Therapeutic Hypothermia Reduces Oxidative Damage and Alters Antioxidant Defenses after Cardiac Arrest

Science.gov (United States)

Hackenhaar, Fernanda S.; Medeiros, Tássia M.; Heemann, Fernanda M.; Behling, Camile S.; Putti, Jordana S.; Mahl, Camila D.; Verona, Cleber; da Silva, Ana Carolina A.; Guerra, Maria C.; Gonçalves, Carlos A. S.; Oliveira, Vanessa M.; Riveiro, Diego F. M.; Vieira, Silvia R. R.

2017-01-01

After cardiac arrest, organ damage consequent to ischemia-reperfusion has been attributed to oxidative stress. Mild therapeutic hypothermia has been applied to reduce this damage, and it may reduce oxidative damage as well. This study aimed to compare oxidative damage and antioxidant defenses in patients treated with controlled normothermia versus mild therapeutic hypothermia during postcardiac arrest syndrome. The sample consisted of 31 patients under controlled normothermia (36°C) and 11 patients treated with 24 h mild therapeutic hypothermia (33°C), victims of in- or out-of-hospital cardiac arrest. Parameters were assessed at 6, 12, 36, and 72 h after cardiac arrest in the central venous blood samples. Hypothermic and normothermic patients had similar S100B levels, a biomarker of brain injury. Xanthine oxidase activity is similar between hypothermic and normothermic patients; however, it decreases posthypothermia treatment. Xanthine oxidase activity is positively correlated with lactate and S100B and inversely correlated with pH, calcium, and sodium levels. Hypothermia reduces malondialdehyde and protein carbonyl levels, markers of oxidative damage. Concomitantly, hypothermia increases the activity of erythrocyte antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione S-transferase while decreasing the activity of serum paraoxonase-1. These findings suggest that mild therapeutic hypothermia reduces oxidative damage and alters antioxidant defenses in postcardiac arrest patients. PMID:28553435

Cardiac function of the naked mole-rat: ecophysiological responses to working underground.

Science.gov (United States)

Grimes, Kelly M; Voorhees, Andrew; Chiao, Ying Ann; Han, Hai-Chao; Lindsey, Merry L; Buffenstein, Rochelle

2014-03-01

The naked mole-rat (NMR) is a strictly subterranean rodent with a low resting metabolic rate. Nevertheless, it can greatly increase its metabolic activity to meet the high energetic demands associated with digging through compacted soils in its xeric natural habitat where food is patchily distributed. We hypothesized that the NMR heart would naturally have low basal function and exhibit a large cardiac reserve, thereby mirroring the species' low basal metabolism and large metabolic scope. Echocardiography showed that young (2-4 yr old) healthy NMRs have low fractional shortening (28 ± 2%), ejection fraction (43 ± 2%), and cardiac output (6.5 ± 0.4 ml/min), indicating low basal cardiac function. Histology revealed large NMR cardiomyocyte cross-sectional area (216 ± 10 μm(2)) and cardiac collagen deposition of 2.2 ± 0.4%. Neither of these histomorphometric traits was considered pathological, since biaxial tensile testing showed no increase in passive ventricular stiffness. NMR cardiomyocyte fibers showed a low degree of rotation, contributing to the observed low NMR cardiac contractility. Interestingly, when the exercise mimetic dobutamine (3 μg/g ip) was administered, NMRs showed pronounced increases in fractional shortening, ejection fraction, cardiac output, and stroke volume, indicating an increased cardiac reserve. The relatively low basal cardiac function and enhanced cardiac reserve of NMRs are likely to be ecophysiological adaptations to life in an energetically taxing environment.

Diabetic db/db mice do not develop heart failure upon pressure overload: a longitudinal in vivo PET, MRI, and MRS study on cardiac metabolic, structural, and functional adaptations.

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Abdurrachim, Desiree; Nabben, Miranda; Hoerr, Verena; Kuhlmann, Michael T; Bovenkamp, Philipp; Ciapaite, Jolita; Geraets, Ilvy M E; Coumans, Will; Luiken, Joost J F P; Glatz, Jan F C; Schäfers, Michael; Nicolay, Klaas; Faber, Cornelius; Hermann, Sven; Prompers, Jeanine J

2017-08-01

Heart failure is associated with altered myocardial substrate metabolism and impaired cardiac energetics. Comorbidities like diabetes may influence the metabolic adaptations during heart failure development. We quantified to what extent changes in substrate preference, lipid accumulation, and energy status predict the longitudinal development of hypertrophy and failure in the non-diabetic and the diabetic heart. Transverse aortic constriction (TAC) was performed in non-diabetic (db/+) and diabetic (db/db) mice to induce pressure overload. Magnetic resonance imaging, 31P magnetic resonance spectroscopy (MRS), 1H MRS, and 18F-fluorodeoxyglucose-positron emission tomography (PET) were applied to measure cardiac function, energy status, lipid content, and glucose uptake, respectively. In vivo measurements were complemented with ex vivo techniques of high-resolution respirometry, proteomics, and western blotting to elucidate the underlying molecular pathways. In non-diabetic mice, TAC induced progressive cardiac hypertrophy and dysfunction, which correlated with increased protein kinase D-1 (PKD1) phosphorylation and increased glucose uptake. These changes in glucose utilization preceded a reduction in cardiac energy status. At baseline, compared with non-diabetic mice, diabetic mice showed normal cardiac function, higher lipid content and mitochondrial capacity for fatty acid oxidation, and lower PKD1 phosphorylation, glucose uptake, and energetics. Interestingly, TAC affected cardiac function only mildly in diabetic mice, which was accompanied by normalization of phosphorylated PKD1, glucose uptake, and cardiac energy status. The cardiac metabolic adaptations in diabetic mice seem to prevent the heart from failing upon pressure overload, suggesting that restoring the balance between glucose and fatty acid utilization is beneficial for cardiac function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions

Alterations in cardiac sarcolemmal Ca2+ pump activity during diabetes mellitus

International Nuclear Information System (INIS)

Heyliger, C.E.; Prakash, A.; McNeill, J.

1987-01-01

Diabetes mellitus is frequently associated with a primary cardiomyopathy. The mechanisms responsible for this heart disease are not clear, but an alteration in myocardial Ca 2+ transport is believed to be involved in its development. Even though sarcolemma plays a crucial role in cellular Ca 2+ transport, little appears to be known about its Ca 2+ transporting capability in the diabetic myocardium. In this regard, the authors have examined the status of the cardiac sarcolemmal Ca 2+ pump during diabetes mellitus. Purified sarcolemmal membranes were isolated from male Wistar diabetic rat hearts 8 wk after streptozotocin injection. Ca 2+ pump activity assessed by measuring its Ca 2+ -stimulated adenosine triphosphatase and Ca 2+ -uptake ability in the absence and presence of calmodulin was significantly depressed in the diabetic myocardium relative to controls. These results did not appear to have been influenced by the minimal sarcoplasmic reticular and mitochondrial contamination of this membrane preparation. Hence, it appears that the sarcolemmal Ca 2+ pump is defective in the diabetic myocardium and may be involved in the altered Ca 2+ transport of the heart during diabetes mellitus

Administration of granulocyte-colony stimulating factor accompanied with a balanced diet improves cardiac function alterations induced by high fat diet in mice.

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Daltro, Pâmela Santana; Alves, Paula Santana; Castro, Murilo Fagundes; Azevedo, Carine M; Vasconcelos, Juliana Fraga; Allahdadi, Kyan James; de Freitas, Luiz Antônio Rodrigues; de Freitas Souza, Bruno Solano; Dos Santos, Ricardo Ribeiro; Soares, Milena Botelho Pereira; Macambira, Simone Garcia

2015-12-03

High fat diet (HFD) is a major contributor to the development of obesity and cardiovascular diseases due to the induction of cardiac structural and hemodynamic abnormalities. We used a model of diabetic cardiomyopathy in C57Bl/6 mice fed with a HFD to investigate the effects of granulocyte-colony stimulating factor (G-CSF), a cytokine known for its beneficial effects in the heart, on cardiac anatomical and functional abnormalities associated with obesity and type 2 diabetes. Groups of C57Bl/6 mice were fed with standard diet (n = 8) or HFD (n = 16). After 36 weeks, HFD animals were divided into a group treated with G-CSF + standard diet (n = 8) and a vehicle control group + standard diet (n = 8). Cardiac structure and function were assessed by electrocardiography, echocardiography and treadmill tests, in addition to the evaluation of body weight, fasting glicemia, insulin and glucose tolerance at different time points. Histological analyses were performed in the heart tissue. HFD consumption induced metabolic alterations characteristic of type 2 diabetes and obesity, as well as cardiac fibrosis and reduced exercise capacity. Upon returning to a standard diet, obese mice body weight returned to non-obese levels. G-CSF administration accelerated the reduction in of body weight in obese mice. Additionally, G-CSF treatment reduced insulin levels, diminished heart fibrosis, increased exercise capacity and reversed cardiac alterations, including bradycardia, elevated QRS amplitude, augmented P amplitude, increased septal wall thickness, left ventricular posterior thickening and cardiac output reduction. Our results indicate that G-CSF administration caused beneficial effects on obesity-associated cardiac impairment.

Sex-dependent alteration of cardiac cytochrome P450 gene expression by doxorubicin in C57Bl/6 mice.

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Grant, Marianne K O; Seelig, Davis M; Sharkey, Leslie C; Zordoky, Beshay N

2017-01-01

There is inconclusive evidence about the role of sex as a risk factor for doxorubicin (DOX)-induced cardiotoxicity. Recent experimental studies have shown that adult female rats are protected against DOX-induced cardiotoxicity. However, the mechanisms of this sexual dimorphism are not fully elucidated. We have previously demonstrated that DOX alters the expression of several cytochrome P450 (CYP) enzymes in the hearts of male rats. Nevertheless, the sex-dependent effect of DOX on the expression of CYP enzymes is still not known. Therefore, in the present study, we determined the effect of acute DOX exposure on the expression of CYP genes in the hearts of both male and female C57Bl/6 mice. Acute DOX cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg DOX in male and female adult C57Bl/6 mice. Cardiac function was assessed 5 days after DOX exposure by trans-thoracic echocardiography. Mice were euthanized 1 day or 6 days after DOX or saline injection. Thereafter, the hearts were harvested and weighed. Heart sections were evaluated for pathological lesions. Total RNA was extracted and expression of natriuretic peptides, inflammatory and apoptotic markers, and CYP genes was measured by real-time PCR. Adult female C57Bl/6 mice were protected from acute DOX-induced cardiotoxicity as they show milder pathological lesions, less inflammation, and faster recovery from DOX-induced apoptosis and DOX-mediated inhibition of beta-type natriuretic peptide. Acute DOX exposure altered the gene expression of multiple CYP genes in a sex-dependent manner. In 24 h, DOX exposure caused male-specific induction of Cyp1b1 and female-specific induction of Cyp2c29 and Cyp2e1. Acute DOX exposure causes sex-dependent alteration of cardiac CYP gene expression. Since cardiac CYP enzymes metabolize several endogenous compounds to biologically active metabolites, sex-dependent alteration of CYP genes may play a role in the sexual dimorphism of acute DOX

Combinatorial therapy of exercise-preconditioning and nanocurcumin formulation supplementation improves cardiac adaptation under hypobaric hypoxia.

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Nehra, Sarita; Bhardwaj, Varun; Bansal, Anju; Saraswat, Deepika

2017-09-26

Chronic hypobaric hypoxia (cHH) mediated cardiac insufficiencies are associated with pathological damage. Sustained redox stress and work load are major causative agents of cardiac insufficiencies under cHH. Despite the advancements made in pharmacological (anti-oxidants, vasodilators) and non-pharmacological therapeutics (acclimatization strategies and schedules), only partial success has been achieved in improving cardiac acclimatization to cHH. This necessitates the need for potent combinatorial therapies to improve cardiac acclimatization at high altitudes. We hypothesize that a combinatorial therapy comprising preconditioning to mild aerobic treadmill exercise and supplementation with nanocurcumin formulation (NCF) consisting of nanocurcumin (NC) and pyrroloquinoline quinone (PQQ) might improve cardiac adaptation at high altitudes. Adult Sprague-Dawley rats pre-conditioned to treadmill exercise and supplemented with NCF were exposed to cHH (7620 m altitude corresponding to pO2~8% at 28±2°C, relative humidity 55%±1%) for 3 weeks. The rat hearts were analyzed for changes in markers of oxidative stress (free radical leakage, lipid peroxidation, manganese-superoxide dismutase [MnSOD] activity), cardiac injury (circulating cardiac troponin I [TnI] and T [cTnT], myocardial creatine kinase [CK-MB]), metabolic damage (lactate dehydrogenase [LDH] and acetyl-coenzyme A levels, lactate and pyruvate levels) and bio-energetic insufficiency (ATP, p-AMPKα). Significant modulations (p≤0.05) in cardiac redox status, metabolic damage, cardiac injury and bio-energetics were observed in rats receiving both NCF supplementation and treadmill exercise-preconditioning compared with rats receiving only one of the treatments. The combinatorial therapeutic strategy showed a tremendous improvement in cardiac acclimatization to cHH compared to either exercise-preconditioning or NCF supplementation alone which was evident from the effective modulation in redox, metabolic, contractile

Mitochondrial Dynamics in Diabetic Cardiomyopathy

Science.gov (United States)

Galloway, Chad A.

2015-01-01

Abstract Significance: Cardiac function is energetically demanding, reliant on efficient well-coupled mitochondria to generate adenosine triphosphate and fulfill the cardiac demand. Predictably then, mitochondrial dysfunction is associated with cardiac pathologies, often related to metabolic disease, most commonly diabetes. Diabetic cardiomyopathy (DCM), characterized by decreased left ventricular function, arises independently of coronary artery disease and atherosclerosis. Dysregulation of Ca2+ handling, metabolic changes, and oxidative stress are observed in DCM, abnormalities reflected in alterations in mitochondrial energetics. Cardiac tissue from DCM patients also presents with altered mitochondrial morphology, suggesting a possible role of mitochondrial dynamics in its pathological progression. Recent Advances: Abnormal mitochondrial morphology is associated with pathologies across diverse tissues, suggesting that this highly regulated process is essential for proper cell maintenance and physiological homeostasis. Highly structured cardiac myofibers were hypothesized to limit alterations in mitochondrial morphology; however, recent work has identified morphological changes in cardiac tissue, specifically in DCM. Critical Issues: Mitochondrial dysfunction has been reported independently from observations of altered mitochondrial morphology in DCM. The temporal relationship and causative nature between functional and morphological changes of mitochondria in the establishment/progression of DCM is unclear. Future Directions: Altered mitochondrial energetics and morphology are not only causal for but also consequential to reactive oxygen species production, hence exacerbating oxidative damage through reciprocal amplification, which is integral to the progression of DCM. Therefore, targeting mitochondria for DCM will require better mechanistic characterization of morphological distortion and bioenergetic dysfunction. Antioxid. Redox Signal. 22, 1545–1562. PMID

Determination of myocardial energetic output for cardiac rhythm pacing

Czech Academy of Sciences Publication Activity Database

Heřman, D.; Převorovská, Světlana; Maršík, František

2007-01-01

Roč. 7, č. 4 (2007), s. 156-161 ISSN 1567-8822 R&D Projects: GA ČR GA106/03/1073 Institutional research plan: CEZ:AV0Z20760514 Keywords : heart arrhythmia * cardiac pacing modes * numerical simulation Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

Therapy with mesenchymal stromal cells or conditioned medium reverse cardiac alterations in a high-fat diet-induced obesity model.

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Daltro, P S; Barreto, B C; Silva, P G; Neto, P Chenaud; Sousa Filho, P H F; Santana Neta, D; Carvalho, G B; Silva, D N; Paredes, B D; de Alcantara, A C; Freitas, L A R; Couto, R D; Santos, R R; Souza, B S F; Soares, M B P; Macambira, S G

2017-10-01

Obesity is associated with numerous cardiac complications, including arrhythmias, cardiac fibrosis, remodeling and heart failure. Here we evaluated the therapeutic potential of mesenchymal stromal cells (MSCs) and their conditioned medium (CM) to treat cardiac complications in a mouse model of high-fat diet (HFD)-induced obesity. After obesity induction and HFD withdrawal, obese mice were treated with MSCs, CM or vehicle. Cardiac function was assessed using electrocardiography, echocardiography and treadmill test. Body weight and biochemical parameters were evaluated. Cardiac tissue was used for real time (RT)-polymerase chain reaction (PCR) and histopathologic analysis. Characterization of CM by protein array showed the presence of different cytokines and growth factors, including chemokines, osteopontin, cystatin C, Serpin E1 and Gas 6. HFD-fed mice presented cardiac arrhythmias, altered cardiac gene expression and fibrosis reflected in physical exercise incapacity associated with obesity and diabetes. Administration of MSCs or CM improved arrhythmias and exercise capacity. This functional improvement correlated with normalization of GATA4 gene expression in the hearts of MSC- or CM-treated mice. The gene expression of connexin 43, troponin I, adiponectin, transforming growth factor (TGF) β, peroxisome proliferator activated receptor gamma (PPARγ), insulin-like growth factor 1 (IGF-1), matrix metalloproteinase-9 (MMP9) and tissue inhibitor of metalloproteinases 1 (TIMP1) were significantly reduced in MSCs, but not in CM-treated mice. Moreover, MSC or CM administration reduced the intensity of cardiac fibrosis. Our results suggest that MSCs and CM have a recovery effect on cardiac disturbances due to obesity and corroborate to the paracrine action of MSCs in heart disease models. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Metabonomics Indicates Inhibition of Fatty Acid Synthesis, β-Oxidation, and Tricarboxylic Acid Cycle in Triclocarban-Induced Cardiac Metabolic Alterations in Male Mice.

Science.gov (United States)

Xie, Wenping; Zhang, Wenpeng; Ren, Juan; Li, Wentao; Zhou, Lili; Cui, Yuan; Chen, Huiming; Yu, Wenlian; Zhuang, Xiaomei; Zhang, Zhenqing; Shen, Guolin; Li, Haishan

2018-02-14

Triclocarban (TCC) has been identified as a new environmental pollutant that is potentially hazardous to human health; however, the effects of short-term TCC exposure on cardiac function are not known. The aim of this study was to use metabonomics and molecular biology techniques to systematically elucidate the molecular mechanisms of TCC-induced effects on cardiac function in mice. Our results show that TCC inhibited the uptake, synthesis, and oxidation of fatty acids, suppressed the tricarboxylic acid (TCA) cycle, and increased aerobic glycolysis levels in heart tissue after short-term TCC exposure. TCC also inhibited the nuclear peroxisome proliferator-activated receptor α (PPARα), confirming its inhibitory effects on fatty acid uptake and oxidation. Histopathology and other analyses further confirm that TCC altered mouse cardiac physiology and pathology, ultimately affecting normal cardiac metabolic function. We elucidate the molecular mechanisms of TCC-induced harmful effects on mouse cardiac metabolism and function from a new perspective, using metabonomics and bioinformatics analysis data.

The influence of midazolam on heart rate arises from cardiac autonomic tones alterations in Burmese pythons, Python molurus.

Science.gov (United States)

Lopes, Ivã Guidini; Armelin, Vinicius Araújo; Braga, Victor Hugo da Silva; Florindo, Luiz Henrique

2017-12-01

The GABA A receptor agonist midazolam is a compound widely used as a tranquilizer and sedative in mammals and reptiles. It is already known that this benzodiazepine produces small to intermediate heart rate (HR) alterations in mammals, however, its influence on reptiles' HR remains unexplored. Thus, the present study sought to verify the effects of midazolam on HR and cardiac modulation in the snake Python molurus. To do so, the snakes' HR, cardiac autonomic tones, and HR variability were evaluated during four different experimental stages. The first stage consisted on the data acquisition of animals under untreated conditions, in which were then administered atropine (2.5mgkg -1 ; intraperitoneal), followed later by propranolol (3.5mgkg -1 ; intraperitoneal) (cardiac double autonomic blockade). The second stage focused on the data acquisition of animals under midazolam effect (1.0mgkg -1 ; intramuscular), which passed through the same autonomic blockade protocol of the first stage. The third and fourth stages consisted of the same protocol of stages one and two, respectively, with the exception that atropine and propranolol injections were reversed. By comparing the HR of animals that received midazolam (second and fourth stages) with those that did not (first and third stages), it could be observed that this benzodiazepine reduced the snakes' HR by ~60%. The calculated autonomic tones showed that such cardiac depression was elicited by an ~80% decrease in cardiac adrenergic tone and an ~620% increase in cardiac cholinergic tone - a finding that was further supported by the results of HR variability analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Alterations in cardiac autonomic control in spinal cord injury

DEFF Research Database (Denmark)

Biering-Sørensen, Fin; Biering-Sørensen, Tor; Liu, Nan

2018-01-01

parasympathetic cardiac control. Decreases in sympathetic activity result in heart rate and the arterial blood pressure changes, and may cause arrhythmias, in particular bradycardia, with the risk of cardiac arrest in those with cervical or high thoracic injuries. The objective of this review is to give an update...

Congenital heart malformations induced by hemodynamic altering surgical interventions

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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.

Energetic stress: The reciprocal relationship between energy availability and the stress response.

Science.gov (United States)

Harrell, C S; Gillespie, C F; Neigh, G N

2016-11-01

The worldwide epidemic of metabolic syndromes and the recognized burden of mental health disorders have driven increased research into the relationship between the two. A maladaptive stress response is implicated in both mental health disorders and metabolic disorders, implicating the hypothalamic-pituitary-adrenal (HPA) axis as a key mediator of this relationship. This review explores how an altered energetic state, such as hyper- or hypoglycemia, as may be manifested in obesity or diabetes, affects the stress response and the HPA axis in particular. We propose that changes in energetic state or energetic demands can result in "energetic stress" that can, if prolonged, lead to a dysfunctional stress response. In this review, we summarize the role of the hypothalamus in modulating energy homeostasis and then briefly discuss the relationship between metabolism and stress-induced activation of the HPA axis. Next, we examine seven mechanisms whereby energetic stress interacts with neuroendocrine stress response systems, including by glucocorticoid signaling both within and beyond the HPA axis; by nutrient-induced changes in glucocorticoid signaling; by impacting the sympathetic nervous system; through changes in other neuroendocrine factors; by inducing inflammatory changes; and by altering the gut-brain axis. Recognizing these effects of energetic stress can drive novel therapies and prevention strategies for mental health disorders, including dietary intervention, probiotics, and even fecal transplant. Copyright © 2015 Elsevier Inc. All rights reserved.

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

Science.gov (United States)

Tian, Fangyun; Liu, Tiecheng; Xu, Gang; Li, Duan; Ghazi, Talha; Shick, Trevor; Sajjad, Azeem; Wang, Michael M.; Farrehi, Peter; Borjigin, Jimo

2018-01-01

Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients. PMID:29487541

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

Directory of Open Access Journals (Sweden)

Fangyun Tian

2018-02-01

Full Text Available Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG and electroencephalogram (EEG signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients.

Cardiac and Metabolic Effects of Dietary Selenomethionine Exposure in Adult Zebrafish.

Science.gov (United States)

Pettem, Connor M; Weber, Lynn P; Janz, David M

2017-10-01

Selenium (Se) is an essential micronutrient involved in important metabolic functions for all vertebrate species. As Se is reported to have a narrow margin between essentiality and toxicity, there is growing concern surrounding the adverse effects of elevated Se exposure caused by anthropogenic activities. Recent studies have reported that elevated dietary exposure of fish to selenomethionine (Se-Met) can alter aerobic metabolic capacity, energetics and swimming performance. This study aims to further investigate mechanisms of sublethal Se-Met toxicity, particularly potential underlying cardiovascular implications of chronic exposure to environmentally relevant concentrations of dietary Se-Met in adult zebrafish (Danio rerio). Adult zebrafish were fed either control food (1.1 μg Se/g dry mass [d.m.]) or Se-Met spiked food (10.3 or 28.8 μg Se/g d.m.) for 90 d at 5% body weight per day. Following exposure, ultrahigh resolution B-mode and Doppler ultrasound was used to characterize cardiac function. Chronic dietary exposure to elevated Se-Met significantly reduced ventricular contractile rate, stroke volume, and cardiac output. Exposure to Se-Met significantly decreased mRNA expression of methionine adenosyltransferase 1 alpha and glutathione-S-transferase pi class in liver, and a key cardiac remodelling enzyme, matrix metalloproteinase 2, in adult zebrafish heart. Se-Met significantly increased echodensity at the junction between atrium and ventricle, and these results combined with increased matrix metalloproteinase 2 expression are consistent with cardiac remodelling and fibrosis. The results of this study suggest that chronic exposure to dietary Se-Met can negatively impact cardiac function, and such physiological consequences could reduce the aerobic capacity and survivability of fish. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Non-dipper treated hypertensive patients do not have increased cardiac structural alterations

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Magrini Fabio

2003-02-01

Full Text Available Abstract Background Non-dipping pattern in hypertensive patients has been shown to be associated with an excess of target organ damage and with an adverse outcome. The aim of our study was to assess whether a reduced nocturnal fall in blood pressure (BP, established on the basis of a single 24-h BP monitoring, in treated essential hypertensives is related to more prominent cardiac alterations. Methods We enrrolled 229 treated hypertensive patients attending the out-patient clinic of our hypertension centre; each patient was subjected to the following procedures : 1 clinic BP measurement; 2 blood and urine sampling for routine blood chemistry and urine examination; 3 standard 12-lead electrocardiogram; 4 echocardiography; 5 ambulatory BP monitoring (ABPM. For the purpose of this study ABPM was carried-out in three subgroups with different clinic BP profile : 1 patients with satisfactory BP control (BP 2 in men and 110 g/m2 in women, ≥51/gm2.7 in men and 47/g/m2.7 in women. Results Of the 229 study participants 119 (51.9% showed a fall in SBP/DBP Conclusions In treated essential hypertensives with or without BP control the extent of nocturnal BP decrease is not associated with an increase in LV mass or LVH prevalence; therefore, the non-dipping profile, diagnosed on the basis of a single ABPM, does not identify hypertensive patients with greater cardiac damage.

Mechanisms Involving Ang II and MAPK/ERK1/2 Signaling Pathways Underlie Cardiac and Renal Alterations during Chronic Undernutrition

Science.gov (United States)

Pereira-Acácio, Amaury; Luzardo, Ricardo; Sampaio, Luzia S.; Luna-Leite, Marcia A.; Lara, Lucienne S.; Einicker-Lamas, Marcelo; Panizzutti, Rogério; Madeira, Caroline; Vieira-Filho, Leucio D.; Castro-Chaves, Carmen; Ribeiro, Valdilene S.; Paixão, Ana D. O.; Medei, Emiliano; Vieyra, Adalberto

2014-01-01

Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood. PMID:24983243

Fatty old hearts: role of cardiac lipotoxicity in age-related cardiomyopathy

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Konstantinos Drosatos

2016-08-01

Full Text Available Age-related cardiomyopathy accounts for a significant part of heart failure cases. Imbalance of the energetic equilibrium of the heart along with mitochondrial dysfunction and impaired β-adrenergic receptor signaling contributes in the aggravation of cardiac function in the elderly. In this review article, studies that correlate cardiac aging with lipotoxicity are summarized. The involvement of inhibition of peroxisome proliferator-activated receptor-α, β-adrenergic receptor desensitization, and mitochondrial dysfunction as underlying mechanisms for the lipid-driven age-related cardiomyopathy are presented with the aim to indicate potential therapeutic targets for cardiac aging.

Regulation of cardiac remodeling by cardiac Na/K-ATPase isoforms

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Lijun Catherine Liu

2016-09-01

Full Text Available Cardiac remodeling occurs after cardiac pressure/volume overload or myocardial injury during the development of heart failure and is a determinant of heart failure. Preventing or reversing remodeling is a goal of heart failure therapy. Human cardiomyocyte Na+/K+-ATPase has multiple α isoforms (1-3. The expression of the α subunit of the Na+/K+-ATPase is often altered in hypertrophic and failing hearts. The mechanisms are unclear. There are limited data from human cardiomyocytes. Abundant evidences from rodents show that Na+/K+-ATPase regulates cardiac contractility, cell signaling, hypertrophy and fibrosis. The α1 isoform of the Na+/K+-ATPase is the ubiquitous isoform and possesses both pumping and signaling functions. The α2 isoform of the Na+/K+-ATPase regulates intracellular Ca2+ signaling, contractility and pathological hypertrophy. The α3 isoform of the Na+/K+-ATPase may also be a target for cardiac hypertrophy. Restoration of cardiac Na+/K+-ATPase expression may be an effective approach for prevention of cardiac remodeling. In this article, we will overview: (1 the distribution and function of isoform specific Na+/K+-ATPase in the cardiomyocytes. (2 the role of cardiac Na+/K+-ATPase in the regulation of cell signaling, contractility, cardiac hypertrophy and fibrosis in vitro and in vivo. Selective targeting of cardiac Na+/K+-ATPase isoform may offer a new target for the prevention of cardiac remodeling.

Warming alters energetic structure and function but not resilience of soil food webs

Science.gov (United States)

Schwarz, Benjamin; Barnes, Andrew D.; Thakur, Madhav P.; Brose, Ulrich; Ciobanu, Marcel; Reich, Peter B.; Rich, Roy L.; Rosenbaum, Benjamin; Stefanski, Artur; Eisenhauer, Nico

2017-12-01

Climate warming is predicted to alter the structure, stability, and functioning of food webs1-5. Yet, despite the importance of soil food webs for energy and nutrient turnover in terrestrial ecosystems, the effects of warming on these food webs—particularly in combination with other global change drivers—are largely unknown. Here, we present results from two complementary field experiments that test the interactive effects of warming with forest canopy disturbance and drought on energy flux in boreal-temperate ecotonal forest soil food webs. The first experiment applied a simultaneous above- and belowground warming treatment (ambient, +1.7 °C, +3.4 °C) to closed-canopy and recently clear-cut forest, simulating common forest disturbance6. The second experiment crossed warming with a summer drought treatment (-40% rainfall) in the clear-cut habitats. We show that warming reduces energy flux to microbes, while forest canopy disturbance and drought facilitates warming-induced increases in energy flux to higher trophic levels and exacerbates the reduction in energy flux to microbes, respectively. Contrary to expectations, we find no change in whole-network resilience to perturbations, but significant losses in ecosystem functioning. Warming thus interacts with forest disturbance and drought, shaping the energetic structure of soil food webs and threatening the provisioning of multiple ecosystem functions in boreal-temperate ecotonal forests.

Preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats.

Science.gov (United States)

Roy, Abhro Jyoti; Stanely Mainzen Prince, P

2013-10-01

The present study evaluated the preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats. Rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days and then injected with isoproterenol (100mg/kg body weight) on 8th and 9th day to induce myocardial infarction. Myocardial infarction induced by isoproterenol was indicated by increased level of cardiac sensitive marker and elevated ST-segments in the electrocardiogram. Also, the levels/concentrations of serum and heart cholesterol, triglycerides and free fatty acids were increased in myocardial infarcted rats. Isoproterenol also increased the levels of serum low density and very low density lipoprotein cholesterol and decreased the levels of high density lipoprotein cholesterol. It also enhanced the activity of liver 3-hydroxy-3 methyl glutaryl-Coenzyme-A reductase. p-Coumaric acid pretreatment revealed preventive effects on all the biochemical parameters and electrocardiogram studied in myocardial infarcted rats. The in vitro study confirmed the free radical scavenging property of p-coumaric acid. Thus, p-coumaric acid prevented cardiac hypertrophy and alterations in lipids, lipoproteins, and electrocardiogram, by virtue of its antihypertrophic, antilipidemic, and free radical scavenging effects in isoproterenol induced myocardial infarcted rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

New fluidized bed reactor for coating of energetic materials

NARCIS (Netherlands)

Abadjieva, E.; Huijser, T.; Creyghton, Y.L.M.; Heijden, A.E.D.M. van der

2009-01-01

The process of altering and changing the properties of the energetic materials by coating has been studied extensively by several scientific groups. According to the desired application different coating techniques have been developed and applied to achieve satisfactory results. Among the already

Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure

Directory of Open Access Journals (Sweden)

McIver Lauren J

2009-12-01

Full Text Available Abstract Background Isoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response of the heart in this model to other animal models of heart failure, as well as to the transcriptional response of human hearts suffering heart failure. Results We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively. We compared our results to 18 different microarray data sets (318 individual arrays representing various other animal models and four human cardiac diseases and identified a canonical set of 64 genes that are generally altered in failing hearts. We also produced a pairwise similarity matrix to illustrate relatedness of animal models with human heart disease and identified ischemia as the human condition that most resembles isoproterenol treatment. Conclusion The overall patterns of gene expression are consistent with observed structural and molecular differences between normal and maladaptive cardiac hypertrophy and support a role for the immune system (or immune cell infiltration in the pathology of stress-induced hypertrophy. Cross-study comparisons such as the results presented here provide targets for further research of cardiac disease that might generally apply to maladaptive cardiac stresses and are also a means of identifying which animal models best recapitulate human disease at the transcriptional level.

[Role of cardiac magnetic resonance in cardiac involvement of Fabry disease].

Science.gov (United States)

Serra, Viviana M; Barba, Miguel Angel; Torrá, Roser; Pérez De Isla, Leopoldo; López, Mónica; Calli, Andrea; Feltes, Gisela; Torras, Joan; Valverde, Victor; Zamorano, José L

2010-09-04

Fabry disease is a hereditary disorder. Clinical manifestations are multisystemic. The majority of the patients remain undiagnosed until late in life, when alterations could be irreversible. Early detection of cardiac symptoms is of major interest in Fabry's disease (FD) in order to gain access to enzyme replacement therapy. Echo-Doppler tissular imaging (TDI) has been used as a cardiologic early marker in FD. This study is intended to determine whether the cardiac magnetic resonance is as useful tool as TDI for the early detection of cardiac affectation in FD. Echocardiography, tissue Doppler and Cardio magnetic resonance was performed in 20 patients with confirmed Fabry Disease. Left ventricular hypertrophy was defined as septum and left ventricular posterior wall thickness ≥12 mm. An abnormal TDI velocity was defined as (Sa), (Ea) and/or (Aa) velocities gadolinium-enhanced images sequences were obtained using magnetic resonance. Twenty patients included in the study were divided into three groups: 1. Those without left ventricular hypertrophy nor tissue Doppler impairment 2. Those without left ventricular hypertrophy and tissue Doppler impairment 3. Those with left ventricular hypertrophy and Tissue Doppler impairment. Late gadolinium enhancement was found in only one patient, who has already altered DTI and LVH. Tissue Doppler imaging (TDI) is the only diagnostic tool able to provide early detection of cardiac affectation in patients with FD. Magnetic resonance provides information of the disease severity in patients with LVH, but can not be used as an early marker of cardiac disease in patients with FD. However MRI could be of great value for diagnostic stratification. Copyright © 2009 Elsevier España, S.L. All rights reserved.

Energetic Techniques For Planetary Defense

Science.gov (United States)

Barbee, B.; Bambacus, M.; Bruck Syal, M.; Greenaugh, K. C.; Leung, R. Y.; Plesko, C. S.

2017-12-01

Near-Earth Objects (NEOs) are asteroids and comets whose heliocentric orbits tend to approach or cross Earth's heliocentric orbit. NEOs of various sizes periodically collide with Earth, and efforts are currently underway to discover, track, and characterize NEOs so that those on Earth-impacting trajectories are discovered far enough in advance that we would have opportunities to deflect or destroy them prior to Earth impact, if warranted. We will describe current efforts by the National Aeronautics and Space Administration (NASA) and the National Nuclear Security Administration (NNSA) to assess options for energetic methods of deflecting or destroying hazardous NEOs. These methods include kinetic impactors, which are spacecraft designed to collide with an NEO and thereby alter the NEO's trajectory, and nuclear engineering devices, which are used to rapidly vaporize a layer of NEO surface material. Depending on the amount of energy imparted, this can result in either deflection of the NEO via alteration of its trajectory, or robust disruption of the NEO and dispersal of the remaining fragments. We have studied the efficacies and limitations of these techniques in simulations, and have combined the techniques with corresponding spacecraft designs and mission designs. From those results we have generalized planetary defense mission design strategies and drawn conclusions that are applicable to a range of plausible scenarios. We will present and summarize our research efforts to date, and describe approaches to carrying out planetary defense missions with energetic NEO deflection or disruption techniques.

Energetic costs of performance in trained and untrained Anolis carolinensis lizards.

Science.gov (United States)

Lailvaux, Simon P; Wang, Andrew Z; Husak, Jerry F

2018-03-12

The energetic costs of performance constitute a non-trivial component of animals' daily energetic budgets. However, we currently lack an understanding of how those costs are partitioned among the various stages of performance development, maintenance, and production. We manipulated individual investment in performance by training Anolis carolinensis lizards for endurance or sprinting ability. We then measured energetic expenditure both at rest and immediately following exercise to test whether such training alters the maintenance and production costs of performance. Trained lizards had lower resting metabolic rates than controls, suggestive of a maintenance saving associated with enhanced performance as opposed to a cost. Production costs also differed, with sprint-trained lizards incurring the largest energetic performance cost and experiencing the longest recovery times compared to endurance trained and control animals. Although performance training modifies metabolism, production costs are probably the key drivers of trade-offs between performance and other life-history traits in this species. © 2018. Published by The Company of Biologists Ltd.

Cardiac function in acute hypothyroidism

International Nuclear Information System (INIS)

Donaghue, K.; Hales, I.; Allwright, S.; Cooper, R.; Edwards, A.; Grant, S.; Morrow, A.; Wilmshurst, E.; Royal North Shore Hospital, Sydney

1985-01-01

It has been established that chronic hypothyroidism may affect cardiac function by several mechanisms. It is not known how long the patient has to be hypothyroid for cardiac involvement to develop. This study was undertaken to assess the effect of a short period of hypothyroidism (10 days) on cardiac function. Nine patients who had had total tyroidectomy, had received ablative radioiodine for thyroid cancer and were euthyroid on replacement therapy were studied while both euthyroid and hypothyroid. Cardiac assessment was performed by X-ray, ECG, echocardiography and gated blood-pool scans. After 10 days of hypothyroidisms, the left-ventricular ejection fraction failed to rise after exercise in 4 of the 9 patients studied, which was significant (P<0.002). No significant changes in cardiac size or function at rest were detected. This functional abnormality in the absence of any demonstrable change in cardiac size and the absence of pericardial effussion with normal basal function suggest that short periods of hypothyroidism may reduce cardiac reserve, mostly because of alterations in metabolic function. (orig.)

Alteration in cardiac uncoupling proteins and eNOS gene expression following high-intensity interval training in favor of increasing mechanical efficiency

OpenAIRE

Fallahi, Ali Asghar; Shekarfroush, Shahnaz; Rahimi, Mostafa; Jalali, Amirhossain; Khoshbaten, Ali

2016-01-01

Objective(s): High-intensity interval training (HIIT) increases energy expenditure and mechanical energy efficiency. Although both uncoupling proteins (UCPs) and endothelial nitric oxide synthase (eNOS) affect the mechanical efficiency and antioxidant capacity, their effects are inverse. The aim of this study was to determine whether the alterations of cardiac UCP2, UCP3, and eNOS mRNA expression following HIIT are in favor of increased mechanical efficiency or decreased oxidative stress. Mat...

Exogenous stress hormones alter energetic and nutrient costs of development and metamorphosis.

Science.gov (United States)

Kirschman, Lucas J; McCue, Marshall D; Boyles, Justin G; Warne, Robin W

2017-09-15

Variation in environmental conditions during larval life stages can shape development during critical windows and have lasting effects on the adult organism. Changes in larval developmental rates in response to environmental conditions, for example, can trade off with growth to determine body size and condition at metamorphosis, which can affect adult survival and fecundity. However, it is unclear how use of energy and nutrients shape trade-offs across life-stage transitions because no studies have quantified these costs of larval development and metamorphosis. We used an experimental approach to manipulate physiological stress in larval amphibians, along with respirometry and 13 C-breath testing to quantify the energetic and nutritional costs of development and metamorphosis. Central to larval developmental responses to environmental conditions is the hypothalamic-pituitary-adrenal/interrenal (HPA/I) axis, which regulates development, as well as energy homeostasis and stress responses across many taxa. Given these pleiotropic effects of HPA/I activity, manipulation of the HPA/I axis may provide insight into costs of metamorphosis. We measured the energetic and nutritional costs across the entire larval period and metamorphosis in a larval amphibian exposed to exogenous glucocorticoid (GC) hormones - the primary hormone secreted by the HPA/I axis. We measured metabolic rates and dry mass across larval ontogeny, and quantified lipid stores and nutrient oxidation via 13 C-breath testing during metamorphosis, under control and GC-exposed conditions. Changes in dry mass match metamorphic states previously reported in the literature, but dynamics of metabolism were influenced by the transition from aquatic to terrestrial respiration. GC-treated larvae had lower dry mass, decreased fat stores and higher oxygen consumption during stages where controls were conserving energy. GC-treated larvae also oxidized greater amounts of 13 C-labelled protein stores. These results

Intrinsic cardiac nervous system in tachycardia induced heart failure.

Science.gov (United States)

Arora, Rakesh C; Cardinal, Rene; Smith, Frank M; Ardell, Jeffrey L; Dell'Italia, Louis J; Armour, J Andrew

2003-11-01

The purpose of this study was to test the hypothesis that early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiac function. After 2 wk of rapid ventricular pacing in nine anesthetized canines, cardiac and right atrial neuronal function were evaluated in situ in response to enhanced cardiac sensory inputs, stimulation of extracardiac autonomic efferent neuronal inputs, and close coronary arterial administration of neurochemicals that included nicotine. Right atrial neuronal intracellular electrophysiological properties were then evaluated in vitro in response to synaptic activation and nicotine. Intrinsic cardiac nicotine-sensitive, neuronally induced cardiac responses were also evaluated in eight sham-operated, unpaced animals. Two weeks of rapid ventricular pacing reduced the cardiac index by 54%. Intrinsic cardiac neurons of paced hearts maintained their cardiac mechano- and chemosensory transduction properties in vivo. They also responded normally to sympathetic and parasympathetic preganglionic efferent neuronal inputs, as well as to locally administered alpha-or beta-adrenergic agonists or angiotensin II. The dose of nicotine needed to modify intrinsic cardiac neurons was 50 times greater in failure compared with normal preparations. That dose failed to alter monitored cardiovascular indexes in failing preparations. Phasic and accommodating neurons identified in vitro displayed altered intracellular membrane properties compared with control, including decreased membrane resistance, indicative of reduced excitability. Early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiodynamics. While maintaining its capacity to transduce cardiac mechano- and chemosensory inputs, as well as inputs from extracardiac autonomic efferent neurons, intrinsic cardiac nicotine-sensitive, local-circuit neurons differentially remodel such that their capacity to

Kruppel-like factor 15 is required for the cardiac adaptive response to fasting.

Science.gov (United States)

Sugi, Keiki; Hsieh, Paishiun N; Ilkayeva, Olga; Shelkay, Shamanthika; Moroney, Bridget; Baadh, Palvir; Haynes, Browning; Pophal, Megan; Fan, Liyan; Newgard, Christopher B; Prosdocimo, Domenick A; Jain, Mukesh K

2018-01-01

Cardiac metabolism is highly adaptive in response to changes in substrate availability, as occur during fasting. This metabolic flexibility is essential to the maintenance of contractile function and is under the control of a group of select transcriptional regulators, notably the nuclear receptor family of factors member PPARα. However, the diversity of physiologic and pathologic states through which the heart must sustain function suggests the possible existence of additional transcriptional regulators that play a role in matching cardiac metabolism to energetic demand. Here we show that cardiac KLF15 is required for the normal cardiac response to fasting. Specifically, we find that cardiac function is impaired upon fasting in systemic and cardiac specific Klf15-null mice. Further, cardiac specific Klf15-null mice display a fasting-dependent accumulation of long chain acylcarnitine species along with a decrease in expression of the carnitine translocase Slc25a20. Treatment with a diet high in short chain fatty acids relieves the KLF15-dependent long chain acylcarnitine accumulation and impaired cardiac function in response to fasting. Our observations establish KLF15 as a critical mediator of the cardiac adaptive response to fasting through its regulation of myocardial lipid utilization.

Modeling of oxygen transport and cellular energetics explains observations on in vivo cardiac energy metabolism.

Directory of Open Access Journals (Sweden)

Daniel A Beard

2006-09-01

Full Text Available Observations on the relationship between cardiac work rate and the levels of energy metabolites adenosine triphosphate (ATP, adenosine diphosphate (ADP, and phosphocreatine (CrP have not been satisfactorily explained by theoretical models of cardiac energy metabolism. Specifically, the in vivo stability of ATP, ADP, and CrP levels in response to changes in work and respiratory rate has eluded explanation. Here a previously developed model of mitochondrial oxidative phosphorylation, which was developed based on data obtained from isolated cardiac mitochondria, is integrated with a spatially distributed model of oxygen transport in the myocardium to analyze data obtained from several laboratories over the past two decades. The model includes the components of the respiratory chain, the F0F1-ATPase, adenine nucleotide translocase, and the mitochondrial phosphate transporter at the mitochondrial level; adenylate kinase, creatine kinase, and ATP consumption in the cytoplasm; and oxygen transport between capillaries, interstitial fluid, and cardiomyocytes. The integrated model is able to reproduce experimental observations on ATP, ADP, CrP, and inorganic phosphate levels in canine hearts over a range of workload and during coronary hypoperfusion and predicts that cytoplasmic inorganic phosphate level is a key regulator of the rate of mitochondrial respiration at workloads for which the rate of cardiac oxygen consumption is less than or equal to approximately 12 mumol per minute per gram of tissue. At work rates corresponding to oxygen consumption higher than 12 mumol min(-1 g(-1, model predictions deviate from the experimental data, indicating that at high work rates, additional regulatory mechanisms that are not currently incorporated into the model may be important. Nevertheless, the integrated model explains metabolite levels observed at low to moderate workloads and the changes in metabolite levels and tissue oxygenation observed during graded

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

Science.gov (United States)

Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

2014-01-01

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

Stimulating endogenous cardiac regeneration

Directory of Open Access Journals (Sweden)

Amanda eFinan

2015-09-01

Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

Energetic Systems

Data.gov (United States)

Federal Laboratory Consortium — The Energetic Systems Division provides full-spectrum energetic engineering services (project management, design, analysis, production support, in-service support,...

[Thromboelastography and its use in cardiac surgery].

Science.gov (United States)

Ak, Koray; Atalan, Nazan; Tekeli, Atike; Işbir, Selim; Civelek, Ali; Emekli, Nesrin; Arsan, Sinan

2008-04-01

Thromboelastography is an alternative method to conventional coagulation tests for the general evaluation of hemostatic system. Cardiac surgery with cardiopulmonary bypass is accomplished by complex alterations of hemostasis, including acquired dysfunction of platelets, consumption coagulopathy and increased fibrinolysis. Despite major advances in blood conservation methods and perioperative care of the patients, transfusion rates in cardiac surgery remain high. Thromboelastography has an ability to assess almost all components of haemostatic system globally. Currently, thromboelastography is used with standard coagulation tests to decrease the microvascular bleeding and homologous blood transfusion in cardiac surgery with cardiopulmonary bypass. In this review, we aimed to discuss thromboelastography technology and its usage in cardiac surgery.

Cardiac remodeling after myocardial infarction is impaired in IGF-1 deficient mice

NARCIS (Netherlands)

Palmen, M.; Daemen, M. J.; Bronsaer, R.; Dassen, W. R.; Zandbergen, H. R.; Kockx, M.; Smits, J. F.; van der Zee, R.; Doevendans, P. A.

2001-01-01

To obtain more insight in the role of IGF-1 in cardiac remodeling and function after experimental myocardial infarction. We hypothesized that cardiac remodeling is altered in IGF-1 deficient mice, which may affect cardiac function. A myocardial infarction was induced by surgical coronary artery

Cardiac sympathetic neuronal imaging using PET

International Nuclear Information System (INIS)

Lautamaeki, Riikka; Tipre, Dnyanesh; Bengel, Frank M.

2007-01-01

Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

Cardiac microvascular rarefaction in hyperthyroidism-induced left ventricle dysfunction.

Science.gov (United States)

Freitas, Felipe; Estato, Vanessa; Carvalho, Vinícius Frias; Torres, Rafael Carvalho; Lessa, Marcos Adriano; Tibiriçá, Eduardo

2013-10-01

The pathophysiology underlying hyperthyroidism-induced left ventricle (LV) dysfunction and hypertrophy directly involves the heart and indirectly involves the neuroendocrine systems. The effects of hyperthyroidism on the microcirculation are still controversial in experimental models. We investigated the effects of hyperthyroidism on the cardiac function and microcirculation of an experimental rat model. Male Wistar rats (170-250 g) were divided into two groups: the euthyroid group (n = 10), which was treated with 0.9% saline solution, and the hyperthyroid group (n = 10), which was treated with l-thyroxine (600 μg/kg/day, i.p.) during 14 days. An echocardiographic study was performed to evaluate the alterations in cardiac function, structure and geometry. The structural capillary density and the expression of angiotensin II AT1 receptor in the LV were analyzed using histochemistry and immunohistochemistry, respectively. Hyperthyroidism was found to induce profound cardiovascular alterations, such as systolic hypertension, tachycardia, LV dysfunction, cardiac hypertrophy, and myocardial fibrosis. This study demonstrates the existence of structural capillary rarefaction and the down-regulation of the cardiac angiotensin II AT1 receptor in the myocardium of hyperthyroid rats in comparison with euthyroid rats. Microvascular rarefaction may be involved in the pathophysiology of hyperthyroidism-induced cardiovascular alterations. © 2013 John Wiley & Sons Ltd.

Mitochondrial oxidative stress and cardiac ageing.

Science.gov (United States)

Martín-Fernández, Beatriz; Gredilla, Ricardo

According with different international organizations, cardiovascular diseases are becoming the first cause of death in western countries. Although exposure to different risk factors, particularly those related to lifestyle, contribute to the etiopathogenesis of cardiac disorders, the increase in average lifespan and aging are considered major determinants of cardiac diseases events. Mitochondria and oxidative stress have been pointed out as relevant factors both in heart aging and in the development of cardiac diseases such as heart failure, cardiac hypertrophy and diabetic cardiomyopathy. During aging, cellular processes related with mitochondrial function, such as bioenergetics, apoptosis and inflammation are altered leading to cardiac dysfunction. Increasing our knowledge about the mitochondrial mechanisms related with the aging process, will provide new strategies in order to improve this process, particularly the cardiovascular ones. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Restricted N-terminal truncation of cardiac troponin T: a novel mechanism for functional adaptation to energetic crisis.

Science.gov (United States)

Feng, Han-Zhong; Biesiadecki, Brandon J; Yu, Zhi-Bin; Hossain, M Moazzem; Jin, J-P

2008-07-15

The N-terminal variable region of cardiac troponin T (TnT) is a regulatory structure that can be selectively removed during myocardial ischaemia reperfusion by mu-calpain proteolysis. Here we investigated the pathophysiological significance of this post-translational modification that removes amino acids 1-71 of cardiac TnT. Working heart preparations were employed to study rat acute myocardial infarction and transgenic mouse hearts over-expressing the N-terminal truncated cardiac TnT (cTnT-ND). Ex vivo myocardial infarction by ligation of the left anterior descending coronary artery induced heart failure and produced cTnT-ND not only in the infarct but also in remote zones, including the right ventricular free wall, indicating a whole organ response in the absence of systemic neurohumoral mechanisms. Left ventricular pressure overload in mouse working hearts produced increased cTnT-ND in both ventricles, suggesting a role of haemodynamic stress in triggering an acute whole organ proteolytic regulation. Transgenic mouse hearts in which the endogenous intact cardiac TnT was partially replaced by cTnT-ND showed lowered contractile velocity. When afterload increased from 55 mmHg to 90 mmHg, stroke volume decreased in the wild type but not in the transgenic mouse hearts. Correspondingly, the left ventricular rapid-ejection time of the transgenic mouse hearts was significantly longer than that of wild type hearts, especially at high afterload. The restricted deletion of the N-terminal variable region of cardiac troponin T demonstrates a novel mechanism by which the thin filament regulation adapts to sustain cardiac function under stress conditions.

Haematological alterations in the cardiac patient after use of an autotransfusion system.

Science.gov (United States)

Luque-Oliveros, M

2018-02-01

There are studies that declare blood recovered with the autotransfusion system that is potentially heparinised and mixed with other drugs, can cause haematological alterations in the patient, according to existing evidence. The proposal was to compare the haematological values of the patients before reinfusing red blood cells from the cell saver and 12h after reinfusion. Observational analytical study of 479 patients who underwent cardiac surgery where the cell saver was used. Haematological variables were collected before reinfusion and 12h after reinfusion. Statistically significant haematological values before reinfusion and 12h after reinfusion were: haemoglobin (9.5 to 12.5g/dL), haematocrit (26 to 38%), platelets (214.2 to 164.210^3/μL), total proteins (7.6 to 5.1g/dL), PCR (8.5 to 22.1mg/L) and D-dimer (493.3 to 875.5μg/L) with P<.05. With the use of the cell saver an increase was observed of haemoglobin, haematocrit, PCR and D-dimer values together with a decrease in platelet and total protein numbers. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Targeting sodium channels in cardiac arrhythmia

NARCIS (Netherlands)

Remme, Carol Ann; Wilde, Arthur A. M.

2014-01-01

Cardiac voltage-gated sodium channels are responsible for proper electrical conduction in the heart. During acquired pathological conditions and inherited sodium channelopathies, altered sodium channel function causes conduction disturbances and ventricular arrhythmias. Although the clinical,

Energetic materials and methods of tailoring electrostatic discharge sensitivity of energetic materials

Energy Technology Data Exchange (ETDEWEB)

Daniels, Michael A.; Heaps, Ronald J.; Wallace, Ronald S.; Pantoya, Michelle L.; Collins, Eric S.

2016-11-01

An energetic material comprising an elemental fuel, an oxidizer or other element, and a carbon nanofiller or carbon fiber rods, where the carbon nanofiller or carbon fiber rods are substantially homogeneously dispersed in the energetic material. Methods of tailoring the electrostatic discharge sensitivity of an energetic material are also disclosed.

Cardiac resynchronization therapy in a patient with amyloid cardiomyopathy.

Science.gov (United States)

Zizek, David; Cvijić, Marta; Zupan, Igor

2013-06-01

Cardiac involvement in systemic light chain amyloidosis carries poor prognosis. Amyloid deposition in the myocardium can alter regional left ventricular contraction and cause dyssynchrony. Cardiac resynchronization therapy (CRT) is an effective treatment strategy for patients with advanced heart failure and echocardiographic dyssynchrony. We report a clinical and echocardiographic response of a patient with amyloid cardiomyopathy, treated with a combination of chemotherapy and CRT.

Energetics Conditioning Facility

Data.gov (United States)

Federal Laboratory Consortium — The Energetics Conditioning Facility is used for long term and short term aging studies of energetic materials. The facility has 10 conditioning chambers of which 2...

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

Science.gov (United States)

González-Guerra, José Luis; Castilla-Cortazar, Inma; Aguirre, Gabriel A; Muñoz, Úrsula; Martín-Estal, Irene; Ávila-Gallego, Elena; Granado, Miriam; Puche, Juan E; García-Villalón, Ángel Luis

2017-01-01

Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R). In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides); carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

Directory of Open Access Journals (Sweden)

José Luis González-Guerra

Full Text Available Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R. In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides; carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

Moderate-Intensity Exercise Affects Gut Microbiome Composition and Influences Cardiac Function in Myocardial Infarction Mice

Directory of Open Access Journals (Sweden)

Zuheng Liu

2017-09-01

Full Text Available Physical exercise is commonly regarded as protective against cardiovascular disease (CVD. Recent studies have reported that exercise alters the gut microbiota and that modification of the gut microbiota can influence cardiac function. Here, we focused on the relationships among exercise, the gut microbiota and cardiac function after myocardial infarction (MI. Four-week-old C57BL/6J mice were exercised on a treadmill for 4 weeks before undergoing left coronary artery ligation. Cardiac function was assessed using echocardiography. Gut microbiomes were evaluated post-exercise and post-MI using 16S rRNA gene sequencing on an Illumina HiSeq platform. Exercise training inhibited declines in cardiac output and stroke volume in post-MI mice. In addition, physical exercise and MI led to alterations in gut microbial composition. Exercise training increased the relative abundance of Butyricimonas and Akkermansia. Additionally, key operational taxonomic units were identified, including 24 lineages (mainly from Bacteroidetes, Barnesiella, Helicobacter, Parabacteroides, Porphyromonadaceae, Ruminococcaceae, and Ureaplasma that were closely related to exercise and cardiac function. These results suggested that exercise training improved cardiac function to some extent in addition to altering the gut microbiota; therefore, they could provide new insights into the use of exercise training for the treatment of CVD.

Refined energetic ordering for sulphate-water (n = 3-6) clusters using high-level electronic structure calculations

Science.gov (United States)

Lambrecht, Daniel S.; McCaslin, Laura; Xantheas, Sotiris S.; Epifanovsky, Evgeny; Head-Gordon, Martin

2012-10-01

This work reports refinements of the energetic ordering of the known low-energy structures of sulphate-water clusters ? (n = 3-6) using high-level electronic structure methods. Coupled cluster singles and doubles with perturbative triples (CCSD(T)) is used in combination with an estimate of basis set effects up to the complete basis set limit using second-order Møller-Plesset theory. Harmonic zero-point energy (ZPE), included at the B3LYP/6-311 + + G(3df,3pd) level, was found to have a significant effect on the energetic ordering. In fact, we show that the energetic ordering is a result of a delicate balance between the electronic and vibrational energies. Limitations of the ZPE calculations, both due to electronic structure errors, and use of the harmonic approximation, probably constitute the largest remaining errors. Due to the often small energy differences between cluster isomers, and the significant role of ZPE, deuteration can alter the relative energies of low-lying structures, and, when it is applied in conjunction with calculated harmonic ZPEs, even alters the global minimum for n = 5. Experiments on deuterated clusters, as well as more sophisticated vibrational calculations, may therefore be quite interesting.

Glutaredoxin-2 is required to control oxidative phosphorylation in cardiac muscle by mediating deglutathionylation reactions.

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Mailloux, Ryan J; Xuan, Jian Ying; McBride, Skye; Maharsy, Wael; Thorn, Stephanie; Holterman, Chet E; Kennedy, Christopher R J; Rippstein, Peter; deKemp, Robert; da Silva, Jean; Nemer, Mona; Lou, Marjorie; Harper, Mary-Ellen

2014-05-23

Glutaredoxin-2 (Grx2) modulates the activity of several mitochondrial proteins in cardiac tissue by catalyzing deglutathionylation reactions. However, it remains uncertain whether Grx2 is required to control mitochondrial ATP output in heart. Here, we report that Grx2 plays a vital role modulating mitochondrial energetics and heart physiology by mediating the deglutathionylation of mitochondrial proteins. Deletion of Grx2 (Grx2(-/-)) decreased ATP production by complex I-linked substrates to half that in wild type (WT) mitochondria. Decreased respiration was associated with increased complex I glutathionylation diminishing its activity. Tissue glucose uptake was concomitantly increased. Mitochondrial ATP output and complex I activity could be recovered by restoring the redox environment to that favoring the deglutathionylated states of proteins. Grx2(-/-) hearts also developed left ventricular hypertrophy and fibrosis, and mice became hypertensive. Mitochondrial energetics from Grx2 heterozygotes (Grx2(+/-)) were also dysfunctional, and hearts were hypertrophic. Intriguingly, Grx2(+/-) mice were far less hypertensive than Grx2(-/-) mice. Thus, Grx2 plays a vital role in modulating mitochondrial metabolism in cardiac muscle, and Grx2 deficiency leads to pathology. As mitochondrial ATP production was restored by the addition of reductants, these findings may be relevant to novel redox-related therapies in cardiac disease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Decreased expression of natriuretic peptides associated with lipid accumulation in cardiac ventricle of obese mice

DEFF Research Database (Denmark)

Bartels, E.D.; Nielsen, J.M.; Bisgaard, L.S.

2010-01-01

% (P depression of ANP mRNA expression in cultured HL-1 atrial myocytes. The data suggest that obesity and altered cardiac lipid metabolism are associated with reduced production of ANP and BNP in the cardiac ventricles in the setting of normal as well as impaired cardiac function....

Mitochondria, Energetics, Epigenetics, and Cellular Responses to Stress

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McAllister, Kimberly; Worth, Leroy; Haugen, Astrid C.; Meyer, Joel N.; Domann, Frederick E.; Van Houten, Bennett; Mostoslavsky, Raul; Bultman, Scott J.; Baccarelli, Andrea A.; Begley, Thomas J.; Sobol, Robert W.; Hirschey, Matthew D.; Ideker, Trey; Santos, Janine H.; Copeland, William C.; Tice, Raymond R.; Balshaw, David M.; Tyson, Frederick L.

2014-01-01

Background: Cells respond to environmental stressors through several key pathways, including response to reactive oxygen species (ROS), nutrient and ATP sensing, DNA damage response (DDR), and epigenetic alterations. Mitochondria play a central role in these pathways not only through energetics and ATP production but also through metabolites generated in the tricarboxylic acid cycle, as well as mitochondria–nuclear signaling related to mitochondria morphology, biogenesis, fission/fusion, mitophagy, apoptosis, and epigenetic regulation. Objectives: We investigated the concept of bidirectional interactions between mitochondria and cellular pathways in response to environmental stress with a focus on epigenetic regulation, and we examined DNA repair and DDR pathways as examples of biological processes that respond to exogenous insults through changes in homeostasis and altered mitochondrial function. Methods: The National Institute of Environmental Health Sciences sponsored the Workshop on Mitochondria, Energetics, Epigenetics, Environment, and DNA Damage Response on 25–26 March 2013. Here, we summarize key points and ideas emerging from this meeting. Discussion: A more comprehensive understanding of signaling mechanisms (cross-talk) between the mitochondria and nucleus is central to elucidating the integration of mitochondrial functions with other cellular response pathways in modulating the effects of environmental agents. Recent studies have highlighted the importance of mitochondrial functions in epigenetic regulation and DDR with environmental stress. Development and application of novel technologies, enhanced experimental models, and a systems-type research approach will help to discern how environmentally induced mitochondrial dysfunction affects key mechanistic pathways. Conclusions: Understanding mitochondria–cell signaling will provide insight into individual responses to environmental hazards, improving prediction of hazard and susceptibility to

Activation of protein kinase C alters the intracellular distribution and mobility of cardiac Na+ channels.

Science.gov (United States)

Hallaq, Haifa; Wang, Dao W; Kunic, Jennifer D; George, Alfred L; Wells, K Sam; Murray, Katherine T

2012-02-01

Na(+) current derived from expression of the cardiac isoform SCN5A is reduced by receptor-mediated or direct activation of protein kinase C (PKC). Previous work has suggested a possible role for loss of Na(+) channels at the plasma membrane in this effect, but the results are controversial. In this study, we tested the hypothesis that PKC activation acutely modulates the intracellular distribution of SCN5A channels and that this effect can be visualized in living cells. In human embryonic kidney cells that stably expressed SCN5A with green fluorescent protein (GFP) fused to the channel COOH-terminus (SCN5A-GFP), Na(+) currents were suppressed by an exposure to PKC activation. Using confocal microscopy, colocalization of SCN5A-GFP channels with the plasma membrane under control and stimulated conditions was quantified. A separate population of SCN5A channels containing an extracellular epitope was immunolabeled to permit temporally stable labeling of the plasma membrane. Our results demonstrated that Na(+) channels were preferentially trafficked away from the plasma membrane by PKC activation, with a major contribution by Ca(2+)-sensitive or conventional PKC isoforms, whereas stimulation of protein kinase A (PKA) had the opposite effect. Removal of the conserved PKC site Ser(1503) or exposure to the NADPH oxidase inhibitor apocynin eliminated the PKC-mediated effect to alter channel trafficking, indicating that both channel phosphorylation and ROS were required. Experiments using fluorescence recovery after photobleaching demonstrated that both PKC and PKA also modified channel mobility in a manner consistent with the dynamics of channel distribution. These results demonstrate that the activation of protein kinases can acutely regulate the intracellular distribution and molecular mobility of cardiac Na(+) channels in living cells.

Cardiovascular responses to apneic facial immersion during altered cardiac filling.

Science.gov (United States)

Journeay, W Shane; Reardon, Francis D; Kenny, Glen P

2003-06-01

The hypothesis that reduced cardiac filling, as a result of lower body negative pressure (LBNP) and postexercise hypotension (PEH), would attenuate the reflex changes to heart rate (HR), skin blood flow (SkBF), and mean arterial pressure (MAP) normally induced by facial immersion was tested. The purpose of this study was to investigate the cardiovascular control mechanisms associated with apneic facial immersion during different cardiovascular challenges. Six subjects randomly performed 30-s apneic facial immersions in 6.0 +/- 1.2 degrees C water under the following conditions: 1) -20 mmHg LBNP, 2) +40 mmHg lower body positive pressure (LBPP), 3) during a period of PEH, and 4) normal resting (control). Measurements included SkBF at one acral (distal phalanx of the thumb) and one nonacral region of skin (ventral forearm), HR, and MAP. Facial immersion reduced HR and SkBF at both sites and increased MAP under all conditions (P filling during LBNP and PEH significantly attenuated the absolute HR nadir observed during the control immersion (P facial immersion can be attenuated when cardiac filling is compromised.

Roles of the creatine kinase system and myoglobin in maintaining energetic state in the working heart

Directory of Open Access Journals (Sweden)

Beard Daniel A

2009-02-01

Full Text Available Abstract Background The heart is capable of maintaining contractile function despite a transient decrease in blood flow and increase in cardiac ATP demand during systole. This study analyzes a previously developed model of cardiac energetics and oxygen transport to understand the roles of the creatine kinase system and myoglobin in maintaining the ATP hydrolysis potential during beat-to-beat transient changes in blood flow and ATP hydrolysis rate. Results The theoretical investigation demonstrates that elimination of myoglobin only slightly increases the predicted range of oscillation of cardiac oxygenation level during beat-to-beat transients in blood flow and ATP utilization. In silico elimination of myoglobin has almost no impact on the cytoplasmic ATP hydrolysis potential (ΔGATPase. In contrast, disabling the creatine kinase system results in considerable oscillations of cytoplasmic ADP and ATP levels and seriously deteriorates the stability of ΔGATPase in the beating heart. Conclusion The CK system stabilizes ΔGATPase by both buffering ATP and ADP concentrations and enhancing the feedback signal of inorganic phosphate in regulating mitochondrial oxidative phosphorylation.

Heart rate variability alters cardiac repolarization and electromechanical dynamics.

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Phadumdeo, Vrishti M; Weinberg, Seth H

2018-04-07

Heart rate continuously varies due to autonomic regulation, stochasticity in pacemaking, and circadian rhythm, collectively termed heart rate variability (HRV), during normal physiological conditions. Low HRV is clinically associated with an elevated risk of cardiac arrhythmias. Alternans, a beat-to-beat alternation in action potential duration (APD) and/or intracellular calcium (Ca) transient, is a well-known risk factor associated with cardiac arrhythmias that is typically studied under conditions of a constant pacing rate, i.e., the absence of HRV. In this study, we investigate the effects of HRV on the interplay between APD, Ca, and electromechanical properties, employing a nonlinear discrete-time map model that governs APD and intracellular Ca cycling with a stochastic pacing period. We find that HRV can decrease variation in APD and peak Ca at fast pacing rates for which alternans is present. Further, increased HRV typically disrupts the alternating pattern for both APD and peak Ca and weakens the correlation between APD and peak Ca, thus decoupling Ca-mediated instabilities from repolarization alternation. We find that the efficacy of these effects is regulated by the sarcoplasmic reticulum Ca uptake rate. Overall, these results demonstrate that HRV disrupts arrhythmogenic alternans and suggests that HRV may be a significant factor in preventing life-threatening arrhythmias. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dioxin-induced acute cardiac mitochondrial oxidative damage and increased activity of ATP-sensitive potassium channels in Wistar rats

International Nuclear Information System (INIS)

Pereira, Susana P.; Pereira, Gonçalo C.; Pereira, Cláudia V.; Carvalho, Filipa S.; Cordeiro, Marília H.; Mota, Paula C.; Ramalho-Santos, João; Moreno, António J.; Oliveira, Paulo J.

2013-01-01

The environmental dioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is classified as a Group 1 human carcinogen and teratogenic agent. We hypothesize that TCDD-induced oxidative stress may also interfere with mitochondrial ATP-sensitive potassium channels (mitoKATP), which are known to regulate and to be regulated by mitochondrial redox state. We investigated the effects of an acute treatment of male Wistar rats with TCDD (50 μg/kg i.p.) and measured the regulation of cardiac mitoKATP. While the function of cardiac mitochondria was slightly depressed, mitoKATP activity was 52% higher in animals treated with TCDD. The same effects were not observed in liver mitochondria isolated from the same animals. Our data also shows that regulation of mitochondrial ROS production by mitoKATP activity is different in both groups. To our knowledge, this is the first report to show that TCDD increases mitoKATP activity in the heart, which may counteract the increased oxidative stress caused by the dioxin during acute exposure. -- Highlights: •Acute TCDD treatment of Wistar rats causes cardiac oxidative stress. •Acute TCDD treatment causes cardiac mitochondrial alterations. •Mitochondrial liver vs. heart alterations are distinct. •TCDD treatment resulted in altered activity of cardiac mitochondrial K-ATP channels. -- Dioxin alters the regulation of cardiac mitochondrial ATP-sensitive potassium channels and disturbs mitochondrial physiology

An analysis of the energetic cost of the branchial and cardiac pumps during sustained swimming in trout

DEFF Research Database (Denmark)

FARRELL, AP; STEFFENSEN, JF

1987-01-01

Experimental data are available for the oxygen cost of the branchial and cardiac pumps in fish. These data were used to theoretically analyze the relative oxygen cost of these pumps during rest and swimming in rainbow troutSalmo gairdneri. Efficiency of the heart increases with activity and so...... the relative oxygen cost of the cardiac pumps decreased from 4.6% at rest to 1.9% at the critical swimming speed. The relative oxygen cost of the branchial pump is significant in the resting and slowly swimming fish, being 10 to 15% of total oxygen uptake. However, when swimming trout switch to a ram mode...... of ventilation, a considerable saving in oxygen cost is accrued by switching the cost of ventilation from the branchial to the tail musculature. Thus, the relative oxygen cost of the branchial and cardiac pumps actually decreases at critical swimming speed compared to rest and therefore is unlikely to be a major...

Electrical initiation of an energetic nanolaminate film

Science.gov (United States)

Tringe, Joseph W.; Gash, Alexander E.; Barbee, Jr., Troy W.

2010-03-30

A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

The Role of Diacylglycerol Acyltransferase (DGAT) 1 and 2 in Cardiac Metabolism and Function.

Science.gov (United States)

Roe, Nathan D; Handzlik, Michal K; Li, Tao; Tian, Rong

2018-03-21

It is increasingly recognized that synthesis and turnover of cardiac triglyceride (TG) play a pivotal role in the regulation of lipid metabolism and function of the heart. The last step in TG synthesis is catalyzed by diacylglycerol:acyltransferase (DGAT) which esterifies the diacylglycerol with a fatty acid. Mammalian heart has two DGAT isoforms, DGAT1 and DGAT2, yet their roles in cardiac metabolism and function remain poorly defined. Here, we show that inactivation of DGAT1 or DGAT2 in adult mouse heart results in a moderate suppression of TG synthesis and turnover. Partial inhibition of DGAT activity increases cardiac fatty acid oxidation without affecting PPARα signaling, myocardial energetics or contractile function. Moreover, coinhibition of DGAT1/2 in the heart abrogates TG turnover and protects the heart against high fat diet-induced lipid accumulation with no adverse effects on basal or dobutamine-stimulated cardiac function. Thus, the two DGAT isoforms in the heart have partially redundant function, and pharmacological inhibition of one DGAT isoform is well tolerated in adult hearts.

Cardiac damage in athlete's heart: When the "supernormal" heart fails!

Science.gov (United States)

Carbone, Andreina; D'Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-06-26

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete's blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete's heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded.

About Russian nuclear energetic perspectives

International Nuclear Information System (INIS)

Laletin, N.I.

2003-01-01

My particular view about Russian nuclear energetics perspectives is presented. The nearest and the further perspectives are considered. The arguments are adduced that the most probable scenario of nuclear energetic development is its stabilization in the near future. Fur further development the arguments of supporters and opponents of nuclear energetics are analyzed. Three points of view are considered. The first point of view that there is not alternative for nuclear energetics. My notes are the following ones. a) I express a skeptic opinion about a statement of quick exhaustion of fossil organic fuel recourses and corresponding estimations are presented. b) It is expressed skeptic opinion about the statement that nuclear energetics can have a visual influence on ''steam effect''. c) I agree that nuclear energetics is the most ecological technology for normal work but however we can't disregard possibilities of catastrophic accidents. The second point of view that the use of nuclear energetics can't have the justification. I adduce the arguments contrary to this statement. The third point of view that nuclear energetics is a usual technology and the only criteria for discussions about what dimension and where one ought develop it is total cost of its unit. Expressed an opinion that the deceived for the choose of a way the skill of the estimate correctly and optimized so named the external parts of the unit energy costs for different energy technologies. (author)

Correlation of cardiac performance with cellular energetic components in the oxygen-deprived turtle heart

DEFF Research Database (Denmark)

Stecyk, Jonathan; Bock, Christian; Overgaard, Johannes

2009-01-01

of an anoxia-tolerant vertebrate, the freshwater turtle (Trachemys scripta) during long-term anoxia exposure ( 3 h at 21°C and 11 days at 5°C). During anoxia, phosphocreatine (PCr), unbound levels of inorganic phosphate (effective Pi2–), intracellular pH (pHi), and free energy of ATP hydrolysis (d......G/d ) exhibited asymptotic patterns of change, indicating that turtle myocardial high-energy phosphate metabolism and energetic state are reset to new, reduced steady states during long-term anoxia exposure. At 21°C, anoxia caused a reduction in pHi from 7.40 to 7.01, a 69% decrease in PCr and a doubling...

Decreased Polycystin 2 Levels Result in Non-Renal Cardiac Dysfunction with Aging.

Science.gov (United States)

Kuo, Ivana Y; Duong, Sophie L; Nguyen, Lily; Ehrlich, Barbara E

2016-01-01

Mutations in the gene for polycystin 2 (Pkd2) lead to polycystic kidney disease, however the main cause of mortality in humans is cardiac related. We previously showed that 5 month old Pkd2+/- mice have altered calcium-contractile activity in cardiomyocytes, but have preserved cardiac function. Here, we examined 1 and 9 month old Pkd2+/- mice to determine if decreased amounts of functional polycystin 2 leads to impaired cardiac function with aging. We observed changes in calcium handling proteins in 1 month old Pkd2+/- mice, and these changes were exacerbated in 9 month old Pkd2+/- mice. Anatomically, the 9 month old Pkd2+/- mice had thinner left ventricular walls, consistent with dilated cardiomyopathy, and the left ventricular ejection fraction was decreased. Intriguingly, in response to acute isoproterenol stimulation to examine β-adrenergic responses, the 9 month old Pkd2+/- mice exhibited a stronger contractile response, which also coincided with preserved localization of the β2 adrenergic receptor. Importantly, the Pkd2+/- mice did not have any renal impairment. We conclude that the cardiac-related impact of decreased polycystin 2 progresses over time towards cardiac dysfunction and altered adrenergic signaling. These results provide further evidence that polycystin 2 provides a critical function in the heart, independent of renal involvement.

Observation of enhanced radial transport of energetic ion due to energetic particle mode destabilized by helically-trapped energetic ion in the Large Helical Device

Science.gov (United States)

Ogawa, K.; Isobe, M.; Kawase, H.; Nishitani, T.; Seki, R.; Osakabe, M.; LHD Experiment Group

2018-04-01

A deuterium experiment was initiated to achieve higher-temperature and higher-density plasmas in March 2017 in the Large Helical Device (LHD). The central ion temperature notably increases compared with that in hydrogen experiments. However, an energetic particle mode called the helically-trapped energetic-ion-driven resistive interchange (EIC) mode is often excited by intensive perpendicular neutral beam injections on high ion-temperature discharges. The mode leads to significant decrease of the ion temperature or to limiting the sustainment of the high ion-temperature state. To understand the effect of EIC on the energetic ion confinement, the radial transport of energetic ions is studied by means of the neutron flux monitor and vertical neutron camera newly installed on the LHD. Decreases of the line-integrated neutron profile in core channels show that helically-trapped energetic ions are lost from the plasma.

Cardiac myofibrillar contractile properties during the progression from hypertension to decompensated heart failure.

Science.gov (United States)

Hanft, Laurin M; Emter, Craig A; McDonald, Kerry S

2017-07-01

Heart failure arises, in part, from a constellation of changes in cardiac myocytes including remodeling, energetics, Ca 2+ handling, and myofibrillar function. However, little is known about the changes in myofibrillar contractile properties during the progression from hypertension to decompensated heart failure. The aim of the present study was to provide a comprehensive assessment of myofibrillar functional properties from health to heart disease. A rodent model of uncontrolled hypertension was used to test the hypothesis that myocytes in compensated hearts exhibit increased force, higher rates of force development, faster loaded shortening, and greater power output; however, with progression to overt heart failure, we predicted marked depression in these contractile properties. We assessed contractile properties in skinned cardiac myocyte preparations from left ventricles of Wistar-Kyoto control rats and spontaneous hypertensive heart failure (SHHF) rats at ~3, ~12, and >20 mo of age to evaluate the time course of myofilament properties associated with normal aging processes compared with myofilaments from rats with a predisposition to heart failure. In control rats, the myofilament contractile properties were virtually unchanged throughout the aging process. Conversely, in SHHF rats, the rate of force development, loaded shortening velocity, and power all increased at ~12 mo and then significantly fell at the >20-mo time point, which coincided with a decrease in left ventricular fractional shortening. Furthermore, these changes occurred independent of changes in β-myosin heavy chain but were associated with depressed phosphorylation of myofibrillar proteins, and the fall in loaded shortening and peak power output corresponded with the onset of clinical signs of heart failure. NEW & NOTEWORTHY This novel study systematically examined the power-generating capacity of cardiac myofilaments during the progression from hypertension to heart disease. Previously

Analysis of the energetic sector through the national energetic matrix

International Nuclear Information System (INIS)

Garzon Lozano, Enrique

2007-01-01

The author shows the results of the national energetic balance 1975-2005, through the energetic matrix of the country, giving an annual growth of 5.1% in this period of offer of primary energy, where the mineral coal participates with 9,6%, the hydraulic energy with 4,8%, natural gas with 4,2%, trash with 2,4% and petroleum with 2,2%, while the firewood fell in 0,5%

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders

DEFF Research Database (Denmark)

den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu

2013-01-01

of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate...

Toll-like receptor 9 mediated responses in cardiac fibroblasts.

Directory of Open Access Journals (Sweden)

Ingrid Kristine Ohm

Full Text Available Altered cardiac Toll-like receptor 9 (TLR9 signaling is important in several experimental cardiovascular disorders. These studies have predominantly focused on cardiac myocytes or the heart as a whole. Cardiac fibroblasts have recently been attributed increasing significance in mediating inflammatory signaling. However, putative TLR9-signaling through cardiac fibroblasts remains non-investigated. Thus, our aim was to explore TLR9-signaling in cardiac fibroblasts and investigate the consequence of such receptor activity on classical cardiac fibroblast cellular functions. Cultivated murine cardiac fibroblasts were stimulated with different TLR9 agonists (CpG A, B and C and assayed for the secretion of inflammatory cytokines (tumor necrosis factor α [TNFα], CXCL2 and interferon α/β. Expression of functional cardiac fibroblast TLR9 was proven as stimulation with CpG B and -C caused significant CXCL2 and TNFα-release. These responses were TLR9-specific as complete inhibition of receptor-stimulated responses was achieved by co-treatment with a TLR9-antagonist (ODN 2088 or chloroquine diphosphate. TLR9-stimulated responses were also found more potent in cardiac fibroblasts when compared with classical innate immune cells. Stimulation of cardiac fibroblasts TLR9 was also found to attenuate migration and proliferation, but did not influence myofibroblast differentiation in vitro. Finally, results from in vivo TLR9-stimulation with subsequent fractionation of specific cardiac cell-types (cardiac myocytes, CD45+ cells, CD31+ cells and cardiac fibroblast-enriched cell-fractions corroborated our in vitro data and provided evidence of differentiated cell-specific cardiac responses. Thus, we conclude that cardiac fibroblast may constitute a significant TLR9 responder cell within the myocardium and, further, that such receptor activity may impact important cardiac fibroblast cellular functions.

Flare energetics

Science.gov (United States)

Wu, S. T.; Dejager, C.; Dennis, B. R.; Hudson, H. S.; Simnett, G. M.; Strong, K. T.; Bentley, R. D.; Bornmann, P. L.; Bruner, M. E.; Cargill, P. J.

1986-01-01

In this investigation of flare energetics, researchers sought to establish a comprehensive and self-consistent picture of the sources and transport of energy within a flare. To achieve this goal, they chose five flares in 1980 that were well observed with instruments on the Solar Maximum Mission, and with other space-borne and ground-based instruments. The events were chosen to represent various types of flares. Details of the observations available for them and the corresponding physical parameters derived from these data are presented. The flares were studied from two perspectives, the impulsive and gradual phases, and then the results were compared to obtain the overall picture of the energics of these flares. The role that modeling can play in estimating the total energy of a flare when the observationally determined parameters are used as the input to a numerical model is discussed. Finally, a critique of the current understanding of flare energetics and the methods used to determine various energetics terms is outlined, and possible future directions of research in this area are suggested.

Pioglitazone improves cardiac function and alters myocardial substrate metabolism without affecting cardiac triglyceride accumulation and high-energy phosphate metabolism in patients with well-controlled type 2 diabetes mellitus

NARCIS (Netherlands)

van der Meer, Rutger W.; Rijzewijk, Luuk J.; de Jong, Hugo W. A. M.; Lamb, Hildo J.; Lubberink, Mark; Romijn, Johannes A.; Bax, Jeroen J.; de Roos, Albert; Kamp, Otto; Paulus, Walter J.; Heine, Robert J.; Lammertsma, Adriaan A.; Smit, Johannes W. A.; Diamant, Michaela

2009-01-01

Cardiac disease is the leading cause of mortality in type 2 diabetes mellitus (T2DM). Pioglitazone has been associated with improved cardiac outcome but also with an elevated risk of heart failure. We determined the effects of pioglitazone on myocardial function in relation to cardiac high-energy

Optogenetic release of norepinephrine from cardiac sympathetic neurons alters mechanical and electrical function.

Science.gov (United States)

Wengrowski, Anastasia M; Wang, Xin; Tapa, Srinivas; Posnack, Nikki Gillum; Mendelowitz, David; Kay, Matthew W

2015-02-01

Release of norepinephrine (NE) from sympathetic neurons enhances heart rate (HR) and developed force through activation of β-adrenergic receptors, and this sympathoexcitation is a key risk for the generation of cardiac arrhythmias. Studies of β-adrenergic modulation of cardiac function typically involve the administration of exogenous β-adrenergic receptor agonists to directly elicit global β-adrenergic receptor activation by bypassing the involvement of sympathetic nerve terminals. In this work, we use a novel method to activate sympathetic fibres within the myocardium of Langendorff-perfused hearts while measuring changes in electrical and mechanical function. The light-activated optogenetic protein channelrhodopsin-2 (ChR2) was expressed in murine catecholaminergic sympathetic neurons. Sympathetic fibres were then photoactivated to examine changes in contractile force, HR, and cardiac electrical activity. Incidence of arrhythmia was measured with and without exposure to photoactivation of sympathetic fibres, and hearts were optically mapped to detect changes in action potential durations and conduction velocities. Results demonstrate facilitation of both developed force and HR after photostimulated release of NE, with increases in contractile force and HR of 34.5 ± 5.5 and 25.0 ± 9.3%, respectively. Photostimulation of sympathetic fibres also made hearts more susceptible to arrhythmia, with greater incidence and severity. In addition, optically mapped action potentials displayed a small but significant shortening of the plateau phase (-5.5 ± 1.0 ms) after photostimulation. This study characterizes a powerful and clinically relevant new model for studies of cardiac arrhythmias generated by increasing the activity of sympathetic nerve terminals and the resulting activation of myocyte β-adrenergic receptors. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

The Energetic Demands and Planetary Footprint of Alternative Human Diets

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Eshel, G.; Martin, P. A.

2005-12-01

Agriculture is one of the major vehicles of human alteration of the planetary environment. Yet different diets vary vastly in terms of both their energetic demands and overall planetary footprint. We present a quantitative argument that demonstrates that plant-based diets exert vastly smaller planetary environmental cost than animal-based ones. We demonstrate that under a reasonable and readily defensible set of assumptions, a plant-based diet differs from the average American diet by as much energy as the difference between driving a compact and efficient sedan and a Sport Utility Vehicle.

Cardiac fatty acid uptake and metabolism in the rat model of polycystic ovary syndrome.

Science.gov (United States)

Tepavčević, Snežana; Milutinović, Danijela Vojnović; Macut, Djuro; Stojiljković, Mojca; Nikolić, Marina; Božić-Antić, Ivana; Ćulafić, Tijana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

2015-09-01

Polycystic ovary syndrome (PCOS) is associated with an altered plasma lipid profile and increased risk for cardiovascular diseases. We hypothesized that molecular mechanisms underlying cardiac pathology in PCOS involve changes in expression and subcellular localization of several key proteins involved in cardiac lipid transport and metabolism, such as fatty acid transporter CD36, lipin 1, peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor γ coactivator-1 (PGC1), and carnitine palmitoyltransferase 1 (CPT1). We used the animal model of PCOS obtained by treating female rats with dihydrotestosterone (DHT). Protein levels of CD36, lipin 1, PPARα, PGC1, and antioxidative enzymes were assessed by Western blot in different cardiac cell compartments. Cardiac triglycerides (TG) and lipid peroxidation were also measured. The content of CD36 was decreased in both the cardiac plasma membranes and intracellular pool. On the other hand, total content of cardiac lipin 1 in DHT-treated rats was elevated, in contrast to decreased microsomal lipin 1 content. An increase in nuclear content of lipin 1 was observed together with elevation of nuclear PPARα and PGC1, and an increase in CPT1 expression. However, lipid peroxidation was reduced in the heart, without alterations in antioxidative enzymes expression and cardiac TG content. The results indicate that treatment of female rats with DHT is accompanied by a decrease of fatty acid uptake and a reduction of lipid peroxidation in the heart. The observed elevation of lipin 1, PPARα, PGC1, and CPT1 expression suggests that cardiac fatty acid metabolism is shifted toward mitochondrial beta oxidation.

Monoamine Oxidases, Oxidative Stress, and Altered Mitochondrial Dynamics in Cardiac Ageing

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Damien Maggiorani

2017-01-01

Full Text Available The advances in healthcare over the past several decades have resulted in populations now living longer. With this increase in longevity, a wider prevalence of cardiovascular diseases is more common and known to be a major factor in rising healthcare costs. A wealth of scientific evidence has implicated cell senescence as an important component in the etiology of these age-dependent pathologies. A number of studies indicate that an excess of reactive oxygen species (ROS contributes to trigger and accelerate the cardiac senescence processes, and a new role of monoamine oxidases, MAO-A and MAO-B, is emerging in this context. These mitochondrial enzymes regulate the level of catecholamines and serotonin by catalyzing their oxidative deamination in the heart. MAOs’ expression substantially increases with ageing (6-fold MAO-A in the heart and 4-fold MAO-B in neuronal tissue, and their involvement in cardiac diseases is supposedly related to the formation of ROS, via the hydrogen peroxide produced during the substrate degradation. Here, we will review the most recent advances in this field and describe why MAOs could be effective targets in order to prevent age-associated cardiovascular disease.

Mechanical perturbation control of cardiac alternans

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Hazim, Azzam; Belhamadia, Youssef; Dubljevic, Stevan

2018-05-01

Cardiac alternans is a disturbance in heart rhythm that is linked to the onset of lethal cardiac arrhythmias. Mechanical perturbation control has been recently used to suppress alternans in cardiac tissue of relevant size. In this control strategy, cardiac tissue mechanics are perturbed via active tension generated by the heart's electrical activity, which alters the tissue's electric wave profile through mechanoelectric coupling. We analyze the effects of mechanical perturbation on the dynamics of a map model that couples the membrane voltage and active tension systems at the cellular level. Therefore, a two-dimensional iterative map of the heart beat-to-beat dynamics is introduced, and a stability analysis of the system of coupled maps is performed in the presence of a mechanical perturbation algorithm. To this end, a bidirectional coupling between the membrane voltage and active tension systems in a single cardiac cell is provided, and a discrete form of the proposed control algorithm, that can be incorporated in the coupled maps, is derived. In addition, a realistic electromechanical model of cardiac tissue is employed to explore the feasibility of suppressing alternans at cellular and tissue levels. Electrical activity is represented in two detailed ionic models, the Luo-Rudy 1 and the Fox models, while two active contractile tension models, namely a smooth variant of the Nash-Panfilov model and the Niederer-Hunter-Smith model, are used to represent mechanical activity in the heart. The Mooney-Rivlin passive elasticity model is employed to describe passive mechanical behavior of the myocardium.

Next generation sequencing for molecular confirmation of hereditary sudden cardiac death syndromes.

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Márquez, Manlio F; Cruz-Robles, David; Ines-Real, Selene; Vargas-Alarcón, Gilberto; Cárdenas, Manuel

2015-01-01

Hereditary sudden cardiac death syndromes comprise a wide range of diseases resulting from alteration in cardiac ion channels. Genes involved in these syndromes represent diverse mutations that cause the altered encoding of the diverse proteins constituting these channels, thus affecting directly the currents of the corresponding ions. In the present article we will briefly review how to arrive to a clinical diagnosis and we will present the results of molecular genetic studies made in Mexican subjects attending the SCD Syndromes Clinic of the National Institute of Cardiology of Mexico City. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Musical Tasks and Energetic Arousal.

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Lim, Hayoung A; Watson, Angela L

2018-03-08

Music is widely recognized as a motivating stimulus. Investigators have examined the use of music to improve a variety of motivation-related outcomes; however, these studies have focused primarily on passive music listening rather than active participation in musical activities. To examine the influence of participation in musical tasks and unique participant characteristics on energetic arousal. We used a one-way Welch's ANOVA to examine the influence of musical participation (i.e., a non-musical control and four different musical task conditions) upon energetic arousal. In addition, ancillary analyses of participant characteristics including personality, age, gender, sleep, musical training, caffeine, nicotine, and alcohol revealed their possible influence upon pretest and posttest energetic arousal scores. Musical participation yielded a significant relationship with energetic arousal, F(4, 55.62) = 44.38, p = .000, estimated ω2 = 0.60. Games-Howell post hoc pairwise comparisons revealed statistically significant differences between five conditions. Descriptive statistics revealed expected differences between introverts' and extraverts' energetic arousal scores at the pretest, F(1, 115) = 6.80, p = .010, partial η2= .06; however, mean differences failed to reach significance at the posttest following musical task participation. No other measured participant characteristics yielded meaningful results. Passive tasks (i.e., listening to a story or song) were related to decreased energetic arousal, while active musical tasks (i.e., singing, rhythm tapping, and keyboard playing) were related to increased energetic arousal. Musical task participation appeared to have a differential effect for individuals with certain personality traits (i.e., extroverts and introverts).

Cardiac, Metabolic and Molecular Profiles of Sedentary Rats in the Initial Moment of Obesity

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Bruno Barcellos Jacobsen

2017-10-01

Full Text Available Abstract Background: Different types of high-fat and/or high-energy diets have been used to induce obesity in rodents. However, few studies have reported on the effects observed at the initial stage of obesity induced by high-fat feeding on cardiac functional and structural remodelling. Objective: To characterize the initial moment of obesity and investigate both metabolic and cardiac parameters. In addition, the role of Ca2+ handling in short-term exposure to obesity was verified. Methods: Thirty-day-old male Wistar rats were randomized into two groups (n = 19 each: control (C; standard diet and high-fat diet (HF, unsaturated high-fat diet. The initial moment of obesity was defined by weekly measurement of body weight (BW complemented by adiposity index (AI. Cardiac remodelling was assessed by morphological, histological, echocardiographic and papillary muscle analysis. Ca2+ handling proteins were determined by Western Blot. Results: The initial moment of obesity occurred at the 3rd week. Compared with C rats, the HF rats had higher final BW (4%, body fat (20%, AI (14.5%, insulin levels (39.7%, leptin (62.4% and low-density lipoprotein cholesterol (15.5% but did not exhibit alterations in systolic blood pressure. Echocardiographic evaluation did not show alterations in cardiac parameters. In the HF group, muscles were observed to increase their +dT/dt (C: 52.6 ± 9.0 g/mm2/s and HF: 68.0 ± 17.0 g/mm2/s; p < 0.05. In addition, there was no changes in the cardiac expression of Ca2+ handling proteins. Conclusion: The initial moment of obesity promotes alterations to hormonal and lipid profiles without cardiac damage or changes in Ca2+ handling.

Can cardiac surgery cause hypopituitarism?

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Francis, Flverly; Burger, Ines; Poll, Eva Maria; Reineke, Andrea; Strasburger, Christian J; Dohmen, Guido; Gilsbach, Joachim M; Kreitschmann-Andermahr, Ilonka

2012-03-01

Apoplexy of pituitary adenomas with subsequent hypopituitarism is a rare but well recognized complication following cardiac surgery. The nature of cardiac on-pump surgery provides a risk of damage to the pituitary because the vascular supply of the pituitary is not included in the cerebral autoregulation. Thus, pituitary tissue may exhibit an increased susceptibility to hypoperfusion, ischemia or intraoperative embolism. After on-pump procedures, patients often present with physical and psychosocial impairments which resemble symptoms of hypopituitarism. Therefore, we analyzed whether on-pump cardiac surgery may cause pituitary dysfunction also in the absence of pre-existing pituitary disease. Twenty-five patients were examined 3-12 months after on-pump cardiac surgery. Basal hormone levels for all four anterior pituitary hormone axes were measured and a short synacthen test and a growth hormone releasing hormone plus arginine (GHRH-ARG)-test were performed. Quality of life (QoL), depression, subjective distress for a specific life event, sleep quality and fatigue were assessed by means of self-rating questionnaires. Hormonal alterations were only slight and no signs of anterior hypopituitarism were found except for an insufficient growth hormone rise in two overweight patients in the GHRH-ARG-test. Psychosocial impairment was pronounced, including symptoms of moderate to severe depression in 9, reduced mental QoL in 8, dysfunctional coping in 6 and pronounced sleep disturbances in 16 patients. Hormone levels did not correlate with psychosocial impairment. On-pump cardiac surgery did not cause relevant hypopituitarism in our sample of patients and does not serve to explain the psychosocial symptoms of these patients.

Titanium dioxide nanoparticle-induced dysfunction of cardiac hemodynamics is involved in cardiac inflammation in mice.

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Hong, Fashui; Wu, Nan; Zhao, Xiangyu; Tian, Yusheng; Zhou, Yingjun; Chen, Ting; Zhai, Yanyu; Ji, Li

2016-12-01

In the past two decades, titanium dioxide nanoparticles (TiO 2 NPs) have been extensively used in medicine, food industry and other daily life, while their possible interactions with the their influence and human body on human health remain not well understood. Thus, the study was designed to examine whether long-term exposure to TiO 2 NPs cause myocardial dysfunction which is involved in cardiac lesions and alter expression of genes and proteins involving inflammatory response in the mouse heart. The findings showed that intragastric feeding for nine consecutive months with TiO 2 NPs resulted in titanium accumulation, infiltration of inflammatory cells and apoptosis of heart, reductions in net increases of body weight, cardiac indices of function (LV systolic pressure, maximal rate of pressure increase over time, maximal rate of pressure decrease over time and coronary flow), and increases in heart indices, cardiac indices of function (LV end-diastolic pressure and heart rate) in mice. TiO 2 NPs also decreased ATP production in the hearts. Furthermore, TiO 2 NPs increased expression of nuclear factor-κB, interleukin-lβ and tumour necrosis factor-α, and reduced expression of anti-inflammatory cytokines including suppressor of cytokine signaling (SOCS) 1 and SOCS3 in the cardiac tissue. These results suggest that TiO 2 NPs may modulate the cardiac function and expression of inflammatory cytokines. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2917-2927, 2016. © 2016 Wiley Periodicals, Inc.

SIMULATION OF ENERGETIC NEUTRAL ATOMS FROM SOLAR ENERGETIC PARTICLES

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Wang, Linghua [Institute of Space Physics and Applied Technology, Peking University, Beijing 100871 (China); Li, Gang [Department of Space Science and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Shih, Albert Y. [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20770 (United States); Lin, Robert P. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Wimmer-Schweingruber, Robert F., E-mail: wanglhwang@gmail.com [Institut fuer Experimentelle und Angewandte Physik, University of Kiel, Leibnizstrasse 11, D-24118 Kiel (Germany)

2014-10-01

Energetic neutral atoms (ENAs) provide the only way to observe the acceleration site of coronal-mass-ejection-driven (CME-driven) shock-accelerated solar energetic particles (SEPs). In gradual SEP events, energetic protons can charge exchange with the ambient solar wind or interstellar neutrals to become ENAs. Assuming a CME-driven shock with a constant speed of 1800 km s{sup –1} and compression ratio of 3.5, propagating from 1.5 to 40 R{sub S} , we calculate the accelerated SEPs at 5-5000 keV and the resulting ENAs via various charge-exchange interactions. Taking into account the ENA losses in the interplanetary medium, we obtain the flux-time profiles of these solar ENAs reaching 1 AU. We find that the arriving ENAs at energies above ∼100 keV show a sharply peaked flux-time profile, mainly originating from the shock source below 5 R{sub S} , whereas the ENAs below ∼20 keV have a flat-top time profile, mostly originating from the source beyond 10 R{sub S} . Assuming the accelerated protons are effectively trapped downstream of the shock, we can reproduce the STEREO ENA fluence observations at ∼2-5 MeV/nucleon. We also estimate the flux of ENAs coming from the charge exchange of energetic storm protons, accelerated by the fast CME-driven shock near 1 AU, with interstellar hydrogen and helium. Our results suggest that appropriate instrumentation would be able to detect ENAs from SEPs and to even make ENA images of SEPs at energies above ∼10-20 keV.

Cardiac molecular-acclimation mechanisms in response to swimming-induced exercise in Atlantic salmon.

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Vicente Castro

Full Text Available Cardiac muscle is a principal target organ for exercise-induced acclimation mechanisms in fish and mammals, given that sustained aerobic exercise training improves cardiac output. Yet, the molecular mechanisms underlying such cardiac acclimation have been scarcely investigated in teleosts. Consequently, we studied mechanisms related to cardiac growth, contractility, vascularization, energy metabolism and myokine production in Atlantic salmon pre-smolts resulting from 10 weeks exercise-training at three different swimming intensities: 0.32 (control, 0.65 (medium intensity and 1.31 (high intensity body lengths s(-1. Cardiac responses were characterized using growth, immunofluorescence and qPCR analysis of a large number of target genes encoding proteins with significant and well-characterized function. The overall stimulatory effect of exercise on cardiac muscle was dependent on training intensity, with changes elicited by high intensity training being of greater magnitude than either medium intensity or control. Higher protein levels of PCNA were indicative of cardiac growth being driven by cardiomyocyte hyperplasia, while elevated cardiac mRNA levels of MEF2C, GATA4 and ACTA1 suggested cardiomyocyte hypertrophy. In addition, up-regulation of EC coupling-related genes suggested that exercised hearts may have improved contractile function, while higher mRNA levels of EPO and VEGF were suggestive of a more efficient oxygen supply network. Furthermore, higher mRNA levels of PPARα, PGC1α and CPT1 all suggested a higher capacity for lipid oxidation, which along with a significant enlargement of mitochondrial size in cardiac myocytes of the compact layer of fish exercised at high intensity, suggested an enhanced energetic support system. Training also elevated transcription of a set of myokines and other gene products related to the inflammatory process, such as TNFα, NFκB, COX2, IL1RA and TNF decoy receptor. This study provides the first

Diet-induced pre-diabetes slows cardiac conductance and promotes arrhythmogenesis

DEFF Research Database (Denmark)

Axelsen, Lene Nygaard; Callø, Kirstine; Braunstein, Thomas Hartig

2015-01-01

BACKGROUND: Type 2 diabetes is associated with abnormal electrical conduction and sudden cardiac death, but the pathogenic mechanism remains unknown. This study describes electrophysiological alterations in a diet-induced pre-diabetic rat model and examines the underlying mechanism. METHODS...

Small Engine, Big Power: MicroRNAs as Regulators of Cardiac Diseases and Regeneration

Directory of Open Access Journals (Sweden)

Darukeshwara Joladarashi

2014-09-01

Full Text Available Cardiac diseases are the predominant cause of human mortality in the United States and around the world. MicroRNAs (miRNAs are small non-coding RNAs that have been shown to modulate a wide range of biological functions under various pathophysiological conditions. miRNAs alter target expression by post-transcriptional regulation of gene expression. Numerous studies have implicated specific miRNAs in cardiovascular development, pathology, regeneration and repair. These observations suggest that miRNAs are potential therapeutic targets to prevent or treat cardiovascular diseases. This review focuses on the emerging role of miRNAs in cardiac development, pathogenesis of cardiovascular diseases, cardiac regeneration and stem cell-mediated cardiac repair. We also discuss the novel diagnostic and therapeutic potential of these miRNAs and their targets in patients with cardiac diseases.

Abnormal Cardiac Autonomic Regulation in Mice Lacking ASIC3

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Ching-Feng Cheng

2014-01-01

Full Text Available Integration of sympathetic and parasympathetic outflow is essential in maintaining normal cardiac autonomic function. Recent studies demonstrate that acid-sensing ion channel 3 (ASIC3 is a sensitive acid sensor for cardiac ischemia and prolonged mild acidification can open ASIC3 and evoke a sustained inward current that fires action potentials in cardiac sensory neurons. However, the physiological role of ASIC3 in cardiac autonomic regulation is not known. In this study, we elucidate the role of ASIC3 in cardiac autonomic function using Asic3−/− mice. Asic3−/− mice showed normal baseline heart rate and lower blood pressure as compared with their wild-type littermates. Heart rate variability analyses revealed imbalanced autonomic regulation, with decreased sympathetic function. Furthermore, Asic3−/− mice demonstrated a blunted response to isoproterenol-induced cardiac tachycardia and prolonged duration to recover to baseline heart rate. Moreover, quantitative RT-PCR analysis of gene expression in sensory ganglia and heart revealed that no gene compensation for muscarinic acetylcholines receptors and beta-adrenalin receptors were found in Asic3−/− mice. In summary, we unraveled an important role of ASIC3 in regulating cardiac autonomic function, whereby loss of ASIC3 alters the normal physiological response to ischemic stimuli, which reveals new implications for therapy in autonomic nervous system-related cardiovascular diseases.

Photoactive energetic materials

Science.gov (United States)

Chavez, David E.; Hanson, Susan Kloek; Scharff, Robert Jason; Veauthier, Jacqueline Marie; Myers, Thomas Winfield

2018-02-27

Energetic materials that are photoactive or believed to be photoactive may include a conventional explosive (e.g. PETN, nitroglycerine) derivatized with an energetic UV-absorbing and/or VIS-absorbing chromophore such as 1,2,4,5-tetrazine or 1,3,5-triazine. Absorption of laser light having a suitably chosen wavelength may result in photodissociation, decomposition, and explosive release of energy. These materials may be used as ligands to form complexes. Coordination compounds include such complexes with counterions. Some having the formula M(L).sub.n.sup.2+ were synthesized, wherein M is a transition metal and L is a ligand and n is 2 or 3. These may be photoactive upon exposure to a laser light beam having an appropriate wavelength of UV light, near-IR and/or visible light. Photoactive materials also include coordination compounds bearing non-energetic ligands; in this case, the counterion may be an oxidant such as perchlorate.

The pathogenesis and treatment of cardiac atrophy in cancer cachexia.

Science.gov (United States)

Murphy, Kate T

2016-02-15

Cancer cachexia is a multifactorial syndrome characterized by a progressive loss of skeletal muscle mass associated with significant functional impairment. In addition to a loss of skeletal muscle mass and function, many patients with cancer cachexia also experience cardiac atrophy, remodeling, and dysfunction, which in the field of cancer cachexia is described as cardiac cachexia. The cardiac alterations may be due to underlying heart disease, the cancer itself, or problems initiated by the cancer treatment and, unfortunately, remains largely underappreciated by clinicians and basic scientists. Despite recent major advances in the treatment of cancer, little progress has been made in the treatment of cardiac cachexia in cancer, and much of this is due to lack of information regarding the mechanisms. This review focuses on the cardiac atrophy associated with cancer cachexia, describing some of the known mechanisms and discussing the current and future therapeutic strategies to treat this condition. Above all else, improved awareness of the condition and an increased focus on identification of mechanisms and therapeutic targets will facilitate the eventual development of an effective treatment for cardiac atrophy in cancer cachexia. Copyright © 2016 the American Physiological Society.

Carbon monoxide exposure enhances arrhythmia after cardiac stress: involvement of oxidative stress.

Science.gov (United States)

André, Lucas; Gouzi, Fares; Thireau, Jérôme; Meyer, Gregory; Boissiere, Julien; Delage, Martine; Abdellaoui, Aldja; Feillet-Coudray, Christine; Fouret, Gilles; Cristol, Jean-Paul; Lacampagne, Alain; Obert, Philippe; Reboul, Cyril; Fauconnier, Jérémy; Hayot, Maurice; Richard, Sylvain; Cazorla, Olivier

2011-11-01

Arrhythmias following cardiac stress are a key predictor of death in healthy population. Carbon monoxide (CO) is a ubiquitous pollutant promoting oxidative stress and associated with hospitalization for cardiovascular disease and cardiac mortality. We investigated the effect of chronic CO exposure on the occurrence of arrhythmic events after a cardiac stress test and the possible involvement of related oxidative stress. Wistar rats exposed chronically (4 weeks) to sustained urban CO pollution presented more arrhythmic events than controls during recovery after cardiac challenge with isoprenaline in vivo. Sudden death occurred in 22% of CO-exposed rats versus 0% for controls. Malondialdehyde (MDA), an end-product of lipid peroxidation, was increased in left ventricular tissue of CO-exposed rats. Cardiomyocytes isolated from CO-exposed rats showed higher reactive oxygen species (ROS) production (measured with MitoSox Red dye), higher diastolic Ca(2+) resulting from SR calcium leak and an higher occurrence of irregular Ca(2+) transients (measured with Indo-1) in comparison to control cells after a high pacing sequence. Acute treatment with a ROS scavenger (N-acetylcysteine, 20 mmol/L, 1 h) prevented this sequence of alterations and decreased the number of arrhythmic cells following high pacing. Chronic CO exposure promotes oxidative stress that alters Ca(2+) homeostasis (through RYR2 and SERCA defects) and thereby mediates the triggering of ventricular arrhythmia after cardiac stress that can lead to sudden death.

Effects of chronic delta-9-THC treatment on cardiac beta-adrenoceptors in rats

Energy Technology Data Exchange (ETDEWEB)

Evans, E.B.; Seifen, E.; Kennedy, R.H.; Kafiluddi, R.; Paule, M.G.; Scallet, A.C.; Ali, S.F.; Slikker, W. Jr.

1987-10-01

This study was designed to determine if chronic treatment with delta-9-tetrahydrocannabinol (THC) alters cardiac beta-adrenoceptors in the rat. Following daily oral administration of 10 or 20 mg/kg THC or an equivalent volume of control solvent for 90 days, rats were sacrificed, and sarcolemmal membranes were prepared from ventricular myocardium. Beta-adrenoceptor density and binding affinity estimated with (-)(/sup 3/H)dihydroalprenolol; a beta-adrenergic antagonist, were not significantly affected by treatment with THC when compared to vehicle controls. These results suggest that the tolerance to cardiovascular effects of THC which develops during chronic exposure in the rat is not associated with alterations in cardiac beta-adrenoceptors as monitored by radiolabeled antagonist binding.

Study on penetration-induced initiation of energetic fragment

Science.gov (United States)

Qiao, Xiangxin; Xu, Heyang

2017-09-01

In order to investigate penetration-induced initiation of energetic fragment penetrating target, PTFE/Al (mass ratio 73.5/26.5) pressed and sintered into a Ф8mm × 8mm cylinder. To form energetic fragment, the cylinder was put into a closed container made by 35CrMnSiA. The container is 12mm long, 2mm thick. Energetic fragments were launched by a 14.5mm ballistic gun with a series of velocities and the penetrate process was simulated by AUTODYN-3D. The results show that the stress peak of energetic material exceed the initiation threshold, and energetic material will deflagrate, when energetic fragments impact velocity more than 800 m/s. The research results can provide reference for designs of energetic warhead.

Mammalian energetics. Flexible energetics of cheetah hunting strategies provide resistance against kleptoparasitism.

Science.gov (United States)

Scantlebury, David M; Mills, Michael G L; Wilson, Rory P; Wilson, John W; Mills, Margaret E J; Durant, Sarah M; Bennett, Nigel C; Bradford, Peter; Marks, Nikki J; Speakman, John R

2014-10-03

Population viability is driven by individual survival, which in turn depends on individuals balancing energy budgets. As carnivores may function close to maximum sustained power outputs, decreased food availability or increased activity may render some populations energetically vulnerable. Prey theft may compromise energetic budgets of mesopredators, such as cheetahs and wild dogs, which are susceptible to competition from larger carnivores. We show that daily energy expenditure (DEE) of cheetahs was similar to size-based predictions and positively related to distance traveled. Theft at 25% only requires cheetahs to hunt for an extra 1.1 hour per day, increasing DEE by just 12%. Therefore, not all mesopredators are energetically constrained by direct competition. Other factors that increase DEE, such as those that increase travel, may be more important for population viability. Copyright © 2014, American Association for the Advancement of Science.

Effects of energetic heavy ions on electromagnetic ion cyclotron wave generation in the plasmapause region

International Nuclear Information System (INIS)

Kozyra, J.U.; Cravens, T.E.; Nagy, A.F.; Fontheim, E.G.; Ong, R.S.B.

1984-01-01

An expression for the linear electromagnetic ion cyclotron convective growth rate has been derived, considering multiple ions in the energetic anisotropic component of the plasma (which provides the free energy for the instability) as well as in the cold component of the plasma. This represents a modification of recent treatments investigating electromagnetic ion cyclotron growth rates which have considered only hydrogen ions in the energetic component. Four major effects on the growth and propagation characteristics result from inclusion of heavy ions in the energetic component. Some wave growth occurs at low frequencies below the corresponding marginally unstable wave mode for each heavy ion. Enhanced quasi-monochronomatic peaks in the convective growth rate appear just below the O + and He + gyrofrequency and can be quite pronounced for certain plasma conditions. Stop bands, decreased group velocity and other effects normally attributed to cold heavy ions can be produced or enhanced by heavy ions in the energetic plasma component. Partial or complete suppression of wave growth at frequencies above the marginally unstable wave mode for a particular energetic heavy ion can greatly alter the growth rates that would occur in the absence of this energetic heavy ion. The expression for the linear electromagnetic ion cyclotron convective growth rate along with appropriate plasma parameters was used to investigate the nature of linear wave growth in the plasmapause region. The frequencies of peaks in the convective growth rate given by this model compare favorably with wave measurements in this region. It is conceivable that through wave-particle interactions, electromagnetic ion cyclotron waves could supply the energy source for various plasmapause region phenomena such as the O + torus, the plasma cloak and stable auroral red arcs

Understanding the physiology of complex congenital heart disease using cardiac magnetic resonance imaging

International Nuclear Information System (INIS)

Kappanayil, Mahesh; Kannan, Rajesh; Kumar, Raman Krishna

2011-01-01

Complex congenital heart diseases are often associated with complex alterations in hemodynamics. Understanding these key hemodynamic changes is critical to making management decisions including surgery and postoperative management. Existing tools for imaging and hemodynamic assessment like echocardiography, computed tomography and cardiac catheterization have inherent limitations. Cardiac magnetic resonance imaging (MRI) is emerging as a powerful bouquet of tools that allow not only excellent imaging, but also a unique insight into hemodynamics. This article introduces the reader to cardiac MRI and its utility through the clinical example of a child with a complex congenital cyanotic heart disease

Assessment of energetic costs of AhR activation by β-naphthoflavone in rainbow trout (Oncorhynchus mykiss) hepatocytes using metabolic flux analysis

International Nuclear Information System (INIS)

Nault, Rance; Abdul-Fattah, Hiba; Mironov, Gleb G.; Berezovski, Maxim V.; Moon, Thomas W.

2013-01-01

Exposure to environmental contaminants such as activators of the aryl hydrocarbon receptor (AhR) leads to the induction of defense and detoxification mechanisms. While these mechanisms allow organisms to metabolize and excrete at least some of these environmental contaminants, it has been proposed that these mechanisms lead to significant energetic challenges. This study tests the hypothesis that activation of the AhR by the model agonist β-naphthoflavone (βNF) results in increased energetic costs in rainbow trout (Oncorhynchus mykiss) hepatocytes. To address this hypothesis, we employed traditional biochemical approaches to examine energy allocation and metabolism including the adenylate energy charge (AEC), protein synthesis rates, Na + /K + -ATPase activity, and enzyme activities. Moreover, we have used for the first time in a fish cell preparation, metabolic flux analysis (MFA) an in silico approach for the estimation of intracellular metabolic fluxes. Exposure of trout hepatocytes to 1 μM βNF for 48 h did not alter hepatocyte AEC, protein synthesis, or Na + /K + -ATPase activity but did lead to sparing of glycogen reserves and changes in activities of alanine aminotransferase and citrate synthase suggesting altered metabolism. Conversely, MFA did not identify altered metabolic fluxes, although we do show that the dynamic metabolism of isolated trout hepatocytes poses a significant challenge for this type of approach which should be considered in future studies. - Highlights: • Energetic costs of AhR activation by βNF was examined in rainbow trout hepatocytes. • Metabolic flux analysis was performed on a fish cell preparation for the first time. • Exposure to βNF led to sparing of glycogen reserves and altered enzyme activities. • Adenylate energy charge was maintained despite temporal changes in metabolism

Assessment of energetic costs of AhR activation by β-naphthoflavone in rainbow trout (Oncorhynchus mykiss) hepatocytes using metabolic flux analysis

Energy Technology Data Exchange (ETDEWEB)

Nault, Rance, E-mail: naultran@msu.edu [Ottawa-Carleton Institute of Biology, Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Abdul-Fattah, Hiba [Ottawa-Carleton Institute of Biology, Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Mironov, Gleb G.; Berezovski, Maxim V. [Ottawa-Carleton Institute of Biology, Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Department of Chemistry, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Moon, Thomas W. [Ottawa-Carleton Institute of Biology, Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada)

2013-08-15

Exposure to environmental contaminants such as activators of the aryl hydrocarbon receptor (AhR) leads to the induction of defense and detoxification mechanisms. While these mechanisms allow organisms to metabolize and excrete at least some of these environmental contaminants, it has been proposed that these mechanisms lead to significant energetic challenges. This study tests the hypothesis that activation of the AhR by the model agonist β-naphthoflavone (βNF) results in increased energetic costs in rainbow trout (Oncorhynchus mykiss) hepatocytes. To address this hypothesis, we employed traditional biochemical approaches to examine energy allocation and metabolism including the adenylate energy charge (AEC), protein synthesis rates, Na{sup +}/K{sup +}-ATPase activity, and enzyme activities. Moreover, we have used for the first time in a fish cell preparation, metabolic flux analysis (MFA) an in silico approach for the estimation of intracellular metabolic fluxes. Exposure of trout hepatocytes to 1 μM βNF for 48 h did not alter hepatocyte AEC, protein synthesis, or Na{sup +}/K{sup +}-ATPase activity but did lead to sparing of glycogen reserves and changes in activities of alanine aminotransferase and citrate synthase suggesting altered metabolism. Conversely, MFA did not identify altered metabolic fluxes, although we do show that the dynamic metabolism of isolated trout hepatocytes poses a significant challenge for this type of approach which should be considered in future studies. - Highlights: • Energetic costs of AhR activation by βNF was examined in rainbow trout hepatocytes. • Metabolic flux analysis was performed on a fish cell preparation for the first time. • Exposure to βNF led to sparing of glycogen reserves and altered enzyme activities. • Adenylate energy charge was maintained despite temporal changes in metabolism.

Cardiac metabolism and mechanics are altered by genetic loss of lipoprotein triglyceride lipolysis.

Science.gov (United States)

Noh, Hye-Lim; Yamashita, Haruyo; Goldberg, Ira J

2006-12-01

Most circulating fatty acids are contained in lipoprotein triglycerides. For the heart to acquire these lipids, they must be broken down into free fatty acids via the enzyme lipoprotein lipase (LpL). Although it has long been known that hearts primarily use esterified fatty acids as fuel, different sources of fatty acids were thought to be interchangeable. By creating mice with neonatal and acute LpL deletion we showed that lipoprotein-derived fatty acids could not be replaced by albumin-associated free fatty acids. Loss of cardiac LpL forces the heart to increase its uptake of glucose, reduce fatty acid oxidation, and eventually leads to cardiac dysfunction. In contrast, cardiomyocyte specific overexpression of an anchored form of LpL leads to excess lipid uptake, induction of fatty acid oxidation genes, and dilated cardiomyopathy. Increasing lipid secretion from the heart or redirecting lipids to adipose tissue can alleviate this lipotoxic situation.

Cardiac effects of electrically induced intrathoracic autonomic reflexes.

Science.gov (United States)

Armour, J A

1988-06-01

Electrical stimulation of the afferent components in one cardiopulmonary nerve (the left vagosympathetic complex at a level immediately caudal to the origin of the left recurrent laryngeal nerve) in acutely decentralized thoracic autonomic ganglionic preparations altered cardiac chronotropism and inotropism in 17 of 44 dogs. Since these neural preparations were acutely decentralized, the effects were mediated presumably via intrathoracic autonomic reflexes. The lack of consistency of these reflexly generated cardiac responses presumably were due in part to anatomical variation of afferent axons in the afferent nerve stimulated. As stimulation of the afferent components in the same neural structure caudal to the heart (where cardiopulmonary afferent axons are not present) failed to elicit cardiac responses in any dog, it is presumed that when cardiac responses were elicited by the more cranially located stimulations, these were due to activation of afferent axons arising from the heart and (or) lungs. When cardiac responses were elicited, intramyocardial pressures in the right ventricular conus as well as the ventral and lateral walls of the left ventricle were augmented. Either bradycardia or tachycardia was elicited. Following hexamethonium administration no responses were produced, demonstrating that nicotonic cholinergic synaptic mechanisms were involved in these intrathoracic cardiopulmonary-cardiac reflexes. In six of the animals, when atropine was administered before hexamethonium, reflexly generated responses were attenuated. The same thing occurred when morphine was administered in four animals. In contrast, in four animals following administration of phentolamine, the reflexly generated changes were enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in NO/ROS ratio and expression of Trx1 and Prdx2 in isoproterenol-induced cardiac hypertrophy

Institute of Scientific and Technical Information of China (English)

Hao Su; Marco Pistolozzi; Xingjuan Shi; Xiaoou Sun; Wen Tan

2017-01-01

The development of cardiac hypertrophy is a complicated process,which undergoes a transition from compensatory hypertrophy to heart failure,and the identification of new biomarkers and targets for this disease is greatly needed.Here we investigated the development of isoproterenol (ISO)-induced cardiac hypertrophy in an in vitro experimental model.After the induction of hypertrophy with ISO treatment in H9c2 cells,cell surface area,cell viability,cellular reactive oxygen species (ROS),and nitric oxide (NO) levels were tested.Our data showed that the cell viability,mitochondrial membrane potential,and NO/ROS balance varied during the development of cardiac hypertrophy in H9c2 cells.It was also found that the expression of thioredoxin1 (Trx1) and peroxiredoxin2 (Prdx2) was decreased during the cardiac hypertrophy of H9c2 cells.These results suggest a critical role for Trx1 and Prdx2 in the cardiac hypertrophy of H9c2 cells and in the transition from compensated hypertrophy to de-compensated hypertrophy in H9c2 cells,and our findings may have important implications for the management of this disease.

Obesity, metabolic dysfunction and cardiac fibrosis: pathophysiologic pathways, molecular mechanisms and therapeutic opportunities

Science.gov (United States)

Cavalera, Michele; Wang, Junhong; Frangogiannis, Nikolaos G

2014-01-01

Cardiac fibrosis is strongly associated with obesity and metabolic dysfunction and may contribute to the increased incidence of heart failure, atrial arrhythmias and sudden cardiac death in obese subjects. Our review discusses the evidence linking obesity and myocardial fibrosis in animal models and human patients, focusing on the fundamental pathophysiologic alterations that may trigger fibrogenic signaling, the cellular effectors of fibrosis and the molecular signals that may regulate the fibrotic response. Obesity is associated with a wide range of pathophysiologic alterations (such as pressure and volume overload, metabolic dysregulation, neurohumoral activation and systemic inflammation); their relative role in mediating cardiac fibrosis is poorly defined. Activation of fibroblasts likely plays a major role in obesity-associated fibrosis; however, inflammatory cells, cardiomyocytes and vascular cells may also contribute to fibrogenic signaling. Several molecular processes have been implicated in regulation of the fibrotic response in obesity. Activation of the Renin-Angiotensin-Aldosterone System, induction of Transforming Growth Factor-β, oxidative stress, advanced glycation end-products (AGEs), endothelin-1, Rho-kinase signaling, leptin-mediated actions and upregulation of matricellular proteins (such as thrombospondin-1) may play a role in the development of fibrosis in models of obesity and metabolic dysfunction. Moreover, experimental evidence suggests that obesity and insulin resistance profoundly affect the fibrotic and remodeling response following cardiac injury. Understanding the pathways implicated in obesity-associated fibrosis may lead to development of novel therapies to prevent heart failure and to attenuate post-infarction cardiac remodeling in obese patients. PMID:24880146

Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

Energy Technology Data Exchange (ETDEWEB)

Minicucci, Marcos; Oliveira, Fernando; Santos, Priscila; Polegato, Bertha; Roscani, Meliza; Fernandes, Ana Angelica; Lustosa, Beatriz; Paiva, Sergio; Zornoff, Leonardo; Azevedo, Paula, E-mail: paulasa@fmb.unesp.br [Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, São Paulo, SP (Brazil)

2016-05-15

Tobacco smoke exposure is an important risk factor for cardiac remodeling. Under this condition, inflammation, oxidative stress, energy metabolism abnormalities, apoptosis, and hypertrophy are present. Pentoxifylline has anti‑inflammatory, anti-apoptotic, anti-thrombotic and anti-proliferative properties. The present study tested the hypothesis that pentoxifylline would attenuate cardiac remodeling induced by smoking. Wistar rats were distributed in four groups: Control (C), Pentoxifylline (PX), Tobacco Smoke (TS), and PX-TS. After two months, echocardiography, invasive blood pressure measurement, biochemical, and histological studies were performed. The groups were compared by two-way ANOVA with a significance level of 5%. TS increased left atrium diameter and area, which was attenuated by PX. In the isolated heart study, TS lowered the positive derivate (+dp/dt), and this was attenuated by PX. The antioxidants enzyme superoxide dismutase and glutathione peroxidase were decreased in the TS group; PX recovered these activities. TS increased lactate dehydrogenase (LDH) and decreased 3-hydroxyacyl Coenzyme A dehydrogenases (OH-DHA) and citrate synthase (CS). PX attenuated LDH, 3-OH-DHA and CS alterations in TS-PX group. TS increased IL-10, ICAM-1, and caspase-3. PX did not influence these variables. TS induced cardiac remodeling, associated with increased inflammation, oxidative stress, apoptosis, and changed energy metabolism. PX attenuated cardiac remodeling by reducing oxidative stress and improving cardiac bioenergetics, but did not act upon cardiac cytokines and apoptosis.

Rural energetic development: cuban experience

International Nuclear Information System (INIS)

Aguilera Barciela, M.

1994-01-01

The development of electro energetic national system in Cuba has been directed to the following objectives: to brake the rural population's exodus toward the cities, electrification of dairy farm, interconnection to the system electro energetic of all the sugar central production, these improves the rural population's conditions life

Myocardin-related transcription factors are required for cardiac development and function

Science.gov (United States)

Mokalled, Mayssa H.; Carroll, Kelli J.; Cenik, Bercin K.; Chen, Beibei; Liu, Ning; Olson, Eric N.; Bassel-Duby, Rhonda

2016-01-01

Myocardin-Related Transcription Factors A and B (MRTF-A and MRTF-B) are highly homologous proteins that function as powerful coactivators of serum response factor (SRF), a ubiquitously expressed transcription factor essential for cardiac development. The SRF/MRTF complex binds to CArG boxes found in the control regions of genes that regulate cytoskeletal dynamics and muscle contraction, among other processes. While SRF is required for heart development and function, the role of MRTFs in the developing or adult heart has not been explored. Through cardiac-specific deletion of MRTF alleles in mice, we show that either MRTF-A or MRTF-B is dispensable for cardiac development and function, whereas deletion of both MRTF-A and MRTF-B causes a spectrum of structural and functional cardiac abnormalities. Defects observed in MRTF-A/B null mice ranged from reduced cardiac contractility and adult onset heart failure to neonatal lethality accompanied by sarcomere disarray. RNA-seq analysis on neonatal hearts identified the most altered pathways in MRTF double knockout hearts as being involved in cytoskeletal organization. Together, these findings demonstrate redundant but essential roles of the MRTFs in maintenance of cardiac structure and function and as indispensible links in cardiac cytoskeletal gene regulatory networks. PMID:26386146

[Cardiac tamponade and myocarditis in Churg-Strauss syndrome].

Science.gov (United States)

Baili, L; Aydi, Z; Soussi, G; Ben Dhaou B, B; Zidi, A; Berraies, A; Boussema, F; Kammoun, S; Hamzaoui, A; Kraiem, S; Ben Miled M'rad, K; Rokbani, L

2014-09-01

The successive occurrence of pericardial tamponade and myocarditis during a Churg-Strauss syndrome is exceptionally described. We report a patient in whom pericardial tamponade and myocarditis were the presenting manifestation of a Churg-Strauss syndrome. A 58-year-old woman was admitted because of alteration of the clinical status with eosinophilia. One month ago, she was hospitalized for a pericardial tamponade treated by pericardial drainage. Acute myocarditis was diagnosed on chest pain during the second hospitalization. The etiologic inquiry ended in the diagnosis of Churg-Strauss complicated with a double cardiac involvement. A good response of clinical and biological anomalies was obtained after corticosteroid and immunosuppressive treatment. Isolated or multiple involvements of cardiac tunics should lead to make diagnosis of systemic vasculitis. A complete initial assessment and a close observation of the patients followed for Churg-Strauss syndrome is imperative to detect a cardiac achievement and set up an early treatment. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Cardiac Development and Transcription Factors: Insulin Signalling, Insulin Resistance, and Intrauterine Nutritional Programming of Cardiovascular Disease

Science.gov (United States)

Govindsamy, Annelene; Naidoo, Strinivasen

2018-01-01

Programming with an insult or stimulus during critical developmental life stages shapes metabolic disease through divergent mechanisms. Cardiovascular disease increasingly contributes to global morbidity and mortality, and the heart as an insulin-sensitive organ may become insulin resistant, which manifests as micro- and/or macrovascular complications due to diabetic complications. Cardiogenesis is a sequential process during which the heart develops into a mature organ and is regulated by several cardiac-specific transcription factors. Disrupted cardiac insulin signalling contributes to cardiac insulin resistance. Intrauterine under- or overnutrition alters offspring cardiac structure and function, notably cardiac hypertrophy, systolic and diastolic dysfunction, and hypertension that precede the onset of cardiovascular disease. Optimal intrauterine nutrition and oxygen saturation are required for normal cardiac development in offspring and the maintenance of their cardiovascular physiology. PMID:29484207

The location of energetic compartments affects energetic communication in cardiomyocytes

Directory of Open Access Journals (Sweden)

Rikke eBirkedal

2014-09-01

Full Text Available The heart relies on accurate regulation of mitochondrial energy supply to match energy demand. The main regulators are Ca2+ and feedback of ADP and Pi. Regulation via feedback has intrigued for decades. First, the heart exhibits a remarkable metabolic stability. Second, diffusion of ADP and other molecules is restricted specifically in heart and red muscle, where a fast feedback is needed the most. To explain the regulation by feedback, compartmentalization must be taken into account. Experiments and theoretical approaches suggest that cardiomyocyte energetic compartmentalization is elaborate with barriers obstructing diffusion in the cytosol and at the level of the mitochondrial outer membrane (MOM. A recent study suggests the barriers are organized in a lattice with dimensions in agreement with those of intracellular structures. Here, we discuss the possible location of these barriers. The more plausible scenario includes a barrier at the level of MOM. Much research has focused on how the permeability of MOM itself is regulated, and the importance of the creatine kinase system to facilitate energetic communication. We hypothesize that at least part of the diffusion restriction at the MOM level is not by MOM itself, but due to the close physical association between the sarcoplasmic reticulum (SR and mitochondria. This will explain why animals with a disabled creatine kinase system exhibit rather mild phenotype modifications. Mitochondria are hubs of energetics, but also ROS production and signaling. The close association between SR and mitochondria may form a diffusion barrier to ADP added outside a permeabilised cardiomyocyte. But in vivo, it is the structural basis for the mitochondrial-SR coupling that is crucial for the regulation of mitochondrial Ca2+-transients to regulate energetics, and for avoiding Ca2+-overload and irreversible opening of the mitochondrial permeability transition pore.

Towards an energetic theory of brittle fracture

International Nuclear Information System (INIS)

Francfort, G.; Marigo, J.J.

2002-01-01

The drawbacks of the classical theory of brittle fracture, based on Griffith's criterion, - a notion of critical energy release rate -, and a fracture toughness k, are numerous (think for instance the issue of crack initiation) and penalize its validity as a good model. Are all attempts at building a macroscopic theory of fracture doomed? The variety and complexity of micro-mechanical phenomena would suggest that this is indeed the case. We believe however that structural effects still preside over fracture and consequently propose to modify slightly Griffith theory without altering its fundamental components so that it becomes amenable to the widest range of situations. The examples presented here will demonstrate that a revisited energetic framework is a sound basis for a theory which can be used at the engineering level and which reconciles seemingly contradictory viewpoints. (authors)

Cardiac Morphology and Function, and Blood Gas Transport in Aquaporin-1 Knockout Mice.

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Samer eAl-Samir

2016-05-01

Full Text Available We have studied cardiac and respiratory functions of aquaporin- 1-deficient mice by the Pressure-Volume-loop technique and by blood gas analysis. In addition, the morphological properties of the animals’ hearts were analysed. In anesthesia under maximal dobutamine stimulation, the mice exhibit a moderately elevated heart rate of < 600 min-1 and an O2 consumption of ~0.6 ml/min/g, which is about twice the basal rate. In this state, which is similar to the resting state of the conscious animal, all cardiac functions including stroke volume and cardiac output exhibited resting values and were identical between deficient and wildtype animals. Likewise, pulmonary and peripheral exchange of O2 and CO2 were normal. In contrast, several morphological parameters of the heart tissue of deficient mice were altered: 1 left ventricular wall thickness was reduced by 12%, 2 left ventricular mass, normalized to tibia length, was reduced by 10-20%, 3 cardiac muscle fiber cross sectional area was decreased by 17%, and 4 capillary density was diminished by 10%. As the P-V-loop technique yielded normal end-diastolic and end-systolic left ventricular volumes, the deficient hearts are characterized by thin ventricular walls in combination with normal intraventricular volumes. The aquaporin-1-deficient heart thus seems to be at a disadvantage compared to the wildtype heart by a reduced left-ventricular wall thickness and an increased diffusion distance between blood capillaries and muscle mitochondria. While under the present quasi-resting conditions these morphological alterations have no consequences for cardiac function, we expect that the deficient hearts will show a reduced maximal cardiac output.

New Altered Non-Fibrillar Collagens in Human Dilated Cardiomyopathy: Role in the Remodeling Process.

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Carolina Gil-Cayuela

Full Text Available In dilated cardiomyopathy (DCM, cardiac failure is accompanied by profound alterations of extracellular matrix associated with the progression of cardiac dilation and left ventricular (LV dysfunction. Recently, we reported alterations of non-fibrillar collagen expression in ischemic cardiomyopathy linked to fibrosis and cardiac remodeling. We suspect that expression changes in genes coding for non-fibrillar collagens may have a potential role in DCM development.This study sought to analyze changes in the expression profile of non-fibrillar collagen genes in patients with DCM and to examine relationships between cardiac remodeling parameters and the expression levels of these genes.Twenty-three human left ventricle tissue samples were obtained from DCM patients (n = 13 undergoing heart transplantation and control donors (n = 10 for RNA sequencing analysis. We found increased mRNA levels of six non-fibrillar collagen genes, such as COL4A5, COL9A1, COL21A1, and COL23A1 (P < 0.05 for all, not previously described in DCM. Protein levels of COL8A1 and COL16A1 (P < 0.05 for both, were correspondingly increased. We also identified TGF-β1 significantly upregulated and related to both COL8A1 and COL16A1. Interestingly, we found a significant relationship between LV mass index and the gene expression level of COL8A1 (r = 0.653, P < 0.05.In our research, we identified new non-fibrillar collagens with altered expression in DCM, being COL8A1 overexpression directly related to LV mass index, suggesting that they may be involved in the progression of cardiac dilation and remodeling.

Cardiometabolic Risk Factors and Cardiac Health in Pre- and Postmenopausal Women

DEFF Research Database (Denmark)

Egelund, Jon

Menopause changes the hormonal milieu drastically. To what extent these changes alter cardiometabolic risk factors and cardiac adaptations to aerobic training is still not entirely clear. In this thesis, these aspects were addressed in a large exercise training intervention study involving late p...

Alterations of left ventricular deformation and cardiac sympathetic derangement in patients with systolic heart failure: a 3D speckle tracking echocardiography and cardiac {sup 123}I-MIBG study

Energy Technology Data Exchange (ETDEWEB)

Leosco, Dario; Parisi, Valentina; Pagano, Gennaro; Femminella, Grazia Daniela; Bevilacqua, Agnese; Formisano, Roberto; Ferro, Gaetana; De Lucia, Claudio; Ferrara, Nicola [University Federico II, Department of Translational Medical Science, Naples (Italy); Pellegrino, Teresa [Italian National Research Council (CNR), Institute of Biostructure and Bioimaging, Naples (Italy); University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Paolillo, Stefania [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Prastaro, Maria; Filardi, Pasquale Perrone; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Rengo, Giuseppe [University Federico II, Department of Translational Medical Science, Naples (Italy); Salvatore Maugeri Foundation, IRCCS, Istituto di Telese, Benevento, BN (Italy)

2015-09-15

Myocardial contractile function is under the control of cardiac sympathetic activity. Three-dimensional speckle tracking echocardiography (3D-STE) and cardiac imaging with {sup 123}I-metaiodobenzylguanidine ({sup 123}I-MIBG) are two sophisticated techniques for the assessment of left ventricular (LV) deformation and sympathetic innervation, respectively, which offer important prognostic information in patients with heart failure (HF). The purpose of this investigation was to explore, in patients with systolic HF, the relationship between LV deformation assessed by 3D-STE and cardiac sympathetic derangement evaluated by {sup 123}I-MIBG imaging. We prospectively studied 75 patients with systolic HF. All patients underwent a 3D-STE study (longitudinal, circumferential, area and radial) and {sup 123}I-MIBG planar and SPECT cardiac imaging. 3D-STE longitudinal, circumferential and area strain values were correlated with {sup 123}I-MIBG late heart to mediastinum (H/M) ratio and late SPECT total defect score. After stratification of the patients according to ischaemic or nonischaemic HF aetiology, we observed a good correlation of all 3D-STE measurements with late H/M ratio and SPECT data in the ischaemic group, but in patients with HF of nonischaemic aetiology, no correlation was found between LV deformation and cardiac sympathetic activity. At the regional level, the strongest correlation between LV deformation and adrenergic innervation was found for the left anterior descending coronary artery distribution territory for all four 3D-STE values. In multivariate linear regression analyses, including age, gender, LV ejection fraction, NYHA class, body mass index, heart rate and HF aetiology, only 3D-STE area and radial strain values significantly predicted cardiac sympathetic derangement on {sup 123}I-MIBG late SPECT. This study indicated that 3D-STE measurements are correlated with {sup 123}I-MIBG planar and SPECT data. Furthermore, 3D-STE area and radial strain values

Hepatic mitochondrial energetics during catch-up fat with high-fat diets rich in lard or safflower oil.

Science.gov (United States)

Crescenzo, Raffaella; Bianco, Francesca; Falcone, Italia; Tsalouhidou, Sofia; Yepuri, Gayathri; Mougios, Vassilis; Dulloo, Abdul G; Liverini, Giovanna; Iossa, Susanna

2012-09-01

We have investigated whether altered hepatic mitochondrial energetics could explain the differential effects of high-fat diets with low or high ω6 polyunsaturated fatty acid content (lard vs. safflower oil) on the efficiency of body fat recovery (catch-up fat) during refeeding after caloric restriction. After 2 weeks of caloric restriction, rats were isocalorically refed with a low-fat diet (LF) or high-fat diets made from either lard or safflower oil for 1 week, and energy balance and body composition changes were assessed. Hepatic mitochondrial energetics were determined from measurements of liver mitochondrial mass, respiratory capacities, and proton leak. Compared to rats refed the LF, the groups refed high-fat diets showed lower energy expenditure and increased efficiency of fat gain; these differences were less marked with high-safflower oil than with high-lard diet. The increase in efficiency of catch-up fat by the high-fat diets could not be attributed to differences in liver mitochondrial activity. By contrast, the lower fat gain with high-safflower oil than with high-lard diet is accompanied by higher mitochondrial proton leak and increased proportion of arachidonic acid in mitochondrial membranes. In conclusion, the higher efficiency for catch-up fat on high-lard diet than on LF cannot be explained by altered hepatic mitochondrial energetics. By contrast, the ability of the high-safflower oil diet to produce a less pronounced increase in the efficiency of catch-up fat may partly reside in increased incorporation of arachidonic acid in hepatic mitochondrial membranes, leading to enhanced proton leak and mitochondrial uncoupling.

[Cardiac rhythm variability as an index of vegetative heart regulation in a situation of psychoemotional tension].

Science.gov (United States)

Revina, N E

2006-01-01

Differentiated role of segmental and suprasegmental levels of cardiac rhythm variability regulation in dynamics of motivational human conflict was studied for the first time. The author used an original method allowing simultaneous analysis of psychological and physiological parameters of human activity. The study demonstrates that will and anxiety, as components of motivational activity spectrum, form the "energetic" basis of voluntary-constructive and involuntary-affective behavioral strategies, selectively uniting various levels of suprasegmental and segmental control of human heart functioning in a conflict situation.

The Principle of Energetic Consistency

Science.gov (United States)

Cohn, Stephen E.

2009-01-01

A basic result in estimation theory is that the minimum variance estimate of the dynamical state, given the observations, is the conditional mean estimate. This result holds independently of the specifics of any dynamical or observation nonlinearity or stochasticity, requiring only that the probability density function of the state, conditioned on the observations, has two moments. For nonlinear dynamics that conserve a total energy, this general result implies the principle of energetic consistency: if the dynamical variables are taken to be the natural energy variables, then the sum of the total energy of the conditional mean and the trace of the conditional covariance matrix (the total variance) is constant between observations. Ensemble Kalman filtering methods are designed to approximate the evolution of the conditional mean and covariance matrix. For them the principle of energetic consistency holds independently of ensemble size, even with covariance localization. However, full Kalman filter experiments with advection dynamics have shown that a small amount of numerical dissipation can cause a large, state-dependent loss of total variance, to the detriment of filter performance. The principle of energetic consistency offers a simple way to test whether this spurious loss of variance limits ensemble filter performance in full-blown applications. The classical second-moment closure (third-moment discard) equations also satisfy the principle of energetic consistency, independently of the rank of the conditional covariance matrix. Low-rank approximation of these equations offers an energetically consistent, computationally viable alternative to ensemble filtering. Current formulations of long-window, weak-constraint, four-dimensional variational methods are designed to approximate the conditional mode rather than the conditional mean. Thus they neglect the nonlinear bias term in the second-moment closure equation for the conditional mean. The principle of

Satisfactory rate of postprocessing visualization of standard fetal cardiac views from 4-dimensional cardiac volumes acquired during routine ultrasound practice by experienced sonographers in peripheral centers.

Science.gov (United States)

Rizzo, Giuseppe; Capponi, Alessandra; Pietrolucci, Maria Elena; Capece, Giuseppe; Cimmino, Ernesto; Colosi, Enrico; Ferrentino, Salvatore; Sica, Carmine; Di Meglio, Aniello; Arduini, Domenico

2011-01-01

The aim of this study was to evaluate the feasibility of visualizing standard cardiac views from 4-dimensional (4D) cardiac volumes obtained at ultrasound facilities with no specific experience in fetal echocardiography. Five sonographers prospectively recorded 4D cardiac volumes starting from the 4-chamber view on 500 consecutive pregnancies at 19 to 24 weeks' gestation undergoing routine ultrasound examinations (100 pregnancies for each sonographer). Volumes were sent to the referral center, and 2 independent reviewers with experience in 4D fetal echocardiography assessed their quality in the display of the abdominal view, 4-chamber view, left and right ventricular outflow tracts, and 3-vessel and trachea view. Cardiac volumes were acquired in 474 of 500 pregnancies (94.8%). The 2 reviewers respectively acknowledged the presence of satisfactory images in 92.4% and 93.6% of abdominal views, 91.5% and 93.0% of 4-chamber views, in 85.0% and 86.2% of left ventricular outflow tracts, 83.9% and 84.5% of right ventricular outflow tracts, and 85.2% and 84.5% of 3-vessel and trachea views. The presence of a maternal body mass index of greater than 30 altered the probability of achieving satisfactory cardiac views, whereas previous maternal lower abdominal surgery did not affect the quality of reconstructed cardiac views. In conclusion, cardiac volumes acquired by 4D sonography in peripheral centers showed high enough quality to allow satisfactory diagnostic cardiac views.

Second School of Nuclear Energetics

International Nuclear Information System (INIS)

2009-01-01

At 3-5 Nov 2009 Institute of Nuclear Energy POLATOM, Association of Polish Electrical Engineers (SEP) and Polish Nuclear Society have organized Second School of Nuclear Energetics. 165 participants have arrived from all Poland and represented both different central institutions (e.g. ministries) and local institutions (e.g. Office of Technical Inspection, The Voivodship Presidential Offices, several societies, consulting firms or energetic enterprises). Students from the Warsaw Technical University and Gdansk Technical University, as well as the PhD students from the Institute of Nuclear Chemistry and Technology (Warsaw) attended the School. 20 invited lectures presented by eminent Polish specialists concerned basic problems of nuclear energetics, nuclear fuel cycle and different problems of the NPP construction in Poland. [pl

Acid-base balance and cardiac index in SO2-bronchitic, papaine-emphysematous and paraquat-fibrotic rats after isoproterenol treatment.

Science.gov (United States)

Vértes, K; Debreczeni, L A

1990-01-01

SO2-bronchitis, papaine-emphysema and paraquat fibrosis were induced in Wistar rats. Blood pressure, cardiac index, total peripheral resistance, arterial blood gas values, parameters of acid-base balance were determined. Effects of 0.1 and 0.3 microgram.-1.min-1 isoproterenol iv. infusion were examined. Morphologic alterations of the lungs were verified by histopathological examinations. All the parameters investigated were found to be normal in the control rats. The treated groups differed from the normal ones: an increased blood pressure was observed in emphysema and fibrosis. A decreased cardiac index was characteristic of chronic bronchitis, high cardiac index of emphysema, high TPR of bronchitis and arterial hypoxaemy of fibrosis. The groups reacted differently to beta adrenergic stimulation: in bronchitic and fibrotic rats the cardiac index was augmented, whereas in emphysematous ones the increase proved to be smaller. The effects of isoproterenol infusion can be related to the altered beta-receptor function in the various experimental pulmonary diseases.

Serum Cytokines in Young Pediatric Patients with Congenital Cardiac Shunts and Altered Pulmonary Hemodynamics

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Leína Zorzanelli

2016-01-01

Full Text Available Background and Objective. Inflammation is central in the pathogenesis of pulmonary hypertension. We investigated how serum cytokines correlate with clinical features, hemodynamics, and lung histology in young patients with pulmonary hypertension associated with congenital cardiac shunts. Design. Prospective, observational study. Methods and Results. Patients (n=44 were aged 2.6 to 37.6 months. Group I patients (n=31 were characterized by pulmonary congestion and higher pulmonary blood flow compared to group II (p=0.022, with no need for preoperative cardiac catheterization. Group II patients (n=13 had no congestive features. At catheterization, they had elevated pulmonary vascular resistance (5.7 [4.4–7.4] Wood units·m2, geometric mean with 95% CI. Cytokines were measured by chemiluminescence. Macrophage migration inhibitory factor (MIF was found to be inversely related to pulmonary blood flow (r=-0.33, p=0.026 and was higher in group II (high pulmonary vascular resistance compared to group I (high pulmonary blood flow (p=0.017. In contrast, RANTES chemokine (regulated on activation, normal T cell expressed and secreted was characteristically elevated in Group I (p=0.022. Interleukin 16 was also negatively related to pulmonary blood flow (rS=-0.33, p=0.029 and was higher in patients with obstructive vasculopathy at intraoperative lung biopsy (p=0.021. Conclusion. Cytokines seem to be important and differentially regulated in subpopulations of young patients with cardiac shunts.

Cardiac regeneration therapy: connections to cardiac physiology.

Science.gov (United States)

Takehara, Naofumi; Matsubara, Hiroaki

2011-12-01

Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility.

Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852)

Energy Technology Data Exchange (ETDEWEB)

Martinez, M.; Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

1994-05-01

Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g dry weight in gills). Furthermore, P. clarkii has a high capacity for lead accumulation from water, and gills were the most important tissue of lead accumulation. Among effects that contaminants have on the physiology of the organisms, energetic state variables are important, since they will alter both survival and reproduction. Hepatopancreas is a major site for the energetic reserve in crayfish and is a site of lead accumulation, although metal concentration in this organ is not as high as gills. The purpose of this study was to examine changes in energy reserves in hepatopancreas and gills of the crayfish P. clarkii, in response to sublethal exposure to lead. Gills are directly exposed to contaminants in the environment, and they are the first organ showing alterations by the action of the contaminants. Hepatopancreas was also chosen due to both, its relevance in the energetic metabolism and its role in heavy metal detoxification mechanisms.

Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

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Chunxiang Yao

Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

Energetic map

International Nuclear Information System (INIS)

2012-01-01

This report explains the energetic map of Uruguay as well as the different systems that delimits political frontiers in the region. The electrical system importance is due to the electricity, oil and derived , natural gas, potential study, biofuels, wind and solar energy

Economical aspects of nuclear energetics

International Nuclear Information System (INIS)

Celinski, Z.

2000-01-01

The economical aspects of nuclear power generation in respect to costs of conventional energetics have been discussed in detail. The costs and competitiveness of nuclear power have been considered on the base of worldwide trends taking into account investment and fuel costs as well as 'social' costs being result of impact of different types of energetics on environment, human health etc

Energetic Sustainability and the Environment: A Transdisciplinary, Economic–Ecological Approach

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Ioan G. Pop

2017-05-01

Full Text Available The paper combines original concepts about eco-energetic systems, in a transdisciplinary sustainable context. Firstly, it introduces the concept of M.E.N. (Mega-Eco-Nega-Watt, the eco-energetic paradigm based on three different but complementary ecological economic spaces: the Megawatt as needed energy, the Ecowatt as ecological energy, and the Negawatt as preserved energy. The paper also deals with the renewable energies and technologies in the context of electrical energy production. Secondly, in the context of the M.E.N. eco-energetic paradigm, comprehensive definitions are given about eco-energetic systems and for pollution. Thirdly, the paper introduces a new formula for the eco-energetic efficiency which correlates the energetic efficiency of the system and the necessary newly defined ecological coefficient. The proposed formula for eco-energetic efficiency enables an interesting form of relating to different situations in which the input energy, output energy, lost energy, and externalities involved in an energetic process, interact to produce energy in a specific energetic system, in connection with the circular resilient economy model. Finally, the paper presents an original energetic diagram to explain different channels to produce electricity in a resilience regime, with high eco-energetic efficiency from primary external energetic sources (gravitation and solar sources, fuels (classical and radioactive, internal energetic sources (geothermal, volcanoes and other kind of sources. Regardless the kind of energetic sources used to obtain electricity, the entire process should be sustainable in what concerns the transdisciplinary integration of the different representative spheres as energy, socio-economy, and ecology (environment.

Safer energetic materials by a nanotechnological approach

Science.gov (United States)

Siegert, Benny; Comet, Marc; Spitzer, Denis

2011-09-01

Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity. Electronic supplementary information (ESI) available: Experimental details for the preparation of the V2O5@CNF/Al nanothermite; X-ray diffractogram of the V2O5@CNF/Al combustion residue; installation instructions and source code for the nt-timeline program. See DOI: 10.1039/c1nr10292c

Optimization of some eco-energetic systems

International Nuclear Information System (INIS)

Purica, I.; Pavelescu, M.; Stoica, M.

1976-01-01

An optimization problem of two eco-energetic systems is described. The first one is close to the actual eco-energetic system in Romania, while the second is a new one, based on nuclear energy as primary source and hydrogen energy as secondary source. The optimization problem solved is to find the optimal structure of the systems so that the objective functions adopted, namely unitary energy cost C and total pollution P, to be minimum at the same time. The problem can be modelated with a bimatrix cooperative mathematical game without side payments. We demonstrate the superiority of the new eco-energetic system. (author)

Energetics Laboratory Facilities

Data.gov (United States)

Federal Laboratory Consortium — These energetic materials laboratories are equipped with explosion proof hoods with blow out walls for added safety, that are certified for safe handling of primary...

Influence of microorganisms on the alteration of glasses; Influence des microorganismes sur l'alteration des verres

Energy Technology Data Exchange (ETDEWEB)

Besnainou, B; Libert, M F [CEA Cadarache, 13 - Saint Paul lez Durance (France). Dept. d' Entreposage et de Stockage des Dechets

1997-07-01

Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

Halogenated anaesthetics and cardiac protection in cardiac and non-cardiac anaesthesia

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Landoni Giovanni

2009-01-01

Full Text Available Volatile anaesthetic agents have direct protective properties against ischemic myocardial damage. The implementation of these properties during clinical anaesthesia can provide an additional tool in the treatment or prevention, or both, of ischemic cardiac dysfunction in the perioperative period. A recent meta-analysis showed that desflurane and sevoflurane reduce postoperative mortality and incidence of myocardial infarction following cardiac surgery, with significant advantages in terms of postoperative cardiac troponin release, need for inotrope support, time on mechanical ventilation, intensive care unit and overall hospital stay. Multicentre, randomised clinical trials had previously demonstrated that the use of desflurane can reduce the postoperative release of cardiac troponin I, the need for inotropic support, and the number of patients requiring prolonged hospitalisation following coronary artery bypass graft surgery either with and without cardiopulmonary bypass. The American College of Cardiology/American Heart Association Guidelines recommend volatile anaesthetic agents during non-cardiac surgery for the maintenance of general anaesthesia in patients at risk for myocardial infarction. Nonetheless, e vidence in non-coronary surgical settings is contradictory and will be reviewed in this paper together with the mechanisms of cardiac protection by volatile agents.

Detection and differentiation of early acute and following age stages of myocardial infarction with quantitative post-mortem cardiac 1.5T MR.

Science.gov (United States)

Schwendener, Nicole; Jackowski, Christian; Persson, Anders; Warntjes, Marcel J; Schuster, Frederick; Riva, Fabiano; Zech, Wolf-Dieter

2017-01-01

Recently, quantitative MR sequences have started being used in post-mortem imaging. The goal of the present study was to evaluate if early acute and following age stages of myocardial infarction can be detected and discerned by quantitative 1.5T post-mortem cardiac magnetic resonance (PMCMR) based on quantitative T1, T2 and PD values. In 80 deceased individuals (25 female, 55 male), a cardiac MR quantification sequence was performed prior to cardiac dissection at autopsy in a prospective study. Focal myocardial signal alterations detected in synthetically generated MR images were MR quantified for their T1, T2 and PD values. The locations of signal alteration measurements in PMCMR were targeted at autopsy heart dissection and cardiac tissue specimens were taken for histologic examinations. Quantified signal alterations in PMCMR were correlated to their according histologic age stage of myocardial infarction. In PMCMR seventy-three focal myocardial signal alterations were detected in 49 of 80 investigated hearts. These signal alterations were diagnosed histologically as early acute (n=39), acute (n=14), subacute (n=10) and chronic (n=10) age stages of myocardial infarction. Statistical analysis revealed that based on their quantitative T1, T2 and PD values, a significant difference between all defined age groups of myocardial infarction can be determined. It can be concluded that quantitative 1.5T PMCMR quantification based on quantitative T1, T2 and PD values is feasible for characterization and differentiation of early acute and following age stages of myocardial infarction. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Bitter tastants alter gastric-phase postprandial haemodynamics.

Science.gov (United States)

McMullen, Michael K; Whitehouse, Julie M; Whitton, Peter A; Towell, Anthony

2014-07-03

Since Greco-Roman times bitter tastants have been used in Europe to treat digestive disorders, yet no pharmacological mechanism has been identified which can account for this practice. This study investigates whether the bitter tastants, gentian root (Gentian lutea L.) and wormwood herb (Artemisia absinthium L.), stimulate cephalic and/or gut receptors to alter postprandial haemodynamics during the gastric-phase of digestion. Normal participants ingested (1) 100 mL water plus capsules containing either cellulose (placebo-control) or 1000 mg of each tastant (n=14); or (2) 100mL of water flavoured with 500 or 1500 mg of each tastant (a) gentian (n=12) and (b) wormwood (n=12). A single beat-to-beat cardiovascular recording was obtained for the entire session. Pre/post-ingestion contrasts with the control were analysed for (1) the encapsulated tastants, in the "10 to 15" minute post-ingestion period, and (2) the flavoured water in the "5 to 10" minute post-ingestion period. Water, the placebo-control, increased cardiac contraction force and blood pressure notwithstanding heart rate decreases. Encapsulated tastants did not further alter postprandial haemodynamics. In contrast gentian (500 and 1500 mg) and wormwood (1500 mg) flavoured water elicited increased peripheral vascular resistance and decreased cardiac output, primarily by reducing stroke volume rather than heart rate. Drinking 100mL water elicits a pressor effect during the gastric-phase of digestion due to increased cardiac contraction force. The addition of bitter tastants to water elicits an additional and parallel pressor effect due to increased peripheral vascular resistance; yet the extent of the post-prandial blood pressure increases are unchanged, presumably due to baroreflex buffering. The vascular response elicited by bitter tastants can be categorised as a sympathetically-mediated cephalic-phase response. A possible mechanism by which bitter tastants could positively influence digestion is altering

Alteration in cardiac uncoupling proteins and eNOS gene expression following high-intensity interval training in favor of increasing mechanical efficiency.

Science.gov (United States)

Fallahi, Ali Asghar; Shekarfroush, Shahnaz; Rahimi, Mostafa; Jalali, Amirhossain; Khoshbaten, Ali

2016-03-01

High-intensity interval training (HIIT) increases energy expenditure and mechanical energy efficiency. Although both uncoupling proteins (UCPs) and endothelial nitric oxide synthase (eNOS) affect the mechanical efficiency and antioxidant capacity, their effects are inverse. The aim of this study was to determine whether the alterations of cardiac UCP2, UCP3, and eNOS mRNA expression following HIIT are in favor of increased mechanical efficiency or decreased oxidative stress. Wistar rats were divided into five groups: control group (n=12), HIIT for an acute bout (AT1), short term HIIT for 3 and 5 sessions (ST3 and ST5), long-term training for 8 weeks (LT) (6 in each group). The rats of the training groups were made to run on a treadmill for 60 min in three stages: 6 min running for warm-up, 7 intervals of 7 min running on treadmill with a slope of 5° to 20° (4 min with an intensity of 80-110% VO2max and 3 min at 50-60% VO2max), and 5-min running for cool-down. The control group did not participate in any exercise program. Rats were sacrificed and the hearts were extracted to analyze the levels of UCP2, UCP3 and eNOS mRNA by RT-PCR. UCP3 expression was increased significantly following an acute training bout. Repeated HIIT for 8 weeks resulted in a significant decrease in UCPs mRNA and a significant increase in eNOS expression in cardiac muscle. This study indicates that Long term HIIT through decreasing UCPs mRNA and increasing eNOS mRNA expression may enhance energy efficiency and physical performance.

Garlic activates SIRT-3 to prevent cardiac oxidative stress and mitochondrial dysfunction in diabetes.

Science.gov (United States)

Sultana, Md Razia; Bagul, Pankaj K; Katare, Parameshwar B; Anwar Mohammed, Soheb; Padiya, Raju; Banerjee, Sanjay K

2016-11-01

Cardiac complications are major contributor in the mortality of diabetic people. Mitochondrial dysfunctioning is a crucial contributor for the cardiac complications in diabetes, and SIRT-3 remains the major mitochondrial deacetylase. We hypothesized whether garlic has any role on SIRT-3 to prevent mitochondrial dysfunction in diabetic heart. Rats with developed hyperglycemia after STZ injection were divided into two groups; diabetic (Dia) and diabetic+garlic (Dia+Garl). Garlic was administered at a dose of 250mg/kg/day, orally for four weeks. An additional group was maintained to evaluate the effect of raw garlic administration on control rat heart. We have observed altered functioning of cardiac mitochondrial enzymes involved in metabolic pathways, and increased levels of cardiac ROS with decreased activity of catalase and SOD in diabetic rats. Cardiac mRNA expression of TFAM, PGC-1α, and CO1 was also altered in diabetes. In addition, reduced levels of electron transport chain complexes that observed in Dia group were normalized with garlic administration. This indicates the presence of increased oxidative stress with mitochondrial dysfunctioning in diabetic heart. We have observed reduced activity of SIRT3 and increased acetylation of MnSOD. Silencing SIRT-3 in cells also revealed the same. However, administration of garlic improved the SIRT-3 and MnSOD activity, by deacetylating MnSOD. Increased SOD activity was correlated with reduced levels of ROS in garlic-administered rat hearts. Collectively, our results provide an insight into garlic's protection to T1DM heart through activation of SIRT3-MnSOD pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

Slovak Republic Act of 11 February 1998 on the energetics and on alterations to Act No. 455/1991 Collection of Acts of CSFR on small business (trade Act) in version of posterior regulations

International Nuclear Information System (INIS)

1998-01-01

This act constitute: (a) conditions of undertaking in electro-energetic, gas industry, and heat supply (in next only 'energetic' branches) ; (b) rights and responsibility of physical and act person undertaking in energetic branches; (c) rights and responsibility of customers of electricity, gas, and heat; counteract measures in the need situations, (d) and at prevention before need situations in energetic branches; (e) state regulation in energetic; (f) authority on keep of this act. The act is divided into for parts: (1) General constitutions, (2) Energetic branches; (3) The state authority; (4) Common, transient and invalidation constitutions.This act deals with the specific conditions for undertaking in nuclear power plants, too (licensing, security). This act shall into effect on 1 July 1998

Loss of microRNA-22 prevents high-fat diet induced dyslipidemia and increases energy expenditure without affecting cardiac hypertrophy.

Science.gov (United States)

Diniz, Gabriela Placoná; Huang, Zhan-Peng; Liu, Jianming; Chen, Jinghai; Ding, Jian; Fonseca, Renata Inzinna; Barreto-Chaves, Maria Luiza; Donato, Jose; Hu, Xiaoyun; Wang, Da-Zhi

2017-12-15

Obesity is associated with development of diverse diseases, including cardiovascular diseases and dyslipidemia. MiRNA-22 (miR-22) is a critical regulator of cardiac function and targets genes involved in metabolic processes. Previously, we generated miR-22 null mice and we showed that loss of miR-22 blunted cardiac hypertrophy induced by mechanohormornal stress. In the present study, we examined the role of miR-22 in the cardiac and metabolic alterations promoted by high-fat (HF) diet. We found that loss of miR-22 attenuated the gain of fat mass and prevented dyslipidemia induced by HF diet, although the body weight gain, or glucose intolerance and insulin resistance did not seem to be affected. Mechanistically, loss of miR-22 attenuated the increased expression of genes involved in lipogenesis and inflammation mediated by HF diet. Similarly, we found that miR-22 mediates metabolic alterations and inflammation induced by obesity in the liver. However, loss of miR-22 did not appear to alter HF diet induced cardiac hypertrophy or fibrosis in the heart. Our study therefore establishes miR-22 as an important regulator of dyslipidemia and suggests it may serve as a potential candidate in the treatment of dyslipidemia associated with obesity. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Imaging alterations of cardiomyocyte cAMP microdomains in disease

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Alexander eFroese

2015-08-01

Full Text Available 3’,5’-cyclic adenosine monophosphate (cAMP is an important second messenger which regulates heart function by acting in distinct subcellular microdomains. Recent years have provided deeper mechanistic insights into compartmentalized cAMP signaling and its link to cardiac disease. In this mini review, we summarize newest developments in this field achieved by cutting-edge biochemical and biophysical techniques. We further compile the data from different studies into a bigger picture of so far uncovered alterations in cardiomyocyte cAMP microdomains which occur in compensated cardiac hypertrophy and chronic heart failure. Finally, future research directions and translational perspectives are briefly discussed.

Structural and functional cardiac changes in myotonic dystrophy type 1: a cardiovascular magnetic resonance study

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Hermans Mieke CE

2012-07-01

Full Text Available Abstract Background Myotonic dystrophy type 1 (MD1 is a neuromuscular disorder with potential involvement of the heart and increased risk of sudden death. Considering the importance of cardiomyopathy as a predictor of prognosis, we aimed to systematically evaluate and describe structural and functional cardiac alterations in patients with MD1. Methods Eighty MD1 patients underwent physical examination, electrocardiography (ECG, echocardiography and cardiovascular magnetic resonance (CMR. Blood samples were taken for determination of NT-proBNP plasma levels and CTG repeat length. Results Functional and structural abnormalities were detected in 35 patients (44%. Left ventricular systolic dysfunction was found in 20 cases, left ventricular dilatation in 7 patients, and left ventricular hypertrophy in 6 patients. Myocardial fibrosis was seen in 10 patients (12.5%. In general, patients had low left ventricular mass indexes. Right ventricular involvement was uncommon and only seen together with left ventricular abnormalities. Functional or structural cardiac involvement was associated with age (p = 0.04, male gender (p Conclusions CMR can be useful to detect early structural and functional myocardial abnormalities in patients with MD1. Myocardial involvement is strongly associated with conduction abnormalities, but a normal ECG does not exclude myocardial alterations. These findings lend support to the hypothesis that MD1 patients have a complex cardiac phenotype, including both myocardial and conduction system alteration.

Rocket measurements of energetic particles in the midlatitude precipitation zone

Science.gov (United States)

Voss, H. D.; Smith, L. G.; Braswell, F. M.

1980-01-01

Measurements of energetic ion and electron properties as a function of altitude in the midlatitude zone of nighttime energetic particle precipitation are reported. The measurements of particle fluxes, energy spectra and pitch angle distributions were obtained by a Langmuir probe, six energetic particle spectrometers and an electrostatic analyzer on board a Nike Apache rocket launched near the center of the midlatitude zone during disturbed conditions. It is found that the incident flux was primarily absorbed rather than backscattered, and consists of mainly energetic hydrogen together with some helium and a small energetic electron component. Observed differential energy spectra of protons having an exponential energy spectrum, and pitch angle distributions at various altitudes indicate that the energetic particle flux decreases rapidly for pitch angles less than 70 deg. An energetic particle energy flux of 0.002 ergs/sq cm per sec is calculated which indicates the significance of energetic particles as a primary nighttime ionization source for altitudes between 120 and 200 km in the midlatitude precipitation zone.

Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)

2014-09-15

Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

Beat-to-beat evaluation of left ventricular ejection in cardiac arrhythmias

International Nuclear Information System (INIS)

Itti, R.; Philippe, L.; Lorgeron, J.M.

1982-01-01

Conventional multi-gated cardiac blood pool studies suffer from two kinds of superimpositions: the spatial overlapping of various heart chambers and the temporal superimposition of a large number of cardiac cycles. The first problem can be partially solved by first pass techniques or by emission tomography. For the second one, which is specially critical arrhythmias, the single probe device (''nuclear stethoscope'') represents an original solution. Patients with normal cardiac rythm and patients presenting various kinds of cardiac rythm alterations were examined using a commercial ''nuclear stethoscope''. Some characteristic results achieved in these cases, were presented. For blood pool labeling, 20 mCi of 99mTc albumin was injected. The single probe detector was then positioned over the left ventricular area. The beat-to-beat left ventricular activity curve was then recorded for several minutes on paper in the same time as the E.C.G. signal. In cases with irregular cardiac rythm, the multigated techniques yield an average value of left ventricular ejection. Due to the relatively constant duration of systole, the superimposition of cycles may be valid during contration: differences mainly appear during diastole. But, as it could be demonstrated using the ''nuclear stethoscope'', individual cycles can show a large variability of ejection and average ejection fraction is only a very partial aspect of the real cardiac function

Cardiac Arrest Secondary to Lightning Strike: Case Report and Review of the Literature.

Science.gov (United States)

Rotariu, Elena L; Manole, Mioara D

2017-08-01

Lightning strike injuries, although less common than electrical injuries, have a higher morbidity rate because of critical alterations of the circulatory system, respiratory system, and central nervous system. Most lightning-related deaths occur immediately after injury because of arrhythmia or respiratory failure. We describe the case of a pediatric patient who experienced cardiorespiratory arrest secondary to a lightning strike, where the Advanced Cardiac Life Support and Basic Life Support chain of survival was well executed, leading to return of spontaneous circulation and intact neurological survival. We review the pathophysiology of lightning injuries, prognostic factors of favorable outcome after cardiac arrest, including bystander cardiopulmonary resuscitation, shockable rhythm, and automatic external defibrillator use, and the importance of temperature management after cardiac arrest.

Changes in cardiac heparan sulfate proteoglycan expression and streptozotocin-induced diastolic dysfunction in rats

Directory of Open Access Journals (Sweden)

Cestari Ismar N

2011-04-01

Full Text Available Abstract Background Changes in the proteoglycans glypican and syndecan-4 have been reported in several pathological conditions, but little is known about their expression in the heart during diabetes. The aim of this study was to investigate in vivo heart function changes and alterations in mRNA expression and protein levels of glypican-1 and syndecan-4 in cardiac and skeletal muscles during streptozotocin (STZ-induced diabetes. Methods Diabetes was induced in male Wistar rats by STZ administration. The rats were assigned to one of the following groups: control (sham injection, after 24 hours, 10 days, or 30 days of STZ administration. Echocardiography was performed in the control and STZ 10-day groups. Western and Northern blots were used to quantify protein and mRNA levels in all groups. Immunohistochemistry was performed in the control and 30-day groups to correlate the observed mRNA changes to the protein expression. Results In vivo cardiac functional analysis performed using echocardiography in the 10-day group showed diastolic dysfunction with alterations in the peak velocity of early (E diastolic filling and isovolumic relaxation time (IVRT indices. These functional alterations observed in the STZ 10-day group correlated with the concomitant increase in syndecan-4 and glypican-1 protein expression. Cardiac glypican-1 mRNA and skeletal syndecan-4 mRNA and protein levels increased in the STZ 30-day group. On the other hand, the amount of glypican in skeletal muscle was lower than that in the control group. The same results were obtained from immunohistochemistry analysis. Conclusion Our data suggest that membrane proteoglycans participate in the sequence of events triggered by diabetes and inflicted on cardiac and skeletal muscles.

Energetic costs of protein synthesis do not differ between red- and white-blooded Antarctic notothenioid fishes.

Science.gov (United States)

Lewis, Johanne M; Grove, Theresa J; O'Brien, Kristin M

2015-09-01

Antarctic icefishes (Family Channichthyidae) within the suborder Notothenioidei lack the oxygen-binding protein hemoglobin (Hb), and six of the 16 species of icefishes lack myoglobin (Mb) in heart ventricle. As iron-centered proteins, Hb and Mb can promote the formation of reactive oxygen species (ROS) that damage biological macromolecules. Consistent with this, our previous studies have shown that icefishes have lower levels of oxidized proteins and lipids in oxidative muscle compared to red-blooded notothenioids. Because oxidized proteins are usually degraded by the 20S proteasome and must be resynthesized, we hypothesized that rates of protein synthesis would be lower in icefishes compared to red-blooded notothenioids, thereby reducing the energetic costs of protein synthesis and conferring a benefit to the loss of Hb and Mb. Rates of protein synthesis were quantified in hearts, and the fraction of oxygen consumption devoted to protein synthesis was measured in isolated hepatocytes and cardiomyocytes of notothenioids differing in the expression of Hb and cardiac Mb. Neither rates of protein synthesis nor the energetic costs of protein synthesis differed among species, suggesting that red-blooded species do not degrade and replace oxidatively modified proteins at a higher rate compared to icefishes but rather, persist with higher levels of oxidized proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulation of cardiac microRNAs by serum response factor

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Wei Jeanne Y

2011-02-01

Full Text Available Abstract Serum response factor (SRF regulates certain microRNAs that play a role in cardiac and skeletal muscle development. However, the role of SRF in the regulation of microRNA expression and microRNA biogenesis in cardiac hypertrophy has not been well established. In this report, we employed two distinct transgenic mouse models to study the impact of SRF on cardiac microRNA expression and microRNA biogenesis. Cardiac-specific overexpression of SRF (SRF-Tg led to altered expression of a number of microRNAs. Interestingly, downregulation of miR-1, miR-133a and upregulation of miR-21 occurred by 7 days of age in these mice, long before the onset of cardiac hypertrophy, suggesting that SRF overexpression impacted the expression of microRNAs which contribute to cardiac hypertrophy. Reducing cardiac SRF level using the antisense-SRF transgenic approach (Anti-SRF-Tg resulted in the expression of miR-1, miR-133a and miR-21 in the opposite direction. Furthermore, we observed that SRF regulates microRNA biogenesis, specifically the transcription of pri-microRNA, thereby affecting the mature microRNA level. The mir-21 promoter sequence is conserved among mouse, rat and human; one SRF binding site was found to be in the mir-21 proximal promoter region of all three species. The mir-21 gene is regulated by SRF and its cofactors, including myocardin and p49/Strap. Our study demonstrates that the downregulation of miR-1, miR-133a, and upregulation of miR-21 can be reversed by one single upstream regulator, SRF. These results may help to develop novel therapeutic interventions targeting microRNA biogenesis.

Astragaloside IV Prevents Cardiac Remodeling in the Apolipoprotein E-Deficient Mice by Regulating Cardiac Homeostasis and Oxidative Stress

Directory of Open Access Journals (Sweden)

Xiong-Zhi Li

2017-12-01

Full Text Available Background: Hypercholesterolemia is a risk factor for the development of cardiac hypertrophy. Astragaloside IV (AST-IV possesses cardiovascular protective properties. We hypothesize that AST-IV prevents cardiac remodeling with hypercholesterolemia via modulating tissue homeostasis and alleviating oxidative stress. Methods: The ApoE-/- mice were treated with AST-IV at 1 or 10 mg/kg for 8 weeks. The blood lipids tests, echocardiography, and TUNEL were performed. The mRNA expression profile was detected by real-time PCR. The myocytes size and number, and the expressions of proliferation (ki67, senescence (p16INK4a, oxidant (NADPH oxidase 4, NOX4 and antioxidant (superoxide dismutase, SOD were observed by immunofluorescence staining. Results: Neither 1 mg/kg nor 10 mg/kg AST-IV treatment could decrease blood lipids in ApoE-/- mice. However, the decreased left ventricular ejection fraction (LVEF and fractional shortening (FS in ApoE–/– mice were significantly improved after AST-IV treatment. The cardiac collagen volume fraction declined nearly in half after AST-IV treatment. The enlarged myocyte size was suppressed, and myocyte number was recovered, and the alterations of genes expressions linked to cell cycle, proliferation, senescence, p53-apoptosis pathway and oxidant-antioxidants in the hearts of ApoE-/- mice were reversed after AST-IV treatment. The decreased ki67 and increased p16INK4a in the hearts of ApoE-/- mice were recovered after AST-IV treatment. The percentages of apoptotic myocytes and NOX4-positive cells in AST-IV treated mice were decreased, which were consistent with the gene expressions. Conclusion: AST-IV treatment could prevent cardiac remodeling and recover the impaired ventricular function induced by hypercholesterolemia. The beneficial effect of AST-IV might partly be through regulating cardiac homeostasis and anti-oxidative stress.

Structure of Energetic Particle Mediated Shocks Revisited

International Nuclear Information System (INIS)

Mostafavi, P.; Zank, G. P.; Webb, G. M.

2017-01-01

The structure of collisionless shock waves is often modified by the presence of energetic particles that are not equilibrated with the thermal plasma (such as pickup ions [PUIs] and solar energetic particles [SEPs]). This is relevant to the inner and outer heliosphere and the Very Local Interstellar Medium (VLISM), where observations of shock waves (e.g., in the inner heliosphere) show that both the magnetic field and thermal gas pressure are less than the energetic particle component pressures. Voyager 2 observations revealed that the heliospheric termination shock (HTS) is very broad and mediated by energetic particles. PUIs and SEPs contribute both a collisionless heat flux and a higher-order viscosity. We show that the incorporation of both effects can completely determine the structure of collisionless shocks mediated by energetic ions. Since the reduced form of the PUI-mediated plasma model is structurally identical to the classical cosmic ray two-fluid model, we note that the presence of viscosity, at least formally, eliminates the need for a gas sub-shock in the classical two-fluid model, including in that regime where three are possible. By considering parameters upstream of the HTS, we show that the thermal gas remains relatively cold and the shock is mediated by PUIs. We determine the structure of the weak interstellar shock observed by Voyager 1 . We consider the inclusion of the thermal heat flux and viscosity to address the most general form of an energetic particle-thermal plasma two-fluid model.

Structure of Energetic Particle Mediated Shocks Revisited

Energy Technology Data Exchange (ETDEWEB)

Mostafavi, P.; Zank, G. P. [Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Webb, G. M. [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

2017-05-20

The structure of collisionless shock waves is often modified by the presence of energetic particles that are not equilibrated with the thermal plasma (such as pickup ions [PUIs] and solar energetic particles [SEPs]). This is relevant to the inner and outer heliosphere and the Very Local Interstellar Medium (VLISM), where observations of shock waves (e.g., in the inner heliosphere) show that both the magnetic field and thermal gas pressure are less than the energetic particle component pressures. Voyager 2 observations revealed that the heliospheric termination shock (HTS) is very broad and mediated by energetic particles. PUIs and SEPs contribute both a collisionless heat flux and a higher-order viscosity. We show that the incorporation of both effects can completely determine the structure of collisionless shocks mediated by energetic ions. Since the reduced form of the PUI-mediated plasma model is structurally identical to the classical cosmic ray two-fluid model, we note that the presence of viscosity, at least formally, eliminates the need for a gas sub-shock in the classical two-fluid model, including in that regime where three are possible. By considering parameters upstream of the HTS, we show that the thermal gas remains relatively cold and the shock is mediated by PUIs. We determine the structure of the weak interstellar shock observed by Voyager 1 . We consider the inclusion of the thermal heat flux and viscosity to address the most general form of an energetic particle-thermal plasma two-fluid model.

Energetic consumption levels and human development indexes

International Nuclear Information System (INIS)

Boa Nova, Antonio Carlos

1999-01-01

The article overviews the energetic consumption levels and human development indexes. The human development indexes are described based on the United Nations Development Programme. A comparison between the energetic consumption levels and human development indexes is also presented

Contrast agents for cardiac angiography: effects of a nonionic agent vs. a standard ionic agent

International Nuclear Information System (INIS)

Bettmann, M.A.; Bourdillon, P.D.; Barry, W.H.; Brush, K.A.; Levin, D.C.

1984-01-01

The effects on cardiac hemodynamics and of a standard contrast agent, sodium methylglucamine diatrizoate [Renografin 76] were compared with the effects of a new nonionic agent (iohexol) in a double-blind study in 51 patietns undergoing coronary angiography and left ventriculography. No significant alteration in measured blood parameters occurred with either contrast agent. Hemodynamic changes occurred with both, but were significantly greater with the standard renografin than with the low-osmolality, nonionic iohexol. After left ventriculography, heart rate increased and peripheral arterial pressure fell with both agents, but less with iohexol. It is concluded that iohexol causes less alteration in cardiac function than does the agent currently most widely used. Nonionic contrast material is likely to improve the safety of coronary angiography, particularly in those patients at greatest risk

Nonperturbative effects of energetic ions on Alfven eigenmodes

International Nuclear Information System (INIS)

Todo, Y.; Nakajima, N.; Shinohara, K.; Takechi, M.; Ishikawa, M.; Yamamoto, S.

2005-01-01

Linear properties and nonlinear evolutions of an energetic-ion driven instability in a JT-60U plasma were investigated using a simulation code for magnetohydrodynamics and energetic particles. The spatial profile of the unstable mode peaks near the plasma center where the safety factor profile is flat. The unstable mode is not a toroidal Alfven eigenmode (TAE) because the spatial profile deviates from the expected location of TAE and the spatial profile consists of a single primary harmonic m/n = 2/1 where m, n are poloidal and toroidal mode numbers. The real frequency of the unstable mode is close to the experimental starting frequency of the fast frequency sweeping mode. The simulation results demonstrate that the energetic ion orbit width and the energetic ion pressure significantly broaden radial profile of the unstable mode. For the smallest value among the investigated energetic ion orbit width, the unstable mode is localized within 20% of the minor radius. This gives an upper limit of the spatial profile width of the unstable mode which the magnetohydrodynamic effects alone can induce. For the experimental condition of the JT-60U plasma, the energetic ions broaden the spatial profile of the unstable mode by a factor of 3 compared with the smallest orbit width case. The unstable mode is primarily induced by the energetic particles. It is demonstrated that the frequency shifts both upward and downward in the nonlinear evolution at the rate close to that of the fast frequency sweeping mode. In addition to the energetic particle mode in the JT-60U plasma, an investigation of TAE in an LHD-like plasma using the simulation code for the helical coordinate system is reported. (author)

Nonperturbative effects of energetic ions on Alfven eigenmodes

International Nuclear Information System (INIS)

Todo, Y.; Nakajima, N.; Shinohara, Kouji; Takechi, Manabu; Ishikawa, Masao

2005-01-01

Linear properties and nonlinear evolutions of an energetic-ion driven instability in a JT-60U plasma were investigated using a simulation code for magnetohydrodynamics and energetic particles. The spatial profile of the unstable mode peaks near the plasma center where the safety factor profile is flat. The unstable mode is not a toroidal Alfven eigenmode (TAE) because the spatial profile deviates from the expected location of TAE and the spatial profile consists of a single primary harmonic m/n=2/1 where m, n are poloidal and toroidal mode numbers. The real frequency of the unstable mode is close to the experimental starting frequency of the fast frequency sweeping mode. The simulation results demonstrate that the energetic ion orbit width and the energetic ion pressure significantly broaden radial profile of the unstable mode. For the smallest value among the investigated energetic ion orbit width, the unstable mode is localized within 20% of the minor radius. This gives an upper limit of the spatial profile width of the unstable mode which the magnetohydrodynamic effects alone can induce. For the experimental condition of the JT-60U plasma, the energetic ions broaden the spatial profile of the unstable mode by a factor of 3 compared with the smallest orbit width case. The unstable mode is primarily induced by the energetic particles. It is demonstrated that the frequency shifts both upward and downward in the nonlinear evolution at the rate close to that of the fast frequency sweeping mode. In addition to the energetic particle mode in the JT-60U plasma, an investigation of TAE in an LHD-like plasma using the simulation code for the helical coordinate system is reported. (author)

Effects of aerobic exercise training on cardiac renin-angiotensin system in an obese Zucker rat strain.

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Diego Lopes Mendes Barretti

Full Text Available OBJECTIVE: Obesity and renin angiotensin system (RAS hyperactivity are profoundly involved in cardiovascular diseases, however aerobic exercise training (EXT can prevent obesity and cardiac RAS activation. The study hypothesis was to investigate whether obesity and its association with EXT alter the systemic and cardiac RAS components in an obese Zucker rat strain. METHODS: THE RATS WERE DIVIDED INTO THE FOLLOWING GROUPS: Lean Zucker rats (LZR; lean Zucker rats plus EXT (LZR+EXT; obese Zucker rats (OZR and obese Zucker rats plus EXT (OZR+EXT. EXT consisted of 10 weeks of 60-min swimming sessions, 5 days/week. At the end of the training protocol heart rate (HR, systolic blood pressure (SBP, cardiac hypertrophy (CH and function, local and systemic components of RAS were evaluated. Also, systemic glucose, triglycerides, total cholesterol and its LDL and HDL fractions were measured. RESULTS: The resting HR decreased (∼12% for both LZR+EXT and OZR+EXT. However, only the LZR+EXT reached significance (p<0.05, while a tendency was found for OZR versus OZR+EXT (p = 0.07. In addition, exercise reduced (57% triglycerides and (61% LDL in the OZR+EXT. The systemic angiotensin I-converting enzyme (ACE activity did not differ regardless of obesity and EXT, however, the OZR and OZR+EXT showed (66% and (42%, respectively, less angiotensin II (Ang II plasma concentration when compared with LZR. Furthermore, the results showed that EXT in the OZR prevented increase in CH, cardiac ACE activity, Ang II and AT2 receptor caused by obesity. In addition, exercise augmented cardiac ACE2 in both training groups. CONCLUSION: Despite the unchanged ACE and lower systemic Ang II levels in obesity, the cardiac RAS was increased in OZR and EXT in obese Zucker rats reduced some of the cardiac RAS components and prevented obesity-related CH. These results show that EXT prevented the heart RAS hyperactivity and cardiac maladaptive morphological alterations in obese Zucker rats.

Ecological problems of thermonuclear energetics. Review

Energy Technology Data Exchange (ETDEWEB)

Sivintsev, Yu V

1980-01-01

A review of preliminary quantitative estimates of radiation hazard of thermonuclear reactors is presented. Main attention is given to three aspects: nonradiation effect on environment, radionuclide blow-ups at normal operation and emergency situations with their consequences. The given data testify to great radiological advantages of thermonuclear energetics as compared with the modern nuclear energetics with thermal and prospective fast reactors.

Cardiac Diastolic Evaluation in Pregnant Women with Abnormal Glucose Tolerance: An Opportunity to Detect the Early and Subclinical Alterations and Prevent Cardiovascular Diseases

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B. Pintaudi

2013-01-01

Full Text Available Objectives of this study were to assess diastolic function in pregnant women with abnormal glucose tolerance (AGT, compared with normal glucose tolerance (NGT women, and to evaluate the insulin resistance status and its association with Doppler-echocardiographic indexes. Echocardiograms of 108 consecutive Caucasian women with singleton pregnancies were performed. Insulin resistance status was estimated by the homeostasis model assessment of insulin resistance (HOMA-IR and the quantitative insulin sensitivity check index (QUICKI. All the studied women showed normal diastolic patterns. Patients with AGT (50.9%, as compared with NGT women, had higher HOMA-IR (1.70±1.30 versus 1.01±0.81, P=0.003, lower QUICKI (0.36±0.005 versus 0.40±0.06, P=0.004, higher lateral mitral annulus late diastolic velocity (13.6±4.9 versus 11.9±4.9, P=0.03, and higher A-wave velocity, the wave responsible for the active atrial contraction component (75.2±14.2 versus 67.7±16.2, P=0.01. At multivariate regression analysis HOMA-IR was the only parameter associated with A-wave velocity. In conclusion, women with AGT had an increased subclinical diastolic active participation, which is associated with higher levels of insulin resistance. For the increased risk of deterioration of cardiac diastolic function, earlier and more seriously than normal pregnancy, AGT women may have a careful followup to detect the early signs of cardiac alteration and to prevent cardiovascular diseases.

Loss of Akap1 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy and Heart Failure

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Gabriele G. Schiattarella

2018-05-01

Full Text Available Left ventricular hypertrophy (LVH is a major contributor to the development of heart failure (HF. Alterations in cyclic adenosine monophosphate (cAMP-dependent signaling pathways participate in cardiomyocyte hypertrophy and mitochondrial dysfunction occurring in LVH and HF. cAMP signals are received and integrated by a family of cAMP-dependent protein kinase A (PKA anchor proteins (AKAPs, tethering PKA to discrete cellular locations. AKAPs encoded by the Akap1 gene (mitoAKAPs promote PKA mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cell survival. To determine the role of mitoAKAPs in LVH development, in the present investigation, mice with global genetic deletion of Akap1 (Akap1-/-, Akap1 heterozygous (Akap1+/-, and their wild-type (wt littermates underwent transverse aortic constriction (TAC or SHAM procedure for 1 week. In wt mice, pressure overload induced the downregulation of AKAP121, the major cardiac mitoAKAP. Compared to wt, Akap1-/- mice did not display basal alterations in cardiac structure or function and cardiomyocyte size or fibrosis. However, loss of Akap1 exacerbated LVH and cardiomyocyte hypertrophy induced by pressure overload and accelerated the progression toward HF in TAC mice, and these changes were not observed upon prevention of AKAP121 degradation in seven in absentia homolog 2 (Siah2 knockout mice (Siah2-/-. Loss of Akap1 was also associated to a significant increase in cardiac apoptosis as well as lack of activation of Akt signaling after pressure overload. Taken together, these results demonstrate that in vivo genetic deletion of Akap1 enhances LVH development and accelerates pressure overload-induced cardiac dysfunction, pointing at Akap1 as a novel repressor of pathological LVH. These results confirm and extend the important role of mitoAKAPs in cardiac response to stress.

Loss of Akap1 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy and Heart Failure.

Science.gov (United States)

Schiattarella, Gabriele G; Boccella, Nicola; Paolillo, Roberta; Cattaneo, Fabio; Trimarco, Valentina; Franzone, Anna; D'Apice, Stefania; Giugliano, Giuseppe; Rinaldi, Laura; Borzacchiello, Domenica; Gentile, Alessandra; Lombardi, Assunta; Feliciello, Antonio; Esposito, Giovanni; Perrino, Cinzia

2018-01-01

Left ventricular hypertrophy (LVH) is a major contributor to the development of heart failure (HF). Alterations in cyclic adenosine monophosphate (cAMP)-dependent signaling pathways participate in cardiomyocyte hypertrophy and mitochondrial dysfunction occurring in LVH and HF. cAMP signals are received and integrated by a family of cAMP-dependent protein kinase A (PKA) anchor proteins (AKAPs), tethering PKA to discrete cellular locations. AKAPs encoded by the Akap1 gene (mitoAKAPs) promote PKA mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cell survival. To determine the role of mitoAKAPs in LVH development, in the present investigation, mice with global genetic deletion of Akap1 ( Akap1 -/- ), Akap1 heterozygous ( Akap1 +/- ), and their wild-type ( wt ) littermates underwent transverse aortic constriction (TAC) or SHAM procedure for 1 week. In wt mice, pressure overload induced the downregulation of AKAP121, the major cardiac mitoAKAP. Compared to wt, Akap1 -/- mice did not display basal alterations in cardiac structure or function and cardiomyocyte size or fibrosis. However, loss of Akap1 exacerbated LVH and cardiomyocyte hypertrophy induced by pressure overload and accelerated the progression toward HF in TAC mice, and these changes were not observed upon prevention of AKAP121 degradation in seven in absentia homolog 2 ( Siah2 ) knockout mice ( Siah2 -/- ). Loss of Akap1 was also associated to a significant increase in cardiac apoptosis as well as lack of activation of Akt signaling after pressure overload. Taken together, these results demonstrate that in vivo genetic deletion of Akap1 enhances LVH development and accelerates pressure overload-induced cardiac dysfunction, pointing at Akap1 as a novel repressor of pathological LVH. These results confirm and extend the important role of mitoAKAPs in cardiac response to stress.

Impact of thoracic surgery on cardiac morphology and function in small animal models of heart disease: a cardiac MRI study in rats.

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Peter Nordbeck

Full Text Available BACKGROUND: Surgical procedures in small animal models of heart disease might evoke alterations in cardiac morphology and function. The aim of this study was to reveal and quantify such potential artificial early or long term effects in vivo, which might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies. METHODS: Female Wistar rats (n = 6 per group were matched for weight and assorted for sham left coronary artery ligation or control. Cardiac morphology and function was then investigated in vivo by cine magnetic resonance imaging at 7 Tesla 1 and 8 weeks after the surgical procedure. The time course of metabolic and inflammatory blood parameters was determined in addition. RESULTS: Compared to healthy controls, rats after sham surgery showed a lower body weight both 1 week (267.5±10.6 vs. 317.0±11.3 g, n<0.05 and 8 weeks (317.0±21.1 vs. 358.7±22.4 g, n<0.05 after the intervention. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw, such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05, or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05. Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in sham operated rats compared to controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass, but not normalized to body weight. Matching these findings, blood testing revealed only minor inflammatory but prolonged metabolic changes after surgery not related to cardiac disease. CONCLUSION: Cardio-thoracic surgical procedures in experimental myocardial infarction

Effects of obstructive sleep apnea on hemodynamic parameters in patients entering cardiac rehabilitation.

Science.gov (United States)

Hargens, Trent A; Aron, Adrian; Newsome, Laura J; Austin, Joseph L; Shafer, Brooke M

2015-01-01

Obstructive sleep apnea (OSA) is a prevalent form of sleep-disordered breathing. Evidence suggests that OSA may lead to cardiac remodeling, although the literature is equivocal. Previous literature suggests a high percentage of individuals entering a cardiac rehabilitation (CR) program also have OSA. The objective of this study was to determine whether resting hemodynamic variables were altered in OSA subjects entering CR compared with those without OSA, as determined by impedance cardiography. Subjects entering an early outpatient CR program were screened for OSA using an at-home screening device and verified by a sleep physician. Subjects were divided into an OSA group (n = 48) or a control group (n = 25) on the basis of the screening results. Hemodynamic variables were measured during supine rest using impedance cardiography. A 6-minute walk test was performed to assess functional capacity. The proportion of cardiac diagnoses was similar between groups. Overall, 66% of the subjects were positive for OSA. Subject groups did not differ by age, body mass index, heart rate, diastolic blood pressure, or functional capacity. Cardiac output, cardiac index, stroke volume, contractility index, and left cardiac work index were all significantly decreased in the OSA group compared with the control group (P disadvantage in recovering from their cardiac event, and place them at increased risk for secondary complications.

Inhibiting Na+/K+ ATPase can impair mitochondrial energetics and induce abnormal Ca2+ cycling and automaticity in guinea pig cardiomyocytes.

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Qince Li

Full Text Available Cardiac glycosides have been used for the treatment of heart failure because of their capabilities of inhibiting Na+/K+ ATPase (NKA, which raises [Na+]i and attenuates Ca2+ extrusion via the Na+/Ca2+ exchanger (NCX, causing [Ca2+]i elevation. The resulting [Ca2+]i accumulation further enhances Ca2+-induced Ca2+ release, generating the positive inotropic effect. However, cardiac glycosides have some toxic and side effects such as arrhythmogenesis, confining their extensive clinical applications. The mechanisms underlying the proarrhythmic effect of glycosides are not fully understood. Here we investigated the mechanisms by which glycosides could cause cardiac arrhythmias via impairing mitochondrial energetics using an integrative computational cardiomyocyte model. In the simulations, the effect of glycosides was mimicked by blocking NKA activity. Results showed that inhibiting NKA not only impaired mitochondrial Ca2+ retention (thus suppressed reactive oxygen species (ROS scavenging but also enhanced oxidative phosphorylation (thus increased ROS production during the transition of increasing workload, causing oxidative stress. Moreover, concurrent blocking of mitochondrial Na+/Ca2+ exchanger, but not enhancing of Ca2+ uniporter, alleviated the adverse effects of NKA inhibition. Intriguingly, NKA inhibition elicited Ca2+ transient and action potential alternans under more stressed conditions such as severe ATP depletion, augmenting its proarrhythmic effect. This computational study provides new insights into the mechanisms underlying cardiac glycoside-induced arrhythmogenesis. The findings suggest that targeting both ion handling and mitochondria could be a very promising strategy to develop new glycoside-based therapies in the treatment of heart failure.

Inhibiting Na+/K+ ATPase can impair mitochondrial energetics and induce abnormal Ca2+ cycling and automaticity in guinea pig cardiomyocytes.

Science.gov (United States)

Li, Qince; Pogwizd, Steven M; Prabhu, Sumanth D; Zhou, Lufang

2014-01-01

Cardiac glycosides have been used for the treatment of heart failure because of their capabilities of inhibiting Na+/K+ ATPase (NKA), which raises [Na+]i and attenuates Ca2+ extrusion via the Na+/Ca2+ exchanger (NCX), causing [Ca2+]i elevation. The resulting [Ca2+]i accumulation further enhances Ca2+-induced Ca2+ release, generating the positive inotropic effect. However, cardiac glycosides have some toxic and side effects such as arrhythmogenesis, confining their extensive clinical applications. The mechanisms underlying the proarrhythmic effect of glycosides are not fully understood. Here we investigated the mechanisms by which glycosides could cause cardiac arrhythmias via impairing mitochondrial energetics using an integrative computational cardiomyocyte model. In the simulations, the effect of glycosides was mimicked by blocking NKA activity. Results showed that inhibiting NKA not only impaired mitochondrial Ca2+ retention (thus suppressed reactive oxygen species (ROS) scavenging) but also enhanced oxidative phosphorylation (thus increased ROS production) during the transition of increasing workload, causing oxidative stress. Moreover, concurrent blocking of mitochondrial Na+/Ca2+ exchanger, but not enhancing of Ca2+ uniporter, alleviated the adverse effects of NKA inhibition. Intriguingly, NKA inhibition elicited Ca2+ transient and action potential alternans under more stressed conditions such as severe ATP depletion, augmenting its proarrhythmic effect. This computational study provides new insights into the mechanisms underlying cardiac glycoside-induced arrhythmogenesis. The findings suggest that targeting both ion handling and mitochondria could be a very promising strategy to develop new glycoside-based therapies in the treatment of heart failure.

Fluorescence lifetime microscopy of NADH distinguishes alterations in cerebral metabolism in vivo.

Science.gov (United States)

Yaseen, Mohammad A; Sutin, Jason; Wu, Weicheng; Fu, Buyin; Uhlirova, Hana; Devor, Anna; Boas, David A; Sakadžić, Sava

2017-05-01

Evaluating cerebral energy metabolism at microscopic resolution is important for comprehensively understanding healthy brain function and its pathological alterations. Here, we resolve specific alterations in cerebral metabolism in vivo in Sprague Dawley rats utilizing minimally-invasive 2-photon fluorescence lifetime imaging (2P-FLIM) measurements of reduced nicotinamide adenine dinucleotide (NADH) fluorescence. Time-resolved fluorescence lifetime measurements enable distinction of different components contributing to NADH autofluorescence. Ostensibly, these components indicate different enzyme-bound formulations of NADH. We observed distinct variations in the relative proportions of these components before and after pharmacological-induced impairments to several reactions involved in glycolytic and oxidative metabolism. Classification models were developed with the experimental data and used to predict the metabolic impairments induced during separate experiments involving bicuculline-induced seizures. The models consistently predicted that prolonged focal seizure activity results in impaired activity in the electron transport chain, likely the consequence of inadequate oxygen supply. 2P-FLIM observations of cerebral NADH will help advance our understanding of cerebral energetics at a microscopic scale. Such knowledge will aid in our evaluation of healthy and diseased cerebral physiology and guide diagnostic and therapeutic strategies that target cerebral energetics.

Segregation and redistribution of end-of-process energetic materials

International Nuclear Information System (INIS)

McCabe, R.A.; Cummins, B.; Gonzalez, M.A.

1993-03-01

A system recovering then recycling or reusing end-of-process energetic materials has been developed at the Lawrence Livermore National Laboratory (LLNL). The system promotes separating energetic materials with high potential for reuse or recycling from those that have no further value. A feature of the system is a computerized electronic bulletin board for advertising the availability of surplus and recovered energetic materials and process chemicals to LLNL researchers, and for posting energetic materials, ''want ads.'' The system was developed and implemented to promote waste minimization and pollution prevention at LLNL

Cardiac, skeletal, and smooth muscle mitochondrial respiration: are all mitochondria created equal?

Science.gov (United States)

Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I; Trinity, Joel D; Hyngstrom, John R; Garten, Ryan S; Diakos, Nikolaos A; Ives, Stephen J; Dela, Flemming; Larsen, Steen; Drakos, Stavros; Richardson, Russell S

2014-08-01

Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial respiration. Therefore, the present study examined mitochondrial respiratory rates in smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscles. Cardiac, skeletal, and smooth muscles were harvested from a total of 22 subjects (53 ± 6 yr), and mitochondrial respiration was assessed in permeabilized fibers. Complex I + II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac to skeletal to smooth muscles (54 ± 1, 39 ± 4, and 15 ± 1 pmol·s(-1)·mg(-1), P respiration rates were normalized by CS (respiration per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, complex I state 2 normalized for CS activity, an index of nonphosphorylating respiration per mitochondrial content, increased progressively from cardiac to skeletal to smooth muscles, such that the respiratory control ratio, state 3/state 2 respiration, fell progressively from cardiac to skeletal to smooth muscles (5.3 ± 0.7, 3.2 ± 0.4, and 1.6 ± 0.3 pmol·s(-1)·mg(-1), P respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation and could potentially alter ROS production.

Experimental and clinical study of cardiac hypertrophy by thallium-201 myocardial scintigraphy

International Nuclear Information System (INIS)

Torii, Yukio

1983-01-01

I studied experimentally the myocardial uptake of 201 Tl in cardiac hypertrophy in rat, and clinically evaluated cardiac shape and dimension in the patients with various types of cardiac hypertrophy. Experimentally, both myocardial blood flow (MBF) and Tl uptake were increased with cardiac weight. There were negative correlations between the extraction fraction and MBF. Tl uptake in Hypertrophy is not always dependent on MBF and affected by the altered metabolism of hypertrophied myocardium. Clinical study was performed in 29 normal subjects and in 90 patients with heart disease. The measurements of left ventricular (LV) size by Tl scintigraphy were well correlated with them by echocardiography. Aortic stenosis and hypertensive heart disease showed thick wall and spherical shape. Both mitral (MR) and aortic (AR) regurgitation showed ventricular dilatation, spherical shape (in chronic MR) and ellipsoid shape (in acute MR and in AR). Decreased ventricular size but normal shape was observed in mitral stenosis and cor pulmonale. Hypertrophic cardiomyopathy showed thick wall with asymmetric septal hypertrophy, while congestive cardiomyopathy showed thin wall with marked ventricular dilatation and spherical shape. I conclude that heart disease has characteristic figures in dimension and shape which may be reflecting cardiac performance or compensating for the load to the heart, and that 201 Tl scintigraphy is useful evaluating cardiac morphology as well as in diagnosing myocardial ischemia. (J.P.N.)

Assessment of accident energetics in LMFBR core-disruptive accidents

International Nuclear Information System (INIS)

Fauske, H.K.

1977-01-01

An assessment of accident energetics in LMFBR core-disruptive accidents is given with emphasis on the generic issues of energetic recriticality and energetic fuel-coolant interaction events. Application of a few general behavior principles to the oxide-fueled system suggests that such events are highly unlikely following a postulated core meltdown event

Heliospheric Observations of Energetic Particles

Science.gov (United States)

Summerlin, Errol J.

2011-01-01

Heliospheric observations of energetic particles have shown that, on long time averages, a consistent v^-5 power-law index arises even in the absence of transient events. This implies an ubiquitous acceleration process present in the solar wind that is required to generate these power-law tails and maintain them against adiabatic losses and coulomb-collisions which will cool and thermalize the plasma respectively. Though the details of this acceleration process are being debated within the community, most agree that the energy required for these tails comes from fluctuations in the magnetic field which are damped as the energy is transferred to particles. Given this source for the tail, is it then reasonable to assume that the turbulent LISM should give rise to such a power-law tail as well? IBEX observations clearly show a power-law tail of index approximately -5 in energetic neutral atoms. The simplest explanation for the origins of these ENAs are that they are energetic ions which have charge-exchanged with a neutral atom. However, this would imply that energetic ions possess a v^-5 power-law distribution at keV energies at the source of these ENAs. If the source is presumed to be the LISM, it provides additional options for explaining the, so called, IBEX ribbon. This presentation will discuss some of these options as well as potential mechanisms for the generation of a power-law spectrum in the LISM.

Physics of energetic ions

International Nuclear Information System (INIS)

1999-01-01

Physics knowledge (theory and experiment) in energetic particles relevant to design of a reactor scale tokamak is reviewed, and projections for ITER are provided in this Chapter of the ITER Physics Basis. The review includes single particle effects such as classical alpha particle heating and toroidal field ripple loss, as well as collective instabilities that might be generated in ITER plasmas by energetic alpha particles. The overall conclusion is that fusion alpha particles are expected to provide an efficient plasma heating for ignition and sustained burn in the next step device. The major concern is localized heat loads on the plasma facing components produced by alpha particle loss, which might affect their lifetime in a tokamak reactor. (author)

Energetic particle observations at the subsolar magnetopause

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A. A. Eccles

Full Text Available The pitch-angle distributions (PAD of energetic particles are examined as the ISEE-1 satellite crosses the Earth’s magnetopause near the subsolar point. The investigation focuses on the possible existence of a particular type of distribution that would be associated with a source of energetic particles in the high-latitude magnetosphere. PADs, demonstrating broad, persistent field-aligned fluxes filling a single hemisphere (upper/northern or lower/southern, were observed just sunward of the magnetopause current layer for an extended period of many minutes. These distributions are a direct prediction of a possible source of energetic particles located in the high altitude dayside cusp and we present five examples in detail of the three-dimensional particle distributions to demonstrate their existence. From these results, other possible causes of such PADs are examined.

Key words. Magnetospheric physics (energetic particles, precipitating; magnetopause, cusp and boundary layers; magnetospheric configuration and dynamics

Energetically resolved multiple-fluid equilibria of tokamak plasmas

International Nuclear Information System (INIS)

Hole, M J; Dennis, G

2009-01-01

In many magnetically confined fusion experiments, a significant fraction of the stored energy of the plasma resides in energetic, or non-thermal, particle populations. Despite this, most equilibrium treatments are based on MHD: a single fluid treatment which assumes a Maxwell-Boltzmann distribution function. Detailed magnetic reconstruction based on this treatment ignore the energetic complexity of the plasma and can result in model-data inconsistencies, such as thermal pressure profiles which are inconsistent with the total stored kinetic energy of the plasma. Alternatively, ad hoc corrections to the pressure profile, such as summing the energetic and thermal pressures, have poor theoretical justification. Motivated by this omission, we generalize ideal MHD one step further: we consider multiple quasi-neutral fluids, each in thermal equilibrium and each thermally insulated from each other-no population mixing occurs. Kinetically, such a model may be able to describe the ion or electron distribution function in regions of velocity phase space with a large number of particles, at the expense of more weakly populated phase space, which may have uncharacteristically high temperature and hence pressure. As magnetic equilibrium effects increase with the increase in pressure, our work constitutes an upper limit to the effect of energetic particles. When implemented into an existing solver, FLOW (Guazzotto et al 2004 Phys. Plasmas 11, 604-14), it becomes possible to qualitatively explore the impact of resolving the energetic populations on plasma equilibrium configurations in realistic geometry. Deploying the modified code, FLOW-M, on a high performance spherical torus configuration, we find that the effect of variations of the pressure, poloidal flow and toroidal flow of the energetic populations is qualitatively similar to variations in the background plasma. We also study the robustness of the equilibrium to uncertainties in the current profile and the energetic

Cardiac tamponade: contrast reflux as an indicator of cardiac chamber equalization

Directory of Open Access Journals (Sweden)

Nauta Foeke Jacob

2012-05-01

Full Text Available Abstract Background Traumatic hemopericardium remains a rare entity; it does however commonly cause cardiac tamponade which remains a major cause of death in traumatic blunt cardiac injury. Objectives We present a case of blunt chest trauma complicated by cardiac tamponade causing cardiac chamber equalization revealed by reflux of contrast. Case report A 29-year-old unidentified male suffered blunt chest trauma in a motor vehicle collision. Computed tomography (CT demonstrated a periaortic hematoma and hemopericardium. Significant contrast reflux was seen in the inferior vena cava and hepatic veins suggesting a change in cardiac chamber pressures. After intensive treatment including cardiac massage this patient expired of cardiac arrest. Conclusion Reflux of contrast on CT imaging can be an indicator of traumatic cardiac tamponade.

Living cardiac patch: the elixir for cardiac regeneration.

Science.gov (United States)

Lakshmanan, Rajesh; Krishnan, Uma Maheswari; Sethuraman, Swaminathan

2012-12-01

A thorough understanding of the cellular and muscle fiber orientation in left ventricular cardiac tissue is of paramount importance for the generation of artificial cardiac patches to treat the ischemic myocardium. The major challenge faced during cardiac patch engineering is to choose a perfect combination of three entities; cells, scaffolds and signaling molecules comprising the tissue engineering triad for repair and regeneration. This review provides an overview of various scaffold materials, their mechanical properties and fabrication methods utilized in cardiac patch engineering. Stem cell therapies in clinical trials and the commercially available cardiac patch materials were summarized in an attempt to provide a recent perspective in the treatment of heart failure. Various tissue engineering strategies employed thus far to construct viable thick cardiac patches is schematically illustrated. Though many strategies have been proposed for fabrication of various cardiac scaffold materials, the stage and severity of the disease condition demands the incorporation of additional cues in a suitable scaffold material. The scaffold may be nanofibrous patch, hydrogel or custom designed films. Integration of stem cells and biomolecular cues along with the scaffold may provide the right microenvironment for the repair of unhealthy left ventricular tissue as well as promote its regeneration.

The Cardiac MR Images and Causes of Paradoxical Septal Motion

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Hun [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Choi, Sang Il; Chun, Eun Ju [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Choi, Sung Hun [Ulsan University Hospital, Ulsan (Korea, Republic of); Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

2010-10-15

Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging.

The Cardiac MR Images and Causes of Paradoxical Septal Motion

International Nuclear Information System (INIS)

Kim, Dong Hun; Choi, Sang Il; Chun, Eun Ju; Choi, Sung Hun; Park, Jae Hyung

2010-01-01

Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging

Dihydrotestosterone deteriorates cardiac insulin signaling and glucose transport in the rat model of polycystic ovary syndrome.

Science.gov (United States)

Tepavčević, Snežana; Vojnović Milutinović, Danijela; Macut, Djuro; Žakula, Zorica; Nikolić, Marina; Božić-Antić, Ivana; Romić, Snježana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

2014-05-01

It is supposed that women with polycystic ovary syndrome (PCOS) are prone to develop cardiovascular disease as a consequence of multiple risk factors that are mostly related to the state of insulin resistance and consequent hyperinsulinemia. In the present study, we evaluated insulin signaling and glucose transporters (GLUT) in cardiac cells of dihydrotestosterone (DHT) treated female rats as an animal model of PCOS. Expression of proteins involved in cardiac insulin signaling pathways and glucose transporters, as well as their phosphorylation or intracellular localization were studied by Western blot analysis in DHT-treated and control rats. Treatment with DHT resulted in increased body mass, absolute mass of the heart, elevated plasma insulin concentration, dyslipidemia and insulin resistance. At the molecular level, DHT treatment did not change protein expression of cardiac insulin receptor and insulin receptor substrate 1, while phosphorylation of the substrate at serine 307 was increased. Unexpectedly, although expression of downstream Akt kinase and its phosphorylation at threonine 308 were not altered, phosphorylation of Akt at serine 473 was increased in the heart of DHT-treated rats. In contrast, expression and phosphorylation of extracellular signal regulated kinases 1/2 were decreased. Plasma membrane contents of GLUT1 and GLUT4 were decreased, as well as the expression of GLUT4 in cardiac cells at the end of androgen treatment. The obtained results provide evidence for alterations in expression and especially in functional characteristics of insulin signaling molecules and glucose transporters in the heart of DHT-treated rats with PCOS, indicating impaired cardiac insulin action. Copyright © 2014 Elsevier Ltd. All rights reserved.

Curcumin ameliorates cardiac dysfunction induced by mechanical trauma.

Science.gov (United States)

Li, Xintao; Cao, Tingting; Ma, Shuo; Jing, Zehao; Bi, Yue; Zhou, Jicheng; Chen, Chong; Yu, Deqin; Zhu, Liang; Li, Shuzhuang

2017-11-05

Curcumin, a phytochemical component derived from turmeric (Carcuma longa), has been extensively investigated because of its anti-inflammatory and anti-oxidative properties. Inflammation and oxidative stress play critical roles in posttraumatic cardiomyocyte apoptosis, which contributes to secondary cardiac dysfunction. This research was designed to identify the protective effect of curcumin on posttraumatic cardiac dysfunction and investigate its underlying mechanism. Noble-Collip drum was used to prepare a mechanical trauma (MT) model of rats, and the hemodynamic responses of traumatized rats were observed by ventricular intubation 12h after trauma. Myocardial apoptosis was determined through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and caspase-3 activity assay. Tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) generated by monocytes and myocardial cells were identified through enzyme-linked immunosorbent assay (ELISA), and the intracellular alteration of Ca 2+ in cardiomyocytes was examined through confocal microscopy. In vivo, curcumin effectively ameliorated MT-induced secondary cardiac dysfunction and significantly decreased the apoptotic indices of the traumatized myocardial cells. In vitro, curcumin inhibited TNF-α production by monocytes and reduced the circulating TNF-α levels. With curcumin pretreatment, ROS production and Ca 2+ overload in H9c2 cells were attenuated when these cells were incubated with traumatic plasma. Therefore, curcumin can effectively ameliorate MT-induced cardiac dysfunction mainly by inhibiting systemic inflammatory responses and by weakening oxidative stress reaction and Ca 2+ overload in cardiomyocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Energetic policies 2005-2030

International Nuclear Information System (INIS)

2008-01-01

This power point exhibition shows the following topics: energy analysis, production and use, supply and demand, consumption, energy sources, energetic prospective of Uruguay country, medium and long term perspectives.

Initial Efficacy of a Cardiac Rehabilitation Transition Program: Cardiac TRUST

Science.gov (United States)

Zullo, Melissa; Boxer, Rebecca; Moore, Shirley M.

2012-01-01

Patients recovering from cardiac events are increasingly using postacute care, such as home health care and skilled nursing facility services. The purpose of this pilot study was to test the initial efficacy, feasibility, and safety of a specially designed postacute care transitional rehabilitation intervention for cardiac patients. Cardiac Transitional Rehabilitation Using Self- Management Techniques (Cardiac TRUST) is a family-focused intervention that includes progressive low-intensity walking and education in self-management skills to facilitate recovery following a cardiac event. Using a randomized two-group design, exercise self-efficacy, steps walked, and participation in an outpatient cardiac rehabilitation program were compared in a sample of 38 older adults; 17 who received the Cardiac TRUST program and 21 who received usual care only. At discharge from postacute care, the intervention group had a trend for higher levels of self-efficacy for exercise outcomes (X=39.1, SD=7.4) than the usual care group (X=34.5; SD=7.0) (t-test 1.9, p=.06). During the 6 weeks following discharge, compared with the usual care group, the intervention group had more attendance in out-patient cardiac rehabilitation (33% compared to 11.8%, F=7.1, p=.03) and a trend toward more steps walked during the first week (X=1,307, SD=652 compared to X=782, SD=544, t-test 1.8, p=.07). The feasibility of the intervention was better for the home health participants than for those in the skilled nursing facility and there were no safety concerns. The provision of cardiac-focused rehabilitation during postacute care has the potential to bridge the gap in transitional services from hospitalization to outpatient cardiac rehabilitation for these patients at high risk for future cardiac events. Further evidence of the efficacy of Cardiac TRUST is warranted. PMID:22084960

Advances in magnetospheric physics, 1971--1974: energetic particles

International Nuclear Information System (INIS)

West, H.I. Jr.

1974-12-01

An account is given of energetic particle research in magnetospheric physics for the time period 1971--1974. Emphasis is on relating the various aspects of energetic particles to magnetospheric processes. 458 refs. (U.S.)

Prediction of tonic parasympathetic cardiac control using respiratory sinus arrhythmia: the need for respiratory control

NARCIS (Netherlands)

GROSSMAN, P.; Karemaker, J.; Wieling, W.

1991-01-01

Respiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal

Sol-Gel Manufactured Energetic Materials

Science.gov (United States)

Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Hrubesh, Lawrence W.; Swansiger, Rosalind W.; Fox, Glenn A.

2005-05-17

Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

The viability and performance characterization of nano scale energetic materials on a semiconductor bridge (SCB)

Science.gov (United States)

Strohm, Gianna Sophia

The move from conventional energetic composites to nano scale energetic mixtures (nano energetics) has shown dramatic improvement in energy release rate and sensitivity to ignition. A possible application of nano energetics is on a semiconductor bridge (SCB). An SCB typically requires a tenth of the energy input as compared to a bridge wire design with the same no-fire and is capable of igniting in tens of microseconds. For very low energy applications, SCBs can be manufactured to extremely small sizes and it is necessary to find materials with particle sizes that are even smaller to function. Reactive particles of comparable size to the bridge can lead to problems with ignition reliability for small bridges. Nano-energetic composites and the use of SCBs have been significantly studied individually, however, the process of combining nano energetics with an SCB has not been investigated extensively and is the focus of this work. Goals of this study are to determine if nano energetics can be used with SCBs to further reduce the minimum energy required and improve reliability. The performance of nano-scale aluminum (nAl) and bismuth oxide (Bi2O3) with nitrocellulose (NC), Fluorel(TM) FC 2175 (chemically equivalent to VitonRTM) and Glycidyl Azide Polymer (GAP) as binders where quantified initially using the SenTest(TM) algorithm at three weight fractions (5, 7, and 9%) of binder. The threshold energy was calculated and compared to previous data using conventional materials such as zirconium potassium chlorate (ZPC), mercuric 5-Nitrotetrazol (DXN-1) and titanium sub-hydride potassium per-chlorate (TSPP). It was found that even though there where only slight differences in performance between the binders with nAl/Bi2O 3 at any of the three binder weight fractions, the results show that these nano energetic materials require about half of the threshold energy compared to conventional materials using an SCB with an 84x42 mum bridge. Binder limit testing was conducted to

A constitutively activating mutation alters the dynamics and energetics of a key conformational change in a ligand-free G protein-coupled receptor.

Science.gov (United States)

Tsukamoto, Hisao; Farrens, David L

2013-09-27

G protein-coupled receptors (GPCRs) undergo dynamic transitions between active and inactive conformations. Usually, these conversions are triggered when the receptor detects an external signal, but some so-called constitutively activating mutations, or CAMs, induce a GPCR to bind and activate G proteins in the absence of external stimulation, in ways still not fully understood. Here, we investigated how a CAM alters the structure of a GPCR and the dynamics involved as the receptor transitions between different conformations. Our approach used site-directed fluorescence labeling (SDFL) spectroscopy to compare opsin, the ligand-free form of the GPCR rhodopsin, with opsin containing the CAM M257Y, focusing specifically on key movements that occur in the sixth transmembrane helix (TM6) during GPCR activation. The site-directed fluorescence labeling data indicate opsin is constrained to an inactive conformation both in detergent micelles and lipid membranes, but when it contains the M257Y CAM, opsin is more dynamic and can interact with a G protein mimetic. Further study of these receptors using tryptophan-induced quenching (TrIQ) methods indicates that in detergent, the CAM significantly increases the population of receptors in the active state, but not in lipids. Subsequent Arrhenius analysis of the TrIQ data suggests that, both in detergent and lipids, the CAM lowers the energy barrier for TM6 movement, a key transition required for conversion between the inactive and active conformations. Together, these data suggest that the lowered energy barrier is a primary effect of the CAM on the receptor dynamics and energetics.

Mechanisms Regulating the Cardiac Output Response to Cyanide Infusion, a Model of Hypoxia

Science.gov (United States)

Liang, Chang-seng; Huckabee, William E.

1973-01-01

When tissue metabolic changes like those of hypoxia were induced by intra-aortic infusion of cyanide in dogs, cardiac output began to increase after 3 to 5 min, reached a peak (220% of the control value) at 15 min, and returned to control in 40 min. This pattern of cardiac output rise was not altered by vagotomy with or without atropine pretreatment. However, this cardiac output response could be differentiated into three phases by pretreating the animals with agents that block specific activities of the sympatho-adrenal system. First, ganglionic blockade produced by mecamylamine or sympathetic nerve blockade by bretylium abolished the middle phase of the cardiac output seen in the untreated animal, but early and late phases still could be discerned. Second, beta-adrenergic receptor blockade produced by propranolol shortened the total duration of the cardiac output rise by abolishing the late phase. Third, when given together, propranolol and mecamylamine (or bretylium) prevented most of the cardiac output rise that follows the early phase. When cyanide was given to splenectomized dogs, the duration of the cardiac output response was not shortened, but the response became biphasic, resembling that seen after chemical sympathectomy. A similar biphasic response of the cardiac output also resulted from splenic denervation; sham operation or nephrectomy had no effect on the monophasic pattern of the normal response. Splenic venous blood obtained from cyanide-treated dogs, when infused intraportally, caused an increase in cardiac output in recipient dogs; similar infusion of arterial blood had no effects. These results suggest that the cardiac output response to cyanide infusion consists of three components: an early phase, related neither to the autonomic nervous system nor to circulating catecholamines; a middle phase, caused by a nonadrenergic humoral substance released from the spleen by sympathetic stimulation; and a late phase, dependent upon adrenergic receptors

Estrogen deprivation aggravates cardiac hypertrophy in nonobese Type 2 diabetic Goto-Kakizaki (GK) rats.

Science.gov (United States)

Apaijai, Nattayaporn; Charoenphandhu, Narattaphol; Ittichaichareon, Jitjiroj; Suntornsaratoon, Panan; Krishnamra, Nateetip; Aeimlapa, Ratchaneevan; Chattipakorn, Siriporn C; Chattipakorn, Nipon

2017-10-31

Both Type 2 diabetes mellitus (T2DM) and estrogen deprivation have been shown to be associated with the development of cardiovascular disease and adverse cardiac remodeling. However, the role of estrogen deprivation on adverse cardiac remodeling in nonobese T2DM rats has not been clearly elucidated. We hypothesized that estrogen-deprivation aggravates adverse cardiac remodeling in Goto-Kakizaki (GK) rats. Wild-type (WT) and GK rats at the age of 9 months old were divided into two subgroups to have either a sham operation (WTS, GKS) or a bilateral ovariectomy (WTO, GKO) ( n = 6/subgroup). Four months after the operation, the rats were killed, and the heart was excised rapidly. Metabolic parameters, cardiomyocytes hypertrophy, cardiac fibrosis, and biochemical parameters were determined. GK rats had hyperglycemia with hypoinsulinemia, and estrogen deprivation did not increase the severity of T2DM. Cardiac hypertrophy, cardiac oxidative stress, and phosphor-antinuclear factor κB were higher in WTO and GKS rats than WTS rats, and they markedly increased in GKO rats compared with GKS rats. Furthermore, cardiac fibrosis, transforming growth factor-β, Bax, phosphor-p38, and peroxisome proliferator- activated receptor γ coactivator-1α expression were increased in GKS and GKO rats compared with the lean rats. However, mitochondrial dynamics proteins including dynamin-related protein 1 and mitofusin-2 were not altered by T2DM and estrogen deprivation. Although estrogen deprivation did not aggravate T2DM in GK rats, it increased the severity of cardiac hypertrophy by provoking cardiac inflammation and oxidative stress in nonobese GK rats. © 2017 The Author(s).

Chemistry and structure of giant molecular clouds in energetic environments

Science.gov (United States)

Anderson, Crystal Nicole

2016-09-01

Throughout the years many studies on Galactic star formation have been conducted. This resulted in the idea that giant molecular clouds (GMCs) are hierarchical in nature with substructures spanning a large range of sizes. The physical processes that determine how molecular clouds fragment, form clumps/cores and then stars depends strongly on both recent radiative and mechanical feed- back from massive stars and, on longer term, from enhanced cooling due to the buildup of metals. Radiative and mechanical energy input from stellar populations can alter subsequent star formation over a large part of a galaxy and hence is relevant to the evolution of galaxies. Much of our knowledge of star formation on galaxy wide scales is based on scaling laws and other parametric descriptions. But to understand the overall evolution of star formation in galaxies we need to watch the feedback processes at work on giant molecular cloud (GMC) scales. By doing this we can begin to answer how strong feedback environments change the properties of the substructure in GMCs. Tests of Galactic star formation theory to other galaxies has been a challenging process due to the lack of resolution with current instruments. Thus, only the nearest galaxies allow us to resolve GMCs and their substructures. The Large Magellanic Cloud (LMC), is one of the closest low metallicity dwarf galaxies (D˜ 50 kpc) and is close enough that current instruments can resolve the sub- structure of its GMCs to molecular gas tracers (e.g. HCO+, HCN, HNC, CS, C2H, N2H+) detected in the LMC at 1.5-40 pc scales and in NGC 5253 at 40 pc scales. I then compare the molecular gas detections to the Central Molecular Zone in our Galaxy. Dense molecular gas was detected in all of the sources. For the regions in the LMC, molecular lines of CS, N2H+, C 2H, HNC, HCO+ and HCN were all detected in N159W and N113 while only HCN, HCO+, HNC, and C2H were detected in 30Dor-10. Toward NGC 5253 only HCO+, HCN, C2H and CS were detected. I

Energetic materials: crystallization, characterization and insensitive plastic bonded explosives

Energy Technology Data Exchange (ETDEWEB)

Heijden, Antoine E.D.M. van der; Creyghton, Yves L.M.; Marino, Emanuela; Bouma, Richard H.B.; Scholtes, Gert J.H.G.; Duvalois, Willem [TNO Defence, Security and Safety, P. O. Box 45, 2280 AA Rijswijk (Netherlands); Roelands, Marc C.P.M. [TNO Science and Industry, P. O. Box 342, 7300 AH Apeldoorn (Netherlands)

2008-02-15

The product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive containing these energetic materials becomes. The application of submicron or nanometric energetic materials is generally considered to further decrease the sensitiveness of explosives. In order to assess the product quality of energetic materials, a range of analytical techniques is available. Recent attempts within the Reduced-sensitivity RDX Round Robin (R4) have provided the EM community a better insight into these analytical techniques and in some cases a correlation between product quality and shock initiation of plastic bonded explosives containing (RS-)RDX was identified, which would provide a possibility to discriminate between conventional and reduced sensitivity grades. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Energetic matrix of Rio de Janeiro State, Brazil - 1994/2004

International Nuclear Information System (INIS)

1996-01-01

This book has been structured into three parts and three appendices. In the first part, named Energetic matrix of Rio de Janeiro State, the most important economic and social aspects of the State and the methodology for elaboration of economic and energetic scenarios has been detailed. In the second part, an analysis of seven consumption sectors components of the energetic matrix structure ( industrial, transports, residential, commercial, energetic, agriculture and cattle-breeding, non energetic) has been performed, with the objective of providing information on the present status and future prospects of energy consumption by sectors up to 2004. Finally, in the third part, the energy supply of Rio de Janeiro State for the consumption sectors has been discussed

Running Economy from a Muscle Energetics Perspective

Directory of Open Access Journals (Sweden)

Jared R. Fletcher

2017-06-01

Full Text Available The economy of running has traditionally been quantified from the mass-specific oxygen uptake; however, because fuel substrate usage varies with exercise intensity, it is more accurate to express running economy in units of metabolic energy. Fundamentally, the understanding of the major factors that influence the energy cost of running (Erun can be obtained with this approach. Erun is determined by the energy needed for skeletal muscle contraction. Here, we approach the study of Erun from that perspective. The amount of energy needed for skeletal muscle contraction is dependent on the force, duration, shortening, shortening velocity, and length of the muscle. These factors therefore dictate the energy cost of running. It is understood that some determinants of the energy cost of running are not trainable: environmental factors, surface characteristics, and certain anthropometric features. Other factors affecting Erun are altered by training: other anthropometric features, muscle and tendon properties, and running mechanics. Here, the key features that dictate the energy cost during distance running are reviewed in the context of skeletal muscle energetics.

In Utero Exposure to a Cardiac Teratogen Causes Reversible Deficits in Postnatal Cardiovascular Function, But Altered Adaptation to the Burden of Pregnancy.

Science.gov (United States)

Aasa, Kristiina L; Maciver, Rebecca D; Ramchandani, Shyamlal; Adams, Michael A; Ozolinš, Terence R S

2015-11-01

Congenital heart defects (CHD) are the most common birth anomaly and while many resolve spontaneously by 1 year of age, the lifelong burden on survivors is poorly understood. Using a rat model of chemically induced CHD that resolve postnatally, we sought to characterize the postnatal changes in cardiac function, and to investigate whether resolved CHD affects the ability to adapt to the increased the cardiovascular (CV) burden of pregnancy. To generate rats with resolved CHD, pregnant rats were administered distilled water or dimethadione (DMO) [300 mg/kg b.i.d. on gestation day (gd) 9 and 10] and pups delivered naturally. To characterize structural and functional changes in the heart, treated and control offspring were scanned by echocardiography on postnatal day 4, 21, and 10-12 weeks. Radiotelemeters were implanted for continuous monitoring of hemodynamics. Females were mated and scanned by echocardiography on gd12 and gd18 during pregnancy. On gd18, maternal hearts were collected for structural and molecular assessment. Postnatal echocardiography revealed numerous structural and functional differences in treated offspring compared with control; however, these resolved by 10-12 weeks of age. The CV demand of pregnancy revealed differences between treated and control offspring with respect to mean arterial pressure, CV function, cardiac strain, and left ventricular gene expression. In utero exposure to DMO also affected the subsequent generation. Gd18 fetal and placental weights were increased in treated F2 offspring. This study demonstrates that in utero chemical exposure may permanently alter the capacity of the postnatal heart to adapt to pregnancy and this may have transgenerational effects. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Energetic magnetospheric protons in the plasma depletion layer

International Nuclear Information System (INIS)

Fuselier, S.A.

1992-01-01

Interplanetary magnetic field draping against the Earth's dayside subsolar magnetopause creates a region of reduced plasma density and increased magnetic field called the plasma depletion layer. In this region, leakage of energetic ions from the Earth's magnetosphere onto magnetic field lines in the plasma depletion layer can be studied without interference from ions accelerated at the Earth's quasi-parallel bow shock. Active Magnetospheric Particle Tracer Experiment/Charge Composition Explorer (AMPTE/CCE) observations for 13 plasma depletion layer events are used to determine the characteristics of energetic protons between a few keV/e and ∼100keV/e leaked from the magnetosphere. Results indicate that the leaked proton distributions resemble those in the magnetosphere except that they have lower densities and temperatures and much higher velocities parallel (or antiparallel) and perpendicular to the magnetic field. Compared to the low-energy magnetosheath proton distributions present in the depletion layer, the leaked energetic proton distributions typically have substantially higher flow velocities along the magnetic field indicate that the leaked energetic proton distributions to contribute to the energetic proton population seen upstream and downstream from the quasi-parallel bow shock. However, their contribution is small compared to the contribution from acceleration of protons at the bow shock because the leaked proton densities are on the order of 10 times smaller than the energetic proton densities typically observed in the vicinity of the quasi-parallel bow shock

Cardiac sarcoplasmic reticulum

International Nuclear Information System (INIS)

Jacobson, M.S.; Ambudkar, I.S.; Young, E.P.; Naseem, S.M.; Heald, F.P.; Shamoo, A.E.

1985-01-01

The effect on the cardiac sarcoplasmic reticulum of an atherogenic (1% cholesterol) diet fed during the neonatal vs the juvenile period of life was studied in Yorkshire swine. Male piglets were randomly assigned at birth to 1 of 4 groups: group I (control), group II (lactation feeding), group III (juvenile period feeding) and group IV (lactation and juvenile feeding). All animals were killed at 55 weeks of age and cardiac sarcoplasmic reticulum (SR) isolated for assay of calcium uptake, Ca 2+ -Mg 2+ ATPase activity, and lipid analysis by thin-layer chromatography and gas chromatography. The amount of cholesterol/mg SR protein and the cholesterol/phospholipid ratio were higher in the animals fed during lactation (groups II and IV) and lower in those fed only during the juvenile period (group III). Phospholipid fatty acid patterns as measured by gas chromatography were unaltered in any group. Calcium uptake was markedly diminished in all experimental conditions: group II 47%, group III 65% and group IV 96%. Compared to the observed changes in calcium transport, the ATP hydrolytic activity was relatively less affected. Only in group IV a significant decrease (41%) was seen. Groups II and III show no change in ATP hydrolytic activity. The decrease in calcium uptake and altered cholesterol/phospholipid ratio without effect on ATP hydrolytic activity is consistent with an uncoupling of calcium transport related to the atherogenic diet in early life. (author)

Cardiac tumors: optimal cardiac MR sequences and spectrum of imaging appearances.

LENUS (Irish Health Repository)

O'Donnell, David H

2012-02-01

OBJECTIVE: This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors. CONCLUSION: Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.

Cutting and machining energetic materials with a femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Roeske, Frank; Benterou, Jerry; Lee, Ronald; Roos, Edward [Energetic Materials Center, Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94550 (United States)

2003-04-01

A femtosecond (fs) laser has been used as a tool for solving many problems involving access, machining, disassembly, inspection and avoidance of undesirable hazardous waste streams in systems containing energetic materials. Because of the unique properties of the interaction of ultrashort laser pulses with matter, the femtosecond laser can be used to safely cut these energetic materials in a precise manner without creating an unacceptable waste stream. Many types of secondary high explosives (HE) and propellants have been cut with the laser for a variety of applications ranging from disassembly of aging conventional weapons (demilitarization), inspection of energetic components of aging systems to creating unique shapes of HE for purposes of initiation and detonation physics studies. Hundreds of samples of energetic materials have been cut with the fs laser without ignition and, in most cases, without changing the surface morphology of the cut surfaces. The laser has also been useful in cutting nonenergetic components in close proximity to energetic materials. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Cardiac gated ventilation

International Nuclear Information System (INIS)

Hanson, C.W. III; Hoffman, E.A.

1995-01-01

There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart

Do right-ventricular trabeculae gain energetic advantage from having a greater velocity of shortening?

Science.gov (United States)

Pham, Toan; Han, June-Chiew; Taberner, Andrew; Loiselle, Denis

2017-10-15

We designed a study to test whether velocity of shortening in right-ventricular tissue preparations is greater than that of the left side under conditions mimicking those encountered by the heart in vivo. Our experiments allowed us to explore whether greater velocity of shortening results in any energetic advantage. We found that velocity of shortening was higher in the rat right-ventricular trabeculae. These results at the tissue level seem paradoxical to the velocity of ventricular ejection at the organ level, and are not always in accord with shortening of unloaded cells. Despite greater velocity of shortening in right-ventricular trabeculae, they neither gained nor lost advantage with respect to both mechanical efficiency and the heat generated during shortening. Our study aimed to ascertain whether the interventricular difference of shortening velocity, reported for isolated cardiac tissues in vitro, affects interventricular mechano-energetic performance when tested under physiological conditions using a shortening protocol designed to mimic those in vivo. We isolated trabeculae from both ventricles of the rat, mounted them in a calorimeter, and performed experiments at 37°C and 5 Hz stimulus frequency to emulate conditions of the rat heart in vivo. Each trabecula was subjected to two experimental protocols: (i) isotonic work-loop contractions at a variety of afterloads, and (ii) isometric contractions at a variety of preloads. Velocity of shortening was calculated from the former protocol during the isotonic shortening phase of the contraction. Simultaneous measurements of force-length work and heat output allowed calculation of mechanical efficiency. The shortening-dependent thermal component was quantified from the difference in heat output between the two protocols. Our results show that both extent of shortening and velocity of shortening were higher in trabeculae from the right ventricle. Despite these differences, trabeculae from both ventricles

Energetic particle physics with applications in fusion and space plasmas

International Nuclear Information System (INIS)

Cheng, C.Z.

1997-01-01

Energetic particle physics is the study of the effects of energetic particles on collective electromagnetic (EM) instabilities and energetic particle transport in plasmas. Anomalously large energetic particle transport is often caused by low frequency MHD instabilities, which are driven by these energetic particles in the presence of a much denser background of thermal particles. The theory of collective energetic particle phenomena studies complex wave-particle interactions in which particle kinetic physics involving small spatial and fast temporal scales can strongly affect the MHD structure and long-time behavior of plasmas. The difficulty of modeling kinetic-MHD multiscale coupling processes stems from the disparate scales which are traditionally analyzed separately: the macroscale MHD phenomena are studied using the fluid MHD framework, while microscale kinetic phenomena are best described by complicated kinetic theories. The authors have developed a kinetic-MHD model that properly incorporates major particle kinetic effects into the MHD fluid description. For tokamak plasmas a nonvariational kinetic-MHD stability code, the NOVA-K code, has been successfully developed and applied to study problems such as the excitation of fishbone and Toroidal Alfven Eigenmodes (TAE) and the sawtooth stabilization by energetic ions in tokamaks. In space plasmas the authors have employed the kinetic-MHD model to study the energetic particle effects on the ballooning-mirror instability which explains the multisatellite observation of the stability and field-aligned structure of compressional Pc 5 waves in the magnetospheric ring current plasma

Neoclassical transport of energetic beam ions in the Large Helical Device

International Nuclear Information System (INIS)

Murakami, Sadayoshi; Yamada, Hiroshi; Kaneko, Osamu

2000-01-01

The neoclassical (collisional) transport of energetic ions is investigated by the global neoclassical transport simulation in the Large Helical Device (LHD). The steady state distributions of energetic ions are evaluated assuming an energetic particle source by NBI heating (tangentally injected). Significant radial transport of energetic ions can be seen due to the radial motion of trapped particles in the velocity region below near critical velocity. Our simulation results show relatively good agreements with the experimental results of fast particle measurements in the LHD. This suggests an important role of neoclassical transport in the radial transport process of energetic ions in heliotrons. (author)

Cardiac function and cognition in older community-dwelling cardiac patients.

Science.gov (United States)

Eggermont, Laura H P; Aly, Mohamed F A; Vuijk, Pieter J; de Boer, Karin; Kamp, Otto; van Rossum, Albert C; Scherder, Erik J A

2017-11-01

Cognitive deficits have been reported in older cardiac patients. An underlying mechanism for these findings may be reduced cardiac function. The relationship between cardiac function as represented by different echocardiographic measures and different cognitive function domains in older cardiac patients remains unknown. An older (≥70 years) heterogeneous group of 117 community-dwelling cardiac patients under medical supervision by a cardiologist underwent thorough echocardiographic assessment including left ventricular ejection fraction, cardiac index, left atrial volume index, left ventricular mass index, left ventricular diastolic function, and valvular calcification. During a home visit, a neuropsychological assessment was performed within 7.1 ± 3.8 months after echocardiographic assessment; the neuropsychological assessment included three subtests of a word-learning test (encoding, recall, recognition) to examine one memory function domain and three executive function tests, including digit span backwards, Trail Making Test B minus A, and the Stroop colour-word test. Regression analyses showed no significant linear or quadratic associations between any of the echocardiographic functions and the cognitive function measures. None of the echocardiographic measures as representative of cardiac function was correlated with memory or executive function in this group of community-dwelling older cardiac patients. These findings contrast with those of previous studies. © 2017 Japanese Psychogeriatric Society.

Cardiac function and cognition in older community-dwelling cardiac patients

NARCIS (Netherlands)

Eggermont, Laura H.P.; Aly, Mohamed F.A.; Vuijk, Pieter J.; de Boer, Karin; Kamp, Otto; van Rossum, Albert C.; Scherder, Erik J.A.

2017-01-01

Background: Cognitive deficits have been reported in older cardiac patients. An underlying mechanism for these findings may be reduced cardiac function. The relationship between cardiac function as represented by different echocardiographic measures and different cognitive function domains in older

Life cycles of energetic systems

International Nuclear Information System (INIS)

Adnot, Jerome; Marchio, Dominique; Riviere, Philippe; Duplessis, B.; Rabl, A.; Glachant, M.; Aggeri, F.; Benoist, A.; Teulon, H.; Daude, J.

2012-01-01

This collective publication aims at being a course for students in engineering of energetic systems, i.e. at learning how to decide to accept or discard a project, to select the most efficient system, to select the optimal system, to select the optimal combination of systems, and to classify independent systems. Thus, it presents methods to analyse system life cycle from an energetic, economic and environmental point of view, describes how to develop an approach to the eco-design of an energy consuming product, how to understand the importance of hypotheses behind abundant and often contradicting publicised results, and to be able to criticise or to put in perspective one's own analysis. The first chapters thus recall some aspects of economic calculation, introduce the assessment of investment and exploitation costs of energetic systems, describe how to assess and internalise environmental costs, present the territorial carbon assessment, discuss the use of the life cycle assessment, and address the issue of environmental management at a product scale. The second part proposes various case studies: an optimal fleet of thermal production of electric power, the eco-design of a refrigerator, the economic and environmental assessment of wind farms

Nuclear energetics all over the world

International Nuclear Information System (INIS)

Wojcik, T.

2000-01-01

The actual state and tendencies of nuclear power further development for different world regions have been presented and discussed. The problem of safety of energetic nuclear reactors, radioactive waste management and related problems have been discussed in respect of regulations in different countries. The economical aspects of nuclear energetics in comparison with different fossil fuel power plants exploitation costs has been presented as well. The official state of international organizations (IAEA, WANO, HASA etc.) have been also shown in respect to subject presented

Association of Cardiac Hemodynamic Factors With Severity of White Matter Hyperintensities in Chronic Valvular Heart Disease.

Science.gov (United States)

Lee, Woo-Jin; Jung, Keun-Hwa; Ryu, Young Jin; Kim, Jeong-Min; Lee, Soon-Tae; Chu, Kon; Kim, Manho; Lee, Sang Kun; Roh, Jae-Kyu

2018-01-01

The cerebral white matter hyperintensity (WMH) is frequently noted in patients with chronic heart disease. Long-term alteration of cardiac hemodynamics might have an influence on the mechanism of cerebral WMH. To investigate the association between chronically altered cardiac hemodynamics and severity of cerebral WMH in patients with chronic valvular heart disease. This cross-sectional analysis identified 303 consecutive patients at a tertiary referral center between 2008 and 2016 who were 50 years or older, and diagnosed with severe chronic valvular heart disease and underwent cardiac catherization, echocardiography, and received brain magnetic resonance imaging. Among these patients, 71 with other demonstrated cardiac disease, central nervous system disease, and/or without sufficient catheterization data were excluded, and the remaining 232 patients were included in further analyses. The site and mechanism of valve diseases, as well as clinical and medication profiles, were reviewed. Cardiac catheterization parameters such as right atrial (RA) mean pressure, right ventricular pressure, and aortic mean pressure were obtained. Comprehensive echocardiographic hemodynamic markers such as left ventricular (LV) ejection fraction, LV mass index, LV end diastolic volume, cardiac index, and E/e' ratio were also obtained. White matter hyperintensity volume was quantitatively evaluated using volumetric analysis. This study included 232 patients (103 men [44.4%] and 129 women [55.6%]; mean [SD] (range) age, 65.6 [8.8] (51-88) years) in the final analysis. The mean (SD) WMH volume was 5.93 (7.14) mL (median [interquartile range], 4.33 [1.33-8.62] mL), and mean (SD) RA pressure was 10.0 (4.7) mm Hg. From the catheterization data, 147 patients (63.4%) were classified as having a disease involving the mitral valve; 93 (40.1%), aortic valve; 37 (15.9%), tricuspid valve; and 4 (1.7%), pulmonary valve. In multivariate linear regression analysis, adjusting the type and mechanism of

Relationship between cardiac 123I-Metaiodobenzylguanidine imaging and the transcardiac gradient of neurohumoral factors in patients with dilated cardiomyopathy

International Nuclear Information System (INIS)

Matsui, Toshiki; Tsutamoto, Takayoshi; Kinoshita, Masahiko

2001-01-01

Cardiac sympathetic nervous function is altered in congestive heart failure (CHF) and the uptake and washout rate of cardiac 123 I-metaiodobenzylguanidine (MIBG) are useful markers for evaluating the severity of it. To assess what parameters predict decreased uptake or increased washout rate of MIBG, the concentrations of neurohumoral factor in both the aorta (Ao) and coronary sinus (CS) were measured, as well as hemodynamic parameters by catheterization, in patients with dilated cardiomyopathy (DCM). MIBG imaging was performed within 1 week of cardiac catheterization. Regarding MIBG parameters, the correlation with the transcardiac gradient of norepinephrine (NE), brain natriuretic peptide (BNP) and hemodynamics was investigated. Stepwise multivariate regression analysis was used to determine which variables closely correlated with cardiac MIBG parameters. There was a significant increase in the NE level between the Ao (446 pg/ml) and the CS (727 pg/ml). According to stepwise multivariate regression analysis, the heart/mediastinum (H/M) ratio independently correlated with the transcardiac gradient of BNP (r=-0.480, p<0.01), and the washout rate independently correlated with the transcardiac gradient of NE (r=0.481, p<0.01). These findings indicate that the H/M ratio may reflect the transcardiac gradient of BNP, which implies the degree of left ventricular dysfunction and/or damage and the washout rate may reflect altered cardiac sympathetic nerve terminal in DCM patients with CHF, suggesting that both the H/M ratio and washout rate provide important information about the failing ventricle. (author)

Lung scan alterations in congenital heart disease

Energy Technology Data Exchange (ETDEWEB)

Dietrich, R; Sanchez, J; Munoz, A; Lanaro, A E; Pico, A M

1975-04-01

This report analyzes the patterns in 54 lung scannings of 34 patients with altered pulmonary blood flow due to congenital heart disease. The technique and the results are presented. According to the images obtained, the patients are classified in three groups: Group I--normal distribution with more concentration of particles over the right lung and the bases. Group II--normal scannings found in left to right shunts unless there is pulmonary venous hypertension in which case the apex-base relationship was inverted. Group III--patients with right to left shunts of different types presenting various patterns according to severity, associated anomalies and palliative surgery. The hemodynamics created by cardiac defects and surgical procedures explain these alterations. This method is recommended in view of its advantages and accurate results.

Energetic certification in Europe

International Nuclear Information System (INIS)

1998-01-01

At community level the problem of energy quality control in a building was introduced by EEC recommendation n. 93/76 in 1993. In this item are reported some notes on energetic certification in European countries [it

Influence of microorganisms on the alteration of glasses

International Nuclear Information System (INIS)

Besnainou, B.; Libert, M.F.

1997-01-01

Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

Energetic Particles Dynamics in Mercury's Magnetosphere

Science.gov (United States)

Walsh, Brian M.; Ryou, A.S.; Sibeck, D. G.; Alexeev, I. I.

2013-01-01

We investigate the drift paths of energetic particles in Mercury's magnetosphere by tracing their motion through a model magnetic field. Test particle simulations solving the full Lorentz force show a quasi-trapped energetic particle population that gradient and curvature drift around the planet via "Shabansky" orbits, passing though high latitudes in the compressed dayside by equatorial latitudes on the nightside. Due to their large gyroradii, energetic H+ and Na+ ions will typically collide with the planet or the magnetopause and will not be able to complete a full drift orbit. These simulations provide direct comparison for recent spacecraft measurements from MESSENGER. Mercury's offset dipole results in an asymmetric loss cone and therefore an asymmetry in particle precipitation with more particles precipitating in the southern hemisphere. Since the planet lacks an atmosphere, precipitating particles will collide directly with the surface of the planet. The incident charged particles can kick up neutrals from the surface and have implications for the formation of the exosphere and weathering of the surface

Abatement by Naringenin of Doxorubicin-Induced Cardiac Toxicity in Rats

International Nuclear Information System (INIS)

Arafa, H.M.; Abd-Ellah, M.F.; Hafez, H.F.

2005-01-01

Doxorubicin is one of the most active cytotoxic agents in current use. It has proven efficacy in various malignancies either alone or combined with other cytocidal agents. The clinical usefulness of the anthracycline drug has been precluded by cardiac toxicity. Many therapeutic interventions have been attempted to improve the therapeutic benefits of the drug. Few, however, have been efficacious in this setting. Purpose: We have addressed in the current study the possible protective effects of naringenin, a flavonoid known to have anti-oxidant properties, on doxorubicin induced cardiac toxicity in male Swiss albino rats. Methods: Forty male Swiss albino rats were used in this study. Naringenin (25 mg/kg body weight) was administered daily by gavage for 7 consecutive days before a cumulative single dose of doxorubicin (15 mg/kg body weight, ip). Doxorubicin induced marked biochemical alterations characteristic of cardiac toxicity including, elevated activities of serum total lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), enhanced lipid peroxidation measured as malonaldehyde (MDA). The anthracycline drug has also reduced the cardiac enzymatic activities of superoxide dismutase (SOD), glutathione-Stransferase (GST) and catalase (CAT). Besides, it reduced significantly the reduced glutathione (GSH) level, but it increased the total NO content in heart tissue. Prior administration of naringenin ahead of doxorubicin challenge ameliorated all these biochemical markers. Taken together, one could conclude that naringenin has a protective role in the abatement of doxorubicin-induced cardiac toxicity that resides, at least in part, on its anti-radical effects and regulatory role on NO production

Longstanding Hyperthyroidism Is Associated with Normal or Enhanced Intrinsic Cardiomyocyte Function despite Decline in Global Cardiac Function

Science.gov (United States)

Redetzke, Rebecca A.; Gerdes, A. Martin

2012-01-01

Thyroid hormones (THs) play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV) contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH). LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function. PMID:23056390

Longstanding hyperthyroidism is associated with normal or enhanced intrinsic cardiomyocyte function despite decline in global cardiac function.

Directory of Open Access Journals (Sweden)

Nathan Y Weltman

Full Text Available Thyroid hormones (THs play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH. LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function.

Energetic Materials Effects on Essential Soil Processes: Decomposition of Orchard Grass (Dactylis glomerata) Litter in Soil Contaminated with Energetic Materials

Science.gov (United States)

2014-02-01

availabilities of their respective food sources (bacteria and fungi ), were also unaffected-or-increasing in soil with CL-20 treatments. This is...ENERGETIC MATERIALS EFFECTS ON ESSENTIAL SOIL PROCESSES: DECOMPOSITION OF ORCHARD...GRASS (DACTYLIS GLOMERATA) LITTER IN SOIL CONTAMINATED WITH ENERGETIC MATERIALS ECBC-TR-1199 Roman G. Kuperman Ronald T. Checkai Michael Simini

Computational studies on energetic properties of nitrogen-rich ...

Indian Academy of Sciences (India)

Computational studies on energetic properties of nitrogen-rich energetic materials with ditetrazoles. LI XIAO-HONGa,b,∗ and ZHANG RUI-ZHOUa. aCollege of Physics and Engineering, Henan University of Science and Technology, Luoyang 471 003, China. bLuoyang Key Laboratory of Photoelectric Functional Materials, ...

The Energetics of Economics (Money as access to Energy)

OpenAIRE

Ternyik, Stephen I.

2013-01-01

Money is being portrayed as temporal access to energy and a new methodical approach to the energetics of the human economy is introduced.The economic evolution of world system energetics is put into the historical focus of all global monetary civilization, reaching back to Sumerian city states.This long wave energetics of human economic action clearly points to the biophysical boundaries of the globalized monetary production economy which is also based on natural law.The future perspective of...

Interaction in the large energetic companies in the Republic of Macedonia

International Nuclear Information System (INIS)

Janevski, Risto

1999-01-01

After disintegration of former power energetic system of Yugoslavia 1991, the Republic of Macedonia has faced enormous problems in the energetic field. It was necessary to realize all options in order to secure enough electric power for normal economic capacities function. In that course a direct involvement of five large companies, which represent very significant energetic subjects, will largely determine the future energetic conditions and circumstances in our country. These are the following companies: P.E. Electric Power Company Of Macedonia; OKTA Crude Oil Refinery; Heat Power Company; HEK Jugohrom; Fenimak. The paper presents the electric power consumption of these macro energetic companies during the period 1991-1998

Observations of Energetic Particle Escape at the Magnetopause: Early Results from the MMS Energetic Ion Spectrometer (EIS)

Science.gov (United States)

Cohen, I. J.; Mauk, B. H.; Anderson, B. J.; Westlake, J. H.; Sibeck, David Gary; Giles, Barbara L.; Pollock, C. J.; Turner, D. L.; Fennell, J. F.; Blake, J. B.;

Quinquennial National Program (1990-1994) for the Energetic Modernization

International Nuclear Information System (INIS)

1990-01-01

The Mexican Energetics Sector currently has the eighth possition regarding reserves of hydrocarbons and the sixth regarding oil production, the installed capacity in electricity matters is among the first 20 of the world. The Program established first, a general balance of the situation in which the energetics sector lays today. It also points out the strategic role that this sector holds, as well an on the solutions to the problems faced. This Program establishes the objectives pursued by the energetics sector and that are as follows: to guarantee enough supply of energetics, to strenghten the link between the energetics sector and economy, society and environmental protection, to consolidate an energetics sector that is more current and better integrated. This Program presents the proposal to tend to five priorities: productivity, saving and effective use of energy, financing of the development and expansion of the offer, to diversify sources, as well as an efficient participation in international markets. In the chapter the effort regarding supply and demand of energy, it is evident that the effort made to expand the offer must be great, facing the total demand of energy demonstrated by the figures. For 1994 this demmand is of 31 - 36 % greater to that observed in 1988. Lastly, two statistic documents are enclosed, one historic, with general pointers of the sector, and another with the basic variables for national energy balance

Cyclin D2 is a critical mediator of exercise-induced cardiac hypertrophy.

Science.gov (United States)

Luckey, Stephen W; Haines, Chris D; Konhilas, John P; Luczak, Elizabeth D; Messmer-Kratzsch, Antke; Leinwand, Leslie A

2017-12-01

A number of signaling pathways underlying pathological cardiac hypertrophy have been identified. However, few studies have probed the functional significance of these signaling pathways in the context of exercise or physiological pathways. Exercise studies were performed on females from six different genetic mouse models that have been shown to exhibit alterations in pathological cardiac adaptation and hypertrophy. These include mice expressing constitutively active glycogen synthase kinase-3β (GSK-3βS9A), an inhibitor of CaMK II (AC3-I), both GSK-3βS9A and AC3-I (GSK-3βS9A/AC3-I), constitutively active Akt (myrAkt), mice deficient in MAPK/ERK kinase kinase-1 (MEKK1 -/- ), and mice deficient in cyclin D2 (cyclin D2 -/- ). Voluntary wheel running performance was similar to NTG littermates for five of the mouse lines. Exercise induced significant cardiac growth in all mouse models except the cyclin D2 -/- mice. Cardiac function was not impacted in the cyclin D2 -/- mice and studies using a phospho-antibody array identified six proteins with increased phosphorylation (greater than 150%) and nine proteins with decreased phosphorylation (greater than 33% decrease) in the hearts of exercised cyclin D2 -/- mice compared to exercised NTG littermate controls. Our results demonstrate that unlike the other hypertrophic signaling molecules tested here, cyclin D2 is an important regulator of both pathologic and physiological hypertrophy. Impact statement This research is relevant as the hypertrophic signaling pathways tested here have only been characterized for their role in pathological hypertrophy, and not in the context of exercise or physiological hypertrophy. By using the same transgenic mouse lines utilized in previous studies, our findings provide a novel and important understanding for the role of these signaling pathways in physiological hypertrophy. We found that alterations in the signaling pathways tested here had no impact on exercise performance. Exercise

The energetic significance of cooking.

Science.gov (United States)

Carmody, Rachel N; Wrangham, Richard W

2009-10-01

While cooking has long been argued to improve the diet, the nature of the improvement has not been well defined. As a result, the evolutionary significance of cooking has variously been proposed as being substantial or relatively trivial. In this paper, we evaluate the hypothesis that an important and consistent effect of cooking food is a rise in its net energy value. The pathways by which cooking influences net energy value differ for starch, protein, and lipid, and we therefore consider plant and animal foods separately. Evidence of compromised physiological performance among individuals on raw diets supports the hypothesis that cooked diets tend to provide energy. Mechanisms contributing to energy being gained from cooking include increased digestibility of starch and protein, reduced costs of digestion for cooked versus raw meat, and reduced energetic costs of detoxification and defence against pathogens. If cooking consistently improves the energetic value of foods through such mechanisms, its evolutionary impact depends partly on the relative energetic benefits of non-thermal processing methods used prior to cooking. We suggest that if non-thermal processing methods such as pounding were used by Lower Palaeolithic Homo, they likely provided an important increase in energy gain over unprocessed raw diets. However, cooking has critical effects not easily achievable by non-thermal processing, including the relatively complete gelatinisation of starch, efficient denaturing of proteins, and killing of food borne pathogens. This means that however sophisticated the non-thermal processing methods were, cooking would have conferred incremental energetic benefits. While much remains to be discovered, we conclude that the adoption of cooking would have led to an important rise in energy availability. For this reason, we predict that cooking had substantial evolutionary significance.

Depression and reduced heart rate variability after cardiac surgery: the mediating role of emotion regulation.

Science.gov (United States)

Patron, Elisabetta; Messerotti Benvenuti, Simone; Favretto, Giuseppe; Gasparotto, Renata; Palomba, Daniela

2014-02-01

Heart rate variability (HRV), as an index of autonomic nervous system (ANS) functioning, is reduced by depression after cardiac surgery, but the underlying mechanisms of this relationship are poorly understood. Poor emotion regulation as a core symptom of depression has also been associated with altered ANS functioning. The present study aimed to examine whether emotion dysregulation could be a mediator of the depression-reduced HRV relationship observed after cardiac surgery. Self-reported emotion regulation and four-minute HRV were measured in 25 depressed and 43 nondepressed patients after cardiac surgery. Mediation analysis was conducted to evaluate emotion regulation as a mediator of the depression-reduced HRV relationship. Compared to nondepressed patients, those with depression showed lower standard deviation of normal-to-normal (NN) intervals (pbehavior partially mediated the effect of depression on LF n.u. and HF n.u. Results confirmed previous findings showing that depression is associated with reduced HRV, especially a reduced vagal tone and a sympathovagal imbalance, after cardiac surgery. This study also provides preliminary evidence that increased trait levels of suppression of emotion-expressive behavior may mediate the depression-related sympathovagal imbalance after cardiac surgery. Copyright © 2013 Elsevier B.V. All rights reserved.

Detecting early cardiac dysfunction with radionuclide cardiac blood-pool imaging

International Nuclear Information System (INIS)

Wu Kegui; Chen Daguang; Lin Haoxue

1992-01-01

Cardiac function was measured by radionuclide cardiac blood-pool imaging in 15 normal persons, 19 cases of hypertension, 32 cases of coronary heart disease, 35 cases of coronary heart disease combined with hypertension and 44 cases of myocardial infarction. Significant differences have been found in indices of cardiac function between normal subjects and patients with coronary heart disease and coronary heart disease combined with hypertension, even though the patients were without any clinical sin of cardiac failure. Lowered regional EF and decreased ventricular was motion were found in 38.8% of patients, while 65.7%of patients revealed marked abnormality in MFR. The results indicate that latent cardiac dysfunction is common in patients with coronary heart disease. The earliest change is diastolic function abnormalities

Evidence of cardiac involvement in the fetal inflammatory response syndrome: disruption of gene networks programming cardiac development in nonhuman primates.

Science.gov (United States)

Mitchell, Timothy; MacDonald, James W; Srinouanpranchanh, Sengkeo; Bammler, Theodor K; Merillat, Sean; Boldenow, Erica; Coleman, Michelle; Agnew, Kathy; Baldessari, Audrey; Stencel-Baerenwald, Jennifer E; Tisoncik-Go, Jennifer; Green, Richard R; Gale, Michael J; Rajagopal, Lakshmi; Adams Waldorf, Kristina M

2018-04-01

Most early preterm births are associated with intraamniotic infection and inflammation, which can lead to systemic inflammation in the fetus. The fetal inflammatory response syndrome describes elevations in the fetal interleukin-6 level, which is a marker for inflammation and fetal organ injury. An understanding of the effects of inflammation on fetal cardiac development may lead to insight into the fetal origins of adult cardiovascular disease. The purpose of this study was to determine whether the fetal inflammatory response syndrome is associated with disruptions in gene networks that program fetal cardiac development. We obtained fetal cardiac tissue after necropsy from a well-described pregnant nonhuman primate model (pigtail macaque, Macaca nemestrina) of intrauterine infection (n=5) and controls (n=5). Cases with the fetal inflammatory response syndrome (fetal plasma interleukin-6 >11 pg/mL) were induced by either choriodecidual inoculation of a hypervirulent group B streptococcus strain (n=4) or intraamniotic inoculation of Escherichia coli (n=1). RNA and protein were extracted from fetal hearts and profiled by microarray and Luminex (Millipore, Billerica, MA) for cytokine analysis, respectively. Results were validated by quantitative reverse transcriptase polymerase chain reaction. Statistical and bioinformatics analyses included single gene analysis, gene set analysis, Ingenuity Pathway Analysis (Qiagen, Valencia, CA), and Wilcoxon rank sum. Severe fetal inflammation developed in the context of intraamniotic infection and a disseminated bacterial infection in the fetus. Interleukin-6 and -8 in fetal cardiac tissues were elevated significantly in fetal inflammatory response syndrome cases vs controls (P1.5-fold change, P<.05) in the fetal heart (analysis of variance). Altered expression of select genes was validated by quantitative reverse transcriptase polymerase chain reaction that included several with known functions in cardiac injury, morphogenesis

Cardiac Function Remains Impaired Despite Reversible Cardiac Remodeling after Acute Experimental Viral Myocarditis

Directory of Open Access Journals (Sweden)

Peter Moritz Becher

2017-01-01

Full Text Available Background. Infection with Coxsackievirus B3 induces myocarditis. We aimed to compare the acute and chronic phases of viral myocarditis to identify the immediate effects of cardiac inflammation as well as the long-term effects after resolved inflammation on cardiac fibrosis and consequently on cardiac function. Material and Methods. We infected C57BL/6J mice with Coxsackievirus B3 and determined the hemodynamic function 7 as well as 28 days after infection. Subsequently, we analyzed viral burden and viral replication in the cardiac tissue as well as the expression of cytokines and matrix proteins. Furthermore, cardiac fibroblasts were infected with virus to investigate if viral infection alone induces profibrotic signaling. Results. Severe cardiac inflammation was determined and cardiac fibrosis was consistently colocalized with inflammation during the acute phase of myocarditis. Declined cardiac inflammation but no significantly improved hemodynamic function was observed 28 days after infection. Interestingly, cardiac fibrosis declined to basal levels as well. Both cardiac inflammation and fibrosis were reversible, whereas the hemodynamic function remains impaired after healed viral myocarditis in C57BL/6J mice.

Current role of cardiac and extra-cardiac pathologies in clinically indicated cardiac computed tomography with emphasis on status before pulmonary vein isolation

Energy Technology Data Exchange (ETDEWEB)

Sohns, J.M.; Lotz, J. [Goettingen University Medical Center (Germany). Inst. for Diagnostic and Interventional Radiology; German Center for Cardiovascular Research (DZHK), Goettingen (Germany); Menke, J.; Staab, W.; Fasshauer, M.; Kowallick, J.T.; Zwaka, P.A.; Schwarz, A. [Goettingen University Medical Center (Germany). Inst. for Diagnostic and Interventional Radiology; Spiro, J. [Koeln University Hospital (Germany). Radiology; Bergau, L.; Unterberg-Buchwald, C. [Goettingen University Medical Center (Germany). Cardiology and Pneumology

2014-09-15

Purpose: The aim of this study was to assess the incidence of cardiac and significant extra-cardiac findings in clinical computed tomography of the heart in patients with atrial fibrillation before pulmonary vein isolation (PVI). Materials and Methods: 224 patients (64 ± 10 years; male 63%) with atrial fibrillation were examined by cardiac 64-slice multidetector CT before PVI. Extra-cardiac findings were classified as 'significant' if they were recommended to additional diagnostics or therapy, and otherwise as 'non-significant'. Additionally, cardiac findings were documented in detail. Results: A total of 724 cardiac findings were identified in 203 patients (91% of patients). Additionally, a total of 619 extra-cardiac findings were identified in 179 patients (80% of patients). Among these extra-cardiac findings 196 (32%) were 'significant', and 423 (68%) were 'non-significant'. In 2 patients (1%) a previously unknown malignancy was detected (esophageal cancer and lung cancer, local stage, no metastasis). 203 additional imaging diagnostics followed to clarify the 'significant' findings (124 additional CT, costs 38,314.69 US dollars). Overall, there were 3.2 cardiac and 2.8 extra-cardiac findings per patient. Extra-cardiac findings appear significantly more frequently in patients over 60 years old, in smokers and in patients with a history of cardiac findings (p < 0.05). Conclusion: Cardiac CT scans before PVI should be screened for extracardiac incidental findings that could have important clinical implications for each patient. (orig.)

Cardiac manifestation's history in the systemic lupus erythematosus

International Nuclear Information System (INIS)

Iglesias Gamarra, Antonio; Rondon, Federico; Restrepo, Jose Felix

2001-01-01

In this paper it is broadly and in depth reviewed the cardiac manifestation's history of systemic lupus erythematosus (SLE), since an historical analysis of clinical manifestations both in pre and post corticosteroids period. The way how the heart and the cardiovascular system's functions have been studied by clinical and semiological views are showed, through clinical manifestations such as myocarditis pericarditis, endocarditis, rhythm alterations, etc, and the evolution of laboratory methods used to its study as well as immunologic prognostic markers and risk factors for coronary disease in SLE

Sawteeth stabilization by energetic trapped ions

International Nuclear Information System (INIS)

Samain, A.; Edery, D.; Garbet, X.; Roubin, J.P.

1991-01-01

The analysis of a possible stabilization of sawteeth by a population of energetic ions is performed by using the Lagrangian of the electromagnetic perturbation. It is shown that the trapped component of such a population has a small influence compared to that of the passing component. The stabilization threshold is calculated assuming a non linear regime in the q=1 resonant layer. The energetic population must create a stable tearing structure if the average curvature effect on thermal particles in the layer is small. However, this effect decreases the actual threshold

Very energetic photons at HERA

International Nuclear Information System (INIS)

Bawa, A.C.; Krawczyk, M.

1991-01-01

We show that every energetic photons in the backward direction can be produced in deep inelastic Compton scattering at HERA. Assuming a fixed energy of 9 GeV for the initial photons and 820 GeV for the protons a high rate is found for the production of final photons with a transverse momentum equal to 5 GeV/c and energy between 40 GeV and 300 GeV. These energetic photons arise mainly from the scattering of the soft gluonic constituents of the initial photon with quarks from the proton. They are produced in the backward direction in coincidence with a photon beam jet of energy ∝ 9 GeV in the forward direction. (orig.)

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.

Study of energetic dependence of LiF TLDs for photons

International Nuclear Information System (INIS)

Cavalieri, Tassio A.; Antunes, Paula C.G.; Paiva, Fabio; Branco, Isabela S.; Sena, Michelle K.S.; Siqueira, Paulo T.D.; Yoriyaz, Helio

2015-01-01

The LiF TLDs are widely used for photon dosimetry. However, in the most case the energetic dependence of these TLDs are not taken into account. This work is a preliminary study of energetic photon dependence in LiF TLD (TLD 700, enriched with 7 Li). For this study it was utilized a methodology already used in others works that seek understand the dependence energetic of TLD. It was utilized three different X-ray spectrum and a 137 Cs source; Beyond the calculus utilized in previous works, it was built the calibration curve for each spectrum to see the difference in dosimetry that the energetic dependence could cause. (author)

Study of energetic dependence of LiF TLDs for photons

Energy Technology Data Exchange (ETDEWEB)

Cavalieri, Tassio A.; Antunes, Paula C.G.; Paiva, Fabio; Branco, Isabela S.; Sena, Michelle K.S.; Siqueira, Paulo T.D.; Yoriyaz, Helio, E-mail: tcavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The LiF TLDs are widely used for photon dosimetry. However, in the most case the energetic dependence of these TLDs are not taken into account. This work is a preliminary study of energetic photon dependence in LiF TLD (TLD 700, enriched with {sup 7}Li). For this study it was utilized a methodology already used in others works that seek understand the dependence energetic of TLD. It was utilized three different X-ray spectrum and a {sup 137}Cs source; Beyond the calculus utilized in previous works, it was built the calibration curve for each spectrum to see the difference in dosimetry that the energetic dependence could cause. (author)

Energetics Manufacturing Technology Center (EMTC)

Data.gov (United States)

Federal Laboratory Consortium — The Energetics Manufacturing Technology Center (EMTC), established in 1994 by the Office of Naval Research (ONR) Manufacturing Technology (ManTech) Program, is Navy...

Myocardial uptake of thallium-201 in rat with cardiac hypertrophy

International Nuclear Information System (INIS)

Torii, Yukio; Adachi, Haruhiko; Kizu, Akira; Nakagawa, Masao; Ijichi, Hamao

1985-01-01

The thallium-201 (TL) has been used in order to diagnose myocardial infarction and ischemia. Although it is well known that TL distributes in the myocardium in proportion to the distribution of coronary blood flow, the biological property of TL in the loaded myocardium remains unclear. We studied the myocardial uptake of TL in rat with cardiac hypertrophy. Experiments were performed in 30 anesthetized rats devided into 3 groups; control group (C,N=14), hypertrophy group (H,N=6) and diltiazem group (D, 0.3 mg/kg/min. IV. N=10). Cardiac hypertrophy was produced with the banding of the ascending aorta. Myocardial blood flow (MBF) was measured by microspheres labeled with Strontium-85. Cardiac weight was increased in H, and both MBF and TL uptake were proportionally increased. MBF was negatively correlated with the extraction fraction in C (r=-0.71), in H (r=-0.66) and in D (r=-0.85), and this relationship in H was significantly different from it in C (p<0.05), but not in D. From these results, we concluded that TL uptake in H is not always dependant on MBF and affected by the altered metabolism of hypertrophied myocardium. (author)

The Effect of Cardiac Surgery on Peripheral Blood Lymphocyte Populations

Directory of Open Access Journals (Sweden)

Karolína Jankovičová

2008-01-01

Full Text Available Background: Cardiac surgery using cardiopulmonary bypass (CPB is associated with some adverse postoperative complications caused by an altered immune response. An alternative approach to cardiac surgery, operating without the use of CPB (i.e. off-pump surgery, seems to display less adverse impacts on the immune response. Patients and Methods: Peripheral blood lymphocytes in 40 patients undergoing cardiac surgery either with CPB (“on-pump” or without CPB (“off-pump” were followed using flow cytometry. The samples of peripheral blood were taken at five intervals: preoperatively, after termination of the surgery, on the first, on the third and on the seventh postoperative day, respectively. Results: The most substantial changes appeared on the first postoperative day in both subgroups of patients. While the percentage of both total T cells and CD4+ T cells were decreased, the percentage of HLA-DR+ activated lymphocytes was increased. These changes were more profound in the “on-pump” subgroup compared to the “off-pump” subgroup. Conclusion: Our results may suggest that the “off-pump” surgical approach reveals less adverse impact on adaptive immune responses.

Proteomics-based network analysis characterizes biological processes and pathways activated by preconditioned mesenchymal stem cells in cardiac repair mechanisms.

Science.gov (United States)

Di Silvestre, Dario; Brambilla, Francesca; Scardoni, Giovanni; Brunetti, Pietro; Motta, Sara; Matteucci, Marco; Laudanna, Carlo; Recchia, Fabio A; Lionetti, Vincenzo; Mauri, Pierluigi

2017-05-01

We have demonstrated that intramyocardial delivery of human mesenchymal stem cells preconditioned with a hyaluronan mixed ester of butyric and retinoic acid (MSCp + ) is more effective in preventing the decay of regional myocardial contractility in a swine model of myocardial infarction (MI). However, the understanding of the role of MSCp + in proteomic remodeling of cardiac infarcted tissue is not complete. We therefore sought to perform a comprehensive analysis of the proteome of infarct remote (RZ) and border zone (BZ) of pigs treated with MSCp + or unconditioned stem cells. Heart tissues were analyzed by MudPIT and differentially expressed proteins were selected by a label-free approach based on spectral counting. Protein profiles were evaluated by using PPI networks and their topological analysis. The proteomic remodeling was largely prevented in MSCp + group. Extracellular proteins involved in fibrosis were down-regulated, while energetic pathways were globally up-regulated. Cardioprotectant pathways involved in the production of keto acid metabolites were also activated. Additionally, we found that new hub proteins support the cardioprotective phenotype characterizing the left ventricular BZ treated with MSCp + . In fact, the up-regulation of angiogenic proteins NCL and RAC1 can be explained by the increase of capillary density induced by MSCp + . Our results show that angiogenic pathways appear to be uniquely positioned to integrate signaling with energetic pathways involving cardiac repair. Our findings prompt the use of proteomics-based network analysis to optimize new approaches preventing the post-ischemic proteomic remodeling that may underlie the limited self-repair ability of adult heart. Copyright © 2017 Elsevier B.V. All rights reserved.

Perflurooctanoic acid induces developmental cardiotoxicity in chicken embryos and hatchlings

International Nuclear Information System (INIS)

Jiang, Qixiao; Lust, Robert M.; Strynar, Mark J.; Dagnino, Sonia; DeWitt, Jamie C.

2012-01-01

Highlights: ► PFOA exposure thinned right ventricular wall thickness in D19 chicken embryo hearts. ► PFOA exposure induced left ventricle hypertrophy in hearts of hatchling chickens. ► PFOA exposure induced altered cardiac function in hatchling chickens. -- Abstract: Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPARα). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that developmental PFOA exposure may not affect cardiac energetics. In summary, structural and functional characteristics of the heart appear to be developmental targets of PFOA, possibly at the level of cardiomyocytes. Additional studies will

Forecast of nuclear energetics

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1976-01-01

The forecast concerning the development of nuclear energetics is presented. Some information on economics of nuclear power plants is given. The nuclear fuel reserves are estimated on the background of power resources of the world. The safety and environment protection problems are mentioned.

Energetic particle pressure in intense ESP events

Science.gov (United States)

Lario, D.; Decker, R. B.; Roelof, E. C.; Viñas, A.-F.

2015-09-01

We study three intense energetic storm particle (ESP) events in which the energetic particle pressure PEP exceeded both the pressure of the background thermal plasma Pth and the pressure of the magnetic field PB. The region upstream of the interplanetary shocks associated with these events was characterized by a depression of the magnetic field strength coincident with the increase of the energetic particle intensities and, when plasma measurements were available, a depleted solar wind density. The general feature of cosmic-ray mediated shocks such as the deceleration of the upstream background medium into which the shock propagates is generally observed. However, for those shocks where plasma parameters are available, pressure balance is not maintained either upstream of or across the shock, which may result from the fact that PEP is not included in the calculation of the shock parameters.

Epidemiology and Outcomes After In-Hospital Cardiac Arrest After Pediatric Cardiac Surgery

Science.gov (United States)

Gupta, Punkaj; Jacobs, Jeffrey P.; Pasquali, Sara K.; Hill, Kevin D.; Gaynor, J. William; O’Brien, Sean M.; He, Max; Sheng, Shubin; Schexnayder, Stephen M.; Berg, Robert A.; Nadkarni, Vinay M.; Imamura, Michiaki; Jacobs, Marshall L.

2014-01-01

Background Multicenter data regarding cardiac arrest in children undergoing heart operations are limited. We describe epidemiology and outcomes associated with postoperative cardiac arrest in a large multiinstitutional cohort. Methods Patients younger than 18 years in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2007 through 2012) were included. Patient factors, operative characteristics, and outcomes were described for patients with and without postoperative cardiac arrest. Multivariable models were used to evaluate the association of center volume with cardiac arrest rate and mortality after cardiac arrest, adjusting for patient and procedural factors. Results Of 70,270 patients (97 centers), 1,843 (2.6%) had postoperative cardiac arrest. Younger age, lower weight, and presence of preoperative morbidities (all p < 0.0001) were associated with cardiac arrest. Arrest rate increased with procedural complexity across common benchmark operations, ranging from 0.7% (ventricular septal defect repair) to 12.7% (Norwood operation). Cardiac arrest was associated with significant mortality risk across procedures, ranging from 15.4% to 62.3% (all p < 0.0001). In multivariable analysis, arrest rate was not associated with center volume (odds ratio, 1.06; 95% confidence interval, 0.71 to 1.57 in low- versus high-volume centers). However, mortality after cardiac arrest was higher in low-volume centers (odds ratio, 2.00; 95% confidence interval, 1.52 to 2.63). This association was present for both high- and low-complexity operations. Conclusions Cardiac arrest carries a significant mortality risk across the stratum of procedural complexity. Although arrest rates are not associated with center volume, lower-volume centers have increased mortality after cardiac arrest. Further study of mechanisms to prevent cardiac arrest and to reduce mortality in those with an arrest is warranted. PMID:25443018

Nuclear energy I, Non-energetic applications

International Nuclear Information System (INIS)

Lartigue G, J.; Navarrete T, M.; Cabrera M, L.; Arandia, P.A.; Arriola S, H.

1986-01-01

The nuclear energy is defined as the energy produced or absorbed in the nuclear reactions, therefore, these are divided in endothermic and exothermic. The exothermic nuclear reactions present more interest from the point of view of its applications and they can show in four main forms: radioactivity (from 0 to 4 MeV/reaction; light nucleus fusion ( ∼ 20 MeV/reaction), heavy nucleus fusion (∼ 200 MeV/reaction) and nucleons annihilation ( ∼ 2000 MeV/reaction). Nowadays only the fission has reached the stage of profitable energetic application, finding the other three forms in research and development. The non-energetic applications of the nuclear energy are characterized by they do not require of prior conversion to another form of energy and they are made through the use of radioisotopes as well as through the use of endothermic reaction caused in particle accelerators. In this work are presented some of the non-energetic applications with its theoretical and experimental basis as well as its benefits of each one. (Author)

Elevated Levels of Asymmetric Dimethylarginine (ADMA in the Pericardial Fluid of Cardiac Patients Correlate with Cardiac Hypertrophy.

Directory of Open Access Journals (Sweden)

Zoltan Nemeth

Full Text Available Pericardial fluid (PF contains several biologically active substances, which may provide information regarding the cardiac conditions. Nitric oxide (NO has been implicated in cardiac remodeling. We hypothesized that L-arginine (L-Arg precursor of NO-synthase (NOS and asymmetric dimethylarginine (ADMA, an inhibitor of NOS, are present in PF of cardiac patients and their altered levels may contribute to altered cardiac morphology.L-Arg and ADMA concentrations in plasma and PF, and echocardiographic parameters of patients undergoing coronary artery bypass graft (CABG, n = 28 or valve replacement (VR, n = 25 were determined.We have found LV hypertrophy in 35.7% of CABG, and 80% of VR patients. In all groups, plasma and PF L-Arg levels were higher than that of ADMA. Plasma L-Arg level was higher in CABG than VR (75.7 ± 4.6 μmol/L vs. 58.1 ± 4.9 μmol/L, p = 0.011, whereas PF ADMA level was higher in VR than CABG (0.9 ± 0.0 μmol/L vs. 0.7 ± 0.0 μmol/L, p = 0.009. L-Arg/ADMA ratio was lower in the VR than CABG (VRplasma: 76.1 ± 6.6 vs. CABGplasma: 125.4 ± 10.7, p = 0.004; VRPF: 81.7 ± 4.8 vs. CABGPF: 110.4 ± 7.2, p = 0.009. There was a positive correlation between plasma L-Arg and ADMA in CABG (r = 0.539, p = 0.015; and plasma and PF L-Arg in CABG (r = 0.357, p = 0.031; and plasma and PF ADMA in VR (r = 0.529, p = 0.003; and PF L-Arg and ADMA in both CABG and VR (CABG: r = 0.468, p = 0.006; VR: r = 0.371, p = 0.034. The following echocardiographic parameters were higher in VR compared to CABG: interventricular septum (14.7 ± 0.5 mm vs. 11.9 ± 0.4 mm, p = 0.000; posterior wall thickness (12.6 ± 0.3 mm vs. 11.5 ± 0.2 mm, p = 0.000; left ventricular (LV mass (318.6 ± 23.5 g vs. 234.6 ± 12.3 g, p = 0.007; right ventricular (RV (33.9 ± 0.9 cm2 vs. 29.7 ± 0.7 cm2, p = 0.004; right atrial (18.6 ± 1.0 cm2 vs. 15.4 ± 0.6 cm2, p = 0.020; left atrial (19.8 ± 1.0 cm2 vs. 16.9 ± 0.6 cm2, p = 0.033 areas. There was a positive correlation

Energetic assessment of soybean biodiesel obtainment in West ...

African Journals Online (AJOL)

SAM

2014-07-16

Jul 16, 2014 ... Energetic outputs added up to 3,003.75 MJ and energy balance was 57,132.54 MJ. ... biodiesel, the study was divided into three stages: soybean farming, ... considering energetic consumptions with labor, seeds, diesel oil, ... model MF 283(4X2 TDA), power 63.2 kW (86 cv) in the engine, board weight.

Resistive interchange mode destabilized by helically trapped energetic ions and its effects on energetic ions and bulk plasmas

International Nuclear Information System (INIS)

Du, X.D.; Toi, K.; Osakabe, M.

2014-10-01

A resistive interchange mode with bursting behavior and rapid frequency chirping in the range less than 10 kHz is observed for the first time in the magnetic hill region of net current-free, low beta LHD (Large Helical Device) plasmas during high power injection of perpendicular neutral beams. The mode resonates with the precession motion of helically trapped energetic beam ions, following the resonant condition. The radial mode structure is found to be very similar to that of usual pressure-driven interchange mode, of which radial displacement eigenfunction has an even function around the rational surface. This beam driven mode is excited when the beta value of helically trapped energetic ions exceed a certain threshold. The radial transport of helically trapped energetic ions induced by the mode transiently generates significant radial electric field near the plasma peripheral region. Thus generated radial electric field clearly suppresses micro turbulence and improves bulk plasma confinement, suggesting strong flow shear generation. (author)

Misalignment with the external light environment drives metabolic and cardiac dysfunction.

Science.gov (United States)

West, Alexander C; Smith, Laura; Ray, David W; Loudon, Andrew S I; Brown, Timothy M; Bechtold, David A

2017-09-12

Most organisms use internal biological clocks to match behavioural and physiological processes to specific phases of the day-night cycle. Central to this is the synchronisation of internal processes across multiple organ systems. Environmental desynchrony (e.g. shift work) profoundly impacts human health, increasing cardiovascular disease and diabetes risk, yet the underlying mechanisms remain unclear. Here, we characterise the impact of desynchrony between the internal clock and the external light-dark (LD) cycle on mammalian physiology. We reveal that even under stable LD environments, phase misalignment has a profound effect, with decreased metabolic efficiency and disrupted cardiac function including prolonged QT interval duration. Importantly, physiological dysfunction is not driven by disrupted core clock function, nor by an internal desynchrony between organs, but rather the altered phase relationship between the internal clockwork and the external environment. We suggest phase misalignment as a major driver of pathologies associated with shift work, chronotype and social jetlag.The misalignment between internal circadian rhythm and the day-night cycle can be caused by genetic, behavioural and environmental factors, and may have a profound impact on human physiology. Here West et al. show that desynchrony between the internal clock and the external environment alter metabolic parameters and cardiac function in mice.

Hexokinase cellular trafficking in ischemia-reperfusion and ischemic preconditioning is altered in type I diabetic heart

NARCIS (Netherlands)

Gurel, Ebru; Ustunova, Savas; Kapucu, Aysegul; Yilmazer, Nadim; Eerbeek, Otto; Nederlof, Rianne; Hollmann, Markus W.; Demirci-Tansel, Cihan; Zuurbier, Coert J.

2013-01-01

Diabetes mellitus (DM) has been reported to alter the cardiac response to ischemia-reperfusion (IR). In addition, cardioprotection induced by ischemic preconditioning (IPC) is often impaired in diabetes. We have previously shown that the subcellular localisation of the glycolytic enzyme hexokinase

Short-Term Caloric Restriction Suppresses Cardiac Oxidative Stress and Hypertrophy Caused by Chronic Pressure Overload.

Science.gov (United States)

Kobara, Miyuki; Furumori-Yukiya, Akiko; Kitamura, Miho; Matsumura, Mihoko; Ohigashi, Makoto; Toba, Hiroe; Nakata, Tetsuo

2015-08-01

Caloric restriction (CR) prevents senescent changes, in which reactive oxygen species (ROS) have a critical role. Left ventricular (LV) hypertrophy is a risk factor for cardiovascular diseases. We examined whether CR alters cardiac redox state and hypertrophy from chronic pressure overload. Male c57BL6 mice were subjected to ascending aortic constriction (AAC) with ad libitum caloric intake (AL + AAC group) or 40% restricted caloric intake (CR + AAC group). CR was initiated 2 weeks before AAC and was continued for 4 weeks. Two weeks after constriction, AAC increased LV wall thickness, impaired transmitral flow velocity, and augmented myocyte hypertrophy and fibrosis, in association with enhancement of BNP and collagen III expressions in the AL + AAC group. In the AL + AAC group, oxidative stress in cardiac tissue and mitochondria were enhanced, and NADPH oxidase activity and mitochondrial ROS production were elevated. These changes were significantly attenuated in the CR + AAC group. Additionally, in antioxidant systems, myocardial glutathione peroxidase and superoxide dismutase activities were enhanced in the CR + AAC group. Chronic pressure overload increased cardiac oxidative damage, in association with cardiac hypertrophy and fibrosis. Short-term CR suppressed oxidative stress and improved cardiac function, suggesting that short-term CR could be a useful strategy to prevent pressure overload-induced cardiac injury. Copyright © 2015 Elsevier Inc. All rights reserved.

Topical thrombin preparations and their use in cardiac surgery

Directory of Open Access Journals (Sweden)

Brianne L Dunn

2009-10-01

Full Text Available Brianne L Dunn1, Walter E Uber1, John S Ikonomidis21Department of Pharmacy Services and 2Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, South Carolina, USAAbstract: Coagulopathic bleeding may lead to increased morbidity and mortality after cardiac surgery. Topical bovine thrombin has been used to promote hemostasis after surgical procedures for over 60 years and is used frequently as a topical hemostatic agent in cardiac surgery. Recently, use of bovine thrombin has been reported to be associated with increased risk for anaphylaxis, thrombosis, and immune-mediated coagulopathy thought secondary to the production of antifactor V and antithrombin antibodies. In patients who develop bovine thrombin-induced immune-mediated coagulopathy, clinical manifestations may range from asymptomatic alterations in coagulation tests to severe hemorrhage and death. Patients undergoing cardiac surgical procedures may be at increased risk for development of antibodies to bovine thrombin products and associated complications. This adverse immunologic profile has led to the development of alternative preparations including a human and a recombinant thrombin which have been shown to be equally efficacious to bovine thrombin and have reduced antigenicity. However, the potential benefit associated with reduced antigenicity is not truly known secondary to the lack of long-term experience with these products. Given the potentially higher margin of safety and less stringent storage concerns compared to human thrombin, recombinant thrombin may be the most reasonable approach in cardiac surgery.Keywords: bovine thrombin, human thrombin, recombinant thrombin, immune-mediated coagulopathy, topical hemostatic agents, thrombin 

Differential gene expression of cardiac ion channels in human dilated cardiomyopathy.

Directory of Open Access Journals (Sweden)

Maria Micaela Molina-Navarro

Full Text Available BACKGROUND: Dilated cardiomyopathy (DCM is characterized by idiopathic dilation and systolic contractile dysfunction of the cardiac chambers. The present work aimed to study the alterations in gene expression of ion channels involved in cardiomyocyte function. METHODS AND RESULTS: Microarray profiling using the Affymetrix Human Gene® 1.0 ST array was performed using 17 RNA samples, 12 from DCM patients undergoing cardiac transplantation and 5 control donors (CNT. The analysis focused on 7 cardiac ion channel genes, since this category has not been previously studied in human DCM. SCN2B was upregulated, while KCNJ5, KCNJ8, CLIC2, CLCN3, CACNB2, and CACNA1C were downregulated. The RT-qPCR (21 DCM and 8 CNT samples validated the gene expression of SCN2B (p < 0.0001, KCNJ5 (p < 0.05, KCNJ8 (p < 0.05, CLIC2 (p < 0.05, and CACNB2 (p < 0.05. Furthermore, we performed an IPA analysis and we found a functional relationship between the different ion channels studied in this work. CONCLUSION: This study shows a differential expression of ion channel genes involved in cardiac contraction in DCM that might partly underlie the changes in left ventricular function observed in these patients. These results could be the basis for new genetic therapeutic approaches.

Whole transcriptome analysis of the fasting and fed Burmese python heart: insights into extreme physiological cardiac adaptation.

Science.gov (United States)

Wall, Christopher E; Cozza, Steven; Riquelme, Cecilia A; McCombie, W Richard; Heimiller, Joseph K; Marr, Thomas G; Leinwand, Leslie A

2011-01-01

The infrequently feeding Burmese python (Python molurus) experiences significant and rapid postprandial cardiac hypertrophy followed by regression as digestion is completed. To begin to explore the molecular mechanisms of this response, we have sequenced and assembled the fasted and postfed Burmese python heart transcriptomes with Illumina technology using the chicken (Gallus gallus) genome as a reference. In addition, we have used RNA-seq analysis to identify differences in the expression of biological processes and signaling pathways between fasted, 1 day postfed (DPF), and 3 DPF hearts. Out of a combined transcriptome of ∼2,800 mRNAs, 464 genes were differentially expressed. Genes showing differential expression at 1 DPF compared with fasted were enriched for biological processes involved in metabolism and energetics, while genes showing differential expression at 3 DPF compared with fasted were enriched for processes involved in biogenesis, structural remodeling, and organization. Moreover, we present evidence for the activation of physiological and not pathological signaling pathways in this rapid, novel model of cardiac growth in pythons. Together, our data provide the first comprehensive gene expression profile for a reptile heart.

Streaming reversal of energetic particles in the magnetotail during a substorm

Science.gov (United States)

Lui, A. T. Y.; Williams, D. J.; Eastman, T. E.; Frank, L. A.; Akasofu, S.-I.

1984-01-01

A case of reversal in the streaming anisotropy of energetic ions and in the plasma flow observed from the IMP 8 spacecraft during a substorm on February 8, 1978 is studied in detail using measurements of energetic particles, plasma, and magnetic field. Four new features emerge when high time resolution data are examined in detail. The times of streaming reversal of energetic particles in different energy ranges do not coincide with the time of plasma flow reversal. Qualitatively different velocity distributions are observed in earthward and tailward plasma flows during the observed flow reversal intervals. Strong tailward streaming of energetic particles can be detected during northward magnetic field environments and, conversely, earthward streaming in southward field environments. During the period of tailward streaming of energetic particles, earthward streaming fluxes are occasionally detected.

Cardiac rehabilitation

Science.gov (United States)

... rehab; Heart failure - cardiac rehab References Anderson L, Taylor RS. Cardiac rehabilitation for people with heart disease: ... of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

Recovery following Thyroxine Treatment Withdrawal, but Not Propylthiouracil, Averts In Vivo and Ex Vivo Thyroxine-Provoked Cardiac Complications in Adult FVB/N Mice

Directory of Open Access Journals (Sweden)

Nancy S. Saad

2017-01-01

Full Text Available Persistent cardiovascular pathology has been described in hyperthyroid patients even with effective antithyroid treatment. Here, we studied the effect of a well-known antithyroid drug, propylthiouracil (PTU; 20 mg/kg/day, on thyroxine (T4; 500 µg/kg/day-induced increase in blood pressure (BP, cardiac hypertrophy, and altered responses of the contractile myocardium both in vivo and ex vivo after 2 weeks of treatment. Furthermore, the potential recovery through 2 weeks of T4 treatment discontinuation was also investigated. PTU and T4 recovery partially reduced the T4-prompted increase in BP. Alternatively, PTU significantly improved the in vivo left ventricular (LV function with no considerable effects on cardiac hypertrophy or ex vivo right ventricular (RV contractile alterations subsequent to T4 treatment. Conversely, T4 recovery considerably enhanced the T4-provoked cardiac changes both in vivo and ex vivo. Altogether, our data is in agreement with the proposal that hyperthyroidism-induced cardiovascular pathology could persevere even with antithyroid treatments, such as PTU. However, this cannot be generalized and further investigation with different antithyroid treatments should be executed. Moreover, we reveal that recovery following experimental hyperthyroidism could potentially ameliorate cardiac function and decrease the risk for additional cardiac complications, yet, this appears to be model-dependent and should be cautiously construed.

Energetic Ion Loss Diagnostic for the Wendelstein 7-AS Stellarator

International Nuclear Information System (INIS)

Darrow, D. S.; Werner, A.; Weller, A.

2000-01-01

A diagnostic to measure the loss of energetic ions from the Wendelstein 7-AS (W7-AS) stellarator has been built. It is capable of measuring losses of both neutral beam ions and energetic ions arising from ion cyclotron resonant heating. The probe can measure losses of both clockwise and counterclockwise-going energetic ions simultaneously, and accepts a wide range of pitch angles in both directions. Initial measurements by the diagnostic are reported

Energetics of hydrogen bonding in proteins: a model compound study.

OpenAIRE

Habermann, S. M.; Murphy, K. P.

1996-01-01

Differences in the energetics of amide-amide and amide-hydroxyl hydrogen bonds in proteins have been explored from the effect of hydroxyl groups on the structure and dissolution energetics of a series of crystalline cyclic dipeptides. The calorimetrically determined energetics are interpreted in light of the crystal structures of the studied compounds. Our results indicate that the amide-amide and amide-hydroxyl hydrogen bonds both provide considerable enthalpic stability, but that the amide-...

Phospholipid alterations in cardiac sarcoplasmic reticulum induced by xanthine oxidase: contamination of commercial preparations of xanthine oxidase by phospholipase A2

International Nuclear Information System (INIS)

Gamache, D.A.; Kornberg, L.J.; Bartolf, M.; Franson, R.C.

1986-01-01

Incubation of cardiac sarcoplasmic reticulum with xanthine oxidase alone at pH 7.0 resulted in a loss of lipid phosphorus that was potentiated by the addition of xanthine. Using autoclaved E.coli with 1- 14 C-oleate in the 2-acyl position of membrane phospholipids, the authors demonstrate that many, but not all, commercial preparations of xanthine oxidase contain significant phospholipase A 2 (PLA 2 ) activity (64.3-545.6 nmols/min/mg). The PLA 2 was maximally active in the neutral-alkaline pH range, was Ca 2+ -dependent, and was unaffected by the addition of xanthine. PLA 2 activity was totally inhibited by 1mM EDTA whereas radical production by optimal concentrations of xanthine/xanthine oxidase (X/XO) was unaffected by EDTA. Chromatographically purified xanthine oxidase (Sigma Grade III) contained high levels of PLA 2 activity (64.3 nmols/min/mg) compared to endogenous levels of neutral-active, Ca 2+ -dependent PLA 2 measured in various tissue homogenates (≤ 0.5 nmols/ min/mg). Because X/XO mixtures are used extensively to study oxygen free radical-induced cell injury and membrane phospholipid alterations, the presence of a potent extracellular PLA 2 may have influenced previously published reports, and such studies should be interpreted cautiously

Cardiac parasympathetic regulation in obese women with binge eating disorder.

Science.gov (United States)

Friederich, H-C; Schild, S; Schellberg, D; Quenter, A; Bode, C; Herzog, W; Zipfel, S

2006-03-01

Obese individuals with a binge eating disorder (BED) differ from obese non-binge eaters (NBED) with respect to (a) eating behaviour, (b) psychiatric comorbidity and (c) level of psychosocial distress. The aim of the study was to explore whether these three factors have an influence on cardiac parasympathetic function, that is independent of obesity: as alterations in cardiac parasympathetic function may have a role in the higher cardiovascular mortality that is present in obese individuals. In total, 38 obese women (BMI>30 kg/m(2)), with a BED and 34 age and BMI matched healthy controls (NBED) completed a laboratory stress protocol that incorporated a baseline resting period, Head-up Tilt Testing (HUT) and two challenging mental tasks. Heart rate and blood pressure were measured continuously during the protocol. Parasympathetic cardiac regulation was assessed as the high frequency component of heart rate variability (HRV-HF). Mental challenge led to an augmented reduction of HRV-HF in obese binge eaters, which was linked to the binge eating frequency and hunger perception, but not to psychiatric comorbidity. During baseline conditions and HUT, no significant differences in parasympathetic measures were observed between the two subject groups. Subjects with a BED showed greater reduction in parasympathetic cardiac control (HRV-HF) during mental stress, suggesting higher stress vulnerability in women with a BED. Longitudinal investigations are necessary to evaluate whether this is associated with an increased cardiovascular mortality.

Theoretical Studies of Alfven Waves and Energetic Particle Physics in Fusion Plasmas

Energy Technology Data Exchange (ETDEWEB)

Chen, Liu [Univ. of California, Irvine, CA (United States)

2017-12-20

This report summarizes major theoretical findings in the linear as well as nonlinear physics of Alfvén waves and energetic particles in magnetically confined fusion plasmas. On the linear physics, a variational formulation, based on the separation of singular and regular spatial scales, for drift-Alfvén instabilities excited by energetic particles is established. This variational formulation is then applied to derive the general fishbone-like dispersion relations corresponding to the various Alfvén eigenmodes and energetic-particle modes. It is further employed to explore in depth the low-frequency Alfvén eigenmodes and demonstrate the non-perturbative nature of the energetic particles. On the nonlinear physics, new novel findings are obtained on both the nonlinear wave-wave interactions and nonlinear wave-energetic particle interactions. It is demonstrated that both the energetic particles and the fine radial mode structures could qualitatively affect the nonlinear evolution of Alfvén eigenmodes. Meanwhile, a theoretical approach based on the Dyson equation is developed to treat self-consistently the nonlinear interactions between Alfvén waves and energetic particles, and is then applied to explain simulation results of energetic-particle modes. Relevant list of journal publications on the above findings is also included.

Autophagic signaling and proteolytic enzyme activity in cardiac and skeletal muscle of spontaneously hypertensive rats following chronic aerobic exercise.

Directory of Open Access Journals (Sweden)

Elliott M McMillan

Full Text Available Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY and spontaneously hypertensive rats (SHR were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG of hypertensive rats had higher (p<0.05 caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05 ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05 Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05 Beclin-1 and ATG7 protein, as well as decreased (p<0.05 caspase-3, calpain, and cathepsin activity. Left ventricle (LV of hypertensive rats had reduced (p<0.05 AMPKα and LC3II protein, as well as elevated (p<0.05 p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05 proteasome activity but reduced (p<0.05 caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats.

19-Hydroxyeicosatetraenoic acid and isoniazid protect against angiotensin II-induced cardiac hypertrophy

Energy Technology Data Exchange (ETDEWEB)

Elkhatali, Samya; El-Sherbeni, Ahmed A.; Elshenawy, Osama H. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada); Abdelhamid, Ghada [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Helwan (Egypt); El-Kadi, Ayman O.S., E-mail: aelkadi@ualberta.ca [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

2015-12-15

We have recently demonstrated that 19-hydroxyeicosatetraenoic acid (19-HETE) is the major subterminal-HETE formed in the heart tissue, and its formation was decreased during cardiac hypertrophy. In the current study, we examined whether 19-HETE confers cardioprotection against angiotensin II (Ang II)-induced cardiac hypertrophy. The effect of Ang II, with and without 19-HETE (20 μM), on the development of cellular hypertrophy in cardiomyocyte RL-14 cells was assessed by real-time PCR. Also, cardiac hypertrophy was induced in Sprague–Dawley rats by Ang II, and the effect of increasing 19-HETE by isoniazid (INH; 200 mg/kg/day) was assessed by heart weight and echocardiography. Also, alterations in cardiac cytochrome P450 (CYP) and their associated arachidonic acid (AA) metabolites were determined by real-time PCR, Western blotting and liquid-chromatography–mass-spectrometry. Our results demonstrated that 19-HETE conferred a cardioprotective effect against Ang II-induced cellular hypertrophy in vitro, as indicated by the significant reduction in β/α-myosin heavy chain ratio. In vivo, INH improved heart dimensions, and reversed the increase in heart weight to tibia length ratio caused by Ang II. We found a significant increase in cardiac 19-HETE, as well as a significant reduction in AA and its metabolite, 20-HETE. In conclusion, 19-HETE, incubated with cardiomyocytes in vitro or induced in the heart by INH in vivo, provides cardioprotection against Ang II-induced hypertrophy. This further confirms the role of CYP, and their associated AA metabolites in the development of cardiac hypertrophy. - Highlights: • We found 19-hydroxy arachidonic acid to protect cardiomyocytes from hypertrophy. • We validated the use of isoniazid as a cardiac 19-hydroxy arachidonic acid inducer. • We found isoniazid to increase protective and inhibit toxic eicosanoides. • We found isoniazid to protect against angiotensin-induced cardiac hypertrophy. • This will help to

Defining the Intrinsic Cardiac Risks of Operations to Improve Preoperative Cardiac Risk Assessments.

Science.gov (United States)

Liu, Jason B; Liu, Yaoming; Cohen, Mark E; Ko, Clifford Y; Sweitzer, Bobbie J

2018-02-01

Current preoperative cardiac risk stratification practices group operations into broad categories, which might inadequately consider the intrinsic cardiac risks of individual operations. We sought to define the intrinsic cardiac risks of individual operations and to demonstrate how grouping operations might lead to imprecise estimates of perioperative cardiac risk. Elective operations (based on Common Procedural Terminology codes) performed from January 1, 2010 to December 31, 2015 at hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program were studied. A composite measure of perioperative adverse cardiac events was defined as either cardiac arrest requiring cardiopulmonary resuscitation or acute myocardial infarction. Operations' intrinsic cardiac risks were derived from mixed-effects models while controlling for patient mix. Resultant risks were sorted into low-, intermediate-, and high-risk categories, and the most commonly performed operations within each category were identified. Intrinsic operative risks were also examined using a representative grouping of operations to portray within-group variation. Sixty-six low, 30 intermediate, and 106 high intrinsic cardiac risk operations were identified. Excisional breast biopsy had the lowest intrinsic cardiac risk (overall rate, 0.01%; odds ratio, 0.11; 95% CI, 0.02 to 0.25) relative to the average, whereas aorto-bifemoral bypass grafting had the highest (overall rate, 4.1%; odds ratio, 6.61; 95% CI, 5.54 to 7.90). There was wide variation in the intrinsic cardiac risks of operations within the representative grouping (median odds ratio, 1.40; interquartile range, 0.88 to 2.17). A continuum of intrinsic cardiac risk exists among operations. Grouping operations into broad categories inadequately accounts for the intrinsic cardiac risk of individual operations.

Reduction in Hexokinase II Levels Results in Decreased Cardiac Function and Altered Remodeling After Ischemia/Reperfusion Injury

NARCIS (Netherlands)

Wu, Rongxue; Smeele, Kirsten M.; Wyatt, Eugene; Ichikawa, Yoshihiko; Eerbeek, Otto; Sun, Lin; Chawla, Kusum; Hollmann, Markus W.; Nagpal, Varun; Heikkinen, Sami; Laakso, Markku; Jujo, Kentaro; Wasserstrom, J. Andrew; Zuurbier, Coert J.; Ardehali, Hossein

2011-01-01

Rationale: Cardiomyocytes switch substrate utilization from fatty acid to glucose under ischemic conditions; however, it is unknown how perturbations in glycolytic enzymes affect cardiac response to ischemia/reperfusion (I/R). Hexokinase (HK)II is a HK isoform that is expressed in the heart and can

Alterations in rat cardiac myosin isozymes induced by whole-body irradiation are prevented by 3,5,3'-L-triiodothyronine

International Nuclear Information System (INIS)

Litten, R.Z.; Fein, H.G.; Gainey, G.T.; Walden, T.L.; Smallridge, R.C.

1990-01-01

Changes in cardiac myosin isozymes and serum thyroid hormone levels were investigated in rats following 10 Gy whole-body gamma irradiation. The percent beta-myosin heavy chain increased from 21.3 ± 1.8 to 28.1 ± 6.8 (NS) at 3-day postirradiation, 37.7 ± 1.9 (P less than .001) at 6-day postirradiation, and 43.8 ± 3.3 (P less than .001) at 9-day postirradiation. Along with the change in myosin isozymes was a significant 53% decrease (P less than .001) in the serum thyroxine (T4) level by day 3 postirradiation, remaining depressed through day 9 postirradiation. The serum 3,5,3'-triiodothyronine (T3) level, however, was normal until day 9, when significant depression was also observed. In contrast, the thyroid-stimulating hormone (TSH) level was significantly increased by fourfold at day 3, returning to near normal values by day 9 postirradiation. Daily injections of physiological doses of T3 (0.3 microgram/100 g body weight) prevented the change in the myosin isozymes following whole-body irradiation. Daily pharmacological injections of T3 (3.0 micrograms/100 g body weight) to the irradiated rats produced a further decrease in the percent beta-myosin heavy chain (below control values) indicating tissue hyperthyroidism. Thus, this study suggests that the change in myosin isozymes following whole-body irradiation is caused by an alteration in thyroid hormone activity

Energetic charged particles above thunderclouds

International Nuclear Information System (INIS)

Fullekrug, Martin; Diver, Declan; Pincon, Jean-Louis; Renard, Jean-Baptiste; Phelps, Alan D.R.; Bourdon, Anne; Helling, Christiane; Blanc, Elisabeth; Honary, Farideh; Kosch, Mike; Harrison, Giles; Sauvaud, Jean-Andre; Lester, Mark; Rycroft, Michael; Kosch, Mike; Horne, Richard B.; Soula, Serge; Gaffet, Stephane

2013-01-01

The French government has committed to launch the satellite TARANIS to study transient coupling processes between the Earth's atmosphere and near-Earth space. The prime objective of TARANIS is to detect energetic charged particles and hard radiation emanating from thunderclouds. The British Nobel prize winner C. T. R. Wilson predicted lightning discharges from the top of thunderclouds into space almost a century ago. However, new experiments have only recently confirmed energetic discharge processes which transfer energy from the top of thunderclouds into the upper atmosphere and near-Earth space; they are now denoted as transient luminous events, terrestrial gamma-ray flashes and relativistic electron beams. This meeting report builds on the current state of scientific knowledge on the physics of plasmas in the laboratory and naturally occurring plasmas in the Earth's atmosphere to propose areas of future research. The report specifically reflects presentations delivered by the members of a novel Franco-British collaboration during a meeting at the French Embassy in London held in November 2011. The scientific subjects of the report tackle ionization processes leading to electrical discharge processes, observations of transient luminous events, electromagnetic emissions, energetic charged particles and their impact on the Earth's atmosphere. The importance of future research in this area for science and society, and towards spacecraft protection, is emphasized. (authors)

Cardiac dysfunction and peri-weaning mortality in malonyl-coenzyme A decarboxylase (MCD) knockout mice as a consequence of restricting substrate plasticity.

Science.gov (United States)

Aksentijević, Dunja; McAndrew, Debra J; Karlstädt, Anja; Zervou, Sevasti; Sebag-Montefiore, Liam; Cross, Rebecca; Douglas, Gillian; Regitz-Zagrosek, Vera; Lopaschuk, Gary D; Neubauer, Stefan; Lygate, Craig A

2014-10-01

Inhibition of malonyl-coenzyme A decarboxylase (MCD) shifts metabolism from fatty acid towards glucose oxidation, which has therapeutic potential for obesity and myocardial ischemic injury. However, ~40% of patients with MCD deficiency are diagnosed with cardiomyopathy during infancy. To clarify the link between MCD deficiency and cardiac dysfunction in early life and to determine the contributing systemic and cardiac metabolic perturbations. MCD knockout mice ((-/-)) exhibited non-Mendelian genotype ratios (31% fewer MCD(-/-)) with deaths clustered around weaning. Immediately prior to weaning (18days) MCD(-/-) mice had lower body weights, elevated body fat, hepatic steatosis and glycogen depletion compared to wild-type littermates. MCD(-/-) plasma was hyperketonemic, hyperlipidemic, had 60% lower lactate levels and markers of cellular damage were elevated. MCD(-/-) hearts exhibited hypertrophy, impaired ejection fraction and were energetically compromised (32% lower total adenine nucleotide pool). However differences between WT and MCD(-/-) converged with age, suggesting that, in surviving MCD(-/-) mice, early cardiac dysfunction resolves over time. These observations were corroborated by in silico modelling of cardiomyocyte metabolism, which indicated improvement of the MCD(-/-) metabolic phenotype and improved cardiac efficiency when switched from a high-fat diet (representative of suckling) to a standard post-weaning diet, independent of any developmental changes. MCD(-/-) mice consistently exhibited cardiac dysfunction and severe metabolic perturbations while on a high-fat, low carbohydrate diet of maternal milk and these gradually resolved post-weaning. This suggests that dysfunction is a common feature of MCD deficiency during early development, but that severity is dependent on composition of dietary substrates. Copyright © 2014. Published by Elsevier Ltd.

Novel regulation of cardiac Na pump via phospholemman.

Science.gov (United States)

Pavlovic, Davor; Fuller, William; Shattock, Michael J

2013-08-01

As the only quantitatively significant Na efflux pathway from cardiac cells, the Na/K ATPase (Na pump) is the primary regulator of intracellular Na. The transmembrane Na gradient it establishes is essential for normal electrical excitability, numerous coupled-transport processes and, as the driving force for Na/Ca exchange, thus setting cardiac Ca load and contractility. As Na influx varies with electrical excitation, heart rate and pathology, the dynamic regulation of Na efflux is essential. It is now widely recognized that phospholemman, a 72 amino acid accessory protein which forms part of the Na pump complex, is the key nexus linking cellular signaling to pump regulation. Phospholemman is the target of a variety of post-translational modifications (including phosphorylation, palmitoylation and glutathionation) and these can dynamically alter the activity of the Na pump. This review summarizes our current understanding of the multiple regulatory mechanisms that converge on phospholemman and govern NA pump activity in the heart. The corrected Fig. 4 is reproduced below. The publisher would like to apologize for any inconvenience caused. [corrected]. Copyright © 2013. Published by Elsevier Ltd.

Disturbance of cardiac gene expression and cardiomyocyte structure predisposes Mecp2-null mice to arrhythmias

Science.gov (United States)

Hara, Munetsugu; Takahashi, Tomoyuki; Mitsumasu, Chiaki; Igata, Sachiyo; Takano, Makoto; Minami, Tomoko; Yasukawa, Hideo; Okayama, Satoko; Nakamura, Keiichiro; Okabe, Yasunori; Tanaka, Eiichiro; Takemura, Genzou; Kosai, Ken-ichiro; Yamashita, Yushiro; Matsuishi, Toyojiro

2015-01-01

Methyl-CpG-binding protein 2 (MeCP2) is an epigenetic regulator of gene expression that is essential for normal brain development. Mutations in MeCP2 lead to disrupted neuronal function and can cause Rett syndrome (RTT), a neurodevelopmental disorder. Previous studies reported cardiac dysfunction, including arrhythmias in both RTT patients and animal models of RTT. In addition, recent studies indicate that MeCP2 may be involved in cardiac development and dysfunction, but its role in the developing and adult heart remains unknown. In this study, we found that Mecp2-null ESCs could differentiate into cardiomyocytes, but the development and further differentiation of cardiovascular progenitors were significantly affected in MeCP2 deficiency. In addition, we revealed that loss of MeCP2 led to dysregulation of endogenous cardiac genes and myocardial structural alterations, although Mecp2-null mice did not exhibit obvious cardiac functional abnormalities. Furthermore, we detected methylation of the CpG islands in the Tbx5 locus, and showed that MeCP2 could target these sequences. Taken together, these results suggest that MeCP2 is an important regulator of the gene-expression program responsible for maintaining normal cardiac development and cardiomyocyte structure. PMID:26073556

Energetic lanthanide complexes: coordination chemistry and explosives applications

International Nuclear Information System (INIS)

Manner, V W; Barker, B J; Sanders, V E; Laintz, K E; Scott, B L; Preston, D N; Sandstrom, M; Reardon, B L

2014-01-01

Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

Aberrant Glycosylation in the Left Ventricle and Plasma of Rats with Cardiac Hypertrophy and Heart Failure.

Directory of Open Access Journals (Sweden)

Chiaki Nagai-Okatani

Full Text Available Targeted proteomics focusing on post-translational modifications, including glycosylation, is a useful strategy for discovering novel biomarkers. To apply this strategy effectively to cardiac hypertrophy and resultant heart failure, we aimed to characterize glycosylation profiles in the left ventricle and plasma of rats with cardiac hypertrophy. Dahl salt-sensitive hypertensive rats, a model of hypertension-induced cardiac hypertrophy, were fed a high-salt (8% NaCl diet starting at 6 weeks. As a result, they exhibited cardiac hypertrophy at 12 weeks and partially impaired cardiac function at 16 weeks compared with control rats fed a low-salt (0.3% NaCl diet. Gene expression analysis revealed significant changes in the expression of genes encoding glycosyltransferases and glycosidases. Glycoproteome profiling using lectin microarrays indicated upregulation of mucin-type O-glycosylation, especially disialyl-T, and downregulation of core fucosylation on N-glycans, detected by specific interactions with Amaranthus caudatus and Aspergillus oryzae lectins, respectively. Upregulation of plasma α-l-fucosidase activity was identified as a biomarker candidate for cardiac hypertrophy, which is expected to support the existing marker, atrial natriuretic peptide and its related peptides. Proteomic analysis identified cysteine and glycine-rich protein 3, a master regulator of cardiac muscle function, as an O-glycosylated protein with altered glycosylation in the rats with cardiac hypertrophy, suggesting that alternations in O-glycosylation affect its oligomerization and function. In conclusion, our data provide evidence of significant changes in glycosylation pattern, specifically mucin-type O-glycosylation and core defucosylation, in the pathogenesis of cardiac hypertrophy and heart failure, suggesting that they are potential biomarkers for these diseases.

Biogas - energetical and environmental point of view

International Nuclear Information System (INIS)

Skele, A.; Upitis, A.; Kristapsons, M.; Goizevskis, O.; Ziemelis, I.

2003-01-01

Energy sector has been one of the most important priorities since reestablishment of independence of Latvia. The deficiency of energy resources in Latvia has created a need to assess all the possibilities to utilise all possibilities to utilise all the energy resources, including the biological ones, to motivate the trends in the development of energetic in Latvia. A huge non-utilised reserve in Latvia is methane fermentation of organic agricultural and municipal residue and sewage from food industry. The organic mass of solid and liquid waste of different origin and its energetic potential for rural region have been investigated. The work deals with an integrated system of the utilisation of agricultural waste with the anaerobic (biogas) and the thermal processes. Presently the anaerobic waste utilisation, in combination with the production of biogas and organic fertiliser, is considered as one of the energetically most efficient and environment-friendly ways of organic fertiliser utilisation (authors)

Chronic fatigue syndrome: illness severity, sedentary lifestyle, blood volume and evidence of diminished cardiac function.

Science.gov (United States)

Hurwitz, Barry E; Coryell, Virginia T; Parker, Meela; Martin, Pedro; Laperriere, Arthur; Klimas, Nancy G; Sfakianakis, George N; Bilsker, Martin S

2009-10-19

the extent to which the cardiac and blood volume alterations in CFS have physiological and clinical significance.

Severe antiphospholipid syndrome and cardiac surgery: Perioperative management.

Science.gov (United States)

Mishra, Pankaj Kumar; Khazi, Fayaz Mohammed; Yiu, Patrick; Billing, John Stephen

2016-06-01

Antiphospholipid syndrome is an antiphospholipid antibody-mediated prothrombotic state leading to arterial and venous thrombosis. This condition alters routine in-vitro coagulation tests, making results unreliable. Antiphospholipid syndrome patients requiring cardiac surgery with cardiopulmonary bypass present a unique challenge in perioperative anticoagulation management. We describe 3 patients with antiphospholipid syndrome who had successful heart valve surgery at our institution. We have devised an institutional protocol for antiphospholipid syndrome patients, and all 3 patients were managed according to this protocol. An algorithm-based approach is recommended because it improves team work, optimizes treatment, and improves patient outcome. © The Author(s) 2015.

E-1020, a water soluble imidazopyridine, has direct effects on Ca(2+)-dependent force and ATP hydrolysis of canine and bovine cardiac myofilaments.

Science.gov (United States)

Powers, F M; Palmiter, K A; Solaro, R J

1996-01-01

E-1020 is a cardiotonic agent that acts as a cyclic-AMP phosphodiesterase inhibitor but also may have actions which alter myofilament response to Ca2+. To identify direct actions of E-1020 on cardiac contractile proteins, effects of E-1020 on myofibrillar Ca2+ dependent MgATPase and force generation in chemically skinned fiber bundles were measured. In bovine cardiac myofibrils, E-1020 (100 microM) significantly increased myofilament Ca2+ sensitivity and Ca(2+)-dependent ATPase activity at submaximal pCa values. At pCa 6.75, E-1020 significantly increased ATPase activity in bovine (10-100 microM) and canine (1-100 microM) cardiac myofibrils but had no effect on rat cardiac myofibrils. Moreover, in one population of canine ventricular fiber bundles, E-1020 (0.01-10 microM) significantly increased isometric tension at pCa 6.5 and 6.0, whereas in another population of bundles E-1020 had no effect on tension. In no case was resting (pCa 8.0) or maximal tension (pCa 4.5) increased by E-1020. Measurements of Ca2+ binding to canine ventricular skinned fiber preparations demonstrated that E-1020 does not alter the affinity of myofilament troponin C for Ca2+. We conclude that part of the mechanism by which E-1020 acts as an inotropic agent may involve alterations in the responsiveness of contractile proteins to Ca2+. The lack of effect of E-1020 on some preparations may be dependent on isoform populations of myofilament proteins.

Mathematical cardiac electrophysiology

CERN Document Server

Colli Franzone, Piero; Scacchi, Simone

2014-01-01

This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

MicroRNA-155 attenuates late sepsis-induced cardiac dysfunction through JNK and β-arrestin 2.

Science.gov (United States)

Zhou, Yu; Song, Yan; Shaikh, Zahir; Li, Hui; Zhang, Haiju; Caudle, Yi; Zheng, Shouhua; Yan, Hui; Hu, Dan; Stuart, Charles; Yin, Deling

2017-07-18

Cardiac dysfunction is correlated with detrimental prognosis of sepsis and contributes to a high risk of mortality. After an initial hyperinflammatory reaction, most patients enter a protracted state of immunosuppression (late sepsis) that alters both innate and adaptive immunity. The changes of cardiac function in late sepsis are not yet known. MicroRNA-155 (miR-155) is previously found to play important roles in both regulations of immune activation and cardiac function. In this study, C57BL/6 mice were operated to develop into early and late sepsis phases, and miR-155 mimic was injected through the tail vein 48 h after cecal ligation and puncture (CLP). The effect of miR-155 on CLP-induced cardiac dysfunction was explored in late sepsis. We found that increased expression of miR-155 in the myocardium protected against cardiac dysfunction in late sepsis evidenced by attenuating sepsis-reduced cardiac output and enhancing left ventricular systolic function. We also observed that miR-155 markedly reduced the infiltration of macrophages and neutrophils into the myocardium and attenuated the inflammatory response via suppression of JNK signaling pathway. Moreover, overexpression of β-arrestin 2 (Arrb2) exacerbated the mice mortality and immunosuppression in late sepsis. Furthermore, transfection of miR-155 mimic reduced Arrb2 expression, and then restored immunocompetence and improved survival in late septic mice. We conclude that increased miR-155 expression through systemic administration of miR-155 mimic attenuates cardiac dysfunction and improves late sepsis survival by targeting JNK associated inflammatory signaling and Arrb2 mediated immunosuppression.

Energetic ions and electrons and their acceleration processes in the magnetotail

International Nuclear Information System (INIS)

Scholer, M.

1984-01-01

Observations of energetic particle fluxes in the geomagnetic tail show that these particles exhibit a bursty appearance on all time scales. Often, however, the bursty appearance is merely due to multiple entries and exits of the spacecraft into and out of the plasma sheet which always contains varying fluxes of energetic particles. Observations of the suprathermal and high-energy component of the plasma sheet are discussed, and observations are presented of energetic particle bursts in the plasma sheet proper, which may be due to a locally ongoing acceleration process. Also discussed are energetic particle phenomena occurring near the edge of the plasma sheet, either during thinning or during recovery. Some recent results from the ISEE 3 deep tail mission bearing on energetic particle acceleration are presented, and the present status of the theory of particle acceleration within the magnetotail is briefly reviewed. 40 references

Recent progress of hybrid simulation for energetic particles and MHD

International Nuclear Information System (INIS)

Todo, Y.

2013-01-01

Several hybrid simulation models have been constructed to study the evolution of Alfven eigenmodes destabilized by energetic particles. Recent hybrid simulation results of energetic particle driven instabilities are presented in this paper. (J.P.N.)

Resting spontaneous baroreflex sensitivity and cardiac autonomic control in anabolic androgenic steroid users

OpenAIRE

Santos, Marcelo R. dos; Sayegh, Ana L.C.; Armani, Rafael; Costa-Hong, Valéria; Souza, Francis R. de; Toschi-Dias, Edgar; Bortolotto, Luiz A.; Yonamine, Mauricio; Negrão, Carlos E.; Alves, Maria-Janieire N.N.

2018-01-01

OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, we tested whether anabolic androgenic steroids could impair resting baroreflex sensitivity and cardiac sympathovagal control. In addition, ...

Internal Transport Barrier Driven by Redistribution of Energetic Ions

International Nuclear Information System (INIS)

Wong, K.L.; Heidbrink, W.W.; Ruskov, E.; Petty, C.C.; Greenfield, C.M.; Nazikian, R.; Budny, R.

2004-01-01

Alfven instabilities excited by energetic ions are used as a means to reduce the central magnetic shear in a tokamak via redistribution of energetic ions. When the central magnetic shear is low enough, ballooning modes become stable for any plasma pressure gradient and an internal transport barrier (ITB) with a steep pressure gradient can exist. This mechanism can sustain a steady-state ITB as demonstrated by experimental data from the DIII-D tokamak. It can also produce a shear in toroidal and poloidal plasma rotation. Possible application of this technique to use the energetic alpha particles for improvement of burning plasma performance is discussed

Out-of-hospital cardiac arrest: determinant factors for immediate survival after cardiopulmonary resuscitation

Directory of Open Access Journals (Sweden)

Daniela Aparecida Morais

2014-08-01

Full Text Available OBJECTIVE: to analyze determinant factors for the immediate survival of persons who receive cardiopulmonary resuscitation from the advanced support units of the Mobile Emergency Medical Services (SAMU of Belo Horizonte.METHOD: this is a retrospective, epidemiological study which analyzed 1,165 assistance forms, from the period 2008 - 2010. The collected data followed the Utstein style, being submitted to descriptive and analytical statistics with tests with levels of significance of 5%.RESULTS: the majority were male, the median age was 64 years, and the ambulance response time, nine minutes. Immediate survival was observed in 239 persons. An association was ascertained of this outcome with "cardiac arrest witnessed by persons trained in basic life support" (OR=3.49; p<0.05; CI 95%, "cardiac arrest witnessed by Mobile Emergency Medical Services teams" (OR=2.99; p<0.05; CI95%, "only the carry out of basic life support" (OR=0.142; p<0.05; CI95%, and "initial cardiac rhythm of asystole" (OR=0.33; p<0.05; CI 95%.CONCLUSION: early access to cardiopulmonary resuscitation was related to a favorable outcome, and the non-undertaking of advanced support, and asystole, were associated with worse outcomes. Basic and advanced life support techniques can alter survival in the event of cardiac arrest.

Association between dental caries and out-of-hospital cardiac arrests of cardiac origin in Japan.

Science.gov (United States)

Suematsu, Yasunori; Miura, Shin-Ichiro; Zhang, Bo; Uehara, Yoshinari; Ogawa, Masahiro; Yonemoto, Naohiro; Nonogi, Hiroshi; Nagao, Ken; Kimura, Takeshi; Saku, Keijiro

2016-04-01

Oral infection contributes to atherosclerosis and coronary heart disease. We hypothesized that dental caries may be associated with out-of-hospital cardiac arrests (OHCA) of cardiac origin, but not non-cardiac origin. We compared the age-adjusted incidence of OHCA (785,591 cases of OHCA: 55.4% of cardiac origin and 44.6% of non-cardiac origin) to the age-adjusted prevalence of dental caries between 2005 and 2011 in the 47 prefectures of Japan. In both the total population and males over 65 years, the number of cases of dental caries was significantly associated with the number of OHCA of total and cardiac origin from 2005 to 2011, but not those of non-cardiac origin. In the total population, the age-adjusted prevalence of dental caries was not significantly associated with the age-adjusted incidence of OHCA (total OHCA: r correlation coefficient=0.22, p=0.14; OHCA of cardiac origin: r=0.25, p=0.09; OHCA of non-cardiac origin: r=-0.002, p=0.99). Among male patients over 65 years, the age-adjusted prevalence of dental caries was significantly associated with OHCA of total and cardiac origin, but not non-cardiac origin (total OHCA: r=0.47, p<0.001; OHCA of cardiac origin: r=0.37, p=0.01; OHCA of non-cardiac origin: r=0.28, p=0.054). While oral hygiene is important in all age groups, it may be particularly associated with OHCAs of cardiac origin in males over 65 years. Copyright © 2015. Published by Elsevier Ltd.

Exercise-related cardiac arrest in cardiac rehabilitation - The ...

African Journals Online (AJOL)

Prescribed physical activity plays a major role in the rehabilitation of patients with coronary artery disease, and as with any other form of treatment its benefits must be weighed against its possible risks. This study attempted to establish the safety of cardiac rehabilitation as a medical intervention at the Johannesburg Cardiac ...

Energetic Particles: From Sun to Heliosphere - and vice versa

Science.gov (United States)

Wimmer-Schweingruber, R. F.; Rodriguez-Pacheco, J.; Boden, S.; Boettcher, S. I.; Cernuda, I.; Dresing, N.; Drews, C.; Droege, W.; Espinosa Lara, F.; Gomez-Herrero, R.; Heber, B.; Ho, G. C.; Klassen, A.; Kulkarni, S. R.; Mann, G. J.; Martin-Garcia, C.; Mason, G. M.; Panitzsch, L.; Prieto, M.; Sanchez, S.; Terasa, C.; Eldrum, S.

2017-12-01

Energetic particles in the heliosphere can be measured at their elevated energetic status after three processes: injection, acceleration, and transport. Suprathermal seed particles have speeds well above the fast magnetosonic speed in the solar wind frame of reference and can vary from location to location and within the solar activity cycle. Acceleration sites include reconnecting current sheets in solar flares or magnetspheric boundaries, shocks in the solar corona, heliosphere and a planetary obstacles, as well as planetary magnetospheres. Once accelerated, particles are transported from the acceleration site into and through the heliosphere. Thus, by investigating properties of energetic particles such as their composition, energy spectra, pitch-angle distribution, etc. one can attempt to distinguish their origin or injection and acceleration site. This in turn allows us to better understand transport effects whose underlying microphysics is also a key ingredient in the acceleration of particles. In this presentation we will present some clear examples which link energetic particles from their observing site to their source locations. These include Jupiter electrons, singly-charged He ions from CIRs, and 3He from solar flares. We will compare these examples with the measurement capabilities of the Energetic Particle Detector (EPD) on Solar Orbiter and consider implications for the key science goal of Solar Orbiter and Solar Proble Plus - How the Sun creates and controls the heliosphere.

Sudden cardiac death

Directory of Open Access Journals (Sweden)

Neeraj Parakh

2015-01-01

Full Text Available Sudden cardiac death is one of the most common cause of mortality worldwide. Despite significant advances in the medical science, there is little improvement in the sudden cardiac death related mortality. Coronary artery disease is the most common etiology behind sudden cardiac death, in the above 40 years population. Even in the apparently healthy population, there is a small percentage of patients dying from sudden cardiac death. Given the large denominator, this small percentage contributes to the largest burden of sudden cardiac death. Identification of this at risk group among the apparently healthy individual is a great challenge for the medical fraternity. This article looks into the causes and methods of preventing SCD and at some of the Indian data. Details of Brugada syndrome, Long QT syndrome, Genetics of SCD are discussed. Recent guidelines on many of these causes are summarised.

Atmospheric CO2 enrichment alters energy assimilation, investment and allocation in Xanthium strumarium.

Science.gov (United States)

Nagel, Jennifer M; Wang, Xianzhong; Lewis, James D; Fung, Howard A; Tissue, David T; Griffin, Kevin L

2005-05-01

Energy-use efficiency and energy assimilation, investment and allocation patterns are likely to influence plant growth responses to increasing atmospheric CO2 concentration ([CO2]). Here, we describe the influence of elevated [CO2] on energetic properties as a mechanism of growth responses in Xanthium strumarium. Individuals of X. strumarium were grown at ambient or elevated [CO2] and harvested. Total biomass and energetic construction costs (CC) of leaves, stems, roots and fruits and percentage of total biomass and energy allocated to these components were determined. Photosynthetic energy-use efficiency (PEUE) was calculated as the ratio of total energy gained via photosynthetic activity (Atotal) to leaf CC. Elevated [CO2] increased leaf Atotal, but decreased CC per unit mass of leaves and roots. Consequently, X. strumarium individuals produced more leaf and root biomass at elevated [CO2] without increasing total energy investment in these structures (CCtotal). Whole-plant biomass was associated positively with PEUE. Whole-plant construction required 16.1% less energy than modeled whole-plant energy investment had CC not responded to increased [CO2]. As a physiological mechanism affecting growth, altered energetic properties could positively influence productivity of X. strumarium, and potentially other species, at elevated [CO2].

Lactate up-regulates the expression of lactate oxidation complex-related genes in left ventricular cardiac tissue of rats.

Directory of Open Access Journals (Sweden)

Daniele Gabriel-Costa

Full Text Available Besides its role as a fuel source in intermediary metabolism, lactate has been considered a signaling molecule modulating lactate-sensitive genes involved in the regulation of skeletal muscle metabolism. Even though the flux of lactate is significantly high in the heart, its role on regulation of cardiac genes regulating lactate oxidation has not been clarified yet. We tested the hypothesis that lactate would increase cardiac levels of reactive oxygen species and up-regulate the expression of genes related to lactate oxidation complex.Isolated hearts from male adult Wistar rats were perfused with control, lactate or acetate (20mM added Krebs-Henseleit solution during 120 min in modified Langendorff apparatus. Reactive oxygen species (O2●-/H2O2 levels, and NADH and NADPH oxidase activities (in enriched microsomal or plasmatic membranes, respectively were evaluated by fluorimetry while SOD and catalase activities were evaluated by spectrophotometry. mRNA levels of lactate oxidation complex and energetic enzymes MCT1, MCT4, HK, LDH, PDH, CS, PGC1α and COXIV were quantified by real time RT-PCR. Mitochondrial DNA levels were also evaluated. Hemodynamic parameters were acquired during the experiment. The key findings of this work were that lactate elevated cardiac NADH oxidase activity but not NADPH activity. This response was associated with increased cardiac O2●-/H2O2 levels and up-regulation of MCT1, MCT4, LDH and PGC1α with no changes in HK, PDH, CS, COXIV mRNA levels and mitochondrial DNA levels. Lactate increased NRF-2 nuclear expression and SOD activity probably as counter-regulatory responses to increased O2●-/H2O2.Our results provide evidence for lactate-induced up-regulation of lactate oxidation complex associated with increased NADH oxidase activity and cardiac O2●-/H2O2 driving to an anti-oxidant response. These results unveil lactate as an important signaling molecule regulating components of the lactate oxidation complex in

Patient position alters attenuation effects in multipinhole cardiac SPECT.

Science.gov (United States)

Timmins, Rachel; Ruddy, Terrence D; Wells, R Glenn

2015-03-01

Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of position-dependent changes were removed with attenuation correction. Translation of a source relative to a multipinhole camera caused only small changes in homogeneous phantoms with SPS changing position-dependent changes in attenuation.

Model applied to wistar rats for analysis of atrial alteration radioinduced: role of the TGFBeta1 cytokine on the lesions development

International Nuclear Information System (INIS)

Silva, Viviane Fernandes da; Andrade, Cherley Borba V. de; Nascimento, Ana Lucia Rosa do; Silva, Claudia Marcello da; Ribeiro, Andreia Fortes; Mandarim-de-Lacerda, Carlos Alberto; Carvalho, Jorge Jose de; Almeida, Carlos Eduardo de

2009-01-01

This paper develops a radiobiological model on Wistar rats for evaluation of atrium radioinduced alterations. Male Wistar rats were anaesthetised, immobilized and irradiated with 500, 1000 and 1500 cGy irradiated doses in the cardiac volume, pre-define through tomography. The animals were sacrificed after 15 days irradiation. The atriums were collected, fixed in formaldehyde and soaked into paraffin. A part of samples were dyed with hematoxyline-eosin (HE) and another submitted to immunohistochemistry for visualization of the cytokine TGFbeta1 expression. The observation of samples with HE indicated lesions om blood vessels and discrete inflamed infiltrated on some samples. The immunohistochemistry shown an intense expression of the TGFbeta1 cytokine, mainly on the only intine of the blood vessels. The data indicate that the atria develop alterations compatible to inflammatory answer as reaction to the damage caused by the tissue irradiation, and this answer is responsible by the production of TGFbeta1 cytokine, considered a cytokine pro-fibrotic on various models of cardiac disease. The lesions at atrium level can reflect on the correct functioning of the system generator of cardiac impulse, and can induce arrythmias and to prejudice the production of natriuretic peptides, molecules involved on the cardiac homeostasis

Moringa oleifera extract (Lam) attenuates Aluminium phosphide-induced acute cardiac toxicity in rats.

Science.gov (United States)

Gouda, Ahmed S; El-Nabarawy, Nagla A; Ibrahim, Samah F

2018-01-01

Moringa oleifera extract (Lam) has many antioxidant and protective properties. Objective: to investigate the antioxidant activities of Lam in counteracting the high oxidative stress caused by acute sub-lethal aluminium phosphide (AlP) intoxication in rat heart. These activities will be detected by histopathological examination and some oxidative stress biomarkers. a single sub-lethal dose of Alp (2 mg/kg body weight) was administered orally, and Lam was given orally at a dose (100 mg/kg body weight) one hour after receiving AlP to rats. aluminium phosphide caused significant cardiac histopathological changes with a significant increase in malondialdehyde (MDA); lipid peroxidation marker; and a significant depletion of antioxidant enzymes (catalase and glutathione reductase). However, treatment with Lam protected efficiently the cardiac tissue of intoxicated rats by increasing antioxidants levels with slight decreasing in MDA production compared to untreated group. This study suggested that Moringa oleifera extract could possibly restore the altered cardiac histopathology and some antioxidant power in AlP intoxicated rats, and it could even be used as adjuvant therapy against AlP-induced cardiotoxicity.

Energetics of dislocation transformations in hcp metals

International Nuclear Information System (INIS)

Wu, Zhaoxuan; Yin, Binglun; Curtin, W.A.

2016-01-01

Dislocation core structures of hcp metals are highly complex and differ significantly among the hcp family. Some dislocations undergo unconventional transformations that have significant effects on the material plastic flow. Here, the energetics of dislocation dissociations are analyzed in a general anisotropic linear elastic theory framework for transformations in which changes in the partial Burgers vectors are small. Quantitative analyses on various transformations are made using DFT-computed stacking fault energies and partial Burgers vectors. Specifically, possible transformations of the mixed, edge, and screw 〈c+a〉 and screw 〈a〉 dislocations in 6 hcp metals (Mg, Ti, Zr, Re, Zn, Cd) are studied. Climb dissociation of mixed or edge 〈c+a〉 dislocations to the Basal plane is energetically favorable in all 6 metals and thus only limited by thermal activation. The 〈c+a〉 screw dislocation is energetically preferable on Pyramidal I for Ti, Zr, and Re, and on Pyramidal II for Zn and Cd. In Mg, the energy difference between screw 〈c+a〉 on Pyramidal I and II planes is small, suggesting relatively easy cross-slip. For the screw 〈a〉, Basal dissociation is energetically favorable in Mg, Re, Zn and Cd, while Prism dissociation is strongly favorable in Ti and Zr. Only Ti, Zr and Re show a metastable state for dissociation on the Prism plane, and the energy difference between screw 〈a〉 on the Prism and Pyramidal I planes is relatively small in all systems, suggesting relatively easy cross-slip of 〈a〉 in Ti and Zr. The elastic analysis thus provides a single framework able to capture the controlling energetics for different dissociations and slip systems in hcp metals. When the calculated energy differences are very small, the results point to the need for detailed modeling of the atomistic core structure. Moreover, the analyses rationalize broad experimental observations on dominant slip systems and dislocation behaviours, and provide

Investigation of energetic particle induced geodesic acoustic mode

Science.gov (United States)

Schneller, Mirjam; Fu, Guoyong; Chavdarovski, Ilija; Wang, Weixing; Lauber, Philipp; Lu, Zhixin

2017-10-01

Energetic particles are ubiquitous in present and future tokamaks due to heating systems and fusion reactions. Anisotropy in the distribution function of the energetic particle population is able to excite oscillations from the continuous spectrum of geodesic acoustic modes (GAMs), which cannot be driven by plasma pressure gradients due to their toroidally and nearly poloidally symmetric structures. These oscillations are known as energetic particle-induced geodesic acoustic modes (EGAMs) [G.Y. Fu'08] and have been observed in recent experiments [R. Nazikian'08]. EGAMs are particularly attractive in the framework of turbulence regulation, since they lead to an oscillatory radial electric shear which can potentially saturate the turbulence. For the presented work, the nonlinear gyrokinetic, electrostatic, particle-in-cell code GTS [W.X. Wang'06] has been extended to include an energetic particle population following either bump-on-tail Maxwellian or slowing-down [Stix'76] distribution function. With this new tool, we study growth rate, frequency and mode structure of the EGAM in an ASDEX Upgrade-like scenario. A detailed understanding of EGAM excitation reveals essential for future studies of EGAM interaction with micro-turbulence. Funded by the Max Planck Princeton Research Center. Computational resources of MPCDF and NERSC are greatefully acknowledged.

Respiratory muscle strength is not decreased in patients undergoing cardiac surgery.

Science.gov (United States)

Urell, Charlotte; Emtner, Margareta; Hedenstrom, Hans; Westerdahl, Elisabeth

2016-03-31

Postoperative pulmonary impairments are significant complications after cardiac surgery. Decreased respiratory muscle strength could be one reason for impaired lung function in the postoperative period. The primary aim of this study was to describe respiratory muscle strength before and two months after cardiac surgery. A secondary aim was to describe possible associations between respiratory muscle strength and lung function. In this prospective observational study 36 adult cardiac surgery patients (67 ± 10 years) were studied. Respiratory muscle strength and lung function were measured before and two months after surgery. Pre- and postoperative respiratory muscle strength was in accordance with predicted values; MIP was 78 ± 24 cmH2O preoperatively and 73 ± 22 cmH2O at two months follow-up (p = 0.19). MEP was 122 ± 33 cmH2O preoperatively and 115 ± 38 cmH2O at two months follow-up (p = 0.18). Preoperative lung function was in accordance with predicted values, but was significantly decreased postoperatively. At two-months follow-up there was a moderate correlation between MIP and FEV1 (r = 0.43, p = 0.009). Respiratory muscle strength was not impaired, either before or two months after cardiac surgery. The reason for postoperative lung function alteration is not yet known. Interventions aimed at restore an optimal postoperative lung function should focus on other interventions then respiratory muscle strength training.

Cancer-induced cardiac cachexia: Pathogenesis and impact of physical activity (Review).

Science.gov (United States)

Belloum, Yassine; Rannou-Bekono, Françoise; Favier, François B

2017-05-01

Cachexia is a wasting syndrome observed in many patients suffering from several chronic diseases including cancer. In addition to the progressive loss of skeletal muscle mass, cancer cachexia results in cardiac function impairment. During the severe stage of the disease, patients as well as animals bearing cancer cells display cardiac atrophy. Cardiac energy metabolism is also impeded with disruption of mitochondrial homeostasis and reduced oxidative capacity, although the available data remain equivocal. The release of inflammatory cytokines by tumor is a key mechanism in the initiation of heart failure. Oxidative stress, which results from the combination of chemotherapy, inadequate antioxidant consumption and chronic inflammation, will further foster heart failure. Protein catabolism is due to the concomitant activation of proteolytic systems and inhibition of protein synthesis, both processes being triggered by the deactivation of the Akt/mammalian target of rapamycin pathway. The reduction in oxidative capacity involves AMP-activated protein kinase and peroxisome proliferator-activated receptor gamma coactivator 1α dysregulation. The nuclear factor-κB transcription factor plays a prominent role in the coordination of these alterations. Physical exercise appears as an interesting non-pharmaceutical way to counteract cancer cachexia-induced-heart failure. Indeed, aerobic training has anti-inflammatory effects, increases anti-oxidant defenses, prevents atrophy and promotes oxidative metabolism. The present review points out the importance of better understanding the concurrent structural and metabolic changes within the myocardium during cancer and the protective effects of exercise against cardiac cachexia.

The heartbreak of depression: 'Psycho-cardiac' coupling in myocardial infarction.

Science.gov (United States)

Headrick, John P; Peart, Jason N; Budiono, Boris P; Shum, David H K; Neumann, David L; Stapelberg, Nicolas J C

2017-05-01

Ample evidence identifies strong links between major depressive disorder (MDD) and both risk of ischemic or coronary heart disease (CHD) and resultant morbidity and mortality. The molecular mechanistic bases of these linkages are poorly defined. Systemic factors linked to MDD, including vascular dysfunction, atherosclerosis, obesity and diabetes, together with associated behavioral changes, all elevate CHD risk. Nonetheless, experimental evidence indicates the myocardium is also directly modified in depression, independently of these factors, impairing infarct tolerance and cardioprotection. It may be that MDD effectively breaks the heart's intrinsic defense mechanisms. Four extrinsic processes are implicated in this psycho-cardiac coupling, presenting potential targets for therapeutic intervention if causally involved: sympathetic over-activity vs. vagal under-activity, together with hypothalamic-pituitary-adrenal (HPA) axis and immuno-inflammatory dysfunctions. However, direct evidence of their involvement remains limited, and whether targeting these upstream mediators is effective (or practical) in limiting the cardiac consequences of MDD is unknown. Detailing myocardial phenotype in MDD can also inform approaches to cardioprotection, yet cardiac molecular changes are similarly ill defined. Studies support myocardial sensitization to ischemic insult in models of MDD, including worsened oxidative and nitrosative damage, apoptosis (with altered Bcl-2 family expression) and infarction. Moreover, depression may de-sensitize hearts to protective conditioning stimuli. The mechanistic underpinnings of these changes await delineation. Such information not only advances our fundamental understanding of psychological determinants of health, but also better informs management of the cardiac consequences of MDD and implementing cardioprotection in this cohort. Copyright © 2017 Elsevier Ltd. All rights reserved.

Premature Ventricular Contraction Coupling Interval Variability Destabilizes Cardiac Neuronal and Electrophysiological Control: Insights From Simultaneous Cardioneural Mapping.

Science.gov (United States)

Hamon, David; Rajendran, Pradeep S; Chui, Ray W; Ajijola, Olujimi A; Irie, Tadanobu; Talebi, Ramin; Salavatian, Siamak; Vaseghi, Marmar; Bradfield, Jason S; Armour, J Andrew; Ardell, Jeffrey L; Shivkumar, Kalyanam

2017-04-01

Variability in premature ventricular contraction (PVC) coupling interval (CI) increases the risk of cardiomyopathy and sudden death. The autonomic nervous system regulates cardiac electrical and mechanical indices, and its dysregulation plays an important role in cardiac disease pathogenesis. The impact of PVCs on the intrinsic cardiac nervous system, a neural network on the heart, remains unknown. The objective was to determine the effect of PVCs and CI on intrinsic cardiac nervous system function in generating cardiac neuronal and electric instability using a novel cardioneural mapping approach. In a porcine model (n=8), neuronal activity was recorded from a ventricular ganglion using a microelectrode array, and cardiac electrophysiological mapping was performed. Neurons were functionally classified based on their response to afferent and efferent cardiovascular stimuli, with neurons that responded to both defined as convergent (local reflex processors). Dynamic changes in neuronal activity were then evaluated in response to right ventricular outflow tract PVCs with fixed short, fixed long, and variable CI. PVC delivery elicited a greater neuronal response than all other stimuli ( P <0.001). Compared with fixed short and long CI, PVCs with variable CI had a greater impact on neuronal response ( P <0.05 versus short CI), particularly on convergent neurons ( P <0.05), as well as neurons receiving sympathetic ( P <0.05) and parasympathetic input ( P <0.05). The greatest cardiac electric instability was also observed after variable (short) CI PVCs. Variable CI PVCs affect critical populations of intrinsic cardiac nervous system neurons and alter cardiac repolarization. These changes may be critical for arrhythmogenesis and remodeling, leading to cardiomyopathy. © 2017 American Heart Association, Inc.

Update on the slow delayed rectifier potassium current (I(Ks)): role in modulating cardiac function.

Science.gov (United States)

Liu, Zhenzhen; Du, Lupei; Li, Minyong

2012-01-01

The slow delayed rectifier current (I(Ks)) is the slow component of cardiac delayed rectifier current and is critical for the late phase repolarization of cardiac action potential. This current is also an important target for Sympathetic Nervous System (SNS) to regulate the cardiac electivity to accommodate to heart rate alterations in response to exercise or emotional stress and can be up-regulated by β- adrenergic or other signal molecules. I(Ks) channel is originated by the co-assembly of pore-forming KCNQ1 α-subunit and accessory KCNE1 β-subunit. Mutations in any subunit can bring about severe long QT syndrome (LQT-1, LQT-5) as characterized by deliquium, seizures and sudden death. This review summarizes the normal physiological functions and molecular basis of I(Ks) channels, as well as illustrates up-to-date development on its blockers and activators. Therefore, the current extensive survey should generate fundamental understanding of the role of I(Ks) channel in modulating cardiac function and donate some instructions to the progression of I(Ks) blockers and activators as potential antiarrhythmic agents or pharmacological tools to determine the physiological and pathological function of I(Ks).

Slow [Na+]i dynamics impacts arrhythmogenesis and spiral wave reentry in cardiac myocyte ionic model.

Science.gov (United States)

Krogh-Madsen, Trine; Christini, David J

2017-09-01

Accumulation of intracellular Na + is gaining recognition as an important regulator of cardiac myocyte electrophysiology. The intracellular Na + concentration can be an important determinant of the cardiac action potential duration, can modulate the tissue-level conduction of excitation waves, and can alter vulnerability to arrhythmias. Mathematical models of cardiac electrophysiology often incorporate a dynamic intracellular Na + concentration, which changes much more slowly than the remaining variables. We investigated the dependence of several arrhythmogenesis-related factors on [Na + ] i in a mathematical model of the human atrial action potential. In cell simulations, we found that [Na + ] i accumulation stabilizes the action potential duration to variations in several conductances and that the slow dynamics of [Na + ] i impacts bifurcations to pro-arrhythmic afterdepolarizations, causing intermittency between different rhythms. In long-lasting tissue simulations of spiral wave reentry, [Na + ] i becomes spatially heterogeneous with a decreased area around the spiral wave rotation center. This heterogeneous region forms a functional anchor, resulting in diminished meandering of the spiral wave. Our findings suggest that slow, physiological, rate-dependent variations in [Na + ] i may play complex roles in cellular and tissue-level cardiac dynamics.

Analysis and verification of a prediction model of solar energetic proton events

Science.gov (United States)

Wang, J.; Zhong, Q.

2017-12-01

The solar energetic particle event can cause severe radiation damages near Earth. The alerts and summary products of the solar energetic proton events were provided by the Space Environment Prediction Center (SEPC) according to the flux of the greater than 10 MeV protons taken by GOES satellite in geosynchronous orbit. The start of a solar energetic proton event is defined as the time when the flux of the greater than 10 MeV protons equals or exceeds 10 proton flux units (pfu). In this study, a model was developed to predict the solar energetic proton events, provide the warning for the solar energetic proton events at least minutes in advance, based on both the soft X-ray flux and integral proton flux taken by GOES. The quality of the forecast model was measured against verifications of accuracy, reliability, discrimination capability, and forecast skills. The peak flux and rise time of the solar energetic proton events in the six channels, >1MeV, >5 MeV, >10 MeV, >30 MeV, >50 MeV, >100 MeV, were also simulated and analyzed.

Titin isoform switching is a major cardiac adaptive response in hibernating grizzly bears.

Science.gov (United States)

Nelson, O Lynne; Robbins, Charles T; Wu, Yiming; Granzier, Henk

2008-07-01

The hibernation phenomenon captures biological as well as clinical interests to understand how organs adapt. Here we studied how hibernating grizzly bears (Ursus arctos horribilis) tolerate extremely low heart rates without developing cardiac chamber dilation. We evaluated cardiac filling function in unanesthetized grizzly bears by echocardiography during the active and hibernating period. Because both collagen and titin are involved in altering diastolic function, we investigated both in the myocardium of active and hibernating grizzly bears. Heart rates were reduced from 84 beats/min in active bears to 19 beats/min in hibernating bears. Diastolic volume, stroke volume, and left ventricular ejection fraction were not different. However, left ventricular muscle mass was significantly lower (300 +/- 12 compared with 402 +/- 14 g; P = 0.003) in the hibernating bears, and as a result the diastolic volume-to-left ventricular muscle mass ratio was significantly greater. Early ventricular filling deceleration times (106.4 +/- 14 compared with 143.2 +/- 20 ms; P = 0.002) were shorter during hibernation, suggesting increased ventricular stiffness. Restrictive pulmonary venous flow patterns supported this conclusion. Collagen type I and III comparisons did not reveal differences between the two groups of bears. In contrast, the expression of titin was altered by a significant upregulation of the stiffer N2B isoform at the expense of the more compliant N2BA isoform. The mean ratio of N2BA to N2B titin was 0.73 +/- 0.07 in the active bears and decreased to 0.42 +/- 0.03 (P = 0.006) in the hibernating bears. The upregulation of stiff N2B cardiac titin is a likely explanation for the increased ventricular stiffness that was revealed by echocardiography, and we propose that it plays a role in preventing chamber dilation in hibernating grizzly bears. Thus our work identified changes in the alternative splicing of cardiac titin as a major adaptive response in hibernating grizzly

Dual scattering foil design for poly-energetic electron beams

International Nuclear Information System (INIS)

Kainz, K K; Antolak, J A; Almond, P R; Bloch, C D; Hogstrom, K R

2005-01-01

The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm 2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly-energetic

Recurrent late cardiac tamponade following cardiac surgery : a deceiving and potentially lethal complication

NARCIS (Netherlands)

Harskamp, Ralf E.; Meuzelaar, Jacobus J.

2010-01-01

Background - Cardiac tamponade, characterized by inflow obstruction of the heart chambers by extracardiac compression, is a potentially lethal complication following cardiac surgery. Case report - We present a case of recurrent cardiac tamponade following valve surgery. At first presentation,

Effects of cigarette smoking on cardiac autonomic function during dynamic exercise.

Science.gov (United States)

Mendonca, Goncalo V; Pereira, Fernando D; Fernhall, Bo

2011-06-01

The purpose of this study was to investigate the acute effect of cigarette smoking on cardiac autonomic function in young adult smokers during dynamic exercise. Fourteen healthy young smokers (21.4 ± 3.4 years) performed peak and submaximal exercise protocols under control and smoking conditions. Resting and submaximal beat-to-beat R-R series were recorded and spectrally decomposed using the fast Fourier transformation. Smoking resulted in a significant decrease in work time, VO(2peak) and peak O(2) pulse (P exercise after smoking (P smoking, both at rest and during exercise (P smoking (P smoking, but only at rest (P smoking is accompanied by acute changes in heart rate spectral components both at rest and during exercise. Therefore, the cardiac autonomic control is altered by smoking not only at rest, but also during exercise, resulting in reduced vagal modulation and increased sympathetic dominance.

Ecstasy (MDMA) Alters Cardiac Gene Expression and DNA Methylation: Implications for Circadian Rhythm Dysfunction in the Heart.

Science.gov (United States)

Koczor, Christopher A; Ludlow, Ivan; Hight, Robert S; Jiao, Zhe; Fields, Earl; Ludaway, Tomika; Russ, Rodney; Torres, Rebecca A; Lewis, William

2015-11-01

MDMA (ecstasy) is an illicit drug that stimulates monoamine neurotransmitter release and inhibits reuptake. MDMA's acute cardiotoxicity includes tachycardia and arrhythmia which are associated with cardiomyopathy. MDMA acute cardiotoxicity has been explored, but neither long-term MDMA cardiac pathological changes nor epigenetic changes have been evaluated. Microarray analyses were employed to identify cardiac gene expression changes and epigenetic DNA methylation changes. To identify permanent MDMA-induced pathogenetic changes, mice received daily 10- or 35-day MDMA, or daily 10-day MDMA followed by 25-day saline washout (10 + 25 days). MDMA treatment caused differential gene expression (p 1.5) in 752 genes following 10 days, 558 genes following 35 days, and 113 genes following 10-day MDMA + 25-day saline washout. Changes in MAPK and circadian rhythm gene expression were identified as early as 10 days. After 35 days, circadian rhythm genes (Per3, CLOCK, ARNTL, and NPAS2) persisted to be differentially expressed. MDMA caused DNA hypermethylation and hypomethylation that was independent of gene expression; hypermethylation of genes was found to be 71% at 10 days, 68% at 35 days, and 91% at 10 + 25 days washout. Differential gene expression paralleled DNA methylation in 22% of genes at 10-day treatment, 17% at 35 days, and 48% at 10 + 25 days washout. We show here that MDMA induced cardiac epigenetic changes in DNA methylation where hypermethylation predominated. Moreover, MDMA induced gene expression of key elements of circadian rhythm regulatory genes. This suggests a fundamental organism-level event to explain some of the etiologies of MDMA dysfunction in the heart. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cardiac macrophages adopt profibrotic/M2 phenotype in infarcted hearts: Role of urokinase plasminogen activator.

Science.gov (United States)

Carlson, Signe; Helterline, Deri; Asbe, Laura; Dupras, Sarah; Minami, Elina; Farris, Stephen; Stempien-Otero, April

2017-07-01

Macrophages (mac) that over-express urokinase plasminogen activator (uPA) adopt a profibrotic M2 phenotype in the heart in association with cardiac fibrosis. We tested the hypothesis that cardiac macs are M2 polarized in infarcted mouse and human hearts and that polarization is dependent on mac-derived uPA. Studies were performed using uninjured (UI) or infarcted (MI) hearts of uPA overexpressing (SR-uPA), uPA null, or nontransgenic littermate (Ntg) mice. At 7days post-infarction, cardiac mac were isolated, RNA extracted and M2 markers Arg1, YM1, and Fizz1 measured with qrtPCR. Histologic analysis for cardiac fibrosis, mac and myofibroblasts was performed at the same time-point. Cardiac macs were also isolated from Ntg hearts and RNA collected after primary isolation or culture with vehicle, IL-4 or plasmin and M2 marker expression measured. Cardiac tissue and blood was collected from humans with ischemic heart disease. Expression of M2 marker CD206 and M1 marker TNFalpha was measured. Macs from WT mice had increased expression of Arg1 and Ym1 following MI (41.3±6.5 and 70.3±36, fold change vs UI, n=8, Padopt a M2 phenotype in association with fibrosis. Plasmin can induce an M2 phenotype in cardiac macs. However, M2 activation can occur in the heart in vivo in the absence of uPA indicating that alternative pathways to activate plasmin are present in the heart. Excess uPA promotes increased fibroblast density potentially via potentiating fibroblast migration or proliferation. Altering macrophage phenotype in the heart is a potential target to modify cardiac fibrosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inferring repeat-protein energetics from evolutionary information.

Directory of Open Access Journals (Sweden)

Rocío Espada

2017-06-01

Full Text Available Natural protein sequences contain a record of their history. A common constraint in a given protein family is the ability to fold to specific structures, and it has been shown possible to infer the main native ensemble by analyzing covariations in extant sequences. Still, many natural proteins that fold into the same structural topology show different stabilization energies, and these are often related to their physiological behavior. We propose a description for the energetic variation given by sequence modifications in repeat proteins, systems for which the overall problem is simplified by their inherent symmetry. We explicitly account for single amino acid and pair-wise interactions and treat higher order correlations with a single term. We show that the resulting evolutionary field can be interpreted with structural detail. We trace the variations in the energetic scores of natural proteins and relate them to their experimental characterization. The resulting energetic evolutionary field allows the prediction of the folding free energy change for several mutants, and can be used to generate synthetic sequences that are statistically indistinguishable from the natural counterparts.

Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

Science.gov (United States)

Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

2016-09-01

Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and

Prenatal exposure to dexamethasone in the mouse alters cardiac growth patterns and increases pulse pressure in aged male offspring.

Directory of Open Access Journals (Sweden)

Lee O'Sullivan

Full Text Available Exposure to synthetic glucocorticoids during development can result in later cardiovascular and renal disease in sheep and rats. Although prenatal glucocorticoid exposure is associated with impaired renal development, less is known about effects on the developing heart. This study aimed to examine the effects of a short-term exposure to dexamethasone (60 hours from embryonic day 12.5 on the developing mouse heart, and cardiovascular function in adult male offspring. Dexamethasone (DEX exposed fetuses were growth restricted compared to saline treated controls (SAL at E14.5, but there was no difference between groups at E17.5. Heart weights of the DEX fetuses also tended to be smaller at E14.5, but not different at E17.5. Cardiac AT1aR, Bax, and IGF-1 mRNA expression was significantly increased by DEX compared to SAL at E17.5. In 12-month-old offspring DEX exposure caused an increase in basal blood pressure of ~3 mmHg. In addition, DEX exposed mice had a widened pulse pressure compared to SAL. DEX exposed males at 12 months had an approximate 25% reduction in nephron number compared to SAL, but no difference in cardiomyocyte number. Exposure to DEX in utero appears to adversely impact on nephrogenesis and heart growth but is not associated with a cardiomyocyte deficit in male mice in adulthood, possibly due to compensatory growth of the myocardium following the initial insult. However, the widened pulse pressure may be indicative of altered vascular compliance.

Small cardiac lesions: fibrosis of papillary muscles and focal cardiac myocytolysis

Energy Technology Data Exchange (ETDEWEB)

Steer, A [Hijiyanna Park, Hiroshima JP; Nakashima, N; Kawashima, T; Lee, K K; Danzig, M D; Robertson, T L; Dock, D S

1977-11-01

Three types of small cardiac lesions were described and illustrated: (1) focal type of papillary muscle fibrosis, evidently a healed infarct of the papillary muscle present in 13% of the autopsies, is a histologically characteristic lesion associated with coronary artery disease and healed myocardial infarction; (2) diffuse type of papillary muscle fibrosis, probably an aging change present in almost half of the autopsies, is associated with sclerosis of the arteries in the papillary muscle, is identifiable histologically; and apparently is not associated with any cardiac abnormality; and (3) focal cardiac myocytolysis, a unique histologic lesion, usually multifocal without predilection for any area of the heart, is associated with ischemic heart disease, death due to cancer complicated by non-bacterial thrombotic endocarditis and microthrombi in small cardiac arteries as well as with other diseases. Differentiation of the 2 types of papillary muscle fibrosis is important in the study of papillary muscle and mitral valve dysfunction. Focal cardiac myocytolysis may contribute to the fatal extension of myocardial infarcts.

Small cardiac lesions: fibrosis of papillary muscles and focal cardiac myocytolysis

Energy Technology Data Exchange (ETDEWEB)

Steer, A; Nakashima, T; Kawashima, T; Lee, K K; Danzig, M D; Robertson, T L; Dock, D S

1977-11-01

Three types of small cardiac lesions were described and illustrated: (1) focal type of papillary muscle fibrosis, evidently a healed infarct of the papillary muscle present in 13% of the autopsies, is a histologically characteristic lesion associated with coronary artery disease and healed myocardial infarction, (2) diffuse type of papillary muscle fibrosis, probably an aging change present in almost half of the autopsies, is associated with sclerosis of the arteries in the papillary muscle, is identifiable histologically, and apparently is not associated with any cardiac abnormality, and (3) focal cardiac myochtolysis, a unique histologic lesion, usually multifocal without predilection for any area of the heart, is associated with ischemic heart disease, death due to cancer complicated by nonbacterial thrombotic endocarditis and microthrombi in small cardiac arteries as well as with other diseases. Differentiation of the 2 types of papillary muscle fibrosis is important in the study of papillary muscle and mitral valve dysfunction. Focal cardiac myocytolysis may contribute to the fatal extension of myocardial infarcts.

Recurrent late cardiac tamponade following cardiac surgery: a deceiving and potentially lethal complication

NARCIS (Netherlands)

Harskamp, Ralf E.; Meuzelaar, Jacobus J.

2010-01-01

Cardiac tamponade, characterized by inflow obstruction of the heart chambers by extracardiac compression, is a potentially lethal complication following cardiac surgery. We present a case of recurrent cardiac tamponade following valve surgery. At first presentation, diagnosis was delayed because of

Electrocardiographic and Blood Pressure Alterations During Electroconvulsive Therapy in Young Adults

Directory of Open Access Journals (Sweden)

Rumi Demetrio Ortega

2002-01-01

Full Text Available OBJECTIVE - To study cardiovascular alterations in young patients with no apparent organic disease who underwent electroconvulsive therapy. METHODS - The study comprised 47 healthy patients (22 males and 25 females with a mean age of 30.3 years, who underwent electroconvulsive therapy. Ambulatory blood pressure monitoring and continuous electrocardiographic monitoring (Holter monitor were performed during 24 hours. Blood pressure and heart rate were assessed 4 hours prior to electric shock administration, during electric shock administration, and 3 hours after electric shock administration. Arrhythmias and alterations in the ST segment in 24 hours were recorded. RESULTS - On electroconvulsive therapy, a significant increase in blood pressure and heart rate was observed and the measurements returned to basal values after 25 minutes. Three females had tracings with depression of the ST segment suggesting myocardial ischemia prior to and after electroconvulsive therapy. Coronary angiography was normal. No severe cardiac arrhythmias were diagnosed. CONCLUSION - 1 Electroconvulsive therapy is a safe therapeutic modality in psychiatry; 2 it causes a significant increase in blood pressure and heart rate; 3 it may be associated with myocardial ischemia in the absence of coronary obstructive disease; 4 electroconvulsive therapy was not associated with the occurrence of severe cardiac arrhythmias.

Cardiomyocyte specific expression of Acyl-coA thioesterase 1 attenuates sepsis induced cardiac dysfunction and mortality

Energy Technology Data Exchange (ETDEWEB)

Xia, Congying [Departments of Internal Medicine and Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Dong, Ruolan [Department of Geriatric Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China); Chen, Chen [Departments of Internal Medicine and Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wang, Hong, E-mail: hong.wang1988@yahoo.com [Departments of Internal Medicine and Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wang, Dao Wen, E-mail: dwwang@tjh.tjmu.edu.cn [Departments of Internal Medicine and Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)

2015-12-25

Compromised cardiac fatty acid oxidation (FAO) induced energy deprivation is a critical cause of cardiac dysfunction in sepsis. Acyl-CoA thioesterase 1 (ACOT1) is involved in regulating cardiac energy production via altering substrate metabolism. This study aims to clarify whether ACOT1 has a potency to ameliorate septic myocardial dysfunction via enhancing cardiac FAO. Transgenic mice with cardiomyocyte specific expression of ACOT1 (αMHC-ACOT1) and their wild type (WT) littermates were challenged with Escherichia coli lipopolysaccharide (LPS; 5 mg/kg i.p.) and myocardial function was assessed 6 h later using echocardiography and hemodynamics. Deteriorated cardiac function evidenced by reduction of the percentage of left ventricular ejection fraction and fractional shortening after LPS administration was significantly attenuated by cardiomyocyte specific expression of ACOT1. αMHC-ACOT1 mice exhibited a markedly increase in glucose utilization and cardiac FAO compared with LPS-treated WT mice. Suppression of cardiac peroxisome proliferator activated receptor alpha (PPARa) and PPARγ-coactivator-1α (PGC1a) signaling observed in LPS-challenged WT mice was activated by the presence of ACOT1. These results suggest that ACOT1 has potential therapeutic values to protect heart from sepsis mediated dysfunction, possibly through activating PPARa/PGC1a signaling. - Highlights: • ACOT1 has potential therapeutic values to protect heart from sepsis mediated dysfunction. • ACOT1 can regulate PPARa/PGC1a signaling pathway. • We first generate the transgenic mice with cardiomyocyte specific expression of ACOT1.

Cardiomyocyte specific expression of Acyl-coA thioesterase 1 attenuates sepsis induced cardiac dysfunction and mortality

International Nuclear Information System (INIS)

Xia, Congying; Dong, Ruolan; Chen, Chen; Wang, Hong; Wang, Dao Wen

2015-01-01

Compromised cardiac fatty acid oxidation (FAO) induced energy deprivation is a critical cause of cardiac dysfunction in sepsis. Acyl-CoA thioesterase 1 (ACOT1) is involved in regulating cardiac energy production via altering substrate metabolism. This study aims to clarify whether ACOT1 has a potency to ameliorate septic myocardial dysfunction via enhancing cardiac FAO. Transgenic mice with cardiomyocyte specific expression of ACOT1 (αMHC-ACOT1) and their wild type (WT) littermates were challenged with Escherichia coli lipopolysaccharide (LPS; 5 mg/kg i.p.) and myocardial function was assessed 6 h later using echocardiography and hemodynamics. Deteriorated cardiac function evidenced by reduction of the percentage of left ventricular ejection fraction and fractional shortening after LPS administration was significantly attenuated by cardiomyocyte specific expression of ACOT1. αMHC-ACOT1 mice exhibited a markedly increase in glucose utilization and cardiac FAO compared with LPS-treated WT mice. Suppression of cardiac peroxisome proliferator activated receptor alpha (PPARa) and PPARγ-coactivator-1α (PGC1a) signaling observed in LPS-challenged WT mice was activated by the presence of ACOT1. These results suggest that ACOT1 has potential therapeutic values to protect heart from sepsis mediated dysfunction, possibly through activating PPARa/PGC1a signaling. - Highlights: • ACOT1 has potential therapeutic values to protect heart from sepsis mediated dysfunction. • ACOT1 can regulate PPARa/PGC1a signaling pathway. • We first generate the transgenic mice with cardiomyocyte specific expression of ACOT1.

Alterations in rat cardiac myosin isozymes induced by whole-body irradiation are prevented by 3,5,3'-L-triiodothyronine

Energy Technology Data Exchange (ETDEWEB)

Litten, R.Z.; Fein, H.G.; Gainey, G.T.; Walden, T.L.; Smallridge, R.C. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

1990-01-01

Changes in cardiac myosin isozymes and serum thyroid hormone levels were investigated in rats following 10 Gy whole-body gamma irradiation. The percent beta-myosin heavy chain increased from 21.3 {plus minus} 1.8 to 28.1 {plus minus} 6.8 (NS) at 3-day postirradiation, 37.7 {plus minus} 1.9 (P less than .001) at 6-day postirradiation, and 43.8 {plus minus} 3.3 (P less than .001) at 9-day postirradiation. Along with the change in myosin isozymes was a significant 53% decrease (P less than .001) in the serum thyroxine (T4) level by day 3 postirradiation, remaining depressed through day 9 postirradiation. The serum 3,5,3'-triiodothyronine (T3) level, however, was normal until day 9, when significant depression was also observed. In contrast, the thyroid-stimulating hormone (TSH) level was significantly increased by fourfold at day 3, returning to near normal values by day 9 postirradiation. Daily injections of physiological doses of T3 (0.3 microgram/100 g body weight) prevented the change in the myosin isozymes following whole-body irradiation. Daily pharmacological injections of T3 (3.0 micrograms/100 g body weight) to the irradiated rats produced a further decrease in the percent beta-myosin heavy chain (below control values) indicating tissue hyperthyroidism. Thus, this study suggests that the change in myosin isozymes following whole-body irradiation is caused by an alteration in thyroid hormone activity.

Decreased adrenoceptor stimulation in heart failure rats reduces NGF expression by cardiac parasympathetic neurons.

Science.gov (United States)

Hasan, Wohaib; Smith, Peter G

2014-04-01

Postganglionic cardiac parasympathetic and sympathetic nerves are physically proximate in atrial cardiac tissue allowing reciprocal inhibition of neurotransmitter release, depending on demands from central cardiovascular centers or reflex pathways. Parasympathetic cardiac ganglion (CG) neurons synthesize and release the sympathetic neurotrophin nerve growth factor (NGF), which may serve to maintain these close connections. In this study we investigated whether NGF synthesis by CG neurons is altered in heart failure, and whether norepinephrine from sympathetic neurons promotes NGF synthesis. NGF and proNGF immunoreactivity in CG neurons in heart failure rats following chronic coronary artery ligation was investigated. NGF immunoreactivity was decreased significantly in heart failure rats compared to sham-operated animals, whereas proNGF expression was unchanged. Changes in neurochemistry of CG neurons included attenuated expression of the cholinergic marker vesicular acetylcholine transporter, and increased expression of the neuropeptide vasoactive intestinal polypeptide. To further investigate norepinephrine's role in promoting NGF synthesis, we cultured CG neurons treated with adrenergic receptor (AR) agonists. An 82% increase in NGF mRNA levels was detected after 1h of isoproterenol (β-AR agonist) treatment, which increased an additional 22% at 24h. Antagonist treatment blocked isoproterenol-induced increases in NGF transcripts. In contrast, the α-AR agonist phenylephrine did not alter NGF mRNA expression. These results are consistent with β-AR mediated maintenance of NGF synthesis in CG neurons. In heart failure, a decrease in NGF synthesis by CG neurons may potentially contribute to reduced connections with adjacent sympathetic nerves. Copyright © 2013 Elsevier B.V. All rights reserved.

Diffuse infiltrative cardiac tuberculosis

International Nuclear Information System (INIS)

Gulati, Gurpreet S; Kothari, Shyam S

2011-01-01

We present the cardiac magnetic resonance images of an unusual form of cardiac tuberculosis. Nodular masses in a sheet-like distribution were seen to infiltrate the outer myocardium and pericardium along most of the cardiac chambers. The lesions showed significant resolution on antitubercular therapy

Cardiac MRI in patients with complex CHD following primary or secondary implantation of MRI-conditional pacemaker system.

Science.gov (United States)

Al-Wakeel, Nadya; O h-Ici, Darach; Schmitt, Katharina R; Messroghli, Daniel R; Riesenkampff, Eugénie; Berger, Felix; Kuehne, Titus; Peters, Bjoern

2016-02-01

In patients with CHD, cardiac MRI is often indicated for functional and anatomical assessment. With the recent introduction of MRI-conditional pacemaker systems, cardiac MRI has become accessible for patients with pacemakers. The present clinical study aims to evaluate safety, susceptibility artefacts, and image reading of cardiac MRI in patients with CHD and MRI-conditional pacemaker systems. Material and methods CHD patients with MRI-conditional pacemaker systems and a clinical need for cardiac MRI were examined with a 1.5-T MRI system. Lead function was tested before and after MRI. Artefacts and image readings were evaluated using a four-point grading scale. A total of nine patients with CHD (mean age 34.0 years, range 19.5-53.6 years) received a total of 11 cardiac MRI examinations. Owing to clinical indications, seven patients had previously been converted from conventional to MRI-conditional pacemaker systems. All MRI examinations were completed without adverse effects. Device testing immediately after MRI and at follow-up showed no alteration of pacemaker device and lead function. Clinical questions could be addressed and answered in all patients. Cardiac MRI can be performed safely with high certainty of diagnosis in CHD patients with MRI-conditional pacemaker systems. In case of clinically indicated lead and box changing, CHD patients with non-MRI-conditional pacemaker systems should be considered for complete conversion to MRI-conditional systems.

Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

Science.gov (United States)

Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

2006-01-01

In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution. RSNA, 2006

Modeling Thermal Ignition of Energetic Materials

National Research Council Canada - National Science Library

Gerri, Norman J; Berning, Ellen

2004-01-01

This report documents an attempt to computationally simulate the mechanics and thermal regimes created when a threat perforates an armor envelope and comes in contact with stowed energetic material...

Energetic adaptations persist after bariatric surgery in severely obese adolescents

Science.gov (United States)

Energetic adaptations induced by bariatric surgery have not been studied in adolescents or for extended periods postsurgery. Energetic, metabolic, and neuroendocrine responses to Roux-en-Y gastric bypass (RYGB) surgery were investigated in extremely obese adolescents. At baseline and at 1.5, 6, and...

4D Flow Analysis of BAV-Related Fluid-Dynamic Alterations: Evidences of Wall Shear Stress Alterations in Absence of Clinically-Relevant Aortic Anatomical Remodeling

Directory of Open Access Journals (Sweden)

Filippo Piatti

2017-06-01

Full Text Available Bicuspid aortic valve (BAV is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs, likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii ten age-matched healthy volunteers. Through the semi-automated processing of 4D Flow data, the aortic bulk flow at peak systole was quantified, and WSSs acting on the endothelium of the ascending aorta were characterized throughout the systolic phase in terms of magnitude and time-dependency through a method recently developed by our group. Variables computed for each BAV patient were compared vs. the corresponding distribution of values obtained for healthy controls. In BAV patients, ascending aorta diameter was measured on cine-CMR images at baseline and at 3-year follow-up. As compared to controls, normo-functional BAV patients were characterized by minor bulk flow disturbances at peak systole. However, they were characterized by evident alterations of WSS distribution and peak values in the ascending aorta. In particular, in four BAV patients, who were characterized by right-left leaflet fusion, WSS peak values exceeded by 27–46% the 90th percentile of the distribution obtained for healthy volunteers. Only in the BAV patient with right-non-coronary leaflet fusion the same threshold was exceeded by 132%. Also, evident alterations in the time-dependency of WSS magnitude and direction were observed. Despite, these fluid

Effect of Trapped Energetic Ions on MHD Activity in Spherical Tori

International Nuclear Information System (INIS)

White, R.B.; Kolesnichenko, Ya.I.; Lutsenko, V.V.; Marchenko, V.S.

2002-01-01

It is shown that the increase of beta (the ratio of plasma pressure to the magnetic field pressure) may change the character of the influence of trapped energetic ions on MHD stability in spherical tori. Namely, the energetic ions, which stabilize MHD modes (such as the ideal-kink mode, collisionless tearing mode, and semi-collisional tearing mode) at low beta, have a destabilizing influence at high beta unless the radial distribution of the energetic ions is very peaked

The HZE radiation problem. [highly-charged energetic galactic cosmic rays

Science.gov (United States)

Schimmerling, Walter

1990-01-01

Radiation-exposure limits have yet to be established for missions envisioned in the framework of the Space Exploration Initiative. The radiation threat outside the earth's magnetosphere encompasses protons from solar particle events and the highly charged energetic particles constituting galactic cosmic rays; radiation biology entails careful consideration of the extremely nonuniform patterns of such particles' energy deposition. The ability to project such biological consequences of exposure to energetic particles as carcinogenicity currently involves great uncertainties from: (1) different regions of space; (2) the effects of spacecraft structures; and (3) the dose-effect relationships of single traversals of energetic particles.

Interaction in the large energetics companies in the Republic of Macedonia (Part 3)

International Nuclear Information System (INIS)

Janevski, Risto

2000-01-01

After the disintegration of former power energetic system of Yugoslavia 1991, the Republic of Macedonia has faced enormous problems in the energetic field. It was necessary to realize all options in order to secure enough electric power for normal economic capacities function. In that course a direct involvement of five large companies, which represent very significant energetic subjects, will largely determine the future energetic conditions and circumstances in our country. These are the following companies: P.E. Electric Power Co. of Macedonia; Heat Power Co.; HEK Jugohrom; Fenimak. In this paper the energetic system of the OKTA Crude Oil Refinery from 1991-1998 is analyzed, as well as its characteristics and plans for the future development

Myostatin from the heart: local and systemic actions in cardiac failure and muscle wasting

Science.gov (United States)

Breitbart, Astrid; Auger-Messier, Mannix; Molkentin, Jeffery D.

2011-01-01

A significant proportion of heart failure patients develop skeletal muscle wasting and cardiac cachexia, which is associated with a very poor prognosis. Recently, myostatin, a cytokine from the transforming growth factor-β (TGF-β) family and a known strong inhibitor of skeletal muscle growth, has been identified as a direct mediator of skeletal muscle atrophy in mice with heart failure. Myostatin is mainly expressed in skeletal muscle, although basal expression is also detectable in heart and adipose tissue. During pathological loading of the heart, the myocardium produces and secretes myostatin into the circulation where it inhibits skeletal muscle growth. Thus, genetic elimination of myostatin from the heart reduces skeletal muscle atrophy in mice with heart failure, whereas transgenic overexpression of myostatin in the heart is capable of inducing muscle wasting. In addition to its endocrine action on skeletal muscle, cardiac myostatin production also modestly inhibits cardiomyocyte growth under certain circumstances, as well as induces cardiac fibrosis and alterations in ventricular function. Interestingly, heart failure patients show elevated myostatin levels in their serum. To therapeutically influence skeletal muscle wasting, direct inhibition of myostatin was shown to positively impact skeletal muscle mass in heart failure, suggesting a promising strategy for the treatment of cardiac cachexia in the future. PMID:21421824

Assessment of cardiac risk before non-cardiac surgery: brain natriuretic peptide in 1590 patients.

Science.gov (United States)

Dernellis, J; Panaretou, M

2006-11-01

To evaluate the predictive value of brain natriuretic peptide (BNP) for assessment of cardiac risk before non-cardiac surgery. Consecutively treated patients (947 men, 643 women) whose BNP was measured before non-cardiac surgery were studied. Clinical and ECG variables were evaluated to identify predictors of postoperative cardiac events. Events occurred in 6% of patients: 21 cardiac deaths, 20 non-fatal myocardial infarctions, 41 episodes of pulmonary oedema and 14 patients with ventricular tachycardia. All of these patients had raised plasma BNP concentrations (best cut-off point 189 pg/ml). The only independent predictor of postoperative events was BNP (odds ratio 34.52, 95% confidence interval (CI) 17.08 to 68.62, p 300 pg/ml); postoperative event rates were 0%, 5%, 12% and 81%, respectively. In this population of patients evaluated before non-cardiac surgery, BNP is an independent predictor of postoperative cardiac events. BNP > 189 pg/ml identified patients at highest risk.

Streaming reversal of energetic particles in the magnetetail during a substorm

International Nuclear Information System (INIS)

Lui, A.T.Y.; Williams, D.J.; Eastman, T.E.; Frank, L.A.; Akasofu, S.

1984-01-01

Reversal from tailward streaming to earthward streaming of energetic ions at 0.29--0.50 MeV during a substorm on February 3, 1978, is studied with measurements of energetic particles, plasma, and magnetic field from that IMP 8 spacecraft near the dusk flank of the magnetotail. Four new features emerge when high time resolution data are examined in detail. The times of reversal from tailward to earthward streaming of energetic ions and from tailward to earthward plasma flow do not coincide. Second, the velocity distribution in the tailward flowing plasma has a cresent shape, whereas the velocity distribution in the earthward flowing plasma has a crescent shape, whereas the velocity distribution in the earthward flowing plasma resembles a convecting Maxwellian. Third, tailward streaming of energetic ions is sometime detected in northward magnetic field regions and conversely, earthward streaming in southward field environments. Fourth, energetic ions scattering earthward are occasionally present in conjunction with a strong tailward streaming population in the same energy range. These new features suggest that the streaming reversal of energetic ions and the plasma flow reversal in this event are due to the spacecraft traversing different plasma regions during the substorm-associated configurational change of the plasma sheet and the magnetotail and is unrelated to the motion of an acceleration region such as an X type neutral line moving past the spacecraft

123I-MIBG imaging detects cardiac involvement and predicts cardiac events in Churg-Strauss syndrome

International Nuclear Information System (INIS)

Horiguchi, Yoriko; Morita, Yukiko; Tsurikisawa, Naomi; Akiyama, Kazuo

2011-01-01

In Churg-Strauss syndrome (CSS) it is important to detect cardiac involvement, which predicts poor prognosis. This study evaluated whether 123 I-metaiodobenzylguanidine (MIBG) scintigraphy could detect cardiac damage and predict cardiac events in CSS. 123 I-MIBG scintigraphy was performed in 28 patients with CSS, 12 of whom had cardiac involvement. The early and delayed heart to mediastinum ratio (early H/M and delayed H/M) and washout rate were calculated by using 123 I-MIBG scintigraphy and compared with those in control subjects. Early H/M and delayed H/M were significantly lower and the washout rate was significantly higher in patients with cardiac involvement than in those without and in controls (early H/M, p = 0.0024, p = 0.0001; delayed H/M, p = 0.0002, p = 0.0001; washout rate, p = 0.0012, p = 0.0052 vs those without and vs controls, respectively). Accuracy for detecting cardiac involvement was 86% for delayed H/M and washout rate and 79% for early H/M and B-type natriuretic peptide (BNP). Kaplan-Meier analysis showed significantly lower cardiac event-free rates in patients with early H/M ≤ 2.18 and BNP > 21.8 pg/ml than those with early H/M > 2.18 and BNP ≤ 21.8 pg/ml (log-rank test p = 0.006). Cardiac sympathetic nerve function was damaged in CSS patients with cardiac involvement. 123 I-MIBG scintigraphy was useful in detecting cardiac involvement and in predicting cardiac events. (orig.)

The gut hormone ghrelin partially reverses energy substrate metabolic alterations in the failing heart.

Science.gov (United States)

Mitacchione, Gianfranco; Powers, Jeffrey C; Grifoni, Gino; Woitek, Felix; Lam, Amy; Ly, Lien; Settanni, Fabio; Makarewich, Catherine A; McCormick, Ryan; Trovato, Letizia; Houser, Steven R; Granata, Riccarda; Recchia, Fabio A

2014-07-01

The gut-derived hormone ghrelin, especially its acylated form, plays a major role in the regulation of systemic metabolism and exerts also relevant cardioprotective effects; hence, it has been proposed for the treatment of heart failure (HF). We tested the hypothesis that ghrelin can directly modulate cardiac energy substrate metabolism. We used chronically instrumented dogs, 8 with pacing-induced HF and 6 normal controls. Human des-acyl ghrelin [1.2 nmol/kg per hour] was infused intravenously for 15 minutes, followed by washout (rebaseline) and infusion of acyl ghrelin at the same dose. (3)H-oleate and (14)C-glucose were coinfused and arterial and coronary sinus blood sampled to measure cardiac free fatty acid and glucose oxidation and lactate uptake. As expected, cardiac substrate metabolism was profoundly altered in HF because baseline oxidation levels of free fatty acids and glucose were, respectively, >70% lower and >160% higher compared with control. Neither des-acyl ghrelin nor acyl ghrelin significantly affected function and metabolism in normal hearts. However, in HF, des-acyl and acyl ghrelin enhanced myocardial oxygen consumption by 10.2±3.5% and 9.9±3.7%, respectively (Pmetabolism in normal dogs, whereas they enhance free fatty acid oxidation and reduce glucose oxidation in HF dogs, thus partially correcting metabolic alterations in HF. This novel mechanism might contribute to the cardioprotective effects of ghrelin in HF. © 2014 American Heart Association, Inc.

Assessment of factors that influence weaning from long-term mechanical ventilation after cardiac surgery

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Emília Nozawa

2003-03-01

Full Text Available OBJECTIVE: To analyze parameters of respiratory system mechanics and oxygenation and cardiovascular alterations involved in weaning tracheostomized patients from long-term mechanical ventilation after cardiac surgery. METHODS: We studied 45 patients in their postoperative period of cardiac surgery, who required long-term mechanical ventilation for more than 10 days and had to undergo tracheostomy due to unsuccessful weaning from mechanical ventilation. The parameters of respiratory system mechanics, oxigenation and the following factors were analyzed: type of surgical procedure, presence of cardiac dysfunction, time of extracorporeal circulation, and presence of neurologic lesions. RESULTS: Of the 45 patients studied, successful weaning from mechanical ventilation was achieved in 22 patients, while the procedure was unsuccessful in 23 patients. No statistically significant difference was observed between the groups in regard to static pulmonary compliance (p=0.23, airway resistance (p=0.21, and the dead space/tidal volume ratio (p=0.54. No difference was also observed in regard to the variables PaO2/FiO2 ratio (p=0.86, rapid and superficial respiration index (p=0.48, and carbon dioxide arterial pressure (p=0.86. Cardiac dysfunction and time of extracorporeal circulation showed a significant difference. CONCLUSION: Data on respiratory system mechanics and oxygenation were not parameters for assessing the success or failure. Cardiac dysfunction and time of cardiopulmonary bypass, however, significantly interfered with the success in weaning patients from mechanical ventilation.

CARDIAC LYMPHOMA IN DOG

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G. D. Cruz

2016-11-01

Full Text Available Lymphoma is a lymphoid tumor that originates in hematopoietic organs such as lymph node, spleen or liver. In dogs, the overall prevalence of cardiac tumors was estimated to be only 0.19% based on the results of the survey of a large database, and lymphomas accounts for approximately 2% of all cardiac tumors. In general, the involvement of the myocardium is rarely described in canine lymphoma. Currently, there is no evidence of a viral association with primary cardiac lymphoma in dogs, but other types of immunosuppression may contribute to abnormal events, such as involvement primary cardiac. The aim of this study was to analyze a case of sudden death of a bitch, SRD, aged 10, who had the final diagnosis of cardiac lymphoma.

The Impact of a Non-Functional Thyroid Receptor Beta upon Triiodotironine-Induced Cardiac Hypertrophy in Mice

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Güínever Eustáquio do Império

2015-08-01

Full Text Available Background/Aims: Thyroid hormone (TH signalling is critical for heart function. The heart expresses thyroid hormone receptors (THRs; THRα1 and THRβ1. We aimed to investigate the regulation mechanisms of the THRβ isoform, its association with gene expression changes and implications for cardiac function. Methods: The experiments were performed using adult male mice expressing TRβΔ337T, which contains the Δ337T mutation of the human THRB gene and impairs ligand binding. Cardiac function and RNA expression were studied after hypo-or hyperthyroidism inductions. T3-induced cardiac hypertrophy was not observed in TRβΔ337T mice, showing the fundamental role of THRβ in cardiac hypertrophy. Results: We identified a group of independently regulated THRβ genes, which includes Adrb2, Myh7 and Hcn2 that were normally regulated by T3 in the TRβΔ337T group. However, Adrb1, Myh6 and Atp2a2 were regulated via THRβ. The TRβΔ337T mice exhibited a contractile deficit, decreased ejection fraction and stroke volume, as assessed by echocardiography. In our model, miR-208a and miR-199a may contribute to THRβ-mediated cardiac hypertrophy, as indicated by the absence of T3-regulated ventricular expression in TRβΔ337T mice. Conclusion: THRβ has important role in the regulation of specific mRNA and miRNA in T3-induced cardiac hypertrophic growth and in the alteration of heart functions.

Cardiac cone-beam CT

International Nuclear Information System (INIS)

Manzke, Robert

2005-01-01

This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net

Energetics, Biomechanics, and Performance in Masters' Swimmers: A Systematic Review.

Science.gov (United States)

Ferreira, Maria I; Barbosa, Tiago M; Costa, Mário J; Neiva, Henrique P; Marinho, Daniel A

2016-07-01

Ferreira, MI, Barbosa, TM, Costa, MJ, Neiva, HP, and Marinho, DA. Energetics, biomechanics, and performance in masters' swimmers: a systematic review. J Strength Cond Res 30(7): 2069-2081, 2016-This study aimed to summarize evidence on masters' swimmers energetics, biomechanics, and performance gathered in selected studies. An expanded search was conducted on 6 databases, conference proceedings, and department files. Fifteen studies were selected for further analysis. A qualitative evaluation of the studies based on the Quality Index (QI) was performed by 2 independent reviewers. The studies were thereafter classified into 3 domains according to the reported data: performance (10 studies), energetics (4 studies), and biomechanics (6 studies). The selected 15 articles included in this review presented low QI scores (mean score, 10.47 points). The biomechanics domain obtained higher QI (11.5 points), followed by energetics and performance (10.6 and 9.9 points, respectively). Stroke frequency (SF) and stroke length (SL) were both influenced by aging, although SF is more affected than SL. Propelling efficiency (ηp) decreased with age. Swimming performance declined with age. The performance declines with age having male swimmers deliver better performances than female counterparts, although this difference tends to be narrow in long-distance events. One single longitudinal study is found in the literature reporting the changes in performance over time. The remaining studies are cross-sectional designs focusing on the energetics and biomechanics. Overall, biomechanics parameters, such as SF, SL, and ηp, tend to decrease with age. This review shows the lack of a solid body of knowledge (reflected in the amount and quality of the articles published) on the changes in biomechanics, energetics, and performance of master swimmers over time. The training programs for this age-group should aim to preserve the energetics as much as possible and, concurrently, improve the

Polymer microfiber meshes facilitate cardiac differentiation of c-kit{sup +} human cardiac stem cells

Energy Technology Data Exchange (ETDEWEB)

Kan, Lijuan [Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (United States); Thayer, Patrick [Department of Chemical Engineering, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA (United States); Fan, Huimin [Research Institute of Heart Failure, Shanghai East Hospital of Tongji University, Shanghai (China); Ledford, Benjamin; Chen, Miao [Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (United States); Goldstein, Aaron [Department of Chemical Engineering, School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA (United States); Cao, Guohua [School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA (United States); He, Jia-Qiang, E-mail: jiahe@vt.edu [Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (United States)

2016-09-10

Electrospun microfiber meshes have been shown to support the proliferation and differentiation of many types of stem cells, but the phenotypic fate of c-kit{sup +} human cardiac stem cells (hCSCs) have not been explored. To this end, we utilized thin (~5 µm) elastomeric meshes consisting of aligned 1.7 µm diameter poly (ester-urethane urea) microfibers as substrates to examine their effect on hCSC viability, morphology, proliferation, and differentiation relative to cells cultured on tissue culture polystyrene (TCPS). The results showed that cells on microfiber meshes displayed an elongated morphology aligned in the direction of fiber orientation, lower proliferation rates, but increased expressions of genes and proteins majorly associated with cardiomyocyte phenotype. The early (NK2 homeobox 5, Nkx2.5) and late (cardiac troponin I, cTnI) cardiomyocyte genes were significantly increased on meshes (Nkx=2.5 56.2±13.0, cTnl=2.9±0.56,) over TCPS (Nkx2.5=4.2±0.9, cTnl=1.6±0.5, n=9, p<0.05 for both groups) after differentiation. In contrast, expressions of smooth muscle markers, Gata6 and myosin heavy chain (SM-MHC), were decreased on meshes. Immunocytochemical analysis with cardiac antibody exhibited the similar pattern of above cardiac differentiation. We conclude that aligned microfiber meshes are suitable for guiding cardiac differentiation of hCSCs and may facilitate stem cell-based therapies for treatment of cardiac diseases. - Highlights: • First study to characterize c-kit{sup +} human cardiac stem cells on microfiber meshes. • Microfiber meshes seem reducing cell proliferation, but no effect on cell viability. • Microfiber meshes facilitate the elongation of human cardiac stem cells in culture. • Cardiac but not smooth muscle differentiation were enhanced on microfiber meshes. • Microfiber meshes may be used as cardiac patches in cell-based cardiac therapy.

Modifying risks to improve outcome in cardiac surgery: An anesthesiologist's perspective

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Murali Chakravarthy

2017-01-01

Full Text Available Challenging times are here for cardiac surgical and anesthesia team. The interventional cardiologist seem to have closed the flow of 'good cases' coming up for any of the surgery,; successful percutaneous interventions seem to be offering reasonable results in these patients, who therefore do not knock on the doors of the surgeons any more . It is a common experience among the cardiac anesthesiologists and surgeons that the type of the cases that come by now are high risk. That may be presence of comorbidities, ongoing medical therapies, unstable angina, uncontrolled heart failure and rhythm disturbances; and in patients with ischemic heart disease, the target coronaries are far from ideal. Several activities such as institution of preoperative supportive circulatory, ventilatory, and systemic disease control maneuvers seem to have helped improving the outcome of these 'high risk ' patients. This review attempts to look at various interventions and the resulting improvement in outcomes. Several changes have happened in the realm of cardiac surgery and several more are en route. At times, for want of evidence, maximal optimization may not take place and the patient may encounter unfavorable outcomes.. This review is an attempt to bring the focus of the members of the cardiac surgical team on the value of preoperative optimization of risks to improve the outcome. The cardiac surgical patients may broadly be divided into adults undergoing coronary artery bypass graft surgery, valve surgery and pediatric patients undergoing repair/ palliation of congenital heart ailments. Optimization of risks appear to be different in each genre of patients. This review also brings less often discussed issues such as anemia, nutritional issues and endocrine problems. The review is an attempt to data on ameliorating modifiable risk factors and altering non modifiable ones.

Atypical energetic particle events observed prior energetic particle enhancements associated with corotating interaction regions

Science.gov (United States)

Khabarova, Olga; Malandraki, Olga; Zank, Gary; Jackson, Bernard; Bisi, Mario; Desai, Mihir; Li, Gang; le Roux, Jakobus; Yu, Hsiu-Shan

2017-04-01

Recent studies of mechanisms of particle acceleration in the heliosphere have revealed the importance of the comprehensive analysis of stream-stream interactions as well as the heliospheric current sheet (HCS) - stream interactions that often occur in the solar wind, producing huge magnetic cavities bounded by strong current sheets. Such cavities are usually filled with small-scale magnetic islands that trap and re-accelerate energetic particles (Zank et al. ApJ, 2014, 2015; le Roux et al. ApJ, 2015, 2016; Khabarova et al. ApJ, 2015, 2016). Crossings of these regions are associated with unusual variations in the energetic particle flux up to several MeV/nuc near the Earth's orbit. These energetic particle flux enhancements called "atypical energetic particle events" (AEPEs) are not associated with standard mechanisms of particle acceleration. The analysis of multi-spacecraft measurements of energetic particle flux, plasma and the interplanetary magnetic field shows that AEPEs have a local origin as they are observed by different spacecraft with a time delay corresponding to the solar wind propagation from one spacecraft to another, which is a signature of local particle acceleration in the region embedded in expanding and rotating background solar wind. AEPEs are often observed before the arrival of corotating interaction regions (CIRs) or stream interaction regions (SIRs) to the Earth's orbit. When fast solar wind streams catch up with slow solar wind, SIRs of compressed heated plasma or more regular CIRs are created at the leading edge of the high-speed stream. Since coronal holes are often long-lived structures, the same CIR re-appears often for several consecutive solar rotations. At low heliographic latitudes, such CIRs are typically bounded by forward and reverse waves on their leading and trailing edges, respectively, that steepen into shocks at heliocentric distances beyond 1 AU. Energetic ion increases have been frequently observed in association with CIR

An endogenously produced fragment of cardiac myosin-binding protein C is pathogenic and can lead to heart failure.

Science.gov (United States)

Razzaque, Md Abdur; Gupta, Manish; Osinska, Hanna; Gulick, James; Blaxall, Burns C; Robbins, Jeffrey

2013-08-16

A stable 40-kDa fragment is produced from cardiac myosin-binding protein C when the heart is stressed using a stimulus, such as ischemia-reperfusion injury. Elevated levels of the fragment can be detected in the diseased mouse and human heart, but its ability to interfere with normal cardiac function in the intact animal is unexplored. To understand the potential pathogenicity of the 40-kDa fragment in vivo and to investigate the molecular pathways that could be targeted for potential therapeutic intervention. We generated cardiac myocyte-specific transgenic mice using a Tet-Off inducible system to permit controlled expression of the 40-kDa fragment in cardiomyocytes. When expression of the 40-kDa protein is induced by crossing the responder animals with tetracycline transactivator mice under conditions in which substantial quantities approximating those observed in diseased hearts are reached, the double-transgenic mice subsequently experience development of sarcomere dysgenesis and altered cardiac geometry, and the heart fails between 12 and 17 weeks of age. The induced double-transgenic mice had development of cardiac hypertrophy with myofibrillar disarray and fibrosis, in addition to activation of pathogenic MEK-ERK pathways. Inhibition of MEK-ERK signaling was achieved by injection of the mitogen-activated protein kinase (MAPK)/ERK inhibitor U0126. The drug effectively improved cardiac function, normalized heart size, and increased probability of survival. These results suggest that the 40-kDa cardiac myosin-binding protein C fragment, which is produced at elevated levels during human cardiac disease, is a pathogenic fragment that is sufficient to cause hypertrophic cardiomyopathy and heart failure.

High-Resolution Mapping of Chromatin Conformation in Cardiac Myocytes Reveals Structural Remodeling of the Epigenome in Heart Failure.

Science.gov (United States)

Rosa-Garrido, Manuel; Chapski, Douglas J; Schmitt, Anthony D; Kimball, Todd H; Karbassi, Elaheh; Monte, Emma; Balderas, Enrique; Pellegrini, Matteo; Shih, Tsai-Ting; Soehalim, Elizabeth; Liem, David; Ping, Peipei; Galjart, Niels J; Ren, Shuxun; Wang, Yibin; Ren, Bing; Vondriska, Thomas M

2017-10-24

Cardiovascular disease is associated with epigenomic changes in the heart; however, the endogenous structure of cardiac myocyte chromatin has never been determined. To investigate the mechanisms of epigenomic function in the heart, genome-wide chromatin conformation capture (Hi-C) and DNA sequencing were performed in adult cardiac myocytes following development of pressure overload-induced hypertrophy. Mice with cardiac-specific deletion of CTCF (a ubiquitous chromatin structural protein) were generated to explore the role of this protein in chromatin structure and cardiac phenotype. Transcriptome analyses by RNA-seq were conducted as a functional readout of the epigenomic structural changes. Depletion of CTCF was sufficient to induce heart failure in mice, and human patients with heart failure receiving mechanical unloading via left ventricular assist devices show increased CTCF abundance. Chromatin structural analyses revealed interactions within the cardiac myocyte genome at 5-kb resolution, enabling examination of intra- and interchromosomal events, and providing a resource for future cardiac epigenomic investigations. Pressure overload or CTCF depletion selectively altered boundary strength between topologically associating domains and A/B compartmentalization, measurements of genome accessibility. Heart failure involved decreased stability of chromatin interactions around disease-causing genes. In addition, pressure overload or CTCF depletion remodeled long-range interactions of cardiac enhancers, resulting in a significant decrease in local chromatin interactions around these functional elements. These findings provide a high-resolution chromatin architecture resource for cardiac epigenomic investigations and demonstrate that global structural remodeling of chromatin underpins heart failure. The newly identified principles of endogenous chromatin structure have key implications for epigenetic therapy. © 2017 The Authors.

Comprehensive cardiac rehabilitation

DEFF Research Database (Denmark)

Kruse, Marie; Hochstrasser, Stefan; Zwisler, Ann-Dorthe O

2006-01-01

OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed...... and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

Autonomic cardiac innervation

Science.gov (United States)

Hasan, Wohaib

2013-01-01

Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targets, upon which target-derived trophic factors take over final maturation, synaptic strength and postnatal survival. Although target-derived neurotrophins have a central role to play in development, alternative sources of neurotrophins may also modulate innervation. Both developing and adult sympathetic neurons express proNGF, and adult parasympathetic cardiac ganglion neurons also synthesize and release NGF. The physiological function of these “non-classical” cardiac sources of neurotrophins remains to be determined, especially in relation to autocrine/paracrine sustenance during development.   Cardiac autonomic nerves are closely spatially associated in cardiac plexuses, ganglia and pacemaker regions and so are sensitive to release of neurotransmitter, neuropeptides and trophic factors from adjacent nerves. As such, in many cardiac pathologies, it is an imbalance within the two arms of the autonomic system that is critical for disease progression. Although this crosstalk between sympathetic and parasympathetic nerves has been well established for adult nerves, it is unclear whether a degree of paracrine regulation occurs across the autonomic limbs during development. Aberrant nerve remodeling is a common occurrence in many adult cardiovascular pathologies, and the mechanisms regulating outgrowth or denervation are disparate. However, autonomic neurons display considerable plasticity in this regard with neurotrophins and inflammatory cytokines having a central regulatory

Maprotiline treatment differentially influences cardiac β-adrenoreceptors expression under normal and stress conditions

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Natasa Spasojevic

2012-12-01

Full Text Available Alterations in cardiac function were observed in antidepressants treated patients and published in several clinical reports. These detected changes could be either a consequence of the treatment or of depression itself, which has already been proved to be a risk factor in heart diseases. In order to determine a possible influence of chronic treatment with norepinephrinergic reuptake inhibitor, maprotiline, on the heart, we investigated gene expression of cardiac β-adrenoceptors both in controls and in animals with signs of depression. The rats were divided into two groups, unstressed controls and those exposed to chronic unpredictable mild stress (CUMS. The groups were further divided into two subgroups, one receiving daily intraperitoneal injections of vehicle (sterile water and another one maprotiline (10 mg/kg for four weeks. Tissue samples were collected after the last application. Gene expression of cardiac β1- and β2-adrenoceptor was determined using Real-time RT-PCR analysis. Our results show that in control animals expression of both adrenoreceptors was decreased in the right atria after 4 weeks of maprotiline application. Contrary, the same treatment led to a significant increase in expression of cardiac β1-adrenoceptor in the stressed rats, with no change in the characteristics of β2-adrenoceptor. Our findings might reflect the that molecular mechanisms are underlying factors involved in the development of cardiovascular diseases linked with antidepressant treatment.

Illness Perception Profiles and Their Association with 10-Year Survival Following Cardiac Valve Replacement.

Science.gov (United States)

Crawshaw, Jacob; Rimington, Helen; Weinman, John; Chilcot, Joseph

2015-10-01

The aim of the present study was to examine whether profiles of illness perceptions are associated with 10-year survival following cardiac valve replacement surgery. Illness perceptions were evaluated in 204 cardiac patients awaiting first-time valve replacement and again 1 year post-operatively using cluster analysis. All-cause mortality was recorded over a 10-year period. At 1 year, 136 patients were grouped into one of four profiles (stable positive, stable negative, changed from positive to negative, changed from negative to positive). The median follow-up was 3063 days (78 deaths). After controlling for clinical covariates, including markers of function, patients who changed illness perceptions from positive to negative beliefs 1 year post-surgery had an increased mortality risk (hazard ratio (HR) = 3.2, 95% confidence interval (CI) 1.2-8.3, p = .02) compared to patients who held positive stable perceptions. Following cardiac valve replacement, developing negative illness perceptions over the first post-operative year predicts long-term mortality. Early screening and intervention to alter this pattern of beliefs may be beneficial.

Particles Alter Diesel Exhaust Gases-Induced Hypotension, Cardiac Arrhythmia,Conduction Disturbance, and Autonomic Imbalance in Heart Failure-Prone Rats

Science.gov (United States)

Epidemiologic studies indicate that acute exposures to vehicular traffic and particulate matter (PM) air pollution are key causes of fatal cardiac arrhythmia, especially in those with preexisting cardiovascular disease. Researchers point to electrophysiologic dysfunction and auto...

Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia

Science.gov (United States)

Longhurst, John C.

2013-01-01

Thinly myelinated Aδ-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 μmol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the

Direct Cardiac Reprogramming: Advances in Cardiac Regeneration

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Olivia Chen

2015-01-01

Full Text Available Heart disease is one of the lead causes of death worldwide. Many forms of heart disease, including myocardial infarction and pressure-loading cardiomyopathies, result in irreversible cardiomyocyte death. Activated fibroblasts respond to cardiac injury by forming scar tissue, but ultimately this response fails to restore cardiac function. Unfortunately, the human heart has little regenerative ability and long-term outcomes following acute coronary events often include chronic and end-stage heart failure. Building upon years of research aimed at restoring functional cardiomyocytes, recent advances have been made in the direct reprogramming of fibroblasts toward a cardiomyocyte cell fate both in vitro and in vivo. Several experiments show functional improvements in mouse models of myocardial infarction following in situ generation of cardiomyocyte-like cells from endogenous fibroblasts. Though many of these studies are in an early stage, this nascent technology holds promise for future applications in regenerative medicine. In this review, we discuss the history, progress, methods, challenges, and future directions of direct cardiac reprogramming.

Radiational and energetic characteristics of diatomic molecules (data base)

International Nuclear Information System (INIS)

Kuznetsova, L.A.; Pazyuk, E.A.; Stolyarov, A.V.

1993-01-01

Data base on radiational and energetic characteristics of diatomic molecules was created. The base consists of two parts: reference system and recommended data system. The reference system contains the information about studies of radiational and energetic parameters of more than 1500 electronic states and 1700 electron transfers for ∼ 350 diatomic molecules and their ions. The base bibliography includes ∼ 3000 publications. 11 refs., 1 figs

Coarctation induces alterations in basement membranes in the cardiovascular system

DEFF Research Database (Denmark)

Lipke, D W; McCarthy, K J; Elton, T S

1993-01-01

ventricular hypertrophy was maximal within 5 days. In immunohistochemical studies, fibronectin and laminin were increased and the basement membrane chondroitin sulfate proteoglycan decreased in both the subendothelial space and smooth muscle cell basement membranes of the aorta above the clip compared...... membrane components in the heart and vasculature peaked before maximal cardiac hypertrophy (5 days). These studies indicate that alterations in basement membrane component deposition in the hypertrophied vasculature occur at both transcriptional and translational levels and suggest that the cell attachment...

Energetic cost of communication.

Science.gov (United States)

Stoddard, Philip K; Salazar, Vielka L

2011-01-15

Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs.

The New York State cardiac registries: history, contributions, limitations, and lessons for future efforts to assess and publicly report healthcare outcomes.

Science.gov (United States)

Hannan, Edward L; Cozzens, Kimberly; King, Spencer B; Walford, Gary; Shah, Nirav R

2012-06-19

In 1988, the New York State Health Commissioner was confronted with hospital-level data demonstrating very large, multiple-year, interhospital variations in short-term mortality and complications for cardiac surgery. The concern with the extent to which these differences were due to variations in patients' pre-surgical severity of illness versus hospitals' quality of care led to the development of clinical registries for cardiac surgery in 1989 and for percutaneous coronary interventions in 1992 in New York. In 1990, the Department of Health released hospitals' risk-adjusted cardiac surgery mortality rates for the first time, and shortly thereafter, similar data were released for hospitals and physicians for percutaneous coronary interventions, cardiac valve surgery, and pediatric cardiac surgery (only hospital data). This practice is still ongoing. The purpose of this communication is to relate the history of this initiative, including changes or purported changes that have occurred since the public release of cardiac data. These changes include decreases in risk-adjusted mortality, cessation of cardiac surgery in New York by low-volume and high-mortality surgeons, out-of-state referral or avoidance of cardiac surgery/angioplasty for high-risk patients, alteration of contracting choices by insurance companies, and modifications in market share of cardiac hospitals. Evidence related to these impacts is reviewed and critiqued. This communication also includes a summary of numerous studies that used New York's cardiac registries to examine a variety of policy issues regarding the choice and use of cardiac procedures, the comparative effectiveness of competing treatment options, and the examination of the relationship among processes, structures, and outcomes of cardiac care. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Stabilized super-thermite colloids: A new generation of advanced highly energetic materials

Science.gov (United States)

Elbasuney, Sherif; Gaber Zaky, M.; Radwan, Mostafa; Mostafa, Sherif F.

2017-10-01

One of the great impetus of nanotechnology on energetic materials is the achievement of nanothermites (metal-oxide/metal) which are characterized by massive heat output. Yet, full exploitation of super-thermites in highly energetic systems has not been achieved. This manuscript reports on the sustainable fabrication of colloidal Fe2O3 and CuO nanoparticles for thermite applications. TEM micrographs demonstrated mono-dispersed Fe2O3 and CuO with an average particle size of 3 and 15 nm respectively. XRD diffractograms demonstrated highly crystalline materials. SEM micrographs demonstrated a great tendency of the developed oxides to aggregate over drying process. The effective integration and dispersion of mono-dispersed colloidal thermite particles into energetic systems are vital for enhanced performance. Aluminum is of interest as highly energetic metal fuel. In this paper, synthesized Fe2O3 and CuO nanoparticles were re-dispersed in isopropyl alcohol (IPA) with aluminum nanoparticles using ultrasonic prope homogenizer. The colloidal thermite peraticles can be intgegrated into highly energetic system for subsequent nanocomposite development. Thanks to stabilization of colloidal CuO nanoparticles in IPA which could offer intimate mixing between oxidizer and metal fuel. The stabilization mechanism of CuO in IPA was correlated to steric stabilization with solvent molecules. This approach eliminated nanoparticle drying and the re-dispersion of dry aggregates into energetic materials. This manuscript shaded the light on the real development of colloidal thermite mixtures and their integration into highly energetic systems.

Biomaterials for cardiac regeneration

CERN Document Server

Ruel, Marc

2015-01-01

This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

Metoclopramide-induced cardiac arrest

Directory of Open Access Journals (Sweden)

Martha M. Rumore

2011-11-01

Full Text Available The authors report a case of cardiac arrest in a patient receiving intravenous (IV metoclopramide and review the pertinent literature. A 62-year-old morbidly obese female admitted for a gastric sleeve procedure, developed cardiac arrest within one minute of receiving metoclopramide 10 mg via slow intravenous (IV injection. Bradycardia at 4 beats/min immediately appeared, progressing rapidly to asystole. Chest compressions restored vital function. Electrocardiogram (ECG revealed ST depression indicative of myocardial injury. Following intubation, the patient was transferred to the intensive care unit. Various cardiac dysrrhythmias including supraventricular tachycardia (SVT associated with hypertension and atrial fibrillation occurred. Following IV esmolol and metoprolol, the patient reverted to normal sinus rhythm. Repeat ECGs revealed ST depression resolution without pre-admission changes. Metoclopramide is a non-specific dopamine receptor antagonist. Seven cases of cardiac arrest and one of sinus arrest with metoclopramide were found in the literature. The metoclopramide prescribing information does not list precautions or adverse drug reactions (ADRs related to cardiac arrest. The reaction is not dose related but may relate to the IV administration route. Coronary artery disease was the sole risk factor identified. According to Naranjo, the association was possible. Other reports of cardiac arrest, severe bradycardia, and SVT were reviewed. In one case, five separate IV doses of 10 mg metoclopramide were immediately followed by asystole repeatedly. The mechanism(s underlying metoclopramide’s cardiac arrest-inducing effects is unknown. Structural similarities to procainamide may play a role. In view of eight previous cases of cardiac arrest from metoclopramide having been reported, further elucidation of this ADR and patient monitoring is needed. Our report should alert clinicians to monitor patients and remain diligent in surveillance and

Intraoperative tight glucose control using hyperinsulinemic normoglycemia increases delirium after cardiac surgery.

Science.gov (United States)

Saager, Leif; Duncan, Andra E; Yared, Jean-Pierre; Hesler, Brian D; You, Jing; Deogaonkar, Anupa; Sessler, Daniel I; Kurz, Andrea

2015-06-01

Postoperative delirium is common in patients recovering from cardiac surgery. Tight glucose control has been shown to reduce mortality and morbidity. Therefore, the authors sought to determine the effect of tight intraoperative glucose control using a hyperinsulinemic-normoglycemic clamp approach on postoperative delirium in patients undergoing cardiac surgery. The authors enrolled 198 adult patients having cardiac surgery in this randomized, double-blind, single-center trial. Patients were randomly assigned to either tight intraoperative glucose control with a hyperinsulinemic-normoglycemic clamp (target blood glucose, 80 to 110 mg/dl) or standard therapy (conventional insulin administration with blood glucose target, battery. The authors considered patients to have experienced postoperative delirium when Confusion Assessment Method testing was positive at any assessment. A positive Confusion Assessment Method was defined by the presence of features 1 (acute onset and fluctuating course) and 2 (inattention) and either 3 (disorganized thinking) or 4 (altered consciousness). Patients randomized to tight glucose control were more likely to be diagnosed as being delirious than those assigned to routine glucose control (26 of 93 vs. 15 of 105; relative risk, 1.89; 95% CI, 1.06 to 3.37; P = 0.03), after adjusting for preoperative usage of calcium channel blocker and American Society of Anesthesiologist physical status. Delirium severity, among patients with delirium, was comparable with each glucose management strategy. Intraoperative hyperinsulinemic-normoglycemia augments the risk of delirium after cardiac surgery, but not its severity.

Sleep disturbances after non-cardiac surgery

DEFF Research Database (Denmark)

Rosenberg, Jacob

2001-01-01

. The sleep disturbances seem to be related to the magnitude of trauma and thereby to the surgical stress response and/or post-operative opioid administration. Post-operative sleep disturbances may contribute to the development of early post-operative fatigue, episodic hypoxaemia, haemodynamic instability......After major non-cardiac surgery sleep pattern is usually disturbed with initial suppression of rapid eye movement sleep with a subsequent rebound during the first post-operative week. Deep sleep is also suppressed for several days after the operation and subjective sleep quality is impaired...... and altered mental status, all with a potential negative effect on post-operative outcome. Minimizing surgical trauma and avoiding or minimizing use of opioids for pain relief may prevent or reduce post-operative sleep disturbances. Post-operative sleep pattern represents an important research field, since...

Preserved cardiac function despite marked impairment of cAMP generation.

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Mei Hua Gao

Full Text Available So many clinical trials of positive inotropes have failed, that it is now axiomatic that agents that increase cAMP are deleterious to the failing heart. An alternative strategy is to alter myocardial Ca(2+ handling or myofilament response to Ca(2+ using agents that do not affect cAMP. Although left ventricular (LV function is tightly linked to adenylyl cyclase (AC activity, the beneficial effects of AC may be independent of cAMP and instead stem from effects on Ca(2+ handling. Here we ask whether an AC mutant molecule that reduces LV cAMP production would have favorable effects on LV function through its effects on Ca(2+ handling alone.We generated transgenic mice with cardiac-directed expression of an AC6 mutant (AC6mut. Cardiac myocytes showed impaired cAMP production in response to isoproterenol (74% reduction; p<0.001, but LV size and function were normal. Isolated hearts showed preserved LV function in response to isoproterenol stimulation. AC6mut expression was associated with increased sarcoplasmic reticulum Ca(2+ uptake and the EC50 for SERCA2a activation was reduced. Cardiac myocytes isolated from AC6mut mice showed increased amplitude of Ca(2+ transients in response to isoproterenol (p = 0.0001. AC6mut expression also was associated with increased expression of LV S100A1 (p = 0.03 and reduced expression of phospholamban protein (p = 0.01.LV AC mutant expression is associated with normal cardiac function despite impaired cAMP generation. The mechanism appears to be through effects on Ca(2+ handling - effects that occur despite diminished cAMP.

Calculation of the energetics of chemical reactions

Energy Technology Data Exchange (ETDEWEB)

Dunning, T.H. Jr.; Harding, L.B.; Shepard, R.L.; Harrison, R.J.

1988-01-01

To calculate the energetics of chemical reactions we must solve the electronic Schroedinger equation for the molecular conformations of importance for the reactive encounter. Substantial changes occur in the electronic structure of a molecular system as the reaction progresses from reactants through the transition state to products. To describe these changes, our approach includes the following three elements: the use of multiconfiguration self-consistent field wave functions to provide a consistent zero-order description of the electronic structure of the reactants, transition state, and products; the use of configuration interaction techniques to describe electron correlation effects needed to provide quantitative predictions of the reaction energetics; and the use of large, optimized basis sets to provide the flexibility needed to describe the variations in the electronic distributions. With this approach we are able to study reactions involving as many as 5--6 atoms with errors of just a few kcal/mol in the predicted reaction energetics. Predictions to chemical accuracy, i.e., to 1 kcal/mol or less, are not yet feasible, although continuing improvements in both the theoretical methodology and computer technology suggest that this will soon be possible, at least for reactions involving small polyatomic species. 4 figs.

Cardiac tumours: non invasive detection and assessment by gated cardiac blood pool radionuclide imaging

International Nuclear Information System (INIS)

Pitcher, D.; Wainwright, R.; Brennand-Roper, D.; Deverall, P.; Sowton, E.; Maisey, M.

1980-01-01

Four patients with cardiac tumours were investigated by gated cardiac blood pool radionuclide imaging and echocardiography. Contrast angiocardiography was performed in three of the cases. Two left atrial tumours were detected by all three techniques. In one of these cases echocardiography alone showed additional mitral valve stenosis, but isotope imaging indicated tumour size more accurately. A large septal mass was detected by all three methods. In this patient echocardiography showed evidence of left ventricular outflow obstruction, confirmed at cardiac catheterisation, but gated isotope imaging provided a more detailed assessment of the abnormal cardiac anatomy. In the fourth case gated isotope imaging detected a large right ventricular tumour which had not been identified by echocardiography. Gated cardiac blood pool isotope imaging is a complementary technique to echocardiography for the non-invasive detection and assessment of cardiac tumours. (author)

Clonidine, an alpha2-receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

Science.gov (United States)

Philbin, Kerry E; Bateman, Ryan J; Mendelowitz, David

2010-08-06

In hypertension, there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Presympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these presympathetic neurons are catecholaminergic. In addition to their projection to the spinal cord, many of these presympathetic neurons have axon collaterals that arborize into neighboring cardiorespiratory locations and likely release norepinephrine onto nearby neurons. Activation of alpha(2)-adrenergic receptors in the central nervous system evokes a diverse range of physiological effects, including reducing blood pressure. This study tests whether clonidine, an alpha(2)-adrenergic receptor agonist, alters excitatory glutamatergic, and/or inhibitory GABAergic or glycinergic synaptic neurotransmission to cardiac vagal neurons in the nucleus ambiguus. Cardiac vagal neurons were identified in an in vitro brainstem slice preparation, and synaptic events were recording using whole cell voltage clamp methodologies. Clonidine significantly inhibited GABAergic neurotransmission but had no effect on glycinergic or glutamatergic pathways to cardiac vagal neurons. This diminished inhibitory GABAergic neurotransmission to cardiac vagal neurons would increase parasympathetic activity to the heart, decreasing heart rate and blood pressure. The results presented here provide a cellular substrate for the clinical use of clonidine as a treatment for hypertension as well as a role in alleviating posttraumatic stress disorder by evoking an increase in parasympathetic cardiac vagal activity, and a decrease in heart rate and blood pressure. Copyright 2010 Elsevier B.V. All rights reserved.

Energetic constraints, size gradients, and size limits in benthic marine invertebrates.

Science.gov (United States)

Sebens, Kenneth P

2002-08-01

Populations of marine benthic organisms occupy habitats with a range of physical and biological characteristics. In the intertidal zone, energetic costs increase with temperature and aerial exposure, and prey intake increases with immersion time, generating size gradients with small individuals often found at upper limits of distribution. Wave action can have similar effects, limiting feeding time or success, although certain species benefit from wave dislodgment of their prey; this also results in gradients of size and morphology. The difference between energy intake and metabolic (and/or behavioral) costs can be used to determine an energetic optimal size for individuals in such populations. Comparisons of the energetic optimal size to the maximum predicted size based on mechanical constraints, and the ensuing mortality schedule, provides a mechanism to study and explain organism size gradients in intertidal and subtidal habitats. For species where the energetic optimal size is well below the maximum size that could persist under a certain set of wave/flow conditions, it is probable that energetic constraints dominate. When the opposite is true, populations of small individuals can dominate habitats with strong dislodgment or damage probability. When the maximum size of individuals is far below either energetic optima or mechanical limits, other sources of mortality (e.g., predation) may favor energy allocation to early reproduction rather than to continued growth. Predictions based on optimal size models have been tested for a variety of intertidal and subtidal invertebrates including sea anemones, corals, and octocorals. This paper provides a review of the optimal size concept, and employs a combination of the optimal energetic size model and life history modeling approach to explore energy allocation to growth or reproduction as the optimal size is approached.

Targeted disruption of the mouse Csrp2 gene encoding the cysteine- and glycine-rich LIM domain protein CRP2 result in subtle alteration of cardiac ultrastructure

Directory of Open Access Journals (Sweden)

Stoll Doris

2008-08-01

Full Text Available Abstract Background The cysteine and glycine rich protein 2 (CRP2 encoded by the Csrp2 gene is a LIM domain protein expressed in the vascular system, particularly in smooth muscle cells. It exhibits a bimodal subcellular distribution, accumulating at actin-based filaments in the cytosol and in the nucleus. In order to analyze the function of CRP2 in vivo, we disrupted the Csrp2 gene in mice and analysed the resulting phenotype. Results A ~17.3 kbp fragment of the murine Csrp2 gene containing exon 3 through 6 was isolated. Using this construct we confirmed the recently determined chromosomal localization (Chromosome 10, best fit location between markers D10Mit203 proximal and D10Mit150 central. A gene disruption cassette was cloned into exon 4 and a mouse strain lacking functional Csrp2 was generated. Mice lacking CRP2 are viable and fertile and have no obvious deficits in reproduction and survival. However, detailed histological and electron microscopic studies reveal that CRP2-deficient mice have subtle alterations in their cardiac ultrastructure. In these mice, the cardiomyocytes display a slight increase in their thickness, indicating moderate hypertrophy at the cellular level. Although the expression of several intercalated disc-associated proteins such as β-catenin, N-RAP and connexin-43 were not affected in these mice, the distribution of respective proteins was changed within heart tissue. Conclusion We conclude that the lack of CRP2 is associated with alterations in cardiomyocyte thickness and hypertrophy.

Pregnancy as a cardiac stress model

Science.gov (United States)

Chung, Eunhee; Leinwand, Leslie A.

2014-01-01

Cardiac hypertrophy occurs during pregnancy as a consequence of both volume overload and hormonal changes. Both pregnancy- and exercise-induced cardiac hypertrophy are generally thought to be similar and physiological. Despite the fact that there are shared transcriptional responses in both forms of cardiac adaptation, pregnancy results in a distinct signature of gene expression in the heart. In some cases, however, pregnancy can induce adverse cardiac events in previously healthy women without any known cardiovascular disease. Peripartum cardiomyopathy is the leading cause of non-obstetric mortality during pregnancy. To understand how pregnancy can cause heart disease, it is first important to understand cardiac adaptation during normal pregnancy. This review provides an overview of the cardiac consequences of pregnancy, including haemodynamic, functional, structural, and morphological adaptations, as well as molecular phenotypes. In addition, this review describes the signalling pathways responsible for pregnancy-induced cardiac hypertrophy and angiogenesis. We also compare and contrast cardiac adaptation in response to disease, exercise, and pregnancy. The comparisons of these settings of cardiac hypertrophy provide insight into pregnancy-associated cardiac adaptation. PMID:24448313

Sudden cardiac death: the pro-arrhythmic interaction of an acute loading with an underlying substrate.

Science.gov (United States)

Sutherland, George R

2017-10-21

Sudden cardiac death (SCD) is a complex phenomenon, occurring either in apparently normal individuals or in those where there is a recognized underlying cardiac abnormality. In both groups, the lethal arrhythmia has frequently been related to the physiologic trigger of either exercise or stress. Prior research into SCD has focused mainly on a combination of identifying either vulnerable myocardial substrates; pharmacological approaches to altering electrical activation/repolarisation in substrates; or the suppression of induced lethal arrhythmias with implantable defibrillators. However, it has been suggested that in a significant number of cases, the interaction of a transient induced trigger with a pre-existing electrical or mechanical substrate is the basis for the induction of the sustained lethal arrhythmia. In this manuscript we will discuss the precise mechanisms whereby one of such potential physiologic trigger: an acute change in systolic blood pressure, can induce a sequence of alterations in global and local cardiac mechanics which in turn result in regional left ventricular post-systolic deformation which, mediated (through stretch-induced changes in local mechano-electrical coupling) provokes local electrical after-depolarisations which can spill over into complex runs of premature ventricular beats. These local acute pressure/stretch induced runs of ventricular ectopy originate in either basal or apical normal myocardium and, in combination with a co-existing distal pro-arrhymic substrate, can interact to induce a lethal arrhythmia. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

Human technology after cardiac epigenesis. Artificial heart versus cardiac transplantation.

Science.gov (United States)

Losman, J G

1977-09-24

Cardiovascular disease is the chief cause of death in technologically advanced countries and accounts for more than 50% of all deaths in the USA. For a patient with end-stage cardiac failure the only treatment presently available is organ replacement, either by transplantation or by the use of a mechanical heart. Transplantation has demonstrated its value: survival of more than 8 years and restoration of a normal quality of life to patients who were in end-stage cardiac decompensation. However, the prospect of routine clinical application of an artificial heart remains distant. The development of a totally implantable artificial heart still presents a series of challenging engineering problems with regard to strict constraints of size, weight, blood-material compatibility, adaptability of output to demand, efficiency and reliability of the power supply, and safety if nuclear fuel is used. The totally artificial heart is presently not an alternative to the cardiac allograft, but could provide short-term support for patients awaiting cardiac transplantation.

Marketing cardiac CT programs.

Science.gov (United States)

Scott, Jason

2010-01-01

There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

Myosin helical pitch angle as a quantitative imaging biomarker for characterization of cardiac programming in fetal growth restriction measured by polarization second harmonic microscopy

Science.gov (United States)

Amat-Roldan, I.; Psilodimitrakopoulos, S.,; Eixarch, E.,; Torre, I.; Wotjas, B.; Crispi, F.; Figueras, F.; Artigas, D.,; Loza-Alvarez, P.; Gratacos, E.,

2009-07-01

Fetal growth restriction (FGR) has recently shown a strong association with cardiac programming which predisposes to cardiovascular mortality in adulthood. Polarization Second Harmonic Microscopy can quantify molecular architecture changes with high sensitivity in cardiac myofibrils. In this work, we use myosin helical pitch angle as an example to quantify such alterations related to this high risk population. Importantly, this shows a potential use of the technique as an early diagnostic tool and an alternative method to understand pathophysiological processes.

Reactive Energetic Plasticizers Utilizing Cu-Free Azide-Alkyne 1,3-Dipolar Cycloaddition for In-Situ Preparation of Poly(THF-co-GAP-Based Polyurethane Energetic Binders

Directory of Open Access Journals (Sweden)

Mingyang Ma

2018-05-01

Full Text Available Reactive energetic plasticizers (REPs coupled with hydroxy-telechelic poly(glycidyl azide-co-tetrahydrofuran (PGT-based energetic polyurethane (PU binders for use in solid propellants and plastic-bonded explosives (PBXs were investigated. The generation of gem-dinitro REPs along with a terminal alkyne stemmed from a series of finely designed approaches to not only satisfy common demands as conventional energetic plasticizers, but also to prevent the migration of plasticizers. The miscibility and rheological behavior of a binary mixture of PGT/REP with various REP fractions were quantitatively determined by differential scanning calorimetry (DSC and rheometer, respectively, highlighting the promising performance of REPs in the formulation process. The kinetics on the distinct reactivity of propargyl vs. 3-butynyl species of REPs towards the azide group of the PGT prepolymer in terms of Cu-free azide-alkyne 1,3-dipolar cycloaddition (1,3-DPCA was studied by monitoring 1H nuclear magnetic resonance spectroscopy and analyzing the activation energies (Ea obtained using DSC. The thermal stability of the finally cured energetic binders with the incorporation of REPs indicated that the thermal stability of the REP/PGT-based PUs was maintained independently of the REP content. The tensile strength and modulus of the PUs increased with an increase in the REP content. In addition, the energetic performance and sensitivity of REP and REP triazole species was predicted.

Cardiac troponin and tropomyosin: structural and cellular perspectives to unveil the Hypertrophic Cardiomyopathy phenotype

Directory of Open Access Journals (Sweden)

Mayra de A. Marques

2016-09-01

Full Text Available Inherited myopathies affect both skeletal and cardiac muscle and are commonly associated with genetic dysfunctions, leading to the production of anomalous proteins. In cardiomyopathies, mutations frequently occur in sarcomeric genes, but the cause-effect scenario between genetic alterations and pathological processes remains elusive. Hypertrophic cardiomyopathy (HCM was the first cardiac disease associated with a genetic background. Since the discovery of the first mutation in the β-myosin heavy chain, more than 1,400 new mutations in 11 sarcomeric genes have been reported, awarding HCM the title of the disease of the sarcomere. The most common macroscopic phenotypes are left ventricle and interventricular septal thickening, but because the clinical profile of this disease is quite heterogeneous, these phenotypes are not suitable for an accurate diagnosis. The development of genomic approaches for clinical investigation allows for diagnostic progress and understanding at the molecular level. Meanwhile, the lack of accurate in vivo models to better comprehend the cellular events triggered by this pathology has become a challenge. Notwithstanding, the imbalance of Ca2+ concentrations, altered signaling pathways, induction of apoptotic factors, and heart remodeling leading to abnormal anatomy have already been reported. Of note, a misbalance of signaling biomolecules, such as kinases and tumor suppressors (e.g., Akt and p53, seems to participate in apoptotic and fibrotic events. In HCM, structural and cellular information about defective sarcomeric proteins and their altered interactome is emerging but still represents a bottleneck for developing new concepts in basic research and for future therapeutic interventions. This review focuses on the structural and cellular alterations triggered by HCM-causing mutations in troponin and tropomyosin proteins and how structural biology can aid in the discovery of new platforms for therapeutics. We

Early dystrophin loss is coincident with the transition of compensated cardiac hypertrophy to heart failure.

Directory of Open Access Journals (Sweden)

Fernanda P Prado

Full Text Available Hypertension causes cardiac hypertrophy, one of the most important risk factors for heart failure (HF. Despite the importance of cardiac hypertrophy as a risk factor for the development of HF, not all hypertrophied hearts will ultimately fail. Alterations of cytoskeletal and sarcolemma-associated proteins are considered markers cardiac remodeling during HF. Dystrophin provides mechanical stability to the plasma membrane through its interactions with the actin cytoskeleton and, indirectly, to extracellular matrix proteins. This study was undertaken to evaluate dystrophin and calpain-1 in the transition from compensated cardiac hypertrophy to HF. Wistar rats were subjected to abdominal aorta constriction and killed at 30, 60 and 90 days post surgery (dps. Cardiac function and blood pressure were evaluated. The hearts were collected and Western blotting and immunofluorescence performed for dystrophin, calpain-1, alpha-fodrin and calpastatin. Statistical analyses were performed and considered significant when p<0.05. After 90 dps, 70% of the animals showed hypertrophic hearts (HH and 30% hypertrophic+dilated hearts (HD. Systolic and diastolic functions were preserved at 30 and 60 dps, however, decreased in the HD group. Blood pressure, cardiomyocyte diameter and collagen content were increased at all time points. Dystrophin expression was lightly increased at 30 and 60 dps and HH group. HD group showed decreased expression of dystrophin and calpastatin and increased expression of calpain-1 and alpha-fodrin fragments. The first signals of dystrophin reduction were observed as early as 60 dps. In conclusion, some hearts present a distinct molecular pattern at an early stage of the disease; this pattern could provide an opportunity to identify these failure-prone hearts during the development of the cardiac disease. We showed that decreased expression of dystrophin and increased expression of calpains are coincident and could work as possible

Organization of the national energetic institutions

International Nuclear Information System (INIS)

Waltenberg, D.A.M.

1983-01-01

This text broaches, in a critical pourt of view, the organization of national energetic institutions, the need of a law revision, the problem of the rising of tariff and shows the decisions of GC01 [pt

Pulsations of Energetic Electron Pulsations In Association With Substorm Onset

Science.gov (United States)

Åsnes, A.; Stadsnes, J.; Bjordal, J.; Østgaard, N.; Haaland, S.; Rosenberg, T. J.; Detrick, D. L.

The Polar Ionospheric X-ray Imaging Experiment (PIXIE) is giving detailed images of the energetic electron precipitation when the POLAR satellite is near perigee over the Antarctica. In this area the PIXIE images have a spatial resolution of the order of 100 km, and a temporal resolution of 10 s can be obtained. In this paper we present the results of a study focusing on the onset and expansion of a substorm occuring on July 24, 1998. In this event we observe strong modulations of the energetic electron precipitation with period around 1 minute following substorm onset. The pulsations were restricted to a narrow magnetic local time sector in the pre-midnight region, about 0.5 hours wide, and showed movement towards higher latitudes and earlier lo- cal times. The event will be discussed in context of measurements from ground sta- tions and satellites in geosynchronous orbit. Precipitation of energetic electrons will be compared with VLF/ELF ground measurements. Features in the energetic elec- tron precipitation will be mapped to the magnetospheric equatorial plane by field line tracing.

Cardiac CT and cardiac MRI - competitive or complementary for nuclear cardiology

International Nuclear Information System (INIS)

Moshage, W.

2004-01-01

In summary, cardiac computed tomography (CT) and cardiac magnetic resonance (MR) are two different technologies with distinct imaging properties that gain increasing importance in clinical cardiology. Even though images may look similar, the areas of application of CT and MR are quite different. Clinical applications of cardiac CT focus on on-invasive imaging of the coronary arteries. In this respect, the higher spatial resolution of cardiac CT constitutes a significant advantage as compared to MR and clinical results are superior. Clinical applications of cardiac MR, next to morphologic imaging of the heart, are most frequently found in the context of intra-and pericardial masses, complex congenital anomalies, and the assessment of left ventricular function (dobutamine) and perfusion (adenosine) under stress. The evaluation of the size and localization of myocardial necrosis, scars, and fibrosis gains increasing importance, for example in the workup of myocardial infarction, but also myocarditis and cardiomyopathies. In this respect, magnetic resonance imaging partly constitutes an alternative to nuclear medicine methods. Due to the lack of ionizing radiation and a relatively high spatial resolution, an increase of MR diagnostic procedures at the expense of nuclear medicine can be expected. (orig.)

ENERGETIC EXTREMES IN REEF FISH OCCUPYING HARSH HABITATS

DEFF Research Database (Denmark)

Steffensen, John Fleng

2009-01-01

document how relatively small changes in fin morphology has afforded some coral reef fish taxa with exceptional locomotor performance and energetic efficiency, and how this key attribute may have played a key role in the evolution and ecology of several diverse Indo-Pacific reef fish families. Using......-finned counterparts. We discuss how such differences in locomotor efficiency are pivotal to the habitat-use of these fishes, and how eco-energetic models may be used to provide new insights into spatial variations in fish demography and ecology among coral reef habitat zones....

Relationship between cardiac output and effective renal plasma flow in patients with cardiac disease

Energy Technology Data Exchange (ETDEWEB)

McGriffin, D; Tauxe, W N; Lewis, C; Karp, R; Mantle, J

1984-12-01

The relationship between effective renal plasma flow (ERPF) and cardiac output was examined in 46 patients (22 with congestive heart failure and 24 following cardiac surgical procedures) by simultaneously measuring the global ERPF by the single-injection method and cardiac output by the thermodilution method. Of the patients in the heart-failure group, 21 also had pulmonary artery end diastolic pressure (PAEDP) recorded at the same time. ERPF and cardiac output were found to be related by the regression equations: cardiac output = 2.08 + 0.0065 ERPF (r, 080), with a SE of estimate of 0.81 l/min. ERPF and PAEDP were related by the regression equation: PAEDP = 42.02 - 0.0675 ERPF (r, 0.86), with a SE of estimate of 5.5 mm Hg. ERPF may be a useful noninvasive method of estimating cardiac output if it is known that no intrinsic kidney disease is present, and if the error of 0.81 l/min (1 SE of estimate) is within the range of clinical usefulness. The error is principally attributable to the determination of cardiac output by the thermodilution method.

Hybrid options for treating cardiac disease.

Science.gov (United States)

Umakanthan, Ramanan; Leacche, Marzia; Zhao, David X; Gallion, Anna H; Mishra, Prabodh C; Byrne, John G

2011-01-01

The options for treating heart disease have greatly expanded during the course of the last 2 1/2 decades with the advent of hybrid technology. The hybrid option for treating cardiac disease implies using the technology of both interventional cardiology and cardiac surgery to treat cardiac disease. This rapidly developing technology has given rise to new and creative techniques to treat cardiac disease involving coronary artery disease, coronary artery disease and cardiac valve disease, and atrial fibrillation. It has also led to the establishment of new procedural suites called hybrid operating rooms that facilitate the integration of technologies of interventional cardiology catheterization laboratories with those of cardiac surgery operating rooms. The development of hybrid options for treating cardiac disease has also greatly augmented teamwork and collaboration between interventional cardiologists and cardiac surgeons. Copyright © 2011 Elsevier Inc. All rights reserved.

Cardiac CT

International Nuclear Information System (INIS)

Dewey, Marc

2011-01-01

Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

Cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

2011-07-01

Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

Dysglycemia, Glycemic Variability, and Outcome After Cardiac Arrest and Temperature Management at 33°C and 36°C

DEFF Research Database (Denmark)

Borgquist, Ola; Wise, Matt P; Nielsen, Niklas

2017-01-01

OBJECTIVES: Dysglycemia and glycemic variability are associated with poor outcomes in critically ill patients. Targeted temperature management alters blood glucose homeostasis. We investigated the association between blood glucose concentrations and glycemic variability and the neurologic outcomes...... of patients randomized to targeted temperature management at 33°C or 36°C after cardiac arrest. DESIGN: Post hoc analysis of the multicenter TTM-trial. Primary outcome of this analysis was neurologic outcome after 6 months, referred to as "Cerebral Performance Category." SETTING: Thirty-six sites in Europe...... and Australia. PATIENTS: All 939 patients with out-of-hospital cardiac arrest of presumed cardiac cause that had been included in the TTM-trial. INTERVENTIONS: Targeted temperature management at 33°C or 36°C. MEASUREMENTS AND MAIN RESULTS: Nonparametric tests as well as multiple logistic regression and mixed...

The cardiovascular and cardiac actions of ecstasy and its metabolites.

Science.gov (United States)

Shenouda, S K; Carvalho, F; Varner, K J

2010-08-01

The recreational use of 3, 4 methylenedioxymethamphetamine (ecstasy or MDMA) has increased dramatically over the past thirty years due to its ability to increase stamina and produce feelings of emotional closeness and wellbeing. In spite of the popular perception that MDMA is a safe drug, there is a large literature documenting that the drug can produce significant neurotoxicity, especially in serotonergic and catecholaminergic systems. There are also experimental and clinical data which document that MDMA can alter cardiovascular function and produce cardiac toxicity, including rhythm disturbances, infarction and sudden death. This manuscript will review the literature documenting the cardiovascular responses elicited by MDMA in humans and experimental animals and will examine the underlying mechanisms mediating these responses. We will also review the available clinical, autopsy and experimental data linking MDMA with cardiac toxicity. Most available data indicate that oxidative stress plays an important role in the cardiotoxic actions of MDMA. Moreover, new data indicates that redox active metabolites of MDMA may play especially important roles in MDMA induced toxicity.

Effect of prolonged space flight on cardiac function and dimensions

Science.gov (United States)

Henry, W. L.; Epstein, S. E.; Griffith, J. M.; Goldstein, R. E.; Redwood, D. R.

1974-01-01

Echocardiographic studies were performed preflight 5 days before launch and on recovery day and 1, 2, 4, 11, 31 and 68 days postflight. From these echocardiograms measurements were made. From these primary measurements, left ventricular end-diastolic volume, end-systolic volume, stroke volume, and mass were derived using the accepted assumptions. Findings in the Scientist Pilot and Pilot resemble those seen in trained distance runners. Wall thickness measurements were normal in all three crewmembers preflight. Postflight basal studies were unchanged in the Commander on recovery day through 68 days postflight in both the Scientist Pilot and Pilot, however, the left ventricular end-diastolic volume, stroke volume, and mass were decreased slightly. Left ventricular function curves were constructed for the Commander and Pilot by plotting stroke volume versus end-diastolic volume. In both astronauts, preflight and postflight data fell on the same straight line demonstrating that no deterioration in cardiac function had occurred. These data indicate that the cardiovascular system adapts well to prolonged weightlessness and suggest that alterations in cardiac dimensions and function are unlikely to limit man's future in space.

Energetic ion driven Alfven eigenmodes in Large Helical Device plasmas with three-dimensional magnetic structure and their impact on energetic ion transport

International Nuclear Information System (INIS)

Toi, K; Yamamoto, S; Nakajima, N; Ohdachi, S; Sakakibara, S; Osakabe, M; Murakami, S; Watanabe, K Y; Goto, M; Kawahata, K; Kolesnichenko, Ya I; Masuzaki, S; Morita, S; Narihara, K; Narushima, Y; Takeiri, Y; Tanaka, K; Tokuzawa, T; Yamada, H; Yamada, I; Yamazaki, K

2004-01-01

In the Large Helical Device (LHD), energetic ion driven Alfven eigenmodes (AEs) and their impact on energetic ion transport have been studied. The magnetic configuration of the LHD is three-dimensional and has negative magnetic shear over a whole plasma radius in the low beta regime. These features introduce the characteristic structures of the shear Alfven spectrum. In particular, a core-localized type of toroidicity-induced AE (TAE) is most likely because the TAE gap frequency rapidly increases towards the plasma edge. Moreover, helicity-induced AEs (HAEs) can be generated through a toroidal mode coupling as well as poloidal one in the three-dimensional configuration. The following experimental results have been obtained in LHD plasmas heated by tangential neutral beam injection: (1) observation of core-localized TAEs having odd as well as even parity, (2) eigenmode transition of the core-localized TAE to global AEs (GAEs), which phenomenon is very similar to that in a reversed shear tokamak, (3) observation of HAEs of which the frequency is about eight times higher than the TAE gap frequency, (4) enhanced radial transport/loss of energetic ions caused by bursting TAEs in a relatively high beta regime, and (5) seed formation of internal transport barriers induced by TAE-induced energetic ion transport. These results will be important and interesting information for AE physics in toroidal plasmas

Energetic Electron Acceleration and Injection During Dipolarization Events in Mercury's Magnetotail

Science.gov (United States)

Dewey, Ryan M.; Slavin, James A.; Raines, Jim M.; Baker, Daniel N.; Lawrence, David J.

2017-12-01

Energetic particle bursts associated with dipolarization events within Mercury's magnetosphere were first observed by Mariner 10. The events appear analogous to particle injections accompanying dipolarization events at Earth. The Energetic Particle Spectrometer (3 s resolution) aboard MESSENGER determined the particle bursts are composed entirely of electrons with energies ≳ 300 keV. Here we use the Gamma-Ray Spectrometer high-time-resolution (10 ms) energetic electron measurements to examine the relationship between energetic electron injections and magnetic field dipolarization in Mercury's magnetotail. Between March 2013 and April 2015, we identify 2,976 electron burst events within Mercury's magnetotail, 538 of which are closely associated with dipolarization events. These dipolarizations are detected on the basis of their rapid ( 2 s) increase in the northward component of the tail magnetic field (ΔBz 30 nT), which typically persists for 10 s. Similar to those at Earth, we find that these dipolarizations appear to be low-entropy, depleted flux tubes convecting planetward following the collapse of the inner magnetotail. We find that electrons experience brief, yet intense, betatron and Fermi acceleration during these dipolarizations, reaching energies 130 keV and contributing to nightside precipitation. Thermal protons experience only modest betatron acceleration. While only 25% of energetic electron events in Mercury's magnetotail are directly associated with dipolarization, the remaining events are consistent with the Near-Mercury Neutral Line model of magnetotail injection and eastward drift about Mercury, finding that electrons may participate in Shabansky-like closed drifts about the planet. Magnetotail dipolarization may be the dominant source of energetic electron acceleration in Mercury's magnetosphere.

Magneto-Hydrodynamic Activity and Energetic Particles - Application to Beta Alfven Eigenmodes

International Nuclear Information System (INIS)

Nguyen, Ch.

2009-12-01

The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on our ability to confine these energetic particles, while keeping the thermonuclear plasma in safe operating conditions. For that purpose, it is necessary to understand and find ways to control the interaction between energetic particles and the thermonuclear plasma. Reaching these two goals is the general motivation for this work. More specifically, our focus is on one type of instability, the Beta Alfven Eigenmode (BAE), which can be driven by energetic particles and impact on the confinement of both energetic and thermal particles. In this work, we study the characteristics of BAEs analytically and derive its dispersion relation and structure. Next, we analyze the linear stability of the mode in the presence of energetic particles. First, a purely linear description is used, which makes possible to get an analytical linear criterion for BAE destabilization in the presence of energetic particles. This criterion is compared with experiments conducted in the Tore-Supra tokamak. Secondly, because the linear analysis reveals some features of the BAE stability which are subject to a strong nonlinear modification, the question is raised of the possibility of a sub-critical activity of the mode. We propose a simple scenario which makes possible the existence of meta-stable modes, verified analytically and numerically. Such a scenario is found to be relevant to the physics and scales characterizing BAEs. (author)

Nitrates for the prevention of cardiac morbidity and mortality in patients undergoing non-cardiac surgery.

Science.gov (United States)

Zhao, Na; Xu, Jin; Singh, Balwinder; Yu, Xuerong; Wu, Taixiang; Huang, Yuguang

2016-08-04

Cardiac complications are not uncommon in patients undergoing non-cardiac surgery, especially in patients with coronary artery disease (CAD) or at high risk of CAD. Perioperative cardiac complications can lead to mortality and morbidity, as well as higher costs for patient care. Nitrates, which are among the most commonly used cardiovascular drugs, perform the function of decreasing cardiac preload while improving cardiac blood perfusion. Sometimes, nitrates are administered to patients undergoing non-cardiac surgery to reduce the incidence of cardiac complications, especially for patients with CAD. However, their effects on patients' relevant outcomes remain controversial. • To assess effects of nitrates as compared with other interventions or placebo in reducing cardiac risk (such as death caused by cardiac factors, angina pectoris, acute myocardial infarction, acute heart failure and cardiac arrhythmia) in patients undergoing non-cardiac surgery.• To identify the influence of different routes and dosages of nitrates on patient outcomes. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Chinese BioMedical Database until June 2014. We also searched relevant conference abstracts of important anaesthesiology or cardiology scientific meetings, the database of ongoing trials and Google Scholar.We reran the search in January 2016. We added three potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate them into our formal review findings for the review update. We included randomized controlled trials (RCTs) comparing nitrates versus no treatment, placebo or other pharmacological interventions in participants (15 years of age and older) undergoing non-cardiac surgery under any type of anaesthesia. We used standard methodological procedures as expected by Cochrane. Two review authors selected trials, extracted data from included studies and assessed risk of bias. We

Therapeutic effect of a novel Wnt pathway inhibitor on cardiac regeneration after myocardial infarction.

Science.gov (United States)

Yang, Dezhong; Fu, Wenbin; Li, Liangpeng; Xia, Xuewei; Liao, Qiao; Yue, Rongchuan; Chen, Hongmei; Chen, Xiongwen; An, Songzhu; Zeng, Chunyu; Wang, Wei Eric

2017-12-15

After myocardial infarction (MI), the heart is difficult to repair because of great loss of cardiomyoctyes and lack of cardiac regeneration. Novel drug candidates that aim at reducing pathological remodeling and stimulating cardiac regeneration are highly desirable. In the present study, we identified if and how a novel porcupine inhibitor CGX1321 influenced MI and cardiac regeneration. Permanent ligation of left anterior descending (LAD) coronary artery was performed in mice to induce MI injury. Cardiac function was measured by echocardiography, infarct size was examined by TTC staining. Fibrosis was evaluated with Masson's trichrome staining and vimentin staining. As a result, CGX1321 administration blocked the secretion of Wnt proteins, and inhibited both canonical and non-canonical Wnt signaling pathways. CGX1321 improved cardiac function, reduced myocardial infarct size, and fibrosis of post-MI hearts. CGX1321 significantly increased newly formed cardiomyocytes in infarct border zone of post-MI hearts, evidenced by the increased EdU + cardiomyocytes. Meanwhile, CGX1321 increased Ki67 + and phosphohistone H3 (PH3 + ) cardiomyocytes in culture, indicating enhanced cardiomyocyte proliferation. The mRNA microarray showed that CGX1321 up-regulated cell cycle regulating genes such as Ccnb1 and Ccne1 CGX1321 did not alter YAP protein phosphorylation and nuclear translocation in cardiomyocytes. In conclusion, porcupine inhibitor CGX1321 reduces MI injury by limiting fibrosis and promoting regeneration. It promotes cardiomyocyte proliferation by stimulating cell cycle regulating genes with a Hippo/YAP-independent pathway. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Sunward-propagating Solar Energetic Electrons inside Multiple Interplanetary Flux Ropes

Energy Technology Data Exchange (ETDEWEB)

Gómez-Herrero, Raúl; Hidalgo, Miguel A.; Carcaboso, Fernando; Blanco, Juan J. [Dpto. de Física y Matemáticas, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid (Spain); Dresing, Nina; Klassen, Andreas; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, University of Kiel, D-24118, Kiel (Germany); Temmer, Manuela; Veronig, Astrid [Institute of Physics/Kanzelhöhe Observatory, University of Graz, A-8010 Graz (Austria); Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Lario, David, E-mail: raul.gomezh@uah.es [The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States)

2017-05-10

On 2013 December 2 and 3, the SEPT and STE instruments on board STEREO-A observed two solar energetic electron events with unusual sunward-directed fluxes. Both events occurred during a time interval showing typical signatures of interplanetary coronal mass ejections (ICMEs). The electron timing and anisotropies, combined with extreme-ultraviolet solar imaging and radio wave spectral observations, are used to confirm the solar origin and the injection times of the energetic electrons. The solar source of the ICME is investigated using remote-sensing observations and a three-dimensional reconstruction technique. In situ plasma and magnetic field data combined with energetic electron observations and a flux-rope model are used to determine the ICME magnetic topology and the interplanetary electron propagation path from the Sun to 1 au. Two consecutive flux ropes crossed the STEREO-A location and each electron event occurred inside a different flux rope. In both cases, the electrons traveled from the solar source to 1 au along the longest legs of the flux ropes still connected to the Sun. During the December 2 event, energetic electrons propagated along the magnetic field, while during the December 3 event they were propagating against the field. As found by previous studies, the energetic electron propagation times are consistent with a low number of field line rotations N < 5 of the flux rope between the Sun and 1 au. The flux rope model used in this work suggests an even lower number of rotations.

Maternal cardiac metabolism in pregnancy

Science.gov (United States)

Liu, Laura X.; Arany, Zolt

2014-01-01

Pregnancy causes dramatic physiological changes in the expectant mother. The placenta, mostly foetal in origin, invades maternal uterine tissue early in pregnancy and unleashes a barrage of hormones and other factors. This foetal ‘invasion’ profoundly reprogrammes maternal physiology, affecting nearly every organ, including the heart and its metabolism. We briefly review here maternal systemic metabolic changes during pregnancy and cardiac metabolism in general. We then discuss changes in cardiac haemodynamic during pregnancy and review what is known about maternal cardiac metabolism during pregnancy. Lastly, we discuss cardiac diseases during pregnancy, including peripartum cardiomyopathy, and the potential contribution of aberrant cardiac metabolism to disease aetiology. PMID:24448314

{sup 123}I-MIBG imaging detects cardiac involvement and predicts cardiac events in Churg-Strauss syndrome

Energy Technology Data Exchange (ETDEWEB)

Horiguchi, Yoriko; Morita, Yukiko [National Hospital Organization Sagamihara National Hospital, Department of Cardiology, Sagamihara City, Kanagawa (Japan); Tsurikisawa, Naomi; Akiyama, Kazuo [National Hospital Organization Sagamihara National Hospital, Clinical Research Centre for Allergy and Rheumatology, Sagamihara City, Kanagawa (Japan)

2011-02-15

In Churg-Strauss syndrome (CSS) it is important to detect cardiac involvement, which predicts poor prognosis. This study evaluated whether {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy could detect cardiac damage and predict cardiac events in CSS. {sup 123}I-MIBG scintigraphy was performed in 28 patients with CSS, 12 of whom had cardiac involvement. The early and delayed heart to mediastinum ratio (early H/M and delayed H/M) and washout rate were calculated by using {sup 123}I-MIBG scintigraphy and compared with those in control subjects. Early H/M and delayed H/M were significantly lower and the washout rate was significantly higher in patients with cardiac involvement than in those without and in controls (early H/M, p = 0.0024, p = 0.0001; delayed H/M, p = 0.0002, p = 0.0001; washout rate, p = 0.0012, p = 0.0052 vs those without and vs controls, respectively). Accuracy for detecting cardiac involvement was 86% for delayed H/M and washout rate and 79% for early H/M and B-type natriuretic peptide (BNP). Kaplan-Meier analysis showed significantly lower cardiac event-free rates in patients with early H/M {<=} 2.18 and BNP > 21.8 pg/ml than those with early H/M > 2.18 and BNP {<=} 21.8 pg/ml (log-rank test p = 0.006). Cardiac sympathetic nerve function was damaged in CSS patients with cardiac involvement. {sup 123}I-MIBG scintigraphy was useful in detecting cardiac involvement and in predicting cardiac events. (orig.)

Energetics of edge oxidization of graphene nanoribbons

Science.gov (United States)

Yasuma, Airi; Yamanaka, Ayaka; Okada, Susumu

2018-06-01

On the basis of the density functional theory, we studied the geometries and energetics of O atoms adsorbed on graphene edges for simulating the initial stage of the edge oxidization of graphene. Our calculations showed that oxygen atoms are preferentially adsorbed onto the graphene edges with the zigzag portion, resulting in a large adsorption energy of about 5 eV. On the other hand, the edges with armchair shape are rarely oxidized, or the oxidization causes substantial structural reconstructions, because of the stable covalent bond at the armchair edge with the triple bond nature. Furthermore, the energetics sensitively depends on the edge angles owing to the inhomogeneity of the charge density at the edge atomic sites.

Energetic particles at venus: galileo results.

Science.gov (United States)

Williams, D J; McEntire, R W; Krimigis, S M; Roelof, E C; Jaskulek, S; Tossman, B; Wilken, B; Stüdemann, W; Armstrong, T P; Fritz, T A; Lanzerotti, L J; Roederer, J G

1991-09-27

At Venus the Energetic Particles Detector (EPD) on the Galileo spacecraft measured the differential energy spectra and angular distributions of ions >22 kiloelectron volts (keV) and electrons > 15 keV in energy. The only time particles were observed by EPD was in a series of episodic events [0546 to 0638 universal time (UT)] near closest approach (0559:03 UT). Angular distributions were highly anisotropic, ordered by the magnetic field, and showed ions arriving from the hemisphere containing Venus and its bow shock. The spectra showed a power law form with intensities observed into the 120- to 280-keV range. Comparisons with model bow shock calculations show that these energetic ions are associated with the venusian foreshock-bow shock region. Shock-drift acceleration in the venusian bow shock seems the most likely process responsible for the observed ions.

CIRCUMSOLAR ENERGETIC PARTICLE DISTRIBUTION ON 2011 NOVEMBER 3

Energy Technology Data Exchange (ETDEWEB)

Gómez-Herrero, R.; Blanco, J.J.; Rodríguez-Pacheco, J. [SRG, Universidad de Alcalá, E-28871 Alcalá de Henares (Spain); Dresing, N.; Klassen, A.; Heber, B.; Banjac, S. [IEAP, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel (Germany); Lario, D. [The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States); Agueda, N. [Departament d' Astronomia i Meteorologia. Institut de Ciències del Cosmos. Universitat de Barcelona, E-08028 Barcelona (Spain); Malandraki, O. E., E-mail: raul.gomezh@uah.es [IAASARS, National Observatory of Athens, GR-15236 Penteli (Greece)

2015-01-20

Late on 2011 November 3, STEREO-A, STEREO-B, MESSENGER, and near-Earth spacecraft observed an energetic particle flux enhancement. Based on the analysis of in situ plasma and particle observations, their correlation with remote sensing observations, and an interplanetary transport model, we conclude that the particle increases observed at multiple locations had a common single-source active region and the energetic particles filled a very broad region around the Sun. The active region was located at the solar backside (as seen from Earth) and was the source of a large flare, a fast and wide coronal mass ejection, and an EIT wave, accompanied by type II and type III radio emission. In contrast to previous solar energetic particle events showing broad longitudinal spread, this event showed clear particle anisotropies at three widely separated observation points at 1 AU, suggesting direct particle injection close to the magnetic footpoint of each spacecraft, lasting for several hours. We discuss these observations and the possible scenarios explaining the extremely broad particle spread for this event.

Deep energetic trap states in organic photovoltaic devices

KAUST Repository

Shuttle, Christopher G.; Treat, Neil D.; Douglas, Jessica D.; Frechet, Jean; Chabinyc, Michael L.

2011-01-01

The nature of energetic disorder in organic semiconductors is poorly understood. In photovoltaics, energetic disorder leads to reductions in the open circuit voltage and contributes to other loss processes. In this work, three independent optoelectronic methods were used to determine the long-lived carrier populations in a high efficiency N-alkylthieno[3,4-c]pyrrole-4,6-dione (TPD) based polymer: fullerene solar cell. In the TPD co-polymer, all methods indicate the presence of a long-lived carrier population of ∼ 10 15 cm -3 on timescales ≤100 μs. Additionally, the behavior of these photovoltaic devices under optical bias is consistent with deep energetic lying trap states. Comparative measurements were also performed on high efficiency poly-3-hexylthiophene (P3HT): fullerene solar cells; however a similar long-lived carrier population was not observed. This observation is consistent with a higher acceptor concentration (doping) in P3HT than in the TPD-based copolymer. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deep energetic trap states in organic photovoltaic devices

KAUST Repository

Shuttle, Christopher G.

2011-11-23

The nature of energetic disorder in organic semiconductors is poorly understood. In photovoltaics, energetic disorder leads to reductions in the open circuit voltage and contributes to other loss processes. In this work, three independent optoelectronic methods were used to determine the long-lived carrier populations in a high efficiency N-alkylthieno[3,4-c]pyrrole-4,6-dione (TPD) based polymer: fullerene solar cell. In the TPD co-polymer, all methods indicate the presence of a long-lived carrier population of ∼ 10 15 cm -3 on timescales ≤100 μs. Additionally, the behavior of these photovoltaic devices under optical bias is consistent with deep energetic lying trap states. Comparative measurements were also performed on high efficiency poly-3-hexylthiophene (P3HT): fullerene solar cells; however a similar long-lived carrier population was not observed. This observation is consistent with a higher acceptor concentration (doping) in P3HT than in the TPD-based copolymer. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

LENUS (Irish Health Repository)

Martos, R

2012-02-01

INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

UCP3 Ablation Exacerbates High-Salt Induced Cardiac Hypertrophy and Cardiac Dysfunction

Directory of Open Access Journals (Sweden)

Hongmei Lang

2018-04-01

Full Text Available Background/Aims: Excessive salt intake and left ventricular hypertrophy (LVH are both critical for the development of hypertension and heart failure. The uncoupling protein 3 (UCP3 plays a cardio-protective role in early heart failure development. However, the potential role for UCP3 in salt intake and LVH is unclear. Methods: UCP3-/- and C57BL/6 mice were placed on either a normal-salt (NS, 0.5% or a high-salt (HS, 8% diet for 24 weeks. The cardiac function, endurance capacity, energy expenditure, and mitochondrial functional capacity were measured in each group. Results: Elevated blood pressure was only observed in HS-fed UCP3-/- mice. High salt induced cardiac hypertrophy and dysfunction were observed in both C57BL/6 and UCP3-/- mice. However, the cardiac lesions were more profound in HS-fed UCP3-/- mice. Furthermore, HS-fed UCP3-/-mice experienced more severe mitochondrial respiratory dysfunction compared with HS-fed C57BL/6 mice, represented by the decreased volume of oxygen consumption and heat production at the whole-body level. Conclusion: UCP3 protein was involved in the incidence of high-salt induced hypertension and the progression of cardiac dysfunction in the early stages of heart failure. UCP3 ablation exacerbated high-salt-induced cardiac hypertrophy and cardiac dysfunction.

Cardiac retransplantation is an efficacious therapy for primary cardiac allograft failure

Directory of Open Access Journals (Sweden)

Acker Michael A

2008-05-01

Full Text Available Abstract Background Although orthotopic heart transplantation has been an effective treatment for end-stage heart failure, the incidence of allograft failure has increased, necessitating treatment options. Cardiac retransplantation remains the only viable long-term solution for end-stage cardiac allograft failure. Given the limited number of available donor hearts, the long term results of this treatment option need to be evaluated. Methods 709 heart transplants were performed over a 20 year period at our institution. Repeat cardiac transplantation was performed in 15 patients (2.1%. A retrospective analysis was performed to determine the efficacy of cardiac retransplantation. Variables investigated included: 1 yr and 5 yr survival, length of hospitalization, post-operative complications, allograft failure, recipient and donor demographics, renal function, allograft ischemic time, UNOS listing status, blood group, allograft rejection, and hemodynamic function. Results Etiology of primary graft failure included transplant arteriopathy (n = 10, acute rejection (n = 3, hyperacute rejection (n = 1, and a post-transplant diagnosis of metastatic melanoma in the donor (n = 1. Mean age at retransplantation was 45.5 ± 9.7 years. 1 and 5 year survival for retransplantation were 86.6% and 71.4% respectively, as compared to 90.9% and 79.1% for primary transplantation. Mean ejection fraction was 67.3 ± 12.2% at a mean follow-up of 32.6 ± 18.5 mos post-retransplant; follow-up biopsy demonstrated either ISHLT grade 1A or 0 rejection (77.5 ± 95.7 mos post-transplant. Conclusion Cardiac retransplantation is an efficacious treatment strategy for cardiac allograft failure.

Cardiac atrophy after bed rest and spaceflight

Science.gov (United States)

Perhonen, M. A.; Franco, F.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.; Zerwekh, J. E.; Peshock, R. M.; Weatherall, P. T.; Levine, B. D.

2001-01-01

Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

Cardiac echinococcosis

Directory of Open Access Journals (Sweden)

Ivanović-Krstić Branislava A.

2002-01-01

Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

An automatic system to study sperm motility and energetics

OpenAIRE

Shi, LZ; Nascimento, JM; Chandsawangbhuwana, C; Botvinick, EL; Berns, MW

2008-01-01

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membr...

The source of multi spectral energy of solar energetic electron

Energy Technology Data Exchange (ETDEWEB)

Herdiwijaya, Dhani [Astronomy Division and Bosscha Observatory, Faculty Mathematics and Natural Sciences, Intitute Technology of Bandung, Ganesha 10, Bandung, Indonesia 40132 dhani@as.itb.ac.id (Indonesia)

2015-04-16

We study the solar energetic electron distribution obtained from ACE and GOES satellites which have different altitudes and electron spectral energy during the year 1997 to 2011. The electron spectral energies were 0.038–0.315 MeV from EPAM instrument onboard ACE satellite and >2 MeV from GOES satellite. We found that the low electron energy has no correlation with high energy. In spite of we have corrected to the altitude differences. It implied that they originated from time dependent events with different sources and physical processes at the solar atmosphere. The sources of multi spectral energetic electron were related to flare and CME phenomena. However, we also found that high energetic electron comes from coronal hole.

Capturing the most energetic cosmic rays

International Nuclear Information System (INIS)

Mantsch, P.

1999-01-01

The methods of energy measurement applied to the most energetic cosmic rays are described. The rays are so rare that two gigantic systems of detectors are proposed to detect at least some of them (the Pierre Auger Project ). (Z.J.)

High frequency fishbone driven by passing energetic ions in tokamak plasmas

Science.gov (United States)

Wang, Feng; Yu, L. M.; Fu, G. Y.; Shen, Wei

2017-05-01

High frequency fishbone instability driven by passing energetic ions was first reported in the Princeton beta experiment with tangential neutral-beam-injection (Heidbrink et al 1986 Phys. Rev. Lett. 57 835-8). It could play an important role for ITER-like burning plasmas, where α particles are mostly passing particles. In this work, a generalized energetic ion distribution function and finite drift orbit width effect are considered to improve the theoretical model for passing particle driving fishbone instability. For purely passing energetic ions with zero drift orbit width, the kinetic energy δ {{W}k} is derived analytically. The derived analytic expression is more accurate as compared to the result of previous work (Wang 2001 Phys. Rev. Lett. 86 5286-8). For a generalized energetic ion distribution function, the fishbone dispersion relation is derived and is solved numerically. Numerical results show that broad and off-axis beam density profiles can significantly increase the beam ion beta threshold {βc} for instability and decrease mode frequency.

The role of conductivity discontinuities in design of cardiac defibrillation

Science.gov (United States)

Lim, Hyunkyung; Cun, Wenjing; Wang, Yue; Gray, Richard A.; Glimm, James

2018-01-01

Fibrillation is an erratic electrical state of the heart, of rapid twitching rather than organized contractions. Ventricular fibrillation is fatal if not treated promptly. The standard treatment, defibrillation, is a strong electrical shock to reinitialize the electrical dynamics and allow a normal heart beat. Both the normal and the fibrillatory electrical dynamics of the heart are organized into moving wave fronts of changing electrical signals, especially in the transmembrane voltage, which is the potential difference between the cardiac cellular interior and the intracellular region of the heart. In a normal heart beat, the wave front motion is from bottom to top and is accompanied by the release of Ca ions to induce contractions and pump the blood. In a fibrillatory state, these wave fronts are organized into rotating scroll waves, with a centerline known as a filament. Treatment requires altering the electrical state of the heart through an externally applied electrical shock, in a manner that precludes the existence of the filaments and scroll waves. Detailed mechanisms for the success of this treatment are partially understood, and involve local shock-induced changes in the transmembrane potential, known as virtual electrode alterations. These transmembrane alterations are located at boundaries of the cardiac tissue, including blood vessels and the heart chamber wall, where discontinuities in electrical conductivity occur. The primary focus of this paper is the defibrillation shock and the subsequent electrical phenomena it induces. Six partially overlapping causal factors for defibrillation success are identified from the literature. We present evidence in favor of five of these and against one of them. A major conclusion is that a dynamically growing wave front starting at the heart surface appears to play a primary role during defibrillation by critically reducing the volume available to sustain the dynamic motion of scroll waves; in contrast, virtual

Energetic proton generation in ultra-intense laser-solid interactions

International Nuclear Information System (INIS)

Wilks, S.C.; Langdon, A.B.; Cowan, T.E.; Roth, M.; Singh, M.; Hatchett, S.; Key, M. H.; Pennington, D.; MacKinnon, A.; Snavely, R.A.

2001-01-01

An explanation for the energetic ions observed in the PetaWatt experiments is presented. In solid target experiments with focused intensities exceeding 10 20 W/cm 2 , high-energy electron generation, hard bremsstrahlung, and energetic protons have been observed on the backside of the target. In this report, an attempt is made to explain the physical process present that will explain the presence of these energetic protons, as well as explain the number, energy, and angular spread of the protons observed in experiment. In particular, we hypothesize that hot electrons produced on the front of the target are sent through to the back off the target, where they ionize the hydrogen layer there. These ions are then accelerated by the hot electron cloud, to tens of MeV energies in distances of order tens of μm, whereupon they end up being detected in the radiographic and spectrographic detectors

Chemical rocket propulsion a comprehensive survey of energetic materials

CERN Document Server

Shimada, Toru; Sinditskii, Valery; Calabro, Max

2017-01-01

Developed and expanded from the work presented at the New Energetic Materials and Propulsion Techniques for Space Exploration workshop in June 2014, this book contains new scientific results, up-to-date reviews, and inspiring perspectives in a number of areas related to the energetic aspects of chemical rocket propulsion. This collection covers the entire life of energetic materials from their conceptual formulation to practical manufacturing; it includes coverage of theoretical and experimental ballistics, performance properties, as well as laboratory-scale and full system-scale, handling, hazards, environment, ageing, and disposal. Chemical Rocket Propulsion is a unique work, where a selection of accomplished experts from the pioneering era of space propulsion and current technologists from the most advanced international laboratories discuss the future of chemical rocket propulsion for access to, and exploration of, space. It will be of interest to both postgraduate and final-year undergraduate students in...

Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

Science.gov (United States)

Convertino, V. A.; Benjamin, B. A.; Keil, L. C.; Sandler, H.

1984-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes, designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients, to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of 6 deg headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate and blood pressure were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20 percent (P less than 0.05) with T, and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

Perfusionist strategies for blood conservation in pediatric cardiac surgery.

Science.gov (United States)

Durandy, Yves

2010-02-26

There is increasing concern about the safety of homologous blood transfusion during cardiac surgery, and a restrictive transfusion practice is associated with improved outcome. Transfusion-free pediatric cardiac surgery is unrealistic for the vast majority of procedures in neonates or small infants; however, considerable progress has been made by using techniques that decrease the need for homologous blood products or even allow bloodless surgery in older infants and children. These techniques involve a decrease in prime volume by downsizing the bypass circuit with the help of vacuum-assisted venous drainage, microplegia, autologous blood predonation with or without infusion of recombinant (erythropoietin), cell salvaging, ultrafiltration and retrograde autologous priming. The three major techniques which are simple, safe, efficient, and cost-effective are: a prime volume as small as possible, cardioplegia with negligible hydric balance and circuit residual blood salvaged without any alteration. Furthermore, these three techniques can be used for all the patients, including emergencies and small babies. In every pediatric surgical unit, a strategy to decrease or avoid blood bank transfusion must be implemented. A strategy to minimize transfusion requirement requires a combined effort involving the entire surgical team with pre-, peri-, and postoperative planning and management.

Nuclear cardiac

International Nuclear Information System (INIS)

Slutsky, R.; Ashburn, W.L.

1982-01-01

The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques

Discovery and progress of direct cardiac reprogramming.

Science.gov (United States)

Kojima, Hidenori; Ieda, Masaki

2017-06-01

Cardiac disease remains a major cause of death worldwide. Direct cardiac reprogramming has emerged as a promising approach for cardiac regenerative therapy. After the discovery of MyoD, a master regulator for skeletal muscle, other single cardiac reprogramming factors (master regulators) have been sought. Discovery of cardiac reprogramming factors was inspired by the finding that multiple, but not single, transcription factors were needed to generate induced pluripotent stem cells (iPSCs) from fibroblasts. We first reported a combination of cardiac-specific transcription factors, Gata4, Mef2c, and Tbx5 (GMT), that could convert mouse fibroblasts into cardiomyocyte-like cells, which were designated as induced cardiomyocyte-like cells (iCMs). Following our first report of cardiac reprogramming, many researchers, including ourselves, demonstrated an improvement in cardiac reprogramming efficiency, in vivo direct cardiac reprogramming for heart regeneration, and cardiac reprogramming in human cells. However, cardiac reprogramming in human cells and adult fibroblasts remains inefficient, and further efforts are needed. We believe that future research elucidating epigenetic barriers and molecular mechanisms of direct cardiac reprogramming will improve the reprogramming efficiency, and that this new technology has great potential for clinical applications.

Optimal Technique in Cardiac Anesthesia Recovery

OpenAIRE

Svircevic, V.

2014-01-01

The aim of this thesis is to evaluate fast-track cardiac anesthesia techniques and investigate their impact on postoperative mortality, morbidity and quality of life. The following topics will be discussed in the thesis. (1.) Is fast track cardiac anesthesia a safe technique for cardiac surgery? (2.) Does thoracic epidural anesthesia have an effect on mortality and morbidity after cardiac surgery? (3.) Does thoracic epidural anesthesia have an effect on quality of life after cardiac surgery? ...

Learning From Experience: Improving Early Tracheal Extubation Success After Congenital Cardiac Surgery.

Science.gov (United States)

Winch, Peter D; Staudt, Anna M; Sebastian, Roby; Corridore, Marco; Tumin, Dmitry; Simsic, Janet; Galantowicz, Mark; Naguib, Aymen; Tobias, Joseph D

2016-07-01

The many advantages of early tracheal extubation following congenital cardiac surgery in young infants and children are now widely recognized. Benefits include avoiding the morbidity associated with prolonged intubation and the consequences of sedation and positive pressure ventilation in the setting of altered cardiopulmonary physiology. Our practice of tracheal extubation of young infants in the operating room following cardiac surgery has evolved and new challenges in the arena of postoperative sedation and pain management have appeared. Review our institutional outcomes associated with early tracheal extubation following congenital cardiac surgery. Inclusion criteria included all children less than 1 year old who underwent congenital cardiac surgery between October 1, 2010, and October 24, 2013. A total of 416 patients less than 1 year old were included. Of the 416 patients, 234 underwent tracheal extubation in the operating room (56%) with 25 requiring reintubation (10.7%), either immediately or following admission to the cardiothoracic ICU. Of the 25 patients extubated in the operating room who required reintubation, 22 failed within 24 hours of cardiothoracic ICU admission; 10 failures were directly related to narcotic doses that resulted in respiratory depression. As a result of this review, we have instituted changes in our cardiothoracic ICU postoperative care plans. We have developed a neonatal delirium score, and have adopted the "Kangaroo Care" approach that was first popularized in neonatal ICUs. This provision allows for the early parental holding of infants following admission to the cardiothoracic ICU and allows for appropriately selected parents to sleep in the same beds alongside their postoperative children.

Rural energetic development: cuban experience; El desarrollo energetico rural: experiencia cubana

Energy Technology Data Exchange (ETDEWEB)

Aguilera Barciela, M [Secretariado Ejecutivo, Comision Nacional de Energia, La Habana(Cuba)

1994-07-01

The development of electro energetic national system in Cuba has been directed to the following objectives: to brake the rural population's exodus toward the cities, electrification of dairy farm, interconnection to the system electro energetic of all the sugar central production, these improves the rural population's conditions life.

Energy transport by energetic electrons released during solar flares. I - Thermal versus nonthermal processes

Science.gov (United States)

Winglee, R. M.; Dulk, G. A.; Pritchett, P. L.

1988-01-01

The propagation of energetic electrons through a flaring flux tube is studied in an attempt to determine how the energy of the electrons is deposited in the flux tube. One-dimensional electrostatic particle simulations are used in the present investigation. As the energetic electrons propagate into the system, a return current of ambient plasma electrons and some of the energetic electrons is drawn into the energetic electron source. It is found that, as the ambient temperature relative to the ion temperature increases above about 3, the heated return-current electrons can excite ion-sound waves.

Silencing of the Drosophila ortholog of SOX5 in heart leads to cardiac dysfunction as detected by optical coherence tomography.

Science.gov (United States)

Li, Airong; Ahsen, Osman O; Liu, Jonathan J; Du, Chuang; McKee, Mary L; Yang, Yan; Wasco, Wilma; Newton-Cheh, Christopher H; O'Donnell, Christopher J; Fujimoto, James G; Zhou, Chao; Tanzi, Rudolph E

2013-09-15

The SRY-related HMG-box 5 (SOX5) gene encodes a member of the SOX family of transcription factors. Recently, genome-wide association studies have implicated SOX5 as a candidate gene for susceptibility to four cardiac-related endophenotypes: higher resting heart rate (HR), the electrocardiographic PR interval, atrial fibrillation and left ventricular mass. We have determined that human SOX5 has a highly conserved Drosophila ortholog, Sox102F, and have employed transgenic Drosophila models to quantitatively measure cardiac function in adult flies. For this purpose, we have developed a high-speed and ultrahigh-resolution optical coherence tomography imaging system, which enables rapid cross-sectional imaging of the heart tube over various cardiac cycles for the measurement of cardiac structural and dynamical parameters such as HR, dimensions and areas of heart chambers, cardiac wall thickness and wall velocities. We have found that the silencing of Sox102F resulted in a significant decrease in HR, heart chamber size and cardiac wall velocities, and a significant increase in cardiac wall thickness that was accompanied by disrupted myofibril structure in adult flies. In addition, the silencing of Sox102F in the wing led to increased L2, L3 and wing marginal veins and increased and disorganized expression of wingless, the central component of the Wnt signaling pathway. Collectively, the silencing of Sox102F resulted in severe cardiac dysfunction and structural defects with disrupted Wnt signaling transduction in flies. This implicates an important functional role for SOX5 in heart and suggests that the alterations in SOX5 levels may contribute to the pathogenesis of multiple cardiac diseases or traits.

Calmodulin Mutations Associated with Recurrent Cardiac Arrest in Infants

Science.gov (United States)

Crotti, Lia; Johnson, Christopher N.; Graf, Elisabeth; De Ferrari, Gaetano M.; Cuneo, Bettina F.; Ovadia, Marc; Papagiannis, John; Feldkamp, Michael D.; Rathi, Subodh G.; Kunic, Jennifer D.; Pedrazzini, Matteo; Wieland, Thomas; Lichtner, Peter; Beckmann, Britt-Maria; Clark, Travis; Shaffer, Christian; Benson, D. Woodrow; Kääb, Stefan; Meitinger, Thomas; Strom, Tim M.; Chazin, Walter J.; Schwartz, Peter J.; George, Alfred L.

2013-01-01

Background Life-threatening disorders of heart rhythm may arise during infancy and can result in the sudden and tragic death of a child. We performed exome sequencing on two unrelated infants presenting with recurrent cardiac arrest to discover a genetic cause. Methods and Results We ascertained two unrelated infants (probands) with recurrent cardiac arrest and dramatically prolonged QTc interval who were both born to healthy parents. The two parent-child trios were investigated using exome sequencing to search for de novo genetic variants. We then performed follow-up candidate gene screening on an independent cohort of 82 subjects with congenital long-QT syndrome without an identified genetic cause. Biochemical studies were performed to determine the functional consequences of mutations discovered in two genes encoding calmodulin. We discovered three heterozygous de novo mutations in either CALM1 or CALM2, two of the three human genes encoding calmodulin, in the two probands and in two additional subjects with recurrent cardiac arrest. All mutation carriers were infants who exhibited life-threatening ventricular arrhythmias combined variably with epilepsy and delayed neurodevelopment. Mutations altered residues in or adjacent to critical calcium binding loops in the calmodulin carboxyl-terminal domain. Recombinant mutant calmodulins exhibited several fold reductions in calcium binding affinity. Conclusions Human calmodulin mutations disrupt calcium ion binding to the protein and are associated with a life-threatening condition in early infancy. Defects in calmodulin function will disrupt important calcium signaling events in heart affecting membrane ion channels, a plausible molecular mechanism for potentially deadly disturbances in heart rhythm during infancy. PMID:23388215

Cardiac disease and arrhythmogenesis: Mechanistic insights from mouse models

Directory of Open Access Journals (Sweden)

Lois Choy

2016-09-01

Full Text Available The mouse is the second mammalian species, after the human, in which substantial amount of the genomic information has been analyzed. With advances in transgenic technology, mutagenesis is now much easier to carry out in mice. Consequently, an increasing number of transgenic mouse systems have been generated for the study of cardiac arrhythmias in ion channelopathies and cardiomyopathies. Mouse hearts are also amenable to physical manipulation such as coronary artery ligation and transverse aortic constriction to induce heart failure, radiofrequency ablation of the AV node to model complete AV block and even implantation of a miniature pacemaker to induce cardiac dyssynchrony. Last but not least, pharmacological models, despite being simplistic, have enabled us to understand the physiological mechanisms of arrhythmias and evaluate the anti-arrhythmic properties of experimental agents, such as gap junction modulators, that may be exert therapeutic effects in other cardiac diseases. In this article, we examine these in turn, demonstrating that primary inherited arrhythmic syndromes are now recognized to be more complex than abnormality in a particular ion channel, involving alterations in gene expression and structural remodelling. Conversely, in cardiomyopathies and heart failure, mutations in ion channels and proteins have been identified as underlying causes, and electrophysiological remodelling are recognized pathological features. Transgenic techniques causing mutagenesis in mice are extremely powerful in dissecting the relative contributions of different genes play in producing disease phenotypes. Mouse models can serve as useful systems in which to explore how protein defects contribute to arrhythmias and direct future therapy.

Introduction to global energetic problems

International Nuclear Information System (INIS)

Gicquel, R.

1992-01-01

This book gives a view on global energetic problems and proposes a thorough economic analysis on principle aspects taken into account: energy supply, depending energy sources and available technologic channels, relationships between macro-economy and energy demand, new size of energy problems (environmental effects, overcosts of renewable energy sources, necessity of an high technologic development...). 38 refs

About the wind energetics development

International Nuclear Information System (INIS)

Strebkov, D.S.; Kharitonov, V.P.; Murugov, V.P.; Sokol'skij, A.K.

1996-01-01

The review of wind power energetics state in USA, Europe, Russia is given. The data of EC on wind power plants production in different periods are presented. The directions of scientific-research works with the purpose of increasing the level of wind power industry of Russia corresponding to economics demands were elaborated. (author). 8 refs., 3 tabs

A comparison of energetic ions in the plasma depletion layer and the quasi-parallel magnetosheath

Science.gov (United States)

Fuselier, Stephen A.

1994-01-01

Energetic ion spectra measured by the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer (AMPTE/CCE) downstream from the Earth's quasi-parallel bow shock (in the quasi-parallel magnetosheath) and in the plasma depletion layer are compared. In the latter region, energetic ions are from a single source, leakage of magnetospheric ions across the magnetopause and into the plasma depletion layer. In the former region, both the magnetospheric source and shock acceleration of the thermal solar wind population at the quasi-parallel shock can contribute to the energetic ion spectra. The relative strengths of these two energetic ion sources are determined through the comparison of spectra from the two regions. It is found that magnetospheric leakage can provide an upper limit of 35% of the total energetic H(+) population in the quasi-parallel magnetosheath near the magnetopause in the energy range from approximately 10 to approximately 80 keV/e and substantially less than this limit for the energetic He(2+) population. The rest of the energetic H(+) population and nearly all of the energetic He(2+) population are accelerated out of the thermal solar wind population through shock acceleration processes. By comparing the energetic and thermal He(2+) and H(+) populations in the quasi-parallel magnetosheath, it is found that the quasi-parallel bow shock is 2 to 3 times more efficient at accelerating He(2+) than H(+). This result is consistent with previous estimates from shock acceleration theory and simulati ons.

An integrated bioimpedance—ECG gating technique for respiratory and cardiac motion compensation in cardiac PET

International Nuclear Information System (INIS)

Koivumäki, Tuomas; Nekolla, Stephan G; Fürst, Sebastian; Loher, Simone; Schwaiger, Markus; Vauhkonen, Marko; Hakulinen, Mikko A

2014-01-01

Respiratory motion may degrade image quality in cardiac PET imaging. Since cardiac PET studies often involve cardiac gating by ECG, a separate respiratory monitoring system is required increasing the logistic complexity of the examination, in case respiratory gating is also needed. Thus, we investigated the simultaneous acquisition of both respiratory and cardiac gating signals using II limb lead mimicking electrode configuration during cardiac PET scans of 11 patients. In addition to conventional static and ECG-gated images, bioimpedance technique was utilized to generate respiratory- and dual-gated images. The ability of the bioimpedance technique to monitor intrathoracic respiratory motion was assessed estimating cardiac displacement between end-inspiration and -expiration. The relevance of dual gating was evaluated in left ventricular volume and myocardial wall thickness measurements. An average 7.6  ±  3.3 mm respiratory motion was observed in the study population. Dual gating showed a small but significant increase (4 ml, p = 0.042) in left ventricular myocardial volume compared to plain cardiac gating. In addition, a thinner myocardial wall was observed in dual-gated images (9.3  ±  1.3 mm) compared to cardiac-gated images (11.3  ±  1.3 mm, p = 0.003). This study shows the feasibility of bioimpedance measurements for dual gating in a clinical setting. The method enables simultaneous acquisition of respiratory and cardiac gating signals using a single device with standard ECG electrodes. (paper)

Simulation study of energetic ion transport due to Alfven eigenmodes in LHD plasma

International Nuclear Information System (INIS)

Todo, Yasushi; Nakajima, Noriyoshi; Osakabe, Masaki; Yamamoto, Satoshi; Spong, Donald A.

2008-01-01

The creation of holes and clumps in an energetic ion energy spectrum associated with Alfven eigenmodes was examined using the neutral particle analyzer (NPA) on the LHD shot no.47645. The difference in slowing-down times between the holes and clumps suggested that the energetic ions were transported over 10% of the plasma minor radius. The spatial profile and frequency of the Alfven eigenmodes were analyzed with the AE3D code. The phase space structures of the energetic ions on the NPA line-of-sight were investigated with Poincare plots, where an oscillating Alfven eigenmode was employed for earth plot. The phase space regions trapped by the Alfven eigenmodes appeared as islands in the Poincare plots. The radial width of the islands corresponded to the transport distance of the energetic ions. Since island width depends on Alfven eigenmode amplitude, it was found that Alfven eigenmodes with amplitude δB r /B - 10 -3 transported energetic ions over 10% of the minor radius. (author)

Cardiac expression of microsomal triglyceride transfer protein is increased in obesity and serves to attenuate cardiac triglyceride accumulation.

Directory of Open Access Journals (Sweden)

Emil D Bartels

Full Text Available Obesity causes lipid accumulation in the heart and may lead to lipotoxic heart disease. Traditionally, the size of the cardiac triglyceride pool is thought to reflect the balance between uptake and beta-oxidation of fatty acids. However, triglycerides can also be exported from cardiomyocytes via secretion of apolipoproteinB-containing (apoB lipoproteins. Lipoprotein formation depends on expression of microsomal triglyceride transfer protein (MTP; the mouse expresses two isoforms of MTP, A and B. Since many aspects of the link between obesity-induced cardiac disease and cardiac lipid metabolism remain unknown, we investigated how cardiac lipoprotein synthesis affects cardiac expression of triglyceride metabolism-controlling genes, insulin sensitivity, and function in obese mice. Heart-specific ablation of MTP-A in mice using Cre-loxP technology impaired upregulation of MTP expression in response to increased fatty acid availability during fasting and fat feeding. This resulted in cardiac triglyceride accumulation but unaffected cardiac insulin-stimulated glucose uptake. Long-term fat-feeding of male C57Bl/6 mice increased cardiac triglycerides, induced cardiac expression of triglyceride metabolism-controlling genes and attenuated heart function. Abolishing cardiac triglyceride accumulation in fat-fed mice by overexpression of an apoB transgene in the heart prevented the induction of triglyceride metabolism-controlling genes and improved heart function. The results suggest that in obesity, the physiological increase of cardiac MTP expression serves to attenuate cardiac triglyceride accumulation albeit without major effects on cardiac insulin sensitivity. Nevertheless, the data suggest that genetically increased lipoprotein secretion prevents development of obesity-induced lipotoxic heart disease.

Mechanotransduction and Metabolism in Cardiomyocyte Microdomains.

Science.gov (United States)

Pasqualini, Francesco S; Nesmith, Alexander P; Horton, Renita E; Sheehy, Sean P; Parker, Kevin Kit

2016-01-01

Efficient contractions of the left ventricle are ensured by the continuous transfer of adenosine triphosphate (ATP) from energy production sites, the mitochondria, to energy utilization sites, such as ionic pumps and the force-generating sarcomeres. To minimize the impact of intracellular ATP trafficking, sarcomeres and mitochondria are closely packed together and in proximity with other ultrastructures involved in excitation-contraction coupling, such as t-tubules and sarcoplasmic reticulum junctions. This complex microdomain has been referred to as the intracellular energetic unit. Here, we review the literature in support of the notion that cardiac homeostasis and disease are emergent properties of the hierarchical organization of these units. Specifically, we will focus on pathological alterations of this microdomain that result in cardiac diseases through energy imbalance and posttranslational modifications of the cytoskeletal proteins involved in mechanosensing and transduction.

Cardiac-specific overexpression of aldehyde dehydrogenase 2 exacerbates cardiac remodeling in response to pressure overload

Directory of Open Access Journals (Sweden)

Sujith Dassanayaka

2018-07-01

Full Text Available Pathological cardiac remodeling during heart failure is associated with higher levels of lipid peroxidation products and lower abundance of several aldehyde detoxification enzymes, including aldehyde dehydrogenase 2 (ALDH2. An emerging idea that could explain these findings concerns the role of electrophilic species in redox signaling, which may be important for adaptive responses to stress or injury. The purpose of this study was to determine whether genetically increasing ALDH2 activity affects pressure overload-induced cardiac dysfunction. Mice subjected to transverse aortic constriction (TAC for 12 weeks developed myocardial hypertrophy and cardiac dysfunction, which were associated with diminished ALDH2 expression and activity. Cardiac-specific expression of the human ALDH2 gene in mice augmented myocardial ALDH2 activity but did not improve cardiac function in response to pressure overload. After 12 weeks of TAC, ALDH2 transgenic mice had larger hearts than their wild-type littermates and lower capillary density. These findings show that overexpression of ALDH2 augments the hypertrophic response to pressure overload and imply that downregulation of ALDH2 may be an adaptive response to certain forms of cardiac pathology. Keywords: Heart failure, Hypertrophy, Oxidative stress, Aldehydes, Cardiac remodeling, Hormesis

Biosynthesis of cardiac natriuretic peptides

DEFF Research Database (Denmark)

Goetze, Jens Peter

2010-01-01

Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well....... An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

Gene Therapy in Cardiac Arrhythmias

Directory of Open Access Journals (Sweden)

Praveen S.V

2006-04-01

Full Text Available Gene therapy has progressed from a dream to a bedside reality in quite a few human diseases. From its first application in adenosine deaminase deficiency, through the years, its application has evolved to vascular angiogenesis and cardiac arrhythmias. Gene based biological pacemakers using viral vectors or mesenchymal cells tested in animal models hold much promise. Induction of pacemaker activity within the left bundle branch can provide stable heart rates. Genetic modification of the AV node mimicking beta blockade can be therapeutic in the management of atrial fibrillation. G protein overexpression to modify the AV node also is experimental. Modification and expression of potassium channel genes altering the delayed rectifier potassium currents may permit better management of congenital long QT syndromes. Arrhythmias in a failing heart are due to abnormal calcium cycling. Potential targets for genetic modulation include the sarcoplasmic reticulum calcium pump, calsequestrin and sodium calcium exchanger.Lastly the ethical concerns need to be addressed.

Strong non-radial propagation of energetic electrons in solar corona

Science.gov (United States)

Klassen, A.; Dresing, N.; Gómez-Herrero, R.; Heber, B.; Veronig, A.

2018-06-01

Analyzing the sequence of solar energetic electron events measured at both STEREO-A (STA) and STEREO-B (STB) spacecraft during 17-21 July 2014, when their orbital separation was 34°, we found evidence of a strong non-radial electron propagation in the solar corona below the solar wind source surface. The impulsive electron events were associated with recurrent flare and jet (hereafter flare/jet) activity at the border of an isolated coronal hole situated close to the solar equator. We have focused our study on the solar energetic particle (SEP) event on 17 July 2014, during which both spacecraft detected a similar impulsive and anisotropic energetic electron event suggesting optimal connection of both spacecraft to the parent particle source, despite the large angular separation between the parent flare and the nominal magnetic footpoints on the source surface of STA and STB of 68° and 90°, respectively. Combining the remote-sensing extreme ultraviolet (EUV) observations, in-situ plasma, magnetic field, and energetic particle data we investigated and discuss here the origin and the propagation trajectory of energetic electrons in the solar corona. We find that the energetic electrons in the energy range of 55-195 keV together with the associated EUV jet were injected from the flare site toward the spacecraft's magnetic footpoints and propagate along a strongly non-radial and inclined magnetic field below the source surface. From stereoscopic (EUV) observations we estimated the inclination angle of the jet trajectory and the respective magnetic field of 63° ± 11° relative to the radial direction. We show how the flare accelerated electrons reach very distant longitudes in the heliosphere, when the spacecraft are nominally not connected to the particle source. This example illustrates how ballistic backmapping can occasionally fail to characterize the magnetic connectivity during SEP events. This finding also provides an additional mechanism (one among others

Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii

Directory of Open Access Journals (Sweden)

Johanna J. Vollenweider

2011-01-01

Full Text Available The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean. Herring that were fed continually and were in relatively good condition at the time of infection (fat never stored lipid despite ad libitum feeding. In feeding herring, the energetic cost of infection was a 30% reduction in total energy content relative to controls 52 days post infection. Following food deprivation (lean condition, infection caused an initial delay in the compensatory response of herring. Thirty-one days after re-feeding, the energetic cost of infection in previously-fasted fish was a 32% reduction in total energy content relative to controls. Body composition of infected herring subsequently recovered to some degree, though infected herring never attained the same energy content as their continuously fed counterparts. Fifty-two days after re-feeding, the energetic cost of infection in previously-fasted fish was a 6% reduction in total energy content relative to controls. The greatest impacts of infection occurred in colder temperatures, suggesting Ichthyophonus-induced reductions in body condition may have greater consequences in the northern extent of herring's range, where juveniles use most of their energy reserves to survive their first winter.

Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii).

Science.gov (United States)

Vollenweider, Johanna J; Gregg, Jake L; Heintz, Ron A; Hershberger, Paul K

2011-01-01

The energetic costs of fasting and Ichthyophonus infection were measured in juvenile Pacific herring (Clupea pallasii) in a lab setting at three temperatures. Infected herring incurred significant energetic costs, the magnitude of which depended on fish condition at the time of infection (fat versus lean). Herring that were fed continually and were in relatively good condition at the time of infection (fat) never stored lipid despite ad libitum feeding. In feeding herring, the energetic cost of infection was a 30% reduction in total energy content relative to controls 52 days post infection. Following food deprivation (lean condition), infection caused an initial delay in the compensatory response of herring. Thirty-one days after re-feeding, the energetic cost of infection in previously-fasted fish was a 32% reduction in total energy content relative to controls. Body composition of infected herring subsequently recovered to some degree, though infected herring never attained the same energy content as their continuously fed counterparts. Fifty-two days after re-feeding, the energetic cost of infection in previously-fasted fish was a 6% reduction in total energy content relative to controls. The greatest impacts of infection occurred in colder temperatures, suggesting Ichthyophonus-induced reductions in body condition may have greater consequences in the northern extent of herring's range, where juveniles use most of their energy reserves to survive their first winter.

Energetic aspects of skeletal muscle contraction: implications of fiber types.

Science.gov (United States)

Rall, J A

1985-01-01

In this chapter fundamental energetic properties of skeletal muscles as elucidated from isolated muscle preparations are described. Implications of these intrinsic properties for the energetic characterization of different fiber types and for the understanding of locomotion have been considered. Emphasis was placed on the myriad of physical and chemical techniques that can be employed to understand muscle energetics and on the interrelationship of results from different techniques. The anaerobic initial processes which liberate energy during contraction and relaxation are discussed in detail. The high-energy phosphate (approximately P) utilized during contraction and relaxation can be distributed between actomyosin ATPase or cross-bridge cycling (70%) and the Ca2+ ATPase of the sacroplasmic reticulum (30%). Muscle shortening increases the rate of approximately P hydrolysis, and stretching a muscle during contraction suppresses the rate of approximately P hydrolysis. The economy of an isometric contraction is defined as the ratio of isometric mechanical response to energetic cost and is shown to be a fundamental intrinsic parameter describing muscle energetics. Economy of contraction varies across the animal kingdom by over three orders of magnitude and is different in different mammalian fiber types. In mammalian skeletal muscles differences in economy of contraction can be attributed mainly to differences in the specific actomyosin and Ca2+ ATPase of muscles. Furthermore, there is an inverse relationship between economy of contraction and maximum velocity of muscle shortening (Vmax) and maximum power output. This is a fundamental relationship. Muscles cannot be economical at developing and maintaining force and also exhibit rapid shortening. Interestingly, there appears to be a subtle system of unknown nature that modulates the Vmax and economy of contraction. Efficiency of a work-producing contraction is defined and contrasted to the economy of contraction

Los Alamos energetic particle sensor systems at geostationary orbit

International Nuclear Information System (INIS)

Baker, D.N.; Aiello, W.; Asbridge, J.R.; Belian, R.D.; Higbie, P.R.; Klebesadel, R.W.; Laros, J.G.; Tech, E.R.

1985-01-01

The Los Alamos National Laboratory has provided energetic particle sensors for a variety of spacecraft at the geostationary orbit (36,000 km altitude). The sensor system called the Charged Particle Analyzer (CPA) consists of four separate subsystems. The LoE and HiE subsystems measure electrons in the energy ranges 30 to 300 keV and 200 to 2000 keV, respectively. The LoP and HiP subsystems measure ions in the ranges 100 to 600 keV and 0.40 to 150 MeV, respectively. A separate sensor system called the spectrometer for energetic electrons (SEE) measures very high-energy electrons (2 to 15 MeV) using advanced scintillator design. In this paper we describe the relationship of operational anomalies and spacecraft upsets to the directly measured energetic particle environments at 6.6 R/sub E/. We also compare and contrast the CPA and SEE instrument design characteristics with the next generation of Los Alamos instruments to be flown at geostationary altitudes

Observation of energetic particle mode by using microwave reflectometer

International Nuclear Information System (INIS)

Tokuzawa, T.; Kawahata, K.; Sakakibara, S.; Toi, K.; Osakabe, M.; Yamamoto, S.

2006-01-01

Two heterodyne reflectometer systems are utilized for the fluctuation measurement in the Large Helical Device (LHD). By using the extraordinary polarized wave, we can measure the corresponding value to the combined fluctuation with the electron density and the magnetic field in the plasma core region even if the radial electron density profile is flat. E-band system has three channels of fixed frequencies of 78, 72, 65 GHz. The system is very convenient to observe magnetohydrodynamics (MHD) phenomena such as energetic particle driven Alfven eigenmodes, even if the system works as an interferometer mode. The detailed behaviour of the energetic particle mode is studied when low-n MHD burst is occurred. It seems to be caused that the spatial distribution of high energy particle is changed by such a MHD-burst. Also to know the radial distribution of MHD mode, frequency swept R-band reflectometer is applied for the first time. It seems to be successfully detected the energetic particle mode and toroidal Alfven eigenmode. (author)

Deletion of FoxO1 Leads to Shortening of QRS by Increasing Na+ Channel Activity through Enhanced Expression of both Cardiac NaV1.5 and β3 Subunit

OpenAIRE

Cai, Benzhi; Wang, Ning; Mao, Weike; You, Tao; Lu, Yan; Li, Xiang; Ye, Bo; Li, Faqian; Xu, Haodong

2014-01-01

Our in vitro studies revealed that a transcription factor, Forkhead box protein O1 (FoxO1), negatively regulates the expression of NaV1.5, a main α subunit of the cardiac Na+ channel, by altering the promoter activity of SCN5a in HL-1 cardiomyocytes. The in vivo role of FoxO1 in the regulation of cardiac NaV1.5 expression remains unknown. The present study aimed to define the role of FoxO1 in the regulation of NaV1.5 expression and cardiac Na+ channel activity in mouse ventricular cardiomyocy...

Bone Morphogenetic Protein 9 Reduces Cardiac Fibrosis and Improves Cardiac Function in Heart Failure.

Science.gov (United States)

Morine, Kevin J; Qiao, Xiaoying; York, Sam; Natov, Peter S; Paruchuri, Vikram; Zhang, Yali; Aronovitz, Mark J; Karas, Richard H; Kapur, Navin K

2018-02-27

Background -Heart failure is a growing cause of morbidity and mortality worldwide. Transforming growth factor beta (TGF-β1) promotes cardiac fibrosis, but also activates counter-regulatory pathways that serve to regulate TGF-β1 activity in heart failure. Bone morphogenetic protein 9 (BMP9) is a member of the TGFβ family of cytokines and signals via the downstream effector protein Smad1. Endoglin is a TGFβ co-receptor that promotes TGF-β1 signaling via Smad3 and binds BMP9 with high affinity. We hypothesized that BMP9 limits cardiac fibrosis by activating Smad1 and attenuating Smad3 and further that neutralizing endoglin activity promotes BMP9 activity. Methods -We examined BMP9 expression and signaling in human cardiac fibroblasts and human subjects with heart failure. We utilized the thoracic aortic constriction (TAC) induced model of heart failure to evaluate the functional effect of BMP9 signaling on cardiac remodeling. Results -BMP9 expression is increased in the circulation and left ventricle (LV) of human subjects with heart failure and is expressed by cardiac fibroblasts. Next, we observed that BMP9 attenuates Type I collagen synthesis in human cardiac fibroblasts using recombinant human BMP9 and an siRNA approach. In BMP9 -/- mice subjected to TAC, loss of BMP9 activity promotes cardiac fibrosis, impairs LV function, and increases LV levels of phosphorylated Smad3 (pSmad3), not pSmad1. In contrast, treatment of wild-type mice subjected to TAC with recombinant BMP9 limits progression of cardiac fibrosis, improves LV function, enhances myocardial capillary density, and increases LV levels of pSmad1, not pSmad3 compared to vehicle treated controls. Since endoglin binds BMP9 with high affinity, we explored the effect of reduced endoglin activity on BMP9 activity. Neutralizing endoglin activity in human cardiac fibroblasts or in wild-type mice subjected to TAC induced heart failure limits collagen production, increases BMP9 protein levels, and increases

Energetic materials standards – Chemical compatibility

NARCIS (Netherlands)

Tuukkanen, I.M.; Bouma, R.H.B.

2014-01-01

Subgroup A Energetic Materials Team, SG/A (EMT), develops and maintains standards that are relevant to all life-cycle phases of ammunition/weapon systems. STANAG 4147 is the standard regarding chemical compatibility of explosives with munition components, and is a document of prime importance.

Evaluation of respiratory and cardiac motion correction schemes in dual gated PET/CT cardiac imaging