Newborn infant with maternal anti-SSA antibody-induced complete heart block accompanying cardiomyopathy.

PubMed

Iida, Midori; Inamura, Noboru; Takeuchi, Makoto

2006-01-01

Newborn case of maternal anti-SSA antibody-induced congenital complete heart block (CCHB) accompanying cardiomyopathy is presented. Unexpectedly, she died of ventricular tachycardia, not bradycardia, 6 days after birth. Autopsy revealed left ventricular cardiomyopathy with endocardial fibroelastosis. Thus, when evaluating fetal cardiac performance in cases of maternal anti-SSA antibody-induced CCHB, it is necessary to pay attention to myocardial attributes such as endocardial hyperplasia.

Discordant U waves in the setting of hyperkalaemia.

PubMed

Chhabra, Lovely; Spodick, David H

2013-07-04

Physiological U wave genesis occurs likely secondary to either late repolarisation of Purkinje fibres, or late repolarisation of some myocardial cells and/or delayed after depolarisation of the ventricular wall occurring during ventricular filling. Hypokalaemia has a well-known association with pathological 'U wave' which actually combines with the T wave (TU complex) and results from slowing of phase 3 of the action potential with resultant electrical interaction between the three myocardial layers. U waves usually tend to disappear in the setting of hyperkalaemia. We report an unusual case where hyperkalaemia and discordant U waves coexisted. We believe that this may have occurred as a result of partial clinical adaptation of cardiac myocytes to the long-standing effects of hyperkalaemia as the patient had underlying history of chronic kidney disease. We also discuss the possible mechanisms of the U wave genesis and the importance of different U wave morphologies encountered in the real clinical practice.

Homozygous factor V Leiden mutation in type IV Ehlers-Danlos patient

PubMed Central

Refaat, Marwan; Hotait, Mostafa; Winston, Brion

2014-01-01

Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders caused by collagen synthesis defects. Several hemostatic abnormalities have been described in EDS patients that increase the bleeding tendencies of these patients. This case report illustrates a patient with an unusual presentation of a patient with type IV EDS, platelet δ-storage pool disease and factor V Leiden mutation. Young woman having previous bilateral deep vein thrombosis and pulmonary emboli coexisting with ruptured splenic aneurysm and multiple other aneurysms now presented with myocardial infarction. Presence of factor V Leiden mutation raises the possibility that the infarct was due to acute coronary thrombosis, although coronary artery aneurysm and dissection with myocardial infarction is known to occur in vascular type EDS. This is the first report in the medical literature of factor V Leiden mutation in an EDS patient which made the management of our patient challenging with propensity to both bleeding and clotting. PMID:24653990

Incidence of three presentations of acute myocarditis in young men in military service. A 20-year experience.

PubMed

Karjalainen, J; Heikkilä, J

1999-08-01

The incidence of myocarditis is uncertain as diagnostic criteria have been vague. We evaluated the incidence of myocarditis presenting in three well defined forms (mimicking myocardial infarction, presenting as dilated cardiomyopathy, and as a cause of sudden death) in young men in military service over a 20-year period. The study population consisted of 672 672 Finnish men at a mean age of 20 years conscripted from 1977-1996. All those suspected of having myocardial disease were studied prospectively in the same institution. A clinical diagnosis of myocarditis mimicking myocardial infarction required ECG signs (ST-segment elevation followed by T-wave inversion) and a simultaneous detection of serum markers of acute myocardial injury (CK-MB and/or troponin T) in an infectious patient with chest pain. This form of myocarditis was diagnosed in 98 men, the incidence being 0.17 (95% CI 0.14-0.21). 1000 man-years(-1). Causative microbes were those commonly infecting the conscripts, but Coxsackievirus aetiology could be confirmed in only 4% of the cases. Nine patients presented with dilated cardiomyopathy of recent origin (incidence 0.02. 1000 man-years(-1)). None had histopathological evidence of myocarditis. Myocarditis caused one of the 10 sudden unexpected deaths (incidence 0.002. 1000 man-years(-1)). The usual presentation of acute myocarditis in young men mimicks alterations evoked by myocardial infarction but not those of dilated cardiomyopathy. Copyright 1999 The European Society of Cardiology.

Sudden unexpected death related to enterovirus myocarditis: histopathology, immunohistochemistry and molecular pathology diagnosis at post-mortem

PubMed Central

2012-01-01

Background Viral myocarditis is a major cause of sudden unexpected death in children and young adults. Until recently, coxsackievirus B3 (CVB3) has been the most commonly implicated virus in myocarditis. At present, no standard diagnosis is generally accepted due to the insensitivity of traditional diagnostic tests. This has prompted health professionals to seek new diagnostic approaches, which resulted in the emergence of new molecular pathological tests and a more detailed immunohistochemical and histopathological analysis. When supplemented with immunohistochemistry and molecular pathology, conventional histopathology may provide important clues regarding myocarditis underlying etiology. Methods This study is based on post-mortem samples from sudden unexpected death victims and controls who were investigated prospectively. Immunohistochemical investigations for the detection of the enteroviral capsid protein VP1 and the characterization and quantification of myocardial inflammatory reactions as well as molecular pathological methods for enteroviral genome detection were performed. Results Overall, 48 sudden unexpected death victims were enrolled. As for controls, 37 cases of unnatural traffic accident victims were studied. Enterovirus was detected in 6 sudden unexpected death cases (12.5 %). The control samples were completely enterovirus negative. Furthermore, the enteroviral capsid protein VP1 in the myocardium was detected in enterovirus-positive cases revealed by means of reverse transcriptase-polymerase chain reaction (RT-PCR). Unlike control samples, immunohistochemical investigations showed a significant presence of T and B lymphocytes in sudden unexpected death victims. Conclusions Our findings demonstrate clearly a higher prevalence of viral myocarditis in cases of sudden unexpected death compared to control subjects, suggesting that coxsackie B enterovirus may contribute to myocarditis pathogenesis significantly. PMID:22966951

Obsessive-compulsive personality disorder and behavioral disinhibition.

PubMed

Villemarette-Pittman, Nicole R; Stanford, Matthew S; Greve, Kevin W; Houston, Rebecca J; Mathias, Charles W

2004-01-01

Although obsessive-compulsive personality disorder (OCPD) is an Axis II diagnosis that is not commonly associated with behavioral disinhibition, the literature contains reports of occasional explosive aggressive outbursts. Existing explanations of OCPD etiology do not address the coexistence of compulsive and impulsive features witnessed in some subpopulations of patients. In this study, the authors present a compensatory theory of OCPD in an effort to explain clinical observations of an unexpectedly large number of OCPD diagnoses among patients clinic referred and self-referred for aggression problems.

Returners and explorers dichotomy in human mobility

PubMed Central

Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

2015-01-01

The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

No elliptic islands for the universal area-preserving map

NASA Astrophysics Data System (ADS)

Johnson, Tomas

2011-07-01

A renormalization approach has been used in Eckmann et al (1982) and Eckmann et al (1984) to prove the existence of a universal area-preserving map, a map with hyperbolic orbits of all binary periods. The existence of a horseshoe, with positive Hausdorff dimension, in its domain was demonstrated in Gaidashev and Johnson (2009a). In this paper the coexistence problem is studied, and a computer-aided proof is given that no elliptic islands with period less than 18 exist in the domain. It is also shown that less than 1.5% of the measure of the domain consists of elliptic islands. This is proven by showing that the measure of initial conditions that escape to infinity is at least 98.5% of the measure of the domain, and we conjecture that the escaping set has full measure. This is highly unexpected, since generically it is believed that for conservative systems hyperbolicity and ellipticity coexist.

Coexistence of tunable Weyl points and topological nodal lines in ternary transition-metal telluride TaIrT e4

NASA Astrophysics Data System (ADS)

Zhou, Xiaoqing; Liu, Qihang; Wu, QuanSheng; Nummy, Tom; Li, Haoxiang; Griffith, Justin; Parham, Stephen; Waugh, Justin; Emmanouilidou, Eve; Shen, Bing; Yazyev, Oleg V.; Ni, Ni; Dessau, Daniel

2018-06-01

We report a combined theoretical and experimental study on TaIrT e4 , a potential candidate for a minimal model of type-II Weyl semimetals. Unexpectedly, an intriguing node structure with 12 Weyl points and a pair of nodal lines protected by mirror symmetry was found by first-principles calculations. Some signatures of the complex electronic structure, such as topologically nontrivial band crossings and topologically trivial Fermi arcs, are cross-validated by angle-resolved photoemission spectroscopy. Through external strain, the number of Weyl points can be reduced to a theoretical minimum of four, and the appearance of the nodal lines can be switched between different mirror planes in momentum space. The coexistence of switchable Weyl points and nodal lines establishes transition-metal chalcogenides as a unique test ground for topological state characterization and engineering.

Magneto-optical fingerprints of distinct graphene multilayers using the giant infrared Kerr effect

NASA Astrophysics Data System (ADS)

Ellis, Chase T.; Stier, Andreas V.; Kim, Myoung-Hwan; Tischler, Joseph G.; Glaser, Evan R.; Myers-Ward, Rachael L.; Tedesco, Joseph L.; Eddy, Charles R.; Gaskill, D. Kurt; Cerne, John

2013-11-01

The remarkable electronic properties of graphene strongly depend on the thickness and geometry of graphene stacks. This wide range of electronic tunability is of fundamental interest and has many applications in newly proposed devices. Using the mid-infrared, magneto-optical Kerr effect, we detect and identify over 18 interband cyclotron resonances (CR) that are associated with ABA and ABC stacked multilayers as well as monolayers that coexist in graphene that is epitaxially grown on 4H-SiC. Moreover, the magnetic field and photon energy dependence of these features enable us to explore the band structure, electron-hole band asymmetries, and mechanisms that activate a CR response in the Kerr effect for various multilayers that coexist in a single sample. Surprisingly, we find that the magnitude of monolayer Kerr effect CRs is not temperature dependent. This unexpected result reveals new questions about the underlying physics that makes such an effect possible.

Invasion waves in the biochemical warfare between living organisms

NASA Astrophysics Data System (ADS)

Carvalho, S. A.; Martins, M. L.

2018-04-01

Microorganisms and plants very commonly release toxic secondary chemical compounds (allelochemicals) that inhibit or kill sensitive strains or individuals from their own or other species. In this work we study a model that describes two species interacting through allelopathic suppression and competing for resources. Employing linear stability analysis, the conditions for coexistence or extinction of species in spatially homogeneous systems were determined. We found that the borders between the regimes of bistability, coexistence, and the extinction of the weaker by the stronger competitor, are altered by allelopathic interactions. In addition, traveling wave solutions for one species invasion were obtained considering the spatially explicit nature of the model. Our findings indicate that the minimum speed of the invasion wavefronts depends primarily on the competition coefficients and the parameters characterizing the species' functional responses to their allelochemicals. As a general rule, the species provided with the most effective chemical weapons dominates the population dynamics. Finally, we found a tristability at the coexistence region due to the combination of allelopathy and patchy population distributions in space. So, our model provides a distinct mechanism, independent of social behaviors, that produces such unexpected tristability impossible in classical competition models involving one-to-one individual interactions.

Invasion waves in the biochemical warfare between living organisms.

PubMed

Carvalho, S A; Martins, M L

2018-04-01

Microorganisms and plants very commonly release toxic secondary chemical compounds (allelochemicals) that inhibit or kill sensitive strains or individuals from their own or other species. In this work we study a model that describes two species interacting through allelopathic suppression and competing for resources. Employing linear stability analysis, the conditions for coexistence or extinction of species in spatially homogeneous systems were determined. We found that the borders between the regimes of bistability, coexistence, and the extinction of the weaker by the stronger competitor, are altered by allelopathic interactions. In addition, traveling wave solutions for one species invasion were obtained considering the spatially explicit nature of the model. Our findings indicate that the minimum speed of the invasion wavefronts depends primarily on the competition coefficients and the parameters characterizing the species' functional responses to their allelochemicals. As a general rule, the species provided with the most effective chemical weapons dominates the population dynamics. Finally, we found a tristability at the coexistence region due to the combination of allelopathy and patchy population distributions in space. So, our model provides a distinct mechanism, independent of social behaviors, that produces such unexpected tristability impossible in classical competition models involving one-to-one individual interactions.

Depression and Heart Diseases: Leading Health Problems.

PubMed

Raič, Matea

2017-12-01

Depression is the most common psychiatric disorder in the world population and the most frequent mental disorder in a primary health care. Unrecognized and untreated depression is associated with a poor outcome of treated chronic diseases which co-exist with depression. Depression and cardiovascular diseases are bidirectional related conditions, risks are for each other, and they often co-exist. Depression is a common disorder in cardiovascular patients with a prevalence of 20% to 45%, which is much more frequent than in the general population. In cardiac patients with acute myocardial infarction, depression occurs three times more often than in the general population. Depression has a direct effect on the pathophysiological changes of various organ systems, changing the values of blood pressure, heart rate, vasomotor tone, vascular resistance, blood viscosity and plasma volume. The potential mechanism for developing heart disease in depressed patients includes hypothalamic-pituitary-adrenal gland dysfunction, increased proinflammatory and prothrombotic factor activity, reduced omega-3 fatty acids, reduced heart rate variability, smoking, physical inactivity, reduced mood, self-esteem and self-efficacy.

Diabetic cardiomyopathy: from the pathophysiology of the cardiac myocytes to current diagnosis and management strategies.

PubMed

Voulgari, Christina; Papadogiannis, Dimitrios; Tentolouris, Nicholas

2010-10-21

Diabetic cardiomyopathy (DCM), although a distinct clinical entity, is also a part of the diabetic atherosclerosis process. It may be independent of the coexistence of ischemic heart disease, hypertension, or other macrovascular complications. Its pathological substrate is characterized by the presence of myocardial damage, reactive hypertrophy, and intermediary fibrosis, structural and functional changes of the small coronary vessels, disturbance of the management of the metabolic cardiovascular load, and cardiac autonomic neuropathy. These alterations make the diabetic heart susceptible to ischemia and less able to recover from an ischemic attack. Arterial hypertension frequently coexists with and exacerbates cardiac functioning, leading to the premature appearance of heart failure. Classical and newer echocardiographic methods are available for early diagnosis. Currently, there is no specific treatment for DCM; targeting its pathophysiological substrate by effective risk management protects the myocardium from further damage and has a recognized primary role in its prevention. Its pathophysiological substrate is also the objective for the new therapies and alternative remedies.

Use of cumulative mortality data in patients with acute myocardial infarction for early detection of variation in clinical practice: observational study.

PubMed

Lawrance, R A; Dorsch, M F; Sapsford, R J; Mackintosh, A F; Greenwood, D C; Jackson, B M; Morrell, C; Robinson, M B; Hall, A S

2001-08-11

Use of cumulative mortality adjusted for case mix in patients with acute myocardial infarction for early detection of variation in clinical practice. Observational study. 20 hospitals across the former Yorkshire region. All 2153 consecutive patients with confirmed acute myocardial infarction identified during three months. Variable life-adjusted displays showing cumulative differences between observed and expected mortality of patients; expected mortality calculated from risk model based on admission characteristics of age, heart rate, and systolic blood pressure. The performance of two individual hospitals over three months was examined as an example. One, the smallest district hospital in the region, had a series of 30 consecutive patients but had five more deaths than predicted. The variable life-adjusted display showed minimal variation from that predicted for the first 15 patients followed by a run of unexpectedly high mortality. The second example was the main tertiary referral centre for the region, which admitted 188 consecutive patients. The display showed a period of apparently poor performance followed by substantial improvement, where the plot rose steadily from a cumulative net lives saved of -4 to 7. These variations in patient outcome are unlikely to have been revealed during conventional audit practice. Variable life-adjusted display has been integrated into surgical care as a graphical display of risk-adjusted survival for individual surgeons or centres. In combination with a simple risk model, it may have a role in monitoring performance and outcome in patients with acute myocardial infarction.

Perpetual Points: New Tool for Localization of Coexisting Attractors in Dynamical Systems

NASA Astrophysics Data System (ADS)

Dudkowski, Dawid; Prasad, Awadhesh; Kapitaniak, Tomasz

Perpetual points (PPs) are special critical points for which the magnitude of acceleration describing the dynamics drops to zero, while the motion is still possible (stationary points are excluded), e.g. considering the motion of the particle in the potential field, at perpetual point, it has zero acceleration and nonzero velocity. We show that using PPs we can trace all the stable fixed points in the system, and that the structure of trajectories leading from former points to stable equilibria may be similar to orbits obtained from unstable stationary points. Moreover, we argue that the concept of perpetual points may be useful in tracing unexpected attractors (hidden or rare attractors with small basins of attraction). We show potential applicability of this approach by analyzing several representative systems of physical significance, including the damped oscillator, pendula, and the Henon map. We suggest that perpetual points may be a useful tool for localizing coexisting attractors in dynamical systems.

Forgetting heart break: a fascinating case of transient left ventricular apical ballooning syndrome associated with dissociative amnesia.

PubMed

Toussi, Amir; Bryk, Jodie; Alam, Abdulkader

2014-01-01

Transient left ventricular apical ballooning syndrome (TLVABS), also known as takotsubo cardiomyopathy, is characterized by transient left ventricular dysfunction, electrocardiographic changes, and release of myocardial enzymes that mimic acute myocardial infarction in patients without angiographic evidence of coronary artery disease. Most patients are post-menopausal women and an emotional or physiologic stressor frequently precedes the presentation. Psychogenic or dissociative amnesia is a memory disorder characterized by sudden retrograde memory loss with inability to recall personal information said to occur for a period of time ranging from hours to years after a stressful event. Interestingly, the mechanism of both disorders has been linked to plasma elevation in catecholamines. Here we present the case of a 66-year-old female diagnosed with both TLVABS and dissociative amnesia following the sudden unexpected death of her sister. To our knowledge, this is surprisingly the first report of the co-occurrence of TLVABS and dissociative amnesia, two processes with a potential shared underlying etiology. © 2013.

Cardiac c-Kit Biology Revealed by Inducible Transgenesis.

PubMed

Gude, Natalie A; Firouzi, Fareheh; Broughton, Kathleen M; Ilves, Kelli; Nguyen, Kristine P; Payne, Christina R; Sacchi, Veronica; Monsanto, Megan M; Casillas, Alexandria R; Khalafalla, Farid G; Wang, Bingyan J; Ebeid, David E; Alvarez, Roberto; Dembitsky, Walter P; Bailey, Barbara A; van Berlo, Jop; Sussman, Mark A

2018-06-22

Biological significance of c-Kit as a cardiac stem cell marker and role(s) of c-Kit+ cells in myocardial development or response to pathological injury remain unresolved because of varied and discrepant findings. Alternative experimental models are required to contextualize and reconcile discordant published observations of cardiac c-Kit myocardial biology and provide meaningful insights regarding clinical relevance of c-Kit signaling for translational cell therapy. The main objectives of this study are as follows: demonstrating c-Kit myocardial biology through combined studies of both human and murine cardiac cells; advancing understanding of c-Kit myocardial biology through creation and characterization of a novel, inducible transgenic c-Kit reporter mouse model that overcomes limitations inherent to knock-in reporter models; and providing perspective to reconcile disparate viewpoints on c-Kit biology in the myocardium. In vitro studies confirm a critical role for c-Kit signaling in both cardiomyocytes and cardiac stem cells. Activation of c-Kit receptor promotes cell survival and proliferation in stem cells and cardiomyocytes of either human or murine origin. For creation of the mouse model, the cloned mouse c-Kit promoter drives Histone2B-EGFP (enhanced green fluorescent protein; H2BEGFP) expression in a doxycycline-inducible transgenic reporter line. The combination of c-Kit transgenesis coupled to H2BEGFP readout provides sensitive, specific, inducible, and persistent tracking of c-Kit promoter activation. Tagging efficiency for EGFP+/c-Kit+ cells is similar between our transgenic versus a c-Kit knock-in mouse line, but frequency of c-Kit+ cells in cardiac tissue from the knock-in model is 55% lower than that from our transgenic line. The c-Kit transgenic reporter model reveals intimate association of c-Kit expression with adult myocardial biology. Both cardiac stem cells and a subpopulation of cardiomyocytes express c-Kit in uninjured adult heart, upregulating c-Kit expression in response to pathological stress. c-Kit myocardial biology is more complex and varied than previously appreciated or documented, demonstrating validity in multiple points of coexisting yet heretofore seemingly irreconcilable published findings. © 2018 American Heart Association, Inc.

A new fossil from the mid-Paleocene of New Zealand reveals an unexpected diversity of world's oldest penguins.

PubMed

Mayr, Gerald; De Pietri, Vanesa L; Paul Scofield, R

2017-04-01

We describe leg bones of a giant penguin from the mid-Paleocene Waipara Greensand of New Zealand. The specimens were found at the type locality of Waimanu manneringi and together with this species they constitute the oldest penguin fossils known to date. Tarsometatarsus dimensions indicate a species that reached the size of Anthropornis nordenskjoeldi, one of the largest known penguin species. Stem group penguins therefore attained a giant size very early in their evolution, with this gigantism existing for more than 30 million years. The new fossils are from a species that is phylogenetically more derived than Waimanu, and the unexpected coexistence of Waimanu with more derived stem group Sphenisciformes documents a previously unknown diversity amongst the world's oldest penguins. The characteristic tarsometatarsus shape of penguins evolved early on, and the significant morphological disparity between Waimanu and the new fossil conflicts with recent Paleocene divergence estimates for penguins, suggesting an older, Late Cretaceous, origin.

A new fossil from the mid-Paleocene of New Zealand reveals an unexpected diversity of world's oldest penguins

NASA Astrophysics Data System (ADS)

Mayr, Gerald; De Pietri, Vanesa L.; Paul Scofield, R.

2017-04-01

We describe leg bones of a giant penguin from the mid-Paleocene Waipara Greensand of New Zealand. The specimens were found at the type locality of Waimanu manneringi and together with this species they constitute the oldest penguin fossils known to date. Tarsometatarsus dimensions indicate a species that reached the size of Anthropornis nordenskjoeldi, one of the largest known penguin species. Stem group penguins therefore attained a giant size very early in their evolution, with this gigantism existing for more than 30 million years. The new fossils are from a species that is phylogenetically more derived than Waimanu, and the unexpected coexistence of Waimanu with more derived stem group Sphenisciformes documents a previously unknown diversity amongst the world's oldest penguins. The characteristic tarsometatarsus shape of penguins evolved early on, and the significant morphological disparity between Waimanu and the new fossil conflicts with recent Paleocene divergence estimates for penguins, suggesting an older, Late Cretaceous, origin.

Severe hypoglycaemia in elderly patients with type 2 diabetes and coexistence of cardiovascular history.

PubMed

Piątkiewicz, Paweł; Buraczewska-Leszczyńska, Bożena; Kuczerowski, Roman; Bernat-Karpińska, Małgorzata; Rabijewski, Michał; Kowrach, Marek

2016-01-01

Hypoglycaemia is a condition that occurs when blood glucose levels fall below 3.9 mmol/L (70 mg/dL), while hypoglycaemic coma is usually associated with glycaemia around 1.1 mmol/L (20 mg/dL). Recurrent severe hypoglycaemia may result in permanent neurological disorders and also has a negative impact on the cardiovascular system. To evaluate the causes of severe hypoglycaemia in elderly patients with type 2 diabetes and coexistence of cardiovascular history. We analysed retrospectively the history of 33 elderly patients with type 2 diabetes and coexistence of cardiovascular history, who were admitted to our clinic due to severe hypoglycaemia with loss of consciousness. The mean age of the patients was 76.0 ± 11.1 years, and the mean duration of diabetes was 12.0 ± 9.8 years. Glycated haemoglobin (HbA1c) was measured and the prevalence of cardiovascular diseases and therapeutic procedures were evaluated. In the group of patients with severe hypoglycaemia, the mean value of HbA1c was 6.3 ± 1.2% (44 ± 13.1 mmol/mol), which indicates a mean glucose value below 7.8 mmol/L (140 mg/dL). Ischaemic heart disease was diagnosed in 18 patients (eight had a history of myocardial infarction), and 22 patients had arterial hypertension. Severe hypoglycaemia requiring hospitalisation in elderly patients with type 2 diabetes and coexistence of cardiovascular history was related to insulin or sulfonylurea therapy. A low HbA1c level indicates inappropriate intensification of therapy and was associated with high risk of severe hypoglycaemic episodes in older people. The majority of severe hypoglycaemic episodes were observed in sulphonylurea or insulin-treated type 2 diabetic patients.

Rheumatoid arthritis and pulmonary nodules: An unexpected final diagnosis.

PubMed

Zurita Prada, Pablo Antonio; Urrego Laurín, Claudia Lía; Assyaaton Bobo, Sow; Faré García, Regina; Estrada Trigueros, Graciliano; Gallardo Romero, José Manuel; Borrego Pintado, Maria Henar

We report the case of a 50-year-old female smoker with an 11-year history of seropositive rheumatoid arthritis (rheumatoid factor and anti-cyclic citrullinated peptide antibodies) receiving triple therapy. She developed pulmonary nodules diagnosed as Langerhans cell histiocytosis by lung biopsy. We found no reported cases of the coexistence of these two diseases. Smoking abstinence led to radiologic resolution without modifying the immunosuppressive therapy. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Physiologic bases for anterior ST segment depression in patients with acute inferior wall myocardial infarction.

PubMed

Mirvis, D M

1988-11-01

Patients with acute inferior myocardial infarction commonly have ST segment depression in the anterior precordial leads. This may reflect either reciprocal changes from the inferior ST elevation or primary ST depression from additional anterior subendocardial ischemia. From a biophysical perspective reciprocal changes should be uniformly anticipated from basic dipole theory. Detection will vary with the size, location, orientation, and electrical intensity of the lesion and with the ECG lead system deployed to register the anterior changes. Alternatively, acute occlusion of the right coronary artery may produce ischemia in the anterior left ventricular wall supplied by a stenotic anterior descending coronary artery. Anterior ischemia may result from the abnormal hemodynamics or the reduced collateral flow produced by acute right coronary artery occlusion. Thus both mechanisms are based on sound physiologic principles. A review of the clinical literature suggests that such patients represent a heterogeneous group. In some instances coexistent anterior ischemia is present, whereas in others the anterior ST depression is the passive reflection of inferior ST elevation augmented in many cases by a large infarct size or more extensive posterobasal or septal involvement.

An analysis of possible mechanisms of unexpected death occurring in hydatid disease (echinococcosis).

PubMed

Byard, Roger W

2009-07-01

Most cases of hydatid disease in human populations are due to Echinococcus granulosus. The hydatid life cycle involves passage between definitive hosts such as dogs and intermediate hosts such as sheep. Humans become accidental intermediate hosts following ingestion of food or water contaminated with eggs or by contact with infected dogs. Although hydatid disease may remain asymptomatic, occasional cases of sudden and unexpected death present to autopsy. Causes of rapid clinical decline involve a wide range of mechanisms including anaphylaxis (with or without cyst rupture), cardiac outflow obstruction or conduction tract disturbance, pulmonary and cerebral embolism, pericarditis, cardiac tamponade, myocardial ischemia, pulmonary hypertension, peritonitis, hollow organ perforation, intracerebral mass effect, obstructive hydrocephalus, seizures, cerebral ischemia/infarction, and pregnancy complications. The autopsy assessment of cases therefore requires careful examination of all organ systems for characteristic cystic lesions, as multiorgan involvement is common, with integration of findings so that possible mechanisms of death can be determined. Measurement of serum tryptase and specific IgE levels should be undertaken for possible anaphylaxis.

Pathophysiological consequences of VEGF-induced vascular permeability

NASA Astrophysics Data System (ADS)

Weis, Sara M.; Cheresh, David A.

2005-09-01

Although vascular endothelial growth factor (VEGF) induces angiogenesis, it also disrupts vascular barrier function in diseased tissues. Accordingly, VEGF expression in cancer and ischaemic disease has unexpected pathophysiological consequences. By uncoupling endothelial cell-cell junctions VEGF causes vascular permeability and oedema, resulting in extensive injury to ischaemic tissues after stroke or myocardial infarction. In cancer, VEGF-mediated disruption of the vascular barrier may potentiate tumour cell extravasation, leading to widespread metastatic disease. Therefore, by blocking the vascular permeability promoting effects of VEGF it may be feasible to reduce tissue injury after ischaemic disease and minimize the invasive properties of circulating tumour cells.

A rare challenging case of co-existent craniopharyngioma, acromegaly and squamous cell lung cancer.

PubMed

Fountas, Athanasios; Chai, Shu Teng; Ayuk, John; Gittoes, Neil; Chavda, Swarupsinh; Karavitaki, Niki

2018-01-01

Co-existence of craniopharyngioma and acromegaly has been very rarely reported. A 65-year-old man presented with visual deterioration, fatigue and frontal headaches. Magnetic resonance imaging revealed a suprasellar heterogeneous, mainly cystic, 1.9 × 2 × 1.9 cm mass compressing the optic chiasm and expanding to the third ventricle; the findings were consistent with a craniopharyngioma. Pituitary hormone profile showed hypogonadotropic hypogonadism, mildly elevated prolactin, increased insulin-like growth factor 1 (IGF-1) and normal thyroid function and cortisol reserve. The patient had transsphenoidal surgery and pathology of the specimen was diagnostic of adamantinomatous craniopharyngioma. Post-operatively, he had diabetes insipidus, hypogonadotropic hypogonadism and adrenocorticotropic hormone and thyroid-stimulating hormone deficiency. Despite the hypopituitarism, his IGF-1 levels remained elevated and subsequent oral glucose tolerance test did not show complete growth hormone (GH) suppression. Further review of the pre-operative imaging revealed a 12 × 4 mm pituitary adenoma close to the right carotid artery and no signs of pituitary hyperplasia. At that time, he was also diagnosed with squamous cell carcinoma of the left upper lung lobe finally managed with radical radiotherapy. Treatment with long-acting somatostatin analogue was initiated leading to biochemical control of the acromegaly. Latest imaging has shown no evidence of craniopharyngioma regrowth and stable adenoma. This is a unique case report of co-existence of craniopharyngioma, acromegaly and squamous lung cell carcinoma that highlights diagnostic and management challenges. Potential effects of the GH hypersecretion on the co-existent tumours of this patient are also briefly discussed. Although an extremely rare clinical scenario, craniopharyngioma and acromegaly can co-exist; aetiopathogenic link between these two conditions is unlikely.Meticulous review of unexpected biochemical findings is vital for correct diagnosis of dual pituitary pathology.The potential adverse impact of GH excess due to acromegaly in a patient with craniopharyngioma (and other neoplasm) mandates adequate biochemical control of the GH hypersecretion.

Coexistence of three calcium carbonate polymorphs in the shell of the Antarctic clam Laternula elliptica

NASA Astrophysics Data System (ADS)

Nehrke, Gernot; Poigner, Harald; Wilhelms-Dick, Dorothee; Brey, Thomas; Abele, Doris

2012-05-01

We analyzed shell cuts of five individuals of the Antarctic bivalve Laternula elliptica from three locations along the Antarctic Peninsula by means of Confocal Raman Microscopy (CRM) as well as Electron Microprobe (EMP). The shell of L. elliptica has been previously described as being composed of aragonite exclusively. Now, CRM mapping reveals that three polymorphs of calcium carbonate - aragonite, calcite, and vaterite - are present in the chondrophore region of the examined individuals. Annual shell growth layers continue through aragonite and vaterite, suggesting simultaneous mineralization of both polymorphs. Spatially congruent EMP scans showed that the calcium carbonate polymorph affects the distribution of magnesium and strontium within the chondrophore. This is, to our knowledge, the first report of the coexistence of these three calcium carbonate polymorphs within the mineralized structures of a marine calcifying organism. Particularly the presence of vaterite is unexpected, but shows striking similarities to some fish otoliths. The strong effect of the calcium carbonate polymorph on trace element incorporation restrict the suitability of magnesium and strontium based proxies for the chondrophore area of L. elliptica.

Percutaneous transvenous mitral commissurotomy in patients with mitral stenosis and coexistent hyperthyroidism.

PubMed

Wang, P W; Hung, J S; Fu, M; Yeh, K H; Wu, J J

1996-01-01

Percutaneous transvenous mitral commissurotomy (PTMC) was performed successfully without complications in 3 patients with severe mitral stenosis and hyperthyroidism. All 3 patients had pliable, noncalcified mitral valves. One patient who had been treated with methimazole for 6 months was still in a hyperthyroid state when she presented with intractable congestive heart failure and was found to have severe mitral stenosis. The heart failure improved immediately after PTMC, but the patient remained in New York Heart Association functional class 2 until a euthyroid state was achieved with I131 therapy. In the other 2 patients, hyperthyroidism was unsuspected at the time of PTMC. Unexpectedly suboptimal symptom improvement led to the diagnosis of hyperthyroidism 1 month after the intervention. In all 3 patients, PTMC resulted in an immediate hemodynamic and clinical improvement. However, complete clinical improvement occurred only when euthyroid state was achieved after antithyroid treatment. The present study suggests that PTMC is a safe and effective intervention modality in patients with coexisting hyperthyroidism and severe mitral stenosis. The procedure may be considered a therapeutic option in patients with hyperthyroidism and severe mitral stenosis.

Copy number variations of six and seven α-globin genes in a family with intermedia and major thalassemia phenotypes.

PubMed

Farashi, Samaneh; Vakili, Shadi; Faramarzi Garous, Negin; Ashki, Mehri; Imanian, Hashem; Azarkeivan, Azita; Najmabadi, Hossein

2015-10-01

Copy number variations in α-globin genes are results of unequal crossover between homologous segments in the α-globin gene cluster that misalign during the meiosis phase of the gametogenesis process. Reduction or augmentation of α-globin genes leads to imbalance of α/β chains in hemoglobin tetramer and consequently attenuate or worsen the β-thal clinical symptoms, respectively. Multiplications in α-globin genes have been found in some populations, justifying unexpected severe phenotype of β-thal carriers. Unexpected severe phenotype in the family members may result from coexistence of extra α-globin genes, which is an important factor in the causation of thalassemia intermedia and major in heterozygous β-thalassemia. We described different multiplications in α-globin locus in an Iranian family with one, two or three extra α-globin genes (ααα/αα, αααα/αα and αααα/ααα). The excess α-globin gene/genes cause increment in β/α chain imbalance and leads to worsening pathophysiology and clinical severity of β-thalassemia carriers.

[Sudden death in Versailles: A review of a cardiovascular treatrise by Dionis (1710)].

PubMed

Charlier, P

2018-02-01

In 1710, the surgeon Pierre Dionis publishes a Dissertation on sudden death. Echoing and expanding the work of his Roman colleague Jean Marie Lancisi, he describes and analyzes dozens of cases of sudden death observed by him. A large number of cases was followed by autopsies allowing clinicopathological confrontation. Are proposed causes of death (pulmonary embolism, myocardial infarction, hemorrhagic stroke, arterial rupture, etc.), pathophysiological mechanisms based on the ancient theory of humors, and preventive actions to avoid these unexpected deaths. In this article, we oppose these old data to those of current literature. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effects of short-term continuous positive airway pressure on myocardial sympathetic nerve function and energetics in patients with heart failure and obstructive sleep apnea: a randomized study.

PubMed

Hall, Allison B; Ziadi, Maria C; Leech, Judith A; Chen, Shin-Yee; Burwash, Ian G; Renaud, Jennifer; deKemp, Robert A; Haddad, Haissam; Mielniczuk, Lisa M; Yoshinaga, Keiichiro; Guo, Ann; Chen, Li; Walter, Olga; Garrard, Linda; DaSilva, Jean N; Floras, John S; Beanlands, Rob S B

2014-09-09

Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics. Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and 11C-acetate and 11C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷Kmono), where Kmono is the monoexponential function fit to the myocardial 11C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the 11C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus -0.006 [-0.013, 0.005] min(-1); P=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index>20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (P<0.05). In patients with heart failure with reduced ejection fraction and OSA, short-term CPAP increased hydroxyephedrine retention, indicating improved myocardial sympathetic nerve function, but overall did not affect energetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted. http://www.clinicaltrials.gov. Unique identifier: NCT00756366. © 2014 American Heart Association, Inc.

Transient left ventricular dysfunction due to coronary spasm after spinal anesthesia with bupivacaine - a case report.

PubMed

Elikowski, Waldemar; Małek-Elikowska, Małgorzata; Słomczyński, Marek; Horbacka, Karolina; Bartkowski, Jarosław; Kalawski, Bartosz

2017-10-23

Bupivacaine is a long-acting local anesthetic (LA) used for cutaneous infiltration, peripheral nerve blocks, epidural and spinal anesthesia. However, its application may result in cardiovascular complications such as: hypotension, bradycardia, cardiac arrest and toxic myocardial injury. The authors describe a 53-year-old male with a history of cigarette smoking, admitted for an elective inguinal hernia surgery. Before surgery, the patient received subarachnoid injection of bupivacaine (20 mg). After the operation, he developed transient hypotension. Blood pressure returned to normal after gelofusine infusion; no sympathomimetics were administered. The male denied chest pain; however, ECG showed ST segment elevation coexisting with left ventricular anterolateral hypokinesia and decreased longitudinal strain in echocardiography. A significant increase in troponin I level was suggestive rather of myocardial infarction than of takotsubo cardiomyopathy. Urgent coronary angiography revealed left anterior descending artery spasm, which remitted after intracoronary nitroglycerin injection. Normalization of ECG and echocardiography was observed within a few days. The authors indicate that the presented atypical adverse effect of bupivacaine manifested itself with delay and that coronary spasm proceeded without angina. A close observation of the patient after anesthetic procedure with LA should be extended over the postoperative period.

Thysanophora penicillioides includes multiple genetically diverged groups that coexist respectively in Abies mariesii forests in Japan.

PubMed

Iwamoto, Susumu; Tokumasu, Seiji; Suyama, Yoshihisa; Kakishima, Makoto

2005-01-01

We investigated intraspecific diversity and genetic structures of a saprotrophic fungus--Thysanophora penicillioides--based on sequences of nuclear ribosomal internal transcribed spacer (ITS) in 15 discontinuous Abies mariesii forests of Japan. In such a well-defined morphological species, numerous unexpected ITS variations were revealed: 12 ITS sequence types detected in 254 isolates collected from 15 local populations were classified into five ITS sequence groups. Maximally, four ITS groups consisted of seven ITS types coexisting in one population. However, group 1 was dominant with approximately 65%; in particular, one haplotype, 1a, was most dominant with approximately 60% in respective populations. Therefore, few differences were recognized in genetic structure among local populations, implying that the gene flow of each lineage of the fungus occurs among local populations without geographic limitations. However, minor haplotypes in some ITS groups were found only in restricted areas, suggesting that they might expand steadily from their places of origin to neighboring A. mariesii forests. Aggregating sequence data of seven European strains and four North American strains from various substrates to those of Japanese strains, 18 ITS sequence types and 28 variable sites were recognized. They were clustered into nine lineages by phylogenetic analyses of the beta-tubulin and combined ITS and beta-tubulin datasets. According to phylogenetic species recognition by the concordance of genealogies, respective lineages correspond to phylogenetic species. Plural phylogenetic species coexist in a local population in an A. mariesii forest in Japan.

Sudden unexpected death due to severe pulmonary and cardiac sarcoidosis.

PubMed

Ginelliová, Alžbeta; Farkaš, Daniel; Farkašová Iannaccone, Silvia; Vyhnálková, Vlasta

2016-09-01

In this paper we report the autopsy findings of a 57 year old woman who died unexpectedly at home. She had been complaining of shortness of breath, episodes of dry coughing, and nausea. Her past medical and social history was unremarkable. She had no previous history of any viral or bacterial disease and no history of oncological disorders. Autopsy revealed multiple grayish-white nodular lesions in the pleura and epicardial fat and areas resembling fibrosis on the cut surface of the anterior and posterior wall of the left ventricle and interventricular septum. Histological examination of the lungs and heart revealed multiple well-formed noncaseating epithelioid cell granulomas with multinucleated giant cells. Death was attributed to myocardial ischemia due to vasculitis of intramural coronary artery branches associated with sarcoidosis. Sarcoidosis is a multisystemic disease of unknown etiology characterized by the formation of noncaseating epithelioid cell granulomas in the affected organs and tissues. The diagnosis of sarcoidosis in this case was established when other causes of granulomatous disease such as tuberculosis, berylliosis, hypersensitivity pneumonitis, and giant cell myocarditis had been reasonably excluded.

Nonclinical and clinical pharmacology evidence for cardiovascular safety of saxagliptin.

PubMed

Pollack, Pia S; Chadwick, Kristina D; Smith, David M; Billger, Martin; Hirshberg, Boaz; Iqbal, Nayyar; Boulton, David W

2017-09-13

In the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR) trial in patients with type 2 diabetes mellitus (T2D) at high risk of cardiovascular (CV) disease, saxagliptin did not increase the risk for major CV adverse events. However, there was an unexpected imbalance in events of hospitalization for heart failure (hHF), one of six components of the secondary CV composite endpoint, with a greater number of events observed with saxagliptin. Here, we examined findings from nonclinical safety and clinical pharmacology studies of saxagliptin with the aim of identifying any potential signals of myocardial injury. In vitro and in vivo (rat, dog, monkey) safety pharmacology and toxicology studies evaluating the potential effects of saxagliptin and its major active metabolite, 5-hydroxy saxagliptin, on the CV system are reviewed. In addition, results from saxagliptin clinical studies are discussed: one randomized, 2-period, double-blind, placebo-controlled single-ascending-dose study (up to 100 mg); one randomized, double-blind, placebo-controlled, sequential, multiple-ascending-high-dose study (up to 400 mg/day for 14 days); and one randomized, double-blind, 4-period, 4-treatment, cross-over thorough QTc study (up to 40 mg/day for 4 days) in healthy volunteers; as well as one randomized, placebo-controlled, sequential multiple-ascending-dose study in patients with T2D (up to 50 mg/day for 14 days). Neither saxagliptin nor 5-hydroxy saxagliptin affected ligand binding to receptors and ion channels (e.g. potassium channels) or action potential duration in in vitro studies. In animal toxicology studies, no changes in the cardiac conduction system, blood pressure, heart rate, contractility, heart weight, or heart histopathology were observed. In healthy participants and patients with T2D, there were no findings suggestive of myocyte injury or fluid overload. Serum chemistry abnormalities indicative of cardiac injury, nonspecific muscle damage, or fluid homeostasis changes were infrequent and balanced across treatment groups. There were no QTc changes associated with saxagliptin. No treatment-emergent adverse events suggestive of heart failure or myocardial damage were reported. The saxagliptin nonclinical and clinical pharmacology programs did not identify evidence of myocardial injury and/or CV harm that may have predicted or may explain the unexpected imbalance in the rate of hHF observed in SAVOR.

Unexpected severe calcification after transplantation of bone marrow cells in acute myocardial infarction.

PubMed

Yoon, Young-Sup; Park, Jong-Seon; Tkebuchava, Tengiz; Luedeman, Corinne; Losordo, Douglas W

2004-06-29

There has been a rapid increase in the number of clinical trials using unselected bone marrow (BM) cells or the mononuclear fraction of BM cells for treating ischemic heart diseases. Thus far, no significant deleterious effects or complications have been reported in any studies using BM-derived cells for treatment of various cardiac diseases. Seven-week-old female Fisher-344 rats underwent surgery to induce acute myocardial infarction and were randomized into 3 groups of 16 rats, each receiving intramyocardial injection of either 7x10(5) DiI-labeled total BM cells (TBMCs), the same number of DiI-labeled, clonally expanded BM multipotent stem cells, or the same volume of phosphate-buffered saline in the peri-infarct area. Echocardiography 2 weeks after cell transplantation indicated intramyocardial calcification in 4 of 14 surviving rats (28.5%) in the TBMC group. Histological examination with hematoxylin and eosin staining and von Kossa staining confirmed the presence of extensive intramyocardial calcification. Alkaline phosphatase staining revealed strong positivity surrounding the calcified area suggestive of ongoing osteogenic activity. Fluorescent microscopic examination revealed that acellular calcific areas were surrounded by DiI-labeled TBMCs, suggesting the direct involvement of transplanted TBMCs in myocardial calcification. In contrast, in hearts receiving equal volumes of saline or BM multipotent stem cells delivered in the same manner, there was no evidence of calcification. These results demonstrate that direct transplantation of unselected BM cells into the acutely infarcted myocardium may induce significant intramyocardial calcification.

Abnormal myocardial repolarisation in response to hypoxaemia and fenoterol.

PubMed Central

Kiely, D. G.; Cargill, R. I.; Grove, A.; Struthers, A. D.; Lipworth, B. J.

1995-01-01

BACKGROUND--Prolongation of the QTc interval has been associated with cardiac dysrhythmias and sudden death. QTc dispersion (interlead variability in QTc interval) has recently been proposed as being a more sensitive marker of repolarisation abnormalities and shown to be a more specific index of arrhythmia risk. Although hypoxaemia and fenoterol have previously been shown to prolong the QTc interval, this does not reflect regional myocardial repolarisation abnormalities. METHODS--Electrophysiological effects were measured at baseline and after 30 minutes steady state hypoxaemia at an arterial oxygen saturation (SaO2) of 75-80% (study 1) and at baseline then 30 minutes after inhaled fenoterol 2.4 mg (study 2). From the ECG, lead II corrected QT interval (QTc) and overall corrected QT dispersion were measured using a computer linked digitising tablet according to standard criteria. RESULTS--QTc dispersion was increased during hypoxia compared with baseline values (mean (SE) 69 (6) ms v 50 (5) ms) and after fenoterol compared with baseline (79 (13) v 46 (4) ms), respectively. There was also an increase in QTc interval and heart rate after fenoterol (493 (23) v 420 (6) ms and 98 (3) v 71 (6) bpm, respectively). The heart rate was increased during hypoxaemia compared with baseline (78 (3) v 64 (2) bpm), but no change occurred in the QTc interval. CONCLUSIONS--Both hypoxaemia and fenoterol cause myocardial repolarisation abnormalities in man in terms of increased QTc dispersion, but only fenoterol increased the QTc interval. This may be relevant in the aetiology of arrhythmias in patients with acute severe asthma where beta agonist therapy and hypoxaemia coexist. PMID:7491554

PEComa of the mesentery coexisting with colon cancer: a case report.

PubMed

Wejman, Jarosław; Nowak, Krzysztof; Gielniewska, Lena; Komorowska, Magdalena; Dąbrowski, Wojciech

2015-04-18

Perivascular epithelioid cell tumor (PEComa) is a rare entity originating from mesenchymal tissue, which stains for both melanocytic and smooth muscle markers. We would like to present an unusual case of the PEComa of the mesentery which was unexpected discovery in a female patient with colonic adenocarcinoma. The tumour was revealed on the computer tomography and then resected during surgery, with subsequent chemotherapy for the colon adenocarcinoma. Furthermore we would like to discuss PEComa biology, emphasizing histological criteria of malignancy, possible treatment options and differential diagnosis which is mostly based on immunohistochemistry. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1809062291157051 .

Clinical, pathological and sonographic characteristics of unexpected gallbladder carcinoma

PubMed Central

Wang, Jin-Huan; Liu, Bo-Ji; Xu, Hui-Xiong; Sun, Li-Ping; Li, Dan-Dan; Guo, Le-Hang; Liu, Lin-Na; Xu, Xiao-Hong

2015-01-01

Objectives: To investigate the clinical, pathological, and sonographic characteristics of unexpected gallbladder carcinoma (UGC). Methods: Of 5424 patients who had undergone cholecystectomy from December 2006 to October 2013, 54 patients with primary gallbladder carcinomas confirmed by pathological diagnosis were identified. The patients were divided into two groups: diagnosed before operation (n=34) and UGC groups (n=20), of whom the clinical, pathological, and sonographic characteristics were compared. Results: No significant differences in age, gender, location of lesion, histological type, length of the gallbladder, existence of biliary sludge, and intestinal gas interference between the two groups were found (all P>0.05). The clinical symptoms, laboratory abnormalities, tumor markers, coexisting gallbladder stones, lesion size, lesion type, degree of differentiation, and tumor staging showed statistically significant differences between the two groups (all P<0.05). On ultrasound, the width of the gallbladder, gallbladder wall thickness, vascularity on color Doppler ultrasound, and bile volume in the gallbladder showed significant differences (all P<0.05). Conclusions: UGCs are commonly found at an early stage, often well-differentiated, wall thickened, and are generally accompanied with cholelithiasis. UGCs should be taken into consideration in cases with cholelithiasis or small gallbladder on ultrasound. PMID:26379911

Loss of Oncogenic Notch1 with Resistance to a PI3K Inhibitor in T Cell Leukaemia

PubMed Central

Dail, Monique; Wong, Jason; Lawrence, Jessica; O’Connor, Daniel; Nakitandwe, Joy; Chen, Shann-Ching; Xu, Jin; Lee, Leslie B; Akagi, Keiko; Li, Qing; Aster, Jon C.; Pear, Warren S.; Downing, James R; Sampath, Deepak; Shannon, Kevin

2014-01-01

Mutations that deregulate Notch1 and Ras/PI3 kinase/Akt signalling are prevalent in T lineage acute lymphoblastic leukaemia (T-ALL), and often coexist. The PI3 kinase inhibitor GDC-0941 was active against primary T-ALLs from wild-type and KrasG12D mice and addition of the MEK inhibitor PD0325901 increased efficacy. Mice invariably relapsed after treatment with drug resistant clones, most of which unexpectedly had reduced levels of activated Notch1 protein, down-regulated many Notch1 target genes, and exhibited cross-resistance to γ secretase inhibitors. Multiple resistant primary T-ALLs that emerged in vivo did not contain somatic Notch1 mutations present in the parental leukaemia. Importantly, resistant clones up-regulated PI3K signalling. Consistent with these data, inhibiting Notch1 activated the PI3K pathway, providing a likely mechanism for selection against oncogenic Notch1 signalling. These studies validate PI3K as a therapeutic target in T-ALL and raise the unexpected possibility that dual inhibition of PI3K and Notch1 signalling could facilitate drug resistance in T-ALL. PMID:25043004

Loss of oncogenic Notch1 with resistance to a PI3K inhibitor in T-cell leukaemia.

PubMed

Dail, Monique; Wong, Jason; Lawrence, Jessica; O'Connor, Daniel; Nakitandwe, Joy; Chen, Shann-Ching; Xu, Jin; Lee, Leslie B; Akagi, Keiko; Li, Qing; Aster, Jon C; Pear, Warren S; Downing, James R; Sampath, Deepak; Shannon, Kevin

2014-09-25

Mutations that deregulate Notch1 and Ras/phosphoinositide 3 kinase (PI3K)/Akt signalling are prevalent in T-cell acute lymphoblastic leukaemia (T-ALL), and often coexist. Here we show that the PI3K inhibitor GDC-0941 is active against primary T-ALLs from wild-type and Kras(G12D) mice, and addition of the MEK inhibitor PD0325901 increases its efficacy. Mice invariably relapsed after treatment with drug-resistant clones, most of which unexpectedly had reduced levels of activated Notch1 protein, downregulated many Notch1 target genes, and exhibited cross-resistance to γ-secretase inhibitors. Multiple resistant primary T-ALLs that emerged in vivo did not contain somatic Notch1 mutations present in the parental leukaemia. Importantly, resistant clones upregulated PI3K signalling. Consistent with these data, inhibiting Notch1 activated the PI3K pathway, providing a likely mechanism for selection against oncogenic Notch1 signalling. These studies validate PI3K as a therapeutic target in T-ALL and raise the unexpected possibility that dual inhibition of PI3K and Notch1 signalling could promote drug resistance in T-ALL.

Differential Effects Of Octanoate And Heptanoate On Myocardial Metabolism During Extracorporeal Membrane Oxygenation In An Infant Swine Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kajimoto, Masaki; Ledee, Dolena R.; Isern, Nancy G.

Background: Nutritional energy support during extracorporeal membrane oxygenation (ECMO) should promote successful myocardial adaptation and eventual weaning from the ECMO circuit. Fatty acids (FAs) are a major myocardial energy source, and medium-chain FAs (MCFAs) are easily taken up by cell and mitochondria without membrane transporters. Oddnumbered MCFAs supply carbons to the citric acid cycle (CAC) via anaplerotic propionyl-CoA as well as acetyl-CoA, the predominant betaoxidation product for even-numbered MCFA. Theoretically, this anaplerotic pathway enhances carbon entry into the CAC, and provides superior energy state and preservation of protein synthesis. We tested this hypothesis in an immature swine model undergoing ECMO.more » Methods: Fifteen male Yorkshire pigs (26-45 days old) with 8-hour ECMO were received either normal saline, heptanoate (odd-numbered MCFA) or octanoate (even-numbered MCFA) at 2.3 μmol/kg body wt/min as MCFAs systemically during ECMO (n = 5 per group). The 13-Carbon (13C)-labeled substrates ([2-13C]lactate, [5,6,7-13C3]heptanoate and [U-13C6]leucine) were systemically infused as metabolic markers for the final 60 minutes before left ventricular tissue extraction. Extracted tissues were analyzed for the 13C-labeled and absolute concentrations of metabolites by nuclear magnetic resonance and gas chromatography-mass spectrometry. Results: Octanoate produced markedly higher myocardial citrate concentration, and led to a higher [ATP]/[ADP] ratio compared with other http://mc.manuscriptcentral.com/jpen Journal of Parenteral and Enteral Nutrition For Peer Review groups. Unexpectedly, octanoate increased the flux of propionyl-CoA relative to acetyl-CoA into the CAC as well as heptanoate. MCFAs promoted increases in leucine oxidation, but were not associated with a difference in fractional protein synthesis rate. Conclusion: Octanoate provides energetic advantages to the heart over heptanoate, while preserving protein synthesis.« less

Calcineurin Regulates Myocardial Function during Acute Endotoxemia

PubMed Central

Joshi, Mandar S.; Julian, Mark W.; Huff, Jennifer E.; Bauer, John A.; Xia, Yong; Crouser, Elliott D.

2006-01-01

Rationale: Cyclosporin A (CsA) is known to preserve cardiac contractile function during endotoxemia, but the mechanism is unclear. Increased nitric oxide (NO) production and altered mitochondrial function are implicated as mechanisms contributing to sepsis-induced cardiac dysfunction, and CsA has the capacity to reduce NO production and inhibit mitochondrial dysfunction relating to the mitochondrial permeability transition (MPT). Objectives: We hypothesized that CsA would protect against endotoxin-mediated cardiac contractile dysfunction by attenuating NO production and preserving mitochondrial function. Methods: Left ventricular function was measured continuously over 4 h in cats assigned as follows: control animals (n = 7); LPS alone (3 mg/kg, n = 8); and CsA (6 mg/kg, n = 7), a calcineurin inhibitor that blocks the MPT, or tacrolimus (FK506, 0.1 mg/kg, n = 7), a calcineurin inhibitor lacking MPT activity, followed in 30 min by LPS. Myocardial tissue was then analyzed for NO synthase-2 expression, tissue nitration, protein carbonylation, and mitochondrial morphology and function. Measurements and Main Results: LPS treatment resulted in impaired left ventricular contractility, altered mitochondrial morphology and function, and increased protein nitration. As hypothesized, CsA pretreatment normalized cardiac performance and mitochondrial respiration and reduced myocardial protein nitration. Unexpectedly, FK506 pretreatment had similar effects, normalizing both cardiac and mitochondrial parameters. However, CsA and FK506 pretreatments markedly increased protein carbonylation in the myocardium despite elevated manganese superoxide dismutase activity during endotoxemia. Conclusions: Our data indicate that calcineurin is a critical regulator of mitochondrial respiration, tissue nitration, protein carbonylation, and contractile function in the heart during acute endotoxemia. PMID:16424445

Diastolic dysfunction in hypertension.

PubMed

Nazário Leão, R; Marques da Silva, P

Hypertension and coronary heart disease, often coexisting, are the most common risk factors for heart failure. The progression of hypertensive heart disease involves myocardial fibrosis and alterations in the left ventricular geometry that precede the functional change, initially asymptomatic. The left ventricular diastolic dysfunction is part of this continuum being defined by the presence of left ventricular diastolic dysfunction without signs or symptoms of heart failure or poor left ventricular systolic function. It is highly prevalent in hypertensive patients and is associated with increased cardiovascular morbidity and mortality. Despite its growing importance in clinical practice it remains poorly understood. This review aims to present the epidemiological fundamentals and the latest developments in the pathophysiology, diagnosis and treatment of left ventricular diastolic dysfunction. Copyright © 2017 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Elevated troponin in patients with acute stroke - Is it a true heart attack?

PubMed

Dous, George V; Grigos, Angela C; Grodman, Richard

2017-09-01

Although the prognostic value of a positive troponin in an acute stroke patient is still uncertain, it is a commonly encountered clinical situation given that Ischemic Heart Disease (IHD) and cerebrovascular disease (CVD) frequently co-exist in the same patient and share similar risk factors. Our objectives in this review are to (1) identify the biologic relationship between acute cerebrovascular stroke and elevated troponin levels, (2) determine the pathophysiologic differences between positive troponin in the setting of acute stroke versus acute myocardial infarction (AMI), and (3) examine whether positive troponin in the setting of acute stroke has prognostic significance. We also will provide an insight analysis of some of the available studies and will provide guidance for a management approach based on the available data according to the current guidelines.

Stress Cardiac MRI in Women With Myocardial Infarction and Nonobstructive Coronary Artery Disease.

PubMed

Mauricio, Rina; Srichai, Monvadi B; Axel, Leon; Hochman, Judith S; Reynolds, Harmony R

2016-10-01

In a prospective study, cardiac MRI (CMR) and intravascular ultrasound were performed in women with myocardial infarction (MI) and nonobstructive coronary artery disease (MINOCA). Forty participants underwent adenosine-stress CMR (sCMR). Abnormal perfusion may co-localize with ischemic late gadolinium enhancement (LGE) and T2-weighted signal hyperintensity (T2+), suggesting microvascular dysfunction contributed to MI. Qualitative perfusion analysis was performed by 2 independent readers. Abnormal myocardial perfusion reserve index (MPRI) was defined as global average ≤1.84. Abnormal rest perfusion was present in 10 patients (25%) and stress perfusion abnormalities in 25 (63%). Abnormal stress perfusion was not associated with LGE but tended to occur with T2+. Among patients with abnormal perfusion and LGE, the LGE pattern was ischemic in half. The locations of abnormal perfusion and LGE matched in 75%, T2+ in 100%. Abnormal stress perfusion was not associated with plaque disruption and matched in location in 63%. MPRI was abnormal in 10 patients (25%) and was not associated with LGE, T2+ or plaque disruption. Abnormal perfusion on sCMR is common among women with MINOCA. Abnormal perfusion usually co-localized with LGE and/or T2+ when present. Variability in LGE pattern leads to uncertainty about whether the finding of abnormal perfusion was cause or consequence of the tissue state leading to LGE. Low MPRI, possibly indicating diffuse microvascular disease, was observed with and without LGE and T2+. Multiple mechanisms may lead to abnormal perfusion on sCMR. Microvascular dysfunction may contribute to the pathogenesis of and coexist with other causes of MINOCA. © 2016 Wiley Periodicals, Inc.

Feasibility of high-resolution quantitative perfusion analysis in patients with heart failure.

PubMed

Sammut, Eva; Zarinabad, Niloufar; Wesolowski, Roman; Morton, Geraint; Chen, Zhong; Sohal, Manav; Carr-White, Gerry; Razavi, Reza; Chiribiri, Amedeo

2015-02-12

Cardiac magnetic resonance (CMR) is playing an expanding role in the assessment of patients with heart failure (HF). The assessment of myocardial perfusion status in HF can be challenging due to left ventricular (LV) remodelling and wall thinning, coexistent scar and respiratory artefacts. The aim of this study was to assess the feasibility of quantitative CMR myocardial perfusion analysis in patients with HF. A group of 58 patients with heart failure (HF; left ventricular ejection fraction, LVEF ≤ 50%) and 33 patients with normal LVEF (LVEF >50%), referred for suspected coronary artery disease, were studied. All subjects underwent quantitative first-pass stress perfusion imaging using adenosine according to standard acquisition protocols. The feasibility of quantitative perfusion analysis was then assessed using high-resolution, 3 T kt perfusion and voxel-wise Fermi deconvolution. 30/58 (52%) subjects in the HF group had underlying ischaemic aetiology. Perfusion abnormalities were seen amongst patients with ischaemic HF and patients with normal LV function. No regional perfusion defect was observed in the non-ischaemic HF group. Good agreement was found between visual and quantitative analysis across all groups. Absolute stress perfusion rate, myocardial perfusion reserve (MPR) and endocardial-epicardial MPR ratio identified areas with abnormal perfusion in the ischaemic HF group (p = 0.02; p = 0.04; p = 0.02, respectively). In the Normal LV group, MPR and endocardial-epicardial MPR ratio were able to distinguish between normal and abnormal segments (p = 0.04; p = 0.02 respectively). No significant differences of absolute stress perfusion rate or MPR were observed comparing visually normal segments amongst groups. Our results demonstrate the feasibility of high-resolution voxel-wise perfusion assessment in patients with HF.

Magnetoresistance in the superconducting state at the (111) LaAlO3/SrTiO3 interface

NASA Astrophysics Data System (ADS)

Davis, S.; Huang, Z.; Han, K.; Ariando, Venkatesan, T.; Chandrasekhar, V.

2017-10-01

Condensed-matter systems that simultaneously exhibit superconductivity and ferromagnetism are rare due the antagonistic relationship between conventional spin-singlet superconductivity and ferromagnetic order. In materials in which superconductivity and magnetic order are known to coexist (such as some heavy-fermion materials), the superconductivity is thought to be of an unconventional nature. Recently, the conducting gas that lives at the interface between the perovskite band insulators LaAlO3 (LAO) and SrTiO3 (STO) has also been shown to host both superconductivity and magnetism. Most previous research has focused on LAO/STO samples in which the interface is on the (001) crystal plane. Relatively little work has focused on the (111) crystal orientation, which has hexagonal symmetry at the interface, and has been predicted to have potentially interesting topological properties, including unconventional superconducting pairing states. Here we report measurements of the magnetoresistance of (111) LAO/STO heterostructures at temperatures at which they are also superconducting. As with the (001) structures, the magnetoresistance is hysteretic, indicating the coexistence of magnetism and superconductivity, but in addition, we find that this magnetoresistance is anisotropic. Such an anisotropic response is completely unexpected in the superconducting state and suggests that (111) LAO/STO heterostructures may support unconventional superconductivity.

ANCA vasculitis in a patient with Alport syndrome: a difficult diagnosis but a treatable disease!

PubMed

Gillion, Valentine; Jadoul, Michel; Aydin, Selda; Godefroid, Nathalie

2017-03-29

Alport syndrome and ANCA-associated vasculitis are both rare diseases. The co-existence of these two conditions has never been reported. There is no obvious pathogenic link between these two glomerular diseases. The management of this case highlights the importance of a systematic approach when investigating the unexpected unfavourable evolution of a known glomerulopathy. A-17 year old caucasian boy with a genetically proven X-linked Alport syndrome presented with progressive dyspnea, fatigue and pallor. His blood tests showed a severe anemia (Hb 6.9 g/dl) with acute worsening of kidney function (serum creatinine, normal 9 months earlier, was now 3.6 mg/dl). Microscopic hematuria and proteinuria also worsened. He soon developed signs of alveolar hemorrhage. Serological tests showed the presence of perinuclear ANCA with anti MPO specificity. Kidney biopsy showed a necrotizing and crescentic glomerulonephritis. Pulses of methylprednisolone were given in combination with plasmapheresis. The patient further received 6 pulses of cyclophosphamide, followed by maintenance oral azathioprine. During the 15-months follow up he remained well with serum creatinine back to normal, and some residual proteinuria and hematuria ascribed to Alport syndrome. We report a young patient with the coexistence of Alport syndrome and ANCA associated vasculitis. Clinicians should be aware of the possibility of a second acquired disease in a patient with a known kidney disease, genetic in this case. This coexistence is very rare, but should be considered even if both diseases are rare, if the evolution is atypical for the single (known) primary disease. The diagnosis of the added vasculitis prompted in our case the initiation of immunosuppressive drugs, with a favourable outcome.

Real-world cardiovascular assessment of mirabegron treatment in patients with overactive bladder and concomitant cardiovascular disease: Results of a Japanese post-marketing study.

PubMed

Katoh, Takao; Kuwamoto, Kana; Kato, Daisuke; Kuroishi, Kentarou

2016-12-01

To assess the effect of 25 or 50 mg mirabegron on cardiovascular end-points and adverse drug reactions in real-world Japanese patients with overactive bladder and cardiovascular disease. Participants had overactive bladder, a history of/coexisting cardiovascular disease and a 12-lead electrocardiogram carried out ≤7 days before initiating 4 weeks of mirabegron treatment. Patients with "serious cardiovascular disease" (class III or IV on the New York Heart Association functional classification and further confirmed by expert analysis) were excluded. Patient demographics, physical characteristics and cardiovascular history were recorded. After 4 weeks, patients underwent another electrocardiogram. Incidence of cardiovascular adverse drug reactions and change from baseline in electrocardiogram parameters (RR, PR, QRS intervals, Fridericia's corrected QT and heart rate) were assessed. Of 316 patients registered, 236 met criteria and had baseline/post-dose electrocardiograms: 61.9% male; 60.2% aged ≥75 years; 93.6% with coexisting cardiovascular disease, notably, arrhythmia (67.8%) and angina pectoris (19.1%). Starting mirabegron daily doses were 25 mg (19.9%) or 50 mg (80.1%). The incidence of cardiovascular adverse drug reactions was 5.51%. After 4 weeks, the mean heart rate increased by 1.24 b.p.m. (statistically significant, but clinically acceptable as per previous trials). No significant changes were observed in PR, QRS or Fridericia's corrected QT. No significant correlations in the total population or age-/sex-segregated subgroups were observed between baseline Fridericia's corrected QT and change at 4 weeks. No correlation for heart rate versus change from baseline heart rate with treatment was observed. Mirabegron was well tolerated in real-world Japanese patients with overactive bladder and coexisting cardiovascular disease. No unexpected cardiovascular safety concerns were observed. © 2016 The Japanese Urological Association.

Reduced heart size and increased myocardial fuel substrate oxidation in ACC2 mutant mice

PubMed Central

Essop, M. Faadiel; Camp, Heidi S.; Choi, Cheol Soo; Sharma, Saumya; Fryer, Ryan M.; Reinhart, Glenn A.; Guthrie, Patrick H.; Bentebibel, Assia; Gu, Zeiwei; Shulman, Gerald I.; Taegtmeyer, Heinrich; Wakil, Salih J.; Abu-Elheiga, Lutfi

2008-01-01

The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC2) is a key regulator of mitochondrial fatty acid (FA) uptake via carnitine palmitoyltransferase 1 (CPT1). To test the hypothesis that oxidative metabolism is upregulated in hearts from animals lacking ACC2 (employing a transgenic Acc2-mutant mouse), we assessed cardiac function in vivo and determined rates of myocardial substrate oxidation ex vivo. When examined by echocardiography, there was no difference in systolic function, but left ventricular mass of the Acc2-mutant (MUT) mouse was significantly reduced (∼25%) compared with wild-types (WT). Reduced activation of the mammalian target of rapamycin (mTOR) and its downstream target p70S6K was found in MUT hearts. Exogenous oxidation rates of oleate were increased ∼22%, and, unexpectedly, exogenous glucose oxidation rates were also increased in MUT hearts. Using a hyperinsulinemic-euglycemic clamp, we found that glucose uptake in MUT hearts was increased by ∼83%. Myocardial triglyceride levels were significantly reduced in MUT vs. WT while glycogen content was the same. In parallel, transcript levels of PPARα and its target genes, pyruvate dehydrogenase kinase-4 (PDK-4), malonyl-CoA decarboxylase (MCD), and mCPT1, were downregulated in MUT mice. In summary, we report that 1) Acc2-mutant hearts exhibit a marked preference for the oxidation of both glucose and FAs coupled with greater utilization of endogenous fuel substrates (triglycerides), 2) attenuated mTOR signaling may result in reduced heart sizes observed in Acc2-mutant mice, and 3) Acc2-mutant hearts displayed normal functional parameters despite a significant decrease in size. PMID:18487439

Mechanism of the α -ɛ phase transformation in iron

NASA Astrophysics Data System (ADS)

Dewaele, A.; Denoual, C.; Anzellini, S.; Occelli, F.; Mezouar, M.; Cordier, P.; Merkel, S.; Véron, M.; Rausch, E.

2015-05-01

The α -Fe↔ɛ -Fe pressure-induced transformation under pure hydrostatic static compression has been characterized with in situ x-ray diffraction using α -Fe single crystals as starting samples. The forward transition starts at 14.9 GPa, and the reverse at 12 GPa, with a width of α -ɛ coexistence domain of the order of 2 GPa. The elastic stress in the sample increases in this domain, and partially relaxes after completion of the transformation. Orientation relations between parent α -Fe and child ɛ -Fe have been determined, which definitely validates the Burgers path for the direct transition. On the reverse transition, an unexpected variant selection is observed. X-ray diffraction data, complemented with ex situ microstructural observations, suggest that this selection is caused by defects and stresses accumulated during the direct transition.

Investigation of Stainless Steel Corrosion in Ultrahigh-Purity Water and Steam Systems by Surface Analytical Techniques

NASA Astrophysics Data System (ADS)

Dong, Xia; Iacocca, Ronald G.; Bustard, Bethany L.; Kemp, Craig A. J.

2010-02-01

Stainless steel pipes with different degrees of rouging and a Teflon®-coated rupture disc with severe corrosion were thoroughly investigated by combining multiple surface analytical techniques. The surface roughness and iron oxide layer thickness increase with increasing rouge severity, and the chromium oxide layer coexists with the iron oxide layer in samples with various degrees of rouging. Unlike the rouging observed for stainless steel pipes, the fast degradation of the rupture disc was caused by a crevice corrosion environment created by perforations in the protective Teflon coating. This failure analysis clearly shows the highly corrosive nature of ultrapure water used in the manufacture of pharmaceutical products, and demonstrates some of the unexpected corrosion mechanisms that can be encountered in these environments.

Unexpectedly high piezoelectricity of Sm-doped lead zirconate titanate in the Curie point region.

PubMed

Seshadri, Shruti B; Nolan, Michelle M; Tutuncu, Goknur; Forrester, Jennifer S; Sapper, Eva; Esteves, Giovanni; Granzow, Torsten; Thomas, Pam A; Nino, Juan C; Rojac, Tadej; Jones, Jacob L

2018-03-07

Large piezoelectric coefficients in polycrystalline lead zirconate titanate (PZT) are traditionally achieved through compositional design using a combination of chemical substitution with a donor dopant and adjustment of the zirconium to titanium compositional ratio to meet the morphotropic phase boundary (MPB). In this work, a different route to large piezoelectricity is demonstrated. Results reveal unexpectedly high piezoelectric coefficients at elevated temperatures and compositions far from the MPB. At temperatures near the Curie point, doping with 2 at% Sm results in exceptionally large piezoelectric coefficients of up to 915 pm/V. This value is approximately twice those of other donor dopants (e.g., 477 pm/V for Nb and 435 pm/V for La). Structural changes during the phase transitions of Sm-doped PZT show a pseudo-cubic phase forming ≈50 °C below the Curie temperature. Possible origins of these effects are discussed and the high piezoelectricity is posited to be due to extrinsic effects. The enhancement of the mechanism at elevated temperatures is attributed to the coexistence of tetragonal and pseudo-cubic phases, which enables strain accommodation during electromechanical deformation and interphase boundary motion. This work provides insight into possible routes for designing high performance piezoelectrics which are alternatives to traditional methods relying on MPB compositions.

Elemental ratios for characterization of quantum-dots populations in complex mixtures by asymmetrical flow field-flow fractionation on-line coupled to fluorescence and inductively coupled plasma mass spectrometry.

PubMed

Menendez-Miranda, Mario; Fernandez-Arguelles, Maria T; Costa-Fernandez, Jose M; Encinar, Jorge Ruiz; Sanz-Medel, Alfredo

2014-08-11

Separation and identification of nanoparticles of different composition, with similar particle diameter, coexisting in heterogeneous suspensions of polymer-coated CdSe/ZnS quantum dots (QDs) have been thoroughly assessed by asymmetric flow field-flow fractionation (AF4) coupled on-line to fluorescence and inductively coupled plasma mass spectrometry (ICPMS) detectors. Chemical characterization of any previously on-line separated nanosized species was achieved by the measurement of the elemental molar ratios of every element involved in the synthesis of the QDs, using inorganic standards and external calibration by flow injection analysis (FIA). Such elemental molar ratios, strongly limited so far to pure single nanoparticles suspensions, have been achieved with adequate accuracy by coupling for the first time an ICP-QQQ instrument to an AF4 system. This hyphenation turned out to be instrumental to assess the chemical composition of the different populations of nanoparticles coexisting in the relatively complex mixtures, due to its capabilities to detect the hardly detectable elements involved in the synthesis. Interestingly such information, complementary to that obtained by fluorescence, was very valuable to detect and identify unexpected nanosized species, present at significant level, produced during QDs synthesis and hardly detectable by standard approaches. Copyright © 2014. Published by Elsevier B.V.

Physician discretion is safe and may lower stress test utilization in emergency department chest pain unit patients.

PubMed

Napoli, Anthony M; Arrighi, James A; Siket, Matthew S; Gibbs, Frantz J

2012-03-01

Chest pain unit (CPU) observation with defined stress utilization protocols is a common management option for low-risk emergency department patients. We sought to evaluate the safety of a joint emergency medicine and cardiology staffed CPU. Prospective observational trial of consecutive patients admitted to an emergency department CPU was conducted. A standard 6-hour observation protocol was followed by cardiology consultation and stress utilization largely at their discretion. Included patients were at low/intermediate risk by the American Heart Association, had nondiagnostic electrocardiograms, and a normal initial troponin. Excluded patients were those with an acute comorbidity, age >75, and a history of coronary artery disease, or had a coexistent problem restricting 24-hour observation. Primary outcome was 30-day major adverse cardiovascular events-defined as death, nonfatal acute myocardial infarction, revascularization, or out-of-hospital cardiac arrest. A total of 1063 patients were enrolled over 8 months. The mean age of the patients was 52.8 ± 11.8 years, and 51% (95% confidence interval [CI], 48-54) were female. The mean thrombolysis in myocardial infarction and Diamond & Forrester scores were 0.6% (95% CI, 0.51-0.62) and 33% (95% CI, 31-35), respectively. In all, 51% (95% CI, 48-54) received stress testing (52% nuclear stress, 39% stress echocardiogram, 5% exercise, 4% other). In all, 0.9% patients (n = 10, 95% CI, 0.4-1.5) were diagnosed with a non-ST elevation myocardial infarction and 2.2% (n = 23, 95% CI, 1.3-3) with acute coronary syndrome. There was 1 (95% CI, 0%-0.3%) case of a 30-day major adverse cardiovascular events. The 51% stress test utilization rate was less than the range reported in previous CPU studies (P < 0.05). Joint emergency medicine and cardiology management of patients within a CPU protocol is safe, efficacious, and may safely reduce stress testing rates.

Anisotropic Reinforcement of Acute Anteroapical Infarcts Improves Pump Function

PubMed Central

Fomovsky, Gregory M.; Clark, Samantha A.; Parker, Katherine M.; Ailawadi, Gorav; Holmes, Jeffrey W.

2012-01-01

Background We hypothesize that a therapy that improves LV pump function early after infarction should decrease the need for compensation through sympathetic activation and dilation, thereby reducing the risk of developing heart failure. The mechanical properties of healing myocardial infarcts are an important determinant of left ventricular (LV) function, yet improving function by altering infarct properties has proven unexpectedly difficult. Using a computational model, we recently predicted that stiffening a large anterior infarct anisotropically (in only one direction) would improve LV function, while isotropic stiffening, the focus of previous studies and therapies, would not. The goal of this study was to test the novel strategy of anisotropic infarct reinforcement. Methods and Results We tested the effects of anisotropic infarct reinforcement in 10 open-chest dogs with large anteroapical infarcts that depressed LV pump function. We measured regional mechanics, LV volumes, and cardiac output at a range of preloads at Baseline, 45 minutes after coronary ligation (Ischemia), and 30 minutes later, following surgical reinforcement in the longitudinal direction (Anisotropic). Ischemia shifted the end-systolic pressure-volume relationship (ESPVR) and cardiac output curves rightward, decreasing cardiac output at matched end-diastolic pressure (EDP) by 44%. Anisotropic reinforcement significantly improved systolic function without impairing diastolic function, recovering half the deficit in overall LV function. Conclusions We conclude that anisotropic reinforcement is a promising new approach to improving LV function following a large myocardial infarction. PMID:22665716

Coronary Artery Development: Progenitor Cells and Differentiation Pathways

PubMed Central

Sharma, Bikram; Chang, Andrew; Red-Horse, Kristy

2017-01-01

Coronary artery disease (CAD) is the number one cause of death worldwide and involves the accumulation of plaques within the artery wall that can occlude blood flow to the heart and cause myocardial infarction. The high mortality associated with CAD makes the development of medical interventions that repair and replace diseased arteries a high priority for the cardiovascular research community. Advancements in arterial regenerative medicine could benefit from a detailed understanding of coronary artery development during embryogenesis and of how these pathways might be reignited during disease. Recent research has advanced our knowledge on how the coronary vasculature is built and revealed unexpected features of progenitor cell deployment that may have implications for organogenesis in general. Here, we highlight these recent findings and discuss how they set the stage to interrogate developmental pathways during injury and disease. PMID:27959616

Diabetic cardiomyopathy is associated with defective myocellular copper regulation and both defects are rectified by divalent copper chelation

PubMed Central

2014-01-01

Background Heart disease is the leading cause of death in diabetic patients, and defective copper metabolism may play important roles in the pathogenesis of diabetic cardiomyopathy (DCM). The present study sought to determine how myocardial copper status and key copper-proteins might become impaired by diabetes, and how they respond to treatment with the Cu (II)-selective chelator triethylenetetramine (TETA) in DCM. Methods Experiments were performed in Wistar rats with streptozotocin (STZ)-induced diabetes with or without TETA treatment. Cardiac function was analyzed in isolated-perfused working hearts, and myocardial total copper content measured by particle-induced x-ray emission spectroscopy (PIXE) coupled with Rutherford backscattering spectrometry (RBS). Quantitative expression (mRNA and protein) and/or activity of key proteins that mediate LV-tissue-copper binding and transport, were analyzed by combined RT-qPCR, western blotting, immunofluorescence microscopy, and enzyme activity assays. Statistical analysis was performed using Student’s t-tests or ANOVA and p-values of < 0.05 have been considered significant. Results Left-ventricular (LV) copper levels and function were severely depressed in rats following 16-weeks’ diabetes, but both were unexpectedly normalized 8-weeks after treatment with TETA was instituted. Localized myocardial copper deficiency was accompanied by decreased expression and increased polymerization of the copper-responsive transition-metal-binding metallothionein proteins (MT1/MT2), consistent with impaired anti-oxidant defences and elevated susceptibility to pro-oxidant stress. Levels of the high-affinity copper transporter-1 (CTR1) were depressed in diabetes, consistent with impaired membrane copper uptake, and were not modified by TETA which, contrastingly, renormalized myocardial copper and increased levels and cell-membrane localization of the low-affinity copper transporter-2 (CTR2). Diabetes also lowered indexes of intracellular (IC) copper delivery via the copper chaperone for superoxide dismutase (CCS) to its target cuproenzyme, superoxide dismutase-1 (SOD1): this pathway was rectified by TETA treatment, which normalized SOD1 activity with consequent bolstering of anti-oxidant defenses. Furthermore, diabetes depressed levels of additional intracellular copper-transporting proteins, including antioxidant-protein-1 (ATOX1) and copper-transporting-ATPase-2 (ATP7B), whereas TETA elevated copper-transporting-ATPase-1 (ATP7A). Conclusions Myocardial copper deficiency and defective cellular copper transport/trafficking are revealed as key molecular defects underlying LV impairment in diabetes, and TETA-mediated restoration of copper regulation provides a potential new class of therapeutic molecules for DCM. PMID:24927960

[Type 2 diabetes mellitus and cardiovascular risk factors: is comprehensive treatment required?].

PubMed

Nadal, Josep Franch; Gutiérrez, Pedro Conthe

2013-09-01

Diabetes mellitus, especially type 2, is a metabolic disease involving the coexistence of several cardiovascular risk factors. Affected patients are therefore at high cardiovascular risk (2-3 times higher than that of men in the general population and 2-6 times higher than that of women). Cardiovascular disease is the main cause of death in the diabetic population, followed by cancer. Cardiovascular risk cannot be compared between diabetic patients and persons who have already shown one or more manifestations of cardiovascular disease (such as myocardial infarction). Single risk factors should be evaluated in combination with other risk factors and a person's cardiovascular risk should be individually assessed. Cardiovascular risk assessment in patients with diabetes through current calculations methods is complex because their ability to predict risk in individuals is very low. Studies such as that by Steno have demonstrated the validity of a comprehensive strategy to control all the risk factors present in persons with type 2 diabetes mellitus, which can reduce the development of micro- and macrovascular complications and mortality by almost 50%. The present article reviews each of the classical cardiovascular risk factors (hypertension, dyslipidemia, smoking, obesity, sedentariness) in relation to diabetes, as well as their recommended targets and the benefits of their control. In view of the above, a comprehensive approach is recommended to control the multiple risk factors that can coexist in persons with type 2 diabetes mellitus. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Potential problems of removing one invasive species at a time: a meta-analysis of the interactions between invasive vertebrates and unexpected effects of removal programs.

PubMed

Ballari, Sebastián A; Kuebbing, Sara E; Nuñez, Martin A

2016-01-01

Although the co-occurrence of nonnative vertebrates is a ubiquitous global phenomenon, the study of interactions between invaders is poorly represented in the literature. Limited understanding of the interactions between co-occurring vertebrates can be problematic for predicting how the removal of only one invasive-a common management scenario-will affect native communities. We suggest a trophic food web framework for predicting the effects of single-species management on native biodiversity. We used a literature search and meta-analysis to assess current understanding of how the removal of one invasive vertebrate affects native biodiversity relative to when two invasives are present. The majority of studies focused on the removal of carnivores, mainly within aquatic systems, which highlights a critical knowledge gap in our understanding of co-occurring invasive vertebrates. We found that removal of one invasive vertebrate caused a significant negative effect on native species compared to when two invasive vertebrates were present. These unexpected results could arise because of the positioning and hierarchy of the co-occurring invasives in the food web (e.g., carnivore-carnivore or carnivore-herbivore). We consider that there are important knowledge gaps to determinate the effects of multiple co-existing invaders on native ecosystems, and this information could be precious for management.

Potential problems of removing one invasive species at a time: a meta-analysis of the interactions between invasive vertebrates and unexpected effects of removal programs

PubMed Central

Kuebbing, Sara E.; Nuñez, Martin A.

2016-01-01

Although the co-occurrence of nonnative vertebrates is a ubiquitous global phenomenon, the study of interactions between invaders is poorly represented in the literature. Limited understanding of the interactions between co-occurring vertebrates can be problematic for predicting how the removal of only one invasive—a common management scenario—will affect native communities. We suggest a trophic food web framework for predicting the effects of single-species management on native biodiversity. We used a literature search and meta-analysis to assess current understanding of how the removal of one invasive vertebrate affects native biodiversity relative to when two invasives are present. The majority of studies focused on the removal of carnivores, mainly within aquatic systems, which highlights a critical knowledge gap in our understanding of co-occurring invasive vertebrates. We found that removal of one invasive vertebrate caused a significant negative effect on native species compared to when two invasive vertebrates were present. These unexpected results could arise because of the positioning and hierarchy of the co-occurring invasives in the food web (e.g., carnivore–carnivore or carnivore–herbivore). We consider that there are important knowledge gaps to determinate the effects of multiple co-existing invaders on native ecosystems, and this information could be precious for management. PMID:27280066

The relationship between admission heart rate and early prognosis in patients with ST-elevation myocardial infarction.

PubMed

Salwa, Paweł; Gorczyca-Michta, Iwona; Wożakowska-Kapłon, Beata

2015-01-01

Heart rate (HR) is a basic cardiovascular parameter. The relationship between HR and cardiovascular mortality and morbidity has been indicated in clinical trials and epidemiological studies. The evaluation of the relationship between HR upon hospital admission and the in-hospital prognosis in a group of patients with ST-elevation myocardial infarction (STEMI). The medical records of 927 patients were subject to retrospective analysis. The patients were classified on the basis of HR upon hospital admission: < 60 bpm (n = 75), 60-69 bpm (n = 169), 70-79 bpm (n = 245), 80-89 bpm (n = 172), 90-99 bpm (n = 134), and ≥ 100 bpm (n = 132). A group of patients with HR of 60-69 bpm on hospital admission (n = 169) constituted a reference group. Patients with atrioventricular blocks and arrhythmias were excluded from the analysis. Early mortality and co-existing diseases were evaluated in the study population. Patients with HR ≥ 90 bpm demonstrated heart failure symptoms considerably more often than patients with HR of 60-69 bpm (p = 0.0010). In-hospital mortality was significantly higher in patients with a HR of more than 90 bpm and bradycardia. The relationship between HR and cardiovascular mortality is shown with a J-shaped curve. HR is strictly correlated with early cardiovascular mortality in a population of patients with STEMI. The relationship between HR and early mortality is demonstrated by a J-shaped curve.

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging.

PubMed

Lauzier, Pascal Theriault; Tang, Jie; Speidel, Michael A; Chen, Guang-Hong

2012-07-01

To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise and streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI.

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lauzier, Pascal Theriault; Tang Jie; Speidel, Michael A.

Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise andmore » streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Methods: Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Results: Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. Conclusions: (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI.« less

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

PubMed Central

Lauzier, Pascal Thériault; Tang, Jie; Speidel, Michael A.; Chen, Guang-Hong

2012-01-01

Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise and streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Methods: Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Results: Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. Conclusions: (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI. PMID:22830741

Highly repeatable nanoscale phase coexistence in vanadium dioxide films

NASA Astrophysics Data System (ADS)

Huffman, T. J.; Lahneman, D. J.; Wang, S. L.; Slusar, T.; Kim, Bong-Jun; Kim, Hyun-Tak; Qazilbash, M. M.

2018-02-01

It is generally believed that in first-order phase transitions in materials with imperfections, the formation of phase domains must be affected to some extent by stochastic (probabilistic) processes. The stochasticity would lead to unreliable performance in nanoscale devices that have the potential to exploit the transformation of physical properties in a phase transition. Here we show that stochasticity at nanometer length scales is completely suppressed in the thermally driven metal-insulator transition (MIT) in sputtered vanadium dioxide (V O2 ) films. The nucleation and growth of domain patterns of metallic and insulating phases occur in a strikingly reproducible way. The completely deterministic nature of domain formation and growth in films with imperfections is a fundamental and unexpected finding about the kinetics of this material. Moreover, it opens the door for realizing reliable nanoscale devices based on the MIT in V O2 and similar phase-change materials.

Tumor morphology and phenotypic evolution driven by selective pressure from the microenvironment.

PubMed

Anderson, Alexander R A; Weaver, Alissa M; Cummings, Peter T; Quaranta, Vito

2006-12-01

Emergence of invasive behavior in cancer is life-threatening, yet ill-defined due to its multifactorial nature. We present a multiscale mathematical model of cancer invasion, which considers cellular and microenvironmental factors simultaneously and interactively. Unexpectedly, the model simulations predict that harsh tumor microenvironment conditions (e.g., hypoxia, heterogenous extracellular matrix) exert a dramatic selective force on the tumor, which grows as an invasive mass with fingering margins, dominated by a few clones with aggressive traits. In contrast, mild microenvironment conditions (e.g., normoxia, homogeneous matrix) allow clones with similar aggressive traits to coexist with less aggressive phenotypes in a heterogeneous tumor mass with smooth, noninvasive margins. Thus, the genetic make-up of a cancer cell may realize its invasive potential through a clonal evolution process driven by definable microenvironmental selective forces. Our mathematical model provides a theoretical/experimental framework to quantitatively characterize this selective pressure for invasion and test ways to eliminate it.

Thrombotic thrombocytopenic purpura or immune thrombocytopenia in a sickle cell/β+-thalassemia patient: a rare and challenging condition.

PubMed

Vlachaki, Efthymia; Agapidou, Aleka; Neokleous, Nikolaos; Adamidou, Despoina; Vetsiou, Evaggelia; Boura, Panagiota

2014-10-01

The diagnosis of thrombotic thrombocytopenic purpura is one of the possible diagnosis when a patient is admitted with unexpected micro-angiopathic hemolytic anemia and thrombocytopenia. The combination of sickle cell/β(+)-thalassemia and thrombotic thrombocytopenic purpura is rare and triggering. This article describes the poor outcome of a patient with sickle cell/β(+)-thalassemia presenting with gingival bleeding, severe thrombocytopenia and anemia. The patient had normal renal function, no neurological deficit and he was initially treated as immune thrombocytopenic purpura. He eventually died due to multi-organ failure and brain hemorrhage even though he had started plasma exchange sessions. The co-existence of thrombotic thrombocytopenic purpura and sickle cell anemia is making the diagnosis of the former difficult. Early and rapid intervention is critical to the outcome. Copyright © 2014 Elsevier Ltd. All rights reserved.

Status and ecological effects of the world's largest carnivores.

PubMed

Ripple, William J; Estes, James A; Beschta, Robert L; Wilmers, Christopher C; Ritchie, Euan G; Hebblewhite, Mark; Berger, Joel; Elmhagen, Bodil; Letnic, Mike; Nelson, Michael P; Schmitz, Oswald J; Smith, Douglas W; Wallach, Arian D; Wirsing, Aaron J

2014-01-10

Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth's largest carnivores and all that depends upon them, including humans.

True Upward Adatom Diffusion and Faceting in fcc metal (110) homoepitaxy

NASA Astrophysics Data System (ADS)

Buatier de Mongeot, Francesco

2004-03-01

Recent studies of Ge heteroepitaxial growth on Si(100) have led to the discovery of an intriguing bimodal growth mode, characterised by the coexistence of smaller hut islands and much larger domes. Efforts aimed to understand the microscopic mechanisms involved have so far been focused predominantly on the role of the thermodynamic driving force associated with stress. Here we report on the observation of bimodal growth in an entirely unexpected system, homoepitaxial growth of Al on Al(110), characterised by the coexistence of smaller mound islands and tenfold taller nanocrystals with well-defined facets (the huts). Whereas the formation of the mounds results from kinetic roughening due to slow downward adatom diffusion at step edges, the formation of the huts demands atom extraction from the mounds and true upward diffusion of such atoms through the (110) terraces onto the facets serving as kinetic traps. A critical role in the faceting instability, is found to be played by the surprisingly low activation barriers for adatom ascent at step edges and island corners(F.Buatier de Mongeot, W.Zhu, A.Molle, R.Buzio, C.Boragno, U. Valbusa, E.G.Wang, Z.Zhang, Physical Review Letters 91, 016102 (2003)),(Physics News Update, AIP, Number 643,2003 Mountain climbing atoms (http://www.aip.org/enews/physnews/2003/split/643-2.html)). Extensions of the results to other related systems will be presented, in particular for the fcc(110) class of substrates Cu, Pb, Ag as well as for heteroepitaxyal systems like Co/Cu(110).

Ruptured pericardial perivascular epithelioid cell tumor (PEComa) leading to sudden death: an autopsy case report and review of the literature.

PubMed

Zhang, Lingxin; Carpenter, Danielle; Dehner, Louis P

2016-01-01

A 30-year-old man with past medical history of atrial fibrillation/flutter passed away after presenting with sudden-onset cardiac dysfunction. The postmortem examination revealed cardiac tamponade secondary to rupture of a 7.2-cm pericardial perivascular epithelioid cell tumor (PEComa). The tumor grossly appeared to arise from the transverse pericardial sinus and focally penetrated the epicardium of the right atrium. Microscopically, it was composed of predominately spindle cells with low nuclear grade, no pleomorphism, or readily apparent mitoses. Immunohistochemistry revealed cytoplasmic reactivity for HMB-45, desmin, and smooth muscle actin. Electron microscopic findings were characterized by melanosome-like structures intermixed with intermediate filaments and abundant stacked endoplasmic reticulum. The present case is unique among previously reported pericardial/myocardial PEComas as a first example resulting in unexpected cardiac tamponade and sudden cardiac death. Copyright © 2016 Elsevier Inc. All rights reserved.

Pre-hospital physical activity status affects in-hospital course of elderly patients with acute myocardial infarction.

PubMed

Miyamoto, Takamichi; Obayashi, Tohru; Hattori, Eijirou; Yamauchi, Yasuteru; Niwa, Akihiro; Isobe, Mitsuaki

2010-03-01

The clinical course of elderly patients with acute myocardial infarction (AMI) can sometimes unexpectedly result in an adverse outcome even when therapy appears to be successful. We suspect that specific factors may characterize this worsening of status during hospitalization. This study examines whether the pre-hospital physical activity status of the elderly treated with percutaneous coronary intervention (PCI) for AMI affects their in-hospital course. We studied 110 consecutive patients, aged 80 or older, who had undergone emergent PCI for AMI. Patients were divided into two groups based on clinical presentation: Better Killip class (Killip classes I and II) and Worse Killip class (Killip classes III and IV). Patients were also divided into two groups based on pre-hospital physical activity status, determined retrospectively by review of medical records: Good physical activity (n=57) comprising those able to go out alone independently and Poor physical activity comprising those mainly confined to home (n=53). The overall in-hospital mortality rate was 9.1% for the study population. The Worse Killip class group had a higher in-hospital mortality rate than the Better Killip class group (27.8% vs 5.4%, respectively; p=0.0102). In addition, the Poor physical activity group had a higher in-hospital mortality rate than the Good physical activity group (15.1% vs. 3.5%, respectively; p=0.047). These data suggest that pre-hospital physical activity status in elderly patients with AMI may affect in-hospital mortality as well as Killip class.

Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores

PubMed Central

Ryzhov, Sergey; Tikhomirov, Oleg; Duarte, Christine W.; Congdon, Clare Bates; Lessard, Craig R.; McFarland, Samuel; Rochette-Egly, Cecile; Tran, Truc-Linh; Galindo, Cristi L.; Favreau-Lessard, Amanda J.; Sawyer, Douglas B.

2016-01-01

To determine whether hepatic depletion of vitamin A (VA) stores has an effect on the postnatal heart, studies were carried out with mice lacking liver retinyl ester stores fed either a VA-sufficient (LRVAS) or VA-deficient (LRVAD) diet (to deplete circulating retinol and extrahepatic stores of retinyl esters). There were no observable differences in the weights or gross morphology of hearts from LRVAS or LRVAD mice relative to sex-matched, age-matched, and genetically matched wild-type (WT) controls fed the VAS diet (WTVAS), but changes in the transcription of functionally relevant genes were consistent with a state of VAD in LRVAS and LRVAD ventricles. In silico analysis revealed that 58/67 differentially expressed transcripts identified in a microarray screen are products of genes that have DNA retinoic acid response elements. Flow cytometric analysis revealed a significant and cell-specific increase in the number of proliferating Sca-1 cardiac progenitor cells in LRVAS animals relative to WTVAS controls. Before myocardial infarction, LRVAS and WTVAS mice had similar cardiac systolic function and structure, as measured by echocardiography, but, unexpectedly, repeat echocardiography demonstrated that LRVAS mice had less adverse remodeling by 1 wk after myocardial infarction. Overall, the results demonstrate that the adult heart is responsive to retinoids, and, most notably, reducing hepatic VA stores (while maintaining circulating levels of VA) impacts ventricular gene expression profiles, progenitor cell numbers, and response to injury. PMID:27084391

Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.

PubMed

Asson-Batres, Mary Ann; Ryzhov, Sergey; Tikhomirov, Oleg; Duarte, Christine W; Congdon, Clare Bates; Lessard, Craig R; McFarland, Samuel; Rochette-Egly, Cecile; Tran, Truc-Linh; Galindo, Cristi L; Favreau-Lessard, Amanda J; Sawyer, Douglas B

2016-06-01

To determine whether hepatic depletion of vitamin A (VA) stores has an effect on the postnatal heart, studies were carried out with mice lacking liver retinyl ester stores fed either a VA-sufficient (LRVAS) or VA-deficient (LRVAD) diet (to deplete circulating retinol and extrahepatic stores of retinyl esters). There were no observable differences in the weights or gross morphology of hearts from LRVAS or LRVAD mice relative to sex-matched, age-matched, and genetically matched wild-type (WT) controls fed the VAS diet (WTVAS), but changes in the transcription of functionally relevant genes were consistent with a state of VAD in LRVAS and LRVAD ventricles. In silico analysis revealed that 58/67 differentially expressed transcripts identified in a microarray screen are products of genes that have DNA retinoic acid response elements. Flow cytometric analysis revealed a significant and cell-specific increase in the number of proliferating Sca-1 cardiac progenitor cells in LRVAS animals relative to WTVAS controls. Before myocardial infarction, LRVAS and WTVAS mice had similar cardiac systolic function and structure, as measured by echocardiography, but, unexpectedly, repeat echocardiography demonstrated that LRVAS mice had less adverse remodeling by 1 wk after myocardial infarction. Overall, the results demonstrate that the adult heart is responsive to retinoids, and, most notably, reducing hepatic VA stores (while maintaining circulating levels of VA) impacts ventricular gene expression profiles, progenitor cell numbers, and response to injury. Copyright © 2016 the American Physiological Society.

Metabolic effects of intra-abdominal fat in GHRKO mice

PubMed Central

Masternak, Michal M.; Bartke, Andrzej; Wang, Feiya; Spong, Adam; Gesing, Adam; Fang, Yimin; Salmon, Adam B.; Hughes, Larry F.; Liberati, Teresa; Boparai, Ravneet; Kopchick, John J.; Westbrook, Reyhan

2011-01-01

SUMMARY Mice with targeted deletion of the growth hormone receptor (GHRKO mice) are GH resistant, small, obese, hypoinsulinemic, highly insulin sensitive and remarkably long-lived. To elucidate the unexpected coexistence of adiposity with improved insulin sensitivity and extended longevity, we examined effects of surgical removal of visceral (epididymal and perinephric) fat on metabolic traits related to insulin signaling and longevity. Comparison of results obtained in GHRKO mice and in normal animals from the same strain revealed disparate effects of visceral fat removal (VFR) on insulin and glucose tolerance, adiponectin levels, accumulation of ectopic fat, phosphorylation of insulin signaling intermediates, body temperature and respiratory quotient (RQ). Overall, VFR produced the expected improvements in insulin sensitivity and reduced body temperature and RQ in normal mice and had opposite effects in GHRKO mice. Some of the examined parameters were altered by VFR in opposite directions in GHRKO and normal mice, others were affected in only one genotype or exhibited significant genotype × treatment interactions. Functional differences between visceral fat of GHRKO and normal mice were confirmed by measurements of adipokine secretion, lipolysis and expression of genes related to fat metabolism. We conclude that in the absence of GH signaling the secretory activity of visceral fat is profoundly altered and unexpectedly promotes enhanced insulin sensitivity. The apparent beneficial effects of visceral fat in GHRKO mice may also explain why reducing adiposity by calorie restriction fails to improve insulin signaling or further extend longevity in these animals. PMID:22040032

Effect of a Quality Improvement Intervention on Clinical Outcomes in Patients in India With Acute Myocardial Infarction: The ACS QUIK Randomized Clinical Trial.

PubMed

Huffman, Mark D; Mohanan, Padinhare P; Devarajan, Raji; Baldridge, Abigail S; Kondal, Dimple; Zhao, Lihui; Ali, Mumtaj; Krishnan, Mangalath N; Natesan, Syam; Gopinath, Rajesh; Viswanathan, Sunitha; Stigi, Joseph; Joseph, Johny; Chozhakkat, Somanathan; Lloyd-Jones, Donald M; Prabhakaran, Dorairaj

2018-02-13

Wide heterogeneity exists in acute myocardial infarction treatment and outcomes in India. To evaluate the effect of a locally adapted quality improvement tool kit on clinical outcomes and process measures in Kerala, a southern Indian state. Cluster randomized, stepped-wedge clinical trial conducted between November 10, 2014, and November 9, 2016, in 63 hospitals in Kerala, India, with a last date of follow-up of December 31, 2016. During 5 predefined steps over the study period, hospitals were randomly selected to move in a 1-way crossover from the control group to the intervention group. Consecutively presenting patients with acute myocardial infarction were offered participation. Hospitals provided either usual care (control group; n = 10 066 participants [step 0: n = 2915; step 1: n = 2649; step 2: n = 2251; step 3: n = 1422; step 4; n = 829; step 5: n = 0]) or care using a quality improvement tool kit (intervention group; n = 11 308 participants [step 0: n = 0; step 1: n = 662; step 2: n = 1265; step 3: n = 2432; step 4: n = 3214; step 5: n = 3735]) that consisted of audit and feedback, checklists, patient education materials, and linkage to emergency cardiovascular care and quality improvement training. The primary outcome was the composite of all-cause death, reinfarction, stroke, or major bleeding using standardized definitions at 30 days. Secondary outcomes included the primary outcome's individual components, 30-day cardiovascular death, medication use, and tobacco cessation counseling. Mixed-effects logistic regression models were used to account for clustering and temporal trends. Among 21 374 eligible randomized participants (mean age, 60.6 [SD, 12.0] years; n = 16 183 men [76%] ; n = 13 689 [64%] with ST-segment elevation myocardial infarction), 21 079 (99%) completed the trial. The primary composite outcome was observed in 5.3% of the intervention participants and 6.4% of the control participants. The observed difference in 30-day major adverse cardiovascular event rates between the groups was not statistically significant after adjustment (adjusted risk difference, -0.09% [95% CI, -1.32% to 1.14%]; adjusted odds ratio, 0.98 [95% CI, 0.80-1.21]). The intervention group had a higher rate of medication use including reperfusion but no effect on tobacco cessation counseling. There were no unexpected adverse events reported. Among patients with acute myocardial infarction in Kerala, India, use of a quality improvement intervention compared with usual care did not decrease a composite of 30-day major adverse cardiovascular events. Further research is needed to understand the lack of efficacy. clinicaltrials.gov Identifier: NCT02256657.

Surgical management in patients with coexistent coronary and cerebrovascular disease. Long-term results.

PubMed

Kaul, T K; Fields, B L; Wyatt, D A; Jones, C R; Kahn, D R

1994-11-01

Between January 1980 and December 1992, 3% (210/6,862) of our patients undergoing myocardial revascularization (CABG) had high grade (> 80%) internal carotid stenosis (CS). One hundred seventy-five of these patients with complete follow up for a minimum of 18 months were studied. Bilateral internal CS was present in 60%, and 75% had other vascular lesions, mainly as peripheral vascular disease (PVD) of the lower limb (50.8%). All patients underwent CAE (carotid endarterectomy) followed by CABG under the same anesthesia. Peripheral vascular lesions, contralateral internal CS and recurrent (n = 43) and progressive vascular lesions (n = 50), were subsequently treated as staged procedures. Hospital mortality was 3.42%. By univariate analysis significant predictors of late mortality were congestive heart failure, COPD, PVD, postoperative myocardial infarction, postoperative stroke, and ischemic cardiomyopathy. Only the latter two were also significant by multivariate analysis. At 12 years, actuarial survival in the presence of these risk factors were 46%, 49%, 22%, 37%, 53%, and 27% respectively. All are significantly lower as compared with the corresponding subsets of patients with the risk factor absent. At 12 years, actuarial survival for the entire series was 65%. Cumulative incidence of postoperative strokes was higher in patients with bilateral internal CS than in patients with unilateral internal CS (p < 0.07) and in patients with neurologic symptoms than asymptomatic patients. At 12 years, actuarial freedom from all cardiac related events, postoperative stroke, and symptomatic PVD were 49%, 82%, and 76% respectively. After successful revascularization these patients should be carefully followed for recurrent and progressive vascular lesions.

Association of Coexisting Diabetes and Depression With Mortality After Myocardial Infarction

PubMed Central

Bot, Mariska; Pouwer, François; Zuidersma, Marij; van Melle, Joost P.; de Jonge, Peter

2012-01-01

OBJECTIVE Diabetes and depression are both linked to an increased mortality risk after myocardial infarction (MI). Population-based studies suggest that having both diabetes and depression results in an increased mortality risk, beyond that of having diabetes or depression alone. The purpose of this study was to examine the joint association of diabetes and depression with mortality in MI patients. RESEARCH DESIGN AND METHODS Data were derived from two multicenter cohort studies in the Netherlands, comprising 2,704 patients who were hospitalized for MI. Depression, defined as a Beck Depression Inventory score ≥10, and diabetes were assessed during hospitalization. Mortality data were retrieved for 2,525 patients (93%). RESULTS During an average follow-up of 6.2 years, 439 patients died. The mortality rate was 14% (226 of 1,673) in patients without diabetes and depression, 23% (49 of 210) in patients with diabetes only, 22% (118 of 544) in patients with depression only, and 47% (46 of 98) in patients with both diabetes and depression. After adjustment for age, sex, smoking, hypertension, left ventricular ejection fraction, prior MI, and Killip class, hazard ratios for all-cause mortality were 1.38 (95% CI 1.00–1.90) for patients with diabetes only, 1.39 (1.10–1.76) for patients with depression only, and as much as 2.90 (2.07–4.07) for patients with both diabetes and depression. CONCLUSIONS We observed an increased mortality risk in post-MI patients with both diabetes and depression, beyond the association with mortality of diabetes and depression alone. PMID:22301118

Cardiovascular Complications of Cancer Therapy: Best Practices in Diagnosis, Prevention, and Management: Part 1.

PubMed

Chang, Hui-Ming; Moudgil, Rohit; Scarabelli, Tiziano; Okwuosa, Tochukwu M; Yeh, Edward T H

2017-11-14

Modern cancer therapy has successfully cured many cancers and converted a terminal illness into a chronic disease. Because cancer patients often have coexisting heart diseases, expert advice from cardiologists will improve clinical outcome. In addition, cancer therapy can also cause myocardial damage, induce endothelial dysfunction, and alter cardiac conduction. Thus, it is important for practicing cardiologists to be knowledgeable about the diagnosis, prevention, and management of the cardiovascular complications of cancer therapy. In this first part of a 2-part review, we will review cancer therapy-induced cardiomyopathy and ischemia. This review is based on a MEDLINE search of published data, published clinical guidelines, and best practices in major cancer centers. With the number of cancer survivors expanding quickly, the time has come for cardiologists to work closely with cancer specialists to prevent and treat cancer therapy-induced cardiovascular complications. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

High unexpected genetic diversity of a narrow endemic terrestrial mollusc

PubMed Central

Madeira, Pedro M.; Chefaoui, Rosa M.; Cunha, Regina L.; Moreira, Francisco; Dias, Susana; Calado, Gonçalo

2017-01-01

The Iberian Peninsula has an extensive record of species displaying strong genetic structure as a result of their survival in isolated pockets throughout the Pleistocene ice ages. We used mitochondrial and nuclear sequence data to analyze phylogeographic patterns in endemic land snails from a valley of central Portugal (Vale da Couda), putatively assigned to Candidula coudensis, that show an exceptionally narrow distributional range. The genetic survey presented here shows the existence of five main mitochondrial lineages in Vale da Couda that do not cluster together suggesting independent evolutionary histories. Our results also indicate a departure from the expectation that species with restricted distributions have low genetic variability. The putative past and contemporary models of geographic distribution of Vale da Couda lineages are compatible with a scenario of species co-existence in more southern locations during the last glacial maximum (LGM) followed by a post-LGM northern dispersal tracking the species optimal thermal, humidity and soil physical conditions. PMID:28321363

Unexpected Huge Dimerization Ratio in One-Dimensional Carbon Atomic Chains.

PubMed

Lin, Yung-Chang; Morishita, Shigeyuki; Koshino, Masanori; Yeh, Chao-Hui; Teng, Po-Yuan; Chiu, Po-Wen; Sawada, Hidetaka; Suenaga, Kazutomo

2017-01-11

Peierls theory predicted atomic distortion in one-dimensional (1D) crystal due to its intrinsic instability in 1930. Free-standing carbon atomic chains created in situ in transmission electron microscope (TEM)1-3 are an ideal example to experimentally observe the dimerization behavior of carbon atomic chain within a finite length. We report here a surprisingly huge distortion found in the free-standing carbon atomic chains at 773 K, which is 10 times larger than the value expected in the system. Such an abnormally distorted phase only dominates at the elevated temperatures, while two distinct phases, distorted and undistorted, coexist at lower or ambient temperatures. Atom-by-atom spectroscopy indeed shows considerable variations in the carbon 1s spectra at each atomic site but commonly observes a slightly downshifted π* peak, which proves its sp 1 bonding feature. These results suggest that the simple model, relaxed and straight, is not fully adequate to describe the realistic 1D structure, which is extremely sensitive to perturbations such as external force or boundary conditions.

Temperature-Dependent Electric Field Poling Effects in CH3NH3PbI3 Optoelectronic Devices.

PubMed

Zhang, Chuang; Sun, Dali; Liu, Xiaojie; Sheng, Chuan-Xiang; Vardeny, Zeev Valy

2017-04-06

Organo-lead halide perovskites show excellent optoelectronic properties; however, the unexpected inconsistency in forward-backward I-V characteristics remains a problem for fabricating solar panels. Here we have investigated the reasons behind this "hysteresis" by following the changes in photocurrent and photoluminescence under electric field poling in transverse CH 3 NH 3 PbI 3 -based devices from 300 to 10 K. We found that the hysteresis disappears at cryogenic temperatures, indicating the "freeze-out" of the ionic diffusion contribution. When the same device is cooled under continuous poling, the built-in electric field from ion accumulation brings significant photovoltaic effect even at 10 K. From the change of photoluminescence upon polling, we found a second dipole-related mechanism which enhances radiative recombination upon the alignment of the organic cations. The ionic origin of hysteresis was also verified by applying a magnetic field to affect the ion diffusion. These findings reveal the coexistence of ionic and dipole-related mechanisms for the hysteresis in hybrid perovskites.

Emergence of superconductivity from the dynamically heterogeneous insulating state in La(2-x)Sr(x)CuO4.

PubMed

Shi, Xiaoyan; Logvenov, G; Bollinger, A T; Božović, I; Panagopoulos, C; Popović, Dragana

2013-01-01

A central issue for copper oxides is the nature of the insulating ground state at low carrier densities and the emergence of high-temperature superconductivity from that state with doping. Even though this superconductor-insulator transition (SIT) is a zero-temperature transition, measurements are not usually carried out at low temperatures. Here we use magnetoresistance to probe both the insulating state at very low temperatures and the presence of superconducting fluctuations in La(2-x)Sr(x)CuO(4) films, for doping levels that range from the insulator to the superconductor (x  =  0.03-0.08). We observe that the charge glass behaviour, characteristic of the insulating state, is suppressed with doping, but it coexists with superconducting fluctuations that emerge already on the insulating side of the SIT. The unexpected quenching of the superconducting fluctuations by the competing charge order at low temperatures provides a new perspective on the mechanism for the SIT.

Topologically nontrivial electronic states in CaSn3

NASA Astrophysics Data System (ADS)

Gupta, Sunny; Juneja, Rinkle; Shinde, Ravindra; Singh, Abhishek K.

2017-06-01

Based on the first-principles calculations, we theoretically propose topologically non-trivial states in a recently experimentally discovered superconducting material CaSn3. When the spin-orbit coupling (SOC) is ignored, the material is a host to three-dimensional topological nodal-line semimetal states. Drumhead like surface states protected by the coexistence of time-reversal and mirror symmetry emerge within the two-dimensional regions of the surface Brillouin zone connecting the nodal lines. When SOC is included, unexpectedly, each nodal line evolves into two Weyl nodes (W1 and W2) in this centrosymmetric material. Berry curvature calculations show that these nodes occur in a pair and act as either a source or a sink of Berry flux. This material also has unique surface states in the form of Fermi arcs, which unlike other known Weyl semimetals forms closed loops of surface states on the Fermi surface. Our theoretical realization of topologically non-trivial states in a superconducting material paves the way towards unraveling the interconnection between topological physics and superconductivity.

Rare case of Takayasu's arteritis associated with Crohn's disease.

PubMed

Kusunoki, Ryusaku; Ishihara, Shunji; Sato, Mariko; Sumita, Yoshiko; Mishima, Yoshiyuki; Okada, Mayumi; Tada, Yasumasa; Oka, Akihiko; Fukuba, Nobuhiko; Oshima, Naoki; Moriyama, Ichiro; Yuki, Takafumi; Sato, Shuichi; Amano, Yuji; Murakawa, Yohko; Kinoshita, Yoshikazu

2011-01-01

Takayasu's arteritis (TA) and Crohn's disease (CD) are chronic inflammatory diseases of uncertain etiology. Although co-existence of these rare diseases is estimated to occur in 1 in 10 billion individuals, a theoretically unexpected association has been reported in several patients and it is suggested that those associations may have been more than an unusual coincidence. Herein, we report a case of TA associated with clinically inactive CD. A Japanese woman was diagnosed with colonic CD at the age of 15, developed aortic valve regurgitation at 19, and then presented with general fatigue, low grade fever, and painful sensations in her left arm at 25. She was diagnosed with TA based on computed tomography scanning and magnetic resonance angiography findings, and treatments with prednisolone and cyclosporine were started. Thereafter, valve replacement and right coronary artery bypass graft surgery were performed. The possible pathophysiological mechanism responsible for concurrent existence of TA and CD may be associated with immune disorders. Early diagnosis of vascular lesions for patients with inflammatory bowel disease is highly encouraged.

Incremental prognostic value of coronary and systemic atherosclerosis after myocardial infarction.

PubMed

Calais, Fredrik; Eriksson Östman, Maja; Hedberg, Pär; Rosenblad, Andreas; Leppert, Jerzy; Fröbert, Ole

2018-06-15

The role of systemic atherosclerosis in myocardial infarction (MI) patients is not fully understood. We investigated the incremental prognostic value of coronary and systemic atherosclerosis after acute MI by estimating extra-cardiac artery disease (ECAD) and extent of coronary atherosclerosis. The study included 544 prospective MI patients undergoing coronary angiography. For all patients, the longitudinal coronary atherosclerotic extent, expressed as Sullivan extent score (SES) was calculated. In addition, the patients underwent non-invasive screening for ECAD in the carotid, aortic, renal and lower limb. SES was found to be associated with ECAD independent of baseline clinical parameters [adjusted odds ratio (OR) 1.04 95% confidence interval (CI) 1.02-1.06, P < 0.001]. Extensive systemic atherosclerosis, defined as the combination of extensive coronary disease (SES ≥ 17) and ECAD, was associated with higher risk for all-cause mortality compared to limited systemic atherosclerosis (SES < 17 and no ECAD) (hazard ratio [HR] 2.9 95% CI 1.9-4.5, P < 0.001, adjusted for Global Registry of Acute Coronary Events risk score parameters 1.8, 95% CI 1.1-3.0, P = 0.019). The risk for the composite endpoint of cardiovascular death or hospitalization was significantly higher in patients with extensive systemic atherosclerosis compared to patients with limited systemic atherosclerosis (HR 3.1, 95% CI 2.1-4.7, P < 0.001, adjusted HR 1.9, 95% CI 1.2-3.1, P < 0.004). Visual estimation of the longitudinal coronary atherosclerotic extent at the time of MI predicts ECAD. Coexistence of extensive coronary disease and ECAD defines a group with particularly poor prognosis after MI. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Temporal trends in the occurrence and outcomes of atrial fibrillation in patients with acute myocardial infarction (from the Atherosclerosis Risk in Communities Surveillance Study).

PubMed

Bengtson, Lindsay G S; Chen, Lin Y; Chamberlain, Alanna M; Michos, Erin D; Whitsel, Eric A; Lutsey, Pamela L; Duval, Sue; Rosamond, Wayne D; Alonso, Alvaro

2014-09-01

Atrial fibrillation (AF) frequently coexists in the setting of myocardial infarction (MI), being associated with increased mortality. Nonetheless, temporal trends in the occurrence of AF complicating MI and in the prognosis of these patients are not well described. We examined temporal trends in prevalence of AF in the setting of MI and the effect of AF on prognosis in the community. We studied a population-based sample of 20,049 validated first-incident nonfatal hospitalized MIs among 35- to 74-year old residents of 4 communities in the Atherosclerosis Risk in Communities (ARIC) Study from 1987 through 2009. Prevalence of AF in the setting of MI increased from 11% to 15% during the 23-year study period. The multivariable adjusted odds ratio for prevalent AF, per 5-year increment, was 1.11 (95% confidence interval 1.04 to 1.19). Overall, in patients with MI, AF was associated with increased 1-year case fatality (odds ratio 1.47, 95% confidence interval 1.07 to 2.01) compared with those without AF. However, there was no evidence that the impact of AF on MI survival changed over time or differed over time by sex, race, or MI classification (all p values >0.10). In conclusion, co-occurrence of AF in MI slightly increased between 1987 and 2009. The adverse impact of AF on survival in the setting of MI was consistent throughout. In the setting of MI, co-occurrence of AF should be viewed as a critical clinical event, and treatment needs unique to this population should be explored further. Copyright © 2014 Elsevier Inc. All rights reserved.

Asymmetric simple exclusion process on chains with a shortcut.

PubMed

Bunzarova, Nadezhda; Pesheva, Nina; Brankov, Jordan

2014-03-01

We consider the asymmetric simple exclusion process (TASEP) on an open network consisting of three consecutively coupled macroscopic chain segments with a shortcut between the tail of the first segment and the head of the third one. The model was introduced by Y.-M. Yuan et al. [J. Phys. A 40, 12351 (2007)] to describe directed motion of molecular motors along twisted filaments. We report here unexpected results which revise the previous findings in the case of maximum current through the network. Our theoretical analysis, based on the effective rates' approximation, shows that the second (shunted) segment can exist in both low- and high-density phases, as well as in the coexistence (shock) phase. Numerical simulations demonstrate that the last option takes place in finite-size networks with head and tail chains of equal length, provided the injection and ejection rates at their external ends are equal and greater than one-half. Then the local density distribution and the nearest-neighbor correlations in the middle chain correspond to a shock phase with completely delocalized domain wall. Upon moving the shortcut to the head or tail of the network, the density profile takes a shape typical of a high- or low-density phase, respectively. Surprisingly, the main quantitative parameters of that shock phase are governed by a positive root of a cubic equation, the coefficients of which linearly depend on the probability of choosing the shortcut. Alternatively, they can be expressed in a universal way through the shortcut current. The unexpected conclusion is that a shortcut in the bulk of a single lane may create traffic jams.

Phase transitions in mixed gas hydrates: experimental observations versus calculated data.

PubMed

Schicks, Judith M; Naumann, Rudolf; Erzinger, Jörg; Hester, Keith C; Koh, Carolyn A; Sloan, E Dendy

2006-06-15

This paper presents the phase behavior of multicomponent gas hydrate systems formed from primarily methane with small amounts of ethane and propane. Experimental conditions were typically in a pressure range between 1 and 6 MPa, and the temperature range was between 260 and 290 K. These multicomponent systems have been investigated using a variety of techniques including microscopic observations, Raman spectroscopy, and X-ray diffraction. These techniques, used in combination, allowed for measurement of the hydrate structure and composition, while observing the morphology of the hydrate crystals measured. The hydrate formed immediately below the three-phase line (V-L --> V-L-H) and contained crystals that were both light and dark in appearance. The light crystals, which visually were a single solid phase, showed a spectroscopic indication for the presence of occluded free gas in the hydrate. In contrast, the dark crystals were measured to be structure II (sII) without the presence of these occluded phases. Along with hydrate measurements near the decomposition line, an unexpected transformation process was visually observed at P-T-conditions in the stability field of the hydrates. Larger crystallites transformed into a foamy solid upon cooling over this transition line (between 5 and 10 K below the decomposition temperature). Below the transition line, a mixture of sI and sII was detected. This is the first time that these multicomponent systems have been investigated at these pressure and temperature conditions using both visual and spectroscopic techniques. These techniques enabled us to observe and measure the unexpected transformation process showing coexistence of different gas hydrate phases.

Kcne2 deletion attenuates acute post-ischaemia/reperfusion myocardial infarction

PubMed Central

Hu, Zhaoyang; Crump, Shawn M.; Zhang, Ping; Abbott, Geoffrey W.

2016-01-01

Aims Most cardiac arrhythmia-associated genes encode ion channel subunits and regulatory proteins that are also expressed outside the heart, suggesting that diseases linked to their disruption may be multifactorial. KCNE2 is a ubiquitously expressed potassium channel β subunit associated with cardiac arrhythmia, atherosclerosis, and myocardial infarction (MI) in human populations. Here, we tested the hypothesis that Kcne2 disruption in mice would influence the acute outcome of experimentally induced MI. Methods and results One-year-old male Kcne2+/+ and Kcne2−/− mice were subjected to cardiac ischaemia/reperfusion injury (IRI) by left anterior descending coronary artery ligation. After reperfusion (3 h), infarct size and markers of tissue damage were quantified. Unexpectedly, post-reperfusion, Kcne2−/− mice exhibited 40% lower infarct size, decreased myocardial apoptosis and damage, and more than two-fold lower serum levels of damage markers, lactate dehydrogenase and creatine kinase, than Kcne2+/+ mice. Kcne2 deletion, despite increasing normalized heart weight and prolonging baseline QTc by 70%, helped preserve post-infarct cardiac function (quantified by a Millar catheter), with parameters including left ventricular maximum pressure, max dP/dt (P < 0.01), contractility index, and pressure/time index (P < 0.05) all greater in Kcne2−/− compared with Kcne2+/+ mice. Western blotting indicated two-fold-increased glycogen synthase kinase 3β (GSK-3β) phosphorylation (inactivation) before and after IRI (P < 0.05) in Kcne2−/− mice compared with Kcne2+/+ mice. GSK-3β inhibition by SB216763 mimicked in Kcne2+/+ mice the cardioprotective effects of Kcne2 deletion, but did not further enhance them in Kcne2−/− mice, suggesting that GSK-3β inactivation was a primary cardioprotective mechanism arising from Kcne2 deletion. Conclusions Kcne2 deletion preconditions the heart, attenuating the acute tissue damage caused by an imposed IRI. The findings contribute further evidence that genetic disruption of arrhythmia-associated ion channel genes has cardiac ramifications beyond abnormal electrical activity. PMID:26952045

Distinct myocardial lineages break atrial symmetry during cardiogenesis in zebrafish

PubMed Central

Stone, Oliver; Arnaout, Rima; Guenther, Stefan; Ahuja, Suchit; Uribe, Verónica; Vanhollebeke, Benoit; Stainier, Didier YR

2018-01-01

The ultimate formation of a four-chambered heart allowing the separation of the pulmonary and systemic circuits was key for the evolutionary success of tetrapods. Complex processes of cell diversification and tissue morphogenesis allow the left and right cardiac compartments to become distinct but remain poorly understood. Here, we describe an unexpected laterality in the single zebrafish atrium analogous to that of the two atria in amniotes, including mammals. This laterality appears to derive from an embryonic antero-posterior asymmetry revealed by the expression of the transcription factor gene meis2b. In adult zebrafish hearts, meis2b expression is restricted to the left side of the atrium where it controls the expression of pitx2c, a regulator of left atrial identity in mammals. Altogether, our studies suggest that the multi-chambered atrium in amniotes arose from a molecular blueprint present before the evolutionary emergence of cardiac septation and provide insights into the establishment of atrial asymmetry. PMID:29762122

An Unexpected Cause of Bradycardia in a Patient with Bacterial Meningitis.

PubMed

Ioannou, Petros; Velegraki, Magdalini; Soundoulounaki, Stella; Gikas, Achilleas; Kofteridis, Diamantis P

2017-01-01

Sinus bradycardia which is a sinus rhythm with a resting heart rate of less than 60 bpm is caused by intrinsic cardiac disorders like sick sinus syndrome or inferior myocardial infarction, metabolic and environmental causes (such as hypothyroidism and electrolyte disorders), medications (such as beta-blockers and amiodarone), infection (such as myocarditis), increased intracranial pressure, and toxic exposure, while it can sometimes be a normal phenomenon, especially during sleep, in athletes, and during pregnancy. Symptomatic sinus bradycardia should warrant a thorough work-up in order to identify any reversible causes; otherwise, placement of a permanent pacemaker could be needed. We present the case of a patient who was admitted due to confusion and fever and was found to have pneumococcal meningitis and bacteremia, and during his hospital stay he developed symptomatic sinus bradycardia that was of intractable cause and persistent. Placement of a permanent pacemaker was chosen until the night staff of the hospital discovered by chance the neglected cause of his bradycardia.

ST-depression in right precordial leads with inferior STEMI and occluded right coronary artery: intertwined anatomy and ischemic areas.

PubMed

De Gennaro, Luisa; Brunetti, Natale Daniele; Ruggiero, Massimo; Rutigliano, David; Locuratolo, Nicola; Di Biase, Matteo; Caldarola, Pasquale

2017-10-01

Right coronary artery (RCA) occlusion in inferior acute myocardial infarction is usually heralded by ST-elevation both in inferior and in right precordial leads. We report the case of a 68-year-old male, who presented marked ST-elevation in inferior leads, mirrored by ST-depression in anterior-septal and lateral leads. Right precordial lead electrocardiogram unexpectedly showed ST-depression V1R-V5R leads. Coronary angiography showed mid-left anterior descending (LAD) coronary near-complete occlusion with distal wrapping LAD. Left circumflex artery was not occluded, while RCA was occluded mid tract. The patient was treated with coronary angioplasty on RCA and LAD. Absence of ST-elevation in right precordial leads may be presumably explained by the presence of a large ischemic area distal to mid-LAD near-occlusive stenosis and of a long-wrapping LAD. Complex coronary anatomy and intertwined ischemic areas may underlie apparently discording electrocardiograms.

Inferior ST-Elevation Acute Myocardial Infarction or an Inferior-Lead Brugada-like Electrocardiogram Pattern Associated With the Use of Pregabalin and Quetiapine?

PubMed

Brunetti, Natale D; Ieva, Riccardo; Correale, Michele; Cuculo, Andrea; Santoro, Francesco; Guaricci, Andrea I; De Gennaro, Luisa; Gaglione, Antonio; Di Biase, Matteo

2016-01-01

The Brugada electrocardiogram pattern is characterized by coved-type ST-elevation (>2 mm) in the right precordial leads. We report the case of a 62-year-old man, with bipolar disorder, admitted to the emergency department because of dyspnea and chest discomfort. The patient was on treatment with pregabalin and quetiapine. Unexpectedly, electrocardiogram at admission showed diffuse ST-elevation, more evident in inferior leads, where a Brugada-like pattern was present. The patient underwent coronary angiography with a diagnosis of suspected acute coronary syndrome. Coronary angiography, however, showed mild coronary artery disease not requiring coronary angioplasty. Echocardiography did not reveal left ventricular dysfunction or pericardial effusion. Troponin levels remained normal over serial controls. Eventually, chest radiography showed lung opacities and consolidation suggestive for pneumonia. To the best of our knowledge, this is one of the first cases showing a transient Brugada-like electrocardiogram pattern in inferior leads, probably amplified by the administration of pregabalin and quetiapine.

Unexpected toxicity of combined modality therapy for small cell carcinoma of the lung. A Southwest oncology group study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livingston, R.B.; Mira, J.; Haas, C.

1979-09-01

Combination chemotherapy with cyclophosphamide, vincristine, methotrexate and Adriamycin was delivered to 35 patients with small-cell carcinoma of the lung (28 with extensive and 7 with limited disease), including elective administration of intrathecal methotrexate. Whole-brain irradiation (3000 rad in 10 fractions) was then administered, with concomitant systemic cyclophosphamide and methotrexate for patients with extensive disease. Those with limited disease received concomitant chest irradiation without chemotherapy. Maintenance therapy then involved cyclophosphamide 750 mg/m/sup 2/ day 1, and methotrexate 30 mg/m/sup 2/ days 1 and 8, every 3 weeks. In only 2 patients reinduction was carried out at 24 weeks with the originalmore » chemotherapy. Myelosuppression was severe; there were at least 2 drug-related deaths from this cause in the induction period, and 15 febrile episodes with leukopenia. Stomatitis was more frequent and more severe in ''maintenance'' than in ''induction'' courses, especially the first maintenance course which was given with concomitant whole-brain irradiation. In addition, 13 episodes of unusual toxicity occurred in close temporal relation to systemic methotrexate administration, usually associated with stomatitis, in patients who were on maintenance therapy. These included 3 episodes of loss of consciousness, 4 of generalized erythroderma, 2 of ''flu''-like syndrome, and 1 each of the following: fatal, bilateral interstitial pneumonia; reversible, eosinophilic pleural effusion; acute myocardial infarction; and renal compromise with hematuria. As a result of this unexpected and protean toxicity, the pilot study was discontinued. However, at this time seven patients (4 with extensive and 3 with limited disease) remain in complete remission.« less

High probability of comorbidities in bronchial asthma in Germany.

PubMed

Heck, S; Al-Shobash, S; Rapp, D; Le, D D; Omlor, A; Bekhit, A; Flaig, M; Al-Kadah, B; Herian, W; Bals, R; Wagenpfeil, S; Dinh, Q T

2017-04-21

Clinical experience has shown that allergic and non-allergic respiratory, metabolic, mental, and cardiovascular disorders sometimes coexist with bronchial asthma. However, no study has been carried out that calculates the chance of manifestation of these disorders with bronchial asthma in Saarland and Rhineland-Palatinate, Germany. Using ICD10 diagnoses from health care institutions, the present study systematically analyzed the co-prevalence and odds ratios of comorbidities in the asthma population in Germany. The odds ratios were adjusted for age and sex for all comorbidities for patients with asthma vs. without asthma. Bronchial asthma was strongly associated with allergic and with a lesser extent to non-allergic comorbidities: OR 7.02 (95%CI:6.83-7.22) for allergic rhinitis; OR 4.98 (95%CI:4.67-5.32) allergic conjunctivitis; OR 2.41 (95%CI:2.33-2.52) atopic dermatitis; OR 2.47 (95%CI:2.16-2.82) food allergy, and OR 1.69 (95%CI:1.61-1.78) drug allergy. Interestingly, increased ORs were found for respiratory diseases: 2.06 (95%CI:1.64-2.58) vocal dysfunction; 1.83 (95%CI:1.74-1.92) pneumonia; 1.78 (95%CI:1.73-1.84) sinusitis; 1.71 (95%CI:1.65-1.78) rhinopharyngitis; 2.55 (95%CI:2.03-3.19) obstructive sleep apnea; 1.42 (95%CI:1.25-1.61) pulmonary embolism, and 3.75 (95%CI:1.64-8.53) bronchopulmonary aspergillosis. Asthmatics also suffer from psychiatric, metabolic, cardiac or other comorbidities. Myocardial infarction (OR 0.86, 95%CI:0.79-0.94) did not coexist with asthma. Based on the calculated chances of manifestation for these comorbidities, especially allergic and respiratory, to a lesser extent also metabolic, cardiovascular, and mental disorders should be taken into consideration in the diagnostic and treatment strategy of bronchial asthma. PREVALENCE OF CO-EXISTING DISEASES IN GERMANY: Patients in Germany with bronchial asthma are highly likely to suffer from co-existing diseases and their treatments should reflect this. Quoc Thai Dinh at Saarland University Hospital in Homburg, Germany, and co-workers conducted a large-scale study of patients presenting with bronchial asthma in the Saarland region between 2009 and 2012. Patients with asthma made up 5.4% of the region's total population, with a higher prevalence occurring in females. They found that bronchial asthma was strongly associated with allergic comorbidities such as rhinitis. Indeed, asthmatic patients had a seven times higher chance to suffer from allergic rhinitis than the rest of the population, and were at higher risk of respiratory diseases like pneumonia and obstructive sleep apnea syndrome. Further associations included cardiovascular, metabolic and mental disorders. Dinh's team call for asthma treatments to take such comorbidities into account.

Different Causes of Death in Patients with Myocardial Infarction Type 1, Type 2, and Myocardial Injury.

PubMed

Lambrecht, Sascha; Sarkisian, Laura; Saaby, Lotte; Poulsen, Tina S; Gerke, Oke; Hosbond, Susanne; Diederichsen, Axel C P; Thygesen, Kristian; Mickley, Hans

2018-05-01

Data outlining the mortality and the causes of death in patients with type 1 myocardial infarction, type 2 myocardial infarction, and those with myocardial injury are limited. During a 1-year period from January 2010 to January 2011, all hospitalized patients who had cardiac troponin I measured on clinical indication were prospectively studied. Patients with at least one cardiac troponin I value >30 ng/L underwent case ascertainment and individual evaluation by an experienced adjudication committee. Patients were classified as having type 1 myocardial infarction, type 2 myocardial infarction, or myocardial injury according to the criteria of the universal definition of myocardial infarction. Follow-up was ensured until December 31, 2014. Data on mortality and causes of death were obtained from the Danish Civil Registration System and the Danish Register of Causes of Death. Overall, 3762 consecutive patients were followed for a mean of 3.2 years (interquartile range 1.3-3.6 years). All-cause mortality differed significantly among categories: Type 1 myocardial infarction 31.7%, type 2 myocardial infarction 62.2%, myocardial injury 58.7%, and 22.2% in patients with nonelevated troponin values (log-rank test; P < .0001). In patients with type 1 myocardial infarction, 61.3% died from cardiovascular causes, vs 42.6% in patients with type 2 myocardial infarction (P = .015) and 41.2% in those with myocardial injury (P < .0001). The overall mortality and the causes of death did not differ substantially between patients with type 2 myocardial infarction and those with myocardial injury. Patients with type 2 myocardial infarction and myocardial injury exhibit a significantly higher long-term mortality compared with patients with type 1 myocardial infarction . However, most patients with type 1 myocardial infarction die from cardiovascular causes in contrast to patients with type 2 myocardial infarction and myocardial injury, in whom noncardiovascular causes of death predominate. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of a Structured Discharge Planning Program on Perceived Functional Status, Cardiac Self-efficacy, Patient Satisfaction, and Unexpected Hospital Revisits Among Filipino Cardiac Patients: A Randomized Controlled Study.

PubMed

Cajanding, Ruff Joseph

Cardiovascular diseases remain the leading cause of morbidity and mortality among Filipinos and are responsible for a very large number of hospital readmissions. Comprehensive discharge planning programs have demonstrated positive benefits among various populations of patients with cardiovascular disease, but the clinical and psychosocial effects of such intervention among Filipino patients with acute myocardial infarction (AMI) have not been studied. In this study we aimed to determine the effectiveness of a nurse-led structured discharge planning program on perceived functional status, cardiac self-efficacy, patient satisfaction, and unexpected hospital revisits among Filipino patients with AMI. A true experimental (randomized control) 2-group design with repeated measures and data collected before and after intervention and at 1-month follow-up was used in this study. Participants were assigned to either the control (n = 68) or the intervention group (n = 75). Intervention participants underwent a 3-day structured discharge planning program implemented by a cardiovascular nurse practitioner, which is comprised of a series of individualized lecture-discussion, provision of feedback, integrative problem solving, goal setting, and action planning. Control participants received standard routine care. Measures of functional status, cardiac self-efficacy, and patient satisfaction were measured at baseline; cardiac self-efficacy and patient satisfaction scores were measured prior to discharge, and perceived functional status and number of revisits were measured 1 month after discharge. Participants in the intervention group had significant improvement in functional status, cardiac self-efficacy, and patient satisfaction scores at baseline and at follow-up compared with the control participants. Furthermore, participants in the intervention group had significantly fewer hospital revisits compared with those who received only standard care. The results demonstrate that a nurse-led structured discharge planning program is an effective intervention in improving perceived functional health status, cardiac self-efficacy, and patient satisfaction, while reducing the number of unexpected hospital revisits, among Filipino patients with AMI. It is recommended that this intervention be incorporated in the optimal care of patients being discharged with an AMI.

Sudden Unexpected Death in Epilepsy: A Retrospective Autopsy Study of 112 Epileptic Patients.

PubMed

Esen Melez, İpek; Arslan, Murat Nihat; Melez, Deniz Oğuzhan; Şanli, Ahmet Necati; Koç, Sermet

2017-09-01

Sudden unexpected deaths comprise the most important and worthy investigation case profiles in both neurology and forensic medicine. Epilepsy, which is one of the neuropathological causes of sudden unexpected deaths, is an important disorder having mysterious aspects. The aim of this study is to make common the points of view between neurology and forensic medicine experts and to discuss the features of the findings together with the related clinical hypotheses, leading to the differential diagnosis of sudden unexpected death in epilepsy (SUDEP) by presenting autopsy findings and available medical data of patients who had a prior diagnosis of epilepsy. In Istanbul, the cases of 20334 autopsied patients who were referred to The Ministry of Justice Council of Forensic Medicine between 2007 and 2011 were identified from the complete forensic autopsy data of the city and were retrospectively reviewed. Patients who had a prior diagnosis of epilepsy were included. Both descriptive and inferential statistical analyses were performed through the parameters of demographical data, physical properties, incident features, macroscopic-microscopic autopsy findings, and cause of death initially for all cases and then separately for SUDEP cases. Among the 20334 patients, 112 were determined to have a prior diagnosis of epilepsy. A possible macroscopic and/or microscopic epileptic focus was present in 23 (20.5%) of these 112 cases. The cause of death was determined to be SUDEP in 40 (35.7%) cases, while it could not be determined in 28 (25%) cases. Among patients whose death cause was considered as SUDEP, the male-to-female ratio was 1.1:1, while the mean age was 31.5±13.9 years in males and 29.6±12.9 years in females. The presence of hypertrophy and myocardial scar tissue findings in the microscopic examination were significantly more frequent among patients determined to have died from cardiovascular diseases compared to patients in the SUDEP group (p=0.001 for each finding). Besides, in 40 SUDEP cases, 38 (95%) patients underwent toxicological analysis and no antiepileptic agent was detected in 21 (55.3%) of these. It can be concluded that there is equality in gender distribution among SUDEP patients, that the young adult population has a slightly increased risk for SUDEP, and that the inconsistent use of antiepileptic medicines is a greater risk factor for SUDEP than polytherapy. Besides, it is important to emphasize that all clinical and postmortem parameters together should be considered for the differential diagnosis of SUDEP, particularly with cardiovascular diseases.

Pharmacokinetics of Rifampin in Peruvian Tuberculosis Patients with and without Comorbid Diabetes or HIV

PubMed Central

Davies, Geraint; Ardrey, Alison; Jave, Oswaldo; López-Romero, Sonia L.; Ward, Stephen A.; Moore, David A. J.

2012-01-01

For drug-compliant patients, poor responses to tuberculosis (TB) treatment might be attributable to subtherapeutic drug concentrations. An impaired absorption of rifampin was previously reported for patients with diabetes mellitus (DM) or HIV. The objectives of this study were to determine whether TB drug pharmacokinetics differed in Peruvian TB patients with DM or HIV. In this cross-sectional study, TB patients, recruited from health centers in Lima, Peru, had blood samples taken at 2 and 6 h after directly observed TB drug ingestion, to determine plasma concentrations of rifampin. Of 105 patients, 50 had TB without a comorbidity, 26 had coexistent DM, and 29 had coexistent HIV. Unexpectedly, the overall median 2- and 6-h levels of rifampin were 1.6 and 3.2 mg/liter, respectively, and the time to the peak concentration was 6 h (slow absorber) instead of 2 h (fast absorber) for 61 patients (62.2%). The geometric mean peak concentration of drug in serum (Cmax) was significantly higher in fast absorbers than in slow absorbers (5.0 versus 3.8 mg/liter; P = 0.05). The rifampin Cmax was significantly lower in male patients than in female patients (3.3 versus 6.3 mg/liter; P < 0.001). Neither slow nor fast absorbers with comorbidities (DM or HIV) had significantly different Cmax results compared to those of TB patients without comorbidities. An analysis of variance regression analysis showed that female gender (P < 0.001) and the time to maximum concentration of drug in serum (Tmax) at 2 h (P = 0.012) were independently correlated with increased exposure to rifampin. Most of this Peruvian study population exhibited rifampin pharmacokinetics different from those conventionally reported, with delayed absorption and low plasma concentrations, independent of the presence of an HIV or DM comorbidity. PMID:22330931

How to couple identical ring oscillators to get quasiperiodicity, extended chaos, multistability, and the loss of symmetry

NASA Astrophysics Data System (ADS)

Hellen, Edward H.; Volkov, Evgeny

2018-09-01

We study the dynamical regimes demonstrated by a pair of identical 3-element ring oscillators (reduced version of synthetic 3-gene genetic Repressilator) coupled using the design of the 'quorum sensing (QS)' process natural for interbacterial communications. In this work QS is implemented as an additional network incorporating elements of the ring as both the source and the activation target of the fast diffusion QS signal. This version of indirect nonlinear coupling, in cooperation with the reasonable extension of the parameters which control properties of the isolated oscillators, exhibits the formation of a very rich array of attractors. Using a parameter-space defined by the individual oscillator amplitude and the coupling strength, we found the extended area of parameter-space where the identical oscillators demonstrate quasiperiodicity, which evolves to chaos via the period doubling of either resonant limit cycles or complex antiphase symmetric limit cycles with five winding numbers. The symmetric chaos extends over large parameter areas up to its loss of stability, followed by a system transition to an unexpected mode: an asymmetric limit cycle with a winding number of 1:2. In turn, after long evolution across the parameter-space, this cycle demonstrates a period doubling cascade which restores the symmetry of dynamics by formation of symmetric chaos, which nevertheless preserves the memory of the asymmetric limit cycles in the form of stochastic alternating "polarization" of the time series. All stable attractors coexist with some others, forming remarkable and complex multistability including the coexistence of torus and limit cycles, chaos and regular attractors, symmetric and asymmetric regimes. We traced the paths and bifurcations leading to all areas of chaos, and presented a detailed map of all transformations of the dynamics.

Stimulated Emission Depletion Live-Cell Super-Resolution Imaging Shows Proliferative Remodeling of T-Tubule Membrane Structures After Myocardial Infarction

PubMed Central

Wagner, Eva; Lauterbach, Marcel A.; Kohl, Tobias; Westphal, Volker; Williams, George S.B.; Steinbrecher, Julia H.; Streich, Jan-Hendrik; Korff, Brigitte; Tuan, Hoang-Trong M.; Hagen, Brian; Luther, Stefan; Hasenfuss, Gerd; Parlitz, Ulrich; Jafri, M. Saleet; Hell, Stefan W.; Lederer, W. Jonathan; Lehnart, Stephan E.

2014-01-01

Rationale Transverse tubules (TTs) couple electric surface signals to remote intracellular Ca2+ release units (CRUs). Diffraction-limited imaging studies have proposed loss of TT components as disease mechanism in heart failure (HF). Objectives Objectives were to develop quantitative super-resolution strategies for live-cell imaging of TT membranes in intact cardiomyocytes and to show that TT structures are progressively remodeled during HF development, causing early CRU dysfunction. Methods and Results Using stimulated emission depletion (STED) microscopy, we characterized individual TTs with nanometric resolution as direct readout of local membrane morphology 4 and 8 weeks after myocardial infarction (4pMI and 8pMI). Both individual and network TT properties were investigated by quantitative image analysis. The mean area of TT cross sections increased progressively from 4pMI to 8pMI. Unexpectedly, intact TT networks showed differential changes. Longitudinal and oblique TTs were significantly increased at 4pMI, whereas transversal components appeared decreased. Expression of TT-associated proteins junctophilin-2 and caveolin-3 was significantly changed, correlating with network component remodeling. Computational modeling of spatial changes in HF through heterogeneous TT reorganization and RyR2 orphaning (5000 of 20 000 CRUs) uncovered a local mechanism of delayed subcellular Ca2+ release and action potential prolongation. Conclusions This study introduces STED nanoscopy for live mapping of TT membrane structures. During early HF development, the local TT morphology and associated proteins were significantly altered, leading to differential network remodeling and Ca2+ release dyssynchrony. Our data suggest that TT remodeling during HF development involves proliferative membrane changes, early excitation-contraction uncoupling, and network fracturing. PMID:22723297

Actin binding GFP allows 4D in vivo imaging of myofilament dynamics in the zebrafish heart and the identification of Erbb2 signaling as a remodeling factor of myofibril architecture.

PubMed

Reischauer, Sven; Arnaout, Rima; Ramadass, Radhan; Stainier, Didier Y R

2014-10-24

Dilated cardiomyopathy is a leading cause of congestive heart failure and a debilitating complication of antineoplastic therapies. Despite disparate causes for dilated cardiomyopathy, maladaptive cardiac remodeling and decreased systolic function are common clinical consequences, begging an investigation of in vivo contractile dynamics in development and disease, one that has been impossible to date. To image myocardial contractile filament dynamics in vivo and to assess potential causes of dilated cardiomyopathy in antineoplastic therapies targeting the epidermal growth factor receptor Erbb2. We generated a transgenic zebrafish line expressing an actin-binding green fluorescent protein in cardiomyocytes, allowing an in vivo imaging of myofilaments. Analysis of this line revealed architectural differences in myofibrils of the distinct cardiomyocyte subtypes. We used this model to investigate the effects of Erbb2 signaling on myofibrillar organization because drugs targeting ERBB2 (HER2/NEU) signaling, a mainstay of breast cancer chemotherapy, cause dilated cardiomyopathy in many patients. High-resolution in vivo imaging revealed that Erbb2 signaling regulates a switch between a dense apical network of filamentous myofibrils and the assembly of basally localized myofibrils in ventricular cardiomyocytes. Using this novel line, we compiled a reference for myofibrillar microarchitecture among myocardial subtypes in vivo and at different developmental stages, establishing this model as a tool to analyze in vivo cardiomyocyte contractility and remodeling for a broad range of cardiovascular questions. Furthermore, we applied this model to study Erbb2 signaling in cardiomyopathy. We show a direct link between Erbb2 activity and remodeling of myofibrils, revealing an unexpected mechanism with potentially important implications for prevention and treatment of cardiomyopathy. © 2014 American Heart Association, Inc.

Pulmonary and cardiac pathology in sudden unexpected death in epilepsy (SUDEP).

PubMed

Nascimento, Fábio A; Tseng, Zian H; Palmiere, Cristian; Maleszewski, Joseph J; Shiomi, Takayuki; McCrillis, Aileen; Devinsky, Orrin

2017-08-01

To review studies on structural pulmonary and cardiac changes in SUDEP cases as well as studies showing pulmonary or cardiac structural changes in living epilepsy patients. We conducted electronic literature searches using the PubMed database for articles published in English, regardless of publication year, that included data on cardiac and/or pulmonary structural abnormalities in SUDEP cases or in living epilepsy patients during the postictal period. Fourteen postmortem studies reported pulmonary findings in SUDEP cases. Two focused mainly on assessing lung weights in SUDEP cases versus controls; no group difference was found. The other 12 reported descriptive autopsy findings. Among all SUDEP cases with available descriptive postmortem pulmonary examination, 72% had pulmonary changes, most often pulmonary edema/congestion, and, less frequently, intraalveolar hemorrhage. Eleven studies reported on cardiac pathology in SUDEP. Cardiac abnormalities were found in approximately one-fourth of cases. The most common findings were myocyte hypertrophy and myocardial fibrosis of various degrees. Among living epilepsy patients, postictal pulmonary pathology was the most commonly reported pulmonary abnormality and the most common postictal cardiac abnormality was transient left ventricular dysfunction - Takotsubo or neurogenic stunned myocardium. Cardiac and pulmonary pathological abnormalities are frequent among SUDEP cases, most commonly pulmonary edema/congestion and focal interstitial myocardial fibrosis. Most findings are not quantified, with subjective elements and undefined interobserver reliability, and lack of controls such as matched epilepsy patients who died from other causes. Further, studies have not systematically evaluated potential confounding factors, including postmortem interval to autopsy, paramedic resuscitation and IV fluids administration, underlying heart/lung disease, and risk factors for cardiac or pulmonary disease. Prospective studies with controls are needed to define the heart and lung changes in SUDEP and understand their potential relationship to mechanisms of death in SUDEP. Copyright © 2017 Elsevier Inc. All rights reserved.

Autopsy interrogation of emergency medicine dispute cases: how often are clinical diagnoses incorrect?

PubMed

Liu, Danyang; Gan, Rongchang; Zhang, Weidi; Wang, Wei; Saiyin, Hexige; Zeng, Wenjiao; Liu, Guoyuan

2018-01-01

Emergency medicine is a 'high risk' specialty. Some diseases develop suddenly and progress rapidly, and sudden unexpected deaths in the emergency department (ED) may cause medical disputes. We aimed to assess discrepancies between antemortem clinical diagnoses and postmortem autopsy findings concerning emergency medicine dispute cases and to figure out the most common major missed diagnoses. Clinical files and autopsy reports were retrospectively analysed and interpreted. Discrepancies between clinical diagnoses and autopsy diagnoses were evaluated using modified Goldman classification as major and minor discrepancy. The difference between diagnosis groups was compared with Pearson χ 2 test. Of the 117 cases included in this study, 71 of cases (58 class I and 13 class II diagnostic errors) were revealed as major discrepancies (60.7%). The most common major diagnoses were cardiovascular diseases (54 cases), followed by pulmonary diseases, infectious diseases and so on. The difference of major discrepancy between the diagnoses groups was significant (p<0.001). Aortic dissection and myocardial infarction were the most common cause of death (15 cases for each disease) and the most common missed class I diagnoses (80% and 66.7% for each), higher than the average 49.6% of all class I errors of the study patients. High major disparities between clinical diagnoses and postmortem examinations exist in emergency medical disputes cases; acute aortic dissection and myocardial infarction are the most frequently major missed diagnoses that ED clinicians should pay special attention to in practice. This study reaffirmed the necessity and usefulness of autopsy in auditing death in EDs. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparative hazards of acute myocardial infarction among hospitalized patients with methamphetamine- or cocaine-use disorders: A retrospective cohort study.

PubMed

Callaghan, Russell C; Halliday, Montana; Gatley, Jodi; Sykes, Jenna; Taylor, Lawren; Benny, Claire; Kish, Stephen J

2018-07-01

It is assumed that recreational use of methamphetamine can trigger acute myocardial infarction (AMI) events, but estimates of longitudinal hazards of AMI among methamphetamine users are lacking. Retrospective cohort study: Competing-risks analysis was used to estimate time-to-AMI patterns in methamphetamine versus matched appendicitis (population-proxy) and matched cocaine (drug-control) groups. Cohorts were propensity-score-matched using demographic and clinical variables. California, 1990-2005. Cohorts of individuals with no prior or concurrent history of AMI hospitalized with methamphetamine- (n = 73,056), cocaine- (n = 47,726), or appendicitis-related conditions (n = 330,109). ICD-9/ICD-10 indications of AMI (ICD-9 410.X; ICD-10 I21.X) in death records or inpatient hospital data. Patients in methamphetamine cohort were more likely to develop subsequent AMI in comparison to those in matched appendicitis cohort [Hazard ratio (HR): 1.41; 95% CI, 1.23-1.62, p < 0.0001], with increased risk most marked in young methamphetamine users (age 15-34 years; HR: 2.04; 95% CI, 1.63-2.57, p = 0. 0001). Risk was slightly increased vs. that in matched cocaine group (HR: 1.19; 95% CI, 1.02-1.39, p = 0. 029). Individuals in cocaine cohort were also more likely to experience AMI outcome vs. appendicitis cohort (HR: 1.25; 95% CI, 1.08-1.45, p = 0. 0023). Our longitudinal data support results of earlier epidemiological studies suggesting that persons with methamphetamine- (or cocaine-) use disorders might have increased AMI risk. However, because of potential study limitations and the unexpectedly modest magnitude of the observed increased AMI hazard, these findings must be considered preliminary and require replication. Copyright © 2018. Published by Elsevier B.V.

Asymmetric simple exclusion process on chains with a shortcut

NASA Astrophysics Data System (ADS)

Bunzarova, Nadezhda; Pesheva, Nina; Brankov, Jordan

2014-03-01

We consider the asymmetric simple exclusion process (TASEP) on an open network consisting of three consecutively coupled macroscopic chain segments with a shortcut between the tail of the first segment and the head of the third one. The model was introduced by Y.-M. Yuan et al. [J. Phys. A 40, 12351 (2007), 10.1088/1751-8113/40/41/006] to describe directed motion of molecular motors along twisted filaments. We report here unexpected results which revise the previous findings in the case of maximum current through the network. Our theoretical analysis, based on the effective rates' approximation, shows that the second (shunted) segment can exist in both low- and high-density phases, as well as in the coexistence (shock) phase. Numerical simulations demonstrate that the last option takes place in finite-size networks with head and tail chains of equal length, provided the injection and ejection rates at their external ends are equal and greater than one-half. Then the local density distribution and the nearest-neighbor correlations in the middle chain correspond to a shock phase with completely delocalized domain wall. Upon moving the shortcut to the head or tail of the network, the density profile takes a shape typical of a high- or low-density phase, respectively. Surprisingly, the main quantitative parameters of that shock phase are governed by a positive root of a cubic equation, the coefficients of which linearly depend on the probability of choosing the shortcut. Alternatively, they can be expressed in a universal way through the shortcut current. The unexpected conclusion is that a shortcut in the bulk of a single lane may create traffic jams.

Assessment and classification of patients with myocardial injury and infarction in clinical practice

PubMed Central

Chapman, Andrew R; Adamson, Philip D

2017-01-01

Myocardial injury is common in patients without acute coronary syndrome, and international guidelines recommend patients with myocardial infarction are classified by aetiology. The universal definition differentiates patients with myocardial infarction due to plaque rupture (type 1) from those due to myocardial oxygen supply-demand imbalance (type 2) secondary to other acute illnesses. Patients with myocardial necrosis, but no symptoms or signs of myocardial ischaemia, are classified as acute or chronic myocardial injury. This classification has not been widely adopted in practice, because the diagnostic criteria for type 2 myocardial infarction encompass a wide range of presentations, and the implications of the diagnosis are uncertain. However, both myocardial injury and type 2 myocardial infarction are common, occurring in more than one-third of all hospitalised patients. These patients have poor short-term and long-term outcomes with two-thirds dead in 5 years. The classification of patients with myocardial infarction continues to evolve, and future guidelines are likely to recognise the importance of identifying coronary artery disease in type 2 myocardial infarction. Clinicians should consider whether coronary artery disease has contributed to myocardial injury, as selected patients are likely to benefit from further investigation and in these patients targeted secondary prevention has the potential to improve outcomes. PMID:27806987

A patient with type I CD36 deficiency whose myocardium accumulated 123I-BMIPP after 4 years.

PubMed

Ito, K; Sugihara, H; Tanabe, T; Zen, K; Hikosaka, T; Adachi, Y; Katoh, S; Azuma, A; Nakagawa, M

2001-06-01

A 73-year-old man with aortic regurgitation was examined by 123I-alpha-methyl-p-iodophenylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) in 1995. Myocardial accumulation was not evident on either the early or the delayed image obtained 15 minutes and 3 hours, respectively, after injecting 123I-BMIPP. Flow cytometric analysis of CD36 expression in monocytes and platelets identified a type I CD36 deficiency. The patient was hospitalized for severe heart failure in 1999. Upon admission, the cardiothoracic ratio on chest X-rays was 73%, and the left ventricular end-diastolic diameter on echocardiograms was enlarged to 77 mm. On the second day, we performed 123I-BMIPP myocardial SPECT. Myocardial accumulation was evident in the delayed, but not in the early image. We repeated 123I-BMIPP myocardial SPECT on the 10th day after admission. Myocardial accumulation was evident on both early and delayed images. 99mTc-tetrofosmin myocardial SPECT was immediately performed after 123I-BMIPP myocardial SPECT to distinguish myocardial from pooling images in the left ventricle, but, because the images from both 99Tc-tetrofosmin and 123I-BMIPP myocardial SPECT were idential, we considered that the 123I-BMIPP myocardial SPECT images reflected the actual myocardial condition. The CD36 molecule transports long-chain fatty acid (LCFA) on the myocardial membrane, but 123I-BMIPP scintigraphy does not show any myocardial accumulation in patients with type I CD36 deficiency, indicating that myocardial LCFA uptake occurs through CD36 on the human myocardial membrane. Even though our patient had type I CD36 deficiency, BMIPP was uptaken by the myocardium during heart failure, suggesting a variant pathway on the human myocardial membrane for LCFA uptake.

Myocardial Bridge

MedlinePlus

... Center > Myocardial Bridge Menu Topics Topics FAQs Myocardial Bridge En español Your heart is made of muscle, ... surface of the heart. What is a myocardial bridge? A myocardial bridge is a band of heart ...

Haloperidol and sudden cardiac death in dementia: autopsy findings in psychiatric inpatients.

PubMed

Ifteni, Petru; Grudnikoff, Eugene; Koppel, Jeremy; Kremen, Neil; Correll, Christoph U; Kane, John M; Manu, Peter

2015-12-01

Treatment with haloperidol has been shown, in studies using death certificates and prescription files, to be associated with an excess of sudden cardiac deaths, and regulatory warnings highlight this risk in patients with dementia. We used autopsy findings to determine whether the rate of sudden cardiac death is greater in cases of unexpected deaths of patients with dementia treated with haloperidol. From 1989 through 2013, 1219 patients with a primary diagnosis of dementia with behavioral disturbance were admitted to a psychiatric hospital, and 65 (5.3%) died suddenly. Sixty-five patients (5.3%) died unexpectedly. Complete post-mortem examinations after the sudden death were performed in 55 (84.6%) patients. Twenty-seven of the autopsied cases (49.1%) had been treated with haloperidol orally (2.2 mg ± 2.1 mg/day), the only antipsychotic used in this cohort. Univariable comparisons and multivariable regression analyses compared the groups of patients with or without sudden cardiac death. The leading causes of death were sudden cardiac death (32.7%), myocardial infarction (25.5% of patients), pneumonia (23.6%), and stroke (10.9%). Patients with sudden cardiac death and those with anatomically established cause of death were similar regarding the use of haloperidol (p = 0.5). Sudden cardiac death patients were more likely to suffer from Alzheimer's dementia (p = 0.027) and to have a past history of heart disease (p = 0.0094), and less likely to have been treated with a mood stabilizer (p = 0.024), but none of these variables were independent predictors of sudden cardiac death. Autopsy data suggest that oral haloperidol is not associated with increased risk of sudden cardiac death in psychiatric inpatients with dementia. Copyright © 2015 John Wiley & Sons, Ltd.

AMPK regulates energy metabolism through the SIRT1 signaling pathway to improve myocardial hypertrophy.

PubMed

Dong, H-W; Zhang, L-F; Bao, S-L

2018-05-01

We investigated the correlations of adenosine monophosphate-activated protein kinase (AMPK), Silence information regulator 1 (SIRT1) and energy metabolism with myocardial hypertrophy. Myocardial hypertrophy experimental model was established via transverse aortic constriction (TAC)-induced myocardial hypertrophy and phenylephrine (PE)-induced hypertrophic myocardial cell culture. After activation of AMPK, the messenger ribonucleic acid (mRNA) expressions in myocardial tissue- and myocardial cell hypertrophy-related genes, atrial natriuretic peptide (ANP) and β-myosin heavy chain (β-MHC), were detected. The production rate of 14C-labeled 14CO2 from palmitic acid was quantitatively determined to detect the fatty acid and glucose oxidation of hypertrophic myocardial tissues or cells, and the glucose uptake of myocardial cells was studied using [14C] glucose. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were performed to detect the changes in SIRT1 mRNA and protein expressions in hypertrophic myocardial tissues. Moreover, SIRT1 small interfering ribonucleic acid (siRNA) was used to interfere in SIRT1 expression to further investigate the role of SIRT1 in the effect of AMPK activation on myocardial hypertrophy. AMPK activation could significantly reduce the mRNA expressions of ANP and β-MHC in vitro and in vivo. AMPK could increase the ejection fraction (EF) and decrease the protein synthesis rate in myocardial cells in mice with myocardial hypertrophy. Besides, AMPK activation could increase the fatty acid oxidation, improve the glucose uptake and reduce the glucose oxidation. After AMPK activation, both SIRT1 mRNA and protein expressions in hypertrophic myocardial tissues and myocardial cells were increased. After SIRT1 siRNA was further used to interfere in SIRT1 expression in myocardial cells, it was found that mRNA expressions and protein synthesis rates of ANP and β-MHC were increased. The activation of AMPK can inhibit the myocardial hypertrophy, which may be realized through regulating the myocardial energy metabolism via SIRT1 signaling pathway.

The way we view cellular (glyco)sphingolipids.

PubMed

Hoetzl, Sandra; Sprong, Hein; van Meer, Gerrit

2007-11-01

Mammalian cells synthesize ceramide in the endoplasmic reticulum (ER) and convert this to sphingomyelin and complex glycosphingolipids on the inner, non-cytosolic surface of Golgi cisternae. From there, these lipids travel towards the outer, non-cytosolic surface of the plasma membrane and all membranes of the endocytic system, where they are eventually degraded. At the basis of the selective, anterograde traffic out of the Golgi lies the propensity of the sphingolipids to self-aggregate with cholesterol into microdomains termed 'lipid rafts'. At the plasma membrane surface these rafts are thought to function as the scaffold for various types of (glyco) signaling domains of different protein and lipid composition that can co-exist on one and the same cell. In the past decade, various unexpected findings on the sites where sphingolipid-mediated events occur have thrown a new light on the localization and transport mechanisms of sphingolipids. These findings are largely based on biochemical experiments. Further progress in the field is hampered by a lack of morphological techniques to localize lipids with nanometer resolution. In the present paper, we critically evaluate the published data and discuss techniques and potential improvements.

Chimeras in leaky integrate-and-fire neural networks: effects of reflecting connectivities

NASA Astrophysics Data System (ADS)

Tsigkri-DeSmedt, Nefeli Dimitra; Hizanidis, Johanne; Schöll, Eckehard; Hövel, Philipp; Provata, Astero

2017-07-01

The effects of attracting-nonlocal and reflecting connectivity are investigated in coupled Leaky Integrate-and-Fire (LIF) elements, which model the exchange of electrical signals between neurons. Earlier investigations have demonstrated that repulsive-nonlocal and hierarchical network connectivity can induce complex synchronization patterns and chimera states in systems of coupled oscillators. In the LIF system we show that if the elements are nonlocally linked with positive diffusive coupling on a ring network, the system splits into a number of alternating domains. Half of these domains contain elements whose potential stays near the threshold and they are interrupted by active domains where the elements perform regular LIF oscillations. The active domains travel along the ring with constant velocity, depending on the system parameters. When we introduce reflecting coupling in LIF networks unexpected complex spatio-temporal structures arise. For relatively extensive ranges of parameter values, the system splits into two coexisting domains: one where all elements stay near the threshold and one where incoherent states develop, characterized by multi-leveled mean phase velocity profiles.

F-18 FDG PET/CT findings in a patient with bilateral orbital and gastric mucosa-associated lymphoid tissue lymphomas.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Hiyama, Atsuto; Takeda, Koumei; Matsunaga, Naofumi

2009-09-01

Orbital mucosa-associated lymphoid tissue (MALT) lymphoma is an uncommon disease, while the incidence is recently increasing. We describe the F-18 fluorodeoxyglucose positron emission tomography computerized tomography (FDG PET/CT) findings in a case of bilateral orbital MALT lymphomas with a coexisting gastric lesion. Although only the lesion in the left orbit was initially identified on MR imaging, FDG PET/CT scan unexpectedly and additionally could identify the tiny lesion of the contralateral orbit and the gastric lesion. This patient received radiotherapy to all these lesions, with a combination of rituximab monoclonal antibody therapy. The follow-up PET/CT studies at 3, 6, and 9 months and 1.5 years after treatment showed regression or disappearance of all these FDG-avid lesions. Accurate localization and staging are crucial to select an adequate treatment in MALT lymphoma at any location. This case indicates the feasibility of FDG PET/CT scan for accurate localization and staging and also for monitoring treatment in patients with orbital MALT lymphoma.

Experimental evidence and modelling of drought induced alternative stable soil moisture states

NASA Astrophysics Data System (ADS)

Robinson, David; Jones, Scott; Lebron, Inma; Reinsch, Sabine; Dominguez, Maria; Smith, Andrew; Marshal, Miles; Emmett, Bridget

2017-04-01

The theory of alternative stable states in ecosystems is well established in ecology; however, evidence from manipulation experiments supporting the theory is limited. Developing the evidence base is important because it has profound implications for ecosystem management. Here we show evidence of the existence of alternative stable soil moisture states induced by drought in an upland wet heath. We used a long-term (15 yrs) climate change manipulation experiment with moderate sustained drought, which reduced the ability of the soil to retain soil moisture by degrading the soil structure, reducing moisture retention. Moreover, natural intense droughts superimposed themselves on the experiment, causing an unexpected additional alternative soil moisture state to develop, both for the drought manipulation and control plots; this impaired the soil from rewetting in winter. Our results show the coexistence of three stable states. Using modelling with the Hydrus 1D software package we are able to show the circumstances under which shifts in soil moisture states are likely to occur. Given the new understanding it presents a challenge of how to incorporate feedbacks, particularly related to soil structure, into soil flow and transport models?

Preservation of myocardium during coronary artery bypass surgery.

PubMed

Kinoshita, Takeshi; Asai, Tohru

2012-08-01

Myocardial protection aims to prevent reversible post-ischemic cardiac dysfunction (myocardial stunning) and irreversible myocardial cell death (myocardial infarction) that occur as a consequence of myocardial ischemia and/or ischemic-reperfusion injury. Although the mortality rate for isolated coronary artery bypass grafting has been markedly reduced during the past decade, myocardial death, as evidenced by elevation in creatine kinase-myocardial band and/or cardiac troponin, is common. This is ascribed to suboptimal myocardial protection during cardiopulmonary bypass or with off-pump technique, early graft failure, distal embolization, and regional or global myocardial ischemia during surgery. An unmet need in contemporary coronary bypass surgery is to find more effective cardioprotective strategies that have the potential for decreasing the morbidity and mortality associated with suboptimal cardioprotection. In the present review article on myocardial protection in contemporary coronary artery bypass surgery, we attempt to elucidate the clinical problems, summarize the outcomes of selected phase III trials, and introduce new perspectives.

Myocardial Rupture in Acute Myocardial Infarction: Mechanistic Explanation Based on the Ventricular Myocardial Band Hypothesis.

PubMed

Vargas-Barron, Jesús; Antunez-Montes, Omar-Yassef; Roldán, Francisco-Javier; Aranda-Frausto, Alberto; González-Pacheco, Hector; Romero-Cardenas, Ángel; Zabalgoitia, Miguel

2015-01-01

Torrent-Guasp explains the structure of the ventricular myocardium by means of a helical muscular band. Our primary purpose was to demonstrate the utility of echocardiography in human and porcine hearts in identifying the segments of the myocardial band. The second purpose was to evaluate the relation of the topographic distribution of the myocardial band with some post-myocardial infarction ruptures. Five porcine and one human heart without cardiopathy were dissected and the ventricular myocardial segments were color-coded for illustration and reconstruction purposes. These segments were then correlated to the conventional echocardiographic images. Afterwards in three cases with post-myocardial infarction rupture, a correlation of the topographic location of the rupture with the distribution of the ventricular band was made. The human ventricular band does not show any differences from the porcine band, which confirms the similarities of the four segments; these segments could be identified by echocardiography. In three cases with myocardial rupture, a correlation of the intra-myocardial dissection with the distribution of the ventricular band was observed. Echocardiography is helpful in identifying the myocardial band segments as well as the correlation with the topographic distribution of some myocardial post-infarction ruptures.

Reduction of myocardial blood flow reserve in idiopathic dilated cardiomyopathy without overt heart failure and its relation with functional indices: an echo-Doppler and positron emission tomography study.

PubMed

Morales, Maria-Aurora; Neglia, Danilo; L'Abbate, Antonio

2008-08-01

Myocardial blood flow during pharmacological vasodilatation is depressed in patients with idiopathic dilated cardiomyopathy even the in absence of overt heart failure; the extent of myocardial blood flow abnormalities is not predictable by left ventricular ejection fraction (LVEF) and diastolic dimensions. To assess whether myocardial blood flow impairment in idiopathic dilated cardiomyopathy without overt heart failure can be related to Doppler-derived dP/dt and to echocardiographically determined left ventricular end systolic stress - which is linked to myocardial blood flow reserve in advanced disease. Twenty-six patients, New York Heart Association Class I-II, (LVEF 37.4 +/- 1.4%, left ventricular diastolic dimensions 62.6 +/- 0.9 mm) underwent resting/dipyridamole [13N]NH3 flow positron emission tomography and an ultrasonic study. Regional myocardial blood flow values (ml/min per g) were computed from positron emission tomography data in 13 left ventricular (LV) myocardial regions and averaged to provide mean myocardial blood flow and myocardial blood flow reserve, defined as dipyridamole/resting mean myocardial blood flow ratio. Resting myocardial blood flow was 0.686 +/- 0.045, dipyridamole myocardial blood flow 1.39 +/- 0.15 and myocardial blood flow reserve 2.12 +/- 0.2, lower than in controls (P < 0.01). The ratio dP/dt was directly related to dipyridamole myocardial blood flow and myocardial blood flow reserve (r = 0.552 and 0.703, P < 0.005 and P < 0.0001); no relation was found between myocardial blood flow and LVEF left ventricular diastolic dimensions, and left ventricular end systolic stress. In idiopathic dilated cardiomyopathy patients without overt heart failure, the extent of myocardial blood flow reserve impairment is related to dP/dt but not to more classical indices of left ventricular function.

The approach to patients with possible cardiac chest pain.

PubMed

Parsonage, William A; Cullen, Louise; Younger, John F

2013-07-08

Chest pain is a common reason for presentation in hospital emergency departments and general practice. Some patients presenting with chest pain to emergency departments and, to a lesser extent, general practice will be found to have a life-threatening cause, but most will not. The challenge is to identify those who do in a safe, timely and cost-effective manner. An acute coronary syndrome cannot be excluded on clinical grounds alone. In patients with ongoing symptoms of chest pain, without an obvious other cause, ST-segment-elevation myocardial infarction should be excluded with a 12-lead electrocardiogram at the first available opportunity. Significant recent advances in the clinical approach to patients with acute chest pain, including better understanding of risk stratification, increasingly sensitive cardiac biomarkers and new non-invasive tests for coronary disease, can help clinicians minimise the risk of unexpected short-term adverse cardiac events. An approach that integrates these advances is needed to deliver the best outcomes for patients with chest pain. All hospital emergency departments should adopt such a strategic approach, and general practitioners should be aware of when and how to access these facilities.

Effects of atrial fibrillation on myocardial washout rate of thallium-201 on myocardial perfusion single-photon emission computed tomography.

PubMed

Kurisu, Satoshi; Nitta, Kazuhiro; Sumimoto, Yoji; Ikenaga, Hiroki; Ishibashi, Ken; Fukuda, Yukihiro; Kihara, Yasuki

2018-04-20

Myocardial perfusion single-photon emission computed tomography (SPECT) with thallium (Tl)-201 is an established modality for evaluating myocardial ischemia. We assessed the effects of atrial fibrillation (AF) on the myocardial washout rate (WR) of Tl-201 on myocardial perfusion SPECT. A total of 231 patients with no evidence of myocardial ischemia were enrolled retrospectively in this study. Patients were divided into two groups on the basis of the ECG at the time of myocardial perfusion SPECT. The mean myocardial WR of Tl-201 was calculated from the stress and the redistribution Bull's eye maps. There were 34 patients with AF and 197 patients with sinus rhythm. There were no significant differences in clinical variables, except for older age and higher heart rate in patients with AF. Myocardial WR of Tl-201 was significantly lower in patients with AF than those with sinus rhythm (46±12 vs. 51±8%, P=0.03). Multivariate analysis including these factors showed that female sex (β=0.18, P=0.02), AF (β=-0.14 P=0.03), hemoglobin (β=-0.18, P<0.01), and serum creatinine (β=0.24, P<0.01) were determinants of myocardial WR of Tl-201. Our data suggest that AF is associated with reduced myocardial WR of Tl-201 on myocardial perfuison SPECT.

Technetium-99m stannous pyrophosphate myocardial scintigraphy after cardiopulmonary resuscitation with cardioversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davison, R.; Spies, S.M.; Przybylek, J.

1979-08-01

Thirty consecutive patients underwent technetium-99m stannous pyrophosphate myocardial scintigraphy 48 to 72 h after successful cardiopulmonary resuscitation and direct current cardioversion. Five patients with transmural myocardial infarctions by ECG and enzyme determinations were correctly identified by scintigraphy. Myocardial scans were positive in five of nine patients with nontransmural infarction. Of 16 patients without evidence of myocardial infarction, only two (13%) had false-positive myocardial scans. The overall accuracy of imaging in this series was 80%. We conclude that false-positive scans after cardiopulmonary resuscitation with electrical cardioversion are infrequent, and do not significantly detract from the value of myocardial scintigraphy in themore » diagnosis of myocardial infarction.« less

Direct Evidence that Myocardial Insulin Resistance following Myocardial Ischemia Contributes to Post-Ischemic Heart Failure

PubMed Central

Fu, Feng; Zhao, Kun; Li, Jia; Xu, Jie; Zhang, Yuan; Liu, Chengfeng; Yang, Weidong; Gao, Chao; Li, Jun; Zhang, Haifeng; Li, Yan; Cui, Qin; Wang, Haichang; Tao, Ling; Wang, Jing; Quon, Michael J; Gao, Feng

2015-01-01

A close link between heart failure (HF) and systemic insulin resistance has been well documented, whereas myocardial insulin resistance and its association with HF are inadequately investigated. This study aims to determine the role of myocardial insulin resistance in ischemic HF and its underlying mechanisms. Male Sprague-Dawley rats subjected to myocardial infarction (MI) developed progressive left ventricular dilation with dysfunction and HF at 4 wk post-MI. Of note, myocardial insulin sensitivity was decreased as early as 1 wk after MI, which was accompanied by increased production of myocardial TNF-α. Overexpression of TNF-α in heart mimicked impaired insulin signaling and cardiac dysfunction leading to HF observed after MI. Treatment of rats with a specific TNF-α inhibitor improved myocardial insulin signaling post-MI. Insulin treatment given immediately following MI suppressed myocardial TNF-α production and improved cardiac insulin sensitivity and opposed cardiac dysfunction/remodeling. Moreover, tamoxifen-induced cardiomyocyte-specific insulin receptor knockout mice exhibited aggravated post-ischemic ventricular remodeling and dysfunction compared with controls. In conclusion, MI induces myocardial insulin resistance (without systemic insulin resistance) mediated partly by ischemia-induced myocardial TNF-α overproduction and promotes the development of HF. Our findings underscore the direct and essential role of myocardial insulin signaling in protection against post-ischemic HF. PMID:26659007

Myocardial contusion following nonfatal blunt chest trauma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, S.A.; Puri, V.K.; Mittal, V.K.

1983-04-01

Currently available diagnostic techniques for myocardial contusion following blunt chest trauma were evaluated. We investigated 30 patients prospectively over a period of 1 year for the presence of myocardial contusion. Among the 30 patients, eight were found to have myocardial contusion on the basis of abnormal electrocardiograms, elevated creatine phosphokinase MB fraction (CPK-MB), and positive myocardial scan. Myocardial scan was positive in seven of eight patients (87.5%). CPK-MB fraction was elevated in four of eight patients (50%). Definitive electrocardiographic changes were seen in only two of eight patients (25%). It appears that myocardial scan using technetium pyrophosphate and CPK-MB fractionmore » determinations are the most reliable aids in diagnosis of myocardial contusion following blunt chest trauma.« less

Myocardial contusion in patients with blunt chest trauma as evaluated by thallium 201 myocardial scintigraphy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bodin, L.; Rouby, J.J.; Viars, P.

1988-07-01

Fifty five patients suffering from blunt chest trauma were studied to assess the diagnosis of myocardial contusion using thallium 201 myocardial scintigraphy. Thirty-eight patients had consistent scintigraphic defects and were considered to have a myocardial contusion. All patients with scintigraphic defects had paroxysmal arrhythmias and/or ECG abnormalities. Of 38 patients, 32 had localized ST-T segment abnormalities; 29, ST-T segment abnormalities suggesting involvement of the same cardiac area as scintigraphic defects; 21, echocardiographic abnormalities. Sixteen patients had segmental hypokinesia involving the same cardiac area as the scintigraphic defects. Fifteen patients had clinical signs suggestive of myocardial contusion and scintigraphic defects. Almostmore » 70 percent of patients with blunt chest trauma had scintigraphic defects related to areas of myocardial contusion. When thallium 201 myocardial scintigraphy directly showed myocardial lesion, two-dimensional echocardiography and standard ECG detected related functional consequences of cardiac trauma.« less

B lymphocytes trigger monocyte mobilization and impair heart function after acute myocardial infarction.

PubMed

Zouggari, Yasmine; Ait-Oufella, Hafid; Bonnin, Philippe; Simon, Tabassome; Sage, Andrew P; Guérin, Coralie; Vilar, José; Caligiuri, Giuseppina; Tsiantoulas, Dimitrios; Laurans, Ludivine; Dumeau, Edouard; Kotti, Salma; Bruneval, Patrick; Charo, Israel F; Binder, Christoph J; Danchin, Nicolas; Tedgui, Alain; Tedder, Thomas F; Silvestre, Jean-Sébastien; Mallat, Ziad

2013-10-01

Acute myocardial infarction is a severe ischemic disease responsible for heart failure and sudden death. Here, we show that after acute myocardial infarction in mice, mature B lymphocytes selectively produce Ccl7 and induce Ly6C(hi) monocyte mobilization and recruitment to the heart, leading to enhanced tissue injury and deterioration of myocardial function. Genetic (Baff receptor deficiency) or antibody-mediated (CD20- or Baff-specific antibody) depletion of mature B lymphocytes impeded Ccl7 production and monocyte mobilization, limited myocardial injury and improved heart function. These effects were recapitulated in mice with B cell-selective Ccl7 deficiency. We also show that high circulating concentrations of CCL7 and BAFF in patients with acute myocardial infarction predict increased risk of death or recurrent myocardial infarction. This work identifies a crucial interaction between mature B lymphocytes and monocytes after acute myocardial ischemia and identifies new therapeutic targets for acute myocardial infarction.

B lymphocytes trigger monocyte mobilization and impair heart function after acute myocardial infarction

PubMed Central

Zouggari, Yasmine; Ait-Oufella, Hafid; Bonnin, Philippe; Simon, Tabassome; Sage, Andrew P; Guérin, Coralie; Vilar, José; Caligiuri, Giuseppina; Tsiantoulas, Dimitrios; Laurans, Ludivine; Dumeau, Edouard; Kotti, Salma; Bruneval, Patrick; Charo, Israel F; Binder, Christoph J; Danchin, Nicolas; Tedgui, Alain; Tedder, Thomas F; Silvestre, Jean-Sébastien; Mallat, Ziad

2014-01-01

Acute myocardial infarction is a severe ischemic disease responsible for heart failure and sudden death. Here, we show that after acute myocardial infarction in mice, mature B lymphocytes selectively produce Ccl7 and induce Ly6Chi monocyte mobilization and recruitment to the heart, leading to enhanced tissue injury and deterioration of myocardial function. Genetic (Baff receptor deficiency) or antibody-mediated (CD20- or Baff-specific antibody) depletion of mature B lymphocytes impeded Ccl7 production and monocyte mobilization, limited myocardial injury and improved heart function. These effects were recapitulated in mice with B cell–selective Ccl7 deficiency. We also show that high circulating concentrations of CCL7 and BAFF in patients with acute myocardial infarction predict increased risk of death or recurrent myocardial infarction. This work identifies a crucial interaction between mature B lymphocytes and monocytes after acute myocardial ischemia and identifies new therapeutic targets for acute myocardial infarction. PMID:24037091

Atrial Fibrillation and Heart Failure - Cause or Effect?

PubMed

Prabhu, Sandeep; Voskoboinik, Aleksandr; Kaye, David M; Kistler, Peter M

2017-09-01

There are emerging epidemics of atrial fibrillation (AF) and heart failure in most developed countries, with a significant health burden. Due to many shared pathophysiological mechanisms, which facilitate the maintenance of each condition, AF and heart failure co-exist in up to 30% of patients. In the circumstance where known structural causes of heart failure (such as myocardial infarction) are absent, patients presenting with both conditions present a unique challenge, particularly as the temporal relationship of each condition can often remain elusive from the clinical history. The question of whether the AF is driving, or significantly contributing to the left ventricular (LV) dysfunction, rather than merely a consequence of heart failure, has become ever more pertinent, especially as catheter ablation now offers a significant advancement over existing rhythm control strategies. This paper will review the inter-related physiological drivers of AF and heart failure before considering the implications from the outcomes of recent clinical trials in patients with AF and heart failure. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Panic disorder and cardiovascular diseases: an overview.

PubMed

Machado, Sergio; Sancassiani, Federica; Paes, Flavia; Rocha, Nuno; Murillo-Rodriguez, Eric; Nardi, Antonio Egidio

2017-10-01

The association between panic disorder (PD) and cardiovascular diseases (CVD) has been extensively studied in recent years and, although some studies have shown anxiety disorders co-existing or increasing the risk of heart disease, no causal hypothesis has been well established. Thus, a critical review was performed of the studies that evaluated the association between PD and cardiovascular diseases; synthesizing the evidence on the mechanisms mediators that theoretically would be the responsible for the causal pathway between PD and CVD, specifically. This overview shows epidemiological studies, and discusses biological mechanisms that could link PD to CVD, such as pleiotropy, heart rate variability, unhealthy lifestyle, atherosclerosis, mental stress, and myocardial perfusion defects. This study tried to provide a comprehensive narrative synthesis of previously published information regarding PD and CVD and open new possibilities of clinical management and pathophysiological understanding. Some epidemiological studies have indicated that PD could be a risk factor for CVD, raising morbidity and mortality in PD, suggesting an association between them. These studies argue that PD pathophysiology could cause or potentiate CVD. However, there is no evidence in favour of a causal relationship between PD and CVD. Therefore, PD patients with suspicions of cardiovascular symptoms need redoubled attention.

Cardiac arrest and clinical characteristics, treatments and outcomes among patients hospitalized with ST-elevation myocardial infarction in contemporary practice: A report from the National Cardiovascular Data Registry.

PubMed

Kontos, Michael C; Scirica, Benjamin M; Chen, Anita Y; Thomas, Laine; Anderson, Monique L; Diercks, Deborah B; Jollis, James G; Roe, Matthew T

2015-04-01

Cardiac arrest (CA) is a major complication of patients with ST-elevation myocardial infarction (STEMI). Its prevalence and prognostic impact in contemporary US practice has not been well assessed. We evaluated STEMI patients included in the National Cardiovascular Data Registry (NCDR) Acute Coronary Treatment Intervention Outcomes Network Registry-Get With the Guidelines (ACTION Registry-GWTG) from 4/1/11 to 6/30/12. Patient clinical characteristics, treatments, and inhospital outcomes were compared by the presence or absence of CA on first medical contact-either before hospital arrival or upon presentation to the ACTION hospital. Of the 49,279 STEMI patients included, 3,716 (7.5%) had CA. Cardiac arrest patients were more likely to have heart failure (15.5% vs 6.9%) and shock (42.9% vs 4.9%) on presentation and higher median (25th and 75th percentiles) ACTION Registry-GWTG mortality risk scores (42 [32, 54] vs 32 [26, 38]) than non-CA patients (all P < .001). Primary percutaneous coronary intervention was performed in most patients with and without CA (76.7% vs 79.1%). Inhospital mortality was significantly higher in patients with than without CA (28.8% vs 4.0%; P < .001), both in patients who presented with cardiogenic shock (46.9% vs 27.1%; P < .001) and those without shock (15.4% vs 2.9%; P < .001). The ACTION Registry-GWTG inhospital mortality model underestimated mortality risk in CA patients; however, prediction significantly improved after adding CA to the model. Almost 8% of STEMI patients present with CA. More than 25% die during the hospitalization, despite high use of primary percutaneous coronary intervention. Cardiogenic shock and CA frequently coexist. Our results suggest that development of systems of care and treatments for both STEMI and CA is needed to reduce the high mortality in these patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Perioperative Assessment of Myocardial Deformation

PubMed Central

Duncan, Andra E.; Alfirevic, Andrej; Sessler, Daniel I.; Popovic, Zoran B.; Thomas, James D.

2014-01-01

Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation which reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis using transthoracic echocardiography are (mean ± SD) −19.7 ± 0.4%, while radial and circumferential strain are 47.3 ± 1.9 and −23.3 ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages −1.10 ± 0.16 sec−1. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to assess components of myocardial systolic and diastolic function. Myocardial deformation analysis is based on either Doppler or a non-Doppler technique, called speckle-tracking echocardiography. Myocardial deformation analysis provides quantitative measures of global and regional myocardial function for use in the perioperative care of the surgical patient. For example, coronary graft occlusion after coronary artery bypass grafting is detected by an acute reduction in strain in the affected coronary artery territory. In addition, assessment of left ventricular mechanics detects underlying myocardial pathology before abnormalities become apparent on conventional echocardiography. Certainly, patients with aortic regurgitation demonstrate reduced longitudinal strain before reduction in LVEF occurs, which allows detection of subclinical left ventricular dysfunction and predicts increased risk for heart failure and impaired myocardial function after surgical repair. In this review we describe the principles, techniques, and clinical application of myocardial deformation analysis. PMID:24557101

Determination of the Role of Oxygen in Suspected Acute Myocardial Infarction by Biomarkers

ClinicalTrials.gov

2017-12-08

Acute Myocardial Infarction (AMI); Acute Coronary Syndrome (ACS); ST Elevation (STEMI) Myocardial Infarction; Ischemic Reperfusion Injury; Non-ST Elevation (NSTEMI) Myocardial Infarction; Angina, Unstable

Pattern Formation in Langmuir Monolayers Due to Long-Range Electrostatic Interactions

NASA Astrophysics Data System (ADS)

Fischer, Thomas M.; Lösche, Mathias

A distinctive characteristic of Langmuir monolayers that bears important consequences for the physics of structure formation within membranes is the uniaxial orientation of the constituent dipolar molecules, brought about by the symmetry break which is induced by the surface of the aqueous substrate. The association of oriented molecular dipoles with the interface leads to the formation of image dipoles within the polarizeable medium - the subphase - such that the effective dipole orientation of every of the individual molecules is strictly normal to the surface, even within molecularly disordered phases. As a result, dipole-dipole repulsions play an eminently important role for the molecular interactions within the system - independent of the state of phase (while the dipole area density does of course depend on the state of phase) - and control the morphogenesis of the phase boundaries in their interplay with the one-dimensional (1D) line tension between coexisting phases. The physics of these phenomena is only now being explored and is particularly exciting for systems within a three-phase coexistence region where complete or partial wetting, as well as dewetting between the coexisting phases may be experimentally observed by applying fluorescence microscopy to the monolayer films. It is revealed that the wetting behavior depends sensitively on the details of the electrostatic interactions, in that the apparent contact angles observed at three-phase contact points depends on the sizes of the coexisting phases. This is in sharp contrast to the physics of wetting in conventional 3D systems where the contact angle is a materials property, independent of the local details. In 3D systems, this leads to Youngs equation - which has been established more than two centuries ago. We report recent progress in the understanding of this unusual and rather unexpected behavior of a quasi-2D system by reviewing recent experimental results from optical microscopy on equilibrium phase shapes, non-equilibrium phenomena - such as relaxation of the shapes after distortions inferred by Laser tweezers or local impulse heating - and rheological properties of the system. The theoretical analysis of the underlying molecular interactions leads to a comprehension of the observed phenomena and reveals microscopic properties of the system in quantitative terms. In view of the recently proposed lipid raft hypothesis, a particularly fascinating implication of our results is the possibility that biochemical reactions which depend on complex interactions between membrane-bound proteins might be controlled by the non-conventional physics of the 2D system: As an electrogenic event - such as ion transfer across the membrane - changes the electrostatic properties of the membrane surface it might concurrently infer wetting between 2D phases and thus lead to the conjunction of membrane areas that were originally separated within the plane. If two reactants (e.g., membrane-bound enzymes) are dissolved in distinct phases, such a colloidal reorganization might rearrange the micro-evironment to bring them into close vicinity - and thus trigger the biochemical reaction.

Differences in symptoms, first medical contact and pre-hospital delay times between patients with ST- and non-ST-elevation myocardial infarction.

PubMed

Ängerud, Karin H; Sederholm Lawesson, Sofia; Isaksson, Rose-Marie; Thylén, Ingela; Swahn, Eva

2017-11-01

In ST-elevation myocardial infarction, time to reperfusion is crucial for the prognosis. Symptom presentation in myocardial infarction influences pre-hospital delay times but studies about differences in symptoms between patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction are sparse and inconclusive. The aim was to compare symptoms, first medical contact and pre-hospital delay times in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction. This multicentre, observational study included 694 myocardial infarction patients from five hospitals. The patients filled in a questionnaire about their pre-hospital experiences within 24 h of hospital admittance. Chest pain was the most common symptom in ST-elevation myocardial infarction and non-ST-elevation myocardial infarction (88.7 vs 87.0%, p=0.56). Patients with cold sweat (odds ratio 3.61, 95% confidence interval 2.29-5.70), jaw pain (odds ratio 2.41, 95% confidence interval 1.04-5.58), and nausea (odds ratio 1.70, 95% confidence interval 1.01-2.87) were more likely to present with ST-elevation myocardial infarction, whereas the opposite was true for symptoms that come and go (odds ratio 0.58, 95% confidence interval 0.38-0.90) or anxiety (odds ratio 0.52, 95% confidence interval 0.29-0.92). Use of emergency medical services was higher among patients admitted with ST-elevation myocardial infarction. The pre-hospital delay time from symptom onset to first medical contact was significantly longer in non-ST-elevation myocardial infarction (2:05 h vs 1:10 h, p=0.001). Patients with ST-elevation myocardial infarction differed from those with non-ST-elevation myocardial infarction regarding symptom presentation, ambulance utilisation and pre-hospital delay times. This knowledge is important to be aware of for all healthcare personnel and the general public especially in order to recognise symptoms suggestive of ST-elevation myocardial infarction and when to decide if there is a need for an ambulance.

Exogenous Nkx2.5- or GATA-4-transfected rabbit bone marrow mesenchymal stem cells and myocardial cell co-culture on the treatment of myocardial infarction in rabbits.

PubMed

Li, Pu; Zhang, Lei

2015-08-01

The present study aimed to investigate the effects of Nkx2.5 or GATA-4 transfection with myocardial extracellular environment co-culture on the transformation of bone marrow mesenchymal stem cells (BMSCs) into differentiated cardiomyocytes. Nkx2.5 or GATA-4 were transfected into myocardial extracellular environment co-cultured BMSCs, and then injected into the periphery of infarcted myocardium of a myocardial infarction rabbit model. The effects of these gene transfections and culture on the infarcted myocardium were observed and the results may provide an experimental basis for the efficient myocardial cell differentiation of BMSCs. The present study also suggested that these cells may provide a source and clinical basis for myocardial injury repair via stem cell transplantation. The present study examined whether Nkx2.5 or GATA-4 exogenous gene transfection with myocardial cell extracellular environment co-culture were able to induce the differentiation of BMSCs into cardiac cells. In addition, the effect of these transfected BMSCs on the repair of the myocardium following myocardial infarction was determined using New Zealand rabbit models. The results demonstrated that myocardial cell differentiation was significantly less effective following exogenous gene transfection of Nkx2.5 or GATA-4 alone compared with that of transfection in combination with extracellular environment co-culture. In addition, the results of the present study showed that exogenous gene transfection of Nkx2.5 or GATA-4 into myocardial cell extracellular environment co-cultured BMSCs was able to significantly enhance the ability to repair, mitigating the death of myocardial cells and activation of the myocardium in rabbits with myocardial infarction compared with those of the rabbits transplanted with untreated BMSCs. In conclusion, the exogenous Nkx2.5 and GATA-4 gene transfection into myocardial extracellular environment co-cultured BMSCs induced increased differentiation into myocardial cells compared with that of gene transfection alone. Furthermore, significantly enhanced reparative effects were observed in the myocardium of rabbits following treatment with Nkx2.5-or GATA-4-transfected myocardial cell extracellular environment co-cultured BMSCs compared with those treated with untreated BMSCs.

Pericardial application as a new route for implanting stem-cell cardiospheres to treat myocardial infarction.

PubMed

Zhang, Jianhua; Wu, Zheng; Fan, Zepei; Qin, Zixi; Wang, Yingwei; Chen, Jiayuan; Wu, Maoxiong; Chen, Yangxin; Wu, Changhao; Wang, Jingfeng

2018-06-01

Cardiospheres (CSps) are a promising new form of cardiac stem cells with advantage over other stem cells for myocardial regeneration, but direct implantation of CSps by conventional routes has been limited due to potential embolism. We have implanted CSps into the pericardial cavity and systematically demonstrated its efficacy regarding myocardial infarction. Stem cell potency and cell viability can be optimized in vitro prior to implantation by pre-conditioning CSps with pericardial fluid and hydrogel packing. Transplantation of optimized CSps into the pericardial cavity improved cardiac function and alleviated myocardial fibrosis, increased myocardial cell survival and promoted angiogenesis. Mechanistically, CSps are able to directly differentiate into cardiomyocytes in vivo and promote regeneration of myocardial cells and blood vessels through a paracrine effect with released growth factors as potential paracrine mediators. These findings establish a new strategy for therapeutic myocardial regeneration to treat myocardial infarction. Cardiospheres (CSps) are a new form of cardiac stem cells with an advantage over other stem cells for myocardial regeneration. However, direct implantation of CSps by conventional routes to treat myocardial infarction has been limited due to potential embolism. We have implanted CSps into the pericardial cavity and systematically assessed its efficacy on myocardial infarction. Preconditioning with pericardial fluid enhanced the activity of CSps and matrix hydrogel prolonged their viability. This shows that pretransplant optimization of stem cell potency and maintenance of cell viability can be achieved with CSps. Transplantation of optimized CSps into the pericardial cavity improved cardiac function and alleviated myocardial fibrosis in the non-infarcted area, and increased myocardial cell survival and promoted angiogenesis in the infarcted area. Mechanistically, CSps were able to directly differentiate into cardiomyocytes in vivo and promoted regeneration of myocardial cells and blood vessels in the infarcted area through a paracrine effect with released growth factors in pericardial cavity serving as possible paracrine mediators. This is the first demonstration of direct pericardial administration of pre-optimized CSps, and its effectiveness on myocardial infarction by functional and morphological outcomes with distinct mechanisms. These findings establish a new strategy for therapeutic myocardial regeneration to treat myocardial infarction. © 2018 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

[The 18F-FDG myocardial metabolic imaging in twenty seven pilots with regular aerobic training].

PubMed

Fang, Ting-Zheng; Zhu, Jia-Rui; Chuan, Ling; Zhao, Wen-Rui; Xu, Gen-Xiang; Yang, Min-Fu; He, Zuo-Xiang

2009-02-01

To evaluate the characteristics of myocardial (18)F-FDG imaging in pilots with regular aerobic exercise training. Twenty seven healthy male pilots with regular aerobic exercise training were included in this study. The subjects were divided into fasting (n = 17) or non-fasting group (n = 10). Fluorine-18-labeled deoxyglucose and Tc-99m-sestamibi dual-nuclide myocardial imaging were obtained at rest and at target heart rate during bicycle ergometer test. The exercise and rest myocardial perfusion imaging were analyzed for myocardial ischemia presence. The myocardial metabolism imaging was analyzed with the visual semi-quantitative analyses model of seventeen segments. The secondary-extreme heart rate (195-age) was achieved in all subjects. There was no myocardial ischemia in all perfusion imaging. In the visual qualitative analyses, four myocardial metabolism imaging failed in the fasting group while one failed in the non-fasting group (P > 0.05). In the visual semi-quantitative analyses, myocardial metabolism imaging scores at rest or exercise in all segments were similar between two groups (P > 0.05). In the fasting group, the myocardial metabolism imaging scores during exercise were significantly higher than those at rest in 6 segments (P < 0.05). In the non-fasting group, the scores of 3 exercise myocardial metabolism imaging were significantly higher than those at rest (P < 0.05). Satisfactory high-quality myocardial metabolism imaging could be obtained at fasting and exercise situations in subjects with regular aerobic exercise.

A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

PubMed

Deylami, Mohammad N; Jovanov, Emil

2014-01-01

The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients

NASA Technical Reports Server (NTRS)

Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

1975-01-01

The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

Naturally derived myocardial matrix as an injectable scaffold for cardiac tissue engineering

PubMed Central

Singelyn, Jennifer M.; DeQuach, Jessica A.; Seif-Naraghi, Sonya B.; Littlefield, Robert B.; Schup-Magoffin, Pamela J.; Christman, Karen L.

2009-01-01

Myocardial tissue lacks the ability to significantly regenerate itself following a myocardial infarction, thus tissue engineering strategies are required for repair. Several injectable materials have been examined for cardiac tissue engineering; however, none have been designed specifically to mimic the myocardium. The goal of this study was to investigate the in vitro properties and in vivo potential of an injectable myocardial matrix designed to mimic the natural myocardial extracellular environment. Porcine myocardial tissue was decellularized and processed to form a myocardial matrix with the ability to gel in vitro at 37°C and in vivo upon injection into rat myocardium. The resulting myocardial matrix maintained a complex composition, including glycosaminoglycan content, and was able to self-assemble to form a nanofibrous structure. Endothelial cells and smooth muscle cells were shown to migrate towards the myocardial matrix both in vitro and in vivo, with a significant increase in arteriole formation at 11 days post-injection. The matrix was also successfully pushed through a clinically used catheter, demonstrating its potential for minimally invasive therapy. Thus, we have demonstrated the initial feasibility and potential of a naturally derived myocardial matrix as an injectable scaffold for cardiac tissue engineering. PMID:19608268

Gross anatomical study on the human myocardial bridges with special reference to the spatial relationship among coronary arteries, cardiac veins, and autonomic nerves.

PubMed

Watanabe, Yuko; Arakawa, Takamitsu; Kageyama, Ikuo; Aizawa, Yukio; Kumaki, Katsuji; Miki, Akinori; Terashima, Toshio

2016-04-01

Coronary arteries are frequently covered by cardiac muscles. This arrangement is termed a myocardial bridge. Previous studies have shown that myocardial bridges can cause myocardial ischemic diseases or cardiac arrhythmia, but the relevant pathogenic mechanisms remain unknown. We examined 60 hearts from Japanese cadavers macroscopically to clarify the spatial relationships among coronary arteries, cardiac veins and autonomic nerves. We found 86 myocardial bridges in 47 hearts from the 60 cadavers examined (78.3%). Next, we dissected out nine hearts with myocardial bridges in detail under the operating microscope. We found no additional branches of coronary arteries on the myocardial bridge surfaces. However, the cardiac veins, which usually accompany the coronary arteries, ran independently on the myocardial bridge surfaces in the same region. Cardiac autonomic nerves comprised two rami: one was associated with the coronary artery under the myocardial bridge and the other ran on the surface of the bridge. Such spatial relationships among the coronary arteries, cardiac veins and cardiac autonomic nerves at the myocardial bridges are quite similar to those in mouse embryo hearts. © 2015 Wiley Periodicals, Inc.

Sepiapterin reduces postischemic injury in the rat heart.

PubMed

Tiefenbacher, Christiane P; Lee, Ching-Hua; Kapitza, Jolanthe; Dietz, Volker; Niroomand, Feraydoon

2003-10-01

A reduced availability of tetrahydrobiopterin (BH4), an essential cofactor for NO-synthesis, is causally involved in the development of endothelial dysfunction associated with ischemia/reperfusion. We, therefore, investigated the effect of sepiapterin, a substrate for BH4 synthesis, on postischemic injury in myocardial infarction and myocardial stunning. In rats, myocardial stunning was induced by repetitive ischemia (5 x 10-min ligature of the left coronary artery, 5 x 20-min reperfusion) and myocardial infarction by 50-min ligature and 60-min reperfusion. Myocardial blood flow was determined by H2-clearance, regional myocardial function by pulsed Doppler and infarct size by tetrazolium staining. Myeloperoxidase (MPO) activity was measured as a marker of neutrophil extravasation. cGMP was determined in rat serum as an indicator of increased NO synthesis. In animals treated with sepiapterin, regional myocardial function was significantly improved in both myocardial stunning and infarction and infarct size was significantly reduced. MPO activity decreased with sepiapterin treatment in both models. The systemic level of cGMP was reduced both following myocardial stunning and myocardial infarction in the control group. Pretreatment with sepiapterin induced a significant increase of cGMP level at the end of the protocol in both models. Substitution of sepiapterin reduces postischemic injury both in myocardial stunning and infarction apparently by ameliorating the availability of NO, thereby attenuating the activation of neutrophils in ischemia/reperfusion.

Two-dimensional strain echocardiography technology for evaluation of myocardial strain in swimming athletes after high-intensity exercise.

PubMed

Liang, Chen; Ma, Yun; Gao, Can; Zhang, Jianhong; Yang, Min; Chen, Gen; Fu, Shan; Zhu, Tiangang

2017-02-01

The aim of this study was to investigate the change in myocardial strain in swimming athletes before and after high-intensity exercise using two-dimensional strain echocardiography (2DSE) technology. To assess whether the local and overall myocardial function and myocardial injury are accurately measured using 2DSE technology, 15 swimming athletes were selected as research objects. We applied 2DSE technology to track the 2D ultrasound images of the apical four chambers, the apical two chambers, and the apical long axis before and after high-intensity, increasing-load exercise. We recorded indices such as the left ventricular global strain (GS) and the left ventricular segmental wall longitudinal peak systolic strain (PS) in 18 systoles and analyzed the myocardial strain change before and after exercise. After high-intensity exercise, the overall myocardial strain decreased, especially the strain of the posterior wall, posterior divider, lateral wall, lower wall, and the basal and middle segments of the anterior wall. The influence of exercise on myocardial strain was greater on the basal and middle segments than on the apical segment. One-time intensive exercise negatively affected the myocardial muscle. Myocardial muscles in the apical segment and the myocardial wall were more sensitive to intensive exercise. The 2DSE technology can precisely position the motion-sensitive areas and help locate myocardial injury. © 2017, Wiley Periodicals, Inc.

Assessment of myocardial viability: comparison of echocardiography versus cardiac magnetic resonance imaging in the current era.

PubMed

Tomlinson, David R; Becher, Harald; Selvanayagam, Joseph B

2008-06-01

Detecting viable myocardium, whether hibernating or stunned, is of clinical significance in patients with coronary artery disease and left ventricular dysfunction. Echocardiographic assessments of myocardial thickening and endocardial excursion during dobutamine infusion provide a highly specific marker for myocardial viability, but with relatively less sensitivity. The additional modalities of myocardial contrast echocardiography and tissue Doppler have recently been proposed to provide further, quantitative measures of myocardial viability assessment. Cardiac magnetic resonance (CMR) has become popular for the assessment of myocardial viability as it can assess cardiac function, volumes, myocardial scar, and perfusion with high-spatial resolution. Both 'delayed enhancement' CMR and dobutamine stress CMR have important roles in the assessment of patients with ischaemic cardiomyopathy. This article reviews the recent advances in both echocardiography and CMR for the clinical assessment of myocardial viability. It attempts to provide a pragmatic approach toward the patient-specific assessment of this important clinical problem.

Periodontitis and myocardial hypertrophy.

PubMed

Suzuki, Jun-Ichi; Sato, Hiroki; Kaneko, Makoto; Yoshida, Asuka; Aoyama, Norio; Akimoto, Shouta; Wakayama, Kouji; Kumagai, Hidetoshi; Ikeda, Yuichi; Akazawa, Hiroshi; Izumi, Yuichi; Isobe, Mitsuaki; Komuro, Issei

2017-04-01

There is a deep relationship between cardiovascular disease and periodontitis. It has been reported that myocardial hypertrophy may be affected by periodontitis in clinical settings. Although these clinical observations had some study limitations, they strongly suggest a direct association between severity of periodontitis and left ventricular hypertrophy. However, the detailed mechanisms between myocardial hypertrophy and periodontitis have not yet been elucidated. Recently, we demonstrated that periodontal bacteria infection is closely related to myocardial hypertrophy. In murine transverse aortic constriction models, a periodontal pathogen, Aggregatibacter actinomycetemcomitans markedly enhanced cardiac hypertrophy with matrix metalloproteinase-2 activation, while another pathogen Porphyromonas gingivalis (P.g.) did not accelerate these pathological changes. In the isoproterenol-induced myocardial hypertrophy model, P.g. induced myocardial hypertrophy through Toll-like receptor-2 signaling. From our results and other reports, regulation of chronic inflammation induced by periodontitis may have a key role in the treatment of myocardial hypertrophy. In this article, we review the pathophysiological mechanism between myocardial hypertrophy and periodontitis.

Symptoms of acute myocardial infarction: A correlational study of the discrepancy between patients' expectations and experiences.

PubMed

Abed, Mona A; Ali, Raeda M Abu; Abu Ras, Motaz M; Hamdallah, Faten O; Khalil, Amani A; Moser, Debra K

2015-10-01

Patients' responses to acute myocardial infarction symptoms are affected by symptom incongruence, which is the difference between the symptoms they expect to experience and the symptoms they actually experienced during an acute myocardial infarction. To examine the relationship of patients' demographics, clinical characteristics and sources of information about acute myocardial infarction with their symptom expectations, actual experiences and symptom incongruence. Descriptive correlational study. Patients were recruited from ten hospitals in the two most populated cities in Jordan (Amman and Al Zarqa). Jordanian patients with acute myocardial infarction were recruited. Inclusion criteria were age 18 years or older, diagnosis of acute myocardial infarction, oriented, mentally competent and fluent in Arabic. Exclusion criteria were experiencing acute myocardial infarction during a hospitalization or having severe psychiatric illnesses. The Morgan Incongruence of Heart Attack Symptoms Index was used to quantify symptom incongruence and identify patients' expected and experienced acute myocardial infarction symptoms. Patients' information sources about acute myocardial infarction and demographic and clinical characteristics were collected by interview and medical chart review. Patients (N=299) were mostly males (80%) and married (92%). The average age was 56±12.3 years. Patients expected a limited number of acute myocardial infarction symptoms and these expectations were largely confined to typical symptoms and matched their experiences. Patients who were female, elderly, nonsmokers, poorly educated, with low income, and those who were normolipidemic, had no personal or family cardiac history, and were informed about acute myocardial infarction by relatives expected fewer symptoms (mostly typical and atypical) than their counterparts. Elderly patients and those with hyperlipidemia experienced fewer typical symptoms than their counterparts. Patients with ST-elevation myocardial infarction or previous myocardial infarction experienced more symptoms than their counterparts, yet only the former had more typical complaints. Characteristics that improved patients' awareness of AMI symptoms were mostly similar to those that decreased symptom incongruence. Patients' expected and experienced acute myocardial infarction symptoms and symptom incongruence varied according to their demographic and clinical characteristics. Information sources that patients used to learn about acute myocardial infarction may contribute to symptom incongruence. Copyright © 2015 Elsevier Ltd. All rights reserved.

Metformin improves cardiac function in mice with heart failure after myocardial infarction by regulating mitochondrial energy metabolism.

PubMed

Sun, Dan; Yang, Fei

2017-04-29

To investigate whether metformin can improve the cardiac function through improving the mitochondrial function in model of heart failure after myocardial infarction. Male C57/BL6 mice aged about 8 weeks were selected and the anterior descending branch was ligatured to establish the heart failure model after myocardial infarction. The cardiac function was evaluated via ultrasound after 3 days to determine the modeling was successful, and the mice were randomly divided into two groups. Saline group (Saline) received the intragastric administration of normal saline for 4 weeks, and metformin group (Met) received the intragastric administration of metformin for 4 weeks. At the same time, Shame group (Sham) was set up. Changes in cardiac function in mice were detected at 4 weeks after operation. Hearts were taken from mice after 4 weeks, and cell apoptosis in myocardial tissue was detected using TUNEL method; fresh mitochondria were taken and changes in oxygen consumption rate (OCR) and respiratory control rate (RCR) of mitochondria in each group were detected using bio-energy metabolism tester, and change in mitochondrial membrane potential (MMP) of myocardial tissue was detected via JC-1 staining; the expressions and changes in Bcl-2, Bax, Sirt3, PGC-1α and acetylated PGC-1α in myocardial tissue were detected by Western blot. RT-PCR was used to detect mRNA levels in Sirt3 in myocardial tissues. Metformin improved the systolic function of heart failure model rats after myocardial infarction and reduced the apoptosis of myocardial cells after myocardial infarction. Myocardial mitochondrial respiratory function and membrane potential were decreased after myocardial infarction, and metformin treatment significantly improved the mitochondrial respiratory function and mitochondrial membrane potential; Metformin up-regulated the expression of Sirt3 and the activity of PGC-1α in myocardial tissue of heart failure after myocardial infarction. Metformin decreases the acetylation level of PGC-1α through up-regulating Sirt3, mitigates the damage to mitochondrial membrane potential of model of heart failure after myocardial infarction and improves the respiratory function of mitochondria, thus improving the cardiac function of mice. Copyright © 2017. Published by Elsevier Inc.

The effect of captopril and losartan on the electrophysiology of myocardial cells of myocardial ischemia rats.

PubMed

Shi, Xiangmin; Shan, Zhaoling; Yuan, Hongtao; Guo, Hongyang; Wang, Yutang

2014-01-01

This study aims to investigate the effect of captopril and losartan on the electrophysiology of myocardial cells parameters in ventricular vulnerable period and effective refractory period of myocardial ischemia rats. 96 wistar rats were enrolled in the study and divided into six groups: Captopril myocardial ischemia group, losartan myocardial ischemia group, myocardial ischemia control group, captopril normal group, losartan normal group and normal control group (n=16). We observed morphological changes of myocardial tissue in each group. The cardiac electrophysiological parameters in effective refractory period of each group were measured. Creatine kinase (CK), alanine aminotransferase (GOT), lactate dehydrogenase (LDH), the expression of Cardiotrophin 1 (CT-1) and malonaldehyde (MDA) were detected. Compared the losartan and captopril group with the control group, (P<0.05). Losartan and captopril can shorten the ventricular vulnerable period of the normal group and ischemic group. There was no interaction effect between losartan and captopril group and the acute myocardial ischemia group. The effect of losartan and captopril on time window in ventricular vulnerable period showed that compared with the control group (P<0.05). Losartan and captopril had a significant effect on prolonged effective refractory period of normal and ischemic rats. There was no interaction effect between losartan and captopril group and the acute myocardial ischemia group. Compared with the myocardial ischemia control group, CK, GOT, LDH and MDA decreased in captopril and losartan myocardial ischemia groups (P<0.05). Losartan and captopril had a significant effect on prolonged effective refractory period and shorten ventricular vulnerable period, they can also effectively prevent arrhythmias.

Relationship of myocardial hibernation, scar, and angiographic collateral flow in ischemic cardiomyopathy with coronary chronic total occlusion.

PubMed

Wang, Li; Lu, Min-Jie; Feng, Lei; Wang, Juan; Fang, Wei; He, Zuo-Xiang; Dou, Ke-Fei; Zhao, Shi-Hua; Yang, Min-Fu

2018-03-07

The relationship between myocardial viability and angiographic collateral flow is not fully elucidated in ischemic cardiomyopathy (ICM) with coronary artery chronic total occlusion (CTO). We aimed to clarify the relationship between myocardial hibernation, myocardial scar, and angiographic collateral flow in these patients. Seventy-one consecutive ICM patients with 122 CTOs and 652 dysfunctional segments within CTO territories were retrospectively analyzed. Myocardial hibernation (perfusion-metabolism mismatch) and the extent of 18 F-fluorodeoxyglucose (FDG) abnormalities were assessed using 99m Tc-sestamibi and 18 F-FDG imaging. Myocardial scar was evaluated by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Collateral flow observed on coronary angiography was assessed using Rentrop classification. In these patients, neither the extent nor frequency of myocardial hibernation or scar was related to the status of collateral flow. Moreover, the matching rate in determining myocardial viability was poor between any 2 imaging indices. The extent of 18 F-FDG abnormalities was linearly related to the extent of LGE rather than myocardial hibernation. Of note, nearly one-third (30.4%) of segments with transmural scar still had hibernating tissue. Hibernation and non-transmural scar had higher sensitivity (63.0% and 66.7%) than collateral flow (37.0%) in predicting global functional improvement. Angiographic collateral cannot accurately predict myocardial viability, and has lower sensitivity in prediction of functional improvement in CTO territories in ICM patients. Hence, assessment of myocardial viability with non-invasive imaging modalities is of importance. Moreover, due to the lack of correlation between myocardial hibernation and scar, these two indices are complementary but not interchangeable.

Myocardial infarction caused by myocardial bridging in a male adolescent athlete.

PubMed

Zhu, Cheng-Gang; Liu, Jun; Liu, Wei-Dong; Xu, Yan-Lu; Wu, Na-Qiong; Guo, Yuan-Lin; Tang, Yi-Da; Jiang, Li-Xin; Li, Jian-Jun

2012-02-01

Myocardial bridging is a common congenital abnormality of a coronary artery, and is usually thought to be a benign anatomical variant. Although rare, previous studies have reported that patients with myocardial bridging may suffer from myocardial ischemia, myocardial infarction (MI), arrhythmias and even sudden death. Here we report the case of an 18-year-old adolescent athlete with myocardial bridging resulting in MI. Coronary angiography revealed 80% luminal narrowing by systolic compression in the proximal and mid segments of the left anterior descending coronary artery, which returned to normal during diastole. We considered that heavy sports might be a potential trigger for his MI attack. Therefore, special attention should be paid to this kind of athlete, especially if adolescent.

Registering myocardial fiber orientations with heart geometry using iterative closest points algorithms

NASA Astrophysics Data System (ADS)

Deng, Dongdong; Jiao, Peifeng; Shou, Guofa; Xia, Ling

2009-10-01

Myocardial electrical excitation propagation is anisotropic, with the most rapid spread of current along the direction of the long axis of the fiber. Fiber orientation is also an important determinant of myocardial mechanics. So myocardial fiber orientations are very important to heart modeling and simulation. Accurately construction of myocardial fiber orientations, however, is still a challenge. The purpose of this paper is to construct a heart geometrical model with myocardial fiber orientations based on CT and 3D laser scanned pictures. The iterative closest points (ICP) algorithms were used to register the fiber orientations with the heart geometry.

Pharmacokinetics of rifampin in Peruvian tuberculosis patients with and without comorbid diabetes or HIV.

PubMed

Requena-Méndez, Ana; Davies, Geraint; Ardrey, Alison; Jave, Oswaldo; López-Romero, Sonia L; Ward, Stephen A; Moore, David A J

2012-05-01

For drug-compliant patients, poor responses to tuberculosis (TB) treatment might be attributable to subtherapeutic drug concentrations. An impaired absorption of rifampin was previously reported for patients with diabetes mellitus (DM) or HIV. The objectives of this study were to determine whether TB drug pharmacokinetics differed in Peruvian TB patients with DM or HIV. In this cross-sectional study, TB patients, recruited from health centers in Lima, Peru, had blood samples taken at 2 and 6 h after directly observed TB drug ingestion, to determine plasma concentrations of rifampin. Of 105 patients, 50 had TB without a comorbidity, 26 had coexistent DM, and 29 had coexistent HIV. Unexpectedly, the overall median 2- and 6-h levels of rifampin were 1.6 and 3.2 mg/liter, respectively, and the time to the peak concentration was 6 h (slow absorber) instead of 2 h (fast absorber) for 61 patients (62.2%). The geometric mean peak concentration of drug in serum (C(max)) was significantly higher in fast absorbers than in slow absorbers (5.0 versus 3.8 mg/liter; P = 0.05). The rifampin C(max) was significantly lower in male patients than in female patients (3.3 versus 6.3 mg/liter; P < 0.001). Neither slow nor fast absorbers with comorbidities (DM or HIV) had significantly different C(max) results compared to those of TB patients without comorbidities. An analysis of variance regression analysis showed that female gender (P < 0.001) and the time to maximum concentration of drug in serum (T(max)) at 2 h (P = 0.012) were independently correlated with increased exposure to rifampin. Most of this Peruvian study population exhibited rifampin pharmacokinetics different from those conventionally reported, with delayed absorption and low plasma concentrations, independent of the presence of an HIV or DM comorbidity.

Myocardial Perfusion and Function Are Distinctly Altered by Sevoflurane Anesthesia in Diet-Induced Prediabetic Rats.

PubMed

van den Brom, Charissa E; Boly, Chantal A; Bulte, Carolien S E; van den Akker, Rob F P; Kwekkeboom, Rick F J; Loer, Stephan A; Boer, Christa; Bouwman, R Arthur

2016-01-01

Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state.

Role of intraspecific competition in the coexistence of mobile populations in spatially extended ecosystems.

PubMed

Yang, Rui; Wang, Wen-Xu; Lai, Ying-Cheng; Grebogi, Celso

2010-06-01

Evolutionary-game based models of nonhierarchical, cyclically competing populations have become paradigmatic for addressing the fundamental problem of species coexistence in spatially extended ecosystems. We study the role of intraspecific competition in the coexistence and find that the competition can strongly promote the coexistence for high individual mobility in the sense that stable coexistence can arise in parameter regime where extinction would occur without the competition. The critical value of the competition rate beyond which the coexistence is induced is found to be independent of the mobility. We derive a theoretical model based on nonlinear partial differential equations to predict the critical competition rate and the boundaries between the coexistence and extinction regions in a relevant parameter space. We also investigate pattern formation and well-mixed spatiotemporal population dynamics to gain further insights into our findings. (c) 2010 American Institute of Physics.

Pollinator Foraging Adaptation and Coexistence of Competing Plants.

PubMed

Revilla, Tomás A; Křivan, Vlastimil

2016-01-01

We use the optimal foraging theory to study coexistence between two plant species and a generalist pollinator. We compare conditions for plant coexistence for non-adaptive vs. adaptive pollinators that adjust their foraging strategy to maximize fitness. When pollinators have fixed preferences, we show that plant coexistence typically requires both weak competition between plants for resources (e.g., space or nutrients) and pollinator preferences that are not too biased in favour of either plant. We also show how plant coexistence is promoted by indirect facilitation via the pollinator. When pollinators are adaptive foragers, pollinator's diet maximizes pollinator's fitness measured as the per capita population growth rate. Simulations show that this has two conflicting consequences for plant coexistence. On the one hand, when competition between pollinators is weak, adaptation favours pollinator specialization on the more profitable plant which increases asymmetries in plant competition and makes their coexistence less likely. On the other hand, when competition between pollinators is strong, adaptation promotes generalism, which facilitates plant coexistence. In addition, adaptive foraging allows pollinators to survive sudden loss of the preferred plant host, thus preventing further collapse of the entire community.

A Study on Coexistence Capability Evaluations of the Enhanced Channel Hopping Mechanism in WBANs

PubMed Central

Wei, Zhongcheng; Sun, Yongmei; Ji, Yuefeng

2017-01-01

As an important coexistence technology, channel hopping can reduce the interference among Wireless Body Area Networks (WBANs). However, it simultaneously brings some issues, such as energy waste, long latency and communication interruptions, etc. In this paper, we propose an enhanced channel hopping mechanism that allows multiple WBANs coexisted in the same channel. In order to evaluate the coexistence performance, some critical metrics are designed to reflect the possibility of channel conflict. Furthermore, by taking the queuing and non-queuing behaviors into consideration, we present a set of analysis approaches to evaluate the coexistence capability. On the one hand, we present both service-dependent and service-independent analysis models to estimate the number of coexisting WBANs. On the other hand, based on the uniform distribution assumption and the additive property of Possion-stream, we put forward two approximate methods to compute the number of occupied channels. Extensive simulation results demonstrate that our estimation approaches can provide an effective solution for coexistence capability estimation. Moreover, the enhanced channel hopping mechanism can significantly improve the coexistence capability and support a larger arrival rate of WBANs. PMID:28098818

Prevalence of myocardial bridging detected with 64-slice multidetector coronary computed tomography angiography in asymptomatic adults.

PubMed

Atar, Eli; Kornowski, Ran; Fuchs, Shmuell; Naftali, Noa; Belenky, Alexander; Bachar, Gil N

2007-10-01

Myocardial bridging is a congenital condition in which a segment of an epicardial artery has an intramural course within the myocardium. The aim of the present study was to evaluate the prevalence of myocardial bridging and the ability of 64-slice coronary computed tomography angiography to identify myocardial bridging in asymptomatic adults. One hundred sixty-nine consecutive asymptomatic subjects underwent 64-row multidetector computed tomography (MDCT) of the coronary arteries. Two experienced CT radiologists identified myocardial bridging >1 mm in thickness, by consensus. We examined the frequency of myocardial bridging and evaluated the length, thickness, and coronary wall lesions. Myocardial bridges were found in 28 (17%) of 165 subjects. Twenty-one subjects (75%) had 1 bridge and 7 subjects (25%) had 2, for a total of 35 myocardial bridges. Twenty-one bridges (60%) were located in the left anterior descending, 8.5% in the diagonal branch, and 2.8% in the circumflex arteries. The segment beneath the myocardial bridge was always free of coronary wall plaques, but the arterial segment proximal to it had significant coronary wall plaques in 24 cases (68.6%). We found that the incidence of myocardial bridging in asymptomatic adults is 7%, which is in agreement with some pathologic studies in the literature. Our study shows that MDCT of the coronary arteries is a reliable and noninvasive technique, which can accurately locate the site of myocardial bridging, and measure its thickness, course, and length.

Vitexin exerts cardioprotective effect on chronic myocardial ischemia/reperfusion injury in rats via inhibiting myocardial apoptosis and lipid peroxidation.

PubMed

Che, Xia; Wang, Xin; Zhang, Junyan; Peng, Chengfeng; Zhen, Yilan; Shao, Xu; Zhang, Gongliang; Dong, Liuyi

2016-01-01

The aim of this study was to explore the cardioprotective effect of vitexin on chronic myocardial ischemia/reperfusion injury in rats and potential mechanisms. A chronic myocardial ischemia/reperfusion injury model was established by ligating left anterior descending coronary for 60 minutes, and followed by reperfusion for 14 days. After 2 weeks ischemia/reperfusion, cardiac function was measured to assess myocardial injury. The level of ST segment was recorded in different periods by electrocardiograph. The change of left ventricular function and myocardial reaction degree of fibrosis of heart was investigated by hematoxylin and eosin (HE) staining and Sirius red staining. Endothelium-dependent relaxations due to acetylcholine were observed in isolated rat thoracic aortic ring preparation. The blood samples were collected to measure the levels of MDA, the activities of SOD and NADPH in serum. Epac1, Rap1, Bax and Bcl-2 were examined by using Western Blotting. Vitexin exerted significant protective effect on chronic myocardial ischemia/reperfusion injury, improved obviously left ventricular diastolic function and reduced myocardial reactive fibrosis degree in rats of myocardial ischemia. Medium and high-dose vitexin groups presented a significant decrease in Bax, Epac1 and Rap1 production and increase in Bcl-2 compared to the I/R group. It may be related to preventing myocardial cells from apoptosis, improving myocardial diastolic function and inhibiting lipid peroxidation. Vitexin is a cardioprotective herb, which may be a promising useful complementary and alternative medicine for patients with coronary heart disease.

Spatial complementarity and the coexistence of species.

PubMed

Velázquez, Jorge; Garrahan, Juan P; Eichhorn, Markus P

2014-01-01

Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric - ecological pressure - we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each species rather than solely through self-limitation.

Spatial Complementarity and the Coexistence of Species

PubMed Central

Velázquez, Jorge; Garrahan, Juan P.; Eichhorn, Markus P.

2014-01-01

Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric — ecological pressure — we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each species rather than solely through self-limitation. PMID:25532018

Reduction of isoprenaline-induced myocardial TGF-{beta}1 expression and fibrosis in osthole-treated mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Rong; The First Hospital Affiliated to Soochow University, Suzhou 215006, Jiangsu Province; Xue Jie

Peroxisome proliferator-activated receptor (PPAR) {alpha} and PPAR{gamma} ligands can attenuate myocardial fibrosis. Osthole, an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, may be a dual PPAR{alpha}/{gamma} agonist, but there has been no report on its effect on myocardial fibrosis. In the present study, we investigated the inhibitory effect of osthole on myocardial fibrotic formation in mice and its possible mechanisms. A mouse model with myocardial fibrosis was induced by hypodermic injection of isoprenaline while the mice were simultaneously treated with 40 and 80 mg/kg osthole for 40 days. After the addition of osthole, the cardiac weightmore » index and hydroxyproline content in the myocardial tissues were decreased, the degree of collagen accumulation in the heart was improved, and the downregulation of myocardial PPAR{alpha}/{gamma} mRNA expression induced by isoprenaline was reversed. Moreover, the mRNA expression of transforming growth factor (TGF)-{beta}1 and the protein levels of nuclear factor (NF)-{kappa}B and TGF-{beta}1 in the myocardial tissues were decreased. These findings suggest that osthole can prevent isoprenaline-induced myocardial fibrosis in mice, and its mechanisms may be related to the reduction of TGF-{beta}1 expression via the activation of PPAR{alpha}/{gamma} and subsequent inhibition of NF-{kappa}B in myocardial tissues. - Highlights: > Osthole could inhibit the myocardial fibrosis induced by isoprenaline in mice. > The mechanism was related to reduction of TGF-{beta}1 expression in myocardial tissue. > The result of osthole was from the activation of PPAR{alpha}/{gamma} and inhibition of NF-{kappa}B.« less

Conditioning the heart to prevent myocardial reperfusion injury during PPCI

PubMed Central

2012-01-01

For patients presenting with a ST-segment elevation myocardial infarction (STEMI), early myocardial reperfusion by primary percutaneous coronary intervention (PPCI) remains the most effective treatment strategy for limiting myocardial infarct size, preserving left ventricular systolic function, and preventing the onset of heart failure. Recent advances in PCI technology to improve myocardial reperfusion and the introduction of novel anti-platelet and anti-thrombotic agents to maintain the patency of the infarct-related coronary artery continue to optimize PPCI procedure. However, despite these improvements, STEMI patients still experience significant major adverse cardiovascular events. One major contributing factor has been the inability to protect the heart against the lethal myocardial reperfusion injury, which accompanies PPCI. Past attempts to translate cardioprotective strategies, discovered in experimental studies to prevent lethal myocardial reperfusion injury, into the clinical setting of PPCI have been disappointing. However, a number of recent proof-of-concept clinical studies suggest that the heart can be ‘conditioned’ to protect itself against lethal myocardial reperfusion injury, as evidenced by a reduction in myocardial infarct size. This can be achieved using either mechanical (such as ischaemic postconditioning, remote ischaemic preconditioning, therapeutic hypothermia, or hyperoxaemia) or pharmacological (such as cyclosporin-A, natriuretic peptide, exenatide) ‘conditioning’ strategies as adjuncts to PPCI. Furthermore, recent developments in cardiac magnetic resonance (CMR) imaging can provide a non-invasive imaging strategy for assessing the efficacy of these novel adjunctive therapies to PPCI in terms of key surrogate clinical endpoints such as myocardial infarct size, myocardial salvage, left ventricular ejection fraction, and the presence of microvascular obstruction or intramyocardial haemorrhage. In this article, we review the therapeutic potential of ‘conditioning’ to protect the heart against lethal myocardial reperfusion injury in STEMI patients undergoing PPCI. PMID:24062884

Real-time myocardial perfusion imaging for pharmacologic stress testing: added value to single photon emission computed tomography.

PubMed

Korosoglou, Grigorios; Dubart, Alain-Eric; DaSilva, K Gaspar C; Labadze, Nino; Hardt, Stefan; Hansen, Alexander; Bekeredjian, Raffi; Zugck, Christian; Zehelein, Joerg; Katus, Hugo A; Kuecherer, Helmut

2006-01-01

Little is known about the incremental value of real-time myocardial contrast echocardiography (MCE) as an adjunct to pharmacologic stress testing. This study was performed to evaluate the diagnostic value of MCE to detect abnormal myocardial perfusion by technetium Tc 99m sestamibi-single photon emission computed tomography (SPECT) and anatomically significant coronary artery disease (CAD) by angiography. Myocardial contrast echocardiography was performed at rest and during vasodilator stress in consecutive patients (N = 120) undergoing SPECT imaging for known or suspected CAD. Myocardial opacification, wall motion, and tracer uptake were visually analyzed in 12 myocardial segments by 2 pairs of blinded observers. Concordance between the 2 methods was assessed using the kappa statistic. Of 1356 segments, 1025 (76%) were interpretable by MCE, wall motion, and SPECT. Sensitivity of wall motion was 75%, specificity 83%, and accuracy 81% for detecting abnormal myocardial perfusion by SPECT (kappa = 0.53). Myocardial contrast echocardiography and wall motion together yielded significantly higher sensitivity (85% vs 74%, P < .05), specificity of 83%, and accuracy of 85% (kappa = 0.64) for the detection of abnormal myocardial perfusion. In 89 patients who underwent coronary angiography, MCE and wall motion together yielded higher sensitivity (83% vs 64%, P < .05) and accuracy (77% vs 68%, P < .05) but similar specificity (72%) compared with SPECT for the detection of high-grade, stenotic (> or = 75%) coronary lesions. Assessment of myocardial perfusion adds value to conventional stress echocardiography by increasing its sensitivity for the detection of functionally abnormal myocardial perfusion. Myocardial contrast echocardiography and wall motion together provide higher sensitivity and accuracy for detection of CAD compared with SPECT.

Radionuclide imaging in myocardial sarcoidosis. Demonstration of myocardial uptake of /sup 99m/Tc pyrophosphate and gallium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forman, M.B.; Sandler, M.P.; Sacks, G.A.

1983-03-01

A patient had severe congestive cardiomyopathy secondary to myocardial sarcoidosis. The clinical diagnosis was confirmed by radionuclide ventriculography, /sup 201/Tl, /sup 67/Ga, and /sup 99m/Tc pyrophosphate (TcPYP) scintigraphy. Myocardial TcPYP uptake has not been reported previously in sarcoidosis. In this patient, TcPYP was as useful as gallium scanning and thallium imaging in documenting the myocardial process.

Myocardialization of the cardiac outflow tract

NASA Technical Reports Server (NTRS)

van den Hoff, M. J.; Moorman, A. F.; Ruijter, J. M.; Lamers, W. H.; Bennington, R. W.; Markwald, R. R.; Wessels, A.

1999-01-01

During development, the single-circuited cardiac tube transforms into a double-circuited four-chambered heart by a complex process of remodeling, differential growth, and septation. In this process the endocardial cushion tissues of the atrioventricular junction and outflow tract (OFT) play a crucial role as they contribute to the mesenchymal components of the developing septa and valves in the developing heart. After fusion, the endocardial ridges in the proximal portion of the OFT initially form a mesenchymal outlet septum. In the adult heart, however, this outlet septum is basically a muscular structure. Hence, the mesenchyme of the proximal outlet septum has to be replaced by cardiomyocytes. We have dubbed this process "myocardialization." Our immunohistochemical analysis of staged chicken hearts demonstrates that myocardialization takes place by ingrowth of existing myocardium into the mesenchymal outlet septum. Compared to other events in cardiac septation, it is a relatively late process, being initialized around stage H/H28 and being basically completed around stage H/H38. To unravel the molecular mechanisms that are responsible for the induction and regulation of myocardialization, an in vitro culture system in which myocardialization could be mimicked and manipulated was developed. Using this in vitro myocardialization assay it was observed that under the standard culture conditions (i) whole OFT explants from stage H/H20 and younger did not spontaneously myocardialize the collagen matrix, (ii) explants from stage H/H21 and older spontaneously formed extensive myocardial networks, (iii) the myocardium of the OFT could be induced to myocardialize and was therefore "myocardialization-competent" at all stages tested (H/H16-30), (iv) myocardialization was induced by factors produced by, most likely, the nonmyocardial component of the outflow tract, (v) at none of the embryonic stages analyzed was ventricular myocardium myocardialization-competent, and finally, (vi) ventricular myocardium did not produce factors capable of supporting myocardialization. Copyright 1999 Academic Press.

Acute myocardial infarction during l-thyroxine therapy in a patient with intermittent changing axis deviation, permanent atrial fibrillation and without significant coronary stenoses.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-01-07

It has been rarely reported intermittent changing axis deviation also occurs during atrial fibrillation. Intermittent changing axis deviation during acute myocardial infarction and changing axis deviation associated with atrial fibrillation and acute myocardial infarction too have been also rarely reported. It has also been reported acute myocardial infarction during l-thyroxine substitution therapy in a patient with elevated levels of free triiodothyronine and without significant coronary artery stenoses. An acute myocardial infarction due to coronary spasm associated with l-thyroxine therapy has also been reported too. We present a case of changing axis deviation during acute myocardial infarction in a 56-year-old Italian woman with permanent atrial fibrillation and l-thyroxine therapy and without significant coronary stenoses. Also this case focuses attention on changing axis deviation in the presence of atrial fibrillation during acute myocardial infarction and on the possible development of acute myocardial infarction without significant coronary stenoses associated with l-thyroxine therapy.

Myocardial bridges of the coronary arteries in the human fetal heart.

PubMed

Cakmak, Yusuf Ozgür; Cavdar, Safiye; Yalin, Aymelek; Yener, Nuran; Ozdogmus, Omer

2010-09-01

During the last century, many investigators reported on myocardial bridges in the adult human heart. In the present study, 39 human fetal hearts (the mean gestastional age was 30 weeks) were studied for myocardial bridging, and the results were correlated with adult data. Among the 39 (27 male and 12 female) fetal hearts studied, 26 bridges were observed on 18 fetal hearts (46.2%). Ten of the bridges had one myocardial bridge, whereas double myocardial bridges were observed in eight fetal hearts. The most frequent myocardial bridges were observed on the left anterior descending artery (LAD), which had 13 bridges (50%). Eight (30.7%) myocardial bridges were on the diagonal artery, and on the posterior descending artery there were five (19.3%). Myocardial bridges were not observed on the circumflex artery. The data presented in this study may provide potentially useful information for the preoperative evaluation of the newborn and may have a clinical implication for sudden fetal death.

[Nuclear cardiology with new radiopharmaceuticals].

PubMed

Bunko, H

1994-08-01

In the field of nuclear cardiology, 99mTc labeled myocardial perfusion agents such as MIBI, Tetrofosmin and Teboroxime, 111In-antimyosin for imaging of myocardial necrosis, 123I-betamethyl-iodophenylpentadecanoic acid (BMIPP) for imaging of myocardial fatty acid metabolism and 123I-metaiodobenzylguanidine (MIBG) for imaging of myocardial adrenergic function are introduced recently in Japan. Improved image quality and simultaneous evaluation of myocardial perfusion, function and wall motion can be obtained with use of 99mTc labeled myocardial perfusion agents. 111In-antimyosin enables specific imaging of myocardial necrosis which leads to the use for wide variety of heart diseases. Discrepancy of the myocardial perfusion and metabolism in case of stunned myocardium or cardiomyopathy can be evaluated by 123I-BMIPP in conjunction with perfusion agent. Recently wide variety of diseases which may have cardiac adrenergic abnormality are targeted for 123I-MIBG imaging. These new radiopharmaceuticals are expected to be powerful tool for evaluation of the pathophysiology including severity and prognosis and evaluation of the etiology of the various heart diseases.

STM on Gate-Tunable Graphene

NASA Astrophysics Data System (ADS)

Zhang, Yuanbo

2009-03-01

We have successfully performed atomically-resolved scanning tunneling microscopy and spectroscopy (STS) on mechanically exfoliated graphene samples having tunable back-gates. We have discovered that the tunneling spectra of graphene flakes display an unexpected gap-like feature that is pinned to the Fermi level for different gate voltages, and which coexists with another depression in density-of-states that moves with gate voltage. Extensive tests and careful analysis show that the gap-feature is due to phonon-assisted inelastic tunneling, and the depression directly marks the location of the graphene Dirac point. Using tunneling spectroscopy as a new tool, we further probe the local energetic variations of the graphene charge neutral point (Dirac point) to map out spatial electron density inhomogeneities in graphene. Such measurements are two orders of magnitude higher in resolution than previous experiments, and they can be directly correlated with nanometer scale topographic features. Based on our observation of energy-dependent periodic electronic interference patterns, our measurements also reveal the nature of impurity scattering of Dirac fermions in graphene. These results are significant for understanding the sources of electron density inhomogeneity and electron scattering in graphene, and the microscopic causes of graphene electron mobility.

Bacteriophage T5 DNA ejection under pressure.

PubMed

Leforestier, A; Brasilès, S; de Frutos, M; Raspaud, E; Letellier, L; Tavares, P; Livolant, F

2008-12-19

The transfer of the bacteriophage genome from the capsid into the host cell is a key step of the infectious process. In bacteriophage T5, DNA ejection can be triggered in vitro by simple binding of the phage to its purified Escherichia coli receptor FhuA. Using electrophoresis and cryo-electron microscopy, we measure the extent of DNA ejection as a function of the external osmotic pressure. In the high pressure range (7-16 atm), the amount of DNA ejected decreases with increasing pressure, as theoretically predicted and observed for lambda and SPP1 bacteriophages. In the low and moderate pressure range (2-7 atm), T5 exhibits an unexpected behavior. Instead of a unique ejected length, multiple populations coexist. Some phages eject their complete genome, whereas others stop at some nonrandom states that do not depend on the applied pressure. We show that contrarily to what is observed for the phages SPP1 and lambda, T5 ejection cannot be explained as resulting from a simple pressure equilibrium between the inside and outside of the capsid. Kinetics parameters and/or structural characteristics of the ejection machinery could play a determinant role in T5 DNA ejection.

Demographic trade-offs in a neutral model explain death-rate--abundance-rank relationship.

PubMed

Lin, Kui; Zhang, Da-Yong; He, Fangliang

2009-01-01

The neutral theory of biodiversity has been criticized for its neglect of species differences. Yet it is much less heeded that S. P. Hubbell's definition of neutrality allows species to differ in their birth and death rates as long as they have an equal per capita fitness. Using the lottery model of competition we find that fitness equalization through birth-death trade-offs can make species coexist longer than expected for demographically identical species, whereas the probability of monodominance for a species under zero-sum neutral dynamics is equal to its initial relative abundance. Furthermore, if newly arising species in a community survive preferentially they are more likely to slip through the quagmire of rareness, thus creating a strong selective bias favoring their community membership. On the other hand, high-mortality species, once having gained a footing in the community, are more likely to become abundant due to their compensatory high birth rates. This unexpected result explains why a positive association between species abundance and per capita death rate can be seen in tropical-forest communities. An explicit incorporation of interspecific trade-offs between birth and death into the neutral theory increases the theory's realism as well as its predictive power.

The influence of myocardial substrate on ventricular fibrillation waveform: A swine model of acute and postmyocardial infarction

PubMed Central

Indik, Julia H.; Donnerstein, Richard L.; Hilwig, Ronald W.; Zuercher, Mathias; Feigelman, Justin; Kern, Karl B.; Berg, Marc D.; Berg, Robert A.

2009-01-01

Objective In cardiac arrest resulting from ventricular fibrillation, the ventricular fibrillation waveform may be a clue to its duration and predict the likelihood of shock success. However, ventricular fibrillation occurs in different myocardial substrates such as ischemia, heart failure, and structurally normal hearts. We hypothesized that ventricular fibrillation is altered by myocardial infarction and varies from the acute to postmyocardial infarction periods. Design An animal intervention study was conducted with comparison to a control group. Setting This study took place in a university animal laboratory. Subjects Study subjects included 37 swine. Interventions Myocardial infarction was induced by occlusion of the midleft anterior descending artery. Ventricular fibrillation was induced in control swine, acute myocardial infarction swine, and in postmyocardial infarction swine after a 2-wk recovery period. Measurements and Main Results Ventricular fibrillation was recorded in 11 swine with acute myocardial infarction, ten post-myocardial infarction, and 16 controls. Frequency (mean, median, dominant, and bandwidth) and amplitude-related content (slope, slope-amp [slope divided by amplitude], and amplitude–spectrum area) were analyzed. Frequencies at 5 mins of ventricular fibrillation were altered in both acute myocardial infarction (p < .001 for all frequency characteristics) and postmyocardial infarction swine (p = .015 for mean, .002 for median, .002 for dominant frequency, and <.001 for bandwidth). At 5 mins, median frequency was highest in controls, 10.9 ± .4 Hz; lowest in acute myocardial infarction, 8.4 ± .5 Hz; and intermediate in postmyocardial infarction, 9.7 ± .5 Hz (p < .001 for acute myocardial infarction and p = .002 for postmyocardial infarction compared with control). Slope and amplitude–spectrum area were similar among the three groups with a shallow decline after minute 2, whereas slope-amp remained significantly altered for acute myocardial infarction swine at 5 mins (p = .003). Conclusions Ventricular fibrillation frequencies depend on myocardial substrate and evolve from the acute through healing phases of myocardial infarction. Amplitude related measures, however, are similar among these groups. It is unknown how defibrillation may be affected by relying on the ventricular fibrillation waveform without considering myocardial substrate. PMID:18552696

SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

PubMed

Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

2016-01-01

Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

Coronary surgery for unstable angina pectoris. Incidence and mortality of perioperative myocardial infarction.

PubMed Central

Langou, R A; Wiles, J C; Cohen, L S

1978-01-01

The incidence of perioperative myocardial infarction determined by electrocardiogram was examined in 123 consecutive patients having only coronary artery bypass grafting for unstable angina pectoris, at Yale-New Haven Hospital from January 1974 to June 1975. The incidence of myocardial infarction and its mortality were correlated with clinical, haemodynamic, anatomical, and operative factors. Myocardial infarction occurred in 18% of all patients (22/123); 15 inferior, 6 anterior, and 1 anterolateral wall. Three factors appeared to be related to the occurrence of myocardial infarction: left main coronary artery disease (LMCD), (47%, 7/15), increased left ventricular end-diastolic pressure (LVEDP), (27%, 14/52), and cardiopulmonary bypass time more than 60 minutes (24%, 21/88). The mortality of perioperative myocardial infarcation was 13.6% (3/22), while for patients without perioperative myocardial infarction the mortality was 2% (2/101). The overall operative mortality was 4% (5/123). The risk of perioperative myocardial infarction is significantly increased by left main coronary artery disease, increased left ventricular end-diastolic pressure, and cardiopulmonary bypass time more than 60 minutes, in patients undergoing coronary artery surgery for unstable angina pectoris. The mortality of perioperative myocardial infarction is high (13.6%) in patients with unstable angina. PMID:308374

Local sympathetic denervation attenuates myocardial inflammation and improves cardiac function after myocardial infarction in mice

PubMed Central

Ziegler, Karin A; Ahles, Andrea; Wille, Timo; Kerler, Julia; Ramanujam, Deepak; Engelhardt, Stefan

2018-01-01

Abstract Aims Cardiac inflammation has been suggested to be regulated by the sympathetic nervous system (SNS). However, due to the lack of methodology to surgically eliminate the myocardial SNS in mice, neuronal control of cardiac inflammation remains ill-defined. Here, we report a procedure for local cardiac sympathetic denervation in mice and tested its effect in a mouse model of heart failure post-myocardial infarction. Methods and results Upon preparation of the carotid bifurcation, the right and the left superior cervical ganglia were localized and their pre- and postganglionic branches dissected before removal of the ganglion. Ganglionectomy led to an almost entire loss of myocardial sympathetic innervation in the left ventricular anterior wall. When applied at the time of myocardial infarction (MI), cardiac sympathetic denervation did not affect acute myocardial damage and infarct size. In contrast, cardiac sympathetic denervation significantly attenuated chronic consequences of MI, including myocardial inflammation, myocyte hypertrophy, and overall cardiac dysfunction. Conclusion These data suggest a critical role for local sympathetic control of cardiac inflammation. Our model of myocardial sympathetic denervation in mice should prove useful to further dissect the molecular mechanisms underlying cardiac neural control. PMID:29186414

Eriodictyol Attenuates Myocardial Ischemia-Reperfusion Injury through the Activation of JAK2

PubMed Central

Li, Defang; Lu, Ning; Han, Jichun; Chen, Xiaoyu; Hao, Wenjin; Xu, Wenjuan; Liu, Xiaona; Ye, Lei; Zheng, Qiusheng

2018-01-01

Myocardial ischemia-reperfusion (I/R) injury remains the leading risk factor of disability and mortality worldwide. In this study, the myocardial protective effect of eriodictyol (EDT) and the underlying mechanism in an ex vivo model of global myocardial I/R was investigated. After treatment with different concentrations of EDT, the decreased hemodynamic parameters induced by myocardial I/R injury were significantly attenuated by EDT. The elevated levels of IL-6, CRP, IL-8, and TNF-α were effectively reduced by EDT treatment. EDT also remarkably suppressed the levels of Bax and cleaved Caspase-3, and up-regulated the level of Bcl-2 in cardiac tissues from EDT-treated groups. Further studies showed that EDT could increase the levels of p-JAK2 and p-STAT3 in cardiac tissues. Meanwhile, treatment of AG490, a specific inhibitor of JAK2, abolished the protective effect of EDT on hemodynamic parameters, myocardial inflammation and myocardial cell apoptosis induced by I/R injury. These results demonstrated that EDT could protect against myocardial I/R injury through the activation of JAK2, providing a potential treatment with EDT during myocardial I/R injury. PMID:29441020

[Clinical implications and angiographic and electrocardiographic correlation of ST segment elevation in leads V7-V9 in patients with ST elevation myocardial infarction].

PubMed

Adawi, Khaled; Atar, Shaul

2008-07-01

The clinical significance and clinical characteristics of patients with myocardial infarction involving the posterior wall of the left ventricle is not well-defined. The angiographic findings and their correlation with the eletrocardiographic (ECG) findings may be of high therapeutic importance. We retrospectively studied consecutive patients with ST elevation myocardial infarction on the admission ECG to the intensive cardiac care. We studied the clinical and demographic characteristics, the clinical course in-hospital and the clinical outcome (including infarct size, congestive heart failure and significant mitral insufficiency). All patients underwent coronary angiography during the index admission. We correlated the ECG findings on admission to the angiographic findings. We studied 198 patients with mean age of 57 +/- 12 years (range 30-88 years), 158 men (79.8%) and 40 women (20.2%). Myocardial infarction involving the inferior wall was noted in 119 patients, of whom 68 had inferior wall myocardial infarction only, and 51 had inferior and lateral wall involvement (leads I, AVL and/or V5-V6). Only 4 patients (2%) had ST elevation in leads V7-V9 only. The left ventricular ejection fraction was lowest in patients with anterior wall myocardial infarction (41% +/- 6) compared to myocardial infarction with the posterior wall involved (44% +/- 8) or myocardial infarction with the inferior wall only (54% +/- 6) (p = 0.023). The largest infarct size by peak creatine phosphokinase was found in the inferoposterior myocardial infarction group, significantly larger from inferior infarction only, and similar to that of anterior myocardial infarction. The incidence of congestive heart failure was slightly more in anterior myocardial infarction; however, significant mitral valve insufficiency was higher in patients with posterior wall involvement, yet with no statistical significance. The infarct related artery causing posterior myocardial infarction was significantly more frequent in the right coronary artery (57.1%) compared to the left circumflex artery (37.5%) (p < 0.01). The major artery causing involvement of the posterior wall is the right coronary artery. In patients with myocardial infarction involving the posterior wall, infarct size is similar to that of anterior wall myocardial infarction, and with similar complications rate. However, the incidence of significant mitral valve insufficiency and congestive heart failure is high in patients with posterior wall involvement. Posterior leads assessment should be conducted routinely in patients with suspected myocardial infarction.

In vivo characterization of acute myocardial ischemia using photoacoustic imaging with a focused transducer

NASA Astrophysics Data System (ADS)

Li, Zhifang; Chen, Haiyu; Xie, Wengming; Li, Hui

2011-03-01

We explore the feasibility of using photoacoustic imaging based on a focused transducer to characterizing acute myocardial ischemia at different stage. In this study, we blocked rat left anterior coronary descending artery (LAD) to induce the acute myocardial ischemia. The results show that the intensity and areas of photoacoustic images of myocardial decrease with the LAD time increasing, which suggests that photoacoustic imaging has a potential for diagnosis of acute myocardial ischemia.

Chagas' heart disease: gender differences in myocardial damage assessed by cardiovascular magnetic resonance.

PubMed

Assunção, Antonildes N; Jerosch-Herold, Michael; Melo, Rodrigo L; Mauricio, Alejandra V; Rocha, Liliane; Torreão, Jorge A; Fernandes, Fabio; Ianni, Barbara M; Mady, Charles; Ramires, José A F; Kalil-Filho, Roberto; Rochitte, Carlos E

2016-11-28

Since a male-related higher cardiovascular morbidity and mortality in patients with Chagas' heart disease has been reported, we aimed to investigate gender differences in myocardial damage assessed by cardiovascular magnetic resonance (CMR). Retrospectively, 62 seropositive Chagas' heart disease patients referred to CMR (1.5 T) and with low probability of having significant coronary artery disease were included in this analysis. Amongst both sexes, there was a strong negative correlation between LV ejection fraction and myocardial fibrosis (male r = 0.64, female r = 0.73, both P < 0.001), with males showing significantly greater myocardial fibrosis (P = 0.002) and lower LV ejection fraction (P < 0.001) than females. After adjustment for potential confounders, gender remained associated with myocardial dysfunction, and 53% of the effect was mediated by myocardial fibrosis (P for mediation = 0.004). Also, the transmural pattern was more prevalent among male patients (23.7 vs. 9.9%, P < 0.001) as well as the myocardial heterogeneity or gray zone (2.2 vs. 1.3 g, P = 0.003). We observed gender-related differences in myocardial damage assessed by CMR in patients with Chagas' heart disease. As myocardial fibrosis and myocardial dysfunction are associated to cardiovascular outcomes, our findings might help to understand the poorer prognosis observed in males in Chagas' disease.

Vitexin exerts cardioprotective effect on chronic myocardial ischemia/reperfusion injury in rats via inhibiting myocardial apoptosis and lipid peroxidation

PubMed Central

Che, Xia; Wang, Xin; Zhang, Junyan; Peng, Chengfeng; Zhen, Yilan; Shao, Xu; Zhang, Gongliang; Dong, Liuyi

2016-01-01

Purpose: The aim of this study was to explore the cardioprotective effect of vitexin on chronic myocardial ischemia/reperfusion injury in rats and potential mechanisms. Methods: A chronic myocardial ischemia/reperfusion injury model was established by ligating left anterior descending coronary for 60 minutes, and followed by reperfusion for 14 days. After 2 weeks ischemia/reperfusion, cardiac function was measured to assess myocardial injury. The level of ST segment was recorded in different periods by electrocardiograph. The change of left ventricular function and myocardial reaction degree of fibrosis of heart was investigated by hematoxylin and eosin (HE) staining and Sirius red staining. Endothelium-dependent relaxations due to acetylcholine were observed in isolated rat thoracic aortic ring preparation. The blood samples were collected to measure the levels of MDA, the activities of SOD and NADPH in serum. Epac1, Rap1, Bax and Bcl-2 were examined by using Western Blotting. Results: Vitexin exerted significant protective effect on chronic myocardial ischemia/reperfusion injury, improved obviously left ventricular diastolic function and reduced myocardial reactive fibrosis degree in rats of myocardial ischemia. Medium and high-dose vitexin groups presented a significant decrease in Bax, Epac1 and Rap1 production and increase in Bcl-2 compared to the I/R group. It may be related to preventing myocardial cells from apoptosis, improving myocardial diastolic function and inhibiting lipid peroxidation. Conclusions: Vitexin is a cardioprotective herb, which may be a promising useful complementary and alternative medicine for patients with coronary heart disease. PMID:27648122

Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand

PubMed Central

Kuesap, Jiraporn; Chaijaroenkul, W.; Rungsihirunrat, K.; Pongjantharasatien, K.; Na-Bangchang, Kesara

2015-01-01

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and α-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and α-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients. PMID:26174819

Pollinator Foraging Adaptation and Coexistence of Competing Plants

PubMed Central

Revilla, Tomás A.; Křivan, Vlastimil

2016-01-01

We use the optimal foraging theory to study coexistence between two plant species and a generalist pollinator. We compare conditions for plant coexistence for non-adaptive vs. adaptive pollinators that adjust their foraging strategy to maximize fitness. When pollinators have fixed preferences, we show that plant coexistence typically requires both weak competition between plants for resources (e.g., space or nutrients) and pollinator preferences that are not too biased in favour of either plant. We also show how plant coexistence is promoted by indirect facilitation via the pollinator. When pollinators are adaptive foragers, pollinator’s diet maximizes pollinator’s fitness measured as the per capita population growth rate. Simulations show that this has two conflicting consequences for plant coexistence. On the one hand, when competition between pollinators is weak, adaptation favours pollinator specialization on the more profitable plant which increases asymmetries in plant competition and makes their coexistence less likely. On the other hand, when competition between pollinators is strong, adaptation promotes generalism, which facilitates plant coexistence. In addition, adaptive foraging allows pollinators to survive sudden loss of the preferred plant host, thus preventing further collapse of the entire community. PMID:27505254

Experimental evidence that evolutionary relatedness does not affect the ecological mechanisms of coexistence in freshwater green algae.

PubMed

Narwani, Anita; Alexandrou, Markos A; Oakley, Todd H; Carroll, Ian T; Cardinale, Bradley J

2013-11-01

The coexistence of competing species depends on the balance between their fitness differences, which determine their competitive inequalities, and their niche differences, which stabilise their competitive interactions. Darwin proposed that evolution causes species' niches to diverge, but the influence of evolution on relative fitness differences, and the importance of both niche and fitness differences in determining coexistence have not yet been studied together. We tested whether the phylogenetic distances between species of green freshwater algae determined their abilities to coexist in a microcosm experiment. We found that niche differences were more important in explaining coexistence than relative fitness differences, and that phylogenetic distance had no effect on either coexistence or on the sizes of niche and fitness differences. These results were corroborated by an analysis of the frequency of the co-occurrence of 325 pairwise combinations of algal taxa in > 1100 lakes across North America. Phylogenetic distance may not explain the coexistence of freshwater green algae. © 2013 John Wiley & Sons Ltd/CNRS.

Zealotry promotes coexistence in the rock-paper-scissors model of cyclic dominance

NASA Astrophysics Data System (ADS)

Verma, Gunjan; Chan, Kevin; Swami, Ananthram

2015-11-01

Cyclic dominance models, such as the classic rock-paper-scissors (RPS) game, have found real-world applications in biology, ecology, and sociology. A key quantity of interest in such models is the coexistence time, i.e., the time until at least one population type goes extinct. Much recent research has considered conditions that lengthen coexistence times in an RPS model. A general finding is that coexistence is promoted by localized spatial interactions (low mobility), while extinction is fostered by global interactions (high mobility). That is, there exists a mobility threshold which separates a regime of long coexistence from a regime of rapid collapse of coexistence. The key finding of our paper is that if zealots (i.e., nodes able to defeat others while themselves being immune to defeat) of even a single type exist, then system coexistence time can be significantly prolonged, even in the presence of global interactions. This work thus highlights a crucial determinant of system survival time in cyclic dominance models.

Recent Advances in Cardiovascular Magnetic Resonance Techniques and Applications

PubMed Central

Salerno, Michael; Sharif, Behzad; Arheden, Håkan; Kumar, Andreas; Axel, Leon; Li, Debiao; Neubauer, Stefan

2018-01-01

Cardiovascular magnetic resonance imaging has become the gold standard for evaluating myocardial function, volumes, and scarring. Additionally, cardiovascular magnetic resonance imaging is unique in its comprehensive tissue characterization, including assessment of myocardial edema, myocardial siderosis, myocardial perfusion, and diffuse myocardial fibrosis. Cardiovascular magnetic resonance imaging has become an indispensable tool in the evaluation of congenital heart disease, heart failure, cardiac masses, pericardial disease, and coronary artery disease. This review will highlight some recent novel cardiovascular magnetic resonance imaging techniques, concepts, and applications. PMID:28611116

Bayesian and “Anti-Bayesian” Biases in Sensory Integration for Action and Perception in the Size–Weight Illusion

PubMed Central

Brayanov, Jordan B.

2010-01-01

Which is heavier: a pound of lead or a pound of feathers? This classic trick question belies a simple but surprising truth: when lifted, the pound of lead feels heavier—a phenomenon known as the size–weight illusion. To estimate the weight of an object, our CNS combines two imperfect sources of information: a prior expectation, based on the object's appearance, and direct sensory information from lifting it. Bayes' theorem (or Bayes' law) defines the statistically optimal way to combine multiple information sources for maximally accurate estimation. Here we asked whether the mechanisms for combining these information sources produce statistically optimal weight estimates for both perceptions and actions. We first studied the ability of subjects to hold one hand steady when the other removed an object from it, under conditions in which sensory information about the object's weight sometimes conflicted with prior expectations based on its size. Since the ability to steady the supporting hand depends on the generation of a motor command that accounts for lift timing and object weight, hand motion can be used to gauge biases in weight estimation by the motor system. We found that these motor system weight estimates reflected the integration of prior expectations with real-time proprioceptive information in a Bayesian, statistically optimal fashion that discounted unexpected sensory information. This produces a motor size–weight illusion that consistently biases weight estimates toward prior expectations. In contrast, when subjects compared the weights of two objects, their perceptions defied Bayes' law, exaggerating the value of unexpected sensory information. This produces a perceptual size–weight illusion that biases weight perceptions away from prior expectations. We term this effect “anti-Bayesian” because the bias is opposite that seen in Bayesian integration. Our findings suggest that two fundamentally different strategies for the integration of prior expectations with sensory information coexist in the nervous system for weight estimation. PMID:20089821

Toxic Myocarditis Caused by Acetaminophen in a Multidrug Overdose.

PubMed

Gosselin, Maxime; Dazé, Yann; Mireault, Pascal; Crahes, Marie

2017-12-01

We report the case of an 18-year-old woman with personality disorders who was hospitalized a few hours after suicidal ingestion of acetaminophen, quetiapine, acetylsalicylic acid, and ethanol. Twelve hours after admission, severe liver damage was evident, but the patient was stable and awaiting hepatic transplantation. Electrolytes were successfully controlled. The condition of the liver stabilized. Cardiac biomarkers then deteriorated unexpectedly. Localized ST-segment elevations were noted on electrocardiogram, but angiography ruled out myocardial infarction. A computed tomographic scan ruled out cerebral edema. The patient died of irreversible cardiac arrest 40 hours after admission. Heart failure remained unexplained, and the body underwent forensic autopsy.At autopsy, histologic findings were indicative of acute toxic myocarditis and were concluded to be caused by acetaminophen intoxication. Acetaminophen overdose is common and typically leads to liver failure requiring supportive treatment and emergency liver transplantation. Toxic myocarditis is an extremely rare complication of acetaminophen overdose. It has only been reported 4 times in the literature despite the widespread use and misuse of acetaminophen. Toxic myocarditis remains a possibility in many cases of overdose but can be overlooked in a clinical picture dominated by hepatorenal failure and encephalopathy. Clinicians and forensic pathologists should be aware of this rare potential complication.

Early detection of myocardial infarction following blunt chest trauma by computed tomography: a case report.

PubMed

Lee, Thung-Lip; Hsuan, Chin-Feng; Shih, Chen-Hsiang; Liang, Huai-Wen; Tsai, Hsing-Shan; Tseng, Wei-Kung; Hsu, Kwan-Lih

2017-02-10

Blunt cardiac trauma encompasses a wide range of clinical entities, including myocardial contusion, cardiac rupture, valve avulsion, pericardial injuries, arrhythmia, and even myocardial infarction. Acute myocardial infarction due to coronary artery dissection after blunt chest trauma is rare and may be life threatening. Differential diagnosis of acute myocardial infarction from cardiac contusion at this setting is not easy. Here we demonstrated a case of blunt chest trauma, with computed tomography detected myocardium enhancement defect early at emergency department. Under the impression of acute myocardial infarction, emergent coronary angiography revealed left anterior descending artery occlusion. Revascularization was performed and coronary artery dissection was found after thrombus aspiration. Finally, the patient survived after coronary stenting. Perfusion defects of myocardium enhancement on CT after blunt chest trauma can be very helpful to suggest myocardial infarction and facilitate the decision making of emergent procedure. This valuable sign should not be missed during the initial interpretation.

Imaging and Modeling of Myocardial Metabolism

PubMed Central

Jamshidi, Neema; Karimi, Afshin; Birgersdotter-Green, Ulrika; Hoh, Carl

2010-01-01

Current imaging methods have focused on evaluation of myocardial anatomy and function. However, since myocardial metabolism and function are interrelated, metabolic myocardial imaging techniques, such as positron emission tomography, single photon emission tomography, and magnetic resonance spectroscopy present novel opportunities for probing myocardial pathology and developing new therapeutic approaches. Potential clinical applications of metabolic imaging include hypertensive and ischemic heart disease, heart failure, cardiac transplantation, as well as cardiomyopathies. Furthermore, response to therapeutic intervention can be monitored using metabolic imaging. Analysis of metabolic data in the past has been limited, focusing primarily on isolated metabolites. Models of myocardial metabolism, however, such as the oxygen transport and cellular energetics model and constraint-based metabolic network modeling, offer opportunities for evaluation interactions between greater numbers of metabolites in the heart. In this review, the roles of metabolic myocardial imaging and analysis of metabolic data using modeling methods for expanding our understanding of cardiac pathology are discussed. PMID:20559785

Myocardial infarction increases progressive visual field defects in well treated early primary open angle glaucoma--a prospective case control study.

PubMed

Mondal, Lakshmikanta; Baidya, Krishnapada; Choudhury, Himadri; Roy, Rupam

2013-06-01

The purpose of the study was to evaluate the progression of glaucomatous field damage in patients with stable primary open angle glaucoma after an attack of myocardial infarction. In this case control study, 62 open angle glaucoma patients were selected and regularly followed up. Among 62 patients, 9 had an attack of myocardial infarction. The intra-ocular pressure and visual field progression of both the groups (myocardial infarction versus no myocardial infarction) were analysed. Three (33.3%) out of 9 patients who had suffered from myocardial infarction showed progressive visual field loss whereas only 9 (16.9%) out of 53 patients who did not suffer from myocardial infarction, showed progressive field changes. Both the groups had stable target intra-ocular pressure between 14 and 16 mm Hg. Myocardial infarction may adversely influence the progression of primary open angle glaucoma which is suspected to result from ischaemia induced neuronal loss and only control of intraocular pressure is not the only solution. We have to look for other drugs that prevents ischaemia induced neuronal damage.

Both Selenium Deficiency and Modest Selenium Supplementation Lead to Myocardial Fibrosis in Mice via Effects on Redox-Methylation Balance

PubMed Central

Metes-Kosik, Nicole; Luptak, Ivan; DiBello, Patricia M.; Handy, Diane E.; Tang, Shiow-Shih; Zhi, Hui; Qin, Fuzhong; Jacobsen, Donald W.; Loscalzo, Joseph; Joseph, Jacob

2013-01-01

Scope Selenium has complex effects in vivo on multiple homeostatic mechanisms such as redox balance, methylation balance, and epigenesis, via its interaction with the methionine-homocysteine cycle. In this study, we examined the hypothesis that selenium status would modulate both redox and methylation balance and thereby modulate myocardial structure and function. Methods and Results We examined the effects of selenium deficient (<0.025 mg/kg), control (0.15 mg/kg), and selenium supplemented (0.5 mg/kg) diets on myocardial histology, biochemistry and function in adult C57/BL6 mice. Selenium deficiency led to reactive myocardial fibrosis and systolic dysfunction accompanied by increased myocardial oxidant stress. Selenium supplementation significantly reduced methylation potential, DNA methyltransferase activity and DNA methylation. In mice fed the supplemented diet, inspite of lower oxidant stress, myocardial matrix gene expression was significantly altered resulting in reactive myocardial fibrosis and diastolic dysfunction in the absence of myocardial hypertrophy. Conclusions Our results indicate that both selenium deficiency and modest selenium supplementation leads to a similar phenotype of abnormal myocardial matrix remodeling and dysfunction in the normal heart. The crucial role selenium plays in maintaining the balance between redox and methylation pathways needs to be taken into account while optimizing selenium status for prevention and treatment of heart failure. PMID:23097236

[Myocardial ultrastructural changes in rats following different levels of acute +Gz exposure].

PubMed

Zheng, Jun; Liu, Cheng-gang; Ren, Li; Xiao, Xiao-guang; Xu, Shu-xuan; Wang, Ping; Ji, Gui-ying

2004-06-01

To observe the effects of different levels of acute +Gz exposure on myocardial ultrastructure of rats and provide experimental basis for further development of anti-G measures. Twenty male Wistar rats were randomly divided into 4 groups (n=5): normal control group, +20 Gz group, +10 Gz group and +5 Gz group. Profile of the centrifuge +Gz exposure was trapezoidal, in which +20 Gz lasted for 30 s, +10 Gz for 1.5 min. +5 Gz exposure was repeated for 3 times with 30 min interval and each for 1.5 min. Myocardial tissue of left ventricle was sampled for transmission electron microscopy 5 h after exposure. +20 Gz and +10 Gz exposure caused obvious edema of myocardial and endothelial cells, myofibril disorder and injuries of mitochondria and nucleus. Breaks of myocardial fiber, formation of contraction bands and rupture of mitochondria were also observed in +20 Gz group. In +5 Gz group, there was still slight edema of myocardial and endothelial cells, while organic changes of myocardial ultrastructure were not observed. High +Gz exposure can cause myocardial ultrastructural injury in rats. Slight reversible injured response can also be observed in myocardial cell after repeated moderate level of +Gz exposure. This indicates that attention should be paid to the study of the effect of high +Gz on heart in pilots.

Effect of beta-adrenergic blockade with timolol on myocardial blood flow during exercise after myocardial infarction in the dog.

PubMed

Herzog, C A; Aeppli, D P; Bache, R J

1984-12-01

The effect of beta-adrenergic blockade with timolol (40 micrograms/kg) on myocardial blood flow during rest and graded treadmill exercise was assessed in 12 chronically instrumented dogs 10 to 14 days after myocardial infarction was produced by acute left circumflex coronary artery occlusion. During exercise at comparable external work loads, the heart rate-systolic blood pressure product was significantly decreased after timilol, with concomitant reductions of myocardial blood flow in normal, border and central ischemic areas (p less than 0.001) and increases in subendocardial/subepicardial blood flow ratios (p less than 0.05). In addition to the blunted chronotropic response to exercise, timolol exerted an effect on myocardial blood flow that was not explained by changes in heart rate or blood pressure. At comparable rate-pressure products during exercise, total myocardial blood flow was 24% lower after timolol (p less than 0.02) and flow was redistributed from subepicardium to subendocardium in all myocardial regions. Thus, timolol altered myocardial blood flow during exercise by two separate mechanisms: a negative chronotropic effect, and a significant selective reduction of subepicardial perfusion independent of changes in heart rate or blood pressure with transmural redistribution of flow toward the subendocardium.

Ilexsaponin A attenuates ischemia-reperfusion-induced myocardial injury through anti-apoptotic pathway.

PubMed

Zhang, Shuang-Wei; Liu, Yu; Wang, Fang; Qiang, Jiao; Liu, Pan; Zhang, Jun; Xu, Jin-Wen

2017-01-01

The protective effects of ilexsaponin A on ischemia-reperfusion-induced myocardial injury were investigated. Myocardial ischemia/reperfusion model was established in male Sprague-Dawley rats. Myocardial injury was evaluated by TTC staining and myocardial marker enzyme leakage. The in vitro protective potential of Ilexsaponin A was assessed on hypoxia/reoxygenation cellular model in neonatal rat cardiomyocytes. Cellular viability and apoptosis were evaluated by MTT and TUNEL assay. Caspase-3, cleaved caspase-3, bax, bcl-2, p-Akt and Akt protein expression levels were detected by western-blot. Ilexsaponin A treatment was able to attenuate the myocardial injury in ischemia/reperfusion model by reducing myocardial infarct size and lower the serum levels of LDH, AST and CK-MB. The in vitro study also showed that ilexsaponin A treatment could increase cellular viability and inhibit apoptosis in hypoxia/reoxygenation cardiomyocytes. Proapoptotic proteins including caspase-3, cleaved caspase-3 and bax were significantly reduced and anti-apoptotic protein bcl-2 was significantly increased by ilexsaponin A treatment in hypoxia/reoxygenation cardiomyocytes. Moreover, Ilexsaponin A treatment was able to increase the expression levels of p-Akt in hypoxia/reoxygenation cellular model and myocardial ischemia/reperfusion animal model. Coupled results from both in vivo and in vitro experiments indicate that Ilexsaponin A attenuates ischemia-reperfusion-induced myocardial injury through anti-apoptotic pathway.

Increase in mean platelet volume in patients with myocardial bridge.

PubMed

Bilen, Emine; Tanboga, Ibrahim Halil; Kurt, Mustafa; Kocak, Umran; Ayhan, Huseyin; Keles, Telat; Bozkurt, Engin

2013-01-01

Myocardial bridge is associated with atherosclerosis altered in shear stress and endothelial dysfunction. Mean platelet volume (MPV), a determinant of platelet activation, is shown to be related with atherosclerosis and endothelial dysfunction. In this study, we aimed to evaluate platelet function assessed by MPV in patients with myocardial bridge. Forty-two patients with myocardial bridge in the left anterior descending artery (LAD) and 43 age- and gender-matched healthy participants were included in the study. Myocardial bridging was defined as an intramyocardial systolic compression or milking of a segment of an epicardial coronary artery on angiography. For the entire study population, MPV was measured using an automatic blood counter. The study population consisted of 42 patients with myocardial bridge (52.7 ± 10.2, 76.2% male) and 43 age- and sex-matched healthy control participants (52.1 ± 10.4, 74.4% male). Compared to the control group, MPV value was significantly higher in patients with myocardial bridge (8.9 ± 1.24 vs 8.3 ± 0.78; P = .01). Further, there were no significant differences between groups regarding hemoglobin level, platelet count, fasting blood glucose, and creatinine levels. Our study findings indicated that myocardial bridge is associated with elevated MPV values. Our results might partly explain the increased cardiovascular events in patients with myocardial bridge.

Changing the diagnostic criteria for myocardial infarction in patients with a suspected heart attack affects the measurement of 30 day mortality but not long term survival

PubMed Central

Packham, C; Gray, D; Weston, C; Large, A; Silcocks, P; Hampton, J

2002-01-01

Objectives: To explore the effects of alternative methods of defining myocardial infarction on the numbers and survival patterns of patients identified as having sustained a confirmed myocardial infarct. Design: An inclusive historical cohort of patients admitted with a suspected heart attack. Patients were recoded from raw clinical data (collected at the index admission) to the epidemiological definitions of myocardial infarction used by the Nottingham heart attack register (NHAR), the World Health Organization (MONICA), and the UK heart attack study. Setting: Single health district. Patients: The NHAR identified all patients admitted in 1992 with suspected myocardial infarction. Outcome measures: Survival at 30 days and four year postdischarge. Results: 2739 patients were identified, of whom 90% survived to discharge. Recoding increased the numbers of patients defined as having confirmed myocardial infarction from 26% under the original NHAR classification to 69%, depending on the classification system used. In confirmed myocardial infarction, subsequent 30 day survival from admission varied from 77–86% depending on the classification system; four year survival after discharge was not affected. The distribution of important prognostic variables differed significantly between groups of patients with confirmed myocardial infarction defined by different systems. Patients with suspected but unconfirmed myocardial infarction under all classification systems had a worse postdischarge mortality. Conclusions: The classification system used had a substantial effect on the numbers of patients identified as having had a myocardial infarct, and on the 30 day survival. There were significant numbers of patients with more atypical presentations, not labelled as myocardial infarction, who did badly following discharge. More research is needed on these patients. PMID:12231586

Cardiac-Specific SOCS3 Deletion Prevents In Vivo Myocardial Ischemia Reperfusion Injury through Sustained Activation of Cardioprotective Signaling Molecules.

PubMed

Nagata, Takanobu; Yasukawa, Hideo; Kyogoku, Sachiko; Oba, Toyoharu; Takahashi, Jinya; Nohara, Shoichiro; Minami, Tomoko; Mawatari, Kazutoshi; Sugi, Yusuke; Shimozono, Koutatsu; Pradervand, Sylvain; Hoshijima, Masahiko; Aoki, Hiroki; Fukumoto, Yoshihiro; Imaizumi, Tsutomu

2015-01-01

Myocardial ischemia reperfusion injury (IRI) adversely affects cardiac performance and the prognosis of patients with acute myocardial infarction. Although myocardial signal transducer and activator of transcription (STAT) 3 is potently cardioprotective during IRI, the inhibitory mechanism responsible for its activation is largely unknown. The present study aimed to investigate the role of the myocardial suppressor of cytokine signaling (SOCS)-3, an intrinsic negative feedback regulator of the Janus kinase (JAK)-STAT signaling pathway, in the development of myocardial IRI. Myocardial IRI was induced in mice by ligating the left anterior descending coronary artery for 1 h, followed by different reperfusion times. One hour after reperfusion, the rapid expression of JAK-STAT-activating cytokines was observed. We precisely evaluated the phosphorylation of cardioprotective signaling molecules and the expression of SOCS3 during IRI and then induced myocardial IRI in wild-type and cardiac-specific SOCS3 knockout mice (SOCS3-CKO). The activation of STAT3, AKT, and ERK1/2 rapidly peaked and promptly decreased during IRI. This decrease correlated with the induction of SOCS3 expression up to 24 h after IRI in wild-type mice. The infarct size 24 h after reperfusion was significantly reduced in SOCS3-CKO compared with wild-type mice. In SOCS3-CKO mice, STAT3, AKT, and ERK1/2 phosphorylation was sustained, myocardial apoptosis was prevented, and the expression of anti-apoptotic Bcl-2 family member myeloid cell leukemia-1 (Mcl-1) was augmented. Cardiac-specific SOCS3 deletion led to the sustained activation of cardioprotective signaling molecules including and prevented myocardial apoptosis and injury during IRI. Our findings suggest that SOCS3 may represent a key factor that exacerbates the development of myocardial IRI.

Cardiac-Specific SOCS3 Deletion Prevents In Vivo Myocardial Ischemia Reperfusion Injury through Sustained Activation of Cardioprotective Signaling Molecules

PubMed Central

Nagata, Takanobu; Yasukawa, Hideo; Kyogoku, Sachiko; Oba, Toyoharu; Takahashi, Jinya; Nohara, Shoichiro; Minami, Tomoko; Mawatari, Kazutoshi; Sugi, Yusuke; Shimozono, Koutatsu; Pradervand, Sylvain; Hoshijima, Masahiko; Aoki, Hiroki; Fukumoto, Yoshihiro; Imaizumi, Tsutomu

2015-01-01

Myocardial ischemia reperfusion injury (IRI) adversely affects cardiac performance and the prognosis of patients with acute myocardial infarction. Although myocardial signal transducer and activator of transcription (STAT) 3 is potently cardioprotective during IRI, the inhibitory mechanism responsible for its activation is largely unknown. The present study aimed to investigate the role of the myocardial suppressor of cytokine signaling (SOCS)-3, an intrinsic negative feedback regulator of the Janus kinase (JAK)-STAT signaling pathway, in the development of myocardial IRI. Myocardial IRI was induced in mice by ligating the left anterior descending coronary artery for 1 h, followed by different reperfusion times. One hour after reperfusion, the rapid expression of JAK-STAT–activating cytokines was observed. We precisely evaluated the phosphorylation of cardioprotective signaling molecules and the expression of SOCS3 during IRI and then induced myocardial IRI in wild-type and cardiac-specific SOCS3 knockout mice (SOCS3-CKO). The activation of STAT3, AKT, and ERK1/2 rapidly peaked and promptly decreased during IRI. This decrease correlated with the induction of SOCS3 expression up to 24 h after IRI in wild-type mice. The infarct size 24 h after reperfusion was significantly reduced in SOCS3-CKO compared with wild-type mice. In SOCS3-CKO mice, STAT3, AKT, and ERK1/2 phosphorylation was sustained, myocardial apoptosis was prevented, and the expression of anti-apoptotic Bcl-2 family member myeloid cell leukemia-1 (Mcl-1) was augmented. Cardiac-specific SOCS3 deletion led to the sustained activation of cardioprotective signaling molecules including and prevented myocardial apoptosis and injury during IRI. Our findings suggest that SOCS3 may represent a key factor that exacerbates the development of myocardial IRI. PMID:26010537

Pharmacological postconditioning with atorvastatin calcium attenuates myocardial ischemia/reperfusion injury in diabetic rats by phosphorylating GSK3β.

PubMed

Chen, Linyan; Cai, Ping; Cheng, Zhendong; Zhang, Zaibao; Fang, Jun

2017-07-01

Diabetes is an independent risk factor for myocardial ischemia, and many epidemiological data and laboratory studies have revealed that diabetes significantly exacerbated myocardial ischemia/reperfusion injury and ameliorated protective effects. The present study aimed to determine whether pharmacological postconditioning with atorvastatin calcium lessened diabetic myocardial ischemia/reperfusion injury, and investigated the role of glycogen synthase kinase (GSK3β) in this. A total of 72 streptozotocin-induced diabetic rats were randomly divided into six groups, and 24 age-matched male non-diabetic Sprague-Dawley rats were randomly divided into two groups. Rats all received 40 min myocardial ischemia followed by 180 min reperfusion, except sham-operated groups. Compared with the non-diabetic ischemia/reperfusion model group, the diabetic ischemia/reperfusion group had a comparable myocardial infarct size, but a higher level of serum cardiac troponin I (cTnI) and morphological alterations to their myocardial cells. Compared with the diabetic ischemia/reperfusion group, the group that received pharmacological postconditioning with atorvastatin calcium had smaller myocardial infarct sizes, lower levels of cTnI, reduced morphological alterations to myocardial cells, higher levels of p-GSK3β, heat shock factor (HSF)-1 and heat shock protein (HSP)70. The cardioprotective effect conferred by atorvastatin calcium did not attenuate myocardial ischemia/reperfusion injury following application of TDZD-8, which phosphorylates and inactivates GSK3β. Pharmacological postconditioning with atorvastatin calcium may attenuate diabetic heart ischemia/reperfusion injury in the current context. The phosphorylation of GSK3β serves a critical role during the cardioprotection in diabetic rats, and p-GSK3β may accelerate HSP70 production partially by activating HSF-1 during myocardial ischemic/reperfusion injury.

Activation of complement factor B contributes to murine and human myocardial ischemia/reperfusion injury

PubMed Central

Hou, Yunfang; Wong, Karen A.; Lee, Daniel; Rushbrook, Julie I.; Gulaya, Karan; Hines, Roberta; Hollis, Tamika; Nistal Nuno, Beatriz; Mangi, Abeel A.; Hashim, Sabet; Pekna, Marcela; Catalfamo, Amy; Chin, Hsiao-ying; Patel, Foramben; Rayala, Sravani; Shevde, Ketan; Heeger, Peter S.

2017-01-01

The pathophysiology of myocardial injury that results from cardiac ischemia and reperfusion (I/R) is incompletely understood. Experimental evidence from murine models indicates that innate immune mechanisms including complement activation via the classical and lectin pathways are crucial. Whether factor B (fB), a component of the alternative complement pathway required for amplification of complement cascade activation, participates in the pathophysiology of myocardial I/R injury has not been addressed. We induced regional myocardial I/R injury by transient coronary ligation in WT C57BL/6 mice, a manipulation that resulted in marked myocardial necrosis associated with activation of fB protein and myocardial deposition of C3 activation products. In contrast, in fB-/- mice, the same procedure resulted in significantly reduced myocardial necrosis (% ventricular tissue necrotic; fB-/- mice, 20 ± 4%; WT mice, 45 ± 3%; P < 0.05) and diminished deposition of C3 activation products in the myocardial tissue (fB-/- mice, 0 ± 0%; WT mice, 31 ± 6%; P<0.05). Reconstitution of fB-/- mice with WT serum followed by cardiac I/R restored the myocardial necrosis and activated C3 deposition in the myocardium. In translational human studies we measured levels of activated fB (Bb) in intracoronary blood samples obtained during cardio-pulmonary bypass surgery before and after aortic cross clamping (AXCL), during which global heart ischemia was induced. Intracoronary Bb increased immediately after AXCL, and the levels were directly correlated with peripheral blood levels of cardiac troponin I, an established biomarker of myocardial necrosis (Spearman coefficient = 0.465, P < 0.01). Taken together, our results support the conclusion that circulating fB is a crucial pathophysiological amplifier of I/R-induced, complement-dependent myocardial necrosis and identify fB as a potential therapeutic target for prevention of human myocardial I/R injury. PMID:28662037

Activation of complement factor B contributes to murine and human myocardial ischemia/reperfusion injury.

PubMed

Chun, Nicholas; Haddadin, Ala S; Liu, Junying; Hou, Yunfang; Wong, Karen A; Lee, Daniel; Rushbrook, Julie I; Gulaya, Karan; Hines, Roberta; Hollis, Tamika; Nistal Nuno, Beatriz; Mangi, Abeel A; Hashim, Sabet; Pekna, Marcela; Catalfamo, Amy; Chin, Hsiao-Ying; Patel, Foramben; Rayala, Sravani; Shevde, Ketan; Heeger, Peter S; Zhang, Ming

2017-01-01

The pathophysiology of myocardial injury that results from cardiac ischemia and reperfusion (I/R) is incompletely understood. Experimental evidence from murine models indicates that innate immune mechanisms including complement activation via the classical and lectin pathways are crucial. Whether factor B (fB), a component of the alternative complement pathway required for amplification of complement cascade activation, participates in the pathophysiology of myocardial I/R injury has not been addressed. We induced regional myocardial I/R injury by transient coronary ligation in WT C57BL/6 mice, a manipulation that resulted in marked myocardial necrosis associated with activation of fB protein and myocardial deposition of C3 activation products. In contrast, in fB-/- mice, the same procedure resulted in significantly reduced myocardial necrosis (% ventricular tissue necrotic; fB-/- mice, 20 ± 4%; WT mice, 45 ± 3%; P < 0.05) and diminished deposition of C3 activation products in the myocardial tissue (fB-/- mice, 0 ± 0%; WT mice, 31 ± 6%; P<0.05). Reconstitution of fB-/- mice with WT serum followed by cardiac I/R restored the myocardial necrosis and activated C3 deposition in the myocardium. In translational human studies we measured levels of activated fB (Bb) in intracoronary blood samples obtained during cardio-pulmonary bypass surgery before and after aortic cross clamping (AXCL), during which global heart ischemia was induced. Intracoronary Bb increased immediately after AXCL, and the levels were directly correlated with peripheral blood levels of cardiac troponin I, an established biomarker of myocardial necrosis (Spearman coefficient = 0.465, P < 0.01). Taken together, our results support the conclusion that circulating fB is a crucial pathophysiological amplifier of I/R-induced, complement-dependent myocardial necrosis and identify fB as a potential therapeutic target for prevention of human myocardial I/R injury.

Toll-like receptor 3 plays a role in myocardial infarction and ischemia/reperfusion injury.

PubMed

Lu, Chen; Ren, Danyang; Wang, Xiaohui; Ha, Tuanzhu; Liu, Li; Lee, Eric J; Hu, Jing; Kalbfleisch, John; Gao, Xiang; Kao, Race; Williams, David; Li, Chuanfu

2014-01-01

Innate immune and inflammatory responses mediated by Toll like receptors (TLRs) have been implicated in myocardial ischemia/reperfusion (I/R) injury. This study examined the role of TLR3 in myocardial injury induced by two models, namely, myocardial infarction (MI) and I/R. First, we examined the role of TLR3 in MI. TLR3 deficient (TLR3(-/-)) and wild type (WT) mice were subjected to MI induced by permanent ligation of the left anterior descending (LAD) coronary artery for 21days. Cardiac function was measured by echocardiography. Next, we examined whether TLR3 contributes to myocardial I/R injury. TLR3(-/-) and WT mice were subjected to myocardial ischemia (45min) followed by reperfusion for up to 3days. Cardiac function and myocardial infarct size were examined. We also examined the effect of TLR3 deficiency on I/R-induced myocardial apoptosis and inflammatory cytokine production. TLR3(-/-) mice showed significant attenuation of cardiac dysfunction after MI or I/R. Myocardial infarct size and myocardial apoptosis induced by I/R injury were significantly attenuated in TLR3(-/-) mice. TLR3 deficiency increases B-cell lymphoma 2 (BCL2) levels and attenuates I/R-increased Fas, Fas ligand or CD95L (FasL), Fas-Associated protein with Death Domain (FADD), Bax and Bak levels in the myocardium. TLR3 deficiency also attenuates I/R-induced myocardial nuclear factor KappaB (NF-κB) binding activity, Tumor necrosis factor alpha (TNF-α) and Interleukin-1 beta (IL-1β) production as well as I/R-induced infiltration of neutrophils and macrophages into the myocardium. TLR3 plays an important role in myocardial injury induced by MI or I/R. The mechanisms involve activation of apoptotic signaling and NF-κB binding activity. Modulation of TLR3 may be an effective approach for ameliorating heart injury in heart attack patients. © 2013.

Cardioprotective Effects of Intracoronary Morphine in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: A Prospective, Randomized Trial.

PubMed

Gwag, Hye Bin; Kim, Eun Kyoung; Park, Taek Kyu; Lee, Joo Myung; Yang, Jeong Hoon; Song, Young Bin; Choi, Jin-Ho; Choi, Seung-Hyuk; Lee, Sang Hoon; Chang, Sung-A; Park, Sung-Ji; Lee, Sang-Chol; Park, Seung Woo; Jang, Woo Jin; Lee, Mirae; Chun, Woo Jung; Oh, Ju Hyeon; Park, Yong Hwan; Choe, Yeon Hyeon; Gwon, Hyeon-Cheol; Hahn, Joo-Yong

2017-04-03

A cardioprotective role of morphine acting via opioid receptors has been demonstrated, and previous preclinical studies have reported that morphine could reduce reperfusion injury and myocardial infarct size in a way similar to that of ischemic periconditioning. This study aimed to evaluate the effect of intracoronary morphine on myocardial infarct size in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. This study was designed as a 2-center, prospective, randomized, open-label, blinded end point trial. A total of 91 ST-elevation myocardial infarction patients with thrombolysis in myocardial infarction flow grade of 0 to 1 undergoing primary percutaneous coronary intervention were randomly assigned to a morphine or control group at a 1:1 ratio. The morphine group received 3 mg of morphine sulfate diluted with 3 mL of normal saline, and the control group received 3 mL of normal saline into a coronary artery immediately after restoration of coronary flow. The primary end point was myocardial infarct size assessed by cardiac magnetic resonance imaging The cardiac magnetic resonance images were evaluated for 42 and 38 patients in the morphine and control groups, respectively. Myocardial infarct size was not different between the 2 groups (25.6±11.2% versus 24.6±10.5%, P =0.77), nor was the extent of microvascular obstruction or myocardial salvage index (6.0±6.3% versus 5.1±4.6%, P =0.91; 31.1±15.2% versus 30.3±10.9%, P =0.75, respectively). There was no difference in peak creatine kinase-MB level, final thrombolysis in myocardial infarction flow, myocardial brush grade, or complete resolution of ST-segment. Intracoronary morphine administration could not reduce myocardial infarct size in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01738100. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Efinaconazole Topical Solution, 10%: Efficacy in Patients with Onychomycosis and Coexisting Tinea Pedis.

PubMed

Markinson, Bryan C; Caldwell, Bryan D

2015-04-13

We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis at baseline, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.

Efinaconazole Topical Solution, 10% Efficacy in Patients with Onychomycosis and Coexisting Tinea Pedis.

PubMed

Markinson, Bryan; Caldwell, Bryan

2015-09-01

We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.

Gause's Principle and the Effect of Resource Partitioning on the Dynamical Coexistence of Replicating Templates

PubMed Central

Szilágyi, András; Zachar, István; Szathmáry, Eörs

2013-01-01

Models of competitive template replication, although basic for replicator dynamics and primordial evolution, have not yet taken different sequences explicitly into account, neither have they analyzed the effect of resource partitioning (feeding on different resources) on coexistence. Here we show by analytical and numerical calculations that Gause's principle of competitive exclusion holds for template replicators if resources (nucleotides) affect growth linearly and coexistence is at fixed point attractors. Cases of complementary or homologous pairing between building blocks with parallel or antiparallel strands show no deviation from the rule that the nucleotide compositions of stably coexisting species must be different and there cannot be more coexisting replicator species than nucleotide types. Besides this overlooked mechanism of template coexistence we show also that interesting sequence effects prevail as parts of sequences that are copied earlier affect coexistence more strongly due to the higher concentration of the corresponding replication intermediates. Template and copy always count as one species due their constraint of strict stoichiometric coupling. Stability of fixed-point coexistence tends to decrease with the length of sequences, although this effect is unlikely to be detrimental for sequences below 100 nucleotides. In sum, resource partitioning (niche differentiation) is the default form of competitive coexistence for replicating templates feeding on a cocktail of different nucleotides, as it may have been the case in the RNA world. Our analysis of different pairing and strand orientation schemes is relevant for artificial and potentially astrobiological genetics. PMID:23990769

On the evidence for species coexistence: a critique of the coexistence program.

PubMed

Siepielski, Adam M; McPeek, Mark A

2010-11-01

A major challenge in ecology is to understand how the millions of species on Earth are organized into biological communities. Mechanisms promoting coexistence are one such class of organizing processes, which allow multiple species to persist in the same trophic level of a given web of species interactions. If some mechanism promotes the coexistence of two or more species, each species must be able to increase when it is rare and the others are at their typical abundances; this invasibility criterion is fundamental evidence for species coexistence regardless of the mechanism. In an attempt to evaluate the level of empirical support for coexistence mechanisms in nature, we surveyed the literature for empirical studies of coexistence at a local scale (i.e., species found living together in one place) to determine whether these studies satisfied the invasibility criterion. In our survey, only seven of 323 studies that drew conclusions about species coexistence evaluated invasibility in some way in either observational or experimental studies. In addition, only three other studies evaluated necessary but not sufficient conditions for invasibility (i.e., negative density dependence and a trade-off in performance that influences population regulation). These results indicate that, while species coexistence is a prevalent assumption for why species are able to live together in one place, critical empirical tests of this fundamental assumption of community structure are rarely performed. These tests are central to developing a more robust understanding of the relative contributions of both deterministic and stochastic processes structuring biological communities.

Current Understanding of the Pathophysiology of Myocardial Fibrosis and Its Quantitative Assessment in Heart Failure

PubMed Central

Liu, Tong; Song, Deli; Dong, Jianzeng; Zhu, Pinghui; Liu, Jie; Liu, Wei; Ma, Xiaohai; Zhao, Lei; Ling, Shukuan

2017-01-01

Myocardial fibrosis is an important part of cardiac remodeling that leads to heart failure and death. Myocardial fibrosis results from increased myofibroblast activity and excessive extracellular matrix deposition. Various cells and molecules are involved in this process, providing targets for potential drug therapies. Currently, the main detection methods of myocardial fibrosis rely on serum markers, cardiac magnetic resonance imaging, and endomyocardial biopsy. This review summarizes our current knowledge regarding the pathophysiology, quantitative assessment, and novel therapeutic strategies of myocardial fibrosis. PMID:28484397

Myocardial signal density levels and beam-hardening artifact attenuation using dual-energy computed tomography.

PubMed

Rodriguez-Granillo, Gaston A; Carrascosa, Patricia; Cipriano, Silvina; de Zan, Macarena; Deviggiano, Alejandro; Capunay, Carlos; Cury, Ricardo C

2015-01-01

The assessment of myocardial perfusion using single-energy (SE) imaging is influenced by beam-hardening artifacts (BHA). We sought to explore the ability of dual-energy (DE) imaging to attenuate the presence of BHA. Myocardial signal density (SD) was evaluated in 2240 myocardial segments (112 for each energy level) and in 320 American Heart Association segments among the SE group. Compared to DE reconstructions at the best energy level, SE acquisitions showed no significant differences overall regarding myocardial SD or signal-to-noise ratio. The segments most commonly affected by BHA showed significantly lower myocardial SD at the lowest energy levels, progressively normalizing at higher energy levels. Copyright © 2015 Elsevier Inc. All rights reserved.

Long-Term Coexistence of Rotifer Cryptic Species

PubMed Central

Serra, Manuel; Gómez, Africa

2011-01-01

Despite their high morphological similarity, cryptic species often coexist in aquatic habitats presenting a challenge in the framework of niche differentiation theory and coexistence mechanisms. Here we use a rotifer species complex inhabiting highly unpredictable and fluctuating salt lakes to gain insights into the mechanisms involved in stable coexistence in cryptic species. We combined molecular barcoding surveys of planktonic populations and paleogenetic analysis of diapausing eggs to reconstruct the current and historical coexistence dynamics of two highly morphologically similar rotifer species, B. plicatilis and B. manjavacas. In addition, we carried out laboratory experiments using clones isolated from eight lakes where both species coexist to explore their clonal growth responses to salinity, a challenging, highly variable and unpredictable condition in Mediterranean salt lakes. We show that both species have co-occurred in a stable way in one lake, with population fluctuations in which no species was permanently excluded. The seasonal occurrence patterns of the plankton in two lakes agree with laboratory experiments showing that both species differ in their optimal salinity. These results suggest that stable species coexistence is mediated by differential responses to salinity and its fluctuating regime. We discuss the role of fluctuating salinity and a persistent diapausing egg banks as a mechanism for species coexistence in accordance with the ‘storage effect’. PMID:21738691

Species coexistence through simultaneous fluctuation-dependent mechanisms.

PubMed

Letten, Andrew D; Dhami, Manpreet K; Ke, Po-Ju; Fukami, Tadashi

2018-06-12

Understanding the origins and maintenance of biodiversity remains one of biology's grand challenges. From theory and observational evidence, we know that variability in environmental conditions through time is likely critical to the coexistence of competing species. Nevertheless, experimental tests of fluctuation-driven coexistence are rare and have typically focused on just one of two potential mechanisms, the temporal storage effect, to the neglect of the theoretically equally plausible mechanism known as relative nonlinearity of competition. We combined experiments and simulations in a system of nectar yeasts to quantify the relative contribution of the two mechanisms to coexistence. Resource competition models parameterized from single-species assays predicted the outcomes of mixed-culture competition experiments with 83% accuracy. Model simulations revealed that both mechanisms have measurable effects on coexistence and that relative nonlinearity can be equal or greater in magnitude to the temporal storage effect. In addition, we show that their effect on coexistence can be both antagonistic and complementary. These results falsify the common assumption that relative nonlinearity is of negligible importance, and in doing so reveal the importance of testing coexistence mechanisms in combination.

Quantification of myocardial infarction: a comparison of single photon-emission computed tomography with pyrophosphate to serial plasma MB-creatine kinase measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, D.E.; Corbett, J.R.; Wolfe, C.L.

1985-08-01

Single photon-emission computed tomography (SPECT) with /sup 99m/Tc-pyrophosphate (PPi) has been shown to estimate size of myocardial infarction accurately in animals. The authors tested the hypothesis that SPECT with /sup /sup 99m//Tc-PPi and blood pool subtraction can provide prompt and accurate estimates of size of myocardial infarction in patients. SPECT estimates are potentially available early after the onset of infarction and should correlate with estimates of infarct size calculated from serial measurements of plasma MB-creatine kinase (CK) activity. Thirty-three patients with acute myocardial infarction and 16 control patients without acute myocardial infarction were studied. Eleven of the patients had transmuralmore » anterior myocardial infarction, 16 had transmural inferior myocardial infarction, and six had nontransmural myocardial infarction. SPECT was performed with a commercially available rotating gamma camera. Identical projection images of the distribution of 99mTc-PPi and the ungated cardiac blood pool were acquired sequentially over 180 degrees. Reconstructed sections were color coded and superimposed for purposes of localization of infarct. Areas of increased PPi uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted to determine the endocardial border for the left ventricle. Myocardial infarcts ranged in size from 1 to 126 gram equivalents (geq) MB-CK. The correlation of MB-CK estimates of size of infarct with size determined by SPECT (both in geq) was good (r = .89 with a regression line of y = 13.1 + 1.5x).« less

Chronic Kidney Disease Exacerbates Myocardial Ischemia Reperfusion Injury: Role of Endoplasmic Reticulum Stress-Mediated Apoptosis.

PubMed

Guo, Junjie; Zhu, Jianbing; Ma, Leilei; Shi, Hongtao; Hu, Jiachang; Zhang, Shuning; Hou, Lei; Xu, Fengqiang; An, Yi; Yu, Haichu; Ge, Junbo

2018-06-01

Chronic kidney disease (CKD) is known to exacerbate myocardial ischemia reperfusion (IR) injury. However, the underlying mechanisms are still not well understood. Despite various strategies for cardioprotection, limited studies have been focused on the prevention of CKD-induced myocardial susceptibility to IR injury. Here, we hypothesized that excessive endoplasmic reticulum (ER) stress-mediated apoptosis involved in myocardial IR injury in CKD mice and pretreatment with chemical ER chaperone rendered the heart resistant to myocardial IR injury in the setting of CKD. CKD was induced by 5/6 subtotal nephrectomy (SN) in mice, whereas sham-operated mice served as control (Sham). CKD significantly aggravated the cardiac injury after IR in SN group than Sham group as reflected by more severe cardiac dysfunction, increased myocardial infarct size and the ratio of myocardial apoptosis. The expression of ER stress-mediated apoptotic proteins (Bcl-2 associated X protein (Bax), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12) was markedly upregulated after IR injury in SN group than Sham group, whereas the expression of anti-apoptotic protein, Bcl-2, was obviously downregulated. In addition, the chemical ER chaperone sodium 4-phenylbutyrate (4PBA) pretreatment ameliorated cardiac dysfunction and lessened the infarct size and myocardial apoptosis after IR injury in mice with CKD. Taken together, these findings demonstrated that excessive activation of ER stress-mediated apoptosis pathway involved in the CKD-induced myocardial susceptibility to IR injury, and chemical ER chaperone 4PBA alleviated myocardial IR injury in mice with CKD.

Melatonin protects against myocardial hypertrophy induced by lipopolysaccharide.

PubMed

Lu, Qi; Yi, Xin; Cheng, Xiang; Sun, Xiaohui; Yang, Xiangjun

2015-04-01

Melatonin is thought to have the ability of antiatherogenic, antioxidant, and vasodilatory. It is not only a promising protective in acute myocardial infarction but is also a useful tool in the treatment of pathological remodeling. However, its role in myocardial hypertrophy remains unclear. In this study, we investigated the protective effects of melatonin on myocardial hypertrophy induced by lipopolysaccharide (LPS) and to identify their precise mechanisms. The cultured myocardial cell was divided into six groups: control group, LPS group, LPS + ethanol (4%), LPS + melatonin (1.5 mg/ml) group, LPS + melatonin (3 mg/ml) group, and LPS + melatonin (6 mg/ml) group. The morphologic change of myocardial cell was observed by inverted phase contrast microscope. The protein level of myocardial cell was measured by Coomassie brilliant blue protein kit. The secretion level of tumor necrosis factor-α (TNF-α) was evaluated by enzyme-linked immunosorbent assay (ELISA). Ca(2+) transient in Fura-2/AM-loaded cells was measured by Till image system. The expression of Ca(2+)/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) was measured by Western blot analysis. Our data demonstrated that LPS induced myocardial hypertrophy, promoted the secretion levels of TNF-α, and increased Ca(2+) transient level and the expression of CaMKII and CaN. Administration of melatonin 30 min prior to LPS stimulation dose-dependently attenuated myocardial hypertrophy. In conclusion, the results revealed that melatonin had the potential to protect against myocardial hypertrophy induced by LPS in vitro through downregulation of the TNF-α expression and retains the intracellular Ca(2+) homeostasis.

Both selenium deficiency and modest selenium supplementation lead to myocardial fibrosis in mice via effects on redox-methylation balance.

PubMed

Metes-Kosik, Nicole; Luptak, Ivan; Dibello, Patricia M; Handy, Diane E; Tang, Shiow-Shih; Zhi, Hui; Qin, Fuzhong; Jacobsen, Donald W; Loscalzo, Joseph; Joseph, Jacob

2012-12-01

Selenium has complex effects in vivo on multiple homeostatic mechanisms such as redox balance, methylation balance, and epigenesis, via its interaction with the methionine-homocysteine cycle. In this study, we examined the hypothesis that selenium status would modulate both redox and methylation balance and thereby modulate myocardial structure and function. We examined the effects of selenium-deficient (<0.025 mg/kg), control (0.15 mg/kg), and selenium-supplemented (0.5 mg/kg) diets on myocardial histology, biochemistry and function in adult C57/BL6 mice. Selenium deficiency led to reactive myocardial fibrosis and systolic dysfunction accompanied by increased myocardial oxidant stress. Selenium supplementation significantly reduced methylation potential, DNA methyltransferase activity and DNA methylation. In mice fed the supplemented diet, inspite of lower oxidant stress, myocardial matrix gene expression was significantly altered resulting in reactive myocardial fibrosis and diastolic dysfunction in the absence of myocardial hypertrophy. Our results indicate that both selenium deficiency and modest selenium supplementation leads to a similar phenotype of abnormal myocardial matrix remodeling and dysfunction in the normal heart. The crucial role selenium plays in maintaining the balance between redox and methylation pathways needs to be taken into account while optimizing selenium status for prevention and treatment of heart failure. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Chinese version of the Myocardial Infarction Dimensional Assessment Scale (MIDAS): Mokken scaling

PubMed Central

2012-01-01

Background Hierarchical scales are very useful in clinical practice due to their ability to discriminate precisely between individuals, and the original English version of the Myocardial Infarction Dimensional Assessment Scale has been shown to contain a hierarchy of items. The purpose of this study was to analyse a Mandarin Chinese translation of the Myocardial Infarction Dimensional Assessment Scale for a hierarchy of items according to the criteria of Mokken scaling. Data from 180 Chinese participants who completed the Chinese translation of the Myocardial Infarction Dimensional Assessment Scale were analysed using the Mokken Scaling Procedure and the 'R' statistical programme using the diagnostics available in these programmes. Correlation between Mandarin Chinese items and a Chinese translation of the Short Form (36) Health Survey was also analysed. Findings Fifteen items from the Mandarin Chinese Myocardial Infarction Dimensional Assessment Scale were retained in a strong and reliable Mokken scale; invariant item ordering was not evident and the Mokken scaled items of the Chinese Myocardial Infarction Dimensional Assessment Scale correlated with the Short Form (36) Health Survey. Conclusions Items from the Mandarin Chinese Myocardial Infarction Dimensional Assessment Scale form a Mokken scale and this offers further insight into how the items of the Myocardial Infarction Dimensional Assessment Scale relate to the measurement of health-related quality of life people with a myocardial infarction. PMID:22221696

Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report

PubMed Central

2012-01-01

Background Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction. Objective Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study. Discussion Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms. Conclusion The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease. PMID:22999016

Panic attack triggering myocardial ischemia documented by myocardial perfusion imaging study. A case report.

PubMed

Soares-Filho, Gastão Luiz Fonseca; Mesquita, Claudio Tinoco; Mesquita, Evandro Tinoco; Arias-Carrión, Oscar; Machado, Sergio; González, Manuel Menéndez; Valença, Alexandre Martins; Nardi, Antonio Egidio

2012-09-21

Chest pain, a key element in the investigation of coronary artery disease is often regarded as a benign prognosis when present in panic attacks. However, panic disorder has been suggested as an independent risk factor for long-term prognosis of cardiovascular diseases and a trigger of acute myocardial infarction. Faced with the extreme importance in differentiate from ischemic to non-ischemic chest pain, we report a case of panic attack induced by inhalation of 35% carbon dioxide triggering myocardial ischemia, documented by myocardial perfusion imaging study. Panic attack is undoubtedly a strong component of mental stress. Patients with coronary artery disease may present myocardial ischemia in mental stress response by two ways: an increase in coronary vasomotor tone or a sympathetic hyperactivity leading to a rise in myocardial oxygen consumption. Coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. Possibly the carbon dioxide challenge test could trigger myocardial ischemia by the same mechanisms. The use of mental stress has been suggested as an alternative method for myocardial ischemia investigation. Based on translational medicine objectives the use of CO2 challenge followed by Sestamibi SPECT could be a useful method to allow improved application of research-based knowledge to the medical field, specifically at the interface of PD and cardiovascular disease.

Puerarin blocks the signaling transmission mediated by P2X3 in SG and DRG to relieve myocardial ischemic damage.

PubMed

Liu, Shuangmei; Zhang, Chunping; Shi, Qingming; Li, Guilin; Song, Miaomiao; Gao, Yun; Xu, Changshui; Xu, Hong; Fan, Bo; Yu, Shicheng; Zheng, Chaoran; Zhu, Qicheng; Wu, Bing; Peng, Lichao; Xiong, Huangui; Wu, Qin; Liang, Shangdong

2014-02-01

P2X₃ receptors in stellate ganglia (SG) and cervical dorsal root ganglia (DRG) neurons are involved in sympathoexcitatory reflex induced by myocardial ischemic damage. Puerarin, a major active ingredient extracted from the traditional Chinese plant medicine Ge-gen, has been widely used in treatment of myocardial and cerebral ischemia. The present study is aimed to observe the effects of puerarin on the signaling transmission mediated by P2X₃ receptor in SG and DRG after myocardial ischemic damage. Our results showed that systolic blood pressure and heart rate increased, and the expression levels of P2X₃ mRNA and protein in SG and DRG were up-regulated after myocardial ischemic damage. Puerarin reduced systolic blood pressure and heart rate, relieved pain and decreased up-regulated expression of P2X₃ mRNA and protein in SG and DRG after myocardial ischemia. Puerarin inhibited the up-regulated ATP-activated currents in DRG neurons after myocardial ischemia. Thus, puerarin can relieve myocardial ischemic damage through blocking the P2X₃ signaling transmission and then depressed the aggravated sympathoexcitatory reflex. Copyright © 2014 Elsevier Inc. All rights reserved.

Myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy.

PubMed

Smith, Caren E; Freeman, Lisa M; Meydani, Mohsen; Rush, John E

2005-09-01

To compare myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy (DCM) with concentrations in control dogs. Myocardial tissues from 7 dogs with DCM and 16 control dogs. Myocardial tissues were homogenized, and total fatty acids were extracted and converted to methyl esters. Myocardial concentrations of fatty acids were analyzed by use of gas chromatography and reported as corrected percentages. The amount of docosatetraenoic acid (C22:4 n-6) was significantly higher in myocardial samples from dogs with DCM (range, 0.223% to 0.774%; median, 0.451%), compared with the amount in samples obtained from control dogs (range, 0.166% to 0.621%; median, 0.280%). There were no significant differences between DCM and control dogs for concentrations of any other myocardial fatty acids. Although concentrations of most myocardial fatty acids did not differ significantly between dogs with DCM and control dogs, the concentration of docosatetraenoic acid was significantly higher in dogs with DCM. Additional investigation in a larger population is warranted to determine whether this is a primary or secondary effect of the underlying disease and whether alterations in fatty acids may be a target for intervention in dogs with DCM.

Myocardial infarction false alarm: initial electrocardiogram and cardiac enzymes.

PubMed

Gupta, Esha Das; Sakthiswary, Rajalingham

2014-05-01

The objectives of this study were to determine the incidence of a myocardial infarction "false alarm" and evaluate the efficacy of the initial electrocardiogram and cardiac enzymes in diagnosing myocardial infarction in Malaysia. We recruited patients who were admitted with suspected myocardial infarction from June to August 2008. The medical records of these patients were reviewed for the initial electrocardiogram, initial cardiac enzyme levels (creatinine kinase-MB and troponin T), and the final diagnosis upon discharge. The subjects were stratified into 2 groups: true myocardial infarction, and false alarm. 125 patients were enrolled in this study. Following admission and further evaluation, the diagnosis was revised from myocardial infarction to other medical conditions in 48 (38.4%) patients. The sensitivity and specificity of the initial ischemic electrocardiographic changes were 54.5% and 70.8%, respectively. Raised cardiac enzymes had a sensitivity of 44.3% and specificity of 95.8%. A significant proportion of patients in Malaysia are admitted with a false-alarm myocardial infarction. The efficacy of the electrocardiogram in diagnosing myocardial infarction in Malaysia was comparable to the findings of Western studies, but the cardiac enzymes had a much lower sensitivity.

Diabetes increases mortality after myocardial infarction by oxidizing CaMKII

PubMed Central

Luo, Min; Guan, Xiaoqun; Luczak, Elizabeth D.; Lang, Di; Kutschke, William; Gao, Zhan; Yang, Jinying; Glynn, Patric; Sossalla, Samuel; Swaminathan, Paari D.; Weiss, Robert M.; Yang, Baoli; Rokita, Adam G.; Maier, Lars S.; Efimov, Igor R.; Hund, Thomas J.; Anderson, Mark E.

2013-01-01

Diabetes increases oxidant stress and doubles the risk of dying after myocardial infarction, but the mechanisms underlying increased mortality are unknown. Mice with streptozotocin-induced diabetes developed profound heart rate slowing and doubled mortality compared with controls after myocardial infarction. Oxidized Ca2+/calmodulin-dependent protein kinase II (ox-CaMKII) was significantly increased in pacemaker tissues from diabetic patients compared with that in nondiabetic patients after myocardial infarction. Streptozotocin-treated mice had increased pacemaker cell ox-CaMKII and apoptosis, which were further enhanced by myocardial infarction. We developed a knockin mouse model of oxidation-resistant CaMKIIδ (MM-VV), the isoform associated with cardiovascular disease. Streptozotocin-treated MM-VV mice and WT mice infused with MitoTEMPO, a mitochondrial targeted antioxidant, expressed significantly less ox-CaMKII, exhibited increased pacemaker cell survival, maintained normal heart rates, and were resistant to diabetes-attributable mortality after myocardial infarction. Our findings suggest that activation of a mitochondrial/ox-CaMKII pathway contributes to increased sudden death in diabetic patients after myocardial infarction. PMID:23426181

Various Types of Coexisting Attractors in a New 4D Autonomous Chaotic System

NASA Astrophysics Data System (ADS)

Lai, Qiang; Akgul, Akif; Zhao, Xiao-Wen; Pei, Huiqin

An unique 4D autonomous chaotic system with signum function term is proposed in this paper. The system has four unstable equilibria and various types of coexisting attractors appear. Four-wing and four-scroll strange attractors are observed in the system and they will be broken into two coexisting butterfly attractors and two coexisting double-scroll attractors with the variation of the parameters. Numerical simulation shows that the system has various types of multiple coexisting attractors including two butterfly attractors with four limit cycles, two double-scroll attractors with a limit cycle, four single-scroll strange attractors, four limit cycles with regard to different parameters and initial values. The coexistence of the attractors is determined by the bifurcation diagrams. The chaotic and hyperchaotic properties of the attractors are verified by the Lyapunov exponents. Moreover, we present an electronic circuit to experimentally realize the dynamic behavior of the system.

Role of Cardiac Myocytes Heart Fatty Acid Binding Protein Depletion (H-FABP) in Early Myocardial Infarction in Human Heart (Autopsy Study).

PubMed

Shabaiek, Amany; Ismael, Nour El-Hoda; Elsheikh, Samar; Amin, Hebat Allah

2016-03-15

Many immunohistochemical markers have been used in the postmortem detection of early myocardial infarction. In the present study we examined the role of Heart-type fatty acid binding protein (H-FABP), in the detection of early myocardial infarction. We obtained samples from 40 human autopsy hearts with/without histopathological signs of ischemia. All cases of definite and probable myocardial infarction showed a well-defined area of H-FABP depletion. All of the control cases showed strong H-FABP expression, except two markedly autolysed myocardial samples that showed affected antigenicity. Thus, we suggest H-FABP as being one of the valuable tools facing the problem of postmortem detection of early myocardial infarction/ischemia, but not in autolysis.

The effects of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 during myocardial ischemia/reperfusion in a model of rats with depression.

PubMed

Wang, Yiming; Zhang, Hongming; Chai, Fangxian; Liu, Xingde; Berk, Michael

2014-12-04

Major depressive disorder (MDD) is an independent risk factor for coronary heart disease (CHD), and influences the occurrence and prognosis of cardiovascular events. Although there is evidence that antidepressants may be cardioprotective after acute myocardial infarction (AMI) comorbid with MDD, the operative pathophysiological mechanisms remain unclear. Our aim was therefore to explore the molecular mechanisms of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 in a rat model of depression during myocardial ischemia/reperfusion (I/R). Rats were divided randomly into 3 groups (n = 8): D group (depression), DI/R group (depression with myocardial I/R) and escitalopram + DI/R group. The rats in all three groups underwent the same chronic mild stress and separation for 21 days, at the same time, in the escitalopram + DI/R group, rats were administered escitalopram by gavage (10 mg/kg/day). Ligation of the rat's left anterior descending branch was done in the myocardial I/R model. Following which behavioral tests were done. The size of the myocardial infarction was detected using 1.5% TTC dye. The Tunel method was used to detect apoptotic myocardial cells, and both the Rt-PCR method and immunohistochemical techniques were used to detect the expression of Bcl-2 and Bax. Compared with the D and DI/R groups, rats in Escitalopram + DI/R group showed significantly increased movements and sucrose consumption (P < .01). Compared with the DI/R group, the myocardial infarct size in the escitalopram + DI/R group was significantly decreased (P < .01). Compared with the D group, there were significantly increased apoptotic myocardial cells in the DI/R and escitalopram + DI/R groups (P < .01); however compared with the DI/R group, apoptotic myocardial cell numbers in the escitalopram + DI/R group were significantly decreased (P < .01). Compared with the DI/R group, there was a down-regulated Bax:Bcl-2 ratio in the escitalopram + DI/R group (P < .01). These results suggest that in patients with AMI comorbid with MDD, there is an increase in pro-apoptotic pathways that is reversed by escitalopram. This suggests that clinically escitalopram may have a direct cardioprotective after acute myocardial infarction.

Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.

PubMed

Du, Guo-Qing; Xue, Jing-Yi; Guo, Yanhui; Chen, Shuang; Du, Pei; Wu, Yan; Wang, Yu-Hang; Zong, Li-Qiu; Tian, Jia-Wei

2015-09-01

Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can accurately measure infarct size. On the basis of the results, we believe the CAD method can quickly and automatically measure myocardial perfusion and infarct size and will, it is hoped, be very helpful in clinical therapeutics. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

School-Family Partnership for Coexistence (SFPC) in the City of Acre: Promoting Arab and Jewish Parents' Role as Facilitators of Children's Literacy Development and as Agents of Coexistence

ERIC Educational Resources Information Center

Zelniker, Tamar; Hertz-Lazarowitz, Rachel

2005-01-01

A two-year (1998-2000) School-Family Partnership for Coexistence (SFPC) programme was implemented in Acre, a mixed Jewish-Arab city in Israel, to promote parents' role as facilitators of their children literacy development and to empower parents to advance coexistence and inter-group relations. The SFPC program was part of a five-year (1995-2000)…

[Effect of edaravone on oxidative stress and myocardial fibrosis induced by isoproterenol in rats].

PubMed

Wang, Shixiang; Lu, Zhifeng; Xu, Wei; Chen, Youquan; Chen, Ximing

2015-11-01

To investigate the effect of edaravone on oxidative stress and myocardial fibrosis induced by isoproterenol in rats. Fifty male SD rats were randomly divided into 5 groups, including a control group, a myocardial fibrosis model (established by injections of isopropyl adrenaline for 10 days) group, and 3 edaravone groups with edaravone treatment at low, medium, or high doses for 14 days. After the treatments, the rats were examined for the degree of myocardial fibrosis, left ventricular mass index (LVMI), collagen volume fraction (CVF), and myocardial contents of collagen I (Col I), collage III (Col III), hydroxyproline (Hyp), superoxide dismutase (SOD), malondialdehyde (MDA), and nitric oxide (NO); The expression of transforming growth factor-β1 (TGF-β1) in the myocardial tissues was examined by immunofluorescence assay and Western blotting. Compared with the control rats, the rat models of myocardial fibrosis showed significantly increased CVF and LVMI (P=0.000), which were lowered by edaravone treatments in a dose-dependent manner (P<0.05). The myocardial contents of Col I, Col III and Hyp also increased in the model group (P=0.000) and were lowered dose-dependently by edaravone; the contents of MDA was higher (P=0.000) and SOD and NO were lower in the model group (P=0.000), and edaravone treatments obviously increased SOD and NO contents (P<0.05). The model rats showed significantly increased myocardial expression of TGF-β1 (P=0.000), which was markedly lowered by edaravone treatments (P=0.000). The myocardial content of MDA was positively correlated while SOD and NO were negatively with LVMI, CVF, Col I, Col III and Hyp; TGF-β1 was positively correlated with LVMI, CVF, Col I, Col III, Hyp and MDA but negatively with SOD and NO. Edaravone can relieve oxidative stress and inhibit TGF-β1 activation to ameliorate myocardial fibrosis in rats.

Clinical Significance of Postinfarct Fever in ST-Segment Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study.

PubMed

Jang, Woo Jin; Yang, Jeong Hoon; Song, Young Bin; Chun, Woo Jung; Oh, Ju Hyeon; Park, Yong Hwan; Lee, Mi Rae; Hwang, Jin Kyung; Hwang, Ji-Won; Hahn, Joo-Yong; Choi, Seung-Hyuk; Lee, Sang-Chol; Choe, Yeon Hyeon; Gwon, Hyeon-Cheol

2017-04-24

Little is known about causality and pathological mechanism underlying association of postinfarct fever with myocardial injury in patients with ST-segment elevation myocardial infarction. In 276 patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, cardiac magnetic resonance imaging was performed a median of 3.4 days after the index procedure. Forty-five patients had postinfarct fever (peak body temperature within 4 days after primary percutaneous coronary intervention ≥37.7°C; Fever group) whereas 231 did not (no-Fever group). Primary outcome was myocardial infarct size as assessed by cardiac magnetic resonance imaging. Secondary outcomes were extent of area at risk, myocardial salvage index, and microvascular obstruction area. In cardiac magnetic resonance imaging analysis, myocardial infarct size (25.6% [19.7-32.4] in the Fever group versus 17.2% [11.8-25.4] in the no-Fever group; P <0.01), extent of area at risk (43.7% [31.9-54.9] versus 35.3% [24.0-43.7]; P <0.01), and microvascular obstruction area (4.4% [0.0-13.2] versus 1.2% [0.0-5.1]; P =0.02) were greater in the Fever group than in the no-Fever group. Myocardial salvage index tended to be lower in the Fever group compared to the no-Fever group (37.7 [28.5-56.1] versus 47.0 [34.1-56.8]; P =0.13). In multivariate analysis, postinfarct fever was associated with larger myocardial infarct (odds ratio, 3.48; 95% CI, 1.71-7.07; P <0.01) and lower MSI (odds ratio, 2.10; 95% CI, 1.01-4.08; P =0.03). Postinfarct fever could predict advanced myocardial injury and less salvaged myocardium in ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Extracellular Vesicle Injection Improves Myocardial Function and Increases Angiogenesis in a Swine Model of Chronic Ischemia.

PubMed

Potz, Brittany A; Scrimgeour, Laura A; Pavlov, Vasile I; Sodha, Neel R; Abid, M Ruhul; Sellke, Frank W

2018-06-12

Mesenchymal stem cell-derived extracellular vesicles (EVs) are believed to be cardioprotective in myocardial infarct. The objective of this study was to examine the effects of human mesenchymal cell-derived EV injection on cardiac function, myocardial blood flow, and vessel density in the setting of chronic myocardial ischemia. Twenty-three Yorkshire swine underwent placement of an ameroid constrictor on their left circumflex artery. Two weeks later, the animals were split into 2 groups: the control group (CON; n=7) and the EV myocardial injection group (MVM; n=10). The MVM group underwent myocardial injection of 50 μg of EVs in 2 mL 0.9% saline into the ischemic myocardium. Five weeks later, the pigs underwent a harvest procedure, and the left ventricular myocardium was analyzed. Absolute blood flow and the ischemic/nonischemic myocardial perfusion ratio were increased in the ischemic myocardium in the MVM group compared with the CON group. Pigs in the MVM group had increased capillary and arteriolar density in the ischemic myocardial tissue compared with CON pigs. There was an increase in expression of the phospho-mitogen-activated protein kinase/mitogen-activated protein kinase ratio, the phospho-endothelial nitric oxide synthase/endothelial nitric oxide synthase ratio, and total protein kinase B in the MVM group compared with CON. There was an increase in cardiac output and stroke volume in the MVM group compared with CON. In the setting of chronic myocardial ischemia, myocardial injection of human mesenchymal cell-derived EVs increases blood flow to ischemic myocardial tissue by induction of capillary and arteriolar growth via activation of the protein kinase B/endothelial nitric oxide synthase and mitogen-activated protein kinase signaling pathways resulting in increased cardiac output and stroke volume. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Association between aortic valve calcification and myocardial ischemia, especially in asymptomatic patients.

PubMed

Yamazato, Ryo; Yamamoto, Hideya; Tadehara, Futoshi; Teragawa, Hiroki; Kurisu, Satoshi; Dohi, Yoshihiro; Ishibashi, Ken; Kunita, Eiji; Utsunomiya, Hiroto; Oka, Toshiharu; Kihara, Yasuki

2012-08-01

Aortic valve calcification (AVC) is recognized as a manifestation of systemic arteriosclerosis. However, it is unclear whether AVC is associated with myocardial ischemia. Stress myocardial perfusion SPECT (MPS) is widely used for the diagnosis of myocardial ischemia. However, routine MPS is not recommended, particularly in asymptomatic patients. Accordingly, we investigated the hypothesis that the presence of AVC is strongly associated with inducible myocardial ischemia, even among asymptomatic patients. We investigated 669 consecutive patients who underwent both adenosine stress (201)Tl MPS and echocardiography. We evaluated the extent and severity of myocardial ischemia by the summed difference score (SDS). We defined the presence of myocardial ischemia as SDS ≥ 3 and moderate to severe ischemia as SDS ≥ 8. We classified the severity of AVC according to the number of affected aortic leaflets. We also compared the mean SDS and the prevalence of SDS ≥ 3 and SDS ≥ 8 among patients stratified by the severity of AVC. The presence of AVC was significantly associated with myocardial ischemia (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.10-2.23; P = 0.013) and moderate to severe ischemia (OR, 2.16; 95% CI, 1.26-3.80; P = 0.0061). In 311 asymptomatic patients, AVC was strongly associated with moderate to severe ischemia (OR, 4.31; 95% CI, 1.67-12.8; P = 0.0043). However, the SDS value and the prevalence of SDS ≥ 3 and SDS ≥ 8 did not increase with increasing number of affected aortic leaflets. The presence of AVC may be associated with the presence of myocardial ischemia, particularly in asymptomatic patients. However, we found no association between the extent of AVC and inducible myocardial ischemia. The presence of AVC may be a useful anatomic marker to help identify patients at high risk of myocardial ischemia, particularly asymptomatic patients.

Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

PubMed Central

McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

2009-01-01

OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These techniques could complement delayed enhancement and wall motion analysis protocols, making MRI a valuable “one-stop shop” for imaging of myocardial ischemia. PMID:19909936

Sgarbossa criteria and acute myocardial infarction.

PubMed

Alang, Neha; Bathina, Jaya; Kranis, Mark; Angelis, Dimitrios

2010-01-01

Diagnosis of acute ST-elevation myocardial infarction in the presence of left bundle branch block is difficult. present a case of acute myocardial infarction with LBBB diagnosed and treated using the Sgarbossa criteria.

Contractility and Ventricular Systolic Stiffening in Hypertensive Heart Disease: Insights into the Pathogenesis of Heart Failure with Preserved Ejection Fraction

PubMed Central

Borlaug, Barry A.; Lam, Carolyn S.P.; Roger, Véronique L.; Rodeheffer, Richard J.; Redfield, Margaret M.

2009-01-01

Objectives: 1) Compare left ventricular (LV) systolic stiffness and contractility in normal subjects, hypertensives without heart failure, and patients with heart failure and preserved ejection fraction (HFpEF); and 2) Determine whether LV systolic stiffness or myocardial contractility are associated with mortality in HFpEF. Background: Arterial load is increased in hypertension and is matched by increased end-systolic LV stiffness (ventricular-arterial coupling). Increased end-systolic LV stiffness may be mediated by enhanced myocardial contractility or processes which increase passive myocardial stiffness. Methods: Healthy controls (n=617), hypertensives (No HF, n=719) and patients with HFpEF (n=244, 96% hypertensive) underwent echo-Doppler characterization of arterial (Ea) and LV end-systolic (Ees) stiffness (elastance), ventricular-arterial coupling (Ea/Ees ratio), chamber-level and myocardial contractility (stress-corrected midwall shortening). Results: Ea and Ees were similarly elevated in hypertensives with or without HFpEF compared with controls, but ventricular-arterial coupling was similar across groups. In hypertensives, elevated Ees was associated with enhanced chamber-level and myocardial contractility, while in HFpEF, chamber and myocardial contractility were depressed compared with both hypertensives and controls. Group differences persisted after adjusting for geometry. In HFpEF, impaired myocardial contractility (but not Ees) was associated with increased age-adjusted mortality. Conclusions: While arterial load is elevated and matched by increased LV systolic stiffness in hypertension with or without HFpEF, the mechanisms of systolic LV stiffening differ substantially. These data suggest that myocardial contractility increases to match arterial load in asymptomatic hypertensive heart disease, but that progression to HFpEF may be mediated by processes which simultaneously impair myocardial contractility and increase passive myocardial stiffness. PMID:19628115

Lower age at first myocardial infarction in female compared to male smokers.

PubMed

Bähler, Caroline; Gutzwiller, Felix; Erne, Paul; Radovanovic, Dragana

2012-10-01

Smoking is one of the most important risk factors for myocardial infarction. Smokers usually suffer their first myocardial infarction earlier in life compared to non-smokers. This age difference seems to be greater in women than in men. The aim of this study was to examine the age and sex differences in terms of smoking in patients with first myocardial infarction who were enrolled in the Swiss National Registry of myocardial infarction, AMIS Plus. Data of 15,711 patients admitted to an AMIS Plus hospital between 1999 and 2008 with a first myocardial infarction were analysed. Several multivariate regression, interaction and sensitivity analyses were conducted. The mean age at first myocardial infarction was 68.5 ± 12.2 years for non-smokers and 56.6 ± 11.7 years for smokers (P < 0.001). After stratification by sex the difference between non-smokers and smokers was 10.2 years in men and 13.1 years in women. Even after adjustment for risk factors (overweight, hypertension, dyslipidaemia, diabetes), comorbidities (peripheral vascular disease, cerebrovascular disease, chronic lung disease), regular cardiovascular medication intake before admission, Killip classification and ECG on admission, male smokers were 8.7 years younger than male non-smokers at first myocardial infarction. In women, the age difference between smokers and non-smokers was 10.8 years, giving a sex-specific difference of 2.1 years (P < 0.001). In the AMIS Plus cohort, smoking was associated with younger age at first myocardial infarction and this was much more pronounced in women. Public health campaigns should take into account the impact of smoking on premature first myocardial infarction, especially in women.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies.

PubMed

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-03-01

To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05). MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.

Nitrogen-13-labeled ammonia for myocardial imaging.

PubMed

Walsh, W F; Fill, H R; Harper, P V

1977-01-01

Cyclotron-produced nitrogen-13 (half-life 10 min), as labeled ammonia (13NH4+), has been evaluated as a myocardial perfusion imaging agent. The regional myocardial uptake of 13NH4+ has been shown to be proportional to regional tissue perfusion in animal studies. Intravenously administered 13NH4+ is rapidly cleared from the circulation, being extracted by the liver (15%), lungs, myocardium (2%-4%), brain, kidney, and bladder. Myocardial ammonia is metabolized mainly to glutamine via the glutamine synthetase pathway. Pulmonary uptake is substantial, but usually transient, except in smokers where clearance may be delayed. The position annihilation irradiation (511 keV) of 13N may be imaged with a scintillation camera, using either a specially designed tungsten collimator or a pinhole collimator. After early technical problems with collimation and the production method of 13NH4+ were overcome, reproducible high quality myocardial images were consistently obtained. The normal myocardial image was established to be of a homogeneous "doughnut" configuration. Imaging studies performed in patients with varying manifestations of ischemic and valvular heart disease showed a high incidence of localized perfusion defects, especially in patients with acute myocardial infarction. Sequential studies at short intervals in patients with acute infarction showed correlation between alterations in regional perfusion and the clinical course of the patient. It is concluded that myocardial imaging with 13NH4+ and a scintillation camera provides a valid and noninvasive means of assessing regional myocardial perfusion. This method is especially suitable for sequential studies of acute cardiac patients at short intervals. Coincidence imaging of the 511 keV annihilation irradiation provides a tomographic and potentially quantitative assessment of the regional myocardial uptake of 13NH4+.

The Na+/H+ exchange inhibitor cariporide is washed out of the myocardium by crystalloid cardioplegia.

PubMed

Bechtel, J F M; Eichler, W; Toerber, K; Weidtmann, B; Hernandez, M; Klotz, K F; Sievers, H H; Bartels, C

2006-08-01

Inhibition of the Na (+)/H (+) exchanger (NHE) is cardioprotective, but dosage and timing of NHE-inhibitors are critical for their efficacy. We studied the effect of a new dosing regime of the NHE-inhibitor cariporide on myocardial function and damage after cardioplegic arrest (CPA) and determined its myocardial and serum concentrations. 3 pigs received a bolus of 180 mg cariporide intravenously (i. v.) and were sacrificed shortly thereafter to allow measurement of the myocardial concentrations of cariporide. Subsequently, 10 pigs were randomized to receive either i. v. cariporide (bolus followed by an infusion of 40 mg/h) or placebo. Cardiopulmonary bypass was initiated, and the heart was arrested for 60 minutes by infusion of St. Thomas Hospital solution. Left ventricular (LV) function was studied using microsonometry. Myocardial damage was assessed by troponin T. Serum concentrations of cariporide were measured throughout the study, and myocardial concentrations were measured before the end of CPA and 180 minutes thereafter. Cariporide was present in all myocardial specimens (median: 1.4 ng/mg) studied previously. In the main study, LV function or myocardial damage did not differ significantly between the groups at any time point. Stable serum cariporide concentrations were achieved (3.4 +/- 0.5 microg/ml). Cariporide was detectable in only one of the myocardial biopsies obtained before the end of CPA, but 180 minutes thereafter, the myocardial cariporide concentration was 2.5 +/- 0.3 ng/mg. We observed no effect of i. v. cariporide on LV function or myocardial damage after cardioplegic arrest. Our data suggest that cariporide is washed out of the myocardium by repeated application of crystalloid cardioplegia. Thus, the mode of delivery also appears to be critical for cardioprotection with NHE-inhibitors.

Taxonomy of segmental myocardial systolic dysfunction

PubMed Central

McDiarmid, Adam K.; Pellicori, Pierpaolo; Cleland, John G.; Plein, Sven

2017-01-01

The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms ‘viable’ and ‘hibernating’ are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction. PMID:27147609

Epicardial FSTL1 reconstitution regenerates the adult mammalian heart.

PubMed

Wei, Ke; Serpooshan, Vahid; Hurtado, Cecilia; Diez-Cuñado, Marta; Zhao, Mingming; Maruyama, Sonomi; Zhu, Wenhong; Fajardo, Giovanni; Noseda, Michela; Nakamura, Kazuto; Tian, Xueying; Liu, Qiaozhen; Wang, Andrew; Matsuura, Yuka; Bushway, Paul; Cai, Wenqing; Savchenko, Alex; Mahmoudi, Morteza; Schneider, Michael D; van den Hoff, Maurice J B; Butte, Manish J; Yang, Phillip C; Walsh, Kenneth; Zhou, Bin; Bernstein, Daniel; Mercola, Mark; Ruiz-Lozano, Pilar

2015-09-24

The elucidation of factors that activate the regeneration of the adult mammalian heart is of major scientific and therapeutic importance. Here we found that epicardial cells contain a potent cardiogenic activity identified as follistatin-like 1 (Fstl1). Epicardial Fstl1 declines following myocardial infarction and is replaced by myocardial expression. Myocardial Fstl1 does not promote regeneration, either basally or upon transgenic overexpression. Application of the human Fstl1 protein (FSTL1) via an epicardial patch stimulates cell cycle entry and division of pre-existing cardiomyocytes, improving cardiac function and survival in mouse and swine models of myocardial infarction. The data suggest that the loss of epicardial FSTL1 is a maladaptive response to injury, and that its restoration would be an effective way to reverse myocardial death and remodelling following myocardial infarction in humans.

Basic and advanced echocardiographic evaluation of myocardial dysfunction in sepsis and septic shock.

PubMed

Vallabhajosyula, S; Pruthi, S; Shah, S; Wiley, B M; Mankad, S V; Jentzer, J C

2018-01-01

Sepsis continues to be a leading cause of mortality and morbidity in the intensive care unit. Cardiovascular dysfunction in sepsis is associated with worse short- and long-term outcomes. Sepsis-related myocardial dysfunction is noted in 20%-65% of these patients and manifests as isolated or combined left or right ventricular systolic or diastolic dysfunction. Echocardiography is the most commonly used modality for the diagnosis of sepsis-related myocardial dysfunction. With the increasing use of ultrasonography in the intensive care unit, there is a renewed interest in sepsis-related myocardial dysfunction. This review summarises the current scope of literature focused on sepsis-related myocardial dysfunction and highlights the use of basic and advanced echocardiographic techniques for the diagnosis of sepsis-related myocardial dysfunction and the management of sepsis and septic shock.

Myocardial ischemia induced by nebulized fenoterol for severe childhood asthma.

PubMed

Zanoni, L Z; Palhares, D B; Consolo, L C T

2005-10-01

We examined for myocardial ischemia induced by continuous inhalation of fenoterol in children with severe acute asthma. Thirty children with severe acute asthma were evaluated for signs of myocardial ischemia when treated with 0.5 mg kg dose (maximum 15 mg) of inhaled fenoterol for one hour. The heart rate was measured before and after inhalation. Cardiac enzymes (creatine kinase, creatine kinase MB fraction and troponin levels) were measured at admission and 12 hours later. An EKG was recorded before inhalation was started and immediately after its completion to detect the presence of any evidence of myocardial ischemia. All patients developed significant increase in heart rate. Six patients showed EKG changes compatible with myocardial ischemia, despite normal enzyme levels. Patients with severe acute asthma show tachycardia and may show EKG changes of myocardial ischemia.

Illness consequences after myocardial infarction: problems with physical functioning and return to work.

PubMed

Brink, Eva; Brändström, Yvonne; Cliffordsson, Christina; Herlitz, Johan; Karlson, Björn W

2008-12-01

This paper is a report of a study to explore health problems, physical and mental functioning, and physical activity in working-age patients after myocardial infarction, in order to assess the possible effects of these factors on return to work. A diagnosis of myocardial infarction may discourage patients from continuing an active working life. Enabling myocardial infarction patients to return to work has benefits for both individuals and society. A convenience sample was recruited of 88 patients,

Geographic and demographic variabilities of quantitative parameters in stress myocardial computed tomography perfusion.

PubMed

Park, Jinoh; Kim, Hyun-Sook; Hwang, Hye Jeon; Yang, Dong Hyun; Koo, Hyun Jung; Kang, Joon-Won; Kim, Young-Hak

2017-09-01

To evaluate the geographic and demographic variabilities of the quantitative parameters of computed tomography perfusion (CTP) of the left ventricular (LV) myocardium in patients with normal coronary artery on computed tomography angiography (CTA). From a multicenter CTP registry of stress and static computed tomography, we retrospectively recruited 113 patients (mean age, 60 years; 57 men) without perfusion defect on visual assessment and minimal (< 20% of diameter stenosis) or no coronary artery disease on CTA. Using semiautomatic analysis software, quantitative parameters of the LV myocardium, including the myocardial attenuation in stress and rest phases, transmural perfusion ratio (TPR), and myocardial perfusion reserve index (MPRI), were evaluated in 16 myocardial segments. In the lateral wall of the LV myocardium, all quantitative parameters except for MPRI were significantly higher compared with those in the other walls. The MPRI showed consistent values in all myocardial walls (anterior to lateral wall: range, 25% to 27%; p = 0.401). At the basal level of the myocardium, all quantitative parameters were significantly lower than those at the mid- and apical levels. Compared with men, women had significantly higher values of myocardial attenuation and TPR. Age, body mass index, and Framingham risk score were significantly associated with the difference in myocardial attenuation. Geographic and demographic variabilities of quantitative parameters in stress myocardial CTP exist in healthy subjects without significant coronary artery disease. This information may be helpful when assessing myocardial perfusion defects in CTP.

Cpg-ODN, a TLR9 Agonist, Aggravates Myocardial Ischemia/Reperfusion Injury by Activation of TLR9-P38 MAPK Signaling.

PubMed

Xie, Liang; He, Songqing; Kong, Na; Zhu, Ying; Tang, Yi; Li, Jianhua; Liu, Zhengbing; Liu, Jing; Gong, Jianbin

2018-06-19

Toll-like receptors (TLRs) have been implicated in myocardial ischemia/ reperfusion (I/R) injury. We examined the effect of CpG-oligodeoxynucleotide (ODN) on myocardial I/R injury. Male Sprague-Dawley rats were treated with either CpG-ODN or control ODN 1 h prior to myocardial ischemia (30 min) followed by reperfusion. Rats treated with phosphate-buffered saline (PBS) served as I/R controls (n = 8/group). Infarct size was determined by 2,3,5-triphenyltetrazolium chloride and Evans blue straining. Cardiac function was examined by echocardiography before and up to 14 days after myocardial I/R. CpG-ODN administration significantly increased infarct size and reduced cardiac function and survival rate after myocardial I/R, compared to the PBS-treated I/R group. Control-ODN did not alter I/R-induced myocardial infarct size, cardiac dysfunction, and survival rate. Additionally, CpG-ODN promoted I/R-induced myocardial apoptosis and cleaved caspase-3 levels in the myocardium. CpG-ODN increased TLR9 activation and p38 phosphorylation in the myocardium. In vitro data also suggested that CpG-ODN treatment induced TLR9 activation and p38 phosphorylation. Importantly, p38 mitogen-activated protein kinase (MAPK) inhibition abolished CpG-ODN-induced cardiac injury. CpG-ODN, the TLR9 ligand, accelerates myocardial I/R injury. The mechanisms involve activation of the TLR9-p38 MAPK signaling pathway. © 2018 The Author(s). Published by S. Karger AG, Basel.

Baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation and oxidative stress in rat

PubMed Central

Chen, Huaguo; Xu, Yongfu; Wang, Jianzhong; Zhao, Wei; Ruan, Huihui

2015-01-01

Baicalin belongs to glucuronic acid glycosides and after hydrolysisbaicalein and glucuronic acid come into being. It has such effects as clearing heat and removing toxicity, anti-inflammation, choleresis, bringing high blood pressure down, diuresis, anti-allergic reaction and so on. In this study, we investigated whether baicalin ameliorates isoproterenol-induced acute myocardial infarction and its mechanism. Rat model of acute myocardial infarction was induced by isoproterenol. Casein kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH), cardiac troponin T (cTnT) and infarct size measurement were used to measure the protective effect of baicalin on isoproterenol-induced acute myocardial infarction. iNOS protein expression in rat was analyzed using western blot analysis. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), malondialdehyde (MDA) and superoxide dismutase (SOD) and caspase-3 activation levels were explored using commercial ELISA kits. In the acute myocardial infarction experiment, baicalin effectively ameliorates the level of CK, CK-MB, LDH and cTnT, reduced infarct size in acute myocardial infarction rat model. Meanwhile, treatment with baicalin effectively decreased the iNOS protein expression, inflammatory factors and oxidative stresses in a rat model of acute myocardial infarction. However, baicalin emerged that anti-apoptosis activity and suppressed the activation of caspase-3 in a rat model of acute myocardial infarction. The data suggest that the protective effect of baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation and oxidative stress in rat. PMID:26617721

(-) Epicatechin prevents alterations in lysosomal glycohydrolases, cathepsins and reduces myocardial infarct size in isoproterenol-induced myocardial infarcted rats.

PubMed

Prince, Ponnian Stanely Mainzen

2013-04-15

The preventive effects of (-) epicatechin on oxidative stress, cardiac mitochondrial damage, altered membrane bound adenosine triphosphatases and minerals were reported previously in isoproterenol-induced myocardial infarction model. Leakage of lysosomal glycohydrolases and cathepsins play an important role in the pathology of myocardial infarction. This study was aimed to evaluate the preventive effects of (-) epicatechin on alterations in lysosomal glycohydrolases, cathepsins and myocardial infarct size in isoproterenol-induced myocardial infarcted rats. Male albino Wistar rats were pretreated with (-) epicatechin (20mg/kg body weight) daily for a period of 21 days. After the pretreatment period, isoproterenol (100mg/kg body weight) was injected subcutaneously into the rats at an interval of 24h for two days to induce myocardial infarction. The levels of serum cardiac troponin-I and the activities of serum and heart lysosomal enzymes (β-glucuronidase, β-N-acetyl glucosaminidase, β-galactosidase, cathepsin-B and cathepsin-D) were increased significantly (P<0.05) and the activities of β-glucuronidase and cathepsin-D in the heart lysosomal fractions were significantly (P<0.05) decreased in isoproterenol-induced myocardial infarcted rats. The in vitro study revealed the potent antioxidant action of (-) epicatechin. Pretreatment with (-) epicatechin daily for a period of 21 days prevented the leakage of cardiac marker, lysosomal glycohydrolases, cathepsins, and reduced infarct size, thereby protecting the lysosomal membranes in isoproterenol-induced myocardial infarcted rats, by virtue of its membrane stabilizing property. Copyright © 2013 Elsevier B.V. All rights reserved.

As if one pain problem was not enough: prevalence and patterns of coexisting chronic pain conditions and their impact on treatment outcomes

PubMed Central

Pagé, M Gabrielle; Fortier, Maude; Ware, Mark A; Choinière, Manon

2018-01-01

Introduction The presence of multiple coexisting chronic pain (CP) conditions (eg, low-back pain and migraines) within patients has received little attention in literature. The goals of this observational longitudinal study were to determine the prevalence of coexisting CP conditions, identify the most frequent ones and patterns of coexistence, investigate the relationships among patients’ biopsychosocial characteristics and number of CP conditions, and determine the impact of coexisting CP conditions on treatment response. Patients and methods A total of 3,966 patients attending multidisciplinary pain-treatment centers who were enrolled in the Quebec Pain Registry were included. Patients completed self-report and nurse-administered questionnaires before their first visit and 6 months later. Results were analyzed using descriptive statistics, factor and cluster analyses, negative binomials with log-link generalized linear models, and linear mixed-effect models. Results A third of patients reported coexisting CP conditions. No specific patterns of comorbidities emerged. The presence of coexisting CP conditions was associated with longer pain duration, older age, being female, and poorer quality of life. The presence of more than one CP condition did not have a clinically significant impact on treatment responses. Discussion The novelty of the study results relate to the heterogeneity that was found in the patterns of coexistence of CP conditions and the fact that having multiple CP conditions did not clinically impact treatment response. These results highlight the need for future research that examines causes of coexistence among CP conditions across the spectrum of CP, as opposed to focusing on specific conditions, and to examine whether multiple CP conditions impact on additional domains, such as treatment satisfaction. These results highlight the importance of studying the pathophysiological mechanisms underlying the development of coexisting CP conditions, in order eventually to prevent/minimize their occurrence and/or develop optimal treatment and management approaches. PMID:29416373

CELF4 Variant and Anthracycline-Related Cardiomyopathy: A Children’s Oncology Group Genome-Wide Association Study

PubMed Central

Wang, Xuexia; Sun, Can-Lan; Quiñones-Lombraña, Adolfo; Singh, Purnima; Landier, Wendy; Hageman, Lindsey; Mather, Molly; Rotter, Jerome I.; Taylor, Kent D.; Chen, Yii-Der Ida; Armenian, Saro H.; Winick, Naomi; Ginsberg, Jill P.; Neglia, Joseph P.; Oeffinger, Kevin C.; Castellino, Sharon M.; Dreyer, Zoann E.; Hudson, Melissa M.; Robison, Leslie L.; Blanco, Javier G.

2016-01-01

Purpose Interindividual variability in the dose-dependent association between anthracyclines and cardiomyopathy suggests that genetic susceptibility could play a role. The current study uses an agnostic approach to identify genetic variants that could modify cardiomyopathy risk. Methods A genome-wide association study was conducted in childhood cancer survivors with and without cardiomyopathy (cases and controls, respectively). Single-nucleotide polymorphisms (SNPs) that surpassed a prespecified threshold for statistical significance were independently replicated. The possible mechanistic significance of validated SNP(s) was sought by using healthy heart samples. Results No SNP was marginally associated with cardiomyopathy. However, SNP rs1786814 on the CELF4 gene passed the significance cutoff for gene-environment interaction (Pge = 1.14 × 10−5). Multivariable analyses adjusted for age at cancer diagnosis, sex, anthracycline dose, and chest radiation revealed that, among patients with the A allele, cardiomyopathy was infrequent and not dose related. However, among those exposed to greater than 300 mg/m2 of anthracyclines, the rs1786814 GG genotype conferred a 10.2-fold (95% CI, 3.8- to 27.3-fold; P < .001) increased risk of cardiomyopathy compared with those who had GA/AA genotypes and anthracycline exposure of 300 mg/m2 or less. This gene-environment interaction was successfully replicated in an independent set of anthracycline-related cardiomyopathy. CUG-BP and ETR-3-like factor proteins control developmentally regulated splicing of TNNT2, the gene that encodes for cardiac troponin T (cTnT), a biomarker of myocardial injury. Coexistence of more than one cTnT variant results in a temporally split myofilament response to calcium, which causes decreased contractility. Analysis of TNNT2 splicing variants in healthy human hearts suggested an association between the rs1786814 GG genotype and coexistence of more than one TNNT2 splicing variant (90.5% GG v 41.7% GA/AA; P = .005). Conclusion We report a modifying effect of a polymorphism of CELF4 (rs1786814) on the dose-dependent association between anthracyclines and cardiomyopathy, which possibly occurs through a pathway that involves the expression of abnormally spliced TNNT2 variants. PMID:26811534

Microhabitat locality allows multi-species coexistence in terrestrial plant communities.

PubMed

Tubay, Jerrold M; Suzuki, Keisuke; Uehara, Takashi; Kakishima, Satoshi; Ito, Hiromu; Ishida, Atsushi; Yoshida, Katsuhiko; Mori, Shigeta; Rabajante, Jomar F; Morita, Satoru; Yokozawa, Masayuki; Yoshimura, Jin

2015-10-20

Most terrestrial plant communities exhibit relatively high species diversity and many competitive species are ubiquitous. Many theoretical studies have been carried out to investigate the coexistence of a few competitive species and in most cases they suggest competitive exclusion. Theoretical studies have revealed that coexistence of even three or four species can be extremely difficult. It has been suggested that the coexistence of many species has been achieved by the fine differences in suitable microhabitats for each species, attributing to niche-separation. So far there is no explicit demonstration of such a coexistence in mathematical and simulation studies. Here we built a simple lattice Lotka-Volterra model of competition by incorporating the minute differences of suitable microhabitats for many species. By applying the site variations in species-specific settlement rates of a seedling, we achieved the coexistence of more than 10 species. This result indicates that competition between many species is avoided by the spatial variations in species-specific microhabitats. Our results demonstrate that coexistence of many species becomes possible by the minute differences in microhabitats. This mechanism should be applicable to many vegetation types, such as temperate forests and grasslands.

Intransitivity is infrequent and fails to promote annual plant coexistence without pairwise niche differences.

PubMed

Godoy, Oscar; Stouffer, Daniel B; Kraft, Nathan J B; Levine, Jonathan M

2017-05-01

Intransitive competition is often projected to be a widespread mechanism of species coexistence in ecological communities. However, it is unknown how much of the coexistence we observe in nature results from this mechanism when species interactions are also stabilized by pairwise niche differences. We combined field-parameterized models of competition among 18 annual plant species with tools from network theory to quantify the prevalence of intransitive competitive relationships. We then analyzed the predicted outcome of competitive interactions with and without pairwise niche differences. Intransitive competition was found for just 15-19% of the 816 possible triplets, and this mechanism was never sufficient to stabilize the coexistence of the triplet when the pair-wise niche differences between competitors were removed. Of the transitive and intransitive triplets, only four were predicted to coexist and these were more similar in multidimensional trait space defined by 11 functional traits than non-coexisting triplets. Our results argue that intransitive competition may be less frequent than recently posed, and that even when it does operate, pairwise niche differences may be key to possible coexistence. © 2017 by the Ecological Society of America.

Microhabitat locality allows multi-species coexistence in terrestrial plant communities

PubMed Central

Tubay, Jerrold M.; Suzuki, Keisuke; Uehara, Takashi; Kakishima, Satoshi; Ito, Hiromu; Ishida, Atsushi; Yoshida, Katsuhiko; Mori, Shigeta; Rabajante, Jomar F.; Morita, Satoru; Yokozawa, Masayuki; Yoshimura, Jin

2015-01-01

Most terrestrial plant communities exhibit relatively high species diversity and many competitive species are ubiquitous. Many theoretical studies have been carried out to investigate the coexistence of a few competitive species and in most cases they suggest competitive exclusion. Theoretical studies have revealed that coexistence of even three or four species can be extremely difficult. It has been suggested that the coexistence of many species has been achieved by the fine differences in suitable microhabitats for each species, attributing to niche-separation. So far there is no explicit demonstration of such a coexistence in mathematical and simulation studies. Here we built a simple lattice Lotka-Volterra model of competition by incorporating the minute differences of suitable microhabitats for many species. By applying the site variations in species-specific settlement rates of a seedling, we achieved the coexistence of more than 10 species. This result indicates that competition between many species is avoided by the spatial variations in species-specific microhabitats. Our results demonstrate that coexistence of many species becomes possible by the minute differences in microhabitats. This mechanism should be applicable to many vegetation types, such as temperate forests and grasslands. PMID:26483077

Multi-species coexistence in Lotka-Volterra competitive systems with crowding effects.

PubMed

Gavina, Maica Krizna A; Tahara, Takeru; Tainaka, Kei-Ichi; Ito, Hiromu; Morita, Satoru; Ichinose, Genki; Okabe, Takuya; Togashi, Tatsuya; Nagatani, Takashi; Yoshimura, Jin

2018-01-19

Classical Lotka-Volterra (LV) competition equation has shown that coexistence of competitive species is only possible when intraspecific competition is stronger than interspecific competition, i.e., the species inhibit their own growth more than the growth of the other species. Note that density effect is assumed to be linear in a classical LV equation. In contrast, in wild populations we can observed that mortality rate often increases when population density is very high, known as crowding effects. Under this perspective, the aggregation models of competitive species have been developed, adding the additional reduction in growth rates at high population densities. This study shows that the coexistence of a few species is promoted. However, an unsolved question is the coexistence of many competitive species often observed in natural communities. Here, we build an LV competition equation with a nonlinear crowding effect. Our results show that under a weak crowding effect, stable coexistence of many species becomes plausible, unlike the previous aggregation model. An analysis indicates that increased mortality rate under high density works as elevated intraspecific competition leading to the coexistence. This may be another mechanism for the coexistence of many competitive species leading high species diversity in nature.

Persistent coexistence of cyclically competing species in spatially extended ecosystems

NASA Astrophysics Data System (ADS)

Park, Junpyo; Do, Younghae; Huang, Zi-Gang; Lai, Ying-Cheng

2013-06-01

A fundamental result in the evolutionary-game paradigm of cyclic competition in spatially extended ecological systems, as represented by the classic Reichenbach-Mobilia-Frey (RMF) model, is that high mobility tends to hamper or even exclude species coexistence. This result was obtained under the hypothesis that individuals move randomly without taking into account the suitability of their local environment. We incorporate local habitat suitability into the RMF model and investigate its effect on coexistence. In particular, we hypothesize the use of "basic instinct" of an individual to determine its movement at any time step. That is, an individual is more likely to move when the local habitat becomes hostile and is no longer favorable for survival and growth. We show that, when such local habitat suitability is taken into account, robust coexistence can emerge even in the high-mobility regime where extinction is certain in the RMF model. A surprising finding is that coexistence is accompanied by the occurrence of substantial empty space in the system. Reexamination of the RMF model confirms the necessity and the important role of empty space in coexistence. Our study implies that adaptation/movements according to local habitat suitability are a fundamental factor to promote species coexistence and, consequently, biodiversity.

Variation in moisture duration as a driver of coexistence by the storage effect in desert annual plants.

PubMed

Holt, Galen; Chesson, Peter

2014-03-01

Temporal environmental variation is a leading hypothesis for the coexistence of desert annual plants. Environmental variation is hypothesized to cause species-specific patterns of variation in germination, which then generates the storage effect coexistence mechanism. However, it has never been shown how sufficient species differences in germination patterns for multispecies coexistence can arise from a shared fluctuating environment. Here we show that nonlinear germination responses to a single fluctuating physical environmental factor can lead to sufficient differences between species in germination pattern for the storage effect to yield coexistence of multiple species. We derive these nonlinear germination responses from experimental data on the effects of varying soil moisture duration. Although these nonlinearities lead to strong species asymmetries in germination patterns, the relative nonlinearity coexistence mechanism is minor compared with the storage effect. However, these asymmetries mean that the storage effect can be negative for some species, which then only persist in the face of interspecific competition through average fitness advantages. This work shows how a low dimensional physical environment can nevertheless stabilize multispecies coexistence when the species have different nonlinear responses to common conditions, as supported by our experimental data. Copyright © 2013 Elsevier Inc. All rights reserved.

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-10-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runnersmore » tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise.« less

Scaling of Myocardial Mass to Flow and Morphometry of Coronary Arteries

PubMed Central

Choy, Jenny Susana; Kassab, Ghassan S.

2009-01-01

There is no doubt that scaling relations exist between myocardial mass and morphometry of coronary vasculature. The purpose of this study is to quantify several morphological (diameter, length, and volume) and functional (flow) parameters of the coronary arterial tree in relation to myocardial mass. Eight normal porcine hearts of 117-244 g (mean of 177.5±32.7) were used in this study. Various coronary sub-trees of the Left Anterior Descending (LAD), Right Coronary (RCA) and Left Circumflex (LCX) arteries were perfused at pressure of 100 mmHg with different colors of a polymer (Microfil) in order to obtain rubber casts of arterial trees corresponding to different regions of myocardial mass. Volume, diameter and cumulative length of coronary arteries were reconstructed from casts to analyze their relationship to the perfused myocardial mass. Volumetric flow was measured in relationship with perfused myocardial mass. Our results show that arterial volume is linearly related to regional myocardial mass, whereas the sum of coronary arterial branch lengths, vessel diameters and volumetric flow show an approximately 3/4, 3/8 and 3/4 power-law relationship, respectively, in relation to myocardial mass. These scaling laws suggest fundamental design principles underlying the structure-function relationship of the coronary arterial tree that may facilitate diagnosis and management of diffuse coronary artery disease. PMID:18323461

Scaling of myocardial mass to flow and morphometry of coronary arteries.

PubMed

Choy, Jenny Susana; Kassab, Ghassan S

2008-05-01

There is no doubt that scaling relations exist between myocardial mass and morphometry of coronary vasculature. The purpose of this study is to quantify several morphological (diameter, length, and volume) and functional (flow) parameters of the coronary arterial tree in relation to myocardial mass. Eight normal porcine hearts of 117-244 g (mean of 177.5 +/- 32.7) were used in this study. Various coronary subtrees of the left anterior descending, right coronary, and left circumflex arteries were perfused at pressure of 100 mmHg with different colors of a polymer (Microfil) to obtain rubber casts of arterial trees corresponding to different regions of myocardial mass. Volume, diameter, and cumulative length of coronary arteries were reconstructed from casts to analyze their relationship to the perfused myocardial mass. Volumetric flow was measured in relationship with perfused myocardial mass. Our results show that arterial volume is linearly related to regional myocardial mass, whereas the sum of coronary arterial branch lengths, vessel diameters, and volumetric flow show an approximately 3/4, 3/8, and 3/4 power-law relationship, respectively, in relation to myocardial mass. These scaling laws suggest fundamental design principles underlying the structure-function relationship of the coronary arterial tree that may facilitate diagnosis and management of diffuse coronary artery disease.

Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

PubMed

Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

2016-06-01

We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction. © Georg Thieme Verlag KG Stuttgart · New York.

Prostate-specific antigen and acute myocardial infarction: a possible new intriguing scenario.

PubMed

Patanè, Salvatore; Marte, Filippo

2009-05-29

Prostate-specific antigen (PSA) has been identified as a member of the human kallikrein family of serine proteases and it is an established marker for detection of prostate cancer. Apparently spurious result has been reported in a work about mean serum PSA concentration during acute myocardial infarction with mean serum PSA concentration significantly lower on day 2 than either day 1 or day 3 and it has been reported that these preliminary results could reflect several factors, such as antiinfarctual treatment, reduced physical activity or an acute-phase response. Elevation of prostate-specific antigen has also been reported during acute myocardial infarction in three patients and in another one also after transurethral resection of the prostate (TURP) and without histological diagnosis of prostate cancer. In our report we present three cases of diminution of serum PSA concentration during acute myocardial infarction. Our report extends the evaluation of PSA during acute myocardial infarction. It seems that when elevation of prostate-specific antigen occurs during acute myocardial infarction, coronary lesions are frequent and often more severe than when diminution of prostate-specific antigen occurs during acute myocardial infarction. It opens a possible new intriguing scenario of the role of the prostate-specific antigen in acute myocardial infarction.

Cocaine, a risk factor for myocardial infarction.

PubMed

Galasko, G I

1997-06-01

Cocaine usage goes back thousands of years, to the times of the Incas. Over the past 20 years, its use has increased dramatically, especially in America, and adverse cardiovascular reactions to the drug have begun to be reported. The first report of myocardial infarction temporally related to the recreational use of cocaine appeared in 1982. Since then, myocardial infarction has become recognized as the drug's most common cardiovascular consequence, with over 250 cases now documented in the literature. This review discusses the history of cocaine use, its pharmacology, the possible pathological mechanisms underlying the pathogenesis of myocardial ischaemia and infarction, and current ideas on the management of cocaine-induced myocardial infarction.

Thallium-201 scintigraphy in the diagnosis and management of myocardial sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, C.L.; Ossorio, M.A.; Roy, T.M.

1990-03-01

We have described three patients with clinical evidence of myocardial sarcoidosis to illustrate the utility of thallium-201 scintigraphy in demonstrating the myocardial lesions. Both the symptomatic and asymptomatic individuals studied showed the characteristic reverse redistribution phenomenon. No abnormalities were seen during the exercise phase of the thallium study, but myocardial defects were detected in each patient when repeat studies were obtained at rest six hours later. Steroid therapy resolved the defects in each case. We propose thallium-201 scintigraphy of the heart as a safe and useful tool for documenting myocardial involvement in sarcoidosis and following the effects of therapy.

Imaging of Myocardial Fatty Acid Oxidation

PubMed Central

Mather, Kieren J; DeGrado, Tim

2016-01-01

Myocardial fuel selection is a key feature of the health and function of the heart, with clear links between myocardial function and fuel selection and important impacts of fuel selection on ischemia tolerance. Radiopharmaceuticals provide uniquely valuable tools for in vivo, non-invasive assessment of these aspects of cardiac function and metabolism. Here we review the landscape of imaging probes developed to provide noninvasive assessment of myocardial fatty acid oxidation (MFAO). Also, we review the state of current knowledge that myocardial fatty acid imaging has helped establish of static and dynamic fuel selection that characterizes cardiac and cardiometabolic disease and the interplay between fuel selection and various aspects of cardiac function. PMID:26923433

Effect of uridine derivatives on myocardial stunning during postischemic reperfusion of rat heart.

PubMed

Sapronov, N S; Eliseev, V V; Rodionova, O M

2000-10-01

Uridine and uridine-5'-monophosphate prevent myocardial stunning during postischemic reperfusion of isolated rat heart. Uridine-5'-diphosphate does not prevent postischemic myocardial dysfunction, while uridine-5'-triphosphate aggravates it.

Meta-Analysis of Stress Myocardial Perfusion Imaging

ClinicalTrials.gov

2017-06-06

Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

Ischaemic heart disease following conventional and hypofractionated radiation treatment in a contemporary breast cancer series.

PubMed

James, Melissa; Swadi, Sami; Yi, Ma; Johansson, Lisa; Robinson, Bridget; Dixit, Ashutosh

2018-06-01

We report the incidence of ischaemic cardiac toxicity in a contemporary cohort of patients receiving conventional (CFRT) or hypofractionated (HFRT) radiation after surgery for early breast cancer and investigate the interplay of cardiac risk factors and fractionation. Included were patients receiving external beam radiation treatment from 2002 to 2006 at the Christchurch public hospital. Hospital coding databases, oncology databases and medical records were reviewed for baseline characteristics, treatment details and outcomes. The primary outcome was cardiac toxicity (including myocardial infarction, admission for cardiac chest pain, coronary angiogram positivity and ischaemic cardiac death). Kaplan-Meier methods were used to derive ischaemic cardiac event free and overall survival. Predefined univariate and multivariate analysis was performed to investigate interaction with radiation fraction size, cardiac risk factors, age and side of cancer. Standardised mortality ratios were constructed. Five hundred and one patients were identified, 220 treated with CFRT and 281 with HFRT. The median age was 56 and median follow-up 10.33 years. The 10-year breast cancer specific survival was 81.8% (95% CI %.78.1-85.0). The 10-year freedom from cardiac death was 98.6% (95% CI 96.9-99.4). There were 27 post radiation cardiac events including 5 cardiac deaths and 19 cases of acute myocardial infarction. 265 (53%) had at least one cardiac risk factor. Twenty five of the 27 patients with a cardiac event had cardiac risk factors. On univariate and multivariate analysis, fractionation schedule was not significantly associated with a post radiation ischaemic event, however, there was a significant relationship with age and the presence of a cardiac risk factor. The standardised mortality ratio was 0.89 (95% CI: 0-3.13). Our study has shown a low rate of ischaemic cardiac disease for both CFRT and HFRT in women treated for breast cancer with no evidence of an effect with fractionation schedule. Coexisting cardiac risk factors are common in the population. © 2018 The Royal Australian and New Zealand College of Radiologists.

What is the mechanism for persistent coexistence of drug-susceptible and drug-resistant strains of Streptococcus pneumoniae?

PubMed Central

Colijn, Caroline; Cohen, Ted; Fraser, Christophe; Hanage, William; Goldstein, Edward; Givon-Lavi, Noga; Dagan, Ron; Lipsitch, Marc

2010-01-01

The rise of antimicrobial resistance in many pathogens presents a major challenge to the treatment and control of infectious diseases. Furthermore, the observation that drug-resistant strains have risen to substantial prevalence but have not replaced drug-susceptible strains despite continuing (and even growing) selective pressure by antimicrobial use presents an important problem for those who study the dynamics of infectious diseases. While simple competition models predict the exclusion of one strain in favour of whichever is ‘fitter’, or has a higher reproduction number, we argue that in the case of Streptococcus pneumoniae there has been persistent coexistence of drug-sensitive and drug-resistant strains, with neither approaching 100 per cent prevalence. We have previously proposed that models seeking to understand the origins of coexistence should not incorporate implicit mechanisms that build in stable coexistence ‘for free’. Here, we construct a series of such ‘structurally neutral’ models that incorporate various features of bacterial spread and host heterogeneity that have been proposed as mechanisms that may promote coexistence. We ask to what extent coexistence is a typical outcome in each. We find that while coexistence is possible in each of the models we consider, it is relatively rare, with two exceptions: (i) allowing simultaneous dual transmission of sensitive and resistant strains lets coexistence become a typical outcome, as does (ii) modelling each strain as competing more strongly with itself than with the other strain, i.e. self-immunity greater than cross-immunity. We conclude that while treatment and contact heterogeneity can promote coexistence to some extent, the in-host interactions between strains, particularly the interplay between coinfection, multiple infection and immunity, play a crucial role in the long-term population dynamics of pathogens with drug resistance. PMID:19940002

Myocardial Dysfunction and Shock after Cardiac Arrest

PubMed Central

Jentzer, Jacob C.; Chonde, Meshe D.; Dezfulian, Cameron

2015-01-01

Postarrest myocardial dysfunction includes the development of low cardiac output or ventricular systolic or diastolic dysfunction after cardiac arrest. Impaired left ventricular systolic function is reported in nearly two-thirds of patients resuscitated after cardiac arrest. Hypotension and shock requiring vasopressor support are similarly common after cardiac arrest. Whereas shock requiring vasopressor support is consistently associated with an adverse outcome after cardiac arrest, the association between myocardial dysfunction and outcomes is less clear. Myocardial dysfunction and shock after cardiac arrest develop as the result of preexisting cardiac pathology with multiple superimposed insults from resuscitation. The pathophysiology involves cardiovascular ischemia/reperfusion injury and cardiovascular toxicity from excessive levels of inflammatory cytokine activation and catecholamines, among other contributing factors. Similar mechanisms occur in myocardial dysfunction after cardiopulmonary bypass, in sepsis, and in stress-induced cardiomyopathy. Hemodynamic stabilization after resuscitation from cardiac arrest involves restoration of preload, vasopressors to support arterial pressure, and inotropic support if needed to reverse the effects of myocardial dysfunction and improve systemic perfusion. Further research is needed to define the role of postarrest myocardial dysfunction on cardiac arrest outcomes and identify therapeutic strategies. PMID:26421284

Myocardial Dysfunction and Shock after Cardiac Arrest.

PubMed

Jentzer, Jacob C; Chonde, Meshe D; Dezfulian, Cameron

2015-01-01

Postarrest myocardial dysfunction includes the development of low cardiac output or ventricular systolic or diastolic dysfunction after cardiac arrest. Impaired left ventricular systolic function is reported in nearly two-thirds of patients resuscitated after cardiac arrest. Hypotension and shock requiring vasopressor support are similarly common after cardiac arrest. Whereas shock requiring vasopressor support is consistently associated with an adverse outcome after cardiac arrest, the association between myocardial dysfunction and outcomes is less clear. Myocardial dysfunction and shock after cardiac arrest develop as the result of preexisting cardiac pathology with multiple superimposed insults from resuscitation. The pathophysiology involves cardiovascular ischemia/reperfusion injury and cardiovascular toxicity from excessive levels of inflammatory cytokine activation and catecholamines, among other contributing factors. Similar mechanisms occur in myocardial dysfunction after cardiopulmonary bypass, in sepsis, and in stress-induced cardiomyopathy. Hemodynamic stabilization after resuscitation from cardiac arrest involves restoration of preload, vasopressors to support arterial pressure, and inotropic support if needed to reverse the effects of myocardial dysfunction and improve systemic perfusion. Further research is needed to define the role of postarrest myocardial dysfunction on cardiac arrest outcomes and identify therapeutic strategies.

[The role of the adreno-cholinergic interaction in the pulmonary hemodynamics changes following myocardial ischemia].

PubMed

Evlakhov, V I; Poiasov, I Z

2014-06-01

In acute experiments in anesthetized rabbits the pulmonary hemodynamics changes were studied following 60 s myocardial ischemia in the region of the descendent left coronary artery in control state and after the blockade of M- or N-cholinoreceptors and acetylcholine infusion. Following myocardial ischemia in control animals the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance was not changed. Following myocardial ischemia after the blockade of M-cholinoreceptors by atropine the changes of pulmonary hemodynamics were the same as in control animals, the cardiac output decreased twice as more as in control animals. Following myocardial ischemia after the blockade of N-cholinoreceptors by hexamethonium the pulmonary hemodynamics changes were the same as in the control rabbits. Following myocardial ischemia after the acetylcholine infusion the pulmonary artery flow decreased more than the cardiac output, the pulmonary vascular resistance was diminished. The disbalance of the cardiac output and pulmonary artery flow changes has revealed the significance of the adreno-cholinergic interaction in the changes of the pulmonary vessels capacitance and resistive functions following myocardial ischemia.

Evaluation of cerebral-cardiac syndrome using echocardiography in a canine model of acute traumatic brain injury.

PubMed

Qian, Rong; Yang, Weizhong; Wang, Xiumei; Xu, Zhen; Liu, Xiaodong; Sun, Bing

2015-01-01

Previous studies have confirmed that traumatic brain injury (TBI) can induce general adaptation syndrome (GAS), which subsequently results in myocardial dysfunction and damage in some patients with acute TBI; this condition is also termed as cerebral-cardiac syndrome. However, most clinicians ignore the detection and treatment of myocardial dysfunction, and instead concentrate only on the serious neural damage that is observed in acute TBI, which is one of the most important fatal factors. Therefore, clarification is urgently needed regarding the relationship between TBI and myocardial dysfunction. In the present study, we evaluated 18 canine models of acute TBI, by using real-time myocardial contrast echocardiography and strain rate imaging to accurately evaluate myocardial function and regional microcirculation, including the strain rate of the different myocardial segments, time-amplitude curves, mean ascending slope of the curve, and local myocardial blood flow. Our results suggest that acute TBI often results in cerebral-cardiac syndrome, which rapidly progresses to the serious stage within 3 days. This study is the first to provide comprehensive ultrasonic characteristics of cerebral-cardiac syndrome in an animal model of TBI.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gropler, R.J.; Siegel, B.A.; Lee, K.J.

In initial studies using fluorine-18-fluorodeoxyglucose (FDG) in normal fasted subjects, we observed disparities in the regional myocardial accumulation of this tracer. Accordingly, we systematically evaluated regional myocardial FDG accumulation in comparison with regional myocardial perfusion assessed with oxygen-15-water and oxidative metabolism assessed with carbon-11-acetate in nine normal subjects (four studied after a 5-hr fast and five studied both fasted and following glucose loading). Under fasting conditions, myocardial accumulation of FDG in the septum and anterior wall averaged 80% of that in the lateral and posterior walls (p less than 0.03). In contrast, after glucose loading the regional distribution of myocardialmore » FDG accumulation became more homogeneous. Regional myocardial perfusion, oxidative metabolism, and accumulation of carbon-11-acetate were homogeneous under both conditions. Thus, under fasting conditions there are regional variations in myocardial accumulation of FDG, which are visually apparent, are not associated with concomitant changes in oxidative metabolism or perfusion, and cannot be attributed to partial-volume effects. This significant heterogeneity may limit the specificity of PET with FDG for detecting myocardial ischemia in fasting subjects.« less

Opting out against defection leads to stable coexistence with cooperation.

PubMed

Zhang, Bo-Yu; Fan, Song-Jia; Li, Cong; Zheng, Xiu-Deng; Bao, Jian-Zhang; Cressman, Ross; Tao, Yi

2016-10-24

Cooperation coexisting with defection is a common phenomenon in nature and human society. Previous studies for promoting cooperation based on kin selection, direct and indirect reciprocity, graph selection and group selection have provided conditions that cooperators outcompete defectors. However, a simple mechanism of the long-term stable coexistence of cooperation and defection is still lacking. To reveal the effect of direct reciprocity on the coexistence of cooperation and defection, we conducted a simple experiment based on the Prisoner's Dilemma (PD) game, where the basic idea behind our experiment is that all players in a PD game should prefer a cooperator as an opponent. Our experimental and theoretical results show clearly that the strategies allowing opting out against defection are able to maintain this stable coexistence.

Gas-liquid phase coexistence in quasi-two-dimensional Stockmayer fluids: A molecular dynamics study.

PubMed

Ouyang, Wen-Ze; Xu, Sheng-Hua; Sun, Zhi-Wei

2011-01-07

The Maxwell construction together with molecular dynamics simulation is used to study the gas-liquid phase coexistence of quasi-two-dimensional Stockmayer fluids. The phase coexistence curves and corresponding critical points under different dipole strength are obtained, and the critical properties are calculated. We investigate the dependence of the critical point and critical properties on the dipole strength. When the dipole strength is increased, the abrupt disappearance of the gas-liquid phase coexistence in quasi-two-dimensional Stockmayer fluids is not found. However, if the dipole strength is large enough, it does lead to the formation of very long reversible chains which makes the relaxation of the system very slow and the observation of phase coexistence rather difficult or even impossible.

38 CFR 4.113 - Coexisting abdominal conditions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SCHEDULE FOR RATING DISABILITIES Disability Ratings The Digestive System § 4.113 Coexisting abdominal conditions. There are diseases of the digestive system, particularly within the abdomen, which, while... coexisting diseases in this area, as indicated in the instruction under the title “Diseases of the Digestive...

38 CFR 4.113 - Coexisting abdominal conditions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SCHEDULE FOR RATING DISABILITIES Disability Ratings The Digestive System § 4.113 Coexisting abdominal conditions. There are diseases of the digestive system, particularly within the abdomen, which, while... coexisting diseases in this area, as indicated in the instruction under the title “Diseases of the Digestive...

38 CFR 4.113 - Coexisting abdominal conditions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SCHEDULE FOR RATING DISABILITIES Disability Ratings The Digestive System § 4.113 Coexisting abdominal conditions. There are diseases of the digestive system, particularly within the abdomen, which, while... coexisting diseases in this area, as indicated in the instruction under the title “Diseases of the Digestive...

38 CFR 4.113 - Coexisting abdominal conditions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SCHEDULE FOR RATING DISABILITIES Disability Ratings The Digestive System § 4.113 Coexisting abdominal conditions. There are diseases of the digestive system, particularly within the abdomen, which, while... coexisting diseases in this area, as indicated in the instruction under the title “Diseases of the Digestive...

38 CFR 4.113 - Coexisting abdominal conditions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SCHEDULE FOR RATING DISABILITIES Disability Ratings The Digestive System § 4.113 Coexisting abdominal conditions. There are diseases of the digestive system, particularly within the abdomen, which, while... coexisting diseases in this area, as indicated in the instruction under the title “Diseases of the Digestive...

78 FR 65960 - Enhancing Agricultural Coexistence; Request for Public Input

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-04

... potential joint coexistence plans,\\3\\ i.e., voluntary written plans specifying farming practices (such as... communication, planning, and crop-specific practices to facilitate successful coexistence. What tools and... in diverse agricultural systems, we are interested in hearing what practices and activities that...

Intraspecific density dependence and a guild of consumers coexisting on one resource.

PubMed

McPeek, Mark A

2012-12-01

The importance of negative intraspecific density dependence to promoting species coexistence in a community is well accepted. However, such mechanisms are typically omitted from more explicit models of community dynamics. Here I analyze a variation of the Rosenzweig-MacArthur consumer-resource model that includes negative intraspecific density dependence for consumers to explore its effect on the coexistence of multiple consumers feeding on a single resource. This analysis demonstrates that a guild of multiple consumers can easily coexist on a single resource if each limits its own abundance to some degree, and stronger intraspecific density dependence permits a wider variety of consumers to coexist. The mechanism permitting multiple consumers to coexist works in a fashion similar to apparent competition or to each consumer having its own specialized predator. These results argue for a more explicit emphasis on how negative intraspecific density dependence is generated and how these mechanisms combine with species interactions to shape overall community structure.

Acute myocardial infarction with changing axis deviation.

PubMed

Patanè, Salvatore; Marte, Filippo

2011-07-01

Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been rarely reported also during acute myocardial infarction associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. Left anterior hemiblock development during acute inferior myocardial infarction can be an indicator of left anterior descending coronary artery lesions, multivessel coronary artery disease, and impaired left ventricular systolic function. We present a case of changing axis deviation in a 62-year-old Italian man with acute myocardial infarction. Also this case focuses attention on changing axis deviation during acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Taxonomy of segmental myocardial systolic dysfunction.

PubMed

McDiarmid, Adam K; Pellicori, Pierpaolo; Cleland, John G; Plein, Sven

2017-04-01

The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms 'viable' and 'hibernating' are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Myocardial inflammation, cellular death, and viral detection in sudden infant death caused by SIDS, suffocation, or myocarditis.

PubMed

Krous, Henry F; Ferandos, Christine; Masoumi, Homeyra; Arnold, John; Haas, Elisabeth A; Stanley, Christina; Grossfeld, Paul D

2009-07-01

The significance of minor myocardial inflammatory infiltrates and viral detection in SIDS is controversial. We retrospectively compared the demographic profiles, myocardial inflammation, cardiomyocyte necrosis, and myocardial virus detection in infants who died of SIDS in a safe sleep environment, accidental suffocation, or myocarditis. Formalin-fixed, paraffin-embedded myocardial sections were semiquantitatively assessed for CD3 lymphocytes and CD68 macrophages using immunohistochemistry and for cardiomyocyte cell death in H&E-stained sections. Enteroviruses and adenoviruses were searched for using PCR technology. The means of lymphocytes, macrophages, and necrotic cardiomyocytes were not statistically different in SIDS and suffocation cases. Enterovirus, not otherwise specified, was detected in one suffocation case and was the only virus detected in the three groups. Very mild myocardial lymphocyte and macrophage infiltration and scattered necrotic cardiomyocytes in SIDS are not pathologic, but may occur after the developing heart is exposed to environmental pathogens, including viruses.

Reducing myocardial infarct size: challenges and future opportunities

PubMed Central

Bulluck, Heerajnarain; Yellon, Derek M; Hausenloy, Derek J

2016-01-01

Despite prompt reperfusion by primary percutaneous coronary intervention (PPCI), the mortality and morbidity of patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) remain significant with 9% death and 10% heart failure at 1 year. In these patients, one important neglected therapeutic target is ‘myocardial reperfusion injury’, a term given to the cardiomyocyte death and microvascular dysfunction which occurs on reperfusing ischaemic myocardium. A number of cardioprotective therapies (both mechanical and pharmacological), which are known to target myocardial reperfusion injury, have been shown to reduce myocardial infarct (MI) size in small proof-of-concept clinical studies—however, being able to demonstrate improved clinical outcomes has been elusive. In this article, we review the challenges facing clinical cardioprotection research, and highlight future therapies for reducing MI size and preventing heart failure in patients presenting with STEMI at risk of myocardial reperfusion injury. PMID:26674987

Norepinephrine turnover in heart and spleen of 7-, 22-, and 34 C-acclimated hamsters

NASA Technical Reports Server (NTRS)

Jones, S. B.; Musacchia, X. J.

1976-01-01

The relationship of norepinephrine (NE) concentration and endogenous turnover rates in both myocardial and spleen tissues in the golden hamster is examined as a function of chronic exposure to either high or low ambient temperatures. Changes in myocardial and spleen NE turnover values are discussed in terms of functional alterations in sympathetic nerve activity and the importance of such changes in temperature acclimation. It is found that acclimation of hamsters to 7 C for 7-10 weeks results in decreased myocardial NE concentration and an apparent increase in myocardial NE turnover. In contrast, exposure to 34 C for 6-8 weeks results in increased myocardial NE concentration and an apparent decrease in NE turnover in both myocardial and spleen tissues. The implication of altered NE synthesis is that sympathetic nerve activity is reduced with heat acclimation and is enhanced with cold acclimation.

Basins of coexistence and extinction in spatially extended ecosystems of cyclically competing species.

PubMed

Ni, Xuan; Yang, Rui; Wang, Wen-Xu; Lai, Ying-Cheng; Grebogi, Celso

2010-12-01

Microscopic models based on evolutionary games on spatially extended scales have recently been developed to address the fundamental issue of species coexistence. In this pursuit almost all existing works focus on the relevant dynamical behaviors originated from a single but physically reasonable initial condition. To gain comprehensive and global insights into the dynamics of coexistence, here we explore the basins of coexistence and extinction and investigate how they evolve as a basic parameter of the system is varied. Our model is cyclic competitions among three species as described by the classical rock-paper-scissors game, and we consider both discrete lattice and continuous space, incorporating species mobility and intraspecific competitions. Our results reveal that, for all cases considered, a basin of coexistence always emerges and persists in a substantial part of the parameter space, indicating that coexistence is a robust phenomenon. Factors such as intraspecific competition can, in fact, promote coexistence by facilitating the emergence of the coexistence basin. In addition, we find that the extinction basins can exhibit quite complex structures in terms of the convergence time toward the final state for different initial conditions. We have also developed models based on partial differential equations, which yield basin structures that are in good agreement with those from microscopic stochastic simulations. To understand the origin and emergence of the observed complicated basin structures is challenging at the present due to the extremely high dimensional nature of the underlying dynamical system. © 2010 American Institute of Physics.

Prospective evaluation of eligibility for thrombolytic therapy in acute myocardial infarction.

PubMed Central

French, J. K.; Williams, B. F.; Hart, H. H.; Wyatt, S.; Poole, J. E.; Ingram, C.; Ellis, C. J.; Williams, M. G.; White, H. D.

1996-01-01

OBJECTIVES--To determine the proportion of patients presenting with acute myocardial infarction who are eligible for thrombolytic therapy. DESIGN--Cohort follow up study. SETTING--The four coronary care units in Auckland, New Zealand. SUBJECTS--All 3014 patients presenting to the units with suspected myocardial infarction in 1993. MAIN OUTCOME MEASURES--Eligibility for reperfusion with thrombolytic therapy (presentation within 12 hours of the onset of ischaemic chest pain with ST elevation > or = 2 mm in leads V1-V3, ST elevation > or = 1 mm in any other two contiguous leads, or new left bundle branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (including causes); definite myocardial infarction. RESULTS--948 patients had definite myocardial infarction, 124 probable myocardial infarction, and nine ST elevation but no infarction; 1274 patients had unstable angina and 659 chest pain of other causes. Of patients with definite or probable myocardial infarction, 576 (53.3%) were eligible for reperfusion, 39 had definite contraindications to thrombolysis (risk of bleeding). Hence 49.7% of patients (537/1081) were eligible for thrombolysis and 43.5% (470) received this treatment. Hospital mortality among patients eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. CONCLUSIONS--On current criteria about half of patients admitted to coronary care units with definite or probable myocardial infarction are eligible for thrombolytic therapy. Few eligible patients have definite contraindications to thrombolytic therapy. Mortality for all community admissions for myocardial infarction remains high. PMID:8664716

Radionuclide imaging of myocardial infarction using Tc-99m TBI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holman, B.L.; Campbell, S.; Kirshenbaum, J.M.

The cationic complex Tc-99m t-butylisonitrile (TBI) concentrates in the myocardial tissue of several animal species. Its myocardial distribution is proportional to blood flow both in zones of ischemia and in normal myocardium at rest. Planar, tomographic, and gated myocardial images have been obtained using Tc-99m TBI in the human. The authors investigated the potential application of Tc-99m TBI imaging to detect and localize myocardial infarction. Four subjects without clinical evidence of cardiovascular disease and five patients with ECG evidence of previous myocardial infarction were studied. Tc-99m TBI (10mCi) was injected intravenously with the patient in a resting state with planarmore » imaging in the anterior, 30 and 70 degree LAO projections beginning one hr after injection. The distribution of the tracer was homogeneous throughout the left ventricular wall in the normal subjects. Regional perfusion defects were present in 4/5 of the patients with myocardial infarction. Location of the defects corresponded to the location of the infarct using ECG criteria (2 inferoposterior and 2 anterior). The patient in whom the Tc-99m TBI image appeared normal had sustained a subendocardial myocardial infarct which could not be localized by ECG; the other 4 pts had transmural infarcts. Anterior and 30 degree LAO images were of excellent quality in all cases; there was overlap of the liver on the inferior wall of the left ventricle on the 70 degree LAO views. The authors conclude that accurate perfusion imaging may be possible using Tc-99m TBI in patients with transmural myocardial infarction.« less

Effects of oxymatrine on sympathoexcitatory reflex induced by myocardial ischemic signaling mediated by P2X₃ receptors in rat SCG and DRG.

PubMed

Li, Guilin; Liu, Shuangmei; Yang, Yang; Xie, Jinyan; Liu, Jun; Kong, Fanjun; Tu, Guihua; Wu, Raoping; Li, Guodong; Liang, Shangdong

2011-04-05

Sympathoexcitatory reflex is characterized by an increase in blood pressure and sympathetic nerve activity. P2X₃ receptors in SCG neurons are involved in increasing sympathoexcitatory reflex after myocardial ischemic (MI) injury. The present study is aimed to explore the effects of oxymatrine (Oxy) on the transmission of myocardial ischemic signaling mediated by P2X₃ receptors in rat superior cervical ganglia (SCG) and cervical dorsal root ganglia (DRG) in the sympathoexcitatory reflex after myocardial ischemic injury. In this study, the expression levels of P2X₃ immunoreactivity, mRNA and protein were analyzed in SCG and DRG neurons by immunohistochemistry, in situ hybridization and Western blotting. The results show that the myocardial ischemic injury induces the increase of the systolic blood pressure and heart rate and upregulates the expression of P2X₃ receptors in SCG and DRG neurons. Upregulated expression of P2X₃ receptors in SCG and DRG neurons subsequently leads to the aggravated sympathoexcitatory reflex. Oxymatrine reduces the systolic blood pressure and heart rate in myocardial ischemic rats. After myocardial ischemic rats are treated with oxymatrine, the expression levels of P2X₃ immunoreactivity, mRNA and protein are lower than those in myocardial ischemic rats. Oxymatrine may decrease the expression of P2X₃ receptor and depress the aggravated sympathoexcitatory reflex induced by the nociceptive transmission of myocardial ischemic injury via P2X₃ receptors of rat SCG and DRG neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

The natural history of prevalent ischaemic heart disease in middle-aged men.

PubMed

Lampe, F C; Whincup, P H; Wannamethee, S G; Shaper, A G; Walker, M; Ebrahim, S

2000-07-01

To describe the long-term outcome of different forms of symptomatic and asymptomatic ischaemic heart disease in middle-aged men. 7735 men aged 40-59, randomly selected from 24 general practices in Britain were classified into one of seven ischaemic heart disease groups according to a questionnaire and electrocardiogram (ECG): I=diagnosed myocardial infarction; II=unrecognized myocardial infarction; III= diagnosed angina; IV=angina symptoms; V=possible myocardial infarction symptoms; VI=ECG ischaemia or possible myocardial infarction; VII=no evidence of ischaemic heart disease. The association of disease group with a range of fatal and non-fatal outcomes during 15 years of follow-up was assessed. At baseline 25% of men had evidence of ischaemic heart disease (groups I-VI). Risks of major ischaemic heart disease events, total and cardiovascular mortality, stroke, and major cardiovascular events tended to increase strongly from group VII to I. Diagnosed myocardial infarction was associated with a much poorer prognosis than all other groups (including unrecognized infarction) for all cardiovascular outcomes other than stroke. The relative risk associated with ischaemic heart disease at baseline declined dramatically over time. However, men with myocardial infarction who survived event-free for 10 years continued to experience a high excess risk in the subsequent 5 years, in contrast to event-free survivors of angina and other ischaemic heart disease. Adjusted to an average age of 50, the percentage of men surviving for 15 years free of a new major cardiovascular event was 44 for diagnosed myocardial infarction, 52 for unrecognized myocardial infarction, 66 for diagnosed angina, 68 for angina symptoms, 73 for possible myocardial infarction symptoms, 73 for ECG ischaemia, and 79 for no ischaemic heart disease. Comparison of outcome between prevalent and incident myocardial infarction illustrated the improved prognosis of men surviving the initial years after their event. Differing manifestations of prevalent ischaemic heart disease are associated with widely differing outcome, and the majority of middle-aged men in the community who have evidence of ischaemic heart disease short of myocardial infarction survive for 15 years without heart attack or stroke. The excess risk associated with myocardial infarction appears more persistent than that associated with angina and other ischaemic heart disease, remaining high even after 10 years of event-free survival.

Erythropoietin alleviates post-resuscitation myocardial dysfunction in rats potentially through increasing the expression of angiotensin II receptor type 2 in myocardial tissues

PubMed Central

Zhou, Hourong; Huang, Jia; Zhu, Li; Cao, Yu

2018-01-01

Activation of renin-angiotensin system (RAS) is one of the pathological mechanisms associated with myocardial ischemia-reperfusion injury following resuscitation. The present study aimed to determine whether erythropoietin (EPO) improves post-resuscitation myocardial dysfunction and how it affects the renin-angiotensin system. Sprague-Dawley rats were randomly divided into sham, vehicle, epinephrine (EP), EPO and EP + EPO groups. Excluding the sham group, all groups underwent cardiopulmonary resuscitation (CPR) 4 min after asphyxia-induced cardiac arrest (CA). EP and/or EPO was administrated by intravenous injection when CPR began. The results demonstrated that the vehicle group exhibited lower mean arterial pressure, left ventricular systolic pressure, maximal ascending rate of left ventricular pressure during left ventricular isovolumic contraction and maximal descending rate of left ventricular pressure during left ventricular isovolumic relaxation (+LVdP/dt max and -LVdP/dt max, respectively), and higher left ventricular end-diastolic pressure, compared with the sham group following return of spontaneous circulation (ROSC). Few significant differences were observed concerning the myocardial function between the vehicle and EP groups; however, compared with the vehicle group, EPO reversed myocardial function indices following ROSC, excluding-LVdP/dt max. Serum renin and angiotensin (Ang) II levels were measured by ELISA. The serum levels of renin and Ang II were significantly increased in the vehicle group compared with the sham group, which was also observed for the myocardial expression of renin and Ang II receptor type 1 (AT1R), as determined by reverse transcription-quantitative polymerase chain reaction and western blotting. EPO alone did not significantly reduce the high serum levels of renin and Ang II post-resuscitation, but changed the protein levels of renin and AT1R expression in myocardial tissues. However, EPO enhanced the myocardial expression of Ang II receptor type 2 (AT2R) following ROSC. In conclusion, the present study confirmed that CA resuscitation activated the renin-Ang II-AT1R signaling pathway, which may contribute to myocardial dysfunction in rats. The present study confirmed that EPO treatment is beneficial for protecting cardiac function post-resuscitation, and the roles of EPO in alleviating post-resuscitation myocardial dysfunction may potentially be associated with enhanced myocardial expression of AT2R. PMID:29393490

Single High-Sensitivity Cardiac Troponin I to Rule Out Acute Myocardial Infarction.

PubMed

Sandoval, Yader; Smith, Stephen W; Love, Sara A; Sexter, Anne; Schulz, Karen; Apple, Fred S

2017-09-01

This study examined the performance of single high-sensitivity cardiac troponin I (hs-cTnI) measurement strategies to rule out acute myocardial infarction. This was a prospective, observational study of consecutive patients presenting to the emergency department (n = 1631) in whom cTnI measurements were obtained using an investigational hs-cTnI assay. The goals of the study were to determine 1) negative predictive value (NPV) and sensitivity for the diagnosis of acute myocardial infarction, type 1 myocardial infarction, and type 2 myocardial infarction; and 2) safety outcome of acute myocardial infarction or cardiac death at 30 days using hs-cTnI less than the limit of detection (LoD) (<1.9 ng/L) or the High-STEACS threshold (<5 ng/L) alone and in combination with normal electrocardiogram (ECG). Acute myocardial infarction occurred in 170 patients (10.4%), including 68 (4.2%) type 1 myocardial infarction and 102 (6.3%) type 2 myocardial infarction. For hs-cTnI

Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR) black-blood technique: Diagnostic accuracy of visual and semi-quantitative assessment

PubMed Central

2012-01-01

Background The short inversion time inversion recovery (STIR) black-blood technique has been used to visualize myocardial edema, and thus to differentiate acute from chronic myocardial lesions. However, some cardiovascular magnetic resonance (CMR) groups have reported variable image quality, and hence the diagnostic value of STIR in routine clinical practice has been put into question. The aim of our study was to analyze image quality and diagnostic performance of STIR using a set of pulse sequence parameters dedicated to edema detection, and to discuss possible factors that influence image quality. We hypothesized that STIR imaging is an accurate and robust way of detecting myocardial edema in non-selected patients with acute myocardial infarction. Methods Forty-six consecutive patients with acute myocardial infarction underwent CMR (day 4.5, +/- 1.6) including STIR for the assessment of myocardial edema and late gadolinium enhancement (LGE) for quantification of myocardial necrosis. Thirty of these patients underwent a follow-up CMR at approximately six months (195 +/- 39 days). Both STIR and LGE images were evaluated separately on a segmental basis for image quality as well as for presence and extent of myocardial hyper-intensity, with both visual and semi-quantitative (threshold-based) analysis. LGE was used as a reference standard for localization and extent of myocardial necrosis (acute) or scar (chronic). Results Image quality of STIR images was rated as diagnostic in 99.5% of cases. At the acute stage, the sensitivity and specificity of STIR to detect infarcted segments on visual assessment was 95% and 78% respectively, and on semi-quantitative assessment was 99% and 83%, respectively. STIR differentiated acutely from chronically infarcted segments with a sensitivity of 95% by both methods and with a specificity of 99% by visual assessment and 97% by semi-quantitative assessment. The extent of hyper-intense areas on acute STIR images was 85% larger than those on LGE images, with a larger myocardial salvage index in reperfused than in non-reperfused infarcts (p = 0.035). Conclusions STIR with appropriate pulse sequence settings is accurate in detecting acute myocardial infarction (MI) and distinguishing acute from chronic MI with both visual and semi-quantitative analysis. Due to its unique technical characteristics, STIR should be regarded as an edema-weighted rather than a purely T2-weighted technique. PMID:22455461

Application of Large-Scale Aptamer-Based Proteomic Profiling to Planned Myocardial Infarctions.

PubMed

Jacob, Jaison; Ngo, Debby; Finkel, Nancy; Pitts, Rebecca; Gleim, Scott; Benson, Mark D; Keyes, Michelle J; Farrell, Laurie A; Morgan, Thomas; Jennings, Lori L; Gerszten, Robert E

2018-03-20

Emerging proteomic technologies using novel affinity-based reagents allow for efficient multiplexing with high-sample throughput. To identify early biomarkers of myocardial injury, we recently applied an aptamer-based proteomic profiling platform that measures 1129 proteins to samples from patients undergoing septal alcohol ablation for hypertrophic cardiomyopathy, a human model of planned myocardial injury. Here, we examined the scalability of this approach using a markedly expanded platform to study a far broader range of human proteins in the context of myocardial injury. We applied a highly multiplexed, expanded proteomic technique that uses single-stranded DNA aptamers to assay 4783 human proteins (4137 distinct human gene targets) to derivation and validation cohorts of planned myocardial injury, individuals with spontaneous myocardial infarction, and at-risk controls. We found 376 target proteins that significantly changed in the blood after planned myocardial injury in a derivation cohort (n=20; P <1.05E-05, 1-way repeated measures analysis of variance, Bonferroni threshold). Two hundred forty-seven of these proteins were validated in an independent planned myocardial injury cohort (n=15; P <1.33E-04, 1-way repeated measures analysis of variance); >90% were directionally consistent and reached nominal significance in the validation cohort. Among the validated proteins that were increased within 1 hour after planned myocardial injury, 29 were also elevated in patients with spontaneous myocardial infarction (n=63; P <6.17E-04). Many of the novel markers identified in our study are intracellular proteins not previously identified in the peripheral circulation or have functional roles relevant to myocardial injury. For example, the cardiac LIM protein, cysteine- and glycine-rich protein 3, is thought to mediate cardiac mechanotransduction and stress responses, whereas the mitochondrial ATP synthase F 0 subunit component is a vasoactive peptide on its release from cells. Last, we performed aptamer-affinity enrichment coupled with mass spectrometry to technically verify aptamer specificity for a subset of the new biomarkers. Our results demonstrate the feasibility of large-scale aptamer multiplexing at a level that has not previously been reported and with sample throughput that greatly exceeds other existing proteomic methods. The expanded aptamer-based proteomic platform provides a unique opportunity for biomarker and pathway discovery after myocardial injury. © 2017 American Heart Association, Inc.

[Myocardial viability: update in nuclear cardiology].

PubMed

Vallejo, Enrique

2007-01-01

Evaluation of myocardial viability with the aid of radionuclides, is a technique that offers reliable, reproducible information, with an attractive cost-benefit relationship, in the study of the myocardial viability, integrating cardiac molecular, metabolic, and functional aspects. Nowadays, coronary risk stratification in post-myocardial infarction patients pretends to locate them as low-, intermediate, and high risk-subjects that can suffer cardiovascular complications in the very near future. Low-risk patients are characterized by a cardiac-related mortality below 1%, whereas high-risk mortality is greater than 3%. Because of clinical complications following a myocardial infarction are observed during the first month of evolution, clinical guidelines suggest to evaluate the cardiovascular risk before hospital discharge.

Protective effects of combination of quercetin and α-tocopherol on mitochondrial dysfunction and myocardial infarct size in isoproterenol-treated myocardial infarcted rats: biochemical, transmission electron microscopic, and macroscopic enzyme mapping evidences.

PubMed

Punithavathi, V R; Stanely Mainzen Prince, P

2010-01-01

Mitochondrial dysfunction plays an important role in the pathology of myocardial infarction. We evaluated the combined protective effects of quercetin and α-tocopherol on mitochondrial damage and myocardial infarct size in isoproterenol-induced myocardia- infarcted rats. Rats were pretreated with quercetin (10 mg/kg) alone, α-tocopherol (10 mg/kg) alone, and combination of quercetin (10 mg/kg) and α-tocopherol (10 mg/kg) orally using an intragastric tube daily for 14 days. After pretreatment, rats were induced myocardial infarction by isoproterenol (100 mg/kg) at an interval of 24 h for 2 days. Isoproterenol treatment caused significant increase in mitochondrial lipid peroxides with significant decrease in mitochondrial antioxidants. Significant decrease in the activities of isocitrate, succinate, malate, and α-ketoglutarate and NADH dehydrogenases and cytochrome-c-oxidase, significant increase in calcium, and significant decrease in adenosine triphosphate were observed in mitochondria of myocardial infarcted rats. Combined pretreatment with quercetin and α-tocopherol normalized all the biochemical parameters and preserved the integrity of heart tissue and restored normal mitochondrial function in myocardial-infarcted rats. Transmission electron microscopic findings on heart mitochondria and macroscopic enzyme mapping assay on the size of myocardial infarct also correlated with these biochemical parameters. The present study showed that combined pretreatment was highly effective than single pretreatment. Copyright 2010 Wiley Periodicals, Inc.

Cardiac CT for myocardial ischaemia detection and characterization--comparative analysis.

PubMed

Bucher, A M; De Cecco, C N; Schoepf, U J; Wang, R; Meinel, F G; Binukrishnan, S R; Spearman, J V; Vogl, T J; Ruzsics, B

2014-11-01

The assessment of patients presenting with symptoms of myocardial ischaemia remains one of the most common and challenging clinical scenarios faced by physicians. Current imaging modalities are capable of three-dimensional, functional and anatomical views of the heart and as such offer a unique contribution to understanding and managing the pathology involved. Evidence has accumulated that visual anatomical coronary evaluation does not adequately predict haemodynamic relevance and should be complemented by physiological evaluation, highlighting the importance of functional assessment. Technical advances in CT technology over the past decade have progressively moved cardiac CT imaging into the clinical workflow. In addition to anatomical evaluation, cardiac CT is capable of providing myocardial perfusion parameters. A variety of CT techniques can be used to assess the myocardial perfusion. The single energy first-pass CT and dual energy first-pass CT allow static assessment of myocardial blood pool. Dynamic cardiac CT imaging allows quantification of myocardial perfusion through time-resolved attenuation data. CT-based myocardial perfusion imaging (MPI) is showing promising diagnostic accuracy compared with the current reference modalities. The aim of this review is to present currently available myocardial perfusion techniques with a focus on CT imaging in light of recent clinical investigations. This article provides a comprehensive overview of currently available CT approaches of static and dynamic MPI and presents the results of corresponding clinical trials.

[Evaluation of left ventricular perfusion and regional wall motion in myocardial infarction: using 201Tl myocardial SPECT and 99mTc-HSAD multigated cardiac blood pool emission computed tomography].

PubMed

Nanjyo, S

1994-09-01

In order to evaluate left ventricular regional wall motion and regional myocardial perfusion, 99mTc-HSAD multigated cardiac blood pool emission computed tomography (cardiac pool SPECT) and 201Tl myocardial SPECT (Tl) were performed on 12 patients with acute myocardial infarction (AMI), 6 patients had treated with only thrombolysis in group I and 6 patients had treated with thrombolysis and selective PTCA in group II, 17 patients with old myocardial infarction (OMI) in group III and 5 normal volunteers (controls). The relationship between left ventricular regional wall motion and regional myocardial perfusion was estimated. The relationship between % length shortening (%LS) by cardiac pool SPECT and %Tl uptake (%TU) was good (r = 0.820) in group III. The value for %TU in the segments of akinesia was low (35%) and in the those of severe hypokinesia was higher (48%). In all phases, two groups showed significant relationships between %LS and %TU in group I and II. The %TU was unchanged in the akinetic segment, the %LS changed 30% in group I and the %LS changed to 49% in group II. If the %TU is more than 50% (AMI) or 40% (OMI), we would observe viable muscle. The combination of Tl and cardiac pool SPECT are useful for evaluating myocardial viability in the patients with AMI.

Unfolded protein response plays a critical role in heart damage after myocardial ischemia/reperfusion in rats

PubMed Central

Li, Yanming; Xie, Liang; Zhuang, Wei; Liu, Jing; Gong, Jianbin

2017-01-01

The unfolded protein response (UPR) plays a critical role in cell death mediated by ischemia/reperfusion (I/R) injury. However, little is known about the exact mechanism of UPR signaling pathways after myocardial I/R injury in rats. An attempt was therefore made to assess whether the myocardial I/R induced UPR, and which branch of UPR (ATF6, IRE1 and PERK) signal pathway was activated. Sprague-Dawley rats were pretreated with UPR stimulator dithiothreitol (DTT) and UPR inhibitor 4-phenylbutyrate (4PBA) and then subjected to myocardial I/R surgery. Compared with sham-operated group, the expression of GRP78, ATF6, CHOP and sXBP1 in the I/R injured group is significantly increased at transcript and protein levels, which indicated that all the three signal pathways of UPR were activated in the myocardial I/R injury. Compared with the I/R injured group, treatment with 4PBA effectively decreased myocardium infarct size, reduced myocardial apoptosis, down-regulated caspase-12 expression, diminished serum creatine kinase and lactate dehydrogenase levels. In contrast, these effects were reversed in DTT treated group. In summary, these results demonstrated that myocardial I/R injury activates UPR and inhibiting cell UPR possesses a cardioprotective effect through the suppression of ER stress-induced apoptosis. Therefore, inhibition of UPR might be used as a therapeutic target during myocardial I/R injury. PMID:28591178

Unfolded protein response plays a critical role in heart damage after myocardial ischemia/reperfusion in rats.

PubMed

Zhang, Chengcheng; Tang, Yi; Li, Yanming; Xie, Liang; Zhuang, Wei; Liu, Jing; Gong, Jianbin

2017-01-01

The unfolded protein response (UPR) plays a critical role in cell death mediated by ischemia/reperfusion (I/R) injury. However, little is known about the exact mechanism of UPR signaling pathways after myocardial I/R injury in rats. An attempt was therefore made to assess whether the myocardial I/R induced UPR, and which branch of UPR (ATF6, IRE1 and PERK) signal pathway was activated. Sprague-Dawley rats were pretreated with UPR stimulator dithiothreitol (DTT) and UPR inhibitor 4-phenylbutyrate (4PBA) and then subjected to myocardial I/R surgery. Compared with sham-operated group, the expression of GRP78, ATF6, CHOP and sXBP1 in the I/R injured group is significantly increased at transcript and protein levels, which indicated that all the three signal pathways of UPR were activated in the myocardial I/R injury. Compared with the I/R injured group, treatment with 4PBA effectively decreased myocardium infarct size, reduced myocardial apoptosis, down-regulated caspase-12 expression, diminished serum creatine kinase and lactate dehydrogenase levels. In contrast, these effects were reversed in DTT treated group. In summary, these results demonstrated that myocardial I/R injury activates UPR and inhibiting cell UPR possesses a cardioprotective effect through the suppression of ER stress-induced apoptosis. Therefore, inhibition of UPR might be used as a therapeutic target during myocardial I/R injury.

Impact of type 2 diabetes mellitus on recurrent myocardial infarction in China.

PubMed

Li, Wentao; Li, Muwei; Gao, Chuanyu; Wang, Xianpei; Qi, Datun; Liu, Jun; Jin, Qiangsong

2016-11-01

To evaluate the influence of type 2 diabetes mellitus on the long-term outcomes of Chinese patients with previous myocardial infarction, we studied 864 patients with previous myocardial infarction, including 251 with type 2 diabetes mellitus and 613 without type 2 diabetes mellitus, over a median follow-up time of 2.9 years. The type 2 diabetes mellitus patients were subdivided into 95 insulin-treated diabetes mellitus and 156 non-insulin-treated diabetes mellitus subjects. The crude incidences (per 1000 patient-years) in the type 2 diabetes mellitus subjects versus the non-type 2 diabetes mellitus subjects were 43.7 versus 25.1 for recurrent myocardial infarction, 68.7 versus 28.3 for all-cause death and 99.8 versus 49.9 for the composite end point (i.e. recurrent myocardial infarction or all-cause death). Cox regression analysis showed that the adjusted hazard ratios for recurrent myocardial infarction, all-cause death and their combination were 1.67 (95% confidence interval: 1.06-2.74), 1.90 (1.25-2.90) and 1.72 (1.23-2.40), respectively. Significant associations were also observed between insulin treatment and all-cause death. Our findings suggested that type 2 diabetes mellitus is an independent risk factor for recurrent myocardial infarction, all-cause death and the composite end point among previous myocardial infarction patients. © The Author(s) 2016.

Non-ischemic diabetic cardiomyopathy may initially exhibit a transient subclinical phase of hyperdynamic myocardial performance.

PubMed

Hensel, Kai O

2016-09-01

Cardiovascular complications are the key cause for mortality in diabetes mellitus. Besides ischemia-related cardiac malfunction there is growing evidence for non-ischemic diabetes-associated heart failure in both type 1 and type 2 diabetes mellitus. The underlying pathophysiology of non-ischemic diabetic cardiomyopathy (NIDC) is poorly understood and data on myocardial mechanics in early stages of the disease are rare. However, several studies in both human and experimental animal settings have reported prima facie unexplained features indicating myocardial hyperdynamics early in the course of the disease. The new hypothesis is that - other than previously thought - NIDC may be non-linear and initially feature an asymptomatic subclinical phase of myocardial hypercontractility that precedes the long-term development of diabetes-associated cardiac dysfunction and ultimately heart failure. Diabetes-induced metabolic imbalances may lead to a paradoxic inotropic increase and inefficient myocardial mechanics that finally result in a gradual deterioration of myocardial performance. In conclusion, diabetic patients should be screened regularly and early in the course of the disease utilizing ultra-sensitive myocardial deformation imaging in order to identify patients at risk for diabetes-associated heart failure. Moreover, hyperdynamic myocardial deformation might help distinguish non-ischemic from ischemic diabetic cardiomyopathy. Further studies are needed to illuminate the underlying pathophysiological mechanisms, the exact spatiotemporal evolvement of diabetic cardiomyopathy and its long-term relation to clinical outcome parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Subclinical myocardial necrosis and cardiovascular risk in stable patients undergoing elective cardiac evaluation.

PubMed

Tang, W H Wilson; Wu, Yuping; Nicholls, Stephen J; Brennan, Danielle M; Pepoy, Michael; Mann, Shirley; Pratt, Alan; Van Lente, Frederick; Hazen, Stanley L

2010-03-01

The presence of subclinical myocardial necrosis as a prodrome to longer-term adverse cardiac event risk has been debated. The debate has focused predominantly within patients with acute coronary syndrome, and on issues of troponin assay variability and accuracy of detection, rather than on the clinical significance of the presence of subclinical myocardial necrosis (ie, "troponin leak") within stable cardiac patients. Herein, we examine the relationship between different degrees of subclinical myocardial necrosis and long-term adverse clinical outcomes within a stable cardiac patient population with essentially normal renal function. Sequential consenting patients (N=3828; median creatinine clearance, 100 mL/min/1.73m(2)) undergoing elective diagnostic coronary angiography with cardiac troponin I (cTnI) levels below the diagnostic cut-off for defining myocardial infarction (<0.03 ng/mL) were evaluated. The relationship of subclinical myocardial necrosis with incident major adverse cardiovascular events (defined as any death, myocardial infarction, or stroke) over 3-year follow-up was examined. "Probable" (cTnI 0.001-0.008 ng/mL) and "definite" (cTnI 0.009-0.029 ng/mL) subclinical myocardial necrosis were observed frequently within the cohort (34% and 18%, respectively). A linear relationship was observed between the magnitude of subclinical myocardial necrosis and risk of 3-year incident major adverse cardiovascular events, particularly in those with cTnI 0.009 ng/mL or higher (hazard ratio, 3.00; 95% confidence interval, 2.4-3.8), even after adjustment for traditional risk factors, C-reactive protein, and creatinine clearance. The presence of subclinical myocardial necrosis was associated with elevations in acute phase proteins (C-reactive protein, ceruloplasmin; P<0.01 each) and reduction in systemic antioxidant enzyme activities (arylesterase; P<0.01) but showed no significant associations with multiple specific measures of oxidant stress, and showed borderline associations with myeloperoxidase, a marker of leukocyte activation. In stable cardiology patients, prodromal subclinical myocardial necrosis is associated with substantially higher long-term risk for major adverse cardiovascular events. The underlying mechanisms contributing to this minimal troponin leak phenomenon warrants further investigation.

[Effect of Xinmailong on hypoxia-inducible factor-1alpha expression in neonatal rats with asphyxia].

PubMed

Huang, Li-Xin; Wu, Xing-Heng

2009-08-01

Xinmailong, a compound extracted from Periplaneta americana, is used for the treatment of cardiovascular diseases. This study investigated the effects of Xinmailong on myocardial hypoxia-inducible factor-1alpha (HIF-1alpha) and plasma endothelin-1(ET-1) levels in neonatal rats with asphyxia and explored the protection mechanism of Xinmailong in hypoxia-ischemic myocardial injury. Seven-day-old Sprague-Dawley rats were randomly divided into three groups (n=30 each): sham-operated, asphyxia, Xinmailong-treated asphyxia. Each group was randomly subdivided into three groups according to the observed time points: 6 hrs, 24 hrs and 72 hrs. Xinmailong (5 mg/kg) was intraperitoneally injected to the rats in the Xinmailong-treated group five minutes before asphyxia. Myocardial HIF-1alpha expression, and plasma ET-1 and creatine kinase (CK) levels were measured. The histopathologic changes of the myocardium were observed by hematoxylin-eosin staining. Four rats died in the asphyxia group while only one died in the Xinmailong-treated group during the experiment. The plasma ET-1 and CK levels as well as myocardial HIF-1alpha expression increased at 6 hrs, reached a peak at 24 hrs, and declined at 72 hrs after asphyxia in the asphyxia group, being higher than that in the sham-operated group (P<0.01). Myocardial ischemia was observed in the three time points, and cell necrosis occurred at 24 hrs after asphyxia in the asphyxia group. Myocardial HIF-1alpha expression was positively correlated with plasma ET-1 levels (r=0.876, P<0.01). In the Xinmailong-treated group, plasma levels of CK and ET-1 as well as myocardial HIF-1alpha expression were significantly lower than those in the asphyxia group (P<0.01). Myocardial ischemia was alleviated and no cell necrosis was found in the Xinmailong-treated group. Asphyxia leads to increase in myocardial HIF-1alpha expression and plasma levels of ET-1 and CK. Xinmailong can reduce the myocardial expression of HIF-1alpha and decrease plasma ET-1 levels, thus alleviating hypoxia-ischemic myocardial injury.

Comparison of hospital variation in acute myocardial infarction care and outcome between Sweden and United Kingdom: population based cohort study using nationwide clinical registries.

PubMed

Chung, Sheng-Chia; Sundström, Johan; Gale, Chris P; James, Stefan; Deanfield, John; Wallentin, Lars; Timmis, Adam; Jernberg, Tomas; Hemingway, Harry

2015-08-07

To assess the between hospital variation in use of guideline recommended treatments and clinical outcomes for acute myocardial infarction in Sweden and the United Kingdom. Population based longitudinal cohort study using nationwide clinical registries. Nationwide registry data comprising all hospitals providing acute myocardial infarction care in Sweden (SWEDEHEART/RIKS-HIA, n=87; 119,786 patients) and the UK (NICOR/MINAP, n=242; 391,077 patients), 2004-10. Between hospital variation in 30 day mortality of patients admitted with acute myocardial infarction. Case mix standardised 30 day mortality from acute myocardial infarction was lower in Swedish hospitals (8.4%) than in UK hospitals (9.7%), with less variation between hospitals (interquartile range 2.6% v 3.5%). In both countries, hospital level variation and 30 day mortality were inversely associated with provision of guideline recommended care. Compared with the highest quarter, hospitals in the lowest quarter for use of primary percutaneous coronary intervention had higher volume weighted 30 day mortality for ST elevation myocardial infarction (10.7% v 6.6% in Sweden; 12.7% v 5.8% in the UK). The adjusted odds ratio comparing the highest with the lowest quarters for hospitals' use of primary percutaneous coronary intervention was 0.70 (95% confidence interval 0.62 to 0.79) in Sweden and 0.68 (0.60 to 0.76) in the UK. Differences in risk between hospital quarters of treatment for non-ST elevation myocardial infarction and secondary prevention drugs for all discharged acute myocardial infarction patients were smaller than for reperfusion treatment in both countries. Between hospital variation in 30 day mortality for acute myocardial infarction was greater in the UK than in Sweden. This was associated with, and may be partly accounted for by, the higher practice variation in acute myocardial infarction guideline recommended treatment in the UK hospitals. High quality healthcare across all hospitals, especially in the UK, with better use of guideline recommended treatment, may not only reduce unacceptable practice variation but also deliver improved clinical outcomes for patients with acute myocardial infarction. Clinical trials registration Clinical trials NCT01359033. © Chung et al 2015.

Berberine inhibits the ischemia-reperfusion injury induced inflammatory response and apoptosis of myocardial cells through the phosphoinositide 3-kinase/RAC-α serine/threonine-protein kinase and nuclear factor-κB signaling pathways.

PubMed

Wang, Lixin; Ma, Hao; Xue, Yan; Shi, Haiyan; Ma, Teng; Cui, Xiaozheng

2018-02-01

Myocardial ischemia-reperfusion injury is one of the most common cardiovascular diseases, and can lead to serious damage and dysfunction of the myocardial tissue. Previous studies have demonstrated that berberine exhibits ameliorative effects on cardiovascular disease. The present study further investigated the efficacy and potential mechanism underlying the effects of berberine on ischemia-reperfusion injury in a mouse model. Inflammatory markers were measured in the serum and levels of inflammatory proteins in myocardial cells were investigated after treatment with berberine. In addition, the apoptosis of myocardial cells was investigated after berberine treatment. Apoptosis-associated gene expression levels and apoptotic signaling pathways were analyzed in myocardial cells after treatment with berberine. The phosphoinositide 3-kinase (PI3K)/RAC-α serine/threonine-protein kinase (AKT) and nuclear factor (NF)-κB signaling pathways were also analyzed in myocardial cells after treatment with berberine. Histological analysis was used to analyze the potential benefits of berberine in ischemia-reperfusion injury. The present study identified that inflammatory responses and inflammatory factors were decreased in the myocardial cells of the mouse model of ischemia-reperfusion injury. Mechanism analysis demonstrated that berberine inhibited apoptotic protease-activating factor 1, caspase-3 and caspase-9 expression in myocardial cells. The expression of Bcl2-associated agonist of cell death, Bcl-2-like protein 1 and cellular tumor antigen p53 was upregulated. Expression of NF-κB p65, inhibitor of NF-κB kinase subunit β (IKK-β), NF-κB inhibitor α (IκBα), and NF-κB activity, were inhibited in myocardial cells in the mouse model of ischemia-reperfusion injury. In conclusion, the results of the present study indicate that berberine inhibits inflammatory responses through the NF-κB signaling pathway and suppresses the apoptosis of myocardial cells via the PI3K/AKT signaling pathway in a mouse model of ischemia-reperfusion injury. These results suggest that berberine is a potential drug for the treatment of patients with ischemia-reperfusion injury.

Berberine inhibits the ischemia-reperfusion injury induced inflammatory response and apoptosis of myocardial cells through the phosphoinositide 3-kinase/RAC-α serine/threonine-protein kinase and nuclear factor-κB signaling pathways

PubMed Central

Wang, Lixin; Ma, Hao; Xue, Yan; Shi, Haiyan; Ma, Teng; Cui, Xiaozheng

2018-01-01

Myocardial ischemia-reperfusion injury is one of the most common cardiovascular diseases, and can lead to serious damage and dysfunction of the myocardial tissue. Previous studies have demonstrated that berberine exhibits ameliorative effects on cardiovascular disease. The present study further investigated the efficacy and potential mechanism underlying the effects of berberine on ischemia-reperfusion injury in a mouse model. Inflammatory markers were measured in the serum and levels of inflammatory proteins in myocardial cells were investigated after treatment with berberine. In addition, the apoptosis of myocardial cells was investigated after berberine treatment. Apoptosis-associated gene expression levels and apoptotic signaling pathways were analyzed in myocardial cells after treatment with berberine. The phosphoinositide 3-kinase (PI3K)/RAC-α serine/threonine-protein kinase (AKT) and nuclear factor (NF)-κB signaling pathways were also analyzed in myocardial cells after treatment with berberine. Histological analysis was used to analyze the potential benefits of berberine in ischemia-reperfusion injury. The present study identified that inflammatory responses and inflammatory factors were decreased in the myocardial cells of the mouse model of ischemia-reperfusion injury. Mechanism analysis demonstrated that berberine inhibited apoptotic protease-activating factor 1, caspase-3 and caspase-9 expression in myocardial cells. The expression of Bcl2-associated agonist of cell death, Bcl-2-like protein 1 and cellular tumor antigen p53 was upregulated. Expression of NF-κB p65, inhibitor of NF-κB kinase subunit β (IKK-β), NF-κB inhibitor α (IκBα), and NF-κB activity, were inhibited in myocardial cells in the mouse model of ischemia-reperfusion injury. In conclusion, the results of the present study indicate that berberine inhibits inflammatory responses through the NF-κB signaling pathway and suppresses the apoptosis of myocardial cells via the PI3K/AKT signaling pathway in a mouse model of ischemia-reperfusion injury. These results suggest that berberine is a potential drug for the treatment of patients with ischemia-reperfusion injury. PMID:29403554

Tunable band alignment in two-phase-coexistence Nb3O7F nanocrystals with enhanced light harvesting and photocatalytic performance

NASA Astrophysics Data System (ADS)

Li, Zhen; Huang, Fei; Feng, Xin; Yan, Aihua; Dong, Haiming; Hu, Miao; Li, Qi

2018-06-01

A two-phase-coexistence technique offers intriguing variables to maneuver novel and enhanced functionality in a single-component material. Most importantly, new band alignment and perfect interfaces between two phases can strongly affect local photoelectronic properties. However, previous efforts to achieve two-phase coexistence were mainly restricted to specific systems and methods. Here we demonstrate a phase-transition route to acquire two-phase-coexistence niobium oxyfluoride (Nb3O7F) nanocrystals for the first time. Based on key distinguishing features of the experimental results and theoretical analysis, the phase transition of Nb3O7F involves an organic/inorganic hybrid, heat treating, Al-doping, lattice deformation and structural rearrangement. The band gap can be effectively tuned from 3.03 eV to 2.84 eV, and the VBM can be tuned from 1.49 eV to 1.69 eV according to the phase proportion. Benefiting from uniform nanocrystal size, tunable band alignment and an optimized interfacial structure, the two-phase coexistence markedly enhances visible-light harvesting and the photocatalytic performance of Nb3O7F nanocrystals. The results not only demonstrate an opportunity to explore two-phase coexistence of novel nanocrystals, but also illustrate the role of two-phase coexistence in achieving enhanced photoelectronic properties.

Effects of intraspecific phenotypic variation on species coexistence.

PubMed

Hausch, Stephen; Vamosi, Steven M; Fox, Jeremy W

2018-06-01

Intraspecific variation can promote or inhibit species coexistence, both by increasing species' competitive abilities, and by altering the relative strengths of intraspecific and interspecific competition. Effects of intraspecific variation on coexistence can occur via complementarity of different variants, and via a selection effect: initially-variable populations are more likely to contain highly competitive variants that might determine the ability of the population as a whole to both invade and resist invasion. We tested the effects of intraspecific variation and composition on coexistence by assaying the mutual invasibility of populations of two competing bean weevil species (Callosobruchus maculatus and C. chinensis) when each was initiated with one, three, or five genetically- and phenotypically-distinct lineages. Our results reveal that intraspecific variation is a double-edged sword for species coexistence. Increasing intraspecific variation increased species' abilities to invade, and to resist invasion, via selection effects and intraspecific niche complementarity among conspecific lineages, thereby creating the potential for exclusion among mismatched competitors. But intraspecific variation also increased the scope for resource partitioning, creating the potential for stable coexistence. Stable coexistence occurred only when intraspecific variation caused species to exhibit both relatively evenly-matched competitive abilities and sufficiently-strong resource partitioning. Our work explains the conflicting results of previous studies. © 2018 by the Ecological Society of America.

Tunable band alignment in two-phase-coexistence Nb3O7F nanocrystals with enhanced light harvesting and photocatalytic performance.

PubMed

Li, Zhen; Huang, Fei; Feng, Xin; Yan, Aihua; Dong, Haiming; Hu, Miao; Li, Qi

2018-06-01

A two-phase-coexistence technique offers intriguing variables to maneuver novel and enhanced functionality in a single-component material. Most importantly, new band alignment and perfect interfaces between two phases can strongly affect local photoelectronic properties. However, previous efforts to achieve two-phase coexistence were mainly restricted to specific systems and methods. Here we demonstrate a phase-transition route to acquire two-phase-coexistence niobium oxyfluoride (Nb 3 O 7 F) nanocrystals for the first time. Based on key distinguishing features of the experimental results and theoretical analysis, the phase transition of Nb 3 O 7 F involves an organic/inorganic hybrid, heat treating, Al-doping, lattice deformation and structural rearrangement. The band gap can be effectively tuned from 3.03 eV to 2.84 eV, and the VBM can be tuned from 1.49 eV to 1.69 eV according to the phase proportion. Benefiting from uniform nanocrystal size, tunable band alignment and an optimized interfacial structure, the two-phase coexistence markedly enhances visible-light harvesting and the photocatalytic performance of Nb 3 O 7 F nanocrystals. The results not only demonstrate an opportunity to explore two-phase coexistence of novel nanocrystals, but also illustrate the role of two-phase coexistence in achieving enhanced photoelectronic properties.

Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies

PubMed Central

Uhlemann, Elisabeth

2018-01-01

Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications. PMID:29570676

Anomalous magnetic configuration of Mn{sub 2}NiAl ribbon and the role of hybridization in the martensitic transformation of Mn{sub 50}Ni{sub 50−x}Al{sub x} ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, R. B.; Department of Physics, Hebei Medical University, Shijiazhuang 050017; Zhao, D. W.

2014-12-08

The magnetic configuration of Mn{sub 2}NiAl ribbon has been investigated. In contrast to Ni{sub 2}MnAl, the compound Mn{sub 2}NiAl with considerable disorder does exhibit ferromagnetism and, due to exchange interaction competition, both ferromagnetic and antiferromagnetic moment orientations can coexist between nearest neighbor Mn atoms. This is unexpected in Heusler alloys. Regarding the mechanism of the martensitic transformation in Mn{sub 50}Ni{sub 50−x}Al{sub x}, it is found that increasing the Al content results in an unusual change in the lattice constant, a decrease of the transformation entropy change, and enhancement of the calculated electron localization. These results indicate that the p-d covalentmore » hybridization between Mn (or Ni) and Al atoms gradually increases at the expense of the d-d hybridization between Ni and Mn atoms. This leads to an increased stability of the austenite phase and a decrease of the martensitic transformation temperature. For 11 ≤ x ≤ 14, Mn{sub 50}Ni{sub 50−x}Al{sub x} ferromagnetic shape memory alloys are obtained.« less

Synthesis and hydration behavior of calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Eun-Hee; Yoo, Jun-Sang; Kim, Bo-Hye

2014-02-15

Calcium zirconium aluminate (Ca{sub 7}ZrAl{sub 6}O{sub 18}) cements were prepared by solid state reaction and polymeric precursor methods, and their phase evolution, morphology, and hydration behavior were investigated. In polymeric precursor method, a nearly single phase Ca{sub 7}ZrAl{sub 6}O{sub 18} was obtained at relatively lower temperature (1200 °C) whereas in solid state reaction, a small amount of CaZrO{sub 3} coexisted with Ca{sub 7}ZrAl{sub 6}O{sub 18} even at higher temperature (1400 °C). Unexpectedly, Ca{sub 7}ZrAl{sub 6}O{sub 18} synthesized by polymeric precursor process was the large-sized and rough-shaped powder. The planetary ball milling was employed to control the particle size and shape.more » The hydration behavior of Ca{sub 7}ZrAl{sub 6}O{sub 18} was similar to that of Ca{sub 3}Al{sub 2}O{sub 6} (C3A), but the hydration products were Ca{sub 3}Al{sub 2}O{sub 6}·6H{sub 2}O (C3AH6) and several intermediate products. Thus, Zr (or ZrO{sub 2}) stabilized the intermediate hydration products of C3A.« less

Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies.

PubMed

Balador, Ali; Uhlemann, Elisabeth; Calafate, Carlos T; Cano, Juan-Carlos

2018-03-23

Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications.

A surface acoustic wave sensor functionalized with a polypyrrole molecularly imprinted polymer for selective dopamine detection.

PubMed

Maouche, Naima; Ktari, Nadia; Bakas, Idriss; Fourati, Najla; Zerrouki, Chouki; Seydou, Mahamadou; Maurel, François; Chehimi, Mohammed Mehdi

2015-11-01

A surface acoustic wave sensor operating at 104 MHz and functionalized with a polypyrrole molecularly imprinted polymer has been designed for selective detection of dopamine (DA). Optimization of pyrrole/DA ratio, polymerization and immersion times permitted to obtain a highly selective sensor, which has a sensitivity of 0.55°/mM (≈ 550 Hz/mM) and a detection limit of ≈ 10 nM. Morphology and related roughness parameters of molecularly imprinted polymer surfaces, before and after extraction of DA, as well as that of the non imprinted polymer were characterized by atomic force microscopy. The developed chemosensor selectively recognized dopamine over the structurally similar compound 4-hydroxyphenethylamine (referred as tyramine), or ascorbic acid,which co-exists with DA in body fluids at a much higher concentration. Selectivity tests were also carried out with dihydroxybenzene, for which an unexpected phase variation of order of 75% of the DA one was observed. Quantum chemical calculations, based on the density functional theory, were carried out to determine the nature of interactions between each analyte and the PPy matrix and the DA imprinted PPy polypyrrole sensing layer in order to account for the important phase variation observed during dihydroxybenzene injection. Copyright © 2015 John Wiley & Sons, Ltd.

A double-edged sword: Benefits and pitfalls of heterogeneous punishment in evolutionary inspection games

PubMed Central

Perc, Matjaž; Szolnoki, Attila

2015-01-01

As a simple model for criminal behavior, the traditional two-strategy inspection game yields counterintuitive results that fail to describe empirical data. The latter shows that crime is often recurrent, and that crime rates do not respond linearly to mitigation attempts. A more apt model entails ordinary people who neither commit nor sanction crime as the third strategy besides the criminals and punishers. Since ordinary people free-ride on the sanctioning efforts of punishers, they may introduce cyclic dominance that enables the coexistence of all three competing strategies. In this setup ordinary individuals become the biggest impediment to crime abatement. We therefore also consider heterogeneous punisher strategies, which seek to reduce their investment into fighting crime in order to attain a more competitive payoff. We show that this diversity of punishment leads to an explosion of complexity in the system, where the benefits and pitfalls of criminal behavior are revealed in the most unexpected ways. Due to the raise and fall of different alliances no less than six consecutive phase transitions occur in dependence on solely the temptation to succumb to criminal behavior, leading the population from ordinary people-dominated across punisher-dominated to crime-dominated phases, yet always failing to abolish crime completely. PMID:26046673

A double-edged sword: Benefits and pitfalls of heterogeneous punishment in evolutionary inspection games.

PubMed

Perc, Matjaž; Szolnoki, Attila

2015-06-05

As a simple model for criminal behavior, the traditional two-strategy inspection game yields counterintuitive results that fail to describe empirical data. The latter shows that crime is often recurrent, and that crime rates do not respond linearly to mitigation attempts. A more apt model entails ordinary people who neither commit nor sanction crime as the third strategy besides the criminals and punishers. Since ordinary people free-ride on the sanctioning efforts of punishers, they may introduce cyclic dominance that enables the coexistence of all three competing strategies. In this setup ordinary individuals become the biggest impediment to crime abatement. We therefore also consider heterogeneous punisher strategies, which seek to reduce their investment into fighting crime in order to attain a more competitive payoff. We show that this diversity of punishment leads to an explosion of complexity in the system, where the benefits and pitfalls of criminal behavior are revealed in the most unexpected ways. Due to the raise and fall of different alliances no less than six consecutive phase transitions occur in dependence on solely the temptation to succumb to criminal behavior, leading the population from ordinary people-dominated across punisher-dominated to crime-dominated phases, yet always failing to abolish crime completely.

Magnetic stripes and skyrmions with helicity reversals.

PubMed

Yu, Xiuzhen; Mostovoy, Maxim; Tokunaga, Yusuke; Zhang, Weizhu; Kimoto, Koji; Matsui, Yoshio; Kaneko, Yoshio; Nagaosa, Naoto; Tokura, Yoshinori

2012-06-05

It was recently realized that topological spin textures do not merely have mathematical beauty but can also give rise to unique functionalities of magnetic materials. An example is the skyrmion--a nano-sized bundle of noncoplanar spins--that by virtue of its nontrivial topology acts as a flux of magnetic field on spin-polarized electrons. Lorentz transmission electron microscopy recently emerged as a powerful tool for direct visualization of skyrmions in noncentrosymmetric helimagnets. Topologically, skyrmions are equivalent to magnetic bubbles (cylindrical domains) in ferromagnetic thin films, which were extensively explored in the 1970s for data storage applications. In this study we use Lorentz microscopy to image magnetic domain patterns in the prototypical magnetic oxide-M-type hexaferrite with a hint of scandium. Surprisingly, we find that the magnetic bubbles and stripes in the hexaferrite have a much more complex structure than the skyrmions and spirals in helimagnets, which we associate with the new degree of freedom--helicity (or vector spin chirality) describing the direction of spin rotation across the domain walls. We observe numerous random reversals of helicity in the stripe domain state. Random helicity of cylindrical domain walls coexists with the positional order of magnetic bubbles in a triangular lattice. Most unexpectedly, we observe regular helicity reversals inside skyrmions with an unusual multiple-ring structure.

Nuclear and chloroplast DNA phylogeny reveals complex evolutionary history of Elymus pendulinus.

PubMed

Yan, Chi; Hu, Qianni; Sun, Genlou

2014-02-01

Evidence accumulated over the last decade has shown that allopolyploid genomes may undergo complex reticulate evolution. In this study, 13 accessions of tetraploid Elymus pendulinus were analyzed using two low-copy nuclear genes (RPB2 and PepC) and two regions of chloroplast genome (Rps16 and trnD-trnT). Previous studies suggested that Pseudoroegneria (St) and an unknown diploid (Y) were genome donors to E. pendulinus, and that Pseudoroegneria was the maternal donor. Our results revealed an extreme reticulate pattern, with at least four distinct gene lineages coexisting within this species that might be acquired through a possible combination of allotetraploidization and introgression from both within and outside the tribe Hordeeae. Chloroplast DNA data identified two potential maternal genome donors (Pseudoroegneria and an unknown species outside Hordeeae) to E. pendulinus. Nuclear gene data indicated that both Pseudoroegneria and an unknown Y diploid have contributed to the nuclear genome of E. pendulinus, in agreement with cytogenetic data. However, unexpected contributions from Hordeum and unknown aliens from within or outside Hordeeae to E. pendulinus without genome duplication were observed. Elymus pendulinus provides a remarkable instance of the previously unsuspected chimerical nature of some plant genomes and the resulting phylogenetic complexity produced by multiple historical reticulation events.

Two-body perturbation theory versus first order perturbation theory: A comparison based on the square-well fluid.

PubMed

Mercier Franco, Luís Fernando; Castier, Marcelo; Economou, Ioannis G

2017-12-07

We show that the Zwanzig first-order perturbation theory can be obtained directly from a truncated Taylor series expansion of a two-body perturbation theory and that such truncation provides a more accurate prediction of thermodynamic properties than the full two-body perturbation theory. This unexpected result is explained by the quality of the resulting approximation for the fluid radial distribution function. We prove that the first-order and the two-body perturbation theories are based on different approximations for the fluid radial distribution function. To illustrate the calculations, the square-well fluid is adopted. We develop an analytical expression for the two-body perturbed Helmholtz free energy for the square-well fluid. The equation of state obtained using such an expression is compared to the equation of state obtained from the first-order approximation. The vapor-liquid coexistence curve and the supercritical compressibility factor of a square-well fluid are calculated using both equations of state and compared to Monte Carlo simulation data. Finally, we show that the approximation for the fluid radial distribution function given by the first-order perturbation theory provides closer values to the ones calculated via Monte Carlo simulations. This explains why such theory gives a better description of the fluid thermodynamic behavior.

Evolution of the Pseudomonas aeruginosa mutational resistome in an international Cystic Fibrosis clone.

PubMed

López-Causapé, Carla; Sommer, Lea Mette; Cabot, Gabriel; Rubio, Rosa; Ocampo-Sosa, Alain A; Johansen, Helle Krogh; Figuerola, Joan; Cantón, Rafael; Kidd, Timothy J; Molin, Soeren; Oliver, Antonio

2017-07-17

Emergence of epidemic clones and antibiotic resistance development compromises the management of Pseudomonas aeruginosa cystic fibrosis (CF) chronic respiratory infections. Whole genome sequencing (WGS) was used to decipher the phylogeny, interpatient dissemination, WGS mutator genotypes (mutome) and resistome of a widespread clone (CC274), in isolates from two highly-distant countries, Australia and Spain, covering an 18-year period. The coexistence of two divergent CC274 clonal lineages was revealed, but without evident geographical barrier; phylogenetic reconstructions and mutational resistome demonstrated the interpatient transmission of mutators. The extraordinary capacity of P. aeruginosa to develop resistance was evidenced by the emergence of mutations in >100 genes related to antibiotic resistance during the evolution of CC274, catalyzed by mutator phenotypes. While the presence of classical mutational resistance mechanisms was confirmed and correlated with resistance phenotypes, results also showed a major role of unexpected mutations. Among them, PBP3 mutations, shaping up β-lactam resistance, were noteworthy. A high selective pressure for mexZ mutations was evidenced, but we showed for the first time that high-level aminoglycoside resistance in CF is likely driven by mutations in fusA1/fusA2, coding for elongation factor G. Altogether, our results provide valuable information for understanding the evolution of the mutational resistome of CF P. aeruginosa.

A double-edged sword: Benefits and pitfalls of heterogeneous punishment in evolutionary inspection games

NASA Astrophysics Data System (ADS)

Perc, Matjaž; Szolnoki, Attila

2015-06-01

As a simple model for criminal behavior, the traditional two-strategy inspection game yields counterintuitive results that fail to describe empirical data. The latter shows that crime is often recurrent, and that crime rates do not respond linearly to mitigation attempts. A more apt model entails ordinary people who neither commit nor sanction crime as the third strategy besides the criminals and punishers. Since ordinary people free-ride on the sanctioning efforts of punishers, they may introduce cyclic dominance that enables the coexistence of all three competing strategies. In this setup ordinary individuals become the biggest impediment to crime abatement. We therefore also consider heterogeneous punisher strategies, which seek to reduce their investment into fighting crime in order to attain a more competitive payoff. We show that this diversity of punishment leads to an explosion of complexity in the system, where the benefits and pitfalls of criminal behavior are revealed in the most unexpected ways. Due to the raise and fall of different alliances no less than six consecutive phase transitions occur in dependence on solely the temptation to succumb to criminal behavior, leading the population from ordinary people-dominated across punisher-dominated to crime-dominated phases, yet always failing to abolish crime completely.

[Impacts of early metoprolol intervention on connexin 43 and phosphorylated connexin 43 expression in rabbits with experimental myocardial infarction].

PubMed

Zhou, M; Lu, Q; Jiang, J Q; Chen, Z N; Gong, Z G; Li, Z G; Fu, W W; Ding, S F

2017-04-24

Objective: To investigate the early intervention effects of metoprolol on connexin 43(Cx43) and phosphorylated Cx43 (p-Cx43) expression in rabbits with post myocardial infarction. Methods: A total of 24 adult male New Zealand white rabbits were divided into sham group ( n =6), early treatment group( n =6), routine treatment group( n =6), and myocardial infarction group( n =6) with a randomized block design blocked by weight. Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation. Rabbits in sham group received similar surgical procedure without LAD ligation. Metoprolol (12.5 mg/kg dissolved in 2 ml distilled water) was applied to rabbits in early treatment group and routine treatment group per gavage immediately after recovery from anesthesia and at 24 hours after myocardial infarction, respectively, then treated daily for 40 days. Rabbits in sham group and myocardial infarction group received 2 ml distilled water per gavage daily for 40 days. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) level were detected by automatic biochemistry analyzer after 6 hours in all rabbits. Ventricular fibrillation threshold (VFT) was measured in vivo by bipolar pacing electrodes at 40 days. Cx43 and p-Cx43 distribution in ventricular tissue was detected by immunofluorescence analyses. Cx43 and p-Cx43 protein level in ventricular tissue was determined by Western blot. Results: (1) Plasma LDH ((851.7±85.9)U/L vs. (332.3±39.6)U/L, P <0.01) and CK ((1 192.7±105.3)U/L vs. (462.3±65.6)U/L, P <0.01) were significantly higher in myocardial infarction group than in sham group (both P <0.01). (2) VFT was significantly lower in myocardial infarction group than that in sham group ((470.0±91.0) beats per minute vs. (683.3±60.9) beats per minute, P <0.05), and VFT was significantly higher in early treatment group ((633.3±43.2) beats per minute) and routine treatment group ((645.0±30.8) beats per minute) than in the myocardial infarction group (both P <0.05). (3) Immunofluorescence analyses showed that Cx43 was mainly localized in the intercalated disk, which was perpendicular to the cell long axis with linear arrangement, and less lateral distribution in sham group, early treatment group and routine treatment group, which was significantly different as the case in the myocardial infarction group. The expression of p-Cx43 in myocardial infarction group was less than in sham group, which was significantly upregulated in in early treatment group and routine treatment group when compared with myocardial infarction group, and expression of p-Cx43 was significantly higher in early treatment group than in routine treatment group. (4)The p-Cx43/Cx43 ratio of protein was significantly lower in myocardial infarction group than in sham group (0.165±0.011 vs. 0.363±0.046, P <0.05), and significantly higher in early treatment group (0.720±0.063) and routine treatment group (0.364±0.030) than in myocardial infarction group (both P <0.05), and this ratio was significantly higher in early treatment group than in routine treatment group ( P <0.05). Conclusion: Metoprolol treatment, especially the early metoprolol treatment (within 24 hours after LAD ligation), could significantly improve VFT by ameliorating the distribution and dephosphorylation of myocardial Cx43 in rabbits with experimental myocardial infarction.

Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer

PubMed Central

Hutchins, G. D.; Perry, K.; Territo, W.; Chisholm, R.; Acton, A.; Glick-Wilson, B.; Considine, R. V.; Moberly, S.; DeGrado, T. R.

2015-01-01

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[18F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([11C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m−2·min−1) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption (P = 0.04) and perfusion (P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids (P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions (P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups (P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM (P = 0.003). Myocardial work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM. PMID:26732686

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies

PubMed Central

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-01-01

Objective To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Methods and results Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2  =  0.92 versus r2  =  0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (κ  =  0.87 v κ  =  0.75, p < 0.05). Conclusion MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine. PMID:15939722

Epicardial infarct repair with bioinductive extracellular matrix promotes vasculogenesis and myocardial recovery.

PubMed

Mewhort, Holly E M; Turnbull, Jeannine D; Satriano, Alessandro; Chow, Kelvin; Flewitt, Jacqueline A; Andrei, Adin-Cristian; Guzzardi, David G; Svystonyuk, Daniyil A; White, James A; Fedak, Paul W M

2016-05-01

Infarcted myocardium can remodel after successful reperfusion, resulting in left ventricular dilation and heart failure. Epicardial infarct repair (EIR) using a bioinductive extracellular matrix (ECM) biomaterial is a novel surgical approach to promote endogenous myocardial repair and functional recovery after myocardial infarction. Using a pre-clinical porcine model of coronary ischemia-reperfusion, we assessed the effects of EIR on regional functional recovery, safety, and possible mechanisms of benefit. An ECM biomaterial (CorMatrix ECM) was applied to the epicardium after 75 minutes of coronary ischemia in a porcine model. Following ischemia-reperfusion injury, animals were randomly assigned in 2:1 fashion to EIR (n = 8) or sham treatment (n = 4). Serial cardiac magnetic resonance imaging was performed on normal (n = 4) and study animals at baseline (1 week) and 6 weeks after treatment. Myocardial function and tissue characteristics were assessed. Functional myocardial recovery was significantly increased by EIR compared with sham treatment (change in regional myocardial contraction at 6 weeks, 28.6 ± 14.0% vs 4.2 ± 13.5% wall thickening, p < 0.05). Animals receiving EIR had reduced adhesions compared with animals receiving sham treatment (1.44 ± 0.51 vs 3.08 ± 0.89, p < 0.05). Myocardial fibrosis was not increased, and EIR did not cause myocardial constriction, as left ventricular compliance by passive pressure distention at matched volumes was similar between groups (13.9 ± 4.0 mm Hg in EIR group vs 16.0 ± 5.2 mm Hg in sham group, p = 0.61). Animals receiving EIR showed evidence of vasculogenesis in the region of functional recovery. In addition to the beneficial effects of successful reperfusion, EIR using a bioinductive ECM enhances myocardial repair and functional recovery. Clinical translation of EIR early after myocardial infarction as an adjunct to surgical revascularization may be warranted in the future. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Transmyocardial drilling revascularization combined with heparinized bFGF-incorporating stent activates resident cardiac stem cells via SDF-1/CXCR4 axis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Guang-Wei; Wen, Ti; Gu, Tian-Xiang, E-mail: cmugtx@sina.com

Objective: To investigate whether transmyocardial drilling revascularization combined with heparinized basic fibroblast growth factor (bFGF)-incorporating degradable stent implantation (TMDRSI) can promote myocardial regeneration after acute myocardial infarction (AMI). Methods: A model of AMI was generated by ligating the mid-third of left anterior descending artery (LAD) of miniswine. After 6 h, the animals were divided into none-treatment (control) group (n = 6) and TMDRSI group (n = 6). For TMDRSI group, two channels with 3.5 mm in diameter were established by a self-made drill in the AMI region, into which a stent was implanted. Expression of stromal cell-derived factor-1{sub {alpha}} (SDF-1{submore » {alpha}}) and CXC chemokine receptor 4 (CXCR4), cardiac stem cell (CSC)-mediated myocardial regeneration, myocardial apoptosis, myocardial viability, and cardiac function were assessed at various time-points. Results: Six weeks after the operation, CSCs were found to have differentiated into cardiomyocytes to repair the infarcted myocardium, and all above indices showed much improvement in the TMDRSI group compared with the control group (P < 0.001). Conclusions: The new method has shown to be capable of promoting CSCs proliferation and differentiation into cardiomyocytes through activating the SDF-1/CXCR4 axis, while inhibiting myocardial apoptosis, thereby enhancing myocardial regeneration following AMI and improving cardiac function. This may provide a new strategy for myocardial regeneration following AMI. -- Highlights: Black-Right-Pointing-Pointer The effects of TMDR and bFGF-stent on myocardial regeneration were studied in a pig model of AMI. Black-Right-Pointing-Pointer TMDR and bFGF-stent implantation activated CSCs via the SDF-1/CXCR4 axis. Black-Right-Pointing-Pointer CSC-mediated myocardial regeneration improved cardiac function. Black-Right-Pointing-Pointer It may be a new therapeutic strategy for AMI.« less

Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer.

PubMed

Mather, K J; Hutchins, G D; Perry, K; Territo, W; Chisholm, R; Acton, A; Glick-Wilson, B; Considine, R V; Moberly, S; DeGrado, T R

2016-03-15

Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[(18)F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([(11)C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m(-2)·min(-1)) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P < 0.01) and significantly increased myocardial oxygen consumption (P = 0.04) and perfusion (P = 0.01) in both groups. Insulin suppressed available nonesterified fatty acids (P < 0.0001), but fatty acid concentrations were higher in T2DM under both conditions (P < 0.001). Insulin-induced suppression of fatty acid oxidation was seen in both groups (P < 0.0001). However, fatty acid oxidation rates were higher under both conditions in T2DM (P = 0.003). Myocardial work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM. Copyright © 2016 the American Physiological Society.

Transmyocardial laser revascularization in the acute ischaemic heart: no improvement of acute myocardial perfusion or prevention of myocardial infarction.

PubMed

Eckstein, F S; Scheule, A M; Vogel, U; Schmid, S T; Miller, S; Jurmann, M J; Ziemer, G

1999-05-01

Transmyocardial laser revascularization (TMLR) has been used to provide enhanced myocardial perfusion in patients not suitable for coronary revascularization or angioplasty. This study investigates the acute changes in myocardial perfusion after TMLR with a Holmium:Yttrium-Aluminium-Garnet (YAG) laser with a thermal imaging camera in a model of acute ischaemia, and confirms its midterm effects by post-mortem investigation of magnetic resonance imaging and histopathological examination. Acute myocardial ischaemia was induced by occlusion of the dominant diagonal branch in ten sheep. Perfusion measurements were undertaken first in the unaffected myocardium, then after temporary occlusion of the coronary to obtain a control measurement for ischaemic myocardium. Myocardial perfusion was then evaluated during reperfusion after release of coronary occlusion. Then the coronary was permanently occluded and 20.5+/-2 channels were drilled with the Holmium:YAG laser and perfusion was measured again. The other four sheep served as control with untreated ischaemia. All animals were sacrificed after 28 days following administration of gadolinium i.v. to serve as contrast medium for magnetic resonance tomography. The hearts were subjected to magnetic resonance tomography and histopathological examination. Intraoperative perfusion measurements revealed a decreased perfusion after temporary occlusion and an increased perfusion in reperfused myocardium. After TMLR, no improvement of myocardial perfusion above the ischaemic level could be shown. Magnetic resonance images could neither confirm patent laser channels nor viable myocardium within ischaemic areas. On histology no patent endocardial laser channel could be detected. The transmural features were myocardial infarct with scar tissue. In the presented sheep model with acute ischaemia, TMLR with a Holmium:YAG laser did not provide acute improvement of myocardial perfusion as assessed by a thermal imaging camera. This would suggest no direct contribution of newly created laser channels to myocardial perfusion. As chronic effects are concerned, no perfused laser channels could be identified by later magnetic resonance imaging or histology.

A fibrin-supported myocardial organ culture for isolation of cardiac stem cells via the recapitulation of cardiac homeostasis.

PubMed

Kim, Jong-Tae; Chung, Hye Jin; Seo, Ji-Yeon; Yang, Young-Il; Choi, Min-Young; Kim, Hyeong-In; Yang, Tae-Hyun; Lee, Won-Jin; Youn, Young Chul; Kim, Hye Jung; Kim, Yeon Mee; Lee, Hyukjin; Jang, Yang-Soo; Lee, Seung-Jin

2015-04-01

There is great interest in the development of cardiac stem cells (CSCs) cell-based therapeutics; thus, clinical translation requires an efficient method for attaining therapeutic quantities of these cells. Furthermore, an in vitro model to investigate the mechanisms regulating the cardiac homeostasis is crucial. We sought to develop a simple myocardial culture method for enabling both the recapitulation of myocardial homeostasis and the simultaneous isolation of CSCs. The intact myocardial fragments were encapsulated 3-dimensionally into the fibrin and cultured under dynamic conditions. The fibrin provided secure physical support and substratum to the myocardium, which mediated integrin-mediated cell signaling that allowed in situ renewal, outgrowth and cardiomyogenic differentiation of CSCs, mimicking myocardial homeostasis. Since our culture maintained the myocardial CSCs niches, it was possible to define the identity of in vitro renewed CSCs that situated in the interstitium between cardiomyocytes and microvessels. Lastly, the use of matrix-restricted fibrinolysis enabled the selective isolation of outgrown CSCs that retained the clonogenicity, long-term growth competency and cardiovascular commitment potential. Collectively, this myocardial culture might be used as an alternative tool for studying cardiac biology and developing cell-based therapeutics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Myocardial scintigraphy with 201thallium in pediatric cardiology: A review of 52 cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bjoerkhem, G.E.; Evander, E.; White, T.

1990-01-01

We report our experience of myocardial scintigraphy with 201thallium (201Tl) in 52 children, aged 4 days to 18 years, in which 80 studies were made primarily to demonstrate or exclude impaired myocardial perfusion. For analysis, the patients were divided into the following eight groups: group I, coronary artery malformations (five patients); group II, Kawasaki's syndrome (six patients); group III, arterial switch operation (seven patients); group IV, dilated cardiomyopathy (18 patients); group V, hypertrophic cardiomyopathy (four patients); group VI, myocardial dysfunction after surgery for congenital heart disease (five patients); group VII, pulmonary atresia (three patients); and group VIII, miscellaneous (four patients).more » Myocardial scintigraphy was performed with a planar or tomographic technique at rest or after exercise (four patients). Isotope-uptake defects, indicating impaired myocardial perfusion, were present in 14 patients, including small infants. Defects were seen in all groups except those with hypertrophic cardiomyopathy and pulmonary atresia. The absence of such defects in several of the patients with Kawasaki's syndrome was particularly valuable as it made coronary angiography unnecessary. In the other groups of patients myocardial scintigraphy was a valuable adjunct to other investigations.« less

[The adrenergic mechanisms are involved in the pulmonary hemodynamics changes following experimental myocardial ischemia in rabbits].

PubMed

Evlakhov, V I; Poiasov, I Z

2012-05-01

In acute experiments in anesthetized rabbits the changes of the pulmonary hemodynamics following myocardial ischemia in the region of the descendent left coronary artery were studied in control animals and after the blockade of alpha-adrenoreceptors by phentolamine or N-cholinoreceptors of autonomic ganglia by hexamethonium. Following myocardial ischemia in control animals the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance was elevated not significantly, the cardiac output decreased more than pulmonary artery flow. Following myocardial ischemia after the blockade of alpha-adrenoreceptors the pulmonary artery flow and cardiac output decreased in the same level and the pulmonary vascular resistance was decreased. In these conditions the pulmonary artery pressure decreased more than in control animals, meanwhile the pulmonary artery flow was decreased in the same level as in the last case. Following myocardial ischemia after the blockade of N-cholinoreceptors the pulmonary hemodynamics changes were the same as they were following myocardial ischemia in the control rabbits, the cardiac output decreased more than pulmonary artery flow. The disbalance of the cardiac output and pulmonary artery flow changes in the case of myocardial ischemia was caused by the pulmonary vessel reactions following activations of the humoral adrenergic mechanisms.

Assessment of vital exhaustion and identification of subjects at increased risk of myocardial infarction in general practice.

PubMed

Schuitemaker, G E; Dinant, G J; van der Pol, G A; Appels, A

2004-01-01

Vital exhaustion, a state characterized by unusual fatigue, loss of energy, increased irritability, and feelings of demoralization, is one of the cardiovascular risk factors. The authors investigated whether vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice. In this prospective cohort study, vital exhaustion was assessed with the Maastricht Interview on Vital Exhaustion. Other cardiovascular risk factors established were age, gender, systolic and diastolic blood pressure, total cholesterol, body mass index, smoking habits, cardiovascular disease, and diabetes mellitus. A Cox regression analysis was used. The subjects were adults (41-66 years) in an average Dutch village population. Outcome measures were fatal and nonfatal myocardial infarction. At the univariate level, vital exhaustion doubled the risk of myocardial infarction. The effect of exhaustion was confounded by gender; women had higher exhaustion scores and a lower incidence of myocardial infarction. With control for gender, age, systolic blood pressure, total cholesterol, smoking habits, self-reported cardiovascular disease, and diabetes mellitus, vital exhaustion almost tripled the risk of myocardial infarction. Assessment of vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice.

Myocardial contrast echocardiography in mice: technical and physiological aspects.

PubMed

Verkaik, Melissa; van Poelgeest, Erik M; Kwekkeboom, Rick F J; Ter Wee, Piet M; van den Brom, Charissa E; Vervloet, Marc G; Eringa, Etto C

2018-03-01

Myocardial contrast echocardiography (MCE) offers the opportunity to study myocardial perfusion defects in mice in detail. The value of MCE compared with single-photon emission computed tomography, positron emission tomography, and computed tomography consists of high spatial resolution, the possibility of quantification of blood volume, and relatively low costs. Nevertheless, a number of technical and physiological aspects should be considered to ensure reproducibility among research groups. The aim of this overview is to describe technical aspects of MCE and the physiological parameters that influence myocardial perfusion data obtained with this technique. First, technical aspects of MCE discussed in this technical review are logarithmic compression of ultrasound data by ultrasound systems, saturation of the contrast signal, and acquisition of images during different phases of the cardiac cycle. Second, physiological aspects of myocardial perfusion that are affected by the experimental design are discussed, including the anesthesia regimen, systemic cardiovascular effects of vasoactive agents used, and fluctuations in body temperature that alter myocardial perfusion. When these technical and physiological aspects of MCE are taken into account and adequately standardized, MCE is an easily accessible technique for mice that can be used to study the control of myocardial perfusion by a wide range of factors.

F-18 sodium fluoride PET/CT does not effectively image myocardial inflammation due to suspected cardiac sarcoidosis.

PubMed

Weinberg, Richard L; Morgenstern, Rachelle; DeLuca, Albert; Chen, Jennifer; Bokhari, Sabahat

2017-12-01

Sarcoidosis is an inflammatory disorder of unknown etiology that can involve the heart. While effective in imaging cardiac sarcoidosis, F-18 fluorodeoxyglucose (FDG) PET/CT often shows non-specific myocardial uptake. F-18 sodium fluoride (NaF) has been used to image inflammation in coronary artery plaques and has low background myocardial uptake. Here, we evaluated whether F-18 NaF can image myocardial inflammation due to clinically suspected cardiac sarcoidosis. We performed a single institution pilot study testing if F-18 NaF PET/CT can detect myocardial inflammation in patients with suspected cardiac sarcoidosis. Patients underwent cardiac PET/CT with F-18 FDG as part of their routine care and subsequently received an F-18 NaF PET/CT scan. Three patients underwent F-18 FDG and F-18 NaF imaging. In all patients, there was F-18 FDG uptake consistent with cardiac sarcoidosis. The F-18 NaF PET/CT scans showed no myocardial uptake. In this small preliminary study, PET/CT scan using F-18 NaF does not appear to detect myocardial inflammation caused by suspected cardiac sarcoidosis.

[Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

PubMed

Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

1994-01-01

Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

Spatial variation and density-dependent dispersal in competitive coexistence.

PubMed Central

Amarasekare, Priyanga

2004-01-01

It is well known that dispersal from localities favourable to a species' growth and reproduction (sources) can prevent competitive exclusion in unfavourable localities (sinks). What is perhaps less well known is that too much emigration can undermine the viability of sources and cause regional competitive exclusion. Here, I investigate two biological mechanisms that reduce the cost of dispersal to source communities. The first involves increasing the spatial variation in the strength of competition such that sources can withstand high rates of emigration; the second involves reducing emigration from sources via density-dependent dispersal. I compare how different forms of spatial variation and modes of dispersal influence source viability, and hence source-sink coexistence, under dominance and pre-emptive competition. A key finding is that, while spatial variation substantially reduces dispersal costs under both types of competition, density-dependent dispersal does so only under dominance competition. For instance, when spatial variation in the strength of competition is high, coexistence is possible (regardless of the type of competition) even when sources experience high emigration rates; when spatial variation is low, coexistence is restricted even under low emigration rates. Under dominance competition, density-dependent dispersal has a strong effect on coexistence. For instance, when the emigration rate increases with density at an accelerating rate (Type III density-dependent dispersal), coexistence is possible even when spatial variation is quite low; when the emigration rate increases with density at a decelerating rate (Type II density-dependent dispersal), coexistence is restricted even when spatial variation is quite high. Under pre-emptive competition, density-dependent dispersal has only a marginal effect on coexistence. Thus, the diversity-reducing effects of high dispersal rates persist under pre-emptive competition even when dispersal is density dependent, but can be significantly mitigated under dominance competition if density-dependent dispersal is Type III rather than Type II. These results lead to testable predictions about source-sink coexistence under different regimes of competition, spatial variation and dispersal. They identify situations in which density-independent dispersal provides a reasonable approximation to species' dispersal patterns, and those under which consideration of density-dependent dispersal is crucial to predicting long-term coexistence. PMID:15306322

Treatment of acute coronary syndrome: part 2: ST-segment elevation myocardial infarction.

PubMed

Trost, Jeffrey C; Lange, Richard A

2012-06-01

Familiarize clinicians with recent information regarding the diagnosis and treatment of ST-segment elevation myocardial infarction. PubMed search and review of relevant medical literature. Definition, pathophysiology, clinical presentation, diagnosis, and treatment of ST-segment elevation myocardial infarction are reviewed. Patients with ST-segment elevation myocardial infarction benefit from prompt reperfusion therapy. Adjunctive antianginal, antiplatelet, antithrombotic, beta blocker, angiotensin-converting enzyme inhibitor, and statin agents minimize ongoing cardiac ischemia, prevent thrombus propagation, and reduce the risk of recurrent cardiovascular events.

The Role of Alcohol Consumption in the Aetiology of Different Cardiovascular Disease Phenotypes: a CALIBER Study

ClinicalTrials.gov

2013-05-28

Chronic Stable Angina; Unstable Angina; Coronary Heart Disease Not Otherwise Specified; Acute Myocardial Infarction; Heart Failure; Ventricular Arrhythmias; Cardiac Arrest; Abdominal Aortic Aneurysm; Peripheral Arterial Disease; Ischaemic Stroke; Subarachnoid Haemorrhagic Stroke; Intracerebral Haemorrhagic Stroke; Stroke Not Otherwise Specified; Sudden Cardiac Death; Unheralded Coronary Death; Mortality; Coronary Heart Disease (CHD); Cardiovascular Disease (CVD); Fatal Cardiovascular Disease (Fatal CVD); ST Elevation Myocardial Infarction (STEMI); Non-ST Elevation Myocardial Infarction (nSTEMI); Myocardial Infarction Not Otherwise Specified (MI NOS)

SPECT imaging with Tl-201 and Ga-67 in myocardial sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurata, C.; Sakata, K.; Taguchi, T.

1990-06-01

Two patients with myocardial sarcoidosis are presented, both of whom underwent SPECT imaging with Tl-201 and Ga-67. The first had Ga-67 myocardial uptake with a Tl-201 defect, which disappeared with corticosteroid therapy. The second had multiple Tl-201 defects without Ga-67 uptake, which persisted despite corticosteroid therapy. Therefore, the combination of Tl-201 and Ga-67 imaging may be useful for recognizing myocardial sarcoidosis and for predicting the response to corticosteroid therapy.

Parvovirus Infection Is Associated With Myocarditis and Myocardial Fibrosis in Young Dogs.

PubMed

Ford, Jordan; McEndaffer, Laura; Renshaw, Randall; Molesan, Alex; Kelly, Kathleen

2017-11-01

Perinatal parvoviral infection causes necrotizing myocarditis in puppies, which results in acute high mortality or progressive cardiac injury. While widespread vaccination has dramatically curtailed the epidemic of canine parvoviral myocarditis, we hypothesized that canine parvovirus 2 (CPV-2) myocardial infection is an underrecognized cause of myocarditis, cardiac damage, and/or repair by fibrosis in young dogs. In this retrospective study, DNA was extracted from formalin-fixed, paraffin-embedded tissues from 40 cases and 41 control dogs under 2 years of age from 2007 to 2015. Cases had a diagnosis of myocardial necrosis, inflammation, or fibrosis, while age-matched controls lacked myocardial lesions. Conventional polymerase chain reaction (PCR) and sequencing targeting the VP1 to VP2 region detected CPV-2 in 12 of 40 cases (30%; 95% confidence interval [CI], 18%-45%) and 2 of 41 controls (5%; 95% CI, 0.1%-16%). Detection of CPV-2 DNA in the myocardium was significantly associated with myocardial lesions ( P = .003). Reverse transcription quantitative PCR amplifying VP2 identified viral messenger RNA in 12 of 12 PCR-positive cases and 2 of 2 controls. PCR results were confirmed by in situ hybridization, which identified parvoviral DNA in cardiomyocytes and occasionally macrophages of juvenile and young adult dogs (median age 61 days). Myocardial CPV-2 was identified in juveniles with minimal myocarditis and CPV-2 enteritis, which may indicate a longer window of cardiac susceptibility to myocarditis than previously reported. CPV-2 was also detected in dogs with severe myocardial fibrosis with in situ hybridization signal localized to cardiomyocytes, suggesting prior myocardial damage by CPV-2. Despite the frequency of vaccination, these findings suggest that CPV-2 remains an important cause of myocardial damage in dogs.

Myocardial bridges, neither rare nor isolated-Autopsy study.

PubMed

Teofilovski-Parapid, G; Jankovic, R; Kanjuh, V; Virmani, R; Danchin, N; Prates, N; Simic, D V; Parapid, B

2017-03-01

Myocardial bridge is a congenital anomaly with a markedly variable reported incidence on autopsy (4.7%-86%), likely related to geographical regions. Our previous retrospective study showed a prevalence of 0.8%, which we doubted to be the true one in the examined sample of the Serbian population. To assess the importance of the phenomenon we conducted a 2-year prospective study at the same institution. Ninety-six cadaver hearts from adult individuals of both genders (51 men, 45 women) who died from natural causes underwent special dissection. Tunneled coronary arteries and myocardium were examined using light microscopy. A total of 14 myocardial bridges were found in 13 (13.54%) hearts. This anomaly was insignificantly more common in men (13.72% vs. 13.33%, p>0.05). In one heart we noted two myocardial bridges (the left anterior interventricular artery and left marginal artery were overbridged). None of the myocardial bridges had been diagnosed during life. The most common causes of death were cardiac related. Myocardial bridges were located in the following areas: left anterior interventricular (50%), left circumflex artery (28.6%), left marginal artery (14.3%), and right coronary artery (7.1%). In 92.3% of cases, the right coronary artery was dominant. The only heart with a balanced-type had two bridges. Most of the myocardial bridges were long and deep. All tunneled coronary arteries, and although surrounded by "coronary cushion," were not protected from atherosclerosis. In 30.8% of hearts with myocardial bridges, we found additional coronary artery anomalies. Myocardial bridges were not rare in the examined sample of the Serbian population and were often associated with other coronary artery anomalies, rendering the carriers at higher risk. Copyright © 2016 Elsevier GmbH. All rights reserved.

Heat and risk of myocardial infarction: hourly level case-crossover analysis of MINAP database

PubMed Central

Armstrong, Ben; Hajat, Shakoor; Haines, Andy; Wilkinson, Paul; Smeeth, Liam

2012-01-01

Objective To quantify the association between exposure to higher temperatures and the risk of myocardial infarction at an hourly temporal resolution. Design Case-crossover study. Setting England and Wales Myocardial Ischaemia National Audit Project (MINAP) database. Participants 24 861 hospital admissions for myocardial infarction occurring in 11 conurbations during the warmest months (June to August) of the years 2003-09. Main outcome measure Odds ratio of myocardial infarction for a 1°C increase in temperature. Results Strong evidence was found for an effect of heat acting 1-6 hours after exposure to temperatures above an estimated threshold of 20°C (95% confidence interval 16°C to 25°C). For each 1°C increase in temperature above this threshold, the risk of myocardial infarction increased by 1.9% (0.5% to 3.3%, P=0.009). Later reductions in risk seemed to offset early increases in risk: the cumulative effect of a 1°C rise in temperature above the threshold was 0.2% (−2.1% to 2.5%) by the end of the third day after exposure. Conclusions Higher ambient temperatures above a threshold of 20°C seem to be associated with a transiently increased risk of myocardial infarction 1-6 hours after exposure. Reductions in risk at longer lags are consistent with heat triggering myocardial infarctions early in highly vulnerable people who would otherwise have had a myocardial infarction some time later (“short term displacement”). Policies aimed at reducing the health effects of hot weather should include consideration of effects operating at sub-daily timescales. PMID:23243290

Twenty-Five-Year (1986-2011) Trends in the Incidence and Death Rates of Stroke Complicating Acute Myocardial Infarction.

PubMed

Hariri, Essa; Tisminetzky, Mayra; Lessard, Darleen; Yarzebski, Jorge; Gore, Joel; Goldberg, Robert

2018-05-04

The occurrence of a stroke after an acute myocardial infarction is associated with increased morbidity and mortality rates. However, limited data are available, particularly from a population-based perspective, about recent trends in the incidence and mortality rates associated with stroke complicating an acute myocardial infarction. The purpose of this study was to examine 25-year trends (1986-2011) in the incidence and in-hospital mortality rates of initial episodes of stroke complicating acute myocardial infarction. The study population consisted of 11,436 adults hospitalized with acute myocardial infarction at all 11 medical centers in central Massachusetts on a biennial basis between 1986 and 2011. In this study cohort, 159 patients (1.4%) experienced an acute first-ever stroke during hospitalization for acute myocardial infarction. The proportion of patients with acute myocardial infarction who developed a stroke increased through the 1990s but decreased slightly thereafter. Compared with patients who did not experience a stroke, those who experienced a stroke were significantly older, were more likely to be female, had a previous acute myocardial infarction, had a significant burden of comorbidities, and were more likely to have died (32.1% vs 10.8%) during their index hospitalization. Patients who developed a first stroke in the most recent study years (2003-2011) were more likely to have died during hospitalization than those hospitalized during earlier study years. Although the incidence rates of acute stroke complicating acute myocardial infarction remained relatively stable during the years under study, the in-hospital mortality rates of those experiencing a stroke have not decreased. Copyright © 2018. Published by Elsevier Inc.

Eotaxin/CCL11 levels correlate with myocardial fibrosis and mast cell density in native and transplanted rat hearts.

PubMed

Zweifel, M; Matozan, K; Dahinden, C; Schaffner, T; Mohacsi, P

2010-09-01

Myocardial fibrosis contributes to hemodynamic and cardiac functional alterations commonly observed posttransplantation. Cardiac mast cells (MC) have been linked to fibrosis in posttransplantation hearts. Eotaxin, which has been shown to be involved in fibrogenesis, has been demonstrated to be increased in production in cardiac macrophages. The aim of our study was to correlate myocardial fibrosis during heart transplant rejection in the rat with eotaxin/chemokine [c-c motif] ligand 11 (CCL11) expression, and with various subtypes of infiltrating cardiac MC, namely connective-type MC (CTMC) and mucosa-type MC (MMC). We used tissues from 2 previous studies of ongoing acute rejection in allogeneic Brown-Norway to Lewis rat and an isogeneic Brown-Norway to Brown-Norway heterotopic heart transplantation models under cyclosporin/prednisolone immunosuppression. Collagen fibrils were stained with Masson's trichrome with myocardial fibrosis expressed as percent fibrotic area per total section area. Eotaxin/CCL11 previously measured in heart tissue using enzyme-linked immunosorbent assay (ELISA) was correlated with the extent of myocardial fibrosis. We compared values from native hearts (n = 4) as well as transplants on days 5, 16, and 28 (n = 4 in each group). The area of myocardial fibrosis was significantly increased in the allogeneic compared with the isogeneic group at day 16 (38% vs 21%) and at day 28 (49% vs 22%) after transplantation. Myocardial fibrosis correlated significantly with eotaxin/CCL11 concentrations and the density of MMC, but not with CTMC in heart tissue. Eotaxin-triggered MC infiltration of the heart may contribute to myocardial fibrosis after transplantation. Targeting eotaxin/CCL11 with monoclonal antibodies, such as bertilimumab, could reduce MC infiltration, possibly resulting in decreased myocardial fibrosis and improved contractile function after heart transplantation. 2010 Elsevier Inc. All rights reserved.

Influence of climate variability on acute myocardial infarction mortality in Havana, 2001-2012.

PubMed

Rivero, Alina; Bolufé, Javier; Ortiz, Paulo L; Rodríguez, Yunisleydi; Reyes, María C

2015-04-01

Death from acute myocardial infarction is due to many factors; influences on risk to the individual include habits, lifestyle and behavior, as well as weather, climate and other environmental components. Changing climate patterns make it especially important to understand how climatic variability may influence acute myocardial infarction mortality. Describe the relationship between climate variability and acute myocardial infarction mortality during the period 2001-2012 in Havana. An ecological time-series study was conducted. The universe comprised 23,744 deaths from acute myocardial infarction (ICD-10: I21-I22) in Havana residents from 2001 to 2012. Climate variability and seasonal anomalies were described using the Bultó-1 bioclimatic index (comprising variables of temperature, humidity, precipitation, and atmospheric pressure), along with series analysis to determine different seasonal-to-interannual climate variation signals. The role played by climate variables in acute myocardial infarction mortality was determined using factor analysis. The Mann-Kendall and Pettitt statistical tests were used for trend analysis with a significance level of 5%. The strong association between climate variability conditions described using the Bultó-1 bioclimatic index and acute myocardial infarctions accounts for the marked seasonal pattern in AMI mortality. The highest mortality rate occurred during the dry season, i.e., the winter months in Cuba (November-April), with peak numbers in January, December and March. The lowest mortality coincided with the rainy season, i.e., the summer months (May-October). A downward trend in total number of deaths can be seen starting with the change point in April 2009. Climate variability is inversely associated with an increase in acute myocardial infarction mortality as is shown by the Bultó-1 index. This inverse relationship accounts for acute myocardial infarction mortality's seasonal pattern.

Menopause and myocardial infarction risk among employed women in relation to work and family psychosocial factors in Lithuania.

PubMed

Malinauskiene, Vilija; Tamosiunas, Abdonas

2010-05-01

To assess the relationship between menopause and age at menopause and the risk of the first non-fatal myocardial infarction taking into account the possible influence of psychosocial job characteristics, marital stress, level of social support, educational level, occupation, age and traditional ischemic heart disease risk factors. Population-based case-control study among 35-61 years old employed women in Kaunas, Lithuania. Totally 122 myocardial infarction cases and 371 controls were interviewed in 2001-2004. The logistic regression analysis was performed. Younger age at menopause (

The role of glycogen synthase kinase 3 beta in brain injury induced by myocardial ischemia/reperfusion injury in a rat model of diabetes mellitus.

PubMed

Zhao, Bo; Gao, Wen-Wei; Liu, Ya-Jing; Jiang, Meng; Liu, Lian; Yuan, Quan; Hou, Jia-Bao; Xia, Zhong-Yuan

2017-10-01

Myocardial ischemia/reperfusion injury can lead to severe brain injury. Glycogen synthase kinase 3 beta is known to be involved in myo-cardial ischemia/reperfusion injury and diabetes mellitus. However, the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear. In this study, we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats. Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin. Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery. Post-conditioning comprised three cycles of ischemia/reperfusion. Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion, the structure of the brain was seriously damaged in the experimental rats compared with normal controls. Expression of Bax, interleukin-6, interleukin-8, terminal deoxynucleotidyl transferase dUTP nick end labeling, and cleaved caspase-3 in the brain was significantly increased, while expression of Bcl-2, interleukin-10, and phospho-glycogen synthase kinase 3 beta was decreased. Diabetes mellitus can aggravate inflammatory reactions and apoptosis. Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes. Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glyco-gen synthase kinase 3 beta. According to these results, glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.

Protective Effects of Ultramicronized Palmitoylethanolamide (PEA-um) in Myocardial Ischaemia and Reperfusion Injury in VIVO.

PubMed

Di Paola, Rosanna; Cordaro, Marika; Crupi, Rosalia; Siracusa, Rosalba; Campolo, Michela; Bruschetta, Giuseppe; Fusco, Roberta; Pugliatti, Pietro; Esposito, Emanuela; Cuzzocrea, Salvatore

2016-08-01

Myocardial infarction is the leading cause of death, occurs after prolonged ischemia of the coronary arteries. Restore blood flow is the first intervention help against heart attack. However, reperfusion of the arteries leads to ischemia/reperfusion injury (I/R). The fatty acid amide palmitoylethanolamide (PEA) is an endogenous compound widely present in living organisms, with analgesic and anti-inflammatory properties. The present study evaluated the effect of ultramicronized palmitoylethanolamide (PEA-um) treatment on the inflammatory process associated with myocardial I/R. Myocardial ischemia reperfusion injury was induced by occlusion of the left anterior descending coronary artery for 30 min followed by 2 h of reperfusion. PEA-um, was administered (10 mg/kg) 15 min after ischemia and 1 h after reperfusion. In this study, we demonstrated that PEA-um treatment reduces myocardial tissue injury, neutrophil infiltration, adhesion molecules (ICAM-1, P-selectin) expression, proinflammatory cytokines (TNF-α, IL-1β) production, nitrotyrosine and PAR formation, nuclear factor kB expression, and apoptosis (Fas-L, Bcl-2) activation. In addition to study whether the protective effect of PEA-um on myocardial ischemia reperfusion injury is also related to the activation of PPAR-α, in a separate set of experiments it has been performed myocardial I/R in PPARα mice. Genetic ablation of peroxisome proliferator activated receptor (PPAR)-α in PPAR-αKO mice exacerbated Myocardial ischemia reperfusion injury when compared with PPAR-αWT mice. PEA-um induced cardioprotection in PPAR-α wild-type mice, but the same effect cannot be observed in PPAR-αKO mice. Our results have clearly shown a modulation of the inflammatory process, associated with myocardial ischemia reperfusion injury, following administration of PEA-um.

Cardiovascular magnetic resonance assessment of ventricular function and myocardial scarring before and early after repair of anomalous left coronary artery from the pulmonary artery

PubMed Central

2014-01-01

Background In patients with anomalous left coronary artery from the pulmonary artery (ALCAPA) left ventricular (LV) dilatation and dysfunction evolves due to diminished myocardial perfusion caused by coronary steal phenomenon. Using late gadolinium enhanced cardiovascular magnetic resonance (LGE-CMR) imaging, myocardial scarring has been shown in ALCAPA patients late after repair, however the incidence of scarring before surgery and its impact on postoperative course after surgical repair remained unknown. Methods 8 ALCAPA-patients (mean age 10.0 ± 5.8 months) underwent CMR before and early after (mean 4.9 ± 2.5 months) coronary reimplantation procedures. CMR included functional analysis and LGE for detection of myocardial scars. Results LV dilatation (mean LVEDVI 171 ± 94 ml/m2) and dysfunction (mean LV-EF 22 ± 10 %) was present in all patients and improved significantly after surgery (mean LVEDV 68 ± 42 ml/m2, p = 0.02; mean LV-EF 58 ± 19 %, p < 0.001). Preoperative CMR revealed myocardial scarring in 2 of the 8 patients and did not predict postoperative course. At follow-up CMR, one LGE-positive patient showed delayed recovery of LV function while myocardial scarring was still present in both patients. In two patients new-onset transmural scarring was found, although functional recovery after operation was sufficient. One of them showed a stenosis of the left coronary artery and required resurgery. Conclusions Despite diminished myocardial perfusion and severely compromised LV function, myocardial scarring was preoperatively only infrequently present. Improvement of myocardial function was independent of new-onset scarring while the impact of preoperative scarring still needs to be defined. PMID:24387660

The 1999 Ji-Ji (Taiwan) earthquake as a trigger for acute myocardial infarction.

PubMed

Tsai, Ching-Hong; Lung, For-Wey; Wang, Shing-Yaw

2004-01-01

The authors evaluated the effect of stress due to the Ji-Ji, Taiwan, earthquake, which occurred at 1:47 a.m. on September 21, 1999, on the onset of acute myocardial infarction in six counties near the earthquake epicenter. The rate of hospitalization due to acute myocardial infarction increased during the 6 weeks after the earthquake, and a significantly higher number of patients were hospitalized with acute myocardial infarction during that period, compared with the same 6-week period in the previous year (99 and 65 patients, respectively). The findings suggest that extreme emotional stress due to the natural disaster, superimposed on the stress of awakening, increased the incidence of acute myocardial infarction in this population.

Coexisting Disorders and Academic Achievement among Children with ADHD

ERIC Educational Resources Information Center

Barnard-Brak, Lucy; Sulak, Tracey N.; Fearon, Danielle D.

2011-01-01

Objective: ADHD is a commonly diagnosed neuropsychological disorder among school-aged children with reported high rates of coexisting or comorbid disorders. As ADHD has been associated with academic underachievement, the current study examines this association in view of the presence of coexisting disorders. The purpose of the current study is to…

"We Cooperate, or We Die": Sustainable Coexistence in Terry Pratchett's "The Amazing Maurice" and "His Educated Rodents"

ERIC Educational Resources Information Center

Oziewicz, Marek

2009-01-01

This article examines Terry Pratchett's "The Amazing Maurice" as a modern example of environmentally informed social dreaming about sustainable coexistence. In our increasingly ecologically-conscious world sustainability and coexistence have become key words in the discourse about social, economic and political relations. The problem of relating…

Species coexistence of communities with intraguild predation: the role of refuges used by the resource and the intraguild prey.

PubMed

Liu, Zhiguang; Zhang, Fengpan

2013-10-01

In this paper, we develop a three-species intraguild predation model which incorporates refuges used by the resource and the intraguild prey, and focus on the effects of refuges on the three species coexistence. The invasion condition and parameter region for coexistence are obtained using invasion analysis. The new invasion condition requires that all boundary states with one missing species can be invaded by the missing species. Numerical simulations show that refuges have a major influence on species coexistence of intraguild predation system, and the results strongly depend on the types of refuges introduced into the model. Our study also shows that prey's refuges are detrimental to species coexistence except the resource using refuges. In contrast to previous research, we find that spatial structure may play an important role in effects of refuges on species coexistence of intraguild predation systems. Our results may shed new light on understanding the mechanisms and the persistence of multi-species predators-prey system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Toward a Theory of Coexistence in Shared Social-Ecological Systems: The Case of Cook Inlet Salmon Fisheries.

PubMed

Loring, Philip A

Coexistence theory (CT) in community ecology provides a functional perspective on how multiple competing species coexist. Here, I explore CT's usefulness for understanding conflict and coexistence among human groups with diverse livelihood interests in shared resources such as fisheries. I add three concepts from social science research on coexistence: adaptability, pluralism, and equity and apply this expanded theoretical framework to the case of salmon fisheries in Alaska's Cook Inlet, synthesizing catch records with anthropological research. The analysis addresses issues of inequity, such as who bears the costs of conservation measures, a lack of pluralism, in that people have come to devalue their neighbors, and a decline in resilience for some sectors, all of which undermine the likelihood of these groups continuing coexistence. I discuss policy options for addressing escalating conflict in the region, such as improving equity in management and the resilience of some fishing groups to temporary closures. Finally, I discuss points of engagement for CT with other areas of sustainability science such as resilience thinking.

Multislice coronary computed tomographic angiography in emergency department presentations of unsuspected acute myocardial infarction.

PubMed

Hecht, Harvey S; Bhatti, Tandeep

2009-01-01

Coronary computed tomographic angiography (CCTA) is not indicated in the setting of acute myocardial infarction in the emergency department (ED). Nonetheless, acute coronary syndromes may have atypical presentations, and CCTA may be inadvertently performed in this setting. This study was designed to determine the frequency and characteristics of CCTA imaging of unsuspected acute myocardial infarction in the ED. All CCTAs performed in the ED at Lenox Hill Hospital were reviewed for clinical indications and subsequent course; patients with documented acute myocardial infarction were identified. Of the 500 CCTAs performed on ED patients in the Lenox Hill laboratory, 5 patients (1%) were imaged during the initial phase of an unsuspected acute myocardial infarction; in all cases the CCTAs were key to the diagnosis. The imaging characteristics were (1) total or subtotal occlusion and (2) transmural hypodensity in the infarct area. Although acute myocardial infarction on CCTA in ED patients is an infrequent event, proper and prompt recognition is critical for appropriate patient care, particularly as applications to the ED increase.

MYOCARDIAL AKT: THE OMNIPRESENT NEXUS

PubMed Central

Sussman, Mark A.; Völkers, Mirko; Fischer, Kimberlee; Bailey, Brandi; Cottage, Christopher T.; Din, Shabana; Gude, Natalie; Avitabile, Daniele; Alvarez, Roberto; Sundararaman, Balaji; Quijada, Pearl; Mason, Matt; Konstandin, Mathias H.; Malhowski, Amy; Cheng, Zhaokang; Khan, Mohsin; McGregor, Michael

2013-01-01

One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses. PMID:21742795

Ultrasound imaging of propagation of myocardial contraction for non-invasive identification of myocardial ischemia

NASA Astrophysics Data System (ADS)

Matsuno, Yuya; Taki, Hirofumi; Yamamoto, Hiroaki; Hirano, Michinori; Morosawa, Susumu; Shimokawa, Hiroaki; Kanai, Hiroshi

2017-07-01

Non-invasive identification of ischemic regions is important for diagnosis and treatment of myocardial infarction. In the present study, ultrasound measurement was applied to the interventricular septum of three open-chest swine hearts. The properties of the myocardial contraction response of the septum were compared between normal and acute ischemic conditions, where the acute ischemic condition of the septum originated from direct avascularization of the left anterior descending (LAD) coronary artery. The result showed that the contraction response propagated from the basal side to the apical side along the septum. The estimated propagation velocities in the normal and acute ischemic conditions were 3.6 and 1.9 m/s, respectively. This finding indicates that acute ischemia which occurred 5 s after the avascularization of the LAD promptly suppressed the propagation velocity through the ventricular septum to about half the normal velocity. It was suggested that the myocardial ischemic region could be identified using the difference in the propagation velocity of the myocardial response to contraction.

Novel cardiovascular magnetic resonance oxygenation approaches in understanding pathophysiology of cardiac diseases.

PubMed

Sree Raman, Karthigesh; Nucifora, Gaetano; Selvanayagam, Joseph B

2018-05-01

Cardiovascular magnetic resonance imaging (CMR) permits accurate phenotyping of many cardiac diseases. CMR's inherent advantages are its non-invasive nature, lack of ionizing radiation and high accuracy and reproducibility. Furthermore, it is able to assess many aspects of cardiac anatomy, structure and function. Specifically, it can characterize myocardial tissue, myocardial function, myocardial mass, myocardial blood flow/perfusion, irreversible and reversible injury, all with a high degree of accuracy and reproducibility. Hence, CMR is a powerful tool in clinical and pre-clinical research. In recent years there have been novel advances in CMR myocardial tissue characterization. Oxygenation-sensitive CMR (OS-CMR) is a novel non-invasive, contrast independent technique that permits direct quantification of myocardial tissue oxygenation, both at rest and during stress. In this review, we will address the principles of the OS-CMR technique, its recent advances and summarize the studies in the effects of oxygenation on cardiac diseases. © 2018 John Wiley & Sons Australia, Ltd.

[Anomalous origin of the left coronary artery from the pulmonary trunk with myocardial infarction and severe left ventricular dysfunction in infancy--assessment of myocardial damage using SPECT studies with 201TlCl and 123I-BMIPP].

PubMed

Miyamoto, T; Horigome, H; Sato, H; Yamada, M; Inai, K; Takeda, T; Ishikawa, N; Hoshino, H; Itai, Y

1996-02-01

A 4-month-old male infant with Bland-White-Garland (BWG) syndrome complicated myocardial infarction was reported. Signs included tachypnea, coughing, and failure to thrive. However, there was no sign of myocardial infarction. A chest radiograph revealed cardiomegaly (CTR = 65%) and electrocardiogram showed abnormal Q waves in I, aVL, V6 leads. Cardiac catheterization and angiography revealed marked dilatation of left ventricle (end-diastolic volume = 384 ml/m2) and extremely depressed ejection fraction (16%), confirming the diagnosis of BWG syndrome. A 201TlCl-myocardial SPECT demonstrated apical defect and hypoperfusion in the anterolateral, inferoposterior walls, whereas 123I-beta-methyl-p-iodophenylpentadecanoic-acid (123I-BMIPP) SPECT showed a wider defect area. SPECT studies with 201TlCl and 123I-BMIPP, are useful to assess myocardial viability more accurately in BWG syndrome.

A Necessary Condition for Coexistence of Autocatalytic Replicators in a Prebiotic Environment

PubMed Central

Hernandez, Andres F.; Grover, Martha A.

2013-01-01

A necessary, but not sufficient, mathematical condition for the coexistence of short replicating species is presented here. The mathematical condition is obtained for a prebiotic environment, simulated as a fed-batch reactor, which combines monomer recycling, variable reaction order and a fixed monomer inlet flow with two replicator types and two monomer types. An extensive exploration of the parameter space in the model validates the robustness and efficiency of the mathematical condition, with nearly 1.7% of parameter sets meeting the condition and half of those exhibiting sustained coexistence. The results show that it is possible to generate a condition of coexistence, where two replicators sustain a linear growth simultaneously for a wide variety of chemistries, under an appropriate environment. The presence of multiple monomer types is critical to sustaining the coexistence of multiple replicator types. PMID:25369813

A necessary condition for coexistence of autocatalytic replicators in a prebiotic environment.

PubMed

Hernandez, Andres F; Grover, Martha A

2013-07-24

A necessary, but not sufficient, mathematical condition for the coexistence of short replicating species is presented here. The mathematical condition is obtained for a prebiotic environment, simulated as a fed-batch reactor, which combines monomer recycling, variable reaction order and a fixed monomer inlet flow with two replicator types and two monomer types. An extensive exploration of the parameter space in the model validates the robustness and efficiency of the mathematical condition, with nearly 1.7% of parameter sets meeting the condition and half of those exhibiting sustained coexistence. The results show that it is possible to generate a condition of coexistence, where two replicators sustain a linear growth simultaneously for a wide variety of chemistries, under an appropriate environment. The presence of multiple monomer types is critical to sustaining the coexistence of multiple replicator types.

Competitive intransitivity promotes species coexistence.

PubMed

Laird, Robert A; Schamp, Brandon S

2006-08-01

Using a spatially explicit cellular automaton model with local competition, we investigate the potential for varied levels of competitive intransitivity (i.e., nonhierarchical competition) to promote species coexistence. As predicted, on average, increased levels of intransitivity result in more sustained coexistence within simulated communities, although the outcome of competition also becomes increasingly unpredictable. Interestingly, even a moderate degree of intransitivity within a community can promote coexistence, in terms of both the length of time until the first competitive exclusion and the number of species remaining in the community after 500 simulated generations. These results suggest that modest levels of intransitivity in nature, such as those that are thought to be characteristic of plant communities, can contribute to coexistence and, therefore, community-scale biodiversity. We explore a potential connection between competitive intransitivity and neutral theory, whereby competitive intransitivity may represent an important mechanism for "ecological equivalence."

Direct evidence for stress-induced transformation between coexisting multiple martensites in a Ni-Mn-Ga multifunctional alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, L.; Cong, D. Y.; Wang, Z. L.

2015-07-08

The structural response of coexisting multiple martensites to stress field in a Ni-Mn-Ga multifunctional alloy was investigated by the in situ high-energy x-ray diffraction technique. Stress-induced transformation between coexisting multiple martensites was observed at 110 K, at which five-layered modulated (5M), seven-layered modulated (7M) and non-modulated (NM) martensites coexist. We found that a tiny stress of as low as 0.5 MPa could trigger the transformation from 5M and 7M martensites to NM martensite and this transformation is partly reversible. Besides the transformation between coexisting multiple martensites, rearrangement of martensite variants also occurs during loading, at least at high stress levels.more » The present study is instructive for designing advanced multifunctional alloys with easy actuation.« less

Direct evidence for stress-induced transformation between coexisting multiple martensites in a Ni-Mn-Ga multifunctional alloy

NASA Astrophysics Data System (ADS)

Huang, L.; Cong, D. Y.; Wang, Z. L.; Nie, Z. H.; Dong, Y. H.; Zhang, Y.; Ren, Y.; Wang, Y. D.

2015-07-01

The structural response of coexisting multiple martensites to stress field in a Ni-Mn-Ga multifunctional alloy was investigated by the in situ high-energy x-ray diffraction technique. Stress-induced transformation between coexisting multiple martensites was observed at 110 K, at which five-layered modulated (5M), seven-layered modulated (7M) and non-modulated (NM) martensites coexist. We found that a tiny stress of as low as 0.5 MPa could trigger the transformation from 5M and 7M martensites to NM martensite and this transformation is partly reversible. Besides the transformation between coexisting multiple martensites, rearrangement of martensite variants also occurs during loading, at least at high stress levels. The present study is instructive for designing advanced multifunctional alloys with easy actuation.

Direct evidence for stress-induced transformation between coexisting multiple martensites in a Ni-Mn-Ga multifunctional alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, L.; Cong, D. Y.; Wang, Z. L.

2015-06-03

The structural response of coexisting multiple martensites to stress field in a Ni-Mn-Ga multifunctional alloy was investigated by the in situ high-energy x-ray diffraction technique. Stress-induced transformation between coexisting multiple martensites was observed at 110 K, at which five-layered modulated (5M), seven-layered modulated (7M) and non-modulated (NM) martensites coexist. We found that a tiny stress of as low as 0.5 MPa could trigger the transformation from 5M and 7M martensites to NM martensite and this transformation is partly reversible. Besides the transformation between coexisting multiple martensites, rearrangement of martensite variants also occurs during loading, at least at high stress levels.more » The present study is instructive for designing advanced multifunctional alloys with easy actuation.« less

Effect of Mobile Phone Radiation on Cardiovascular Development of Chick Embryo.

PubMed

Ye, W; Wang, F; Zhang, W; Fang, N; Zhao, W; Wang, J

2016-06-01

The biological effects on cardiovascular development of chicken embryos were examined after radiation exposure using mobile phone (900 MHz; specific absorption rate˜1.07 W/kg) intermittently 3 h per day during incubation. Samples were selected by morphological and histological methods. The results showed the rate of embryonic mortality and cardiac deformity increased significantly in exposed group (P < 0.05). No any histological pathological changes were observed on Day 5-7 (D5-D7) of incubation. A higher distribution of lipid droplets was unexpectedly present in myocardial tissue from the exposure groups on D10-D13. Soon afterwards, myofilament disruption, atrioventricular valve focal necrosis, mitochondria vacuolization and atrial natriuretic peptide (ANP) decrease appeared on D15-D21 of incubation. Comet assay data showed the haemocyte mean tail in the exposed group was significantly larger than that of the control (P < 0.01). The arterial vascular wall of exposed group was thicker (P < 0.05) than that of the control on D13, which was reversed to normal in later stages. Our findings suggest that long-term exposure of MPR may induce myocardium pathological changes, DNA damage and increased mortality; however, there was little effect on vascular development. © 2015 Blackwell Verlag GmbH.

Wnt/β-catenin signaling enables developmental transitions during valvulogenesis

PubMed Central

Bosada, Fernanda M.; Devasthali, Vidusha; Jones, Kimberly A.; Stankunas, Kryn

2016-01-01

Heart valve development proceeds through coordinated steps by which endocardial cushions (ECs) form thin, elongated and stratified valves. Wnt signaling and its canonical effector β-catenin are proposed to contribute to endocardial-to-mesenchymal transformation (EMT) through postnatal steps of valvulogenesis. However, genetic redundancy and lethality have made it challenging to define specific roles of the canonical Wnt pathway at different stages of valve formation. We developed a transgenic mouse system that provides spatiotemporal inhibition of Wnt/β-catenin signaling by chemically inducible overexpression of Dkk1. Unexpectedly, this approach indicates canonical Wnt signaling is required for EMT in the proximal outflow tract (pOFT) but not atrioventricular canal (AVC) cushions. Furthermore, Wnt indirectly promotes pOFT EMT through its earlier activity in neighboring myocardial cells or their progenitors. Subsequently, Wnt/β-catenin signaling is activated in cushion mesenchymal cells where it supports FGF-driven expansion of ECs and then AVC valve extracellular matrix patterning. Mice lacking Axin2, a negative Wnt regulator, have larger valves, suggesting that accumulating Axin2 in maturing valves represents negative feedback that restrains tissue overgrowth rather than simply reporting Wnt activity. Disruption of these Wnt/β-catenin signaling roles that enable developmental transitions during valvulogenesis could account for common congenital valve defects. PMID:26893350

Long working hours and occupational stress-related cardiovascular attacks among middle-aged workers in Japan.

PubMed

Uehata, T

1991-12-01

Two hundred and three Karoshi victims who suffered cardiovascular attacks and for whom workers' compensations was claimed were surveyed. These cases were 196 males and 7 females in middle age, and comprised 123 strokes, 50 acute cardiac failures, 27 myocardial infarctions and 4 aortic ruptures. As a sociomedical background, it was shown that two-thirds of them were working for long hours such as more than 60 hr per week, more than 50 hr overtime per month, or more than half of their fixed holidays before the attack. Moreover, among the white-collar workers, these long working hours were accompanied with other stressful work issues such as career problems, excessive business trips, strident norms, and changes of work places; among the blue-collar workers, they were accompanied with those such as irregular midnight work, insufficient manpower and long-distance driving, etc. On the other hand, eighty-eight cases of them experienced several minor and sudden events including work-related emotional anxiety or excitement, rapid increase of workload, unexpected work trouble or environmental changes of work places anticipated at least within 24 hr directly before the attack. It was concluded that Karoshi, meaning fatal attacks by overload, was one of the work-related diseases mainly triggered by long working hours.

Vitamin C deficiency exerts paradoxical cardiovascular effects in osteogenic disorder Shionogi (ODS) rats.

PubMed

Vergely, Catherine; Goirand, Françoise; Ecarnot-Laubriet, Aline; Renard, Céline; Moreau, Daniel; Guilland, Jean-Claude; Dumas, Monique; Rochette, Luc

2004-04-01

Vitamin C is considered to be a very efficient water-soluble antioxidant, for which several new cardiovascular properties were recently described. The aim of this study was to determine in vivo the effects of a severe depletion of vitamin C on cardiac and vascular variables and reperfusion arrhythmias. For this purpose, we used a mutant strain of Wistar rats, osteogenic disorder Shionogi (ODS). After 15 d of consuming a vitamin C-deficient diet, ODS rats had a 90% decrease in plasma and tissue levels of ascorbate compared with ODS vitamin C-supplemented rats and normal Wistar rats. However, plasma antioxidant capacity, proteins, alpha-tocopherol, urate, catecholamines, lipids, and nitrate were not influenced by the vitamin C deficiency in ODS rats. Moreover, there was no difference between ODS vitamin C-deficient and -supplemented rats in heart rate and arterial pressure. After 5 min of an in vivo regional myocardial ischemia, various severe arrhythmias were observed, but their intensities were not modified by vitamin C in vitamin C-deficient ODS rats. The vascular reactivity, measured in vitro on thoracic arteries, was not altered by ascorbate deficiency in ODS rats. These unexpected results suggest that unidentified compensatory mechanisms play a role in maintaining normal cardiac function and vascular reactivity in vitamin C-deficient rats.

Causes of sudden death in Addis Ababa, Ethiopia.

PubMed

Schneider, J; Bezabih, K

2001-10-01

The aim of this study was to evaluate the causes of death in individuals who died suddenly in Addis Ababa, Ethiopia. The selection of the cases was based on police reports, which contained a description of sudden unexpected or instantaneous death. The study was performed on necropsies of the Medico legal Department of Menelik II Hospital, in Addis Ababa during the years 1998 and 1999. According to the pathological features of the heart, we classified 92 dead bodies in 3 groups: Group A: Hearts showing adequate morphological changes to explain sudden death (n = 63). Group B: Hearts showing some structural changes, but inadequate to explain sudden death (n = 20). Group C: Normal hearts (n = 7). In two bodies the general autopsy revealed an extra cardiac cause of death. The single most relevant cause of death in group A was coronary artery disease (44 cases) followed by excessive myocardial hypertrophy due to post-rheumatic valvular lesions (7 cases). While the high prevalence of rheumatic heart disease in Ethiopia is well known, the proportion of cases who died due to coronary heart disease is surprising. Though during the last years some African authors assumed that coronary atherosclerosis is on the increase in developing countries the percentage is higher than expected and higher than in other countries where similar studies exist.

NGF and proNGF Reciprocal Interference in Immunoassays: Open Questions, Criticalities, and Ways Forward

PubMed Central

Malerba, Francesca; Paoletti, Francesca; Cattaneo, Antonino

2016-01-01

The homeostasis between mature neurotrophin NGF and its precursor proNGF is thought to be crucial in physiology and in pathological states. Therefore, the measurement of the relative amounts of NGF and proNGF could serve as a footprint for the identification of disease states, for diagnostic purposes. Since NGF is part of proNGF, their selective identification with anti-NGF antibodies is not straightforward. Currently, many immunoassays for NGF measurement are available, while the proNGF assays are few and not validated by published information. The question arises, as to whether the commercially available assays are able to distinguish between the two forms. Also, since in biological samples the two forms coexist, are the measurements of one species affected by the presence of the other? We describe experiments addressing these questions. For the first time, NGF and proNGF were measured together and tested in different immunoassays. Unexpectedly, NGF and proNGF were found to reciprocally interfere with the experimental outcome. The interference also calls into question the widely used NGF ELISA methods, applied to biological samples where NGF and proNGF coexist. Therefore, an immunoassay, able to distinguish between the two forms is needed. We propose possible ways forward, toward the development of a selective assay. In particular, the use of the well validated anti-NGF αD11 antibody in an alphaLISA assay with optimized incubation times would be a solution to avoid the interference in the measurement of a mixed sample containing NGF and proNGF. Furthermore, we explored the possibility of measuring proNGF in a biological sample. But the available commercial kit for the detection of proNGF does not allow the measurement of proNGF in mouse brain tissues. Therefore, we validated an SPR approach for the measurement of proNGF in a biological sample. Our experiments help in understanding the technical limits in the measurement of the NGF/proNGF ratio in biological samples, and propose concrete solutions toward the solution of this problem. PMID:27536217

Protective role of Osthole on myocardial cell apoptosis induced by doxorubicin in rats.

PubMed

Xu, Hongdang; Han, Yu; Zhang, Mengwei; Yan, Min; Gao, Chuanyu

2015-01-01

To explore the effect of Osthole on protecting myocardial cell apoptosis induced by doxorubicin during cardiac failure in rats. Myocardial cells isolated from the newborn SD rats were separated into three groups: cells treated with 1 μmol doxorubicin, cells treated with Osthole at three concentrations of 10, 20, and 40 μmol, cells treated neither with Osthole nor with doxorubicin were the control groups. Consequently, cell apoptosis of myocardial cells in each group was analyzed using TUNEL assay. Also, expressions of oxidase, NADPH, and ROS in myocardial cells were analyzed using different biological methods. Moreover, expressions of cell apoptosis associated proteins were analyzed using Western blotting. Compared with the controls, the results showed that cells received Osthole and doxorubicin treatments performed high percentage of cell apoptosis, suggesting that Osthole could anesis myocardial cell apoptosis induced by doxorubicin (P<0.05). Osthole of 10 μmol depressed the expressions of cell apoptosis associated proteins including Caspase-3 and Cytc, and enhancing expression of Bcl-XL expression (P<0.05). Osthole of 20 μmol significantly decreased the generation of intracellar superoxidase, NADPH, and NADPH activity in myocardial cells treated with doxorubicin (P<0.05). Moreover, Osthole of 20 μmol could significantly increase phosphorylated elF2α level in cells. Our study suggested that Osthole may play a protective role in suppressing myocardial apoptosis induced by doxorubicin through inhibiting NADPH and superoxidase production and downstream phosphorylated elF2α.

Protective role of Osthole on myocardial cell apoptosis induced by doxorubicin in rats

PubMed Central

Xu, Hongdang; Han, Yu; Zhang, Mengwei; Yan, Min; Gao, Chuanyu

2015-01-01

Objective: To explore the effect of Osthole on protecting myocardial cell apoptosis induced by doxorubicin during cardiac failure in rats. Methods: Myocardial cells isolated from the newborn SD rats were separated into three groups: cells treated with 1 μmol doxorubicin, cells treated with Osthole at three concentrations of 10, 20, and 40 μmol, cells treated neither with Osthole nor with doxorubicin were the control groups. Consequently, cell apoptosis of myocardial cells in each group was analyzed using TUNEL assay. Also, expressions of oxidase, NADPH, and ROS in myocardial cells were analyzed using different biological methods. Moreover, expressions of cell apoptosis associated proteins were analyzed using Western blotting. Results: Compared with the controls, the results showed that cells received Osthole and doxorubicin treatments performed high percentage of cell apoptosis, suggesting that Osthole could anesis myocardial cell apoptosis induced by doxorubicin (P<0.05). Osthole of 10 μmol depressed the expressions of cell apoptosis associated proteins including Caspase-3 and Cytc, and enhancing expression of Bcl-XL expression (P<0.05). Osthole of 20 μmol significantly decreased the generation of intracellar superoxidase, NADPH, and NADPH activity in myocardial cells treated with doxorubicin (P<0.05). Moreover, Osthole of 20 μmol could significantly increase phosphorylated elF2α level in cells. Conclusion: Our study suggested that Osthole may play a protective role in suppressing myocardial apoptosis induced by doxorubicin through inhibiting NADPH and superoxidase production and downstream phosphorylated elF2α. PMID:26617794

A 1-year randomized controlled trial of deferasirox vs deferoxamine for myocardial iron removal in β-thalassemia major (CORDELIA)

PubMed Central

Porter, John B.; Piga, Antonio; Lai, Yongrong; El-Beshlawy, Amal; Belhoul, Khawla M.; Elalfy, Mohsen; Yesilipek, Akif; Kilinç, Yurdanur; Lawniczek, Tomasz; Habr, Dany; Weisskopf, Marianne; Zhang, Yiyun; Aydinok, Yesim

2014-01-01

Randomized comparison data on the efficacy and safety of deferasirox for myocardial iron removal in transfusion dependent patients are lacking. CORDELIA was a prospective, randomized comparison of deferasirox (target dose 40 mg/kg per day) vs subcutaneous deferoxamine (50-60 mg/kg per day for 5-7 days/week) for myocardial iron removal in 197 β-thalassemia major patients with myocardial siderosis (T2* 6-20 milliseconds) and no signs of cardiac dysfunction (mean age, 19.8 years). Primary objective was to demonstrate noninferiority of deferasirox for myocardial iron removal, assessed by changes in myocardial T2* after 1 year using a per-protocol analysis. Geometric mean (Gmean) myocardial T2* improved with deferasirox from 11.2 milliseconds at baseline to 12.6 milliseconds at 1 year (Gmeans ratio, 1.12) and with deferoxamine (11.6 milliseconds to 12.3 milliseconds; Gmeans ratio, 1.07). The between-arm Gmeans ratio was 1.056 (95% confidence interval [CI], 0.998, 1.133). The lower 95% CI boundary was greater than the prespecified margin of 0.9, establishing noninferiority of deferasirox vs deferoxamine (P = .057 for superiority of deferasirox). Left ventricular ejection fraction remained stable in both arms. Frequency of drug-related adverse events was comparable between deferasirox (35.4%) and deferoxamine (30.8%). CORDELIA demonstrated the noninferiority of deferasirox compared with deferoxamine for myocardial iron removal. This trial is registered at www.clinicaltrials.gov as #NCT00600938. PMID:24385534

Gender differences in the assessment and treatment of myocardial infarction.

PubMed

Jortveit, Jarle; Govatsmark, Ragna Elise Støre; Langørgen, Jørund; Hole, Torstein; Mannsverk, Jan; Olsen, Siv; Risøe, Cecilie; Halvorsen, Sigrun

2016-08-01

Previous studies have shown that there are gender-related differences in the assessment and treatment of myocardial infarction, despite international guidelines that prescribe identical treatment for women and men. We investigated whether these differences occurred in Norway. All patients admitted to Norwegian hospitals with myocardial infarction from 1 January 2013 to 31 December 2014 and registered in the Norwegian Myocardial Infarction Registry were included. Data from the registry were used to analyse differences in the assessment, treatment, complications and survival of women and men in different age groups. A total of 26 447 myocardial infarctions were registered in the Norwegian Myocardial Infarction Registry in the period 2013 – 2014. Fewer women than men were assessed by means of coronary angiography. Percutaneous coronary intervention (PCI) was used to virtually the same extent for both genders if coronary stenosis was found. Women were recommended secondary prophylactic medication to a lesser extent than men. There were no major differences between men and women in the incidence of complications in the course following myocardial infarction or in survival. Fewer women than men suffering acute myocardial infarction were assessed by means of coronary angiography, and women were recommended secondary prophylactic medication less often than men. The reason for the gender differences is not known, but comorbidity and a potentially greater risk of adverse reactions in women may be contributory factors. The different views of doctors providing treatment may also play a part.

Endothelial function is associated with myocardial diastolic function in women with systemic lupus erythematosus.

PubMed

Chin, Calvin W L; Chin, Chee-Yang; Ng, Marie X R; Le, Thu-Thao; Huang, Fei-Qiong; Fong, Kok-Yong; Thumboo, Julian; Tan, Ru-San

2014-09-01

Endothelial dysfunction is associated with traditional and systemic lupus erythematosus (SLE)-specific risk factors, and early data suggest reversibility of endothelial dysfunction with therapy. The clinical relevance of endothelial function assessment has been limited by the lack of studies, demonstrating its prognostic significance and impact on early myocardial function. Therefore, we aimed to determine the association between endothelial and myocardial diastolic function in SLE women. Women with SLE and no coronary artery disease were prospectively recruited and underwent radionuclide myocardial perfusion imaging (MPI) (Jetstream, Philips, the Netherlands) to exclude subclinical myocardial ischemia. Cardiac and vascular functions were assessed in all patients (Alpha 10, Aloka, Tokyo). Diastolic function was assessed using pulse wave early (E) and late mitral blood inflow and myocardial tissue Doppler (mean of medial and lateral annulus e') velocities. Endothelial function was measured using brachial artery flow-mediated vasodilatation (FMD%). Univariate and multivariate linear regressions were used to assess the association between FMD% and myocardial diastolic function, adjusting for potential confounders. Thirty-eight patients without detectable myocardial ischemia on MPI were studied (mean age 44 ± 10 years; mean disease duration 14 ± 6 years). About 61 % of patients had normal diastolic function (E/e' ≤ 8), and 5 % of patients had definite diastolic dysfunction with E/e' > 13 (mean 7.1 ± 2.9). FMD% was associated with E/e' (regression coefficient β = -0.35; 95 % CI -0.62 to -0.08; p = 0.01) independent of systolic blood pressure, age, and SLICC/ACR Damage Index.

Phellinus linteus Mycelium Alleviates Myocardial Ischemia-Reperfusion Injury through Autophagic Regulation.

PubMed

Su, Hsing-Hui; Chu, Ya-Chun; Liao, Jiuan-Miaw; Wang, Yi-Hsin; Jan, Ming-Shiou; Lin, Chia-Wei; Wu, Chiu-Yeh; Tseng, Chin-Yin; Yen, Jiin-Cherng; Huang, Shiang-Suo

2017-01-01

The incidence of myocardial ischemia-reperfusion (IR) injury is rapidly increasing around the world and this disease is a major contributor to global morbidity and mortality. It is known that regulation of programmed cell death including apoptosis and autophagy reduces the impact of myocardial IR injury. In this study, the cardioprotective effects and underlying mechanisms of Phellinus linteus (Berk. and Curt.) Teng, Hymenochaetaceae (PL), a type of medicinal mushroom, were examined in rats subjected to myocardial IR injury. The left main coronary artery of rats was ligated for 1 h and reperfused for 3 h. The arrhythmia levels were monitored during the entire process and the infarct size was evaluated after myocardial IR injury. Furthermore, the expression levels of proteins in apoptotic and autophagic pathways were observed. Pretreatment with PL mycelium (PLM) significantly reduced ventricular arrhythmia and mortality due to myocardial IR injury. PLM also significantly decreased myocardial infarct size and plasma lactate dehydrogenase level after myocardial IR injury. Moreover, PLM administration resulted in decreased caspase 3 and caspase 9 activation and increased Bcl-2/Bax ratio. Phosphorylation level of AMPK was elevated while mTOR level was reduced. Becline-1 and p62 levels decreased. These findings suggest that PLM is effective in protecting the myocardium against IR injury. The mechanism involves mediation through suppressed pro-apoptotic signaling and regulation of autophagic signaling, including stimulation of AMPK-dependent pathway and inhibition of beclin-1-dependent pathway, resulting in enhancement of protective autophagy and inhibition of excessive autophagy.

Myocardial uptake and kinetic properties of technetium-99m-Q3 in dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerson, M.C.; Millard, R.W.; McGoron, A.J.

1994-10-01

We postulated that {sup 99m}Tc-Q3, a cationic imaging agent, produces myocardial activity related to myocardial blood flow during myocardial ischemia and pharmacologic coronary artery vasodilation, and shows little or no myocardial redistribution over 4 hr after intravenous injection. In six Group 1 dogs, the chest was opened, the left circumflex coronary artery was acutely ligated, and dipyridamole (0.32, 0.56 or 0.84 mg/kg) was infused into the right atrium, followed by 10 mCi of {sup 99m}Tc-Q3. Myocardial blood flow was measured by radiolabeled microspheres. The animals were euthanized and 357 myocardial samples were assayed in a well counter for {sup 99m}Tcmore » activity. One week later, radiolabeled microsphere activity was counted and myocardial blood flow calculated. In nine Group 2 dogs, a variable occluder was placed around the left circumflex coronary artery and an ischemic level of circumflex blood flow was maintained constant over 4 hr as measured by an ultrasonic flow meter. Dipyridamole (0.56 mg/kg) was then infused into the right atrium followed by 10mCi of {sup 99m}Tc-Q3. Gamma camera images were acquired at 5, 15, 30, 60, 120 and 240 min following k{sup 99m}Tc-Q3 injection. Microsphere blood flow and endocardial biopsies (n - 6 dogs) were performed at 30, 60, 120 and 240 min following {sup 99m}TcQ3 injection. 31 refs., 9 figs., 1 tab.« less

Clinical and Virological Characteristics of Chronic Hepatitis B Patients with Coexistence of HBsAg and Anti-HBs.

PubMed

Liu, Yong; Zhang, Le; Zhou, Jin-Yong; Pan, Jinshun; Hu, Wei; Zhou, Yi-Hua

2016-01-01

Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) comprises an atypical serological profile in patients with chronic hepatitis B virus (HBV) infection. In this study, in total 94 patients with coexisting HBsAg and anti-HBs and 94 age- and sex-matched patients with positive HBsAg were characterized by quantitatively measuring HBsAg and HBV DNA, sequencing large S genes, and observing clinical features. Compared with common hepatitis B patients, the patients with coexisting HBsAg and anti-HBs had lower HBsAg and HBV DNA levels. These two groups had similar rate of pre-S deletion mutations. However, in patients with coexisting HBsAg and anti-HBs, more amino acid substitutions in the a determinant of S gene were observed in HBV genotype C, but not in genotype B. Fourteen patients with coexisting HBsAg and anti-HBs were followed up for an average of 15.5 months. There were no significant changes in the levels of HBsAg, anti-HBs, HBV DNA and ALT over the follow-up period. Compared with the baseline sequences, amino acid substitutions in the MHR of HBsAg occurred in 14.3% (2/14) patients. In conclusion, coexistence of HBsAg and anti-HBs may be associated with higher frequency of mutations in the a determinant of HBV genotype C.

Coexisting infectious diseases on admission as a risk factor for mechanical ventilation in patients with Guillain-Barré syndrome.

PubMed

Kobori, Shinichiro; Kubo, Tatsuhiko; Otani, Makoto; Muramatsu, Keiji; Fujino, Yoshihisa; Adachi, Hiroaki; Horiguchi, Hiromasa; Fushimi, Kiyohide; Matsuda, Shinya

2017-07-01

The aim of this study was to investigate patient characteristics on admission to hospital that increase the risk of subsequent mechanical ventilation (MV) use for patients with Guillain-Barré syndrome (GBS). We extracted data from the Japanese Diagnosis Procedure Combination (DPC) database for 4132 GBS patients admitted to hospital. Clinical characteristics of GBS patients with and without MV were compared. Multivariate logistic regression analyses were performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of requirement for MV with coexisting infectious diseases, after adjustment for potential confounding variables, age, sex, hospital type, and ambulance transportation. In total, 281 patients required MV, and 493 patients had coexisting respiratory diseases on admission. After adjustment for covariates and stratification by coexisting respiratory diseases, multivariate logistic regression analysis revealed that coexisting cytomegaloviral (CMV) disease (OR 8.81; 95% CI, 2.34-33.1) and herpes simplex viral (HSV) infections (OR 4.83; 95% CI, 1.16-20.1) were significantly associated with the requirement for MV in the group without coexisting respiratory diseases. Our findings suggest that coexisting CMV and HSV infections on admission might be significantly associated with increased risk of respiratory failure in GBS patients. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

On the globality of motor suppression: unexpected events and their influence on behavior and cognition

PubMed Central

Wessel, Jan R.; Aron, Adam R.

2016-01-01

SUMMARY Unexpected events are part of everyday experience. They come in several varieties – action errors, unexpected action outcomes, and unexpected perceptual events – and they lead to motor slowing and cognitive distraction. While different varieties of unexpected events have been studied largely independently, and many different mechanisms are thought to explain their effects on action and cognition, we suggest a unifying theory. We propose that unexpected events recruit a fronto-basal-ganglia network for stopping. This network includes specific prefrontal cortical nodes and is posited to project to the subthalamic nucleus, with a putative global suppressive effect on basal-ganglia output. We argue that unexpected events interrupt action and impact cognition, partly at least, by recruiting this global suppressive network. This provides a common mechanistic basis for different types of unexpected events, links the literatures on motor inhibition, performance-monitoring, attention, and working memory, and is relevant for understanding clinical symptoms of distractibility and mental inflexibility. PMID:28103476

On the Globality of Motor Suppression: Unexpected Events and Their Influence on Behavior and Cognition.

PubMed

Wessel, Jan R; Aron, Adam R

2017-01-18

Unexpected events are part of everyday experience. They come in several varieties-action errors, unexpected action outcomes, and unexpected perceptual events-and they lead to motor slowing and cognitive distraction. While different varieties of unexpected events have been studied largely independently, and many different mechanisms are thought to explain their effects on action and cognition, we suggest a unifying theory. We propose that unexpected events recruit a fronto-basal-ganglia network for stopping. This network includes specific prefrontal cortical nodes and is posited to project to the subthalamic nucleus, with a putative global suppressive effect on basal-ganglia output. We argue that unexpected events interrupt action and impact cognition, partly at least, by recruiting this global suppressive network. This provides a common mechanistic basis for different types of unexpected events; links the literatures on motor inhibition, performance monitoring, attention, and working memory; and is relevant for understanding clinical symptoms of distractibility and mental inflexibility. Copyright © 2017 Elsevier Inc. All rights reserved.

The Coexistence Claim and Its Possible Implications for Success in Teaching for Conceptual "Change"

ERIC Educational Resources Information Center

Potvin, Patrice

2017-01-01

This article presents recent research results in mental chronometry and neuroimaging that support the coexistence of multiple conceptions. It then presents and elaborates on six possible implications for an adherence to the coexistence claim within the context of scientific conceptual learning: (1) stop the war on misconceptions; (2) use a…

Changing axis deviation during acute myocardial infarction.

PubMed

Patanè, Salvatore; Marte, Filippo

2010-07-09

Changing axis deviation has been reported during acute myocardial infarction also associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. We present a case of changing axis deviation in a 70-year-old Italian man with acute myocardial infarction. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Cardiac magnetic resonance imaging parameters as surrogate endpoints in clinical trials of acute myocardial infarction

PubMed Central

2011-01-01

Cardiac magnetic resonance (CMR) offers a variety of parameters potentially suited as surrogate endpoints in clinical trials of acute myocardial infarction such as infarct size, myocardial salvage, microvascular obstruction or left ventricular volumes and ejection fraction. The present article reviews each of these parameters with regard to the pathophysiological basis, practical aspects, validity, reliability and its relative value (strengths and limitations) as compared to competitive modalities. Randomized controlled trials of acute myocardial infarction which have used CMR parameters as a primary endpoint are presented. PMID:21917147

[Assessment of myocardial perfusion and left ventricular function with 99mTc-PPN 1011].

PubMed

Kumita, S; Mizumura, S; Oishi, T; Kumazaki, T; Sano, J; Yamazaki, Y; Munakata, K

1993-04-01

First-pass radionuclide angiography (FPRNA) was performed with the new myocardial perfusion agent 99mTc-1,2,bis[bis(2-ethoxyethyl)phosphino] ethane (99mTc-PPN 1011) on stress and at rest. One hour after that, myocardial perfusion was counted by 99mTc-PPN 1011 SPECT. Left ventricular ejection fraction (LVEF) obtained by FPRNA correlated with that by multigated image with 99mTc-HSAD (r = 0.94, n = 11). The reduction of left ventricular function under the exercise (delta LVEF) and the increase of severity score (delta Severity score) have a good relation (r = 0.88) in 7 patients with prior myocardial infarction. Thus 99mTc-PPN 1011 appears to be an ideal radiopharmaceutical for evaluation of ventricular function and myocardial perfusion.

Practical implications of liver and heart iron load assessment by T2*-MRI in children and adults with transfusion-dependent anemias

PubMed Central

Chirnomas, Sarah Deborah; Geukes-Foppen, Marnix; Barry, Kristen; Braunstein, Jennifer; Kalish, Leslie A.; Neufeld, Ellis J.; Powell, Andrew J.

2017-01-01

This study examined the relationship between hepatic and myocardial iron concentration, assessed by T2*-MRI in 66 patients (3–82 years) with transfusion-dependent anemias and thalassemia intermedia, to determine whether hepatic iron levels alone suffice for chelation adjustments. We found a poor correlation between hepatic and myocardial iron (r = 0.10, P = 0.43) and identified a subgroup (14%) with increased myocardial iron without a matched degree of hepatic hemosiderosis. Left ventricular ejection fraction was insensitive for detecting elevated myocardial iron. These findings were present in both adult and pediatric patients. We recommend therapeutic monitoring of iron burden by evaluation of both liver and myocardial iron with T2*-MRI. PMID:18661491

[Performance of Thallium 201 rest-redistribution spect to predict viability in recent myocardial infarction].

PubMed

Coll, Claudia; González, Patricio; Massardo, Teresa; Sierralta, Paulina; Humeres, Pamela; Jofré, Josefina; Yovanovich, Jorge; Aramburú, Ivonne; Brugère, Solange; Chamorro, Hernán; Ramírez, Alfredo; Kunstmann, Sonia; López, Héctor

2002-03-01

The detection of viability after acute myocardial infarction is primordial to select the most appropriate therapy, to decrease cardiac events and abnormal remodeling. Thallium201 SPECT is one of the radionuclide techniques used to detect viability. To evaluate the use of Thallium201 rest-redistribution SPECT to detect myocardial viability in reperfused patients after a recent myocardial infarction. Forty one patients with up to of 24 days of evolution of a myocardial infarction were studied. All had angiographically demonstrated coronary artery disease and were subjected to a successful thrombolysis, angioplasty or bypass grafting. SPECT Thallium201 images were acquired at rest and after 4 h of redistribution. These results were compared with variations in wall motion score, studied at baseline and after 3 or 4 months with echocardiography. The sensitivity of rest-redistribution Thallium201 SPECT, to predict recovery of wall motion was 91% when patient analysis was performed and 79% when segmental analysis was done in the culprit region. The figures for specificity were 56 and 73% respectively. Rest-distribution Thallium201 SPECT has an excellent sensitivity to predict myocardial viability in recent myocardial infarction. The data obtained in this study is similar to that reported for chronic coronary artery disease.

Myocardial perfusion characteristics during machine perfusion for heart transplantation.

PubMed

Peltz, Matthias; Cobert, Michael L; Rosenbaum, David H; West, LaShondra M; Jessen, Michael E

2008-08-01

Optimal parameters for machine perfusion preservation of hearts prior to transplantation have not been determined. We sought to define regional myocardial perfusion characteristics of a machine perfusion device over a range of conditions in a large animal model. Dog hearts were connected to a perfusion device (LifeCradle, Organ Transport Systems, Inc, Frisco, TX) and cold perfused at differing flow rates (1) at initial device startup and (2) over the storage interval. Myocardial perfusion was determined by entrapment of colored microspheres. Myocardial oxygen consumption (MVO(2)) was estimated from inflow and outflow oxygen differences. Intra-myocardial lactate was determined by (1)H magnetic resonance spectroscopy. MVO(2) and tissue perfusion increased up to flows of 15 mL/100 g/min, and the ratio of epicardial:endocardial perfusion remained near 1:1. Perfusion at lower flow rates and when low rates were applied during startup resulted in decreased capillary flow and greater non-nutrient flow. Increased tissue perfusion correlated with lower myocardial lactate accumulation but greater edema. Myocardial perfusion is influenced by flow rates during device startup and during the preservation interval. Relative declines in nutrient flow at low flow rates may reflect greater aortic insufficiency. These factors may need to be considered in clinical transplant protocols using machine perfusion.

Role of leukocytes and platelets in acute myocardial infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bednar, M.M.

1986-01-01

Myocardial ischemia initiates an inflammatory-like response in which invading neutrophils exacerbate the degree of injury. The effects of nafazatrom, a new antithrombotic agent, on leukocyte function in vitro and in vivo were related to its ability to salvage ischemic myocardium in an occulsion-reperfusion model of myocardial injury in the anesthetized dogs. Measurements of the neutrophil-specific myeloperoxidase enzyme in ischemic myocardium indicate that the smaller infarct size in dogs treated with nafazatrom is accompanied by a diminished leukocyte infiltration. The results obtained with nafazatrom emphasize the important role of the neutrophil in ischemia-induced myocardial damage. The possibility that myocardial ischemia-induced plateletmore » deposition was secondary to a neutrophil-mediated event was assessed by the injection of PGI{sub 2}-washed autologous {sup 111}indium-labeled platelets and measuring the amount of radioactivity in different regions of the heart following a 90 min. occlusion of the left anterior descending coronary artery followed by reperfusion for periods up to 5 hrs. Neutropenia, induced with specific sheep anti-dog neutrophil antiserum, significantly reduced platelet accumulation in the ischemic myocardium following 5 hrs. reperfusion and abolished the transmural platelet distribution. These results suggest that myocardial platelet deposition is secondary to a neutrophil-mediated event in this occlusion-reperfusion model of myocardial injury.« less

Myocardial T2* Mapping at Ultrahigh Field: Physics and Frontier Applications

NASA Astrophysics Data System (ADS)

Huelnhagen, Till; Paul, Katharina; Ku, Min-Chi; Serradas Duarte, Teresa; Niendorf, Thoralf

2017-06-01

Cardiovascular magnetic resonance imaging (CMR) has become an indispensable clinical tool for the assessment of morphology, function and structure of the heart muscle. By exploiting quantification of the effective transverse relaxation time (T2*) CMR also affords myocardial tissue characterization and probing of cardiac physiology, both being in the focus of ongoing research. These developments are fueled by the move to ultrahigh magnetic field strengths, which permits enhanced sensitivity and spatial resolution that help to overcome limitations of current clinical MR systems with the goal to contribute to a better understanding of myocardial (patho)physiology in vivo. In this context, the aim of this report is to introduce myocardial T2* mapping at ultrahigh magnetic fields as a promising technique to non-invasively assess myocardial (patho)physiology. For this purpose the basic principles of T2* assessment, the biophysical mechanisms determining T2* and (pre)clinical applications of myocardial T2* mapping are presented. Technological challenges and solutions for T2* sensitized CMR at ultrahigh magnetic field strengths are discussed followed by a review of acquisition techniques and post processing approaches. Preliminary results derived from myocardial T2* mapping in healthy subjects and cardiac patients at 7.0 Tesla are presented. A concluding section discusses remaining questions and challenges and provides an outlook on future developments and potential clinical applications.

Detection and monitoring of cardiotoxicity-what does modern cardiology offer?

PubMed

Jurcut, Ruxandra; Wildiers, Hans; Ganame, Javier; D'hooge, Jan; Paridaens, Robert; Voigt, Jens-Uwe

2008-05-01

With new anticancer therapies, many patients can have a long life expectancy. Treatment-related comorbidities become an issue for cancer survivors. Cardiac toxicity remains an important side effect of anticancer therapies. Myocardial dysfunction can become apparent early or long after end of therapy and may be irreversible. Detection of cardiac injury is crucial since it may facilitate early therapeutic measures. Traditionally, chemotherapy-induced cardiotoxicity has been detected by measuring changes in left ventricular ejection fraction. This parameter is, however, insensitive to subtle changes in myocardial function as they occur in early cardiotoxicity. This review will discuss conventional and modern cardiologic approaches of assessing myocardial function. It will focus on Doppler myocardial imaging, a method which allows to sensitively measure myocardial function parameters like myocardial velocity, deformation (strain), or deformation rate (strain rate) and which has been shown to reliably detect early abnormalities in both regional and global myocardial function in an early stage. Other newer echocardiographic function estimators are based on automated border detection algorithms and ultrasonic integrated backscatter analysis. A further technique to be discussed is dobutamine stress echocardiography. The use of new biomarkers like B-type natriuretic peptide and troponin and less often used imaging techniques like magnetic resonance imaging and computed tomography will also be mentioned.

REDUCING TOXICITY AND INCREASING EFFICIENCY: ACONITINE WITH LIQUIRITIN AND GLYCYRRHETINIC ACID REGULATE CALCIUM REGULATORY PROTEINS IN RAT MYOCARDIAL CELL.

PubMed

Zhang, Yuyan; Yu, Li; Jin, Weifeng; Fan, Hongjing; Li, Min; Zhou, Tianmei; Wan, Haitong; Yang, Jiehong

2017-01-01

Compatibility of Radix Aconiti Carmichaeli and Liquorice is known to treat heart diseases such as heart failure and cardiac arrhythmias. This work answers the question that whether the active components (Aconitine, Liquiritin and Glycyrrhetinic Acid) of Radix Aconiti Carmichaeli and Liquorice could result in regulating intracellular calcium homeostasis and calcium cycling, and thereby verifies the therapeutic material basis. The myocardial cells were divided into twelve groups randomly as control group, Aconitine group, nine different dose groups that orthogonal combined with Aconitine, Liquiritin and Glycyrrhetinic Acid, and Verapamil group. The myocardial cellular survival rate and morphology were assessed. The expression of calcium regulation protein(RyR2, NCX1, DHPR-a1) in the myocardial cell by Western-blotting. The results exhibited that Aconitine (120 uM) significantly damaged on myocardial cell, decreased the survival rate and expression of Na + /Ca 2+ exchangers (NCX1) and dihydropteridine reducta-α1 (DHPR-a1), and increased the expression of ryanodine receptor type2 (RyR2) obviously. The compatibility groups (Aconitine, Liquiritin and Glycyrrhetinic Acid) all could against the damage on the myocardial cell by Aconitine at different levels. Aconitine with Liquiritin and Glycyrrhetinic Acid may regulate the expression of calcium-regulated proteins to protect myocardial cells from damage.

Budget impact of applying appropriateness criteria for myocardial perfusion scintigraphy: The perspective of a developing country.

PubMed

Dos Santos, Mauro Augusto; Santos, Marisa Silva; Tura, Bernardo Rangel; Félix, Renata; Brito, Adriana Soares X; De Lorenzo, Andrea

2016-10-01

Myocardial perfusion imaging is widely used for the risk stratification of coronary artery disease. In view of its cost, besides radiation issues, judicious evaluation of the appropriateness of its indications is essential to prevent an unnecessary economic burden on the health system. We evaluated, at a tertiary-care, public Brazilian hospital, the appropriateness of myocardial perfusion scintigraphy indications, and estimated the budget impact of applying appropriateness criteria. An observational, cross-sectional study of 190 patients with suspected or known coronary artery disease referred for myocardial perfusion imaging was conducted. The appropriateness of myocardial perfusion imaging indications was evaluated with the Appropriate Use Criteria for Cardiac Radionuclide Imaging published in 2009. Budget impact analysis was performed with a deterministic model. The prevalence of appropriate requests was 78%; of inappropriate indications, 12%; and of uncertain indications, 10%. Budget impact analysis showed that the use of appropriateness criteria, applied to the population referred to myocardial perfusion scintigraphy within 1 year, could generate savings of $ 64,252.04 dollars. The 12% inappropriate requests for myocardial perfusion scintigraphy at a tertiary-care hospital suggest that a reappraisal of MPI indications is needed. Budget impact analysis estimated resource savings of 18.6% with the establishment of appropriateness criteria for MPI.

Protective effects of circulating microvesicles derived from myocardial ischemic rats on apoptosis of cardiomyocytes in myocardial ischemia/reperfusion injury.

PubMed

Wang, Yao; Wei, Su; Wang, Yi-Lu; Liu, Miao; Shang, Man; Zhang, Qi; Wu, Yan-Na; Liu, Ming-Lin; Song, Jun-Qiu; Liu, Yan-Xia

2017-08-15

To investigate the effects of circulating microvesicles derived from myocardial ischemia (I-MVs) on apoptosis in myocardial ischemia/reperfusion (I/R) injury in rats. I-MVs from rats undergoing myocardial left anterior descending (LAD) coronary artery ligation were isolated by ultracentrifugation from circulating blood and characterized by flow cytometry. I-MVs were administered intravenously (4.8 mg/kg) at 5 min before reperfusion procedure in I/R injury model which was induced by 30-min of ischemia and 120-min of reperfusion of LAD in rats. Treatment with I-MVssignificantly reduced the size of myocardial infarction, the activities of serum CK-MB and LDH, and the number of apoptotic cardiomyocytes. The activities of caspase 3, caspase 9 and caspase 12 in myocardium were also decreased significantly with I-MVs treatment. Moreover, the expression of Bax was decreased but Bcl-2 was increased. The expression of glucose regulated protein 78 (GRP78), sarco/endoplasmic reticulum Ca 2+ -ATPase 2 (SERCA2) and phosphorylated phospholamban (p-PLB) were increased after being treated with I-MVs. I-MVs could protect hearts from I/R injury in rats through SERCA2 and p-PLB of calcium regulatory proteins to alleviate intrinsic myocardial apoptosis including mitochondrial and endoplasmic reticulum pathways.

Comparison of hospital variation in acute myocardial infarction care and outcome between Sweden and United Kingdom: population based cohort study using nationwide clinical registries

PubMed Central

Sundström, Johan; Gale, Chris P; James, Stefan; Deanfield, John; Wallentin, Lars; Timmis, Adam; Jernberg, Tomas; Hemingway, Harry

2015-01-01

Objective To assess the between hospital variation in use of guideline recommended treatments and clinical outcomes for acute myocardial infarction in Sweden and the United Kingdom. Design Population based longitudinal cohort study using nationwide clinical registries. Setting and participants Nationwide registry data comprising all hospitals providing acute myocardial infarction care in Sweden (SWEDEHEART/RIKS-HIA, n=87; 119 786 patients) and the UK (NICOR/MINAP, n=242; 391 077 patients), 2004-10. Main outcome measures Between hospital variation in 30 day mortality of patients admitted with acute myocardial infarction. Results Case mix standardised 30 day mortality from acute myocardial infarction was lower in Swedish hospitals (8.4%) than in UK hospitals (9.7%), with less variation between hospitals (interquartile range 2.6% v 3.5%). In both countries, hospital level variation and 30 day mortality were inversely associated with provision of guideline recommended care. Compared with the highest quarter, hospitals in the lowest quarter for use of primary percutaneous coronary intervention had higher volume weighted 30 day mortality for ST elevation myocardial infarction (10.7% v 6.6% in Sweden; 12.7% v 5.8% in the UK). The adjusted odds ratio comparing the highest with the lowest quarters for hospitals’ use of primary percutaneous coronary intervention was 0.70 (95% confidence interval 0.62 to 0.79) in Sweden and 0.68 (0.60 to 0.76) in the UK. Differences in risk between hospital quarters of treatment for non-ST elevation myocardial infarction and secondary prevention drugs for all discharged acute myocardial infarction patients were smaller than for reperfusion treatment in both countries. Conclusion Between hospital variation in 30 day mortality for acute myocardial infarction was greater in the UK than in Sweden. This was associated with, and may be partly accounted for by, the higher practice variation in acute myocardial infarction guideline recommended treatment in the UK hospitals. High quality healthcare across all hospitals, especially in the UK, with better use of guideline recommended treatment, may not only reduce unacceptable practice variation but also deliver improved clinical outcomes for patients with acute myocardial infarction. Clinical trials registration Clinical trials NCT01359033. PMID:26254445

Effect of QiShenYiQi pill on myocardial collagen metabolism in experimental autoimmune myocarditis rats.

PubMed

Lv, Shi-Chao; Wu, Meifang; Li, Meng; Wang, Qiang; Wang, Xiao-Jing; Zhang, Ao; Xu, Ling; Zhang, Jun-Ping

2017-04-01

To observe the effect of QiShenYiQi pill (QSYQ) on myocardial collagen metabolism in experimental autoimmune myocarditis rats, and to explore its mechanism of action. Lewis rats underwent the injection of myocardial myosin mixed with freund's complete adjuvant were randomized into three groups: model, valsartan and QSYQ groups. And we treated rats which were injected phosphate buffered saline (PBS) mixed with freund's complete adjuvant as control group. Rats were intervened and euthanized at 4 and 8 weeks. We use alkaline hydrolysis to detect the content of myocardial hydroxyproline (HYP), and ELISA to detect the level of serum procollagen type I carboxyterminal peptide (PICP), procollagen type III amino-terminal peptide (PIIINP), and collagen C telopeptide type I (CTX-I). Myocardial MMP-1 and TIMP-1 protein expression was detected by immunohistochemistry, and myocardial MMP-1 and TIMP-1 mRNA expression was detected by real-time qPCR. QSYQ reduced the content of myocardial HYP, and this reduction was greater over time. QSYQ also reduced the serum concentration of PICP, PIIINP, CTX-I and the PICP/PIIINP ratio, which further reduced over time, whereas its effect on lowering PICP was significantly greater than that of valsartan at 4 and 8 weeks, and lowering CTX-I was significantly greater than that of valsartan at 8 weeks. In addition, after 4 weeks, QSYQ enhanced the protein and mRNA expression of MMP-1 and TIMP-1, and its effect on highering TIMP-1 was significantly greater than that of valsartan, whereas there was no significant difference in the expression of myocardial MMP-1 or TIMP-1 at 8 weeks. QSYQ reduced the ratio of MMP-1/TIMP-1, which further reduced over time, and the effect of QYSQ was significantly greater than that of valsartan after 4 weeks. This study provides evidence that QSYQ can reduce the rate of myocardial collagen synthesis and degradation. It also effectively improved the degree of myocardial fibrosis in experimental autoimmune myocarditis rats and it had a tendency to have a greater effect with longer treatment duration, which is related to the mechanism of regulation of MMP-1 and TIMP-1 expression in the myocardial rat. Copyright © 2017. Published by Elsevier Masson SAS.

Elevated serum uric acid affects myocardial reperfusion and infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

PubMed

Mandurino-Mirizzi, Alessandro; Crimi, Gabriele; Raineri, Claudia; Pica, Silvia; Ruffinazzi, Marta; Gianni, Umberto; Repetto, Alessandra; Ferlini, Marco; Marinoni, Barbara; Leonardi, Sergio; De Servi, Stefano; Oltrona Visconti, Luigi; De Ferrari, Gaetano M; Ferrario, Maurizio

2018-05-01

Elevated serum uric acid (eSUA) was associated with unfavorable outcome in patients with ST-segment elevation myocardial infarction (STEMI). However, the effect of eSUA on myocardial reperfusion injury and infarct size has been poorly investigated. Our aim was to correlate eSUA with infarct size, infarct size shrinkage, myocardial reperfusion grade and long-term mortality in STEMI patients undergoing primary percutaneous coronary intervention. We performed a post-hoc patients-level analysis of two randomized controlled trials, testing strategies for myocardial ischemia/reperfusion injury protection. Each patient underwent acute (3-5 days) and follow-up (4-6 months) cardiac magnetic resonance. Infarct size and infarct size shrinkage were outcomes of interest. We assessed T2-weighted edema, myocardial blush grade (MBG), corrected Thrombolysis in myocardial infarction Frame Count, ST-segment resolution and long-term all-cause mortality. A total of 101 (86.1% anterior) STEMI patients were included; eSUA was found in 16 (15.8%) patients. Infarct size was larger in eSUA compared with non-eSUA patients (42.3 ± 22 vs. 29.1 ± 15 ml, P = 0.008). After adjusting for covariates, infarct size was 10.3 ml (95% confidence interval 1.2-19.3 ml, P = 0.001) larger in eSUA. Among patients with anterior myocardial infarction the difference in delayed enhancement between groups was maintained (respectively, 42.3 ± 22.4 vs. 29.9 ± 15.4 ml, P = 0.015). Infarct size shrinkage was similar between the groups. Compared with non-eSUA, eSUA patients had larger T2-weighted edema (53.8 vs. 41.2 ml, P = 0.031) and less favorable MBG (MBG < 2: 44.4 vs. 13.6%, P = 0.045). Corrected Thrombolysis in myocardial infarction Frame Count and ST-segment resolution did not significantly differ between the groups. At a median follow-up of 7.3 years, all-cause mortality was higher in the eSUA group (18.8 vs. 2.4%, P = 0.028). eSUA may affect myocardial reperfusion in patients with STEMI undergoing percutaneous coronary intervention and is associated with larger infarct size and higher long-term mortality.

The impact on the family of the co-existing conditions of children with autism spectrum disorder.

PubMed

Petrou, Alexandra M; Soul, Abigail; Koshy, Beena; McConachie, Helen; Parr, Jeremy R

2018-05-01

We aimed to investigate whether the impact on families of children with Autism Spectrum Disorder (ASD) is associated with the number and/or type of emotional and behavioral co-existing conditions that parents/carers of children with ASD reported as occurring frequently. In addition, we examined whether there was a greater impact on families if their child was male, had lower levels of language, had more severe autism symptomatology, and whether impact was associated with the number and/or type of co-existing conditions. Families were recruited from large UK research databases. 420 parents/carers of children aged 3 years 2 months to 18 years 8 months completed the revised Impact on Family (IoF) Scale and reported on the frequency/rate of their child's co-existing conditions. Parents/carers reported higher mean IoF scores if their child: had a greater number of frequent co-existing conditions; had sleep problems; was only able to communicate physically; and had more severe autism symptomatology. The development and implementation of targeted treatment and management approaches are needed to reduce the impact of co-existing conditions on family life. Autism Res 2018, 11: 776-787. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Autism Spectrum Disorder (ASD) is commonly associated with emotional and/or behavior conditions that affect family life. Parents/carers of children with ASD who: (a) reported a greater number of frequent co-existing conditions, (b) had sleep problems, (c) were only able to communicate physically, and (d) had more severe symptoms characteristic of autism, reported a greater burden/strain on the family. Treatment approaches to target co-existing conditions alongside characteristics of ASD are needed to reduce their impact on family life. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Theory of mind for processing unexpected events across contexts.

PubMed

Dungan, James A; Stepanovic, Michael; Young, Liane

2016-08-01

Theory of mind, or mental state reasoning, may be particularly useful for making sense of unexpected events. Here, we investigated unexpected behavior across both social and non-social contexts in order to characterize the precise role of theory of mind in processing unexpected events. We used functional magnetic resonance imaging to examine how people respond to unexpected outcomes when initial expectations were based on (i) an object's prior behavior, (ii) an agent's prior behavior and (iii) an agent's mental states. Consistent with prior work, brain regions for theory of mind were preferentially recruited when people first formed expectations about social agents vs non-social objects. Critically, unexpected vs expected outcomes elicited greater activity in dorsomedial prefrontal cortex, which also discriminated in its spatial pattern of activity between unexpected and expected outcomes for social events. In contrast, social vs non-social events elicited greater activity in precuneus across both expected and unexpected outcomes. Finally, given prior information about an agent's behavior, unexpected vs expected outcomes elicited an especially robust response in right temporoparietal junction, and the magnitude of this difference across participants correlated negatively with autistic-like traits. Together, these findings illuminate the distinct contributions of brain regions for theory of mind for processing unexpected events across contexts. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Phase Coexistence in a Dynamic Phase Diagram.

PubMed

Gentile, Luigi; Coppola, Luigi; Balog, Sandor; Mortensen, Kell; Ranieri, Giuseppe A; Olsson, Ulf

2015-08-03

Metastability and phase coexistence are important concepts in colloidal science. Typically, the phase diagram of colloidal systems is considered at the equilibrium without the presence of an external field. However, several studies have reported phase transition under mechanical deformation. The reason behind phase coexistence under shear flow is not fully understood. Here, multilamellar vesicle (MLV)-to-sponge (L3 ) and MLV-to-Lα transitions upon increasing temperature are detected using flow small-angle neutron scattering techniques. Coexistence of Lα and MLV phases at 40 °C under shear flow is detected by using flow NMR spectroscopy. The unusual rheological behavior observed by studying the lamellar phase of a non-ionic surfactant is explained using (2) H NMR and diffusion flow NMR spectroscopy with the coexistence of planar lamellar-multilamellar vesicles. Moreover, a dynamic phase diagram over a wide range of temperatures is proposed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of levosimendan on myocardial ischemia–reperfusion injury in streptozotocin-induced diabetic rats

PubMed Central

Kiraz, Hasan Ali; Poyraz, Fatih; Kip, Gülay; Erdem, Özlem; Alkan, Metin; Arslan, Mustafa; Özer, Abdullah; Şivgin, Volkan; Çomu, Faruk Metin

2015-01-01

Objective Ischemia/reperfusion (I/R) injury is an important cause of myocardial damage by means of oxidative, inflammatory, and apoptotic mechanisms. The aim of the present study was to examine the potential cardio protective effects of levosimendan in a diabetic rat model of myocardial I/R injury. Methods A total of 18 streptozotocin-induced diabetic Wistar Albino rats (55 mg/kg) were randomly divided into three equal groups as follows: the diabetic I/R group (DIR) in which myocardial I/R was induced following left thoracotomy, by ligating the left anterior descending coronary artery for 60 min, followed by 2 h of reperfusion; the diabetic I/R levosimendan group (DIRL), which underwent I/R by the same method while taking levosimendan intraperitoneal 12 µg kg−1; and the diabetic control group (DC) which underwent sham operations without tightening of the coronary sutures. As a control group (C), six healthy age-matched Wistar Albino rats underwent sham operations similar to the DC group. Two hours after the operation, the rats were sacrificed and the myocardial tissue samples were examined by light microscopy for evidence of myonecrosis and inflammatory cell infiltration. Results Myonecrosis findings were significantly different among groups (p=0.008). Myonecrosis was more pronounced in the DIR group compared with the C, DC, and DIRL groups (p=0.001, p=0.007 and p=0.037, respectively). Similarly, the degree of inflammatory cell infiltration showed significant difference among groups (p<0.0001). Compared with C, DC, and DIRL groups, the inflammatory cell infiltration was significantly higher among the DIR group (p<0.0001, p<0.0001, and p=0.020, respectively). Also, myocardial tissue edema was significantly different among groups (p=0.006). The light microscopic myocardial tissue edema levels were significantly higher in the DIR group than the C, DC, and DIRL groups (p=0.001, p=0.037, and p=0.014, respectively). Conclusion Taken together, our data indicate that levosimendan may be helpful in reducing myocardial necrosis, myocardial inflammation, and myocardial tissue edema resulting from ischemia–reperfusion injury. PMID:26649830

Diabetes Mellitus and Cardiogenic Shock Complicating Acute Myocardial Infarction.

PubMed

Echouffo-Tcheugui, Justin B; Kolte, Dhaval; Khera, Sahil; Aronow, Herbert D; Abbott, J Dawn; Bhatt, Deepak L; Fonarow, Gregg C

2018-03-27

Diabetes mellitus (diabetes) increases the risk of acute myocardial infarction, which can result in cardiogenic shock. Data on the relation of diabetes and the occurrence and prognosis of cardiogenic shock postacute myocardial infarction are scant. Among the National Inpatient Sample patients aged ≥18 years and hospitalized for acute myocardial infarction during the 2012-2014 period, we examined the association between diabetes and the incidence and outcomes of cardiogenic shock complicating acute myocardial infarction, using multivariable logistic and linear regression models. Of 1,332,530 hospitalizations for acute myocardial infarction, 72,765 (5.5%) were complicated by cardiogenic shock. In acute myocardial infarction patients, cardiogenic shock incidence was higher among those with vs without diabetes (5.8% vs 5.2%; adjusted odds ratio [aOR] 1.14; 95% confidence interval [CI], 1.11-1.19; P < .001), with 42.8% (n = 31,135) of patients with acute myocardial infarction and cardiogenic shock having diabetes. Diabetic patients were less likely to undergo revascularization (percutaneous coronary intervention or coronary artery bypass grafting) (67.1% vs 68.7%; aOR 0.88; 95% CI, 0.80-0.96; P = .003). Diabetes was associated with higher in-hospital mortality in patients with acute myocardial infarction and cardiogenic shock (37.9% vs 36.8%; aOR 1.18; 95% CI, 1.09-1.28; P < .001). Among survivors, patients with diabetes had a longer hospital stay (mean ± SEM: 11.6 ± 0.16 vs 10.9 ± 0.16 days; adjusted estimate 1.12; 95% CI, 1.06-1.18; P < .001) and were more likely to be discharged to a skilled nursing home or with home health care (56.0% vs 50.5%; aOR 1.19; 95% CI, 1.07-1.33; P = .001). In a large cohort of acute myocardial infarction patients, preexisting diabetes was associated with an increased risk of cardiogenic shock and worse outcomes in those with cardiogenic shock. Copyright © 2018 Elsevier Inc. All rights reserved.

Early Use of N-acetylcysteine With Nitrate Therapy in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction Reduces Myocardial Infarct Size (the NACIAM Trial [N-acetylcysteine in Acute Myocardial Infarction]).

PubMed

Pasupathy, Sivabaskari; Tavella, Rosanna; Grover, Suchi; Raman, Betty; Procter, Nathan E K; Du, Yang Timothy; Mahadavan, Gnanadevan; Stafford, Irene; Heresztyn, Tamila; Holmes, Andrew; Zeitz, Christopher; Arstall, Margaret; Selvanayagam, Joseph; Horowitz, John D; Beltrame, John F

2017-09-05

Contemporary ST-segment-elevation myocardial infarction management involves primary percutaneous coronary intervention, with ongoing studies focusing on infarct size reduction using ancillary therapies. N-acetylcysteine (NAC) is an antioxidant with reactive oxygen species scavenging properties that also potentiates the effects of nitroglycerin and thus represents a potentially beneficial ancillary therapy in primary percutaneous coronary intervention. The NACIAM trial (N-acetylcysteine in Acute Myocardial Infarction) examined the effects of NAC on infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. This randomized, double-blind, placebo-controlled, multicenter study evaluated the effects of intravenous high-dose NAC (29 g over 2 days) with background low-dose nitroglycerin (7.2 mg over 2 days) on early cardiac magnetic resonance imaging-assessed infarct size. Secondary end points included cardiac magnetic resonance-determined myocardial salvage and creatine kinase kinetics. Of 112 randomized patients with ST-segment-elevation myocardial infarction, 75 (37 in NAC group, 38 in placebo group) underwent early cardiac magnetic resonance imaging. Median duration of ischemia pretreatment was 2.4 hours. With background nitroglycerin infusion administered to all patients, those randomized to NAC exhibited an absolute 5.5% reduction in cardiac magnetic resonance-assessed infarct size relative to placebo (median, 11.0%; [interquartile range 4.1, 16.3] versus 16.5%; [interquartile range 10.7, 24.2]; P =0.02). Myocardial salvage was approximately doubled in the NAC group (60%; interquartile range, 37-79) compared with placebo (27%; interquartile range, 14-42; P <0.01) and median creatine kinase areas under the curve were 22 000 and 38 000 IU·h in the NAC and placebo groups, respectively ( P =0.08). High-dose intravenous NAC administered with low-dose intravenous nitroglycerin is associated with reduced infarct size in patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention. A larger study is required to assess the impact of this therapy on clinical cardiac outcomes. Australian New Zealand Clinical Trials Registry. URL: http://www.anzctr.org.au/. Unique identifier: 12610000280000. © 2017 American Heart Association, Inc.

Effect of limb ischemic preconditioning on myocardial apoptosis-related proteins in ischemia-reperfusion injury

PubMed Central

GAO, JIANZHI; ZHAO, LINJING; WANG, YONGLING; TENG, QINGLEI; LIANG, LIDONG; ZHANG, JINYING

2013-01-01

The aim of this study was to investigate the effect of limb ischemic preconditioning (LIPC) on myocardial apoptosis in myocardial ischemia-reperfusion injury (MIRI), as well as the regulation of caspase-3 and the B cell lymphoma 2 (Bcl-2) gene in LIPC. A total of 50 rats were divided randomly into 5 groups (n=10). Four rats in each group were drawn out for detection of apoptosis. The sham, MIRI and LIPC groups underwent surgery without additional treatment. In the LY294002 group, LY294002 preconditioning was administered 15 min before reperfusion. In the LY294002+LIPC group, following LIPC, LY294002 was administered 15 min before reperfusion. The relative expression of myocardial Bcl-2 and caspase-3 mRNA and the apoptotic index for each group were determined by reverse transcription-polymerase chain reaction (RT-PCR) and terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), respectively. The ultrastructure of the cardiac muscle tissues was observed by election microscopy. Compared with the sham group, the expression of caspase-3 mRNA in the MIRI group significantly increased (P<0.05) and the expression of Bcl-2 mRNA clearly decreased. Compared with the MIRI group, LIPC reduced the expression of caspase-3 and increased the expression of Bcl-2 mRNA (P<0.05). There were no significant differences between the LY294002+LIPC group and the MIRI group. Compared with the sham group, the apoptotic index of myocardial cells in the MIRI group significantly increased (P<0.05). Compared with the MIRI group, LIPC significantly decreased the apoptotic index of myocardial cells (P<0.05) and LY294002 increased the apoptotic index of myocardial cells. Compared with the LIPC group, LY294002+LIPC significantly increased the apoptotic index of myocardial cells (P<0.05). There were no significant differences between the LY294002+LIPC and MIRI groups. In conclusion, LIPC increased the expression of Bcl-2 and decreased caspase-3 mRNA and apoptosis in myocardial tissue following MIRI. Therefore, LIPC plays a protective role in myocardial tissue. PMID:23737869

Febuxostat pretreatment attenuates myocardial ischemia/reperfusion injury via mitochondrial apoptosis.

PubMed

Wang, Shulin; Li, Yunpeng; Song, Xudong; Wang, Xianbao; Zhao, Cong; Chen, Aihua; Yang, Pingzhen

2015-07-02

Febuxostat is a selective inhibitor of xanthine oxidase (XO). XO is a critical source of reactive oxygen species (ROS) during myocardial ischemia/reperfusion (I/R) injury. Inhibition of XO is therapeutically effective in I/R injury. Evidence suggests that febuxostat exerts antioxidant effects by directly scavenging ROS. The present study was performed to investigate the effects of febuxostat on myocardial I/R injury and its underlying mechanisms. We utilized an in vivo mouse model of myocardial I/R injury and an in vitro neonatal rat cardiomyocyte (NRC) model of hypoxia/reoxygenation (H/R) injury. Mice were randomized into five groups: Sham, I/R (I/R + Vehicle), I/R + FEB (I/R + febuxostat), AL + I/R (I/R + allopurinol) and FEB (febuxostat), respectively. The I/R + FEB mice were pretreated with febuxostat (5 mg/kg; i.p.) 24 and 1 h prior to I/R. NRCs received febuxostat (1 and 10 µM) at 24 and 1 h before exposure to hypoxia for 3 h followed by reoxygenation for 3 h. Cardiac function, myocardial infarct size, serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH), and myocardial apoptotic index (AI) were measured in order to ascertain the effects of febuxostat on myocardial I/R injury. Hypoxia/reperfusion (H/R) injury in NRCs was examined using MTT, LDH leakage assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The underlying mechanisms were determined by measuring ROS production, mitochondrial membrane potential (ΔΨm), and expression of cytochrome c, cleaved caspases as well as Bcl-2 protein levels. Myocardial I/R led to an elevation in the myocardial infarct size, serum levels of CK and LDH, cell death and AI. Furthermore, I/R reduced cardiac function. These changes were significantly attenuated by pretreatment with febuxostat and allopurinol, especially by febuxostat. Febuxostat also protected the mitochondrial structure following myocardial I/R, inhibited H/R-induced ROS generation, stabilized the ΔΨm, alleviated cytosolic translocation of mitochondrial cytochrome C, inhibited activation of caspase-3 and -9, upregulated antiapoptotic proteins and downregulated proapoptotic proteins. This study revealed that febuxostat pretreatment mediates the cardioprotective effects against I/R and H/R injury by inhibiting mitochondrial-dependent apoptosis.

Association of Exercise Training with Tobacco Smoking Prevents Fibrosis but has Adverse Impact on Myocardial Mechanics.

PubMed

Reis Junior, Dermeval; Antonio, Ednei Luiz; de Franco, Marcello Fabiano; de Oliveira, Helenita Antonia; Tucci, Paulo José Ferreira; Serra, Andrey Jorge

2016-12-01

There was no data for cardiac repercussion of exercise training associated with tobacco smoking. This issue is interesting because some smoking people can be enrolled in an exercise-training program. Thus, we evaluated swimming training effects on the function and structural myocardial in rats exposed to tobacco smoking. Male Wistar rats were assigned to one of four groups: C, untrained rats without exposure to tobacco smoking; E, exercised rats without exposure to tobacco smoking; CS, untrained rats exposed to tobacco smoking; ECS, exercised rats exposed to tobacco smoking. Rats swam five times a week twice daily (60min per session) for 8 weeks. Before each bout exercise, rats breathed smoke from 20 cigarettes for 60min. Twenty-four hours after the last day of the protocol, papillary muscles were isolated for in vitro analysis of myocardial mechanics. The myocardial mass and nuclear cardiomyocyte volume were used as hypertrophy markers, and collagen content was determined by picrosirius red staining. There was a well-pronounced myocardial hypertrophic effect for two interventions. The exercise blunted myocardial collagen increases induced by tobacco smoking. However, exercise and tobacco-smoking association was deleterious to myocardial performance. Thereby, in vitro experiments with papillary muscles contracting in isometric showed impairment myocardial inotropism in exercised rats exposed to tobacco smoking. This work presents novel findings on the role of exercise training on cardiac remodeling induced by tobacco smoking. Although exercise has mitigated tissue fibrosis, their association with tobacco smoking exacerbated hypertrophy and in vitro myocardial dysfunction. This is first study to show that the association of an aerobic exercise training with tobacco smoking intensifies the phenotype of pathological cardiac hypertrophy. Therefore, the combination of interventions resulted in exacerbated myocardial hypertrophy and contractility dysfunction. These findings have significant clinical implication because some smoking people can be enrolled in an exercise-training program. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

N-terminal pro B-type natriuretic peptide in the early evaluation of suspected acute myocardial infarction.

PubMed

Haaf, Philip; Balmelli, Cathrin; Reichlin, Tobias; Twerenbold, Raphael; Reiter, Miriam; Meissner, Julia; Schaub, Nora; Stelzig, Claudia; Freese, Michael; Paniz, Patricia; Meune, Christophe; Drexler, Beatrice; Freidank, Heike; Winkler, Katrin; Hochholzer, Willibald; Mueller, Christian

2011-08-01

Myocardial ischemia is a strong trigger of N-terminal pro-B-type natriuretic peptide (NT-proBNP) release. As ischemia precedes necrosis in acute myocardial infarction, we hypothesized that NT-proBNP might be useful in the early diagnosis and risk stratification of patients with suspected acute myocardial infarction. In a prospective multicenter study, NT-proBNP was measured at presentation in 658 consecutive patients with acute chest pain. The final diagnosis was adjudicated by 2 independent cardiologists. Patients were followed long term regarding mortality. Acute myocardial infarction was the adjudicated final diagnosis in 117 patients (18%). NT-proBNP levels at presentation were significantly higher in acute myocardial infarction as compared with patients with other final diagnoses (median 886 pg/mL vs 135 pg/mL, P <.001). The diagnostic accuracy of NT-proBNP for acute myocardial infarction as quantified by the area under the receiver operating characteristic curve (AUC) was 0.79 (95% confidence interval [CI], 0.75-0.83). When added to cardiac troponin T, NT-proBNP significantly increased the AUC from 0.89 (95% CI, 0.84-0.93) to 0.91 (95% CI, 0.88-0.94; P=.033). Cumulative 24-month mortality rates were 0% in the first, 1.3% in the second, 8.3% in the third, and 23.3% in the fourth quartile of NT-proBNP (P <.001). NT-proBNP (AUC 0.85, 95% CI, 0.81-0.89) predicted all-cause mortality independently of and more accurately than both cardiac troponin T (AUC 0.66, 95% CI, 0.58-0.74; P <.001) and the Thrombolysis in Myocardial Infarction risk score (AUC 0.79, 95% CI, 0.74-0.84; P <.001). Net reclassification improvement (Thrombolysis in Myocardial Infarction vs additionally NT-proBNP) was 0.188 (P <.009), and integrated discrimination improvement was 0.100 (P <.001). Use of NT-proBNP improves the early diagnosis and risk stratification of patients with suspected acute myocardial infarction. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of glutamine treatment on myocardial damage and cardiac function in rats after severe burn injury.

PubMed

Yan, Hong; Zhang, Yong; Lv, Shang-jun; Wang, Lin; Liang, Guang-ping; Wan, Qian-xue; Peng, Xi

2012-01-01

Treatment with glutamine has been shown to reduce myocardial damage associated with ischemia/reperfusion injury. However, the cardioprotective effect of glutamine specifically after burn injury remains unclear. The present study explores the ability of glutamine to protect against myocardial damage in rats that have been severely burned. Seventy-two Wistar rats were randomly divided into three groups: normal controls (C), burned controls (B) and a glutamine-treated group (G). Groups B and G were subjected to full thickness burns comprising 30% of total body surface area. Group G was administered 1.5 g/ (kg•d) glutamine and group B was given the same dose of alanine via intragastric administration for 3 days. Levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and blood lactic acid were measured, as well as myocardial ATP and glutathione (GSH) contents. Cardiac function indices and histopathological changes were analyzed at 12, 24, 48 and 72 post-burn hours. In both burned groups, levels of serum CK, LDH, AST and blood lactic acid increased significantly, while myocardial ATP and GSH contents decreased. Compared with group B, CK, LDH, and AST levels were lower and blood lactic acid, myocardial ATP and GSH levels were higher in group G. Moreover, cardiac contractile function inhibition and myocardial histopathological damage were significantly reduced in group G compared to B. Taken together, these results show that glutamine supplementation protects myocardial structure and function after burn injury by improving energy metabolism and by promoted the synthesis of ATP and GSH in cardiac myocytes.

Lipid Biomarkers in Acute Myocardial Infarction Before and After Percutaneous Coronary Intervention by Lipidomics Analysis.

PubMed

Feng, Limin; Yang, Jianzhou; Liu, Wennan; Wang, Qing; Wang, Huijie; Shi, Le; Fu, Liyan; Xu, Qiang; Wang, Baohe; Li, Tian

2018-06-18

BACKGROUND Reperfusion injury is one of the leading causes of myocardial cell death and heart failure. This study was performed to identify new candidate lipid biomarkers for the purpose of optimizing the diagnosis of myocardial ischemia reperfusion (I/R) injury, assessing the severity of myocardial I/R injury and trying to find the novel mechanism related to lipids. MATERIAL AND METHODS Forty patients who were diagnosed with ST-segment elevation myocardial infarction (STEMI) were randomly selected for this study. Serum samples from all the patients with STEMI were collected at 3 time periods: after STEMI diagnosis but prior to reperfusion (T0); and then at 2 hours (T2) and 24 hours (T24) after the end of the percutaneous coronary intervention procedure. Plasma lipidomics profiling analysis was performed to identify the lipid metabolic signatures of myocardial I/R injury using lipidomics. RESULTS Sixteen types of potential lipid biomarkers at different time periods (T0, T2, T24) were identified by using lipidomics technology. The T0 time periods exhibited 16 differentially metabolized lipid peaks in the patients after STEMI diagnosis but prior to reperfusion. With the increase of reperfusion times, the contents of these 16 lipid biomarkers decreased gradually, but there was a 1.5- to 2-fold increase of those 16 lipid biomarkers contents at T2 compared with T24. CONCLUSIONS Lipidomics analysis demonstrated differential change before and after reperfusion, suggesting a potential role of some of these lipids as biomarkers for optimizing the diagnosis of myocardial I/R, as well as for therapeutic targets against myocardial I/R injury.

Effects of glutamine treatment on myocardial damage and cardiac function in rats after severe burn injury

PubMed Central

Yan, Hong; Zhang, Yong; Lv, Shang-jun; Wang, Lin; Liang, Guang-ping; Wan, Qian-xue; Peng, Xi

2012-01-01

Treatment with glutamine has been shown to reduce myocardial damage associated with ischemia/reperfusion injury. However, the cardioprotective effect of glutamine specifically after burn injury remains unclear. The present study explores the ability of glutamine to protect against myocardial damage in rats that have been severely burned. Seventy-two Wistar rats were randomly divided into three groups: normal controls (C), burned controls (B) and a glutamine-treated group (G). Groups B and G were subjected to full thickness burns comprising 30% of total body surface area. Group G was administered 1.5 g/ (kg•d) glutamine and group B was given the same dose of alanine via intragastric administration for 3 days. Levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and blood lactic acid were measured, as well as myocardial ATP and glutathione (GSH) contents. Cardiac function indices and histopathological changes were analyzed at 12, 24, 48 and 72 post-burn hours. In both burned groups, levels of serum CK, LDH, AST and blood lactic acid increased significantly, while myocardial ATP and GSH contents decreased. Compared with group B, CK, LDH, and AST levels were lower and blood lactic acid, myocardial ATP and GSH levels were higher in group G. Moreover, cardiac contractile function inhibition and myocardial histopathological damage were significantly reduced in group G compared to B. Taken together, these results show that glutamine supplementation protects myocardial structure and function after burn injury by improving energy metabolism and by promotedthe synthesis of ATP and GSH in cardiac myocytes. PMID:22977661

Comparison between fragmented QRS and Q waves in myocardial scar detection using myocardial perfusion single photon emission computed tomography.

PubMed

Dabbagh Kakhki, Vahid Reza; Ayati, Narjess; Zakavi, Seyed Rasoul; Sadeghi, Ramin; Tayyebi, Mohammad; Shariati, Farzaneh

2015-01-01

Accurate diagnosis of myocardial infarction (MI) is of paramount importance in patient management, which necessitates the development of efficient and accurate diagnostic methods. Q wave is not present in all patients with MI, and its prevalence is declining. Recently, fragmented QRS (fQRS) complex has been introduced as a marker of prior MI. To investigate diagnostic value of fQRS compared to Q wave. We included 500 consecutive patients with known or suspected coronary artery disease who underwent two days of gated myocardial perfusion imaging using dipyridamole pharmacologic stress. Electrocardiogram (ECG) was evaluated to detect fQRS as well as Q-wave. Finally, subjects were compared in terms of ventricular perfusion and function indices. A total of 207 men and 269 women with mean age of 57.06 ± 12 years were studied. ECG analysis showed that 14.3% of the patients had both fQRS and Q waves, 30.7% had fQRS, and 3.8% had Q waves. Fixed myocardial perfusion defect was noted in 22.3% of patients according to MPIs. Sensitivity, specificity, and positive and negative predictive values for myocardial scar detection were 78%, 65%, 39%, and 91%, respectively, for fQRS and 61%, 94%, 76%, and 89%, respectively, for Q wave. Although fQRS had lower specificity compared to Q wave in the detection of myocardial scar, due to higher sensitivity and negative predictive value can be an invaluable diagnostic index. There is also an incremental value for fQRS in association with Q-wave in myocardial scar assessment.

Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

PubMed

Gewirtz, Henry; Dilsizian, Vasken

2016-05-31

In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. © 2016 American Heart Association, Inc.

Sevoflurane postconditioning improves myocardial mitochondrial respiratory function and reduces myocardial ischemia-reperfusion injury by up-regulating HIF-1

PubMed Central

Yang, Long; Xie, Peng; Wu, Jianjiang; Yu, Jin; Yu, Tian; Wang, Haiying; Wang, Jiang; Xia, Zhengyuan; Zheng, Hong

2016-01-01

Background: Sevoflurane postconditioning (SPostC) can exert myocardial protective effects similar to ischemic preconditioning. However, the exact myocardial protection mechanism by SPostC is unclear. Studies indicate that hypoxia-inducible factor-1 (HIF-1) maintains cellular respiration homeostasis by regulating mitochondrial respiratory chain enzyme activity under hypoxic conditions. This study investigated whether SPostC could regulate the expression of myocardial HIF-1α and to improve mitochondrial respiratory function, thereby relieving myocardial ischemia-reperfusion injury in rats. Methods: The myocardial ischemia-reperfusion rat model was established using the Langendorff isolated heart perfusion apparatus. Additionally, postconditioning was performed using sevoflurane alone or in combination with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). The changes in hemodynamic parameters, HIF-1α protein expression levels, mitochondrial respiratory function and enzyme activity, mitochondrial reactive oxygen species (ROS) production rates, and mitochondrial ultrastructure were measured or observed. Results: Compared to the ischemia-reperfusion (I/R) group, HIF-1α expression in the SPostC group was significantly up-regulated. Additionally, cardiac function indicators, mitochondrial state 3 respiratory rate, respiratory control ratio (RCR), cytochrome C oxidase (CcO), NADH oxidase (NADHO), and succinate oxidase (SUCO) activities, mitochondrial ROS production rate, and mitochondrial ultrastructure were significantly better than those in the I/R group. However, these advantages were completely reversed by the HIF-1α specific inhibitor 2ME2 (P<0.05). Conclusion: The myocardial protective function of SPostC might be associated with the improvement of mitochondrial respiratory function after up-regulation of HIF-1α expression. PMID:27830025

Sevoflurane postconditioning improves myocardial mitochondrial respiratory function and reduces myocardial ischemia-reperfusion injury by up-regulating HIF-1.

PubMed

Yang, Long; Xie, Peng; Wu, Jianjiang; Yu, Jin; Yu, Tian; Wang, Haiying; Wang, Jiang; Xia, Zhengyuan; Zheng, Hong

2016-01-01

Sevoflurane postconditioning (SPostC) can exert myocardial protective effects similar to ischemic preconditioning. However, the exact myocardial protection mechanism by SPostC is unclear. Studies indicate that hypoxia-inducible factor-1 (HIF-1) maintains cellular respiration homeostasis by regulating mitochondrial respiratory chain enzyme activity under hypoxic conditions. This study investigated whether SPostC could regulate the expression of myocardial HIF-1α and to improve mitochondrial respiratory function, thereby relieving myocardial ischemia-reperfusion injury in rats. The myocardial ischemia-reperfusion rat model was established using the Langendorff isolated heart perfusion apparatus. Additionally, postconditioning was performed using sevoflurane alone or in combination with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). The changes in hemodynamic parameters, HIF-1α protein expression levels, mitochondrial respiratory function and enzyme activity, mitochondrial reactive oxygen species (ROS) production rates, and mitochondrial ultrastructure were measured or observed. Compared to the ischemia-reperfusion (I/R) group, HIF-1α expression in the SPostC group was significantly up-regulated. Additionally, cardiac function indicators, mitochondrial state 3 respiratory rate, respiratory control ratio (RCR), cytochrome C oxidase (C c O), NADH oxidase (NADHO), and succinate oxidase (SUCO) activities, mitochondrial ROS production rate, and mitochondrial ultrastructure were significantly better than those in the I/R group. However, these advantages were completely reversed by the HIF-1α specific inhibitor 2ME2 ( P <0.05). The myocardial protective function of SPostC might be associated with the improvement of mitochondrial respiratory function after up-regulation of HIF-1α expression.

Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction (TATORT-NSTEMI): study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Current guidelines recommend thrombus aspiration in patients with ST-elevation myocardial infarction (STEMI); however, there are insufficient data to unequivocally support thrombectomy in patients with non-STEMI (NSTEMI). Methods/Design The TATORT-NSTEMI (Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction) trial is a prospective, controlled, multicenter, randomized, open-label trial enrolling 460 patients. The hypothesis is that, against a background of early revascularization, adjunctive thrombectomy leads to less microvascular obstruction (MO) compared with conventional percutaneous coronary intervention (PCI) alone, as assessed by cardiac magnetic resonance imaging (CMR) in patients with NSTEMI. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary endpoint is the extent of late MO assessed by CMR. Secondary endpoints include early MO, infarct size, and myocardial salvage assessed by CMR as well as enzymatic infarct size and angiographic parameters, such as thrombolysis in myocardial infarction flow post-PCI and myocardial blush grade. Furthermore, clinical endpoints including death, myocardial re-infarction, target vessel revascularization, and new congestive heart failure will be recorded at 6 and 12 months. Safety will be assessed by the incidence of bleeding and stroke. Summary The TATORT-NSTEMI trial has been designed to test the hypothesis that thrombectomy will improve myocardial perfusion in patients with NSTEMI and relevant thrombus burden in the culprit vessel reperfused by early PCI. Trial registration The trial is registered under http://www.clinicaltrials.gov: NCT01612312. PMID:23782681

Decision making processes in people with symptoms of acute myocardial infarction: qualitative study

PubMed Central

Pattenden, Jill; Watt, Ian; Lewin, Robert J P; Stanford, Neil

2002-01-01

Objective To identify the themes that influence decision making processes used by patients with symptoms of acute myocardial infarction. Design Qualitative study using semistructured interviews. Setting Two district hospitals in North Yorkshire. Participants 22 patients admitted to hospital with confirmed second, third, or fourth acute myocardial infarction. Main outcome measure Patients' perceptions of their experience between the onset of symptoms and the decision to seek medical help. Results Six main themes that influence the decision making process were identified: appraisal of symptoms, perceived risk, previous experience, psychological and emotional factors, use of the NHS, and context of the event. Conclusions Knowledge of symptoms may not be enough to promote prompt action in the event of an acute myocardial infarction. Cognitive and emotional processes, individual beliefs and values, and the influence of the context of the event should also be considered in individual interventions designed to reduce delay in the event of symptoms of acute myocardial infarction. What is already known on this topicIndividual sociodemographic and clinical characteristics affect the time to seeking medical care in patients with symptoms of acute myocardial infarctionAppraisal of symptoms is difficult; people with classic and severe symptoms are more likely to take prompt actionWhat this study addsThe decision to seek medical help in patients who have had one or more previous myocardial infarctions is a complex processSimply providing patients with information on symptoms of acute myocardial infarction, and what to do in the event of these symptoms, may not be sufficient to promote prompt action PMID:11976241

Current trend of acute myocardial infarction in Korea (from the Korea Acute Myocardial Infarction Registry from 2006 to 2013).

PubMed

Kook, Hyun Yi; Jeong, Myung Ho; Oh, Sangeun; Yoo, Sung-Hee; Kim, Eun Jung; Ahn, Youngkeun; Kim, Ju Han; Chai, Leem Soon; Kim, Young Jo; Kim, Chong Jin; Chan Cho, Myeong

2014-12-15

Although the incidence of acute myocardial infarction (AMI) in Korea has been rapidly changed because of westernization of diet, lifestyle, and aging of the population, the recent trend of the myocardial infarction have not been reported by classification. We investigated recent trends in the incidence and mortality associated with the 2 major types of AMI. We reviewed 39,978 patients registered in the Korea Acute Myocardial Infarction Registry for either ST-segment elevation acute myocardial infarction (STEMI) or non-ST-segment elevation acute myocardial infarction (NSTEMI) from 2006 to 2013. When the rate for AMI were investigated according to each year, the incidence rates of STEMI decreased markedly from 60.5% in 2006 to 48.1% in 2013 (p <0.001). In contrast, a gradual increase in the incidence rates of NSTEMI was observed from 39.5% in 2006 to 51.9% in 2013 (p <0.001). As risk factors, hypertension, diabetes mellitus, and dyslipidemia were much more common in patients with NSTEMI than STEMI. Among medical treatments, the use of β blockers, angiotensin receptor blocker, and statin were increased from 2006 to 2013 in patients with STEMI and NSTEMI. Patients with STEMI and NSTEMI were more inclined to be increasingly treated by invasive treatments with percutaneous coronary intervention. In conclusion, this study demonstrated that the trend of myocardial infarction has been changed rapidly in the aspect of risk factors, ratio of STEMI versus NSTEMI, and therapeutic strategies during the recent 8 years in Korea. Copyright © 2014 Elsevier Inc. All rights reserved.

Helical structure of the cardiac ventricular anatomy assessed by diffusion tensor magnetic resonance imaging with multiresolution tractography.

PubMed

Poveda, Ferran; Gil, Debora; Martí, Enric; Andaluz, Albert; Ballester, Manel; Carreras, Francesc

2013-10-01

Deeper understanding of the myocardial structure linking the morphology and function of the heart would unravel crucial knowledge for medical and surgical clinical procedures and studies. Several conceptual models of myocardial fiber organization have been proposed but the lack of an automatic and objective methodology prevented an agreement. We sought to deepen this knowledge through advanced computer graphical representations of the myocardial fiber architecture by diffusion tensor magnetic resonance imaging. We performed automatic tractography reconstruction of unsegmented diffusion tensor magnetic resonance imaging datasets of canine heart from the public database of the Johns Hopkins University. Full-scale tractographies have been built with 200 seeds and are composed by streamlines computed on the vector field of primary eigenvectors at the diffusion tensor volumes. We also introduced a novel multiscale visualization technique in order to obtain a simplified tractography. This methodology retains the main geometric features of the fiber tracts, making it easier to decipher the main properties of the architectural organization of the heart. Output analysis of our tractographic representations showed exact correlation with low-level details of myocardial architecture, but also with the more abstract conceptualization of a continuous helical ventricular myocardial fiber array. Objective analysis of myocardial architecture by an automated method, including the entire myocardium and using several 3-dimensional levels of complexity, reveals a continuous helical myocardial fiber arrangement of both right and left ventricles, supporting the anatomical model of the helical ventricular myocardial band described by F. Torrent-Guasp. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Effects of aluminum oxide (Al2O3) nanoparticles on ECG, myocardial inflammatory cytokines, redox state, and connexin 43 and lipid profile in rats: possible cardioprotective effect of gallic acid.

PubMed

El-Hussainy, El-Hussainy M A; Hussein, Abdelaziz M; Abdel-Aziz, Azza; El-Mehasseb, Ibrahim

2016-08-01

The objectives of present study were to examine the effects of aluminum oxide (Al2O3) nanoparticles on myocardial functions, electrical activities, morphology, inflammation, redox state, and myocardial expression of connexin 43 (Cx43) and the effect of gallic acid (GA) on these effects in a rat animal model. Forty male albino rats were divided into 4 equal groups: the control (normal) group; the Al2O3 group, rats received Al2O3 (30 mg·kg(-1), i.p.) daily for 14 days; the nano-alumina group, rats received nano-alumina (30 mg·kg(-1), i.p.) daily for 14 days; and the nano-alumina + GA group, rats received GA (100 mg·kg(-1) orally once daily) for 14 days before nano-alumina administration. The results showed disturbed ECG variables and significant increases in serum levels of LDH, creatine phosphokinase (CPK), CK-MB, triglycerides (TGs), cholesterol and LDL, nitric oxide (NO), and TNF-α and myocardial concentrations of NO, TNF-α, and malondialdehyde (MDA), with significant decreases in serum HDL and myocardial GSH, SOD, catalase (CAT), and Cx43 expression in the nano-alumina group. Pretreatment with GA improved significantly all parameters except serum and myocardial NO. We concluded that chronic administration of Al2O3 NPs caused myocardial dysfunctions, and pretreatment with GA ameliorates myocardial injury induced by nano-alumina, probably through its hypolipidaemic, anti-inflammatory, and antioxidant effects and upregulation of Cx43 in heart.

Tissue Inhibitor of Matrix Metalloproteinase-1 Promotes Myocardial Fibrosis by Mediating CD63-Integrin β1 Interaction.

PubMed

Takawale, Abhijit; Zhang, Pu; Patel, Vaibhav B; Wang, Xiuhua; Oudit, Gavin; Kassiri, Zamaneh

2017-06-01

Myocardial fibrosis is excess accumulation of the extracellular matrix fibrillar collagens. Fibrosis is a key feature of various cardiomyopathies and compromises cardiac systolic and diastolic performance. TIMP1 (tissue inhibitor of metalloproteinase-1) is consistently upregulated in myocardial fibrosis and is used as a marker of fibrosis. However, it remains to be determined whether TIMP1 promotes tissue fibrosis by inhibiting extracellular matrix degradation by matrix metalloproteinases or via an matrix metalloproteinase-independent pathway. We examined the function of TIMP1 in myocardial fibrosis using Timp1 -deficient mice and 2 in vivo models of myocardial fibrosis (angiotensin II infusion and cardiac pressure overload), in vitro analysis of adult cardiac fibroblasts, and fibrotic myocardium from patients with dilated cardiomyopathy (DCM). Timp1 deficiency significantly reduced myocardial fibrosis in both in vivo models of cardiomyopathy. We identified a novel mechanism for TIMP1 action whereby, independent from its matrix metalloproteinase-inhibitory function, it mediates an association between CD63 (cell surface receptor for TIMP1) and integrin β1 on cardiac fibroblasts, initiates activation and nuclear translocation of Smad2/3 and β-catenin, leading to de novo collagen synthesis. This mechanism was consistently observed in vivo, in cultured cardiac fibroblasts, and in human fibrotic myocardium. In addition, after long-term pressure overload, Timp1 deficiency persistently reduced myocardial fibrosis and ameliorated diastolic dysfunction. This study defines a novel matrix metalloproteinase-independent function of TIMP1 in promoting myocardial fibrosis. As such targeting TIMP1 could prove to be a valuable approach in developing antifibrosis therapies. © 2017 American Heart Association, Inc.

[Myocardial imaging in acute myocardial infarction using beta-methyl-p-(123I)-iodophenylpentadecanoic acid: comparison with 201Tl imaging and wall motion].

PubMed

Naruse, H; Itano, M; Kondo, T; Kogame, T; Yamamoto, J; Morita, M; Kawamoto, H; Fukutake, N; Ohyanagi, M; Iwasaki, T

1992-01-01

Myocardial imaging using beta-methyl-p-(123I)-iodophenylpentadecanoic acid (BMIPP) was performed in 11 patients with acute myocardial infarction. The left ventricular images were divided into 12 segments, and myocardial imagings with BMIPP were compared with coronary angiography (CAG), thallium-201 myocardial scintigraphy (TL) and wall motion obtained by two-dimensional echocardiography (WM). When the culprit lesion was at the proximal point of the left anterior descending artery (LAD), all segments showed depressed uptake. In 3 cases with single vessel disease of the LAD, inferior wall of the basis showed reduced uptake of BMIPP despite the location of the culprit lesion. In cases with discordant uptake between the two tracers, BMIPP frequently showed more severely depressed uptake than TL in the subacute phase, although the uptake of BMIPP correlated with that of TL (tau = 0.82, p less than 0.001). In such cases, the discordance was related to the improvement in WM from the acute phase to the convalescent phase. BMIPP uptake correlated with WM in the subacute phase (tau = 0.50, p less than 0.001). BMIPP showed more severely depressed uptake while WM showed mild asynergy in most cases in which discordance was found between the BMIPP and WM findings. However, there was no correlation between the change in WM from the acute to subacute phases, or the uptakes of BMIPP and TL alone. We concluded that the myocardial condition can be evaluated in detail in acute myocardial infarction by comparing the findings of BMIPP with those of TL and WM.

Management of onychomycosis and co-existing tinea pedis.

PubMed

Lipner, Shari R; Scher, Richard K

2015-05-01

Onychomycosis is a common nail infection that often co-exists with tinea pedis. Surveys have suggested the diseases co-exist in at least one third of patients, although actual numbers may be a lot higher due to significant under-reporting. The importance of evaluating and treating both diseases is being increasingly recognized, however, data on improved outcomes, and the potential to minimize re-infection are limited. We review a recent post hoc analysis of two large studies treating mild to moderate onychomycosis with efinaconazole topical solution, 10%, demonstrating that complete cure rates of onychomycosis are significantly improved when any co-existing tinea pedis is also treated.

Dynamic phase coexistence in glass-forming liquids.

PubMed

Pastore, Raffaele; Coniglio, Antonio; Ciamarra, Massimo Pica

2015-07-09

One of the most controversial hypotheses for explaining the heterogeneous dynamics of glasses postulates the temporary coexistence of two phases characterized by a high and by a low diffusivity. In this scenario, two phases with different diffusivities coexist for a time of the order of the relaxation time and mix afterwards. Unfortunately, it is difficult to measure the single-particle diffusivities to test this hypothesis. Indeed, although the non-Gaussian shape of the van-Hove distribution suggests the transient existence of a diffusivity distribution, it is not possible to infer from this quantity whether two or more dynamical phases coexist. Here we provide the first direct observation of the dynamical coexistence of two phases with different diffusivities, by showing that in the deeply supercooled regime the distribution of the single-particle diffusivities acquires a transient bimodal shape. We relate this distribution to the heterogeneity of the dynamics and to the breakdown of the Stokes-Einstein relation, and we show that the coexistence of two dynamical phases occurs up to a timescale growing faster than the relaxation time on cooling, for some of the considered models. Our work offers a basis for rationalizing the dynamics of supercooled liquids and for relating their structural and dynamical properties.

Competitive Exclusion and Coexistence of Pathogens in a Homosexually-Transmitted Disease Model

PubMed Central

Chai, Caichun; Jiang, Jifa

2011-01-01

A sexually-transmitted disease model for two strains of pathogen in a one-sex, heterogeneously-mixing population has been studied completely by Jiang and Chai in (J Math Biol 56:373–390, 2008). In this paper, we give a analysis for a SIS STD with two competing strains, where populations are divided into three differential groups based on their susceptibility to two distinct pathogenic strains. We investigate the existence and stability of the boundary equilibria that characterizes competitive exclusion of the two competing strains; we also investigate the existence and stability of the positive coexistence equilibrium, which characterizes the possibility of coexistence of the two strains. We obtain sufficient and necessary conditions for the existence and global stability about these equilibria under some assumptions. We verify that there is a strong connection between the stability of the boundary equilibria and the existence of the coexistence equilibrium, that is, there exists a unique coexistence equilibrium if and only if the boundary equilibria both exist and have the same stability, the coexistence equilibrium is globally stable or unstable if and only if the two boundary equilibria are both unstable or both stable. PMID:21347222

Coexistence in streams: Do source-sink dynamics allow salamanders to persist with fish predators?

USGS Publications Warehouse

Sepulveda, A.J.; Lowe, W.H.

2011-01-01

Theory suggests that source-sink dynamics can allow coexistence of intraguild predators and prey, but empirical evidence for this coexistence mechanism is limited. We used capture-mark-recapture, genetic methods, and stable isotopes to test whether source-sink dynamics promote coexistence between stream fishes, the intraguild predator, and stream salamanders (Dicamptodon aterrimus), the intraguild prey. Salamander populations from upstream reaches without fish were predicted to maintain or supplement sink populations in downstream reaches with fish. We found instead that downstream reaches with fish were not sinks even though fish consumed salamander larvae-apparent survival, recruitment, and population growth rate did not differ between upstream and downstream reaches. There was also no difference between upstream and downstream reaches in net emigration. We did find that D. aterrimus moved frequently along streams, but believe that this is a response to seasonal habitat changes rather than intraguild predation. Our study provides empirical evidence that local-scale mechanisms are more important than dispersal dynamics to coexistence of streams salamanders and fish. More broadly, it shows the value of empirical data on dispersal and gene flow for distinguishing between local and spatial mechanisms of coexistence. ?? 2011 Springer-Verlag.

Climate variability has a stabilizing effect on the coexistence of prairie grasses

PubMed Central

Adler, Peter B.; HilleRisLambers, Janneke; Kyriakidis, Phaedon C.; Guan, Qingfeng; Levine, Jonathan M.

2006-01-01

How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of “storage effect” theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. PMID:16908862

Coexistence of Fabry disease and IgA nephropathy: a report of two cases.

PubMed

Yin, G; Wu, Y; Zeng, C-H; Chen, H-P; Liu, Z-H

2014-12-01

Coexistence of Fabry disease and IgA nephropathy is rare. Moreover, the coexisting Fabry disease may be unrecognized due to unapparent clinical manifestations. We described two cases with coexisting Fabry disease and IgA nephropathy. The clinicopathological features of these two patients were studied. A 54-year-old male presented with proteinuria, hematuria, and hypertension, and a 33-year-old male presented with proteinuria without clinical signs or family history of Fabry disease. Both of them were diagnosed with IgA nephropathy at admission, whereas Fabry disease was not suspected. Subsequent immunofluorescent study confirmed the diagnosis of IgA nephropathy by showing positive staining for IgA and complement C3 in the mesangium. Meanwhile, light microscopy showed remarkable vacuolation of podocytes with mild mesangial expansion, which was characteristic of Fabry nephropathy. Further examination of toluidine blue-stained semi-thin sections and electron microscopy demonstrated blue bodies and myelin figures in the cytoplasm of podocytes, respectively. The diagnosis of coexisting Fabry disease was finally established based on deficient α-galactosidase A activity in both patients. This case study is an important reminder of the role of kidney biopsy as an indicator of Fabry disease and its rare coexistence with IgA nephropathy.

PubMed Central

Beaudry, Philippe R.

1991-01-01

How widespread is silent myocardial ischemia and should we be actively looking for it? If found, how should it be treated? Is the prognosis for silent myocardial ischemia different from that for symptomatic myocardial ischemia? In this article, we shall summarize what is known about this coronary disease, then present a practical approach which, hopefully, will answer these questions. PMID:21229092

Myocardial metabolism during exposure to carbon monoxide in the conscious dog.

NASA Technical Reports Server (NTRS)

Adams, J. D.; Erickson, H. H.; Stone, H. L.

1973-01-01

Investigation of the relationship between coronary flow, heart rate, left ventricular function, and myocardial oxygen consumption at increasing levels of carboxyhemoglobin in conscious dogs. The results demonstrate a linear increase in coronary flow and heart rate as the carboxyhemoglobin increases up to 20%. Myocardial oxygen consumption declined during the same period.

Regional Myocardial Blood Flow and Ultrastructure Following Acute Temporary Ischemia.

DTIC Science & Technology

1982-01-01

relationship of vascular injury and myocardial hemorrhage to necrosis after reperfusion. Circulation 62:1274-1279 39. Flores J, DiBona DR, Beck CH, Leaf A...the reptilian and amphibian circulations. Anat Rec 3:75-109 87. Powell WF, Flores J, DiBona DR, Leaf A (1973) The role of cell swelling in myocardial

An alternative method for neonatal cerebro-myocardial perfusion.

PubMed

Luciani, Giovanni Battista; De Rita, Fabrizio; Faggian, Giuseppe; Mazzucco, Alessandro

2012-05-01

Several techniques have already been described for selective cerebral perfusion during repair of aortic arch pathology in children. One method combining cerebral with myocardial perfusion has also been proposed. A novel technique is reported here for selective and independent cerebro-myocardial perfusion for neonatal and infant arch surgery. Technical aspects and potential advantages are discussed.

Myocardial uptake of cocaine and effects of cocaine on myocardial substrate utilization and perfusion in hypertensive rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Som, P.; Wang, G.J.; Oster, Z.H.

Cocaine abuse is a problem causing world-wide concern and the number of deaths following cocaine use is increasing. Cardiovascular complications following cocaine include severe tachyarrythmias, pulmonary edema, myocardial infarction, and acute renal failure, which are major problems confronting emergency facilities. While the studies of cocaine effects on the brain have been given the most attention, it is clear that the effects of cocaine on the cardiovascular system are of great importance, given the increasing number of reports on sudden death and myocardial infarctions in young adults related to cocaine use. The precise mechanisms of cardiotoxic actions of cocaine are unclear.more » We investigated the whole-body distribution of C-14-labeled cocaine to determine the cocaine-binding sites, including blocking experiments to determine the nature of regional binding sites, and differential response of the normal vs. diseased heart (hypertensive cardiomyopathy) in an animal model to mimic a potentially high risk population. We investigated the acute effects of cocaine on myocardial metabolism using two myocardial energy substrate analogs, fatty acid and glucose with comparison with regional perfusion.« less

Nitroglycerin Use in Myocardial Infarction Patients: Risks and Benefits

PubMed Central

Ferreira, Julio C.B.; Mochly-Rosen, Daria

2012-01-01

Acute myocardial infarction and its sequelae are leading causes of morbidity and mortality worldwide. Nitroglycerin remains a first-line treatment for angina pectoris and acute myocardial infarction. Nitroglycerin achieves its benefit by giving rise to nitric oxide, which causes vasodilation and increases blood flow to the myocardium. However, continuous delivery of nitroglycerin results in tolerance, limiting the use of this drug. Nitroglycerin tolerance is due, at least in part, to inactivation of aldehyde dehydrogenase 2 (ALDH2), an enzyme that converts nitroglycerin to the vasodilator, nitric oxide. We have recently found that, in addition to nitroglycerin’s effect on the vasculature, sustained treatment with nitroglycerin negatively affects cardiomyocyte viability following ischemia, thus resulting in increased infarct size in a myocardial infarction model in animals. Co-administration of Alda-1, an activator of ALDH2, with nitroglycerin improves metabolism of reactive aldehyde adducts and prevents the nitroglycerin-induced increase in cardiac dysfunction following myocardial infarction. In this review, we describe the molecular mechanisms associated with the benefits and risks of nitroglycerin administration in myocardial infarction. (167 of 200). PMID:22040938

Myocardial perfusion imaging study of CO(2)-induced panic attack.

PubMed

Soares-Filho, Gastão L F; Machado, Sergio; Arias-Carrión, Oscar; Santulli, Gaetano; Mesquita, Claudio T; Cosci, Fiammetta; Silva, Adriana C; Nardi, Antonio E

2014-01-15

Chest pain is often seen alongside with panic attacks. Moreover, panic disorder has been suggested as a risk factor for cardiovascular disease and even a trigger for acute coronary syndrome. Patients with coronary artery disease may have myocardial ischemia in response to mental stress, in which panic attack is a strong component, by an increase in coronary vasomotor tone or sympathetic hyperactivity setting off an increase in myocardial oxygen consumption. Indeed, coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. These findings correlating panic disorder with coronary artery disease lead us to raise questions about the favorable prognosis of chest pain in panic attack. To investigate whether myocardial ischemia is the genesis of chest pain in panic attacks, we developed a myocardial perfusion study through research by myocardial scintigraphy in patients with panic attacks induced in the laboratory by inhalation of 35% carbon dioxide. In conclusion, from the data obtained, some hypotheses are discussed from the viewpoint of endothelial dysfunction and microvascular disease present in mental stress response. Copyright © 2014 Elsevier Inc. All rights reserved.

Cardiac troponin I: A potent biomarker for myocardial damage assessment following high voltage electric burn

PubMed Central

Bose, Arindam; Chhabra, Chandra B.; Chamania, Shobha; Hemvani, Nanda; Chitnis, Dhananjay S.

2016-01-01

Myocardial infarction (MI) following high voltage electric burn is very rare, and its pathogenesis remains controversial. Electrical burns represent only 4% of all burns. Hence, clinical managements have taken a slow pace in developing. The recent guidelines laid down by the cardiology societies include cardiac troponin I (cTnI) as the gold standard marker for the assessment of myocardial damage assessment. Two patients were admitted to our hospital at the different time with the same kind of high voltage electric burn. Both patients had complained with chest discomfort during admission, and cardiac parameter assessment was done for both the patients. cTnI was also measured for both patients, and marked increase in the values was seen within 5 h of onset of myocardial damage and got into normal range within 72 h. Myocardial damage following electric burn needs to be suspected and assessed as early as possible. Hence, cTnI should be the valuable tool to detect the severity of myocardial damage incurred in the electric burn cases. PMID:28216824

[Cardiac protection is a clinical evidence].

PubMed

Guarracino, F; Doroni, L; Cariello, C; Baldassarri, R; Vullo, C

2004-05-01

Anaesthetics may have protective effect against myocardial ischemia. We aimed to investigate if sevoflurane administration could exert myocardial protection during following coronary occlusion in patients with coronary artery disease. a). prospective, randomized study. b). University Hospital, cardiac surgical operative theatre. c). 42 patients with coronary artery disease, scheduled to undergo coronary surgery. severe coronary stenosis of anterior descending coronary artery; no collateral flow on angiography; at least two normokinetic segments in the myocardial region supplied by the vessel being bypassed. PATIENTS were randomized to receive (group S) or not (group C) sevoflurane administration for 15 min just before coronary occlusion. d). Transoesophageal Tissue Doppler echocardiographic examination of myocardial systolic and early diastolic velocities in both groups basally and 60 s after coronary occlusion by the surgeon. e). systolic and early diastolic velocities were registered by Tissue Doppler from a long-axis view of the interventricular septum or the anterior wall of the left ventricle. In group C a significant reduction of systolic and diastolic intramyocardial velocities was found during myocardial ischemia due to coronary occlusion. Treatment with sevoflurane before coronary occlusion seem effective in reducing functional myocardial impairment due to ischemia.

Parametric methods for characterizing myocardial tissue by magnetic resonance imaging (part 2): T2 mapping.

PubMed

Perea Palazón, R J; Solé Arqués, M; Prat González, S; de Caralt Robira, T M; Cibeira López, M T; Ortiz Pérez, J T

2015-01-01

Cardiac magnetic resonance imaging is considered the reference technique for characterizing myocardial tissue; for example, T2-weighted sequences make it possible to evaluate areas of edema or myocardial inflammation. However, traditional sequences have many limitations and provide only qualitative information. Moreover, traditional sequences depend on the reference to remote myocardium or skeletal muscle, which limits their ability to detect and quantify diffuse myocardial damage. Recently developed magnetic resonance myocardial mapping techniques enable quantitative assessment of parameters indicative of edema. These techniques have proven better than traditional sequences both in acute cardiomyopathy and in acute ischemic heart disease. This article synthesizes current developments in T2 mapping as well as their clinical applications and limitations. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

An Unusual Complication Following Transarterial Chemoembolization: Acute Myocardial Infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai Yiliang; Chang Weichou; Kuo Wuhsien

Transarterial chemoembolization has been widely used to treat unresectable hepatocellular carcinoma. Various complications have been reported, but they have not included acute myocardial infarction. Acute myocardial infarction results mainly from coronary artery occlusion by plaques that are vulnerable to rupture or from coronary spasm, embolization, or dissection of the coronary artery. It is associated with significant morbidity and mortality. We present a case report that describes a patient with hepatocellular carcinoma who underwent transarterial chemoembolization and died subsequently of acute myocardial infarction. To our knowledge, there has been no previous report of this complication induced by transarterial chemoembolization for hepatocellularmore » carcinoma. This case illustrates the need to be aware of acute myocardial infarction when transarterial chemoembolization is planned for the treatment of hepatocellular carcinoma, especially in patients with underlying coronary artery disease.« less

Amifostine Pretreatment Attenuates Myocardial Ischemia/Reperfusion Injury by Inhibiting Apoptosis and Oxidative Stress.

PubMed

Wu, Shao-Ze; Tao, Lu-Yuan; Wang, Jiao-Ni; Xu, Zhi-Qiang; Wang, Jie; Xue, Yang-Jing; Huang, Kai-Yu; Lin, Jia-Feng; Li, Lei; Ji, Kang-Ting

2017-01-01

The present study was aimed at investigating the effect of amifostine on myocardial ischemia/reperfusion (I/R) injury of mice and H9c2 cells cultured with TBHP (tert-butyl hydroperoxide). The results showed that pretreatment with amifostine significantly attenuated cell apoptosis and death, accompanied by decreased reactive oxygen species (ROS) production and lower mitochondrial potential (ΔΨm). In vivo, amifostine pretreatment alleviated I/R injury and decreased myocardial apoptosis and infarct area, which was paralleled by increased superoxide dismutase (SOD) and reduced malondialdehyde (MDA) in myocardial tissues, increased Bcl2 expression, decreased Bax expression, lower cleaved caspase-3 level, fewer TUNEL positive cells, and fewer DHE-positive cells in heart. Our results indicate that amifostine pretreatment has a protective effect against myocardial I/R injury via scavenging ROS.

Mathematical Model of the Role of RdCVF in the Coexistence of Rods and Cones in a Healthy Eye.

PubMed

Camacho, Erika T; Léveillard, Thierry; Sahel, José-Alain; Wirkus, Stephen

2016-07-01

Understanding the essential components and processes for coexistence of rods and cones is at the forefront of retinal research. The recent discovery on RdCVF's mechanism and mode of action for enhancing cone survival brings us a step closer to unraveling key questions of coexistence and codependence of these neurons. In this work, we build from ecological and enzyme kinetic work on functional response kinetics and present a mathematical model that allows us to investigate the role of RdCVF and its contribution to glucose intake. Our model results and analysis predict a dual role of RdCVF for enhancing and repressing the healthy coexistence of the rods and cones. Our results show that maintaining RdCVF above a threshold value allows for coexistence. However, a significant increase above this value threatens the existence of rods as the cones become extremely efficient at uptaking glucose and begin to take most of it for themselves. We investigate the role of natural glucose intake and that due to RdCVF in both high and low nutrient levels. Our analysis reveals that under low nutrient levels coexistence is not possible regardless of the amount of RdCVF present. With high nutrient levels coexistence can be achieved with a relative small increase in glucose uptake. By understanding the contributions of rods to cones survival via RdCVF in a non-diseased retina, we hope to shed light on degenerative diseases such as retinitis pigmentosa.

Gender differences in physical activity following acute myocardial infarction in adults: A prospective, observational study.

PubMed

Minges, Karl E; Strait, Kelly M; Owen, Neville; Dunstan, David W; Camhi, Sarah M; Lichtman, Judith; Geda, Mary; Dreyer, Rachel P; Bueno, Héctor; Beltrame, John F; Curtis, Jeptha P; Krumholz, Harlan M

2017-01-01

Aims Despite the benefits of regular physical activity participation following acute myocardial infarction, little is known about gender differences in physical activity among patients after acute myocardial infarction. We described, by gender, physical activity trajectories pre- and post-acute myocardial infarction, and determined whether gender was independently associated with physical activity. Methods and results The Variation in Recovery: Role of Gender on Outcomes of Young AMI patients (VIRGO) study, conducted at 103 US, 24 Spanish, and three Australian hospitals, was designed, in part, to evaluate gender differences in lifestyle behaviors following acute myocardial infarction. We used baseline, one-month, and 12-month data collected from patients aged 18-55 years ( n = 3572). Patients were assigned to American Heart Association-defined levels of physical activity. A generalized estimating equation model was used to account for repeated measures within the same individual over time. Men were more active (≥150 min/wk moderate or ≥75 min/wk vigorous activity) than women at baseline (42% vs 34%), one month (45% vs 34%), and 12 months (48% vs 36%) (all p < 0.0001). Men engaged in a significantly longer duration of activity at each time point. When controlling for all other factors, women had 1.37 times the odds of being less active than men from pre-acute myocardial infarction to 12-months post-acute myocardial infarction (95% confidence interval: 1.21-1.55). Non-white race, non-active workplaces, smoking, diabetes, hypertension, and obesity were also associated independently with being less active over time (all p < 0.05). Conclusions Although activity increased modestly over time, women recovering from acute myocardial infarction were less likely to meet physical activity recommendations than were men. By identifying factors associated with low levels of activity during acute myocardial infarction recovery, targeted interventions can be introduced prior to hospital discharge.

Acute Effect of Hookah Smoking on the Human Coronary Microcirculation

PubMed Central

Nelson, Michael D.; Rezk-Hanna, Mary; Rader, Florian; Mason, O’Neil R.; Tang, Xiu; Shidban, Sarah; Rosenberry, Ryan; Benowitz, Neal L.; Tashkin, Donald P.; Elashoff, Robert M.; Lindner, Jonathan R.; Victor, Ronald G.

2017-01-01

Hookah (water pipe) smoking is a major new understudied epidemic affecting youth. Because burning charcoal is used to heat the tobacco product, hookah smoke delivers not only nicotine but also large amounts of charcoal combustion products, including carbon-rich nanoparticles that constitute putative coronary vasoconstrictor stimuli and carbon monoxide, a known coronary vasodilator. We used myocardial contrast echocardiography perfusion imaging with intravenous lipid shelled microbubbles in young adult hookah smokers to determine the net effect of smoking hookah on myocardial blood flow. In 9 hookah smokers (age 27 – 5 years, mean – SD), we measured myocardial blood flow velocity (β), myocardial blood volume (A), myocardial blood flow (A × β) as well as myocardial oxygen consumption (MVO2) before and immediately after 30 minutes of ad lib hookah smoking. Myocardial blood flow did not decrease with hookah smoking but rather increased acutely (88 – 10 to 120 – 19 a.u./s, mean – SE, p = 0.02), matching a mild increase in MVO2 (6.5 – 0.3 to 7.6 – 0.4 ml·minute−1, p <0.001). This was manifested primarily by increased myocardial blood flow velocity (0.7 – 0.1 to 0.9 – 0.1 second−1, p = 0.01) with unchanged myocardial blood volume (133 – 7 to 137 – 7 a.u., p = ns), the same pattern of coronary microvascular response seen with a low-dose β-adrenergic agonist. Indeed, with hookah, the increased MVO2 was accompanied by decreased heart rate variability, an indirect index of adrenergic overactivity, and eliminated by β-adrenergic blockade (i.v. propranolol). In conclusion, nanoparticle-enriched hookah smoke either is not an acute coronary vasoconstrictor stimulus or its vasoconstrictor effect is too weak to overcome the physiologic dilation of coronary microvessels matching mild cardiac β-adrenergic stimulation. PMID:27067622

Evaluation of effect of atorvastatin on left ventricular systolic function in rats with myocardial infarction via 2D-STI technique.

PubMed

Hua, Yan; Xie, Manying; Yin, Jiabao; Wang, Yu; Gan, Ling; Sang, Ming; Sun, Xiaodong; Li, Mingyang; Liu, Shanjun; Xu, Jinzhi

2018-05-01

This report aims to evaluate the effect of atorvastatin (Ator) on left ventricular systolic function in myocardial infarction (MI) rats. Forty healthy adult Sprague-Dawley rats were randomly divided into four groups: Ator group, MI group, sham-operation group and normal group. The left anterior descending coronary arteries were ligated to establish the MI model; after modeling, the Ator group was treated with Ator for 4 consecutive weeks. The echocardiographic detection was performed; the left ventricular myocardial systolic peak velocities, strain and strain rates were analyzed using the 2D-STI technique. After 4 weeks, myocardial tissues were taken from all rats and received the pathological examination. Left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) in Ator group and MI group were increased after operation, but left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were decreased; myocardial function were decreased significantly (p<0.05). After Ator treatment, myocardial function at the 3rd and 4th week after operation increased significantly (p<0.05). After Ator treatment, LVEDD and LVESD decreased while LVEF and LVFS increased in Ator group at the 3rd and 4th week after operation compared with MI group (p<0.05). At the 4th week after operation, LVEDD and LVESD in Ator group were decreased compared with those at the 1st and 2nd week after operation, but LVEF and LVFS were increased compared with those at the 1st, 2nd and 3rd week after operation (p<0.05). Pathological examination showed that necrosis and fibrosis of myocardial cells and inflammatory reaction were obvious in MI group. The inflammatory reaction of myocardial cells and myocardial fibrosis were lighter in Ator group. Ator can effectively improve the left ventricular systolic function in MI rats, which could be related to the reduction of response to inflammation and fibrosis.

Association between low-dose acetylsalicylic acid reinitiation and the risk of myocardial infarction or coronary heart disease death.

PubMed

Sáez, María E; González-Pérez, Antonio; Johansson, Saga; Himmelmann, Anders; García Rodríguez, Luis A

2016-07-01

In secondary cardiovascular prevention, discontinuation of acetylsalicylic acid (ASA) is associated with an increased risk of cardiovascular events. This study assessed the impact of ASA reinitiation on the risk of myocardial infarction and coronary heart disease death. Patients prescribed ASA for secondary cardiovascular prevention and who had had a period of ASA discontinuation of ≥90 days in 2000-2007 were identified from The Health Improvement Network (N = 10,453). Incidence of myocardial infarction/coronary heart disease death was calculated. Survival analyses using adjusted Cox proportional hazard models were performed to calculate hazard ratios and 95% confidence intervals for the risk of myocardial infarction/coronary heart disease death associated with ASA use patterns after the initial period of discontinuation. Individuals who were prescribed ASA during follow-up were considered reinitiators. The incidence of myocardial infarction/coronary heart disease death was 8.90 cases per 1000 person-years. Risk of myocardial infarction/coronary heart disease death was similar for current ASA users, who had been continuously exposed since reinitiation, and patients who had not reinitiated ASA (hazard ratio 1.27, 95% confidence interval 0.93-1.73). Among reinitiators, an additional period of ASA discontinuation was associated with increased risk of myocardial infarction/coronary heart disease death compared with no reinitiation (current users: hazard ratio 1.46, 95% confidence interval 1.13-1.90; noncurrent users: hazard ratio 1.70, 95% confidence interval 1.31-2.21). ASA reinitiation was not associated with a decreased risk of myocardial infarction/coronary heart disease death. This may be explained by confounding by indication/comorbidity, whereby higher-risk patients are more likely to reinitiate therapy. An additional period of ASA discontinuation among reinitiators was associated with an increased risk of myocardial infarction/coronary heart disease death. © The European Society of Cardiology 2015.

Subacute cardiac rubidium-82 positron emission tomography (82Rb-PET) to assess myocardial area at risk, final infarct size, and myocardial salvage after STEMI.

PubMed

Ghotbi, Adam Ali; Kjaer, Andreas; Nepper-Christensen, Lars; Ahtarovski, Kiril Aleksov; Lønborg, Jacob Thomsen; Vejlstrup, Niels; Kyhl, Kasper; Christensen, Thomas Emil; Engstrøm, Thomas; Kelbæk, Henning; Holmvang, Lene; Bang, Lia E; Ripa, Rasmus Sejersten; Hasbak, Philip

2018-06-01

Determining infarct size and myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) is important when assessing the efficacy of new reperfusion strategies. We investigated whether rest 82 Rb-PET myocardial perfusion imaging can estimate area at risk, final infarct size, and myocardial salvage index when compared to cardiac SPECT and magnetic resonance (CMR). Twelve STEMI patients were injected with 99m Tc-Sestamibi intravenously immediate prior to reperfusion. SPECT, 82 Rb-PET, and CMR imaging were performed post-reperfusion and at a 3-month follow-up. An automated algorithm determined area at risk, final infarct size, and hence myocardial salvage index. SPECT, CMR, and PET were performed 2.2 ± 0.5, 34 ± 8.5, and 32 ± 24.4 h after reperfusion, respectively. Mean (± SD) area at risk were 35.2 ± 16.6%, 34.7 ± 11.3%, and 28.1 ± 16.1% of the left ventricle (LV) in SPECT, CMR, and PET, respectively, P = 0.04 for difference. Mean final infarct size estimates were 12.3 ± 15.4%, 13.7 ± 10.4%, and 11.9 ± 14.6% of the LV in SPECT, CMR, and PET imaging, respectively, P = .72. Myocardial salvage indices were 0.64 ± 0.33 (SPECT), 0.65 ± 0.20 (CMR), and 0.63 ± 0.28 (PET), (P = .78). 82 Rb-PET underestimates area at risk in patients with STEMI when compared to SPECT and CMR. However, our findings suggest that PET imaging seems feasible when assessing the clinical important parameters of final infarct size and myocardial salvage index, although with great variability, in a selected STEMI population with large infarcts. These findings should be confirmed in a larger population.

Glucagon-like peptide-1 increases myocardial glucose uptake via p38alpha MAP kinase-mediated, nitric oxide-dependent mechanisms in conscious dogs with dilated cardiomyopathy.

PubMed

Bhashyam, Siva; Fields, Anjali V; Patterson, Brandy; Testani, Jeffrey M; Chen, Li; Shen, You-Tang; Shannon, Richard P

2010-07-01

We have shown that glucagon-like peptide-1 (GLP-1[7-36] amide) stimulates myocardial glucose uptake in dilated cardiomyopathy (DCM) independent of an insulinotropic effect. The cellular mechanisms of GLP-1-induced myocardial glucose uptake are unknown. Myocardial substrates and glucoregulatory hormones were measured in conscious, chronically instrumented dogs at control (n=6), DCM (n=9) and DCM after treatment with a 48-hour infusion of GLP-1 (7-36) amide (n=9) or vehicle (n=6). GLP-1 receptors and cellular pathways implicated in myocardial glucose uptake were measured in sarcolemmal membranes harvested from the 4 groups. GLP-1 stimulated myocardial glucose uptake (DCM: 20+/-7 nmol/min/g; DCM+GLP-1: 61+/-12 nmol/min/g; P=0.001) independent of increased plasma insulin levels. The GLP-1 receptors were upregulated in the sarcolemmal membranes (control: 98+/-2 density units; DCM: 256+/-58 density units; P=0.046) and were expressed in their activated (65 kDa) form in DCM. The GLP-1-induced increases in myocardial glucose uptake did not involve adenylyl cyclase or Akt activation but was associated with marked increases in p38alpha MAP kinase activity (DCM+vehicle: 97+/-22 pmol ATP/mg/min; DCM+GLP-1: 170+/-36 pmol ATP/mg/min; P=0.051), induction of nitric oxide synthase 2 (DCM+vehicle: 151+/-13 density units; DCM+GLP-1: 306+/-12 density units; P=0.001), and GLUT-1 translocation (DCM+vehicle: 21+/-3% membrane bound; DCM+GLP-1: 39+/-3% membrane bound; P=0.005). The effects of GLP-1 on myocardial glucose uptake were blocked by pretreatment with the p38alpha MAP kinase inhibitor or the nonspecific nitric oxide synthase inhibitor nitro-l-arginine. GLP-1 stimulates myocardial glucose uptake through a non-Akt-1-dependent mechanism by activating cellular pathways that have been identified in mediating chronic hibernation and the late phase of ischemic preconditioning.

Protective effects of melatonin on ischemia-reperfusion induced myocardial damage and hemodynamic recovery in rats.

PubMed

Liu, L-F; Qin, Q; Qian, Z-H; Shi, M; Deng, Q-C; Zhu, W-P; Zhang, H; Tao, X-M; Liu, Y

2014-01-01

To investigate the mechanism of melatonin (MT) protection of adult rate myocardial ischemia-reperfusion injury and its influence on rat's hemodynamic recovery. 48 rats were randomly divided into MT group (n=36) and the control group (n=12), MT group was divided into three sub-groups according to different dosages: Group I (n=12) was administered with 2.5 mg/kg MT; Group II (n=12) was administered with 5 mg/kg MT; Group III (n=12) was administered with 10 mg/kg MT. The electrocardiogram of four groups was observed with the left coronary artery blocked for 10min at first and then reperfused for 15min. Hemodynamic evolving was observed and changes in energy metabolism of rat myocardium were monitored. TUNEL and immunohistochemistry were applied to detect the cell apoptosis index, protein expression of Bcl-2 and Bax. LVDP (left ventricular developed pressure) and ± dp/dt in MT group presented better recovery at various time points than the control group. Among them, Group III had the optimal recovery degree (p < 0.05). After MT administration, ATP content in myocardial cells in MT group was significantly higher than the control group. Compared with the control group, the concentration of mitochondrial MDA and Ca2+ in myocardial cells in MT group showed a downward trend. But its GSH concentration was significantly higher than the control group (p < 0.05). The improvement degree of ATP, MDA, GSH and Ca2+ concentration in Group II over-performed Group I (p < 0.05). MT-intervened myocardial apoptosis index (AI) and Bax positive expression index declined while Bcl-2 positive expression index increased (p < 0.01). MT effectively inhibited myocardial apoptosis during the myocardial ischemia-reperfusion of rats, protected the structural integrity of mitochondria in myocardial cells, promoted ATP synthesis, and avoided heart damage in many ways. This protection mechanism was related with anti-oxidative damage. Meanwhile, MT could promote the hemodynamic recovery after myocardial ischemia-reperfusion in rats.

Penehyclidine hydrochloride regulates mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provides cardioprotection in rats with myocardial ischemia-reperfusion injury.

PubMed

Feng, Min; Wang, Lirui; Chang, Siyuan; Yuan, Pu

2018-05-31

The potential mechanism of penehyclidine hydrochloride (PHC) against myocardial ischemia-reperfusion (I/R) injury has not been fully elucidated. The aim of the present study was to reveal whether mitochondrial dynamics, apoptosis, and MAPKs were involved in the cardioprotective effect of this drug on myocardial I/R injury. Ninety healthy adult male Wistar rats were separately pretreated with normal saline (0.9%); PHC; and signal pathway blockers of MAPKs, Drp1, and Bcl-2. Coronary artery ligation and subsequent reperfusion were performed to induce myocardial I/R injury. Echocardiography was performed. Myocardial enzymes and oxidative stress markers were detected. Myocardial cell apoptotic rates and infarct sizes were measured. Mitochondrial function was evaluated. Expression levels of MAPKs, mitochondria regulatory proteins (Drp1, Mfn1/2), and apoptosis-related proteins (Bcl-2, Bax) were determined. PHC pretreatment improved myocardial abnormalities (dysfunction, injury, infarct size, and apoptotic rate), mitochondrial abnormalities (dysfunction and fission), and excessive oxidative stress and inhibited the activities of p38MAPK and JNK signal pathways in rats with myocardial I/R injury (P < 0.05). Additionally, p38MAPK and JNK blockers (SB239063 and SP600125, respectively) had an effect on rats same as that of PHC. Although Drp1 blocker (Mdivi-1) showed a similar cardioprotective effect (P < 0.05), it did not affect the expression of MAPKs and apoptosis-related proteins (P > 0.05). In addition, Bcl-2 blocker (ABT-737) caused a high expression of Drp1 and a low expression of Mfn1/2 (P < 0.05). PHC regulated mitochondrial dynamics and apoptosis through p38MAPK and JNK signal pathways and provided cardioprotection in rats with myocardial I/R injury. Copyright © 2018 Elsevier B.V. All rights reserved.

Reversibility by dipyridamole of thallium-201 myocardial scan defects in patients with sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tellier, P.; Paycha, F.; Antony, I.

1988-08-01

In order to clarify the significance of anginal pain and myocardial thallium-201 scan defects in cardiac sarcoidosis, the pharmacologic effect of dipyridamole on myocardial perfusion was assessed by planar thallium-201 myocardial scintigraphy in patients with sarcoidosis. Thallium-201 myocardial scintigraphy was performed at rest and after 0.56 mg/kg intravenous dipyridamole during four minutes in 16 patients with sarcoidosis. The myocardial scan (45-degree and 70-degree left anterior oblique, and anterior views) was divided into 15 segments. Results were evaluated by the number of segmental defects and with a global perfusion score (from 0 to 60) by a semi-quantitative index depending on themore » size and severity of myocardial thallium-201 defects. Thirteen of the 16 patients showed partial or total reversion of their thallium-201 defects on redistribution scanning either at rest or after dipyridamole. The mean (+/- SD) number of myocardial perfusion defects that were present in all the patients decreased from 5.31 +/- 1.78 at rest to 3.25 +/- 2.52 after redistribution (p less than 0.001) and to 2.19 +/- 2.10 after dipyridamole (p less than 0.001). The mean global perfusion score increased from 53.2 +/- 3.0 at rest to 56.2 +/- 2.9 after redistribution (p less than 0.001) and to 57.2 +/- 2.7 after dipyridamole (p less than 0.001). A significant correlation (r = 0.82, p less than 0.001) was found between the increase of global perfusion score on redistribution and after dipyridamole. The reversibility of myocardial scan defects is a common finding in sarcoidosis. It makes unlikely the role of scar fibrosis or extensive confluent granulomas as a mechanism for such defects. The effect of dipyridamole suggests the presence of reversible disorders lying at the coronary microvascular level.« less

Proteinuria and Reduced Estimated Glomerular Filtration Rate Independently Predict Risk for Acute Myocardial Infarction: Findings from a Population-Based Study in Keelung, Taiwan.

PubMed

Chang, Shu-Hsuan; Tsai, Chia-Ti; Yen, Amy Ming-Fang; Lei, Meng-Huan; Chen, Hsiu-Hsi; Tseng, Chuen-Den

2015-03-01

The aim of this study was to evaluate the independent roles of proteinuria and reduced estimated glomerular filtration rate (GFR) in the development of acute myocardial infarction in a northern Taiwanese population. We conducted a community-based prospective cohort study in Keelung, the northernmost county of Taiwan. A total of 63,129 subjects (63% women) ≥ 20 years of age who had no history of coronary heart disease were recruited and followed-up. Univariate and multivariate proportional hazards regression analysis was performed to assess the association between proteinuria and estimated GFR and the risk of acute myocardial infarction. There were 305 new cases of acute myocardial infarction (114 women and 191 men) documented during a four-year follow-up period. After adjustment of potential confounding covariates, heavier proteinuria (dipstick urinalysis reading 3+) and estimated GFR of less than 60 ml/min/1.73 m(2) independently predicted increased risk of developing acute myocardial infarction. The adjusted hazard ratio (aHR) of heavier proteinuria for occurrence of acute myocardial infarction was 1.85 [95% confidence intervals (CI), 1.17-2.91, p < 0.01] (vs. the reference group: negative dipstick proteinuria). The aHR of estimated GFR of 30-59 ml/min/1.73 m(2) for occurrence of acute myocardial infarction was 2.4 (95% CI, 1.31-4.38, p < 0.01) (vs. the reference group: estimated GFR ≥ 90 ml/ min/1.73 m(2)), and that of estimated GFR of 15-29 ml/min/1.73 m(2) was 5.26 (95% CI, 2.26-12.26, p < 0.01). We demonstrated that both heavier proteinuria and lower estimated GFR are significant independent predictors of developing future acute myocardial infarction in a northern Taiwanese population. Acute myocardial infarction; Estimated glomerular filtration rate; Proteinuria.

Agreement between Myocardial Infarction Patients and Their Spouses on Reporting of Data on 82 Cardiovascular Risk Exposures.

PubMed

Quintana, Hedley Knewjen; Vikström, Max; Andersson, Tomas; Hallqvist, Johan; Leander, Karin

2015-01-01

The validity of exposure data collected from proxy respondents of myocardial infarction patients has scarcely been studied. We assessed the level of disagreement between myocardial infarction patients and their spouses with respect to the reporting of the patient´s cardiovascular risk exposures. Within the frame of the Stockholm Heart Epidemiology Program (SHEEP), a case-control study of risk factors of myocardial infarction performed in Stockholm county 1992-1994, a subset of 327 first time myocardial infarction cases aged 45-70 who survived >28 days after the event and who co-habited with a spouse or common-law spouse (proxy) were identified between 1993-04-05 and 1993-12-31. Among these, 243 cases participated along with their respective proxy in the present study. Control individuals, matched to cases by age, sex and residential area were also included (n = 243). Data were collected using questionnaires. Using conditional logistic regression we calculated for each of 82 exposures the odds ratio based on information collected from 1) myocardial infarction cases and controls [odds ratio A] and 2) proxies and the same set of controls [odds ratio B]. Disagreement was measured by calculating the ratio between odds ratio B and odds ratio A with 95% confidence intervals (CI) calculated using resampling bootstrap. For the vast majority of the exposures considered including diet, smoking, education, work-related stress, and family history of CVD, there was no statistically significant disagreement between myocardial infarction patients and proxies (n = 243 pairs). However, leisure time physical inactivity (proxy bias = 1.59, 95% CI 1.05-3.57) was overestimated by spouses compared to myocardial infarction patients. A few other exposures including some sleep-related problems and work-related issues also showed disagreement. Myocardial infarction patients and their spouses similarly reported data on a wide range of exposures including the majority of the traditional cardiovascular risk factors, leisure time physical inactivity being an exception.

Identification of ADAMTS7 as a novel locus for coronary atherosclerosis and association of ABO with myocardial infarction in the presence of coronary atherosclerosis: two genome-wide association studies.

PubMed

Reilly, Muredach P; Li, Mingyao; He, Jing; Ferguson, Jane F; Stylianou, Ioannis M; Mehta, Nehal N; Burnett, Mary Susan; Devaney, Joseph M; Knouff, Christopher W; Thompson, John R; Horne, Benjamin D; Stewart, Alexandre F R; Assimes, Themistocles L; Wild, Philipp S; Allayee, Hooman; Nitschke, Patrick Linsel; Patel, Riyaz S; Martinelli, Nicola; Girelli, Domenico; Quyyumi, Arshed A; Anderson, Jeffrey L; Erdmann, Jeanette; Hall, Alistair S; Schunkert, Heribert; Quertermous, Thomas; Blankenberg, Stefan; Hazen, Stanley L; Roberts, Robert; Kathiresan, Sekar; Samani, Nilesh J; Epstein, Stephen E; Rader, Daniel J

2011-01-29

We tested whether genetic factors distinctly contribute to either development of coronary atherosclerosis or, specifically, to myocardial infarction in existing coronary atherosclerosis. We did two genome-wide association studies (GWAS) with coronary angiographic phenotyping in participants of European ancestry. To identify loci that predispose to angiographic coronary artery disease (CAD), we compared individuals who had this disorder (n=12,393) with those who did not (controls, n=7383). To identify loci that predispose to myocardial infarction, we compared patients who had angiographic CAD and myocardial infarction (n=5783) with those who had angiographic CAD but no myocardial infarction (n=3644). In the comparison of patients with angiographic CAD versus controls, we identified a novel locus, ADAMTS7 (p=4·98×10(-13)). In the comparison of patients with angiographic CAD who had myocardial infarction versus those with angiographic CAD but no myocardial infarction, we identified a novel association at the ABO locus (p=7·62×10(-9)). The ABO association was attributable to the glycotransferase-deficient enzyme that encodes the ABO blood group O phenotype previously proposed to protect against myocardial infarction. Our findings indicate that specific genetic predispositions promote the development of coronary atherosclerosis whereas others lead to myocardial infarction in the presence of coronary atherosclerosis. The relation to specific CAD phenotypes might modify how novel loci are applied in personalised risk assessment and used in the development of novel therapies for CAD. The PennCath and MedStar studies were supported by the Cardiovascular Institute of the University of Pennsylvania, by the MedStar Health Research Institute at Washington Hospital Center and by a research grant from GlaxoSmithKline. The funding and support for the other cohorts contributing to the paper are described in the webappendix. Copyright © 2011 Elsevier Ltd. All rights reserved.

Beam hardening artifact reduction using dual energy computed tomography: implications for myocardial perfusion studies

PubMed Central

Carrascosa, Patricia; Cipriano, Silvina; De Zan, Macarena; Deviggiano, Alejandro; Capunay, Carlos; Cury, Ricardo C.

2015-01-01

Background Myocardial computed tomography perfusion (CTP) using conventional single energy (SE) imaging is influenced by the presence of beam hardening artifacts (BHA), occasionally resembling perfusion defects and commonly observed at the left ventricular posterobasal wall (PB). We therefore sought to explore the ability of dual energy (DE) CTP to attenuate the presence of BHA. Methods Consecutive patients without history of coronary artery disease who were referred for computed tomography coronary angiography (CTCA) due to atypical chest pain and a normal stress-rest SPECT and had absence or mild coronary atherosclerosis constituted the study population. The study group was acquired using DE and the control group using SE imaging. Results Demographical characteristics were similar between groups, as well as the heart rate and the effective radiation dose. Myocardial signal density (SD) levels were evaluated in 280 basal segments among the DE group (140 PB segments for each energy level from 40 to 100 keV; and 140 reference segments), and in 40 basal segments (at the same locations) among the SE group. Among the DE group, myocardial SD levels and myocardial SD ratio evaluated at the reference segment were higher at low energy levels, with significantly lower SD levels at increasing energy levels. Myocardial signal-to-noise ratio was not significantly influenced by the energy level applied, although 70 keV was identified as the energy level with the best overall signal-to-noise ratio. Significant differences were identified between the PB segment and the reference segment among the lower energy levels, whereas at ≥70 keV myocardial SD levels were similar. Compared to DE reconstructions at the best energy level (70 keV), SE acquisitions showed no significant differences overall regarding myocardial SD levels among the reference segments. Conclusions BHA that influence the assessment of myocardial perfusion can be attenuated using DE at 70 keV or higher. PMID:25774354

Early diagnosis of interferon-induced myocardial disorder in patients with chronic hepatitis C: evaluation by myocardial imaging with 123I-BMIPP.

PubMed

Kondo, Y; Yukinaka, M; Nomura, M; Nakaya, Y; Ito, S

2000-01-01

Interferon (IFN) therapy for chronic hepatitis C is sometimes associated with cardiac complications. In the present study, we performed myocardial imaging with 123I-labeled beta-methyl-p-iodophenylpentadecanoic acid (123I-BMIPP) in order to evaluate myocardial disorders caused by IFN. We studied 40 healthy subjects (H group) and 25 patients with chronic hepatitis C who had been treated with IFN (IFN group). A Holter electrocardiogram (ECG) was performed and the autonomic nervous function was assessed by analyzing the spectral variability and 1/f fluctuation of heart rate. Myocardial planner imaging with 123I-BMIPP was performed to obtain the time activity curve for 20min immediately after administration of 123I-BMIPP (dynamic study). Early and delayed myocardial single photon emission computed tomography (SPECT) images were expressed as Bull's eyes and the myocardium was divided into four segments to calculate the washout rate for each segment on early and late SPECT images (early and late SPECT study). No significant differences in autonomic nervous function were observed between the two groups in heart rate variability. In a dynamic study, the reduction rate from the time activity curve was significantly higher in the IFN group compared with the H group (reduction rate, IFN group, 5.3 +/- 3.7% vs H group, 1.2 +/- 3.3%; P < 0.05). In the early and delayed myocardial SPECT study, the washout rate for the IFN group was significantly increased in all myocardial areas compared to that in the H group. However, the metabolic disorder of fatty acids caused by IFN was reversed on the second 123I-BMIPP myocardial scintigraphy examination several months after IFN therapy. These results indicate that metabolic disorders of fatty acids caused by IFN therapy can be detected before abnormalities are observed by Holter-ECG or echocardiography.

New imaging technology: measurement of myocardial perfusion by contrast echocardiography

NASA Technical Reports Server (NTRS)

Rubin, D. N.; Thomas, J. D.

2000-01-01

Myocardial perfusion imaging has long been a goal for the non-invasive echocardiographic assessment of the heart. However, many factors at play in perfusion imaging have made this goal elusive. Harmonic imaging and triggered imaging with newer contrast agents have made myocardial perfusion imaging potentially practical in the very near future. The application of indicator dilution theory to the coronary circulation and bubble contrast agents is fraught with complexities and sources of error. Therefore, quantification of myocardial perfusion by non-invasive echocardiographic imaging requires further investigation in order to make this technique clinically viable.

Hydrogen‑rich solution against myocardial injury and aquaporin expression via the PI3K/Akt signaling pathway during cardiopulmonary bypass in rats.

PubMed

Song, Dandan; Liu, Xuelei; Diao, Yugang; Sun, Yingjie; Gao, Guangjie; Zhang, Tiezheng; Chen, Keyan; Pei, Ling

2018-06-20

Myocardial ischemia, hypoxia and reperfusion injury are induced by aortic occlusion, cardiac arrest and resuscitation during cardiopulmonary bypass (CPB), which can severely affect cardiac function. The aim of the present study was to investigate the effects of hydrogen‑rich solution (HRS) and aquaporin (AQP) on cardiopulmonary bypass (CPB)‑induced myocardial injury, and determine the mechanism of the phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (Akt) signaling pathway. Sprague Dawley rats were divided into a sham operation group, a CPB surgery group and a HRS group. A CPB model was established, and the hemodynamic parameters were determined at the termination of CPB. The myocardial tissues were observed by hematoxylin and eosin, and Masson staining. The levels of myocardial injury markers [adult cardiac troponin I (cTnI), lactate dehydrogenase (LDH), creatine kinase MB (CK‑MB) and brain natriuretic peptide (BNP)], inflammatory factors [interleukin (IL)‑1β, IL‑6 and tumor necrosis factor‑α (TNF‑α)] and oxidative stress indicators [superoxide dismutase (SOD), malondialdehyde (MDA) and myeloperoxidase (MPO)] were determined by ELISA. Furthermore, H9C2 cells were treated with HRS following hypoxia/reoxygenation. Cell viability and cell apoptosis were investigated. The expression of apoptosis regulator Bcl‑2 (Bcl‑2), apoptosis regulator Bax (Bax), caspase 3, AQP‑1, AQP‑4, phosphorylated (p)‑Akt, heme oxygenase 1 (HO‑1) and nuclear factor erythroid 2‑related factor 2 (Nrf2) were investigated using western blotting and quantitative‑polymerase chain reaction of tissues and cells. Following CPB, myocardial cell arrangement was disordered, myocardial injury markers (cTnI, LDH, CK‑MB and BNP), inflammatory cytokines (IL‑1β, IL‑6 and TNF‑α) and MDA levels were significantly increased compared with the sham group; whereas the SOD levels were significantly downregulated following CPB compared with the sham group. HRS attenuated myocardial injury, reduced the expression levels of cTnI, LDH, CK‑MB, BNP, IL‑1β, IL‑6, TNF‑α, MDA and MPO, and increased SOD release. Levels of Bcl‑2, AQP‑1, AQP‑4, p‑Akt, HO‑1 and Nrf2 were significantly increased following HRS; whereas Bax and caspase‑3 expression levels were significantly reduced following CPB. HRS treatment significantly increased the viability of myocardial cells, reduced the rate of myocardial cell apoptosis and the release of MDA and LDH compared with the CPB group. A PI3K inhibitor (LY294002) was revealed to reverse the protective effect of HRS treatment. HRS was demonstrated to attenuate CPB‑induced myocardial injury, suppress AQP‑1 and AQP‑4 expression following CPB treatment and protect myocardial cells via the PI3K/Akt signaling pathway.

Relaxin protects against myocardial injury caused by ischemia and reperfusion in rat heart.

PubMed Central

Bani, D.; Masini, E.; Bello, M. G.; Bigazzi, M.; Sacchi, T. B.

1998-01-01

Myocardial injury caused by ischemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, platelet and mast cell activation, and peroxidation of cell membrane lipids, which are followed by myocardial cell alterations resulting eventually in cell necrosis. The current study was designed to test the possible cardioprotective effect of the hormone relaxin, which has been found to cause coronary vessel dilation and to inhibit platelet and mast cell activation. Ischemia (for 30 minutes) was induced in rat hearts in vivo by ligature of the left anterior descending coronary artery; reperfusion (for 60 minutes or less if the rats died before this predetermined time) was induced by removal of the ligature. Relaxin (100 ng) was given intravenously 30 minutes before ischemia. The results obtained showed that relaxin strongly reduces 1) the extension of the myocardial areas affected by ischemia-reperfusion-induced damage, 2) ventricular arrhythmias, 3) mortality, 4) myocardial neutrophil number, 5) myeloperoxidase activity, a marker of neutrophil accumulation, 6) production of malonyldialdehyde, an end product of lipid peroxidation, 7) mast cell granule release, 8) calcium overload, and 9) morphological signs of myocardial cell injury. This study shows that relaxin can be regarded as an agent with a marked cardioprotective action against ischemia-reperfusion-induced myocardial injury. Images Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:9588905

Diagnosis of myocardial ischemia combining multiphase postmortem CT-angiography, histology, and postmortem biochemistry.

PubMed

Vanhaebost, Jessica; Ducrot, Kewin; de Froidmont, Sébastien; Scarpelli, Maria Pia; Egger, Coraline; Baumann, Pia; Schmit, Gregory; Grabherr, Silke; Palmiere, Cristian

2017-02-01

The aim of this study was to assess whether the identification of pathological myocardial enhancement at multiphase postmortem computed tomography angiography was correlated with increased levels of troponin T and I in postmortem serum from femoral blood as well as morphological findings of myocardial ischemia. We further aimed to investigate whether autopsy cases characterized by increased troponin T and I concentrations as well as morphological findings of myocardial ischemia were also characterized by pathological myocardial enhancement at multiphase postmortem computed tomography angiography. Two different approaches were used. In one, 40 forensic autopsy cases that had pathological enhancement of the myocardium (mean Hounsfield units ≥95) observed at postmortem angiography were retrospectively selected. In the second approach, 40 forensic autopsy cases that had a cause of death attributed to acute myocardial ischemia were retrospectively selected. The preliminary results seem to indicate that the identification of a pathological enhancement of the myocardium at postmortem angiography is associated with the presence of increased levels of cardiac troponins in postmortem serum and morphological findings of ischemia. Analogously, a pathological enhancement of the myocardium at postmortem angiography can be retrospectively found in the great majority of autopsy cases characterized by increased cardiac troponin levels in postmortem serum and morphological findings of myocardial ischemia. Multiphase postmortem computed tomography angiography is a useful tool in the postmortem setting for investigating ischemically damaged myocardium.

Assessment of residual tissue viability by exercise testing in recent myocardial infarction: comparison of the electrocardiogram and myocardial perfusion scintigraphy.

PubMed

Margonato, A; Ballarotto, C; Bonetti, F; Cappelletti, A; Sciammarella, M; Cianflone, D; Chierchia, S L

1992-04-01

The assessment of residual myocardial viability in infarcted areas is relevant for subsequent management and prognosis but requires expensive technology. To evaluate the possibility that simple, easily obtainable clinical markers may detect the presence of within-infarct viable tissue, the significance of exercise-induced ST elevation occurring in leads exploring the area of a recent Q wave myocardial infarction was assessed. Twenty-five patients with recent (less than 6 months) myocardial infarction were studied. All had angiographically documented coronary artery disease, diagnostic Q waves (n = 24) or negative T waves (n = 25) on the rest 12-lead electrocardiogram and exhibited during exercise greater than or equal to 1.5 mm ST segment elevation (n = 17) or isolated T wave pseudonormalization (n = 8) in the infarct-related leads. ST-T wave changes were reproduced in all patients during thallium-201 exercise myocardial scintigraphy. A fixed perfusion defect was observed in 24 of the 25 patients. A reversible defect was seen in 16 (94%) of 17 patients who exhibited transient ST elevation during exercise but in only 4 (50%) of the 8 patients who had only T wave pseudonormalization. In conclusion, in patients with recent myocardial infarction, analysis of simple ST segment variables obtained during exercise testing may allow a first-line discrimination of those who may potentially benefit from a revascularization procedure.

REDUCING TOXICITY AND INCREASING EFFICIENCY: ACONITINE WITH LIQUIRITIN AND GLYCYRRHETINIC ACID REGULATE CALCIUM REGULATORY PROTEINS IN RAT MYOCARDIAL CELL

PubMed Central

Zhang, Yuyan; Yu, Li; Jin, Weifeng; Fan, Hongjing; Li, Min; Zhou, Tianmei; Wan, Haitong; Yang, Jiehong

2017-01-01

Background: Compatibility of Radix Aconiti Carmichaeli and Liquorice is known to treat heart diseases such as heart failure and cardiac arrhythmias. This work answers the question that whether the active components (Aconitine, Liquiritin and Glycyrrhetinic Acid) of Radix Aconiti Carmichaeli and Liquorice could result in regulating intracellular calcium homeostasis and calcium cycling, and thereby verifies the therapeutic material basis. Materials and Methods: The myocardial cells were divided into twelve groups randomly as control group, Aconitine group, nine different dose groups that orthogonal combined with Aconitine, Liquiritin and Glycyrrhetinic Acid, and Verapamil group. The myocardial cellular survival rate and morphology were assessed. The expression of calcium regulation protein(RyR2, NCX1, DHPR-a1) in the myocardial cell by Western-blotting. Results: The results exhibited that Aconitine (120 uM) significantly damaged on myocardial cell, decreased the survival rate and expression of Na+/Ca2+ exchangers (NCX1) and dihydropteridine reducta-α1 (DHPR-a1), and increased the expression of ryanodine receptor type2 (RyR2) obviously. The compatibility groups (Aconitine, Liquiritin and Glycyrrhetinic Acid) all could against the damage on the myocardial cell by Aconitine at different levels. Conclusion: Aconitine with Liquiritin and Glycyrrhetinic Acid may regulate the expression of calcium-regulated proteins to protect myocardial cells from damage. PMID:28638869

Role of CD11b+Gr-1+ myeloid cells in AGEs-induced myocardial injury in a mice model of acute myocardial infarction.

PubMed

Yao, Tongqing; Lu, Wenbin; Zhu, Jian; Jin, Xian; Ma, Genshan; Wang, Yuepeng; Meng, Shu; Zhang, Yachen; Li, Yigang; Shen, Chengxing

2015-01-01

Polymorph neutrophils are the predominant inflammatory cells and play a crucial role on the pathogenesis of myocardial injury at the early stage of acute myocardial infarction (AMI). However, the precursors and the differentiation of neutrophils are not fully understood. Here we explored the role of CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) on myocardial injury in the absence and presence of advanced glycation end-products (AGEs) in a mice model of AMI. Male C57BL/6J mice were selected. Fluorescent actived cell sortor (FACS) data demonstrated significantly increased CD11b+Gr-1+ MDSCs both in peripheral blood circulation and in the ischemic myocardium at 24 hours post AMI. Quantitative-real-time PCR results also revealed significantly upregulated CD11b and Ly6G mRNA expression in the ischemic myocardium. AGEs treatment further aggravated these changes in AMI mice but not in sham mice. Moreover, AGEs treatment also significantly increased infarction size and enhanced cardiomyocyte apoptosis. The mRNA expression of pro-inflammatory cytokine IL-6 and iNOS2 was also significantly increased in AMI + AGEs group compared to AMI group. These data suggest enhanced infiltration of MDSCs by AGEs contributes to aggravated myocardial injury in AMI mice, which might be one of the mechanisms responsible for severer myocardial injury in AMI patients complicating diabetes.

Systemic pretreatment with dimethyloxalylglycine increases myocardial HIF-1α and VEGF production and improves functional recovery after acute ischemia/reperfusion.

PubMed

Poynter, Jeffrey A; Manukyan, Mariuxi C; Wang, Yue; Brewster, Benjamin D; Herrmann, Jeremy L; Weil, Brent R; Abarbanell, Aaron M; Meldrum, Daniel R

2011-08-01

Stem cells protect the heart from ischemic damage in part by the release of cytoprotective growth factors, particularly vascular endothelial growth factor (VEGF). Production of VEGF is regulated in part by levels of the transcription factor hypoxia inducible factor 1-α (HIF-1α). Dimethyloxalylglycine (DMOG) prevents the deactivation of HIF-1α and increases VEGF production. However, the effects of systemic DMOG treatment on myocardial tolerance for ischemia are unknown. We hypothesized that systemic pretreatment with DMOG would improve myocardial ischemic tolerance. To study this hypothesis, adult male rats were randomly given an intraperitoneal injection of DMOG (40 mg/kg in 1 mL saline, n = 5) or saline (1 mL, n = 6) 24 h before cardiectomy and isolated heart perfusion. All hearts were subjected to 15 min equilibration, 25 min ischemia and 40 min reperfusion. Myocardial function was continuously monitored. Following reperfusion, myocardial homogenates were analyzed for HIF-1α and VEGF production. We observed that hearts in the DMOG group exhibited greater recovery of left ventricular developed pressure LVDP, +dP/dt and -dP/dt. Myocardial HIF-1α and VEGF levels were increased by DMOG therapy. In conclusion, systemic pretreatment with DMOG augments post-ischemic myocardial functional recovery through increased HIF-1α levels and greater VEGF production. Copyright © 2011 Mosby, Inc. All rights reserved.

VO(2peak), myocardial hypertrophy, and myocardial blood flow in endurance-trained men.

PubMed

Laaksonen, Marko S; Heinonen, Ilkka; Luotolahti, Matti; Knuuti, Juhani; Kalliokoski, Kari K

2014-08-01

Endurance training induces cardiovascular and metabolic adaptations, leading to enhanced endurance capacity and exercise performance. Previous human studies have shown contradictory results in functional myocardial vascular adaptations to exercise training, and we hypothesized that this may be related to different degrees of hypertrophy in the trained heart. We studied the interrelationships between peak aerobic power (V˙O2peak), myocardial blood flow (MBF) at rest and during adenosine-induced vasodilation, and parameters of myocardial hypertrophy in endurance-trained (ET, n = 31) and untrained (n = 17) subjects. MBF and myocardial hypertrophy were studied using positron emission tomography and echocardiography, respectively. Both V˙O2peak (P < 0.001) and left ventricular (LV) mass index (P < 0.001) were higher in the ET group. Basal MBF was similar between the groups. MBF during adenosine was significantly lower in the ET group (2.88 ± 1.01 vs 3.64 ± 1.11 mL·g·min, P < 0.05) but not when the difference in LV mass was taken into account. V˙O2peak correlated negatively with adenosine-stimulated MBF, but when LV mass was taken into account as a partial correlate, this correlation disappeared. The present results show that increased LV mass in ET subjects explains the reduced hyperemic myocardial perfusion in this subject population and suggests that excessive LV hypertrophy has negative effect on cardiac blood flow capacity.

[Effect and mechanism of icariin on myocardial ischemia-reperfusion injury model in diabetes rats].

PubMed

Hu, Yan-wu; Liu, Kai; Yan, Meng-tong

2015-11-01

To study the therapeutic effect and possible mechanism of icariin on myocardial ischemia-reperfusion injury ( MIRI) model in diabetes rats. The model of diabetic rats were induced by Streptozotocin (STZ), then the model of MIRI was established by ligating the reversible left anterior descending coronary artery for 30 min, and then reperfusing for 120 min. totally 40 male SD were randomly divided into five groups: the control group (NS), the ischemia reperfusion group (NIR), the diabetes control group (MS), the diabetic ischemia reperfusion group (MIR) and the diabetic ischemia reperfusion with icariin group (MIRI). The changes in blood glucose, body weight and living status were observed; the enzyme activity of serum CK-MB, LDH, GSH-Px and myocardium SOD and the content MDA and NO in myocardium were detected; the myocardial pathological changes were observed by HE staining; the myocardial Caspase-3, the Bcl-2, Bax protein expressions were detected by Western blot. The result showed that the diabetes model was successfully replicated; myocardial ischemia-reperfusion injury was more serious in diabetes rats; icariin can increase NO, SOD, GSH-Px, Bcl-2 protein expression, decrease MDA formation, CK-MB and LDH activities and Caspase-3 and Bcl-2 protein expressions and myocardial damage. The result suggested that icariin may play a protective role against ischemia reperfusion myocardial injury in diabetes rats by resisting oxidative stress and inhibiting cell apoptosis.

[Effect and mechanism of total flavonoids of bugloss on rats with myocardial ischemia and reperfusion injury].

PubMed

Xu, Xiao-Na; Niu, Zi-Ran; Wang, Shou-Bao; Chen, Yu-Cai; Gao, Li; Fang, Lian-Hu; Du, Guan-Hua

2014-06-01

This study is to investigate the effect of total flavonoids of Uygur medicine bugloss (BTF) on rats with myocardial ischemia/reperfusion injury, and to explore the mechanisms by which it acts. Left anterior descending (LAD) coronary artery in rats was occluded for 30 min followed by 4 h reperfusion. Meanwhile, BTF dissolved in saline was administered intraperitoneally at dosage of 10, 30 and 50 mg x kg(-1). Electrocardiograph, infarction index, serum myocardial enzymes and heart function were determined to evaluate the effect of BTF. Some other observations were carried out to explore whether inhibiting inflammation and apoptosis is involved in the mechanisms underlying BTF. Our results showed that in ischemia/reperfusion injured rats BTF could dose-dependently reduce myocardial infarction index and myocardial enzyme leakage, and enhance heart function, indicating that it possesses significant cardio protection. ELISA analysis showed that BTF could decrease the content of myocardial inflammatory cytokines such as IL-1beta, IL-6 and TNF-alpha. Western-blotting confirmed that BTF could increase the expression of anti-apoptotic protein Bcl-2 and reduce the expression of proapoptosis protein Bax. Further more, the phosphorylation level of PI3K and Akt was upregulated by BTF treatment. BTF can protect rat against myocardial ischemia/reperfusion injury. Anti-inflammation and inhibition of apoptosis through upregulating PI3K/Akt signal pathway may contribute to the protective effect of BTF.

Empowering Adult Stem Cells for Myocardial Regeneration V2.0: Success in Small Steps

PubMed Central

Broughton, Kathleen; Sussman, Mark A.

2016-01-01

Much has changed since our survey of the landscape for myocardial regeneration powered by adult stem cells four years ago (Mohsin et al., Empowering adult stem cells for myocardial regeneration. Circ Res. 2011; 109(12):1415–1428) [1]. The intervening years since that first review has witnessed an explosive expansion of studies that advance both understanding and implementation of adult stem cells in promoting myocardial repair. Painstaking research from innumerable laboratories throughout the world is prying open doors that may lead to restoration of myocardial structure and function in the wake of pathologic injury. This global effort has produced deeper mechanistic comprehension coupled with an evolving appreciation for the complexity of myocardial regeneration in the adult context. Undaunted by both known and (as yet) unknown challenges, pursuit of myocardial regenerative medicine mediated by adult stem cell therapy has gathered momentum fueled by tantalizing clues and visionary goals. This concise review takes a somewhat different perspective than our initial treatise, taking stock of the business sector that has become an integral part of the field while concurrently updating “state of affairs” in cutting edge research. Looking retrospectively at advancement over the years as all reviews eventually must, the fundamental lesson to be learned is best explained by Jonatan Mårtensson: “Success will never be a big step in the future. Success is a small step taken just now.” PMID:26941423

Experimental myocardial infarction

PubMed Central

Kumar, Raj; Joison, Julio; Gilmour, David P.; Molokhia, Farouk A.; Pegg, C. A. S.; Hood, William B.

1971-01-01

The hemodynamic effects of tachycardia induced by atrial pacing were investigated in left ventricular failure of acute and healing experimental myocardial infarction in 20 intact, conscious dogs. Myocardial infarction was produced by gradual inflation of a balloon cuff device implanted around the left anterior descending coronary artery 10-15 days prior to the study. 1 hr after acute myocardial infarction, atrial pacing at a rate of 180 beats/min decreased left ventricular end-diastolic pressure from 19 to 8 mm Hg and left atrial pressure from 17 to 12 mm Hg, without change in cardiac output. In the healing phase of myocardial infarction 1 wk later, atrial pacing decreased left ventricular end-diastolic pressure from 17 to 9 mm Hg and increased the cardiac output by 37%. This was accompanied by evidence of peripheral vasodilation. In two dogs with healing anterior wall myocardial infarction, left ventricular failure was enhanced by partial occlusion of the circumflex coronary artery. Both the dogs developed pulmonary edema. Pacing improved left ventricular performance and relieved pulmonary edema in both animals. In six animals propranolol was given after acute infarction, and left ventricular function deteriorated further. However the pacing-induced augmentation of cardiac function was unaltered and, hence, is not mediated by sympathetics. The results show that the spontaneous heart rate in left ventricular failure of experimental canine myocardial infarction may be less than optimal and that maximal cardiac function may be achieved at higher heart rates. Images PMID:4395910

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

PubMed

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.

Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia

PubMed Central

McCommis, Kyle S.; Goldstein, Thomas A.; Abendschein, Dana R.; Misselwitz, Bernd; Pilgram, Thomas; Gropler, Robert J.

2010-01-01

Objective To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand. Methods A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and 99mTc-labeled red blood cells were injected to obtain respective gold standards. Results Microsphere-measured MBF and 99mTc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity. Conclusions MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion. PMID:20182731

Educating Jewish and Arab Children for Tolerance and Coexistence in a Situation of Ongoing Conflict: An Encounter Program

ERIC Educational Resources Information Center

Lazovsky, Rivka

2007-01-01

The "Children Teach Children" (CTC) program aimed to educate Jewish and Arab children in Israel for tolerance and coexistence is first described against the general background of coexistence programs in Israel and in other countries. Results of a study that examined the influence of the program implementation in Grade 7 in a pair of…

Critical behavior in the system cyclopentanone + water + secondary butyl alcohol

NASA Astrophysics Data System (ADS)

Krishna, U. Santhi; Unni, P. K. Madhavan

2018-05-01

We report detailed measurements of coexistence surface in the ternary system cylcopentanone + water + secondary butyl alcohol. The coexistence surface is seen to have an unusual tunnel like feature and is a potential system in which special critical points such as the Quadruple Critical Point (QCP) could be studied. Analysis of coexistence curves indicates that the system shows 3D-Ising like critical behavior.

Ethnic Division in Cyprus and a Policy Initiative on Promoting Peaceful Coexistence: Toward an Agonistic Democracy for Citizenship Education

ERIC Educational Resources Information Center

Zembylas, Michalinos

2011-01-01

This article uses as a point of departure for its analysis a recent educational policy initiative to promote peaceful coexistence in the context of ongoing ethnic division in Cyprus. It is argued that, although it seems as if the teaching of peaceful coexistence is a laudable initiative that can contribute toward unity and democratic…

Level of physical activity, well-being, stress and self-rated health in persons with migraine and co-existing tension-type headache and neck pain.

PubMed

Krøll, Lotte Skytte; Hammarlund, Catharina Sjödahl; Westergaard, Maria Lurenda; Nielsen, Trine; Sloth, Louise Bönsdorff; Jensen, Rigmor Højland; Gard, Gunvor

2017-12-01

The prevalence of migraine with co-existing tension-type headache and neck pain is high in the general population. However, there is very little literature on the characteristics of these combined conditions. The aim of this study was to investigate a) the prevalence of migraine with co-existing tension-type headache and neck pain in a clinic-based sample, b) the level of physical activity, psychological well-being, perceived stress and self-rated health in persons with migraine and co-existing tension-type headache and neck pain compared to healthy controls, c) the perceived ability of persons with migraine and co-existing tension-type headache and neck pain to perform physical activity, and d) which among the three conditions (migraine, tension-type headache or neck pain) is rated as the most burdensome condition. The study was conducted at a tertiary referral specialised headache centre where questionnaires on physical activity, psychological well-being, perceived stress and self-rated health were completed by 148 persons with migraine and 100 healthy controls matched by sex and average age. Semi-structured interviews were conducted to assess characteristics of migraine, tension-type headache and neck pain. Out of 148 persons with migraine, 100 (67%) suffered from co-existing tension-type headache and neck pain. Only 11% suffered from migraine only. Persons with migraine and co-existing tension-type headache and neck pain had lower level of physical activity and psychological well-being, higher level of perceived stress and poorer self-rated health compared to healthy controls. They reported reduced ability to perform physical activity owing to migraine (high degree), tension-type headache (moderate degree) and neck pain (low degree). The most burdensome condition was migraine, followed by tension-type headache and neck pain. Migraine with co-existing tension-type headache and neck pain was highly prevalent in a clinic-based sample. Persons with migraine and co-existing tension-type headache and neck pain may require more individually tailored interventions to increase the level of physical activity, and to improve psychological well-being, perceived stress and self-rated health.

An alternative method for neonatal cerebro-myocardial perfusion

PubMed Central

Luciani, Giovanni Battista; De Rita, Fabrizio; Faggian, Giuseppe; Mazzucco, Alessandro

2012-01-01

Several techniques have already been described for selective cerebral perfusion during repair of aortic arch pathology in children. One method combining cerebral with myocardial perfusion has also been proposed. A novel technique is reported here for selective and independent cerebro-myocardial perfusion for neonatal and infant arch surgery. Technical aspects and potential advantages are discussed. PMID:22307393

Effect of high-dose oral multivitamins and minerals in participants not treated with statins in the randomized Trial to Assess Chelation Therapy (TACT).

PubMed

Issa, Omar M; Roberts, Rhonda; Mark, Daniel B; Boineau, Robin; Goertz, Christine; Rosenberg, Yves; Lewis, Eldrin F; Guarneri, Erminia; Drisko, Jeanne; Magaziner, Allan; Lee, Kerry L; Lamas, Gervasio A

2018-01-01

In a prespecified subgroup analysis of participants not on statin therapy at baseline in the TACT, a high-dose complex oral multivitamins and multimineral regimen was found to have a large unexpected benefit compared with placebo. The regimen tested was substantially different from any vitamin regimen tested in prior clinical trials. To explore these results, we performed detailed additional analyses of participants not on statins at enrollment in TACT. TACT was a factorial trial testing chelation treatments and a 28-component high-dose oral multivitamins and multiminerals regimen versus placebo in post-myocardial infarction (MI) patients 50 years or older. There were 460 (27%) of 1,708 TACT participants not taking statins at baseline, 224 (49%) were in the active vitamin group and 236 (51%) were in the placebo group. Patients were enrolled at 134 sites around the United States and Canada. Daily high-dose oral multivitamins and multiminerals (6 tablets, active or placebo). The primary end point of TACT was time to the first occurrence of any component of the composite end point: all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for angina. The primary end point occurred in 137 nonstatin participants (30%), of which 51 (23%) of 224 were in the active group and 86 (36%) of 236 were taking placebo (hazard ratio, 0.62; 95% confidence interval, 0.44-0.87; P=.006). Results in the key TACT secondary end point, a combination of cardiovascular mortality, stroke, or recurrent MI, was consistent in favoring the active vitamin group (hazard ratio, 0.46; 95% confidence interval, 0.28-0.75; P=.002). Multiple end point analyses were consistent with these results. High-dose oral multivitamin and multimineral supplementation seem to decrease combined cardiac events in a stable, post-MI population not taking statin therapy at baseline. These unexpected findings are being retested in the ongoing TACT2. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Nuclear medicine program progress report for quarter ending March 31, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knapp, F.F. Jr.; Ambrose, K.R.; Beets, A.L.

1996-10-01

Biodistribution studies with the radioiodinated 3(R)- and 3(S)-BMIPP isomers in rats have shown that 3(R)-BMIPP has 20-25% higher heart uptake (15-180 min) than 3(S)-BMIPP, while uptake in other tissues examined is similar. To evaluate the possible differences in metabolic fate of the two isomers, a mixture of [I-125]-3(R)/[I-131]- 3(S)-BMIPP was administered to fasted female Fisher rats. Groups (n=3 rats per group) were sacrificed after 15, 60 and 180 min, and urine and feces collected from another group. Samples of blood, heart, liver, lungs, kidney, and urine were Folch-extracted. The distribution of I-125 and I-131 in the organic, aqueous, and pelletmore » samples were determined. Organic samples were then analyzed by thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC). The relative distribution of I-125/I-131 in the lipid, aqueous, and pellet samples was similar for both isomers. Distribution of I-125/I-131 in the various components of the lipid extracts observed by TLC was similar, with principal incorporation into the free fatty acid (FFA) and triglyceride (TG) pools. HPLC analyses (Cl8) of the FFA fraction showed similar I-125/I-131 profiles, corresponding to BMIPP, and the {alpha}-methyl-C,4 (PIPA) and C12, Cl0 and C6 carbon chain-length catabolites. By TLC, urine I-125/I-131 chromatographed with hippuric acid. HPLC analyses (Cl 8) of acid-hydrolyzed urine gave a single I-125/I-131 component with the same RRT as 2-({beta}-iodophenyl)acetic acid, the final {alpha}/{beta}-oxidative BMIPP catabolite. Unexpectedly, HPLC of lipids from base hydrolyzed TG from the heart tissue, showed I-125/I-125 co-chromatographing with short-chain fatty acids, with only levels in BMIPP. These unexpected results demonstrate that the 3(R)-BMIPP and 3(S)-BMIPP isomers are metabolized similarly in rat tissues, and that the higher myocardial extraction observed for the 3(R)-BMIPP may reflect differences in the relative membrane transport of the two isomers.« less