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  1. Assessment of cardiac function and hemodynamics in children and adults with right ventricular pressure overload: role of cardiac magnetic resonance imaging

    NARCIS (Netherlands)

    Romeih, Soha

    2014-01-01

    Accumulating evidence suggests that pressure overload on the right ventricle (RV) leads to RV dysfunction, with considerable morbidity and mortality. Therefore, appropriate RV evaluation is essential because timely intervention may preserve RV function and prevent irreversible RV damage. Currently,

  2. Shift Work, Role Overload, and the Transition to Parenthood

    Science.gov (United States)

    Perry-Jenkins, Maureen; Goldberg, Abbie E.; Pierce, Courtney P.; Sayer, Aline G.

    2007-01-01

    This article examines how the work hours, work schedules, and role overload of working-class couples are related to depressive symptoms and relationship conflict across the transition to parenthood. Data are from 132 dual-earner couples interviewed 5 times across the transition. Multilevel modeling analyses revealed that working evening or night…

  3. Fetal liver iron overload: the role of MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cassart, Marie; Avni, Freddy Efraim [Erasme Hospital, Medical imaging, Brussels, Brabant (Belgium); Guibaud, Laurent [Hopital femme mere enfant, Imagerie Pediatrique et Foetale, Lyon-Bron (France); Molho, Marc [C.H.I Poissy/St Germain-en-Laye, Imagerie Medicale, Poissy (France); D' Haene, Nicky [Erasme Hospital, Anatomopathology Department, Brussels (Belgium); Paupe, Alain [C.H.I Poissy/St Germain-en-Laye, Pediatrie, Poissy (France)

    2011-02-15

    To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload. We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n = 2), digestive tract anomalies (n = 3) and hydrops fetalis (n = 2). The average GA of the fetuses was 31 weeks. The antenatal diagnoses were compared with histological data (n = 6) and postnatal work-up (n = 1). Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n = 2) and fetopathology (n = 4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n = 2) and syndromal anomalies (n = 2)) and congenital haemochromatosis (n = 3). In all cases, the liver appeared normal on US. Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante - (in the case of recurrence) or neonatal treatment, which might improve the prognosis. (orig.)

  4. Positive end-expiratory pressure attenuates hemodynamic effects induced by an overload of inspiratory muscles in patients with COPD

    Directory of Open Access Journals (Sweden)

    Schaper-Magalhães F

    2017-10-01

    Full Text Available Flavia Schaper-Magalhães,1 José Felippe Pinho,1 Carolina Andrade Bragança Capuruço,2 Maria Glória Rodrigues-Machado1 1Medical Sciences Faculty of Minas Gerais, Post-Graduation Program in Health Sciences, Belo Horizonte, Brazil; 2Department of Cardiology, Clinics Hospital, Federal University of Minas Gerais, Belo Horizonte, Brazil Background: Inspiratory muscle training (IMT using a Threshold® device is commonly used to improve the strength and endurance of inspiratory muscles. However, the effect of IMT, alone or with positive end-expiratory pressure (PEEP, on hemodynamic parameters in patients with chronic obstructive pulmonary disease (COPD remains unknown.Objective: To assess the effects of an overload of inspiratory muscles using IMT fixed at 30% of the maximal inspiratory pressure (MIP, and IMT associated with 5 cmH2O of PEEP (IMT + PEEP, on the echocardiographic parameters in healthy subjects and patients with COPD.Methods: Twenty patients with COPD (forced expiratory volume in 1 second 53.19±24.71 pred% and 15 age-matched healthy volunteers were evaluated using spirometry, MIP, the COPD assessment test (CAT, and the modified Medical Research Council (mMRC dyspnea scale. The E- (fast-filling phase and A- (atrial contraction phase waves were evaluated at the tricuspid and mitral valves during inspiration and expiration in the following sequence: at basal conditions, using IMT, and using IMT + PEEP.Results: Patients with COPD had reduced MIPs versus the control group. Ten patients had CAT scores <10 and 12 patients had mMRC scores <2. E-wave values at the mitral valve were significantly decreased with IMT during the inspiratory phase in both groups. These effects were normalized with IMT + PEEP. During the expiratory phase, use of IMT + PEEP normalized the reduction in E-wave values in the COPD group. During inspiration at the tricuspid valve, reduction in E-wave values during IMT was normalized by IMT + PEEP in COPD group. During the

  5. "Something's Gotta Give:" Advanced-Degree Seeking Women's Experiences of Sexism, Role Overload, and Psychological Distress

    Science.gov (United States)

    West, Lindsey M.

    2014-01-01

    With the rise in advanced-degree seeking women and the minimal research on the dual impact of sexism and role overload, the current study aims to better understand the impact of sexism and role overload on psychological distress in a particular sample of advanced-degree seeking women. Seventy-six female medical student participants (mean age 24.7)…

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

    Science.gov (United States)

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

    2013-01-01

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

  7. Role ambiguity, role conflict and work overload and their influence ...

    African Journals Online (AJOL)

    For some educators who assume the dual role of teaching in the classroom and taking on a further role of sport facilitator within a school environment can become highly emotional. The potential for stress is high since they have to work with class sizes of 40 and more learners for long periods of time and at the same time ...

  8. The role of echocardiography in hemodynamic monitoring.

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    Boyd, John H; Walley, Keith R

    2009-06-01

    Echocardiography has become more widely available to noncardiologists because of the technological advances in smaller, multipurpose ultrasound units with basic cardiac capabilities. In this review, we discuss the type of clinical information a trained intensivist can hope to obtain from bedside echocardiography and suggest the ways in which this complements traditional hemodynamic monitoring. Following a 10-h hands-on course, intensivists are able to perform and interpret a goal-oriented echocardiogram in approximately 10 min with good accuracy. Bedside echocardiography can aid in determining fluid status and qualitative cardiac ejection fraction, which can then be used immediately to guide therapy. Intensivists can safely and accurately perform goal-oriented echocardiography. Although not yet proven to influence clinical outcome, we suggest that the major utility of echocardiography is for those with distributive or mixed shock in whom target central venous pressure has been achieved without evidence of adequate tissue perfusion. In this subset of patients, echocardiography can aid in selecting those most likely to benefit from further fluid or inotropic support.

  9. Provider role attitudes, marital satisfaction, role overload, and housework: a dyadic approach.

    Science.gov (United States)

    Helms, Heather M; Walls, Jill K; Crouter, Ann C; McHale, Susan M

    2010-10-01

    Treating the marital dyad as the unit of analysis, this study examined the within-couple patterning of 272 dual-earner spouses' provider role attitudes and their longitudinal associations with marital satisfaction, role overload, and the division of housework. Based on the congruence of husbands' and wives' provider role attitudes, couples were classified into one of four types: (a) main-secondary, (b) coprovider, (c) ambivalent coprovider, and (d) mismatched couples. Nearly half of all spouses differed in their attitudes about breadwinning. A series of mixed model ANCOVAs revealed significant between- and within-couple differences in human capital characteristics, spouses' perceptions of marital satisfaction and role overload, and the division of housework across 3 years of measurement. Coprovider couples reported higher levels of marital satisfaction and a more equitable division of housework than the other couple groups. Wives in the ambivalent coprovider couples' group reported higher levels of role overload than their husbands to a greater extent than was found in the other couple groups. As the first study to adopt a dyadic approach that considers the meanings that both spouses in dual-earner couples ascribe to paid employment, these findings advance understanding of how dual-earner spouses' provider role attitudes serve as contexts for marital quality, behavior, and role-related stress.

  10. When more is less: An examination of the relationship between hours in telework and role overload.

    Science.gov (United States)

    Duxbury, Linda; Halinski, Michael

    2014-01-01

    Proponents of telework arrangements assert that those who telework have more control over their work and family domains than their counterparts who are not permitted to work from home. Using Karasek's theory we hypothesized that the relationship between demands (hours in work per week; hours in childcare per week) and strain (work role overload; family role overload) would be moderated by the number of hours the employee spent per week teleworking (control). To determine how the number of telework hours relates to work role overload and family role overload, we follow the test for moderation and mediation using hierarchical multiple regression analysis as outlined by Frazier et al. [50] We used survey data collected from 1,806 male and female professional employees who spent at least one hour per week working from home during regular hours (i.e. teleworking). As hypothesized, the number of hours in telework per week negatively moderated the relation between work demands (total hours in paid employment per week) and work strain (work role overload). Contrary to our hypothesis, the number of hours in telework per week only partially mediated the relation between family demands (hours a week in childcare) and family role overload (strain). The findings from this study support the idea that the control offered by telework is domain specific (helps employees meet demands at work but not at home).

  11. Standard and Strain Measurements by Echocardiography Detect Early Overloaded Right Ventricular Dysfunction: Validation against Hemodynamic and Myocyte Contractility Changes in a Large Animal Model.

    Science.gov (United States)

    Hodzic, Amir; Bobin, Pierre; Mika, Delphine; Ly, Mohamed; Lefebvre, Florence; Lechêne, Patrick; Le Bret, Emmanuel; Gouadon, Elodie; Coblence, Mathieu; Vandecasteele, Grégoire; Capderou, André; Leroy, Jérôme; Rucker-Martin, Catherine; Lambert, Virginie

    2017-11-01

    Early detection of right ventricular (RV) failure is required to improve the management of patients with congenital heart diseases. The aim of this study was to validate echocardiography for the early detection of overloaded RV dysfunction, compared with hemodynamic and myocyte contractility assessment. Using a porcine model reproducing repaired tetralogy of Fallot, RV function was evaluated over 4 months using standard echocardiography and speckle-tracking compared with hemodynamic parameters (conductance catheter). Sarcomere shortening and calcium transients were recorded in RV isolated myocytes. Contractile reserve (ΔEmax) was assessed by β-adrenergic stimulation in vivo (dobutamine 5 μg/kg) and ex vivo (isoproterenol 100 nM). Six operated animals were compared with four age- and sex-matched controls. In the operated group, hemodynamic RV efficient ejection fraction was significantly decreased (29.7% [26.2%-34%] vs 42.9% [40.7%-48.6%], P < .01), and inotropic responses to dobutamine were attenuated (ΔEmax was 51% vs 193%, P < .05). Echocardiographic measurements of fraction of area change, tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity (S') and RV free wall longitudinal systolic strain and strain rate were significantly decreased. Strain rate, S', and tricuspid annular plane systolic excursion were correlated with ΔEmax (r = 0.75, r = 0.78, and r = 0.65, respectively, P < .05). These alterations were associated in RV isolated myocytes with the decrease of sarcomere shortening in response to isoproterenol and perturbations of calcium homeostasis assessed by the increase of spontaneous calcium waves. In this porcine model, both standard and strain echocardiographic parameters detected early impairments of RV function and cardiac reserve, which were associated with cardiomyocyte excitation-contraction coupling alterations. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc

  12. Role Overload, Role Self Distance, Role Stagnation as Determinants of Job Satisfaction and Turnover Intention in Banking Sector.

    Science.gov (United States)

    Kunte, Monica; Gupta, Priya; Bhattacharya, Sonali; Neelam, Netra

    2017-01-01

    This study examined the relationship of the organizational role stress: Role overload, role self-distance, and role stagnation with job satisfaction and turnover intention with a sample of banking employees in India. In this research, we used the RODS scale developed by Prohit and Pareek (2010) for measuring occupational role scale. The reliability of the scale came out to be 0.71. The majority of employees of all ranks, in both private and public sector banks, suffer from high role stress of all types. It was found that role overload and role stagnation are inversely associated with banking employees' job satisfaction. Private sector bank employees have more role stress and more unsatisfied than employees of public sector banks. Employees Turnover intention was found to be positively impacted by job satisfaction, contrary to many other studies. Possible reasons have been suggested. Job satisfaction was found to play a partial mediating role in the relationship between role overload and turnover intention with 40% mediation. Further, employees with longer tenure (work experience) have less role stress and are more satisfied. This study is unique in the sense there is hardly any study linking role stress to job satisfaction and turnover intention, specially in Indian context.

  13. Role Overload, Role Self Distance, Role Stagnation as Determinants of Job Satisfaction and Turnover Intention in Banking Sector

    Science.gov (United States)

    Kunte, Monica; Gupta, Priya; Bhattacharya, Sonali; Neelam, Netra

    2017-01-01

    Purpose: This study examined the relationship of the organizational role stress: Role overload, role self-distance, and role stagnation with job satisfaction and turnover intention with a sample of banking employees in India. Methodology: In this research, we used the RODS scale developed by Prohit and Pareek (2010) for measuring occupational role scale. The reliability of the scale came out to be 0.71. Findings: The majority of employees of all ranks, in both private and public sector banks, suffer from high role stress of all types. It was found that role overload and role stagnation are inversely associated with banking employees' job satisfaction. Private sector bank employees have more role stress and more unsatisfied than employees of public sector banks. Employees Turnover intention was found to be positively impacted by job satisfaction, contrary to many other studies. Possible reasons have been suggested. Job satisfaction was found to play a partial mediating role in the relationship between role overload and turnover intention with 40% mediation. Further, employees with longer tenure (work experience) have less role stress and are more satisfied. Originality: This study is unique in the sense there is hardly any study linking role stress to job satisfaction and turnover intention, specially in Indian context. PMID:29200554

  14. Fear of Success: A Personality Trait or a Response to Occupational Deviance and Role Overload?

    Science.gov (United States)

    Bremer, Teresa Hargrave; Wittig, Michele Andrisin

    1980-01-01

    Clarifies the extent to which an individual's fear of success scores may vary with the presence or absence of occupational deviance and/or role overload in stimulus materials describing situations of female competitive success. Results suggest that fear of success is a misnomer for responses to women's role descriptions. (Author/JLF)

  15. SIRT1 may play a crucial role in overload-induced hypertrophy of skeletal muscle.

    Science.gov (United States)

    Koltai, Erika; Bori, Zoltán; Chabert, Clovis; Dubouchaud, Hervé; Naito, Hisashi; Machida, Shuichi; Davies, Kelvin Ja; Murlasits, Zsolt; Fry, Andrew C; Boldogh, Istvan; Radak, Zsolt

    2017-06-01

    Silent mating type information regulation 2 homologue 1 (SIRT1) activity and content increased significantly in overload-induced hypertrophy. SIRT1-mediated signalling through Akt, the endothelial nitric oxide synthase mediated pathway, regulates anabolic process in the hypertrophy of skeletal muscle. The regulation of catabolic signalling via forkhead box O 1 and protein ubiquitination is SIRT1 dependent. Overload-induced changes in microRNA levels regulate SIRT1 and insulin-like growth factor 1 signalling. Significant skeletal muscle mass guarantees functional wellbeing and is important for high level performance in many sports. Although the molecular mechanism for skeletal muscle hypertrophy has been well studied, it still is not completely understood. In the present study, we used a functional overload model to induce plantaris muscle hypertrophy by surgically removing the soleus and gastrocnemius muscles in rats. Two weeks of muscle ablation resulted in a 40% increase in muscle mass, which was associated with a significant increase in silent mating type information regulation 2 homologue 1 (SIRT1) content and activity (P overload-induced hypertrophy. These findings, along with the well-known regulatory roles that SIRT1 plays in modulating both anabolic and catabolic pathways, allow us to propose the hypothesis that SIRT1 may actually play a crucial causal role in overload-induced hypertrophy of skeletal muscle. This hypothesis will now require rigorous direct and functional testing. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  16. Sport coaching officials and their stressors: Work overload, role ...

    African Journals Online (AJOL)

    Correlations and regression analysis were used to test the nature of the relationships among the examined job stressors and their predictive effect on job satisfaction. The results of the correlation and regression analysis show that role ambiguity and role conflict negatively impacts on the job satisfaction of sport coaches.

  17. Hemodynamic stability during hemodialysis : A role for vasopressin?

    NARCIS (Netherlands)

    Ettema, Esmee Marlien

    2016-01-01

    Despite technological advances, intradialytic hypotension remains a serious complication for hemodialysis patients. A measure to prevent intradialytic hypotension is the biofeedback system Hemocontrol. The mechanism behind the improved hemodynamic stability with Hemocontrol dialysis is not fully

  18. A multilevel cross-cultural examination of role overload and organizational commitment: investigating the interactive effects of context.

    Science.gov (United States)

    Fisher, David M

    2014-07-01

    Considering the influential nature of context, the current investigation examined whether the relationship between role overload and organizational commitment was affected by various contextual factors. Drawing on the occupational stress literature, structural empowerment and cooperative climate were examined as factors that would mitigate the negative effects of role overload on organizational commitment. In addition, national culture was examined to determine whether empowerment and cooperative climate had consistent moderating effects across cultures. The relationships among these variables were examined using hierarchical linear modeling in a sample of 6,264 employees working at a multinational organization in 337 different work locations across 18 countries. Results suggested that the negative effect of role overload on organizational commitment did not vary as a function of culture in the current sample, but empowerment and cooperative climate had a moderating influence on this relationship. Furthermore, a 3-way interaction was observed between the cultural variable of power distance, empowerment, and role overload in predicting organizational commitment, suggesting that factors that serve to mitigate the negative effects of role overload in one culture may be ineffectual in another. This 3-way interaction was observed regardless of whether Hofstede's (2001) cultural value indices were used or the cultural practice scores from the Global Leadership and Organizational Behavior Effectiveness (GLOBE) project (R. J. House, Hanges, Javidan, Dorfman, & Gupta, 2004).

  19. Nicotinamide overload may play a role in the development of type 2 diabetes.

    Science.gov (United States)

    Zhou, Shi-Sheng; Li, Da; Sun, Wu-Ping; Guo, Ming; Lun, Yong-Zhi; Zhou, Yi-Ming; Xiao, Fu-Cheng; Jing, Li-Xin; Sun, Shen-Xia; Zhang, Li-Bin; Luo, Ning; Bian, Fu-Ning; Zou, Wei; Dong, Lai-Bin; Zhao, Zhi-Gang; Li, Sheng-Fan; Gong, Xiao-Jie; Yu, Zeng-Guo; Sun, Chang-Bin; Zheng, Cong-Long; Jiang, Dong-Ju; Li, Zheng-Ning

    2009-12-07

    To investigate whether nicotinamide overload plays a role in type 2 diabetes. Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N(1)-methylnicotinamide on glucose metabolism, plasma H(2)O(2) levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. Diabetic subjects had significantly higher plasma N(1)-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 +/- 0.13 micromol/L vs 0.6 +/- 0.13 micromol/L, P nicotinamide (2 g/kg) significantly increased rat plasma N(1)-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by N(1)-methylnicotinamide. Moreover, cumulative exposure to N(1)-methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/NADH ratio, and increased plasma H(2)O(2) levels. Decrease in NAD/NADH ratio and increase in H(2)O(2) generation were also observed in human erythrocytes after exposure to N(1)-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N(1)-methylnicotinamide clearance. These findings suggest that nicotinamide overload, which induced an increase in plasma N(1)-methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.

  20. Self-Control, Self-Efficacy, Role Overload, and Stress Responses among Siblings of Children with Cancer

    Science.gov (United States)

    Hamama, Liat; Ronen, Tammie; Rahav, Giora

    2008-01-01

    The study focuses on healthy children's responses to a sibling's cancer and its aftermath, with particular scrutiny directed toward these healthy siblings' stress factors, duress responses, and coping resources. The authors investigated role overload as these siblings' stress factor, anxiety and psychosomatic symptoms as their duress responses,…

  1. Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Eveno, Clarisse, E-mail: clarisse.eveno@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Dautry, Raphael, E-mail: raphael.dautry@lrb.aphp.fr; Guerrache, Youcef, E-mail: docyoucef05@yahoo.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Camus, Marine, E-mail: marine.camus@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Boudiaf, Mourad, E-mail: mourad.boudiaf@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France); Gayat, Etienne, E-mail: etienne.gayat@lrb.aphp.fr [Université Paris-Diderot, Sorbonne Paris Cité (France); Dref, Olivier Le, E-mail: olivier.ledref@lrb.aphp.fr; Sirol, Marc, E-mail: marc.sirol@lrb.aphp.fr; Soyer, Philippe, E-mail: philippe.soyer@lrb.aphp.fr [Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Department of Abdominal and Interventional Imaging (France)

    2015-08-15

    PurposeTo assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA).Materials and MethodsSeventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed.ResultsSeventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53 %). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88 %). Technical success rate of TAE was 100 %. TAE was performed using metallic coils in all patients (100 %), in association with gelatin sponge in 5/17 patients (29 %). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94 %). In 1/17 patient (6 %), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12 %, respectively. Morbidity consisted in coil migration in 1/17 patient (6 %) and transient serum liver enzyme elevation in 1/17 patient (6 %).ConclusionTAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94 %. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA.

  2. Hemodynamic regulation of MMP-2 and MMP-9: roles in angiogenesis and migration

    OpenAIRE

    Von Offenberg Sweeney, Nicholas

    2004-01-01

    Hemodynamic forces generated by the flow of blood are crucial in maintaining homeostasis within the blood vessel wall. These forces, namely cyclic strain and shear stress are intricately involved in vascular remodeling, a process which underlies the pathogenesis of cardiovascular diseases such as atherosclerosis and restenosis. Since degradation of the extracellular matrix scaffold enables reshaping of tissue, the role matrix metalloproteinases (MMPs) has become the object of intense recen...

  3. Efeitos hemodinâmicos da sobrecarga ventricular direita aguda experimental Efectos hemodinámicos de la sobrecarga ventricular derecha aguda experimental Hemodynamic effects of experimental acute right ventricular overload

    Directory of Open Access Journals (Sweden)

    Flávio Brito Filho

    2011-04-01

    el estudio, siendo divididos en 4 grupos: uno control, no sometido a la oclusión vascular pulmonar, y tres de sobrecarga ventricular derecha sometidos a la oclusión de las siguientes arterias pulmonares: SVD1 (arteria pulmonar izquierda; SVD2 (arteria pulmonar izquierda y del lóbulo inferior derecho y SVD3 (arteria pulmonar izquierda, del lóbulo inferior derecho y del lóbulo mediastinal, obstruyendo la vasculatura pulmonar en 42, 76 y 82,0% respectivamente. Variables de hemodinámica fueron medidas cada 15 minutos durante una hora del estudio. En el análisis estadístico, fueron utilizados ajustes de modelos lineares mixtos con estructura de variancias y covariancias. RESULTADOS:En las comparaciones intergrupales, hubo aumento significativo de la frecuencia cardíaca (p = 0,004, presión arterial pulmonar media (p = 0,001 y presión capilar pulmonar (p BACKGROUND: Acute right ventricular overload is associated with high morbidity and mortality clinical situations such as: extensive lung resection, pulmonary thromboembolism, lung transplantation and high altitude pulmonary edema. Some points of its pathophysiology remain unclear. OBJECTIVE: To assess the hemodynamic effects of experimental acute right ventricular overload in pigs. METHODS: Right ventricular overload was induced through the occlusion of the pulmonary arteries using ligationss. Twenty pigs were used in the study, divided into 04 groups: one control group not subject to pulmonary vascular occlusion, and three right ventricular overload groups subject to occlusion of the following pulmonary arteries: SVD1 (left pulmonary artery; SVD2 (left pulmonary artery and right lower lobe and SVD3 (left pulmonary artery, right lower lobe and mediastinal lobe, obstructing the pulmonary vasculature in 42, 76 and 82.0% respectively. Hemodynamic variables were measured every 15 minutes during one hour of study. The statistical analysis employed mixed linear models with variance and covariance structures. RESULTS

  4. [The role of monitoring of hemodynamic parameters in intensive infusion therapy].

    Science.gov (United States)

    2005-01-01

    Pathophysiological mechanisms of intensive infusion therapy (IT) should be understood to provide effective practical use of this method for treating patients in critical states. Adequate IT should take into account the decrease in the efficiency of compensation mechanism and absence of reserve capacity of basic functional systems of human body. This allows the results of treatment of heavy patients to be improved, The goal of this work was to demonstrate that IT can be used not only as a therapeutic procedure but also as a diagnostic test intended to determine specific individual features of the compensatory adaptive reactions of the cardiovascular system (CVS) of patient. The tactics of IT can be adapted and optimized using the results of the CVS reaction to the liquid volume load test. The role of monitoring of hemodynamic parameters in IT was analyzed. Evaluation of patent reserves allows the following parameters of infusion to be varied: flow rate, volume, temperature, pH, and osmolarity of infusion solutions; succession and time of their infusion. Circadian rhythms of human CVS should also be taken into account. The following hemodynamic parameters should be monitored during IT: cardiac output, general peripheral resistance of blood vessels, and aqueous sectors. This monitoring can be used in mathematical simulation of changes in the parameters of central hemodynamics and determination of prognostic criteria.

  5. Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice.

    Science.gov (United States)

    Mimura, Hiroaki; Takaya, Tatsuo; Matsuda, Saeka; Nakano, Keisuke; Muraoka, Rina; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

    2016-01-01

    We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship's lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload.

  6. Pivotal role of cardiomyocyte TGF-β signaling in the murine pathological response to sustained pressure overload

    NARCIS (Netherlands)

    Koitabashi, Norimichi; Danner, Thomas; Zaiman, Ari L.; Pinto, Yigal M.; Rowell, Janelle; Mankowski, Joseph; Zhang, Dou; Nakamura, Taishi; Takimoto, Eiki; Kass, David A.

    2011-01-01

    The cardiac pathological response to sustained pressure overload involves myocyte hypertrophy and dysfunction along with interstitial changes such as fibrosis and reduced capillary density. These changes are orchestrated by mechanical forces and factors secreted between cells. One such secreted

  7. Information overload and data overload in lexicography

    DEFF Research Database (Denmark)

    Tarp, Sven; Gouws, Rufus H.

    2017-01-01

    the often uncritical inclusion of too much data. This paper discusses the general term information overload and its lexicographical counterpart data overload. Different types of data overload are identified and the problems users have when retrieving the necessary information from dictionary articles......Too often online dictionaries still display too many features determined by the restrictions that applied to printed dictionaries. Data overload in dictionary articles can be regarded as one such relic from the past. However, the idea that online dictionaries have unlimited space has furthered...

  8. Hemodynamic correction of univentricular congenital heart diseases: the role of additional sources of pulmonary blood flow

    Directory of Open Access Journals (Sweden)

    Ю. Н. Горбатых

    2015-10-01

    Full Text Available Analysis of the impact of additional sources of pulmonary blood flow on the outcomes of hemodynamic correction of univentricular congenital heart disease is presented. From 2003 to 2010 31 patients received a bidirectional cavopulmonary shunt (BCPS with/without preservation of additional pulmonary blood flow sources. The latter were preserved in 18 patients (1st group and eliminated in 13 patients (2nd group. Later on all patients had Fontan procedure. Our results showed no significant impact of additional pulmonary blood flow sources on the system ventricle function and systemic AV valve regurgitation. Preservation of adequate additional pulmonary blood flow during BCPS promotes pulmonary arterial growth and increases the degree of freedom from operative intervention, while optimizing hemodynamic features of Fontan-borderline patients.

  9. Role of phenolics from Spondias pinnata bark in amelioration of iron overload induced hepatic damage in Swiss albino mice.

    Science.gov (United States)

    Chaudhuri, Dipankar; Ghate, Nikhil Baban; Panja, Sourav; Mandal, Nripendranath

    2016-07-26

    Crude Spondias pinnata bark extract was previously assessed for its antioxidant, anticancer and iron chelating potentials. The isolated compounds gallic acid (GA) and methyl gallate (MG) were evaluated for their curative potential against iron overload-induced liver fibrosis and hepatocellular damage. In vitro iron chelation property and in vivo ameliorating potential from iron overload induced liver toxicity of GA and MG was assessed by different biochemical assays and histopathological studies. MG and GA demonstrated excellent reducing power activities but iron chelation potential of MG is better than GA. Oral MG treatment in mice displayed excellent efficacy (better than GA) to significantly restore the levels of liver antioxidants, serum markers and cellular reactive oxygen species in a dose-dependent fashion. Apart from these, MG exceptionally prevented lipid peroxidation and protein oxidation whereas GA demonstrated better activity to reduce collagen content, thereby strengthening its position as an efficient drug against hepatic damage/fibrosis, which was further supported by histopathological studies. Alongside, MG efficiently eliminated the cause of liver damage, i.e., excess iron, by chelating free iron and reducing the ferritin-bound iron. The present study confirmed the curative effect of GA and MG against iron overload hepatic damage via their potent antioxidant and iron-chelating potential.

  10. Clarifications on Continuous Renal Replacement Therapy and Hemodynamics.

    Science.gov (United States)

    Wang, Xiao-Ting; Wang, Cui; Zhang, Hong-Min; Liu, Da-Wei

    2017-05-20

    Continuous renal replacement therapy (CRRT) is a continuous process of bedside blood purification which is widely used in the treatment of acute kidney injury (AKI) and for fluid management. However, since AKI and fluid overload are often found to be associated with hemodynamic abnormalities, determining the relationship between CRRT and hemodynamics remains a challenge in the treatment of critically ill patients. The aim of this review was to summarize key points in the relationship between CRRT and hemodynamics and to understand and monitor renal hemodynamics in critically ill patients, especially those with AKI. This review was based on data in articles published in the PubMed databases up to January 30, 2017, with the following keywords: "continuous renal replacement therapy," "Hemodynamics," and "Acute kidney injury." Original articles and critical reviews on CRRT were selected for this review. CRRT might treat AKI by hemodynamic therapy, and it was an important form of hemodynamic therapy. The targets of hemodynamic therapy should be established when using CRRT. Therefore, hemodynamic management and stability were very important during CRRT. Most studies suggested that renal hemodynamics should be clearly identified. CRRT is not only a replacement for organ function, but an important form of hemodynamic therapy. Improved hemodynamic management of critically ill patients can be achieved by establishing specific therapeutic hemodynamic targets and maintaining circulatory stability during CRRT. Over the long term, observation of renal hemodynamics will provide greater opportunities for the progression of CRRT hemodynamic therapy.

  11. Hemodynamics of Cerebral Aneurysms

    Science.gov (United States)

    Sforza, Daniel M.; Putman, Christopher M.; Cebral, Juan Raul

    2009-01-01

    The initiation and progression of cerebral aneurysms are degenerative processes of the arterial wall driven by a complex interaction of biological and hemodynamic factors. Endothelial cells on the artery wall respond physiologically to blood-flow patterns. In normal conditions, these responses are associated with nonpathological tissue remodeling and adaptation. The combination of abnormal blood patterns and genetics predisposition could lead to the pathological formation of aneurysms. Here, we review recent progress on the basic mechanisms of aneurysm formation and evolution, with a focus on the role of hemodynamic patterns.

  12. Role and mechanism of endoplasmic reticulum stress and Ca2+ overload in pulmonary endothelial cell damage induced by heat stress

    Directory of Open Access Journals (Sweden)

    Bao-jun YU

    2017-08-01

    Full Text Available Objective To observe the effect of different temperatures on endoplasmic reticulum stress, calcium overload, mitochondria and cell damage in pulmonary microvascular endothelial cells (PMVEC induced by heat stress, and clarify the mechanism of endothelial cell injury in the process of heat stress to provide experimental basis for clinical prevention and treatment of heat stree. Methods Heat stress model of PMVEC cell was set up. Control group cells were incubated at 37℃, 5%CO2, while heat stress group cells were incubated at 39℃, 41℃, 43℃ for 2h, respectively, then further incubated at 37℃, 5%CO2 for 6h. Pretreatment of cells with 20μmol/L BAPTA-AM or 50μmol/L CsA before heat stress at 43℃. The protein levels of p-PERK, PERK p-eIF2a, eIF2a, ATF4 and GRP78 were analyzed by Western blotting. Intracellular Ca2+, mitochondrial membrane potential and the changes in mitochondrial permeability transition pore were investigated by flow cytometry. The change of caspase-3 was detected by Caspase Assay Kit. Millicell-ERS Volt-Ohm Meter and Accessories was used for determining the changes of transepithelium electrical resistance (TER. Results Compared with the control group, with the increase of heat stress temperature (41-43℃, the phosphorylation of p-PERK and p-eIF2a protein and the expressions of ATF4 and GRP78 proteins were gradually activated, intracellular Ca2+ increased, MPTP pore was opened, mitochondrial membrane potential decreased, cell permeability increased and apoptosis occurred, and it was the most obvious in the 43℃ heat stress group, and the difference was statistically significant (P<0.05. Pretreatment with Ca2+ inhibitors promoted the recovery of the MPTP hole, mitochondrial membrane potential and cell permeability, and reduced the occurrence of apoptosis. While pretreatment with the mitochondrial protective agent did not reduce the release of Ca2+, but it could promote the recovery of cell permeability and reduce the

  13. Iron-overload injury and cardiomyopathy in acquired and genetic models is attenuated by resveratrol therapy.

    Science.gov (United States)

    Das, Subhash K; Wang, Wang; Zhabyeyev, Pavel; Basu, Ratnadeep; McLean, Brent; Fan, Dong; Parajuli, Nirmal; DesAulniers, Jessica; Patel, Vaibhav B; Hajjar, Roger J; Dyck, Jason R B; Kassiri, Zamaneh; Oudit, Gavin Y

    2015-12-07

    Iron-overload cardiomyopathy is a prevalent cause of heart failure on a world-wide basis and is a major cause of mortality and morbidity in patients with secondary iron-overload and genetic hemochromatosis. We investigated the therapeutic effects of resveratrol in acquired and genetic models of iron-overload cardiomyopathy. Murine iron-overload models showed cardiac iron-overload, increased oxidative stress, altered Ca(2+) homeostasis and myocardial fibrosis resulting in heart disease. Iron-overload increased nuclear and acetylated levels of FOXO1 with corresponding inverse changes in SIRT1 levels in the heart corrected by resveratrol therapy. Resveratrol, reduced the pathological remodeling and improved cardiac function in murine models of acquired and genetic iron-overload at varying stages of iron-overload. Echocardiography and hemodynamic analysis revealed a complete normalization of iron-overload mediated diastolic and systolic dysfunction in response to resveratrol therapy. Myocardial SERCA2a levels were reduced in iron-overloaded hearts and resveratrol therapy restored SERCA2a levels and corrected altered Ca(2+) homeostasis. Iron-mediated pro-oxidant and pro-fibrotic effects in human and murine cardiomyocytes and cardiofibroblasts were suppressed by resveratrol which correlated with reduction in iron-induced myocardial oxidative stress and myocardial fibrosis. Resveratrol represents a clinically and economically feasible therapeutic intervention to reduce the global burden from iron-overload cardiomyopathy at early and chronic stages of iron-overload.

  14. Role of vascular potassium channels in the regulation of renal hemodynamics

    DEFF Research Database (Denmark)

    Sørensen, Charlotte Mehlin; Braunstein, Thomas Hartig; von Holstein-Rathlou, Niels-Henrik

    2012-01-01

    function. Results from in vivo experiments are sparse. We discuss the role of the different classes of renal vascular K+ channels and their possible role in the integrated function of the renal microvasculature. Since several pathological conditions, among them hypertension, are associated with alterations...

  15. Role of the Primary Cilia on the Macula Densa and Thick Ascending Limbs in Regulation of Sodium Excretion and Hemodynamics.

    Science.gov (United States)

    Song, Jiangping; Wang, Lei; Fan, Fan; Wei, Jin; Zhang, Jie; Lu, Yan; Fu, Yiling; Wang, Shaohui; Juncos, Luis A; Liu, Ruisheng

    2017-08-01

    We investigated the significance of the primary cilia on the macula densa and thick ascending limb (TAL) in regulation of renal hemodynamics, sodium excretion, and blood pressure in this study. A tissue-specific primary cilia knock-out (KO) mouse line was generated by crossing NKCC2-Cre mice with IFT88-Δ/flox mice (NKCC2CRE; IFT88Δ/flox), in which the primary cilia were deleted from the macula densa and TAL. NO generation was measured with a fluorescent dye (4,5-diaminofluorescein diacetate) in isolated perfused juxtaglomerular apparatus. Deletion of the cilia reduced NO production by 56% and 42% in the macula densa and TAL, respectively. NO generation by the macula densa was inhibited by both a nonselective and a selective nitric oxide synthesis inhibitors, whereas TAL-produced NO was inhibited by a nonselective and not by a selective NO synthesis 1 inhibitor. The tubuloglomerular feedback response was enhanced in the KO mice both in vitro measured with isolated perfused juxtaglomerular apparatuses and in vivo measured with micropuncture. In response to an acute volume expansion, the KO mice exhibited limited glomerular filtration rate elevation and impaired sodium excretion compared with the wild-type mice. The mean arterial pressure measured with telemetry was the same for wild-type and KO mice fed a normal salt diet. After a high salt diet, the mean arterial pressure increased by 17.4±1.6 mm Hg in the KO mice. On the basis of these findings, we concluded that the primary cilia on the macula densa and TAL play an essential role in the control of sodium excretion and blood pressure. © 2017 The Authors.

  16. Right ventricular pressure overload: hemodynamic and proteomic changes

    NARCIS (Netherlands)

    M.J. Faber (Matthijs Jan)

    2012-01-01

    textabstractThe incidence of congenital heart disease (CHD) is estimated to vary between 4 to 50 per 1000 live births [1, 2] . This wide range of incidence is due to different phenotypes of CHD, as well as the inclusion criteria used. All together, CHD can be seen as the most common birth defect

  17. Effects of exercise on endothelium and endothelium/smooth muscle cross talk: role of exercise-induced hemodynamics

    NARCIS (Netherlands)

    Newcomer, S.C.; Thijssen, D.H.J.; Green, D.J.

    2011-01-01

    Physical activity, exercise training, and fitness are associated with decreased cardiovascular risk. In the context that a risk factor "gap" exists in the explanation for the beneficial effects of exercise on cardiovascular disease, it has recently been proposed that exercise generates hemodynamic

  18. Interdisciplinary Research and Information Overload.

    Science.gov (United States)

    Wilson, Patrick

    1996-01-01

    Discusses information overload and examines several ways in which actual and potential overload affects research choices for the solo researcher in interdisciplinary areas. Topics include information overload and teamwork; entry barriers to certain specialties, including necessary background knowledge; and information utilization and knowledge…

  19. Role of ferritin in the rice tolerance to iron overload Papel da ferritina na tolerância de arroz ao excesso de ferro

    Directory of Open Access Journals (Sweden)

    Vivian Chagas da Silveira

    2009-08-01

    Full Text Available Plants ordinarily face iron (Fe deficiency, since this mineral is poorly available in soils under aerobic conditions. Nonetheless, wetland and irrigated rice plants can be exposed to excess, highly toxic Fe. Ferritin is a ubiquitous Fe-storage protein, important for iron homeostasis. Increased ferritin accumulation resulting from higher Fe availability was shown in some plant species. However, the role of ferritin in tolerance mechanisms to Fe overload in rice is yet to be established. In this study, recombinant rice ferritin was expressed in Escherichia coli, producing an anti-rice ferritin polyclonal antibody which was used to evaluate ferritin accumulation in two rice (Oryza sativa L. cultivars, either susceptible (BR-IRGA 409 or tolerant (EPAGRI 108 to Fe toxicity. Increased ferritin mRNA and protein levels resulting from excess Fe treatment were detected in both cultivars, with higher ferritin protein accumulation in EPAGRI 108 plants, which also reached lower shoot Fe concentrations when submitted to iron overload. The tolerance mechanism to excess Fe in EPAGRI 108 seems to include both restricted Fe translocation and increased ferritin accumulation. This is the first work that shows higher accumulation of the ferritin protein in an iron-excess tolerant Oryza sativa cultivar, providing evidence of a possible role of this protein in iron tolerance mechanisms.Deficiência de ferro (Fe ocorre freqüentemente em plantas, uma vez que este mineral é pouco disponível em condições aeróbicas. Plantas de arroz cultivadas sob alagamento, no entanto, estão sujeitas ao excesso de Fe, que pode ser extremamente tóxico. Alguns cultivares de arroz são resistentes a altas concentrações de ferro, mas os mecanismos fisiológicos responsáveis por essa resistência são pouco conhecidos. A ferritina é uma proteína de ampla distribuição e capaz de armazenar ferro, sendo considerada importante para a homeostase deste metal. Acúmulo de ferritina em

  20. Role of Methylene Blue in the Maintenance of Postinduction Hemodynamic Status in Patients with Perforation Peritonitis: A Pilot Study.

    Science.gov (United States)

    Senthilnathan, Muthapillai; Cherian, Anusha; Balachander, Hemavathi; Maroju, Nanda Kishore

    2017-01-01

    Methylene blue is an inhibitor of guanylate cyclase and hence prevents vasoplegia mediated by nitric oxide in patients with sepsis. This study aimed to analyze the effect of methylene blue on blood pressure maintenance following induction of anesthesia in patients presenting with peritonitis. Thirty patients diagnosed to have perforation peritonitis were randomized into two groups (Group MB, Group NS). Patients in Group MB were given injection methylene blue 2 mg/kg over 20 min and patients in Group NS were given 50 ml of normal saline over 20 min, before induction. Heart rate, mean arterial pressure (MAP), cardiac output, and systemic vascular resistance (SVR) were recorded every 5 min for 1 h after infusion. Hemodynamic parameters were analyzed using repeated-measures analysis of variance with Bonferroni's test. Blood gas analysis was analyzed using independent Student's t -test, and P methylene blue were noted. Methylene blue contributes to the maintenance of postinduction hemodynamic stability in patients with perforation peritonitis.

  1. Impaired cardiac contractility response to hemodynamic stress in S100A1-deficient mice.

    Science.gov (United States)

    Du, Xiao-Jun; Cole, Timothy J; Tenis, Nora; Gao, Xiao-Ming; Köntgen, Frank; Kemp, Bruce E; Heierhorst, Jörg

    2002-04-01

    Ca(2+) signaling plays a central role in cardiac contractility and adaptation to increased hemodynamic demand. We have generated mice with a targeted deletion of the S100A1 gene coding for the major cardiac isoform of the large multigenic S100 family of EF hand Ca(2+)-binding proteins. S100A1(-/-) mice have normal cardiac function under baseline conditions but have significantly reduced contraction rate and relaxation rate responses to beta-adrenergic stimulation that are associated with a reduced Ca(2+) sensitivity. In S100A1(-/-) mice, basal left-ventricular contractility deteriorated following 3-week pressure overload by thoracic aorta constriction despite a normal adaptive hypertrophy. Surprisingly, heterozygotes also had an impaired response to acute beta-adrenergic stimulation but maintained normal contractility in response to chronic pressure overload that coincided with S100A1 upregulation to wild-type levels. In contrast to other genetic models with impaired cardiac contractility, loss of S100A1 did not lead to cardiac hypertrophy or dilation in aged mice. The data demonstrate that high S100A1 protein levels are essential for the cardiac reserve and adaptation to acute and chronic hemodynamic stress in vivo.

  2. Exercise Training Prevents Cardiovascular Derangements Induced by Fructose Overload in Developing Rats.

    Directory of Open Access Journals (Sweden)

    Daniela Farah

    Full Text Available The risks of chronic diseases associated with the increasing consumption of fructose-laden foods are amplified by the lack of regular physical activity and have become a serious public health issue worldwide. Moreover, childhood eating habits are strongly related to metabolic syndrome in adults. Thus, we aimed to investigate the preventive role of exercise training undertaken concurrently with a high fructose diet on cardiac function, hemodynamics, cardiovascular autonomic modulation and oxidative stress in male rats after weaning. Male Wistar rats were divided into 4 groups (n = 8/group: Sedentary control (SC, Trained control (TC, Sedentary Fructose (SF and Trained Fructose (TF. Training was performed on a treadmill (8 weeks, 40-60% of maximum exercise test. Evaluations of cardiac function, hemodynamics, cardiovascular autonomic modulation and oxidative stress in plasma and in left ventricle (LV were performed. Chronic fructose overload induced glucose intolerance and an increase in white adipose tissue (WAT weight, in myocardial performance index (MPI (SF:0.42±0.04 vs. SC:0.24±0.05 and in arterial pressure (SF:122±3 vs. SC:113±1 mmHg associated with increased cardiac and vascular sympathetic modulation. Fructose also induced unfavorable changes in oxidative stress profile (plasmatic protein oxidation- SF:3.30±0.09 vs. SC:1.45±0.08 nmol/mg prot; and LV total antioxidant capacity (TRAP- SF: 2.5±0.5 vs. SC:12.7±1.7 uM trolox. The TF group showed reduced WAT, glucose intolerance, MPI (0.35±0.04, arterial pressure (118±2mmHg, sympathetic modulation, plasmatic protein oxidation and increased TRAP when compared to SF group. Therefore, our findings indicate that cardiometabolic dysfunctions induced by fructose overload early in life may be prevented by moderate aerobic exercise training.

  3. Exercise Training Prevents Cardiovascular Derangements Induced by Fructose Overload in Developing Rats.

    Science.gov (United States)

    Farah, Daniela; Nunes, Jonas; Sartori, Michelle; Dias, Danielle da Silva; Sirvente, Raquel; Silva, Maikon B; Fiorino, Patrícia; Morris, Mariana; Llesuy, Susana; Farah, Vera; Irigoyen, Maria-Cláudia; De Angelis, Kátia

    2016-01-01

    The risks of chronic diseases associated with the increasing consumption of fructose-laden foods are amplified by the lack of regular physical activity and have become a serious public health issue worldwide. Moreover, childhood eating habits are strongly related to metabolic syndrome in adults. Thus, we aimed to investigate the preventive role of exercise training undertaken concurrently with a high fructose diet on cardiac function, hemodynamics, cardiovascular autonomic modulation and oxidative stress in male rats after weaning. Male Wistar rats were divided into 4 groups (n = 8/group): Sedentary control (SC), Trained control (TC), Sedentary Fructose (SF) and Trained Fructose (TF). Training was performed on a treadmill (8 weeks, 40-60% of maximum exercise test). Evaluations of cardiac function, hemodynamics, cardiovascular autonomic modulation and oxidative stress in plasma and in left ventricle (LV) were performed. Chronic fructose overload induced glucose intolerance and an increase in white adipose tissue (WAT) weight, in myocardial performance index (MPI) (SF:0.42±0.04 vs. SC:0.24±0.05) and in arterial pressure (SF:122±3 vs. SC:113±1 mmHg) associated with increased cardiac and vascular sympathetic modulation. Fructose also induced unfavorable changes in oxidative stress profile (plasmatic protein oxidation- SF:3.30±0.09 vs. SC:1.45±0.08 nmol/mg prot; and LV total antioxidant capacity (TRAP)- SF: 2.5±0.5 vs. SC:12.7±1.7 uM trolox). The TF group showed reduced WAT, glucose intolerance, MPI (0.35±0.04), arterial pressure (118±2mmHg), sympathetic modulation, plasmatic protein oxidation and increased TRAP when compared to SF group. Therefore, our findings indicate that cardiometabolic dysfunctions induced by fructose overload early in life may be prevented by moderate aerobic exercise training.

  4. The Mythology of Information Overload.

    Science.gov (United States)

    Tidline, Tonyia J.

    1999-01-01

    Combines ideas from mythology, folklore, and library and information science to conclude that information overload is a myth of modern culture. Reports results of a pilot project intended to describe information overload experienced by a particular folk group composed of future library and information professionals. (Author/LRW)

  5. Volume Overload in Heart Failure: An Evidence-Based Review of Strategies for Treatment and Prevention.

    Science.gov (United States)

    Houston, Brian A; Kalathiya, Rohan J; Kim, Daniel A; Zakaria, Sammy

    2015-09-01

    Acute decompensated heart failure is the leading cause of hospital admission in the United States, with a high risk of readmission within 30 days. Most acute decompensated heart failure admissions are driven by congestive signs and symptoms resulting from fluid and sodium overload. We reviewed the evidence base addressing the management and prevention of fluid overload in heart failure, focusing on recent clinical trials. All the references in this review were obtained through PubMed and had at least 1 of the following key words: heart failure and volume overload, congestion, loop diuretics, thiazide diuretics, aldosterone antagonists, dopamine, cardiorenal syndrome, nesiritide, vasopressin antagonists, ultrafiltration, sodium restriction, fluid restriction, telemonitoring, and invasive hemodynamic monitoring. We also reviewed relevant references cited in the obtained articles, especially articles addressing methods of treating or preventing volume overload in patients with heart failure. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  6. Chronic Kidney Disease, Fluid Overload and Diuretics: A Complicated Triangle

    OpenAIRE

    Yusra Habib Khan; Azmi Sarriff; Azreen Syazril Adnan; Amer Hayat Khan; Tauqeer Hussain Mallhi

    2016-01-01

    Background Despite promising role of diuretics to manage fluid overload among chronic kidney disease (CKD) patients, their use is associated with adverse renal outcomes. Current study aimed to determine the extent of renal deterioration with diuretic therapy. Methods A total 312 non-dialysis dependent CKD (NDD-CKD) patients were prospectively followed-up for one year. Fluid overload was assessed via bioimpedance spectroscopy. Estimated GFR (eGFR) was calculated from serum creatinine values by...

  7. The role of n terminal - probrain natriuretic peptide in the diagnosis of hemodynamic persistent asrteriosus ductus in premature neonates patient

    Science.gov (United States)

    Dasraf, D.; Djer, M. M.; Advani, N.

    2017-08-01

    Persistent ductus arteriosus is one of the most frequent congenital heart diseases found in infants, mainly in preterms. Echocardiography is the gold standard for the diagnosis of hemodynamically significant patent ductus arteriosus (hs-PDA) in preterm neonates. A few studies have suggested that the use of a simple blood assay to detect N-terminal pro-brain natriuretic peptide (NT-proBNP) may be useful in determining the diagnosis and management of hs-PDA. No such studies have been conducted in Indonesia, although the assay kit and characteristics of the patient (gestational age and chronological age) influence the accuracy of NT-proBNP levels in determining hs-PDA. The aim of this study was to determine the association between the NT-proBNP level and the prevalence of hs-PDA in an Indonesian patient population. A cross-sectional study was conducted at Dr. Cipto Mangunkusumo Hospital. PDA was determined using echocardiography in 49 preterm neonates (gestational age groups: non-PDA, non-hsPDA, and hs-PDA. The blood NT-proBNP level was then determined in the non-hsPDA and hs-PDA groups, and between-group differences were compared. Among the 49 neonates, 33 patients had PDA, and 16 of these had hs-PDA. The results revealed a significant association between the NT-proBNP level and hs-PDA (p < 0.001).

  8. CFD: computational fluid dynamics or confounding factor dissemination? The role of hemodynamics in intracranial aneurysm rupture risk assessment.

    Science.gov (United States)

    Xiang, J; Tutino, V M; Snyder, K V; Meng, H

    2014-10-01

    Image-based computational fluid dynamics holds a prominent position in the evaluation of intracranial aneurysms, especially as a promising tool to stratify rupture risk. Current computational fluid dynamics findings correlating both high and low wall shear stress with intracranial aneurysm growth and rupture puzzle researchers and clinicians alike. These conflicting findings may stem from inconsistent parameter definitions, small datasets, and intrinsic complexities in intracranial aneurysm growth and rupture. In Part 1 of this 2-part review, we proposed a unifying hypothesis: both high and low wall shear stress drive intracranial aneurysm growth and rupture through mural cell-mediated and inflammatory cell-mediated destructive remodeling pathways, respectively. In the present report, Part 2, we delineate different wall shear stress parameter definitions and survey recent computational fluid dynamics studies, in light of this mechanistic heterogeneity. In the future, we expect that larger datasets, better analyses, and increased understanding of hemodynamic-biologic mechanisms will lead to more accurate predictive models for intracranial aneurysm risk assessment from computational fluid dynamics. © 2014 by American Journal of Neuroradiology.

  9. [Hemodynamic changes in hypoglycemic shock].

    Science.gov (United States)

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

    1977-01-01

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

  10. Overload road damage model

    CSIR Research Space (South Africa)

    Roux, MP

    2005-03-01

    Full Text Available .02 1.07 1.02 1.07 1.05 Current Condition: Provincial 1.07 1.17 1.03 1.08 1.05 1.12 1.05 1.12 1.09 Deteriorated Condition 1.14 1.27 1.06 1.14 1.10 1.18 1.10 1.20 1.15 TR 2005/26 - TBP51: Overload Road Damage Model Report – March 2005 CSIR... million Ave. O/L E80s/vehicle (n=4) Low High Average 1996 50,595 14,220 16% 1.28 19.7 40.4 30.1 1997 45,657 13,691 15% 1.31 18.8 38.9 28.9 1998 33,235 14,291 15% 1.22 17.6 36.2 26.9 1999 72,546 25,788 15% 1.13 16.3 33.4 24.9 2000 135...

  11. Death by information overload.

    Science.gov (United States)

    Hemp, Paul

    2009-09-01

    The value of information in the knowledge economy is indisputable, but so is its capacity to overwhelm consumers of it. HBR contributing editor Hemp reports on practical ways for individuals and organizations to avoid getting too much of a good thing. Ready access to useful information comes at a cost: As the volume increases, the line between the worthwhile and the distracting starts to blur. And ready access to you--via e-mail, social networking, and so on--exacerbates the situation: On average, Intel executives get 300 e-mails a day, and Microsoft workers need 24 minutes to return to work after each e-mail interruption. Clearly, productivity is taking a hit. Technological aids can help, such as e-mail management software for you, a message-volume regulation system for your organization, or even more-sophisticated solutions being developed by Microsoft, IBM, and others. Yet, battling technological interruptions on their own turf only goes so far. You also need to change your mind-set, perhaps by seeking help from personal-productivity experts or by simply accepting that you can't respond to every distraction that flits across your screen. Similarly, organizations must change their cultures, for instance by establishing clear e-communication protocols. In the end, only a multipronged approach will help you and your organization subdue the multiheaded monster of information overload. The secret is to manage the beast while still respecting it for the beautiful creature it is.

  12. Tanshinone IIA inhibits myocardial remodeling induced by pressure overload via suppressing oxidative stress and inflammation: Possible role of silent information regulator 1.

    Science.gov (United States)

    Feng, Jun; Li, Shusheng; Chen, Huawen

    2016-11-15

    Tanshinone IIA (Tan) exerts potential protective effects against cardiovascular diseases. Oxidative stress and inflammation are involved in cardiac hypertrophy. Activation of silent information regulator 1 (SIRT1) signaling has been suggested to attenuate cardiac hypertrophy. This study aims to evaluate the antioxidative and anti-inflammatory effects of Tan treatment in pressure overload-induced myocardial remodeling and elucidated its potential mechanisms. Sprague-Dawley rats were treated with Tan in the absence or presence of the SIRT1 inhibitor sirtinol (Snl) and then subjected to transverse aortic constriction (TAC). Tan conferred cardioprotective effects by improving cardiac function, reducing apoptosis and myocardial remodeling, upregulating SIRT1, Bcl-2 expressions, and downregulating Bax and caspase-3 expressions. Snl attenuated these effects by inhibiting SIRT1 signaling. Tan treatment also reduced myocardium malondialdehyde (MDA) content, and cardiac inflammatory cytokines (TNF-α and IL-6) and increased myocardium superoxide dismutase (SOD) level. However, these effects were also abolished by Snl. In conclusion, these results indicate that Tan significantly attenuates TAC-induced myocardial remodeling possibly due to its strong anti-oxidative and anti-inflammatory activity. Importantly, SIRT1 signaling activation is involved in this process. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. The roles of endoplasmic reticulum overload response induced by HCV and NS4B protein in human hepatocyte viability and virus replication.

    Directory of Open Access Journals (Sweden)

    Lingbao Kong

    Full Text Available Hepatitis C virus (HCV replication is associated with endoplasmic reticulum (ER and its infection triggers ER stress. In response to ER stress, ER overload response (EOR can be activated, which involves the release of Ca2+ from ER, production of reactive oxygen species (ROS and activation of nuclear factor κB (NF-κB. We have previously reported that HCV NS4B expression activates NF-κB via EOR-Ca2+-ROS pathway. Here, we showed that NS4B expression and HCV infection activated cancer-related NF-κB signaling pathway and induced the expression of cancer-related NF-κB target genes via EOR-Ca2+-ROS pathway. Moreover, we found that HCV-activated EOR-Ca2+-ROS pathway had profound effects on host cell viability and HCV replication. HCV infection induced human hepatocyte death by EOR-Ca2+-ROS pathway, whereas activation of EOR-Ca2+-ROS-NF-κB pathway increased the cell viability. Meanwhile, EOR-Ca2+-ROS-NF-κB pathway inhibited acute HCV replication, which could alleviate the detrimental effect of HCV on cell viability and enhance chronic HCV infection. Together, our findings provide new insights into the functions of EOR-Ca2+-ROS-NF-κB pathway in natural HCV replication and pathogenesis.

  14. Hemodynamic and neurohumoral effects of various grades of selective adenosine transport inhibition in humans. Implications for its future role in cardioprotection

    OpenAIRE

    Rongen, G.A.; Smits, P.; Verdonck, K.; Willemsen, J.J.; Abreu, R.A. de; Belle, H. van; Thien, Th.

    1995-01-01

    In 12 healthy male volunteers (27-53 yr), a placebo-controlled randomized double blind cross-over trial was performed to study the effect of the intravenous injection of 0.25, 0.5, 1, 2, 4, and 6 mg draflazine (a selective nucleoside transport inhibitor) on hemodynamic and neurohumoral parameters and ex vivo nucleoside transport inhibition. We hypothesized that an intravenous draflazine dosage without effect on hemodynamic and neurohumoral parameters would still be able to augment the forearm...

  15. Correlation between volume overload, chronic inflammation, and left ventricular dysfunction in chronic kidney disease patients.

    Science.gov (United States)

    Hassan, Muzamil Olamide; Duarte, Raquel; Dix-Peek, Therese; Vachiat, Ahmed; Naidoo, Sagren; Dickens, Caroline; Grinter, Sacha; Manga, Pravin; Naicker, Saraladevi

    Fluid overload is common in chronic kidney disease (CKD) patients, potentially driving chronic inflammation and left ventricular dysfunction. We investigated the association between volume overload, chronic inflammation, and left ventricular dysfunction across subgroups of CKD patients. The study included 160 participants, comprising peritoneal dialysis (PD), hemodialysis (HD), stage-3 CKD patients, and age- and sex-matched controls (40 in each group). Fluid status was assessed using a body composition monitor (BCM); serum endotoxin, lipopolysaccharide binding protein (LBP), C-reactive protein (CRP). and interleukin-6 (IL-6) levels were measured as markers of inflammation. Echocardiography was done to assess left ventricular dimension and function. Endotoxemia and volume overload were common across the spectrum of CKD patients and were aggravated by worsening kidney function. Among HD cohorts, postdialysis endotoxemia was increased among patients with dialysis-induced hemodynamic instability and was also closely related to ultrafiltration volume. Endotoxin, IL-6, CRP, and LBP levels were elevated in patients with volume overload compared to euvolemic patients (p < 0.05). Patients with elevated circulating endotoxemia had higher left ventricular mass index (LVMI) compared to patients with lower endotoxin levels. Fluid overload correlated with endotoxin levels, IL-6, and LVMI; while LVMI correlated weakly with LBP and CRP. CKD patients typically presented with significant endotoxemia and overt volume overload, which may contribute significantly to chronic low-grade inflammation and left ventricular dysfunction. An additive contribution from hemodialysis treatment may strongly enhance the severity of endotoxemia in HD patients.

  16. Genetics Home Reference: African iron overload

    Science.gov (United States)

    ... beer develop African iron overload , and not all individuals of African descent with iron overload drink the beer. Therefore, researchers are seeking genetic differences that affect the risk of developing this condition. ...

  17. Information overload in medical practice.

    Science.gov (United States)

    Zeldes, Nathan; Baum, Neil

    2011-01-01

    Most practices are inundated with an excess of information. This information overload, or "infoglut," results in distractions and a loss of productivity. This article will discuss the concept of infoglut and what every practice can do to manage the tsunami of information that threatens to consume our practices.

  18. [The use of gravitation overloading in the treatment of obliterative atherosclerosis of lower extremity arteries].

    Science.gov (United States)

    Galkin, R A; Kotel'nikov, G P; Makarov, I V; Oparin, A N

    2003-01-01

    The article sums up results of treatment of 152 patients with obliterating atherosclerosis of the lower extremity arteries which were exposed to 2-3 G gravitation overloading made in a centrifuge of a short radius in direction head--pelvis. The gravitation overloading in the regimen followed were not found to have negative effects of central hemodynamics. Peripheral circulation was noted to considerably improve which is confirmed: 1) by clinical data showing 2-5 times longer distance of painless walking; 2) by the data of ultrasound dopplerography manifested as larger volume rate of blood flow and regional perfusion index; 3) by thermographic explorations evidencing the recovery of the thermoprophile of the legs and feet. Thus, the application of gravitation overloading is a new effective method of conservative treatment of patients with the pathology in question.

  19. Role of terminal and anastomotic circulation in the patency of arteries jailed by flow-diverting stents: from hemodynamic changes to ostia surface modifications.

    Science.gov (United States)

    Iosif, Christina; Berg, Philipp; Ponsonnard, Sebastien; Carles, Pierre; Saleme, Suzana; Ponomarjova, Sanita; Pedrolo-Silveira, Eduardo; Mendes, George A C; Waihrich, Eduardo; Trolliard, Gilles; Couquet, Claude-Yves; Yardin, Catherine; Mounayer, Charbel

    2017-05-01

    OBJECTIVE The outcome for jailing arterial branches that emerge near intracranial aneurysms during flow-diverting stent (FDS) deployment remains controversial. In this animal study, the authors aimed to elucidate the role of collateral supply with regard to the hemodynamic changes and neointimal modifications that occur from jailing arteries with FDSs. To serve this purpose, the authors sought to quantify 1) the hemodynamic changes that occur at the jailed arterial branches immediately after stent placement and 2) the ostia surface values at 3 months after stenting; both parameters were investigated in the presence or absence of collateral arterial flow. METHODS After an a priori power analysis, 2 groups (Group A and Group B) were created according to an animal flow model for terminal and anastomotic arterial circulation; each group contained 7 Large White swine. Group A animals possessed an anastomotic-type arterial configuration to supply the territory of the right ascending pharyngeal artery (APhA), while Group B animals possessed a terminal-type arterial configuration to supply the right APhA territory. Subsequently, all animals underwent FDS placement, thereby jailing the right APhAs. Mean flow rates and velocities inside the jailed branches were quantified using time-resolved 3D phase-contrast MR angiography before and after stenting. Three months after stent placement, the jailed ostia surface values were quantified on scanning electron micrographs. The data were analyzed using descriptive statistics and group comparisons with parametric and nonparametric tests. RESULTS The endovascular procedures were feasible, and there were no findings of in situ thrombus formation on postprocedural optical coherence tomography or ischemia on postprocedural diffusion-weighted imaging. In Group A, the mean flow rate values at the jailed right APhAs were reduced immediately following stent placement as compared with values obtained before stent placement (p = 0.02, power: 0

  20. Hemodynamic Support in Sepsis

    Directory of Open Access Journals (Sweden)

    Fatih Yildiz

    2014-04-01

    Full Text Available Sepsis is called systemic inflammatory response syndrome due to infection. When added to organs failure and perfusion abnormality is defined in severe sepsis, Hypotension that do not respond to fluid therapy is as defined septic shock. Fluid resuscitation is a most important parts of the treatment in patients with septic shock. Ongoing hypotension that despite of the adequate fluid therapy, vasopressor support initiation is required. Sepsis and septic shock, hemodynamic support is often understood as the hemodynamic support. The different approaches to the development of methods to track and objective comes up. Patients with severe sepsis and septic shock should be follow in the intensive care unit and rapid fluid replacement and effectual hemodynamic support should be provided.

  1. New diagnostic and therapeutic approaches to treat ventricular tachycardias originating at the summit of the left ventricle role of merged hemodynamic-MRI and alternative ablation sources

    OpenAIRE

    Atienza, Felipe; Arenal Maíz, Ángel; Pérez David, Esther; Elízaga, Jaime; Ortuño Fisac, Juan Enrique; Ledesma Carbayo, María Jesús; Sánchez Quintana, Damian; Fernández Avilés, Francisco

    2013-01-01

    The left ventricular (LV) summit is the most common site of idiopathic epicardial LV arrhythmias and frequently represents a diagnostic and a therapeutic challenge.1 We present a case of sustained monomorphic ventricular tachycardia (SMVT) originating at the LV summit that underwent failed cryosurgical epicardial ablation and was successfully treated with the aid of merged hemodynamic and contrast-enhanced MRI (CE-MRI).

  2. [Chronic nicotinamide overload and type 2 diabetes].

    Science.gov (United States)

    Zhou, Shi-Sheng; Li, Da; Zhou, Yi-Ming; Sun, Wu-Ping; Liu, Xing-Xing; Lun, Yong-Zhi

    2010-02-25

    Type 2 diabetes is a major global health problem. It is generally accepted that type 2 diabetes is the result of gene-environmental interaction. However, the mechanism underlying the interaction is unclear. Diet change is known to play an important role in type 2 diabetes. The fact that the global high prevalence of type 2 diabetes has occurred following the spread of food fortification worldwide suggests a possible involvement of excess niacin intake. Our recent study found that nicotinamide overload and low nicotinamide detoxification may induce oxidative stress associated with insulin resistance. Based on the relevant facts, this review briefly summarized the relationship between the prevalence of type 2 diabetes and the nicotinamide metabolism changes induced by excess niacin intake, aldehyde oxidase inhibitors, liver diseases and functional defects of skin. We speculate that the gene-environmental interaction in type 2 diabetes may be a reflection of the outcome of the association of chronic nicotinamide overload-induced toxicity and the relatively low detoxification/excretion capacity of the body. Reducing the content of niacin in foods may be a promising strategy for the control of type 2 diabetes.

  3. Dietary Fat Overload Reprograms Brown Fat Mitochondria

    Directory of Open Access Journals (Sweden)

    DANIELE eLETTIERI BARBATO

    2015-09-01

    Full Text Available Chronic nutrient overload accelerates the onset of several aging-related diseases reducing life expectancy. Although the mechanisms by which overnutrition affects metabolic processes in many tissues are known, its role on BAT physiology is still unclear. Herein, we investigated the mitochondrial responses in BAT of female mice exposed to high fat diet (HFD at different steps of life. Although adult mice showed an unchanged mitochondrial amount, both respiration and OxPHOS subunits were strongly affected. Differently, offspring pups exposed to HFD during pregnancy and lactation displayed reduced mitochondrial mass but high oxidative efficiency that, however, resulted in increased bioenergetics state of BAT rather than augmented uncoupling respiration. Interestingly, the metabolic responses triggered by HFD were accompanied by changes in mitochondrial dynamics characterized by decreased content of the fragmentation marker Drp1 both in mothers and offspring pups. HFD-induced inactivation of the FoxO1 transcription factor seemed to be the up-stream modulator of Drp1 levels in brown fat cells. Furthermore, HFD offspring pups weaned with normal diet only partially reverted the mitochondrial dysfunctions caused by HFD. Finally these mice failed in activating the thermogenic program upon cold exposure. Collectively our findings suggest that maternal dietary fat overload irreversibly commits BAT unresponsiveness to physiological stimuli such as cool temperature and this dysfunction in the early stage of life might negatively modulates health and lifespan.

  4. Hemodynamic Profiling in Complicated Pregnancies

    NARCIS (Netherlands)

    J.M.J. Cornette (Jérôme)

    2016-01-01

    textabstractIn order to permit a successful pregnancy outcome, the cardiovascular system must undergo substantial changes. This thesis addresses the hemodynamics in several pregnancy complications. A general overview of normal hemodynamic adaptation to pregnancy is provided . Several techniques of

  5. Obesity and renal hemodynamics

    NARCIS (Netherlands)

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

    2006-01-01

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

  6. Physiology of hemodynamic homeostasis

    NARCIS (Netherlands)

    de Hert, Stefan

    2012-01-01

    Homeostasis of hemodynamics refers to the regulation of the blood circulation to meet the demands of the different organ and tissue systems. This homeostasis involves an intimate interaction between peripheral metabolic needs, vascular adaptations to meet these needs and cardiac adaptation to

  7. The C57BL/6 genetic background confers cardioprotection in iron-overloaded mice

    Science.gov (United States)

    Musumeci, Marco; Maccari, Sonia; Sestili, Paola; Massimi, Alessia; Corritore, Elisa; Marano, Giuseppe; Catalano, Liviana

    2013-01-01

    Background Chronic transfusion therapy causes a progressive iron overload that damages many organs including the heart. Recent evidence suggests that L-type calcium channels play an important role in iron uptake by cardiomyocytes under conditions of iron overload. Given that beta-adrenergic stimulation significantly enhances L-type calcium current, we hypothesised that beta-adrenergic blocking drugs could reduce the deleterious effects of iron overload on the heart. Methods Iron overload was generated by intraperitoneal injections of iron dextran (1g/kg) administered once a week for 8 weeks in male C57bl/6 mice, while propranolol was administered in drinking water at the dose of 40 mg/kg/day. Cardiac function and ventricular remodelling were evaluated by echocardiography and histological methods. Results As compared to placebo, iron injection caused cardiac iron deposition. Surprisingly, despite iron overload, myocardial function and ventricular geometry in the iron-treated mice resulted unchanged as compared to those in the placebo-treated mice. Administration of propranolol increased cardiac performance in iron-overloaded mice. Specifically, as compared to the values in the iron-overloaded group, in iron-overloaded animals treated with propranolol left ventricular fractional shortening increased (from 31.6% to 44.2%, P =0.01) whereas left ventricular end-diastolic diameter decreased (from 4.1±0.1 mm to 3.5±0.1 mm, P =0.03). Propranolol did not alter cardiac systolic function or left ventricular sizes in the placebo group. Conclusions These results demonstrate that C57bl/6 mice are resistant to iron overload-induced myocardial injury and that treatment with propranolol is able to increase cardiac performance in iron-overloaded mice. However, since C57bl/6 mice were resistant to iron-induced injury, it remains to be evaluated further whether propranolol could prevent iron-overload cardiomyopathy. PMID:22790263

  8. Sex differences play a role in cardiac endoplasmic reticulum stress (ERS) and ERS-initiated apoptosis induced by pressure overload and thapsigargin.

    Science.gov (United States)

    Sari, Flori R; Watanabe, Kenichi; Widyantoro, Bambang; Thandavarayan, Rajarajan A; Harima, Meilei; Kodama, Makoto; Aizawa, Yoshifusa

    2011-01-01

    Excessive endoplasmic reticulum stress (ERS) triggers myocardial apoptosis. Sex differences appear to be an important determinant in the occurrence of stress and apoptosis through many pathways, but the roles of sex differences in the cardiac ERS and ERS-initiated apoptosis are largely unknown. In the present study, we investigated the in vivo role of sex differences in the cardiac ERS and apoptosis elicited by ascending aortic banding surgery or thapsigargin (Thap) injection using male and female C57BL/6 JAX mice. The surgery significantly increased the expression levels of cardiac glucose-regulated protein (GRP)78 and CCAAT/enhancer binding protein homology protein (CHOP) protein, increased the myocardial apoptosis and decreased the sarcoplasmic reticulum Ca(2+)-ATPase isoform (SERCA)2 immunoreactivity in the male mice relative to female mice. Furthermore, during ERS induction using Thap, myocardial apoptosis and the expression levels of cardiac GRP78, inositol-requiring enzyme (Ire)1α and tumor necrosis factor receptor-associated factor (TRAF)2 were significantly increased in male mice relative to female mice. Sex differences significantly affected the above results. Our data suggest that sex differences affected the response of myocardial tissues in dealing with cardiac ERS and further result of ERS, apoptosis, at least in part through the regulation of SERCA2, CHOP, Ire1α and TRAF2. Copyright © 2011. Published by Elsevier Inc.

  9. Noninvasive assessment of filling pressure and left atrial pressure overload in severe aortic valve stenosis: relation to ventricular remodeling and clinical outcome after aortic valve replacement

    DEFF Research Database (Denmark)

    Dahl, Jordi S; Videbæk, Lars; Poulsen, Mikael K

    2011-01-01

    One of the hemodynamic consequences of aortic valve stenosis is pressure overload leading to left atrial dilatation. Left atrial size is a known risk factor providing prognostic information in several cardiac conditions. It is not known if this is also the case in patients with aortic valve...

  10. Intelligent Overload Control for Composite Web Services

    NARCIS (Netherlands)

    Meulenhoff, P.J.; Ostendorf, D.R.; Zivkovic, Miroslav; Meeuwissen, H.B.; Gijsen, B.M.M.

    In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules

  11. Intelligent overload control for composite web services

    NARCIS (Netherlands)

    Meulenhoff, P.J.; Ostendorf, D.R.; Živković, M.; Meeuwissen, H.B.; Gijsen, B.M.M.

    2009-01-01

    In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules

  12. Intelligent Overload Control for Composite Web Services

    NARCIS (Netherlands)

    Meulenhoff, P.J.; Ostendorf, D.R.; Zivkovic, Miroslav; Meeuwissen, H.B.; Gijsen, B.M.M.

    2009-01-01

    In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules

  13. A Test of the Urban Overload Hypothesis.

    Science.gov (United States)

    McCauley, Clark R.

    This paper briefly discusses three studies aimed at exploring the overload hypothesis posited by Stanley Milgram. That hypothesis suggests that impoverished social interaction in the city is an adaptation to overload of interpersonal contacts. The three studies examine various aspects of the phenomenon using different methodologies. Comparing city…

  14. The role of platelet-endothelial cell adhesion molecule-1 in atheroma formation varies depending on the site-specific hemodynamic environment.

    Science.gov (United States)

    Harrison, Matthew; Smith, Emily; Ross, Ewan; Krams, Robert; Segers, Dolf; Buckley, Christopher D; Nash, Gerard B; Rainger, G Ed

    2013-04-01

    Polymorphisms in the platelet-endothelial cell adhesion molecule (PECAM-1)-1 gene are linked to increased risk of coronary artery disease. Because PECAM-1 has been demonstrated to form a mechanosensory complex that can modulate inflammatory responses in murine arterial endothelial cells, we hypothesized that PECAM-1 contributes to atherogenesis in a shear-dependent and site-specific manner. ApoE(-/-) mice that were wild-type, heterozygous, or deficient in PECAM-1 were placed on a high-fat diet. Detailed analysis of the aorta at sites with differing hemodynamics revealed that PECAM-1-deficient mice had reduced disease in areas of disturbed flow, whereas plaque burden was increased in areas of steady, laminar flow. In concordance with these observations, bone marrow chimera experiments revealed that hematopoietic PECAM-1 resulted in accelerated atheroma formation in areas of laminar and disturbed flow, however endothelial PECAM-1 moderated disease progression in areas of high sheer stress. Moreover, using shear stress-modifying carotid cuffs, PECAM-1 was shown to promote macrophage recruitment into lesions developing in areas of low shear stress. PECAM-1 on bone marrow cells is proatherogenic irrespective of the hemodynamic environment, however endothelial cell PECAM-1 is antiatherogenic in high shear environments. Thus, targeting this pathway therapeutically would require a cell-type and context-specific strategy.

  15. Effects of pressure- or volume-overload hypertrophy on passive stiffness in isolated adult cardiac muscle cells

    Science.gov (United States)

    Kato, S.; Koide, M.; Cooper, G. 4th; Zile, M. R.

    1996-01-01

    It has been hypothesized that the changes in myocardial stiffness induced by chronic hemodynamic overloading are dependent on changes in the passive stiffness of the cardiac muscle cell (cardiocyte). However, no previous studies have examined the passive constitutive properties of cardiocytes isolated from animals with myocardial hypertrophy. Accordingly, changes in relative passive stiffness of cardiocytes isolated from animals with chronic pressure- or volume-overload hypertrophy were determined by examining the effects of anisosmotic stress on cardiocyte size. Anisosmotic stress was produced by altering superfusate osmolarity. Hypertrophied cardiocytes were enzymatically isolated from 16 adult cats with right ventricular (RV) pressure-overload hypertrophy induced by pulmonary artery banding (PAB) and from 6 adult cats with RV volume-overload hypertrophy induced by creating an atrial septal defect (ASD). Left ventricular (LV) cardiocytes from each cat served as nonhypertrophied, normally loaded, same-animal controls. Superfusate osmolarity was decreased from 305 +/- 3 to 135 +/- 5 mosM and increased to 645 +/- 4 mosM. During anisosmotic stress, there were no significant differences between hypertrophied RV and normal LV cardiocytes in pressure overload PAB cats with respect to percent change in cardiocyte area (47 +/- 2% in RV vs. 48 +/- 2% in LV), diameter (46 +/- 3% in RV vs. 48 +/- 2% in LV), or length (2.4 +/- 0.2% in RV vs. 2.0 +/- 0.3% in LV), or sarcomere length (1.5 +/- 0.1% in RV vs. 1.3 +/- 0.3% in LV). Likewise, there were no significant differences in cardiocyte strain between hypertrophied RV and normal LV cardiocytes from ASD cats. In conclusion, chronic pressure-overload hypertrophy and chronic volume-overload hypertrophy did not alter the cardiocyte response to anisosmotic stress. Thus chronic overload hypertrophy did not alter relative passive cardiocyte stiffness.

  16. Hemodynamic and neurohumoral effects of various grades of selective adenosine transport inhibition in humans. Implications for its future role in cardioprotection.

    Science.gov (United States)

    Rongen, G A; Smits, P; Ver Donck, K; Willemsen, J J; De Abreu, R A; Van Belle, H; Thien, T

    1995-02-01

    In 12 healthy male volunteers (27-53 yr), a placebo-controlled randomized double blind cross-over trial was performed to study the effect of the intravenous injection of 0.25, 0.5, 1, 2, 4, and 6 mg draflazine (a selective nucleoside transport inhibitor) on hemodynamic and neurohumoral parameters and ex vivo nucleoside transport inhibition. We hypothesized that an intravenous draflazine dosage without effect on hemodynamic and neurohumoral parameters would still be able to augment the forearm vasodilator response to intraarterially infused adenosine. Heart rate (electrocardiography), systolic blood pressure (Dinamap 1846 SX; Critikon, Portanje Electronica BV, Utrecht, The Netherlands) plasma norepinephrine and epinephrine increased dose-dependently and could almost totally be abolished by caffeine pretreatment indicating the involvement of adenosine receptors. Draflazine did not affect forearm blood flow (venous occlusion plethysmography). Intravenous injection of 0.5 mg draflazine did not affect any of the measured hemodynamic parameters but still induced a significant ex vivo nucleoside-transport inhibition of 31.5 +/- 4.1% (P < 0.05 vs placebo). In a subgroup of 10 subjects the brachial artery was cannulated to infuse adenosine (0.15, 0.5, 1.5, 5, 15, and 50 micrograms/100 ml forearm per min) before and after intravenous injection of 0.5 mg draflazine. Forearm blood flow amounted 1.9 +/- 0.3 ml/100 ml forearm per min for placebo and 1.8 +/- 0.2, 2.0 +/- 0.3, 3.8 +/- 0.9, 6.3 +/- 1.2, 11.3 +/- 2.2, and 19.3 +/- 3.9 ml/100 ml forearm per min for the six incremental adenosine dosages, respectively. After the intravenous draflazine infusion, these values were 1.6 +/- 0.2 ml/100 ml forearm per min for placebo and 2.1 +/- 0.3, 3.3 +/- 0.6, 5.8 +/- 1.1, 6.9 +/- 1.4, 14.4 +/- 2.9, and 23.5 +/- 4.0 ml/100 ml forearm per min, respectively (Friedman ANOVA: P < 0.05 before vs after draflazine infusion). In conclusion, a 30-50% inhibition of adenosine transport significantly

  17. Cerebrovascular hemodynamics during pranayama techniques

    Directory of Open Access Journals (Sweden)

    L Nivethitha

    2017-01-01

    Full Text Available Background: Pranayama techniques are known to produce variable physiological effects on the body. We evaluated the effect of the two commonly practiced Pranayama techniques on cerebral hemodynamics. Materials and Methods: Fifteen healthy male volunteers, trained in Yoga and Pranayama, were included in the study. Mean age was 24 years (range 22–32 years. Study participants performed 2 Pranayamas in 2 different orders. Order 1 (n = 7 performed Bhastrika (bellows breaths followed by Kumbhaka (breath retention while order 2 (n = 8 performed Kumbhaka followed by Bhastrika. Both breathing techniques were performed for 1 min each. Continuous transcranial Doppler (TCD monitoring was performed during the breathing techniques. TCD parameters that were recorded included peak systolic velocity (PSV, end-diastolic velocity (EDV, mean flow velocity (MFV, and pulsatility index (PI of the right middle cerebral artery at baseline, 15, 30, 45, and 60 s. Results: Significant reductions in EDV (3.67 ± 6.48; P< 0.001 and MFV (22.00 ± 7.30; P< 0.001 with a significant increase in PI (2.43 ± 0.76; P< 0.001 were observed during Bhastrika. On the contrary, a significant increase in PSV (65.27 ± 13.75; P< 0.001, EDV (28.67 ± 12.03; P< 0.001, and MFV (43.67 ± 12.85; P< 0.001 with a significant reduction in PI (0.89 ± 0.28; P< 0.01 was observed only during Kumbhaka. Conclusion: Bhastrika and Kumbhaka practices of Pranayama produce considerable and opposing effects on cerebral hemodynamic parameters. Our findings may play a potential role in designing the Pranayama techniques according to patients' requirements.

  18. Congenital heart malformations induced by hemodynamic altering surgical interventions

    Directory of Open Access Journals (Sweden)

    Madeline eMidgett

    2014-08-01

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

  19. Thermal Characterization of the Overload Carbon Resistors

    Directory of Open Access Journals (Sweden)

    Ivana Kostić

    2013-01-01

    Full Text Available In many applications, the electronic component is not continuously but only intermittently overloaded (e.g., inrush current, short circuit, or discharging interference. With this paper, we provide insight into carbon resistors that have to hold out a rarely occurring transient overload. Using simple electrical circuit, the resistor is overheating with higher current than declared, and dissipation is observed by a thermal camera.

  20. Cinnamaldehyde attenuates pressure overload-induced cardiac hypertrophy.

    Science.gov (United States)

    Yang, Liu; Wu, Qing-Qing; Liu, Yuan; Hu, Zhe-Fu; Bian, Zhou-Yan; Tang, Qi-Zhu

    2015-01-01

    Cinnamaldehyde is a major bioactive compound isolated from the leaves of Cinnamomum osmophloeum. Studies have demonstrated that cinnamaldehyde has anti-bacterial activity, anti-tumorigenic effect, immunomodulatory effect, anti-fungal activity, anti-oxidative effect, anti-inflammatory and anti-diabetic effect. It has been proven that Cinnamaldehyde improves ischemia/reperfusion injury of pre-treatment. However, little is known about the effect of cinnamaldehyde on cardiac hypertrophy. Aortic banding (AB) was performed to induce cardiac hypertrophy in mice. Cinnamaldehyde premixed in diets was administered to mice after one week of AB. Echocardiography and catheter-based measurements of hemodynamic parameters were performed at week 7 after starting cinnamaldehyde (8 weeks after surgery). The extent of cardiac hypertrophy was evaluated by pathological and molecular analyses of heart samples. Meanwhile, the effect of cinnamaldehyde on myocardial hypertrophy, fibrosis and dysfunction induced by AB was investigated, as was assessed by heart weigh/body weight, lung weight/body weight, heart weight/tibia length, echocardiographic and haemodynamic parameters, histological analysis, and gene expression of hypertrophic and fibrotic markers. Our data demonstrated that echocardiography and catheter-based measurements of hemodynamic parameters at week 7 revealed the amelioration of systolic and diastolic abnormalities by cinnamaldehyde intervention. Cardiac fibrosis in AB mice was also decreased by cinnamaldehyde. Moreover, the beneficial effect of cinnamaldehyde was associated with the normalization in gene expression of hypertrophic and fibrotic markers. Further studies showed that pressure overload significantly induced the activation of extracellular signal-regulated kinase (ERK) signaling pathway, which was blocked by cinnamaldehyde. Cinnamaldehyde may be able to retard the progression of cardiac hypertrophy and fibrosis, probably via blocking ERK signaling pathway.

  1. The impact of pressure overload on coronary vascular changes following myocardial infarction in rats

    Science.gov (United States)

    Chen, Jiqiu; Petrov, Artiom; Yaniz-Galende, Elisa; Liang, Lifan; de Haas, Hans J.; Narula, Jagat

    2013-01-01

    This study investigates the impact of pressure overload on vascular changes after myocardial infarction (MI) in rats. To evaluate the effect of pressure overload, MI was induced in three groups: 1) left coronary artery ligation for 1 mo (MI-1m), 2) ischemia 30 min/reperfusion for 1 mo (I/R-1m), and 3) ischemia-reperfusion (I/R) was performed after pressure overload induced by aortic banding for 2 mo; 1 mo post-I/R, aortic constriction was released (Ab+I/R+DeAb). Heart function was assessed by echocardiography and in vivo hemodynamics. Resin casting and three-dimensional imaging with microcomputed tomography were used to characterize changes in coronary vasculature. TTC (triphenyltetrazohum chloride) staining and Masson's Trichrome were conducted in parallel experiments. In normal rats, MI induced by I/R and permanent occlusion was transmural or subendocardial. Occluded arterial branches vanished in MI-1m rats. A short residual tail was retained, distal to the occluded site in the ischemic area in I/R-1m hearts. Vascular pathological changes in transmural MI mostly occurred in ischemic areas and remote vasculature remained normal. In pressure overloaded rats, I/R injury induced a sub-MI in which ischemia was transmural, but myocardium in the involved area had survived. The ischemic arterial branches were preserved even though the capillaries were significantly diminished and the pathological changes were extended to remote areas, characterized by fibrosis, atrial thrombus, and pulmonary edema in the Ab+I/R+DeAb group. Pressure overload could increase vascular tolerance to I/R injury, but also trigger severe global ventricular fibrosis and results in atrial thrombus and pulmonary edema. PMID:23275620

  2. Role of levosimendan in the management of subarachnoid hemorrhage.

    Science.gov (United States)

    Varvarousi, Giolanda; Xanthos, Theodoros; Sarafidou, Pavlina; Katsioula, Ellisavet; Georgiadou, Marianthi; Eforakopoulou, Maria; Pavlou, Hlias

    2016-02-01

    Aneurysmal subarachnoid hemorrhage (aSAH) is one of the leading causes of neurologic disability accounting for dismal long term survival rates. aSAH leads to a sudden increase in intracranial pressure and a massive sympathetic discharge. Excessive sympathetic stimulation leads to catecholamine mediated myocardial dysfunction and hemodynamic instability which may critically hamper brain perfusion and oxygenation. In the setting of acute aSAH, administration of vasoactive drugs aims at stabilizing impaired hemodynamics. However, studies have shown that conventional treatment with vasoactive drugs that lead to Ca(+2) overload and increase myocardial oxygen consumption, fail to restore hemodynamics and decrease cerebral blood flow. Levosimendan is a non-adrenergic inotropic Ca(+2) sensitizer with not only beneficial hemodynamic properties but also pleiotropic effects, contributing to its cardioprotective and neuroprotective role. Although there have been limited data available regarding the use of levosimendan in patients with aSAH, current evidence suggests that levosimendan may have a role in the setting of post-aSAH cardiomyopathy and decreased cerebral blood flow both in the emergency departments and in intensive care units. The purpose of this review is to provide an overview of studies of levosimendan therapy for aSAH, and describe current knowledge about the effects of levosimendan in the management of aSAH. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Myocardial ECV Fraction Assessed by CMR Is Associated With Type of Hemodynamic Load and Arrhythmia in Repaired Tetralogy of Fallot.

    Science.gov (United States)

    Chen, Chun-An; Dusenbery, Susan M; Valente, Anne Marie; Powell, Andrew J; Geva, Tal

    2016-01-01

    The aim of this study was to investigate the extent of diffuse myocardial fibrosis by measuring left (LV) and right ventricular (RV) extracellular volume fraction (ECV) in patients with repaired tetralogy of Fallot (rTOF) and to explore its association with ventricular remodeling, hemodynamic load, and clinical parameters. Focal myocardial fibrosis is prevalent in patients with rTOF. However, little is known about the extent of diffuse myocardial fibrosis and its clinical implications in this population. We measured ECV by pre- and post-gadolinium T1 measurements using a 1.5-T scanner in 84 patients with rTOF (median age 23.3 years). LV ECV was determined by averaging values from 6 short-axis mid-ventricular segments, and RV ECV was calculated by averaging values from the anterior-inferior and the diaphragmatic RV wall segments. LV ECV above the upper limit of normal (>28%) was observed in 11 patients and for RV ECV (>41%) in 9 patients. LV ECV correlated positively with RV ECV (r = 0.54; p ECV was associated with female gender, lower RV mass-to-volume ratio, lower RV outflow tract pressure gradient, and having volume overload as the predominant hemodynamic burden (all p ECV. In multivariable analysis, increased LV ECV was independently associated with arrhythmia, adjusting for age and RV mass index (odds ratio: 5.69; p = 0.031). In this cohort, LV and RV ECV values were positively correlated, indicating an adverse ventricular-ventricular interaction at the tissue level. Increased ECV was associated with RV volume overload and arrhythmia. These findings may lead to future studies exploring the role of ECV in improving risk stratification and guiding therapeutic interventions. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Natural history and information overload: The case of Linnaeus.

    Science.gov (United States)

    Müller-Wille, Staffan; Charmantier, Isabelle

    2012-03-01

    Natural History can be seen as a discipline paradigmatically engaged in 'data-driven research.' Historians of early modern science have begun to emphasize its crucial role in the Scientific Revolution, and some observers of present day genomics see it as engaged in a return to natural history practices. A key concept that was developed to understand the dynamics of early modern natural history is that of 'information overload.' Taxonomic systems, rules of nomenclature, and technical terminologies were developed in botany and zoology to catch up with the ever increasing amount of information on hitherto unknown plant and animal species. In our contribution, we want to expand on this concept. After all, the same people who complain about information overload are usually the ones who contribute to it most significantly. In order to understand this complex relationship, we will turn to the annotation practices of the Swedish naturalist Carl Linnaeus (1707-1778). The very tools that Linnaeus developed to contain and reduce information overload, as we aim to demonstrate, facilitated a veritable information explosion that led to the emergence of a new research object in botany: the so-called 'natural' system. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Baroreflex function in conscious rats submitted to iron overload

    Directory of Open Access Journals (Sweden)

    L.M. Cardoso

    2005-02-01

    Full Text Available Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12, 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19, a smaller amount of elemental iron was injected (10 mg, daily for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg or sodium nitroprusside (1.0 to 10.0 µg/kg. Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold, in contrast to the TIO group (2-fold. Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively. The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity.

  6. Toll‐Like Receptor‐2 Mediates Adaptive Cardiac Hypertrophy in Response to Pressure Overload Through Interleukin‐1β Upregulation via Nuclear Factor κB Activation

    Science.gov (United States)

    Higashikuni, Yasutomi; Tanaka, Kimie; Kato, Megumi; Nureki, Osamu; Hirata, Yasunobu; Nagai, Ryozo; Komuro, Issei; Sata, Masataka

    2013-01-01

    Background Inflammation is induced in the heart during the development of cardiac hypertrophy. The initiating mechanisms and the role of inflammation in cardiac hypertrophy, however, remain unclear. Toll‐like receptor‐2 (TLR2) recognizes endogenous molecules that induce noninfectious inflammation. Here, we examined the role of TLR2‐mediated inflammation in cardiac hypertrophy. Methods and Results At 2 weeks after transverse aortic constriction, Tlr2−/− mice showed reduced cardiac hypertrophy and fibrosis with greater left ventricular dilatation and impaired systolic function compared with wild‐type mice, which indicated impaired cardiac adaptation in Tlr2−/− mice. Bone marrow transplantation experiment revealed that TLR2 expressed in the heart, but not in bone marrow–derived cells, is important for cardiac adaptive response to pressure overload. In vitro experiments demonstrated that TLR2 signaling can induce cardiomyocyte hypertrophy and fibroblast and vascular endothelial cell proliferation through nuclear factor–κB activation and interleukin‐1β upregulation. Systemic administration of a nuclear factor–κB inhibitor or anti–interleukin‐1β antibodies to wild‐type mice resulted in impaired adaptive cardiac hypertrophy after transverse aortic constriction. We also found that heat shock protein 70, which was increased in murine plasma after transverse aortic constriction, can activate TLR2 signaling in vitro and in vivo. Systemic administration of anti–heat shock protein 70 antibodies to wild‐type mice impaired adaptive cardiac hypertrophy after transverse aortic constriction. Conclusions Our results demonstrate that TLR2‐mediated inflammation induced by extracellularly released heat shock protein 70 is essential for adaptive cardiac hypertrophy in response to pressure overload. Thus, modulation of TLR2 signaling in the heart may provide a novel strategy for treating heart failure due to inadequate adaptation to hemodynamic

  7. The role of ventilation mode using a laryngeal mask airway during gynecological laparoscopy on lung mechanics, hemodynamic response and blood gas analysis.

    Science.gov (United States)

    Jarahzadeh, Mohammad Hossein; Halvaei, Iman; Rahimi-Bashar, Farshid; Behdad, Shekoufeh; Abbasizadeh Nasrabady, Rouhollah; Yasaei, Elahe

    2016-12-01

    There are two methods for ventilation in gynecological laparoscopy: volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). To compare the lung mechanics, hemodynamic response and arterial blood gas analysis and gas exchange of two modes of VCV and PCV using laryngeal mask airway (LMA) at different time intervals. Sixty infertile women referred for diagnostic laparoscopy, based on ventilation mode, were randomly divided into two groups of VCV (tidal volume: 10 ml/kg) and PCV. In the PCV group, ventilation was initiated with a peak airway pressure (tidal volume: 10 ml/kg, upper limit: 35 cm H2O). In both groups, the arterial blood samples were taken in several time intervals (5, 10 and 15 min after LMA insertion) for blood gas evaluation. Also the lung mechanics parameters were continuously monitored and were recorded at different time intervals. There were no significant differences for patient's age, weight, height and BMI in two groups. The peak and plateau airway pressure were significantly higher in VCV group compared to PCV group 5 and 10 min after insertion of LMA. PaO2 was significantly higher after 10 and 15 min in VCV group compared to PCV group (p=0.005 and p=0.03, respectively). PaCO2 showed significant increase after 5 min in PCV group, but the differences were not significant after 10 and 15 min in two groups. The end tidal CO2 showed significant increase after 10 and 15 min in VCV compared to PCV group. Both VCV and PCV seem to be suitable for gynecological laparoscopy. However, airway pressures are significantly lower in PCV compared to VCV.

  8. GLUT4 Is Not Necessary for Overload-Induced Glucose Uptake or Hypertrophic Growth in Mouse Skeletal Muscle.

    Science.gov (United States)

    McMillin, Shawna L; Schmidt, Denise L; Kahn, Barbara B; Witczak, Carol A

    2017-06-01

    GLUT4 is necessary for acute insulin- and contraction-induced skeletal muscle glucose uptake, but its role in chronic muscle loading (overload)-induced glucose uptake is unknown. Our goal was to determine whether GLUT4 is required for overload-induced glucose uptake. Overload was induced in mouse plantaris muscle by unilateral synergist ablation. After 5 days, muscle weights and ex vivo [3H]-2-deoxy-d-glucose uptake were assessed. Overload-induced muscle glucose uptake and hypertrophic growth were not impaired in muscle-specific GLUT4 knockout mice, demonstrating that GLUT4 is not necessary for these processes. To assess which transporters mediate overload-induced glucose uptake, chemical inhibitors were used. The facilitative GLUT inhibitor cytochalasin B, but not the sodium-dependent glucose cotransport inhibitor phloridzin, prevented overload-induced uptake demonstrating that GLUTs mediate this effect. To assess which GLUT, hexose competition experiments were performed. Overload-induced [3H]-2-deoxy-d-glucose uptake was not inhibited by d-fructose, demonstrating that the fructose-transporting GLUT2, GLUT5, GLUT8, and GLUT12 do not mediate this effect. To assess additional GLUTs, immunoblots were performed. Overload increased GLUT1, GLUT3, GLUT6, and GLUT10 protein levels twofold to fivefold. Collectively, these results demonstrate that GLUT4 is not necessary for overload-induced muscle glucose uptake or hypertrophic growth and suggest that GLUT1, GLUT3, GLUT6, and/or GLUT10 mediate overload-induced glucose uptake. © 2017 by the American Diabetes Association.

  9. Hepatic iron overload following liver transplantation of a C282y homozygous allograft: a case report and literature review.

    LENUS (Irish Health Repository)

    Dwyer, Jeremy P

    2011-11-01

    Hereditary haemochromatosis is a common genetic disease associated with progressive iron overload and parenchymal organ damage including liver, pancreas and heart. We report a case of inadvertent transplantation of a liver from a haemochromatosis donor to a 56-year-old Asian female. Progressive iron overload occurred over a 2 year follow up as assessed by liver biopsy and iron studies in the absence of a secondary cause of iron overload, supporting a primary role of liver rather than small intestine in the regulation of iron homeostasis in hereditary haemochromatosis.

  10. Control over Permissible Short Emergency Overloads in Power Transformers

    Directory of Open Access Journals (Sweden)

    V. A. Anischenko

    2010-01-01

    Full Text Available The paper proposes a method for determination a permissible duration of short intermittent overloads of power transformers that permits to avoid non-permissible over-heating of winding insulation and fully utilize overloading transformer ability.

  11. Overload blunts baroreflex only in overreached athletes.

    Science.gov (United States)

    Bourdillon, Nicolas; Yazdani, Sasan; Nilchian, Masih; Mariano, Alessio; Vesin, Jean-Marc; Millet, Grégoire P

    2018-01-31

    Heart rate variability (HRV) is commonly used to diagnose overreaching and monitor athletes' responses to training. Baroreflex sensitivity (BRS) is modified by changes in training load and might be another means to detect overreaching. The goal of this study was to assess BRS and HRV changes in two groups of athletes responding either negatively (FOR) or positively (AF) to similar training overload. Fifteen athletes performed 2-week baseline (BSL) training followed by 3-week overload (+45%; OVL) and 2-week recovery (-20%; RCV). HRV, training load and subjective fatigue were measured daily via questionnaires. BRS, salivary cortisol and testosterone, and submaximal exercise and maximal 3-km run performances were measured at the end of each period. Based on their performance change during OVL, 8 athletes were diagnosed as FOR and 7 as AF. Subjective fatigue was increased in FOR athletes during OVL. BRS increased in AF but not in FOR athletes during RCV. At the end of RCV, cortisol and testosterone were higher than BSL in both groups. Three weeks of similar training overload can induce either performance enhancement or overreaching. The changes in submaximal exercise and maximal performances and in subjective fatigue were the fastest-responding parameters that distinguished the two groups of athletes during OVL. Training overload blunted the increase in BRS in FOR only. Most of the differences in BRS were observed during the recovery period. BRS appears to be a more sensitive parameter than HRV for early monitoring of responses to training. Copyright © 2018. Published by Elsevier Ltd.

  12. Iron overload in myelodysplastic syndromes (MDS).

    Science.gov (United States)

    Gattermann, Norbert

    2018-01-01

    Iron overload (IOL) starts to develop in MDS patients before they become transfusion-dependent because ineffective erythropoiesis suppresses hepcidin production in the liver and thus leads to unrestrained intestinal iron uptake. However, the most important cause of iron overload in MDS is chronic transfusion therapy. While transfusion dependency by itself is a negative prognostic factor reflecting poor bone marrow function, the ensuing transfusional iron overload has an additional dose-dependent negative impact on the survival of patients with lower risk MDS. Cardiac dysfunction appears to be important in this context, as a consequence of chronic anemia, age-related cardiac comorbidity, and iron overload. Another potential problem is iron-related endothelial dysfunction. There is some evidence that with increasing age, high circulating iron levels worsen the atherosclerotic phenotype. Transfusional IOL also appears to aggravate bone marrow failure in MDS, through unfavorable effects on mesenchymal stromal cells as well a hematopoietic cells, particularly erythroid precursors. Patient series and clinical trials have shown that the iron chelators deferoxamine and deferasirox can improve hematopoiesis in a minority of transfusion-dependent patients. Analyses of registry data suggest that iron chelation provides a survival benefit for patients with MDS, but data from a prospective randomized clinical trial are still lacking.

  13. Aggradation in rivers due to overloading

    NARCIS (Netherlands)

    Ribberink, J.S.; Van der Sande, J.T.M.

    1984-01-01

    The problem of aggradation in a river due to overloading is tackled with a mathematical model consisting of a set of one-dimensional (in space) basic equations in which the water motion is assumed to be quasi-steady and the sediment transport is determined by local conditions. Analytical solutions

  14. Immediate hemodynamic response to furosemide in patients undergoing chronic hemodialysis.

    Science.gov (United States)

    Schmieder, R E; Messerli, F H; deCarvalho, J G; Husserl, F E

    1987-01-01

    To evaluate the effect of furosemide on cardiovascular hemodynamics in patients with end-stage renal failure, we studied ten patients undergoing hemodialysis three times a week. Arterial pressure, heart rate, and cardiac output (indocyanine green dye) were measured in triplicate; total peripheral resistance and central blood volume were calculated by standard formulas. Hemodynamics were determined at baseline and 5, 10, 15, and 30 minutes after intravenous (IV) bolus injection of furosemide 60 mg. Furosemide produced a decrease in central blood volume of -13% +/- 2.2% from pretreatment values (P less than .01) that was most pronounced five minutes after injection, together with a fall in cardiac output (from 6.76 +/- 0.59 to 6.17 +/- 0.52 L/min, P less than .10). Stroke volume decreased with a maximum fall occurring after 15 minutes (from 84 +/- 7 to 79 +/- 7 mL/min, P less than .05), and total peripheral resistance increased (from 15.8 +/- 2.1 to 17.8 +/- 2.3 units, P less than .05) after furosemide. Arterial pressure and heart rate did not change. The decrease in central blood volume reflects a shift of the total blood volume from the cardiopulmonary circulation to the periphery, suggesting dilation of the peripheral venous bed. Thus, even in patients undergoing hemodialysis, furosemide acutely decreases left ventricular preload by venous dilation and should therefore prove to be beneficial in acute volume overload.

  15. Effect of anabolic steroids on overloaded and overloaded suspended skeletal muscle

    Science.gov (United States)

    Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

    1987-01-01

    The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass, the subcellular protein content, and the myosin patterns of normal overloaded and suspended overloaded plantaris muscle in female rat was investigated, dividing rats into six groups: normal control (NC), overload (OV), OV steroid (OV-S), normal suspended (N-sus), OV suspended (OV-sus), and OV suspended steroid (OV-sus-S). Relative to control values, overload produced a sparing effect on the muscle weight of the OV-sus group as well as increases of muscle weight of the OV group; increased protein content; and an increased expression of slow myosin in both OV and OV-sus groups. Steroid treatment of OV animals did not after the response of any parameter analyzed for the OV group, but in the OV-sus group steroid treatment induced increases in muscle weight and in protein content of the OV-sus-S group. The treatment did not alter the pattern of isomyosin expression observed in the OV or the OV-sus groups. These result suggest that the steroid acts synergistically with functional overload only under conditions in which the effect of overload is minimized by suspension.

  16. News and the overloaded consumer: factors influencing information overload among news consumers.

    Science.gov (United States)

    Holton, Avery E; Chyi, Hsiang Iris

    2012-11-01

    News producers continue to increase their volume of production and delivery platforms in an effort to reach and maintain news consumers. However, consumers may not necessarily find more news desirable. Previous studies have suggested that information surplus can lead to negative outcomes for consumers, but research of outcomes related to news production and consumption has been scant. This study explores novel areas of news surplus and overload, empirically examining factors associated with the degree of perceived overload across a broad spectrum of news delivery platforms. The findings reveal that the majority of today's news consumers feel overloaded with the amount of news they are confronted with. Gender, news interest, and the use of specific news platforms and outlets predict the degree of that overload. News access through platforms and outlets such as computers, e-readers, and Facebook is positively associated with overload, whereas other platforms such as television and the iPhone are negatively associated with overload. Implications for media psychology and news consumption are discussed.

  17. The importance of tricuspid regurgitation and right ventricular overload in ICD/CRT recipients: beside the left, beyond the left.

    Science.gov (United States)

    Fazio, Serafino; Carlomagno, Guido

    2011-10-01

    Device therapy for advanced heart failure has become increasingly employed in the last 10 years. Several retrospective studies have postulated a harmful effect of implantable cardioverter-defibrillator (ICD) lead placement on tricuspid valve function and right heart hemodynamics, in particular among patients with preexisting pulmonary vascular overload and both left and right ventricular remodeling/dysfunction. This functional hypothesis is also supported by long-term clinical follow-up analyses of ICD and cardiac resynchronization therapy recipients. In this viewpoint, we propose that the possibility of worsening tricuspid regurgitation and consequent hemodynamic deterioration following device implantation should be considered in future studies, as well as in the preimplant evaluation of individual candidates among other clinical factors.  ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

  18. Hemodynamics Modeling and Simulation of Anterior Communicating Artery Aneurysms

    Directory of Open Access Journals (Sweden)

    Jianjun Li

    2014-07-01

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

  19. Childhood moyamoya disease: hemodynamic MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-01

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

  20. Uncoupling and oxidative stress in liver mitochondria isolated from rats with acute iron overload

    Energy Technology Data Exchange (ETDEWEB)

    Pardo Andreu, G.L. [Centro de Quimica Farmaceutica, Departamento de Investigaciones Biomedicas, Ciudad de La Habana (Cuba); Inada, N.M.; Vercesi, A.E. [Universidade Estadual de Campinas, Departamento de Patologia Clinica, Faculdade de Ciencias Medicas, Campinas, SP (Brazil); Curti, C. [Universidade de Sao Paulo, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, SP (Brazil)

    2009-01-15

    One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21{+-}4 to 130{+-}7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H{sup +} leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria. (orig.)

  1. Biochemical Competition Makes Fatty-Acid beta-Oxidation Vulnerable to Substrate Overload

    NARCIS (Netherlands)

    van Eunen, Karen; Simons, Sereh M. J.; Gerding, Albert; Bleeker, Aycha; den Besten, Gijs; Touw, Catharina M. L.; Houten, Sander M.; Groen, Bert K.; Krab, Klaas; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid beta-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and

  2. CQ Switch Analysis under Traffic Overload

    Directory of Open Access Journals (Sweden)

    I. Maljević

    2011-06-01

    Full Text Available An analysis of 2x2 crossbar packet switch with buffers at crosspoints and round robin scheduling algorithm is presented in this paper. The analysis is performed for a non-admissible traffic pattern, where output ports are overloaded. The case of full offered load is observed and output ports are loaded with packets that have different arrival probabilities. In addition to the parameters that are commonly observed in such an analysis (throughput and average packet delay, memory requirements for the implementation of the buffer, as well as fair representation when servicing the buffer - the so-called fairness are also analyzed. The results show that even for a switch with a small number of ports very large buffers should be implemented, if we want to achieve satisfactory performance under traffic overload.

  3. Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle.

    Directory of Open Access Journals (Sweden)

    Satoshi Nakada

    Full Text Available External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK, moderate (MO, middle (MI, and strong (ST overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity increased with increasing overload, with increases of 1.8-fold (MO, 2.2-fold (MI, and 2.5-fold (ST, respectively, relative to non-overloaded muscle (NL in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98. The phosphorylated form of p70S6K (a positive regulator of translational efficiency showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO, 17.4-fold (MI, and 18.2-fold (ST, respectively, relative to NL in the WK group. These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size.

  4. Ablation of biglycan attenuates cardiac hypertrophy and fibrosis after left ventricular pressure overload.

    Science.gov (United States)

    Beetz, Nadine; Rommel, Carolin; Schnick, Tilman; Neumann, Elena; Lother, Achim; Monroy-Ordonez, Elsa Beatriz; Zeeb, Martin; Preissl, Sebastian; Gilsbach, Ralf; Melchior-Becker, Ariane; Rylski, Bartosz; Stoll, Monika; Schaefer, Liliana; Beyersdorf, Friedhelm; Stiller, Brigitte; Hein, Lutz

    2016-12-01

    Biglycan, a small leucine-rich proteoglycan, has been shown to play an important role in stabilizing fibrotic scars after experimental myocardial infarction. However, the role of biglycan in the development and regression of cardiomyocyte hypertrophy and fibrosis during cardiac pressure overload and unloading remains elusive. Thus, the aim of the present study was to assess the effect of biglycan on cardiac remodeling in a mouse model of left ventricular pressure overload and unloading. Left ventricular pressure overload induced by transverse aortic constriction (TAC) in mice resulted in left ventricular dysfunction, fibrosis and increased biglycan expression. Fluorescence- and magnetic-assisted sorting of cardiac cell types revealed upregulation of biglycan in the fibroblast population, but not in cardiomyocytes, endothelial cells or leukocytes after TAC. Removal of the aortic constriction (rTAC) after short-term pressure overload (3weeks) improved cardiac contractility and reversed ventricular hypertrophy but not fibrosis in wild-type (WT) mice. Biglycan ablation (KO) enhanced functional recovery but did not resolve cardiac fibrosis. After long-term TAC for 9weeks, ablation of biglycan attenuated the development of cardiac hypertrophy and fibrosis. In vitro, biglycan induced hypertrophy of neonatal rat cardiomyocytes and led to activation of a hypertrophic gene program. Putative downstream mediators of biglycan signaling include Rcan1, Abra and Tnfrsf12a. These genes were concordantly induced by TAC in WT but not in biglycan KO mice. Left ventricular pressure overload induces biglycan expression in cardiac fibroblasts. Ablation of biglycan improves cardiac function and attenuates left ventricular hypertrophy and fibrosis after long-term pressure overload. In vitro biglycan induces hypertrophy of cardiomyocytes, suggesting that biglycan may act as a signaling molecule between cell types to modulate cardiac remodeling. Copyright © 2016 Elsevier Ltd. All rights

  5. Chronic Kidney Disease, Fluid Overload and Diuretics: A Complicated Triangle.

    Science.gov (United States)

    Khan, Yusra Habib; Sarriff, Azmi; Adnan, Azreen Syazril; Khan, Amer Hayat; Mallhi, Tauqeer Hussain

    2016-01-01

    Despite promising role of diuretics to manage fluid overload among chronic kidney disease (CKD) patients, their use is associated with adverse renal outcomes. Current study aimed to determine the extent of renal deterioration with diuretic therapy. A total 312 non-dialysis dependent CKD (NDD-CKD) patients were prospectively followed-up for one year. Fluid overload was assessed via bioimpedance spectroscopy. Estimated GFR (eGFR) was calculated from serum creatinine values by using Chronic Kidney Disease- Epidemiology Collaboration (CKD-EPI) equation. Out of 312 patients, 64 (20.5%) were hypovolemic while euvolemia and hypervolemia were observed in 113 (36.1%) and 135 (43.4%) patients. Overall 144 patients were using diuretics among which 98 (72.6%) were hypervolemic, 35 (30.9%) euvolemic and 11 (17.2%) were hypovolemic. The mean decline in estimated GFR of entire cohort was -2.5 ± 1.4 ml/min/1.73m2 at the end of follow up. The use of diuretics was significantly associated with decline in eGFR. A total of 36 (11.5%) patients initiated renal replacement therapy (RRT) and need of RRT was more profound among diuretic users. The use of diuretics was associated with adverse renal outcomes indicated by decline in eGFR and increasing risk of RRT initiation in our cohort of NDD-CKD patients. Therefore, it is cautiously suggested to carefully prescribe diuretics by keeping in view benefit versus harm for each patient.

  6. Information overload in healthcare: too much of a good thing?

    Science.gov (United States)

    Klerings, Irma; Weinhandl, Alexandra S; Thaler, Kylie J

    2015-01-01

    The rapidly growing production of healthcare information - both scientific and popular - increasingly leads to a situation of information overload affecting all actors of the healthcare system and threatening to impede the adoption of evidence-based practice. In preparation for the 2015 Cochrane Colloquium in Vienna, we discuss the issues faced by three major actors of this system: patients, healthcare practitioners, and systematic reviewers. We analyze their situation through the concept of "filter failure", positing that the main problem is not that there is "too much information", but that the traditional means of managing and evaluating information are ill-suited to the realities of the digital age. Some of the major instances of filter failure are inadequate information retrieval systems for point-of-care settings, the problem of identifying all relevant evidence in an exceedingly diverse landscape of information resources, and the very basic lack of health information literacy, concerning not only the general public. Finally, we give an overview of proposed solutions to the problem of information overload. These new or adapted filtering systems include adapting review literature to the specific needs of practitioners or patients, technological improvements to information systems, strengthening the roles of intermediaries, as well as improving health literacy. Copyright © 2015. Published by Elsevier GmbH.

  7. Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Shin Fujimaki

    2016-01-01

    Full Text Available Skeletal muscle represents a plentiful and accessible source of adult stem cells. Skeletal-muscle-derived stem cells, termed satellite cells, play essential roles in postnatal growth, maintenance, repair, and regeneration of skeletal muscle. Although it is well known that the number of satellite cells increases following physical exercise, functional alterations in satellite cells such as proliferative capacity and differentiation efficiency following exercise and their molecular mechanisms remain unclear. Here, we found that functional overload, which is widely used to model resistance exercise, causes skeletal muscle hypertrophy and converts satellite cells from quiescent state to activated state. Our analysis showed that functional overload induces the expression of MyoD in satellite cells and enhances the proliferative capacity and differentiation potential of these cells. The changes in satellite cell properties coincided with the inactivation of Notch signaling and the activation of Wnt signaling and likely involve modulation by transcription factors of the Sox family. These results indicate the effects of resistance exercise on the regulation of satellite cells and provide insight into the molecular mechanism of satellite cell activation following physical exercise.

  8. Altering hemodynamics leads to congenital heart defects (Conference Presentation)

    Science.gov (United States)

    Ford, Stephanie M.; McPheeters, Matthew T.; Wang, Yves T.; Gu, Shi; Doughman, Yong Qiu; Strainic, James P.; Rollins, Andrew M.; Watanabe, Michiko; Jenkins, Michael W.

    2016-03-01

    The role of hemodynamics in early heart development is poorly understood. In order to successfully assess the impact of hemodynamics on development, we need to monitor and perturb blood flow, and quantify the resultant effects on morphology. Here, we have utilized cardiac optical pacing to create regurgitant flow in embryonic hearts and OCT to quantify regurgitation percentage and resultant morphology. Embryonic quail in a shell-less culture were optically paced at 3 Hz (well above the intrinsic rate or 1.33-1.67 Hz) on day 2 of development (3-4 weeks human) for 5 minutes. The pacing fatigued the heart and led to a prolonged period (> 1 hour) of increased regurgitant flow. Embryos were kept alive until day 3 (cardiac looping - 4-5 weeks human) or day 8 (4 chambered heart - 8 weeks human) to quantify resultant morphologic changes with OCT. All paced embryos imaged at day 3 displayed cardiac defects. The extent of regurgitant flow immediately after pacing was correlated with cardiac cushion size 24-hours post pacing (p-value cardio-facial/DiGeorge syndrome models suggesting that hemodynamics plays a role in these syndromes as well. Utilizing OCT and optical pacing to understand hemodynamics in development is an important step towards determining CHD mechanisms and ultimately developing earlier treatments.

  9. Iron Overload in Patients Undergoing Hematopoietic Stem Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Vinod Pullarkat

    2010-01-01

    Full Text Available Recipients of hematopoietic stem cell transplantation (HSCT frequently have iron overload resulting from chronic transfusion therapy for anemia. In some cases, for example, in patients with myelodysplastic syndromes and thalassemia, this can be further exacerbated by increased absorption of iron from the gut as a result of ineffective erythropoiesis. Accumulating evidence has established the negative impact of elevated pretransplantation serum ferritin, a surrogate marker of iron overload, on overall survival and nonrelapse mortality after HSCT. Complications of HSCT associated with iron overload include increased bacterial and fungal infections as well as sinusoidal obstruction syndrome and possibly other regimen-related toxicities. Based on current evidence, particular attention should be paid to prevention and management of iron overload in allogeneic HSCT candidates, especially in patients with thalassemia and myelodysplastic syndromes. The pathophysiology of iron overload in the HSCT patient and optimum strategies to deal with iron overload during and after HSCT require further study.

  10. The overloaded right heart and ventricular interdependence.

    Science.gov (United States)

    Naeije, Robert; Badagliacca, Roberto

    2017-10-01

    The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights

  11. Mitochondrial DNA damage in iron overload.

    Science.gov (United States)

    Gao, Xueshan; Campian, Jian Li; Qian, Mingwei; Sun, Xiao-Feng; Eaton, John W

    2009-02-20

    Chronic iron overload has slow and insidious effects on heart, liver, and other organs. Because iron-driven oxidation of most biologic materials (such as lipids and proteins) is readily repaired, this slow progression of organ damage implies some kind of biological "memory." We hypothesized that cumulative iron-catalyzed oxidant damage to mtDNA might occur in iron overload, perhaps explaining the often lethal cardiac dysfunction. Real time PCR was used to examine the "intactness" of mttDNA in cultured H9c2 rat cardiac myocytes. After 3-5 days exposure to high iron, these cells exhibited damage to mtDNA reflected by diminished amounts of near full-length 15.9-kb PCR product with no change in the amounts of a 16.1-kb product from a nuclear gene. With the loss of intact mtDNA, cellular respiration declined and mRNAs for three electron transport chain subunits and 16 S rRNA encoded by mtDNA decreased, whereas no decrements were found in four subunits encoded by nuclear DNA. To examine the importance of the interactions of iron with metabolically generated reactive oxygen species, we compared the toxic effects of iron in wild-type and rho(o) cells. In wild-type cells, elevated iron caused increased production of reactive oxygen species, cytostasis, and cell death, whereas the rho(o) cells were unaffected. We conclude that long-term damage to cells and organs in iron-overload disorders involves interactions between iron and mitochondrial reactive oxygen species resulting in cumulative damage to mtDNA, impaired synthesis of respiratory chain subunits, and respiratory dysfunction.

  12. Design of vehicle overload detection system based on geophone

    Science.gov (United States)

    Hu, Siquan; Kong, Min; She, Chundong

    2017-08-01

    A vehicle overload detection system is proposed based on geophone. Under normal circumstances, when overloaded vehicles and ordinary vehicles pass through the road, the amplitude of the ground vibration will be different, and the geophone sensor can detect tiny vibrations of the ground. The system includes information acquisition module, signal conditioning module and wireless transmission module. The collected vibration data is transmitted through the wireless transmission module to the background, and the SVM algorithm is used to classify the information and determine whether the vehicle is overloaded. Experiments show that the system can detect overload accurately.

  13. Clarifications on Continuous Renal Replacement Therapy and Hemodynamics

    Directory of Open Access Journals (Sweden)

    Xiao-Ting Wang

    2017-01-01

    Conclusions: CRRT is not only a replacement for organ function, but an important form of hemodynamic therapy. Improved hemodynamic management of critically ill patients can be achieved by establishing specific therapeutic hemodynamic targets and maintaining circulatory stability during CRRT. Over the long term, observation of renal hemodynamics will provide greater opportunities for the progression of CRRT hemodynamic therapy.

  14. We Restrict CRRT to Only the Most Hemodynamically Unstable Patients.

    Science.gov (United States)

    Kashani, Kianoush; Mehta, Ravindra L

    2016-07-01

    From the initial version of an extended renal replacement therapy, the initiative to provide safer, more efficient means for detoxification and volume removal in comparison with intermittent renal replacement therapies (IRRT) has been evaluated. As a result, the Kidney Disease Improving Global Outcomes guidelines for acute kidney injury recommend the preferential use of continuous renal replacement therapy (CRRT) in patients who are hemodynamically unstable or who suffer from intracranial hypertension. The choice of dialysis modality is also influenced by other factors including clinical expertise, and the availability of each treatment option in individual medical centers. In the scientific community, there is an ongoing debate regarding the choice of dialysis modality. On one side, the inability of recent studies to demonstrate any mortality or renal recovery benefit for CRRT, the need for patient immobilization, and prohibitive additional costs impede widespread adoption of the method.On the other side, the physiological advantages of CRRT in detoxification and volume removal and the identified flaws related to the comparative literature regarding CRRT and IRRT fuel this debate. Fluid overload is a recognized and yet clinically underappreciated factor that increases morbidity and mortality in the intensive care unit (ICU). Continuous renal replacement therapy has a distinct advantage over IRRT in achieving euvolemia and thus the potential for improving outcomes in all patients in the ICU setting in which extensive fluid administration is often obligatory. With this in mind, perhaps CRRT should not be restricted to only those patients in whom their hemodynamic status requires it. This article reviews the current literature and the myths that may influence the selection of one mode of therapy over the other among patients requiring renal replacement therapy in the ICU. © 2016 Wiley Periodicals, Inc.

  15. Extracellular high-mobility group box 1 mediates pressure overload-induced cardiac hypertrophy and heart failure.

    Science.gov (United States)

    Zhang, Lei; Liu, Ming; Jiang, Hong; Yu, Ying; Yu, Peng; Tong, Rui; Wu, Jian; Zhang, Shuning; Yao, Kang; Zou, Yunzeng; Ge, Junbo

    2016-03-01

    Inflammation plays a key role in pressure overload-induced cardiac hypertrophy and heart failure, but the mechanisms have not been fully elucidated. High-mobility group box 1 (HMGB1), which is increased in myocardium under pressure overload, may be involved in pressure overload-induced cardiac injury. The objectives of this study are to determine the role of HMGB1 in cardiac hypertrophy and cardiac dysfunction under pressure overload. Pressure overload was imposed on the heart of male wild-type mice by transverse aortic constriction (TAC), while recombinant HMGB1, HMGB1 box A (a competitive antagonist of HMGB1) or PBS was injected into the LV wall. Moreover, cardiac myocytes were cultured and given sustained mechanical stress. Transthoracic echocardiography was performed after the operation and sections for histological analyses were generated from paraffin-embedded hearts. Relevant proteins and genes were detected. Cardiac HMGB1 expression was increased after TAC, which was accompanied by its translocation from nucleus to both cytoplasm and intercellular space. Exogenous HMGB1 aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction, as demonstrated by echocardiographic analyses, histological analyses and foetal cardiac genes detection. Nevertheless, the aforementioned pathological change induced by TAC could partially be reversed by HMGB1 inhibition. Consistent with the in vivo observations, mechanical stress evoked the release and synthesis of HMGB1 in cultured cardiac myocytes. This study indicates that the activated and up-regulated HMGB1 in myocardium, which might partially be derived from cardiac myocytes under pressure overload, may be of crucial importance in pressure overload-induced cardiac hypertrophy and cardiac dysfunction. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  16. Iron excretion in iron dextran-overloaded mice.

    Science.gov (United States)

    Musumeci, Marco; Maccari, Sonia; Massimi, Alessia; Stati, Tonino; Sestili, Paola; Corritore, Elisa; Pastorelli, Augusto; Stacchini, Paolo; Marano, Giuseppe; Catalano, Liviana

    2014-10-01

    Iron homeostasis in humans is tightly regulated by mechanisms aimed to conserve iron for reutilisation, with a negligible role played by excretory mechanisms. In a previous study we found that mice have an astonishing ability to tolerate very high doses of parenterally administered iron dextran. Whether this ability is linked to the existence of an excretory pathway remains to be ascertained. Iron overload was generated by intraperitoneal injections of iron dextran (1 g/kg) administered once a week for 8 weeks in two different mouse strains (C57bl/6 and B6D2F1). Urinary and faecal iron excretion was assessed by inductively coupling plasma-mass spectrometry, whereas cardiac and liver architecture was evaluated by echocardiography and histological methods. For both strains, 24-hour faeces and urine samples were collected and iron concentration was determined on days 0, 1 and 2 after iron administration. In iron-overloaded C57bl/6 mice, the faecal iron concentration increased by 218% and 157% on days 1 and 2, respectively (piron excreted represented a loss of 14% of total iron administered. Similar but smaller changes was also found in B6D2F1 mice. Conversely, we found no significant changes in the concentration of iron in the urine in either of the strains of mice. In both strains, histological examination showed accumulation of iron in the liver and heart which tended to decrease over time. This study indicates that mice have a mechanism for removal of excess body iron and provides insights into the possible mechanisms of excretion.

  17. Fluoride induced endoplasmic reticulum stress and calcium overload in ameloblasts.

    Science.gov (United States)

    Zhang, Ying; Zhang, KaiQiang; Ma, Lin; Gu, HeFeng; Li, Jian; Lei, Shuang

    2016-09-01

    The aim of the study was to evaluate the involvement of endoplasmic reticulum stress and intracellular calcium overload on the development of dental fluorosis. We cultured and exposed rat ameloblast HAT-7 cells to various concentrations of fluoride and measured apoptosis with flow cytometry and intracellular Ca2+ changes using confocal microscopy, investigated the protein levels of GRP78, calreticulin, XBP1 and CHOP by western blotting, and their transcriptional levels with RT-PCR. We also created an in vivo model of dental fluorosis by exposing animals to various concentrations of fluoride. Subsequently, thin dental tissue slices were analyzed with H&E staining, immunohistochemical staining, and transmission electron microscopy, TUNEL assay was also performed on dental tissue slices for assessment of apoptosis. High fluoride concentration was associated with decreased ameloblast proliferation, elevated ameloblast apoptosis, and increased intracellular Ca2+ in vitro. The translation and transcription of the proteins associated with endoplasmic reticulum stress were significantly elevated with high concentrations of fluoride. Based on immunohistochemical staining, these proteins were also highly expressed in animals exposed to high fluoride concentrations. Histologically, we found significant fluorosis-like changes in tissues from animals exposed to high fluoride concentrations. Transmission electron microscopy cytology indicated significant apoptotic changes in tissues exposed to high concentrations of fluoride. These results indicate that exposure to high levels of fluoride led to endoplasmic reticulum stress which induced apoptosis in cultured ameloblasts and in vivo rat model, suggesting an important role of calcium overload and endoplasmic reticulum stress triggered by high concentrations of fluoride in the development of dental fluorosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Iron excretion in iron dextran-overloaded mice

    Science.gov (United States)

    Musumeci, Marco; Maccari, Sonia; Massimi, Alessia; Stati, Tonino; Sestili, Paola; Corritore, Elisa; Pastorelli, Augusto; Stacchini, Paolo; Marano, Giuseppe; Catalano, Liviana

    2014-01-01

    Background Iron homeostasis in humans is tightly regulated by mechanisms aimed to conserve iron for reutilisation, with a negligible role played by excretory mechanisms. In a previous study we found that mice have an astonishing ability to tolerate very high doses of parenterally administered iron dextran. Whether this ability is linked to the existence of an excretory pathway remains to be ascertained. Materials and methods Iron overload was generated by intraperitoneal injections of iron dextran (1 g/kg) administered once a week for 8 weeks in two different mouse strains (C57bl/6 and B6D2F1). Urinary and faecal iron excretion was assessed by inductively coupling plasma-mass spectrometry, whereas cardiac and liver architecture was evaluated by echocardiography and histological methods. For both strains, 24-hour faeces and urine samples were collected and iron concentration was determined on days 0, 1 and 2 after iron administration. Results In iron-overloaded C57bl/6 mice, the faecal iron concentration increased by 218% and 157% on days 1 and 2, respectively (p<0.01). The iron excreted represented a loss of 14% of total iron administered. Similar but smaller changes was also found in B6D2F1 mice. Conversely, we found no significant changes in the concentration of iron in the urine in either of the strains of mice. In both strains, histological examination showed accumulation of iron in the liver and heart which tended to decrease over time. Conclusions This study indicates that mice have a mechanism for removal of excess body iron and provides insights into the possible mechanisms of excretion. PMID:24960657

  19. measurements of iron status and survival in african iron overload

    African Journals Online (AJOL)

    Introduction. Dietary iron overload is common in southern. Africa and there is a misconception that the condition is benign. 'Early descriptions of the condition relied on autopsy studies, and the use of indirect measurements of iron status to diagnose this form of iron overload has not been clarified. Methods. The study ...

  20. Evaluation of thermal overload in boiler operators.

    Science.gov (United States)

    Braga, Camila Soares; Rodrigues, Valéria Antônia Justino; Campos, Julio César Costa; de Souza, Amaury Paulo; Minette, Luciano José; de Moraes, Angêlo Casali; Sensato, Guilherme Luciano

    2012-01-01

    The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload.

  1. Planetary Overload, Limits to Growth and Health.

    Science.gov (United States)

    Butler, Colin D

    2016-12-01

    Since the use of atomic weapons in 1945 visionaries have warned that without major changes the survival of global civilization is in question. These concerns deepened in following decades, during the Cold War, with The Limits to Growth, the best-selling environmental book of the 1970s. Yet, since then, most concern has faded, fuelled by technological developments and a shift in dominant global ideology. Public health, with a few exceptions (one of which is the book Planetary Overload), has been slow to recognize this debate, even as evidence emerges that civilization may indeed be at risk, driven by an increasingly ominous complex of events. This article outlines the key relevant literature and concepts, attempting to bring emerging and future health consequences to the attention of health workers, including the idea of a "social vaccine," conveying sufficient anxiety to provoke action for environmental protection, but insufficient to induce paralysis.

  2. Avoiding Program-Induced Cumulative Overload (PICO).

    Science.gov (United States)

    Orr, Robin; Knapik, Joseph J; Pope, Rodney

    2016-01-01

    This article defines the concept of program-induced cumulative overload (PICO), provides examples, and advises ways to mitigate the adverse effects. PICO is the excessive cumulative physical workload that can be imparted to military personnel by a military training program with an embedded physical training component. PICO can be acute (accumulating within a single day) or chronic (accumulating across the entirety of the program) and results in adverse outcomes for affected personnel, including detrimental fatigue, performance degradation, injuries, or illness. Strategies to mitigate PICO include focusing administration and logistic practices during the development and ongoing management of a trainee program and implementing known musculoskeletal injury prevention strategies. More training is not always better, and trainers need to consider the total amount of physical activity that military personnel experience across both operational training and physical training if PICO is to be mitigated. 2016.

  3. Differential requirement for satellite cells during overload-induced muscle hypertrophy in growing versus mature mice.

    Science.gov (United States)

    Murach, Kevin A; White, Sarah H; Wen, Yuan; Ho, Angel; Dupont-Versteegden, Esther E; McCarthy, John J; Peterson, Charlotte A

    2017-07-10

    Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age. Pax7(CreER)-R26R(DTA) mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day synergist ablation overload of the plantaris (n = 6-9 per group). The surgical approach minimized regeneration, de novo fiber formation, and fiber splitting while promoting muscle fiber growth. Satellite cell density (Pax7+ cells/fiber), embryonic myosin heavy chain expression (eMyHC), and muscle fiber cross sectional area (CSA) were evaluated via immunohistochemistry. Myonuclei (myonuclei/100 mm) were counted on isolated single muscle fibers. Tamoxifen treatment depleted satellite cells by ≥90% and prevented myonuclear accretion with overload in young and mature mice (p Satellite cells did not recover in SC- mice after overload. Average muscle fiber CSA increased ~20% in young SC+ (p = 0.07), mature SC+ (p satellite cells for overload-induced hypertrophy is dependent on maturational age, and global responses to overload differ in young versus mature mice.

  4. Overload and neovascularization of shoulder tendons in volleyball players

    Science.gov (United States)

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  5. Overload and neovascularization of shoulder tendons in volleyball players.

    Science.gov (United States)

    Notarnicola, Angela; Fischetti, Francesco; Gallone, Donato; Moretti, Lorenzo; Pignataro, Pasquale; Tafuri, Silvio; Moretti, Biagio

    2012-08-01

    In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.

  6. Overload and neovascularization of shoulder tendons in volleyball players

    Directory of Open Access Journals (Sweden)

    Notarnicola Angela

    2012-08-01

    Full Text Available Abstract Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7% than middle hitters (53.7% (p = 0.01, opposite hitters (55.5% (p = 0.02 and libero players (54.4% (p = 0.008, whereas there were no differences in setters (56.2% (p > 0.05. Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.

  7. The hepcidin-ferroportin system as a therapeutic target in anemias and iron overload disorders.

    Science.gov (United States)

    Ganz, Tomas; Nemeth, Elizabeta

    2011-01-01

    The review summarizes the current understanding of the role of hepcidin and ferroportin in normal iron homeostasis and its disorders. The various approaches to therapeutic targeting of hepcidin and ferroportin in iron-overload disorders (mainly hereditary hemochromatosis and β-thalassemia) and iron-restrictive anemias (anemias associated with infections, inflammatory disorders, and certain malignancies, anemia of chronic kidney diseases, and iron-refractory iron-deficiency anemia) are also discussed.

  8. Hemodynamic effects of ventricular defibrillation

    Science.gov (United States)

    Pansegrau, Donald G.; Abboud, François M.

    1970-01-01

    Hemodynamic responses to ventricular defibrillation were studied in anesthetized dogs. Observations were made on arterial, right atrial and left ventricular end-diastolic pressures, on cardiac output (dye dilution), heart rate, and right atrial electrocardiogram. Ventricular fibrillation was induced electrically with a bipolar electrode catheter placed in the right ventricle. Fibrillation was maintained for 15 or 30 sec and terminated with a 400 w sec capacitor discharge across the thoracic cage. Responses lasted 1-10 min after conversion and included a cholinergic and an adrenergic component. The cholinergic component was characterized by sinus bradycardia, periods of sinus arrest, atrioventricular block, and ventricular premature beats. The adrenergic component included increases in arterial pressure, in cardiac output, and in left ventricular stroke work at a time when left ventricular end-diastolic pressure was normal; there was no change in total peripheral resistance. The pH of arterial blood decreased slightly and pCO2 increased but pO2 and the concentration of lactate were unchanged. Bilateral vagotomy and intravenous administration of atropine blocked the cholinergic component, unmasked a sinus tachycardia, and accentuated the adrenergic component of the response. The latter was blocked by intravenous administration of propranolol and phenoxybenzamine. These responses were related primarily to conversion of ventricular fibrillation rather than to the electrical discharge of countershock because countershock without ventricular fibrillation caused more transient and smaller responses than those observed with defibrillation: furthermore, the hemodynamic effects of defibrillation were augmented by prolongation of the duration of fibrillation. The results suggest that the cholinergic component of the response may be detrimental in that it favors spontaneous recurrence of fibrillation; on the other hand, the adrenergic component may be essential for conversion

  9. Postural effects on hemodynamic response to interpersonal interaction.

    Science.gov (United States)

    Waldstein, S R; Neumann, S A; Merrill, J A

    1998-05-01

    Laboratory studies of stress-induced cardiovascular reactivity have been conducted predominantly with participants in a seated posture. This procedure may contribute to limited laboratory-field generalization of cardiovascular response. The present study examined hemodynamic adjustments underlying pressor responses, in addition to heart rate and systolic time intervals, during seated and standing role-played, interpersonal interaction in 60 young adults. Irrespective of gender or race, blood pressure responses to the seated and standing interactions were comparable. However, seated interactions yielded a significantly greater increase in heart rate, shortened preejection period and decreased stroke index as compared to standing. Alternatively, interacting while standing yielded a significantly increased left ventricular ejection time and total peripheral resistance in comparison to sitting. These results suggest that hemodynamic adjustments during stressful interpersonal interaction vary as a function of posture, with somewhat greater cardiac influences apparent while seated and a more pronounced vascular response while standing.

  10. Quantitative hemodynamic studies in moyamoya disease: A review

    Science.gov (United States)

    Lee, Marco; Zaharchuk, Greg; Guzman, Raphael; Achrol, Achal; Bell-Stephens, Teresa; Steinberg, Gary K.

    2010-01-01

    Moyamoya disease is characterized by a chronic stenoocclusive vasculopathy affecting the terminal internal carotid arteries. The clinical presentation and outcome of moyamoya disease remain varied based on angiographic studies alone, and much work has been done to study cerebral hemodynamics in this group of patients. The ability to measure cerebral blood flow (CBF) accurately continues to improve with time, and with it a better understanding of the pathophysiological mechanisms in patients with moyamoya disease. The main imaging techniques used to evaluate cerebral hemodynamics include PET, SPECT, xenon-enhanced CT, dynamic perfusion CT, MR imaging with dynamic susceptibility contrast and with arterial spin labeling, and Doppler ultrasonography. More invasive techniques include intraoperative ultrasonography. The authors review the current knowledge of CBF in this group of patients and the role each main quantitative method has played in evaluating them, both in the disease state and after surgical intervention. PMID:19335131

  11. Hemodynamic Monitorization of the Burn Patient

    Directory of Open Access Journals (Sweden)

    Ahmet Coşar

    2011-07-01

    Full Text Available Hemodynamic monitorization is the basic component of the medical care of the burn patients. It provides valuable information of the cardiopulmonary performance which is essential in the rapid diagnosis and treatment in the case of hemodynamic disturbance. The clinical importance of any monitorization parameter, associated risks – benefits, cost effectivity, and also assessment and management skills of the health care providers should be taken into consideration in the selection process of the monitorization method. This paper reviews the methods of the hemodynamic monitorization for the clinical care of the burn patients. (Journal of the Turkish Society Intensive Care 2011; 9 Suppl: 11-20

  12. Overload and work-family conflict among Australian dual-career families: moderating effects of support.

    Science.gov (United States)

    Elloy, David F; Mackie, Beth

    2002-12-01

    Individuals in dual-career situations have become increasingly common all over the world. For couples dealing with multiple demands, this lifestyle often generates stresses and strains at home and at work, which can have negative consequences for organizations. Most empirical research into this lifestyle has been conducted in the United States and Britain, and very little in Australia. This particular study, based on data from an Australian sample of 65 dual-career couples, analyzed the relation between overload and work-family conflict and the moderating effects of support (supervisor, coworkers, and friends). Results confirm that overload was significantly related to work-family conflict but no moderating effects were found for support. Limitations of the study and an organizational role in managing the work-family interface dual-career couples are discussed.

  13. [Non-transferrin-bound iron: a promising biomarker in iron overload disorders].

    Science.gov (United States)

    Maas, Roderick P P W M; Voets, Philip J G M; de Swart, Louise; Swinkels, Dorine W

    2013-01-01

    Iron overload disorders are common and, if left untreated, severe systemic diseases that can have both genetic and acquired causes. Hereditary haemochromatosis, β-thalassaemia, myelodysplastic syndromes and sickle cell disease are among the most important examples. Iron that is not bound to transferrin, haem or ferritin (non-transferrin-bound iron, NTBI) seems to play a key role in the pathophysiology of these disorders. NTBI is a heterogeneous group of potentially toxic iron complexes in plasma which are generated almost exclusively under pathological conditions. Cellular uptake of NTBI contributes to its toxicity and is mediated by several organ-specific transporters and receptors. NTBI-induced toxicity is the result of oxidative damage to various macromolecules by reactive oxygen species (ROS). In the near future, we hypothesize that NTBI will have important implications for both diagnosis and treatment of iron overload disorders. However, before NTBI can be applied to patient care, the currently available assays need further clinical and analytical validation.

  14. Obesity versus osteoarthritis: beyond the mechanical overload.

    Science.gov (United States)

    Sartori-Cintra, Angélica Rossi; Aikawa, Priscila; Cintra, Dennys Esper Correa

    2014-09-01

    Obesity is currently considered a major public health problem in the world, already reaching epidemic characteristics, according to the World Health Organization. Excess weight is the major risk factor associated with various diseases, such as type 2 diabetes mellitus, hypertension, dyslipidemia and osteometabolic diseases, including osteoporosis and osteoarthritis. Osteoarthritis is the most prevalent rheumatic disease and the leading cause of physical disability and reduced quality of life of the population over 65 years. It mainly involves the joints that bear weight - knees and hips. However, along with the cases of obesity, its prevalence is increasing, and even in other joints, such as hands. Thus, it is assumed that the influence of obesity on the development of OA is beyond mechanical overload. The purpose of this review was to correlate the possible mechanisms underlying the genesis and development of these two diseases. Increased fat mass is directly proportional to excessive consumption of saturated fatty acids, responsible for systemic low-grade inflammation condition and insulin and leptin resistance. At high levels, leptin assumes inflammatory characteristics and acts in the articular cartilage, triggering the inflammatory process and changing homeostasis this tissue with consequent degeneration. We conclude that obesity is a risk factor for osteoarthritis and that physical activity and changes in diet composition can reverse the inflammatory and leptin resistance, reducing progression or preventing the onset of osteoarthritis.

  15. [Navigation aid through the information overload].

    Science.gov (United States)

    Günther, Judith; Schindler, Birgit; Suter, Katja

    2014-10-01

    We live in the modern information society. "To be informed" has a crucial impact on the personal, professional, economic and social development. The knowledge of things and their relationships is essential for acute decisions as well as for long-term planning. And at no time it was easier to get the information required within shorter time periods--no matter to whatsoever. The offer of information of the World Wide Web is inexhaustible. This also applies to information about all possible therapeutic and pharmaceutical issues. But is the information found reliable, too? And are easily accessible sources credible? Can we deal with the information overload at these days or do we actually risk paddling only on the surface of the "information-sea", without ever perceiving the actual information depth and width, less to use it? How can we protect being taken in by marketing strategies? The present article describes a structured proceed when seeking literature to find useful medical and pharmaceutical information in a time saving manner.

  16. VOLUME OVERLOAD IS ASSOCIATED WITH MALNUTRITION IN PERITONEAL DIALYSIS

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    Jin Joo Cha

    2012-06-01

    Volume overload is associated with malnutrition and seems to be an independent predictor of mortality in PD population. Further study should evaluate the effects of intervention of volume control in PD patients.

  17. Overload truck wheel load distribution on bridge decks.

    Science.gov (United States)

    2009-04-01

    There is a need to accurately analyze the load effects on bridge decks from permitted overload trucks on : Michigans roads. The AASHTO Standard Specifications for Highway Bridges, 17th edition, provides a : distribution width of live loads when re...

  18. Hemodynamic Monitorization of the Burn Patient

    OpenAIRE

    Ahmet Coşar; Burak Eşkin

    2011-01-01

    Hemodynamic monitorization is the basic component of the medical care of the burn patients. It provides valuable information of the cardiopulmonary performance which is essential in the rapid diagnosis and treatment in the case of hemodynamic disturbance. The clinical importance of any monitorization parameter, associated risks – benefits, cost effectivity, and also assessment and management skills of the health care providers should be taken into consideration in the selection process of ...

  19. Hemodynamic and tubular changes induced by contrast media.

    Science.gov (United States)

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

    2014-01-01

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

  20. Non-invasive diagnosis and follow-up of right ventricular overload

    NARCIS (Netherlands)

    Henkens, Ivo Reinier

    2008-01-01

    Right ventricular overload covers a spectrum ranging from volume overload to pressure overload, and often is a combination of these, compromising cardiac function. Part I focuses on right ventricular volume overload in adults with Fallot’s tetralogy corrected in early childhood. We determined

  1. Hemodynamics of a hydrodynamic injection

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    Tsutomu Kanefuji

    2014-01-01

    Full Text Available The hemodynamics during a hydrodynamic injection were evaluated using cone beam computed tomography (CBCT and fluoroscopic imaging. The impacts of hydrodynamic (5 seconds and slow (60 seconds injections into the tail veins of mice were compared using 9% body weight of a phase-contrast medium. Hydrodynamically injected solution traveled to the heart and drew back to the hepatic veins (HV, which led to liver expansion and a trace amount of spillover into the portal vein (PV. The liver volumes peaked at 165.6 ± 13.3% and 165.5 ± 11.9% of the original liver volumes in the hydrodynamic and slow injections, respectively. Judging by the intensity of the CBCT images at the PV, HV, right atrium, liver parenchyma (LP, and the inferior vena cava (IVC distal to the HV conjunction, the slow injection resulted in the higher intensity at PV than at LP. In contrast, a significantly higher intensity was observed in LP after hydrodynamic injection in comparison with that of PV, suggesting that the liver took up the iodine from the blood flow. These results suggest that the enlargement speed of the liver, rather than the expanded volume, primarily determines the efficiency of hydrodynamic delivery to the liver.

  2. Hemodynamics driven cardiac valve morphogenesis.

    Science.gov (United States)

    Steed, Emily; Boselli, Francesco; Vermot, Julien

    2016-07-01

    Mechanical forces are instrumental to cardiovascular development and physiology. The heart beats approximately 2.6 billion times in a human lifetime and heart valves ensure that these contractions result in an efficient, unidirectional flow of the blood. Composed of endocardial cells (EdCs) and extracellular matrix (ECM), cardiac valves are among the most mechanically challenged structures of the body both during and after their development. Understanding how hemodynamic forces modulate cardiovascular function and morphogenesis is key to unraveling the relationship between normal and pathological cardiovascular development and physiology. Most valve diseases have their origins in embryogenesis, either as signs of abnormal developmental processes or the aberrant re-expression of fetal gene programs normally quiescent in adulthood. Here we review recent discoveries in the mechanobiology of cardiac valve development and introduce the latest technologies being developed in the zebrafish, including live cell imaging and optical technologies, as well as modeling approaches that are currently transforming this field. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. Copyright © 2015. Published by Elsevier B.V.

  3. Central Hemodynamics and Microcirculation in Critical Conditions

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    A. A. Kosovskikh

    2013-01-01

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

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

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    Jinyu Xu

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

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

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    Daniel Brönnimann

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

  6. Application of Chaos Theory in Trucks' Overloading Enforcement

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    Abbas Mahmoudabadi

    2013-01-01

    Full Text Available Trucks' overloading is considered as one of the most substantial concerns in road transport due to a possible road surface damage, as well as, are less reliable performance of trucks' braking system. Sufficient human resource and adequate time scheduling are to be planned for surveying trucks' overloading; hence, it seems required to prepare an all-around model to be able to predict the number of overloaded vehicles. In the present research work, the concept of chaos theory has been utilized to predict the ratio of trucks which might be guessed overloaded. The largest Lyapunov exponent is utilized to determine the presence of chaos using experimental data and concluded that the ratio of overloaded trucks reflects chaotic behavior. The prediction based on chaos theory is compared with the results of simple smoothing and moving average methods according to the well-known criterion of mean square errors. The results have also revealed that the chaotic prediction model would act more capably comparing the analogous methods including simple smoothing and moving average to predict the ratio of passing trucks to be possibly overloaded.

  7. Increase in Vascular Injury of Sodium Overloaded Mice May be Related to Vascular Angiotensin Modulation.

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    Cintia Taniguti Lima

    Full Text Available This study aimed to analyzing the effect of chronic sodium overload upon carotid and femoral injury, and its relation to vascular angiotensin modulation. Male C57Bl6 mice were divided in: control (cont, receiving 1% NaCl solution for 2 weeks (salt-2 or 12 weeks (salt-12. Two-weeks before the end of the study, a 2mm catheter was implanted around the left femoral and carotid arteries to induce injury. Blood pressure (BP and heart rate (HR were measured at the end of the study by tail plethysmography. Arteries were collected and prepared for histological analysis to determine arterial thickening and perivascular collagen deposition. Angiotensin II and Ang(1-7 were quantified in fresh arteries using the HPLC method. There were no differences in body weight, BP and HR. Intima/media ratio had a similar increase in both injured arteries of cont and salt-2 mice, but a more pronounced increase was observed in salt-12 mice (31.1±6%. On the other hand, sodium overload modified perivascular collagen deposition, increasing thick fibers (cont: 0.5%; salt-2: 3.4%; salt-12: 0.6% and decreasing thin fibers (cont: 7.4%; salt-2: 0.5%; salt-12: 6.8% in non-injured arteries. Injured arteries presented similar collagen fiber distribution. Angiotensin quantification showed increased Ang(1-7 in salt treated mice (salt-2: +72%; salt-12: +45% with a concomitant decrease in Ang II (salt-2: -54%; salt-12: -60%. Vascular injury increased significantly Ang(1-7 in salt-12 mice (+80%, maintaining Ang II reduction similar to that of a non-injured artery. The lack of changes in BP and HR suggests that the structural changes observed may be due to non-hemodynamic mechanisms such as local renin-angiotensin system. Collagen evaluation suggests that sodium overload induces time-related changes in vascular remodeling. The increase of artery injury with concomitant increase in Ang(1-7 in 12-week treated mice shows a direct association between the duration of salt treatment and the

  8. Multimedia reviews: multimedia overload produces "symplexity".

    Science.gov (United States)

    Zingrone, Frank

    2003-03-01

    We humans "know" from information mediated through our "natural senses." All outside signals come to us through some medium-sound waves, pressure and touch, light waves, radio and television waves, and so forth. McLuhan's famous mantra "The medium is the message" paradoxically highlighted the critical transformation of meaning when each type of medium-radio, television, drums, hand signals-by its very nature modifies the message it is transmitting. In this month's column Dr. Zingrone brings challenging new ideas to the field of human communication and vividly describes the communication distortions that occur when the overload of increasingly complex modern media results in a paradoxical diminution of meaning itself. He has coined a term for this unintended consequence and given it to his exciting new book, The Media Symplex: At the Edge of Meaning in the Age of Chaos (1). Many of us may recognize the effect created by this accelerating phenomenon-our stupefaction as we experience the onslaught of sound and visual signals produced by a television news screen, where an avalanche of rapidly changing, overlapping, and distorted visual images flash at our eyes while screeching, undulating synthetic "music" crashes about our ears. And in that chaos we struggle to find meaning,Dr. Zingrone, who worked with McLuhan and who has written extensively about his work (2,3), has succeeded in his new book to move the pioneering work of human communication scientists forward and thereby help us all to understand the developing paradox and danger of more communication yet less meaning.

  9. Augmented cardiac hypertrophy in response to pressure overload in mice lacking ELTD1.

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    Jinfeng Xiao

    Full Text Available BACKGROUND: Epidermal growth factor (EGF, latrophilin and seven transmembrane domain-containing protein 1 (ELTD1 is developmentally upregulated in the heart. Little is known about the relationship between ELTD1 and cardiac diseases. Therefore, we aimed to clarify the role of ELTD1 in pressure overload-induced cardiac hypertrophy. METHODS AND RESULTS: C57BL/6J wild-type (WT mice and ELTD1-knockout (KO mice were subjected to left ventricular pressure overload by descending aortic banding (AB. KO mice exhibited more unfavorable cardiac remodeling than WT mice 28 days post AB; this remodeling was characterized by aggravated cardiomyocyte hypertrophy, thickening of the ventricular walls, dilated chambers, increased fibrosis, and blunted systolic and diastolic cardiac function. Analysis of signaling pathways revealed enhanced extracellular signal-regulated kinase (ERK and the c-Jun amino-terminal kinase (JNK phosphorylation in response to ELTD1 deletion. CONCLUSIONS: ELTD1 deficiency exacerbates cardiac hypertrophy and cardiac function induced by AB-induced pressure overload by promoting both cardiomyocyte hypertrophy and cardiac fibrosis. These effects are suggested to originate from the activation of the ERK and JNK pathways, suggesting that ELTD1 is a potential target for therapies that prevent the development of cardiac disease.

  10. Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.

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    Karen van Eunen

    Full Text Available Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH. The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.

  11. Analysis of occupational stress in a high fashion clothing factory with upper limb biomechanical overload.

    Science.gov (United States)

    Forcella, Laura; Bonfiglioli, Roberta; Cutilli, Piero; Siciliano, Eugenio; Di Donato, Angela; Di Nicola, Marta; Antonucci, Andrea; Di Giampaolo, Luca; Boscolo, Paolo; Violante, Francesco Saverio

    2012-07-01

    To study job stress and upper limb biomechanical overload due to repetitive and forceful manual activities in a factory producing high fashion clothing. A total of 518 workers (433 women and 85 men) were investigated to determine anxiety, occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms (using the Italian version of the Somatization scale of Symptom Checklist SCL-90). Biomechanical overload was analyzed using the OCRA Check list. Biomechanical assessment did not reveal high-risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due to very low decision latitude. Occupational stress resulted partially in line with biomechanical risk factors; however, the perception of low decision latitude seems to play a major role in determining job strain. Interactions between physical and psychological factors cannot be demonstrated. Anyway, simultaneous long-term monitoring of occupational stress features and biomechanical overload could guide workplace interventions aimed at reducing the risk of adverse health effects.

  12. Pioglitazone Alleviates Cardiac Fibrosis and Inhibits Endothelial to Mesenchymal Transition Induced by Pressure Overload

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    Wen-Ying Wei

    2017-12-01

    Full Text Available Background/Aims: Cardiac fibrosis, characterized by an unbalanced production and degradation of extracellular matrix components, is a common pathophysiology of multiple cardiovascular diseases. Recent studies suggested that endothelial to mesenchymal transition (EndMT could be a source of activated fibroblasts and contribute to cardiac fibrosis. Here, the role of pioglitazone (PIO in cardiac fibrosis and EndMT was elaborated. Methods: Male C57BL/6 mice were subjected to aortic banding (AB, which was used to construct a model of pressure overload-induced cardiac hypertrophy. PIO and GW9662 was given for 4 weeks to detect the effects of PIO on EndMT. Results: Our results showed PIO treatment attenuated cardiac hypertrophy, dysfunction and fibrosis response to pressure overload. Mechanistically, PIO suppressed the TGF-β/Smad signaling pathway activated by 4-week AB surgery. Moreover, PIO dramatically inhibited EndMT in vivo and in vitro stimulated by pressure overload or TGF-β. A selective antagonist of PPAR-γ, GW9662, neutralized the anti-fibrotic effect and abolished the inhibitory effect of EndMT during the treatment of PIO. Conclusion: Our data implied that PIO exerts an alleviative effect on cardiac fibrosis via inhibition of the TGF-β/Smad signaling pathway and EndMT by activating PPAR-γ.

  13. Mononuclear Phagocytes Are Dispensable for Cardiac Remodeling in Established Pressure-Overload Heart Failure.

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    Bindiya Patel

    Full Text Available Although cardiac and splenic mononuclear phagocytes (MPs, i.e., monocytes, macrophages and dendritic cells (DCs, are key contributors to cardiac remodeling after myocardial infarction, their role in pressure-overload remodeling is unclear. We tested the hypothesis that these immune cells are required for the progression of remodeling in pressure-overload heart failure (HF, and that MP depletion would ameliorate remodeling.C57BL/6 mice were subjected to transverse aortic constriction (TAC or sham operation, and assessed for alterations in MPs. As compared with sham, TAC mice exhibited expansion of circulating LyC6hi monocytes and pro-inflammatory CD206- cardiac macrophages early (1 w after pressure-overload, prior to significant hypertrophy and systolic dysfunction, with subsequent resolution during chronic HF. In contrast, classical DCs were expanded in the heart in a biphasic manner, with peaks both early, analogous to macrophages, and late (8 w, during established HF. There was no significant expansion of circulating DCs, or Ly6C+ monocytes and DCs in the spleen. Periodic systemic MP depletion from 2 to 16 w after TAC in macrophage Fas-induced apoptosis (MaFIA transgenic mice did not alter cardiac remodeling progression, nor did splenectomy in mice with established HF after TAC. Lastly, adoptive transfer of splenocytes from TAC HF mice into naïve recipients did not induce immediate or long-term cardiac dysfunction in recipient mice.Mononuclear phagocytes populations expand in a phasic manner in the heart during pressure-overload. However, they are dispensable for the progression of remodeling and failure once significant hypertrophy is evident and blood monocytosis has normalized.

  14. Longitudinal hemodynamic measurements in swine heart failure using a fully implantable telemetry system.

    Directory of Open Access Journals (Sweden)

    Jenny S Choy

    Full Text Available Chronic monitoring of heart rate, blood pressure, and flow in conscious free-roaming large animals can offer considerable opportunity to understand the progression of cardiovascular diseases and can test new diagnostics and therapeutics. The objective of this study was to demonstrate the feasibility of chronic, simultaneous measurement of several hemodynamic parameters (left ventricular pressure, systemic pressure, blood flow velocity, and heart rate using a totally implantable multichannel telemetry system in swine heart failure models. Two solid-state blood pressure sensors were inserted in the left ventricle and the descending aorta for pressure measurements. Two Doppler probes were placed around the left anterior descending (LAD and the brachiocephalic arteries for blood flow velocity measurements. Electrocardiographic (ECG electrodes were attached to the surface of the left ventricle to monitor heart rate. The telemeter body was implanted in the right side of the abdomen under the skin for approximately 4 to 6 weeks. The animals were subjected to various heart failure models, including volume overload (A-V fistula, n = 3, pressure overload (aortic banding, n = 2 and dilated cardiomyopathy (pacing-induced tachycardia, n = 3. Longitudinal changes in hemodynamics were monitored during the progression of the disease. In the pacing-induced tachycardia animals, the systemic blood pressure progressively decreased within the first 2 weeks and returned to baseline levels thereafter. In the aortic banding animals, the pressure progressively increased during the development of the disease. The pressure in the A-V fistula animals only showed a small increase during the first week and remained stable thereafter. The results demonstrated the ability of this telemetry system of long-term, simultaneous monitoring of blood flow, pressure and heart rate in heart failure models, which may offer significant utility for understanding cardiovascular disease

  15. Bioaugmentation of overloaded anaerobic digesters restores function and archaeal community.

    Science.gov (United States)

    Tale, V P; Maki, J S; Zitomer, D H

    2015-03-01

    Adding beneficial microorganisms to anaerobic digesters for improved performance (i.e. bioaugmentation) has been shown to decrease recovery time after organic overload or toxicity upset. Compared to strictly anaerobic cultures, adding aerotolerant methanogenic cultures may be more practical since they exhibit higher methanogenic activity and can be easily dried and stored in ambient air for future shipping and use. In this study, anaerobic digesters were bioaugmented with both anaerobic and aerated, methanogenic propionate enrichment cultures after a transient organic overload. Digesters bioaugmented with anaerobic and moderately aerated cultures recovered 25 and 100 days before non-bioaugmented digesters, respectively. Increased methane production due to bioaugmentation continued a long time, with 50-120% increases 6 to 12 SRTs (60-120 days) after overload. In contrast to the anaerobic enrichment, the aerated enrichments were more effective as bioaugmentation cultures, resulting in faster recovery of upset digester methane and COD removal rates. Sixty days after overload, the bioaugmented digester archaeal community was not shifted, but was restored to one similar to the pre-overload community. In contrast, non-bioaugmented digester archaeal communities before and after overload were significantly different. Organisms most similar to Methanospirillum hungatei had higher relative abundance in well-operating, undisturbed and bioaugmented digesters, whereas organisms similar to Methanolinea tarda were more abundant in upset, non-bioaugmented digesters. Bioaugmentation is a beneficial approach to increase digester recovery rate after transient organic overload events. Moderately aerated, methanogenic propionate enrichment cultures were more beneficial augments than a strictly anaerobic enrichment. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Sgouralis, Ioannis; Layton, Anita T

    2015-06-01

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

  17. FALLS-protocol: lung ultrasound in hemodynamic assessment of shock.

    Science.gov (United States)

    Lichtenstein, D

    2013-01-01

    The assessment of acute circulatory failure is a challenge in absence of solid gold standard. It is suggested that artifacts generated by lung ultrasound can be of help. The FALLS-protocol (Fluid Administration Limited by Lung Sonography) follows Weil's classification of shocks. Firstly, it searches for pericardial fluid, then right heart enlargment, lastly abolished lung sliding. In this setting, the diagnoses of pericardial tamponade, pulmonary embolism and tension pneumothorax, i.e. obstructive shock, can be schematically ruled out. Moreover, the search of diffuse lung rockets (i.e. multiple B-lines, a comet-tail artifact) is performed. Its absence excludes pulmonary edema, that in clinical practice is left cardiogenic shock (most cases). At this step, the patient (defined FALLS-responder) receives fluid therapy. He/she has usually a normal sonographic lung surface, an A-profile. Any clinical improvement suggests hypovolemic shock. The absence of improvement generates continuation of fluid therapy, eventually yielding fluid overload. This condition results in the change from A-profile to B-profile. Lung ultrasound has the advantage to demonstrate this interstitial syndrome at an early and infraclinical stage (FALLS-endpoint). The change from horizontal A-lines to vertical B-lines can be considered as a direct marker of volemia in this use. By elimination, this change indicates schematically distributive shock, while in current practice septic shock. The major limitation is the B-profile on admission generated by an initial lung disorder. FALLS-protocol, which can be associated with no drawback with traditional hemodynamic tools, uses a simple machine (without Doppler) and a suitable microconvex probe allowing for heart, lung and vein assessment.

  18. MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKIIδ

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Min-Ji [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jang, Jin-Kyung [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Lee, Chang Yeon; Park, Jun-Hee [Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, 50 Yonsei-ro, Seodamun-gu, Seoul 120-759 (Korea, Republic of); Lee, Jiyun; Seo, Hyang-Hee [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Choi, Eunhyun [Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University Health System, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jeon, Woo-min [Department of Animal Resource, Sahmyook University, Seoul 139-742 (Korea, Republic of); Hwang, Hye Jin [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Shin, Hyun-Taek [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); and others

    2013-06-14

    Highlights: •CaMKIIδ mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca{sup 2+} overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

  19. Nitric oxide transport in normal human thoracic aorta: effects of hemodynamics and nitric oxide scavengers.

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    Full Text Available Despite the crucial role of nitric oxide (NO in the homeostasis of the vasculature, little quantitative information exists concerning NO transport and distribution in medium and large-sized arteries where atherosclerosis and aneurysm occur and hemodynamics is complex. We hypothesized that local hemodynamics in arteries may govern NO transport and affect the distribution of NO in the arteries, hence playing an important role in the localization of vascular diseases. To substantiate this hypothesis, we presented a lumen/wall model of the human aorta based on its MRI images to simulate the production, transport and consumption of NO in the arterial lumen and within the aortic wall. The results demonstrated that the distribution of NO in the aorta was quite uneven with remarkably reduced NO bioavailability in regions of disturbed flow, and local hemodynamics could affect NO distribution mainly via flow dependent NO production rate of endothelium. In addition, erythrocytes in the blood could moderately modulate NO concentration in the aorta, especially at the endothelial surface. However, the reaction of NO within the wall could only slightly affect NO concentration on the luminal surface, but strongly reduce NO concentration within the aortic wall. A strong positive correlation was revealed between wall shear stress and NO concentration, which was affected by local hemodynamics and NO reaction rate. In conclusion, the distribution of NO in the aorta may be determined by local hemodynamics and modulated differently by NO scavengers in the lumen and within the wall.

  20. Fat overload syndrome after the rapid infusion of SMOFlipid emulsion.

    Science.gov (United States)

    Hojsak, Iva; Kolaček, Sanja

    2014-01-01

    Fat overload syndrome is a well-known complication of intravenous lipid emulsion therapy. It is characterized by headaches, fever, jaundice, hepatosplenomegaly, respiratory distress, and spontaneous hemorrhage. Other symptoms include anemia, leukopenia, thrombocytopenia, low fibrinogen levels, and coagulopathy. Several reports in the literature describe fat overload syndrome caused by rapid infusion of lipid emulsions, all with soybean-based lipid emulsions. We report fat overload syndrome in a 2-year-old girl with short bowel syndrome on home parenteral nutrition. Fat overload syndrome occurred as a result of accidental, very rapid infusion of a 20% soy oil, medium-chain triglyceride, olive and fish oil-based lipid emulsion (SMOFlipid) that showed the same complications seen with an earlier lipid emulsion (Intralipid). The patient was successfully treated with supportive care combining fluid infusion, transfusion of platelets, and substitution of serum albumin (0.5 g/kg/d) and fresh-frozen plasma (10 mL/kg). In the next couple of days, she received extra platelets, erythrocyte transfusion, and filgrastim (Neupogen; 5 µg/kg/d) due to a very low leukocyte count. To the best of our knowledge, this is the first case of fat overload syndrome caused by SMOFlipid emulsion described in the literature.

  1. Symmetrical and overloaded effect of diffusion in information filtering

    Science.gov (United States)

    Zhu, Xuzhen; Tian, Hui; Chen, Guilin; Cai, Shimin

    2017-10-01

    In physical dynamics, mass diffusion theory has been applied to design effective information filtering models on bipartite network. In previous works, researchers unilaterally believe objects' similarities are determined by single directional mass diffusion from the collected object to the uncollected, meanwhile, inadvertently ignore adverse influence of diffusion overload. It in some extent veils the essence of diffusion in physical dynamics and hurts the recommendation accuracy and diversity. After delicate investigation, we argue that symmetrical diffusion effectively discloses essence of mass diffusion, and high diffusion overload should be published. Accordingly, in this paper, we propose an symmetrical and overload penalized diffusion based model (SOPD), which shows excellent performances in extensive experiments on benchmark datasets Movielens and Netflix.

  2. Diagnosis and quantification of the iron overload through Magnetic resonance.

    Science.gov (United States)

    Alústiza Echeverría, J M; Barrera Portillo, M C; Guisasola Iñiguiz, A; Ugarte Muño, A

    There are different magnetic resonance techniques and models to quantify liver iron concentration. T2 relaxometry methods evaluate the iron concentration in the myocardium, and they are able to discriminate all the levels of iron overload in the liver. Signal intensity ratio methods saturate with high levels of liver overload and can not assess iron concentration in the myocardium but they are more accessible and are very standardized. This article reviews, in different clinical scenarios, when Magnetic Resonance must be used to assess iron overload in the liver and myocardium and analyzes the current challenges to optimize the aplication of the technique and to be it included in the clinical guidelines. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. [Hemodynamic evaluation of the patient with microvarices].

    Science.gov (United States)

    Alvarez Sánchez, J A; Vega Gómez, M E; Rodríguez Lacaba, B; Martínez Griñán, M A

    1992-01-01

    The present study included 21 lower limbs with micro varicosities, 56 lower limbs with retrograde flow-varicosities (positive Rivlin) and 35 health lower limbs. Technics used for diagnosis were: Doppler ultrasonography and strain gauge plethysmography. We found a higher incidence of valvular failure on the varicose patients with retrograde flow (showing changes on their viscoelastic features of their venous walls). On the contrary, patient with microvaricosities showed an hemodynamics similar to the healty patient: we did not found any difference on the variables analyzed between the two groups. We conclude that the presence of microvaricosities has no influence on the analyzed hemodynamic parametres.

  4. Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

    Science.gov (United States)

    Ballak, Sam B; Busé-Pot, Tinelies; Harding, Peter J; Yap, Moi H; Deldicque, Louise; de Haan, Arnold; Jaspers, Richard T; Degens, Hans

    2016-04-01

    We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity.

  5. Overload Control in Smart Transformer-Fed Grid

    Directory of Open Access Journals (Sweden)

    Giovanni De Carne

    2017-02-01

    Full Text Available Renewable energy resources and new loads—such as electric vehicles—challenge grid management. Among several scenarios, the smart transformer represents a solution for simultaneously managing low- and medium-voltage grids, providing ancillary services to the distribution grid. However, unlike conventional transformers, the smart transformer has a very limited overload capability, because the junction temperature—which must always be below its maximum limit—is characterized by a short time constant. In this work, an overload control for smart transformer by means of voltage and frequency variations has been proposed and verified by means of simulations and experiments.

  6. Employed Mexican women as mothers and partners: valued, empowered and overloaded.

    Science.gov (United States)

    Meleis, A I; Douglas, M K; Eribes, C; Shih, F; Messias, D K

    1996-01-01

    This study was designed to explore the daily lived experiences of a group of employed, low-income Mexican women in their maternal and spousal roles. The participants were 41 auxiliary nurses recruited from two large urban hospitals in Mexico. Data were collected through the Women's Roles Interview Protocol (WRIP), which solicited the participants' perceptions of the satisfaction and stresses they experienced in their roles as mothers and spouses, and their descriptions of the coping strategies and the resources they used to deal with stressful life experiences related to these roles. Data analysis consisted of a qualitative thematic analysis of the narrative responses to open-ended questions in the WRIP. Satisfying aspects of the maternal and spousal roles, as identified by the participants, included giving to and receiving from their children and being valued and supported by their partners. Spousal approval of their work was also satisfying. These employed mothers, however, experienced many stressful aspects of functioning in multiple roles, including lack of resources, being absent from their children, self-doubt about their maternal role functioning, role overload and spousal absences. The women coped by juggling priorities and utilizing family resources. From the data analysis, the investigators developed a conceptual framework for understanding these women's experiences with parenting and marriage. The centrality of the family, a sense of value and empowerment as women in maternal and spousal roles, and the reality of role overload are discussed within the Mexican culture context of machismo, its female counterpart hembrismo, and family life. Implications for women's health are framed within a context of family and work.

  7. A review of hemodynamic monitoring techniques, methods and devices for the emergency physician.

    Science.gov (United States)

    Laher, Abdullah E; Watermeyer, Matthew J; Buchanan, Sean K; Dippenaar, Nicole; Simo, Nelly Clotilde Tchouambou; Motara, Feroza; Moolla, Muhammed

    2017-09-01

    The emergency department (ED) is frequently the doorway to the intensive care unit (ICU) for a significant number of critically ill patients presenting to the hospital. Hemodynamic monitoring (HDM) which is a key component in the effective management of the critically ill patient presenting to the ED, is primarily concerned with assessing the performance of the cardiovascular system and determining the correct therapeutic intervention to optimise end-organ oxygen delivery. The spectrum of hemodynamic monitoring ranges from simple clinical assessment and routine bedside monitoring to point of care ultrasonography and various invasive monitoring devices. The clinician must be aware of the range of available techniques, methods, interventions and technological advances as well as possess a sound approach to basic hemodynamic monitoring prior to selecting the optimal modality. This article comprises an in depth discussion of an approach to hemodynamic monitoring techniques and principles as well as methods of predicting fluid responsiveness as it applies to the ED clinician. We review the role, applicability and validity of various methods and techniques that include; clinical assessment, passive leg raising, blood pressure, finger based monitoring devices, the mini-fluid challenge, the end-expiratory occlusion test, central venous pressure monitoring, the pulmonary artery catheter, ultrasonography, bioreactance and other modern invasive hemodynamic monitoring devices. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The renin-angiotensin system in obesity : metabolic and hemodynamic effects

    NARCIS (Netherlands)

    Goossens, G.H.

    2006-01-01

    Abdominal obesity plays a central role in the metabolic syndrome and is a major risk factor for type 2 diabetes mellitus and cardiovascular disease. Unravelling the underlying mechanisms of obesity and obesity-related metabolic and hemodynamic disorders, such as insulin resistance and hypertension,

  9. Hemodynamic significance of internal carotid artery disease

    DEFF Research Database (Denmark)

    Schroeder, T

    1988-01-01

    a significant improvement in baseline flow occur. Flow reserve determined by cerebral vasodilation, however, will improve in most patients with hemodynamic failure. In addition, some patients in the low-pressure group develop marked, but temporary, hyperperfusion after reconstruction of very high grade carotid...

  10. Central Hemodynamics for Management of Arteriosclerotic Diseases.

    Science.gov (United States)

    Hashimoto, Junichiro

    2017-08-01

    Arteriosclerosis, particularly aortosclerosis, is the most critical risk factor associated with cardiovascular, cerebrovascular, and renal diseases. The pulsatile hemodynamics in the central aorta consists of blood pressure, flow, and stiffness and substantially differs from the peripheral hemodynamics in muscular arteries. Arteriosclerotic changes with age appear earlier in the elastic aorta, and age-dependent increases in central pulse pressure are more marked than those apparent from brachial pressure measurement. Central pressure can be affected by lifestyle habits, metabolic disorders, and endocrine and inflammatory diseases in a manner different from brachial pressure. Central pulse pressure widening due to aortic stiffening increases left ventricular afterload in systole and reduces coronary artery flow in diastole, predisposing aortosclerotic patients to myocardial hypertrophy and ischemia. The widened pulse pressure is also transmitted deep into low-impedance organs such as the brain and kidney, causing microvascular damage responsible for lacunar stroke and albuminuria. In addition, aortic stiffening increases aortic blood flow reversal, which can lead to retrograde embolic stroke and renal function deterioration. Central pressure has been shown to predict cardiovascular events in most previous studies and potentially serves as a surrogate marker for intervention. Quantitative and comprehensive evaluation of central hemodynamics is now available through various noninvasive pressure/flow measurement modalities. This review will focus on the clinical usefulness and mechanistic rationale of central hemodynamic measurements for cardiovascular risk management.

  11. Iron overload and apoptosis of HL-1 cardiomyocytes: effects of calcium channel blockade.

    Directory of Open Access Journals (Sweden)

    Mei-pian Chen

    Full Text Available Iron overload cardiomyopathy that prevails in some forms of hemosiderosis is caused by excessive deposition of iron into the heart tissue and ensuing damage caused by a raise in labile cell iron. The underlying mechanisms of iron uptake into cardiomyocytes in iron overload condition are still under investigation. Both L-type calcium channels (LTCC and T-type calcium channels (TTCC have been proposed to be the main portals of non-transferrinic iron into heart cells, but controversies remain. Here, we investigated the roles of LTCC and TTCC as mediators of cardiac iron overload and cellular damage by using specific Calcium channel blockers as potential suppressors of labile Fe(II and Fe(III ingress in cultured cardiomyocytes and ensuing apoptosis.Fe(II and Fe(III uptake was assessed by exposing HL-1 cardiomyocytes to iron sources and quantitative real-time fluorescence imaging of cytosolic labile iron with the fluorescent iron sensor calcein while iron-induced apoptosis was quantitatively measured by flow cytometry analysis with Annexin V. The role of calcium channels as routes of iron uptake was assessed by cell pretreatment with specific blockers of LTCC and TTCC.Iron entered HL-1 cardiomyocytes in a time- and dose-dependent manner and induced cardiac apoptosis via mitochondria-mediated caspase-3 dependent pathways. Blockade of LTCC but not of TTCC demonstrably inhibited the uptake of ferric but not of ferrous iron. However, neither channel blocker conferred cardiomyocytes with protection from iron-induced apoptosis.Our study implicates LTCC as major mediators of Fe(III uptake into cardiomyocytes exposed to ferric salts but not necessarily as contributors to ensuing apoptosis. Thus, to the extent that apoptosis can be considered a biological indicator of damage, the etiopathology of cardiosiderotic damage that accompanies some forms of hemosiderosis would seem to be unrelated to LTCC or TTCC, but rather to other routes of iron ingress present in

  12. Self regulation initiative to address the heavy vehicle overloading problem in South Africa

    CSIR Research Space (South Africa)

    Nordengen, Paul A

    2004-07-01

    Full Text Available Heavy vehicle overloading continues to be a major problem in South Africa notwithstanding efforts at more effective overload control by the authorities. This paper describes a pilot project, funded by the Department of Trade and Industry...

  13. Development of an overload control strategy for the Republic of Senegal

    CSIR Research Space (South Africa)

    Nordengen, Paul A

    2006-09-01

    Full Text Available traffic in Senegal. An assessment of the commodities transported during the surveys found that cement; sand, steel and general goods are the cargoes that contribute most significantly to overloading of heavy vehicles. The overload control strategy...

  14. Designing a Personalized Guide Recommendation System to Mitigate Information Overload in Museum Learning

    National Research Council Canada - National Science Library

    Yong-Ming Huang; Chien-Hung Liu; Chun-Yi Lee; Yueh-Min Huang

    2012-01-01

    .... However, a problem with information overload has caused in engaging in such learning. Information overload signifies that users encounter a mass of information and need to determine whether certain information needs to be retained...

  15. Iron deficiency and overload in relation to nutrition

    NARCIS (Netherlands)

    Spanjersberg MQI; Jansen EHJM; LEO

    2000-01-01

    Nutritional iron intake in the Netherlands has been reviewed with respect to both iron deficiency and iron overload. In general, iron intake and iron status in the Netherlands are adequate and therefore no change in nutrition policy is required. The following aspects and developments, however, need

  16. Dietary iron rural blacks overload In southern African

    African Journals Online (AJOL)

    1990-09-15

    Sep 15, 1990 ... This finding was ascribed to the fact that traditional brews are not only associated with alcohol- induced hepatic damage but are also a very rich source of ... liver/,J glucose intolerance;4 scurvy and osteoporosis;5 and possibly oesophageal carcinoma.6. There is also evidence to suggest that iron overload ...

  17. Mitochondrial dysfunction may explain the cardiomyopathy of chronic iron overload.

    Science.gov (United States)

    Gao, Xueshan; Qian, Mingwei; Campian, Jian Li; Marshall, James; Zhou, Zhanxiang; Roberts, Andrew M; Kang, Y James; Prabhu, Sumanth D; Sun, Xiao-Feng; Eaton, John W

    2010-08-01

    In patients with hemochromatosis, cardiac dysfunction may appear years after they have reached a state of iron overload. We hypothesized that cumulative iron-catalyzed oxidant damage to mitochondrial DNA (mtDNA) might explain the cardiomyopathy of chronic iron overload. Mice were given repetitive injections of iron dextran for a total of 4weeks after which the iron-loaded mice had elevated cardiac iron, modest cardiac hypertrophy, and cardiac dysfunction. qPCR amplification of near-full-length ( approximately 16kb) mtDNA revealed >50% loss of full-length product, whereas amounts of a qPCR product of a nuclear gene (13kb region of beta globin) were unaffected. Quantitative rtPCR analyses revealed 60-70% loss of mRNA for proteins encoded by mtDNA with no change in mRNA abundance for nuclear-encoded respiratory subunits. These changes coincided with proportionate reductions in complex I and IV activities and decreased respiration of isolated cardiac mitochondria. We conclude that chronic iron overload leads to cumulative iron-mediated damage to mtDNA and impaired synthesis of mitochondrial respiratory chain subunits. The resulting respiratory dysfunction may explain the slow development of cardiomyopathy in chronic iron overload and similar accumulation of damage to mtDNA may also explain the mitochondrial dysfunction observed in slowly progressing diseases such as neurodegenerative disorders. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Fatigue crack growth due to overloads in plain concrete using ...

    Indian Academy of Sciences (India)

    The predicted results are compared with experimental crack growth data for variable amplitude loading and are found to capture the overload effect with sufficient accuracy. Through a sensitivity analysis, fracture toughness is found to be the most dominant parameter in accelerating the crack length due to application of ...

  19. Dietary iron overload in southern African rural blacks | Friedman ...

    African Journals Online (AJOL)

    A survey conducted in rural southern African black subjects indicated that dietary iron overload remains a major health problem. A full blood count, erythrocyte sedimentation rate, serum concentrations of iron, total iron-binding capacity, ferritin, C-reactive protein (CRP), 1'-glutamyltransferase (GGn and serological screening ...

  20. Overload prevention in model supports for wind tunnel model testing

    Directory of Open Access Journals (Sweden)

    Anton IVANOVICI

    2015-09-01

    Full Text Available Preventing overloads in wind tunnel model supports is crucial to the integrity of the tested system. Results can only be interpreted as valid if the model support, conventionally called a sting remains sufficiently rigid during testing. Modeling and preliminary calculation can only give an estimate of the sting’s behavior under known forces and moments but sometimes unpredictable, aerodynamically caused model behavior can cause large transient overloads that cannot be taken into account at the sting design phase. To ensure model integrity and data validity an analog fast protection circuit was designed and tested. A post-factum analysis was carried out to optimize the overload detection and a short discussion on aeroelastic phenomena is included to show why such a detector has to be very fast. The last refinement of the concept consists in a fast detector coupled with a slightly slower one to differentiate between transient overloads that decay in time and those that are the result of aeroelastic unwanted phenomena. The decision to stop or continue the test is therefore conservatively taken preserving data and model integrity while allowing normal startup loads and transients to manifest.

  1. Information Overload in Multi-Stage Selection Procedures

    NARCIS (Netherlands)

    S.S. Ficco (Stefano); V.A. Karamychev (Vladimir)

    2004-01-01

    textabstractThe paper studies information processing imperfections in a fully rational decision-making network. It is shown that imperfect information transmission and imperfect information acquisition in a multi-stage selection game yield information overload. The paper analyses the mechanisms

  2. Stress 2.0: Social Media Overload among Swiss Teenagers

    NARCIS (Netherlands)

    Lutz, Christoph; Ranzini, Giulia; Meckel, Miriam

    2014-01-01

    Technostress and information overload are serious challenges of the information age. An alarming number of people exhibit dangerously intensive media consumption, while Internet and mobile phone addictions are a widespread phenomenon. At the same time, new media overexposure among young people is

  3. Information Overload and Viral Marketing: Countermeasures and Strategies

    Science.gov (United States)

    Cheng, Jiesi; Sun, Aaron; Zeng, Daniel

    Studying information diffusion through social networks has become an active research topic with important implications in viral marketing applications. One of the fundamental algorithmic problems related to viral marketing is the Influence Maximization (IM) problem: given an social network, which set of nodes should be considered by the viral marketer as the initial targets, in order to maximize the influence of the advertising message. In this work, we study the IM problem in an information-overloaded online social network. Information overload occurs when individuals receive more information than they can process, which can cause negative impacts on the overall marketing effectiveness. Many practical countermeasures have been proposed for alleviating the load of information on recipients. However, how these approaches can benefit viral marketers is not well understood. In our work, we have adapted the classic Information Cascade Model to incorporate information overload and study its countermeasures. Our results suggest that effective control of information overload has the potential to improve marketing effectiveness, but the targeting strategy should be re-designed in response to these countermeasures.

  4. Duplex Doppler ultrasound assessment of clitoral hemodynamics after topical administration of alprostadil in women with arousal and orgasmic disorders.

    Science.gov (United States)

    Bechara, A; Bertolino, M V; Casabé, A; Munarriz, R; Goldstein, I; Morin, A; Secin, F; Literat, B; Pesaresi, M; Fredotovich, N

    2003-01-01

    There are limited hemodynamic data in women with arousal or orgasmic disorders and even fewer normative control hemodynamic data in women without sexual dysfunction. In addition, there is limited experience with topical vasoactive agents (used to maximize genital smooth muscle relaxation) applied to the external genitalia during hemodynamic evaluations. The aim of this study was to report duplex Doppler ultrasound clitoral cavernosal arterial changes before and after topical PGE-1 (Alprostadil) administration in control women and in patients with arousal and orgasmic sexual disorders. We found that women with sexual arousal and orgasmic disorders had significantly (p < 0.05) diminished clitoral peak systolic and end diastolic velocity responses compared to controls. Further research is needed to establish the diagnostic role of topical vasoactive agents in the hemodynamic evaluation of women with sexual dysfunction.

  5. Determination of Permissible Short-Time Emergency Overloading of Turbo-Generators and Synchronous Compensators

    Directory of Open Access Journals (Sweden)

    V. A. Anischenko

    2011-01-01

    Full Text Available The paper shows that failure to take into account variable ratio of short-time emergency overloading of turbo-generators (synchronous compensators that can lead to underestimation of overloading capacity or impermissible insulation over-heating.A method has been developed for determination of permissible duration of short-time emergency over-loading that takes into account changes of over-loading ratio in case of a failure.

  6. Cytoskeletal mechanics in pressure-overload cardiac hypertrophy

    Science.gov (United States)

    Tagawa, H.; Wang, N.; Narishige, T.; Ingber, D. E.; Zile, M. R.; Cooper, G. 4th

    1997-01-01

    We have shown that the cellular contractile dysfunction characteristic of pressure-overload cardiac hypertrophy results not from an abnormality intrinsic to the myofilament portion of the cardiocyte cytoskeleton but rather from an increased density of the microtubule component of the extramyofilament portion of the cardiocyte cytoskeleton. To determine how, in physical terms, this increased microtubule density mechanically overloads the contractile apparatus at the cellular level, we measured cytoskeletal stiffness and apparent viscosity in isolated cardiocytes via magnetic twisting cytometry, a technique by which magnetically induced force is applied directly to the cytoskeleton through integrin-coupled ferromagnetic beads coated with Arg-Gly-Asp (RGD) peptide. Measurements were made in two groups of cardiocytes from cats with right ventricular (RV) hypertrophy induced by pulmonary artery banding: (1) those from the pressure-overloaded RV and (2) those from the normally loaded same-animal control left ventricle (LV). Cytoskeletal stiffness increased almost twofold, from 8.53 +/- 0.77 dyne/cm2 in the normally loaded LV cardiocytes to 16.46 +/- 1.32 dyne/cm2 in the hypertrophied RV cardiocytes. Cytoskeletal apparent viscosity increased almost fourfold, from 20.97 +/- 1.92 poise in the normally loaded LV cardiocytes to 87.85 +/- 6.95 poise in the hypertrophied RV cardiocytes. In addition to these baseline data showing differing stiffness and, especially, apparent viscosity in the two groups of cardiocytes, microtubule depolymerization by colchicine was found to return both the stiffness and the apparent viscosity of the pressure overload-hypertrophied RV cells fully to normal. Conversely, microtubule hyperpolymerization by taxol increased the stiffness and apparent viscosity values of normally loaded LV cardiocytes to the abnormal values given above for pressure-hypertrophied RV cardiocytes. Thus, increased microtubule density constitutes primarily a viscous load on

  7. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Science.gov (United States)

    2010-07-01

    ... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric equipment shall be provided with overload protection that will deenergize all three phases in the event that... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and...

  8. Smad Nuclear Interacting Protein 1 Acts as a Protective Regulator of Pressure Overload-Induced Pathological Cardiac Hypertrophy.

    Science.gov (United States)

    Lu, Yu-Yan; Xu, Da-Chun; Zhao, Yi-Fan; Zhu, Guo-Fu; Zhu, Meng-Yun; Liu, Wei-Jing; Yu, Xue-Jing; Chen, Wei; Liu, Zheng; Xu, Ya-Wei

    2016-10-26

    Smad nuclear interacting protein 1 (SNIP1) plays a critical role in cell proliferation, transformation of embryonic fibroblasts, and immune regulation. However, the role of SNIP1 in cardiac hypertrophy remains unclear. Here we examined the role of SNIP1 in pressure overload-induced cardiac hypertrophy and its mechanisms. Our results demonstrated that SNIP1 expression was downregulated in human dilated cardiomyopathic hearts, aortic banding-induced mice hearts, and angiotensin II-treated cardiomyocytes. Accordingly, SNIP1 deficiency significantly exacerbated aortic banding-induced cardiac hypertrophy, fibrosis, and contractile dysfunction, whereas cardiac-specific overexpression of SNIP1 markedly recovered pressure overload-induced cardiac hypertrophy and fibrosis. Besides that, SNIP1 protected neonatal rat cardiomyocytes against angiotensin II-induced hypertrophy in vitro. Moreover, we identified that SNIP1 suppressed nuclear factor-κB signaling during pathological cardiac hypertrophy, and inhibition of nuclear factor-κB signaling by a cardiac-specific conditional inhibitor of κB S 32A/S36A transgene blocked these adverse effects of SNIP1 deficiency on hearts. Together, our findings demonstrated that SNIP1 had protective effects in pressure overload-induced pathological cardiac hypertrophy via inhibition of nuclear factor-κB signaling. Thus, SNIP1 may be a novel approach for the treatment of heart failure. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  9. Sympathectomy or doxazosin, but not propranolol, blunt myocardial interstitial fibrosis in pressure-overload hypertrophy.

    Science.gov (United States)

    Perlini, Stefano; Palladini, Giuseppina; Ferrero, Ivana; Tozzi, Rossana; Fallarini, Silvia; Facoetti, Angelica; Nano, Rosanna; Clari, Francesca; Busca, Giuseppe; Fogari, Roberto; Ferrari, Alberto U

    2005-11-01

    The adaptive changes that develop in the pressure-overloaded left ventricular (LV) myocardium include cardiomyocyte hypertrophy and interstitial fibrosis. Although the former is known to depend to a sizeable extent on sympathetic (over)activity, little information exists whether the same applies to the latter, ie, whether excess catecholamine exposure contributes to the imbalance between collagen deposition by fibroblasts and degradation by matrix metalloproteases (MMPs), eventually leading to LV collagen accumulation. Sprague-Dawley rats were subjected to abdominal aortic banding (B) or sham operation (S) and treated with beta-blockade (Bb, oral propranolol, 40 mg/kg per day), chemical sympathectomy (Sx, 6-hydroxydopamine, 150 mg/kg intraperitoneal twice per week) or vehicle (Vh). Ten weeks later, systolic blood pressure, LV weight, collagen abundance (computer-aided histology), zymographic matrix metalloproteinase (MMP)-2 activity and its specific tissue inhibitor concentration (TIMP-2) were measured. Both sympathectomy and beta-blockade failed to attenuate the banding-induced blood pressure elevation but significantly attenuated the attendant LV hypertrophy. As expected, pressure-overload hypertrophy was associated with interstitial fibrosis (collagen: 4.37+/-1.23% BVh versus 1.23+/-0.44% SVh, P<0.05), which was abolished by sympathectomy (2.55+/-1.31%, P=not significant versus SSx) but left unchanged by beta-blockade (4.11+/-1.23%, P<0.05 versus both SBb and BSx). beta-blockade, but not sympathectomy, was also associated with an increased TIMP-2/MMP-2 ratio (P<0.05), indicating reduced interstitial collagenolytic activity. In separate groups of banded and sham-operated rats, treatment with the alpha-receptor blocker doxazosin (10 mg/kg per day) displayed similar antifibrotic and biochemical effects as sympathectomy. Thus in the course of experimental pressure overload, the sympathetic nervous system plays a major pro-fibrotic role, which is mediated via alpha

  10. Combination of Urinary Sodium/Creatinine Ratio and Plasma Brain Natriuretic Peptide Level Predicts Successful Tolvaptan Therapy in Patients With Heart Failure and Volume Overload.

    Science.gov (United States)

    Sato, Yuichi; Dohi, Kaoru; Watanabe, Kiyotaka; Tanimura, Muneyoshi; Takeuchi, Tetsushiro; Sugiura, Emiyo; Sugimoto, Tadafumi; Kumagai, Naoto; Ogura, Toru; Nakamori, Shiro; Fujimoto, Naoki; Yamada, Norikazu; Ito, Masaaki

    2016-01-01

    To evaluate the short-term clinical and hemodynamic effects of tolvaptan therapy and to identify predictors of the therapeutic outcomes, we retrospectively recruited 60 consecutive hospitalized heart failure (HF) patients (70 ± 11 years) with volume overload. The subjects were divided into two groups on the basis of the changes in HF symptom scores and hemodynamic status assessed by right heart catheterization after tolvaptan therapy (median: 7 days). The majority of patients were successfully treated (group 1). However, 22% of patients (group 2) were unsuccessfully treated, in whom 1) the HF symptom score worsened or 2) there was a stationary HF symptom score ≥ 6 points, and mean PCWP > 18 mmHg and mean RAP > 10 mmHg, after tolvaptan therapy. HF symptom scores, hemodynamic parameters, and plasma brain natriuretic peptide (BNP) level improved in group 1, but all of these parameters remained unchanged in group 2. Lower urine sodium/creatinine ratio (UNa/UCr) and higher BNP level at baseline were independently associated with unsuccessful tolvaptan therapy, and UNa/UCr best predicts unsuccessful tolvaptan therapy with a cut-off value of 46.5 mEq/g·Cr (AUC 0.847, 95% CI: 0.718-0.976, sensitivity 77%, specificity 81%, P 778 pg/mL predicted unsuccessful tolvaptan therapy with high diagnostic accuracy (sensitivity 54%, specificity 100%, positive predictive value 100%, negative predictive value 89%, and accuracy 90%). In summary, short-term tolvaptan therapy ameliorated HF symptoms and provided hemodynamic improvement in the majority of patients, and UNa/UCr and BNP level strongly predicted the therapeutic outcomes.

  11. An RNAi therapeutic targeting Tmprss6 decreases iron overload in Hfe(-/-) mice and ameliorates anemia and iron overload in murine β-thalassemia intermedia

    National Research Council Canada - National Science Library

    Schmidt, Paul J; Toudjarska, Iva; Sendamarai, Anoop K; Racie, Tim; Milstein, Stuart; Bettencourt, Brian R; Hettinger, Julia; Bumcrot, David; Fleming, Mark D

    2013-01-01

    .... -thalassemia is a congenital anemia caused by partial or complete loss of -globin synthesis causing ineffective erythropoiesis, anemia, decreased hepcidin production, and secondary iron overload...

  12. Emergency management of hemodynamically unstable pelvic fractures

    Directory of Open Access Journals (Sweden)

    ZHAO Xiao-gang

    2012-02-01

    Full Text Available 【Abstract】Pelvic fractures are serious injuries. Death within 24 hours is most often a result of acute blood loss. The emergency management of these patients is challenging and controversial. The key issues in its management are identifying the site(s of hemorrhage and then controlling the bleeding. Management of hemodynamically unstable patients with pelvic fracture requires a multidisci- plinary team. The issues addressed in this management algorithm are diagnostic evaluation, damage control resuscitation, indications for noninvasive pelvic stabilization, preperitoneal pelvic packing and the critical decisions concerning surgical options and angiography. This review article focuses on the recent body of know- ledge on those determinations. Key words: Pelvis; Hemodynamic; Emergencies; Practice management

  13. Immunologic, hemodynamic, and adrenal incompetence in cirrhosis

    DEFF Research Database (Denmark)

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

    2015-01-01

    Acute kidney injury (AKI) is one of the most severe complications of cirrhosis and is associated with significant morbidity and mortality. Liver fibrosis and liver insufficiency, portal hypertension, systemic vasodilation, and a subsequent hyperdynamic circulation undermine the renal and cardiac...... function, making cirrhotic patients more susceptible to hemodynamic incidents. In addition, the immune system is impaired in cirrhosis, leading to an exaggerated production of vasoactive mediators, and the adrenal cortisol response is insufficient, which causes further impairment of the vascular tonus...

  14. HEMODYNAMIC EFFECTS OF XENON ANESTHESIA IN CHILDREN

    Directory of Open Access Journals (Sweden)

    M. V. Bykov

    2014-01-01

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

  15. Conservative hemodynamic surgery for varicose veins.

    Science.gov (United States)

    Criado, Enrique; Luján, Salvador; Izquierdo, Luis; Puras, Enrique; Gutierrez, Miguel; Fontcuberta, Juan

    2002-03-01

    Conservative hemodynamic surgery for varicose veins is a minimally invasive, nonablative technique that preserves the saphenous vein and helps avoid excision of varicosities. It represents a physiologic approach to the surgical treatment of varicose veins based on knowledge of the underlying venous pathophysiology gained through detailed duplex scanning. A change in venous hemodynamics is attained through fragmentation of the blood column by interruption of the refluxing saphenous trunks, closure of the origin of the refluxing varicose branches, and preservation of the communicating veins that drain the incompetent varicose veins into the deep venous system. After surgery, varicose veins regress through a reduction in hydrostatic pressure and efficient emptying of the superficial system by the musculo-venous pump. Obvious advantages of this technique are that it is done in an ambulatory setting, minimizes the risk of surgical complications, and permits a rapid return to full activity. The long-term hemodynamic improvement and recurrence rate of this technique remain to be established. Copyright 2002 by W.B. Saunders Company

  16. Practice of hemodynamic monitoring and management in German, Austrian, and Swiss intensive care units: the multicenter cross-sectional ICU-CardioMan Study.

    Science.gov (United States)

    Funcke, Sandra; Sander, Michael; Goepfert, Matthias S; Groesdonk, Heinrich; Heringlake, Matthias; Hirsch, Jan; Kluge, Stefan; Krenn, Claus; Maggiorini, Marco; Meybohm, Patrick; Salzwedel, Cornelie; Saugel, Bernd; Wagenpfeil, Gudrun; Wagenpfeil, Stefan; Reuter, Daniel A

    2016-12-01

    Hemodynamic instability is frequent and outcome-relevant in critical illness. The understanding of complex hemodynamic disturbances and their monitoring and management plays an important role in treatment of intensive care patients. An increasing number of treatment recommendations and guidelines in intensive care medicine emphasize hemodynamic goals, which go beyond the measurement of blood pressures. Yet, it is not known to which extent the infrastructural prerequisites for extended hemodynamic monitoring are given in intensive care units (ICUs) and how hemodynamic management is performed in clinical practice. Further, it is still unclear which factors trigger the use of extended hemodynamic monitoring. In this multicenter, 1-day (November 7, 2013, and the preceding 24 h) cross-sectional study, we retrieved data on patient monitoring from ICUs in Germany, Austria, and Switzerland by means of a web-based case report form. One hundred and sixty-one intensive care units contributed detailed information on availability of hemodynamic monitoring. In addition, detailed information on hemodynamic monitoring of 1789 patients that were treated on due date was collected, and independent factors triggering the use of extended hemodynamic monitoring were identified by multivariate analysis. Besides basic monitoring with electrocardiography (ECG), pulse oximetry, and blood pressure monitoring, the majority of patients received invasive arterial (77.9 %) and central venous catheterization (55.2 %). All over, additional extended hemodynamic monitoring for assessment of cardiac output was only performed in 12.3 % of patients, while echocardiographic examination was used in only 1.9 %. The strongest independent predictors for the use of extended hemodynamic monitoring of any kind were mechanical ventilation, the need for catecholamine therapy, and treatment backed by protocols. In 71.6 % of patients in whom extended hemodynamic monitoring was added during the study period

  17. Effect of physiological overload on pregnancy in women with mitral regurgitation

    Directory of Open Access Journals (Sweden)

    Vera T. M Borges

    2011-01-01

    Full Text Available OBJECTIVES: to evaluate the structural and functional heart abnormalities in women with mitral regurgitation during pregnancy. INTRODUCTION: Women with mitral regurgitation progress well during pregnancy. However, the effects on the heart of the association between pregnancy and mitral regurgitation are not well established. METHODS: This is a case-control, longitudinal prospective study. Echocardiograms were performed in 18 women with mitral regurgitation at the 12th and 36th week of pregnancy and on the 45th day of the puerperium. Twelve age-matched healthy and pregnant women were included as controls and underwent the same evaluation as the study group. RESULTS: Compared with controls, women with mitral regurgitation presented increased left cardiac chambers in all evaluations. Increasing left atrium during pregnancy occurred only in the mitral regurgitation group. At the end of the puerperium, women with mitral regurgitation showed persistent enlargement of the left atrium compared with the beginning of pregnancy (5.0 ± 1.1 cm vs 4.6 ± 0.9 cm; p<0.05. Reduced left ventricular relative wall thickness (0.13 ± 0.02 vs 0.16 ± 0.02; p<0.05 and an increased peak of afterload (278 ± 55 g/cm² vs 207 ± 28 g/cm²;p<0.05 was still observed on the 45th day after delivery in the mitral regurgitation group compared with controls. CONCLUSIONS: Pregnancy causes unfavorable structural alterations in women with mitral regurgitation that are associated with an aggravation of the hemodynamic overload.

  18. Aging is protective against pressure overload cardiomyopathy via adaptive extracellular matrix remodeling.

    Science.gov (United States)

    Geng, Xiaoyong; Hwang, Joy; Ye, Jianqin; Shih, Henry; Coulter, Brianna; Naudin, Crystal; Jun, Kristine; Sievers, Richard; Yeghiazarians, Yerem; Lee, Randall J; Boyle, Andrew J

    2017-01-01

    When challenged by hemodynamic stress, aging hearts respond differently to young hearts. Preclinical models of heart disease should take into account the effects of age. However, in the transverse aortic constriction (TAC) model of pressure-overload cardiomyopathy, the larger aorta of aging mice has not previously been taken into account. First, we studied the aortic size in mice, and found that the aortic cross-sectional area (CSA) is 28% larger in aging mice than in young adult mice (P=0.001). We then performed TAC to make the same proportional reduction in CSA in young and aging mice. This produced the same pressure gradient across the constriction and the same rise in B-type natriuretic peptide expression. Young mice showed acute deterioration in systolic function assessed by pressure-volume loops, progressive LV remodeling on echocardiography, and a 50% mortality at 12 weeks post-TAC. In contrast, aging mice showed no acute deterioration in systolic function, much less ventricular remodeling and were protected from death. Aging mice also showed significantly increased levels of matrix metalloproteinase-3 (MMP-3; 3.2 fold increase, P<0.001) and MMP-12 (1.5-fold increase, P<0.001), which were not seen in young mice. Expression of tissue inhibitor of MMP-1 (TIMP-1) increased 8.6-fold in aging hearts vs 4.3-fold in young hearts (P<0.01). In conclusion, following size-appropriate TAC, aging mice exhibit less LV remodeling and lower mortality than young adult mice. This is associated with induction of protective ECM changes.

  19. CHIP protects against cardiac pressure overload through regulation of AMPK

    Science.gov (United States)

    Schisler, Jonathan C.; Rubel, Carrie E.; Zhang, Chunlian; Lockyer, Pamela; Cyr, Douglas M.; Patterson, Cam

    2013-01-01

    Protein quality control and metabolic homeostasis are integral to maintaining cardiac function during stress; however, little is known about if or how these systems interact. Here we demonstrate that C terminus of HSC70-interacting protein (CHIP), a regulator of protein quality control, influences the metabolic response to pressure overload by direct regulation of the catalytic α subunit of AMPK. Induction of cardiac pressure overload in Chip–/– mice resulted in robust hypertrophy and decreased cardiac function and energy generation stemming from a failure to activate AMPK. Mechanistically, CHIP promoted LKB1-mediated phosphorylation of AMPK, increased the specific activity of AMPK, and was necessary and sufficient for stress-dependent activation of AMPK. CHIP-dependent effects on AMPK activity were accompanied by conformational changes specific to the α subunit, both in vitro and in vivo, identifying AMPK as the first physiological substrate for CHIP chaperone activity and establishing a link between cardiac proteolytic and metabolic pathways. PMID:23863712

  20. Culinary plants and their potential impact on metabolic overload.

    Science.gov (United States)

    Kim, Ji Yeon; Kwon, Oran

    2011-07-01

    Contemporary human behavior has led a large proportion of the population to metabolic overload and obesity. Postprandial hyperlipidemia and hyperglycemia evoke redox imbalance in the short term and lead to complex chronic disease in the long term with repeated occurrence. Complex diseases are best prevented with complex components of plants; thus, current nutrition research has begun to focus on the development of plant-based functional foods and dietary supplements for health and well-being. Furthermore, given the wide range of species, parts, and secondary metabolites, culinary plants can contribute significant variety and complexity to the human diet. Although understanding the health benefits of culinary plants has been one of the great challenges in nutritional science due to their inherent complexity, it is an advantageous pursuit. This review will address the challenges and opportunities relating to studies of the health benefits of culinary plants, with an emphasis on obesity attributed to metabolic overload. © 2011 New York Academy of Sciences.

  1. Indecisiveness, Undesirability and Overload Revealed Through Rational Choice Deferral

    OpenAIRE

    Gerasimou, Georgios

    2015-01-01

    Three reasons why decision makers may defer choice are *indecisiveness* between various feasible options, *unattractiveness* of these options, and *choice overload*. This paper provides a choice-theoretic explanation for each of these phenomena by means of three deferral-permitting models of decision making that are driven by preference incompleteness, undesirability and complexity constraints, respectively. These models feature *rational* choice deferral in the sense that whenever the indivi...

  2. Congenital sideroblastic anemia without clinical iron overload. A case report.

    Science.gov (United States)

    Pignon, J M; Breton-Gorius, J; Bachir, D; Rochant, H

    1990-01-01

    An 18 year old boy presented with microcytic hypochromic anemia. Erythrocytic abnormalities and family studies suggested congenital sideroblastic anemia (CSA), but atypical features included absence of clinical iron overload, scanty iron deposits in mitochondria of late erythroblasts and reticulocytes, and a high platelet count. An unusual adhesion between bone marrow macrophages and reticulocytes was observed by electron microscopy. Haematological response was seen following pyridoxine administration, thus fending support to the diagnosis of CSA.

  3. Formal Constraints on Memory Management for Composite Overloaded Operations

    Directory of Open Access Journals (Sweden)

    Damian W.I. Rouson

    2006-01-01

    Full Text Available The memory management rules for abstract data type calculus presented by Rouson, Morris & Xu [15] are recast as formal statements in the Object Constraint Language (OCL and applied to the design of a thermal energy equation solver. One set of constraints eliminates memory leaks observed in composite overloaded expressions with three current Fortran 95/2003 compilers. A second set of constraints ensures economical memory recycling. The constraints are preconditions, postconditions and invariants on overloaded operators and the objects they receive and return. It is demonstrated that systematic run-time assertion checking inspired by the formal constraints facilitated the pinpointing of an exceptionally hard-to-reproduce compiler bug. It is further demonstrated that the interplay between OCL's modeling capabilities and Fortran's programming capabilities led to a conceptual breakthrough that greatly improved the readability of our code by facilitating operator overloading. The advantages and disadvantages of our memory management rules are discussed in light of other published solutions [11,19]. Finally, it is demonstrated that the run-time assertion checking has a negligible impact on performance.

  4. RCAN1 overexpression exacerbates calcium overloading-induced neuronal apoptosis.

    Directory of Open Access Journals (Sweden)

    Xiulian Sun

    Full Text Available Down Syndrome (DS patients develop characteristic Alzheimer's Disease (AD neuropathology after their middle age. Prominent neuronal loss has been observed in the cortical regions of AD brains. However, the underlying mechanism leading to this neuronal loss in both DS and AD remains to be elucidated. Calcium overloading and oxidative stress have been implicated in AD pathogenesis. Two major isoforms of regulator of calcineurin 1 (RCAN1, RCAN1.1 and RCAN1.4, are detected in human brains. In this report we defined the transcriptional regulation of RCAN1.1 and RCAN1.4 by two alternative promoters. Calcium overloading upregulated RCAN1.4 expression by activating RCAN1.4 promoter through calcineurin-NFAT signaling pathway, thus forming a negative feedback loop in isoform 4 regulation. Furthermore, RCAN1.4 overexpression exacerbated calcium overloading-induced neuronal apoptosis, which was mediated by caspase-3 apoptotic pathway. Our results suggest that downregulating RCAN1.4 expression in neurons could be beneficial to AD patients.

  5. RCAN1 overexpression exacerbates calcium overloading-induced neuronal apoptosis.

    Science.gov (United States)

    Sun, Xiulian; Wu, Yili; Herculano, Bruno; Song, Weihong

    2014-01-01

    Down Syndrome (DS) patients develop characteristic Alzheimer's Disease (AD) neuropathology after their middle age. Prominent neuronal loss has been observed in the cortical regions of AD brains. However, the underlying mechanism leading to this neuronal loss in both DS and AD remains to be elucidated. Calcium overloading and oxidative stress have been implicated in AD pathogenesis. Two major isoforms of regulator of calcineurin 1 (RCAN1), RCAN1.1 and RCAN1.4, are detected in human brains. In this report we defined the transcriptional regulation of RCAN1.1 and RCAN1.4 by two alternative promoters. Calcium overloading upregulated RCAN1.4 expression by activating RCAN1.4 promoter through calcineurin-NFAT signaling pathway, thus forming a negative feedback loop in isoform 4 regulation. Furthermore, RCAN1.4 overexpression exacerbated calcium overloading-induced neuronal apoptosis, which was mediated by caspase-3 apoptotic pathway. Our results suggest that downregulating RCAN1.4 expression in neurons could be beneficial to AD patients.

  6. Acute Effects of Eccentric Overload on Concentric Front Squat Performance.

    Science.gov (United States)

    Munger, Cameron N; Archer, David C; Leyva, Whitney D; Wong, Megan A; Coburn, Jared W; Costa, Pablo B; Brown, Lee E

    2017-05-01

    Munger, CN, Archer, DC, Leyva, WD, Wong, MA, Coburn, JW, Costa, PB, and Brown, LE. Acute effects of eccentric overload on concentric front squat performance. J Strength Cond Res 31(5): 1192-1197, 2017-Eccentric overload is used to enhance performance. The purpose of this study was to investigate the acute effects of eccentric overload on concentric front squat performance. Twenty resistance-trained men (age = 23.80 ± 1.82 years, height = 176.95 ± 5.21 cm, mass = 83.49 ± 10.43 kg, 1 repetition maximum [1RM] front squat = 131.02 ± 21.32 kg) volunteered. A dynamic warm-up and warm-up sets of front squat were performed. Eccentric hooks were added to the barbell. They descended for 3 seconds, until eccentric hooks released, and performed the concentric phase as fast as possible. There were 3 randomly ordered conditions with the concentric phase always at 90% 1RM and the eccentric phase at 105, 110, and 120% of 1RM. Two repetitions were performed for each condition. A repeated measures analysis of variance was used to determine differences. For peak velocity, there were main effects for time and condition (p front squat is a precursor.

  7. Influence, information overload, and information technology in health care.

    Science.gov (United States)

    Rebitzer, James B; Rege, Mari; Shepard, Christopher

    2008-01-01

    We investigate whether information technology (IT) can help physicians more efficiently acquire new knowledge in a clinical environment characterized by information overload. We combine analysis of data from a randomized trial with a theoretical model of the influence that IT has on the acquisition of new medical knowledge. Although the theoretical framework we develop is conventionally microeconomic, the model highlights the non-market and non-pecuniary influence activities that have been emphasized in the sociological literature on technology diffusion. We report three findings. First, empirical evidence and theoretical reasoning suggests that computer-based decision support will speed the diffusion of new medical knowledge when physicians are coping with information overload. Second, spillover effects will likely lead to "underinvestment" in this decision support technology. Third, alternative financing strategies common to new IT, such as the use of marketing dollars to pay for the decision support systems, may lead to undesirable outcomes if physician information overload is sufficiently severe and if there is significant ambiguity in how best to respond to the clinical issues identified by the computer. This is the first paper to analyze empirically and theoretically how computer-based decision support influences the acquisition of new knowledge by physicians.

  8. Occupational exposure in hemodynamic; Exposicao ocupacional em hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-26

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

  9. Arteriovenous fistulas aggravate the hemodynamic effect of vein bypass stenoses

    DEFF Research Database (Denmark)

    Nielsen, Tina G; Djurhuus, Christian Born; Morre-Pedersen, Erik

    1996-01-01

    PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced...... hemodynamic conditions of a more severe stenosis. Assessment of the hemodynamic impact of fistulas must be undertaken in the evaluation of in situ vein bypass stenoses....

  10. Hemodynamic features and recurrence risk analysis of subtotally embolized ophthalmic aneurysms

    Directory of Open Access Journals (Sweden)

    Chuan-hui LI

    2011-12-01

    Full Text Available Objective The present study investigates the hemodynamic features in the residual necks of subtotally embolized ophthalmic aneurysms and their influence on the recurrence after operation.Methods Four ophthalmic aneurysm cases from January 2007 to July 2008 were studied.The aneurysms of the patients had residual necks after being embolized.Three-dimensional cerebral angiography images were taken before and after embolization,and the aneurysm modes were determined based on these images.The hemodynamic features in the residual neck before and after operation and during recurrence were analyzed by using a hydrodynamic software program and the finite-element method.Results The hemodynamic analysis shows that the residual neck had high shear stress and blood flow velocity regions after embolization in all four cases.Out of the four patients,three experienced recurrence,where blood flowed into the tumor cavity coinciding with the high shear stress regions.Conclusions High shear stress and blood flow velocity in the residual neck of embolized ophthalmic aneurysms manifested in the location of recurrence.Thus,hemodynamic factors may have an important role in the recurrence of ophthalmic aneurysms after embolization.

  11. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    Directory of Open Access Journals (Sweden)

    Matthias Weuster

    2015-01-01

    Full Text Available Background. The deterioration of hemodynamics instantly endangers the patients’ life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals’ hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia.

  12. Iron overload patients with unknown etiology from national survey in Japan.

    Science.gov (United States)

    Ikuta, Katsuya; Hatayama, Mayumi; Addo, Lynda; Toki, Yasumichi; Sasaki, Katsunori; Tatsumi, Yasuaki; Hattori, Ai; Kato, Ayako; Kato, Koichi; Hayashi, Hisao; Suzuki, Takahiro; Kobune, Masayoshi; Tsutsui, Miyuki; Gotoh, Akihiko; Aota, Yasuo; Matsuura, Motoo; Hamada, Yuzuru; Tokuda, Takahiro; Komatsu, Norio; Kohgo, Yutaka

    2017-03-01

    Transfusion is believed to be the main cause of iron overload in Japan. A nationwide survey on post-transfusional iron overload subsequently led to the establishment of guidelines for iron chelation therapy in this country. To date, however, detailed clinical information on the entire iron overload population in Japan has not been fully investigated. In the present study, we obtained and studied detailed clinical information on the iron overload patient population in Japan. Of 1109 iron overload cases, 93.1% were considered to have occurred post-transfusion. There were, however, 76 cases of iron overload of unknown origin, which suggest that many clinicians in Japan may encounter some difficulty in correctly diagnosing and treating iron overload. Further clinical data were obtained for 32 cases of iron overload of unknown origin; median of serum ferritin was 1860.5 ng/mL. As occurs in post-transfusional iron overload, liver dysfunction was found to be as high as 95.7% when serum ferritin levels exceeded 1000 ng/mL in these patients. Gene mutation analysis of the iron metabolism-related genes in 27 cases of iron overload with unknown etiology revealed mutations in the gene coding hemojuvelin, transferrin receptor 2, and ferroportin; this indicates that although rare, hereditary hemochromatosis does occur in Japan.

  13. Hemodynamic significance of internal carotid artery disease

    DEFF Research Database (Denmark)

    Schroeder, T

    1988-01-01

    . Examination of periorbital flow direction or oculoplethysmography could be used as a screening procedure. Negative tests most certainly rule out any severe pressure gradient across the stenosis, irrespective of the luminal reduction. A positive result, on the other hand, should be further quantified since...... a significant improvement in baseline flow occur. Flow reserve determined by cerebral vasodilation, however, will improve in most patients with hemodynamic failure. In addition, some patients in the low-pressure group develop marked, but temporary, hyperperfusion after reconstruction of very high grade carotid...

  14. Right ventricular Hemodynamic Alteration after Pulmonary Valve Replacement in Children with Congenital Heart Disease

    Directory of Open Access Journals (Sweden)

    Hamid Bigdelian

    2015-03-01

    Full Text Available Introduction:  In patients who underwent surgery to repair Tetralogy of Fallot, right ventricular dilation from pulmonary regurgitation may be result in right ventricular failure, arrhythmias and cardiac arrest. Hence, pulmonary valve replacement may be necessary to reduce right ventricular volume overload. The aim of present study was to assess the effects of pulmonary valve replacement on right ventricular function after repair of Tetralogy of Fallot.   Materials and  Method:  This retrospective study was carried out between July 2011 and October 2013 on 21 consecutive patients in Chamran Heart Center (Esfahan. The study included 13 male (61.9% and 8 female (38.1%. Cardiac magnetic resonance was performed before, 6 and 12 months after pulmonary valve replacement in all patients (Babak Imaging Center, Tehran with the 1.5 Tesla system. The main reason for surgery at Tetralogy of Fallot repaired time was Tetralogy of Fallot + Pulmonary insufficiency (17 cases and Tetralogy of Fallot + Pulmonary atresia (4 cases. Right ventricular function was assessed before and after pulmonary valve replacement with Two-dimensional echocardiography and ttest was used to evaluate follow-up data.   Results:  Right ventricular end-diastolic volume, right ventricular end- systolic volume significantly decreased (P value ˂ 0.05.Right ventricular ejection fraction had a significant increase (P value ˂ 0.05. Right ventricular mass substantially shrank after pulmonary valve replacement. Moreover, pulmonary regurgitation noticeably decreased in patients. The other hemodynamic parameter such as left ventricular ejection fraction improved but was not significant (P value= 0.79. Conclusion:  Pulmonary valve replacement can successfully restores the impaired hemodynamic function of right ventricle which is caused by direct consequence of volume unloading in patient. Pulmonary valve surgery in children with Tetralogy of Fallot who have moderate to severe pulmonary

  15. Lactulose efficacy in reduction of nitrogen products, blood potassium and fluid overload in patients with end-stage renal failure

    Directory of Open Access Journals (Sweden)

    Negin Aleagha

    2017-06-01

    Full Text Available Introduction: Chronic kidney disease (CKD is a major public health problem that often goes unrecognized until its late-stage. Patients with chronic kidney disease face uremic toxins and hyperkalemia. Also, fluid overload in CKD patients is associated with rapid decline in kidney function. Lactulose is a hyperosmotic agent and as a prebiotic, it plays an important role in regulating serum urea and potassium levels and has some effects on fluid overload. The aim of this study was to evaluate the effect of lactulose on serum levels of biochemical products in patients with CKD. Materials and Methods: In this interventional study, 17 patients with end stage of CKD ( 76.47 % men; mean age 65.88 ± 13.4 were evaluated.All patients received lactulose, 10 ml, 3 times per day for 3 months. Blood samples from all participants were collected before and at the end of intervention to examine changes in biochemical parameters, including potassium, urea, creatinine and uric acid. Results: Lactulose significantly decreased urea levels (p=0.001, blood potassium (0.001 and fluid overload(considering the patient’s weight p=0.001 in patients with end-stage renal failure. The decrease in serum creatinine and uric acid were not significant. Conclusion: Lactulose administration in CKD patients could decrease levels of various deleterious elements, especially urea and blood potassium and its daily use can be recommended in these patients.

  16. Coordinated and interactive expression of genes of lipid metabolism and inflammation in adipose tissue and liver during metabolic overload.

    Directory of Open Access Journals (Sweden)

    Wen Liang

    Full Text Available BACKGROUND: Chronic metabolic overload results in lipid accumulation and subsequent inflammation in white adipose tissue (WAT, often accompanied by non-alcoholic fatty liver disease (NAFLD. In response to metabolic overload, the expression of genes involved in lipid metabolism and inflammatory processes is adapted. However, it still remains unknown how these adaptations in gene expression in expanding WAT and liver are orchestrated and whether they are interrelated. METHODOLOGY/PRINCIPAL FINDINGS: ApoE*3Leiden mice were fed HFD or chow for different periods up to 12 weeks. Gene expression in WAT and liver over time was evaluated by micro-array analysis. WAT hypertrophy and inflammation were analyzed histologically. Bayesian hierarchical cluster analysis of dynamic WAT gene expression identified groups of genes ('clusters' with comparable expression patterns over time. HFD evoked an immediate response of five clusters of 'lipid metabolism' genes in WAT, which did not further change thereafter. At a later time point (>6 weeks, inflammatory clusters were induced. Promoter analysis of clustered genes resulted in specific key regulators which may orchestrate the metabolic and inflammatory responses in WAT. Some master regulators played a dual role in control of metabolism and inflammation. When WAT inflammation developed (>6 weeks, genes of lipid metabolism and inflammation were also affected in corresponding livers. These hepatic gene expression changes and the underlying transcriptional responses in particular, were remarkably similar to those detected in WAT. CONCLUSION: In WAT, metabolic overload induced an immediate, stable response on clusters of lipid metabolism genes and induced inflammatory genes later in time. Both processes may be controlled and interlinked by specific transcriptional regulators. When WAT inflammation began, the hepatic response to HFD resembled that in WAT. In all, WAT and liver respond to metabolic overload by

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

    Directory of Open Access Journals (Sweden)

    Sebastian Haas

    2012-01-01

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

  18. Cardiac Hemodynamics in the Pathogenesis of Congenital Heart Disease and Aortic Valve Calcification

    Science.gov (United States)

    Nigam, Vishal

    2011-11-01

    An improved understanding of the roles of hemodynamic forces play in cardiac development and the pathogenesis of cardiac disease will have significant scientific and clinical impact. I will focus on the role of fluid dynamics in congenital heart disease and aortic valve calcification. Congenital heart defects are the most common form of birth defect. Aortic valve calcification/stenosis is the third leading cause of adult heart disease and the most common form of acquired valvular disease in developed countries. Given the high incidence of these diseases and their associated morbidity and mortality, the potential translational impact of an improved understanding of cardiac hemodynamic forces is very large. Division of Pediatric Cardiology, Rady Children's Hospital, San Diego

  19. Review: hemodynamic response to carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Penney, D.G.

    1988-04-01

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

  20. Patient-Specific Modeling of Intraventricular Hemodynamics

    Science.gov (United States)

    Vedula, Vijay; Marsden, Alison

    2017-11-01

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

  1. Surgeon-Performed Hemodynamic Transesophageal Echocardiography in the Burn Intensive Care Unit.

    Science.gov (United States)

    Held, Jenny M; Litt, Jeffrey; Kennedy, Jason D; McGrane, Stuart; Gunter, Oliver L; Rae, Lisa; Kahn, Steven A

    2016-01-01

    The use of transesophageal echocardiography (TEE) for resuscitation after burn injury has been reported in small case studies. Conventional TEE is invasive and often requires a subspecialist with a high level of training. The authors report a series of surgeon-performed hemodynamic TEE with an indwelling, less bulky, user-friendly probe. Records of patients treated in a regional burn center who underwent hemodynamic TEE between October 1, 2012 and May 30, 2014 were reviewed. The clinical course of each patient was recorded. All bedside interpretations were retrospectively reviewed for accuracy by a cardiac anesthesiologist. Eleven patients were included in the study. Median age was 68.5 years (interquartile range, 49.5-79.5). Median burn size was 37% TBSA (interquartile range: 16.3-53%). Seven patients were male, and four suffered inhalation injury. The operator's interpretation matched that of the echocardiography technician and cardiac anesthesiologist in all instances. No complications occurred from probe placement. Four patients underwent hemodynamic TEE to determine volume status during resuscitation. Changes in volume status on echocardiography preceded the eventual changes in urine output and vital signs for one patient. Hemodynamic TEE diagnosed cardiogenic shock and was used to titrate inotropes and vasopressors in seven elderly patients. Hemodynamic TEE is a useful adjunct to manage the burn patient who deviates off the expected course, especially if there is a question of cardiac function or volume status. It is less invasive and can be accurately performed by surgical intensivists when transthoracic echo windows are limited. The role of echocardiography in optimizing routine burn resuscitations needs to be further studied.

  2. Urgent ultrasound guided hemodynamic assessments by a pediatric medical emergency team: a pilot study.

    Directory of Open Access Journals (Sweden)

    David J Zorko

    Full Text Available PURPOSE: To determine the feasibility of using the Ultrasound Cardiac Output Monitor (USCOM as an adjunct during hemodynamic assessments by a pediatric medical emergency team (PMET. METHODS: Pediatric in-patients at McMaster Children's Hospital aged under 18 years requiring urgent PMET consultation, were eligible. Patients with known cardiac outflow valve defects, Pediatric Critical Care Unit in-patients, and those in cardiorespiratory arrest, were excluded. The primary outcome was feasibility, and the ease of USCOM transport and application as assessed by a self-administered user questionnaire. Secondary outcomes included the quality of USCOM measurements, and agreement in clinical versus USCOM-derived assessments. RESULTS: Forty-one patients from 85 eligible PMET consultations were enrolled between March and August 2011. A total of 55 USCOM assessments were performed on 36 of 41 (87.8% participants. USCOM could not be completed in 5 (12.2% participants due to patient agitation (n = 4 and emergent care (n = 1. USCOM was reported as easy to transport and apply by 97.4% and 94.7% of respondents respectively, not obstructive to patient care by 94.7%, and yielded timely measurements by 84.2% respondents. USCOM tracings were of good quality in 41 (75.9% assessments. Agreement between clinical and USCOM-derived hemodynamic assessments by two independent raters was poor (Rater 1: κ = 0.094; Rater 2: κ = 0.146. CONCLUSION: USCOM can be applied by a PMET during urgent hemodynamic assessments in children. While USCOM has been validated in stable children, its role in guiding hemodynamic resuscitation and informing therapeutic goals in a hemodynamically unstable pediatric population requires further investigation.

  3. On TCP-based Session Initiation Protocol (SIP) Server Overload Control

    OpenAIRE

    Shen, Charles; Schulzrinne, Henning

    2010-01-01

    The Session Initiation Protocol (SIP) server overload management has attracted interest since SIP is being widely deployed in the Next Generation Networks (NGN) as a core signaling protocol. Yet all existing SIP overload control work is focused on SIP-over-UDP, despite the fact that TCP is increasingly seen as the more viable choice of SIP transport. This paper answers the following questions: is the existing TCP flow control capable of handling the SIP overload problem? If not, why and how c...

  4. Disruption of the Hepcidin/Ferroportin Regulatory System Causes Pulmonary Iron Overload and Restrictive Lung Disease

    Directory of Open Access Journals (Sweden)

    Joana Neves

    2017-06-01

    Full Text Available Emerging evidence suggests that pulmonary iron accumulation is implicated in a spectrum of chronic lung diseases. However, the mechanism(s involved in pulmonary iron deposition and its role in the in vivo pathogenesis of lung diseases remains unknown. Here we show that a point mutation in the murine ferroportin gene, which causes hereditary hemochromatosis type 4 (Slc40a1C326S, increases iron levels in alveolar macrophages, epithelial cells lining the conducting airways and lung parenchyma, and in vascular smooth muscle cells. Pulmonary iron overload is associated with oxidative stress, restrictive lung disease with decreased total lung capacity and reduced blood oxygen saturation in homozygous Slc40a1C326S/C326S mice compared to wild-type controls. These findings implicate iron in lung pathology, which is so far not considered a classical iron-related disorder.

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

    African Journals Online (AJOL)

    Igor Victorovich Lakhno

    2017-01-16

    Jan 16, 2017 ... Objectives: Idiopathic fetal growth restriction is considered to be associated with hemodynamic abnor- malities. Objectives: The study was aimed to the investigation of the relationship between fetal and maternal autonomic balance, arterial and venous hemodynamic Doppler indices and CTG variables in ...

  6. Bayesian model comparison in nonlinear BOLD fMRI hemodynamics

    DEFF Research Database (Denmark)

    Jacobsen, Danjal Jakup; Hansen, Lars Kai; Madsen, Kristoffer Hougaard

    2008-01-01

    Nonlinear hemodynamic models express the BOLD (blood oxygenation level dependent) signal as a nonlinear, parametric functional of the temporal sequence of local neural activity. Several models have been proposed for both the neural activity and the hemodynamics. We compare two such combined model...

  7. Hemodynamic effects of sevoflurane versus propofol anesthesia for ...

    African Journals Online (AJOL)

    Adele

    opposed to propofol anesthesia might lead to hemodynamic instability during LRFA surgery due to its possible effect on baroreceptors. We, therefore, investigated the hemodynamic profiles of patients undergoing LRFA of liver tumors under either sevoflurane or propofol anesthesia. Purpose. Laparoscopic radiofrequency ...

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

    African Journals Online (AJOL)

    Objectives: Idiopathic fetal growth restriction is considered to be associated with hemodynamic abnormalities. Objectives: The study was aimed to the investigation of the relationship between fetal and maternal autonomic balance, arterial and venous hemodynamic Doppler indices and CTG variables in case of normal fetal ...

  9. Non-invasive assessment of maternal hemodynamics in early pregnancy

    NARCIS (Netherlands)

    van der Graaf, Anne Marijn; Zeeman, Gerda G.; Groen, Henk; Roberts, Claire; Dekker, Gus A.

    2013-01-01

    Objectives: Non-invasive assessment of maternal hemodynamics in early pregnancy may be promising in evaluating maternal hemodynamic (mal)adaptation to pregnancy. We explored usage of applanation tonometry and Doppler ultrasound for assessment of cardiac output (CO), systemic vascular resistance

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

    DEFF Research Database (Denmark)

    Andersen, Mads Jønsson; Borlaug, Barry A

    2014-01-01

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

  11. Venous hemodynamic changes in lower limb venous disease

    DEFF Research Database (Denmark)

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

    2016-01-01

    There are excellent guidelines for clinicians to manage venous diseases but few reviews to assess their hemodynamic background. Hemodynamic concepts that evolved in the past have largely remained unchallenged in recent decades, perhaps due to their often complicated nature and in part due...... not provide the physiological basis for understanding the hemodynamics of flow, pressure, compliance and resistance. Hemodynamic investigations appear to provide a better correlation with post-treatment clinical outcome and quality of life than ultrasound findings. There is a far better prospect...... for understanding the complete picture of the patient's disability and response to management by combining ultrasound with hemodynamic studies. Accordingly, at the instigation of Dr Angelo Scuderi, the Union Internationale de Phlebologie (UIP) executive board commissioned a large number of experts to assess all...

  12. Stress overload: a new approach to the assessment of stress.

    Science.gov (United States)

    Amirkhan, James H

    2012-03-01

    The link between stress and health has not received strong empirical support, possibly due to problems in the stress measures used. Here, the first wholly empirical development of a new "Stress Overload Scale" is described. A pool of 150 items was formed to reflect "overload", a common denominator in stress theories. Then, the results of five sequenced studies, conducted in heterogeneous community samples, were used to pare the item pool. Exploratory (n = 431) and confirmatory (n = 433) analyses revealed two factors (Event Load and Personal Vulnerability) corresponding to theoretical constructs; only the best factor markers were submitted to further construct validity (n = 310) and reliability tests (n = 342). The 24 strongest items were selected for the SOS, which demonstrated criterion validity in predicting who (n = 285) would become sick following a common stressor. The SOS is (1) psychometrically strong, especially in its validity relative to popular measures; (2) appropriate to community research, due to its brevity and fit to a broad demographic spectrum; (3) unique in its ability to cross-section individuals into risk categories. It should prove useful to community psychologists in determining etiology, diagnosing risk for pathology, and evaluating the efficacy of interventions.

  13. Iron Loading and Overloading due to Ineffective Erythropoiesis

    Directory of Open Access Journals (Sweden)

    Toshihiko Tanno

    2010-01-01

    Full Text Available Erythropoiesis describes the hematopoietic process of cell proliferation and differentiation that results in the production of mature circulating erythrocytes. Adult humans produce 200 billion erythrocytes daily, and approximately 1 billion iron molecules are incorporated into the hemoglobin contained within each erythrocyte. Thus, iron usage for the hemoglobin production is a primary regulator of plasma iron supply and demand. In many anemias, additional sources of iron from diet and tissue stores are needed to meet the erythroid demand. Among a subset of anemias that arise from ineffective erythropoiesis, iron absorption and accumulation in the tissues increases to levels that are in excess of erythropoiesis demand even in the absence of transfusion. The mechanisms responsible for iron overloading due to ineffective erythropoiesis are not fully understood. Based upon data that is currently available, it is proposed in this review that loading and overloading of iron can be regulated by distinct or combined mechanisms associated with erythropoiesis. The concept of erythroid regulation of iron is broadened to include both physiological and pathological hepcidin suppression in cases of ineffective erythropoiesis.

  14. Immune overload: Parental attitudes toward combination and single antigen vaccines.

    Science.gov (United States)

    Hulsey, Ella; Bland, Tami

    2015-05-21

    Parental concerns have led to a recent decline in immunization coverage, resulting in outbreaks of diseases that were once under control in the US. As the CDC vaccination schedule continues to increase in complexity, the number of required injections per office visit increases as well. Some parents perceive that there is trauma associated with the administration of multiple injections, and research shows that having multiple vaccines due in a single visit is associated with delays and lower immunization rates. Combination vaccines make vaccination more efficient by incorporating the antigens of several different diseases into a single injection, but many parents worry that they may overload the child's developing immune system and leave him or her susceptible to secondary infections. This literature review synthesizes current evidence regarding the parental fear of vaccine-induced immune system overload and the fear of vaccine-associated trauma, in an attempt to understand the scope and nature of these fears. Despite the wealth of knowledge about each of these fears individually, it is still unknown which is of greater concern and how this affects parental decision-making. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Electrochemical sensor for predicting transformer overload by phenol measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bosworth, Timothy; Setford, Steven; Saini, Selwayan [Cranfield Centre for Analytical Science, Cranfield University, Silsoe, Beds MK45 4DT (United Kingdom); Heywood, Richard [National Grid Company Plc, Kelvin Avenue, Leatherhead, Surrey KT22 7ST (United Kingdom)

    2003-03-10

    Transformer overload is a significant problem to the power transmission industry, with severe safety and cost implications. Overload may be predicted by measuring phenol levels in the transformer-insulating oil, arising from the thermolytic degradation of phenol-formaldehyde resins. The development of two polyphenol oxidase (PPO) sensors, based on monitoring the enzymatic consumption of oxygen using an oxygen electrode, or reduction of enzymatically generated o-quinone at a screen-printed electrode (SPE), for the measurement of phenol in transformer oil is reported. Ex-service oils were prepared either by extraction into aqueous electrolyte-buffer, or by direct dilution in propan-2-ol, the latter method being more amenable to simple at-line operation. The oxygen electrode, with a sensitivity of 2.87 nA {mu}g{sup -1} ml{sup -1}, RSD of 7.0-19.9% and accuracy of {+-}8.3% versus the industry standard International Electrotechnical Commission (IEC) method, proved superior to the SPE (sensitivity: 3.02 nA {mu}g{sup -1} ml{sup -1}; RSD: 8.9-18.3%; accuracy: {+-}7.9%) and was considerably more accurate at low phenol concentrations. However, the SPE approach is more amenable to field-based usage for reasons of device simplicity. The method has potential as a rapid and simple screening tool for the at-site monitoring of phenol in transformer oils, thereby reducing incidences of transformer failure.

  16. Criterion validation of a stress measure: the Stress Overload Scale.

    Science.gov (United States)

    Amirkhan, James H; Urizar, Guido G; Clark, Sarah

    2015-09-01

    Validating stress scales poses problems beyond those of other psychological measures. Here, 3 studies were conducted to address those problems and assess the criterion validity of scores from a new theory-derived measure, the Stress Overload Scale (SOS; Amirkhan, 2012). In Study 1, the SOS was tested for its ability to predict postsemester illness in a sample of college students (n = 127). Even with precautions to minimize criterion contamination, scores were found to predict health problems in the month following a final exam on all of 5 different criteria. In Study 2, a community sample (n = 231) was used to test the SOS' ability to differentiate people in stressful circumstances from those in more relaxed contexts. SOS scores demonstrated excellent sensitivity (96%) and specificity (100%) in this general population application. In Study 3, the SOS was tested for its ability to differentiate salivary cortisol responses to a laboratory stressor in a group of pregnant women (n = 40). High scores were found to be associated with a blunted cortisol response, which is indicative of HPA-axis overload and typical of persons suffering chronic stress and stress-related pathology. Across all 3 studies, despite variations in the stressor, criterion, population, and methods, SOS scores emerged as valid indicators of stress. However, each study also introduced new problems that beg additional corrective steps in future stress-scale validity tests. These strategies, and the SOS' utility as a research and diagnostic tool in varied applications and populations, are discussed. (c) 2015 APA, all rights reserved.

  17. Information overload within the health care system: a literature review.

    Science.gov (United States)

    Hall, Amanda; Walton, Graham

    2004-06-01

    There is a widespread view held by health clinicians that their work effectiveness is impaired by 'information overload.' Building upon a previous work by Wilson, a review of the literature was undertaken to look for the evidence of this. It was found that the literature, particularly in the context of the clinical environment, was limited. This review explores the diverse overarching theories of information overload, effects of the phenomenon that are perceived to occur and proposed solutions to this problem. Many of the papers noted an information explosion but only three authors explicitly attempted to measure both the quantity and the complexity of this information. It was also found that the typology of the information studied was severely limited with most studies exploring information such as guidelines, access to journals, research findings and other knowledge intensive areas. Solutions proposed seem to concentrate on technological means rather than exploring the use of humans either in management of information or as a step in the filtering process.

  18. Competing for Attention in Social Media under Information Overload Conditions.

    Science.gov (United States)

    Feng, Ling; Hu, Yanqing; Li, Baowen; Stanley, H Eugene; Havlin, Shlomo; Braunstein, Lidia A

    2015-01-01

    Modern social media are becoming overloaded with information because of the rapidly-expanding number of information feeds. We analyze the user-generated content in Sina Weibo, and find evidence that the spread of popular messages often follow a mechanism that differs from the spread of disease, in contrast to common belief. In this mechanism, an individual with more friends needs more repeated exposures to spread further the information. Moreover, our data suggest that for certain messages the chance of an individual to share the message is proportional to the fraction of its neighbours who shared it with him/her, which is a result of competition for attention. We model this process using a fractional susceptible infected recovered (FSIR) model, where the infection probability of a node is proportional to its fraction of infected neighbors. Our findings have dramatic implications for information contagion. For example, using the FSIR model we find that real-world social networks have a finite epidemic threshold in contrast to the zero threshold in disease epidemic models. This means that when individuals are overloaded with excess information feeds, the information either reaches out the population if it is above the critical epidemic threshold, or it would never be well received.

  19. Does the renin-angiotensin system determine the renal and systemic hemodynamic response to sodium in patients with essential hypertension?

    NARCIS (Netherlands)

    vanPaassen, P; deZeeuw, D; Navis, G; deJong, PE

    Many patients with essential hypertension respond to a high dietary sodium intake with a rise in blood pressure. Experimental evidence suggests that the renal hemodynamic response to sodium determines, at least partially, this rise in blood pressure. Our aim was to clarify the role of the

  20. Taxifolin protects against cardiac hypertrophy and fibrosis during biomechanical stress of pressure overload

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Haipeng; Zhang, Xin [Department of Critical Care Medicine, Qilu Hospital of Shandong University, Jinan (China); Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China); Cui, Yuqian [Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China); Zhou, Heng [Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan (China); Xu, Dachun [Department of Cardiology, Shanghai Tenth People' s Hospital of Tongji University, Shanghai (China); Shan, Tichao; Zhang, Fan [Department of Critical Care Medicine, Qilu Hospital of Shandong University, Jinan (China); Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China); Guo, Yuan [Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China); Chen, Yuguo, E-mail: chen919085@163.com [Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China); Department of Emergency, Qilu Hospital of Shandong University, Jinan (China); Wu, Dawei, E-mail: wdwu55@163.com [Department of Critical Care Medicine, Qilu Hospital of Shandong University, Jinan (China); Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan (China)

    2015-09-01

    Cardiac hypertrophy is a key pathophysiological component to biomechanical stress, which has been considered to be an independent and predictive risk factor for adverse cardiovascular events. Taxifolin (TAX) is a typical plant flavonoid, which has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether TAX can influence the development of cardiac hypertrophy. In vitro studies, we found that TAX concentration-dependently inhibited angiotensin II (Ang II) induced hypertrophy and protein synthesis in cardiac myocytes. Then we established a mouse model by transverse aortic constriction (TAC) to further confirm our findings. It was demonstrated that TAX prevented pressure overload induced cardiac hypertrophy in mice, as assessed by ventricular mass/body weight, echocardiographic parameters, myocyte cross-sectional area, and the expression of ANP, BNP and β-MHC. The excess production of reactive oxygen species (ROS) played critical role in the development of cardiac hypertrophy. TAX arrested oxidative stress and decreased the expression of 4-HNE induced by pressure overload. Moreover, TAX negatively modulated TAC-induced phosphorylation of ERK1/2 and JNK1/2. Further studies showed that TAX significantly attenuated left ventricular fibrosis and collagen synthesis through abrogating the phosphorylation of Smad2 and Smad2/3 nuclear translocation. These results demonstrated that TAX could inhibit cardiac hypertrophy and attenuate ventricular fibrosis after pressure overload. These beneficial effects were at least through the inhibition of the excess production of ROS, ERK1/2, JNK1/2 and Smad signaling pathways. Therefore, TAX might be a potential candidate for the treatment of cardiac hypertrophy and fibrosis. - Highlights: • We focus on the protective effect of taxifolin on cardiac remodeling. • Taxifolin inhibited cardiac hypertrophy and attenuated ventricular fibrosis. • Taxifolin

  1. Efficacy and Safety of Renal Sympathetic Denervation on Dogs with Pressure Overload-Induced Heart Failure.

    Science.gov (United States)

    Chen, Pingan; Leng, Shuilong; Luo, Yishan; Li, Shaonan; Huang, Zicheng; Liu, Zhenxi; Liu, Zhen; Wang, Jie; Lei, Xiaoming

    2017-02-01

    In dogs with heart failure (HF) induced by overload pressure, the role of renal sympathetic denervation (RSD) on heart failure and in the renal artery is unclear. Therefore, we investigated the efficacy and safety of RSD in dogs with pressure overload-induced heart failure. Twenty mongrel dogs were divided into a sham-operated group, an HF group and an HF + RSD group. In the sham-operated group, the abdominal aorta was located but was not constricted, in the HF group, the abdominal aorta was constricted without RSD, and the HF+RSD group underwent RSD with constriction of the abdominal aorta after 10 weeks. Blood sampling assays, echocardiography, intravascular ultrasound (IVUS) measurement and histopathological examination were performed. Renal sympathetic denervation caused a significant reduction in the levels of noradrenaline (166.62±6.84 vs. 183.48±13.66 pg/ml, P<0.05), plasma renin activity (1.93±0.12 vs. 2.10±0.13 ng/mlh, P<0.05) and B-type natriuretic peptide (71.14±3.86 vs. 83.15±5.73 pg/ml, P<0.05) at eight weeks after RSD in the HF+RSD group. Compared with the HF group at eight weeks, the left ventricular internal dimension at end-diastole and end-systole were lower and the left ventricular ejection fraction was higher (all P<0.05) at eight weeks after RSD in the HF+RSD group. Intravenous ultrasound images showed no changes in the renal artery lumen, and intimal hyperplasia and vascular lumen stenosis were not observed after RSD. Renal sympathetic denervation could improve cardiac function in dogs with HF induced by pressure overload; RSD had no adverse influence on the renal artery. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  2. Saccades and prefrontal hemodynamics in basketball players.

    Science.gov (United States)

    Fujiwara, K; Kiyota, N; Maekawa, M; Kunita, K; Kiyota, T; Maeda, K

    2009-09-01

    We investigated saccade performance and prefrontal hemodynamics in basketball players with different skill levels. Subjects were 27 undergraduate basketball players and 13 non-athlete undergraduates (control group: CON). The players were divided into two groups: those who had played in the National Athletic Meet during high school or played regularly (n=13, elite group: ELI) and those who were bench warmers (n=14, skilled group: SKI). Horizontal eye movement and oxy-, deoxy-, and total-hemoglobin (Hb) concentration in the prefrontal cortex during pro- and anti-saccade were measured using electro-oculography and near-infrared spectroscopy, respectively. Only error rate in anti-saccade was less in ELI (4.8+/-4.0%) than SKI (13.7+/-12.6%) and CON (13.9+/-8.3%) (pbasketball. Georg Thieme Verlag KG Stuttgart.

  3. A Shape Memory Polymer Dialysis Needle Adapter for the Reduction of Hemodynamic Stress within Arteriovenous Grafts

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J M; Small, W; Wilson, T S; Benett, W; Loge, J; Maitland, D J

    2006-08-16

    A deployable, shape memory polymer adapter is investigated for reducing the hemodynamic stress caused by a dialysis needle flow within an arteriovenous graft. Computational fluid dynamics simulations of dialysis sessions with and without the adapter demonstrate that the adapter provides a significant decrease in the wall shear stress. In vitro flow visualization measurements are made within a graft model following delivery and actuation of a prototype shape memory polymer adapter. Vascular access complications resulting from arteriovenous (AV) graft failures account for over $1 billion per year in the health care costs of dialysis patients in the U.S.[1] The primary mode of failure of arteriovenous fistulas (AVF's) and polytetrafluoroethylene (PTFE) grafts is the development of intimal hyperplasia (IH) and the subsequent formation of stenotic lesions, resulting in a graft flow decline. The hemodynamic stresses arising within AVF's and PTFE grafts play an important role in the pathogenesis of IH. Studies have shown that vascular damage can occur in regions where there is flow separation, oscillation, or extreme values of wall shear stress (WSS).[2] Nevaril et al.[3] show that exposure of red blood cells to WSS's on the order of 1500 dynes/cm2 can result in hemolysis. Hemodynamic stress from dialysis needle flow has recently been investigated for the role it plays in graft failure. Using laser Doppler velocimetry measurements, Unnikrishnan et al.[4] show that turbulence intensities are 5-6 times greater in the AV flow when the needle flow is present and that increased levels of turbulence exist for approximately 7-8cm downstream of the needle. Since the AVF or PTFE graft is exposed to these high levels of hemodynamic stress several hours each week during dialysis sessions, it is quite possible that needle flow is an important contributor to vascular access occlusion.[4] We present a method for reducing the hemodynamic stress in an AV graft by tailoring

  4. Induced and spontaneous hemodynamic oscillations in cerebral and extracerebral tissue for coherent hemodynamics spectroscopy

    Science.gov (United States)

    Sassaroli, Angelo; Zang, Xuan; Tgavalekos, Kristen T.; Fantini, Sergio

    2017-02-01

    We report preliminary results of a study for investigating the spatial homogeneity of induced and spontaneous oscillations in the concentration of oxyhemoglobin on the scalp/skull layer of two human subjects. Hemodynamic oscillations were induced by modulation of arterial blood pressure, which triggers the cerebral autoregulation mechanism. Induced hemodynamic oscillations are used in coherent hemodynamics spectroscopy to derive physiological parameters of interest for medical diagnostics. For example, our dedicated mathematical model translates typical near-infrared spectroscopy observables, like the amplitude and phase relationship of the oscillations of oxy- and deoxyhemoglobin concentrations into capillary and venous blood transit times, cutoff frequency of the autoregulation process, and other parameters related to microvascular blood volume. In this study, we focused on the phase relationship between the oscillations of oxyhemoglobin concentrations in three optical channels, two of which feature a short (5 mm) source-detector separation (sampling the scalp/skull only) and the third one features a long (30 mm) source-detector separation (sampling both extracerebral and cerebral tissues). The two main goals of the study were: a) to compare the coherence of induced and spontaneous oscillations; b) to assess if induced and spontaneous oscillations may be assumed to be uniform in the extracerebral layer. This was assessed by studying the phase relationship of oscillations in oxyhemoglobin concentration at the two short source-detector separations. About point a) we verified that induced oscillations have a higher incidence of coherence than spontaneous oscillations: 74% for induced oscillations, and 30% for spontaneous oscillations. About point b) the results show an overall trend for both spontaneous and induced oscillations to be homogeneous or "quasi-homogeneous" in the extracerebral tissue; however, we observed cases where a significant non-zero phase

  5. The associations of supervisor support and work overload with burnout and depression: a cross-sectional study in two nursing settings.

    Science.gov (United States)

    Weigl, Matthias; Stab, Nicole; Herms, Isabel; Angerer, Peter; Hacker, Winfried; Glaser, Jürgen

    2016-08-01

    To investigate the moderating effects of work overload and supervisor support on the emotional exhaustion-depressive state relationship. Burnout and depression are prevalent in human service professionals and have a detrimental impact on clients. Work overload and supervisor support are two key job demands and job resources, whose role and interplay for the development and maintenance of burnout and depression are not fully understood yet. Two consecutive cross-sectional surveys: survey 1 investigated 111 hospital nursing professionals and survey 2 examined 202 day care professionals. Data collection was completed in 2010. After controlling for general well-being and sociodemographic characteristics, nurses' emotional exhaustion was associated with increased depressive state in both samples. We found a meaningful three-way interaction: our results show consistently that the relationship between emotional exhaustion and depressive state was strongest for nurses with high work overload and low supervisor support. Additionally, nurses with low work overload and low supervisor support were also found to have stronger associations between emotional exhaustion and depressive state. The findings indicate that nurses' reported supervisor support exerts its buffering effect on the burnout-depression link differentially and serves as an important resource for nurses dealing with high self-reported work stress. © 2016 John Wiley & Sons Ltd.

  6. Work overload, burnout, and psychological ill-health symptoms: a three-wave mediation model of the employee health impairment process.

    Science.gov (United States)

    de Beer, Leon T; Pienaar, Jaco; Rothmann, Sebastiaan

    2016-07-01

    The study reported here investigated the causal relationships in the health impairment process of employee well-being, and the mediating role of burnout in the relationship between work overload and psychological ill-health symptoms, over time. The research is deemed important due to the need for longitudinal evidence of the health impairment process of employee well-being over three waves of data. A quantitative survey design was followed. Participants constituted a longitudinal sample of 370 participants, at three time points, after attrition. Descriptive statistics and structural equation modeling methods were implemented. Work overload at time one predicted burnout at time two, and burnout at time two predicted psychological ill-health symptoms at time three. Indirect effects were found between work overload time one and psychological ill-health symptoms time three via burnout time two, and also between burnout time one and psychological ill-health symptoms time three, via burnout time two. The results provided supportive evidence for an "indirect-only" mediation effect, for burnout's causal mediation mechanism in the health impairment process between work overload and psychological ill-health symptoms.

  7. Time evolution and hemodynamics of cerebral aneurysms

    Science.gov (United States)

    Sforza, Daniel M.; Putman, Christopher; Tateshima, Satoshi; Viñuela, Fernando; Cebral, Juan

    2011-03-01

    Cerebral aneurysm rupture is a leading cause of hemorrhagic strokes. Because they are being more frequently diagnosed before rupture and the prognosis of subarachnoid hemorrhage is poor, clinicians are often required to judge which aneurysms are prone to progression and rupture. Unfortunately, the processes of aneurysm initiation, growth and rupture are not well understood. Multiple factors associated to these processes have been identified. Our goal is to investigate two of them, arterial hemodynamics (using computational fluid dynamics) and the peri-aneurysmal environment, by studying a group of growing cerebral aneurysms that are followed longitudinally in time. Six patients with unruptured untreated brain aneurysms which exhibited growth during the observation period were selected for the study. Vascular models of each aneurysm at each observation time were constructed from the corresponding computed tomography angiography (CTA) images. Subsequently, models were aligned, and geometrical differences quantified. Blood flow was modeled with the 3D unsteady incompressible Navier-Stokes equation for a Newtonian fluid, and wall shear stress distribution and flow patterns were calculated and visualized. Analysis of the simulations and changes in geometry revealed asymmetric growth patterns and suggests that areas subject to vigorous flows, i.e. relative high wall shear stress and concentrated streamlines patterns; correspond to regions of aneurysm growth. Furthermore, in some cases the geometrical evolution of aneurysms is clearly affected by contacts with bone structures and calcifications in the wall, and as a consequence the hemodynamics is greatly modified. Thus, in these cases the peri-aneurysmal environment must be considered when analyzing aneurysm evolution.

  8. Glutathione S transferase polymorphisms influence on iron overload in β-thalassemia patients

    Directory of Open Access Journals (Sweden)

    Serena Sclafani

    2013-11-01

    Full Text Available In patients with β-thalassemia iron overload that leads to damage to vital organs is observed. Glutathione S transferase (GST enzymes have an antioxidant role in detoxification processes of toxic substances. This role is determined genetically. In this study, we correlated GSTT1 and GSTM1 genotypes with iron overload measured with direct and indirect non-invasive methods; in particular, we used serum ferritin and signal intensity of the magnetic resonance image (MRI in 42 patients with β-thalassemia, which were regularly subjected to chelation and transfusion therapy. Multiplex polymerase chain reaction was used to determine the genotype. The loss of both alleles leads to a decreased value of liver and heart MRI-signal intensity with a consequent iron accumulation in these organs; the loss of only one allele doesn’t lead to relevant overload. Serum ferritin doesn’t appear to be correlated to iron overload instead. 对于β-地中海贫血患者,由于铁过量而造成重要器官受损的情况也在观察之中。谷胱甘肽S转移酶(GST 酶类在对有毒物质进行解毒的过程中有着抗氧化剂的作用。该作用是由基因决定的。 在这份研究中,我们运用了直接和间接非侵入性的方法对基因型铁过量GSTT1 和GSTM1进行了相关性测量;特别地,我们对42位定期接受螯合和输血治疗的β-地中海贫血患者进行了血清铁蛋白和磁共振强度图像(MRI 的测试。 多重聚合酶链反应的测试也被运用来确定该基因型。 该两种等位基因的缺失,导致了肝功能减损及心脏磁共振强度的下降,并造成了在这些器官中铁含量的积累;其中一种等位基因的缺失并不会导致过度的铁含量。血清蛋白和铁过量之间,看起来并不存在相关性。

  9. Increased natriuretic peptide receptor A and C gene expression in rats with pressure-overload cardiac hypertrophy

    DEFF Research Database (Denmark)

    Christoffersen, Tue E.H.; Aplin, Mark; Strom, Claes C.

    2006-01-01

    Both atrial (ANP) and brain (BNP) natriuretic peptide affect development of cardiac hypertrophy and fibrosis via binding to natriuretic peptide receptor (NPR)-A in the heart. A putative clearance receptor, NPR-C, is believed to regulate cardiac levels of ANP and BNP. The renin-angiotensin system...... also affects cardiac hypertrophy and fibrosis. In this study we examined the expression of genes for the NPRs in rats with pressure-overload cardiac hypertrophy. The ANG II type 1 receptor was blocked with losartan (10 mg.kg(-1).day(-1)) to investigate a possible role of the renin-angiotensin system...

  10. Circulating Biologically Active Adrenomedullin (bio-ADM) Predicts Hemodynamic Support Requirement and Mortality During Sepsis.

    Science.gov (United States)

    Caironi, Pietro; Latini, Roberto; Struck, Joachim; Hartmann, Oliver; Bergmann, Andreas; Maggio, Giuseppe; Cavana, Marco; Tognoni, Gianni; Pesenti, Antonio; Gattinoni, Luciano; Masson, Serge

    2017-08-01

    The biological role of adrenomedullin (ADM), a hormone involved in hemodynamic homeostasis, is controversial in sepsis because administration of either the peptide or an antibody against it may be beneficial. Plasma biologically active ADM (bio-ADM) was assessed on days 1, 2, and 7 after randomization of 956 patients with sepsis or septic shock to albumin or crystalloids for fluid resuscitation in the multicenter Albumin Italian Outcome Sepsis trial. We tested the association of bio-ADM and its time-dependent variation with fluid therapy, vasopressor administration, organ failures, and mortality. Plasma bio-ADM on day 1 (median [Q1-Q3], 110 [59-198] pg/mL) was higher in patients with septic shock, associated with 90-day mortality, multiple organ failures and the average extent of hemodynamic support therapy (fluids and vasopressors), and serum lactate time course over the first week. Moreover, it predicted incident cardiovascular dysfunction in patients without shock at enrollment (OR [95% CI], 1.9 [1.4-2.5]; P sepsis, the circulating, biologically active form of ADM may help individualizing hemodynamic support therapy, while avoiding harmful effects. Its possible pathophysiologic role makes bio-ADM a potential candidate for future targeted therapies. ClinicalTrials.gov; No.: NCT00707122. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  11. Hemodynamics investigation for a giant aneurysm treated by a flow diverter implantation.

    Science.gov (United States)

    Wang, Shengzhang; Li, Jianjun; Wang, Chao; Yang, Xinjian; Mu, Shiqing; Wang, Wuqing

    2015-01-01

    Flow diverter is a kind of stent-like devices with higher metal coverage rate, and it is deployed endovascularly to treat cerebral aneurysms, especially to treat giant aneurysms. However, there exist some arguments about its safety and efficacy. Hemodynamics is considered to play very important role during the initiation, growth and rupture of cerebral aneurysms. In this study, the models of a giant cerebral aneurysm involved a small branch at the aneurysmal sac before and after flow diverter implantation were constructed by virtual deployment, the blood flows in the models were simulated by computational fluid dynamics method. Analyzing the variations of the hemodynamics, the following conclusions were summarized. The flow diverter is very effective device to occlude the aneurysm, the flow rate at the small branch was rarely changed when the flow diverter deployed and the flow diverter.

  12. [Contributions to the assessment of hemodynamic status in metabolic syndrome].

    Science.gov (United States)

    Pădure, Livia; Ignat, Ileana Sînziana; Eşanu, Irina; Hurjui, J

    2011-01-01

    The concept of normohemodynamics is based on the fact that the main function of the cardiovascular system is the transport of oxygen. The cardiovascular system is adapting to a new hemodynamic status with every heartbeat. Only one class, called the normohemodynamic state, containing a simultaneous normotension and normodynamic flow, can serve as therapeutic goal. Metabolic syndrome includes a constellation of clinical and biological features that confer an increased cardiovascular risk. Clutter hemodynamic modulators in metabolic syndrome and assessment of hemodynamic status both overall and by its components, open new perspectives in the management of patients with hypertension and metabolic syndrome. In the current study were included 32 patients meeting the criteria for metabolic syndrome and hypertension and 32 controls. Patients were monitored and assessed for the global hemodynamic status and for the modulators of hemodynamics, intravascular volume, vasoactivity and inotropy, respectively. There are no significant differences in the global hemodynamic status between the study group and the control group; in the study group there is a clear weathering of hemodynamic modulators. The improvement of these factors opens a new perspective in the global cardiovascular assessment and therapeutic directions.

  13. Tomoregulin-1 prevents cardiac hypertrophy after pressure overload in mice by inhibiting TAK1-JNK pathways

    Directory of Open Access Journals (Sweden)

    Dan Bao

    2015-08-01

    Full Text Available Cardiac hypertrophy is associated with many forms of heart disease, and identifying important modifier genes involved in the pathogenesis of cardiac hypertrophy could lead to the development of new therapeutic strategies. Tomoregulin-1 is a growth factor that is primarily involved in embryonic development and adult central nervous system (CNS function, and it is expressed abnormally in a variety of CNS pathologies. Tomoregulin-1 is also expressed in the myocardium. However, the effects of tomoregulin-1 on the heart, particularly on cardiac hypertrophy, remains unknown. The aim of the study is to examine whether and by what mechanism tomoregulin-1 regulates the development of cardiac hypertrophy induced by pressure overload. In this study, we found that tomoregulin-1 was significantly upregulated in two cardiac hypertrophy models: cTnTR92Q transgenic mice and thoracic aorta constriction (TAC-induced cardiac hypertrophy mice. The transgenic overexpression of tomoregulin-1 increased the survival rate, improved the cardiac geometry and functional parameters of echocardiography, and decreased the degree of cardiac hypertrophy of the TAC mice, whereas knockdown of tomoregulin-1 expression resulted in an opposite phenotype and exacerbated phenotypes of cardiac hypertrophy induced by TAC. A possible mechanism by which tomoregulin-1 regulates the development of cardiac hypertrophy in TAC-induced cardiac hypertrophy is through inhibiting TGFβ non-canonical (TAK1-JNK pathways in the myocardium. Tomoregulin-1 plays a protective role in the modulation of adverse cardiac remodeling from pressure overload in mice. Tomoregulin-1 could be a therapeutic target to control the development of cardiac hypertrophy.

  14. The A736V TMPRSS6 polymorphism influences hepatic iron overload in nonalcoholic fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Luca Valenti

    Full Text Available Hepatic iron accumulation due to altered trafficking is frequent in patients with nonalcoholic fatty liver disease (NAFLD, and is associated with more severe liver damage and hepatocellular carcinoma. The p.Ala736Val TMPRSS6 variant influences iron metabolism regulating the transcription of the hepatic hormone hepcidin, but its role in the pathogenesis of iron overload disorders is controversial. Aim of this study was to evaluate the whether the TMPRSS6 p.Ala736Val variant influences hepatic iron accumulation in a well-characterized series of Italian patients with histological NAFLD.216 patients with histological NAFLD. TMPRSS6 and HFE variants were assessed by allele specific PCR, liver histology by the NAFLD activity score and Perls' staining for iron.Homozygosity for the p.736Val allele previously linked to higher hepcidin did not influence transferrin saturation (TS, but was associated with lower hepatic iron stores (p = 0.01, and ferritin levels (median 223 IQR 102-449 vs. 308 IQR 141-618 ng/ml; p = 0.01. Homozygosity for TMPRSS6 p.736Val was nearly associated with lower ballooning (p = 0.05, reflecting hepatocellular damage related to oxidative stress. The influence of TMPRSS6 on hepatic iron accumulation was more marked in patients negative for HFE genotypes predisposing to iron overload (p.Cys282Tyr + and p.His63Asp +/+; p = 0.01, and the p.736Val variant was negatively associated with hepatic iron accumulation independently of age, gender, HFE genotype, and beta-thalassemia trait (OR 0.59, 0.39-0.88.The p.Ala736Val TMPRSS6 variant influences secondary hepatic iron accumulation in patients with NAFLD.

  15. Desmin loss and mitochondrial damage precede left ventricular systolic failure in volume overload heart failure.

    Science.gov (United States)

    Guichard, Jason L; Rogowski, Michael; Agnetti, Giulio; Fu, Lianwu; Powell, Pamela; Wei, Chih-Chang; Collawn, James; Dell'Italia, Louis J

    2017-07-01

    Heart failure due to chronic volume overload (VO) in rats and humans is characterized by disorganization of the cardiomyocyte desmin/mitochondrial network. Here, we tested the hypothesis that desmin breakdown is an early and continuous process throughout VO. Male Sprague-Dawley rats had aortocaval fistula (ACF) or sham surgery and were examined 24 h and 4 and 12 wk later. Desmin/mitochondrial ultrastructure was examined by transmission electron microscopy (TEM) and immunohistochemistry (IHC). Protein and kinome analysis were performed in isolated cardiomyocytes, and desmin cleavage was assessed by mass spectrometry in left ventricular (LV) tissue. Echocardiography demonstrated a 40% decrease in the LV mass-to-volume ratio with spherical remodeling at 4 wk with ACF and LV systolic dysfunction at 12 wk. Starting at 24 h and continuing to 4 and 12 wk, with ACF there is TEM evidence of extensive mitochondrial clustering, IHC evidence of disorganization associated with desmin breakdown, and desmin protein cleavage verified by Western blot analysis and mass spectrometry. IHC results revealed that ACF cardiomyocytes at 4 and 12 wk had perinuclear translocation of αB-crystallin from the Z disk with increased α, β-unsaturated aldehyde 4-hydroxynonelal. Use of protein markers with verification by TUNEL staining and kinome analysis revealed an absence of cardiomyocyte apoptosis at 4 and 12 wk of ACF. Significant increases in protein indicators of mitophagy were countered by a sixfold increase in p62/sequestosome-1, which is indicative of an inability to complete autophagy. An early and continuous disruption of the desmin/mitochondrial architecture, accompanied by oxidative stress and inhibition of apoptosis and mitophagy, suggests its causal role in LV dilatation and systolic dysfunction in VO. NEW & NOTEWORTHY This study provides new evidence of early onset (24 h) and continuous (4-12 wk) desmin misarrangement and disruption of the normal sarcomeric and mitochondrial

  16. A novel aldosterone synthase inhibitor ameliorates mortality in pressure-overload mice with heart failure.

    Science.gov (United States)

    Furuzono, Shinji; Meguro, Masaki; Miyauchi, Satoru; Inoue, Shinichi; Homma, Tsuyoshi; Yamada, Keisuke; Tagawa, Yoh-Ichi; Nara, Futoshi; Nagayama, Takahiro

    2017-01-15

    It has been elucidated that mineralocorticoid receptor antagonists reduce mortality in patients with congestive heart failure and post-acute myocardial infarction. A direct inhibition of aldosterone synthase (CYP11B2) is also expected to have therapeutic benefits equal in quality to mineralocorticoid receptor antagonists in terms of reducing mineralocorticoid receptor signaling. Therefore, we have screened our chemical libraries and identified a novel and potent aldosterone synthase inhibitor, 2,2,2-trifluoro-1-{4-[(4-fluorophenyl)amino]pyrimidin-5-y}-1-[1-(methylsulfonyl)piperidin-4-yl]ethanol (compound 1), by lead optimization. Pharmacological properties of compound 1 were examined in in vitro cell-based assays and an in vivo mouse model of pressure-overload hypertrophy by transverse aortic constriction (TAC). Compound 1 showed potent CYP11B2 inhibition against human and mouse enzymes (IC50; 0.003μM and 0.096μM, respectively) in a cell-based assay. The oral administration of 0.06% compound 1 in the food mixture of a mouse TAC model significantly reduced the plasma aldosterone level and ameliorated mortality rate. This study is the first to demonstrate that a CYP11B2 inhibitor improved survival rates of heart failure induced by pressure-overload in mice. The treatment of 0.06% compound 1 did not elevate plasma potassium level in this model, although further evaluation of hyperkalemia is needed. These results suggest that compound 1 can be developed as a promising oral CYP11B2 inhibitor for pharmaceutical applications. Compound 1 could also be a useful compound for clarifying the role of aldosterone in cardiac hypertrophy. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Reliability Analysis and Overload Capability Assessment of Oil-Immersed Power Transformers

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2016-01-01

    Full Text Available Smart grids have been constructed so as to guarantee the security and stability of the power grid in recent years. Power transformers are a most vital component in the complicated smart grid network. Any transformer failure can cause damage of the whole power system, within which the failures caused by overloading cannot be ignored. This research gives a new insight into overload capability assessment of transformers. The hot-spot temperature of the winding is the most critical factor in measuring the overload capacity of power transformers. Thus, the hot-spot temperature is calculated to obtain the duration running time of the power transformers under overloading conditions. Then the overloading probability is fitted with the mature and widely accepted Weibull probability density function. To guarantee the accuracy of this fitting, a new objective function is proposed to obtain the desired parameters in the Weibull distributions. In addition, ten different mutation scenarios are adopted in the differential evolutionary algorithm to optimize the parameter in the Weibull distribution. The final comprehensive overload capability of the power transformer is assessed by the duration running time as well as the overloading probability. Compared with the previous studies that take no account of the overloading probability, the assessment results obtained in this research are much more reliable.

  18. Data Overload Impact on Project Management: How Knowledge Management Systems Can Improve Federal Agencies Effectiveness

    Science.gov (United States)

    Rodriguez, Jacinto

    2013-01-01

    This mixed method exploratory case study was used to explore the effect data overload has on project management, how data overload affects project management effectiveness, how prepared program office staff is to manage multiple projects effectively, and how the program office's organizational structure and data management systems affect project…

  19. Designing a Personalized Guide Recommendation System to Mitigate Information Overload in Museum Learning

    Science.gov (United States)

    Huang, Yong-Ming; Liu, Chien-Hung; Lee, Chun-Yi; Huang, Yueh-Min

    2012-01-01

    Museum learning has received a lot of attention in recent years. Museum learning refers to people's use of museums to acquire knowledge. However, a problem with information overload has caused in engaging in such learning. Information overload signifies that users encounter a mass of information and need to determine whether certain information…

  20. Managing Information Overload for Senior Leaders in the 21st Century

    Science.gov (United States)

    Jackson, Jason M.

    2013-01-01

    Information overload is a state where information input exceeds processing capability by an individual, and adverse effects of information overload, such as becoming less productive, making bad decisions, and becoming highly selective, are growing. Guided by Glaser and Strauss' work on grounded theory, this study examined adverse impact of…

  1. Choice overload and the quaterlife phase : Do higher educated quaterlifers experience more stress?

    NARCIS (Netherlands)

    Launspach, T.; Deijl, M. van der; Spiering, M.; Heemskerk, M.M.; Maas, E.N.; Marckelbach, D.

    2016-01-01

    The hypothesis that higher educated twenty-somethings experience more choice overload than lower educated twenty-somethings was tested. 146 participants, either in university or in community college, filled in questionnaires asserting their levels of choice overload. As expected, higher educated

  2. Static axial overloading primes lumbar caprine intervertebral discs for posterior herniation

    NARCIS (Netherlands)

    Paul, Cornelis P. L.; de Graaf, Magda; Bisschop, Arno; Holewijn, Roderick M.; van de Ven, Peter M.; van Royen, Barend J.; Mullender, Margriet G.; Smit, Theodoor H.; Helder, Marco N.

    2017-01-01

    Lumbar hernias occur mostly in the posterolateral region of IVDs and mechanical loading is an important risk factor. Studies show that dynamic and static overloading affect the nucleus and annulus of the IVD differently. We hypothesize there is also variance in the effect of overloading on the IVD's

  3. The Use of Graphs as Decision Aids in Relation to Information Overload and Managerial Decision Quality.

    Science.gov (United States)

    Chan, Siu Y.

    2001-01-01

    Discussion of information overload focuses on a study of masters degree students at a Hong Kong university that investigated the effectiveness of graphs as decision aids to reduce adverse effects of information overload on decision quality. Results of a simulation of a business prediction task with a sample of business managers are presented.…

  4. Designing immersive surgical training against information technology-related overload in the operating room

    NARCIS (Netherlands)

    Pluyter, J.R.

    2012-01-01

    On a theoretical level, this dissertation demonstrates that the “classical” conceptualization of overload in the field of Information Systems being an excessive amount of information is too simplistic. Based on the Emotional-Cognitive Overload Model by Rutkowski and Saunders (2011) this dissertation

  5. Information Overload in the New World of Work: Qualitative Study into the Reasons and Countermeasures

    NARCIS (Netherlands)

    ter Heerdt, Jeroen; Bondarouk, Tatiana; Ruel, Hubertus Johannes Maria; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    2009-01-01

    In this chapter the authors present a revision of the information overload concept elaborated by Eppler and Mengis (2004). The main elements of our approach are literature synopsis and analysis, qualitative semi-structured interviews, and discussion. Their review of the information overload concept

  6. Spreading the Load: Mobile Information and Communications Technologies and Their Effect on Information Overload

    Science.gov (United States)

    Allen, David K.; Shoard, M.

    2005-01-01

    Introduction: We report on a small-scale research project which examined the impact of mobile technologies on the users' experience of information overload. The project focused on a group of worker who have had relatively little attention in both the mobile technology and information overload literatures: senior managers. Method: The case study…

  7. Learners' Perceived Information Overload in Online Learning via Computer-Mediated Communication

    Science.gov (United States)

    Chen, Chun-Ying; Pedersen, Susan; Murphy, Karen L.

    2011-01-01

    Many studies report information overload as one of the main problems that students encounter in online learning via computer-mediated communication. This study aimed to explore the sources of online students' information overload and offer suggestions for increasing students' cognitive resources for learning. Participants were 12 graduate students…

  8. Crack tip strain evolution and crack closure during overload of a growing fatigue crack

    Directory of Open Access Journals (Sweden)

    De-Qiang Wang

    2017-07-01

    Full Text Available It is generally accepted that fatigue crack growth is retarded after an overload, which has been explained either by plasticity-induced crack closure or near-tip residual stress. However, any interpretation of overload effect is insufficient if strain evolution in front of crack tip is not properly considered. The current understanding of overload-induced retardation lacks the clarification of the relationship between crack closure at crack wake and strain evolution at crack tip. In this work, a material with low work hardening coefficient was used to study the effect of overload on crack tip strain evolution and crack closure by in-situ SEM observation and digital image correlation technique. Crack opening displacement (COD and crack tip strain were measured before and after the overload. It was observed that the evolution of crack tip strain follows the crack opening behaviour behind the crack tip, indicating a smaller influence of overload on micro-mechanical behaviour of fatigue crack growth. After the overload, plastic strain accumulation was responsible for crack growth. The strain at a certain distance to crack tip was mapped, and it was found that the crack tip plastic zone size correlated well with crack growth rate during post-overload fatigue crack propagation.

  9. Eccentric overload training in patients with a chronic Achilles tendinopathy: a systematic review.

    NARCIS (Netherlands)

    R. de Knikker; T. Takken; J.J. Kingma; Dr. H.M. Wittink

    2007-01-01

    Background: Eccentric overload training seems to be a promising conservative intervention in patients with chronic Achilles tendinopathy. The efficacy of eccentric overload training on the outcome measures of pain and physical functioning are not exactly clear. Study design: Systematic review of the

  10. Coping with Overload and Stress: Men and Women in Dual-Earner Families

    Science.gov (United States)

    Higgins, Chris A.; Duxbury, Linda E.; Lyons, Sean T.

    2010-01-01

    This study tested gender differences in a model positing relationships between work and family demands, overload, 4 coping mechanisms, and stress. The coping mechanisms were hypothesized to moderate the relationship between overload and stress. The sample consisted of 1,404 men and 1,623 women in dual-earner families. Respondents relied on 2…

  11. Hemodynamic monitoring in the era of evidence-based medicine.

    Science.gov (United States)

    Saugel, Bernd; Malbrain, Manu L N G; Perel, Azriel

    2016-12-20

    Hemodynamic instability frequently occurs in critically ill patients. Pathophysiological rationale suggests that hemodynamic monitoring (HM) may identify the presence and causes of hemodynamic instability and therefore may allow targeting therapeutic approaches. However, there is a discrepancy between this pathophysiological rationale to use HM and a paucity of formal evidence (as defined by the strict criteria of evidence-based medicine (EBM)) for its use. In this editorial, we discuss that this paucity of formal evidence that HM can improve patient outcome may be explained by both the shortcomings of the EBM methodology in the field of intensive care medicine and the shortcomings of HM itself.

  12. β3 integrin in cardiac fibroblast is critical for extracellular matrix accumulation during pressure overload hypertrophy in mouse.

    Directory of Open Access Journals (Sweden)

    Sundaravadivel Balasubramanian

    Full Text Available The adhesion receptor β3 integrin regulates diverse cellular functions in various tissues. As β3 integrin has been implicated in extracellular matrix (ECM remodeling, we sought to explore the role of β3 integrin in cardiac fibrosis by using wild type (WT and β3 integrin null (β3-/- mice for in vivo pressure overload (PO and in vitro primary cardiac fibroblast phenotypic studies. Compared to WT mice, β3-/- mice upon pressure overload hypertrophy for 4 wk by transverse aortic constriction (TAC showed a substantially reduced accumulation of interstitial fibronectin and collagen. Moreover, pressure overloaded LV from β3-/- mice exhibited reduced levels of both fibroblast proliferation and fibroblast-specific protein-1 (FSP1 expression in early time points of PO. To test if the observed impairment of ECM accumulation in β3-/- mice was due to compromised cardiac fibroblast function, we analyzed primary cardiac fibroblasts from WT and β3-/- mice for adhesion to ECM proteins, cell spreading, proliferation, and migration in response to platelet derived growth factor-BB (PDGF, a growth factor known to promote fibrosis stimulation. Our results showed that β3-/- cardiac fibroblasts exhibited a significant reduction in cell-matrix adhesion, cell spreading, proliferation and migration. In addition, the activation of PDGF receptor associated tyrosine kinase and non-receptor tyrosine kinase Pyk2, upon PDGF stimulation were impaired in β3-/- cells. Adenoviral expression of a dominant negative form of Pyk2 (Y402F resulted in reduced accumulation of fibronectin. These results indicate that β3 integrin-mediated Pyk2 signaling in cardiac fibroblasts plays a critical role in PO-induced cardiac fibrosis.

  13. The role of the medical physic on radiologic, hemodynamic and surgery unit at Hospital das Clinicas de Porto Alegre, Rio Grande do Sul State, Brazil; Atuacao do fisico medico nos servicos de radiologia, hemodinamica e unidade de bloco cirurgico no Hospital de Clinicas de Porto Alegre

    Energy Technology Data Exchange (ETDEWEB)

    Bacelar, A.; Furtado, A.P.A.; Krebs, E.M.; Oliveira, S.S.; Lima, A.A.; Jacques, L.C.; Silveira, C.S. [Hospital das Clinicas, Porto Alegre, RS (Brazil). Grupo de Pesquisa e Pos-graduacao em Fisica Medica

    1996-12-31

    The activities executed by the medical physic in the radiologic, hemodynamic and surgery unit are presented. Topics such as organization of a radiologic protection project and a quality assurance program, monthly information of the individual doses, sanitary inspection and training of the professionals involved are emphasized. The methodology and results are briefly presented 2 refs.

  14. Hemodynamic and hormonal actions of adrenomedullin

    Directory of Open Access Journals (Sweden)

    M.G. Nicholls

    2004-08-01

    Full Text Available Adrenomedullin, a 52-amino acid residue peptide, has numerous biological actions which are of potential importance to cardiovascular homeostasis, growth and development of cardiovascular tissues and bone, prevention of infection, and regulation of body fluid and electrolyte balance. Studies in man using intravenous infusion of the peptide have demonstrated that, at plasma levels detected after myocardial infarction or in heart failure, adrenomedullin reduces arterial pressure, increases heart rate and cardiac output, and activates the sympathetic and renin-angiotensin systems but suppresses aldosterone. The thresholds for these responses differ, being lower under some experimental circumstances for arterial pressure than for the other biological effects. Adrenomedullin administration inhibits the pressor and aldosterone-stimulating action of angiotensin II in man. By contrast, the pressor effect of norepinephrine is little altered by concomitant adrenomedullin administration. Although in the absence of a safe, specific antagonist of the actions of endogenous adrenomedullin it is difficult to be certain about the physiological and pathophysiological importance of this peptide in man, current evidence suggests that it serves to protect against cardiovascular overload and injury. Hope has been expressed that adrenomedullin or an agonist specific for adrenomedullin receptors might find a place in the treatment of cardiovascular disorders.

  15. Biological tissue magnetism in the frame of iron overload diseases

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, Francisco J. [Departamento de Ciencia y Tecnologia de Materiales y Fluidos, Universidad de Zaragoza, Zaragoza 50018 (Spain) and Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Zaragoza 50009 (Spain)]. E-mail: osoro@unizar.es; Gutierrez, Lucia [Departamento de Ciencia y Tecnologia de Materiales y Fluidos, Universidad de Zaragoza, Zaragoza 50018 (Spain); Abadia, Ana R. [Departamento de Farmacologia y Fisiologia, Universidad de Zaragoza, Zaragoza 50013 (Spain); Romero, Maria S. [Departamento de Medicina y Psiquiatria, Universidad de Zaragoza, Zaragoza 50009 (Spain); Lopez, A. [CNAM-Salesianos Zaragoza, Zaragoza 50009 (Spain)

    2007-09-15

    The conspicuous magnetic properties of iron, paradoxically, rarely participate in the methods routinely employed in the clinical environment to detect iron containing species in tissues. In the organism iron is just a trace metal and it mostly occurs as part of haemoproteins or ferritin, which show paramagnetic, diamagnetic or antiferromagnetic behaviour, hence resulting in a very low contribution to the tissue susceptibility. Detailed magnetic measurements make it nowadays possible to identify such species in tissues that correspond to individuals with iron overload pathologies. Since, as alternatives to the conventional biopsy, magnetism-based noninvasive techniques to diagnose and manage such diseases are recently under development, the deep knowledge of the magnetic properties of the different forms of iron in tissues is of high applied interest.

  16. Iron overload in the liver diagnostic and quantification

    Energy Technology Data Exchange (ETDEWEB)

    Alustiza, Jose M. [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain)]. E-mail: jmalustiza@osatek.es; Castiella, Agustin [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain); Juan, Maria D. de [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain); Emparanza, Jose I. [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain); Artetxe, Jose [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain); Uranga, Maite [Osatek SA, P Dr. Beguiristain 109, 20014, San Sebastian, Guipuzcoa (Spain)

    2007-03-15

    Hereditary Hemochromatosis is the most frequent modality of iron overload. Since 1996 genetic tests have facilitated significantly the non-invasive diagnosis of the disease. There are however many cases of negative genetic tests that require confirmation by hepatic iron quantification which is traditionally performed by hepatic biopsy. There are many studies that have demonstrated the possibility of performing hepatic iron quantification with Magnetic Resonance. However, a consensus has not been reached yet regarding the technique or the possibility to reproduce the same method of calculus in different machines. This article reviews the state of the art of the question and delineates possible future lines to standardise this non-invasive method of hepatic iron quantification.

  17. Echocardiogram in the Evaluation of Hemodynamically Stable Acute Pulmonary Embolism: National Practices and Clinical Outcomes.

    Science.gov (United States)

    Cohen, David M; Winter, Michael; Lindenauer, Peter K; Walkey, Allan J

    2018-01-03

    Societal guideline recommendations vary with regard to the role of routine trans-thoracic echocardiography (TTE) to screen for right ventricular strain in patients with hemodynamically-stable, acute pulmonary embolism (PE). To characterize national patterns in use of early TTE for the evaluation of patients with hemodynamically-stable, acute PE, and determine associations between TTE use and patient outcomes. Retrospective cohort study using Premier, Inc. database of approximately 20% of patients hospitalized in the United States with hemodynamically stable, acute PE between 2008-2011. Multivariable, risk-adjusted hierarchical regression models were used to evaluate hospital variation in use of TTE for PE and associations between hospital TTE rates and patient outcomes. Patient-level TTE exposure was used in sensitivity analyses. We identified 64,037 patients (mean age 61.7 years, 54% women, 68% white) hospitalized at 363 US hospitals. TTE rates for hemodynamically-stable, acute PE varied widely among hospitals (median TTE rate 41.4%, range 0-89%, IQR 32.7-51.7%). Hospital rates of TTE were not associated with significant differences in risk-adjusted mortality (TTE rate quartile 4 vs. quartile 1: OR 0.88, 95% CI 0.69-1.13) or use of thrombolytics (OR 1.28, 95% CI 0.84-1.96), but rates of ICU admission (OR 1.57, 95% CI 1.18-2.07), hospital length of stay (RR 1.08, 95% CI 1.03-1.15) and costs (RR 1.15, 95% CI 1.07-1.23) were significantly higher at high TTE-rate hospitals. Analyses of patient-level TTE exposure produced similar results, except with higher rates of thrombolysis (OR 5.58, 95% CI 4.40-7.09) and bleeding (OR 1.37, 95% CI 1.24-1.51) among patients receiving TTE. TTE use in the evaluation of patients with hemodynamically-stable, acute PE varied widely between hospitals. Hospitals with high rates of PE-associated TTE use did not achieve different patient mortality outcomes, but had higher resource utilization and costs. Our findings support the 2016

  18. [Excessive fluoride inducing calcium overload and apoptosis of ameloblasts].

    Science.gov (United States)

    Ying, Zhang; Lin, Ma; Jian, Li; Ming, Zhong; Kaiqiang, Zhang; Hefeng, Gu

    2014-12-01

    To study the effect of excessive fluoride on calcium overload and apoptosis in cultured rat ameloblasts in vitro. Logarithmic-phase ameloblasts (HAT-7) were treated with 0, 0.4, 0.8, 1.6, 3.2, and 6.4 mmol · L(-1) sodium fluoride (NaF) solution. Cell activities were detected by using a Cell Counting Kit 8 (CCK-8) assay after 48 h of treatment. The effect of fluoride on cell apoptosis was analyzed by using flow cytometry. Excessive fluoride-induced calcium concentration and calreticulin expression changes in ameloblasts were detected by using laser scanning confocal microscopy, Western blot analysis, and real-time quantitative polymerase chain reaction. NaF inhibited ameloblast activity at 1.6, 3.2, and 6.4 mmol · L(-1) (dose-dependent) after 48 h of induction. The Ca2+ fluorescence intensity of HAT-7 cells incubated with 1.6 and 3.2 mmol · L(-1) NaF was higher than that in the control group. The fluoride-induced early-stage apoptosis of ameloblasts after 48 h of induction and the early-stage apoptosis rate was positively correlated with fluoride concentration. Calreticulin mRNA expression in HAT-7 cells was higher than that in the control group after 48 h of incubation with 0.8, 1.2, and 1.6 mmol · L(-1) NaF. Excessive fluoride-induced calcium overload in ameloblasts and further caused endoplasmic reticulum stress-mediated apoptosis.

  19. Role of renal hemodynamics in obesity associated renal risk

    NARCIS (Netherlands)

    Bosma, Renate Jolanda

    2008-01-01

    Het voorkomen van overgewicht (body mass index (BMI) tussen 25 en 30 kg/m2) en obesitas (body mass index groter dan 30 kg/m2; zorgelijke vetzucht) neemt sterk toe en dreigt – door de ermee samenhangence ziekten – het grootste gezondheidsprobleem van de 21, eeuw te worden. Obesitas gaat samen met een

  20. Journal of Clinical Monitoring and Computing 2017 end of year summary: cardiovascular and hemodynamic monitoring.

    Science.gov (United States)

    Saugel, Bernd; Bendjelid, Karim; Critchley, Lester A H; Scheeren, Thomas W L

    2018-02-26

    Hemodynamic monitoring provides the basis for the optimization of cardiovascular dynamics in intensive care medicine and anesthesiology. The Journal of Clinical Monitoring and Computing (JCMC) is an ideal platform to publish research related to hemodynamic monitoring technologies, cardiovascular (patho)physiology, and hemodynamic treatment strategies. In this review, we discuss selected papers published on cardiovascular and hemodynamic monitoring in the JCMC in 2017.

  1. Hemodynamic changes during robotic radical prostatectomy

    Directory of Open Access Journals (Sweden)

    Vanlal Darlong

    2012-01-01

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

  2. New approach to intracardiac hemodynamic measurements in small animals

    DEFF Research Database (Denmark)

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

    2012-01-01

    Invasive measurements of intracardiac hemodynamics in animal models have allowed important advances in the understanding of cardiac disease. Currently they are performed either through a carotid arteriotomy or via a thoracotomy and apical insertion. Both of these techniques have disadvantages...

  3. Automated Assessment of Hemodynamics in the Conjunctival Microvasculature Network.

    Science.gov (United States)

    Khansari, Maziyar M; Wanek, Justin; Felder, Anthony E; Camardo, Nicole; Shahidi, Mahnaz

    2016-02-01

    The conjunctival microcirculation is accessible for direct visualization and quantitative assessment of microvascular hemodynamic properties. Currently available methods to assess hemodynamics in the conjunctival microvasculature use manual or semi-automated algorithms, which can be inefficient for application to a large number of microvessels within the microvascular network. We present an automated image analysis method for measurements of diameter and blood velocity in microvessels. The method was applied to conjunctival microcirculation images acquired in 15 healthy human subjects. Frangi filtering, thresholding, and morphological closing were applied to automatically segment microvessels, while variance filtering was used to detect blood flow. Diameter and blood velocity were measured in arterioles and venules within the conjunctival microvascular network, and blood flow and wall shear rate were calculated. Repeatability and validity of hemodynamic measurements were established. The automated image analysis method allows reliable, rapid and quantitative assessment of hemodynamics in the conjunctival microvascular network and can be potentially applied to microcirculation images of other tissues.

  4. Hemodynamic changes after levothyroxine treatment in subclinical hypothyroidism

    DEFF Research Database (Denmark)

    Faber, J; Petersen, L; Wiinberg, N

    2002-01-01

    In hypothyroidism, lack of thyroid hormones results in reduced cardiac function (cardiac output [CO]), and an increase of systemic vascular resistance (SVR). We speculated whether hemodynamic regulation in subjects with subclinical hypothyroidism (SH) (defined as mildly elevated thyrotropin [TSH...

  5. Hemodynamic effects of sevoflurane versus propofol anesthesia for ...

    African Journals Online (AJOL)

    Adele

    Hemodynamic measurements were undertaken at specific time-points during anesthesia and surgery. Mean arterial pressure (MAP) and heart rate (HR) measured oscillometrically, cardiac index determined with thoracic bioimpedance readings , systemic vascular resistance index, central venous pressure, nasopharyngeal.

  6. Nobiletin, a Polymethoxy Flavonoid, Protects Against Cardiac Hypertrophy Induced by Pressure-Overload via Inhibition of NAPDH Oxidases and Endoplasmic Reticulum Stress

    OpenAIRE

    Ning Zhang; Wen-Ying Wei; Zheng Yang; Yan Che; Ya-Ge Jin; Hai-Han Liao; Sha-sha Wang; Wei Deng; Qi-Zhu Tang

    2017-01-01

    Background/Aims: An increase in oxidative stress has been implicated in the pathophysiology of pressure-overload induced cardiac hypertrophy. Nobiletin (NOB), extracted from the fruit peel of citrus, possesses anti-oxidative property. Our study aimed to investigate the protective role of NOB in the progression of cardiac hypertrophy in vivo and in vitro. Methods: Mice received aortic banding (AB) operation to induce cardiac hypertrophy. Experimental groups were as follows: sham+vehicle (VEH/S...

  7. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... protection against overload which does not conform to the provisions of the National Electric Code, 1968... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload and...

  8. An Integrative Model of the Cardiovascular System Coupling Heart Cellular Mechanics with Arterial Network Hemodynamics

    Science.gov (United States)

    Kim, Young-Tae; Lee, Jeong Sang; Youn, Chan-Hyun; Choi, Jae-Sung

    2013-01-01

    The current study proposes a model of the cardiovascular system that couples heart cell mechanics with arterial hemodynamics to examine the physiological role of arterial blood pressure (BP) in left ventricular hypertrophy (LVH). We developed a comprehensive multiphysics and multiscale cardiovascular model of the cardiovascular system that simulates physiological events, from membrane excitation and the contraction of a cardiac cell to heart mechanics and arterial blood hemodynamics. Using this model, we delineated the relationship between arterial BP or pulse wave velocity and LVH. Computed results were compared with existing clinical and experimental observations. To investigate the relationship between arterial hemodynamics and LVH, we performed a parametric study based on arterial wall stiffness, which was obtained in the model. Peak cellular stress of the left ventricle and systolic blood pressure (SBP) in the brachial and central arteries also increased; however, further increases were limited for higher arterial stiffness values. Interestingly, when we doubled the value of arterial stiffness from the baseline value, the percentage increase of SBP in the central artery was about 6.7% whereas that of the brachial artery was about 3.4%. It is suggested that SBP in the central artery is more critical for predicting LVH as compared with other blood pressure measurements. PMID:23960442

  9. Modeling of the acute effects of primary hypertension and hypotension on the hemodynamics of intracranial aneurysms.

    Science.gov (United States)

    Sarrami-Foroushani, Ali; Villa-Uriol, Maria-Cruz; Nasr Esfahany, Mohsen; Coley, Stuart C; Di Marco, Luigi Yuri; Frangi, Alejandro F; Marzo, Alberto

    2015-01-01

    Hemodynamics is a risk factor in intracranial aneurysms (IA). Hypertension and pharmacologically induced hypotension are common in IA patients. This study investigates how hypertension and hypotension may influence aneurysmal hemodynamics. Images of 23 IAs at typical locations were used to build patient-specific Computational Fluid Dynamics models. The effects of hypotension and hypertension were simulated through boundary conditions by modulating the normotensive flow and pressure waveforms, in turn produced by a 1D systemic vascular model. Aneurysm location and flow pattern types were used to categorize the influence of hypotension and hypertension on relevant flow variables (velocity, pressure and wall shear stress). Results indicate that, compared to other locations, vertebrobasilar aneurysms (VBA) are more sensitive to flow changes. In VBAs, space-averaged velocity at peak systole increased by 30% in hypertension (16-21% in other locations). Flow in VBAs in hypotension decreased by 20% (10-13% in other locations). Momentum-driven hemodynamic types were also more affected by hypotension and hypertension, than shear-driven types. This study shows how patient-specific modeling can be effectively used to identify location-specific flow patterns in a clinically-relevant study, thus reinforcing the role played by modeling technologies in furthering our understanding of cardiovascular disease, and their potential in future healthcare.

  10. An integrative model of the cardiovascular system coupling heart cellular mechanics with arterial network hemodynamics.

    Science.gov (United States)

    Kim, Young-Tae; Lee, Jeong Sang; Youn, Chan-Hyun; Choi, Jae-Sung; Shim, Eun Bo

    2013-08-01

    The current study proposes a model of the cardiovascular system that couples heart cell mechanics with arterial hemodynamics to examine the physiological role of arterial blood pressure (BP) in left ventricular hypertrophy (LVH). We developed a comprehensive multiphysics and multiscale cardiovascular model of the cardiovascular system that simulates physiological events, from membrane excitation and the contraction of a cardiac cell to heart mechanics and arterial blood hemodynamics. Using this model, we delineated the relationship between arterial BP or pulse wave velocity and LVH. Computed results were compared with existing clinical and experimental observations. To investigate the relationship between arterial hemodynamics and LVH, we performed a parametric study based on arterial wall stiffness, which was obtained in the model. Peak cellular stress of the left ventricle and systolic blood pressure (SBP) in the brachial and central arteries also increased; however, further increases were limited for higher arterial stiffness values. Interestingly, when we doubled the value of arterial stiffness from the baseline value, the percentage increase of SBP in the central artery was about 6.7% whereas that of the brachial artery was about 3.4%. It is suggested that SBP in the central artery is more critical for predicting LVH as compared with other blood pressure measurements.

  11. Bilirubin, Renal Hemodynamics and Blood Pressure

    Directory of Open Access Journals (Sweden)

    David E. Stec

    2012-02-01

    Full Text Available Bilirubin is generated from the breakdown of heme by heme oxygenase and the reduction of biliverdin by the enzyme biliverdin reductase. Several large population studies have reported a significant inverse correlation between plasma bilirubin levels and the incidence of cardiovascular disease. Protection from cardiovascular disease is also observed in patients with Gilbert’s syndrome which is a disease characterized by mutations in hepatic UGT1A1, the enzyme responsible for the conjugation of bilirubin into the bile. Despite the strong correlation between plasma bilirubin levels and the protection from cardiovascular disease, the mechanism by which increases in plasma bilirubin acts to protect against cardiovascular disease is unknown. Since the chronic antihypertensive actions of bilirubin are likely due to its renal actions, the effects of moderate increases in plasma bilirubin on renal hemodynamics as well as bilirubin’s potential effects on renal tubule function will be discussed in this review. Mechanisms of action as well as the potential for antihypertensive therapies targeting moderate increases in plasma bilirubin levels will also be highlighted.

  12. Increased Hemodynamic Load in Early Embryonic Stages Alters Myofibril and Mitochondrial Organization in the Myocardium

    Directory of Open Access Journals (Sweden)

    Madeline Midgett

    2017-08-01

    Full Text Available Normal blood flow is essential for proper heart formation during embryonic development, as abnormal hemodynamic load (blood pressure and shear stress results in cardiac defects seen in congenital heart disease (CHD. However, the detrimental remodeling processes that relate altered blood flow to cardiac malformation and defects remain unclear. Heart development is a finely orchestrated process with rapid transformations that occur at the tissue, cell, and subcellular levels. Myocardial cells play an essential role in cardiac tissue maturation by aligning in the direction of stretch and increasing the number of contractile units as hemodynamic load increases throughout development. This study elucidates the early effects of altered blood flow on myofibril and mitochondrial configuration in the outflow tract myocardium in vivo. Outflow tract banding was used to increase hemodynamic load in the chicken embryo heart between Hamburger and Hamilton stages 18 and 24 (~24 h during tubular heart stages. 3D focused ion beam scanning electron microscopy analysis determined that increased hemodynamic load induced changes in the developing myocardium, characterized by thicker myofibril bundles that were more disbursed in circumferential orientation, and mitochondria that organized in large clusters around the nucleus. Proteomic mass-spectrometry analysis quantified altered protein composition after banding that is consistent with altered myofibril thin filament assembly and function, and mitochondrial maintenance and organization. Additionally, pathway analysis of the proteomics data identified possible activation of signaling pathways in response to banding, including the renin-angiotensin system (RAS. Imaging and proteomic data combined indicate that myofibril and mitochondrial arrangement in early embryonic stages is a critical developmental process that when disturbed by altered blood flow may contribute to cardiac malformation and defects.

  13. Coronary Artery Remodeling in a Model of Left Ventricular Pressure Overload Is Influenced by Platelets and Inflammatory Cells

    Science.gov (United States)

    Yang, Fanmuyi; Dong, Anping; Mueller, Paul; Caicedo, Jessica; Sutton, Alyssa Moore; Odetunde, Juliana; Barrick, Cordelia J.; Klyachkin, Yuri M.; Abdel-Latif, Ahmed; Smyth, Susan S.

    2012-01-01

    Left ventricular hypertrophy (LVH) is usually accompanied by intensive interstitial and perivascular fibrosis, which may contribute to arrhythmogenic sudden cardiac death. The mechanisms underlying the development of cardiac fibrosis are incompletely understood. To investigate the role of perivascular inflammation in coronary artery remodeling and cardiac fibrosis during hypertrophic ventricular remodeling, we used a well-established mouse model of LVH (transverse aortic constriction [TAC]). Three days after pressure overload, macrophages and T lymphocytes accumulated around and along left coronary arteries in association with luminal platelet deposition. Consistent with these histological findings, cardiac expression of IL-10 was upregulated and in the systemic circulation, platelet white blood cell aggregates tended to be higher in TAC animals compared to sham controls. Since platelets can dynamically modulate perivascular inflammation, we investigated the impact of thrombocytopenia on the response to TAC. Immunodepletion of platelets decreased early perivascular T lymphocytes' accumulation and altered subsequent coronary artery remodeling. The contribution of lymphocytes were examined in Rag1−/− mice, which displayed significantly more intimal hyperplasia and perivascular fibrosis compared to wild-type mice following TAC. Collectively, our studies support a role of early perivascular accumulation of platelets and T lymphocytes in pressure overload-induced inflammation. PMID:22916095

  14. Study of overload effects in bainitic steel by synchrotron X-ray diffraction

    Directory of Open Access Journals (Sweden)

    P. Lopez-Crespo

    2013-07-01

    Full Text Available This work presents an in-situ characterisation of crack-tip strain fields following an overload by means of synchrotron X-ray diffraction. The study is made on very fine grained bainitic steel, thus allowing a very high resolution so that small changes occurring around the crack-tip were captured along the crack plane at the mid-thickness of the specimen. We have followed the crack as it grew through the overload location. Once the crack-tip has progressed past the overload event there is strong evidence that the crack faces contact in the region of the overload event (though not in the immediate vicinity of the current locations of the crack tip at Kmin even when the crack has travelled 1mm beyond the overload location. It was also found that at Kmax the peak tensile strain ahead of the crack-tip decreases soon after the overload is applied and then gradually recovers as the crack grows past the compressive region created by the overload.

  15. Angiotensin II Facilitates Matrix Metalloproteinase-9-Mediated Myosin Light Chain Kinase Degradation in Pressure Overload-Induced Cardiac Hypertrophy

    Directory of Open Access Journals (Sweden)

    Shun Wang

    2017-12-01

    Full Text Available Background/Aims: Angiotensin II (Ang II has been shown to promote cardiac remodeling during the process of hypertrophy. Myosin light chain kinase (MLCK, a specific kinase for the phosphorylation of myosin light chain 2 (MLC2, plays an important role in regulating cardiac muscle contraction and hypertrophy. However, whether Ang II could facilitate cardiac hypertrophy by altering the expression of MLCK remains unclear. This study aimed to investigate this effect and the underlying mechanisms. Methods: Cardiac hypertrophy was induced via pressure overload in rats, which were then evaluated via histological and biochemical measurements and echocardiography. Angiotensin-converting enzyme inhibitor (ACEI was used to inhibit Ang II. Neonatal rat cardiomyocytes were stimulated with Ang II to induce hypertrophy and were treated with a matrix metalloproteinase 9 (MMP9 inhibitor. Myocyte hypertrophy was evaluated using immunofluorescence and qRT-PCR. Degradation of recombinant human MLCK by recombinant human MMP9 was tested using a cleavage assay. The expression levels of MLCK, MLC2, phospho-myosin light chain 2 (p-MLC2, myosin phosphatase 2 (MYPT2, and calmodulin (CaM were measured using western blotting. Results: ACEI improved cardiac function and remodeling and increased the levels of MLCK and p-MLC2 as well as reduced the expression of MMP9 in pressure overload-induced cardiac hypertrophy. Moreover, the MMP9 inhibitor alleviated myocyte hypertrophy and upregulated the levels of MLCK and p-MLC2 in Ang II-induced cardiomyocyte hypertrophy. Recombinant human MLCK was concentration- and time-dependently degraded by recombinant human MMP9 in vitro, and this process was prevented by the MMP9 inhibitor. Conclusion: Our results suggest that Ang II is involved in the degradation of MLCK in pressure overload-induced cardiac hypertrophy and that this process was mediated by MMP9.

  16. Modulation of overload-induced inflammation by aging and anabolic steroid administration.

    Science.gov (United States)

    Thompson, Raymond W; McClung, Joseph M; Baltgalvis, Kristen A; Davis, J Mark; Carson, James A

    2006-11-01

    Aging can alter the skeletal muscle growth response induced by overload. The initiation of overload induces muscle extracellular matrix expansion, increased cellularity, and inflammatory gene expression, which are all related to processes important for myofiber growth. These remodeling processes are also biological targets of testosterone. It is not certain how aging affects the inflammatory response to functional overload and whether anabolic steroid administration can alter this response. The effect of anabolic steroid administration on inflammatory processes during functional overload is not known. The purpose of this study was to determine if age altered the skeletal muscle inflammatory response at the onset of functional overload and whether anabolic steroid administration would modulate this response in young or older animals. Five-month and 25 month F344 x BRN rats were given nandrolone decanoate (ND) (6 mg/kg bw/wk) or sham injections for 3 weeks, and then the soleus muscle was overloaded (OV) for 3 days by synergist ablation. ND alone induced a 230% increase in ED1(+) cells in 5 month muscle. Three days of OV had no effect on ED1(+) cell number at either age. OV combined with ND induced a 90% increase in ED2(+) cells in 5 month muscle, while there was no effect of either treatment alone at this age. In 25 month muscle, OV induced a 40% increase in ED2(+) cells. Regardless of age, OV induced muscle TNF-alpha mRNA expression (300%) and IL-6 mRNA expression (900%). ND attenuated OV-induced IL-6 mRNA but not TNF-alpha expression in both age groups. The overload induction of IL-1beta mRNA was 3-fold greater in 25 month muscle (1400%), compared to 5 month muscle (400%). ND administration ablated the overload IL-1beta mRNA induction in 25 month muscle. Anabolic steroid administration can suppress inflammatory cytokine gene expression at the onset of overload and this effect is age dependent.

  17. The Impact of Hemodynamic Transesophageal Echocardiography on the Use of Continuous Renal Replacement Therapy in Trauma.

    Science.gov (United States)

    Griffin, Madison; Howard, Brett; Devictor, Sam; Ferenczy, Josh; Cobb, Frances; Christie, D Benjamin

    2017-08-01

    Post-traumatic fluid management is a widely debated topic. No best-practice consensus exists. Adverse outcomes such as acute kidney injury or volume overload are common. Continuous renal replacement therapy (CRRT) is an adjunct therapy for severe acute renal failure and volume overload, but is costly and not without risk. Hemodynamic transesophageal echocardiography (hTEE) is widely accepted as a reliable way to monitor volume status of intensive care unit (ICU) patients. Although data exist evaluating hTEE and CRRT independently, there is a lack of research mutually inclusive of the two. We hypothesized that the use of hTEE is associated with less need for CRRT. Retrospective review of a level I trauma center from 2009 to 2015 identified patients that required CRRT. In 2013, we implemented a protocol using hTEE in trauma patients with significant resuscitation needs. We compared CRRT use before and after implementation of the protocol (pre- and post-hTEE). Multivariate analysis using two sample t tests and χ2 test of the odds ratio (O.R.) was completed on variables such as injury severity score (ISS), acute kidney injury network (AKIN), days of CRRT, ICU length of stay (LOS), and hospital LOS. A total of 5037 and 6699 trauma patients were evaluated in the pre- and post-hTEE groups, respectively. Mean ISS was 22 and 28 for pre- and post-hTEE, respectively (P value 0.19). Mean AKIN was 2.7 for both groups. Mean days on CRRT was eight before hTEE and seven after hTEE (P value 0.7); 23 patients required CRRT pre-hTEE, and 15 required CRRT post-hTEE (P value 0.01 O.R. 2.4). Given, the odds of CRRT pre-hTEE are more than twice that of CRRT post-hTEE; we conclude that the use of hTEE is associated with a reduction of CRRT.

  18. Deferasirox for managing iron overload in people with thalassaemia.

    Science.gov (United States)

    Bollig, Claudia; Schell, Lisa K; Rücker, Gerta; Allert, Roman; Motschall, Edith; Niemeyer, Charlotte M; Bassler, Dirk; Meerpohl, Joerg J

    2017-08-15

    Thalassaemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusions. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone are effective; however, a review of the effectiveness and safety of the newer oral chelator deferasirox in people with thalassaemia is needed. To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and iron overload. We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 12 August 2016.We also searched MEDLINE, Embase, the Cochrane Library, Biosis Previews, Web of Science Core Collection and three trial registries: ClinicalTrials.gov; the WHO International Clinical Trials Registry Platform; and the Internet Portal of the German Clinical Trials Register: 06 and 07 August 2015. Randomised controlled studies comparing deferasirox with no therapy or placebo or with another iron-chelating treatment. Two authors independently assessed risk of bias and extracted data. We contacted study authors for additional information. Sixteen studies involving 1807 randomised participants (range 23 to 586 participants) were included. Twelve two-arm studies compared deferasirox to placebo (two studies) or deferoxamine (seven studies) or deferiprone (one study) or the combination of deferasirox and deferoxamine to deferoxamine alone (one study). One study compared the combination of deferasirox and deferiprone to deferiprone in combination with deferoxamine. Three three-arm studies compared deferasirox to deferoxamine and deferiprone (two studies) or the combination of deferasirox and deferiprone to deferiprone and deferasirox monotherapy respectively (one study). One four-arm study compared two different doses of deferasirox to matching placebo groups.The two studies (a pharmacokinetic and a dose-escalation study

  19. Sex differences in volume overload in skinned fibers.

    Science.gov (United States)

    Bening, C; Hamouda, K; Leyh, R

    2016-10-14

    The impact of sex on cardiac morphology and function in chronic volume overload has been described in detail. However, the relation between sex and contractile properties at the actin-myosin level has not been well defined. Therefore, we evaluated the influence of sex on the contractile capacities of patients with chronic volume overload. In 36 patients (18 males, 65 ± 9 years; 18 females, 65 ± 13 years) scheduled for elective mitral valve surgery due to severe mitral regurgitation (MR) with preserved left ventricular function, right auricle samples were obtained prior to extracorporal circulation. The fibers were prepared and skinned and exposed to a gradual increase in the calcium concentration (from pCa of 6.5-4.0) for calcium-induced force-developing measurements. Calcium sensitivity was also measured and recorded. The pCa-force relationship of the fibers obtained from males and females was significantly different, with the force values of the female fibers greater than those of male fibers at maximum calcium concentrations (pCa of 4.0: 3.6 ± 0.3 mN versus 3.2 ± 0.4 mN, p 0.02) and pCa of 4.5 2.6 ± 0.6 versus 2.0 ± 0.5, p 0.002). In contrast, the force values of female fibers were lower at mean calcium concentrations compared to those of male fibers (at 5.5 and pCa of 6.0: 1.0 ± 0.3 mN versus 1.2 ± 0.5 mN, p 0.04; 0.61 ± 0.05 versus 0.88 ± 0.09, p 0.04). Calcium sensitivity was observed at pCa of 5.0 in females and pCa of 4.5 in males. This study demonstrated that female fibers from patients exposed to chronic volume overload developed higher force values at a given calcium concentration compared to fibers from male patients. We assume that female patients might tap the full force potential, which is required when exposed to the highest calcium concentrations in our experimental cycle. The calcium sensitivity among genders was significantly different, with the results suggesting that males have higher calcium

  20. Information overload an international challenge to professional engineers and technical communicators

    CERN Document Server

    Ulijn, J M; Fazal, Zohra

    2012-01-01

    "This book covers the ever-increasing problem of information overload from both the professional and academic perspectives. Focusing on the needs of practicing engineers and professional communicators, it addresses the causes and costs of information overload, along with strategies and techniques for reducing and minimizing its negative effects. The theoretical framework of information overload and ideas for future research are also presented. The book brings together an international group of authors, providing a truly global point of view on this important, rarely covered topic"--

  1. Overload-mediated skeletal muscle hypertrophy is not impaired by loss of myofiber STAT3.

    Science.gov (United States)

    Pérez-Schindler, Joaquín; Esparza, Mary C; McKendry, James; Breen, Leigh; Philp, Andrew; Schenk, Simon

    2017-09-01

    Although the signal pathways mediating muscle protein synthesis and degradation are well characterized, the transcriptional processes modulating skeletal muscle mass and adaptive growth are poorly understood. Recently, studies in mouse models of muscle wasting or acutely exercised human muscle have suggested a potential role for the transcription factor signal transducer and activator of transcription 3 (STAT3), in adaptive growth. Hence, in the present study we sought to define the contribution of STAT3 to skeletal muscle adaptive growth. In contrast to previous work, two different resistance exercise protocols did not change STAT3 phosphorylation in human skeletal muscle. To directly address the role of STAT3 in load-induced (i.e., adaptive) growth, we studied the anabolic effects of 14 days of synergist ablation (SA) in skeletal muscle-specific STAT3 knockout (mKO) mice and their floxed, wild-type (WT) littermates. Plantaris muscle weight and fiber area in the nonoperated leg (control; CON) was comparable between genotypes. As expected, SA significantly increased plantaris weight, muscle fiber cross-sectional area, and anabolic signaling in WT mice, although interestingly, this induction was not impaired in STAT3 mKO mice. Collectively, these data demonstrate that STAT3 is not required for overload-mediated hypertrophy in mouse skeletal muscle. Copyright © 2017 the American Physiological Society.

  2. Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Hu, Jin; Zhang, Qiang; Liu, Bo [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo, E-mail: xhb_6505@163.com [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Sun, Xiao-bo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

    2014-08-15

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

  3. The impact of volume overload on right heart function in end-stage renal disease patients on hemodialysis.

    Science.gov (United States)

    Ünlü, Serkan; Şahinarslan, Asife; Gökalp, Gökhan; Seçkin, Özden; Arınsoy, Selim Turgay; Boyacı, Nuri Bülent; Çengel, Atiye

    2017-12-11

    The aim of this study was to evaluate the impact of volume overload on echocardiographic parameters used for the assessment of the right ventricle (RV) and right atrium (RA), to determine volume-independent parameters and to noninvasively investigate the physio-mechanics of RV and RA by examining end-stage kidney patients before and after hemodialysis (HD). The echocardiographic images were obtained from 67 patients (49.2 ± 17.3 years, 23 f) before and after HD. Changes in echocardiographic parameters with HD were examined. The average ultrafiltrated volume was 3088.1 ± 1103.7 mL. The size of RV and RA and tricuspid annular plane systolic excursion (TAPSE) decreased after HD, whereas myocardial performance index increased. RV fractional area change and iso-volumetric contraction acceleration time remained unchanged. RV global longitudinal strain (GLS) and RV early diastolic strain rate (SR) decreased after HD. Systolic and late diastolic SR of the RV showed no statistically significant difference after HD. Longitudinal strain and SR of RA contraction were not significantly different after HD. The changes in RV GLS (r = .641, P = .027), RV free wall longitudinal strain (r = .643, P information on RA physio-mechanics. This might lead to a better evaluation of the cardiac pathophysiology and hemodynamics of patients. Moreover, providing novel volume-independent parameters for the evaluation of right heart chambers would improve the clinical perspectives of patients. © 2017, Wiley Periodicals, Inc.

  4. Long Non-Coding RNA Malat-1 Is Dispensable during Pressure Overload-Induced Cardiac Remodeling and Failure in Mice.

    Directory of Open Access Journals (Sweden)

    Tim Peters

    Full Text Available Long non-coding RNAs (lncRNAs are a class of RNA molecules with diverse regulatory functions during embryonic development, normal life, and disease in higher organisms. However, research on the role of lncRNAs in cardiovascular diseases and in particular heart failure is still in its infancy. The exceptionally well conserved nuclear lncRNA Metastasis associated in lung adenocarcinoma transcript 1 (Malat-1 is a regulator of mRNA splicing and highly expressed in the heart. Malat-1 modulates hypoxia-induced vessel growth, activates ERK/MAPK signaling, and scavenges the anti-hypertrophic microRNA-133. We therefore hypothesized that Malat-1 may act as regulator of cardiac hypertrophy and failure during cardiac pressure overload induced by thoracic aortic constriction (TAC in mice.Absence of Malat-1 did not affect cardiac hypertrophy upon pressure overload: Heart weight to tibia length ratio significantly increased in WT mice (sham: 5.78±0.55, TAC 9.79±1.82 g/mm; p<0.001 but to a similar extend also in Malat-1 knockout (KO mice (sham: 6.21±1.12, TAC 8.91±1.74 g/mm; p<0.01 with no significant difference between genotypes. As expected, TAC significantly reduced left ventricular fractional shortening in WT (sham: 38.81±6.53%, TAC: 23.14±11.99%; p<0.01 but to a comparable degree also in KO mice (sham: 37.01±4.19%, TAC: 25.98±9.75%; p<0.05. Histological hallmarks of myocardial remodeling, such as cardiomyocyte hypertrophy, increased interstitial fibrosis, reduced capillary density, and immune cell infiltration, did not differ significantly between WT and KO mice after TAC. In line, the absence of Malat-1 did not significantly affect angiotensin II-induced cardiac hypertrophy, dysfunction, and overall remodeling. Above that, pressure overload by TAC significantly induced mRNA levels of the hypertrophy marker genes Nppa, Nppb and Acta1, to a similar extend in both genotypes. Alternative splicing of Ndrg2 after TAC was apparent in WT (isoform ratio

  5. Echocardiographic Evaluation of Hemodynamics in Neonates and Children

    Directory of Open Access Journals (Sweden)

    Yogen Singh

    2017-09-01

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

  6. Lack of chemokine signaling through CXCR5 causes increased mortality, ventricular dilatation and deranged matrix during cardiac pressure overload.

    Directory of Open Access Journals (Sweden)

    Anne Waehre

    Full Text Available RATIONALE: Inflammatory mechanisms have been suggested to play a role in the development of heart failure (HF, but a role for chemokines is largely unknown. Based on their role in inflammation and matrix remodeling in other tissues, we hypothesized that CXCL13 and CXCR5 could be involved in cardiac remodeling during HF. OBJECTIVE: We sought to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF. METHODS AND RESULTS: Mice harboring a systemic knockout of the CXCR5 (CXCR5(-/- displayed increased mortality during a follow-up of 80 days after aortic banding (AB. Following three weeks of AB, CXCR5(-/- developed significant left ventricular (LV dilatation compared to wild type (WT mice. Microarray analysis revealed altered expression of several small leucine-rich proteoglycans (SLRPs that bind to collagen and modulate fibril assembly. Protein levels of fibromodulin, decorin and lumican (all SLRPs were significantly reduced in AB CXCR5(-/- compared to AB WT mice. Electron microscopy revealed loosely packed extracellular matrix with individual collagen fibers and small networks of proteoglycans in AB CXCR5(-/- mice. Addition of CXCL13 to cultured cardiac fibroblasts enhanced the expression of SLRPs. In patients with HF, we observed increased myocardial levels of CXCR5 and SLRPs, which was reversed following LV assist device treatment. CONCLUSIONS: Lack of CXCR5 leads to LV dilatation and increased mortality during pressure overload, possibly via lack of an increase in SLRPs. This study demonstrates a critical role of the chemokine CXCL13 and CXCR5 in survival and maintaining of cardiac structure upon pressure overload, by regulating proteoglycans essential for correct collagen assembly.

  7. Lack of chemokine signaling through CXCR5 causes increased mortality, ventricular dilatation and deranged matrix during cardiac pressure overload.

    Science.gov (United States)

    Waehre, Anne; Halvorsen, Bente; Yndestad, Arne; Husberg, Cathrine; Sjaastad, Ivar; Nygård, Ståle; Dahl, Christen P; Ahmed, M Shakil; Finsen, Alexandra V; Reims, Henrik; Louch, William E; Hilfiker-Kleiner, Denise; Vinge, Leif E; Roald, Borghild; Attramadal, Håvard; Lipp, Martin; Gullestad, Lars; Aukrust, Pål; Christensen, Geir

    2011-04-18

    Inflammatory mechanisms have been suggested to play a role in the development of heart failure (HF), but a role for chemokines is largely unknown. Based on their role in inflammation and matrix remodeling in other tissues, we hypothesized that CXCL13 and CXCR5 could be involved in cardiac remodeling during HF. We sought to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF. Mice harboring a systemic knockout of the CXCR5 (CXCR5(-/-)) displayed increased mortality during a follow-up of 80 days after aortic banding (AB). Following three weeks of AB, CXCR5(-/-) developed significant left ventricular (LV) dilatation compared to wild type (WT) mice. Microarray analysis revealed altered expression of several small leucine-rich proteoglycans (SLRPs) that bind to collagen and modulate fibril assembly. Protein levels of fibromodulin, decorin and lumican (all SLRPs) were significantly reduced in AB CXCR5(-/-) compared to AB WT mice. Electron microscopy revealed loosely packed extracellular matrix with individual collagen fibers and small networks of proteoglycans in AB CXCR5(-/-) mice. Addition of CXCL13 to cultured cardiac fibroblasts enhanced the expression of SLRPs. In patients with HF, we observed increased myocardial levels of CXCR5 and SLRPs, which was reversed following LV assist device treatment. Lack of CXCR5 leads to LV dilatation and increased mortality during pressure overload, possibly via lack of an increase in SLRPs. This study demonstrates a critical role of the chemokine CXCL13 and CXCR5 in survival and maintaining of cardiac structure upon pressure overload, by regulating proteoglycans essential for correct collagen assembly.

  8. Competing for Attention in Social Media under Information Overload Conditions

    CERN Document Server

    Feng, Ling; Li, Baowen; Stanley, H Eugene; Havlin, Shlomo; Braunstein, Lidia A

    2014-01-01

    Although the many forms of modern social media have become major channels for the dissemination of information, they are becoming overloaded because of the rapidly-expanding number of information feeds. We analyze the expanding user-generated content in Sina Weibo, the largest micro-blog site in China, and find evidence that popular messages often follow a mechanism that differs from that found in the spread of disease, in contrast to common believe. In this mechanism, an individual with more friends needs more repeated exposures to spread further the information. Moreover, our data suggest that in contrast to epidemics, for certain messages the chance of an individual to share the message is proportional to the fraction of its neighbours who shared it with him/her. Thus the greater the number of friends an individual has the greater the number of repeated contacts needed to spread the message, which is a result of competition for attention. We model this process using a fractional susceptible infected recove...

  9. Game-Theoretic Models of Information Overload in Social Networks

    Science.gov (United States)

    Borgs, Christian; Chayes, Jennifer; Karrer, Brian; Meeder, Brendan; Ravi, R.; Reagans, Ray; Sayedi, Amin

    We study the effect of information overload on user engagement in an asymmetric social network like Twitter. We introduce simple game-theoretic models that capture rate competition between celebrities producing updates in such networks where users non-strategically choose a subset of celebrities to follow based on the utility derived from high quality updates as well as disutility derived from having to wade through too many updates. Our two variants model the two behaviors of users dropping some potential connections (followership model) or leaving the network altogether (engagement model). We show that under a simple formulation of celebrity rate competition, there is no pure strategy Nash equilibrium under the first model. We then identify special cases in both models when pure rate equilibria exist for the celebrities: For the followership model, we show existence of a pure rate equilibrium when there is a global ranking of the celebrities in terms of the quality of their updates to users. This result also generalizes to the case when there is a partial order consistent with all the linear orders of the celebrities based on their qualities to the users. Furthermore, these equilibria can be computed in polynomial time. For the engagement model, pure rate equilibria exist when all users are interested in the same number of celebrities, or when they are interested in at most two. Finally, we also give a finite though inefficient procedure to determine if pure equilibria exist in the general case of the followership model.

  10. Semicircular Canals Circumvent Brownian Motion Overload of Mechanoreceptor Hair Cells.

    Directory of Open Access Journals (Sweden)

    Mees Muller

    Full Text Available Vertebrate semicircular canals (SCC first appeared in the vertebrates (i.e. ancestral fish over 600 million years ago. In SCC the principal mechanoreceptors are hair cells, which as compared to cochlear hair cells are distinctly longer (70 vs. 7 μm, 10 times more compliant to bending (44 vs. 500 nN/m, and have a 100-fold higher tip displacement threshold (< 10 μm vs. <400 nm. We have developed biomechanical models of vertebrate hair cells where the bundle is approximated as a stiff, cylindrical elastic rod subject to friction and thermal agitation. Our models suggest that the above differences aid SCC hair cells in circumventing the masking effects of Brownian motion noise of about 70 nm, and thereby permit transduction of very low frequency (<10 Hz signals. We observe that very low frequency mechanoreception requires increased stimulus amplitude, and argue that this is adaptive to circumvent Brownian motion overload at the hair bundles. We suggest that the selective advantage of detecting such low frequency stimuli may have favoured the evolution of large guiding structures such as semicircular canals and otoliths to overcome Brownian Motion noise at the level of the mechanoreceptors of the SCC.

  11. Fluid overload in a South African pediatric intensive care unit.

    Science.gov (United States)

    Ketharanathan, Naomi; McCulloch, Mignon; Wilson, Clare; Rossouw, Beyra; Salie, Shamiel; Ahrens, Johan; Morrow, Brenda M; Argent, Andrew C

    2014-12-01

    Fluid resuscitation is integral to resuscitation guidelines and critical care. However, fluid overload (FO) yields increased morbidity. Prospective observational study of Red Cross War Memorial Children's Hospital pediatric intensive care unit admissions (February to March 2013). FO % = (fluid in minus fluid out) [liters]/weight [kg] × 100%. FO ≥ 10%, 28 day mortality. Median [interquartile range (IQR)] age: 9.5 (2.0-39.0) months, median (IQR) admission weight: 7.9 (3.6-13.7) kg. Median (IQR) FO with admission weight: 3.5 (2.1-4.9)%; three patients had FO ≥ 10%. The 28 day mortality was 10% (n = 10). Patients who died had higher mean (IQR) FO using admission weight [4.9 (2.9-9.3)% vs. 3.4 (1.9-4.8)%; p = 0.04]. Low FO ≥ 10% prevalence with 28 day mortality 10%. Higher FO% with admission weight associated with mortality (p = 0.04). We advocate further investigation of FO% as a simple bedside tool. © The Author [2014]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Performance Analysis of Novel Overload Control with Threshold Mechanism

    Directory of Open Access Journals (Sweden)

    Doo Il Choi

    2016-01-01

    Full Text Available We propose a novel overload control method with hysteresis property; that is, we analyze the M/G/1/K queueing system where the service and arrival rates are varied depending on the queue-length. We use two threshold values: L1(≤L2 and L2(≤K. When the queue-length increases by an amount between L1 and L2, we apply one of the following two strategies to reduce the queue-length, either we decrease the mean service time or we decrease the arrival rate. If the queue-length exceeds L2 with one strategy, we apply the other; thus, there are two models that depend on the method that was applied first. We derive the queue-length distribution at departure and at arbitrary epochs using the embedded Markov chain method and the supplementary variable method. We investigate performance measures including the loss probability and mean waiting time using various numerical examples.

  13. Right ventricular failure secondary to chronic overload in congenital heart diseases: benefits of cell therapy using human embryonic stem cell-derived cardiac progenitors.

    Science.gov (United States)

    Lambert, Virginie; Gouadon, Elodie; Capderou, André; Le Bret, Emmanuel; Ly, Mohamed; Dinanian, Sylvie; Renaud, Jean-Francois; Pucéat, Michel; Rücker-Martin, Catherine

    2015-03-01

    Despite the increasing incidence of right ventricular (RV) failure in adult patients with congenital heart disease, current therapeutic options are still limited. By contrast to left-heart diseases, cell-based myocardial regeneration applied to the right ventricle is poorly studied, even though it may be a therapeutic solution. As human embryonic stem cell-derived cardiac progenitors seem to be good candidates owing to their proliferation capacity, our aim was to assess, in a large animal model of overloaded RV dysfunction, the feasibility and effects of such a cell therapy. Human MesP1(+)/SSEA-1(+) cardiogenic mesodermal cells were administered using multiple intramyocardial injections 4 months after a surgical procedure mimicking the repaired tetralogy of Fallot, and their effects were observed 3 months later on hemodynamic, rhythmic, and histologic parameters. All pigs (sham n = 6, treated n = 6) survived without complication, and cell therapy was clinically well tolerated. Although functional, contractility, and energetics parameters evolved similarly in both groups, benefits regarding arrhythmic susceptibility were observed in the treated group, associated with a significant decrease of peri-myocyte fibrosis (5.71% ± 2.49% vs 12.12% ± 1.85%; P cells could be detected within the myocardium. Cell therapy using intramyocardial injections of human MesP1(+)/SSEA-1(+) cardiogenic mesodermal cells seems to have benefits regarding overloaded RV tissue remodeling and arrhythmic susceptibility, but this mode of administration is not sufficient to obtain a significant improvement in RV function. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  14. Iron overload in adults with sickle cell disease who have received intermittent red blood cell transfusions.

    Science.gov (United States)

    Pack-Mabien, Ardie; Brown, Brittany; Herbert, Donald E; Haynes, Johnson

    2015-10-01

    To assess the prevalence of iron overload in adults with sickle cell disease (SCD) not on a chronic transfusion protocol. Retrospective chart review. University of South Alabama Comprehensive Sickle Cell Center adult outpatient clinic. There was no significant difference in units transfused across the four genotypes (HbSS, HbSC, HbSβ(0)-thalassemia, and HbSβ(+)-thalassemia). Only individuals with HbSS (n = 63) met criteria for iron overload with ferritins of ≥1500 ng/mL. Forty-eight had ferritins clinical significance of iron overload in SCD can be established and guide the healthcare provider's management in the prevention of iron overload. ©2015 American Association of Nurse Practitioners.

  15. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Costa, Fernando Ferreira [Universidade Estadual de Campinas, Campinas, SP (Brazil); Silveira, Paulo Augusto Achucarro [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Wood, John [University of Southern California, California (United States); Hamerschlak, Nelson [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

    2013-07-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

  16. Effects of fluid overload on heart rate variability in chronic kidney disease patients on hemodialysis

    National Research Council Canada - National Science Library

    Ferrario, Manuela; Moissl, Ulrich; Garzotto, Francesco; Cruz, Dinna N; Clementi, Anna; Brendolan, Alessandra; Tetta, Ciro; Gatti, Emanuele; Signorini, Maria G; Cerutti, Sergio; Ronco, Claudio

    2014-01-01

    While fluid overload (FO) and alterations in the autonomic nervous system (ANS) such as hypersympathetic activity, are known risk factors for cardiovascular morbidity and mortality in patients on chronic hemodialysis (HD...

  17. WORK OVERLOAD AND TURNOVER INTENTION OF JUNIOR AUDITORS IN GREATER JAKARTA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Andika Pradana

    2015-11-01

    Full Text Available This paper aims to analyze how work overload influences turnover intentions of newly hired junior auditors in public accounting offices. Job satisfaction, work related stress and work life conflicts are used as mediating variables between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. The sample was selected using purposive sampling. Three mediation hypotheses were tested using Structural Equation Modeling (SEM. The results show that work overload has a significant effect on increas- ing turnover intention through both job satisfaction and work related stress. In comparison, work overload does not influence turnover intention through work life balance. This may be due to the nature of the respondents, in which a majority of the newly hired accountants employed in this study are unmarried.

  18. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging.

    Science.gov (United States)

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

    2013-12-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

  19. Method study of improving overload characteristic of counter type nuclear instrument

    CERN Document Server

    Xiong Jian Ping

    2002-01-01

    The output characteristic of GM counter can be improved by changing bias voltage of advanced circuit, so that makes overload characteristic of nuclear instrument is well improved. Above mentioned method is introduced

  20. Changes in hemodynamic parameters and cerebral saturation during supraventricular tachycardia.

    Science.gov (United States)

    Hershenson, Jared A; Ro, Pamela S; Miao, Yongjie; Tobias, Joseph D; Olshove, Vincent; Naguib, Aymen N

    2012-02-01

    Induced supraventricular tachycardia (SVT) during electrophysiology studies (EPS) can be associated with hemodynamic changes. Traditionally, invasive arterial blood pressure has been used for continuous monitoring of these changes. This prospective study evaluated the efficacy of near-infrared spectroscopy (NIRS) monitoring during SVT. The use of NIRS has expanded with evidence of its accuracy and benefit in detecting cerebral hypoperfusion. This study aimed first to determine the hemodynamic changes associated with electrophysiology testing for SVT and second to determine whether the hemodynamic changes are associated with similar changes in the cerebral saturation as determined by NIRS. The study enrolled 30 patients 5-20 years of age with a history of SVT who underwent an EPS. The demographic data included age, gender, weight, height, and type of SVT. Hemodynamic data (invasive blood pressure and heart rate), NIRS, bispectral index (BIS), end-tidal carbon dioxide, and pulse oximetry were collected before and during three episodes of induced SVT. The linear correlation coefficient (r) was measured to calculate the relationship of the changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) to the changes in NIRS values during the SVT episodes. Data from 22 patients were collected. The induction of SVT was associated mainly with a change in SBP and a less prominent change in DBP and MAP from baseline. The changes in hemodynamic status were associated with minimal changes in cerebral saturations, as evidenced by an average absolute change in NIRS of SVT during electrophysiology testing is associated with hemodynamic changes, mainly in SBP. In this study, these hemodynamic changes resulted in a minimal decrease in cerebral perfusion, as evidenced by minimal changes in the cerebral saturation measured by NIRS (0.7% from baseline). Although the changes in the cerebral saturation were minimal, these changes were

  1. In vitro hemodynamic model of the arm arteriovenous circulation to study hemodynamics of native arteriovenous fistula and the distal revascularization and interval ligation procedure.

    Science.gov (United States)

    Varble, Nicole; Day, Steven; Phillips, Daniel; Mix, Doran; Schwarz, Karl; Illig, Karl A; Chandra, Ankur

    2014-05-01

    . Flow through the AVF for both DR no IL and DRIL was preserved. Through the construction and validation of an in vitro, pulsatile arteriovenous model, the intricate hemodynamics of AVF and treatments for ischemic steal can be studied. DR with or without IL improved distal blood flow in addition to preserving AVF flow. IL decreased the blood flow through the DR bypass itself. The findings of the AVF as a pressure sink and the relative role of IL with DR bypass has allowed this model to provide hemodynamic insight difficult or impossible to obtain in animal or human models. Further study of these phenomena with this model should allow for more effective AVF placement and maturation while personalizing treatment for associated ischemic steal. The complications of arteriovenous fistula (AVF)-associated steal with its concurrent surgical treatments have been clinically described but have relatively little published, concrete hemodynamic data. A further understanding of the underlying hemodynamics is necessary to prevent the occurrence of steal and improve treatment when it occurs. Specific objectives are to study the blood flow through an AVF with varying anatomic and physiologic parameters, determine what factors contribute to the development of arterial steal distal to an AVF, and create optimal interventions to treat arterial steal from an AVF when it occurs. The long-term goal is creation of AVF tailored to patient-specific parameters, resulting in higher rates of functional fistulas with decreases in fistula-related complications. The ability to study fluid dynamics using a unique, in vitro, upper extremity pulsatile arteriovenous circulation simulator creates the ideal platform for this work. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  2. Hemodynamics in Idealized Stented Coronary Arteries: Important Stent Design Considerations.

    Science.gov (United States)

    Beier, Susann; Ormiston, John; Webster, Mark; Cater, John; Norris, Stuart; Medrano-Gracia, Pau; Young, Alistair; Cowan, Brett

    2016-02-01

    Stent induced hemodynamic changes in the coronary arteries are associated with higher risk of adverse clinical outcome. The purpose of this study was to evaluate the impact of stent design on wall shear stress (WSS), time average WSS, and WSS gradient (WSSG), in idealized stent geometries using computational fluid dynamics. Strut spacing, thickness, luminal protrusion, and malapposition were systematically investigated and a comparison made between two commercially available stents (Omega and Biomatrix). Narrower strut spacing led to larger areas of adverse low WSS and high WSSG but these effects were mitigated when strut size was reduced, particularly for WSSG. Local hemodynamics worsened with luminal protrusion of the stent and with stent malapposition, adverse high WSS and WSSG were identified around peak flow and throughout the cardiac cycle respectively. For the Biomatrix stent, the adverse effect of thicker struts was mitigated by greater strut spacing, radial cell offset and flow-aligned struts. In conclusion, adverse hemodynamic effects of specific design features (such as strut size and narrow spacing) can be mitigated when combined with other hemodynamically beneficial design features but increased luminal protrusion can worsen the stent's hemodynamic profile significantly.

  3. How Do I Integrate Hemodynamic Variables When Managing Septic Shock?

    Directory of Open Access Journals (Sweden)

    Olfa Hamzaoui

    2016-11-01

    Full Text Available Hemodynamic management of sepsis-induced circulatory failure is complex since this pathological state includes multiple cardiovascular derangements that can vary from patient to patient according to the degree of hypovolemia, of vascular tone depression, of myocardial depression and of microvascular dysfunction. The treatment of the sepsis-induced circulatory failure is thus not univocal and should be adapted on an individual basis. As physical examination is insufficient to obtain a comprehensive picture of the hemodynamic status, numerous hemodynamic variables more or less invasively collected, have been proposed to well assess the severity of each component of the circulatory failure and to monitor the response to therapy. In this article, we first describe the hemodynamic variables, which are the most relevant to be used, emphasizing on their physiological meaning, their validation and their limitations in patients with septic shock. We then proposed a general approach for managing patients with septic shock by describing the logical steps that need to be followed in order to select and deliver the most appropriate therapies. This therapeutic approach is essentially based on knowledge of physiology, of pathophysiology of sepsis, and of published data from clinical studies that addressed the issue of hemodynamic management of septic shock.

  4. Diagnostic Capacity of Central Hemodynamic Monitoring at Thoracic Cancer Surgery

    Directory of Open Access Journals (Sweden)

    A. M. Batyrshina

    2011-01-01

    Full Text Available Objective: to study hemodynamic changes and the development rate of adaptive reactions in patients with hypokinetic circulation during lung resections varying in volumes. Subjects and methods. Thirty-eight patients with hypo-kinetic circulation, who had undergone sublobar resections, lobectomies, and pneumonectomies, were examined. The values of hemodynamics and gas exchange were recorded at the basic surgical stages and in the early postoperative period (on days 1, 3, 7, and 10. Results. When the patient is placed in the lateral position, the lung is switched off, or the surgical pneumothorax is less than 10—12%, cardiac index changes generally fail to give rise to the decompensation of adaptive processes in the cardiovascular system if the volume of a surgical intervention does not exceed that of sublobar resections or lobectomies. A 15% or more change in cardiac index during controlled lung collapse even with the minimum volume of surgery is indicative of the breakdown of physiological adaptation processes and may manifest itself through the symptoms of cardiorespiratory decompensation in both intra- and postoperative periods. Conclusion. The patients with baseline poor, hypokinetic circulation need not only adequate preoperative estimation of central hemodynamic values, but also continuous intraoperative monitoring of the basic parameters of central hemodynamics. The magnitude of a reduction in cardiac index is prognostically important at the stage of one-lung ventilation during surgical pneumothorax. Key words: hypokinetic circulation, thoracic cancer surgery, central hemodynamic monitoring.

  5. A computational model of hemodynamic parameters in cortical capillary networks.

    Science.gov (United States)

    Safaeian, Navid; Sellier, Mathieu; David, Tim

    2011-02-21

    The analysis of hemodynamic parameters and functional reactivity of cerebral capillaries is still controversial. To assess the hemodynamic parameters in the cortical capillary network, a generic model was created using 2D voronoi tessellation in which each edge represents a capillary segment. This method is capable of creating an appropriate generic model of cerebral capillary network relating to each part of the brain cortex because the geometric model is able to vary the capillary density. The modeling presented here is based on morphometric parameters extracted from physiological data of the human cortex. The pertinent hemodynamic parameters were obtained by numerical simulation based on effective blood viscosity as a function of hematocrit and microvessel diameter, phase separation and plasma skimming effects. The hemodynamic parameters of capillary networks with two different densities (consistent with the variation of the morphometric data in the human cortical capillary network) were analyzed. The results show pertinent hemodynamic parameters for each model. The heterogeneity (coefficient variation) and the mean value of hematocrits, flow rates and velocities of the both network models were specified. The distributions of blood flow throughout the both models seem to confirm the hypothesis in which all capillaries in a cortical network are recruited at rest (normal condition). The results also demonstrate a discrepancy of the network resistance between two models, which are derived from the difference in the number density of capillary segments between the models. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. [Fasting insulinemie levels and after overload with oral glucose in overweight children (author's transl)].

    Science.gov (United States)

    López, M J; Colomer, J; Borrajo, E; Alpera, R

    1978-02-01

    Fasting insulinemie levels and after overload with oral glucose are studied in a group of 30 overweight children aged between 2--12 years. The results are: An increase in insulin secretion according to the age only in the overload test. The insulin and glucose areas in the overweight child is statistically bigger than in the healthy child. We conclude that hyperinsulinism in obesity, may be related with a insuline-resistance and with some kind of glucose intolerance.

  7. Over-exposed portraits : Technology overload and the identities of the young

    OpenAIRE

    Lutz, Christoph; Ranzini, Giulia; Meckel, Miriam

    2013-01-01

    Technostress and information overload represent serious challenges of the Information Age. An alarming number of people exhibit dangerously intensive media consumption, while Internet and mobile phone addictions are a widespread phenomenon, especially among teens. Despite increasing evidence for technostress and information overload within the literature, the consequences of new media overexposure on young individuals are so far understudied. When it comes to Social Network Sites (SNS), in pa...

  8. Haemochromatosis genotype and iron overload: association with hypertension and left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Ellervik, C; Tybjaerg-Hansen, A; Appleyard, M

    2010-01-01

    We hypothesized that there is an association between haemochromatosis genotype C282Y/C282Y and/or iron overload and risk of hypertension and/or left ventricular hypertrophy (LVH).......We hypothesized that there is an association between haemochromatosis genotype C282Y/C282Y and/or iron overload and risk of hypertension and/or left ventricular hypertrophy (LVH)....

  9. Quantifying Information Overload in Social Media and its Impact on Social Contagions

    OpenAIRE

    Rodriguez, Manuel Gomez; Gummadi, Krishna; Schoelkopf, Bernhard

    2014-01-01

    Information overload has become an ubiquitous problem in modern society. Social media users and microbloggers receive an endless flow of information, often at a rate far higher than their cognitive abilities to process the information. In this paper, we conduct a large scale quantitative study of information overload and evaluate its impact on information dissemination in the Twitter social media site. We model social media users as information processing systems that queue incoming informati...

  10. Static axial overloading primes lumbar caprine intervertebral discs for posterior herniation

    OpenAIRE

    Paul, Cornelis P. L.; Magda de Graaf; Arno Bisschop; Holewijn, Roderick M.; van de Ven, Peter M.; van Royen, Barend J; Mullender, Margriet G.; Smit, Theodoor H.; Helder, Marco N.

    2017-01-01

    Introduction Lumbar hernias occur mostly in the posterolateral region of IVDs and mechanical loading is an important risk factor. Studies show that dynamic and static overloading affect the nucleus and annulus of the IVD differently. We hypothesize there is also variance in the effect of overloading on the IVD?s anterior, lateral and posterior annulus, which could explain the predilection of herniations in the posterolateral region. We assessed the regional mechanical and cellular responses o...

  11. Static axial overloading primes lumbar caprine intervertebral discs for posterior herniation.

    Directory of Open Access Journals (Sweden)

    Cornelis P L Paul

    Full Text Available Lumbar hernias occur mostly in the posterolateral region of IVDs and mechanical loading is an important risk factor. Studies show that dynamic and static overloading affect the nucleus and annulus of the IVD differently. We hypothesize there is also variance in the effect of overloading on the IVD's anterior, lateral and posterior annulus, which could explain the predilection of herniations in the posterolateral region. We assessed the regional mechanical and cellular responses of lumbar caprine discs to dynamic and static overloading.IVDs (n = 125 were cultured in a bioreactor and subjected to simulated-physiological loading (SPL, high dynamic (HD, or high static (HS overloading. The effect of loading was determined in five disc regions: nucleus, inner-annulus and anterior, lateral and posterior outer-annulus. IVD height loss and external pressure transfer during loading were measured, cell viability was mapped and quantified, and matrix integrity was assessed.During culture, overloaded IVDs lost a significant amount of height, yet the distribution of axial pressure remained unchanged. HD loading caused cell death and disruption of matrix in all IVD regions, whereas HS loading particularly affected cell viability and matrix integrity in the posterior region of the outer annulus.Axial overloading is detrimental to the lumbar IVD. Static overloading affects the posterior annulus more strongly, while the nucleus is relatively spared. Hence, static overloading predisposes the disc for posterior herniation. These findings could have implications for working conditions, in particular of sedentary occupations, and the design of interventions aimed at prevention and treatment of early intervertebral disc degeneration.

  12. Static axial overloading primes lumbar caprine intervertebral discs for posterior herniation.

    Science.gov (United States)

    Paul, Cornelis P L; de Graaf, Magda; Bisschop, Arno; Holewijn, Roderick M; van de Ven, Peter M; van Royen, Barend J; Mullender, Margriet G; Smit, Theodoor H; Helder, Marco N

    2017-01-01

    Lumbar hernias occur mostly in the posterolateral region of IVDs and mechanical loading is an important risk factor. Studies show that dynamic and static overloading affect the nucleus and annulus of the IVD differently. We hypothesize there is also variance in the effect of overloading on the IVD's anterior, lateral and posterior annulus, which could explain the predilection of herniations in the posterolateral region. We assessed the regional mechanical and cellular responses of lumbar caprine discs to dynamic and static overloading. IVDs (n = 125) were cultured in a bioreactor and subjected to simulated-physiological loading (SPL), high dynamic (HD), or high static (HS) overloading. The effect of loading was determined in five disc regions: nucleus, inner-annulus and anterior, lateral and posterior outer-annulus. IVD height loss and external pressure transfer during loading were measured, cell viability was mapped and quantified, and matrix integrity was assessed. During culture, overloaded IVDs lost a significant amount of height, yet the distribution of axial pressure remained unchanged. HD loading caused cell death and disruption of matrix in all IVD regions, whereas HS loading particularly affected cell viability and matrix integrity in the posterior region of the outer annulus. Axial overloading is detrimental to the lumbar IVD. Static overloading affects the posterior annulus more strongly, while the nucleus is relatively spared. Hence, static overloading predisposes the disc for posterior herniation. These findings could have implications for working conditions, in particular of sedentary occupations, and the design of interventions aimed at prevention and treatment of early intervertebral disc degeneration.

  13. Captopril improves postresuscitation hemodynamics protective against pulmonary embolism by activating the ACE2/Ang-(1-7)/Mas axis.

    Science.gov (United States)

    Xiao, Hong-Li; Li, Chun-Sheng; Zhao, Lian-Xing; Yang, Jun; Tong, Nan; An, Le; Liu, Qi-Tong

    2016-11-01

    Acute pulmonary embolism (APE) has a very high mortality rate, especially at cardiac arrest and even after the return of spontaneous circulation (ROSC). This study investigated the protective effect of the angiotensin-converting enzyme (ACE) inhibitor captopril on postresuscitation hemodynamics, in a porcine model of cardiac arrest established by APE. Twenty-nine Beijing Landrace pigs were infused with an autologous thrombus leading to cardiac arrest and subjected to standard cardiopulmonary resuscitation and thrombolysis. Ten resuscitated pigs were randomly and equally apportioned to receive either captopril (22.22 mg/kg) infusion or the same volume saline, 30 min after ROSC. Hemodynamic changes and ACE-Ang II-angiotensin II type 1 receptor (AT1R) and ACE2/Ang-(1-7)/Mas receptor axis levels were determined. APE was associated with a decline in mean arterial pressure and a dramatic increase in pulmonary artery pressure and mean right ventricular pressure. After ROSC, captopril infusion was associated with significantly lower mean right ventricular pressure and systemic and pulmonary vascular resistance, faster heart rate, and higher Ang-(1-7) levels, ACE2/ACE, and Ang-(1-7)/Ang II, compared with the saline infusion. The ACE2/Ang-(1-7)/Mas pathway correlated negatively with external vascular lung water and pulmonary vascular permeability and positively with the right cardiac index. In conclusion, in a pig model of APE leading to cardiac arrest, captopril infusion was associated with less mean right ventricular pressure overload after resuscitation, compared with saline infusion. The reduction in systemic and pulmonary vascular resistance associated with captopril may be by inhibiting the ACE-Ang II-AT1R axis and activating the ACE2/Ang-(1-7)/Mas axis.

  14. Interactions of Aging, Overload, and Creatine Supplementation in Rat Plantaris Muscle

    Directory of Open Access Journals (Sweden)

    Mark D. Schuenke

    2011-01-01

    Full Text Available Attenuation of age-related sarcopenia by creatine supplementation has been equivocal. In this study, plantaris muscles of young (Y; 5m and aging (A; 24m Fisher 344 rats underwent four weeks of either control (C, creatine supplementation (Cr, surgical overload (O, or overload plus creatine (OCr. Creatine alone had no effect on muscle fiber cross-sectional area (CSA or heat shock protein (HSP70 and increased myonuclear domain (MND only in young rats. Overload increased CSA and HSP70 content in I and IIA fibers, regardless of age, and MND in IIA fibers of YO rats. CSA and MND increased in all fast fibers of YOCr, and CSA increased in I and IIA fibers of AOCr. OCR did not alter HSP70, regardless of age. MND did not change in aging rats, regardless of treatment. These data indicate creatine alone had no significant effect. Creatine with overload produced no additional hypertrophy relative to overload alone and attenuated overload-induced HSP70 expression.

  15. “Hydraulic Cushion” Type Overload Protection Devices Usable in Mechanical Presses. A Patent Study

    Science.gov (United States)

    Cioară, R.

    2016-11-01

    The possible consequences of machine-tool overload are well-known. In order to prevent such, machine-tools are equipped with various overload protection devices. Mechanical presses, intensively strained machine-tools, are typically equipped with three protection systems: against accidental access to the working area during machine deployment, against torque overload and force overload. Force overload protection systems include either destructible parts and are used in small to medium nominal force mechanical presses, or non-destructible ones used mostly in medium to large nominal force (H-frame) presses. A particular class of force overload protection systems without destructible parts are “hydraulic cushion” type devices. While such systems do not necessarily cause the machine to stop, the slide's stroke does not reach the initial dead centre and consequently cannot exert the designed technological force on the workpiece. By a patent study referencing 19 relevant patents the paper captures both the diversity of the constrictive solutions of “hydraulic cushion” type protection devices and their positioning modalities within the structure of a mechanical press. An important aim of the study is to highlight the reserve of creativity existing in this field, at least from the viewpoint of the hydraulic cushion positioning, as well as to emphasize the essential requirement of a relative motion between the mobile and the fixed parts of the tool, a motion of opposite sense to that of the slide-crank mechanism.

  16. Aluminium overload after 5 years in skin biopsy following post-vaccination with subcutaneous pseudolymphoma.

    Science.gov (United States)

    Guillard, Olivier; Fauconneau, Bernard; Pineau, Alain; Marrauld, Annie; Bellocq, Jean-Pierre; Chenard, Marie-Pierre

    2012-10-01

    Aluminium hydroxide is used as an effective adjuvant in a wide range of vaccines for enhancing immune response to the antigen. The pathogenic role of aluminium hydroxide is now recognized by the presence of chronic fatigue syndrome, macrophagic myofasciitis and subcutaneous pseudolymphoma, linked to intramuscular injection of aluminium hydroxide-containing vaccines. The aim of this study is to verify if the subcutaneous pseudolymphoma observed in this patient in the site of vaccine injection is linked to an aluminium overload. Many years after vaccination, a subcutaneous nodule was discovered in a 45-year-old woman with subcutaneous pseudolymphoma. In skin biopsy at the injection site for vaccines, aluminium (Al) deposits are assessed by Morin stain and quantification of Al is performed by Zeeman Electrothermal Atomic Absorption Spectrophotometry. Morin stain shows Al deposits in the macrophages, and Al assays (in μg/g, dry weight) were 768.10±18 for the patient compared with the two control patients, 5.61±0.59 and 9.13±0.057. Given the pathology of this patient and the high Al concentration in skin biopsy, the authors wish to draw attention when using the Al salts known to be particularly effective as adjuvants in single or repeated vaccinations. The possible release of Al may induce other pathologies ascribed to the well-known toxicity of this metal. Copyright © 2012 Elsevier GmbH. All rights reserved.

  17. ER calcium release promotes mitochondrial dysfunction and hepatic cell lipotoxicity in response to palmitate overload

    Science.gov (United States)

    Egnatchik, Robert A.; Leamy, Alexandra K.; Jacobson, David A.; Shiota, Masakazu; Young, Jamey D.

    2014-01-01

    Palmitate overload induces hepatic cell dysfunction characterized by enhanced apoptosis and altered citric acid cycle (CAC) metabolism; however, the mechanism of how this occurs is incompletely understood. We hypothesize that elevated doses of palmitate disrupt intracellular calcium homeostasis resulting in a net flux of calcium from the ER to mitochondria, activating aberrant oxidative metabolism. We treated primary hepatocytes and H4IIEC3 cells with palmitate and calcium chelators to identify the roles of intracellular calcium flux in lipotoxicity. We then applied 13C metabolic flux analysis (MFA) to determine the impact of calcium in promoting palmitate-stimulated mitochondrial alterations. Co-treatment with the calcium-specific chelator BAPTA resulted in a suppression of markers for apoptosis and oxygen consumption. Additionally, 13C MFA revealed that BAPTA co-treated cells had reduced CAC fluxes compared to cells treated with palmitate alone. Our results demonstrate that palmitate-induced lipoapoptosis is dependent on calcium-stimulated mitochondrial activation, which induces oxidative stress. PMID:25061559

  18. Cardiomyocyte Overexpression of FABP4 Aggravates Pressure Overload-Induced Heart Hypertrophy.

    Directory of Open Access Journals (Sweden)

    Ji Zhang

    Full Text Available Fatty acid binding protein 4 (FABP4 is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG mice using α myosin-heavy chain (α-MHC promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway.

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

    Science.gov (United States)

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

    1998-01-01

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

  20. [Hemodynamic monitoring - imaging procedures / cardiac ultrasound].

    Science.gov (United States)

    Batz, Gerhard; Dinkel, Michael

    2016-10-01

    Echocardiography as an imaging method in anaesthesia and intensive care medicine has enabled a new dimension of hemodynamic monitoring: the direct visualization of the cardiac function and its disruptions. Preconditions for a broad application in this area was the development of mobile, high-definition ultrasonic devices and the origination of focused examination techniques. A successful application of this method requires the respective know-how of the examiner, in order to take relevant decisions and avoid misdiagnoses. The following article shows the advantages and limitations of echocardiography in the diagnosis of hemodynamic instability. For TTE and TEE focused examination techniques are illustrated and evaluated with regards to their applicability to hemodynamic monitoring. Furthermore, the requirements on devices and education of the examiner are discussed. © Georg Thieme Verlag Stuttgart · New York.

  1. Ambient Temperature and Cerebrovascular Hemodynamics in the Elderly.

    Directory of Open Access Journals (Sweden)

    Wen-Chi Pan

    Full Text Available Some prior studies have linked ambient temperature with risk of cerebrovascular events. If causal, the pathophysiologic mechanisms underlying this putative association remain unknown. Temperature-related changes in cerebral vascular function may play a role, but this hypothesis has not been previously evaluated.We evaluated the association between ambient temperature and cerebral vascular function among 432 participants ≥65 years old from the MOBILIZE Boston Study with data on cerebrovascular blood flow, cerebrovascular resistance, and cerebrovascular reactivity in the middle cerebral artery. We used linear regression models to assess the association of mean ambient temperature in the previous 1 to 28 days with cerebrovascular hemodynamics adjusting for potential confounding factors.A 10°C increase in the 21-day moving average of ambient temperature was associated with a 10.1% (95% confidence interval [CI], 2.2%, 17.3% lower blood flow velocity, a 9.0% (95% CI, 0.7%, 18.0% higher cerebrovascular resistance, and a 15.3% (95%CI, 2.7%, 26.4% lower cerebral vasoreactivity. Further adjustment for ozone and fine particulate matter (PM2.5 did not materially alter the results. However, we found statistically significant interactions between ambient temperature and PM2.5 such that the association between temperature and blood flow velocity was attenuated at higher levels of PM2.5.In this elderly population, we found that ambient temperature was negatively associated with cerebral blood flow velocity and cerebrovascular vasoreactivity and positively associated with cerebrovascular resistance. Changes in vascular function may partly underlie the observed associations between ambient temperature and risk of cerebrovascular events.

  2. Damage in Total Knee Replacements from Mechanical Overload

    Science.gov (United States)

    Zimmerman, William F.; Miller, Mark A.; Cleary, Richard J.; Izant, Timothy H.; Mann, Kenneth A.

    2016-01-01

    The mechanical loads acting across the knee joint following total knee replacements (TKR) during activities of daily living have recently been measured using instrumented TKRs. Using a series of postmortem retrieved TKR constructs we investigated whether these mechanical loads could result in damage to the implant bone interface or supporting bone in the tibia. Eighteen cemented en bloc tibial components (0 to 22 years in service) were loaded under axial compression in increments from 1 to 10 times body weight and digital image correlation was used to measure bone strain and interface micromotion during loading and unloading. Failure was considered to occur when micromotion exceeded 150 μm or compressive bone strain exceeded 7300 με. The results show that all retrieved specimens had sufficient bone strength to support most activities of daily living, but ~40% would be at risk under larger physiologic loads that might occur secondary to a higher impacts such as jogging or a stumble. The tray-bone micromotion (regression model R2=0.48, p=0.025) was greater for donors with lower age at implantation (p=0.0092). Proximal bone strain (model R2=0.46, p=0.03) was greater for donors with longer time in service (p=0.021). Distal bone strain (model R2=0.58, p=0.005) was greater for donors with more time in service (p=0.0054) and lower peri-implant BMD (p=0.049). High mechanical overload of a single or repetitive nature may be an initiating factor in aseptic loosening of total joint arthroplasties and should be avoided in order to prolong the life of the implant. PMID:27237382

  3. Mechanisms of cardiac hypertrophy in canine volume overload

    Science.gov (United States)

    Matsuo, T.; Carabello, B. A.; Nagatomo, Y.; Koide, M.; Hamawaki, M.; Zile, M. R.; McDermott, P. J.

    1998-01-01

    This study tested whether the modest hypertrophy that develops in dogs in response to mitral regurgitation is due to a relatively small change in the rate of protein synthesis or, alternatively, is due to a decreased rate of protein degradation. After 3 mo of severe experimental mitral regurgitation, the left ventricular (LV) mass-to-body weight ratio increased by 23% compared with baseline values. This increase in LV mass occurred with a small, but not statistically significant, increase in the fractional rate of myosin heavy chain (MHC) synthesis (Ks), as measured using continuous infusion with [3H]leucine in dogs at 2 wk, 4 wk, and 3 mo after creation of severe mitral regurgitation. Translational efficiency was unaffected by mitral regurgitation as measured by the distribution of MHC mRNA in polysome gradients. Furthermore, there was no detectable increase in translational capacity as measured by either total RNA content or the rate of ribosome formation. These data indicate that translational mechanisms that accelerate the rate of cardiac protein synthesis are not responsive to the stimulus of mitral regurgitation. Most of the growth after mitral regurgitation was accounted for by a decrease in the fractional rate of protein degradation, calculated by subtracting fractional rates of protein accumulation at each time point from the corresponding Ks values. We conclude that 1) volume overload produced by severe mitral regurgitation does not trigger substantial increases in the rate of protein synthesis and 2) the modest increase in LV mass results primarily from a decrease in the rate of protein degradation.

  4. Cucurbitacin B Protects Against Pressure Overload Induced Cardiac Hypertrophy.

    Science.gov (United States)

    Xiao, Yang; Yang, Zheng; Wu, Qing-Qing; Jiang, Xiao-Han; Yuan, Yuan; Chang, Wei; Bian, Zhou Yan; Zhu, Jin Xiu; Tang, Qi-Zhu

    2017-11-01

    Lack of effective anti-cardiac hypertrophy drugs creates a major cause for the increasing prevalence of heart failure. In the present study, we determined the anti-hypertrophy and anti-fibrosis potential of a natural plant triterpenoid, Cucurbitacin B both in vitro and in vivo. Aortic banding (AB) was performed to induce cardiac hypertrophy. After 1 week of surgery, mice were receive cucurbitacin B treatment (Gavage, 0.2 mg/kg body weight/2 day). After 4 weeks of AB, cucurbitacin B demonstrated a strong anti-hypertrophy and -fibrosis ability as evidenced by decreased of heart weight, myocardial cell cross-sectional area and interstitial fibrosis, ameliorated of systolic and diastolic abnormalities, normalized in gene expression of hypertrophic and fibrotic markers, reserved microvascular density in pressure overload induced hypertrophic mice. Cucurbitacin B also showed significant hypertrophy inhibitory effect in phenylephrine stimulated cardiomyocytes. The Cucurbitacin B-mediated mitigated cardiac hypertrophy was attributable to the increasing level of autophagy, which was associated with the blockade of Akt/mTOR/FoxO3a signal pathway, validated by SC79, MK2206, and 3-MA, the Akt agonist, inhibitor and autophagy inhibitor in vitro. The overexpression of constitutively active Akt completely abolished the Cucurbitacin B-mediated protection of cardiac hypertrophy in human cardiomyocytes AC16. Collectively, our findings suggest that cucurbitacin B protects against cardiac hypertrophy through increasing the autophagy level in cardiomyocytes, which is associated with the inhibition of Akt/mTOR/FoxO3a signal axis. J. Cell. Biochem. 118: 3899-3910, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Novel paradigms for dialysis vascular access: upstream hemodynamics and vascular remodeling in dialysis access stenosis.

    Science.gov (United States)

    Remuzzi, Andrea; Ene-Iordache, Bogdan

    2013-12-01

    Failure of hemodialysis access is caused mostly by venous intimal hyperplasia, a fibro-muscular thickening of the vessel wall. The pathogenesis of venous neointimal hyperplasia in primary arteriovenous fistulae consists of processes that have been identified as upstream and downstream events. Upstream events are the initial events producing injury of the endothelial layer (surgical trauma, hemodynamic shear stress, vessel wall injury due to needle punctures, etc.). Downstream events are the responses of the vascular wall at the endothelial injury that consist of a cascade of processes including leukocyte adhesion, migration of smooth muscle cells from the media to the intimal layer, and proliferation. In arteriovenous fistulae, the stenoses occur in specific sites, consistently related to the local hemodynamics determined by the vessel geometry and blood flow pattern. Recent findings that the localization of these sites matches areas of disturbed flow may add new insights into the pathogenesis of neointimal hyperplasia in the venous side of vascular access after the creation of the anastomosis. The detailed study of fluid flow motion acting on the vascular wall in anastomosed vessels and in the arm vasculature at the patient-specific level may help to elucidate the role of hemodynamics in vascular remodeling and neointimal hyperplasia formation. These computational approaches may also help in surgical planning for the amelioration of clinical outcome. This review aims to discuss the role of the disturbed flow condition in acting as upstream event in the pathogenesis of venous intimal hyperplasia and in producing subsequent local vascular remodeling in autogenous arteriovenous fistulae used for hemodialysis access. The potential use of blood flow analysis in the management of vascular access is also discussed.

  6. Hemodynamic characteristics of hyperplastic remodeling lesions in cerebral aneurysms.

    Directory of Open Access Journals (Sweden)

    Kazuhiro Furukawa

    Full Text Available Hyperplastic remodeling (HR lesions are sometimes found on cerebral aneurysm walls. Atherosclerosis is the results of HR, which may cause an adverse effect on surgical treatment for cerebral aneurysms. Previous studies have demonstrated that atherosclerotic changes had a correlation with certain hemodynamic characteristics. Therefore, we investigated local hemodynamic characteristics of HR lesions of cerebral aneurysms using computational fluid dynamics (CFD.Twenty-four cerebral aneurysms were investigated using CFD and intraoperative video recordings. HR lesions and red walls were confirmed on the intraoperative images, and the qualification points were determined on the center of the HR lesions and the red walls. The qualification points were set on the virtual operative images for evaluation of wall shear stress (WSS, normalized WSS (NWSS, oscillatory shear index (OSI, relative residence time (RRT, and aneurysm formation indicator (AFI. These hemodynamic parameters at the qualification points were compared between HR lesions and red walls.HR lesions had lower NWSS, lower AFI, higher OSI and prolonged RRT compared with red walls. From analysis of the receiver-operating characteristic curve for hemodynamic parameters, OSI was the most optimal hemodynamic parameter to predict HR lesions (area under the curve, 0.745; 95% confidence interval, 0.603-0.887; cutoff value, 0.00917; sensitivity, 0.643; specificity, 0.893; P<0.01. With multivariate logistic regression analyses using stepwise method, NWSS was significantly associated with the HR lesions.Although low NWSS was independently associated with HR lesions, OSI is the most valuable hemodynamic parameter to distinguish HR lesions from red walls.

  7. Radius of proximal isovelocity surface area in the assessment of rheumatic mitral stenosis: Connecting flow to anatomy and hemodynamics

    OpenAIRE

    Omar, Alaa Mabrouk Salem; Abdel-Rahman, Mohamed Ahmed; Raslan, Hala; Rifaie, Osama

    2015-01-01

    Background: Echocardiographic assessment of left atrial pressure (LAP) in mitral stenosis (MS) is controversial. We sought to examine the role of the radius of the proximal isovelocity surface area (PISA-r) in the assessment of the hemodynamic status of MS after fixing the aliasing velocity (Val). Methods and results: We studied 42 candidates of balloon mitral valvuloplasty (BMV), for whom pre-BMV echocardiography was done and LAP invasively measured before dilatation. PISA-r was calculate...

  8. Hemodynamic monitoring in the era of digital health.

    Science.gov (United States)

    Michard, Frederic

    2016-12-01

    Digital innovations are changing medicine, and hemodynamic monitoring will not be an exception. Five to ten years from now, we can envision a world where clinicians will learn hemodynamics with simulators and serious games, will monitor patients with wearable or implantable sensors in the hospital and after discharge, will use medical devices able to communicate and integrate the historical, clinical, physiologic and biological information necessary to predict adverse events, propose the most rationale therapy and ensure it is delivered properly. Considerable intellectual and financial investments are currently made to ensure some of these new ideas and products soon become a reality.

  9. Rifaximin has no effect on hemodynamics in decompensated cirrhosis

    DEFF Research Database (Denmark)

    Kimer, Nina; Pedersen, Julie Steen; Busk, Troels Malte

    2017-01-01

    Decompensated cirrhosis is characterized by disturbed systemic and splanchnic hemodynamics. Bacterial translocation from the gut is considered the key driver in this process. Intestinal decontamination with rifaximin may improve hemodynamics. This double-blind, randomized, controlled trial...... years (±8.4), average Child score 8.3 (±1.3), and Model for End-Stage Liver Disease score 11.7 (±3.9). Measurements of hepatic venous pressure gradient, cardiac output, and systemic vascular resistance were made at baseline and after 4 weeks. The glomerular filtration rate and plasma renin...

  10. Does information overload prevent chronic patients from reading self-management educational materials?

    Science.gov (United States)

    Liu, Chung-Feng; Kuo, Kuang-Ming

    2016-05-01

    Self-care management is becoming an important part of care for chronic patients. However, various kinds of self-management educational materials which government or healthcare institutions provide for patients may not achieve the expected outcome. One of the critical reasons affecting patients' use intention could be patients' perceived information overload regarding the self-management educational materials. This study proposed an extended model of the Theory of Planned Behavior (TPB), which incorporated perceived information overload, to explore if information overload will prevent chronic patients from reading educational materials for self-care management. The independent variables are attitude, subject norm, perceived behavior control and perceived information overload while the dependent variable is behavior intention to use the self-management educational materials. Perceived information overload is also referred to as an antecedent variable which may has impacts on attitude and perceived behavior control. The cross-sectional study interviewed newly diagnosed chronic patients with coronary artery disease, who are the potential users of the self-management educational materials, in a medical center in Taiwan. Data were analyzed using descriptive statistics of the basic information distribution of the respondents, and structural equation modeling to study the reliability and validity for testing hypotheses. A total of 110 respondents were enrolled in this study and successful interview data were collected from 106 respondents. The result indicates that the patients' perceived information overload of self-management educational materials was validated to have impacts on attitude and perceived behavioral control constructs of the TPB as well as contributing a direct impact on patients' intentions to use self-management educational materials. Besides, subjective norm and perceived behavioral control constructs were validated to have significant impacts on

  11. ω-3 Polyunsaturated fatty acids prevent pressure overload-induced ventricular dilation and decrease in mitochondrial enzymes despite no change in adiponectin

    Directory of Open Access Journals (Sweden)

    O'Shea Karen M

    2010-09-01

    Full Text Available Abstract Background Pathological left ventricular (LV hypertrophy frequently progresses to dilated heart failure with suppressed mitochondrial oxidative capacity. Dietary marine ω-3 polyunsaturated fatty acids (ω-3 PUFA up-regulate adiponectin and prevent LV dilation in rats subjected to pressure overload. This study 1 assessed the effects of ω-3 PUFA on LV dilation and down-regulation of mitochondrial enzymes in response to pressure overload; and 2 evaluated the role of adiponectin in mediating the effects of ω-3 PUFA in heart. Methods Wild type (WT and adiponectin-/- mice underwent transverse aortic constriction (TAC and were fed standard chow ± ω-3 PUFA for 6 weeks. At 6 weeks, echocardiography was performed to assess LV function, mice were terminated, and mitochondrial enzyme activities were evaluated. Results TAC induced similar pathological LV hypertrophy compared to sham mice in both strains on both diets. In WT mice TAC increased LV systolic and diastolic volumes and reduced mitochondrial enzyme activities, which were attenuated by ω-3 PUFA without increasing adiponectin. In contrast, adiponectin-/- mice displayed no increase in LV end diastolic and systolic volumes or decrease in mitochondrial enzymes with TAC, and did not respond to ω-3 PUFA. Conclusion These findings suggest ω-3 PUFA attenuates cardiac pathology in response to pressure overload independent of an elevation in adiponectin.

  12. 'Combined vaccines are like a sudden onslaught to the body's immune system': parental concerns about vaccine 'overload' and 'immune-vulnerability'.

    Science.gov (United States)

    Hilton, Shona; Petticrew, Mark; Hunt, Kate

    2006-05-15

    The recent controversy surrounding the safety of the measles, mumps, and rubella vaccine (MMR) has heightened parents' concerns about the safety of vaccines, and led some to believe that giving vaccines in a combined form may 'overload' children's immune systems. However, to date no studies have been published examining how British parents conceptualise the notion of 'immune-overload' or how they relate this concept to their own children. Eighteen focus groups were conducted with parents between November 2002 and March 2003. The literature on vaccine decision-making suggests that parents base their immunisation decisions on two key risks: those posed by the diseases, and those associated with the vaccines aimed at preventing those diseases. Our study suggested that for some parents a third factor plays an important role, namely their assessment of the ability of their child's immune system to 'cope' with the challenge of combined vaccines, or to fight the disease. We conclude that although there is no scientific evidence that supports parents' fears about combined vaccines causing 'immune-overload', policy makers need to recognise these concerns if they are to successfully persuade parents that combined vaccines are safe.

  13. The ATP-binding cassette transporter ABCG2 protects against pressure overload-induced cardiac hypertrophy and heart failure by promoting angiogenesis and antioxidant response.

    Science.gov (United States)

    Higashikuni, Yasutomi; Sainz, Julie; Nakamura, Kazuto; Takaoka, Minoru; Enomoto, Soichiro; Iwata, Hiroshi; Tanaka, Kimie; Sahara, Makoto; Hirata, Yasunobu; Nagai, Ryozo; Sata, Masataka

    2012-03-01

    ATP-binding cassette transporter subfamily G member 2 (ABCG2), expressed in microvascular endothelial cells in the heart, has been suggested to regulate several tissue defense mechanisms. This study was performed to elucidate its role in pressure overload-induced cardiac hypertrophy. Pressure overload was induced in 8- to 12-week-old wild-type and Abcg2-/- mice by transverse aortic constriction (TAC). Abcg2-/- mice showed exaggerated cardiac hypertrophy and ventricular remodeling after TAC compared with wild-type mice. In the early phase after TAC, functional impairment in angiogenesis and antioxidant response in myocardium was found in Abcg2-/- mice. In vitro experiments demonstrated that ABCG2 regulates transport of glutathione, an important endogenous antioxidant, from microvascular endothelial cells. Besides, glutathione transported from microvascular endothelial cells in ABCG2-dependent manner ameliorated oxidative stress-induced cardiomyocyte hypertrophy. In vivo, glutathione levels in plasma and the heart were increased in wild-type mice but not in Abcg2-/- mice after TAC. Treatment with the superoxide dismutase mimetic ameliorated cardiac hypertrophy in Abcg2-/- mice after TAC to the same extent as that in wild-type mice, although cardiac dysfunction with impaired angiogenesis was observed in Abcg2-/- mice. ABCG2 protects against pressure overload-induced cardiac hypertrophy and heart failure by promoting angiogenesis and antioxidant response.

  14. NHE inhibition does not improve Na(+ or Ca(2+ overload during reperfusion: using modeling to illuminate the mechanisms underlying a therapeutic failure.

    Directory of Open Access Journals (Sweden)

    Byron N Roberts

    2011-10-01

    Full Text Available Reperfusion injury results from pathologies of cardiac myocyte physiology that develop when previously ischemic myocardium experiences a restoration of normal perfusion. Events in the development of reperfusion injury begin with the restoration of a proton gradient upon reperfusion, which then allows the sodium-proton exchanger (NHE to increase flux, removing protons from the intracellular space while importing sodium. The resulting sodium overload drives increased reverse-mode sodium-calcium exchanger (NCX activity, creating a secondary calcium overload that has pathologic consequences. One of the attempts to reduce reperfusion-related damage, NHE inhibition, has shown little clinical benefit, and only when NHE inhibitors are given prior to reperfusion. In an effort to further understand why NHE inhibitors have been largely unsuccessful, we employed a new mathematical cardiomyocyte model that we developed for the study of ischemia and reperfusion. Using this model, we simulated 20 minutes of ischemia and 10 minutes of reperfusion, while also simulating NHE inhibition by reducing NHE flux in our model by varying amounts and at different time points. In our simulations, when NHE inhibition is applied at the onset of reperfusion, increasing the degree of inhibition increases the peak sodium and calcium concentrations, as well as reducing intracellular pH recovery. When inhibition was instituted at earlier time points, some modest improvements were seen, largely due to reduced sodium concentrations prior to reperfusion. Analysis of all sodium flux pathways suggests that the sodium-potassium pump (NaK plays the largest role in exacerbated sodium overload during reperfusion, and that reduced NaK flux is largely the result of impaired pH recovery. While NHE inhibition does indeed reduce sodium influx through that exchanger, the resulting prolongation of intracellular acidosis paradoxically increases sodium overload, largely mediated by impaired Na

  15. Proteomic and transcriptomic analysis of heart failure due to volume overload in a rat aorto-caval fistula model provides support for new potential therapeutic targets - monoamine oxidase A and transglutaminase 2

    Directory of Open Access Journals (Sweden)

    Petrak Jiri

    2011-11-01

    Full Text Available Abstract Background Chronic hemodynamic overloading leads to heart failure (HF due to incompletely understood mechanisms. To gain deeper insight into the molecular pathophysiology of volume overload-induced HF and to identify potential markers and targets for novel therapies, we performed proteomic and mRNA expression analysis comparing myocardium from Wistar rats with HF induced by a chronic aorto-caval fistula (ACF and sham-operated rats harvested at the advanced, decompensated stage of HF. Methods We analyzed control and failing myocardium employing iTRAQ labeling, two-dimensional peptide separation combining peptide IEF and nano-HPLC with MALDI-MS/MS. For the transcriptomic analysis we employed Illumina RatRef-12v1 Expression BeadChip. Results In the proteomic analysis we identified 2030 myocardial proteins, of which 66 proteins were differentially expressed. The mRNA expression analysis identified 851 differentially expressed mRNAs. Conclusions The differentially expressed proteins confirm a switch in the substrate preference from fatty acids to other sources in the failing heart. Failing hearts showed downregulation of the major calcium transporters SERCA2 and ryanodine receptor 2 and altered expression of creatine kinases. Decreased expression of two NADPH producing proteins suggests a decreased redox reserve. Overexpression of annexins supports their possible potential as HF biomarkers. Most importantly, among the most up-regulated proteins in ACF hearts were monoamine oxidase A and transglutaminase 2 that are both potential attractive targets of low molecular weight inhibitors in future HF therapy.

  16. Omega-3-fatty acid adds to the protective effect of flax lignan concentrate in pressure overload-induced myocardial hypertrophy in rats via modulation of oxidative stress and apoptosis.

    Science.gov (United States)

    Ghule, Arvindkumar E; Kandhare, Amit D; Jadhav, Suresh S; Zanwar, Anand A; Bodhankar, Subhash L

    2015-09-01

    Objective of the present investigation was to study the effect of the flax lignan concentrate (FLC) and Omega-3-fatty acid (O-3-FA) on myocardial apoptosis, left ventricular (LV) contractile dysfunction and electrocardiographic abnormalities in pressure overload-induced cardiac hypertrophy. The rats were divided into five groups such as sham, aortic stenosis (AS), AS+FLC, AS+O-3-FA and AS+FLC+O-3-FA. Cardiac hypertrophy was produced in rats by abdominal aortic constriction. The rats were treated with FLC (400mg/kg, p.o.), O-3-FA (400mg/kg, p.o.) and FLC+O-3-FA orally per day for four weeks. The LV function, myocardial apoptosis, and oxidative stress were quantified. FLC+O-3-FA treatment significantly reduced hemodynamic changes, improved LV contractile dysfunction, reduced cardiomyocyte apoptosis and cellular oxidative stress. Moreover, it significantly up-regulated the VEGF expression and decreased TNF-alpha level in serum. The histological analysis also revealed that FLC+O-3-FA treatment markedly preserved the cardiac structure and inhibited interstitial fibrosis. In conclusion, FLC+O-3-FA treatment improved LV dysfunction, inhibited cardiomyocyte apoptosis, improved myocardial angiogenesis, conserved activities of membrane-bound phosphatase enzymes and suppressed inflammation through reduced oxidative stress in an additive manner than FLC alone and O-3-FA alone treatment in pressure overload-induced cardiac hypertrophy. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

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    Nick Youssefi

    2015-09-01

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

  19. ASCERTAINMENT OF ADMISSIBLE SYSTEMATIC OVERLOADS IN THE DISTRIBUTIVE OIL-TRANSFORMERS

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    V. A. Anishchenko

    2015-01-01

    Full Text Available The capacity of power-distributive oil-transformers is selected on the basis of their operational mode cost-effectiveness and power-supply reliability of the electrical recipients on condition that the transformers duty should not lead to reduction of their normal life-in-service. Unconscionable and protracted overloads intrinsically decrease reliability and respectively service life of the transformers owing to increased wear of the winding insulation because of the excessive heat. The unaccounted previous loading history and possible changes of the risen overload in the course of its further development can lead to poor accuracy in the admissible overload time estimation. Therefore, that may lead to intolerable excessive heat in the winding insulation or underutilization of the potential overload capacity of the transformers. Which limits the potentiality of complete demand satisfaction of the electrical consumers. This is exactly why the acting GOST 14209–97 strongly recommends the consumers to make their own calculations of the load-carrying capacity based on the real load curves.The authors present a method for ascertainment of the admissible duration of the systematic non-emergency overload of a distributive oil-transformer. The ascertainment method accounts for the overload repetition-factor alteration on the time-interval of its occurrence and respectively the variation in the transformer thermal state. The employment of this method will allow improving accuracy in ascertainment of the admissible duration of the systematic non-emergency overloads and eventually the reliability of the transformer operation and the power-supply system in its entirety. The method realization is intended by means of the transformer-load monitoring as one of the tasks of the electric-energy automated control and accounting system.

  20. The Family in Care for the Elderly: Managing the Overload and Coping with Difficulties

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    Lisete dos Santos Mendes Mónico

    2017-08-01

    Full Text Available Introduction: Family is considered the main support of the elderly in a situation of dependency. Caregiving often results in overloading, leading to diverse problems. Aim: To evaluate the self-perception of the family caregiver’s overload and the strategies used to provide informal care to the dependent elderly considering their level of dependence. Method: The sample consisted of 21 children, 16 spouses, and nine other relatives of elderly dependents who responded to the Caregiver’s Overload Scale (Sequeira, 2007, the Portuguese version of Caregivers’ Assessment Management Index (CAMI, Nolan, Keady, & Grant, 1995 and the Barthel Index (Mahoney & Barthel, 1965. Results: The Barthel Index showed 34.8% of the elderly as severely dependent and 37.0% as totally dependent. The care most provided respected to medication, hygiene, food, and monitoring. Above 56.5% of the caregivers had an intense overload, both at the objective (impact of care and interpersonal relationship and subjective (F3-Expectations regarding care and F4-Perceived self-efficacy levels. The main reason for maintaining caregivers was family/personal obligation (95.7%. Caregivers reasonably assessed the effectiveness of their strategies in dealing with their dependent elderly (CAMI; M = 101.0, SD = 15.0. There was a negative relationship between the perception of the caregiver’s overload and the age and health status of the elderly, as well as between the number of strategies used by the caregiver to overcome difficulties and the self-perception of the overload. Conclusion: The multiplicity of daily tasks performed in support of a family member in a situation of severe dependence translates into situations of intense overload, negatively impacting on care, interpersonal relationship, expectations regarding caring, and perception of self-efficacy of care.

  1. Clinical outcomes of transfusion-associated iron overload in patients with refractory chronic anemia

    Directory of Open Access Journals (Sweden)

    Gao C

    2014-04-01

    Full Text Available Chong Gao, Li Li, Baoan Chen, Huihui Song, Jian Cheng, Xiaoping Zhang, Yunyu SunDepartment of Hematology and Oncology, Key Department of Jiangsu Medicine, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province, People’s Republic of ChinaBackground: The purpose of this study was to evaluate the clinical outcomes of transfusion-associated iron overload in patients with chronic refractory anemia.Methods: Clinical manifestations, main organ function, results of computed tomography (CT, endocrine evaluation, and serum ferritin levels were analyzed retrospectively in 13 patients who were transfusion-dependent for more than 1 year (receiving >50 units of red blood cells to determine the degree of iron overload and efficacy of iron-chelating therapy.Results: Serum ferritin levels increased to 1,830–5,740 ng/mL in all patients. Ten patients had abnormal liver function. The CT Hounsfield units in the liver increased significantly in eleven patients, and were proportional to their serum ferritin levels. Skin pigmentation, liver dysfunction, and endocrine dysfunction were observed in nine patients with serum ferritin >3,500 ng/mL, eight of whom have since died. Interestingly, serum ferritin levels did not decrease significantly in nine transfusion-dependent patients who had received 15–60 days of iron-chelating therapy.Conclusion: Transfusion-dependent patients may progress to secondary iron overload with organ impairment, which may be fatal in those who are heavily iron-overloaded. The CT Hounsfield unit is a sensitive indicator of iron overload in the liver. Iron chelation therapy should be initiated when serum ferritin is >1,000 ng/mL and continued until it is <1,000 ng/mL in transfusional iron-overloaded patients.Keywords: anemia, aplastic, iron overload, myelodysplastic syndromes

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    OBJECTIVES: The authors sought to obtain hemodynamic estimates across a wide age span and in both sexes for future reference and compare these estimates with current guideline diagnostic hemodynamic thresholds for abnormal filling pressure and pulmonary hypertension. BACKGROUND: At present....... Participants had hemodynamic parameters measured using right heart catheterization during rest, passive leg raise, and incremental exercise. RESULTS: During rest, all hemodynamic parameters were similar between age groups, apart from blood pressure. During leg raise and incremental exercise...

  3. Protective effects of deferasirox and N-acetyl-L-cysteine on iron overload-injured bone marrow

    Directory of Open Access Journals (Sweden)

    J.C. Shen

    2017-10-01

    Full Text Available Using an iron overload mouse model, we explored the protective effect of deferasirox (DFX and N-acetyl-L-cysteine (NAC on injured bone marrow hematopoietic stem/progenitor cells (HSPC induced by iron overload. Mice were intraperitoneally injected with 25 mg iron dextran every 3 days for 4 weeks to establish an iron overload (Fe model. DFX or NAC were co-administered with iron dextran in two groups of mice (Fe+DFX and Fe+NAC, and the function of HSPCs was then examined. Iron overload markedly decreased the number of murine HSPCs in bone marrow. Subsequent colony-forming cell assays showed that iron overload also decreased the colony forming capacity of HSPCs, the effect of which could be reversed by DFX and NAC. The bone marrow hematopoiesis damage caused by iron overload could be alleviated by DFX and NAC.

  4. Visceral Congestion in Heart Failure: Right Ventricular Dysfunction, Splanchnic Hemodynamics, and the Intestinal Microenvironment.

    Science.gov (United States)

    Polsinelli, Vincenzo B; Sinha, Arjun; Shah, Sanjiv J

    2017-12-01

    Visceral venous congestion of the gut may play a key role in the pathogenesis of right-sided heart failure (HF) and cardiorenal syndromes. Here, we review the role of right ventricular (RV) dysfunction, visceral congestion, splanchnic hemodynamics, and the intestinal microenvironment in the setting of right-sided HF. We review recent literature on this topic, outline possible mechanisms of disease pathogenesis, and discuss potential therapeutics. There are several mechanisms linking RV-gut interactions via visceral venous congestion which could result in (1) hypoxia and acidosis in enterocytes, which may lead to enhanced sodium-hydrogen exchanger 3 (NHE3) expression with increased sodium and fluid retention; (2) decreased luminal pH in the intestines, which could lead to alteration of the gut microbiome which could increase gut permeability and inflammation; (3) alteration of renal hemodynamics with triggering of the cardiorenal syndrome; and (4) altered phosphate metabolism resulting in increased pulmonary artery stiffening, thereby increasing RV afterload. A wide variety of therapeutic interventions that act on the RV, pulmonary vasculature, intestinal microenvironment, and the kidney could alter these pathways and should be tested in patients with right-sided HF. The RV-gut axis is an important aspect of HF pathogenesis that deserves more attention. Modulation of the pathways interconnecting the right heart, visceral congestion, and the intestinal microenvironment could be a novel avenue of intervention for right-sided HF.

  5. Dual specific phosphatase 12 ameliorates cardiac hypertrophy in response to pressure overload.

    Science.gov (United States)

    Li, Wei-Ming; Zhao, Yi-Fan; Zhu, Guo-Fu; Peng, Wen-Hui; Zhu, Meng-Yun; Yu, Xue-Jing; Chen, Wei; Xu, Da-Chun; Xu, Ya-Wei

    2017-01-01

    Pathological cardiac hypertrophy is an independent risk factor of heart failure. However, we still lack effective methods to reverse cardiac hypertrophy. DUSP12 is a member of the dual specific phosphatase (DUSP) family, which is characterized by its DUSP activity to dephosphorylate both tyrosine and serine/threonine residues on one substrate. Some DUSPs have been identified as being involved in the regulation of cardiac hypertrophy. However, the role of DUSP12 during pathological cardiac hypertrophy is still unclear. In the present study, we observed a significant decrease in DUSP12 expression in hypertrophic hearts and cardiomyocytes. Using a genetic loss-of-function murine model, we demonstrated that DUSP12 deficiency apparently aggravated pressure overload-induced cardiac hypertrophy and fibrosis as well as impaired cardiac function, whereas cardiac-specific overexpression of DUPS12 was capable of reversing this hypertrophic and fibrotic phenotype and improving contractile function. Furthermore, we demonstrated that JNK1/2 activity but neither ERK1/2 nor p38 activity was increased in the DUSP12 deficient group and decreased in the DUSP12 overexpression group both in vitro and in vivo under hypertrophic stress conditions. Pharmacological inhibition of JNK1/2 activity (SP600125) is capable of reversing the hypertrophic phenotype in DUSP12 knockout (KO) mice. DUSP12 protects against pathological cardiac hypertrophy and related pathologies. This regulatory role of DUSP12 is primarily through c-Jun N-terminal kinase (JNK) inhibition. DUSP12 could be a promising therapeutic target of pathological cardiac hypertrophy. DUSP12 is down-regulated in hypertrophic hearts. An absence of DUSP12 aggravated cardiac hypertrophy, whereas cardiomyocyte-specific DUSP12 overexpression can alleviate this hypertrophic phenotype with improved cardiac function. Further study demonstrated that DUSP12 inhibited JNK activity to attenuate pathological cardiac hypertrophy. © 2016 The

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

    NARCIS (Netherlands)

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

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

  7. Multiphase hemodynamic simulation of pulsatile flow in a coronary artery.

    Science.gov (United States)

    Jung, Jonghwun; Lyczkowski, Robert W; Panchal, Chandrakant B; Hassanein, Ahmed

    2006-01-01

    A multiphase transient non-Newtonian three-dimensional (3-D) computational fluid dynamics (CFD) simulation has been performed for pulsatile hemodynamics in an idealized curved section of a human coronary artery. We present the first prediction, to the authors' knowledge, of particulate buildup on the inside curvature using the multiphase theory of dense suspension hemodynamics. In this study, the particulates are red blood cells (RBCs). The location of RBC buildup on the inside curvature correlates with lower wall shear stress (WSS) relative to the outside curvature. These predictions provide insight into how blood-borne particulates interact with artery walls and hence, have relevance for understanding atherogenesis since clinical observations show that atherosclerotic plaques generally form on the inside curvatures of arteries. The buildup of RBCs on the inside curvature is driven by the secondary flow and higher residence times. The higher viscosity in the central portion of the curved vessel tends to block their flow, causing them to migrate preferentially through the boundary layer. The reason for this is the nearly neutrally buoyant nature of the dense two-phase hemodynamic flow. The two-phase non-Newtonian viscosity model predicts greater shear thinning than the single-phase non-Newtonian model. Consequently, the secondary flow induced in the curvature is weaker. The waveforms for computed hemodynamic parameters, such as hematocrit, WSS, and viscosity, follow the prescribed inlet velocity waveforms. The lower oscillatory WSS produced on the inside curvature has implications for understanding thickening of the intimal layer.

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

    Directory of Open Access Journals (Sweden)

    Kulkarni H

    1996-01-01

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

  9. The hemodynamic basis of exercise intolerance in tricuspid regurgitation

    DEFF Research Database (Denmark)

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

    2014-01-01

    BACKGROUND:Patients with severe tricuspid regurgitation (TR) frequently present with exertional fatigue and dyspnea, but the hemodynamic basis for exercise limitation in people with TR remains unclear. METHODS AND RESULTS:Twelve subjects with normal left ventricular (LV) ejection fraction and gra...

  10. Hemodynamic causes of exercise intolerance in Fontan patients

    DEFF Research Database (Denmark)

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

    2014-01-01

    BACKGROUND: Exercise intolerance is frequent among Fontan patients and an important determinant for quality of life. This study investigated the hemodynamic causes of impaired exercise capacity in Fontan patients with particular focus on the influence of stroke volume index (SVI) and heart rate (HR...

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

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    Gustavo Teixeira Fulton Schimit

    2013-06-01

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

  12. Hemodynamic Changes during Epidural Anesthesia with Various Local Anesthetics

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    Ye. M. Shifman

    2008-01-01

    Full Text Available Central hemodynamic stability during gynecological laparoscopic operations remains an important problem of anes-thesiological monitoring. Subjects and methods. Fifty-eight patients who had undergone various gynecological laparoscopic operations were examined. According to the mode of anesthesia, the patients were divided into 2 groups: 1 29 patients who received epidural anesthesia with ropivacaine; 2 29 who had epidural anesthesia using lidocaine. The indices of cardiac performance (stroke volume, stroke index, and cardiac output, blood (diastolic, systolic, and mean pressure, vascular parameters (linear blood flow velocity, total peripheral vascular resistance were determined by volumetric compression oscillometry. Results. The study indicated that all the modes of anesthesia demonstrated the satisfactory condition of the cardiovascular system, but the highest stability of hemodynamic parameters was recorded in the epidural ropivacaine group. In this group, there were steady-state reductions in diastolic, systolic, mean blood pressures, and total vascular peripheral resistance and increases in stroke index, stroke volume, and linear blood flow velocity. Conclusion. Epidural anesthesia using ropivacaine during gynecological surgical endoscopic interventions is the method of analgesia causing minimal hemodynamic disorders. Key words: hemodynamics, epidural anesthesia, laparoscopic gynecological operations.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    Science.gov (United States)

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

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

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    Hideki Uedono

    2015-06-01

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

  16. Less invasive hemodynamic monitoring in critically ill patients

    NARCIS (Netherlands)

    Teboul, Jean-Louis; Saugel, Bernd; Cecconi, Maurizio; De Backer, Daniel; Hofer, Christoph K.; Monnet, Xavier; Perel, Azriel; Pinsky, Michael R.; Reuter, Daniel A.; Rhodes, Andrew; Squara, Pierre; Vincent, Jean-Louis; Scheeren, Thomas W.

    Over the last decade, the way to monitor hemodynamics at the bedside has evolved considerably in the intensive care unit as well as in the operating room. The most important evolution has been the declining use of the pulmonary artery catheter along with the growing use of echocardiography and of

  17. Clinical monitoring of systemic hemodynamics in critically ill newborns.

    NARCIS (Netherlands)

    Boode, W.P. de

    2010-01-01

    Circulatory failure is a major cause of mortality and morbidity in critically ill newborn infants. Since objective measurement of systemic blood flow remains very challenging, neonatal hemodynamics is usually assessed by the interpretation of various clinical and biochemical parameters. An overview

  18. Effects of perioperative medication on hemodynamics and blood loss

    NARCIS (Netherlands)

    van Haelst, I.M.M.

    2013-01-01

    Intraoperative hemodynamic changes and loss of blood with the associated risk of allogeneic blood transfusion are risk factors for complications in surgical patients. The use of medication in the perioperative period may influence these risk factors and consequently the frequency of complications.

  19. Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

    Science.gov (United States)

    Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

    2014-09-01

    Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (pmuscle, both ND and OV decreased LDH-A and LDH-B activity. However, there was no synergistic or additive effect. In 5-month muscle, ND and OV decreased LDH-A mRNA expression with no change in LDH-B expression. In 25-month muscle, ND and OV increased LDH-A and LDH-B activity. LDH-A mRNA expression was not altered by ND or OV in aged muscle. However, there was a main effect of OV to decrease LDH-B mRNA expression. There was also an age-induced LDH isoform shift. ND and OV treatment increased the "fast" LDH isoforms in aged muscle, whereas ND and OV increased the "slow" isoforms in young muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid administration. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Hemodynamic Behavior During Hemodialysis: Effects of Dialysate Concentrations of Bicarbonate and Potassium

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    Bruno C. Silva

    2014-11-01

    Full Text Available Background/Aims: Ultrafiltration that occurs during hemodialysis (HD promotes profound alterations in a relatively short period of time. The dialysate content of bicarbonate (DBic and potassium (DK may have impact over intradialytic hemodynamics, which goes beyond ultrafiltration, and its impact was evaluated in a prospective cohort. Methods: 30 patients under HD were submitted to hemodynamic assessment (HA at the beginning and at the end of HD sessions, through a non-invasive method. Serum minus dialysate potassium concentration was expressed as K-Gap. Cardiac index (CI and peripheral arterial resistance (PAR variation (post-HD minus pre-HD were expressed as ΔCI and ΔPAR. Dialysate content of sodium and calcium were expressed as DNa and DCa, respectively. Results: Mean DNa, DK and DBic were, respectively, 136.4 ± 1.1, 2.1 ± 0.6 and 38.2 ± 2.1 mEq/L. In 15 patients, DCa was >1.5 mmol/L and in the other 15 patients ≤ 1.5 mmol/L. The K-Gap ranged from 1.4 to 5.1 mEq/l (median 3.0 mEq/L. There was a reduction in post-HD CI and systolic blood pressure (ΔCI = -0.72l/min/m2 and -11.3±15.1mmHg, respectively, p5, pConclusion: We confirmed that Na and Ca dialysate content exerts and important role on hemodynamic during HD. In addition, our findings pointed out that higher dialysate concentrations of bicarbonate and potassium promote lower cardiac performance at the end of hemodialysis session.

  1. Bench-to-bedside review: An approach to hemodynamic monitoring--Guyton at the bedside.

    Science.gov (United States)

    Magder, Sheldon

    2012-10-29

    Hemodynamic monitoring is used to identify deviations from hemodynamic goals and to assess responses to therapy. To accomplish these goals one must understand how the circulation is regulated. In this review I begin with an historical review of the work of Arthur Guyton and his conceptual understanding of the circulation and then present an approach by which Guyton's concepts can be applied at the bedside. Guyton argued that cardiac output and central venous pressure are determined by the interaction of two functions: cardiac function, which is determined by cardiac performance; and a return function, which is determined by the return of blood to the heart. This means that changes in cardiac output are dependent upon changes of one of these two functions or of both. I start with an approach based on the approximation that blood pressure is determined by the product of cardiac output and systemic vascular resistance and that cardiac output is determined by cardiac function and venous return. A fall in blood pressure with no change in or a rise in cardiac output indicates that a decrease in vascular resistance is the dominant factor. If the fall in blood pressure is due to a fall in cardiac output then the role of a change in the return function and cardiac function can be separated by the patterns of changes in central venous pressure and cardiac output. Measurement of cardiac output is a central component to this approach but until recently it was not easy to obtain and was estimated from surrogates. However, there are now a number of non-invasive devices that can give measures of cardiac output and permit the use of physiological principles to more rapidly appreciate the primary pathophysiology behind hemodynamic abnormalities and to provide directed therapy.

  2. Bench-to-bedside review: An approach to hemodynamic monitoring - Guyton at the bedside

    Science.gov (United States)

    2012-01-01

    Hemodynamic monitoring is used to identify deviations from hemodynamic goals and to assess responses to therapy. To accomplish these goals one must understand how the circulation is regulated. In this review I begin with an historical review of the work of Arthur Guyton and his conceptual understanding of the circulation and then present an approach by which Guyton's concepts can be applied at the bedside. Guyton argued that cardiac output and central venous pressure are determined by the interaction of two functions: cardiac function, which is determined by cardiac performance; and a return function, which is determined by the return of blood to the heart. This means that changes in cardiac output are dependent upon changes of one of these two functions or of both. I start with an approach based on the approximation that blood pressure is determined by the product of cardiac output and systemic vascular resistance and that cardiac output is determined by cardiac function and venous return. A fall in blood pressure with no change in or a rise in cardiac output indicates that a decrease in vascular resistance is the dominant factor. If the fall in blood pressure is due to a fall in cardiac output then the role of a change in the return function and cardiac function can be separated by the patterns of changes in central venous pressure and cardiac output. Measurement of cardiac output is a central component to this approach but until recently it was not easy to obtain and was estimated from surrogates. However, there are now a number of non-invasive devices that can give measures of cardiac output and permit the use of physiological principles to more rapidly appreciate the primary pathophysiology behind hemodynamic abnormalities and to provide directed therapy. PMID:23106914

  3. Shape-memory alloy overload protection device for osseointegrated transfemoral implant prosthetic limb attachment system

    Science.gov (United States)

    Xu, Wei; Shao, Fei; Hughes, Steven

    2002-11-01

    The osseointegrated trans-femoral implant system provides a direct anchoring technique to attach prosthetic limb. This technique was first introduced PI Brenmark in Sweden. The UK had the first clinical trial in 1997 and currently has 6 active limb wearers. The success of this procedure has the potential for improved gait function and mobility, increased employability and significant long-term improvements in the quality of life for above knee amputees. However, the significant load involved in the trans-femoral implant system has caused permanent deformation and/or fractures of the implant abutment in several occasions. To protect the implant system, the implant abutment in particularly, an overloading protection device was introduced. The device uses mechanical mechanism to release torsion overload on the abutment. However, the bending overload protection remains unsolved. To solve the problem, a new overload protection device was developed. This device uses SMA component for bending overload protection. In this paper, the results of non-linear finite element modelling of the SMA and steel (AISI 1040) components were presented. Experiments were also carried out using steel components to assess the design which is based on the non-linear property of the materials.

  4. Update on the use of deferasirox in the management of iron overload

    Directory of Open Access Journals (Sweden)

    Ali Taher

    2009-10-01

    Full Text Available Ali Taher,1 Maria Domenica Cappellini21American University of Beirut, Beirut, Lebanon; 2Universitá di Milano, Policlinico Foundation IRCCS, Milan, ItalyAbstract: Regular blood transfusions as supportive care for patients with chronic anemia inevitably lead to iron overload as humans cannot actively remove excess iron. The cumulative effects of iron overload cause significant morbidity and mortality if not effectively treated with chelation therapy. Based on a comprehensive clinical development program, the once-daily, oral iron chelator deferasirox (Exjade® is approved for the treatment of transfusional iron overload in adult and pediatric patients with various transfusion-dependent anemias, including β-thalassemia and the myelodysplastic syndromes. Deferasirox dose should be titrated for each individual patient based on transfusional iron intake, current iron burden and whether the goal is to decrease or maintain body iron levels. Doses of >30 mg/kg/day have been shown to be effective with a safety profile consistent with that observed at doses <30 mg/kg/day. Recent data have highlighted the ability of deferasirox to decrease cardiac iron levels and to prevent the accumulation of iron in the heart. The long-term efficacy and safety of deferasirox for up to 5 years of treatment have now been established. The availability of this effective and generally well tolerated oral therapy represents a significant advance in the management of transfusional iron overload. Keywords: deferasirox, Exjade, oral, iron chelation, iron overload, cardiac iron 

  5. Oral exfoliative cytology as a screening tool for iron overload in β-thalassemia patients.

    Science.gov (United States)

    Rathore, Ajit Singh; Keshri, Neha; Shetty, Devi Charan; Juneja, Saurabh

    2016-01-01

    Increased iron overload is frequent problem in thalassemia patients, and this is monitored by serum ferritin levels or chemical assessment of the iron levels in liver tissue. However, repeated monitoring of serum ferritin levels to assess the iron overload is an invasive procedure associated with practical problems. To use Perl's Prussian blue reaction to evaluate the iron overload in beta-thalassemia patients by staining the oral cytosmears. The study comprised 35 patients diagnosed with beta-thalassemia. Cytosmears were prepared from exfoliated oral epithelial cells, fixed in 70% ethanol and stained with Perl's Prussian blue stain for detection of blue colored granules in the cytoplasm. 29/35 (82.9%) cases showed a positive reaction for Perl's Prussian blue reaction while 6/35 (17%) cases did not show the presence of blue colored granules in the oral cytosmears. The presence of iron detected by Perl's Prussian blue reaction correlated with serum ferritin level (P < 0.05). Perl's Prussian blue reaction can be used to evaluate the iron overload in beta-thalassemia patients by staining the oral cytosmears. It is a simple and noninvasive method for assessment of iron overload in such patients.

  6. Iron overload detection in rats by means of a susceptometer operating at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, M; Gianesin, B [Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Avignolo, C; Parodi, S [Department of Oncology, Biology and Genetics, Largo R Benzi 10, 16132 (Italy); Minganti, V [Department of Chemistry and Pharmaceutical and Alimentary Technology, Via Brigata Salerno 13, 16147 Genoa (Italy)

    2008-12-07

    Biosusceptometry is a non-invasive procedure for determination of iron overload in a human body; it is essentially an assessment of the diamagnetic (water) and paramagnetic (iron) properties of tissues. We measured in vivo iron overload in the liver region of 12 rats by a room temperature susceptometer. The rats had been injected with sub-toxic doses of iron dextran. A quantitative relationship has been observed between the measurements and the number of treatments. The assessment of iron overload requires evaluating the magnetic signal corresponding to the same rat ideally without the overload. This background value was extrapolated on the basis of the signal measured in control rats versus body weight (R{sup 2} = 0.73). The mean iron overload values for the treated rats, obtained after each iron injection, were significantly different from the means of the corresponding control rats (p < 0.01). The in vivo measurements have been complemented by chemical analysis on excised livers and other organs (R{sup 2} = 0.89). The magnetic moment of iron atoms in liver tissues was measured to be 3.6 Bohr magneton. Evaluation of the background signal is the limit to the measure; the error corresponds to about 30 mg (1 SD) of iron while the instrument sensitivity is more than a factor of 10 better.

  7. Danshen (Salvia miltiorrhiza injection suppresses kidney injury induced by iron overload in mice.

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    Shengjiang Guan

    Full Text Available OBJECTIVES: Excessive iron can accumulate in the kidney and induce tissue damage. Danshen (Salvia miltiorrhiza injection is a traditional Chinese medicinal preparation used for preventing and treating chronic renal failure. The aim of the present study was to evaluate the effects of treatment with Danshen injection on iron overload-induced kidney damage. METHODS: Mice were mock-treated with saline (control group or given a single dose of iron dextran without treatment (iron overload group, 50 mg/kg/day for 2 weeks or with daily treatments of low-dose Danshen (3 g/kg/day, high-dose Danshen (6 g/kg/day or deferoxamine (100 mg/kg/day. RESULTS: Treatment of iron-overloaded mice with Danshen injection led to significant improvements of body weight and decreased iron levels in the kidney. Danshen injection treatment also reduced concentrations of blood urea nitrogen, creatinine and malondialdehyde and enhanced glutathione peroxidase and superoxide dismutase activities. Histopathological examinations showed that Danshen injection ameliorated pathological changes and reduced iron deposition in kidneys of iron overloaded mice. Furthermore, the treatment was demonstrated to suppress apoptosis in nephrocytes. CONCLUSIONS: These results indicated that Danshen injection exerted significant renal protective effects in iron-overloaded mice, which were closely associated with the decrease of iron deposition and suppression of lipid peroxidation and apoptosis in the kidney.

  8. Learners' perceived information overload in online learning via computer-mediated communication

    Directory of Open Access Journals (Sweden)

    Karen L. Murphy

    2011-12-01

    Full Text Available Many studies report information overload as one of the main problems that students encounter in online learning via computer-mediated communication. This study aimed to explore the sources of online students' information overload and offer suggestions for increasing students' cognitive resources for learning. Participants were 12 graduate students from two online courses in the United States. Their learning experiences in both online discussions and on the course website were explored through semi-structured interviews. They also completed a background questionnaire that assessed three constructs that limit learner readiness and are likely to lead to online students' perceived information overload: inadequate prior knowledge, inadequate English proficiency, and lack of technical skills for participating in computer-mediated communications. The findings suggest that varied learner characteristics led some students to be more susceptible than others to information overload. Emerging data-driven risk factors were: lack of efficiency in reading from computer screens, visual and auditory learning preferences, and time constraints. Difficulties associated with students' perceptions of information overload are addressed and implications for course design are offered.

  9. Resilience of electricity grids against transmission line overloads under wind power injection at different nodes.

    Science.gov (United States)

    Schiel, Christoph; Lind, Pedro G; Maass, Philipp

    2017-09-14

    A steadily increasing fraction of renewable energy sources for electricity production requires a better understanding of how stochastic power generation affects the stability of electricity grids. Here, we assess the resilience of an IEEE test grid against single transmission line overloads under wind power injection based on the dc power flow equations and a quasi-static grid response to wind fluctuations. Thereby we focus on the mutual influence of wind power generation at different nodes. We find that overload probabilities vary strongly between different pairs of nodes and become highly affected by spatial correlations of wind fluctuations. An unexpected behaviour is uncovered: for a large number of node pairs, increasing wind power injection at one node can increase the power threshold at the other node with respect to line overloads in the grid. We find that this seemingly paradoxical behaviour is related to the topological distance of the overloaded line from the shortest path connecting the wind nodes. In the considered test grid, it occurs for all node pairs, where the overloaded line belongs to the shortest path.

  10. Regulation of brain copper homeostasis by the brain barrier systems: Effects of Fe-overload and Fe-deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Monnot, Andrew D.; Behl, Mamta; Ho, Sanna; Zheng, Wei, E-mail: wzheng@purdue.edu

    2011-11-15

    Maintaining brain Cu homeostasis is vital for normal brain function. The role of systemic Fe deficiency (FeD) or overload (FeO) due to metabolic diseases or environmental insults in Cu homeostasis in the cerebrospinal fluid (CSF) and brain tissues remains unknown. This study was designed to investigate how blood-brain barrier (BBB) and blood-SCF barrier (BCB) regulated Cu transport and how FeO or FeD altered brain Cu homeostasis. Rats received an Fe-enriched or Fe-depleted diet for 4 weeks. FeD and FeO treatment resulted in a significant increase (+ 55%) and decrease (- 56%) in CSF Cu levels (p < 0.05), respectively; however, neither treatment had any effect on CSF Fe levels. The FeD, but not FeO, led to significant increases in Cu levels in brain parenchyma and the choroid plexus. In situ brain perfusion studies demonstrated that the rate of Cu transport into the brain parenchyma was significantly faster in FeD rats (+ 92%) and significantly slower (- 53%) in FeO rats than in controls. In vitro two chamber Transwell transepithelial transport studies using primary choroidal epithelial cells revealed a predominant efflux of Cu from the CSF to blood compartment by the BCB. Further ventriculo-cisternal perfusion studies showed that Cu clearance by the choroid plexus in FeD animals was significantly greater than control (p < 0.05). Taken together, our results demonstrate that both the BBB and BCB contribute to maintain a stable Cu homeostasis in the brain and CSF. Cu appears to enter the brain primarily via the BBB and is subsequently removed from the CSF by the BCB. FeD has a more profound effect on brain Cu levels than FeO. FeD increases Cu transport at the brain barriers and prompts Cu overload in the CNS. The BCB plays a key role in removing the excess Cu from the CSF.

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

    Science.gov (United States)

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

    2015-08-01

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

  12. A Review of Central Venous Pressure and Its Reliability as a Hemodynamic Monitoring Tool in Veterinary Medicine.

    Science.gov (United States)

    Hutchinson, Kristen M; Shaw, Scott P

    2016-09-01

    To review the current literature regarding central venous pressure (CVP) in veterinary patients pertaining to placement (of central line), measurement, interpretation, use in veterinary medicine, limitations, and controversies in human medicine. CVP use in human medicine is a widely debated topic, as numerous sources have shown poor correlation of CVP measurements to the volume status of a patient. Owing to the ease of placement and monitoring in veterinary medicine, CVP remains a widely used modality for evaluating the hemodynamic status of a patient. A thorough evaluation of the veterinary and human literature should be performed to evaluate the role of CVP measurements in assessing volume status in veterinary patients. Veterinary patients that benefit from accurate CVP readings include those suffering from hypovolemic or septic shock, heart disease, or renal disease or all of these. Other patients that may benefit from CVP monitoring include high-risk anesthetic patients undergoing major surgery, trending of fluid volume status in critically ill patients, patients with continued shock, and patients that require rapid or large amounts of fluids. The goal of CVP use is to better understand a patient's intravascular volume status, which would allow early goal-directed therapy. CVP would most likely continue to play an important role in the hemodynamic monitoring of the critically ill veterinary patient; however, when available, cardiac output methods should be considered the first choice for hemodynamic monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The hemodynamic effects of diltiazem in the isolated perfused rat liver are Ca(2+)-dependent.

    Science.gov (United States)

    Bracht, A; Schmeisch, A P; Constantin, J; Sampaio, E; Pagadigorria, C S; D'Avila, R B

    1999-04-01

    Diltiazem reduces systemic blood pressure by decreasing the vascular smooth muscle tone. In the liver however, diltiazem seems to cause vasoconstriction, as evidenced by increases in portal pressure. The questions raised by this observation are concerned with a) the site of action of diltiazem (large vessels or sinusoids), b) the formation of permeability barriers and c) the role of Ca2+. The experiments in the present study should provide an answer to these questions. The experimental system was the hemoglobin-free perfused rat liver. The multiple-indicator dilution technique was employed with simultaneous injection of [14C]sucrose and [3H]water. Mean transit times and distribution spaces were calculated from the normalized outflow profiles. Calcium alone did not affect the hemodynamics of the liver. Diltiazem, however, changed several hemodynamic parameters when Ca2+ was present, but it was inactive in the absence of this cation. The hemodynamic effects of 500 microM diltiazem were: a) diminution of the transit time through the large vessels (t(o)) and, consequently, of the accessible vascular space (66.9%); b) diminution of the mean transit time of [14C]sucrose (tsuc) and, consequently, of the accessible sinusoidal space (28.1%); c) diminution of the mean transit time of tritiated water (twater) and, consequently, of the accessible cellular space (68.9%); d) diminution of the cellular to extracellular space ratio (theta) from 1.42 +/- 0.05 to 0.46 +/- 0.11. The linear superposition of the tritiated water and labeled sucrose curves, predicted by Goresky's model, could be optimized even when the curves were obtained with diltiazem + Ca2+, indicating that the distribution of both tracers was still flow-limited. The hemodynamic effects of diltiazem seem to be restricted to a vasoconstriction of the great vessels, an action which was strictly dependent on Ca2+. At the concentration of 500 microM, the effects of diltiazem were pronounced to the point of excluding

  14. Baricity of Bupivacaine on Maternal Hemodynamics after Spinal Anesthesia for Cesarean Section: A Randomized Controlled Trial

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    Simin Atashkhoei

    2017-03-01

    Full Text Available Background: After spinal anesthesia, patients undergoing cesarean section are more likely to develop hemodynamic changes. The baricity of local anesthetic has an important role on spinal blockade effects. The aim of this study was to compare the isobar and hyperbaric bupivacaine 0.5% plus fentanyl on maternal hemodynamics after spinal anesthesia for C/S. Methods: In this double-blind study, 84 healthy pregnant women undergoing C/S using bupivacaine 0.5% isobar (study group, n=42 or hyperbaric (control group, n=42 for spinal anesthesia were scheduled. The study was conducted from 21 April 2014 to 21 November 2014 at Al-Zahra Hospital, Tabriz, Iran. Parameters such as maternal hemodynamics, block characteristics, side effects, and neonatal Apgar scores were recorded. Data were analyzed using the SPSS software by performing chi-square test, Fisher’s exact test, one-way ANOVA, Mann-Whitney U-test, and student’s t test. Results: The incidence of hypotension in the isobar group was lower than the hyperbaric group, although it was not statistically significant (40.47% vs. 61.9%, P=0.08. The duration of hypotension was shorter in the study group (1.6±7.8 min vs. 7.4±12.5 min, P=0.004. The dose of ephedrine was lower in the study group (2.4±6.6 mg vs. 5.3±10.7 mg, P=0.006. The main maternal side effect is sustained hypotension that was seen in 0 patients of the isobar and 7 (16.66% of hyperbaric groups (P=0.006. None of the neonates had Apgar score≤7 at 5 min of delivery (P=1.0. Sensory and motor block duration was shorter in the study group (P=0.01. Conclusion: Isobaric bupivacaine is associated with more hemodynamic stability and shorter sensory and motor blockade in mothers under spinal anesthesia for C/S. Trial Registration Number: IRCT201401287013N7

  15. Hepatoprotective Potential of Caesalpinia crista against Iron-Overload-Induced Liver Toxicity in Mice

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    Rhitajit Sarkar

    2012-01-01

    Full Text Available The present study was carried out to evaluate the ameliorating effect of Caesalpinia crista Linn. (CCME extract on iron-overload-induced liver injury. Iron overload was induced by intraperitoneal administration of iron dextran into mice. CCME attenuated the percentage increase in liver iron and serum ferritin levels when compared to control group. CCME also showed a dose-dependent inhibition of lipid peroxidation, protein oxidation, and liver fibrosis. The serum enzyme markers were found to be less, whereas enhanced levels of liver antioxidant enzymes were detected in CCME-treated group. In presence of CCME, the reductive release of ferritin iron was increased significantly. Furthermore, CCME exhibited DPPH radical scavenging and protection against Fe2+-mediated oxidative DNA damage. The current study confirmed the hepatoprotective effect of CCME against the model hepatotoxicant iron overload and the activity is likely related to its potent antioxidant and iron-chelating property.

  16. Information Diffusion in Facebook-Like Social Networks Under Information Overload

    Science.gov (United States)

    Li, Pei; Xing, Kai; Wang, Dapeng; Zhang, Xin; Wang, Hui

    2013-07-01

    Research on social networks has received remarkable attention, since many people use social networks to broadcast information and stay connected with their friends. However, due to the information overload in social networks, it becomes increasingly difficult for users to find useful information. This paper takes Facebook-like social networks into account, and models the process of information diffusion under information overload. The term view scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated is proposed to characterize the information diffusion efficiency. Through theoretical analysis, we find that factors such as network structure and view scope number have no impact on the information diffusion efficiency, which is a surprising result. To verify the results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly.

  17. Psychological distance can improve decision making under information overload via gist memory.

    Science.gov (United States)

    Fukukura, Jun; Ferguson, Melissa J; Fujita, Kentaro

    2013-08-01

    Making a decision can be especially difficult when it is based upon a large amount of information. A number of demonstrations in the literature suggest that decision making under information overload leads to suboptimal outcomes. In this article, we draw on construal level theory (Trope & Liberman, 2003) and fuzzy-trace theory (Brainerd & Reyna, 1993) to suggest that psychologically distancing oneself from the information can be beneficial to decision making under information overload. Specifically, we propose that distancing prompts organization of information in terms of its gist. Across 4 studies, we demonstrated that increasing spatial distance, temporal distance, and abstraction lead to better decision outcomes when decision makers were overloaded with many pieces of information per decision. Furthermore, we showed that the relationship between psychological distance and decision outcome is mediated by gist memory. PsycINFO Database Record (c) 2013 APA, all rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1973-04-15

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

  19. Assessment of Iron Overload in Homozygous and Heterozygous Beta Thalassemic Children below 5 Years of Age

    Directory of Open Access Journals (Sweden)

    Dhiraj J. Trivedi

    2014-07-01

    Full Text Available Background: Thalassemia is a genetic disease having 3-7% carrier rate in Indians. It is transfusion dependent anemia having high risk of iron overloading. A clinical symptom of iron overload becomes detectable in second decade causing progressive liver, heart and endocrine glands damage. There is a need to assess iron overload in thalassemics below 5 years of age to protect them from complications at later age of life. Aims and objectives: Present study was undertaken to estimate serum iron status and evaluate serum transferrin saturation in both homozygous & heterozygous form of thalassemia as an index of iron overload among children of one to five years of age. Materials and Methods: Clinically diagnosed thirty cases of β thalassemia major & thirty cases of β thalassemia minor having severe anemia, hepatospleenomegaly and between 1 year to 5 years of age were included in study group and same age matched healthy controls were included in the study. RBC indices and HbA, HbA2 and HbF were estimated along with serum iron & serum Total Iron Binding Capacity (TIBC and serum transferrin levels. Results: Significant difference was observed in hemoglobin levels between control and both beta thalassemia groups. Mean Corpuscular Volume (MCV and Mean Corpuscular Hemoglobin (MCH values were reduced. Hemoglobin electrophoresis showed the elevated levels of HbF and HbA2 in both beta thalassemia groups. Among serum iron parameters, serum iron, TIBC and transferrin saturation were elevated whereas serum transferrin levels were low in thalassemia major in children below 5 years of age. Conclusion: Although clinical symptoms of iron overload have been absent in thalassemic children below five years of age, biochemical iron overloading has started at much lower age which is of great concern.

  20. Worse cardiac remodeling in response to pressure overload in type 2 diabetes mellitus.

    Science.gov (United States)

    Gonçalves, N; Gomes-Ferreira, C; Moura, C; Roncon-Albuquerque, R; Leite-Moreira, A F; Falcão-Pires, I

    2016-08-15

    Diabetic cardiomyopathy is characterized by cardiac structural and functional abnormalities. Additionally, chronic pressure overload conditions are highly prevalent amongst diabetic population and this association leads to a more severe myocardial impairment. The differences in myocardial pathophysiology between type 1 and type 2 diabetes mellitus (DM) still remain to be clarified. Thus, we aimed to investigate biventricular structural and functional changes promoted by the two types of DM and the impact of concomitant chronic pressure overload. Wistar rats were injected with streptozotocin (Type 1 DM, T1DM) or fed with a hypercaloric diet (Type 2 DM, T2DM). Pressure overload was imposed in DM animals by aortic constriction and after 5weeks of DM the cardiac function and structure were evaluated. Both types of DM promoted hypertrophy, increased fibrosis and advanced glycation end-products deposition, in the two ventricles. Interestingly, the induced myocardial alterations were distinct. While T1DM stimulated a pronounced hypertrophy and extracellular matrix remodeling, T2DM induced functional impairment. The negative impact of the association of DM with aortic constriction was more pronounced in T2DM, promoting impaired function and increased stiffness, particularly in the right ventricle. Our study demonstrated that the two types of diabetes induce distinct cardiac alterations per se or when combined with chronic pressure overload. T1DM promoted a more extensive remodeling in cardiac structure while T2DM significantly impaired ventricular function. The impact of pressure overload was more notorious in T2DM as observed by worse myocardial remodeling, suggesting a higher susceptibility to the deleterious effects of chronic pressure overload, namely hypertension, among this diabetic population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Antagonism of cysteinyl leukot-riene receptor 1 (cysLT1R) by montelukast regulates differentiation of MC3T3-E1 cells under overloaded mechanical environment.

    Science.gov (United States)

    Wei, Jinsong; Chen, Siyuan; Huang, Chengshuo; Guo, Weixiong; Yang, Shukai; Feng, Bailin; Chu, Jiaqi

    2017-10-11

    Long-term exposure to overloaded mechanical environment induces bone fatigue damage symptoms and osteoblast damages. Montelukast is a selective cysteinyl leukot-riene receptor 1 (cysLT1R) antagonist, which has been used for the treatment of bronchial asthma in clinics. In the current study, we have identified a novel pharmacological role of montelukast by finding that it has protective properties against overload damage in osteoblastic MC3T3-E1 cells. Firstly, our results show that CysLT1R is expressed in MC3T3-E1 cells. Mechanical tensile strain of 5000-7000 με resulted in a significant upregulation of CysLT1R in osteoblastic MC3T3-E1 cells in an intensity dependent manner. Secondly, MTT assay indicates that loading with 5000 με mechanical strain inhibited cell proliferation, which was suppressed by montelukast treatment. Furthermore, montelukast promotes cell differentiation by increasing the expression of ALP and RUNX2. Alizarin Red S staining assay showed that montelukast abolished the inhibitory effects of overload mechanics on osteoblast mineralization. Mechanistically, the effect of montelukast on osteoblastic differentiation acted by activating the extracellular regulated protein kinases (ERK) pathway. The obtained results suggested that montelukast promotes proliferation and differentiation in osteoblasts exposed to overload mechanics. Copyright © 2017. Published by Elsevier Inc.

  2. Implementing Filters to Identify and Prioritize Industrial Base Risk: Rules of Thumb to Reduce Cognitive Overload

    Science.gov (United States)

    2015-04-30

    Thumb to Reduce Cognitive Overload Sally Sleeper, ODASD[M&IBP] John F. Starns, Northrop Grumman Published April 30, 2015 Disclaimer: The views...Prioritize Industrial Base Risk: Rules of Thumb to Reduce Cognitive Overload 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...ãW= `êÉ~íáåÖ=póåÉêÖó=Ñçê=fåÑçêãÉÇ=`Ü~åÖÉ= - 337 - Implementing Filters to Identify and Prioritize Industrial Base Risk: Rules of Thumb to Reduce

  3. Controlling Price-Responsive Heat Pumps for Overload Elimination in Distribution Systems

    DEFF Research Database (Denmark)

    Csetvei, Zsuzsa; Østergaard, Jacob; Nyeng, Preben

    2011-01-01

    This paper investigates the possibility of applying electric heat pumps with the control-by-price-concept in order to avoid overload in a local distribution system. The proposed control algorithm is based upon a centrally dispatched real-time market price, reflecting the state of a larger power...... system, and is extended with a local price control for overload elimination on the corresponding feeder. The paper presents the mathematical models of a two-node system with price-responsive heat pumps, the chosen methodology of the central price calculation, and the proposed local feedback control...

  4. Iron Overload Leading to Torsades de Pointes in β-Thalassemia and Long QT Syndrome

    DEFF Research Database (Denmark)

    Refaat, Marwan M; El Hage, Lea; Steffensen, Annette Buur

    2016-01-01

    The authors present a unique case of torsades de pointes in a β-thalassemia patient with early iron overload in the absence of any structural abnormalities as seen in hemochromatosis. Genetic testing showed a novel KCNQ1 gene mutation 1591C>T [Gln531Ter(X)]. Testing of the gene mutation in Xenopus...... laevis oocytes showed loss of function of the IKs current. The authors hypothesize that iron overload combined with the KCNQ1 gene mutation leads to prolongation of QTc and torsades de pointes....

  5. Dasatinib Attenuates Pressure Overload Induced Cardiac Fibrosis in a Murine Transverse Aortic Constriction Model.

    Directory of Open Access Journals (Sweden)

    Sundaravadivel Balasubramanian

    Full Text Available Reactive cardiac fibrosis resulting from chronic pressure overload (PO compromises ventricular function and contributes to congestive heart failure. We explored whether nonreceptor tyrosine kinases (NTKs play a key role in fibrosis by activating cardiac fibroblasts (CFb, and could potentially serve as a target to reduce PO-induced cardiac fibrosis. Our studies were carried out in PO mouse myocardium induced by transverse aortic constriction (TAC. Administration of a tyrosine kinase inhibitor, dasatinib, via an intraperitoneally implanted mini-osmotic pump at 0.44 mg/kg/day reduced PO-induced accumulation of extracellular matrix (ECM proteins and improved left ventricular geometry and function. Furthermore, dasatinib treatment inhibited NTK activation (primarily Pyk2 and Fak and reduced the level of FSP1 positive cells in the PO myocardium. In vitro studies using cultured mouse CFb showed that dasatinib treatment at 50 nM reduced: (i extracellular accumulation of both collagen and fibronectin, (ii both basal and PDGF-stimulated activation of Pyk2, (iii nuclear accumulation of Ki67, SKP2 and histone-H2B and (iv PDGF-stimulated CFb proliferation and migration. However, dasatinib did not affect cardiomyocyte morphologies in either the ventricular tissue after in vivo administration or in isolated cells after in vitro treatment. Mass spectrometric quantification of dasatinib in cultured cells indicated that the uptake of dasatinib by CFb was greater that that taken up by cardiomyocytes. Dasatinib treatment primarily suppressed PDGF but not insulin-stimulated signaling (Erk versus Akt activation in both CFb and cardiomyocytes. These data indicate that dasatinib treatment at lower doses than that used in chemotherapy has the capacity to reduce hypertrophy-associated fibrosis and improve ventricular function.

  6. Efferent pathways in sodium overload-induced renal vasodilation in rats.

    Directory of Open Access Journals (Sweden)

    Nathalia O Amaral

    Full Text Available Hypernatremia stimulates the secretion of oxytocin (OT, but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g were anesthetized with sodium thiopental (40 mg. kg(-1, i.v.. A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP and renal blood flow (RBF. Renal vascular conductance (RVC was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6, OT infusion (0.03 µg • kg(-1, i.v. induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg(-1 b.wt., i.v. was infused over 60 s. In sham rats (n = 6, hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg(-1 • h(-1, i.v.; n = 7 and renal denervation (RX reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7 completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively, whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia.

  7. C-C Motif Chemokine Receptor 9 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy and Dysfunction.

    Science.gov (United States)

    Xu, Zhengxi; Mei, Fanghua; Liu, Hanning; Sun, Cheng; Zheng, Zhe

    2016-05-04

    Maladaptive cardiac hypertrophy is a major risk factor for heart failure, which is the leading cause of death worldwide. C-C motif chemokine receptor 9 (CCR9), a subfamily of the G protein-coupled receptor supergene family, has been highlighted as an immunologic regulator in the development and homing of immune cells and in immune-related diseases. Recently, CCR9 was found to be involved in the pathogenesis of other diseases such as cardiovascular diseases; however, the effects that CCR9 exerts in cardiac hypertrophy remain elusive. We observed significantly increased CCR9 protein levels in failing human hearts and in a mouse or cardiomyocyte hypertrophy model. In loss- and gain-of-function experiments, we found that pressure overload-induced hypertrophy was greatly attenuated by CCR9 deficiency in cardiac-specific CCR9 knockout mice, whereas CCR9 overexpression in cardiac-specific transgenic mice strikingly enhanced cardiac hypertrophy. The prohypertrophic effects of CCR9 were also tested in vitro, and a similar phenomenon was observed. Consequently, we identified a causal role for CCR9 in pathological cardiac hypertrophy. Mechanistically, we revealed a lack of difference in the expression levels of mitogen-activated protein kinases between groups, whereas the phosphorylation of AKT/protein kinase B and downstream effectors significantly decreased in CCR9 knockout mice and increased in CCR9 transgenic mice after aortic binding surgery. The prohypertrophic effects of CCR9 were not attributable to the mitogen-activated protein kinase signaling pathway but rather to the AKT-mammalian target of rapamycin-glycogen synthase kinase 3β signaling cascade. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  8. Targeted disruption of the hepatic transferrin receptor 2 gene in mice leads to iron overload.

    Science.gov (United States)

    Wallace, Daniel F; Summerville, Lesa; Subramaniam, V Nathan

    2007-01-01

    Transferrin receptor 2 (TfR2) plays a key role in the regulation of iron metabolism. Mutations of TfR2 in humans cause type 3 hereditary hemochromatosis. Although highly expressed in liver, several studies have reported TfR2 expression in other tissues. To determine the contribution of liver expressed TfR2 in iron homeostasis, we have generated and characterized a liver-specific TfR2-knockout (KO) mouse. Liver-specific TfR2-KO mice were generated by crossing TfR2-floxed mice with transgenic albumin-Cre mice. Tissue and serum from homozygous TfR2-floxed mice with and without albumin-Cre were analyzed. Serum transferrin saturation, hepatic, and splenic iron concentrations were determined. The expression of iron-related mRNA transcripts was analyzed by real-time PCR. Levels of the iron-related proteins TfR1, TfR2, ferritin, and prohepcidin were analyzed by immunoblotting. Liver-specific TfR2-KO mice develop significant iron overload comparable to complete TfR2-KO mice. At all ages studied, transferrin saturation, hepatic iron concentration, and hepatic ferritin were significantly elevated. Hepatic TfR2 mRNA and protein were absent in the livers of liver-specific TfR2-KO mice, and TfR1 expression was reduced consistent with liver iron loading. At 5 weeks of age, hepcidin1 mRNA, and prohepcidin protein were decreased in liver-specific TfR2-KO compared to control mice. The significant iron loading and modulation of expression of iron-related genes in liver-specific TfR2-KO mice demonstrates that the liver is the primary site for TfR2 expression and activity and that liver-expressed TfR2 is required for the regulation of hepcidin1.

  9. Efferent pathways in sodium overload-induced renal vasodilation in rats.

    Science.gov (United States)

    Amaral, Nathalia O; de Oliveira, Thiago S; Naves, Lara M; Filgueira, Fernando P; Ferreira-Neto, Marcos L; Schoorlemmer, Gerard H M; de Castro, Carlos H; Freiria-Oliveira, André H; Xavier, Carlos H; Colugnati, Diego B; Rosa, Daniel A; Blanch, Graziela T; Borges, Clayton L; Soares, Célia M A; Reis, Angela A S; Cravo, Sergio L; Pedrino, Gustavo R

    2014-01-01

    Hypernatremia stimulates the secretion of oxytocin (OT), but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g) were anesthetized with sodium thiopental (40 mg. kg(-1), i.v.). A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP) and renal blood flow (RBF). Renal vascular conductance (RVC) was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6), OT infusion (0.03 µg • kg(-1), i.v.) induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR) reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg(-1) b.wt., i.v.) was infused over 60 s. In sham rats (n = 6), hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg(-1) • h(-1), i.v.; n = 7) and renal denervation (RX) reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7) completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively), whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia.

  10. Echocardiographic Monitoring of Intracardiac Hemodynamics in Neonatal Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa

    2010-01-01

    Full Text Available Objective: to perform an early neonatal ultrasound study of intracardiac hemodynamics in premature neonates with respiratory distress syndrome (RDS during mechanical ventilation. Subjects and methods. The paper presents the results of ultrasound study of intracardiac hemodynamics in 51 premature neonates. Two patient groups were identified. Group 1 comprised 34 infants with severe RDS who received the exogenous surfactant Curosurf and Group 2 consisted of 17 apparently healthy premature newborn infants. Results. Functional tension of the cardiovascular system was characterized for premature neonates with RDS. There were signs of left ventricular systolic dysfunction within the first 24 hours of life and those of right ventricular dysfunction by day 5 of postnatal age. Within 5 days of life, there were echocardiographic signs of pump dysfunction of both ventricles: stroke volume, cardiac index, and blood minute volume. Analysis of changes in peak blood flow velocity and peak pressure gradient across the atrioventricular valves of the right and left ventricles indicated that 17.6% of the children showed increases in peak blood flow velocity and tricuspid valve pressure gradient in the systolic phase. The greatest peak blood flow velocity changes were recorded in the pulmonary artery trunk. By day 5 of life, signs of pulmonary hypertension concurrent with hydropericardium remained in 29.4% of cases. RDS – was shown to be accompanied by higher Qp/Qs ratio in premature neonates. The lower index was attended by the alleviated signs of respiratory failure. In RDS, mainly left-to-right blood shunt was accomplished through the open oval window, but the shunt intensity decreased when the pathological process was resolved in the lung. The functioning patent ductus arteriosus was hemodynami-cally significant in none case. Conclusion. The premature neonates with RDS were found to have intracardiac hemo-dynamic changes. By day 5 of postnatal age, there was

  11. Effect of inhibition of converting enzyme on renal hemodynamics and sodium management in polycystic kidney disease.

    Science.gov (United States)

    Torres, V E; Wilson, D M; Burnett, J C; Johnson, C M; Offord, K P

    1991-10-01

    We compared the tubular transport of sodium and the erythrocyte sodium-lithium countertransport activity in hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD) and in normotensive control subjects. In addition, we assessed the effects of inhibition of converting enzyme on renal hemodynamics and sodium excretion in hypertensive patients with ADPKD to provide information on mechanisms responsible for the increased renal vascular resistance and filtration fraction and the adjustment of the pressure-natriuresis relationship during saline expansion, observed in patients with ADPKD, hypertension, and preserved renal function. In comparison with normotensive control subjects, the hypertensive patients with ADPKD had lower renal plasma flows, higher renal vascular resistances and filtration fractions, and similar proximal and distal fractional reabsorptions of sodium. The administration of enalapril resulted in significant increases in the renal plasma flow and significant reductions in mean arterial pressure, renal vascular resistance, and filtration fraction, but the glomerular filtration rate remained unchanged. Despite the significant reduction in mean arterial pressure during inhibition of converting enzyme, the distal fractional reabsorption of sodium decreased while the total fractional excretion of sodium remained unchanged or increased slightly. No significant differences were detected between the normotensive control subjects and the hypertensive patients with ADPKD in erythrocyte sodium-lithium countertransport activity, plasma renin activity, plasma aldosterone concentration, or atrial natriuretic factor. These results suggest that the renal renin-angiotensin system plays a central role in the alterations in renal hemodynamics and sodium management associated with the development of hypertension in ADPKD.

  12. Hemodynamics, inflammation, vascular remodeling, and the development and rupture of intracranial aneurysms: a review

    Directory of Open Access Journals (Sweden)

    Francesco Signorelli

    2015-06-01

    Full Text Available The central nervous system is an immunologically active environment where several components of the immune and inflammatory response interact among them and with the constituents of nervous tissue and vasculature in a critically orchestrated manner, influencing physiologic and pathologic processes. In particular, inflammation takes a central role in the pathogenesis of intracranial aneurysms (IAs. The common pathway for aneurysm formation involves endothelial dysfunction and injury, a mounting inflammatory response, vascular smooth muscle cells (VSMCs phenotypic modulation, extracellular matrix remodeling, and subsequent cell death and vessel wall degeneration. We conducted a literature review (1980-2014 by Medline and EMBASE databases using the searching terms "IA" and "cerebral aneurysm" and further search was performed to link the search terms with the following key words: inflammation, hemodynamic(s, remodeling, macrophages, neutrophils, lymphocytes, complement, VSMCs, mast cells, cytokines, and inflammatory biomarkers. The aim of this review was to summarize the most recent and pertinent evidences regarding the articulated processes of aneurysms formation, growth, and rupture. Knowledge of these processes may guide the diagnosis and treatment of these vascular malformations, the most common cause of subarachnoid hemorrhage, which prognosis remains dismal.

  13. Acute dark chocolate ingestion is beneficial for hemodynamics via enhancement of erythrocyte deformability in healthy humans.

    Science.gov (United States)

    Radosinska, Jana; Horvathova, Martina; Frimmel, Karel; Muchova, Jana; Vidosovicova, Maria; Vazan, Rastislav; Bernatova, Iveta

    2017-03-01

    Erythrocyte deformability is an important property of erythrocytes that considerably affects blood flow and hemodynamics. The high content of polyphenols present in dark chocolate has been reported to play a protective role in functionality of erythrocytes. We hypothesized that chocolate might influence erythrocytes not only after repeated chronic intake, but also immediately after its ingestion. Thus, we determined the acute effect of dark chocolate and milk (with lower content of biologically active substances) chocolate intake on erythrocyte deformability. We also focused on selected factors that may affect erythrocyte deformability, specifically nitric oxide production in erythrocytes and total antioxidant capacity of plasma. We determined posttreatment changes in the mentioned parameters 2hours after consumption of chocolate compared with their levels before consumption of chocolate. In contrast to milk chocolate intake, the dark chocolate led to a significantly higher increase in erythrocyte deformability. Nitric oxide production in erythrocytes was not changed after dark chocolate intake, but significantly decreased after milk chocolate. The plasma total antioxidant capacity remained unaffected after ingestion of both chocolates. We conclude that our hypothesis was confirmed. Single ingestion of dark chocolate improved erythrocyte deformability despite unchanged nitric oxide production and antioxidant capacity of plasma. Increased deformability of erythrocytes may considerably improve rheological properties of blood and thus hemodynamics in humans, resulting in better tissue oxygenation. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The hemodynamic effects of methylene blue when administered at the onset of cardiopulmonary bypass.

    Science.gov (United States)

    Maslow, Andrew D; Stearns, Gary; Butala, Parag; Batula, Parag; Schwartz, Carl S; Gough, Jeffrey; Singh, Arun K

    2006-07-01

    Hypotension occurs during cardiopulmonary bypass (CPB), in part because of induction of the inflammatory response, for which nitric oxide and guanylate cyclase play a central role. In this study we examined the hemodynamic effects of methylene blue (MB), an inhibitor of guanylate cyclase, administered during cardiopulmonary bypass (CPB) to patients taking angiotensin-converting enzyme inhibitors. Thirty patients undergoing cardiac surgery were randomized to receive either MB (3 mg/kg) or saline (S) after institution of CPB and cardioplegic arrest. CPB was managed similarly for all study patients. Hemodynamic data were assessed before, during, and after CPB. The use of vasopressors was recorded. All study patients experienced a similar reduction in mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) with the onset of CPB and cardioplegic arrest. MB increased MAP and SVR and this effect lasted for 40 minutes. The saline group demonstrated a persistently reduced MAP and SVR throughout CPB. The saline group received phenylephrine more frequently during CPB, and more norepinephrine after CPB to maintain a desirable MAP. The MB group recorded significantly lower serum lactate levels despite equal or greater MAP and SVR. In conclusion, administration of MB after institution of CPB for patients taking angiotensin-converting enzyme inhibitors increased MAP and SVR and reduced the need for vasopressors. Furthermore, serum lactate levels were lower in MB patients, suggesting more favorable tissue perfusion.

  15. Hemodynamic properties and arterial structure in male rat offspring with fetal hypothyroidism.

    Science.gov (United States)

    Ghanbari, Mahboubeh; Bagheripuor, Fatemeh; Piryaei, Abbas; Zahediasl, Saleh; Noroozzadeh, Mahsa; Ghasemi, Asghar

    2016-10-01

    Thyroid hormones (THs) play a crucial role in the development of different systems during fetal life; fetal hypothyroidism (FH) is associated with reduced cardiac function and dimensions in neonates. The aim of this study is to determine whether TH deficiency during fetal life is associated with arterial structural and hemodynamic changes during adulthood. Hypothyroidism was induced by adding 0.025% 6-propyl-2-thiouracil in drinking water throughout pregnancy, while controls consumed only tap water. Hemodynamic parameters, cross-sectional area, intima-media thickness (IMT), and density of nuclei of smooth muscle cells and endothelial cells (ECs) in the aorta and mesenteric arteries were measured. Compared to controls, in the FH group, baseline systolic blood pressure (105.7 ± 3.1 vs. 87.9 ± 3.3 mm Hg, p < 0.01), diastolic blood pressure (64.4 ± 1.7 vs. 53.2 ± 2.1 mm Hg, p < 0.05), and mean arterial pressure (80.9 ± 2.1 vs. 67.1 ± 2.1 mm Hg, p < 0.01) were significantly lower. In addition, in the FH group, intensity and latency of response to phenylephrine were significantly lower and longer, respectively, as were the IMT and density of ECs in the aorta and superior mesenteric arteries. In conclusion, this study showed that TH deficiency during fetal life can have long-lasting functional and histological effects, which can compromise cardiovascular function during adulthood.

  16. CFD and PIV analysis of hemodynamics in a growing intracranial aneurysm.

    Science.gov (United States)

    Raschi, Marcelo; Mut, Fernando; Byrne, Greg; Putman, Christopher M; Tateshima, Satoshi; Viñuela, Fernando; Tanoue, Tetsuya; Tanishita, Kazuo; Cebral, Juan R

    2012-02-01

    Hemodynamics is thought to be a fundamental factor in the formation, progression, and rupture of cerebral aneurysms. Understanding these mechanisms is important to improve their rupture risk assessment and treatment. In this study, we analyze the blood flow field in a growing cerebral aneurysm using experimental particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques. Patient-specific models were constructed from longitudinal 3D computed tomography angiography images acquired at 1-y intervals. Physical silicone models were constructed from the computed tomography angiography images using rapid prototyping techniques, and pulsatile flow fields were measured with PIV. Corresponding CFD models were created and run under matching flow conditions. Both flow fields were aligned, interpolated, and compared qualitatively by inspection and quantitatively by defining similarity measures between the PIV and CFD vector fields. Results showed that both flow fields were in good agreement. Specifically, both techniques provided consistent representations of the main intra-aneurysmal flow structures and their change during the geometric evolution of the aneurysm. Despite differences observed mainly in the near wall region, and the inherent limitations of each technique, the information derived is consistent and can be used to study the role of hemodynamics in the natural history of intracranial aneurysms.

  17. Loss of TRADD attenuates pressure overload-induced cardiac hypertrophy through regulating TAK1/P38 MAPK signalling in mice.

    Science.gov (United States)

    Wu, Lianpin; Cao, Zhiyong; Ji, Ling; Mei, Liqin; Jin, Qike; Zeng, Jingjing; Lin, Jiafeng; Chu, Maoping; Li, Lei; Yang, Xiangjun

    2017-02-05

    We investigated the role of tumour necrosis factor receptor (TNFR)-associated death domain (TRADD) on pressure overload-induced cardiac hypertrophy and the underlying molecular mechanisms by using a TRADD deficiency mice model. 6-8 weeks wild-type and TRADD knockout mice were performed to transverse aorta constriction (TAC) or sham operation (6-8 mice for each group). 14 days after TAC, cardiac function was measured by echocardiography, as well as by pathological and molecular analyses of heart samples. The expressions of cardiac hypertrophic and fibrotic markers were detected by qPCR. Phosphorylated and total TAK1, Akt, and p38 MAPK levels were examined by Western blotting. The ratios of lung or heart/body weight, wall thickness/chamber diameter of left ventricular and cross area of cardiomyocyte were significantly reduced in TRADD knockout (KO) mice than those of wild-type mice after TAC. Moreover, cardiac hypertrophic and fibrotic markers were downregulated in TRADD knockout mice than those of wild-type mice following TAC. Protein expression analysis showed phosphorylated TAK1, p38 MAPK and AKT were upregulated after TAC in both wild-type and TRADD KO mice, phosphorylation of TAK1 and p38 MAPK was reduced more remarkably after TRADD deficiency, while phosphorylated AKT expression was similar between TRADD KO and wild-type mice following TAC. Our data suggest that TRADD KO blunts pressure overload-induced cardiac hypertrophy through mediating TAK1/p38 MAPK but not AKT phosphorylation in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. ELABELA-APJ axis protects from pressure overload heart failure and angiotensin II-induced cardiac damage.

    Science.gov (United States)

    Sato, Teruki; Sato, Chitose; Kadowaki, Ayumi; Watanabe, Hiroyuki; Ho, Lena; Ishida, Junji; Yamaguchi, Tomokazu; Kimura, Akinori; Fukamizu, Akiyoshi; Penninger, Josef M; Reversade, Bruno; Ito, Hiroshi; Imai, Yumiko; Kuba, Keiji

    2017-06-01

    Elabela/Toddler/Apela (ELA) has been identified as a novel endogenous peptide ligand for APJ/Apelin receptor/Aplnr. ELA plays a crucial role in early cardiac development of zebrafish as well as in maintenance of self-renewal of human embryonic stem cells. Apelin was the first identified APJ ligand, and exerts positive inotropic heart effects and regulates the renin-angiotensin system. The aim of this study was to investigate the biological effects of ELA in the cardiovascular system. Continuous infusion of ELA peptide significantly suppressed pressure overload-induced cardiac hypertrophy, fibrosis and impaired contractility in mice. ELA treatment reduced mRNA expression levels of genes associated with heart failure and fibrosis. The cardioprotective effects of ELA were diminished in APJ knockout mice, indicating that APJ is the key receptor for ELA in the adult heart. Mechanistically, ELA downregulated angiotensin-converting enzyme (ACE) expression in the stressed hearts, whereas it showed little effects on angiotensin-converting enzyme 2 (ACE2) expression, which are distinct from the effects of Apelin. FoxM1 transcription factor, which induces ACE expression in the stressed hearts, was downregulated by ELA but not by Apelin. ELA antagonized angiotensin II-induced hypertension, cardiac hypertrophy, and fibrosis in mice. The ELA-APJ axis protects from pressure overload-induced heart failure possibly via suppression of ACE expression and pathogenic angiotensin II signalling. The different effects of ELA and Apelin on the expression of ACE and ACE2 implicate fine-tuned mechanisms for a ligand-induced APJ activation and downstream signalling.

  19. Superoxide scavenging and Akt inhibition in myocardium ameliorate pressure overload-induced NF-κB activation and cardiac hypertrophy.

    Science.gov (United States)

    Hingtgen, Shawn D; Li, Zhenbo; Kutschke, William; Tian, Xin; Sharma, Ram V; Davisson, Robin L

    2010-04-01

    Recent studies from our laboratory and others have shown that increases in cytoplasmic superoxide (O(2)(·-)) levels and Akt activation play a key role in agonist-stimulated NF-κB activation and cardiomyocyte hypertrophy in vitro. In this study, we tested the hypothesis that adenovirus (Ad)-mediated intramyocardial gene transfer of cytoplasmic superoxide dismutase (AdCu/ZnSOD) or a dominant-negative form of Akt (AdDNAkt) in mice would attenuate pressure overload-induced increases in activation of the redox-sensitive transcription factor NF-κB and cardiac hypertrophy. Adult C57BL/6 mice were subjected to thoracic aortic banding (TAB) or sham surgery, and intramyocardial injections of viral vectors (AdCu/ZnSOD, AdDNAkt, or control) were performed. There was robust transgene expression in the heart, which peaked 6-7 days after injection and then declined to undetectable levels by 12-14 days. In mice injected with AdBgL II, TAB caused a significant increase in O(2)(·-) generation and cardiac mass at 1 wk, and these responses were markedly attenuated by AdCu/ZnSOD. In addition, TAB induced time-dependent activation of NF-κB in the myocardium as measured longitudinally by in vivo bioluminescent imaging of NF-κB-dependent luciferase expression. This was also abolished by intracardiac AdCu/ZnSOD or AdDNAkt, but not the control vector. The inhibition of Akt and O(2)(·-)-mediated NF-κB activation in TAB hearts was associated with an attenuation of cardiac hypertrophy. Since a direct cause-and-effect relationship between NF-κB activation and cardiomyocyte hypertrophy has been established previously, our data support the hypothesis that increased O(2)(·-) generation and Akt activation are key signaling intermediates in pressure overload-induced activation of NF-κB and cardiac hypertrophy.

  20. Implementing Filters to Identify and Prioritize Industrial Base Risk: Rules of Thumb to Reduce Cognitive Overload (Briefing Charts)

    Science.gov (United States)

    2015-05-01

    Month Day, Year Implementing Filters to Identify and Prioritize Industrial Base Risk: Rules of Thumb to Reduce Cognitive Overload May 2015...Base Risk: Rules of Thumb to Reduce Cognitive Overload 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT

  1. Mitigating Information Overload: The Impact of "Context-Based Approach" to the Design of Tools for Intelligence Analysts

    Science.gov (United States)

    2008-03-01

    Reference Meetings Allen G. Schick, Lawrence A. Gordon, and Susan Haka , “Information overload: A temporal approach,” Accounting Organizations and...conversations Allen G. Schick, Lawrence A. Gordon, and Susan Haka , “Information overload: A temporal approach,” Accounting Organizations and

  2. Suitable Method of Overloading for Fast Primary Frequency Control from Offshore Wind Power Plants in Multi-Terminal DC Grid

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Hansen, Anca Daniela; Altin, Müfit

    2017-01-01

    Increased penetration of offshore wind power plants (OWPPs) demands frequency control services from them. Overloading the wind turbine, for few seconds after the under frequency event, to utilize its kinetic energy seems promising option for fast primary frequency control. Two methods of overload...

  3. The Impact of Information Overload on Task Completion: A Study of Scientists and Engineers in a Typical Work Environment

    Science.gov (United States)

    Salyers, Jessica L.

    2013-01-01

    As use of technology has increasingly infiltrated the daily lives of many Americans, information overload has become a more prevalent fixture for men and women both at home and in the workplace. While information overload has been established in the field of psychology in various forms, it lacks a universal definition within the discipline.…

  4. Coordinated and Interactive Expression of Genes of Lipid Metabolism and Inflammation in Adipose Tissue and Liver during Metabolic Overload

    NARCIS (Netherlands)

    Liang, W.; Tonini, G.; Mulder, P.; Kelder, T.; Erk, M. van; Hoek, A.M. van den; Mariman, R.; Wielinga, P.Y.; Baccini, M.; Kooistra, T.; Biggeri, A.; Kleemann, R.

    2013-01-01

    Background:Chronic metabolic overload results in lipid accumulation and subsequent inflammation in white adipose tissue (WAT), often accompanied by non-alcoholic fatty liver disease (NAFLD). In response to metabolic overload, the expression of genes involved in lipid metabolism and inflammatory

  5. Is hemifacial spasm accompanied by hemodynamic changes detectable by ultrasound?

    Science.gov (United States)

    Perren, Fabienne; Magistris, Michel R

    2014-08-01

    Arterial tortuosity of the posterior circulation compressing the facial nerve induces the ephaptic axono-axonal cross-talk that sparks hemifacial spasm. We sought if a noninvasive method such as color duplex of these arteries might detect hemodynamical changes in this condition. Nine patients with hemifacial spasm, successfully treated with botulinum toxin, were examined with color-coded duplex ultrasound. Mean blood flow velocities of the vertebral, basilar, posterior inferior cerebellar, and anterior inferior cerebellar arteries were measured and side-to-side comparison performed. In all nine patients, the mean blood flow velocity, averaging across the two arteries, was higher on the side of the hemifacial spasm (Fisher's exact p hemifacial spasm. There was no significant association between the mean flow velocity of the vertebral artery and the side of spasm (p = 0.523). Hemifacial spasm also seems to relate to hemodynamic changes, which may be detectable by color duplex imaging.

  6. [The hemodynamic characterization of the diabetic patient with arterial calcifications].

    Science.gov (United States)

    Vega Gómez, M E; Ley Pozo, J; Aldama Figueroa, A; Lima Santana, B; Montalvo Diago, J; Bustillo, C; Fernández Boloña, A; Gutiérrez Jiménez, O; Ramirez Muñoz, O; Martínez Hernández, R

    1993-01-01

    This study was designed to describe the presence of calcifications according to the clinical features of the diabetic patient and the hemodynamics of the calcified arteries. With this purpose, 197 lower limbs from diabetic patients (type I and II) and carbon-hydrate intolerant patients, were studied. In all of the patients, the pressure ratio leg/arm was measured. On the same way, the arterial flow velocity was recorded using the Doppler ultrasonography on the pedia and postero-tibial arteries. The arterial calcifications, evident on the radiography of the foot, were more frequent between the type I patients and the neuro-infections diabetic foot. According to the hemodynamics point of view, we found a trend of association of more pathologic arterial flow velocity curves with the presence of calcifications (specially on the intima layer). It was also remarkable that an arterial incomprensibility was always associated with arterial calcifications.

  7. Optimal control of CPR procedure using hemodynamic circulation model

    Science.gov (United States)

    Lenhart, Suzanne M.; Protopopescu, Vladimir A.; Jung, Eunok

    2007-12-25

    A method for determining a chest pressure profile for cardiopulmonary resuscitation (CPR) includes the steps of representing a hemodynamic circulation model based on a plurality of difference equations for a patient, applying an optimal control (OC) algorithm to the circulation model, and determining a chest pressure profile. The chest pressure profile defines a timing pattern of externally applied pressure to a chest of the patient to maximize blood flow through the patient. A CPR device includes a chest compressor, a controller communicably connected to the chest compressor, and a computer communicably connected to the controller. The computer determines the chest pressure profile by applying an OC algorithm to a hemodynamic circulation model based on the plurality of difference equations.

  8. Coronary hemodynamic responses during local hemodilution in canine hearts

    Energy Technology Data Exchange (ETDEWEB)

    Crystal, G.J. (Illinois Masonic Medical Center, Chicago (USA))

    1988-03-01

    To evaluate the effect of hemodilution per se on coronary hemodynamics, experiments were performed in 36 anesthetized, open-chest dogs whose left anterior descending coronary artery (LAD) was perfused selectively with either normal arterial blood or arterial blood diluted with lactated Ringer solution. LAD blood flow (CBF) was measured with an electromagnetic flowmeter and its transmural distribution assessed with 15-{mu}m radioactive microspheres. With perfusion pressure normal, graded hemodilution caused progressive, transmurally uniform increases in CBF that showed an nonlinear relationship to inflow hematocrit. Increased peak reactive hyperemic flow and decreased dilator reserve ratio indicated that both reduced viscosity and vasodilation contributed to increased CBF during hemodilution. Hypotension alone reduced CBF, with greater effect in the subendocardium. Additional hemodilution returned CBF to normotensive value, but relative subendocardial hypoperfusion persisted. The present study provides fundamental information on effects of hemodilution on coronary hemodynamics without the systemic responses that complicated previous studies utilizing whole body exchange transfusions.

  9. [Vasopressin for treatment of hemodynamic disorders].

    Science.gov (United States)

    Adukauskiene, Dalia; Sirvinskas, Edmundas; Kevelaitis, Egidijus

    2008-01-01

    Vasopressin is a 9-amino acid peptide synthesized by magnocellular neurons of the hypothalamus and released from posterior pituitary gland. The primary physiological role of vasopressin is the maintenance of fluid homeostasis. In this review, the classification of vasopressin receptors, namely V1 vascular, V2 renal, V3 pituitary, oxytocin receptors, and purinergic receptors, and the effects of vasopressin on vascular smooth muscles, the heart, and the kidneys are discussed. Mortality rates of vasodilatory (or distributive), for example septic shock, are high. The use of vasopressin is an alternative therapy for vasodilatory shock with better outcome. Vasopressin is effective in resuscitation of adults after ventricular fibrillation or pulseless tachycardia, when epinephrine is not effective.

  10. Vascular remodeling of the mouse yolk sac requires hemodynamic force

    OpenAIRE

    Lucitti, Jennifer L.; Jones, Elizabeth; Huang, Chengqun; Chen, Ju; Fraser, Scott E.; Dickinson, Mary E.

    2007-01-01

    The embryonic heart and vessels are dynamic and form and remodel while functional. Much has been learned about the genetic mechanisms underlying the development of the cardiovascular system, but we are just beginning to understand how changes in heart and vessel structure are influenced by hemodynamic forces such as shear stress. Recent work has shown that vessel remodeling in the mouse yolk sac is secondarily effected when cardiac function is reduced or absent. These findings indicate that p...

  11. Hemodynamic Signals Of Mixed Messages During A Social Exchange

    OpenAIRE

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

    2011-01-01

    The present study used functional magnetic resonance imaging (fMRI) to characterize hemodynamic activation patterns recruited when participants view mixed social communicative messages during a common interpersonal exchange. Mixed messages were defined as conflicting sequences of biological motion and facial affect signals that are unexpected within a particular social context (for example, observing the reception of a gift). Across four social vignettes, valenced facial expressions were cros...

  12. Hemodynamics in CHD: mechanical regulation of congenital heart defects

    OpenAIRE

    Yalçın, Hüseyin Çağatay

    2011-01-01

    This is the periodic report for the HEMODYNAMICS IN CHD project, which received funding under the Seventh Framework Programme (FP7). The project will be applying the techniques developed in to a well established animal model for a severe CHD, hypoplastic left heart syndrome, to dissect the contribution of blood flow related forces on this disease. The report includes images generated to study embryonic development of congenital heart defects.

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

    Directory of Open Access Journals (Sweden)

    Ayan Sen

    2014-07-01

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

  14. Investigation of hemodynamics in the assisted isolated porcine heart.

    Science.gov (United States)

    Granegger, Marcus; Mahr, Stephane; Horvat, Johann; Aigner, Philipp; Roehrich, Michael; Stoiber, Martin; Plasenzotti, Roberto; Zimpfer, Daniel; Schima, Heinrich; Moscato, Francesco

    2013-12-01

    Currently, the interaction between rotary blood pumps (RBP) and the heart is investigated in silico, in vitro, and in animal models. Isolated and defined changes in hemodynamic parameters are unattainable in animal models, while the heart-pump interaction in its whole complexity cannot be modeled in vitro or in silico. The aim of this work was to develop an isolated heart setup to provide a realistic heart-pump interface with the possibility of easily adjusting hemodynamic parameters. A mock circuit mimicking the systemic circulation was developed. Eight porcine hearts were harvested using a protocol similar to heart transplantation. Then, the hearts were resuscitated using Langendorff perfusion with rewarmed, oxygenated blood. An RBP was implanted and the setup was switched to the "working mode" with the left heart and the RBP working as under physiologic conditions. Both the unassisted and assisted hemodynamics were monitored. In the unassisted condition, cardiac output was up to 9.5 l/min and dP/dtmax ranged from 521 to 3621 mmHg/s at a preload of 15 mmHg and afterload of 70 mmHg. With the RBP turned on, hemodynamics similar to heart-failure patients were observed in each heart. Mean pump flow and flow pulsatility ranged from 0 to 11 l/min. We were able to reproduce conditions with an open and closed aortic valve as well as suction events. An isolated heart setup including an RBP was developed, which combines the advantages of in silico/vitro methods and animal experiments. This tool thus provides further insight into the interaction between the heart and an RBP.

  15. Association between cerebral hemodynamic changes and neonatal hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    LIU Shuyan

    2017-10-01

    Full Text Available ObjectiveTo investigate the association between cerebral hemodynamic changes and neonatal hyperbilirubinemia. MethodsA total of 67 neonates with hyperbilirubinemia who were admitted to our hospital from January 2014 to November 2015 were enrolled as study group, and another 36 normal healthy neonates were enrolled as control group. The two groups were compared in terms of end-diastolic velocity (Vd, systolic peak velocity (Vs, mean blood flow velocity (Vm, resistance index (RI, and pulsatility index (PI, and the serum level of bilirubin and systemic symptoms were observed after treatment. The t-test was used for comparison of continuous data between groups, and a Pearson correlation analysis was also performed. ResultsAt the time of enrolment and on day 3 of treatment, the control group had significantly lower Vd, Vs, and Vm than the study group (before treatment: t=75873,81589,64600,19834,30453; day 3 of treatment: t=39476,55729,35274,6069,9382, all P<0.001. The study group had improvements in Vd, Vs, Vm, RI, and PI on day 3 of treatment. On day 5 of treatment, there were no significant differences in hemodynamic parameters between the two groups (all P>0.05. Serum level of bilirubin was positively correlated with Vd (r=0.387, P<0.001, Vs (r=0.483, P<0.001, and Vm (r=0.412, P<0.001 and negatively correlated with RI (r=-0.492, P<0.001 and PI (r=-0.497, P<0.001. ConclusionSerum level of bilirubin interacts with cerebral hemodynamics, and cerebral hemodynamic parameters can provide objective evidence for evaluating disease progression and prognosis of neonatal hyperbilirubinemia.

  16. Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

    Science.gov (United States)

    Moghimi, Saba; Schudlo, Larissa; Chau, Tom; Guerguerian, Anne-Marie

    2015-01-01

    Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

  17. Diagnosis, management and response criteria of iron overload in myelodysplastic syndromes (MDS): updated recommendations of the Austrian MDS platform.

    Science.gov (United States)

    Valent, Peter; Stauder, Reinhard; Theurl, Igor; Geissler, Klaus; Sliwa, Thamer; Sperr, Wolfgang R; Bettelheim, Peter; Sill, Heinz; Pfeilstöcker, Michael

    2018-01-02

    Despite the availability of effective iron chelators, transfusion-related morbidity is still a challenge in chronically transfused patients with myelodysplastic syndromes (MDS). In these patients, transfusion-induced iron overload may lead to organ dysfunction or even organ failure. In addition, iron overload is associated with reduced overall survival in MDS. Areas covered: During the past 10 years, various guidelines for the management of MDS patients with iron overload have been proposed. In the present article, we provide our updated recommendations for the diagnosis, prevention and therapy of iron overload in MDS. In addition, we propose refined treatment response criteria. As in 2006 and 2007, recommendations were discussed and formulated by participants of our Austrian MDS platform in a series of meetings in 2016 and 2017. Expert commentary: Our updated recommendations should support early recognition of iron overload, optimal patient management and the measurement of clinical responses to chelation treatment in daily practice.

  18. Coherent hemodynamics spectroscopy: initial applications in the neurocritical care unit

    Science.gov (United States)

    Tgavalekos, Kristen T.; Sassaroli, Angelo; Cai, Xuemei; Kornbluth, Joshua; Fantini, Sergio

    2017-02-01

    We used coherent hemodynamics spectroscopy (CHS) and near-infrared spectroscopy (NIRS) to measure the absolute cerebral blood flow (CBF) and cerebral autoregulation efficiency of a patient with intraventricular hemorrhage in the neurocritical care unit. Mean arterial pressure oscillations were induced with cyclic thigh cuff inflations at a super-systolic pressure. The oscillations in oxyhemoglobin ([HbO2]) and deoxyhemoglobin ([Hb]) cerebral concentrations were used to compute CHS amplitude and phase spectra that were fit with the frequency-domain equations of our hemodynamic model. From the fitted parameters, we obtained measures of local autoregulation efficiency (cutoff frequency: 0.07 +/- 0.02 Hz) and absolute regional CBF (33 +/- 9 ml/100g/min). We introduce a new approach for computing CHS spectra using coherence criteria and time-varying transfer function analysis. We show that with this approach we can maximize the number of frequency points in the CHS spectra for more effective fitting with our hemodynamic model. Finally, we show how absolute measurements of the cerebral concentrations of [HbO2] and [Hb] at baseline can be used to further enhance the fitting procedure.

  19. Comprehensive cognitive and cerebral hemodynamic evaluation after cranioplasty

    Directory of Open Access Journals (Sweden)

    Coelho F

    2014-05-01

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

  20. Fetal brain activity and hemodynamic response to a vibroacoustic stimulus.

    Science.gov (United States)

    Fulford, Jonathan; Vadeyar, Shantala H; Dodampahala, Sanani H; Ong, Stephen; Moore, Rachel J; Baker, Philip N; James, David K; Gowland, Penny

    2004-06-01

    Previous studies have demonstrated the practicality of using functional magnetic resonance imaging (fMRI) techniques to assess fetal brain activity. The purpose of this study was to compare the fetal hemodynamic response to that of the adult. Seventeen pregnant subjects, all of whom were at more than 36 weeks gestation were scanned while the fetus was exposed to a vibroacoustic stimulus. Thirteen adult subjects were scanned with an equivalent acoustic stimulus. Of the fetal subjects, two could not be analyzed due to technical problems, eight did not show significant activation, and seven showed significant activation. In all cases, activation was localized within the temporal region. Measures of fetal hemodynamic responses revealed an average time to peak (ttp) of 7.36 +/- 0.94 sec and an average percentage change of 2.67 +/- 0.93%. In contrast, activation was detected in 5 of 13 adults with an average ttp of 6.54 +/- 0.54 sec and an average percentage change of 1.02 +/- 0.40%. The measurement of changes in the fetal hemodynamic response may be important in assessing compromised pregnancies. Copyright 2004 Wiley-Liss, Inc.

  1. Quantifying the abnormal hemodynamics of sickle cell anemia

    Science.gov (United States)

    Lei, Huan; Karniadakis, George

    2012-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Jan Frederick Cornelius

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Desanka Dragosavac

    1999-08-01

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

  4. Hemodynamic and ventilatory response to different levels of hypoxia and hypercapnia in carotid body-denervated rats

    Directory of Open Access Journals (Sweden)

    João Paulo J. Sabino

    2013-01-01

    Full Text Available OBJECTIVE: Chemoreceptors play an important role in the autonomic modulation of circulatory and ventilatory responses to changes in arterial O2 and/or CO2. However, studies evaluating hemodynamic responses to hypoxia and hypercapnia in rats have shown inconsistent results. Our aim was to evaluate hemodynamic and respiratory responses to different levels of hypoxia and hypercapnia in conscious intact or carotid body-denervated rats. METHODS: Male Wistar rats were submitted to bilateral ligature of carotid body arteries (or sham-operation and received catheters into the left femoral artery and vein. After two days, each animal was placed into a plethysmographic chamber and, after baseline measurements of respiratory parameters and arterial pressure, each animal was subjected to three levels of hypoxia (15, 10 and 6% O2 and hypercapnia (10% CO2. RESULTS: The results indicated that 15% O2 decreased the mean arterial pressure and increased the heart rate (HR in both intact (n = 8 and carotid body-denervated (n = 7 rats. In contrast, 10% O2did not change the mean arterial pressure but still increased the HR in intact rats, and it decreased the mean arterial pressure and increased the heart rate in carotid body-denervated rats. Furthermore, 6% O2 increased the mean arterial pressure and decreased the HR in intact rats, but it decreased the mean arterial pressure and did not change the HR in carotid body-denervated rats. The 3 levels of hypoxia increased pulmonary ventilation in both groups, with attenuated responses in carotid body-denervated rats. Hypercapnia with 10% CO2 increased the mean arterial pressure and decreased HR similarly in both groups. Hypercapnia also increased pulmonary ventilation in both groups to the same extent. CONCLUSION: This study demonstrates that the hemodynamic and ventilatory responses varied according to the level of hypoxia. Nevertheless, the hemodynamic and ventilatory responses to hypercapnia did not depend on the

  5. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Science.gov (United States)

    2010-07-01

    ... protection, if the lamp is not more than 8 feet in distance from such circuits. ... protection. 75.518-2 Section 75.518-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps installed...

  6. Iron overload in very low birth weight infants: Serum Ferritin and adverse outcomes

    LENUS (Irish Health Repository)

    Barrett, M

    2011-11-01

    Adequate iron isessential for growth and haematpoiesis. Oral iron supplementation is the standard of care in VLBW infants. Post mortem evidence has confirmed significant iron overload. Excessive free iron has been associated with free radical formation and brain injury in term infants.

  7. Estimation of iron overloads using oral exfoliative cytology in beta-thalassemia major patients.

    Science.gov (United States)

    Leekha, Swati; Nayar, Amit Kumar; Bakshi, Preeti; Sharma, Aman; Parhar, Swati; Soni, Sugandhi

    2016-01-01

    Iron overload is a medical condition that occurs when too much of the mineral iron builds up inside the body and produces a toxic reaction. Thalassemia is a genetic disorder of hemoglobin synthesis, which requires regular blood transfusion therapy, and the lack of specific excretory pathways for iron in humans leads to iron overload in the body tissues. It is a major cause of morbidity and mortality in these patients. The estimation of iron levels in exfoliated buccal mucosal cells may provide a simple, noninvasive, and a safe procedure for estimating the iron overload by using the Perls' Prussian blue stain. Smears were obtained from buccal mucosa of 40 randomly selected beta-thalassemia major patients and 40 healthy subjects as controls. Smears were stained with Perls' Prussian blue method. Blood samples were taken for estimation of serum ferritin levels. Images of smears were analyzed using the software image J software version 1.47v and correlated with serum ferritin. Perls' positivity was observed in 87.5% of thalassemic patients with a positive correlation to serum ferritin levels. The use of exfoliative buccal mucosal cells for the evaluation of iron overloads in the body provides us with a diagnostic medium that is noninvasive, easy to collect, store, and transport, cost effective, and above all reliable.

  8. Estimation of iron overloads using oral exfoliative cytology in beta-thalassemia major patients

    Directory of Open Access Journals (Sweden)

    Swati Leekha

    2016-01-01

    Full Text Available Background: Iron overload is a medical condition that occurs when too much of the mineral iron builds up inside the body and produces a toxic reaction. Thalassemia is a genetic disorder of hemoglobin synthesis, which requires regular blood transfusion therapy, and the lack of specific excretory pathways for iron in humans leads to iron overload in the body tissues. It is a major cause of morbidity and mortality in these patients. The estimation of iron levels in exfoliated buccal mucosal cells may provide a simple, noninvasive, and a safe procedure for estimating the iron overload by using the Perls′ Prussian blue stain. Methods: Smears were obtained from buccal mucosa of 40 randomly selected beta-thalassemia major patients and 40 healthy subjects as controls. Smears were stained with Perls′ Prussian blue method. Blood samples were taken for estimation of serum ferritin levels. Images of smears were analyzed using the software image J software version 1.47v and correlated with serum ferritin. Results: Perls′ positivity was observed in 87.5% of thalassemic patients with a positive correlation to serum ferritin levels. Conclusion: The use of exfoliative buccal mucosal cells for the evaluation of iron overloads in the body provides us with a diagnostic medium that is noninvasive, easy to collect, store, and transport, cost effective, and above all reliable.

  9. Electrophysiologic Remodeling of the Left Ventricle in Pressure Overload-Induced Right Ventricular Failure

    NARCIS (Netherlands)

    Hardziyenka, Maxim; Campian, Maria E.; Verkerk, Arie O.; Surie, Sulaiman; van Ginneken, Antoni C. G.; Hakim, Sara; Linnenbank, André C.; de Bruin-Bon, Rianne H. A. C. M.; Beekman, Leander; van der Plas, Mart N.; Remme, Carol A.; van Veen, Toon A. B.; Bresser, Paul; de Bakker, Jacques M. T.; Tan, Hanno L.

    2012-01-01

    Objectives The purpose of this study was to analyze the electrophysiologic remodeling of the atrophic left ventricle (LV) in right ventricular (RV) failure (RVF) after RV pressure overload. Background The LV in pressure-induced RVF develops dysfunction, reduction in mass, and altered gene

  10. The Effects of Technological Overload on Children: An Art Therapist's Perspective

    Science.gov (United States)

    Klorer, P. Gussie

    2009-01-01

    Children today are continually bombarded with visual and auditory stimulation, and many make their connections in cyberspace to the detriment of real-time face-to-face encounters with other people. The negative effects of multitasking and technological overload on children and adolescents are discussed in this viewpoint article from the…

  11. Association between filial responsibility when caring for parents and the caregivers overload

    Directory of Open Access Journals (Sweden)

    Marinês Aires

    Full Text Available ABSTRACT Objective: To analyze the association between filial responsibility and the overload of the children when caring for their older parents. Method: Cross-sectional study with 100 caregiver children of older adults. Filial liability was assessed by the attitudes of the responsible child (scale of expectation and filial duty and by care behaviors (assistance in activities of daily living, emotional and financial support, and keeping company. The overload was assessed by the Caregiver Burden Inventory. To assess the associations, the correlation coefficients of Pearson and Spearman, Kruskal-Wallis Test, and Mann-Whitney were employed. Variables that presented p-value<0.20 in the bivariate analysis were inserted in a multivariate linear regression model. Results: The factors associated with overload were: formal employment (p=0.002, feelings regarding family life (p<0.001, financial support (p=0.027, and assistance with Activities of Daily Living (ADLs (p<0.001. Conclusion: Children who were more involved with the ADLs and provided financial support showed higher levels of overload.

  12. Choosing To Examine Electronic Information: A Message Ranking Model To Minimize Information Overload.

    Science.gov (United States)

    Losee, Robert M., Jr.

    Designed to minimize information overload in telecommunications systems, the formal model developed in this paper predicts the usefulness of a message based on the available message features, and may be used to rank messages by expected importance or economic worth. The assumptions of binary and two Poisson independent probabilistic distributions…

  13. Population pharmacokinetic modeling of furosemide in patients with hypertension and fluid overload conditions.

    Science.gov (United States)

    Kodati, Devender; Yellu, Narsimhareddy

    2017-06-01

    Furosemide is a loop diuretic drug frequently indicated in hypertension and fluid overload conditions such as congestive heart failure and hepatic cirrhosis. The purpose of the study was to establish a population pharmacokinetic model for furosemide in Indian hypertensive and fluid overload patients, and to evaluate effects of covariates on the volume of distribution (V/F) and oral clearance (CL/F) of furosemide. A total of 188 furosemide plasma sample concentrations from 63 patients with hypertension or fluid overload conditions were collected in this study. The population pharmacokinetic model for furosemide was built using Phoenix NLME 1.3 software. The covariates included age, sex, body surface area, bodyweight, height and creatinine clearance (CRCL). The pharmacokinetic data of furosemide was adequately explained by a two-compartment linear pharmacokinetic model with first-order absorption and an absorption lag-time. The mean values of CL/F and Vd/F of furosemide in the patients were 15.054Lh -1 and 4.419L, respectively. Analysis of covariates showed that CRCL was significantly influencing the clearance of furosemide. The final population pharmacokinetic model was demonstrated to be appropriate and effective and it can be used to assess the pharmacokinetic parameters of furosemide in Indian patients with hypertension and fluid overload conditions. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

  14. Media Overload in Instructional Web Pages and the Impact on Learning.

    Science.gov (United States)

    Hartley, Kendall W.

    1999-01-01

    Discussion of the use of the Internet to deliver instruction and multimedia opportunities for Web-page design focuses on working memory and its implications for Web-based instruction. Topics include media overload; cognitive load theory; static visual displays; animations; audio; and research questions. (Author/LRW)

  15. Load characterization, overload prediction, and anomaly detection for voice over IP traffic

    NARCIS (Netherlands)

    Mandjes, Michel; Saniee, Iraj; Stolyar, Alexander; Heidelberger, P.

    2001-01-01

    We consider the problem of traffic anomaly detection in IP networks. Traffic anomalies arise when there is overload due to failures in a network. We present general formulae for the variance of the cumulative traffic over a fixed time interval and show how the derived analytical expression

  16. Peak rates of diuresis in healthy humans during oral fluid overload ...

    African Journals Online (AJOL)

    Objective. To determine whether rates of intestinal fluid absorption and renal diuresis can match high rates of fluid ingestion in healthy humans exposed to oral fluid overload, thereby preventing the development of hyponatraemia either by reverse sodium movement across the intestine (the Priestley-Haldane effect) or by ...

  17. Exploring the Influence of Information Overload on Middle Management Decision-Making in Organizations

    Science.gov (United States)

    Carlevale, Edward A.

    2010-01-01

    This phenomenological study was an exploration of information overload and how it influenced middle management decision-making in a single organization. In-depth interviews were used to gather lived experiences of 22 middle managers at XYZ Defense Company in California. Data were analyzed using both HyperRESEARCH TM 2.8 software and a manual…

  18. When Enough Is Not Enough: Information Overload and Metacognitive Decisions to Stop Studying Information

    Science.gov (United States)

    Murayama, Kou; Blake, Adam B.; Kerr, Tyson; Castel, Alan D.

    2016-01-01

    People are often exposed to more information than they can actually remember. Despite this frequent form of information overload, little is known about how much information people choose to remember. Using a novel "stop" paradigm, the current research examined whether and how people choose to stop receiving new--possibly…

  19. Iron overload of human colon adenocarcinoma cells studied by synchrotron-based X-ray techniques

    NARCIS (Netherlands)

    Mihucz, Victor G.; Meirer, Florian; Polgári, Zsófia; Réti, Andrea; Pepponi, Giancarlo; Ingerle, Dieter; Szoboszlai, Norbert; Streli, Christina

    2016-01-01

    Fast- and slow-proliferating human adenocarcinoma colorectal cells, HT-29 and HCA-7, respectively, overloaded with transferrin (Tf), Fe(III) citrate, Fe(III) chloride and Fe(II) sulfate were studied by synchrotron radiation total-reflection X-ray spectrometry (TXRF), TXRF-X-ray absorption near edge

  20. Compensation for Overloads and Summer Employment: A Survey of Current Practice in Texas.

    Science.gov (United States)

    Hardy, James C.

    A survey was sent to 58 chief academic officers to gain information about compensation for instructional overloads and summer employment at public and private Texas colleges and universities. Responses were received from 42 institutions. Only two indicated that their institutions did not have a uniform policy guiding summer compensation amounts.…

  1. Recent advances in the understanding of iron overload in sideroblastic myelodysplastic syndrome.

    Science.gov (United States)

    Cuijpers, Maria L H; Raymakers, Reinier A P; Mackenzie, Marius A; de Witte, Theo J M; Swinkels, Dorine W

    2010-05-01

    Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal haematopoietic stem cell malignancies. A subgroup, the so-called sideroblastic MDS, shows ring sideroblasts in the bone marrow aspirate that represent mitochondrial iron accumulation. Patients with sideroblastic MDS also develop systemic iron overload and generally have a low-risk MDS. Therefore it is important to understand the mechanisms responsible for iron accumulation and the associated toxicity in these patients. Recently, low levels of the iron-regulatory peptide hepcidin were found to contribute to body iron overload in beta-thalassaemia patients. A similar mechanism may account for systemic iron accumulation in sideroblastic MDS. Mitochondrial iron accumulation is observed in several subtypes of MDS, and predominantly in refractory anaemia with ring sideroblasts. The presence of ring sideroblasts is also the diagnostic hallmark in patients with inherited forms of sideroblastic anaemia. The ever-increasing insights into the affected pathways in inherited sideroblastic anaemia may lead to a better comprehension of the pathogenesis of mitochondrial iron accumulation in MDS patients. Overall, an improved understanding of the mechanisms responsible for iron overload in MDS will lead to novel treatment strategies to reduce both systemic and mitochondrial iron overload, resulting in less tissue damage and more effective erythropoiesis.

  2. 77 FR 11598 - Thermal Overload Protection for Electric Motors on Motor-Operated Valves

    Science.gov (United States)

    2012-02-27

    ... COMMISSION Thermal Overload Protection for Electric Motors on Motor-Operated Valves AGENCY: Nuclear... for Electric Motors on Motor-Operated Valves.'' This regulatory guide describes a method acceptable to... devices that are integral with the motor starter for electric motors on motor-operated valves. ADDRESSES...

  3. Tackling Fluid Overload in a High-transporter Diabetic Patient on ...

    African Journals Online (AJOL)

    CAPD) are more prone to fluid overload than non-diabetic patients, but the use of hypertonic glucose solutions to improve their ultrafiltration (UF) may hamper their glycemic control. Maintaining euvolemia in such patients may be tricky and needs ...

  4. The Influence of Fluid Overload on the Length of Mechanical Ventilation in Pediatric Congenital Heart Surgery.

    Science.gov (United States)

    Sampaio, Tatiana Z A L; O'Hearn, Katie; Reddy, Deepti; Menon, Kusum

    2015-12-01

    Fluid overload and prolonged mechanical ventilation lead to worse outcomes in critically ill children. However, the association between these variables in children following congenital heart surgery is unknown. The objectives of this study were to describe the association between fluid overload and duration of mechanical ventilation, oxygen requirement and radiologic findings of pulmonary and chest wall edema. This study is a retrospective chart review of patients who underwent congenital heart surgery between June 2010 and December 2013. Univariate and multivariate associations between maximum cumulative fluid balance and length of mechanical ventilation and OI were tested using the Spearman correlation test and multiple linear regression models, respectively. There were 85 eligible patients. Maximum cumulative fluid balance was associated with duration of mechanical ventilation (adjusted analysis beta coefficient = 0.53, CI 0.38-0.66, P mechanical ventilation (P = 0.012 and 0.014, respectively). Fluid overload is associated with prolonged duration of mechanical ventilation and PICU length of stay after congenital heart surgery. Fluid overload was also associated with physiological markers of respiratory restriction. A randomized controlled trial of a restrictive versus liberal fluid replacement strategy is necessary in this patient population, but in the meantime, accumulating observational evidence suggests that cautious use of fluid in the postoperative care may be warranted.

  5. An Investigation of Data Overload in Team-Based Distributed Cognition Systems

    Science.gov (United States)

    Hellar, David Benjamin

    2009-01-01

    The modern military command center is a hybrid system of computer automated surveillance and human oriented decision making. In these distributed cognition systems, data overload refers simultaneously to the glut of raw data processed by information technology systems and the dearth of actionable knowledge useful to human decision makers.…

  6. Fluid Overload and Cumulative Thoracostomy Output Are Associated With Surgical Site Infection After Pediatric Cardiothoracic Surgery.

    Science.gov (United States)

    Sochet, Anthony A; Nyhan, Aoibhinn; Spaeder, Michael C; Cartron, Alexander M; Song, Xiaoyan; Klugman, Darren; Brown, Anna T

    2017-08-01

    To determine the impact of cumulative, postoperative thoracostomy output, amount of bolus IV fluids and peak fluid overload on the incidence and odds of developing a deep surgical site infection following pediatric cardiothoracic surgery. A single-center, nested, retrospective, matched case-control study. A 26-bed cardiac ICU in a 303-bed tertiary care pediatric hospital. Cases with deep surgical site infection following cardiothoracic surgery were identified retrospectively from January 2010 through December 2013 and individually matched to controls at a ratio of 1:2 by age, gender, Risk Adjustment for Congenital Heart Surgery score, Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery category, primary cardiac diagnosis, and procedure. None. Twelve cases with deep surgical site infection were identified and matched to 24 controls without detectable differences in perioperative clinical characteristics. Deep surgical site infection cases had larger thoracostomy output and bolus IV fluid volumes at 6, 24, and 48 hours postoperatively compared with controls. For every 1 mL/kg of thoracostomy output, the odds of developing a deep surgical site infection increase by 13%. By receiver operative characteristic curve analysis, a cutoff of 49 mL/kg of thoracostomy output at 48 hours best discriminates the development of deep surgical site infection (sensitivity 83%, specificity 83%). Peak fluid overload was greater in cases than matched controls (12.5% vs 6%; p analysis, a threshold value of 10% peak fluid overload was observed to identify deep surgical site infection (sensitivity 67%, specificity 79%). Conditional logistic regression of peak fluid overload greater than 10% on the development of deep surgical site infection yielded an odds ratio of 9.4 (95% CI, 2-46.2). Increased postoperative peak fluid overload and cumulative thoracostomy output were associated with deep surgical site infection after pediatric cardiothoracic surgery. We

  7. Exposure of Induced Pluripotent Stem Cell-Derived Vascular Endothelial and Smooth Muscle Cells in Coculture to Hemodynamics Induces Primary Vascular Cell-Like Phenotypes.

    Science.gov (United States)

    Collado, Maria S; Cole, Banumathi K; Figler, Robert A; Lawson, Mark; Manka, David; Simmers, Michael B; Hoang, Steve; Serrano, Felipe; Blackman, Brett R; Sinha, Sanjay; Wamhoff, Brian R

    2017-08-01

    Human induced pluripotent stem cells (iPSCs) can be differentiated into vascular endothelial (iEC) and smooth muscle (iSMC) cells. However, because iECs and iSMCs are not derived from an intact blood vessel, they represent an immature phenotype. Hemodynamics and heterotypic cell:cell communication play important roles in vascular cell phenotypic modulation. Here we tested the hypothesis that hemodynamic exposure of iECs in coculture with iSMCs induces an in vivo-like phenotype. iECs and iSMCs were cocultured under vascular region-specific blood flow hemodynamics, and compared to hemodynamic cocultures of blood vessel-derived endothelial (pEC) and smooth muscle (pSMC) cells. Hemodynamic flow-induced gene expression positively correlated between pECs and iECs as well as pSMCs and iSMCs. While endothelial nitric oxide synthase 3 protein was lower in iECs than pECs, iECs were functionally mature as seen by acetylated-low-density lipoprotein (LDL) uptake. SMC contractile protein markers were also positively correlated between pSMCs and iSMCs. Exposure of iECs and pECs to atheroprone hemodynamics with oxidized-LDL induced an inflammatory response in both. Dysfunction of the transforming growth factor β (TGFβ) pathway is seen in several vascular diseases, and iECs and iSMCs exhibited a transcriptomic prolife similar to pECs and pSMCs, respectively, in their responses to LY2109761-mediated transforming growth factor β receptor I/II (TGFβRI/II) inhibition. Although there are differences between ECs and SMCs derived from iPSCs versus blood vessels, hemodynamic coculture restores a high degree of similarity in their responses to pathological stimuli associated with vascular diseases. Thus, iPSC-derived vascular cells exposed to hemodynamics may provide a viable system for modeling rare vascular diseases and testing new therapeutic approaches. Stem Cells Translational Medicine 2017;6:1673-1683. © 2017 The Authors Stem Cells Translational Medicine published by Wiley

  8. Incidental splenic nodules found on MR imaging done for assessment of iron overload in children.

    Science.gov (United States)

    Ahyad, Rayan A; Lam, Christopher Z; Shearkhani, Omid; Navarro, Oscar M

    2017-06-01

    MR imaging is used to assess iron overload in patients with hemoglobinopathies and in those who have undergone multiple blood transfusions. Sometimes splenic nodules are found incidentally on these examinations and this may cause diagnostic uncertainty. To determine the prevalence, imaging characteristics and evolution of splenic nodules found on MR imaging for iron overload evaluation. Retrospective review of all MR imaging examinations performed for iron overload assessment from 2005 to 2015 in a tertiary pediatric hospital. The presence of focal splenic nodules including number, size, signal characteristics and changes on follow-up MR imaging were recorded. Relevant patient clinical information including underlying hematological disease was also documented. A total of 318 patients had MR imaging for iron overload assessment. Of these, 25 (8%) had at least one incidental splenic nodule. Sickle cell disease was present in 22 patients (88%) and thalassemia in 3 (12%). On intermediate-weighted spin-echo images, the nodules had high signal intensity compared to the remainder of the spleen in 23 patients (92%) and low signal intensity in the remaining 2 (8%). In all patients (100%) the nodules showed progressive loss of signal intensity with increasing echo time values. Follow-up MR imaging was performed in 20 (80%) patients, which showed an increase in the size of the splenic nodules in 7 patients (35%) stability in 11 (55%) and a decrease in size in 2 (10%). It is not uncommon to find splenic nodules during MR evaluation of iron overload. In patients with sickle cell disease, most of these nodules are thought to represent preserved splenic tissue and appear hyperintense compared to the remainder of the spleen. They frequently remain stable on follow-up imaging, although about a third of them may show growth. Awareness of these nodules is important to avoid concern for potential malignancy and unnecessary investigations.

  9. Cardiac iron overload in chronically transfused patients with thalassemia, sickle cell anemia, or myelodysplastic syndrome.

    Directory of Open Access Journals (Sweden)

    Mariane de Montalembert

    Full Text Available The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS. In patients with sickle cell anemia (SCA, iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15% patients with thalassemia, none with SCA, and 4 (16% with MDS. The liver iron content (LIC ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29. Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001. Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001. Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation.

  10. Incidental splenic nodules found on MR imaging done for assessment of iron overload in children

    Energy Technology Data Exchange (ETDEWEB)

    Ahyad, Rayan A.; Lam, Christopher Z.; Navarro, Oscar M. [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada); Shearkhani, Omid [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada)

    2017-06-15

    MR imaging is used to assess iron overload in patients with hemoglobinopathies and in those who have undergone multiple blood transfusions. Sometimes splenic nodules are found incidentally on these examinations and this may cause diagnostic uncertainty. To determine the prevalence, imaging characteristics and evolution of splenic nodules found on MR imaging for iron overload evaluation. Retrospective review of all MR imaging examinations performed for iron overload assessment from 2005 to 2015 in a tertiary pediatric hospital. The presence of focal splenic nodules including number, size, signal characteristics and changes on follow-up MR imaging were recorded. Relevant patient clinical information including underlying hematological disease was also documented. A total of 318 patients had MR imaging for iron overload assessment. Of these, 25 (8%) had at least one incidental splenic nodule. Sickle cell disease was present in 22 patients (88%) and thalassemia in 3 (12%). On intermediate-weighted spin-echo images, the nodules had high signal intensity compared to the remainder of the spleen in 23 patients (92%) and low signal intensity in the remaining 2 (8%). In all patients (100%) the nodules showed progressive loss of signal intensity with increasing echo time values. Follow-up MR imaging was performed in 20 (80%) patients, which showed an increase in the size of the splenic nodules in 7 patients (35%) stability in 11 (55%) and a decrease in size in 2 (10%). It is not uncommon to find splenic nodules during MR evaluation of iron overload. In patients with sickle cell disease, most of these nodules are thought to represent preserved splenic tissue and appear hyperintense compared to the remainder of the spleen. They frequently remain stable on follow-up imaging, although about a third of them may show growth. Awareness of these nodules is important to avoid concern for potential malignancy and unnecessary investigations. (orig.)

  11. Genistein alleviates pressure overload-induced cardiac dysfunction and interstitial fibrosis in mice.

    Science.gov (United States)

    Qin, Wei; Du, Ning; Zhang, Longyin; Wu, Xianxian; Hu, Yingying; Li, Xiaoguang; Shen, Nannan; Li, Yang; Yang, Baofeng; Xu, Chaoqian; Fang, Zhiwei; Lu, Yanjie; Zhang, Yong; Du, Zhimin

    2015-12-01

    Pressure overload-induced cardiac interstitial fibrosis is viewed as a major cause of heart failure in patients with hypertension or aorta atherosclerosis. The purpose of this study was to investigate the effects and the underlying mechanisms of genistein, a natural phytoestrogen found in soy bean extract, on pressure overload-induced cardiac fibrosis. Genisten was administered to mice with pressure overload induced by transverse aortic constriction. Eight weeks later, its effects on cardiac dysfunction, hypertrophy and fibrosis were determined. Its effects on proliferation, collagen production and myofibroblast transformation of cardiac fibroblasts (CFs) and the signalling pathways were also assessed in vitro. Pressure overload-induced cardiac dysfunction, hypertrophy and fibrosis were markedly attenuated by genistein. In cultured CFs, genistein inhibited TGFβ1-induced proliferation, collagen production and myofibroblast transformation. Genistein suppressed TGFβ-activated kinase 1 (TAK1) expression and produced anti-fibrotic effects by blocking the TAK1/MKK4/JNK pathway. Further analysis indicated that it up-regulated oestrogen-dependent expression of metastasis-associated gene 3 (MTA3), which was found to be a negative regulator of TAK1. Silencing MTA3 by siRNA, or inhibiting the activity of the MTA3-NuRD complex with trichostatin A, abolished genistein's anti-fibrotic effects. Genistein improved cardiac function and inhibited cardiac fibrosis in response to pressure overload. The underlying mechanism may involve regulation of the MTA3/TAK1/MKK4/JNK signalling pathway. Genistein may have potential as a novel agent for prevention and therapy of cardiac disorders associated with fibrosis. © 2014 The British Pharmacological Society.

  12. Calcium overload injury of rats' enterocyte IEC-6 by heat stress in vitro

    Directory of Open Access Journals (Sweden)

    Yan GENG

    2013-07-01

    Full Text Available Objective To investigate the effect of gradient heat stress on calcium overload of rats' enterocyte IEC-6 and calcium overload-related cell injury in vitro. Methods Thermal gradient was set in culturing IEC-6 cells in vitro. After thermal stimulation, Fluo-3Am probe with fluorescence microscope or flow cytometry was used to detect the change in intracellular Ca2+ concentration of IEC-6 cells. Phase contrast microscope was used to observe the morphological change in IEC-6. Coomassie blue dying method was employed to test the change in IEC-6 cytoskeleton. CCK-8 assay was used to assess cellular viability. Adhesion assay was applied to test the change in basilar membrane adhesiveness of IEC-6 cells. Results Compared with normal control group, cells of heat stress groups showed a thermal-dependent increase in intracellular Ca2+ concentration (P<0.01. Cells of heat stress groups were rounded in shape, the pseudopod was shorter, and cell space was enlarged. These phenomena were more obvious in 45℃ culture than in that of 43℃. Coomassie blue dying showed that the cytoskeleton of cells in heat stress groups became thickened and disordered, and stress fibers appeared. These phenomena were also more obvious in 45℃ culture than in that of 43℃. A thermal-dependant decline of cell viability in heat stress groups was observed via CCK-8 assay (P<0.01, and a thermal-dependant decline of basilar membrane adhesiveness in heat stress groups was observed via adhesion assay (P<0.01. Conclusion Heat stress may cause calcium overload of IEC-6 cells, and thus resulting in a series of calcium overload-related cell injury. Further investigation of the effect and mechanism of heat stress on calcium overload of intestinal mucosa endothelial cells may help further understand the mechanism of the pathogenesis of heat stroke.

  13. Ultrasound Changes in Achilles Tendon and Gastrocnemius Medialis Muscle on Squat Eccentric Overload and Running Performance.

    Science.gov (United States)

    Sanz-López, Fernando; Berzosa Sánchez, César; Hita-Contreras, Fidel; Cruz-Diaz, David; Martínez-Amat, Antonio

    2016-07-01

    Sanz-López, F, Berzosa Sánchez, C, Hita-Contreras, F, Cruz-Diaz, D, and Martínez-Amat, A. Ultrasound changes in Achilles tendon and gastrocnemius medialis muscle on squat eccentric overload and running performance. J Strength Cond Res XX(X): 000-000, 2015-Previous studies have proven the adaptation to load in the Achilles tendon and gastrocnemius muscle after different types of exercise, such as running, heel drop training, and a variety of sports. These findings have been applied to improve performance and in the treatment and prevention of overuse injuries. However, the effects that squat performance may have on the Achilles tendon and gastrocnemius muscle are still unknown. Squats are a widely used training exercise that involves calf-muscle activation. Similarly, no reports have been published regarding the adaptation to load of trained and untrained subjects during several consecutive days of running. The purpose of this study was to analyze changes in the Achilles tendon and in the pennation angles of the gastrocnemius medialis after eccentric overload training and within 3 days of running. Twenty healthy males who volunteered for this study were divided into 2 groups. Subjects in the eccentric overload training (ECC) group performed 6 weeks of eccentric overload training (twice weekly, 4 sets of 7 repetitions in a Yoyo squat device) before the running intervention. All participants, ECC and control (CONT) groups, ran on 3 consecutive days. After the eccentric training, an increase in the cross-sectional area of the Achilles tendon and in the pennation angle was observed. As for the running intervention, the behavior of tissues in both groups was similar. These results suggest that eccentric overload training with squats promotes changes in the Achilles tendon and in the pennation angle of the gastrocnemius medialis muscle. Nevertheless, significant changes in the tissue do not appear between the running performance of trained and untrained subjects.

  14. Biochemical assessment of lead overload and the protective effect of ...

    African Journals Online (AJOL)

    Abstract. The kidney in addition to the excretion of waste, plays a significant role in the regulation of total body homeostasis and is the predominant organ involved in the regulation of extra cellular fluid volume. ... Urea, creatinine, uric acid, calcium, phosphate and electrolytes were determined by spectrophotometric methods

  15. Managing the Role Stress of Public Relations Practitioners in International Schools

    Science.gov (United States)

    Bunnell, Tristan

    2006-01-01

    This article examines the diverse role and work of public relations practitioners in the growing body of international schools. It examines evidence of "role stress" in the form of the subsets of role overload, role ambiguity, role conflict and role preparedness. Three particular aspects were identified. The role seems prone to change alongside…

  16. Hemodynamic numerical simulation and analysis of oscillatory blood flow in growing aneurysms.

    Science.gov (United States)

    Wang, Lifang; Zhou, Xiaohua; Shen, Mingxiu; Sun, Yanping; Sun, Guifang

    2014-01-01

    Hemodynamics plays a crucial role in the formation, progression and rupture of intracranial aneurysms. Understanding these mechanisms is important to improve current diagnosis and treatment of intracranial aneurysms. In this study we simulate and analyze the pressure gradients and the blood flow fields in growing intracranial aneurysms. Firstly, the pressure gradients are obtained according to the blood velocity waveform at the axis of the inlet to the artery, which can be acquired by transcranial Doppler technology. Then, blood flow fields are calculated by solving the linearized Navier-Stokes equations and continuity equation using the Fourier series method. Results show that the higher the aneurysm dilatation degree is, the lower the maximum oscillatory velocity will be. Therefore, the oscillatory velocity may be used to analyze the characteristics of blood flow signals from aneurysm and to forecast the size of aneurysm. This sensitive parameter can be utilized for the detection of vessel diseases, which is promising to provide a useful reference in clinical application.

  17. Stretch-Induced Regulation of Angiotensinogen Gene Expression in Cardiac Myocytes and Fibroblasts: Opposing Roles of JNK1/2 and p38α MAP Kinases

    OpenAIRE

    Lal, Hind; Verma, Suresh K.; Golden, Honey B.; Foster, Donald M.; Smith, Manuela; Dostal, David E.

    2008-01-01

    The cardiac renin-angiotensin system (RAS) has been implicated in mediating myocyte hypertrophy, remodeling, and fibroblast proliferation in the hemodynamically overloaded heart. However, the intracellular signaling mechanisms responsible for regulation of angiotensinogen (Ao), a substrate of the RAS system, are largely unknown. Here we report the identification of JNK1/2 as a negative, and p38α as a major positive regulator of Ao gene expression. Isolated neonatal rat ventricular myocytes (N...

  18. The Diagnosis and Hemodynamic Monitoring of Circulatory Shock: Current and Future Trends

    Directory of Open Access Journals (Sweden)

    Hendy Adham

    2016-07-01

    Full Text Available Circulatory shock is a complex clinical syndrome encompassing a group of conditions that can arise from different etiologies and presented by several different hemodynamic patterns. If not corrected, cell dysfunction, irreversible multiple organ insufficiency, and death may occur. The four basic types of shock, hypovolemic, cardiogenic, obstructive and distributive, have features similar to that of hemodynamic shock. It is therefore essential, when monitoring hemodynamic shock, to making accurate clinical assessments which will guide and dictate appropriate management therapy. The European Society of Intensive Care has recently made recommendations for monitoring hemodynamic shock. The present paper discusses the issues raised in the new statements, including individualization of blood pressure targets, prediction of fluid responsiveness, and the use of echocardiography as the first means during the initial evaluation of circulatory shock. Also, the place of more invasive hemodynamic monitoring techniques and future trends in hemodynamic and metabolic monitoring in circulatory shock, will be debated.

  19. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

    Directory of Open Access Journals (Sweden)

    Chalmers AW

    2016-02-01

    Full Text Available Anna W Chalmers, Jamile M Shammo Department of Internal Medicine, Division of Hematology/Oncology, Rush University Medical Center, Chicago, IL, USA Abstract: Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelodysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. Keywords: iron chelation therapy, transfusional iron overload, deferasirox

  20. Cushing′s surgery: Role of the anesthesiologist

    Directory of Open Access Journals (Sweden)

    Rudin Domi

    2011-01-01

    Full Text Available Cushing′s syndrome is a clinical situation, caused by excessive glucocorticoid level, resulting in several features such as central obesity, supraclavicular fat, "moon face," "buffalo hump," hyperglycemia, metabolic alkalosis, hypokalemia, poor wound healing, easy bruising, hypertension, proximal muscle weakness, thin extremities, skin thinning, menstrual irregularities, and purple striae. In the perioperative period, the anesthesiologist must deal with difficult ventilation and intubation, hemodynamic disturbances, volume overload and hypokalemia, glucose intolerance, and diabetes, maintaining the blood cortisol level and preventing the glucocorticoid deficiency. This syndrome is quite rare and its features make these patients very difficult to the anesthesiologist.

  1. Effects of induced Na+/Ca2+ exchanger overexpression on the spatial distribution of L-type Ca2+ channels and junctophilin-2 in pressure-overloaded hearts.

    Science.gov (United States)

    Ujihara, Yoshihiro; Mohri, Satoshi; Katanosaka, Yuki

    2016-11-25

    The Na+/Ca2+ exchanger 1 (NCX1) is an essential Ca2+ efflux system in cardiomyocytes. Although NCX1 is distributed throughout the sarcolemma, a subpopulation of NCX1 is localized to transverse (T)-tubules. There is growing evidence that T-tubule disorganization is a causal event that shifts the transition from hypertrophy to heart failure (HF). However, the detailed molecular mechanisms have not been clarified. Previously, we showed that induced NCX1 expression in pressure-overloaded hearts attenuates defective excitation-contraction coupling and HF progression. Here, we examined the effects of induced NCX1 overexpression on the spatial distribution of L-type Ca2+ channels (LTCCs) and junctophilin-2 (JP2), a structural protein that connects the T-tubule and sarcoplasmic reticulum membrane, in pressure-overloaded hearts. Quantitative analysis showed that the regularity of NCX1 localization was significantly decreased at 8 weeks after transverse aortic constriction (TAC)-surgery; however, T-tubule organization and the regularities of LTCC and JP2 immunofluorescent signals were maintained at this time point. These observations demonstrated that release of NCX1 from the T-tubule area occurred before the onset of T-tubule disorganization and LTCC and JP2 mislocalization. Moreover, induced NCX1 overexpression at 8 weeks post-TAC not only recovered NCX1 regularity but also prevented the decrease in LTCC and JP2 regularities at 16 weeks post-TAC. These results suggested that NCX1 may play an important role in the proper spatial distribution of LTCC and JP2 in T-tubules in the context of pressure-overloading. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Fluid overload and survival in critically ill patients with acute kidney injury receiving continuous renal replacement therapy

    Science.gov (United States)

    Kim, Il Young; Kim, Joo Hui; Lee, Dong Won; Lee, Soo Bong; Rhee, Harin; Seong, Eun Young; Kwak, Ihm Soo

    2017-01-01

    Background Fluid overload is known to be associated with increased mortality in patients with acute kidney injury (AKI) who are critically ill. In this study, we intended to uncover whether the adverse effect of fluid overload on survival could be applied to all of the patients with AKI who received continuous renal replacement therapy (CRRT). Methods We analyzed 341 patients with AKI who received CRRT in our intensive care units. The presence of fluid overload was defined as a minimum 10% increase in body weight from the baseline. Demographics, comorbid diseases, clinical data, severity of illness [the sequential organ failure assessment (SOFA) score, number of vasopressors, diagnosis of sepsis, use of ventilator] upon ICU admission, fluid overload status, and time elapsed from AKI diagnosis until CRRT initiation were reviewed from the medical charts. Results Patients with total fluid overload from 3 days before CRRT initiation to ICU discharge had a significantly lower survival rate after ICU admission, as compared to patients with no fluid overload (P < 0.001). Among patients with sepsis (P < 0.001) or with high SOFA scores (P < 0.001), there was a significant difference in survival of the patients with and without fluid overload. In patients without sepsis or with low SOFA score, there was no significant difference in survival of patients irrespective of fluid overload. Conclusion Our study demonstrates that the adverse effect of fluid overload on survival is more evident in patients with sepsis or with more severe illness, and that it might not apply to patients without sepsis or with less severe illness. PMID:28196107

  3. Impact of iron overload on interleukin-10 levels, biochemical parameters and oxidative stress in patients with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    Maritza Cavalcante Barbosa

    2013-01-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the impact of iron overload on the profile of interleukin-10 levels, biochemical parameters and oxidative stress in sickle cell anemia patients. METHODS: A cross-sectional study was performed of 30 patients with molecular diagnosis of sickle cell anemia. Patients were stratified into two groups, according to the presence of iron overload: Iron overload (n = 15 and Non-iron overload (n = 15. Biochemical analyses were performed utilizing the Wiener CM 200 automatic analyzer. The interleukin-10 level was measured by capture ELISA using the BD OptEIAT commercial kit. Oxidative stress parameters were determined by spectrophotometry. Statistical analysis was performed using GraphPad Prism software (version 5.0 and statistical significance was established for p-values < 0.05 in all analyses. RESULTS: Biochemical analysis revealed significant elevations in the levels of uric acid, triglycerides, very low-density lipoprotein (VLDL, alanine aminotransferase (ALT, lactate dehydrogenase (LDH, urea and creatinine in the Iron overload Group compared to the Non-iron overload Group and significant decreases in the high-density lipoprotein (HDL and low-density lipoprotein (LDL. Ferritin levels correlated positively with uric acid concentrations (p-value < 0.05. The Iron overload Group showed lower interleukin-10 levels and catalase activity and higher nitrite and malondialdehyde levels compared with the Non-iron overload Group. CONCLUSION: The results of this study are important to develop further consistent studies that evaluate the effect of iron overload on the inflammatory profile and oxidative stress of patients with sickle cell anemia.

  4. Effects of Hemodynamic Instability on Early Outcomes and Late Survival Following Repair of Acute Type A Aortic Dissection.

    Science.gov (United States)

    Conway, Brian D; Stamou, Sotiris C; Kouchoukos, Nicholas T; Lobdell, Kevin W; Khabbaz, Kamal; Patzelt, Lawrence H; Hagberg, Robert C

    2014-02-01

    The goal of this study was to compare operative mortality and actuarial survival between patients presenting with and without hemodynamic instability who underwent repair of acute Type A aortic dissection. Previous studies have demonstrated that hemodynamic instability is related to differences in early and late outcomes following acute Type A dissection occurrence. However, it is unknown whether hemodynamic instability at the initial presentation affects early clinical outcomes and survival after repair of Type A aortic dissection. A total of 251 patients from four academic medical centers underwent repair of acute Type A aortic dissection between January 2000 and October 2010. Of those, 30 presented with hemodynamic instability while 221 patients did not. Median ages were 63 years (range 38-82) and 60 years (range 19-87) for patients presenting with hemodynamic instability compared to patients without hemodynamic instability, respectively (P = 0.595). Major morbidity, operative mortality, and 10-year actuarial survival were compared between groups. Operative mortality was profoundly influenced by hemodynamic instability (patients with hemodynamic instability 47% versus 14% for patients without hemodynamic instability, P < 0.001). Actuarial 10-year survival rates for patients with hemodynamic instability were 44% versus 63% for patients without hemodynamic instability (P = 0.007). Hemodynamic instability has a profoundly negative impact on early outcomes and operative mortality in patients with acute Type A aortic dissection. However, late survival is comparable between hemodynamically unstable and non-hemodynamically unstable patients.

  5. Prevalence and risk factors of fluid overload in Southern Chinese continuous ambulatory peritoneal dialysis patients.

    Directory of Open Access Journals (Sweden)

    Qunying Guo

    Full Text Available BACKGROUND: Fluid overload is frequently present in CAPD patients and one of important predictors of mortality. The aim of this study is to investigate the prevalence and associated risk factors in a cohort study of Southern Chinese CAPD patients. METHODS: The patients (receiving CAPD 3 months and more in our center were investigated from January 1, 2008 to December 31, 2009. Multi-frequency bioelectrical impedance analysis was used to assess the patient's body composition and fluid status. RESULTS: A total of 307 CAPD patients (43% male, mean age 47.8±15.3 years were enrolled, with a median duration of PD 14.6 (5.9-30.9 months. Fluid overload (defined by Extracellular water/Total body water (ECW/TBW≥0.40 was present in 205 (66.8% patients. Univariate analysis indicated that ECW/TBW were inversely associated with body mass index (r = -0.11, P = 0.047, subjective global assessment score (r = -0.11, P = 0.004, body fat mass (r = -0.15, P = 0.05, serum albumin (r = -0.32, P<0.001, creatinine (r = -0.14, P = 0.02, potassium (r = -0.15, P = 0.02, and residual urine output (r = -0.14, P = 0.01, positively associated with age (r = 0.27, P<0.001, Chalrlson Comorbidity Index score (r = 0.29, P<0.001, and systolic blood pressure (r = 0.22, P<0.001. Multivariate linear regression showed that lower serum albumin (β = -0.223, P<0.001, lower body fat mass (β = -0.166, P = 0.033, old age (β = 0.268, P<0.001, higher systolic blood pressure (β = 0.16, P = 0.006, less residual urine output (β = -0.116, P = 0.042, and lower serum potassium (β = -0.126, P = 0.03 were independently associated with higher ECW/TBW. After 1 year of follow-up, the cardiac event rate was significantly higher in the patients with fluid overload (17.1% vs 6.9%, P = 0.023 than that of the normal hydrated patients. CONCLUSIONS: The prevalence of fluid overload was high in CAPD patients. Fluid overload in CAPD patients were independently associated with protein-energy wasting, old

  6. Road signage comprehension and overload: The role of driving style and need for closure

    DEFF Research Database (Denmark)

    Bortei-Doku, Shaun; Kaplan, Sigal; Prato, Carlo Giacomo

    2017-01-01

    This study looks at the provision of information via traffic signs and its relation with driving styles, need for closure and socio-economic characteristics of road users. A web-based questionnaire allowed collecting information about traffic signs and road surface markings in 12 traffic locations...... the road environment without signs and a second configuration added traffic signs to verify information redundancy. Respondents indicated for each location which manoeuvres they deemed legal and how many conflicts they estimated without traffic signs, and safety perception and comfort level improved......, and results reveal that: (i) road users are heterogeneous in their perception and processing of information, as the number of manoeuvres correctly identified as legal relates to their socio-economic characteristics; (ii) the perception of improvements after the provision of information relates also...

  7. Computational study of anterior communicating artery hemodynamics before aneurysm formation

    Science.gov (United States)

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

    2012-03-01

    It is widely accepted that complexity in the flow pattern at the anterior communicating artery (AComA) is associated with the high rate of aneurysm formation in that location observed in large studies. A previous computational hemodynamic study showed a possible association between high maximum intraaneurysmal wall shear stress (WSS) at the systolic peak with rupture in a cohort of AComA aneurysms. In another study it was observed a connection between location of aneurysm blebs and regions of high WSS in models where blebs were virtually removed. However, others reported associations between low WSS and either rupture or blister formation. The purpose of this work is to study associations between hemodynamic patterns and AComA aneurysm initiation by comparing hemodynamics in the aneurysm and the normal model where the aneurysm was computationally removed. Vascular models of both right and left circulation were independently reconstructed from three-dimensional rotational angiography images using deformable models, and fused using a surface merging algorithm. The geometric models were then used to generate high-quality volumetric finite element grids of tetrahedra with an advancing front technique. For each patient, the second anatomical model was created by digitally removing the aneurysm. It was iteratively achieved by applying a Laplacian smoothing filter and remeshing the surface. Finite element blood flow numerical simulations were performed. It was observed that aneurysms initiated in regions of high and moderate WSS in the counterpart normal models. Adjacent or close to those regions, low WSS portions of the arterial wall were not affected by the disease.

  8. Echocardiographic and Hemodynamic Predictors of Mortality in Idiopathic Pulmonary Fibrosis

    Science.gov (United States)

    Rivera-Lebron, Belinda N.; Forfia, Paul R.; Kreider, Maryl; Lee, James C.; Holmes, John H.

    2013-01-01

    Background: Idiopathic pulmonary fibrosis (IPF) can lead to the development of pulmonary hypertension, which is associated with an increased risk of death. In pulmonary arterial hypertension, survival is directly related to the capacity of the right ventricle to adapt to elevated pulmonary vascular load. The relative importance of right ventricular function in IPF is not well understood. Our objective was to evaluate right ventricular echocardiographic and hemodynamic predictors of mortality in a cohort of patients with IPF referred for lung transplant evaluation. Methods: We performed a retrospective cohort study of 135 patients who met 2011 American Thoracic Society/European Respiratory Society criteria for IPF and who were evaluated for lung transplantation at the Hospital of the University of Pennsylvania. Results: Right ventricle:left ventricle diameter ratio (hazard ratio [HR], 4.5; 95% CI, 1.7-11.9), moderate to severe right atrial and right ventricular dilation (HR, 2.9; 95% CI, 1.4-5.9; and HR, 2.7; 95% CI, 1.4-5.4, respectively) and right ventricular dysfunction (HR, 5.5; 95% CI, 2.6-11.5) were associated with an increased risk of death. Higher pulmonary vascular resistance was also associated with increased mortality (HR per 1 Wood unit, 1.3; 95% CI, 1.1-1.5). These risk factors were independent of age, sex, race, height, weight, FVC, and lung transplantation status. Other hemodynamic indices, such as mean pulmonary artery pressure and cardiac index, were not associated with outcome. Conclusions: Right-sided heart size and right ventricular dysfunction measured by echocardiography and higher pulmonary vascular resistance by invasive hemodynamic assessment predict mortality in patients with IPF evaluated for lung transplantation. PMID:23450321

  9. Current and Potential Therapeutic Strategies for Hemodynamic Cardiorenal Syndrome.

    Science.gov (United States)

    Obi, Yoshitsugu; Kim, Taehee; Kovesdy, Csaba P; Amin, Alpesh N; Kalantar-Zadeh, Kamyar

    2016-02-01

    Cardiorenal syndrome (CRS) encompasses conditions in which cardiac and renal disorders co-exist and are pathophysiologically related. The newest classification of CRS into seven etiologically and clinically distinct types for direct patient management purposes includes hemodynamic, uremic, vascular, neurohumoral, anemia- and/or iron metabolism-related, mineral metabolism-related and protein-energy wasting-related CRS. This classification also emphasizes the pathophysiologic pathways. The leading CRS category remains hemodynamic CRS, which is the most commonly encountered type in patient care settings and in which acute or chronic heart failure leads to renal impairment. This review focuses on selected therapeutic strategies for the clinical management of hemodynamic CRS. This is often characterized by an exceptionally high ratio of serum urea to creatinine concentrations. Loop diuretics, positive inotropic agents including dopamine and dobutamine, vasopressin antagonists including vasopressin receptor antagonists such as tolvaptan, nesiritide and angiotensin-neprilysin inhibitors are among the pharmacologic agents used. Additional therapies include ultrafiltration (UF) via hemofiltration or dialysis. The beneficial versus unfavorable effects of these therapies on cardiac decongestion versus renal blood flow may act in opposite directions. Some of the most interesting options for the outpatient setting that deserve revisiting include portable continuous dobutamine infusion, peritoneal dialysis and outpatient UF via hemodialysis or hemofiltration. The new clinically oriented CRS classification system is helpful in identifying therapeutic targets and offers a systematic approach to an optimal management algorithm with better understanding of etiologies. Most interventions including UF have not shown a favorable impact on outcomes. Outpatient portable dobutamine infusion is underutilized and not well studied. Revisiting traditional and novel strategies for outpatient

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-16

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

  11. Hemodynamic effects of prazosin in chronic heart failure.

    Science.gov (United States)

    Parmley, W W; Chatterjee, K; Arnold, S; Rubin, S A; Brundage, B H; Williams, R L; Ports, T; Chuck, L; Rouleau, J

    1981-09-01

    Three series of investigations were carried out with prazosin (PZN) hydrochloride. In the first, hemodynamic effects of PZN were compared with those of hydralazine (HDZ) in 11 patients with chronic congestive heart failure (CHF). In doses up to 5 mg, PZN increased cardiac output (CO) 20% accompanied by a 20% decrease in pulmonary capillary wedge pressure (LVFP). HDZ increased CO by 50% with little or no effect on LVFP. An additional 12 patients were given multiple 5 mg doses of PZN at 6-hour intervals with measurements of hemodynamic and plasma blood levels. Results suggested an attenuation of the effects of PZN on increasing CO but not on decreasing LVFP. This attenuation of CO was not due to inadequate plasma levels. Acute exercise studies (supine bicycle) were performed in 10 patients with severe CHF before and after the administration of several doses of PZN. There appeared to be a greater effect of PZN during exercise than at rest, with a beneficial increase in CO and reduction in LVFP. These data suggest that, despite hemodynamic attenuation of its effects on CO at rest, PZN may still be beneficial to active patients with CHF. In vitro studies with various vasodilators were performed to evaluate potential intropic effects. Isometric force (cat papillary muscle) increased 2% with 10-4M and 31% with 10-3M HDZ. PZN increased force 4% at 10-6M and 18% at 10-4M. Captopril did not increase force development at any dose level. The doses of HDZ and PZN that increased force development were higher than usual clinical doses.

  12. Central and regional hemodynamics in prolonged space flights

    Science.gov (United States)

    Gazenko, O. G.; Shulzhenko, E. B.; Turchaninova, V. F.; Egorov, A. D.

    This paper presents the results of measuring central and regional (head, forearm, calf) hemodynamics at rest and during provocative tests by the method of tetrapolar rheography in the course of Salyut-6-Soyuz and Salyut-7-Soyuz missions. The measurements were carried out during short-term (19 man-flights of 7 days in duration) and long-term (21 man-flights of 65-237 days in duration) manned missions. At rest, stroke volume (SV) and cardiac output (CO) as well as heart rate (HR) decreased insignificantly (in short-term flights) or remained essentially unchanged (in long-term flights). In prolonged flights CO increased significantly in response to exercise tests due to an increase in HR and the lack of changes in SV. After exercise tests SV and CO decreased as compared to the preflight level. During lower body negative pressure (LBNP) tests HR and CO were slightly higher than preflight. Changes in regional hemodynamics included a distinct decrease of pulse blood filling (PBF) of the calf, a reduction of the tone of large vessels of the calf and small vessels of the forearm. Head examination (in the region of the internal carotid artery) showed a decrease of PBF of the left hemisphere (during flight months 2-8) and a distinct decline of the tone of small vessels, mainly, in the right hemisphere. During LBNP tests the tone of pre- and postcapillary vessels of the brain returned to normal while PBF of the right and left hemisphere vessels declined. It has been shown that regional circulation variations depend on the area examined and are induced by a rearrangement of total hemodynamics of the human body in microgravity. This paper reviews the data concerning changes in central and regional circulation of men in space flights of different duration.

  13. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    Energy Technology Data Exchange (ETDEWEB)

    Rogue, Alexandra [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Biologie Servier, Gidy (France); Anthérieu, Sébastien; Vluggens, Aurore [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Umbdenstock, Thierry [Technologie Servier, Orléans (France); Claude, Nancy [Institut de Recherches Servier, Courbevoie (France); Moureyre-Spire, Catherine de la; Weaver, Richard J. [Biologie Servier, Gidy (France); Guillouzo, André, E-mail: Andre.Guillouzo@univ-rennes1.fr [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France)

    2014-04-01

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

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

    KAUST Repository

    Zayane, Chadia

    2014-06-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Pidnebesna, Anna; Tomeček, David; Hlinka, Jaroslav

    2018-01-01

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

  16. Effects of Dietary Nitrates on Systemic and Cerebrovascular Hemodynamics

    Directory of Open Access Journals (Sweden)

    Vernon Bond

    2013-01-01

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

  17. Cerebral hemodynamic and metabolic changes in fulminant hepatic failure

    Directory of Open Access Journals (Sweden)

    Fernando Mendes Paschoal Junior

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

  18. Arteriovenous fistulas aggravate the hemodynamic effect of vein bypass stenoses

    DEFF Research Database (Denmark)

    Nielsen, Tina G; Djurhuus, Christian Born; Morre-Pedersen, Erik

    1996-01-01

    Doppler spectra obtained 10 cm downstream of the fistula. All measurements were carried out with open and clamped fistula. RESULTS: At 30% diameter reducing stenosis opening of the fistula induced a 12% systolic pressure drop across the stenosis but had no adverse effect on the Doppler waveform parameters......PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced...

  19. [Evaluation of the results of lumbar sympathectomy using hemodynamic variables].

    Science.gov (United States)

    Ley Pozo, J; Vega Gómez, M E; Ochoa Bizet, M; Cardona Alvarez, M; Romero Valdés, A; Fernández Boloña, A; Gutiérrez Jiménez, O

    1990-01-01

    In order to evaluate the results of the lumbar sympathectomy, we studied 49 patients in the National Institute of Angiology and Vascular Surgery during two years. The hemodynamic tests were performed the day before and one month after the surgical intervention; they included: skin thermometry, measurement of arterial blood flow and resistance in the foot and in the leg, and reactive hyperemia under photoplethysmographic control. Objectively, it could be seen only an increase in the distal skin temperature and an increase of skin blood flow after this treatment.

  20. From hemodynamic towards cardiomechanic sensors in implantable devices

    Science.gov (United States)

    Ferek-Petric, Bozidar

    2013-06-01

    Sensor could significantly improve the cardiac electrotherapy. It has to provide long-term stabile signal not impeding the device longevity and lead reliability. It may not introduce special implantation and adjustment procedures. Hemodynamic sensors based on the blood flow velocity and cardiomechanic sensors based on the lead bending measurement are disclosed. These sensors have a broad clinical utility. Triboelectric and high-frequency lead bending sensors yield accurate and stable signals whereby functioning with every cardiac lead. Moreover, high frequency measurement avoids use of any kind of special hardware mounted on the cardiac lead.