume, white matter hyperintensity [WMH] volume, hippocampal volume), normalized against intracranial volume, and the effects of vascular risk factors on these relationships. First-ever stroke was associated with smaller hippocampal volume ( p = 0.025) and greater WMH volume ( p = 0.004) relative to controls. Recurrent stroke was in turn associated with smaller hippocampal volume relative to both first-ever stroke ( p = 0.017) and controls ( p = 0.001). These associations remained significant after adjustment for age, sex, education, and, in stroke patients, infarct volume. Total brain volume was not significantly smaller in first-ever stroke patients than in controls ( p = 0.056), but the association became significant after further adjustment for atrial fibrillation ( p = 0.036). Cortical thickness and brain volumes did not differ as a function of stroke type, infarct volume, or etiology. Brain structure is likely to be compromised before ischemic stroke by vascular risk factors. Smaller hippocampal and total brain volumes and increased WMH load represent proxies for underlying vascular brain injury. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  14. Stroke subtype classification by geometrical descriptors of lesion shape.

    Directory of Open Access Journals (Sweden)

    Bastian Cheng

    Full Text Available Inference of etiology from lesion pattern in acute magnetic resonance imaging is valuable for management and prognosis of acute stroke patients. This study aims to assess the value of three-dimensional geometrical lesion-shape descriptors for stroke-subtype classification, specifically regarding stroke of cardioembolic origin.Stroke Etiology was classified according to ASCOD in retrospectively selected patients with acute stroke. Lesions were segmented on diffusion-weighed datasets, and descriptors of lesion shape quantified: surface area, sphericity, bounding box volume, and ratio between bounding box and lesion volume. Morphological measures were compared between stroke subtypes classified by ASCOD and between patients with embolic stroke of cardiac and non-cardiac source.150 patients (mean age 77 years; 95% CI, 65-80 years; median NIHSS 6, range 0-22 were included. Group comparison of lesion shape measures demonstrated that lesions caused by small-vessel disease were smaller and more spherical compared to other stroke subtypes. No significant differences of morphological measures were detected between patients with cardioembolic and non-cardioembolic stroke.Stroke lesions caused by small vessel disease can be distinguished from other stroke lesions based on distinctive morphological properties. However, within the group of embolic strokes, etiology could not be inferred from the morphology measures studied in our analysis.

  15. Stroke rehabilitation.

    Science.gov (United States)

    Langhorne, Peter; Bernhardt, Julie; Kwakkel, Gert

    2011-05-14

    Stroke is a common, serious, and disabling global health-care problem, and rehabilitation is a major part of patient care. There is evidence to support rehabilitation in well coordinated multidisciplinary stroke units or through provision of early supported provision of discharge teams. Potentially beneficial treatment options for motor recovery of the arm include constraint-induced movement therapy and robotics. Promising interventions that could be beneficial to improve aspects of gait include fitness training, high-intensity therapy, and repetitive-task training. Repetitive-task training might also improve transfer functions. Occupational therapy can improve activities of daily living; however, information about the clinical effect of various strategies of cognitive rehabilitation and strategies for aphasia and dysarthria is scarce. Several large trials of rehabilitation practice and of novel therapies (eg, stem-cell therapy, repetitive transcranial magnetic stimulation, virtual reality, robotic therapies, and drug augmentation) are underway to inform future practice. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Multiple Strokes

    Directory of Open Access Journals (Sweden)

    Obododimma Oha

    2008-12-01

    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. Principles of maximally classical and maximally realistic quantum ...

    Indian Academy of Sciences (India)

    Principles of maximally classical and maximally realistic quantum mechanics. S M ROY. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2N-dimensional phase space, ...

  18. Rehabilitation of a patient with stroke

    Directory of Open Access Journals (Sweden)

    Apurba Barman

    2013-01-01

    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.

  19. Effect of sex on wasted left ventricular effort following maximal exercise.

    Science.gov (United States)

    Lane, A D; Ranadive, S M; Yan, H; Kappus, R M; Cook, M D; Sun, P; Woods, J A; Wilund, K; Fernhall, B

    2013-09-01

    Wasted left ventricular effort (∆Ew) refers to work required of the left ventricle to eject blood that does not result in increased stroke volume and is related to left ventricular hypertrophy. Literature shows that men and women have differing ventricular and vascular responses to and following exercise. Our purpose was to determine how ∆Ew changes post-exercise in men and women and examine potential mechanisms. We hypothesized a reduction in ∆Ew that would be greater in men and that central pulse wave velocity and wave intensity (WIA) would be related to ∆Ew. Blood pressures, central pulse wave velocity (cPWV), and WIA were obtained at rest, 15 and 30 min after maximal exercise. Both sexes reduced ∆Ew post-maximal exercise (p>0.05 for interaction), but women had higher ∆Ew at each time point (p<0.05). The first peak of WIA increased 15 min post-exercise only in women (p<0.05). cPWV was attenuated (p<0.05) in women at 15 min and men at 30 min (p<0.05) post-exercise with a significant time by sex interaction (p<0.05). WIA (1st peak) was correlated (p<0.05) to ∆Ew in both sexes before and 15 min post-exercise, but cPWV was only associated with ∆Ew in men at 30 min post-exercise. We conclude that both sexes decrease ∆Ew after maximal exercise, but vascular and ventricular changes associated with the attenuation of ∆Ew are not uniform between sexes. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Postoperative volume balance

    DEFF Research Database (Denmark)

    Frost, H; Mortensen, C.R.; Secher, Niels H.

    2017-01-01

    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 determin...

  1. Prevention Of Stroke

    Directory of Open Access Journals (Sweden)

    Nagaraja D

    2005-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Linda Lai

    2011-06-01

    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.

  3. Implications of maximal Jarlskog invariant and maximal CP violation

    International Nuclear Information System (INIS)

    Rodriguez-Jauregui, E.; Universidad Nacional Autonoma de Mexico

    2001-04-01

    We argue here why CP violating phase Φ in the quark mixing matrix is maximal, that is, Φ=90 . In the Standard Model CP violation is related to the Jarlskog invariant J, which can be obtained from non commuting Hermitian mass matrices. In this article we derive the conditions to have Hermitian mass matrices which give maximal Jarlskog invariant J and maximal CP violating phase Φ. We find that all squared moduli of the quark mixing elements have a singular point when the CP violation phase Φ takes the value Φ=90 . This special feature of the Jarlskog invariant J and the quark mixing matrix is a clear and precise indication that CP violating Phase Φ is maximal in order to let nature treat democratically all of the quark mixing matrix moduli. (orig.)

  4. Phenomenology of maximal and near-maximal lepton mixing

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, M. C.; Pena-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

    2001-01-01

    The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ε(equivalent to)1-2sin 2 θ ex and quantify the present experimental status for |ε| e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 -8 eV 2 ∼ 2 ∼ -7 eV 2 . In the mass ranges Δm 2 ∼>1.5x10 -5 eV 2 and 4x10 -10 eV 2 ∼ 2 ∼ -7 eV 2 the full interval |ε| e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay

  5. Maximal quantum Fisher information matrix

    International Nuclear Information System (INIS)

    Chen, Yu; Yuan, Haidong

    2017-01-01

    We study the existence of the maximal quantum Fisher information matrix in the multi-parameter quantum estimation, which bounds the ultimate precision limit. We show that when the maximal quantum Fisher information matrix exists, it can be directly obtained from the underlying dynamics. Examples are then provided to demonstrate the usefulness of the maximal quantum Fisher information matrix by deriving various trade-off relations in multi-parameter quantum estimation and obtaining the bounds for the scalings of the precision limit. (paper)

  6. Maximize x(a - x)

    Science.gov (United States)

    Lange, L. H.

    1974-01-01

    Five different methods for determining the maximizing condition for x(a - x) are presented. Included is the ancient Greek version and a method attributed to Fermat. None of the proofs use calculus. (LS)

  7. Finding Maximal Quasiperiodicities in Strings

    DEFF Research Database (Denmark)

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

    2000-01-01

    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...... in the suffix tree that have a superprimitive path-label....

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

    DEFF Research Database (Denmark)

    Møgelvang, J; Stubgaard, M; Thomsen, C

    1988-01-01

    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......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...... 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...

  9. Driving After a Stroke

    Science.gov (United States)

    ... 23,2015 Can I drive after a stroke? Driving is often a major concern after someone has a stroke. It’s not unusual for stroke survivors to want to drive. Being able to get around after a stroke is important. Safety behind the wheel is even more important after ...

  10. Leukocytosis in acute stroke

    DEFF Research Database (Denmark)

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

    1999-01-01

    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...

  11. On the maximal diphoton width

    CERN Document Server

    Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo

    2016-01-01

    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.

  12. Benefits of aerobic exercise after stroke.

    Science.gov (United States)

    Potempa, K; Braun, L T; Tinknell, T; Popovich, J

    1996-05-01

    The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

  13. EFFECT OF SELF-SELECTED AND INDUCED SLOW AND FAST PADDLING ON STROKE KINEMATICS DURING 1000 M OUTRIGGER CANOEING ERGOMETRY

    Directory of Open Access Journals (Sweden)

    Rebecca M. Sealey

    2011-03-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Caplan Louis

    2005-06-01

    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

  15. Maximization

    Directory of Open Access Journals (Sweden)

    A. Garmroodi Asil

    2017-09-01

    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. Maximizing Entropy over Markov Processes

    DEFF Research Database (Denmark)

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

    2013-01-01

    The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... 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...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code....

  17. Maximizing entropy over Markov processes

    DEFF Research Database (Denmark)

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

    2014-01-01

    The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... 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...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code. © 2014 Elsevier...

  18. Airplane stroke syndrome.

    Science.gov (United States)

    Humaidan, Hani; Yassi, Nawaf; Weir, Louise; Davis, Stephen M; Meretoja, Atte

    2016-07-01

    Only 37 cases of stroke during or soon after long-haul flights have been published to our knowledge. In this retrospective observational study, we searched the Royal Melbourne Hospital prospective stroke database and all discharge summaries from 1 September 2003 to 30 September 2014 for flight-related strokes, defined as patients presenting with stroke within 14days of air travel. We hypothesised that a patent foramen ovale (PFO) is an important, but not the only mechanism, of flight-related stroke. We describe the patient, stroke, and flight characteristics. Over the study period, 131 million passengers arrived at Melbourne airport. Our centre admitted 5727 stroke patients, of whom 42 (0.73%) had flight-related strokes. Flight-related stroke patients were younger (median age 65 versus 73, p<0.001), had similar stroke severity, and received intravenous thrombolysis more often than non-flight-related stroke patients. Seven patients had flight-related intracerebral haemorrhage. The aetiology of the ischaemic strokes was cardioembolic in 14/35 (40%), including seven patients with confirmed PFO, one with atrial septal defect, four with atrial fibrillation, one with endocarditis, and one with aortic arch atheroma. Paradoxical embolism was confirmed in six patients. Stroke related to air travel is a rare occurrence, less than one in a million. Although 20% of patients had a PFO, distribution of stroke aetiologies was diverse and was not limited to PFO and paradoxical embolism. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Hyo Suk Nam

    Full Text Available 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.

  20. High Intensity Interval Training for Maximizing Health Outcomes.

    Science.gov (United States)

    Karlsen, Trine; Aamot, Inger-Lise; Haykowsky, Mark; Rognmo, Øivind

    Regular physical activity and exercise training are important actions to improve cardiorespiratory fitness and maintain health throughout life. There is solid evidence that exercise is an effective preventative strategy against at least 25 medical conditions, including cardiovascular disease, stroke, hypertension, colon and breast cancer, and type 2 diabetes. Traditionally, endurance exercise training (ET) to improve health related outcomes has consisted of low- to moderate ET intensity. However, a growing body of evidence suggests that higher exercise intensities may be superior to moderate intensity for maximizing health outcomes. The primary objective of this review is to discuss how aerobic high-intensity interval training (HIIT) as compared to moderate continuous training may maximize outcomes, and to provide practical advices for successful clinical and home-based HIIT. Copyright © 2017. Published by Elsevier Inc.

  1. Maximizing car insurance online sales by developing superior webshop

    OpenAIRE

    Pylväs, Paula

    2014-01-01

    The purpose of this thesis work was to investigate what kind of webshop and what kind of improvements would increase customer satisfaction and maximize car insurance online sales by volume and by value. Main measure for this is the conversion rate, percentage of the potential buyers entering the site who actually make a purchase.

  2. Bicarbonate attenuates arterial desaturation during maximal exercise in humans

    DEFF Research Database (Denmark)

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

    2002-01-01

    The contribution of pH to exercise-induced arterial O2 desaturation was evaluated by intravenous infusion of sodium bicarbonate (Bic, 1 M; 200-350 ml) or an equal volume of saline (Sal; 1 M) at a constant infusion rate during a "2,000-m" maximal ergometer row in five male oarsmen. Blood...

  3. Difficulty Swallowing After Stroke (Dysphagia)

    Science.gov (United States)

    ... 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 ...

  4. Chamaebatiaria millefolium (Torr.) Maxim.: fernbush

    Science.gov (United States)

    Nancy L. Shaw; Emerenciana G. Hurd

    2008-01-01

    Fernbush - Chamaebatiaria millefolium (Torr.) Maxim. - the only species in its genus, is endemic to the Great Basin, Colorado Plateau, and adjacent areas of the western United States. It is an upright, generally multistemmed, sweetly aromatic shrub 0.3 to 2 m tall. Bark of young branches is brown and becomes smooth and gray with age. Leaves are leathery, alternate,...

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

    Science.gov (United States)

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

    2014-02-01

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Myocardial functional responses do not contribute to maximal exercise performance in the heat.

    Science.gov (United States)

    Smith, Denise L; DeBlois, Jacob P; Wharton, Margaret; Rowland, Thomas

    2015-01-01

    Both the extent and means by which maximal oxygen uptake ([Formula: see text]) is depressed by elevated ambient temperature are uncertain. Particularly, information is currently unavailable regarding the possible influence of alterations in myocardial function on [Formula: see text] and performance during exercise in the heat. This study investigated the effects of environmental heat on [Formula: see text], peak work capacity, and myocardial function during a standard, progressive cycle test to exhaustion. Twelve euhydrated men (aged 20.7 ± 1.7 years) performed a maximal cycle test in an environmental chamber in both heat stress [35°C, 30% relative humidity (RH)] and temperate (20°C, 30% RH) conditions with measurement of standard gas exchange variables, core temperature, and echocardiographic measures of cardiac function. A small but statistically significant reduction of peak work capacity was observed in the heat stress versus temperate conditions (253 ± 30 and 259 ± 30 W, respectively, p = 0.02). Mean [Formula: see text] was not statistically different in the two conditions (p = 0.16) but values were 3.4% lower in the heat, and 9 of 12 participants demonstrated lower values in the heat stress trial. No differences in responses of heart rate, cardiac output, stroke volume, core temperature, hydration status, or myocardial systolic or diastolic function were observed between the two conditions, but perceived body temperature was higher in the heat. The small, negative impact of heat on exercise performance and [Formula: see text] could not be explained by disturbances in myocardial functional responses to exercise in young adult males.

  7. Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

    OpenAIRE

    Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

    2014-01-01

    Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects...

  8. Brain Basics: Preventing Stroke

    Science.gov (United States)

    ... NINDS) are committed to reducing that burden through biomedical research. What is a Stroke? A stroke, or "brain ... Testimony Legislative Updates Impact NINDS Contributions to Approved Therapies ... Director, Division of Intramural Research

  9. Stroke Warning Signs

    Science.gov (United States)

    ... person to repeat a simple sentence, like "The sky is blue." Is the person able to correctly ... to Your Doctor to Create a Plan The Life After Stroke Journey Every stroke recovery is different. ...

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

    NARCIS (Netherlands)

    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.)

    2015-01-01

    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

  11. Maximizing profitability in a hospital outpatient pharmacy.

    Science.gov (United States)

    Jorgenson, J A; Kilarski, J W; Malatestinic, W N; Rudy, T A

    1989-07-01

    This paper describes the strategies employed to increase the profitability of an existing ambulatory pharmacy operated by the hospital. Methods to generate new revenue including implementation of a home parenteral therapy program, a home enteral therapy program, a durable medical equipment service, and home care disposable sales are described. Programs to maximize existing revenue sources such as increasing the capture rate on discharge prescriptions, increasing "walk-in" prescription traffic and increasing HMO prescription volumes are discussed. A method utilized to reduce drug expenditures is also presented. By minimizing expenses and increasing the revenues for the ambulatory pharmacy operation, net profit increased from +26,000 to over +140,000 in one year.

  12. [Genetics of ischemic stroke].

    Science.gov (United States)

    Gschwendtner, A; Dichgans, M

    2013-02-01

    Stroke is one of the most widespread causes of mortality und disability worldwide. Around 80 % of strokes are ischemic and different forms of intracranial bleeding account for the remaining cases. Monogenic stroke disorders are rare but the diagnosis may lead to specific therapeutic consequences for the affected patients who are predominantly young. In common sporadic stroke, genetic factors play a role in the form of susceptibility genes. Their discovery may give rise to new therapeutic options in the future.

  13. IMNN: Information Maximizing Neural Networks

    Science.gov (United States)

    Charnock, Tom; Lavaux, Guilhem; Wandelt, Benjamin D.

    2018-04-01

    This software trains artificial neural networks to find non-linear functionals of data that maximize Fisher information: information maximizing neural networks (IMNNs). As compressing large data sets vastly simplifies both frequentist and Bayesian inference, important information may be inadvertently missed. Likelihood-free inference based on automatically derived IMNN summaries produces summaries that are good approximations to sufficient statistics. IMNNs are robustly capable of automatically finding optimal, non-linear summaries of the data even in cases where linear compression fails: inferring the variance of Gaussian signal in the presence of noise, inferring cosmological parameters from mock simulations of the Lyman-α forest in quasar spectra, and inferring frequency-domain parameters from LISA-like detections of gravitational waveforms. In this final case, the IMNN summary outperforms linear data compression by avoiding the introduction of spurious likelihood maxima.

  14. Is the β phase maximal?

    International Nuclear Information System (INIS)

    Ferrandis, Javier

    2005-01-01

    The current experimental determination of the absolute values of the CKM elements indicates that 2 vertical bar V ub /V cb V us vertical bar =(1-z), with z given by z=0.19+/-0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase β is approximately the maximum allowed by the measured absolute values of the CKM elements. This is β=(π/6-z/3) for γ=(π/3+z/3), which implies α=π/2. Alternatively, assuming that β is exactly maximal and using the experimental measurement sin(2β)=0.726+/-0.037, the phase γ is predicted to be γ=(π/2-β)=66.3 o +/-1.7 o . The maximality of β, if confirmed by near-future experiments, may give us some clues as to the origin of CP violation

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100......%. An active LA emptying fraction heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively. CONCLUSION: Dogs with MMVD appear to have larger LA...... 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...

  16. Ischemic stroke destabilizes circadian rhythms

    Directory of Open Access Journals (Sweden)

    Borjigin Jimo

    2008-10-01

    Full Text Available Abstract Background The central circadian pacemaker is a remarkably robust regulator of daily rhythmic variations of cardiovascular, endocrine, and neural physiology. Environmental lighting conditions are powerful modulators of circadian rhythms, but regulation of circadian rhythms by disease states is less clear. Here, we examine the effect of ischemic stroke on circadian rhythms in rats using high-resolution pineal microdialysis. Methods Rats were housed in LD 12:12 h conditions and monitored by pineal microdialysis to determine baseline melatonin timing profiles. After demonstration that the circadian expression of melatonin was at steady state, rats were subjected to experimental stroke using two-hour intralumenal filament occlusion of the middle cerebral artery. The animals were returned to their cages, and melatonin monitoring was resumed. The timing of onset, offset, and duration of melatonin secretion were calculated before and after stroke to determine changes in circadian rhythms of melatonin secretion. At the end of the monitoring period, brains were analyzed to determine infarct volume. Results Rats demonstrated immediate shifts in melatonin timing after stroke. We observed a broad range of perturbations in melatonin timing in subsequent days, with rats exhibiting onset/offset patterns which included: advance/advance, advance/delay, delay/advance, and delay/delay. Melatonin rhythms displayed prolonged instability several days after stroke, with a majority of rats showing a day-to-day alternation between advance and delay in melatonin onset and duration. Duration of melatonin secretion changed in response to stroke, and this change was strongly determined by the shift in melatonin onset time. There was no correlation between infarct size and the direction or amplitude of melatonin phase shifting. Conclusion This is the first demonstration that stroke induces immediate changes in the timing of pineal melatonin secretion, indicating

  17. Strategy to maximize maintenance operation

    OpenAIRE

    Espinoza, Michael

    2005-01-01

    This project presents a strategic analysis to maximize maintenance operations in Alcan Kitimat Works in British Columbia. The project studies the role of maintenance in improving its overall maintenance performance. It provides strategic alternatives and specific recommendations addressing Kitimat Works key strategic issues and problems. A comprehensive industry and competitive analysis identifies the industry structure and its competitive forces. In the mature aluminium industry, the bargain...

  18. Scalable Nonlinear AUC Maximization Methods

    OpenAIRE

    Khalid, Majdi; Ray, Indrakshi; Chitsaz, Hamidreza

    2017-01-01

    The area under the ROC curve (AUC) is a measure of interest in various machine learning and data mining applications. It has been widely used to evaluate classification performance on heavily imbalanced data. The kernelized AUC maximization machines have established a superior generalization ability compared to linear AUC machines because of their capability in modeling the complex nonlinear structure underlying most real world-data. However, the high training complexity renders the kernelize...

  19. FLOUTING MAXIMS IN INDONESIA LAWAK KLUB CONVERSATION

    Directory of Open Access Journals (Sweden)

    Rahmawati Sukmaningrum

    2017-04-01

    Full Text Available This study aims to identify the types of maxims flouted in the conversation in famous comedy show, Indonesia Lawak Club. Likewise, it also tries to reveal the speakers‘ intention of flouting the maxim in the conversation during the show. The writers use descriptive qualitative method in conducting this research. The data is taken from the dialogue of Indonesia Lawak club and then analyzed based on Grice‘s cooperative principles. The researchers read the dialogue‘s transcripts, identify the maxims, and interpret the data to find the speakers‘ intention for flouting the maxims in the communication. The results show that there are four types of maxims flouted in the dialogue. Those are maxim of quality (23%, maxim of quantity (11%, maxim of manner (31%, and maxim of relevance (35. Flouting the maxims in the conversations is intended to make the speakers feel uncomfortable with the conversation, show arrogances, show disagreement or agreement, and ridicule other speakers.

  20. Sex Disparities in Stroke

    DEFF Research Database (Denmark)

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

    2015-01-01

    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.......5%) or 1 month (6.9%), respectively. After the age of 60 years, women had more severe strokes than men. Up to ages in the mid-60s, no difference in the risk of death from stroke was seen between the 2 sexes. For people aged >65 years, however, the risk gradually became greater in men than in women...

  1. Seizure development after stroke.

    Science.gov (United States)

    Misirli, H; Ozge, A; Somay, G; Erdoğan, N; Erkal, H; Erenoğlu, N Y

    2006-12-01

    Although there have been many studies on seizures following stroke, there is still much we do not know about them. In this study, we evaluated the characteristics of seizures in stroke patients. There were 2267 patients with a first-ever stroke, and after excluding 387 patients, 1880 were available for analysis. Of these 1880 patients, we evaluated 200 patients with seizures and 400 patients without seizures. We investigated the seizures according to age, gender, stroke type, the aetiology of ischaemic stroke and the localisation of the lesion. The seizures were classified as early onset and late onset and the seizure type as partial, generalised or secondarily generalised. Seizures occurred in 200 (10.6%) of 1880 strokes. The number of patients with seizures were 138 (10.6%) in ischaemic stroke group and 62 (10.7%) in haemorrhagic stroke group. Patients with ischaemic strokes had 41 embolic (29.7%) and 97 thrombotic (70.3%) origin, and these were not statistically significant in comparison with controls. Cortical involvement for the development of seizures was the most important risk factor (odds ratios = 4.25, p < 0.01). It was concluded that embolic strokes, being younger than 65 years old, and cortical localisation of stroke were important risks for developing seizures.

  2. Clinical Epidemiology Of Stroke

    Directory of Open Access Journals (Sweden)

    Nagaraja D

    2005-01-01

    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.

  3. Mathematical Explorations: Maximizing Volume with Solids and Nets

    Science.gov (United States)

    Miles, Victoria L.

    2014-01-01

    One of the most common household polyhedra is a cereal box. For over 100 years, American companies like Kellogg's™ have packaged cereal in containers shaped like rectangular prisms. Why is a rectangular prism the most commonly used solid for holding cereal? Would another design work equally or more efficient? This article describes an…

  4. Registration of acute stroke

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  5. Increased cardiac output and maximal oxygen uptake in response to ten sessions of high intensity interval training.

    Science.gov (United States)

    Astorino, Todd A; Edmunds, Ross M; Clark, Amy; King, Leesa; Gallant, Rachael M; Namm, Samantha; Fischer, Anthony; Wood, Kimi A

    2018-01-01

    Increases in maximal oxygen uptake (VO2max) are widely reported in response to completion of high intensity interval training (HIIT), yet the mechanism explaining this result is poorly understood. This study examined changes in VO2max and cardiac output (CO) in response to 10 sessions of low-volume HIIT. Participants included 30 active men and women (mean age and VO2max=22.9±5.4 years and 39.6±5.6 mL/kg/min) who performed HIIT and 30 men and women (age and VO2max=25.7±4.5 years and 40.7±5.2 mL/kg/min) who served as non-exercising controls (CON). High intensity interval training consisted of 6-10 s bouts of cycling per session at 90-110 percent peak power output (PPO) interspersed with 75 s recovery. Before and after training, progressive cycling to exhaustion was completed during which CO, stroke volume (SV), and heart rate (HR) were estimated using thoracic impedance. To confirm VO2max attainment, a verification test was completed after progressive cycling at a work rate equal to 110%PPO. Data demonstrated significant improvements in VO2max (2.71±0.63 L/min to 2.86±0.63 L/min, Psessions of HIIT is due to improvements in oxygen delivery.

  6. Herniation despite Decompressive Hemicraniectomy in Large Hemispherical Ischemic Strokes.

    Science.gov (United States)

    Hinduja, Archana; Samant, Rohan; Feng, Dongxia; Hannawi, Yousef

    2018-02-01

    Despite decompressive hemicraniectomy (DHC), progressive herniation resulting in death has been reported following middle cerebral artery (MCA) strokes. We aimed to determine the surgical parameters measured on brain computed tomography (CT) scan that are associated with progressive herniation despite DHC in large MCA strokes. Retrospective chart review of medical records of patients with malignant hemispheric infarction who underwent DHC for cerebral edema was performed. Infarct volume was calculated on CT scans obtained within 24 hours of ictus. Radiological parameters of craniectomy bone flap size, brain volume protruding out of the skull, adequate centering of the craniectomy over the stroke bed, and the infarct volume outside the craniectomy bed (volume not centered [VNC]) were measured on the postoperative brain CT. Of 41 patients who underwent DHC, 7 had progressive herniation leading to death. Radiographic parameters significantly associated with progressive herniation included insufficient centering of craniectomy bed on the stroke bed (P = .03), VNC (P = .011), additional anterior cerebral artery infarction (P = .047), and smaller craniectomy length (P = .05). Multivariate logistic regression analysis for progressive herniation using craniectomy length and VNC as independent variables demonstrated that a higher VNC was significantly associated with progressive herniation despite surgery (P = .029). In large MCA strokes, identification of large infarct volume outside the craniectomy bed was associated with progressive herniation despite surgery. These results will need to be verified in larger prospective studies. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    1996-01-01

    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

  8. Stroke And Substance Abuse

    Directory of Open Access Journals (Sweden)

    A Chitsaz

    2017-02-01

    Full Text Available Introduction: stroke in recreational substance users can be an indirect complication, like endocarditis and cardio embolism in parenteral drug users. With some drug like cocaine, stroke appear to be the result of a direct effect. In young subjects without other risk factors provide persuasive evidence for causality . OPIATES: Heroine is the most abused opiate drug, which is administered by injection, by snorting or by smoking. Stroke affects heroin users by diverse mechanisms,. Injectors are at risk of infections endocarditis, which carries risk for both ischemic and hemorrhagic stroke. Cerebral or subarachnoid hemorrhage usually occurs after rupture of a septic (mycotic aneurysm. Heroine users can are also at risk for hemorrhagic stroke secondary to liver failure with deranged clotting and to heroin nephropathy with uremia or malignant hypertension. In some heroin users the drug it self is directly causal due to vasculitis, hypersensitivity and immunologic changes. Embolization of foreign material to brain due to mixed of heroine with quinine can cause cerebral embolism. AMPHETAMINE AND other psychostimulants: In abuser of amphetamine hemorrhagic stroke can occur, oral, intravenous, nasal, and inhalational routes of administration have been reported. Most were chronic user, but in several patients, stroke followed a first exposure. Some of amphetamine induced intracranial hemorrhages are secondary to acute hypertension, some to cerebral vacuities, and some to a combination of two. Decongestants and diet pills: Phenylpropanolamine (PPA, an amphetamine – like drug, in decongestants and diet pills, induce acute hypertension, sever headache, psychiatric symptoms, seizures and hemorrhagic stroke. Ephedrine and pseudo ephedrine are present in decongestants and bronchodilators and induce headache, tachyarrhythmia, hypertensive emergency, and hemorrhagic and occlusive stroke. Ecstasy, 3,4 Methylenedioxymethamphetamin (MDMA with amphetamine like can

  9. Stroke in Commercial Flights.

    Science.gov (United States)

    Álvarez-Velasco, Rodrigo; Masjuan, Jaime; DeFelipe, Alicia; Corral, Iñigo; Estévez-Fraga, Carlos; Crespo, Leticia; Alonso-Cánovas, Araceli

    2016-04-01

    Stroke on board aircraft has been reported in retrospective case series, mainly focusing on economy class stroke syndrome. Data on the actual incidence, pathogenesis, and prognosis of stroke in commercial flights are lacking. A prospective registry was designed to include all consecutive patients referred from an international airport (40 million passengers a year) to our hospital with a diagnosis of ischemic stroke or transient ischemic attack and onset of symptoms during a flight or immediately after landing. Forty-four patients (32 ischemic strokes and 12 transient ischemic attacks) were included over a 76-month period (January 2008 to April 2014). The estimated incidence of stroke was 1 stroke in 35 000 flights. Pathogeneses of stroke or transient ischemic attack were atherothrombotic in 16 (36%), economy class stroke syndrome in 8 (18%), cardioembolic in 7 (16%), arterial dissection in 4 (9%), lacunar stroke in 4 (9%), and undetermined in 5 (12%) patients. Carotid stenosis >70% was found in 12 (27%) of the patients. Overall prognosis was good, and thrombolysis was applied in 44% of the cases. The most common reason for not treating patients who had experienced stroke onset midflight was the delay in reaching the hospital. Only 1 patient with symptom onset during the flight prompted a flight diversion. We found a low incidence of stroke in the setting of air travel. Economy class stroke syndrome and arterial dissection were well represented in our sample. However, the main pathogenesis was atherothrombosis with a high proportion of patients with high carotid stenosis. © 2016 American Heart Association, Inc.

  10. Maximal Abelian sets of roots

    CERN Document Server

    Lawther, R

    2018-01-01

    In this work the author lets \\Phi be an irreducible root system, with Coxeter group W. He considers subsets of \\Phi which are abelian, meaning that no two roots in the set have sum in \\Phi \\cup \\{ 0 \\}. He classifies all maximal abelian sets (i.e., abelian sets properly contained in no other) up to the action of W: for each W-orbit of maximal abelian sets we provide an explicit representative X, identify the (setwise) stabilizer W_X of X in W, and decompose X into W_X-orbits. Abelian sets of roots are closely related to abelian unipotent subgroups of simple algebraic groups, and thus to abelian p-subgroups of finite groups of Lie type over fields of characteristic p. Parts of the work presented here have been used to confirm the p-rank of E_8(p^n), and (somewhat unexpectedly) to obtain for the first time the 2-ranks of the Monster and Baby Monster sporadic groups, together with the double cover of the latter. Root systems of classical type are dealt with quickly here; the vast majority of the present work con...

  11. The model of the dependence of the abrasive wear value on the maximal linear wear

    Directory of Open Access Journals (Sweden)

    О.А. Вишневський

    2004-01-01

    Full Text Available  The relation of the contact area of the rubber roll with a sample and the maximal linear wear value is found. The mathematical model of the dependence of the wear volume weight value on the maximal dimple depth is presented with the friction on abrasive particles fixed nonrigidly. The relation of volume weight wear with the rubber roll contact surface area with a sample with the friction on abrasive particles fixed nonrigidly is established.

  12. Blood Pressure Control: Stroke and Stroke Prevention

    Directory of Open Access Journals (Sweden)

    Hans-Christoph Diener

    2005-03-01

    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.

  13. Ischemic Stroke Profile, Risk Factors, and Outcomes in India: The Indo-US Collaborative Stroke Project.

    Science.gov (United States)

    Sylaja, P N; Pandian, Jeyaraj Durai; Kaul, Subhash; Srivastava, M V Padma; Khurana, Dheeraj; Schwamm, Lee H; Kesav, Praveen; Arora, Deepti; Pannu, Aman; Thankachan, Tijy K; Singhal, Aneesh B

    2018-01-01

    The Indo-US Collaborative Stroke Project was designed to characterize ischemic stroke across 5 high-volume academic tertiary hospitals in India. From January 2012 to August 2014, research coordinators and physician coinvestigators prospectively collected data on 2066 patients with ischemic stroke admitted <2 weeks after onset. Investigator training and supervision and data monitoring were conducted by the US site (Massachusetts General Hospital, Boston). The mean age was 58.3±14.7 years, 67.2% men. The median admission National Institutes of Health Stroke Scale score was 10 (interquartile range, 5-15) and 24.5% had National Institutes of Health Stroke Scale ≥16. Hypertension (60.8%), diabetes mellitus (35.7%), and tobacco use (32.2%, including bidi/smokeless tobacco) were common risk factors. Only 4% had atrial fibrillation. All patients underwent computed tomography or magnetic resonance imaging; 81% had cerebrovascular imaging. Stroke etiologic subtypes were large artery (29.9%), cardiac (24.9%), small artery (14.2%), other definite (3.4%), and undetermined (27.6%, including 6.7% with incomplete evaluation). Intravenous or intra-arterial thrombolysis was administered in 13%. In-hospital mortality was 7.9%, and 48% achieved modified Rankin Scale score 0 to 2 at 90 days. On multivariate analysis, diabetes mellitus predicted poor 3-month outcome and younger age, lower admission National Institutes of Health Stroke Scale and small-artery etiology predicted excellent 3-month outcome. These comprehensive and novel clinical imaging data will prove useful in refining stroke guidelines and advancing stroke care in India. © 2017 American Heart Association, Inc.

  14. Knowledge of Stroke Risk Factors among Stroke Survivors in Nigeria

    OpenAIRE

    Grace Vincent-Onabajo; Taritei Moses

    2016-01-01

    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 fac...

  15. Stroke And Substance Abuse

    OpenAIRE

    A Chitsaz

    2017-01-01

    Introduction: stroke in recreational substance users can be an indirect complication, like endocarditis and cardio embolism in parenteral drug users. With some drug like cocaine, stroke appear to be the result of a direct effect. In young subjects without other risk factors provide persuasive evidence for causality . OPIATES: Heroine is the most abused opiate drug, which is administered by injection, by snorting or by smoking. Stroke affects heroin users by diverse mechanisms,. Injec...

  16. Maximizing benefits from resource development

    International Nuclear Information System (INIS)

    Skjelbred, B.

    2002-01-01

    The main objectives of Norwegian petroleum policy are to maximize the value creation for the country, develop a national oil and gas industry, and to be at the environmental forefront of long term resource management and coexistence with other industries. The paper presents a graph depicting production and net export of crude oil for countries around the world for 2002. Norway produced 3.41 mill b/d and exported 3.22 mill b/d. Norwegian petroleum policy measures include effective regulation and government ownership, research and technology development, and internationalisation. Research and development has been in five priority areas, including enhanced recovery, environmental protection, deep water recovery, small fields, and the gas value chain. The benefits of internationalisation includes capitalizing on Norwegian competency, exploiting emerging markets and the assurance of long-term value creation and employment. 5 figs

  17. Maximizing synchronizability of duplex networks

    Science.gov (United States)

    Wei, Xiang; Emenheiser, Jeffrey; Wu, Xiaoqun; Lu, Jun-an; D'Souza, Raissa M.

    2018-01-01

    We study the synchronizability of duplex networks formed by two randomly generated network layers with different patterns of interlayer node connections. According to the master stability function, we use the smallest nonzero eigenvalue and the eigenratio between the largest and the second smallest eigenvalues of supra-Laplacian matrices to characterize synchronizability on various duplexes. We find that the interlayer linking weight and linking fraction have a profound impact on synchronizability of duplex networks. The increasingly large inter-layer coupling weight is found to cause either decreasing or constant synchronizability for different classes of network dynamics. In addition, negative node degree correlation across interlayer links outperforms positive degree correlation when most interlayer links are present. The reverse is true when a few interlayer links are present. The numerical results and understanding based on these representative duplex networks are illustrative and instructive for building insights into maximizing synchronizability of more realistic multiplex networks.

  18. Maximal respiratory pressures and pulmonary function in male runners.

    OpenAIRE

    Cordain, L; Glisan, B J; Latin, R W; Tucker, A; Stager, J M

    1987-01-01

    To determine the effects of long term exercise on respiratory muscle strength, maximal inspiratory (Pl max) and expiratory (PE max) pressures, pulmonary volumes and capacities and anthropometric parameters were measured in a group of 101 male runners aged 16 to 58 years. The runners exhibited significantly (p less than 0.05) lower PE max (202 +/- 41 cm H2O and significantly greater residual lung volumes (RV) (2.08 +/- 0.49 L) than predicted values for normal subjects of similar height and age...

  19. Economic strategies to maximize profits from satellite field developments

    International Nuclear Information System (INIS)

    Antia, D.D.J.

    1994-01-01

    The main strategies that can be used to maximize profits from integrated satellite field developments are: (1) restructuring the cost, production and revenue profile of the satellite field; and (2) increasing the volume of oil/gas processed, and available for future use, by the central processing and distribution facility through: (a) using a combined strategy of low tariffs, volume discount, and netback agreements; (b) using reusable facilities, shared facilities, extended reach wells, contractor finance, partnering agreements, netback agreements, oil/gas price swaps; and (c) improving development, discovery and exploration efficiency

  20. Paradoxical centrally increased diffusivity in perinatal arterial ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2016-01-15

    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.)

  1. Paradoxical centrally increased diffusivity in perinatal arterial ischemic stroke

    International Nuclear Information System (INIS)

    Stence, Nicholas V.; Mirsky, David M.; Deoni, Sean C.L.; Armstrong-Wells, Jennifer

    2016-01-01

    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 3 vs. 36,995 mm 3 ; P = 0.008), higher average apparent diffusion coefficient (ADC) values in the infarct core (1,679 x 10 -6 mm 2 /s vs. 611 x 10 -6 mm 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.)

  2. Stroke Prevention & Treatment: Diet & Nutrition

    Science.gov (United States)

    ... Prevention & Treatment: Diet & Nutrition Stroke Prevention & Treatment: Diet & Nutrition A healthy diet can reduce your risk for ... Treatment How does a stroke affect eating and nutrition? Stroke can devastate a person's nutritional health because ...

  3. Acute stroke imaging research roadmap

    NARCIS (Netherlands)

    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

  4. Risks for Heart Disease & Stroke

    Science.gov (United States)

    ... Prevent Risks for Heart Disease & Stroke Risks for Heart Disease & Stroke About 1.5 million heart attacks and ... can’t change some of your risks for heart disease and stroke, but you can manage many of ...

  5. VIOLATION OF CONVERSATION MAXIM ON TV ADVERTISEMENTS

    Directory of Open Access Journals (Sweden)

    Desak Putu Eka Pratiwi

    2015-07-01

    Full Text Available Maxim is a principle that must be obeyed by all participants textually and interpersonally in order to have a smooth communication process. Conversation maxim is divided into four namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner of speaking. Violation of the maxim may occur in a conversation in which the information the speaker has is not delivered well to his speaking partner. Violation of the maxim in a conversation will result in an awkward impression. The example of violation is the given information that is redundant, untrue, irrelevant, or convoluted. Advertisers often deliberately violate the maxim to create unique and controversial advertisements. This study aims to examine the violation of maxims in conversations of TV ads. The source of data in this research is food advertisements aired on TV media. Documentation and observation methods are applied to obtain qualitative data. The theory used in this study is a maxim theory proposed by Grice (1975. The results of the data analysis are presented with informal method. The results of this study show an interesting fact that the violation of maxim in a conversation found in the advertisement exactly makes the advertisements very attractive and have a high value.

  6. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

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

    2013-01-01

    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. Body Mass Index and Stroke

    DEFF Research Database (Denmark)

    Andersen, Klaus Kaae; Olsen, Tom Skyhøj

    2013-01-01

    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)....

  8. Ischemic Stroke: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Thrombolytic therapy (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Ischemic Stroke updates ... cardiogenic embolism Stroke - slideshow Thrombolytic therapy Related Health Topics Hemorrhagic Stroke Stroke Stroke Rehabilitation National Institutes of ...

  9. Effects of the bilateral isokinetic strengthening training on functional parameters, gait, and the quality of life in patients with stroke

    OpenAIRE

    Büyükvural Şen, Sıdıka; Özbudak Demir, Sibel; Ekiz, Timur; Özgirgin, Neşe

    2015-01-01

    Objective: To evaluate the effects of the bilateral isokinetic strengthening training applied to knee and ankle muscles on balance, functional parameters, gait, and the quality of in stroke patients. Methods: Fifty patients (33 M, 17 F) with subacute-chronic stroke and 30 healthy subjects were included. Stroke patients were allocated into isokinetic and control groups. Conventional rehabilitation program was applied to all cases; additionally maximal concentric isokinetic strengthening traini...

  10. Diagnostic neuroimaging in stroke

    International Nuclear Information System (INIS)

    Jarenwattananon, A.; Khandji, A.; Brust, J.C.M.

    1988-01-01

    Since the development of cerebral angiography 60 years ago, there has been a proliferation of increasingly sophisticated, expensive, and, fortunately, safe imaging techniques for patients with cerebrovascular disease. In addition, occlusive and hemorrhagic stroke are now recognized as having a wide variety of possible causes. This chapter addresses the different imaging options available for particular kinds of stroke

  11. Relational Processing Following Stroke

    Science.gov (United States)

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

    2013-01-01

    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…

  12. Stroke (For Kids)

    Science.gov (United States)

    ... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body Works ... for Educators Search English Español Stroke KidsHealth / For Kids / Stroke What's in this article? What Happens During ...

  13. Maximizing ROI (return on information)

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, B.

    2000-05-01

    The role and importance of managing information are discussed, underscoring the importance by quoting from the report of the International Data Corporation, according to which Fortune 500 companies lost $ 12 billion in 1999 due to inefficiencies resulting from intellectual re-work, substandard performance , and inability to find knowledge resources. The report predicts that this figure will rise to $ 31.5 billion by 2003. Key impediments to implementing knowledge management systems are identified as : the cost and human resources requirement of deployment; inflexibility of historical systems to adapt to change; and the difficulty of achieving corporate acceptance of inflexible software products that require changes in 'normal' ways of doing business. The author recommends the use of model, document and rule-independent systems with a document centered interface (DCI), employing rapid application development (RAD) and object technologies and visual model development, which eliminate these problems, making it possible for companies to maximize their return on information (ROI), and achieve substantial savings in implementation costs.

  14. Burden of stroke in Bangladesh.

    Science.gov (United States)

    Islam, Md Nazmul; Moniruzzaman, Mohammed; Khalil, Md Ibrahim; Basri, Rehana; Alam, Mohammad Khursheed; Loo, Keat Wei; Gan, Siew Hua

    2013-04-01

    Stroke is the third leading cause of death in Bangladesh. The World Health Organization ranks Bangladesh's mortality rate due to stroke as number 84 in the world. The reported prevalence of stroke in Bangladesh is 0.3%, although no data on stroke incidence have been recorded. Hospital-based studies conducted in past decades have indicated that hypertension is the main cause of ischaemic and haemorrhagic stroke in Bangladesh. The high number of disability-adjusted life-years lost due to stroke (485 per 10,000 people) show that stroke severely impacts Bangladesh's economy. Although two non-governmental organizations, BRAC and the Centre for the Rehabilitation of the Paralysed, are actively involved in primary stroke prevention strategies, the Bangladeshi government needs to emphasize healthcare development to cope with the increasing population density and to reduce stroke occurrence. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

  15. Mitochondrial Impairment in Cerebrovascular Endothelial Cells is Involved in the Correlation between Body Temperature and Stroke Severity

    Science.gov (United States)

    Hu, Heng; Doll, Danielle N.; Sun, Jiahong; Lewis, Sara E.; Wimsatt, Jeffrey H.; Kessler, Matthew J.; Simpkins, James W.; Ren, Xuefang

    2016-01-01

    Stroke is the second leading cause of death worldwide. The prognostic influence of body temperature on acute stroke in patients has been recently reported; however, hypothermia has confounded experimental results in animal stroke models. This work aimed to investigate how body temperature could prognose stroke severity as well as reveal a possible mitochondrial mechanism in the association of body temperature and stroke severity. Lipopolysaccharide (LPS) compromises mitochondrial oxidative phosphorylation in cerebrovascular endothelial cells (CVECs) and worsens murine experimental stroke. In this study, we report that LPS (0.1 mg/kg) exacerbates stroke infarction and neurological deficits, in the mean time LPS causes temporary hypothermia in the hyperacute stage during 6 hours post-stroke. Lower body temperature is associated with worse infarction and higher neurological deficit score in the LPS-stroke study. However, warming of the LPS-stroke mice compromises animal survival. Furthermore, a high dose of LPS (2 mg/kg) worsens neurological deficits, but causes persistent severe hypothermia that conceals the LPS exacerbation of stroke infarction. Mitochondrial respiratory chain complex I inhibitor, rotenone, replicates the data profile of the LPS-stroke study. Moreover, we have confirmed that rotenone compromises mitochondrial oxidative phosphorylation in CVECs. Lastly, the pooled data analyses of a large sample size (n=353) demonstrate that stroke mice have lower body temperature compared to sham mice within 6 hours post-surgery; the body temperature is significantly correlated with stroke outcomes; linear regression shows that lower body temperature is significantly associated with higher neurological scores and larger infarct volume. We conclude that post-stroke body temperature predicts stroke severity and mitochondrial impairment in CVECs plays a pivotal role in this hypothermic response. These novel findings suggest that body temperature is prognostic for

  16. Post-stroke depression among stroke survivors attending two ...

    African Journals Online (AJOL)

    Background: The burden of stroke worldwide is increasing rapidly. There is paucity of data on post-stroke depression (PSD) among stroke survivors in Uganda, despite the high prevalence of PSD reported elsewhere. Methods: In a cross-sectional study, we assessed adult participants with confirmed first stroke with a ...

  17. Stroke mimic diagnoses presenting to a hyperacute stroke unit.

    Science.gov (United States)

    Dawson, Ang; Cloud, Geoffrey C; Pereira, Anthony C; Moynihan, Barry J

    2016-10-01

    Stroke services have been centralised in several countries in recent years. Diagnosing acute stroke is challenging and a high proportion of patients admitted to stroke units are diagnosed as a non-stroke condition (stroke mimics). This study aims to describe the stroke mimic patient group, including their impact on stroke services. We analysed routine clinical data from 2,305 consecutive admissions to a stroke unit at St George's Hospital, London. Mimic groupings were derived from 335 individual codes into 17 groupings. From 2,305 admissions, 555 stroke mimic diagnoses were identified (24.2%) and 72% of stroke mimics had at least one stroke risk factor. Common mimic diagnoses were headache, seizure and syncope. Medically unexplained symptoms and decompensation of underlying conditions were also common. Median length of stay was 1 day; a diagnosis of dementia (p=0.028) or needing MRI (p=0.006) was associated with a longer stay. Despite emergency department assessment by specialist clinicians and computed tomography brain, one in four suspected stroke patients admitted to hospital had a non-stroke diagnosis. Stroke mimics represent a heterogeneous patient group with significant impacts on stroke services. Co-location of stroke and acute neurology services may offer advantages where service reorganisation is being considered. © Royal College of Physicians 2016. All rights reserved.

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

    Science.gov (United States)

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

    2014-01-01

    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 kinesthetic taping of the anterior thigh and knee provides an immediate improvement in walking function in patients with stroke. Such a positive effect on motor function could be a valuable adjunct in physical therapy and rehabilitation of patients with stroke.

  19. Neural correlates supporting sensory discrimination after left hemisphere stroke

    Science.gov (United States)

    Borstad, Alexandra; Schmalbrock, Petra; Choi, Seongjin; Nichols-Larsen, Deborah S.

    2012-01-01

    Background Nearly half of stroke patients have impaired sensory discrimination, however, the neural structures that support post-stroke sensory function have not been described. Objectives 1) To evaluate the role of the primary somatosensory (S1) cortex in post-stroke sensory discrimination and 2) To determine the relationship between post-stroke sensory discrimination and structural integrity of the sensory component of the superior thalamic radiation (sSTR). Methods 10 healthy adults and 10 individuals with left hemisphere stroke participated. Stroke participants completed sensory discrimination testing. An fMRI was conducted during right, impaired hand sensory discrimination. Fractional anisotropy and volume of the sSTR were quantified using diffusion tensor tractography. Results Sensory discrimination was impaired in 60% of participants with left stroke. Peak activation in the left (S1) did not correlate with sensory discrimination ability, rather a more distributed pattern of activation was evident in post-stroke subjects with a positive correlation between peak activation in the parietal cortex and discrimination ability (r=.70, p=.023). The only brain region in which stroke participants had significantly different cortical activation than control participants was the precuneus. Region of interest analysis of the precuneus across stroke participants revealed a positive correlation between peak activation and sensory discrimination ability (r=.77, p=.008). The L/R ratio of sSTR fractional anisotropy also correlated with right hand sensory discrimination (r=.69, p=.027). Conclusions Precuneus cortex, distributed parietal lobe activity, and microstructure of the sSTR support sensory discrimination after left hemisphere stroke. PMID:22592076

  20. Acute MRI changes in progressive ischemic stroke

    DEFF Research Database (Denmark)

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

    2008-01-01

    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...... 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...... (chi(2), p = 0.005). All lacunar infarcts with a DWI volume >1.5 cm(3) at baseline (4 patients) developed SIP (p SSS scores with severer symptoms than non-SIP patients (p Udgivelsesdato: 2008...

  1. Effect of 3-aminobenzamide, PARP inhibitor, on matrix metalloproteinase-9 level in plasma and brain of ischemic stroke model

    International Nuclear Information System (INIS)

    Koh, Seong-Ho; Chang, Dae-Il; Kim, Hee-Tae; Kim, Juhan; Kim, Myung-Ho; Kim, Kyung Suk; Bae, Inhee; Kim, Haekwon; Kim, Dong Won; Kim, Seung Hyun

    2005-01-01

    We investigated the effect of poly(ADP-ribose) polymerase (PARP) inhibitor on the levels of plasma and brain matrix metalloproteinase-9 (MMP-9) and the expression of nuclear factor kappa B (NF-κB) during experimental focal cerebral ischemia. The 3-aminobenzamide (3-AB), a PARP inhibitor, and saline were administered to 80 Sprague-Dawley rats [3-AB group; 5 rats for plasma sampling, 35 for brain sampling, and 40 for TTC staining] and to 85 rats (10, 35, and 40, respectively), respectively, 10 min before the occlusion of the left middle cerebral artery (MCAo) for 2 h. Infarct volume was measured by TTC staining, the serial levels of plasma and brain MMP-9 were measured by zymography just before and 2, 4, 8, 24, 48, and 72 h after MCAo, brain NF-κB activity was determined by Western blotting, and neutrophil infiltration was evaluated by assessing myeloperoxidase activity. Compared with control group, the levels of plasma and brain MMP-9, brain NF-κB, and MPO activities were significantly reduced in 3-AB group at each time point (p < 0.05). Plasma MMP-9 increased maximally at 4 h and then decreased rapidly, brain MMP-9 increased maximally at 24 h and persisted until 72 h, and NF-κB increased maximally at 24 h and then decreased slowly in both groups. Therefore, the PARP inhibitor reduces the expression of MMP-9 and NF-κB and the infiltration of neutrophils in ischemic stroke

  2. The Influence of Acute Hyperglycemia in an Animal Model of Lacunar Stroke That Is Induced by Artificial Particle Embolization

    Science.gov (United States)

    Tsai, Ming-Jun; Lin, Ming-Wei; Huang, Yaw-Bin; Kuo, Yu-Min; Tsai, Yi-Hung

    2016-01-01

    Animal and clinical studies have revealed that hyperglycemia during ischemic stroke increases the stroke's severity and the infarct size in clinical and animal studies. However, no conclusive evidence demonstrates that acute hyperglycemia worsens post-stroke outcomes and increases infarct size in lacunar stroke. In this study, we developed a rat model of lacunar stroke that was induced via the injection of artificial embolic particles during full consciousness. We then used this model to compare the acute influence of hyperglycemia in lacunar stroke and diffuse infarction, by evaluating neurologic behavior and the rate, size, and location of the infarction. The time course of the neurologic deficits was clearly recorded from immediately after induction to 24 h post-stroke in both types of stroke. We found that acute hyperglycemia aggravated the neurologic deficit in diffuse infarction at 24 h after stroke, and also aggravated the cerebral infarct. Furthermore, the infarct volumes of the basal ganglion, thalamus, hippocampus, and cerebellum but not the cortex were positively correlated with serum glucose levels. In contrast, acute hyperglycemia reduced the infarct volume and neurologic symptoms in lacunar stroke within 4 min after stroke induction, and this effect persisted for up to 24 h post-stroke. In conclusion, acute hyperglycemia aggravated the neurologic outcomes in diffuse infarction, although it significantly reduced the size of the cerebral infarct and improved the neurologic deficits in lacunar stroke. PMID:27226775

  3. Early Change in Stroke Size Performs Best in Predicting Response to Therapy.

    Science.gov (United States)

    Simpkins, Alexis Nétis; Dias, Christian; Norato, Gina; Kim, Eunhee; Leigh, Richard

    2017-01-01

    Reliable imaging biomarkers of response to therapy in acute stroke are needed. The final infarct volume and percent of early reperfusion have been used for this purpose. Early fluctuation in stroke size is a recognized phenomenon, but its utility as a biomarker for response to therapy has not been established. This study examined the clinical relevance of early change in stroke volume and compared it with the final infarct volume and percent of early reperfusion in identifying early neurologic improvement (ENI). Acute stroke patients, enrolled between 2013 and 2014 with serial magnetic resonance imaging (MRI) scans (pretreatment baseline, 2 h post, and 24 h post), who received thrombolysis were included in the analysis. Early change in stroke volume, infarct volume at 24 h on diffusion, and percent of early reperfusion were calculated from the baseline and 2 h MRI scans were compared. ENI was defined as ≥4 point decrease in National Institutes of Health Stroke Scales within 24 h. Logistic regression models and receiver operator characteristics analysis were used to compare the efficacy of 3 imaging biomarkers. Serial MRIs of 58 acute stroke patients were analyzed. Early change in stroke volume was significantly associated with ENI by logistic regression analysis (OR 0.93, p = 0.048) and remained significant after controlling for stroke size and severity (OR 0.90, p = 0.032). Thus, for every 1 mL increase in stroke volume, there was a 10% decrease in the odds of ENI, while for every 1 mL decrease in stroke volume, there was a 10% increase in the odds of ENI. Neither infarct volume at 24 h nor percent of early reperfusion were significantly associated with ENI by logistic regression. Receiver-operator characteristic analysis identified early change in stroke volume as the only biomarker of the 3 that performed significantly different than chance (p = 0.03). Early fluctuations in stroke size may represent a more reliable biomarker for response to therapy than the

  4. Stroke Risk Factors and Symptoms

    Science.gov (United States)

    ... » [ pdf, 433 kb ] Order Materials » Stroke Risk Factors and Symptoms Risk Factors for a Stroke Stroke prevention is still ... it. Treatment can delay complications that increase the risk of stroke. Transient ischemic attacks (TIAs). Seek help. ...

  5. Middle cerebral artery occlusion in Macaca fascicularis: acute and chronic stroke evolution.

    Science.gov (United States)

    D'Arceuil, Helen E; Duggan, Michael; He, Julian; Pryor, Johnny; de Crespigny, Alex

    2006-04-01

    An intravascular stroke model designed for magnetic resonance imaging was developed in Macaca fascicularis (M. fascicularis) to characterize serial stroke lesion evolution. This model produces a range of stroke lesion sizes which closely mimics human stroke evolution. This paper describes the care of animals undergoing this stroke procedure, the range of outcomes we experienced and the cause of mortality in this model. Anesthesia was induced with atropine and ketamine and maintained with isoflurane or propofol. Non-invasive blood pressure, oxygen saturation, heart rate, respiration rate, temperature and end tidal CO2 were monitored continuously. The stroke was created by occluding a distal branch of the middle cerebral artery. During catheter placement animals were heparinized and vasospasm was minimized using verapamil. Anesthetic induction and maintenance were smooth. Animals with small strokes showed very rapid recovery, were able to ambulate and self-feed within 2 hours of recovery. Animals with strokes of >or=4% of the hemispheric volume required lengthy observation during recovery and parenteral nutrition. Large strokes resulted in significant brain edema, herniation and brainstem compression. Intracerebral hemorrhage and or subarachnoid hemorrhage coupled with a stroke of any size was acutely fatal. In the absence of an effective acute stroke therapy, the spectrum of outcomes seen in our primate model is very similar to that observed in human stroke patients.

  6. The neural substrates of impaired finger tapping regularity after stroke.

    Science.gov (United States)

    Calautti, Cinzia; Jones, P Simon; Guincestre, Jean-Yves; Naccarato, Marcello; Sharma, Nikhil; Day, Diana J; Carpenter, T Adrian; Warburton, Elizabeth A; Baron, Jean-Claude

    2010-03-01

    Not only finger tapping speed, but also tapping regularity can be impaired after stroke, contributing to reduced dexterity. The neural substrates of impaired tapping regularity after stroke are unknown. Previous work suggests damage to the dorsal premotor cortex (PMd) and prefrontal cortex (PFCx) affects externally-cued hand movement. We tested the hypothesis that these two areas are involved in impaired post-stroke tapping regularity. In 19 right-handed patients (15 men/4 women; age 45-80 years; purely subcortical in 16) partially to fully recovered from hemiparetic stroke, tri-axial accelerometric quantitative assessment of tapping regularity and BOLD fMRI were obtained during fixed-rate auditory-cued index-thumb tapping, in a single session 10-230 days after stroke. A strong random-effect correlation between tapping regularity index and fMRI signal was found in contralesional PMd such that the worse the regularity the stronger the activation. A significant correlation in the opposite direction was also present within contralesional PFCx. Both correlations were maintained if maximal index tapping speed, degree of paresis and time since stroke were added as potential confounds. Thus, the contralesional PMd and PFCx appear to be involved in the impaired ability of stroke patients to fingertap in pace with external cues. The findings for PMd are consistent with repetitive TMS investigations in stroke suggesting a role for this area in affected-hand movement timing. The inverse relationship with tapping regularity observed for the PFCx and the PMd suggests these two anatomically-connected areas negatively co-operate. These findings have implications for understanding the disruption and reorganization of the motor systems after stroke. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  7. Does mental exertion alter maximal muscle activation?

    Directory of Open Access Journals (Sweden)

    Vianney eRozand

    2014-09-01

    Full Text Available Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i high mental exertion (incongruent Stroop task, ii moderate mental exertion (congruent Stroop task, iii low mental exertion (watching a movie. In each condition, mental exertion was combined with ten intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 minutes. Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.

  8. AUC-Maximizing Ensembles through Metalearning.

    Science.gov (United States)

    LeDell, Erin; van der Laan, Mark J; Petersen, Maya

    2016-05-01

    Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree.

  9. Dizziness in stroke

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2015-01-01

    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.

  10. Interleukin-6 is increased in plasma and cerebrospinal fluid of community-dwelling domestic dogs with acute ischaemic stroke

    DEFF Research Database (Denmark)

    Gredal, Hanne; Thomsen, Barbara B; Boza-Serrano, Antonio

    2017-01-01

    and cerebrospinal fluid (CSF) in dogs with acute ischaemic stroke and to search for correlations between infarct volume and cytokine concentrations. Blood and CSF were collected from dogs less than 72 h after a spontaneous ischaemic stroke. Infarct volumes were estimated on MRIs. Interleukin (IL)-2, IL-6, IL-8, IL...

  11. On maximal massive 3D supergravity

    OpenAIRE

    Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K

    2010-01-01

    ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...

  12. Inclusive Fitness Maximization:An Axiomatic Approach

    OpenAIRE

    Okasha, Samir; Weymark, John; Bossert, Walter

    2014-01-01

    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 qu...

  13. Stroke in tuberculous meningitis.

    Science.gov (United States)

    Misra, Usha Kant; Kalita, Jayantee; Maurya, Pradeep Kumar

    2011-04-15

    Stroke in tuberculous meningitis (TBM) occurs in 15-57% of patients especially in advance stage and severe illness. The majority of strokes may be asymptomatic because of being in a silent area, deep coma or associated pathology such as spinal arachnoiditis or tuberculoma. Methods of evaluation also influence the frequency of stroke. MRI is more sensitive in detecting acute (DWI) and chronic (T2, FLAIR) stroke. Most of the strokes in TBM are multiple, bilateral and located in the basal ganglia especially the 'tubercular zone' which comprises of the caudate, anterior thalamus, anterior limb and genu of the internal capsule. These are attributed to the involvement of medial striate, thalamotuberal and thalamostriate arteries which are embedded in exudates and likely to be stretched by a coexistent hydrocephalus. Cortical stroke can also occur due to the involvement of proximal portion of the middle, anterior and posterior cerebral arteries as well as the supraclinoid portion of the internal carotid and basilar arteries which are documented in MRI, angiography and autopsy studies. Arteritis is more common than infarction in autopsy study. The role of cytokines especially tumor necrosis factor (TNFα), vascular endothelial growth factor (VEGF) and matrix metaloproteineases (MMPs) in damaging the blood brain barrier, attracting leucocytes and release of vasoactive autocoids have been suggested. The prothrombotic state may also contribute to stroke in TBM. Corticosteroids with antitubercular therapy were thought to reduce mortality and morbidity but their role in reducing strokes has not been proven. Aspirin also reduces mortality and its role in reducing stroke in TBM needs further studies. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Hyponatremia in stroke

    Directory of Open Access Journals (Sweden)

    Sheikh Saleem

    2014-01-01

    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.

  15. Perfusion CT in acute stroke

    International Nuclear Information System (INIS)

    Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

    2015-01-01

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  16. Activity versus outcome maximization in time management.

    Science.gov (United States)

    Malkoc, Selin A; Tonietto, Gabriela N

    2018-04-30

    Feeling time-pressed has become ubiquitous. Time management strategies have emerged to help individuals fit in more of their desired and necessary activities. We provide a review of these strategies. In doing so, we distinguish between two, often competing, motives people have in managing their time: activity maximization and outcome maximization. The emerging literature points to an important dilemma: a given strategy that maximizes the number of activities might be detrimental to outcome maximization. We discuss such factors that might hinder performance in work tasks and enjoyment in leisure tasks. Finally, we provide theoretically grounded recommendations that can help balance these two important goals in time management. Published by Elsevier Ltd.

  17. On the maximal superalgebras of supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

    2009-01-01

    In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

  18. Task-oriented maximally entangled states

    International Nuclear Information System (INIS)

    Agrawal, Pankaj; Pradhan, B

    2010-01-01

    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.

  19. Cost of stroke

    DEFF Research Database (Denmark)

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

    2015-01-01

    . 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......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...

  20. Clinical neurogenetics: stroke.

    Science.gov (United States)

    Rost, Natalia S

    2013-11-01

    Understanding the genetic architecture of cerebrovascular disease holds promise of novel stroke prevention strategies and therapeutics that are both safe and effective. Apart from a few single-gene disorders associated with cerebral ischemia or intracerebral hemorrhage, stroke is a complex genetic phenotype that requires careful ascertainment and robust association testing for discovery and validation analyses. The recently uncovered shared genetic contribution between clinically manifest stroke syndromes and closely related intermediate cerebrovascular phenotypes offers effective and efficient approaches to complex trait analysis. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Determinan Penyakit Stroke

    Directory of Open Access Journals (Sweden)

    Woro Riyadina

    2013-02-01

    Full Text Available Penyakit stroke merupakan penyebab kematian dan kecacatan kronik yang paling tinggi pada kelompok umur diatas usia 45 tahun terbanyak di Indonesia. Tujuan penelitian ini untuk mengidentifikasi determinan utama yang berhubungan dengan penyakit stroke pada masyarakat di kelurahan Kebon Kalapa Bogor. Analisis lanjut terhadap 1.912 responden subset baseline data penelitian “Studi Kohort Faktor Risiko Penyakit Tidak Menular” Data dikumpulkan dengan metode wawancara pada penduduk tetap di kelurahan Kebon Kalapa, Kecamatan Bogor Tengah, Bogor tahun 2012. Diagnosis stroke berdasarkan anamnesis dan pemeriksaan dokter spesialis syaraf. Variabel independen meliputi karakteristik sosiodemografi, status kesehatan dan perilaku berisiko. Data dianalisis dengan uji regresi logistik ganda. Penyakit stroke ditemukan pada 49 (2,6% orang. Determinan utama stroke meliputi hipertensi (OR = 4,20; IK 95% = 2,20 – 8,03, penyakit jantung koroner (OR = 2,74; IK 95% = 1,51 – 4,99, diabetes melitus (OR = 2,89; IK 95% = 1,47 – 5,64, dan status ekonomi miskin (OR = 1,83 ; IK 95% = 1,03 – 3,33. Pencegahan penyakit stroke dilakukan dengan peningkatan edukasi (kampanye/penyuluhan melalui pengendalian faktor risiko utama yaitu hipertensi dan pencegahan terjadinya penyakit degeneratif lain yaitu penyakit jantung koroner dan diabetes melitus. Stroke disease is the leading cause of death and chronic disabi lity in most over the age of 45 years in Indonesia. The aim of study was to identify the major determinants of stroke disease in Kebon Kalapa community in Bogor. A deep analyze was conducted in 1.912 respondents based on the subset of baseline data “Risk Factors Cohort Study of Non Communicable Diseases.” Data was collected by interviews on Kebon Kalapa community, Bogor in 2012. Stroke diagnosis was determined by anamnesis and neu-rological examination with specialist. Independent variables were sociodemographic characteristics, health status and risk behavior

  2. Relations of morphological characteristics and maximal oxygen consumption of fourth grade pupils based on gender

    Directory of Open Access Journals (Sweden)

    Jakovljević Vladimir

    2014-01-01

    Full Text Available On a sample of 71 respondents, 37 boys and 34 girls, age of fourth grade elementary school, accordingly 9 years +/- 6 months, it is assessed correlation and prediction of maximal oxygen consumption based measures of morphological range. Maximum oxygen consumption was measured by indirect method, using a field test of maximal multiple load of feedback running at 20 meters. Range of morphology was analyzed based on 5 measures of longitudinal dimensionality, 4 measures of volume and body mass and 3 measures of transversal dimensionality. Results of correlation analysis showed that in both sexes there was no statistically significant correlation between results of maximal oxygen consumption and measures of longitudinal dimensionality, while regression analysis confirmed that there was no statistically significant prediction of maximum oxygen consumption based on measures of longitudinal dimensionality. While the correlation analysis deduced that part of volume measures and body mass and transversal dimensionality have statistically significant correlation only with female respondents with results of maximal oxygen consumption. Regression analysis showed statistically significant prediction of maximal oxygen consumption based on part of volume measures and body mass and transversal dimensionality. It is determined that female respondents with larger volumes of the thigh and lower leg, accordingly with smaller diameters of knee joint and ankle joint most likely will achieve better results in applied test, and therefore higher maximal oxygen consumption.

  3. Hypertension and experimental stroke therapies

    OpenAIRE

    O'Collins, Victoria E; Donnan, Geoffrey A; Macleod, Malcolm R; Howells, David W

    2013-01-01

    Hypertension is an established target for long-term stroke prevention but procedures for management of hypertension in acute stroke are less certain. Here, we analyze basic science data to examine the impact of hypertension on candidate stroke therapies and of anti-hypertensive treatments on stroke outcome. Methods: Data were pooled from 3,288 acute ischemic stroke experiments (47,899 animals) testing the effect of therapies on infarct size (published 1978–2010). Data were combined using meta...

  4. Epicardial left ventricular lead placement for cardiac resynchronization therapy: optimal pace site selection with pressure-volume loops.

    Science.gov (United States)

    Dekker, A L A J; Phelps, B; Dijkman, B; van der Nagel, T; van der Veen, F H; Geskes, G G; Maessen, J G

    2004-06-01

    Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.

  5. The Reticulospinal Pathway Does Not Increase Its Contribution to the Strength of Contralesional Muscles in Stroke Survivors as Compared to Ipsilesional Side or Healthy Controls

    Directory of Open Access Journals (Sweden)

    Sheng Li

    2017-11-01

    Full Text Available ObjectiveStartling acoustic stimulation (SAS, via activation of reticulospinal (RS pathways, has shown to increase muscle strength in healthy subjects. We hypothesized that, given RS hyperexcitability in stroke survivors, SAS could increase muscle strength in stroke survivors. The objective was to quantify the effect of SAS on maximal and sub-maximal voluntary elbow flexion on the contralesional (impaired side in stroke survivors as compared to ipsilesional (non-impaired side and healthy controls.DesignThirteen hemiparetic stroke survivors and 12 healthy subjects volunteered for this investigation. Acoustic stimulation was given at rest, during ballistic maximal and sustained sub-maximal isometric elbow contractions using low (80 dB and high intensity sound (105 dB. The effect of acoustic stimuli was evaluated from EMG and force recordings.ResultsPrevalence of acoustic startle reflex with shorter latency in the impaired biceps was greater as compared to the response in the non-impaired side of stroke subjects and in healthy subjects. Delivery of SAS resulted in earlier initiation of elbow flexion and greater peak torque in healthy subjects and in stroke subjects with spastic hemiplegia during maximal voluntary elbow flexion tasks. During sub-maximal elbow flexion tasks, SAS-induced force responses were slightly greater on the impaired side than the non-impaired side. However, no statistically significant difference was found in SAS-induced responses between impaired and non-impaired sides at maximal and sub-maximal elbow flexion tasks.ConclusionThe findings suggest RS hyperexcitability in stroke survivors with spastic hemiplegia. The results of similar SAS-induced responses between healthy and stroke subjects indicate that RS projections via acoustic stimulation are not likely to contribute to muscle strength for stroke survivors to a significant extent.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-08-15

    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.)

  7. Stroke: Hope through Research

    Science.gov (United States)

    ... in a compromised state for several hours. With timely treatment these cells can be saved. The ischemic ... this research is the use of transcranial magnetic stimulation (TMS) in stroke rehabilitation. Some evidence suggests that ...

  8. Healthy Living after Stroke

    Science.gov (United States)

    ... Nutrition Cooking for Health Food for Thought: Heart-healthy Diet is Also Good For Your Brain Physical Activity Get Moving and Boost Your Brain Power Understanding Risky Conditions Converging Risk Factors for Stroke ...

  9. The "Know Stroke" Campaign

    Science.gov (United States)

    ... Issue Past Issues Special Section The "Know Stroke" Campaign Past Issues / Summer 2007 Table of Contents For ... Javascript on. NINDS is conducting a public awareness campaign across the United States to educate people about ...

  10. Recovering after stroke

    Science.gov (United States)

    ... urine from their body. To prevent skin or pressure sores: Clean up after incontinence Change position often and ... artery surgery - discharge Daily bowel care program Preventing pressure ulcers Stroke - discharge References Dobkin BH. Neurological rehabilitation In: ...

  11. National Stroke Association

    Science.gov (United States)

    ... partnership will offer free access to the RapidSOS Haven app for one year, providing individuals with enhanced ... of care to thrive after stroke. Make your tax-deductible donation today to support the growing needs ...

  12. Strokes (For Parents)

    Science.gov (United States)

    ... paralysis or weakness on one side of the body language or speech delays or changes, such as slurring ... uses many different types of therapy to help children recover from stroke. Outlook At this time, no ...

  13. Stroke - risk factors

    Science.gov (United States)

    ... oxygen. Brain cells can die, causing lasting damage. Risk factors are things that increase your chance of ... a disease or condition. This article discusses the risk factors for stroke and things you can do ...

  14. Epilepsy after stroke

    DEFF Research Database (Denmark)

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

    1987-01-01

    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...... with other severe diseases. Cerebral angiography, CT, and EEG were performed in all patients. The patients were followed clinically for 2 to 4 years. Seven patients (9%) developed epilepsy. Of 23 patients with lesions involving the cortex, 6 (26%) developed epilepsy. Of 54 patients in whom the cortex...... was not involved, only 1 (2%) developed epilepsy. Patients with persisting paresis and cortical involvement seem to be at particularly high risk of developing epilepsy, as 50% of such patients (6 of 12) developed the disease....

  15. Common variants at 6q22 and 17q21 are associated with intracranial volume

    NARCIS (Netherlands)

    Arfan Ikram, M.; Fornage, M.; Smith, A.V.; Seshadri, S.; Schmidt, R.; Debette, S.; Vrooman, H.A.; Sigurdsson, S.; Ropele, S.; Taal, H.R.; Mook-Kanamori, D.O.; Coker, L.H.; Longstreth, Jr. W.T.; Niessen, W.J.; DeStefano, A.L.; Beiser, A.; Zijdenbos, A.P.; Struchalin, M.; Jack, C.R.; Rivadeneira, F.; Uitterlinden, A.G.; Knopman, D.S.; Hartikainen, A.-L.; Pennell, C.E.; Thiering, E.; Steegers, E.A.P.; Hakonarson, H.; Heinrich, J.; Palmer, L.J.; Jarvelin, M.-R.; McCarthy, M.I.; Grant, S.F.A.; St Pourcain, B.; Timpson, N.J.; Smith, G.D.; Sovio, U.; van Beijsterveldt, C.E.M.; Groen-Blokhuis, M.M.; Hottenga, J.J.; Middeldorp, C.M.; Nivard, M.G.; Willemsen, G.; Boomsma, D.I.; Nalls, M.A.; Au, R.; Hofman, A.; Gudnason, H.; van der Lugt, A.; Harris, T.B.; Meeks, W.M.; Vernooij, M.W.; van Buchem, M.A.; Catellier, D.; Jaddoe, V.W.V.; Gudnason, V.; Windham, B.G.; Wolf, P.A.; van Duijn, C.M.; Mosley, T.H.; Schmidt, H.; Launer, L.J.; Breteler, M.M.B.; DeCarli, C.S.

    2012-01-01

    During aging, intracranial volume remains unchanged and represents maximally attained brain size, while various interacting biological phenomena lead to brain volume loss. Consequently, intracranial volume and brain volume in late life reflect different genetic influences. Our genome-wide

  16. Common variants at 6q22 and 17q21 are associated with intracranial volume

    NARCIS (Netherlands)

    M.A. Ikram (Arfan); M. Fornage (Myriam); G.D. Smith; S. Seshadri (Sudha); R. Schmidt (Reinhold); S. Debette (Stéphanie); H.A. Vrooman (Henri); S. Sigurdsson (Stefan); S. Ropele (Stefan); H.R. Taal (Rob); D.O. Mook-Kanamori (Dennis); L.H. Coker (Laura); W.T. Longstreth Jr; W.J. Niessen (Wiro); A.L. DeStefano (Anita); A. Beiser (Alexa); A.P. Zijdenbos; M.V. Struchalin (Maksim); C.R. Jack Jr. (Clifford); F. Rivadeneira Ramirez (Fernando); A.G. Uitterlinden (André); D.S. Knopman (David); A.L. Hartikainen; C.E. Pennell (Craig); E. Thiering (Eelisabeth); E.A.P. Steegers (Eric); H. Hakonarson (Hakon); J. Heinrich (Joachim); C. Palmer (Cameron); M.-R. Jarvelin (Marjo-Riitta); M.I. McCarthy (Mark); S.F.A. Grant (Struan); B.S. Pourcain (Beate); N.J. Timpson (Nicholas); G.D. Smith; U. Sovio (Ulla); M.A. Nalls (Michael); R. Au (Rhoda); A. Hofman (Albert); H. Gudnason (Haukur); A. van der Lugt (Aad); T.B. Harris (Tamara); W.M. Meeks (William); M.W. Vernooij (Meike); M.A. van Buchem (Mark); D.J. Catellier (Diane); V.W.V. Jaddoe (Vincent); V. Gudnason (Vilmundur); B.G. Windham (B Gwen); P.A. Wolf (Philip); C.M. van Duijn (Cornelia); T.H. Mosley (Thomas); R. Schmidt (Reinhold); L.J. Launer (Lenore); M.M.B. Breteler (Monique); C. DeCarli (Charles); L.S. Adair (Linda); W.Q. Ang (Wei); M. Atalay (Mustafa); C.E.M. van Beijsterveldt (Toos); N.E. Bergen (Nienke); P.J. Benke (Paul); D. Berry (Diane); L. Coin (Lachlan); O.S.P. Davis (Oliver S.); P. Elliott (Paul); C. Flexeder (Claudia); T.M. Frayling (Timothy); R. Gaillard (Romy); M. Groen-Blokhuis (Maria); L.-K. Goh; C.M.A. Haworth (Claire M.); D. Hadley (David); J. Hedebrand (Johannes); A. Hinney (Anke); J.N. Hirschhorn (Joel); J.W. Holloway (John); J.J. Holst; J.J. Hottenga (Jouke Jan); M. Horikoshi (Momoko); V. Huikari (Ville); E. Hypponen (Elina); T.O. Kilpeläinen (Tuomas); M. Kirin (Mirna); M. Kowgier (Matthew); T.A. Lakka (Timo); L.A. Lange (Leslie); D.A. Lawlor (Debbie); T. Lehtimäki (Terho); A. Lewin (Alex); C.M. Lindgren (Cecilia); V. Lindi (Virpi); R. Maggi (Reedik); J.A. Marsh (Julie); C.M. Middeldorp (Christel); I.Y. Millwood (Iona); J.C. Murray (Jeffrey); M. Nivard (Michel); C. Nohr (Christian); I. Ntalla (Ioanna); E. Oken (Emily); K. Panoutsopoulou (Kalliope); J. Pararajasingham (Jennifer); A. Rodriguez (Alfredo Chapin); R.M. Salem (Rany); S. Sebert (Sylvain); N. Siitonen (Niina); D.P. Strachan (David); Y.Y. Teo (Yik Ying); B. Valcárcel (Beatriz); G.A.H.M. Willemsen (Gonneke); E. Zeggini (Eleftheria); D.I. Boomsma (Dorret); C. Cooper (Charles); M.H. Gillman (Matthew); B. Hocher (Berthold); T.A. Lakka (Timo); K.L. Mohlke (Karen); G.V. Dedoussis (George); K.K. Ong (Ken); E. Pearson (Ewan); T.S. Price (Thomas); C. Power (Christopher); O. Raitakari (Olli); S-M. Saw (Seang-Mei); A. Scherag (Andre); O. Simell (Olli); T.I.A. Sørensen (Thorkild); J.F. Wilson (James)

    2012-01-01

    textabstractDuring aging, intracranial volume remains unchanged and represents maximally attained brain size, while various interacting biological phenomena lead to brain volume loss. Consequently, intracranial volume and brain volume in late life reflect different genetic influences. Our

  17. Maximally Entangled Multipartite States: A Brief Survey

    International Nuclear Information System (INIS)

    Enríquez, M; Wintrowicz, I; Życzkowski, K

    2016-01-01

    The problem of identifying maximally entangled quantum states of a composite quantum systems is analyzed. We review some states of multipartite systems distinguished with respect to certain measures of quantum entanglement. Numerical results obtained for 4-qubit pure states illustrate the fact that the notion of maximally entangled state depends on the measure used. (paper)

  18. Utility maximization and mode of payment

    NARCIS (Netherlands)

    Koning, R.H.; Ridder, G.; Heijmans, R.D.H.; Pollock, D.S.G.; Satorra, A.

    2000-01-01

    The implications of stochastic utility maximization in a model of choice of payment are examined. Three types of compatibility with utility maximization are distinguished: global compatibility, local compatibility on an interval, and local compatibility on a finite set of points. Keywords:

  19. Corporate Social Responsibility and Profit Maximizing Behaviour

    OpenAIRE

    Becchetti, Leonardo; Giallonardo, Luisa; Tessitore, Maria Elisabetta

    2005-01-01

    We examine the behavior of a profit maximizing monopolist in a horizontal differentiation model in which consumers differ in their degree of social responsibility (SR) and consumers SR is dynamically influenced by habit persistence. The model outlines parametric conditions under which (consumer driven) corporate social responsibility is an optimal choice compatible with profit maximizing behavior.

  20. Autopsy approach to stroke.

    Science.gov (United States)

    Love, Seth

    2011-02-01

    Stroke is a major cause of morbidity and mortality but the brain and other relevant tissues are often examined only cursorily when stroke patients come to autopsy. The pathological findings and clinical implications vary according to the type of stroke and its location and cause. Large ischaemic strokes are usually associated with atherosclerosis of extracranial or major intracranial arteries but can be caused by dissection. Most small cerebral infarcts are caused by arteriosclerosis or, in the elderly, cerebral amyloid angiopathy (CAA). However, vasculitides and coagulopathies can cause a range of different patterns of ischaemic (and, occasionally, haemorrhagic) stroke. Global brain ischaemia, caused by severe hypotension or raised intracranial pressure, produces damage that is accentuated in certain regions and neuronal populations and may be confused with hypoglycaemic injury. The main cause of subarachnoid haemorrhage is a ruptured berry aneurysm but CAA, arteriovenous malformations and infective aneurysms are occasionally responsible. These can also cause parenchymal brain haemorrhage, although this most often complicates hypertensive small vessel disease. Sometimes the haemorrhage arises from a neoplasm. Performing an adequate autopsy in stroke requires proper preparation, awareness of the likely pathological processes, familiarity with intracranial vascular anatomy, careful gross examination and dissection, and appropriate use of histology. © 2010 Blackwell Publishing Limited.

  1. Inclusive fitness maximization: An axiomatic approach.

    Science.gov (United States)

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

    2014-06-07

    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.

  2. Maximal Entanglement in High Energy Physics

    Directory of Open Access Journals (Sweden)

    Alba Cervera-Lierta, José I. Latorre, Juan Rojo, Luca Rottoli

    2017-11-01

    Full Text Available We analyze how maximal entanglement is generated at the fundamental level in QED by studying correlations between helicity states in tree-level scattering processes at high energy. We demonstrate that two mechanisms for the generation of maximal entanglement are at work: i $s$-channel processes where the virtual photon carries equal overlaps of the helicities of the final state particles, and ii the indistinguishable superposition between $t$- and $u$-channels. We then study whether requiring maximal entanglement constrains the coupling structure of QED and the weak interactions. In the case of photon-electron interactions unconstrained by gauge symmetry, we show how this requirement allows reproducing QED. For $Z$-mediated weak scattering, the maximal entanglement principle leads to non-trivial predictions for the value of the weak mixing angle $\\theta_W$. Our results are a first step towards understanding the connections between maximal entanglement and the fundamental symmetries of high-energy physics.

  3. Nursing care for stroke patients

    DEFF Research Database (Denmark)

    Tulek, Zeliha; Poulsen, Ingrid; Gillis, Katrin

    2018-01-01

    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...

  4. Accuracy of Emergency Medical Services Dispatcher and Crew Diagnosis of Stroke in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Judy Jia

    2017-09-01

    Full Text Available BackgroundAccurate recognition of stroke symptoms by Emergency Medical Services (EMS is necessary for timely care of acute stroke patients. We assessed the accuracy of stroke diagnosis by EMS in clinical practice in a major US city.Methods and resultsPhiladelphia Fire Department data were merged with data from a single comprehensive stroke center to identify patients diagnosed with stroke or TIA from 9/2009 to 10/2012. Sensitivity and positive predictive value (PPV were calculated. Multivariable logistic regression identified variables associated with correct EMS diagnosis. There were 709 total cases, with 400 having a discharge diagnosis of stroke or TIA. EMS crew sensitivity was 57.5% and PPV was 69.1%. EMS crew identified 80.2% of strokes with National Institutes of Health Stroke Scale (NIHSS ≥5 and symptom duration <6 h. In a multivariable model, correct EMS crew diagnosis was positively associated with NIHSS (NIHSS 5–9, OR 2.62, 95% CI 1.41–4.89; NIHSS ≥10, OR 4.56, 95% CI 2.29–9.09 and weakness (OR 2.28, 95% CI 1.35–3.85, and negatively associated with symptom duration >270 min (OR 0.41, 95% CI 0.25–0.68. EMS dispatchers identified 90 stroke cases that the EMS crew missed. EMS dispatcher or crew identified stroke with sensitivity of 80% and PPV of 50.9%, and EMS dispatcher or crew identified 90.5% of patients with NIHSS ≥5 and symptom duration <6 h.ConclusionPrehospital diagnosis of stroke has limited sensitivity, resulting in a high proportion of missed stroke cases. Dispatchers identified many strokes that EMS crews did not. Incorporating EMS dispatcher impression into regional protocols may maximize the effectiveness of hospital destination selection and pre-notification.

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

    Science.gov (United States)

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

    2007-01-01

    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. PMID:17371603

  6. Arterial stiffness and functional outcome in acute ischemic stroke.

    Science.gov (United States)

    Lee, Yeong-Bae; Park, Joo-Hwan; Kim, Eunja; Kang, Chang-Ki; Park, Hyeon-Mi

    2014-03-01

    Arterial stiffness is a common change associated with aging and can be evaluated by measuring pulse wave velocity (PWV) between sites in the arterial tree, with the stiffer artery having the higher PWV. Arterial stiffness is associated with the risk of stroke in the general population and of fatal stroke in hypertensive patients. This study is to clarify whether PWV value predicts functional outcome of acute ischemic stroke. ONE HUNDRED PATIENTS WERE ENROLLED WITH A DIAGNOSIS OF ACUTE ISCHEMIC STROKE AND CATEGORIZED INTO TWO GROUPS: large-artery atherosclerosis (LAAS) or small vessel disease (SVD) subtype of Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Each group was divided into two sub-groups based on the functional outcome of acute ischemic stroke, indicated by modified Rankin Scale (mRS) at discharge. Poor functional outcome group was defined as a mRS ≥ 3 at discharge. Student's t-test or Mann-Whitney U-test were used to compare maximal brachial-ankle PWV (baPWV) values. Twenty-four patients whose state was inadequate to assess baPWV or mRS were excluded. There were 38 patients with good functional outcome (mRS vs. 1,789.80 ± 421.91, p = 0.022), while there was no significant difference of baPWV among patients with LAAS subtype (2,071.76 ± 618.42 vs. 1,878.00 ± 365.35, p = 0.579). Arterial stiffness indicated by baPWV is associated with the functional outcome of acute ischemic stroke. This finding suggests that measurement of baPWV predicts functional outcome in patients with stroke especially those whose TOAST classification was confirmed as SVD subtype.

  7. Possible Anandamide and Palmitoylethanolamide involvement in human stroke

    Directory of Open Access Journals (Sweden)

    Pizzolato Gilberto

    2010-05-01

    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

  8. Relearning the Basics: Rehabilitation after a Stroke

    Science.gov (United States)

    ... 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 ...

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

    Science.gov (United States)

    Uzdin, Raam; Kosloff, Ronnie

    2014-09-01

    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.

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

    International Nuclear Information System (INIS)

    Uzdin, Raam; Kosloff, Ronnie

    2014-01-01

    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. (paper)

  11. Oral Consumption of Vitamin K2 for 8 Weeks Associated With Increased Maximal Cardiac Output During Exercise.

    Science.gov (United States)

    McFarlin, Brian K; Henning, Andrea L; Venable, Adam S

    2017-07-01

    separately for each outcome variable at each treatment time point. Results • Vitamin K2 supplementation was associated with a 12% increase in maximal cardiac output, with P = .031, with a trend toward an increase in heart-rate AUC, with P = .070. No significant changes occurred in stroke volume. Conclusions • Although vitamin K2 supplementation has previously been reported to improve cardiovascular function in diseased patients, to the research team's knowledge, the current study is the first to report its potential in active individuals. More research is needed to fully evaluate the potential effects of the observed effects.

  12. Code stroke in Asturias.

    Science.gov (United States)

    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

    2016-04-01

    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.

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

    International Nuclear Information System (INIS)

    Marsden, J.E.; Tipler, F.J.; Texas Univ., Austin

    1980-01-01

    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 specetimes 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 foliantions by constant mean curvature hypersurfaces can be extended to global ones is obtained. (orig.)

  14. Late night activity regarding stroke codes: LuNAR strokes.

    Science.gov (United States)

    Tafreshi, Gilda; Raman, Rema; Ernstrom, Karin; Rapp, Karen; Meyer, Brett C

    2012-08-01

    There is diurnal variation for cardiac arrest and sudden cardiac death. Stroke may show a similar pattern. We assessed whether strokes presenting during a particular time of day or night are more likely of vascular etiology. To compare emergency department stroke codes arriving between 22:00 and 8:00 hours (LuNAR strokes) vs. others (n-LuNAR strokes). The purpose was to determine if late night strokes are more likely to be true strokes or warrant acute tissue plasminogen activator evaluations. We reviewed prospectively collected cases in the University of California, San Diego Stroke Team database gathered over a four-year period. Stroke codes at six emergency departments were classified based on arrival time. Those arriving between 22:00 and 8:00 hours were classified as LuNAR stroke codes, the remainder were classified as 'n-LuNAR'. Patients were further classified as intracerebral hemorrhage, acute ischemic stroke not receiving tissue plasminogen activator, acute ischemic stroke receiving tissue plasminogen activator, transient ischemic attack, and nonstroke. Categorical outcomes were compared using Fisher's Exact test. Continuous outcomes were compared using Wilcoxon's Rank-sum test. A total of 1607 patients were included in our study, of which, 299 (19%) were LuNAR code strokes. The overall median NIHSS was five, higher in the LuNAR group (n-LuNAR 5, LuNAR 7; P=0·022). There was no overall differences in patient diagnoses between LuNAR and n-LuNAR strokes (P=0·169) or diagnosis of acute ischemic stroke receiving tissue plasminogen activator (n-LuNAR 191 (14·6%), LuNAR 42 (14·0%); P=0·86). Mean arrival to computed tomography scan time was longer during LuNAR hours (n-LuNAR 54·9±76·3 min, LuNAR 62·5±87·7 min; P=0·027). There was no significant difference in 90-day mortality (n-LuNAR 15·0%, LuNAR 13·2%; P=0·45). Our stroke center experience showed no difference in diagnosis of acute ischemic stroke between day and night stroke codes. This

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

    Directory of Open Access Journals (Sweden)

    Meghan Kirking

    2017-01-01

    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.

  16. Risk Factors and Stroke Characteristic in Patients with Postoperative Strokes.

    Science.gov (United States)

    Dong, Yi; Cao, Wenjie; Cheng, Xin; Fang, Kun; Zhang, Xiaolong; Gu, Yuxiang; Leng, Bing; Dong, Qiang

    2017-07-01

    Intravenous thrombolysis and intra-arterial thrombectomy are now the standard therapies for patients with acute ischemic stroke. In-house strokes have often been overlooked even at stroke centers and there is no consensus on how they should be managed. Perioperative stroke happens rather frequently but treatment protocol is lacking, In China, the issue of in-house strokes has not been explored. The aim of this study is to explore the current management of in-house stroke and identify the common risk factors associated with perioperative strokes. Altogether, 51,841 patients were admitted to a tertiary hospital in Shanghai and the records of those who had a neurological consult for stroke were reviewed. Their demographics, clinical characteristics, in-hospital complications and operations, and management plans were prospectively studied. Routine laboratory test results and risk factors of these patients were analyzed by multiple logistic regression model. From January 1, 2015, to December 31, 2015, over 1800 patients had neurological consultations. Among these patients, 37 had an in-house stroke and 20 had more severe stroke during the postoperative period. Compared to in-house stroke patients without a procedure or operation, leukocytosis and elevated fasting glucose levels were more common in perioperative strokes. In multiple logistic regression model, perioperative strokes were more likely related to large vessel occlusion. Patients with perioperative strokes had different risk factors and severity from other in-house strokes. For these patients, obtaining a neurological consultation prior to surgery may be appropriate in order to evaluate the risk of perioperative stroke. Copyright © 2017. Published by Elsevier Inc.

  17. Child-Mediated Stroke Communication: findings from Hip Hop Stroke.

    Science.gov (United States)

    Williams, Olajide; DeSorbo, Alexandra; Noble, James; Gerin, William

    2012-01-01

    Low thrombolysis rates for acute ischemic stroke are linked to delays in seeking immediate treatment due to low public stroke awareness. We aimed to assess whether "Child-Mediated Stroke Communication" could improve stroke literacy of parents of children enrolled in a school-based stroke literacy program called Hip Hop Stroke. Parents of children aged 9 to 12 years from 2 public schools in Harlem, New York City, were recruited to participate in stroke literacy questionnaires before and after their child's participation in Hip Hop Stroke, a novel Child-Mediated Stroke Communication intervention delivered in school auditoriums. Parental recall of stroke information communicated through their child was assessed 1-week after the intervention. Fifth and sixth grade students (n=182) were enrolled into Hip Hop Stroke. One hundred two parents were approached in person to participate; 75 opted to participate and 71 completed both the pretest and post-test (74% response rate and 95% retention rate). Parental stroke literacy improved after the program; before the program, 3 parents of 75 (3.9%) were able to identify the 5 cardinal stroke symptoms, distracting symptom (chest pains), and had an urgent action plan (calling 911) compared with 21 of 71 parents (29.6%) postintervention (P<0.001). The FAST mnemonic was known by 2 (2.7%) of participants before the program versus 29 (41%) after program completion (P<0.001). Knowledge of stroke signs and symptoms remains low among residents of this high-risk population. The use of Child-Mediated Stroke Communication suggests that school children aged 9 to 12 years may be effective conduits of critical stroke knowledge to their parents.

  18. Swallowing Kinematics and Factors Associated with Laryngeal Penetration and Aspiration in Stroke Survivors with Dysphagia.

    Science.gov (United States)

    Seo, Han Gil; Oh, Byung-Mo; Han, Tai Ryoon

    2016-04-01

    The purpose of this study was to investigate swallowing kinematics and explore kinematic factors related with penetration-aspiration in patients with post-stroke dysphagia. Videofluoroscopic images of 68 patients with post-stroke dysphagia and 34 sex- and age-matched healthy controls swallowing a thin liquid were quantitatively analyzed using two-dimensional motion digitization. The measurements included the movement distances and velocities of the hyoid and larynx, and the maximal tilt angles and angular velocities of the epiglottis. All velocity variables were significantly decreased in the stroke patients compared to the controls. There was a significant difference in the maximal horizontal displacement of the larynx, but there were no significant differences in other displacements of the larynx, the maximal displacements of the hyoid bone, and the maximum tilt angle of the epiglottis between the two groups. The maximal tilt angle of the epiglottis was lower in the aspiration subgroup than in the no penetration/aspiration and penetration subgroups as well as the controls. The maximal tilt angle from the y axis showed a dichotomous pattern at 90° of the angle, and all 11 patients with an angle dysphagia. The association of reduced epiglottic movement with the risk of aspiration in patients with post-stroke dysphagia was supported by the quantitative analysis.

  19. Diabetes, Heart Disease, and Stroke

    Science.gov (United States)

    ... Disease, & Other Dental Problems Diabetes, Sexual, & Bladder 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 ...

  20. Preventable Pediatric Stroke via Vaccination?

    Directory of Open Access Journals (Sweden)

    Craig A. Press

    2015-11-01

    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.

  1. Heart Disease and Stroke Statistics

    Science.gov (United States)

    ... Media for Heart.org Heart and Stroke Association Statistics Each year, the American Heart Association, in conjunction ... health and disease in the population. Heart & Stroke Statistics FAQs What is Prevalence? Prevalence is an estimate ...

  2. Bipartite Bell Inequality and Maximal Violation

    International Nuclear Information System (INIS)

    Li Ming; Fei Shaoming; Li-Jost Xian-Qing

    2011-01-01

    We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum states more effectively. (general)

  3. HEALTH INSURANCE: CONTRIBUTIONS AND REIMBURSEMENT MAXIMAL

    CERN Document Server

    HR Division

    2000-01-01

    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...

  4. Maximal Inequalities for Dependent Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jorgensen, Jorgen

    2016-01-01

    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......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

  5. Maximizing Function through Intelligent Robot Actuator Control

    Data.gov (United States)

    National Aeronautics and Space Administration — Maximizing Function through Intelligent Robot Actuator Control Successful missions to Mars and beyond will only be possible with the support of high-performance...

  6. An ethical justification of profit maximization

    DEFF Research Database (Denmark)

    Koch, Carsten Allan

    2010-01-01

    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...... utility) maximizing actions are ruled out, e.g., by behavioural norms or formal institutions....

  7. A definition of maximal CP-violation

    International Nuclear Information System (INIS)

    Roos, M.

    1985-01-01

    The unitary matrix of quark flavour mixing is parametrized in a general way, permitting a mathematically natural definition of maximal CP violation. Present data turn out to violate this definition by 2-3 standard deviations. (orig.)

  8. A cosmological problem for maximally symmetric supergravity

    International Nuclear Information System (INIS)

    German, G.; Ross, G.G.

    1986-01-01

    Under very general considerations it is shown that inflationary models of the universe based on maximally symmetric supergravity with flat potentials are unable to resolve the cosmological energy density (Polonyi) problem. (orig.)

  9. Insulin resistance and maximal oxygen uptake

    DEFF Research Database (Denmark)

    Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

    2003-01-01

    BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

  10. Maximal supergravities and the E10 model

    International Nuclear Information System (INIS)

    Kleinschmidt, Axel; Nicolai, Hermann

    2006-01-01

    The maximal rank hyperbolic Kac-Moody algebra e 10 has been conjectured to play a prominent role in the unification of duality symmetries in string and M theory. We review some recent developments supporting this conjecture

  11. Maximal potential patent foramen diameter does not correlate with the type or frequency of the neurologic event prior to closure.

    Science.gov (United States)

    Kutty, Shelby; Brown, Kimberly; Qureshi, Athar M; Latson, Larry A

    2009-01-01

    We analyzed our data on patients undergoing transcatheter patent foramen ovale (PFO) closure to determine if the maximal potential PFO diameter (MPPD) by balloon sizing correlates with important clinical characteristics in this population. We defined stroke as a focal neurologic deficit lasting >24 h, or focal deficit of shorter duration associated with permanent MRI/CT changes consistent with a focal infarction. Parameters analyzed included age, gender, anticoagulation, hypertension, smoking, MRI/CT findings and MPPD at catheterization. We specifically analyzed the type of neurologic event (stroke/transient ischemic attack, TIA), and number of recorded preceding clinical neurologic events. In 216 consecutive patients, 167 suffered a stroke. MRI/CT changes consistent with one or more embolic events were seen in 156 patients; 49 had a clinical TIA. There was no significant difference in MPPD between stroke (11.0 +/- 3.6 mm) and TIA groups (10.9 +/- 3.9 mm; 95% confidence interval for difference: -1.33 to 1.00). MPPD did not differ between MRI/CT-positive vs. -negative strokes, and had no correlation with the number of identified pre-closure clinical neurologic events. Continued investigation is needed to determine whether other PFO characteristics, or other anatomic/physiologic parameters, may be useful to identify patients at high risk for cryptogenic stroke/TIA, even before they have their first neurologic event. Copyright 2008 S. Karger AG, Basel.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

    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.

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

    International Nuclear Information System (INIS)

    Jeong, K.; Choo, Y. S.; Hong, H. J.; Yoon, Y. S.; Song, M. H.

    2015-01-01

    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

  14. Gaussian maximally multipartite-entangled states

    Science.gov (United States)

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

    2009-12-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, 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 these states and their frustration for n≤7 .

  15. Gaussian maximally multipartite-entangled states

    International Nuclear Information System (INIS)

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

    2009-01-01

    We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, 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 these states and their frustration for n≤7.

  16. Neutrino mass textures with maximal CP violation

    International Nuclear Information System (INIS)

    Aizawa, Ichiro; Kitabayashi, Teruyuki; Yasue, Masaki

    2005-01-01

    We show three types of neutrino mass textures, which give maximal CP violation as well as maximal atmospheric neutrino mixing. These textures are described by six real mass parameters: one specified by two complex flavor neutrino masses and two constrained ones and the others specified by three complex flavor neutrino masses. In each texture, we calculate mixing angles and masses, which are consistent with observed data, as well as Majorana CP phases

  17. Why firms should not always maximize profits

    OpenAIRE

    Kolstad, Ivar

    2006-01-01

    Though corporate social responsibility (CSR) is on the agenda of most major corporations, corporate executives still largely support the view that corporations should maximize the returns to their owners. There are two lines of defence for this position. One is the Friedmanian view that maximizing owner returns is the corporate social responsibility of corporations. The other is a position voiced by many executives, that CSR and profits go together. This paper argues that the first position i...

  18. Maximally Informative Observables and Categorical Perception

    OpenAIRE

    Tsiang, Elaine

    2012-01-01

    We formulate the problem of perception in the framework of information theory, and prove that categorical perception is equivalent to the existence of an observable that has the maximum possible information on the target of perception. We call such an observable maximally informative. Regardless whether categorical perception is real, maximally informative observables can form the basis of a theory of perception. We conclude with the implications of such a theory for the problem of speech per...

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

    Science.gov (United States)

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

    2016-11-01

    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

  20. Burden of Stroke in Qatar.

    Science.gov (United States)

    Ibrahim, Faisal; Deleu, Dirk; Akhtar, Naveed; Al-Yazeedi, Wafa; Mesraoua, Boulenouar; Kamran, Sadaat; Shuaib, Ashfaq

    2015-12-01

    Qatar is located on the northeastern coast of the Arabian Peninsula. The total population is over 2.1 million with around 15% being Qatari citizens. Hamad General Hospital (HGH) is the only tertiary referral governmental hospital in Qatar which admits acute (thrombolysis-eligible) stroke patients. To provide an overview of the burden of stroke in Qatar. Data from literature databases, online sources and our stroke registry were collated to identify information on the burden of stroke in Qatar. Overall, over 80% of all stroke patients in Qatar are admitted in HGH. In 2010, the age-standardized incidence for first-ever ischemic stroke was 51.88/100,000 person-years. To date our stroke registry reveals that 79% of all stroke patients are male and almost 50% of stroke patients are 50 years or less. Hypertension, diabetes and dyslipidemia are the main predisposing factors for stroke, with ischemic stroke being more common (87%) than hemorrhagic stroke (13%). Despite the lack of a stroke unit, 9% of ischemic stroke patients are being thrombolyzed. However the presence of a stroke ward allows swift turnover of patients with a length of stay of less than 5 days before discharge or, if required, transfer to the fully-equipped hospital-based rehabilitation service. Several community awareness programs are ongoing, in addition to several research programs funded by the Qatar National Research Fund and Hamad Medical Corporation. In a country where over 15% of the population suffers from diabetes there is continuous need for national community-based awareness campaigns, prevention and educational programs particularly targeting patients and health care workers. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  1. SAR: Stroke Authorship Recognition

    KAUST Repository

    Shaheen, Sara; Rockwood, Alyn; Ghanem, Bernard

    2015-01-01

    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.

  2. Rehabilitation after stroke.

    Science.gov (United States)

    Knecht, Stefan; Hesse, Stefan; Oster, Peter

    2011-09-01

    Stroke is becoming more common in Germany as the population ages. Its long-term sequelae can be alleviated by early reperfusion in stroke units and by complication management and functional restoration in early-rehabilitation and rehabilitation centers. Selective review of the literature. Successful rehabilitation depends on systematic treatment by an interdisciplinary team of experienced specialists. In the area of functional restoration, there has been major progress in our understanding of the physiology of learning, relearning, training, and neuroenhancement. There have also been advances in supportive pharmacotherapy and robot technology. Well-organized acute and intermediate rehabilitation after stroke can provide patients with the best functional results attainable on the basis of our current scientific understanding. Further experimental and clinical studies will be needed to expand our knowledge and improve the efficacy of rehabilitation.

  3. Mortality after hemorrhagic stroke

    DEFF Research Database (Denmark)

    González-Pérez, Antonio; Gaist, David; Wallander, Mari-Ann

    2013-01-01

    OBJECTIVE: To investigate short-term case fatality and long-term mortality after intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) using data from The Health Improvement Network database. METHODS: Thirty-day case fatality was stratified by age, sex, and calendar year after ICH...... = 0.03). CONCLUSIONS: More than one-third of individuals die in the first month after hemorrhagic stroke, and patients younger than 50 years are more likely to die after ICH than SAH. Short-term case fatality has decreased over time. Patients who survive hemorrhagic stroke have a continuing elevated......, 54.6% for 80-89 years; SAH: 20.3% for 20-49 years, 56.7% for 80-89 years; both p-trend stroke patients...

  4. SAR: Stroke Authorship Recognition

    KAUST Repository

    Shaheen, Sara

    2015-10-15

    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.

  5. Questions and Answers about Stroke

    Science.gov (United States)

    ... stroke. High blood pressure increases your risk of stroke four to six times. Heart disease, especially a condition ... leading cause of serious, long-term adult disability. Four million Americans are living with the effects of stroke. The length of time to recover from a ...

  6. Stroke and Episodic Memory Disorders

    Science.gov (United States)

    Lim, Chun; Alexander, Michael P.

    2009-01-01

    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…

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

    Science.gov (United States)

    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

    2015-07-01

    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, Pstroke (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.

  8. Mridangam stroke dataset

    OpenAIRE

    CompMusic

    2014-01-01

    The audio examples were recorded from a professional Carnatic percussionist in a semi-anechoic studio conditions by Akshay Anantapadmanabhan using SM-58 microphones and an H4n ZOOM recorder. The audio was sampled at 44.1 kHz and stored as 16 bit wav files. The dataset can be used for training models for each Mridangam stroke. /n/nA detailed description of the Mridangam and its strokes can be found in the paper below. A part of the dataset was used in the following paper. /nAkshay Anantapadman...

  9. Stroke and Therapeutic Hypothermia

    Directory of Open Access Journals (Sweden)

    Ozlem Ozkan Kuscu

    2016-09-01

    Full Text Available Stroke is significant cause of morbidity and mortality caused by disruption of blood flow. Neural injury occurs with two stage; while primary neural injury occurs with disruption of blood flow, after days and hours with metabolic processes secondary injury develops in tissues which is non injured in the first stage. Therefore it is important to prevent and treat the secondary injury as much as preventing and treating the primary neural injury. In this article developing pathophysiological changes after stroke, mechanisms of therapeutic hypothermia, application methods, the factors that determine the effectiveness, side effects and complications were reviewed. [Archives Medical Review Journal 2016; 25(3.000: 351-368

  10. Biotherapies in stroke.

    Science.gov (United States)

    Detante, O; Jaillard, A; Moisan, A; Barbieux, M; Favre, I M; Garambois, K; Hommel, M; Remy, C

    2014-12-01

    Stroke is the second leading cause of death worldwide and the most common cause of severe disability. Neuroprotection and repair mechanisms supporting endogenous brain plasticity are often insufficient to allow complete recovery. While numerous neuroprotective drugs trials have failed to demonstrate benefits for patients, they have provided interesting translational research lessons related to neurorestorative therapy mechanisms in stroke. Stroke damage is not limited to neurons but involve all brain cell type including the extracellular matrix in a "glio-neurovascular niche". Targeting a range of host brain cells, biotherapies such as growth factors and therapeutic cells, currently hold great promise as a regenerative medical strategy for stroke. These techniques can promote both neuroprotection and delayed neural repair through neuro-synaptogenesis, angiogenesis, oligodendrogliogenesis, axonal sprouting and immunomodulatory effects. Their complex mechanisms of action are interdependent and vary according to the particular growth factor or grafted cell type. For example, while "peripheral" stem or stromal cells can provide paracrine trophic support, neural stem/progenitor cells (NSC) or mature neurons can act as more direct neural replacements. With a wide therapeutic time window after stroke, biotherapies could be used to treat many patients. However, guidelines for selecting the optimal time window, and the best delivery routes and doses are still debated and the answers may depend on the chosen product and its expected mechanism including early neuroprotection, delayed neural repair, trophic systemic transient effects or graft survival and integration. Currently, the great variety of growth factors, cell sources and cell therapy products form a therapeutic arsenal that is available for stroke treatment. Their effective clinical use will require prior careful considerations regarding safety (e.g. tumorgenicity, immunogenicity), potential efficacy, cell

  11. Shareholder, stakeholder-owner or broad stakeholder maximization

    OpenAIRE

    Mygind, Niels

    2004-01-01

    With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating stakeholder-owner. Maximization of shareholder value is a special case of owner-maximization, and only under quite re-strictive assumptions shareholder maximization is larger or equal to stakeholder-owner...

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

    Science.gov (United States)

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

    2015-09-01

    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

  13. Electromyography Exposes Heterogeneity in Muscle Co-Contraction following Stroke

    Directory of Open Access Journals (Sweden)

    Caitlin L. Banks

    2017-12-01

    Full Text Available Walking after stroke is often described as requiring excessive muscle co-contraction, yet, evidence that co-contraction is a ubiquitous motor control strategy for this population remains inconclusive. Co-contraction, the simultaneous activation of agonist and antagonist muscles, can be assessed with electromyography (EMG but is often described qualitatively. Here, our goal is to determine if co-contraction is associated with gait impairments following stroke. Fifteen individuals with chronic stroke and nine healthy controls walked on an instrumented treadmill at self-selected speed. Surface EMGs were collected from the medial gastrocnemius (MG, soleus (SOL, and tibialis anterior (TA of each leg. EMG envelope amplitudes were assessed in three ways: (1 no normalization, (2 normalization to the maximum value across the gait cycle, or (3 normalization to maximal M-wave. Three co-contraction indices were calculated across each agonist/antagonist muscle pair (MG/TA and SOL/TA to assess the effect of using various metrics to quantify co-contraction. Two factor ANOVAs were used to compare effects of group and normalization for each metric. Co-contraction during the terminal stance (TSt phase of gait is not different between healthy controls and the paretic leg of individuals post-stroke, regardless of the metric used to quantify co-contraction. Interestingly, co-contraction was similar between M-max and non-normalized EMG; however, normalization does not impact the ability to resolve group differences. While a modest correlation is revealed between the amount of TSt co-contraction and walking speed, the relationship is not sufficiently strong to motivate further exploration of a causal link between co-contraction and walking function after stroke. Co-contraction does not appear to be a common strategy employed by individuals after stroke. We recommend exploration of alternative EMG analysis approaches in an effort to learn more about the causal

  14. Family History in Young Patients With Stroke.

    Science.gov (United States)

    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

    2015-07-01

    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: http://www.clinicaltrials.gov. Unique identifier: NCT00414583. © 2015 American Heart Association, Inc.

  15. Stroke Connection Magazine

    Science.gov (United States)

    ... controlling blood pressure over the long term than exercise, diet, not smoking and reducing alcohol consumption. Combo of Smaller Meds May Just Be the Dose to Lower Blood Pressure Combined smaller doses of blood pressure medications may be effective with ... Exercise May Lessen Stroke Severity Being physically active may ...

  16. Neurorehabilitation after Stroke

    Directory of Open Access Journals (Sweden)

    Rüdiger J. Seitz

    2013-08-01

    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.

  17. Ischemic strokes and migraine

    Energy Technology Data Exchange (ETDEWEB)

    Bousser, M.G.; Baron, J.C.; Chiras, J.

    1985-11-01

    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).

  18. The Optimal Golf Stroke

    DEFF Research Database (Denmark)

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

    2006-01-01

    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...

  19. Hypercholesterolemia, Stroke And Statins

    Directory of Open Access Journals (Sweden)

    Prabhakar S

    2005-01-01

    Full Text Available The link between serum cholesterol levels and the incidence of stroke still remain to be established. There are conflicting reports from a series of observational cohort studies. However, clinical trials with HMG CoA reductase inhibitors (also called statins have shown that cholesterol lowering therapy used in the primary and secondary prevention of myocardial infarction significantly reduced cardiovascular events including strokes. Meta analysis of trials with statins have shown a relative risk reduction in stroke of 12 to 48% in patients with coronary heart disease after MI. It has been postulated that the clinical action of statins is the result of pleiotropic / antiatherogenic effects rather than simply a reduction in cholesterol. The putative beneficial effect of statins in stroke involve blocking of macrophage and platelet activation, improvement of endothelial cell vasomotor function, enhancement of endothelial fibrinolytic function, immunosuppressive and anti-inflammatory action, inhibition of smooth muscle cell proliferation and particularly enhancement of endothelial nitric oxide synthase (eNOS.

  20. Stroke? Localized, otogenic meningitis!

    DEFF Research Database (Denmark)

    Ingolfsdottir, Harpa Maria; Thomasen, Per Caye

    2011-01-01

    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. Vacua of maximal gauged D=3 supergravities

    International Nuclear Information System (INIS)

    Fischbacher, T; Nicolai, H; Samtleben, H

    2002-01-01

    We analyse the scalar potentials of maximal gauged three-dimensional supergravities which reveal a surprisingly rich structure. In contrast to maximal supergravities in dimensions D≥4, all these theories possess a maximally supersymmetric (N=16) ground state with negative cosmological constant Λ 2 gauged theory, whose maximally supersymmetric groundstate has Λ = 0. We compute the mass spectra of bosonic and fermionic fluctuations around these vacua and identify the unitary irreducible representations of the relevant background (super)isometry groups to which they belong. In addition, we find several stationary points which are not maximally supersymmetric, and determine their complete mass spectra as well. In particular, we show that there are analogues of all stationary points found in higher dimensions, among them are de Sitter (dS) vacua in the theories with noncompact gauge groups SO(5, 3) 2 and SO(4, 4) 2 , as well as anti-de Sitter (AdS) vacua in the compact gauged theory preserving 1/4 and 1/8 of the supersymmetries. All the dS vacua have tachyonic instabilities, whereas there do exist nonsupersymmetric AdS vacua which are stable, again in contrast to the D≥4 theories

  2. Functional significance of ipsilesional motor deficits after unilateral stroke.

    Science.gov (United States)

    Chestnut, Caitilin; Haaland, Kathleen Y

    2008-01-01

    To determine whether ipsilesional motor skills, which have been related to independent functioning, are present chronically after unilateral stroke and are more common in people with apraxia than in those without apraxia. Observational cohort comparing the performance of an able-bodied control group, stroke patients with left- or right-hemisphere damage matched for lesion volume, and left-hemisphere stroke patients with and without ideomotor limb apraxia. Primary care Veterans Affairs and private medical center. Volunteer right-handed sample; stroke patients with left- or right-hemisphere damage about 4 years poststroke; a control group of demographically matched, able-bodied adults. Not applicable. Total time to perform the (1) Williams doors test and the (2) timed manual performance test (TMPT), which includes parts of the Jebsen-Taylor Hand Function Test. Ipsilesional motor deficits were present after left- or right-hemisphere stroke when using both measures, but deficits were consistently more common in patients with limb apraxia only for the TMPT. These findings add to a growing literature that suggests that ipsilesional motor deficits may have a functional impact in unilateral stroke patients, especially in patients with ideomotor limb apraxia.

  3. Thrombolysis in Postoperative Stroke.

    Science.gov (United States)

    Voelkel, Nicolas; Hubert, Nikolai Dominik; Backhaus, Roland; Haberl, Roman Ludwig; Hubert, Gordian Jan

    2017-11-01

    Intravenous thrombolysis (IVT) is beneficial in reducing disability in selected patients with acute ischemic stroke. There are numerous contraindications to IVT. One is recent surgery. The aim of this study was to analyze the safety of IVT in patients with postoperative stroke. Data of consecutive IVT patients from the Telemedical Project for Integrative Stroke Care thrombolysis registry (February 2003 to October 2014; n=4848) were retrospectively searched for keywords indicating preceding surgery. Patients were included if surgery was performed within the last 90 days before stroke. The primary outcome was defined as surgical site hemorrhage. Subgroups with major/minor surgery and recent/nonrecent surgery (within 10 days before IVT) were analyzed separately. One hundred thirty-four patients underwent surgical intervention before IVT. Surgery had been performed recently (days 1-10) in 49 (37%) and nonrecently (days 11-90) in 85 patients (63%). In 86 patients (64%), surgery was classified as major, and in 48 (36%) as minor. Nine patients (7%) developed surgical site hemorrhage after IVT, of whom 4 (3%) were serious, but none was fatal. One fatal bleeding occurred remotely from surgical area. Rate of surgical site hemorrhage was significantly higher in recent than in nonrecent surgery (14.3% versus 2.4%, respectively, odds ratio adjusted 10.73; 95% confidence interval, 1.88-61.27). Difference between patients with major and minor surgeries was less distinct (8.1% and 4.2%, respectively; odds ratio adjusted 4.03; 95% confidence interval, 0.65-25.04). Overall in-hospital mortality was 8.2%. Intracranial hemorrhage occurred in 9.7% and was asymptomatic in all cases. IVT may be administered safely in postoperative patients as off-label use after appropriate risk-benefit assessment. However, bleeding risk in surgical area should be taken into account particularly in patients who have undergone surgery shortly before stroke onset. © 2017 American Heart Association, Inc.

  4. Rehabilitating the Stroke Collection

    Directory of Open Access Journals (Sweden)

    Mary Grimmond

    2006-06-01

    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.

  5. Imaging of Hemorrhagic Stroke.

    Science.gov (United States)

    Hakimi, Ryan; Garg, Ankur

    2016-10-01

    Hemorrhagic stroke comprises approximately 15% to 20% of all strokes. This article provides readers with an understanding of the indications and significance of various neuroimaging techniques available for patients presenting with hemorrhagic strokes of distinct causes. The most common initial neuroimaging study is a noncontrast head CT, which allows for the identification of hemorrhage. Once an intracranial hemorrhage has been identified, the pattern of blood and the patient's medical history, neurologic examination, and laboratory studies lead the practitioner to pursue further neuroimaging studies to guide the medical, surgical, and interventional management. Given that hemorrhagic stroke constitutes a heterogeneous collection of diagnoses, the subsequent neuroimaging pathway necessary to better evaluate and care for these patients is variable based on the etiology.With an increasing incidence and prevalence of atrial fibrillation associated with the aging population and the introduction of three new direct factor Xa inhibitors and one direct thrombin inhibitor to complement vitamin K antagonists, oral anticoagulant use continues to increase. Patients on oral anticoagulants have a sevenfold to tenfold increased risk for intracerebral hemorrhage (ICH). Furthermore, patients who have an ICH associated with oral anticoagulant use have a higher mortality rate than those with primary ICH. Despite the reduced incidence of hypertension-related ICH over the past decade, it is expected that the incidence of ICH will continue to increase. Neuroimaging studies are integral to the identification of hemorrhagic stroke, determination of the underlying etiology, prevention of hematoma expansion, treatment of acute complications, and treatment of the underlying etiology, if indicated. Neuroimaging is essential for prognostication and thus directly impacts patient care.

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

    Science.gov (United States)

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

    2016-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Samar M Hatem

    2016-09-01

    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.

  8. An information maximization model of eye movements

    Science.gov (United States)

    Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

    2005-01-01

    We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

  9. Utility Maximization in Nonconvex Wireless Systems

    CERN Document Server

    Brehmer, Johannes

    2012-01-01

    This monograph formulates a framework for modeling and solving utility maximization problems in nonconvex wireless systems. First, a model for utility optimization in wireless systems is defined. The model is general enough to encompass a wide array of system configurations and performance objectives. Based on the general model, a set of methods for solving utility maximization problems is developed. The development is based on a careful examination of the properties that are required for the application of each method. The focus is on problems whose initial formulation does not allow for a solution by standard convex methods. Solution approaches that take into account the nonconvexities inherent to wireless systems are discussed in detail. The monograph concludes with two case studies that demonstrate the application of the proposed framework to utility maximization in multi-antenna broadcast channels.

  10. Neurochemical changes underpinning the development of adjunct therapies in recovery after stroke: A role for GABA?

    Science.gov (United States)

    Johnstone, Ainslie; Levenstein, Jacob M; Hinson, Emily L; Stagg, Charlotte J

    2017-01-01

    Stroke is a leading cause of long-term disability, with around three-quarters of stroke survivors experiencing motor problems. Intensive physiotherapy is currently the most effective treatment for post-stroke motor deficits, but much recent research has been targeted at increasing the effects of the intervention by pairing it with a wide variety of adjunct therapies, all of which aim to increase cortical plasticity, and thereby hope to maximize functional outcome. Here, we review the literature describing neurochemical changes underlying plasticity induction following stroke. We discuss methods of assessing neurochemicals in humans, and how these measurements change post-stroke. Motor learning in healthy individuals has been suggested as a model for stroke plasticity, and we discuss the support for this model, and what evidence it provides for neurochemical changes. One converging hypothesis from animal, healthy and stroke studies is the importance of the regulation of the inhibitory neurotransmitter GABA for the induction of cortical plasticity. We discuss the evidence supporting this hypothesis, before finally summarizing the literature surrounding the use of adjunct therapies such as non-invasive brain stimulation and SSRIs in post-stroke motor recovery, both of which have been show to influence the GABAergic system.

  11. Outcome Determinants of Stroke in a Brazilian Primary Stroke Center

    Directory of Open Access Journals (Sweden)

    Gustavo W. Kuster

    2014-01-01

    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.

  12. Stroke treatment outcomes in hospitals with and without Stroke Units.

    Science.gov (United States)

    Masjuan, J; Gállego Culleré, J; Ignacio García, E; Mira Solves, J J; Ollero Ortiz, A; Vidal de Francisco, D; López-Mesonero, L; Bestué, M; Albertí, O; Acebrón, F; Navarro Soler, I M

    2017-10-23

    Organisational capacity in terms of resources and care circuits to shorten response times in new stroke cases is key to obtaining positive outcomes. This study compares therapeutic approaches and treatment outcomes between traditional care centres (with stroke teams and no stroke unit) and centres with stroke units. We conducted a prospective, quasi-experimental study (without randomisation of the units analysed) to draw comparisons between 2 centres with stroke units and 4 centres providing traditional care through the neurology department, analysing a selection of agreed indicators for monitoring quality of stroke care. A total of 225 patients participated in the study. In addition, self-administered questionnaires were used to collect patients' evaluations of the service and healthcare received. Centres with stroke units showed shorter response times after symptom onset, both in the time taken to arrive at the centre and in the time elapsed from patient's arrival at the hospital to diagnostic imaging. Hospitals with stroke units had greater capacity to respond through the application of intravenous thrombolysis than centres delivering traditional neurological care. Centres with stroke units showed a better fit to the reference standards for stroke response time, as calculated in the Quick study, than centres providing traditional care through the neurology department. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Maximizing band gaps in plate structures

    DEFF Research Database (Denmark)

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard

    2006-01-01

    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......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...... theoretically and experimentally and the issue of finite size effects is addressed....

  14. Singularity Structure of Maximally Supersymmetric Scattering Amplitudes

    DEFF Research Database (Denmark)

    Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy

    2014-01-01

    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)....

  15. Learning curves for mutual information maximization

    International Nuclear Information System (INIS)

    Urbanczik, R.

    2003-01-01

    An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed [S. Becker and G. Hinton, Nature (London) 355, 161 (1992)]. For a generic data model, I show that in the large sample limit the structure in the data is recognized by mutual information maximization. For a more restricted model, where the networks are similar to perceptrons, I calculate the learning curves for zero-temperature Gibbs learning. These show that convergence can be rather slow, and a way of regularizing the procedure is considered

  16. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.

    1999-01-01

    . In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

  17. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H.; Skipper-Kallal, Laura M.; Jiang, Xiong; Harris-Love, Michelle L.; Zeng, Jinsheng

    2016-01-01

    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

  18. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    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

  19. Urinary Retention Associated with Stroke.

    Science.gov (United States)

    Umemura, Takeru; Ohta, Hirotsugu; Yokota, Akira; Yarimizu, Shiroh; Nishizawa, Shigeru

    Patients often exhibit urinary retention following a stroke. Various neuropathological and animal studies have implicated the medulla oblongata, pons, limbic system, frontal lobe as areas responsible for micturition control, although the exact area responsible for urinary retention after stroke is not clear. The purpose of this study was to identify the stroke area responsible for urinary retention by localizing the areas where strokes occur. We assessed 110 patients with cerebral infarction and 27 patients with cerebral hemorrhage (78 men, 59 women; mean age, 73.0 years) who had been admitted to our hospital between October, 2012 and September, 2013. We used computed tomography (CT) and magnetic resonance imaging (MRI) to investigate the stroke location, and evaluated whether post-stroke urinary retention occurred. Twelve (8.8%) of the 137 patients (7 men, 5 women; mean age, 78.8 years) exhibited urinary retention after a stroke. Stroke occurred in the right/left dominant hemisphere in 7 patients; nondominant hemisphere in 1; cerebellum in 3; and brainstem in 1. Strokes in the dominant hemisphere were associated with urinary retention (P = 0.0314), particularly in the area of the insula (P < 0.01). We concluded that stroke affecting the insula of the dominant hemisphere tends to cause urinary retention.

  20. Stroke Lesions in a Large Upper Limb Rehabilitation Trial Cohort Rarely Match Lesions in Common Preclinical Models

    Science.gov (United States)

    Edwardson, Matthew A.; Wang, Ximing; Liu, Brent; Ding, Li; Lane, Christianne J.; Park, Caron; Nelsen, Monica A.; Jones, Theresa A; Wolf, Steven L; Winstein, Carolee J; Dromerick, Alexander W.

    2017-01-01

    Background Stroke patients with mild-moderate upper extremity (UE) motor impairments and minimal sensory and cognitive deficits provide a useful model to study recovery and improve rehabilitation. Laboratory-based investigators use lesioning techniques for similar goals. Objective Determine whether stroke lesions in an UE rehabilitation trial cohort match lesions from the preclinical stroke recovery models used to drive translational research. Methods Clinical neuroimages from 297 participants enrolled in the Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) study were reviewed. Images were characterized based on lesion type (ischemic or hemorrhagic), volume, vascular territory, depth (cortical gray matter, cortical white matter, subcortical), old strokes, and leukoaraiosis. Lesions were compared with those of preclinical stroke models commonly used to study upper limb recovery. Results Among the ischemic stroke participants, median infarct volume was 1.8 mL, with most lesions confined to subcortical structures (61%) including the anterior choroidal artery territory (30%) and the pons (23%). Of ICARE participants, stroke patients, but they represent a clinically and scientifically important subgroup. Compared to lesions in general stroke populations and widely-studied animal models of recovery, ICARE participants had smaller, more subcortically-based strokes. Improved preclinical-clinical translational efforts may require better alignment of lesions between preclinical and human stroke recovery models. PMID:28337932

  1. Organizational issues in stroke treatment: The Swiss paradigm - Stroke units

    Directory of Open Access Journals (Sweden)

    Georgios K Matis

    2013-01-01

    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.

  2. Computed Tomography Perfusion Alberta Stroke Program Early Computed Tomography Score Is Associated with Hemorrhagic Transformation after Acute Cardioembolic Stroke

    Directory of Open Access Journals (Sweden)

    Lan Liu

    2017-11-01

    Full Text Available Alberta Stroke Program Early Computed Tomography (CT score (ASPECTS has been applied to CT perfusion (CTP with good interrater agreement to predict early ischemic stroke, and it can be useful in decision making in acute ischemic stroke. The aim of the present study was to assess the predictive value of CTP ASPECTS of hemorrhagic transformation (HT in acute cardioembolic stroke. This is a single-enter, retrospective study. All patients hospitalized with acute cardioembolic stroke from January 2008 to September 2013 were included. ASPECTS of baseline non-contrast CT, CTP maps of cerebral blood volume (CBV, cerebral blood flow, and mean transit time were collected from 52 consecutive patients with less than 12-h anterior circulation ischemic stroke. MRI scan was performed within 72 h of symptom onset after index stroke including T2*-weighted gradient echo to identify HT. For bleeding risk assessment, CTP and diffusion-weighted imaging ASPECTS were categorized into 0–7 or 8–10. Baseline characteristics, ASPCETS scores and HT were compared. Eighteen (34.6% patients had HT and four (7.7% developed symptomatic HT. On univariate analysis, the proportion of patients with CBV-ASPECTS 0–7 was significantly higher in HT patients as compared to patients without HT (44 versus 9%, P = 0.005. CBV ASPECTS 0–7 remained independent prognostic factors for HT after adjustment for clinical baseline variables. CBV ASPECTS could be of value to predict HT risk after acute cardioembolic stroke and may be a quick risk assessment approach before reperfusion therapy.

  3. Maximizing the Range of a Projectile.

    Science.gov (United States)

    Brown, Ronald A.

    1992-01-01

    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)

  4. Robust Utility Maximization Under Convex Portfolio Constraints

    International Nuclear Information System (INIS)

    Matoussi, Anis; Mezghani, Hanen; Mnif, Mohamed

    2015-01-01

    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

  5. Ehrenfest's Lottery--Time and Entropy Maximization

    Science.gov (United States)

    Ashbaugh, Henry S.

    2010-01-01

    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…

  6. Reserve design to maximize species persistence

    Science.gov (United States)

    Robert G. Haight; Laurel E. Travis

    2008-01-01

    We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based, metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and...

  7. Maximal indecomposable past sets and event horizons

    International Nuclear Information System (INIS)

    Krolak, A.

    1984-01-01

    The existence of maximal indecomposable past sets MIPs is demonstrated using the Kuratowski-Zorn lemma. A criterion for the existence of an absolute event horizon in space-time is given in terms of MIPs and a relation to black hole event horizon is shown. (author)

  8. Maximization of eigenvalues using topology optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2000-01-01

    to localized modes in low density areas. The topology optimization problem is formulated using the SIMP method. Special attention is paid to a numerical method for removing localized eigenmodes in low density areas. The method is applied to numerical examples of maximizing the first eigenfrequency, One example...

  9. Maximizing Resource Utilization in Video Streaming Systems

    Science.gov (United States)

    Alsmirat, Mohammad Abdullah

    2013-01-01

    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…

  10. A THEORY OF MAXIMIZING SENSORY INFORMATION

    NARCIS (Netherlands)

    Hateren, J.H. van

    1992-01-01

    A theory is developed on the assumption that early sensory processing aims at maximizing the information rate in the channels connecting the sensory system to more central parts of the brain, where it is assumed that these channels are noisy and have a limited dynamic range. Given a stimulus power

  11. Maximizing scientific knowledge from randomized clinical trials

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Atar, Dan; Pitt, Bertram

    2010-01-01

    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 vari...

  12. A Model of College Tuition Maximization

    Science.gov (United States)

    Bosshardt, Donald I.; Lichtenstein, Larry; Zaporowski, Mark P.

    2009-01-01

    This paper develops a series of models for optimal tuition pricing for private colleges and universities. The university is assumed to be a profit maximizing, price discriminating monopolist. The enrollment decision of student's is stochastic in nature. The university offers an effective tuition rate, comprised of stipulated tuition less financial…

  13. Logit Analysis for Profit Maximizing Loan Classification

    OpenAIRE

    Watt, David L.; Mortensen, Timothy L.; Leistritz, F. Larry

    1988-01-01

    Lending criteria and loan classification methods are developed. Rating system breaking points are analyzed to present a method to maximize loan revenues. Financial characteristics of farmers are used as determinants of delinquency in a multivariate logistic model. Results indicate that debt-to-asset and operating ration are most indicative of default.

  14. Role of Acute Lesion Topography in Initial Ischemic Stroke Severity and Long-Term Functional Outcomes.

    Science.gov (United States)

    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

    2015-09-01

    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.

  15. Left atrial appendage morphology in patients with suspected cardiogenic stroke without known atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    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.

  16. METABOLIC THERAPY IN PATIENTS WITH ISCHEMIC STROKE

    Directory of Open Access Journals (Sweden)

    L. B. Zavaliy

    2018-01-01

    Full Text Available The article shows the world experience of metabolic therapy use in the treatment of ischemic stroke. The issue still remains prominent. The reasonability of prescribing metabolic drugs is not completely clear, its effectiveness has not been fully proved, despite numerous studies which show only trends. The article presents an overview of the most popular drugs of different pharmacological groups with a metabolic effect which affect different parts of the ischemic cascade. Ethylmethylhydroxypyridine succinate and cytoflavin have predominantly antihypoxic effect, improve functional outcome and neurological functions, and normalize overall well-being and adaptation. Cerebrolysin is a complex of low molecular weight biologically active peptides derived from the pig’s brain. It has a multimodal effect on the brain, helps to reduce the volume of cerebral infarction, restores neurologic functions and improves the functional outcome. Cortexin is a mixture of cattle brain polypeptides, also has a complex action that provides the most complete reversion of neurological deficit, improves cognitive functions and the functional outcome, reduces the level of paroxysmal convulsive readiness and improves bioelectric activity of the brain. Citicoline is a precursor of cell membrane key ultrastructures, contributes to significant reduction in the volume of cortical brain damage, improves cholinergic transmission, which results in better clinical outcome, even despite the questionable impact on the neurological status. Choline Alfoscerate is a precursor of choline, and the use of the drug significantly limits the growth of the cerebral infarction area starting from the first day of therapy, leads to reversion of neurological symptoms and achievement of rehabilitation goals. Actovegin is deproteinized derivative of calf blood, activates metabolism in tissues, improves trophism and stimulates regeneration. In a large study, it was shown that Actovegin improved

  17. Developing maximal neuromuscular power: Part 1--biological basis of maximal power production.

    Science.gov (United States)

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2011-01-01

    This series of reviews focuses on the most important neuromuscular function in many sport performances, the ability to generate maximal muscular power. Part 1 focuses on the factors that affect maximal power production, while part 2, which will follow in a forthcoming edition of Sports Medicine, explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability of the neuromuscular system to generate maximal power is affected by a range of interrelated factors. Maximal muscular power is defined and limited by the force-velocity relationship and affected by the length-tension relationship. The ability to generate maximal power is influenced by the type of muscle action involved and, in particular, the time available to develop force, storage and utilization of elastic energy, interactions of contractile and elastic elements, potentiation of contractile and elastic filaments as well as stretch reflexes. Furthermore, maximal power production is influenced by morphological factors including fibre type contribution to whole muscle area, muscle architectural features and tendon properties as well as neural factors including motor unit recruitment, firing frequency, synchronization and inter-muscular coordination. In addition, acute changes in the muscle environment (i.e. alterations resulting from fatigue, changes in hormone milieu and muscle temperature) impact the ability to generate maximal power. Resistance training has been shown to impact each of these neuromuscular factors in quite specific ways. Therefore, an understanding of the biological basis of maximal power production is essential for developing training programmes that effectively enhance maximal power production in the human.

  18. Guidelines for acute ischemic stroke treatment: part II: stroke treatment

    Directory of Open Access Journals (Sweden)

    Sheila Cristina Ouriques Martins

    2012-11-01

    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 (www.sbdcv.com.br.

  19. Effect of maturation on hemodynamic and autonomic control recovery following maximal running exercise in highly-trained young soccer players

    Directory of Open Access Journals (Sweden)

    Martin eBuchheit

    2011-10-01

    Full Text Available The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly-trained young male soccer players (12-18 yr classified as pre-, circum- or post-peak height velocity (PHV performed a graded running test to exhaustion on a treadmill. Before (Pre and after (5th-10th min, Post exercise, heart rate (HR, stroke volume (SV, cardiac ouput (CO, arterial pressure (AP and total peripheral resistance (TPR were monitored. Parasympathetic (high-frequency [HFRR] of HR variability (HRV and baroreflex sensitivity [Ln BRS] and sympathetic activity (low-frequency [LFSAP] of systolic AP variability were estimated. Post-exercise blood lactate [La]b, the HR recovery (HRR time constant and parasympathetic reactivation (time varying HRV analysis were assessed. In all three groups, exercise resulted in increased HR, CO, AP and LFSAP (P<0.001, decreased SV, HFRR and Ln BRS (all P<0.001, and no change in TPRI (P=0.98. There was no ‘maturation x time’ interaction for any of the hemodynamic or autonomic variables (all P>0.22. After exercise, pre-PHV players displayed lower SV, CO and [La]b, faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La]b and Pre parasympathetic activity were the strongest predictors of HRR (r2=0.62, P<0.001. While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.

  20. Understanding Violations of Gricean Maxims in Preschoolers and Adults

    Directory of Open Access Journals (Sweden)

    Mako eOkanda

    2015-07-01

    Full Text Available This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants’ understanding of the following maxims was assessed: be informative (first maxim of quantity, avoid redundancy (second maxim of quantity, be truthful (maxim of quality, be relevant (maxim of relation, avoid ambiguity (second maxim of manner, and be polite (maxim of politeness. Sensitivity to violations of Gricean maxims increased with age: 4-year-olds’ understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner, and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.

  1. Hemichorea after ischemic stroke

    Directory of Open Access Journals (Sweden)

    Sadullah Saglam

    2016-03-01

    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

  2. Dysarthria following stroke: the patient's perspective on management and rehabilitation.

    Science.gov (United States)

    Brady, Marian C; Clark, Alexander M; Dickson, Sylvia; Paton, Gillian; Barbour, Rosaline S

    2011-10-01

    To explore the perceptions of people with stroke-related dysarthria in relation to the management and rehabilitation of dysarthria. Qualitative semi-structured interviews. Community setting Subjects: Twenty-four people with an acquired dysarthria as a result of a stroke in the previous three years. All were living at home at the time of the interview. None exhibited a co-existing impairment (for example, aphasia, apraxia or cognitive impairment) that might have contributed to their communicative experiences. Participants described the considerable efforts they made to maximize their communicative effectiveness prior to, and during, communicative interactions. Activities described included careful articulation and vocal projection as well as more inconspicuous strategies including pre-planning interactions, focused, effortful speech and word substitution. Communication was facilitated by a range of strategies including drafting, rehearsal, manoeuvring and ongoing monitoring and repair. Self-led speech rehabilitation activities were functionally based and often undertaken regularly. Some novel reading-aloud and speaking-aloud activities were described. The quantity and nature of inconspicuous, internalized, cognitive activities people with dysarthria engage in to maximize their communicative effectiveness should be considered in evaluating the impact of dysarthria following stroke. Focusing upon externally observable characteristics alone is insufficient. Challenging, functionally relevant, patient-focused activities, materials and targets are more likely to be perceived by the patient as relevant and worthwhile and are thus more likely to ensure adherence to recommended rehabilitation activities.

  3. Khat and stroke

    Directory of Open Access Journals (Sweden)

    Sanjay V Kulkarni

    2012-01-01

    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.

  4. Influence of statin therapy at time of stroke onset on functional outcome among patients with atrial fibrillation.

    Science.gov (United States)

    Ko, Darae; Thigpen, Jonathan L; Otis, James A; Forster, Kristen; Henault, Lori; Quinn, Emily; Tripodis, Yorghos; Berger, Peter B; Limdi, Nita; Hylek, Elaine M

    2017-01-15

    Statin pretreatment has been associated with reduced infarct volume in nonlacunar strokes. The effect of statins on functional outcomes of strokes related to atrial fibrillation (AF) is unknown. We aimed to define the influence of prestroke statin use on functional outcome in AF. We assembled a cohort of consecutive ischemic stroke patients from 2006 to 2010. All patients underwent CT or MRI and were adjudicated by site investigators. AF was confirmed by electrocardiogram in 100% of patients. Site neurologists blinded to the study hypothesis affirmed the type of stroke and assessed the severity of disability at the time of hospital discharge. The frequency of death at 30-days was calculated. Ischemic stroke (n=1030) resulted in a severe neurological deficit or death (modified Rankin scale ≥4) at 30days in 711 patients (69%). Using multivariable logistic regression models adjusting for factors associated with statin treatment and factors associated with functional outcome, prestroke statin use was associated with a 32% reduction in frequency of severe stroke (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.50-0.92; P=0.011). Other independent factors associated with severe stroke included older age, female sex, non-White race, diabetes mellitus, prior ischemic stroke, prior venous thromboembolism, and dementia. Ischemic strokes in AF are associated with high mortality and morbidity. Statin use at time of stroke onset among patients with AF was associated in this study with less severe stroke and warrant validation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Maximizing Macromolecule Crystal Size for Neutron Diffraction Experiments

    Science.gov (United States)

    Judge, R. A.; Kephart, R.; Leardi, R.; Myles, D. A.; Snell, E. H.; vanderWoerd, M.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    A challenge in neutron diffraction experiments is growing large (greater than 1 cu mm) macromolecule crystals. In taking up this challenge we have used statistical experiment design techniques to quickly identify crystallization conditions under which the largest crystals grow. These techniques provide the maximum information for minimal experimental effort, allowing optimal screening of crystallization variables in a simple experimental matrix, using the minimum amount of sample. Analysis of the results quickly tells the investigator what conditions are the most important for the crystallization. These can then be used to maximize the crystallization results in terms of reducing crystal numbers and providing large crystals of suitable habit. We have used these techniques to grow large crystals of Glucose isomerase. Glucose isomerase is an industrial enzyme used extensively in the food industry for the conversion of glucose to fructose. The aim of this study is the elucidation of the enzymatic mechanism at the molecular level. The accurate determination of hydrogen positions, which is critical for this, is a requirement that neutron diffraction is uniquely suited for. Preliminary neutron diffraction experiments with these crystals conducted at the Institute Laue-Langevin (Grenoble, France) reveal diffraction to beyond 2.5 angstrom. Macromolecular crystal growth is a process involving many parameters, and statistical experimental design is naturally suited to this field. These techniques are sample independent and provide an experimental strategy to maximize crystal volume and habit for neutron diffraction studies.

  6. On Maximal Hard-Core Thinnings of Stationary Particle Processes

    Science.gov (United States)

    Hirsch, Christian; Last, Günter

    2018-02-01

    The present paper studies existence and distributional uniqueness of subclasses of stationary hard-core particle systems arising as thinnings of stationary particle processes. These subclasses are defined by natural maximality criteria. We investigate two specific criteria, one related to the intensity of the hard-core particle process, the other one being a local optimality criterion on the level of realizations. In fact, the criteria are equivalent under suitable moment conditions. We show that stationary hard-core thinnings satisfying such criteria exist and are frequently distributionally unique. More precisely, distributional uniqueness holds in subcritical and barely supercritical regimes of continuum percolation. Additionally, based on the analysis of a specific example, we argue that fluctuations in grain sizes can play an important role for establishing distributional uniqueness at high intensities. Finally, we provide a family of algorithmically constructible approximations whose volume fractions are arbitrarily close to the maximum.

  7. Problematising risk in stroke rehabilitation.

    Science.gov (United States)

    Egan, Mary Y; Kessler, Dorothy; Ceci, Christine; Laliberté-Rudman, Debbie; McGrath, Colleen; Sikora, Lindsey; Gardner, Paula

    2016-11-01

    Following stroke, re-engagement in personally valued activities requires some experience of risk. Risk, therefore, must be seen as having positive as well as negative aspects in rehabilitation. Our aim was to identify the dominant understanding of risk in stroke rehabilitation and the assumptions underpinning these understandings, determine how these understandings affect research and practise, and if necessary, propose alternate ways to conceptualise risk in research and practise. Alvesson and Sandberg's method of problematisation was used. We began with a historical overview of stroke rehabilitation, and proceeded through five steps undertaken in an iterative fashion: literature search and selection; data extraction; syntheses across texts; identification of assumptions informing the literature and; generation of alternatives. Discussion of risk in stroke rehabilitation is largely implicit. However, two prominent conceptualisations of risk underpin both knowledge development and clinical practise: the risk to the individual stroke survivor of remaining dependent in activities of daily living and the risk that the health care system will be overwhelmed by the costs of providing stroke rehabilitation. Conceptualisation of risk in stroke rehabilitation, while implicit, drives both research and practise in ways that reinforce a focus on impairment and a generic, decontextualised approach to rehabilitation. Implications for rehabilitation Much of stroke rehabilitation practise and research seems to centre implicitly on two risks: risk to the patient of remaining dependent in ADL and risk to the health care system of bankruptcy due to the provision of stroke rehabilitation. The implicit focus on ADL dependence limits the ability of clinicians and researchers to address other goals supportive of a good life following stroke. The implicit focus on financial risk to the health care system may limit access to rehabilitation for people who have experienced either milder or

  8. Post-stroke cognitive impairments

    Directory of Open Access Journals (Sweden)

    Elena Anatolyevna Katunina

    2013-01-01

    Full Text Available Post-stroke cognitive impairments are common effects of stroke. Vascular cognitive impairments are characterized by the heterogeneity of the neuropsychological profile in relation to the site and pattern of stroke. Their common trait is the presence of dysregulation secondary to frontal dysfunction. The treatment of vascular cognitive impairments should be multimodality and aimed at stimulating neuroplasticity processes, restoring neurotransmitter imbalance, and preventing recurrent vascular episodes.

  9. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

    Directory of Open Access Journals (Sweden)

    Shazlin Shaharudin

    2014-12-01

    Full Text Available The slides ergometer (SE was an improvisation from fixed ergometer (FE to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE and fixed ergometers (FE. The laterality of muscle synergy was also examined. Surface electromyography activity, power output, heart rate, stroke length and stroke rate were analyzed from nine physically active subjects to assess the rowing performance. Physically active subjects, who were not specifically trained in rowing, were chosen to exclude the training effect on muscle synergy. Principal component analysis (PCA with varimax rotation was applied to extract muscle synergy. Three muscle synergies were sufficient to explain the majority of variance in SE (94.4 ± 2.2 % and FE (92.8 ± 1.7 %. Subjects covered more rowing distance, exerted greater power output and attained higher maximal heart rate during rowing on SE than on FE. The results proved the flexibility of muscle synergy to adapt to the mechanical constraints. Rowing on SE emphasized on bi-articular muscles contrary to rowing on FE which relied on cumulative effect of trunk and upper limb muscles during propulsive phase.

  10. Management of acute ischemic stroke. What is the role of tPA and antithrombotic agents?

    Science.gov (United States)

    Meschia, J F

    2000-05-15

    Every patient with acute stroke who presents to a medical center that has appropriate resources should undergo evaluation for intravenous tPA therapy. Such therapy should not be given unless the patient meets strict eligibility criteria based on clinical, radiographic, and laboratory data. Intra-arterial thrombolysis may be a promising alternative to intravenous tPA therapy, but it should still be regarded as experimental. Daily aspirin therapy should be initiated immediately in most patients who do not receive intravenous tPA therapy and after 24 hours in most patients who receive this treatment. Measures should be taken to prevent medical complications, such as aspiration pneumonia, deep vein thrombosis, contractures, and pressure sores. Early initiation of rehabilitation can maximize stroke recovery. Whenever feasible, institutions should have stroke teams or units to streamline care and provide expertise for patients with acute stroke.

  11. Epidermoid Causing Ischemic Stroke in the Brainstem

    Directory of Open Access Journals (Sweden)

    Raghvendra Ramdasi

    2014-01-01

    Full Text Available Intracranial tumors may rarely cause stroke. We report an epidermoid cyst causing stroke in a pediatric patient. We have also reviewed the literature and pathogenesis of stroke caused by intracranial tumors.

  12. Guide to Choosing Stroke Rehabilitation Services

    Science.gov (United States)

    National Stroke Association’s Guide to Choosing Stroke Rehabilitation Services Rehabilitation, often referred to as rehab, is an important part of stroke recovery. Through rehab, you:  Re-learn basic skills such ...

  13. Therapeutic hypothermia for acute stroke

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Weber, Uno Jakob; Kammersgaard, Lars Peter

    2003-01-01

    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...... 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...

  14. Burden of stroke in Cambodia.

    Science.gov (United States)

    Loo, Keat Wei; Gan, Siew Hua

    2013-08-01

    In Cambodia, stroke is not ranked among the top 10 leading causes of death, but infectious disease are among the top three leading causes of death. This finding could be attributed to a lack of awareness among Cambodians of the signs and symptoms of stroke or to poor reporting, incomplete data, lack of neurologists and neurosurgeons, or low accessibility to the hospitals. The only study of stroke in Cambodia is the Prevalence of Non-Communicable Disease Risk Factors in Cambodia survey, which identified several stroke-related risk factors in the population. Tobacco chewing or smoking is the main risk factor for stroke in Cambodia. Traditional therapies, such as oyt pleung (moxibustion) and jup (cupping), are widely practiced for stroke rehabilitation. In Cambodia, there are few neurologists and few important equipment, such as magnetic resonance imaging machines and computed tomography scanners. The Cambodian government should cooperate with the World Health Organization and the United Nations Children's Fund to attract foreign expertise and technologies to treat stroke patients. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

  15. Cerebrogenic tachyarrhythmia in acute stroke

    Directory of Open Access Journals (Sweden)

    A S Praveen Kumar

    2012-01-01

    Full Text Available The electrocardiac abnormalities following acute stroke are frequent and seen in both ischemic and hemorrhagic stroke. The changes seen in electrocardiogram (ECG consist of repolarization abnormalities such as ST elevation, ST depression, negative T waves, and QT prolongation. Among tachyarrhythmias, atrial fibrillation is the most common and occurrence of focal atrial tachycardia is very rare though any cardiac arrhythmias can follow acute stroke. We report a case of focal atrial tachycardia following acute ischemic stroke in 50-year-old female without structural heart disease, and their mechanisms and clinical implications.

  16. Stroke scale score and early prediction of outcome after stroke

    International Nuclear Information System (INIS)

    Ahmed, R.; Zuberi, F.Z.; Afsar, S.

    2004-01-01

    Objective: To evaluate the baseline National Institute of Health Stroke Scale (NIHSS) score as a predictor of functional outcome after ischemic stroke. Subjects and Methods: The study included 50 patients who presented to Civil Hospital, Karachi, during the study period with acute stroke and were evaluated with CT scan of brain. Only those patients were enrolled in the study that had acute ischemic stroke. The enrolled subjects were then evaluated for the neurological impairment using National Institute of Health Stroke Scale (NIHSS). The subjects were followed-up and their functional outcome was assessed using Barthel index (BI) on the 7th day of their admission. Results: Of the fifty patients enrolled in the study, 31 (62%) were males and 19 (38%) were females, with age ranging from 45 years to 95 years and a mean age of 59.9 years. Neurological impairment at presentation was assessed by NIHSS. The score ranged between 2 and 28. The functional outcome was evaluated on the 7th day using Barthel index (BI), which ranged from 0 to 80. NIHSS score was found to be a good predictor of functional outcome in patients with ischemic stroke (p<0.001). Other factors like gender, hypertension and heart disease did not affect the functional recovery in such patients. Various factors were found to be significant for early prediction of stroke recovery. The NIHSS score was the strongest predictor of outcome after ischemic stroke. Age at the time of the event was also found to be an important predictor for stroke recovery. Conclusion: The NIHSS score is a good predictor of patient's recovery after stroke. Assessing the patient's neurological impairment at first presentation of ischemic stroke can guide the physician regarding the prognosis and management plan. (author)

  17. Identification of stroke mimics among clinically diagnosed acute strokes.

    Science.gov (United States)

    Tuntiyatorn, Lojana; Saksornchai, Pichaya; Tunlayadechanont, Supoch

    2013-09-01

    Stroke is a clinically syndrome of a sudden onset of neurological deficit in a vascular cause. Stroke mimics is the non-vascular disorders with stroke-like clinical symptoms. It is important to distinguish true stroke from mimics since treatment plan may differ To determine the incidence of the stroke mimics and identify their etiologies. All non-contrast head CT of the patients with clinically diagnosed stroke who immediately received imaging upon arrival at the emergency department of the university hospital were retrospectively reviewed in 12-month period between January 1 and December 31, 2008. Medical records, laboratory results, MRI, and 6-month clinical follow-up records were reviewed for final diagnosis. Seven hundred four patients were included in this study, including 363 (51.5%) men and 341 (48.5%) women with range in age from 24 to 108 years. Amongst those, 417 (59.2%) were ischemic stroke, 80 (11.40%) were hemorrhagic stroke, 186 (26.4%) were stroke-mimics, and 21 (3%) were inconclusive. The etiologies among stroke-mimics were metabolic/intoxication (35, 18.8%), sepsis (28, 15.0%), seizure (21, 11.3%), syncope (20, 10.8%), subdural hemorrhage (14, 7.5%), vertigo (11, 6.0%), brain tumor (10, 5.30%), central nervous system infection (5, 2.7%), others (26, 14.0%), and unspecified (16, 8.6%). Incidence rates and etiologies of the stroke mimics were similar to the western reports. However the frequency of each mimic was not.

  18. Usability testing of two e-learning resources: methods to maximize potential for clinician use.

    Science.gov (United States)

    Menon, Anita; Korner-Bitensky, Nicol; Chignell, Mark; Straus, Sharon

    2012-04-01

    Rigorous usability testing of e-learn-ing resources is an important prerequisite to their wide-spread use among clinicians. This study demonstrates the application of an evidence-based approach to usability testing of two stroke-related e-learning resources (StrokEngine). 14 stroke rehabilitation clinicians (occupational therapists and physiotherapists) from Ontario, Canada participated in a 1.5 h in-person testing session. Clinicians navigated StrokEngine in search of information to answer questions on stroke assessment/intervention. Their search patterns were observed and clinicians provided verbal/written feedback about StrokEngine. Content analysis was used to generate themes and categorize them under two broad categories: facilitators and barriers to use. Five key facilitators and three key barriers to Strok-Engine use were identified and related to screen format, layout/organization, ease of navigation, quality of content, likelihood of using StrokEngine in the future, and system dysfunctions. All 14 clinicians were very or extremely satisfied with the layout/organization, quality and clinical relevance of the content, stating that they were likely to use StrokEngine in the future. All identified barriers from this study were addressed with website modifications in order to maximize the usability and navigability of StrokEngine. This rigorous methodology for usability testing can be applied during the design process of any e-learning resource.

  19. Stroke in Saudi children

    International Nuclear Information System (INIS)

    Salih, Mustafa A.; Al-Jarallah, Ahmed A.; Kentab, Anal Y.; Al-Nasser, Mohammad N.; Bahakim, Hassan M.; Kurban, Khadija M.; Zahraa, Jihad N.; Nasir, Ali A.; Abdel-Gader, Abdel-Galil M.; Alorainy, Ibrahim A.; Hassan, Hamdy H.; Kabiraj, Mohammad M.; Khoja, Waleed A.

    2006-01-01

    To describe the epidemiology and clinical features of stroke in a prospective and retrospective cohort of Saudi children and ascertain the causes, pathogenesis, and risk factors. The Retrospective Study Group (RSG) included children with stroke who were evaluated at the Division of Pediatric Neurology, or admitted to King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia during the period July 1992 to February 2001. The Prospective Study Group (PSG) included those seen between February 2001 and March 2003. During the combined study periods of 10 years and 7 months, 117 children (61 males and 56 females, aged one month-12 years) were evaluated; the majority (89%) of these were Saudis. The calculated annual hospital frequency rate of stroke was 27.1/100,000 of the pediatric (1month-12 years) population The mean age at onset of the initial stroke in the 104 Saudi children was 27.1 months (SD=39.3 months) median and median was 6 months. Ischemic strokes accounted for the majority of cases (76%). Large-vessel infarcts (LVI, 51.9%) were more common than small-vessel lacunar lesions (SVLL, 19.2%). Five patients (4.8%) had combined LVI and SVLL. Intracranial hemorrhage was less common (18.2%), whereas sinovenous thrombosis was diagnosed in 6 (5.8%) patients. A major risk factor was identified in 94 of 104 (89.4%) Saudi children. Significantly more hematologic disorders and coagulopathies were identified in the PSG compared to the RSG (p=0.001), reflecting a better yield following introduction of more comprehensive hematologic and cogulation laboratory tests during the prospective study period. Hematologic disorders were the most common risk factor (46.2%); presumed perinatal ischemic cerebral injury was risk factor in 23 children (22.1) and infectious and inflammatory disorders of the circulatory system in 18 (17.3%). Congenital and genetic cerebrovascular anomalies were the underlying cause in 7 patients (6.7%) and

  20. Refined reservoir description to maximize oil recovery

    International Nuclear Information System (INIS)

    Flewitt, W.E.

    1975-01-01

    To assure maximized oil recovery from older pools, reservoir description has been advanced by fully integrating original open-hole logs and the recently introduced interpretive techniques made available through cased-hole wireline saturation logs. A refined reservoir description utilizing normalized original wireline porosity logs has been completed in the Judy Creek Beaverhill Lake ''A'' Pool, a reefal carbonate pool with current potential productivity of 100,000 BOPD and 188 active wells. Continuous porosity was documented within a reef rim and cap while discontinuous porous lenses characterized an interior lagoon. With the use of pulsed neutron logs and production data a separate water front and pressure response was recognized within discrete environmental units. The refined reservoir description aided in reservoir simulation model studies and quantifying pool performance. A pattern water flood has now replaced the original peripheral bottom water drive to maximize oil recovery

  1. Maximal frustration as an immunological principle.

    Science.gov (United States)

    de Abreu, F Vistulo; Mostardinha, P

    2009-03-06

    A fundamental problem in immunology is that of understanding how the immune system selects promptly which cells to kill without harming the body. This problem poses an apparent paradox. Strong reactivity against pathogens seems incompatible with perfect tolerance towards self. We propose a different view on cellular reactivity to overcome this paradox: effector functions should be seen as the outcome of cellular decisions which can be in conflict with other cells' decisions. We argue that if cellular systems are frustrated, then extensive cross-reactivity among the elements in the system can decrease the reactivity of the system as a whole and induce perfect tolerance. Using numerical and mathematical analyses, we discuss two simple models that perform optimal pathogenic detection with no autoimmunity if cells are maximally frustrated. This study strongly suggests that a principle of maximal frustration could be used to build artificial immune systems. It would be interesting to test this principle in the real adaptive immune system.

  2. Derivative pricing based on local utility maximization

    OpenAIRE

    Jan Kallsen

    2002-01-01

    This paper discusses a new approach to contingent claim valuation in general incomplete market models. We determine the neutral derivative price which occurs if investors maximize their local utility and if derivative demand and supply are balanced. We also introduce the sensitivity process of a contingent claim. This process quantifies the reliability of the neutral derivative price and it can be used to construct price bounds. Moreover, it allows to calibrate market models in order to be co...

  3. Control of Shareholders’ Wealth Maximization in Nigeria

    OpenAIRE

    A. O. Oladipupo; C. O. Okafor

    2014-01-01

    This research focuses on who controls shareholder’s wealth maximization and how does this affect firm’s performance in publicly quoted non-financial companies in Nigeria. The shareholder fund was the dependent while explanatory variables were firm size (proxied by log of turnover), retained earning (representing management control) and dividend payment (representing measure of shareholders control). The data used for this study were obtained from the Nigerian Stock Exchange [NSE] fact book an...

  4. Definable maximal discrete sets in forcing extensions

    DEFF Research Database (Denmark)

    Törnquist, Asger Dag; Schrittesser, David

    2018-01-01

    Let  be a Σ11 binary relation, and recall that a set A is -discrete if no two elements of A are related by . We show that in the Sacks and Miller forcing extensions of L there is a Δ12 maximal -discrete set. We use this to answer in the negative the main question posed in [5] by showing...

  5. Dynamic Convex Duality in Constrained Utility Maximization

    OpenAIRE

    Li, Yusong; Zheng, Harry

    2016-01-01

    In this paper, we study a constrained utility maximization problem following the convex duality approach. After formulating the primal and dual problems, we construct the necessary and sufficient conditions for both the primal and dual problems in terms of FBSDEs plus additional conditions. Such formulation then allows us to explicitly characterize the primal optimal control as a function of the adjoint process coming from the dual FBSDEs in a dynamic fashion and vice versa. Moreover, we also...

  6. Chinese medicines and bioactive compounds for treatment of stroke.

    Science.gov (United States)

    Jayakumar, Thanasekaran; Elizebeth, Antoinet Ramola; Yen, Ting-lin; Sheu, Joen-rong

    2015-02-01

    Stroke is an important cause of mortality and morbidity worldwide but effective therapeutic strategy for the prevention of brain injury in patients with cerebral ischemia is lacking. Although tissue plasminogen activator has been used to treat stroke patients, this therapeutic strategy is confronted with ill side effects and is limited to patients within 3 h of a stroke. Due to the complexity of the events and the disappointing results from single agent trials, the combination of thrombolytic therapy and effective neural protection therapy may be an alternative strategy for patients with cerebral ischemia. Chinese medicine (CM) is the most widely practiced form of herbalism worldwide, as it is a sophisticated system of medical theory and practice that is specifically different from Western medicine. Most traditional therapeutic formulations consist of a combination of several drugs. The combination of multiple drugs is thought to maximize therapeutic efficacy by facilitating synergistic actions and preventing possible adverse effects while at the same time marking at multiple targets. CM has been labeled in ancient medicine systems as a treatment for various diseases associated with stroke. This review summarizes various CMs, bioactive compounds and their effects on cerebral ischemia.

  7. Single maximal versus combination punch kinematics.

    Science.gov (United States)

    Piorkowski, Barry A; Lees, Adrian; Barton, Gabor J

    2011-03-01

    The aim of this study was to determine the influence of punch type (Jab, Cross, Lead Hook and Reverse Hook) and punch modality (Single maximal, 'In-synch' and 'Out of synch' combination) on punch speed and delivery time. Ten competition-standard volunteers performed punches with markers placed on their anatomical landmarks for 3D motion capture with an eight-camera optoelectronic system. Speed and duration between key moments were computed. There were significant differences in contact speed between punch types (F(2,18,84.87) = 105.76, p = 0.001) with Lead and Reverse Hooks developing greater speed than Jab and Cross. There were significant differences in contact speed between punch modalities (F(2,64,102.87) = 23.52, p = 0.001) with the Single maximal (M+/- SD: 9.26 +/- 2.09 m/s) higher than 'Out of synch' (7.49 +/- 2.32 m/s), 'In-synch' left (8.01 +/- 2.35 m/s) or right lead (7.97 +/- 2.53 m/s). Delivery times were significantly lower for Jab and Cross than Hook. Times were significantly lower 'In-synch' than a Single maximal or 'Out of synch' combination mode. It is concluded that a defender may have more evasion-time than previously reported. This research could be of use to performers and coaches when considering training preparations.

  8. Formation Control for the MAXIM Mission

    Science.gov (United States)

    Luquette, Richard J.; Leitner, Jesse; Gendreau, Keith; Sanner, Robert M.

    2004-01-01

    Over the next twenty years, a wave of change is occurring in the space-based scientific remote sensing community. While the fundamental limits in the spatial and angular resolution achievable in spacecraft have been reached, based on today s technology, an expansive new technology base has appeared over the past decade in the area of Distributed Space Systems (DSS). A key subset of the DSS technology area is that which covers precision formation flying of space vehicles. Through precision formation flying, the baselines, previously defined by the largest monolithic structure which could fit in the largest launch vehicle fairing, are now virtually unlimited. Several missions including the Micro-Arcsecond X-ray Imaging Mission (MAXIM), and the Stellar Imager will drive the formation flying challenges to achieve unprecedented baselines for high resolution, extended-scene, interferometry in the ultraviolet and X-ray regimes. This paper focuses on establishing the feasibility for the formation control of the MAXIM mission. MAXIM formation flying requirements are on the order of microns, while Stellar Imager mission requirements are on the order of nanometers. This paper specifically addresses: (1) high-level science requirements for these missions and how they evolve into engineering requirements; and (2) the development of linearized equations of relative motion for a formation operating in an n-body gravitational field. Linearized equations of motion provide the ground work for linear formation control designs.

  9. Gradient Dynamics and Entropy Production Maximization

    Science.gov (United States)

    Janečka, Adam; Pavelka, Michal

    2018-01-01

    We compare two methods for modeling dissipative processes, namely gradient dynamics and entropy production maximization. Both methods require similar physical inputs-how energy (or entropy) is stored and how it is dissipated. Gradient dynamics describes irreversible evolution by means of dissipation potential and entropy, it automatically satisfies Onsager reciprocal relations as well as their nonlinear generalization (Maxwell-Onsager relations), and it has statistical interpretation. Entropy production maximization is based on knowledge of free energy (or another thermodynamic potential) and entropy production. It also leads to the linear Onsager reciprocal relations and it has proven successful in thermodynamics of complex materials. Both methods are thermodynamically sound as they ensure approach to equilibrium, and we compare them and discuss their advantages and shortcomings. In particular, conditions under which the two approaches coincide and are capable of providing the same constitutive relations are identified. Besides, a commonly used but not often mentioned step in the entropy production maximization is pinpointed and the condition of incompressibility is incorporated into gradient dynamics.

  10. Stroke: advances in medical therapy and acute stroke intervention.

    Science.gov (United States)

    Barrett, Kevin M; Lal, Brajesh K; Meschia, James F

    2015-10-01

    Evidence-based therapeutic options for stroke continue to emerge based on results from well-designed clinical studies. Ischemic stroke far exceeds hemorrhagic stroke in terms of prevalence and incidence, both in the USA and worldwide. The public health effect of reducing death and disability related to ischemic stroke justifies the resources that have been invested in identifying safe and effective treatments. The emergence of novel oral anticoagulants for ischemic stroke prevention in atrial fibrillation has introduced complexity to clinical decision making for patients with this common cardiac arrhythmia. Some accepted ischemic stroke preventative strategies, such as carotid revascularization for asymptomatic carotid stenosis, require reassessment, given advances in risk factor management, antithrombotic therapy, and surgical techniques. Intra-arterial therapy, particularly with stent retrievers after intravenous tissue plasminogen activator, has recently been demonstrated to improve functional outcomes and will require investment in system-based care models to ensure that effective treatments are received by patients in a timely fashion. The purpose of this review is to describe recent advances in medical and surgical approaches to ischemic stroke prevention and acute treatment. Results from recently published clinical trials will be highlighted along with ongoing clinical trials addressing key questions in ischemic stroke management and prevention where equipoise remains.

  11. Stroke subtypes and factors associated with ischemic stroke in ...

    African Journals Online (AJOL)

    Stroke subtypes assessed four OCSP (Oxfordshire Communi-. African Health Sciences Vol 15 Issue 1, March 2015. 68. 69 ty Stroke Project Classification) subtypes classification. 13 was used with lacunar circulation infarct (LACI) and total anterior (TACI), partial anterior (PACI), posterior. (POCI) circulation infarcts as non ...

  12. 'This stroke was sent…': Stroke-related illness concepts and ...

    African Journals Online (AJOL)

    Though there is evidence that stroke incidence is increasing even in low and middle income countries, there is no study of stroke-related illness concepts and HSB in Nigerians. Data from 960 educated Nigerians were analysed. Eight hundred and fifty four respondents (431 aged 20-40 years and 423 aged 41 years or ...

  13. Thromboxane biosynthesis in stroke and post-stroke dementia

    NARCIS (Netherlands)

    F. van Kooten (Fop)

    2002-01-01

    textabstractWith 25 to 30 thousand new patients per year and an incidence of 170/100.000, stroke is a major health problem in the Netherlands, as it is in other western countries. It accounts for almost I 0% of the annual death in the Netherlands. Approximately 80% of stroke is of ischemic

  14. Yoga for stroke rehabilitation.

    Science.gov (United States)

    Lawrence, Maggie; Celestino Junior, Francisco T; Matozinho, Hemilianna Hs; Govan, Lindsay; Booth, Jo; Beecher, Jane

    2017-12-08

    Stroke is a major health issue and cause of long-term disability and has a major emotional and socioeconomic impact. There is a need to explore options for long-term sustainable interventions that support stroke survivors to engage in meaningful activities to address life challenges after stroke. Rehabilitation focuses on recovery of function and cognition to the maximum level achievable, and may include a wide range of complementary strategies including yoga.Yoga is a mind-body practice that originated in India, and which has become increasingly widespread in the Western world. Recent evidence highlights the positive effects of yoga for people with a range of physical and psychological health conditions. A recent non-Cochrane systematic review concluded that yoga can be used as self-administered practice in stroke rehabilitation. To assess the effectiveness of yoga, as a stroke rehabilitation intervention, on recovery of function and quality of life (QoL). We searched the Cochrane Stroke Group Trials Register (last searched July 2017), Cochrane Central Register of Controlled Trials (CENTRAL) (last searched July 2017), MEDLINE (to July 2017), Embase (to July 2017), CINAHL (to July 2017), AMED (to July 2017), PsycINFO (to July 2017), LILACS (to July 2017), SciELO (to July 2017), IndMED (to July 2017), OTseeker (to July 2017) and PEDro (to July 2017). We also searched four trials registers, and one conference abstracts database. We screened reference lists of relevant publications and contacted authors for additional information. We included randomised controlled trials (RCTs) that compared yoga with a waiting-list control or no intervention control in stroke survivors. Two review authors independently extracted data from the included studies. We performed all analyses using Review Manager (RevMan). One review author entered the data into RevMan; another checked the entries. We discussed disagreements with a third review author until consensus was reached. We used

  15. Transcranial Direct Current Stimulation in Stroke Rehabilitation: A Review of Recent Advancements

    Science.gov (United States)

    Gomez Palacio Schjetnan, Andrea; Faraji, Jamshid; Metz, Gerlinde A.; Tatsuno, Masami; Luczak, Artur

    2013-01-01

    Transcranial direct current stimulation (tDCS) is a promising technique to treat a wide range of neurological conditions including stroke. The pathological processes following stroke may provide an exemplary system to investigate how tDCS promotes neuronal plasticity and functional recovery. Changes in synaptic function after stroke, such as reduced excitability, formation of aberrant connections, and deregulated plastic modifications, have been postulated to impede recovery from stroke. However, if tDCS could counteract these negative changes by influencing the system's neurophysiology, it would contribute to the formation of functionally meaningful connections and the maintenance of existing pathways. This paper is aimed at providing a review of underlying mechanisms of tDCS and its application to stroke. In addition, to maximize the effectiveness of tDCS in stroke rehabilitation, future research needs to determine the optimal stimulation protocols and parameters. We discuss how stimulation parameters could be optimized based on electrophysiological activity. In particular, we propose that cortical synchrony may represent a biomarker of tDCS efficacy to indicate communication between affected areas. Understanding the mechanisms by which tDCS affects the neural substrate after stroke and finding ways to optimize tDCS for each patient are key to effective rehabilitation approaches. PMID:23533955

  16. Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

    Directory of Open Access Journals (Sweden)

    Wei-Te Wang

    2014-01-01

    Full Text Available Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects’ exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. Results. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO2 peak was 1.21±0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Conclusions. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

  17. Nonparetic knee extensor strength is the determinant of exercise capacity of community-dwelling stroke survivors.

    Science.gov (United States)

    Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

    2014-01-01

    To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO₂ peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

  18. Cardiorespiratory Coordination in Repeated Maximal Exercise

    Directory of Open Access Journals (Sweden)

    Sergi Garcia-Retortillo

    2017-06-01

    Full Text Available Increases in cardiorespiratory coordination (CRC after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1 were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax, maximal oxygen consumption (VO2 max, or ventilatory threshold (VT, an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08 was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43 in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC

  19. Evaluation of left atrial function by multidetector computed tomography before left atrial radiofrequency-catheter ablation: Comparison of a manual and automated 3D volume segmentation method

    International Nuclear Information System (INIS)

    Wolf, Florian; Ourednicek, Petr; Loewe, Christian; Richter, Bernhard; Goessinger, Heinz David; Gwechenberger, Marianne; Plank, Christina; Schernthaner, Ruediger Egbert; Toepker, Michael; Lammer, Johannes; Feuchtner, Gudrun M.

    2010-01-01

    Introduction: The purpose of this study was to compare a manual and automated 3D volume segmentation tool for evaluation of left atrial (LA) function by 64-slice multidetector-CT (MDCT). Methods and materials: In 33 patients with paroxysmal atrial fibrillation a MDCT scan was performed before radiofrequency-catheter ablation. Atrial function (minimal volume (LAmin), maximal volume (LAmax), stroke volume (SV), ejection fraction (EF)) was evaluated by two readers using a manual and an automatic tool and measurement time was evaluated. Results: Automated LA volume segmentation failed in one patient due to low LA enhancement (103HU). Mean LAmax, LAmin, SV and EF were 127.7 ml, 93 ml, 34.7 ml, 27.1% by the automated, and 122.7 ml, 89.9 ml, 32.8 ml, 26.3% by the manual method with no significant difference (p > 0.05) and high Pearsons correlation coefficients (r = 0.94, r = 0.94, r = 0.82 and r = 0.85, p < 0.0001), respectively. The automated method was significantly faster (p < 0.001). Interobserver variability was low for both methods with Pearson's correlation coefficients between 0.98 and 0.99 (p < 0.0001). Conclusions: Evaluation of LA volume and function with 64-slice MDCT is feasible with a very low interobserver variability. The automatic method is as accurate as the manual method but significantly less time consuming permitting a routine use in clinical practice before RF-catheter ablation.

  20. Left ventricle expands maximally preceding end-diastole. Radionuclide ventriculography study

    International Nuclear Information System (INIS)

    Horinouchi, Osamu

    2002-01-01

    It has been considered that left ventricle (LV) expands maximally at the end-diastole. However, is it exactly coincident with this point? This study was aimed to determine whether the maximal expansion of LV coincides with the peak of R wave on electrocardiogram. Thirty-three angina pectoris patients with normal LV motion were examined using radionuclide ventriculography. Data were obtained from every 30 ms backward frame from the peak of R wave. All patients showed the time of maximal expansion preceded the peak of R wave. The intervals from the peak of R wave and the onset of P wave to maximal expansion of LV was 105±29 ms and 88±25 ms, respectively. This period corresponds to the timing of maximal excurtion of mitral valve by atrial contraction, and the centripetal motion of LV without losing its volume before end-diastole may be interpreted on account of the movement of mitral valve toward closure. These findings suggest that LV expands maximally between P and R wave after atrial contraction, preceding the peak of R wave thought conventionally as the end-diastole. (author)

  1. Analysis of Relationships between the Level of Errors in Leg and Monofin Movement and Stroke Parameters in Monofin Swimming

    Science.gov (United States)

    Rejman, Marek

    2013-01-01

    The aim of this study was to analyze the error structure in propulsive movements with regard to its influence on monofin swimming speed. The random cycles performed by six swimmers were filmed during a progressive test (900m). An objective method to estimate errors committed in the area of angular displacement of the feet and monofin segments was employed. The parameters were compared with a previously described model. Mutual dependences between the level of errors, stroke frequency, stroke length and amplitude in relation to swimming velocity were analyzed. The results showed that proper foot movements and the avoidance of errors, arising at the distal part of the fin, ensure the progression of swimming speed. The individual stroke parameters distribution which consists of optimally increasing stroke frequency to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Identification of key elements in the stroke structure based on the analysis of errors committed should aid in improving monofin swimming technique. Key points The monofin swimming technique was evaluated through the prism of objectively defined errors committed by the swimmers. The dependences between the level of errors, stroke rate, stroke length and amplitude in relation to swimming velocity were analyzed. Optimally increasing stroke rate to the maximal possible level that enables the stabilization of stroke length leads to the minimization of errors. Propriety foot movement and the avoidance of errors arising at the distal part of fin, provide for the progression of swimming speed. The key elements improving monofin swimming technique, based on the analysis of errors committed, were designated. PMID:24149742

  2. Pre-existing hypertension dominates γδT cell reduction in human ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Mateusz G Adamski

    Full Text Available T lymphocytes may play an important role in the evolution of ischemic stroke. Depletion of γδT cells has been found to abrogate ischemia reperfusion injury in murine stroke. However, the role of γδT cells in human ischemic stroke is unknown. We aimed to determine γδT cell counts and γδT cell interleukin 17A (IL-17A production in the clinical setting of ischemic stroke. We also aimed to determine the associations of γδT cell counts with ischemic lesion volume, measures of clinical severity and with major stroke risk factors. Peripheral blood samples from 43 acute ischemic stroke patients and 26 control subjects matched on race and gender were used for flow cytometry and complete blood count analyses. Subsequently, cytokine levels and gene expression were measured in γδT cells. The number of circulating γδT cells was decreased by almost 50% (p = 0.005 in the stroke patients. γδT cell counts did not correlate with lesion volume on magnetic resonance diffusion-weighted imaging or with clinical severity in the stroke patients, but γδT cells showed elevated levels of IL-17A (p = 0.048. Decreased γδT cell counts were also associated with older age (p = 0.004, pre-existing hypertension (p = 0.0005 and prevalent coronary artery disease (p = 0.03, with pre-existing hypertension being the most significant predictor of γδT cell counts in a multivariable analysis. γδT cells in human ischemic stroke are reduced in number and show elevated levels of IL-17A. A major reduction in γδT lymphocytes also occurs in hypertension and may contribute to the development of hypertension-mediated stroke and vascular disease.

  3. Stroke-Related Translational Research

    Science.gov (United States)

    Caplan, Louis R.; Arenillas, Juan; Cramer, Steven C.; Joutel, Anne; Lo, Eng H.; Meschia, James; Savitz, Sean; Tournier-Lasserve, Elizabeth

    2013-01-01

    Stroke-related translational research is multifaceted. Herein, we highlight genome-wide association studies and genetic studies of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, COL4A1 mutations, and cerebral cavernous malformations; advances in molecular biology and biomarkers; newer brain imaging research; and recovery from stroke emphasizing cell-based and other rehabilitative modalities. PMID:21555605

  4. [Sports and heat stroke].

    Science.gov (United States)

    Yuzawa, Itsuki; Miyake, Yasufumi; Aruga, Tohru

    2012-06-01

    We described Characteristic of the heat stroke in the sports activity in Japan. It was common in teenage men, and 15 years old had a peak with a man, the woman. Most patients did not need specific treatment. Many happened from the end of July on the outdoors around 3:00 p.m. in mid-August. There are many in order of baseball, football, tennis, and a basketball. Running and cycling had high severity of illness. Probably, grasp of an environmental condition, suitable sportswear, suitable hydration, and condition management are the best things as preventive measures.

  5. Perfusion differences on SPECT and PWI in patients with acute ischemic stroke

    International Nuclear Information System (INIS)

    Nuutinen, Juho; Liu, Yawu; Laakso, Mikko P.; Karonen, Jari O.; Vanninen, Esko J.; Kuikka, Jyrki T.; Aronen, Hannu J.; Vanninen, Ritva L.

    2009-01-01

    The purposes of the present study were to compare the flow defect volumes on perfusion-weighted magnetic resonance imaging (PWI) and 99m Tc-labeled ethylcysteinate dimer ( 99m Tc-ECD) single photon emission computed tomography (SPECT) at acute and subacute stages of ischemic stroke and to analyze the relationship between the detected flow defects on the two methods and neurological status and clinical outcomes. Perfusion defects on PWI and SPECT were measured within 48 h and on day 8 of the onset of stroke from 22 patients with their first-ever acute supratentorial ischemic stroke. The primary neurological status was evaluated prior to the imaging. Clinical outcome was assessed at 3 months after the onset of the stroke. The volumes of cerebral blood flow (CBF) defects did not differ between SPECT and PWI within the 48-h examinations. However, the volume of CBF defect was significantly larger on SPECT than on PWI on day 8 (p = 0.03). Within the 48-h examinations, the CBF defect volumes on SPECT and PWI were comparably related to the neurological status. On day 8, the CBF defect volume on SPECT showed higher correlation to the neurological status and more precisely predicted the clinical outcomes at 3 months than PWI. 99m TC-ECD-SPECT and PWI both have ability to detect cerebral hypoperfusion in patients with ischemic stroke but with some differences. The value of SPECT is more accurate in terms of the delayed outcome, such as prognosis and rehabilitation planning. (orig.)

  6. Incidence of DWI-positive stroke in patients with vertigo of unclear etiology, preliminary results.

    Science.gov (United States)

    Leker, Ronen R; Hur, Tamir Ben; Gomori, John M; Paniri, R; Eichel, Roni; Cohen, Jose E

    2013-03-01

    Acute vertigo may be secondary to stroke or to non-ischemic causes. Accurate identification of vertigo secondary to ischemia may lead to appropriate timely intervention that can minimize stroke-related damage and can help in tailoring the most appropriate individual therapy for affected patients. Diffusion weighted MRI (DWI) is very accurate for diagnosing stroke and we therefore aimed to test whether it can aid in making a correct diagnosis of vertigo secondary to stroke. All patients presenting with vertigo in which the diagnosis of stroke was considered underwent DWI only MRI. Data regarding the symptoms and neurological deficits, vascular risk factors, imaging findings, and outcomes was accrued. Patients with stroke on DWI were compared with those without ischemia. Between June 2010 and August 2011, 28 patients fulfilling the entry criteria were identified with a mean age of 62·2±12·8 (60% male). The final diagnosis was stroke in 11 patients (39%). Patients with stroke did not differ from those without stroke in their risk factor profile. However, patients with stroke more often tended to present with vertigo accompanied by other neurological symptoms (73% versus 12% respectively, P = 0·001). After adjusting for age and the presence of diabetes, the presence of multiple symptoms remained the only variable that was associated with a positive DWI scan (odds ratio: 30: 95% confidence interval: 2·6-349). Most patients with stroke had very mild strokes with a median admission NIHSS score of 3 and DWI lesion volumes >2 cm were found in only three patients. Most stroke patients made a good recovery (modified Rankin score ≤2 in seven of nine patients with 90 day data). The most common diagnosis in patients without stroke was of vertigo of peripheral origin (14/17). DWI only MRI can be used to rapidly screen patients presenting with vertigo and suspected vertebrobasilar stroke. The occurrence of vertigo in combination with other focal neurological symptoms may

  7. The imaging of ischaemic stroke

    International Nuclear Information System (INIS)

    Hoggard, Nigel; Wilkinson, Iain D.; Griffiths, Paul D.

    2001-01-01

    Stroke is a clinical syndrome of a rapidly developing focal neurological deficit that may be classified for practical purposes into ischaemic and haemorrhagic. The role of imaging is to exclude mimics of ischaemic stroke or intracranial haemorrhage and confirm the presence of an ischaemic stroke. Computed tomography (CT) remains the investigation of choice to exclude acute intracranial haemorrhage but diffusion weighted magnetic resonance (MR) has proved to be a sensitive method of detecting early ischaemic infarction. Perfusion weighted MR allows further assessment at the same examination that could help guide the clinician in the risk/benefit analysis of treatment with thrombolytics or neuroprotective agents under evaluation. This can also be achieved with CT. This review article discusses the imaging of ischaemic stroke, relating the pathophysiology of stroke to it. It deals separately in more detail with these newer MR techniques. Hoggard, N. et al. (2001)

  8. Circadian Variation Of Stroke Onset

    Directory of Open Access Journals (Sweden)

    Kamath vasantha

    2003-01-01

    Full Text Available Diurnal variations in various physiological and biochemical functions and certain pathological events like myocardial infarction and stroke have been documented. We studied prospectively one hundred and seven patients of acute onset stroke confirmed by computed tomography for the exact time of onset, risk factors and type of stroke. Patients who were unclear of time of onset and with a diagnosis of cerebral venous thrombosis or sub-arachnoid hemorrhage were excluded. Infarction was detected in 71 patients and hemorrhage in 33 patients. Men out numbered women (1:6:1. Hypertension was more frequent in hemorrhage in the morning time (5 AM-12 noon and more infarction between 12-6 pm. However there was no relation between the time of onset of stroke and various risk-factors of stroke.

  9. Auditory Hallucinations in Acute Stroke

    Directory of Open Access Journals (Sweden)

    Yair Lampl

    2005-01-01

    Full Text Available Auditory hallucinations are uncommon phenomena which can be directly caused by acute stroke, mostly described after lesions of the brain stem, very rarely reported after cortical strokes. The purpose of this study is to determine the frequency of this phenomenon. In a cross sectional study, 641 stroke patients were followed in the period between 1996–2000. Each patient underwent comprehensive investigation and follow-up. Four patients were found to have post cortical stroke auditory hallucinations. All of them occurred after an ischemic lesion of the right temporal lobe. After no more than four months, all patients were symptom-free and without therapy. The fact the auditory hallucinations may be of cortical origin must be taken into consideration in the treatment of stroke patients. The phenomenon may be completely reversible after a couple of months.

  10. Rehabilitative Games for Stroke Patients

    Directory of Open Access Journals (Sweden)

    A. Pyae

    2015-07-01

    Full Text Available Stroke is one of the major problems in medical and healthcare that can cause severe disability and death of patients especially for older population. Rehabilitation plays an important role in stroke therapy. However, most of the rehabilitative exercises are monotonous and tiring for the patients. For a particular time, they can easily get bored in doing these exercises. The role of patient’s motivation in rehabilitation is vital. Motivation and rehabilitative outcomes are strongly related. Digital games promise to help stroke patients to feel motivated and more engaged in rehabilitative training through motivational gameplay. Most of the commercial games available in the market are not well-designed for stroke patients and their motivational needs in rehabilitation. This study aims at understanding the motivational requirements of stroke patients in doing rehabilitative exercises and living in a post-stroke life. Based on the findings from the literature review, we report factors that can influence the stroke patients’ level of motivation such as social functioning, patient-therapist relationship, goal-setting, and music. These findings are insightful and useful for ideating and designing interactive motivation-driven games for stroke patients. The motivational factors of stroke patients in rehabilitation may help the game designers to design motivation-driven game contexts, contents, and gameplay. Moreover, these findings may also help healthcare professionals who concern stroke patient’s motivation in rehabilitative context. In this paper, we reported our Virtual Nursing Home (VNH concept and the games that we are currently developing and re-designing. Based on this literature review, we will present and test out the ideas how we can integrate these motivational factors in our future game design, development, and enhancement.

  11. Basics of acute stroke treatment

    International Nuclear Information System (INIS)

    Haass, A.

    2005-01-01

    Acute stroke presents an emergency that requires immediate referral to a specialized hospital, preferably with a stroke unit. Disability and mortality are reduced by 30% in patients treated in stroke units compared to those treated on regular wards, even if a specialized team is present on the ward. Systolic blood pressure may remain high at 200-220 mmHg in the acute phase and should not be lowered too quickly. Further guidelines for basic care include: optimal O 2 delivery, blood sugar levels below 100-150 mg%, and lowering body temperature below 37.5 C using physical means or drugs. Increased intracranial pressure should be treated by raising the upper body of the patient, administration of glycerol, mannitol, and/or sorbitol, artificial respiration, and special monitoring of Tris buffer. Decompressive craniectomy may be considered in cases of ''malignant'' media stroke and expansive cerebellar infarction. Fibrinolysis is the most effective stroke treatment and is twice as effective in the treatment of stroke than myocardial infarction. Fibrinolysis may be initiated within 3 h of a stroke in the anterior circulation. If a penumbra is detectable by ''PWI-DWI mismatch MRI,'' specialized hospitals may perform fibrinolysis up to 6 h after symptom onset. In cases of stroke in the basilar artery, fibrinolysis may be performed even later after symptom onset. Intra-arterial fibrinolysis is performed in these cases using rt-PA or urokinase. Follow-up treatment of stroke patients should not only address post-stroke depression and neuropsychological deficits, but also include patient education about risk factors such as high blood pressure, diabetes mellitus, and cardiac arrhythmias. (orig.) [de

  12. Postactivation potentiation biases maximal isometric strength assessment.

    Science.gov (United States)

    Lima, Leonardo Coelho Rabello; Oliveira, Felipe Bruno Dias; Oliveira, Thiago Pires; Assumpção, Claudio de Oliveira; Greco, Camila Coelho; Cardozo, Adalgiso Croscato; Denadai, Benedito Sérgio

    2014-01-01

    Postactivation potentiation (PAP) is known to enhance force production. Maximal isometric strength assessment protocols usually consist of two or more maximal voluntary isometric contractions (MVCs). The objective of this study was to determine if PAP would influence isometric strength assessment. Healthy male volunteers (n = 23) performed two five-second MVCs separated by a 180-seconds interval. Changes in isometric peak torque (IPT), time to achieve it (tPTI), contractile impulse (CI), root mean square of the electromyographic signal during PTI (RMS), and rate of torque development (RTD), in different intervals, were measured. Significant increases in IPT (240.6 ± 55.7 N·m versus 248.9 ± 55.1 N·m), RTD (746 ± 152 N·m·s(-1) versus 727 ± 158 N·m·s(-1)), and RMS (59.1 ± 12.2% RMSMAX  versus 54.8 ± 9.4% RMSMAX) were found on the second MVC. tPTI decreased significantly on the second MVC (2373 ± 1200 ms versus 2784 ± 1226 ms). We conclude that a first MVC leads to PAP that elicits significant enhancements in strength-related variables of a second MVC performed 180 seconds later. If disconsidered, this phenomenon might bias maximal isometric strength assessment, overestimating some of these variables.

  13. Gain maximization in a probabilistic entanglement protocol

    Science.gov (United States)

    di Lorenzo, Antonio; Esteves de Queiroz, Johnny Hebert

    Entanglement is a resource. We can therefore define gain as a monotonic function of entanglement G (E) . If a pair with entanglement E is produced with probability P, the net gain is N = PG (E) - (1 - P) C , where C is the cost of a failed attempt. We study a protocol where a pair of quantum systems is produced in a maximally entangled state ρm with probability Pm, while it is produced in a partially entangled state ρp with the complementary probability 1 -Pm . We mix a fraction w of the partially entangled pairs with the maximally entangled ones, i.e. we take the state to be ρ = (ρm + wUlocρpUloc+) / (1 + w) , where Uloc is an appropriate unitary local operation designed to maximize the entanglement of ρ. This procedure on one hand reduces the entanglement E, and hence the gain, but on the other hand it increases the probability of success to P =Pm + w (1 -Pm) , therefore the net gain N may increase. There may be hence, a priori, an optimal value for w, the fraction of failed attempts that we mix in. We show that, in the hypothesis of a linear gain G (E) = E , even assuming a vanishing cost C -> 0 , the net gain N is increasing with w, therefore the best strategy is to always mix the partially entangled states. Work supported by CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico, proc. 311288/2014-6, and by FAPEMIG, Fundação de Amparo à Pesquisa de Minas Gerais, proc. IC-FAPEMIG2016-0269 and PPM-00607-16.

  14. Strategies for stroke rehabilitation.

    Science.gov (United States)

    Dobkin, Bruce H

    2004-09-01

    Rehabilitation after hemiplegic stroke has typically relied on the training of patients in compensatory strategies. The translation of neuroscientific research into care has led to new approaches and renewed promise for better outcomes. Improved motor control can progress with task-specific training incorporating increased use of proximal and distal movements during intensive practice of real-world activities. Functional gains are incorrectly said to plateau by 3-6 months. Many patients retain latent sensorimotor function that can be realised any time after stroke with a pulse of goal-directed therapy. The amount of practice probably best determines gains for a given level of residual movement ability. Clinicians should encourage patients to build greater strength, speed, endurance, and precision of multijoint movements on tasks that increase independence and enrich daily activity. Imaging tools may help clinicians determine the capacity of residual networks to respond to a therapeutic approach and help establish optimal dose-response curves for training. Promising adjunct approaches include practice with robotic devices or in a virtual environment, electrical stimulation to increase cortical excitability during training, and drugs to optimise molecular mechanisms for learning. Biological strategies for neural repair may augment rehabilitation in the next decade.

  15. A biochemical marker panel in MRI-proven hyperacute ischemic stroke-a prospective study

    Directory of Open Access Journals (Sweden)

    Knauer Carolin

    2012-03-01

    Full Text Available Abstract Background Computer tomography (CT is still the fastest and most robust technique to rule out ICH in acute stroke. However CT-sensitivity for detection of ischemic stroke in the hyperacute phase is still relatively low. Moreover the validity of pure clinical judgment is diminished by several stroke imitating diseases (mimics. The "Triage® Stroke Panel", a biochemical multimarker assay, detects Brain Natriuretic Peptide (BNP, D-Dimers (DD, Matrix-Metalloproteinase-9 (MMP-9, and S100B protein and promptly generates a Multimarkerindex of these values (MMX. This index has been licensed for diagnostic purposes as it might increase the validity of the clinical diagnosis to differentiate between stroke imitating diseases and true ischemic strokes. Our aim was to prove whether the panel is a reliable indicating device for the diagnosis of ischemic stroke in a time window of 6 h to fasten the pre- and intrahospital pathway to fibrinolysis. Methods We investigated all consecutive patients admitted to our stroke unit during a time period of 5 months. Only patients with clinical investigation, blood sample collection and MRI within six hours from symptom onset were included. Values of biochemical markers were analyzed according to the results of diffusion weighted MR-imaging. In addition MMX-values in ischemic strokes were correlated with the TOAST-criteria. For statistical analysis the SAS Analyst software was used. Correlation coefficients were analyzed and comparison tests for two or more groups were performed. Statistical significance was assumed in case of p Results In total 174 patients were included into this study (n = 100 strokes, n = 49 mimics, n = 25 transitoric ischemic attacks. In patients with ischemic strokes the mean NIHSS was 7.6 ± 6.2, while the mean DWI-lesion volume was 20.6 ml (range 186.9 to 4.2 ml. According to the MMX or the individual markers there was no statistically significant difference between the group of ischemic

  16. Maximizing percentage depletion in solid minerals

    International Nuclear Information System (INIS)

    Tripp, J.; Grove, H.D.; McGrath, M.

    1982-01-01

    This article develops a strategy for maximizing percentage depletion deductions when extracting uranium or other solid minerals. The goal is to avoid losing percentage depletion deductions by staying below the 50% limitation on taxable income from the property. The article is divided into two major sections. The first section is comprised of depletion calculations that illustrate the problem and corresponding solutions. The last section deals with the feasibility of applying the strategy and complying with the Internal Revenue Code and appropriate regulations. Three separate strategies or appropriate situations are developed and illustrated. 13 references, 3 figures, 7 tables

  17. What currency do bumble bees maximize?

    Directory of Open Access Journals (Sweden)

    Nicholas L Charlton

    2010-08-01

    Full Text Available In modelling bumble bee foraging, net rate of energetic intake has been suggested as the appropriate currency. The foraging behaviour of honey bees is better predicted by using efficiency, the ratio of energetic gain to expenditure, as the currency. We re-analyse several studies of bumble bee foraging and show that efficiency is as good a currency as net rate in terms of predicting behaviour. We suggest that future studies of the foraging of bumble bees should be designed to distinguish between net rate and efficiency maximizing behaviour in an attempt to discover which is the more appropriate currency.

  18. New Maximal Two-distance Sets

    DEFF Research Database (Denmark)

    Lisonek, Petr

    1996-01-01

    A two-distance set in E^d is a point set X inthe d-dimensional Euclidean spacesuch that the distances between distinct points in Xassume only two different non-zero values. Based on results from classical distance geometry, we developan algorithm to classify, for a given dimension, all maximal...... (largest possible)two-distance sets in E^d.Using this algorithm we have completed the full classificationfor all dimensions less than or equal to 7, andwe have found one set in E^8 whosemaximality follows from Blokhuis' upper bound on sizes of s-distance sets.While in the dimensions less than or equal to 6...

  19. Maximizing policy learning in international committees

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2007-01-01

    , this article demonstrates that valuable lessons can be learned about policy learning, in practice and theoretically, by analysing the cooperation in the OMC committees. Using the Advocacy Coalition Framework as the starting point of analysis, 15 hypotheses on policy learning are tested. Among other things......, it is concluded that in order to maximize policy learning in international committees, empirical data should be made available to committees and provided by sources close to the participants (i.e. the Commission). In addition, the work in the committees should be made prestigious in order to attract well...

  20. Pouliot type duality via a-maximization

    International Nuclear Information System (INIS)

    Kawano, Teruhiko; Ookouchi, Yutaka; Tachikawa, Yuji; Yagi, Futoshi

    2006-01-01

    We study four-dimensional N=1Spin(10) gauge theory with a single spinor and N Q vectors at the superconformal fixed point via the electric-magnetic duality and a-maximization. When gauge invariant chiral primary operators hit the unitarity bounds, we find that the theory with no superpotential is identical to the one with some superpotential at the infrared fixed point. The auxiliary field method in the electric theory offers a satisfying description of the infrared fixed point, which is consistent with the better picture in the magnetic theory. In particular, it gives a clear description of the emergence of new massless degrees of freedom in the electric theory

  1. mStroke: "Mobile Stroke"-Improving Acute Stroke Care with Smartphone Technology.

    Science.gov (United States)

    Andrew, Benjamin Y; Stack, Colleen M; Yang, Julian P; Dodds, Jodi A

    2017-07-01

    This study aimed to evaluate the effect of method and time of system activation on clinical metrics in cases utilizing the Stop Stroke (Pulsara, Inc.) mobile acute stroke care coordination application. A retrospective cohort analysis of stroke codes at 12 medical centers using Stop Stroke from March 2013 to May 2016 was performed. Comparison of metrics (door-to-needle time [DTN] and door-to-CT time [DTC], and rate of DTN ≤ 60 minutes [goal DTN]) was performed between subgroups based on method (emergency medical service [EMS] versus emergency department [ED]) and time of activation. Effects were adjusted for confounders (age, sex, National Institutes of Health Stroke Scale [NIHSS] score) using multiple linear and logistic regression. The final dataset included 2589 cases. Cases activated by EMS were more severe (median NIHSS score 8 versus 4, P technology provides unique insight into acute stroke codes. Activation of mobile electronic stroke coordination in the field appears to promote a more expedited and successful care process. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  2. Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

    Science.gov (United States)

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2011-02-01

    This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

  3. Pre-stroke use of beta-blockers does not affect ischaemic stroke severity and outcome

    NARCIS (Netherlands)

    De Raedt, S.; Haentjens, P.; De Smedt, A.; Brouns, R.; Uyttenboogaart, Maarten; Luijckx, G. J.; De Keyser, J.

    Background and purpose: It is unclear whether pre-stroke beta-blockers use may influence stroke outcome. This study evaluates the independent effect of pre-stroke use of beta-blockers on ischaemic stroke severity and 3 months functional outcome. Methods: Pre-stroke use of beta-blockers was

  4. What about self-management post-stroke? Challenges for stroke survivors, spouses and professionals

    NARCIS (Netherlands)

    Satink, A.J.H.

    2016-01-01

    Self-management post-stroke is challenging for many persons after a stroke. In this thesis is explored how stroke survivors, spouses and professionals perceived self-management post-stroke and how the process of self-management post-stroke evolved over time. The following studies are conducted: a

  5. Association of serial biochemical markers with acute ischemic stroke: the National Institute of Neurological Disorders and Stroke recombinant tissue plasminogen activator Stroke Study.

    Science.gov (United States)

    Jauch, Edward C; Lindsell, Christopher; Broderick, Joseph; Fagan, Susan C; Tilley, Barbara C; Levine, Steven R

    2006-10-01

    Biochemical markers of acute neuronal injury may aid in the diagnosis and management of acute ischemic stroke. Serum samples from the National Institute for Neurological Disorders and Stroke (NINDS) recombinant tissue plasminogen activator Stroke Study were analyzed for the presence of 4 biochemical markers of neuronal, glial, and endothelial cell injury. These biochemical markers, myelin basic protein (MBP), neuron-specific enolase (NSE), S100beta, and soluble thrombomodulin, were studied for an association with initial stroke severity, infarct volume, and functional outcome. In the original NINDS study, serum samples were drawn from all patients on presentation to the Emergency Department and at approximately 2 and 24 hours after initiation of study therapy. In this analysis, stored serum samples were available for 359 patients; 107 patients had samples for all 3 time points. Serum marker concentrations were measured by ELISA techniques. We examined the relation between serum concentrations of each marker and the degree of baseline neurological deficit, functional outcome, and infarct size on computed tomography at 24 hours and the effect of fibrinolytic therapy. Higher 24-hour peak concentrations of MBP, NSE, and S100beta were associated with higher National Institutes of Health Stroke Scale baseline scores (r=0.186, P<0.0001; r=0.117, P=0.032; and r=0.263, P<0.0001, respectively). Higher peak concentrations of MBP and S100beta (r=0.209, P<0.0001; r=0.239, P<0.0001) were associated with larger computed tomography lesion volumes. Patients with favorable outcomes had smaller changes in MBP and S100beta (P<0.05) concentrations in the first 24 hours. Soluble thrombomodulin was not associated with any severity or outcome measure. This study corroborates previous work demonstrating correlations of MBP, NSE, and S100beta with clinical and radiographic features in acute stroke. Despite significantly better outcomes in the tissue plasminogen activator-treated group, we

  6. Stroke, social support and the partner

    NARCIS (Netherlands)

    Kruithof, WJ

    2016-01-01

    Stroke is one of the most common conditions with about 45,000 people suffering a first stroke in the Netherlands each year. Although survival after stroke has increased in recent decades, a substantial part of the survivors of stroke remain physically or cognitively impaired and in need of support

  7. Basic Land Drills for Swimming Stroke Acquisition

    Science.gov (United States)

    Zhang, Peng

    2014-01-01

    Teaching swimming strokes can be a challenging task in physical education. The purpose of the article is to introduce 12 on land drills that can be utilized to facilitate the learning of swimming strokes, including elementary back stroke, sidestroke, front crawl, back stroke, breaststroke, and butterfly. Each drill consists of four components…

  8. Early infection and prognosis after acute stroke

    DEFF Research Database (Denmark)

    Kammersgaard, L P; Jørgensen, H S; Reith, J

    2001-01-01

    Infection is a frequent complication in the early course of acute stroke and may adversely affect stroke outcome. In the present study, we investigate early infection developing in patients within 3 days of admission to the hospital and its independent relation to recovery and stroke outcome....... In addition, we identify predictors for early infections, infection subtypes, and their relation to initial stroke severity....

  9. Maximization techniques for oilfield development profits

    International Nuclear Information System (INIS)

    Lerche, I.

    1999-01-01

    In 1981 Nind provided a quantitative procedure for estimating the optimum number of development wells to emplace on an oilfield to maximize profit. Nind's treatment assumed that there was a steady selling price, that all wells were placed in production simultaneously, and that each well's production profile was identical and a simple exponential decline with time. This paper lifts these restrictions to allow for price fluctuations, variable with time emplacement of wells, and production rates that are more in line with actual production records than is a simple exponential decline curve. As a consequence, it is possible to design production rate strategies, correlated with price fluctuations, so as to maximize the present-day worth of a field. For price fluctuations that occur on a time-scale rapid compared to inflation rates it is appropriate to have production rates correlate directly with such price fluctuations. The same strategy does not apply for price fluctuations occurring on a time-scale long compared to inflation rates where, for small amplitudes in the price fluctuations, it is best to sell as much product as early as possible to overcome inflation factors, while for large amplitude fluctuations the best strategy is to sell product as early as possible but to do so mainly on price upswings. Examples are provided to show how these generalizations of Nind's (1981) formula change the complexion of oilfield development optimization. (author)

  10. Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque

    Directory of Open Access Journals (Sweden)

    Masahiro Oomura

    2015-05-01

    Full Text Available We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

  11. Cognitive performance after ischaemic stroke

    Directory of Open Access Journals (Sweden)

    Maria Gabriela R. Ferreira

    Full Text Available Cognitive impairment after stroke affects the patient recovery process. Therefore, the identification of factors associated with cognitive outcomes is important since it allows risk profiles of stroke survivors to be determined. OBJECTIVE: To assess cognitive outcome of stroke outpatients and investigate associations among clinical and demographic variables, vascular risk factors, depression symptoms and functional ability; and to describe the neuropsychological profile of these patients. METHODS: A cross-sectional design study was conducted. Subjects who suffered a first-ever ischaemic stroke 6 to 10 months prior to data collection underwent neuropsychological assessment and screening for depressive symptoms and functional ability. The outcome "cognitive performance" was analyzed considering two groups: "cognitive impairment" and "no cognitive impairment". RESULTS: There was a statistically significant association between cognitive impairment and female gender, age, stroke severity and functional ability. Regarding neuropsychological profile, the cognitive impairment group exhibited more generalized deficits in attention, visuospatial organization, verbal functions and verbal memory domains compared to the community control group. CONCLUSION: The occurrence of cognitive impairment among patients was high, especially in women, older participants, individuals with more severe stroke, and greater impairment in functional ability. Multiple cognitive domains are affected and this may hamper recovery and negatively impact independence and quality of life after stroke.

  12. Atrial fibrillation and risk of stroke

    DEFF Research Database (Denmark)

    Christiansen, Christine Benn; Gerds, Thomas A.; Olesen, Jonas Bjerring

    2016-01-01

    AIM: Although the relation between stroke risk factors and stroke in patients with atrial fibrillation (AF) has been extensively examined, only few studies have explored the association of AF and the risk of ischaemic stroke/systemic thromboembolism/transient ischaemic attack (stroke.......5-10.6), and 15.4% (14.5-16.4), respectively. CONCLUSIONS: Stroke/TE/TIA risk was particularly increased when prior stroke/TE/TIA was present. Atrial fibrillation is associated with an increase in risk of stroke/TE/TIA in the absence of other risk factors but only a moderate increase in risk when other risk...

  13. Stroke rehabilitation: recent advances and future therapies.

    LENUS (Irish Health Repository)

    Brewer, L

    2012-09-27

    Despite advances in the acute management of stroke, a large proportion of stroke patients are left with significant impairments. Over the coming decades the prevalence of stroke-related disability is expected to increase worldwide and this will impact greatly on families, healthcare systems and economies. Effective neuro-rehabilitation is a key factor in reducing disability after stroke. In this review, we discuss the effects of stroke, principles of stroke rehabilitative care and predictors of recovery. We also discuss novel therapies in stroke rehabilitation, including non-invasive brain stimulation, robotics and pharmacological augmentation. Many trials are currently underway, which, in time, may impact on future rehabilitative practice.

  14. Stroke Unit: General principles and standards

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Topçuoğlu

    2015-04-01

    Full Text Available Evidence-based medicinal methods have convincingly shown that stroke unit approach reduces mortality and disability rates, improves the quality of life and economic burden resulting from acute ischemic and hemorrhagic stroke. Any contemporary stroke system of care cannot be successful without putting the stroke unit concept in the center of its organization. Stroke units are the main elements of primary and comprehensive stroke centers. As a modernization process, this article focuses on practical issues and suggestions related to integration of the stroke unit approach to a regionally organized stroke system of care for perusal by not only national health authorities and service providers, but also neurologists. Stroke unit quality metrics revisited herein are of critical importance for hospitals establishing or renovating primary and comprehensive stroke centers.

  15. Experimental acute thrombotic stroke in baboons

    International Nuclear Information System (INIS)

    Del Zoppo, G.J.; Copeland, B.R.; Harker, L.A.; Waltz, T.A.; Zyroff, J.; Hanson, S.R.; Battenberg, E.

    1986-01-01

    To study the effects of antithrombotic therapy in experimental stroke, we have characterized a baboon model of acute cerebrovascular thrombosis. In this model an inflatable silastic balloon cuff has been implanted by transorbital approach around the right middle cerebral artery (MCA), proximal to the take-off of the lenticulostriate arteries (LSA). Inflation of the balloon for 3 hours in six animals produced a stereotypic sustained stroke syndrome characterized by contralateral hemiparesis. An infarction volume of 3.2 +/- 1.5 cm3 in the ipsilateral corpus striatum was documented by computerized tomographic (CT) scanning at 10 days following stroke induction and 3.9 +/- 1.9 cm3 (n = 4) at 14 days by morphometric neuropathologic determinations of brain specimens fixed in situ by pressure-perfusion with 10% buffered formalin. Immediate pressure-perfusion fixation following deflation of the balloon was performed in 16 additional animals given Evans blue dye intravenously prior to the 3 hour MCA balloon occlusion. Light microscopy and transmission electron microscopy consistently confirmed the presence of thrombotic material occluding microcirculatory branches of the right LSA in the region of Evans blue stain, but not those of the contralateral corpus striatum. When autologous 111In-platelets were infused intravenously in four animals from the above group prior to the transient 3 hour occlusion of the right MCA, gamma scintillation camera imaging of each perfused-fixed whole brain demonstrated the presence of a single residual focus of 111In-platelet activity involving only the Evans blue-stained right corpus striatum. Focal right hemispheric activity was equivalent to 0.55 +/- 0.49 ml of whole blood, and the occlusion score derived from histologic examination of the microcirculation of the Evans blue-stained corpus striatum averaged 34.8 +/- 2.8

  16. Frequencies of circulating B- and T-lymphocytes as indicators for stroke outcomes

    Directory of Open Access Journals (Sweden)

    Wang Y

    2017-10-01

    Full Text Available Yanling Wang,1 Jihong Liu,1 Xuemei Wang,1 Zongjian Liu,2 Fengwu Li,1 Fenghua Chen,3 Xiaokun Geng,1 Zhili Ji,2 Huishan Du,1 Xiaoming Hu1,3 1Department of Neurology, China-America Institute of Neuroscience, 2Central Laboratory, Beijing Luhe Hospital, Capital Medical University, Beijing, People’s Republic of China; 3Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Background: Stroke has high mortality and morbidity. Biomarkers are required for to predict stroke outcomes, which could help clinicians to provide rationale approaches for patient management. The dynamic changes in circulating immune cells have been reported in stroke patients and animal models of stroke.Aim: The aim of this study was to explore biomarkers to predict stroke outcomes by investigating the relationship between the frequencies of circulating immune cells and stroke outcomes.Methods: In all, 50 acute ischemic stroke (AIS patients were enrolled. Their blood samples were collected upon hospital admission and on day 1 and day 7 after stroke, and the leukocyte subsets were analyzed by flow cytometry. The dynamic changes in some types of immune cells in the AIS course and their correlation with clinical parameters were analyzed. Blood samples from 123 age- and gender-matched healthy subjects were used as controls.Results: The proportions of T-lymphocytes and NK cells in stroke patients were significantly lower than in healthy controls. The frequencies of B- and T-lymphocytes were negatively correlated with stroke severity at onset, including neurological deficits as assessed by National Institutes of Health Stroke Scale (NIHSS, and infarct volume as measured by the diffusion-weighted images (DWIs of magnetic resonance (MR. Logistic regression analysis showed that modified Rankin scale (mRs scores, a score system for the long-term neurological dysfunctions, were negatively correlated

  17. Heat stroke in Hajj ceremonies

    Directory of Open Access Journals (Sweden)

    Sadr Sh

    1995-04-01

    Full Text Available Three hundred and seventy seven patients with different degrees of heat stroke were treated by the haji medical team of the Islamic Republic of Iran in 1371 (1992. Studies were carried out on sex of the patients, time and intensity of occurance and the vital signs after a medical examination. The most important method of treatment employed for intense heat stroke was iced bath. This procedure leads to 64.5% of patients being treated in te specific heat stroke unit and 35% were sent to a general hospital ward for furthur treatment. Morbidity and mortality were seen in less than 0.5% of the patients.

  18. Chuanxiong preparations for preventing stroke.

    Science.gov (United States)

    Yang, Xunzhe; Zeng, Xiaoxi; Wu, Taixiang

    2010-01-20

    Stroke is a major healthcare problem and is one of the leading causes of death and serious long-term disability. Prevention of stroke is considered an important strategy. Chuanxiong is traditionally used in China in the treatment and prevention of stroke. In recent years, Chinese researchers have developed new patented Chuanxiong preparations. To assess the effects and safety of Chuanxiong preparations in preventing stroke in high-risk adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2008, Issue 1), MEDLINE (1950 to March 2008), EMBASE (1980 to March 2008), AMED (1985 to March 2008), Chinese Biomedical Database (CBM) (1975 to March 2008), China National Knowledge Infrastructure (CNKI) (1994 to March 2008), and the VIP Database (1989 to March 2008). Trials registers were searched for ongoing studies. No language restrictions were applied. Randomised controlled trials (RCTs) studying the effects of Chuanxiong preparations in preventing stroke were included. Three reviewers independently selected studies for inclusion and two reviewers independently extracted data. Authors of identified RCTs were telephoned to confirm the randomisation procedure. Outcomes assessed included: stroke, composite cardiovascular outcomes, changes in cardiovascular and cerebrovascular haemodynamic indices and adverse events. Peto odds ratio (OR) with 95% confidence intervals (CI) were calculated for dichotomous variables and mean differences for continuous outcomes. Three RCTs (5042 participants) were included. One higher quality study (4415 participants) compared Nao-an capsule with aspirin for primary prevention in high-risk stroke populations. Nao-an capsule appeared to reduce the incidence of stroke compared with aspirin (OR 0.56 95% CI 0.33 to 0.96). One study of low methodological quality indicated that a self-prepared Xifenwan tablet reduced the incidence of stroke in people with transient ischaemia attack (TIA) (OR 0.18, 95% CI 0.04 to 0.78). The

  19. Plasma cytokines in acute stroke

    DEFF Research Database (Denmark)

    Christensen, Hanne Krarup; Boysen, Gudrun; Christensen, Erik

    2011-01-01

    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...... months later plasma levels of interleukin 1 beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), interleukin-1 receptor antagonist (IL-1RA), interleukin 6 (IL-6), interleukin 10 (IL-10), soluble tumor necrosis factor receptor 1 (sTNF-R1), and soluble tumor necrosis factor receptor 2 (sTNF-R2) were...

  20. Improving Stroke Management through Specialized Stroke Units in ...

    African Journals Online (AJOL)

    Alasia Datonye

    seeking help early enough are also highlighted. Conclusion: The evidence ... Stroke as defined by the World Health Organization. (WHO) is a syndrome of ... parenteral nutrition and prevention of constipation by using stool softeners. The case ...

  1. Post-stroke depression among stroke survivors attending two ...

    African Journals Online (AJOL)

    African Health Sci

    The Patient Health Questionnaire-9 was used to assess for depression ... Stroke is a common neurological problem and one of ... students. Nsambya hospital is a private not for profit, church aided institution, while Mulago is a government.

  2. Strokes in young adults: epidemiology and prevention

    Directory of Open Access Journals (Sweden)

    Smajlović D

    2015-02-01

    Full Text Available Dževdet Smajlović Department of Neurology, University Clinical Centre Tuzla, School of Medicine, University of Tuzla, Bosnia and Herzegovina Abstract: Strokes in young adults are reported as being uncommon, comprising 10%–15% of all stroke patients. However, compared with stroke in older adults, stroke in the young has a disproportionately large economic impact by leaving victims disabled before their most productive years. Recent publications report an increased incidence of stroke in young adults. This is important given the fact that younger stroke patients have a clearly increased risk of death compared with the general population. The prevalence of standard modifiable vascular risk factors in young stroke patients is different from that in older patients. Modifiable risk factors for stroke, such as dyslipidemia, smoking, and hypertension, are highly prevalent in the young stroke population, with no significant difference in geographic, climatic, nutritional, lifestyle, or genetic diversity. The list of potential stroke etiologies among young adults is extensive. Strokes of undetermined and of other determined etiology are the most common types among young patients according to TOAST (Trial of Org 10172 in Acute Stroke Treatment criteria. Prevention is the primary treatment strategy aimed at reducing morbidity and mortality related to stroke. Therefore, primary prevention is very important with regard to stroke in young adults, and aggressive treatment of risk factors for stroke, such as hypertension, smoking, and dyslipidemia, is essential. The best form of secondary stroke prevention is directed toward stroke etiology as well as treatment of additional risk factors. However, there is a lack of specific recommendations and guidelines for stroke management in young adults. In conclusion, strokes in young adults are a major public health problem and further research, with standardized methodology, is needed in order to give us more

  3. Recovery of Dysphagia in Lateral Medullary Stroke

    OpenAIRE

    Gupta, Hitesh; Banerjee, Alakananda

    2014-01-01

    Lateral medullary stroke is typically associated with increased likelihood of occurrence of dysphagia and exhibits the most severe and persistent form. Worldwide little research exists on dysphagia in brainstem stroke. An estimated 15% of all patients admitted to stroke rehabilitation units experience a brainstem stroke out of which about 47% suffer from dysphagia. In India, a study showed that 22.3% of posterior circulation stroke patients develop dysphagia. Dearth of literature on dysphagia...

  4. Secondary stroke prevention: challenges and solutions

    OpenAIRE

    Esenwa, Charles; Gutierrez, Jose

    2015-01-01

    Charles Esenwa, Jose GutierrezDepartment of Neurology, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USAAbstract: Stroke is the leading cause of disability in the USA and a major cause of mortality worldwide. One out of four strokes is recurrent. Secondary stroke prevention starts with deciphering the most likely stroke mechanism. In general, one of the main goals in stroke reduction is to control vascular risk factors such as hypertension, diabetes, dy...

  5. Ipsilesional upper limb performance in stroke individuals: relationship among outcomes of different tests used to assess hand function

    Directory of Open Access Journals (Sweden)

    Bianca Pinto Cunha

    Full Text Available Abstract Introduction: Stroke individuals have sensorimotor repercussions on their ipsilesional upper limb. Therefore, it is important to use tests that allow an adequate assessment and follow-up of such deficits. Physical and occupational therapists commonly use maximal grip strength tests to assess the functional condition of stroke individuals. However, one could ask whether a single test is able to characterize the hand function in this population. Objective: The aim of this study was to investigate the relationship among outcomes of different tests frequently used to describe the function of the hand in the ipsilesional upper limb of stroke individuals. Methods: Twenty-two stroke individuals performed four hand function tests: maximal handgrip strength (HGSMax, maximal pinch grip strength (PGSMax, Jebsen-Taylor Hand Function Test (JTHFT and Nine Hole Peg Test (9-HPT. All tests were performed with the ipsilesional hand. Pearson's correlation analyses were performed. Results: the results indicated a moderate and positive relationship between HGSMax and JTHFT (r = 0.50 and between JTHFT and 9-HPT (r = 0.55. Conclusion: We conclude that the existence of only moderate relationships between test outcomes demonstrates the need to use at least two instruments to better describe the ipsilesional hand function of stroke individuals.

  6. [Post-stroke apathy].

    Science.gov (United States)

    López-Dóriga Bonnardeaux, Pedro; Andrino Díaz, Nuria

    2016-01-01

    Apathy is a motivational disturbance that can be defined as a quantitative reduction of goal-directed behaviour. Patients present with loss of motivation, concern, interest, and emotional response, resulting in a loss of initiative, decreased interaction with their environment, and a reduced interest in social life. Apathy not only appears to be common in stroke patients, but it has also been related to a wide range of negative consequences for the patients and their caregivers, including poor functional recovery, loss of social independence, and caregiver distress. Clear definition and consensus diagnostic criteria for apathy are needed to accomplish an accurate assessment and an individualised treatment plan. Although there have been reports of successful behavioural therapy treatment of apathetic states, there is a paucity of controlled clinical trials on the efficacy of apathetic behaviours using pharmacotherapy. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

  7. Association between seizures after ischemic stroke and stroke outcome

    OpenAIRE

    Xu, Tao; Ou, Shu; Liu, Xi; Yu, Xinyuan; Yuan, Jinxian; Huang, Hao; Chen, Yangmei

    2016-01-01

    Abstract A systematic review and meta-analysis were performed to investigate a potential association between post-ischemic stroke seizures (PISS) and subsequent ischemic stroke (IS) outcome. A systematic search of two electronic databases (Medline and Embase) was conducted to identify studies that explored an association between PISS and IS outcome. The primary and secondary IS outcomes of interest were mortality and disability, respectively, with the latter defined as a score of 3 to 5 on th...

  8. Stroke code improves intravenous thrombolysis administration in acute ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Chih-Hao Chen

    Full Text Available Timely intravenous (IV thrombolysis for acute ischemic stroke is associated with better clinical outcomes. Acute stroke care implemented with "Stroke Code" (SC may increase IV tissue plasminogen activator (tPA administration. The present study aimed to investigate the impact of SC on thrombolysis.The study period was divided into the "pre-SC era" (January 2006 to July 2010 and "SC era" (August 2010 to July 2013. Demographics, critical times (stroke symptom onset, presentation to the emergency department, neuroimaging, thrombolysis, stroke severity, and clinical outcomes were recorded and compared between the two eras.During the study period, 5957 patients with acute ischemic stroke were admitted; of these, 1301 (21.8% arrived at the emergency department within 3 h of stroke onset and 307 (5.2% received IV-tPA. The number and frequency of IV-tPA treatments for patients with an onset-to-door time of <3 h increased from the pre-SC era (n = 91, 13.9% to the SC era (n = 216, 33.3% (P<0.001. SC also improved the efficiency of IV-tPA administration; the median door-to-needle time decreased (88 to 51 min, P<0.001 and the percentage of door-to-needle times ≤60 min increased (14.3% to 71.3%, P<0.001. The SC era group tended to have more patients with good outcome (modified Rankin Scale ≤2 at discharge (49.5 vs. 39.6%, P = 0.11, with no difference in symptomatic hemorrhage events or in-hospital mortality.The SC protocol increases the percentage of acute ischemic stroke patients receiving IV-tPA and decreases door-to-needle time.

  9. Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke.

    Science.gov (United States)

    Sporns, Peter; Schmidt, Rene; Minnerup, Jens; Dziewas, Rainer; Kemmling, André; Dittrich, Ralf; Zoubi, Tarek; Heermann, Philipp; Cnyrim, Christian; Schwindt, Wolfram; Heindel, Walter; Niederstadt, Thomas; Hanning, Uta

    2016-01-01

    Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone. © 2016 S. Karger AG, Basel.

  10. Shareholder, stakeholder-owner or broad stakeholder maximization

    DEFF Research Database (Denmark)

    Mygind, Niels

    2004-01-01

    With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating...... including the shareholders of a company. Although it may be the ultimate goal for Corporate Social Responsibility to achieve this kind of maximization, broad stakeholder maximization is quite difficult to give a precise definition. There is no one-dimensional measure to add different stakeholder benefits...... not traded on the mar-ket, and therefore there is no possibility for practical application. Broad stakeholder maximization instead in practical applications becomes satisfying certain stakeholder demands, so that the practical application will be stakeholder-owner maximization un-der constraints defined...

  11. Usefulness of perfusion MR imaging in hyperacute ischemic stroke

    International Nuclear Information System (INIS)

    Park, Ji Hoon; Kim, Jae Hyoung; Shin, Tae Min; Lee, Eun Ja; Chung, Sung Hoon; Choi, Nack Cheon; Lim, Byeong Hoon; Kim, In One

    1998-01-01

    Perfusion MR imaging is a new technique for the assessment of acute ischemic stroke. The aim of this study was to evaluate the usefulness of this imaging in hyperacute ischemic stroke in comparison with conventional CT and MR imaging. Eight patients presenting the symptoms of acute ischemic stroke due to middle cerebral artery occlusion were included in this study. Within 2 hours of initial CT scan and 6 hours after the onset of stroke, perfusion MR imaging was performed in all patients using a single-section dynamic contrast-enhanced T2*-weighted imager in conjunction with conventional routine MR imaging and MR angiography. Cerebral blood volume (CBV) maps were then obtained from dynamic MR imaging data by using numerical integration techniques. The findings of CBV maps were compared with those of initial and follow-up CT or MR images. The findings of CBV maps were obviously abnormal in all patients, as compared with normal or focal subtle abnormal findings seen on initial CT and MR images. CBV in the occluded arterial territory was lower in all eight patients;two had focal regions of increased CBV within the affected territory, indicating reperfusion hyperemia. In all patients, regions of abnormal CBV were eventually converted to infarctions on follow-up images. Perfusion MR imaging was useful for the evaluation of hemodynamic change occurring during cerebral perfusion in hyperacute ischemic stroke, and prediction of the final extent of infarction. These results suggest that pertusion MR imaging can play an important role in the diagnosis and management of hyperacute ischemic stroke.=20

  12. Stroke Laterality Bias in the Management of Acute Ischemic Stroke.

    Science.gov (United States)

    McCluskey, Gavin; Wade, Carrie; McKee, Jacqueline; McCarron, Peter; McVerry, Ferghal; McCarron, Mark O

    2016-11-01

    Little is known of the impact of stroke laterality on the management process and outcome of patients with acute ischemic stroke (AIS). Consecutive patients admitted to a general hospital over 1 year with supratentorial AIS were eligible for inclusion in the study. Baseline characteristics and risk factors, delays in hospital admission, imaging, intrahospital transfer to an acute stoke unit, stroke severity and classification, length of hospital admission, as well as 10-year mortality were measured and compared among right and left hemisphere AIS patients. There were 141 patients (77 men, 64 women; median age 73 [interquartile range 63-79] years), There were 71 patients with left hemisphere AIS and 70 with right hemisphere AIS. Delays to hospital admission from stroke onset to neuroimaging were similar among right and left hemisphere AIS patients. Delay in transfer to an acute stroke unit (ASU) following hospital admission was on average 14 hours more for right hemisphere compared to left hemisphere AIS patients (P = .01). Laterality was not associated with any difference in 10-year survival. Patients with mild and nondominant AIS merit particular attention to minimize their intrahospital transfer time to an ASU. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  13. First results with two light flavours of quarks with maximally twisted mass

    International Nuclear Information System (INIS)

    Jansen, K.; Urbach, C.

    2006-10-01

    We report on first results of an ongoing effort to simulate lattice QCD with two degenerate flavours of quarks by means of the twisted mass formulation tuned to maximal twist. By utilising recent improvements of the HMC algorithm, pseudo-scalar masses well below 300 MeV are simulated on volumes L 3 .T with T=2L and L>2 fm and at values of the lattice spacing a f =2+1+1 flavours are discussed. (orig.)

  14. Left ventricular pressure and volume data acquisition and analysis using LabVIEW.

    Science.gov (United States)

    Cassidy, S C; Teitel, D F

    1997-03-01

    To automate analysis of left ventricular pressure-volume data, we used LabVIEW to create applications that digitize and display data recorded from conductance and manometric catheters. Applications separate data into cardiac cycles, calculate parallel conductance, and calculate indices of left ventricular function, including end-systolic elastance, preload-recruitable stroke work, stroke volume, ejection fraction, stroke work, maximum and minimum derivative of ventricular pressure, heart rate, indices of relaxation, peak filling rate, and ventricular chamber stiffness. Pressure-volume loops can be graphically displayed. These analyses are exported to a text-file. These applications have simplified and automated the process of evaluating ventricular function.

  15. Maximizing Lumen Gain With Directional Atherectomy.

    Science.gov (United States)

    Stanley, Gregory A; Winscott, John G

    2016-08-01

    To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization. © The Author(s) 2016.

  16. Primordial two-component maximally symmetric inflation

    Science.gov (United States)

    Enqvist, K.; Nanopoulos, D. V.; Quirós, M.; Kounnas, C.

    1985-12-01

    We propose a two-component inflation model, based on maximally symmetric supergravity, where the scales of reheating and the inflation potential at the origin are decoupled. This is possible because of the second-order phase transition from SU(5) to SU(3)×SU(2)×U(1) that takes place when φ≅φcinflation at the global minimum, and leads to a reheating temperature TR≅(1015-1016) GeV. This makes it possible to generate baryon asymmetry in the conventional way without any conflict with experimental data on proton lifetime. The mass of the gravitinos is m3/2≅1012 GeV, thus avoiding the gravitino problem. Monopoles are diluted by residual inflation in the broken phase below the cosmological bounds if φcUSA.

  17. Distributed-Memory Fast Maximal Independent Set

    Energy Technology Data Exchange (ETDEWEB)

    Kanewala Appuhamilage, Thejaka Amila J.; Zalewski, Marcin J.; Lumsdaine, Andrew

    2017-09-13

    The Maximal Independent Set (MIS) graph problem arises in many applications such as computer vision, information theory, molecular biology, and process scheduling. The growing scale of MIS problems suggests the use of distributed-memory hardware as a cost-effective approach to providing necessary compute and memory resources. Luby proposed four randomized algorithms to solve the MIS problem. All those algorithms are designed focusing on shared-memory machines and are analyzed using the PRAM model. These algorithms do not have direct efficient distributed-memory implementations. In this paper, we extend two of Luby’s seminal MIS algorithms, “Luby(A)” and “Luby(B),” to distributed-memory execution, and we evaluate their performance. We compare our results with the “Filtered MIS” implementation in the Combinatorial BLAS library for two types of synthetic graph inputs.

  18. Quench dynamics of topological maximally entangled states.

    Science.gov (United States)

    Chung, Ming-Chiang; Jhu, Yi-Hao; Chen, Pochung; Mou, Chung-Yu

    2013-07-17

    We investigate the quench dynamics of the one-particle entanglement spectra (OPES) for systems with topologically nontrivial phases. By using dimerized chains as an example, it is demonstrated that the evolution of OPES for the quenched bipartite systems is governed by an effective Hamiltonian which is characterized by a pseudospin in a time-dependent pseudomagnetic field S(k,t). The existence and evolution of the topological maximally entangled states (tMESs) are determined by the winding number of S(k,t) in the k-space. In particular, the tMESs survive only if nontrivial Berry phases are induced by the winding of S(k,t). In the infinite-time limit the equilibrium OPES can be determined by an effective time-independent pseudomagnetic field Seff(k). Furthermore, when tMESs are unstable, they are destroyed by quasiparticles within a characteristic timescale in proportion to the system size.

  19. Maximizing policy learning in international committees

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2007-01-01

    , this article demonstrates that valuable lessons can be learned about policy learning, in practice and theoretically, by analysing the cooperation in the OMC committees. Using the Advocacy Coalition Framework as the starting point of analysis, 15 hypotheses on policy learning are tested. Among other things......In the voluminous literature on the European Union's open method of coordination (OMC), no one has hitherto analysed on the basis of scholarly examination the question of what contributes to the learning processes in the OMC committees. On the basis of a questionnaire sent to all participants......, it is concluded that in order to maximize policy learning in international committees, empirical data should be made available to committees and provided by sources close to the participants (i.e. the Commission). In addition, the work in the committees should be made prestigious in order to attract well...

  20. Lovelock black holes with maximally symmetric horizons

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hideki; Willison, Steven; Ray, Sourya, E-mail: hideki@cecs.cl, E-mail: willison@cecs.cl, E-mail: ray@cecs.cl [Centro de Estudios CientIficos (CECs), Casilla 1469, Valdivia (Chile)

    2011-08-21

    We investigate some properties of n( {>=} 4)-dimensional spacetimes having symmetries corresponding to the isometries of an (n - 2)-dimensional maximally symmetric space in Lovelock gravity under the null or dominant energy condition. The well-posedness of the generalized Misner-Sharp quasi-local mass proposed in the past study is shown. Using this quasi-local mass, we clarify the basic properties of the dynamical black holes defined by a future outer trapping horizon under certain assumptions on the Lovelock coupling constants. The C{sup 2} vacuum solutions are classified into four types: (i) Schwarzschild-Tangherlini-type solution; (ii) Nariai-type solution; (iii) special degenerate vacuum solution; and (iv) exceptional vacuum solution. The conditions for the realization of the last two solutions are clarified. The Schwarzschild-Tangherlini-type solution is studied in detail. We prove the first law of black-hole thermodynamics and present the expressions for the heat capacity and the free energy.