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Sample records for myocardial alterations due

  1. Myocardial failure with altered response to adrenaline in endotoxin shock

    PubMed Central

    Archer, L.T.; Black, M.R.; Hinshaw, L.B.

    1975-01-01

    1 There is a growing concensus that myocardial performance in the early stages of experimental endotoxic and septic shock is relatively normal; however, recent reports have identified an intermediate phase of shock when myocardial dysfunction is clearly apparent. 2 The mechanism of dysfunction has become a subject of intense investigation. A current view is that altered myocardial responsiveness to circulating catecholamines may play an important role in the dysfunction observed after endotoxin administration. The present studies, in which an isolated working heart preparation of the dog was used, were designed to test this hypothesis. This particular experimental preparation was selected to provide an adequate interpretation of results; cardiac output, afterload, and concentrations of adrenaline reaching the coronary vascular bed were controlled in all experiments. Responses to infusions of adrenaline were recorded in the `steady-state' condition. Control (non-shocked) heart responses to adrenaline were highly reproducible in terms of inotropic, chronotropic and coronary vascular behaviour. 3 Results from the study document myocardial dysfunction within 4-6 h following an LD70 endotoxin administration on the basis of increased left ventricular end diastolic pressure (LVEDP), decreased cardiac power and myocardial efficiency, and depressed negative and positive dP/dt parameters. 4 Findings suggest significantly altered responsiveness of the myocardium to infused adrenaline at rates of 1, 2, and 5 μg/min with concentrations between 10 and 1 ng/ml blood. LVEDP was elevated while calculated power and efficiency parameters remained significantly below control values during infusion of adrenaline in endotoxin-treated hearts. Depressions of responsiveness were interpreted to occur on the basis of failure to restore positive and negative dP/dt to normal values and depressed coronary blood flow responses during adrenaline administration. Increases in coronary flow were

  2. Cardiovascular collapse after myocardial infarction due to centipede bite.

    PubMed

    Üreyen, Çağin Mustafa; Arslan, Şakir; Baş, Cem Yunus

    2015-07-01

    Centipede bites have been reported to cause localized and/or systemic symptoms including local pain, erythema and edema, nausea and vomiting, palpitations, headache, lymphadenopathy, and rhabdomyolysis. However, acute myocardial infarction due to centipede envenomation is reported in only three cases in English medical literature.We present a case of 31-year-old male bitten by a golden colored centipede leading to myocardial infarction and cardiopulmonary arrest which is seen very rarely. The patient was admitted to emergency department with a swollen and painful right foot. However, typical chest pain became the major complaint and cardiopulmonary arrest developed while electrocardiography was being obtained. The patient was resuscitated successfully for 5 min and acute infero-posterolateral myocardial infarction was detected on electrocardiography. PMID:25994876

  3. Acute myocardial infarction due to blunt chest trauma.

    PubMed

    Sinha, Ajay Kumar; Agrawal, R K; Singh, Arun; Kumar, Rajiv; Kumar, Sanjeev; Sinha, Ajay; Saurabh; Kumar, Amit

    2002-01-01

    We report a case of blunt chest injury following a road accident leading to damage of the left main and left anterior descending coronary arteries causing acute myocardial infarction in a young person. PMID:12674188

  4. 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. PMID:26824042

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

    PubMed Central

    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. PMID:26824042

  6. Nitrendipine binding in congestive heart failure due to myocardial infarction

    SciTech Connect

    Dixon, I.M.; Lee, S.L.; Dhalla, N.S. )

    1990-03-01

    Depressed cardiac pump function is the hallmark of congestive heart failure, and it is suspected that decreased influx of Ca2+ into the cardiac cell is responsible for depressed contractile function. Since Ca2+ channels in the sarcolemmal membrane are considered to be an important route for the entry of Ca2+, we examined the status of Ca2+ receptors/channels in failing rat hearts after myocardial infarction of the left ventricular free wall. For this purpose, the left coronary artery was ligated and hearts were examined 4, 8, and 16 weeks later; sham-operated animals served as controls. Hemodynamic assessment revealed decreased total mechanical energy (left ventricular systolic pressure x heart rate), increased left ventricular diastolic pressure, and decreased positive and negative dP/dt in experimental animals at 4, 8, and 16 weeks. Although accumulation of ascites in the abdominal cavity was evident at 4 weeks, other clinical signs of congestive heart failure in experimental rats were evident from the presence of lung congestion and cardiac dilatation at 8 and 16 weeks after induction of myocardial infarction. The density of Ca2+ receptors/channels in crude membranes, as assessed by (3H)nitrendipine binding assay, was found to be decreased in the uninfarcted experimental left ventricle at 8 and 16 weeks; however, no change in the affinity of nitrendipine was evident. A similar depression in the specific binding of another dihydropyridine compound, (3H)PN200-110, was also evident in failing hearts. Brain and skeletal muscle crude membrane preparations, unlike those of the right ventricle and liver, revealed a decrease in Ca2+ receptors/channels density in experimental animals at 16 weeks.

  7. Acute myocardial infarction due to left main compression aortic dissection treated by direct stenting.

    PubMed

    Cardozo, Carlos; Riadh, Rihani; Mazen, Moukahal

    2004-02-01

    We describe a case of acute myocardial infarction (AMI) due to compression of the left main coronary artery (LMCA) by a false channel created by an acute aortic dissection (AAD). The dynamic pattern of artery obstruction is detailed as a key element to the diagnosis of extrinsic coronary compression throughout the angiography. Treatment by direct stenting restored complete anterograde coronary flow and improved myocardial perfusion. PMID:14760201

  8. Altered phosphate metabolism in myocardial infarction: P-31 MR spectroscopy

    SciTech Connect

    Bottomley, P.A.; Herfkens, R.J.; Smith, L.S.; Bashore, T.M.

    1987-12-01

    The high-energy myocardial phosphate metabolism of four patients with acute anterior myocardial infarction after coronary angioplasty and drug therapy was evaluated with cardiac-gated phosphorus magnetic resonance (MR) depth-resolved surface coil spectroscopy (DRESS) 5-9 days after the onset of symptoms. Significant reductions (about threefold) in the phosphocreatine (PCr) to inorganic phosphate (Pi) ratio and elevations in the Pi to adenosine triphosphate (ATP) ratio were observed in endocardially or transmurally derived MR spectra when compared with values from epicardially displaced spectra and values from seven healthy volunteers (P less than .05). High-energy phosphate metabolites and Pi ratios did not vary significantly during the cardiac cycle in healthy volunteers. However, contamination of Pi resonances by phosphomonoester components, including blood 2,3-diphosphoglycerate, precluded accurate spectral quantification of Pi and pH. The results indicate that localized P-31 MR spectroscopy may be used to directly assess cellular energy reserve in clinical myocardial infarction and to evaluate metabolic response to interventions.

  9. Altered filtrability of white blood cells after myocardial infarction.

    PubMed

    Bogár, L; Mikita, J; Nash, G B; Smith, M J; Dormandy, J A; Tekeres, M

    1989-01-01

    Abnormal white blood cell rheological behaviour has been implicated as a cause of blood flow disturbances under conditions of ischaemia and reduced perfusion pressure. Accordingly, we have tested the mechanical properties of white cells following myocardial infarction by measuring the rate at which suspension of these cells cause plugging of Nuclepore filters. The number of clogging particles in a standard white cell suspension increased by the third day after infarction but subsequently decreased to the control levels. Since white cells can cause blockage of narrow blood vessels, it is assumed that such changes in cellular properties may influence the eventual extent of infarction. PMID:2812961

  10. Altered Gene Expression Pattern in Peripheral Blood Mononuclear Cells in Patients with Acute Myocardial Infarction

    PubMed Central

    Kiliszek, Marek; Burzynska, Beata; Michalak, Marcin; Gora, Monika; Winkler, Aleksandra; Maciejak, Agata; Leszczynska, Agata; Gajda, Ewa; Kochanowski, Janusz; Opolski, Grzegorz

    2012-01-01

    Background Despite a substantial progress in diagnosis and therapy, acute myocardial infarction (MI) is a major cause of mortality in the general population. A novel insight into the pathophysiology of myocardial infarction obtained by studying gene expression should help to discover novel biomarkers of MI and to suggest novel strategies of therapy. The aim of our study was to establish gene expression patterns in leukocytes from acute myocardial infarction patients. Methods and Results Twenty-eight patients with ST-segment elevation myocardial infarction (STEMI) were included. The blood was collected on the 1st day of myocardial infarction, after 4–6 days, and after 6 months. Control group comprised 14 patients with stable coronary artery disease, without history of myocardial infarction. Gene expression analysis was performed with Affymetrix Human Gene 1.0 ST microarrays and GCS3000 TG system. Lists of genes showing altered expression levels (fold change >1.5, p<0.05) were submitted to Ingenuity Pathway Analysis. Gene lists from each group were examined for canonical pathways and molecular and cellular functions. Comparing acute phase of MI with the same patients after 6 months (stable phase) and with control group we found 24 genes with changed expression. In canonical analysis three pathways were highlighted: signaling of PPAR (peroxisome proliferator-activated receptor), IL-10 and IL-6 (interleukin 10 and 6). Conclusions In the acute phase of STEMI, dozens of genes from several pathways linked with lipid/glucose metabolism, platelet function and atherosclerotic plaque stability show altered expression. Up-regulation of SOCS3 and FAM20 genes in the first days of myocardial infarction is observed in the vast majority of patients. PMID:23185530

  11. Adenylyl cyclase regulation in heart failure due to myocardial infarction in rats.

    PubMed

    Bräunig, Jörg H; Albrecht-Küpper, Barbara; Seifert, Roland

    2014-04-01

    Cardiac adenylyl cyclase (AC) activity was described to be differentially regulated in left and right ventricles (LVs and RVs) of rats with heart failure (HF) due to LV myocardial infarction (MI) (Sethi et al. Am J Physiol 272:H884-H893, 1997). AC activities in LVs and RVs were increased and decreased respectively in rats 8 and 16 weeks post MI under basal and stimulatory conditions including AC activation via β-adrenergic receptors (β-ARs), stimulatory G protein (Gs), and direct AC activation with forskolin (FS). The current study aimed to detect alterations in rat heart AC activities in a comparable model of HF 9 weeks post LV MI. Therefore, cardiac AC activities were measured under basal and β-AR-, Gs-, or FS-stimulated conditions as well as under inhibition with various MANT [2'(3')-O-(N-methylanthraniloyl)]-nucleotide AC inhibitors and the P-site AC inhibitors NKY80 [2-amino-7-(2-furanyl)-7,8-dihydro-5(6H)-quinazolinone] and vidarabine (9-β-D-arabinosyladenine, AraAde). Basal and stimulated AC activities along with AC inhibition experiments did not reveal evidence for changes in AC activity in LVs and RVs from MI group animals despite the presence of congestive HF. However, our study is indeterminate. Further studies are required to identify the factors responsible for previously described changes in cardiac AC activity in MI induced HF and to elucidate the role of altered AC regulation in the pathophysiology of HF. In order to detect small changes in AC regulation, larger group sizes than the ones used in our present study are required. PMID:24276219

  12. Case of angina pectoris at rest and during effort due to coronary spasm and myocardial bridging

    PubMed Central

    Teragawa, Hiroki; Fujii, Yuichi; Ueda, Tomohiro; Murata, Daiki; Nomura, Shuichi

    2015-01-01

    We present a case of a 71-year-old male who had chest symptoms at rest and during effort. He had felt chest oppression during effort for 1 year, and his chest symptoms had recently worsened. One month before admission he felt chest squeezing at rest in the early morning. He presented at our institution to evaluate his chest symptoms. Electrocardiography and echocardiography failed to show any specific changes. Because of the possibility that his chest symptoms were due to myocardial ischemia, he was admitted to our institution for coronary angiography (CAG). An initial CAG showed mild atherosclerotic changes in the proximal segment of the left anterior descending coronary artery (LAD) and mid-segment of the left circumflex coronary artery. Subsequent spasm provocation testing using acetylcholine revealed a bilateral coronary vasospasm, which was relieved after the intracoronary infusion of nitroglycerin. Finally, a CAG showed myocardial bridging (MB) of the mid-distal segments of the LAD. Fractional flow reserve using the intravenous administration of adenosine triphosphate was positive at 0.77, which jumped up to 0.90 through the myocardial bridging segments when the pressure wire was pulled back. Thus, coronary vasospasm and MB might have contributed to his chest symptoms at rest and during effort. Interventional cardiologists should consider the presence of MB as a potential cause of myocardial ischemia. PMID:26131343

  13. Myocardial uptake of thallium and rubidium during alterations in perfusion and oxygenation in isolated rabbit hearts

    SciTech Connect

    Leppo, J.A.

    1987-05-01

    The comparative effects of altered cellular function and coronary perfusion on myocardial /sup 201/Tl and /sup 83/Rb uptake were evaluated in three groups of isolated rabbit hearts having isovolumic contractions. Paired-indication dilution experiments were performed with /sup 201/Tl, /sup 83/Rb, and /sup 111/In-labeled albumin as an intravascular reference marker. In Group A hearts (n = 12), isotope transport was determined during control, hypoxia, and ischemia. In Group B hearts (n = 8), isotope transport was measured at control flow and again at a 50% and 80% reduction. In Group C hearts (n = 8) only /sup 201/Tl uptake was determined at control and following coronary reperfusion. Myocardial /sup 201/Tl and /sup 83/Rb transport were not significantly different and were proportional to flow. Although all interventions caused significant hemodynamic alterations, neither tracer was affected by hypoxia at constant flow. Thallium-201 permeation, however, was transiently decreased immediately after coronary reperfusion. We conclude that myocardial uptake of /sup 201/Tl and /sup 83/Rb are similar and directly related to flow, but do not reflect hypoxia induced cellular dysfunction.

  14. Myocardial Reloading After Extracorporeal Membrane Oxygenation Alters Substrate Metabolism While Promoting Protein Synthesis

    PubMed Central

    Kajimoto, Masaki; O'Kelly Priddy, Colleen M.; Ledee, Dolena R.; Xu, Chun; Isern, Nancy; Olson, Aaron K.; Rosiers, Christine Des; Portman, Michael A.

    2013-01-01

    Background Extracorporeal membrane oxygenation (ECMO) unloads the heart, providing a bridge to recovery in children after myocardial stunning. ECMO also induces stress which can adversely affect the ability to reload or wean the heart from the circuit. Metabolic impairments induced by altered loading and/or stress conditions may impact weaning. However, cardiac substrate and amino acid requirements upon weaning are unknown. We assessed the hypothesis that ventricular reloading with ECMO modulates both substrate entry into the citric acid cycle (CAC) and myocardial protein synthesis. Methods and Results Sixteen immature piglets (7.8 to 15.6 kg) were separated into 2 groups based on ventricular loading status: 8‐hour ECMO (UNLOAD) and postwean from ECMO (RELOAD). We infused into the coronary artery [2‐13C]‐pyruvate as an oxidative substrate and [13C6]‐L‐leucine as an indicator for amino acid oxidation and protein synthesis. Upon RELOAD, each functional parameter, which were decreased substantially by ECMO, recovered to near‐baseline level with the exclusion of minimum dP/dt. Accordingly, myocardial oxygen consumption was also increased, indicating that overall mitochondrial metabolism was reestablished. At the metabolic level, when compared to UNLOAD, RELOAD altered the contribution of various substrates/pathways to tissue pyruvate formation, favoring exogenous pyruvate versus glycolysis, and acetyl‐CoA formation, shifting away from pyruvate decarboxylation to endogenous substrate, presumably fatty acids. Furthermore, there was also a significant increase of tissue concentrations for all CAC intermediates (≈80%), suggesting enhanced anaplerosis, and of fractional protein synthesis rates (>70%). Conclusions RELOAD alters both cytosolic and mitochondrial energy substrate metabolism, while favoring leucine incorporation into protein synthesis rather than oxidation in the CAC. Improved understanding of factors governing these metabolic perturbations may

  15. Mechanical Chest Compressions in Prolonged Cardiac Arrest due to ST Elevation Myocardial Infarction Can Cause Myocardial Contusion.

    PubMed

    Stechovsky, Cyril; Hajek, Petr; Cipro, Simon; Veselka, Josef

    2016-09-01

    Acute coronary syndrome is a common cause of sudden cardiac death. We present a case report of a 60-year-old man without a history of coronary artery disease who presented with ST-elevation myocardial infarction. During transportation to the hospital, he developed ventricular fibrillation (VF) and later pulseless electrical activity. Chest compressions with LUCAS 2 (Medtronic, Minneapolis, MN) automated mechanical compression-decompression device were initiated. Coronary angiography showed total occlusion of the left main coronary artery and primary percutaneous coronary intervention (PCI) was performed. After the PCI, his heart started to generate effective contractions and LUCAS could be discontinued. Return of spontaneous circulation was achieved after 90 minutes of cardiac arrest. The patient died of cardiogenic shock 11 hours later. An autopsy revealed a transmural anterolateral myocardial infarction but also massive subepicardial hemorrhage and interstitial edema and hemorrhages on histologic samples from regions of the myocardium outside the infarction itself and also from the right ventricle. These lesions were concluded to be a myocardial contusion. The true incidence of myocardial contusion as a consequence of mechanical chest compressions is not known. We speculate that severe myocardial contusion might have influenced outcome of our patient. PMID:27574387

  16. Acute myocardial infarction due to vasospasm in a 13-year-old-boy.

    PubMed

    Hosoi, T; Koyama, Y; Tange, S; Sumino, H; Kawai, Y; Kumakura, H; Takayama, Y; Ichikawa, S; Imai, S; Suzuki, T

    1997-06-01

    We describe an unusual case of acute myocardial infarction due to vasospasm in a 13-year-old boy. He was admitted to our hospital with severe congestive heart failure and shock. He had experienced a feeling of chest oppression with dyspnea while running, which grew worse. He then lost consciousness and was brought by ambulance to our intensive care unit. He had had similar but milder episodes of chest oppression months earlier. The family history revealed that his father had died suddenly from hypertrophic cardiomyopathy and that his grandmother also had hypertrophic cardiomyopathy. On admission, the patient was bathed in a cold sweat, his pulse was weak, and his blood pressure was too low to measure. Coarse crackling and wheezing were audible in both lung fields. Administration of catecholamine and intra-aortic balloon pumping failed to stabilize the hemodynamic variables, but percutaneous cardiopulmonary support proved to be lifesaving. Coronary arteriography performed during his convalescence showed on evidence of atherosclerosis. The acetylcholine provocation test ultimately revealed a diagnosis of acute myocardial infarction due to vasospasm. PMID:9225201

  17. Permeability alteration due to mineral dissolution in partially saturated fractures

    NASA Astrophysics Data System (ADS)

    Detwiler, Russell L.

    2010-09-01

    During reactive fluid flow in saturated fractures, the relative rates of dissolved mineral transport and local reactions strongly influence local aperture alterations and the resulting changes in fracture permeability (or transmissivity). In the presence of an entrapped residual nonaqueous phase (e.g., CO2 or oil), the spatial distribution of the entrapped phase will influence flow and transport and thus, local aperture alterations. These aperture alterations will in turn alter the balance of forces acting on immobile regions of the trapped phase. The resulting mobilization of the entrapped phase may subsequently alter flow pathways and fracture transmissivity in a manner that defies quantification with currently used constitutive relationships. I present results from quantitative visualization experiments in which fracture aperture and entrapped phase distribution were directly measured at high spatial resolution (75 × 75 μm) during reactive fluid flow. The experiments differed only in the orientation of the fracture with respect to gravity, which influenced both the initial entrapped phase geometry and the evolution of the entrapped phase as dissolution altered fracture apertures. The presence of the entrapped phase leads to a much earlier formation of distinct dissolution channels than has been observed in saturated fractures. Compared to a similar experiment in a fully saturated fracture, dissolution in the partially saturated fractures leads to as much as a 6-fold increase in transmissivity after an equal amount of dissolution from the fracture surface (doubling of the mean fracture aperture). Furthermore, the relative influence of gravity determines whether trapped bubbles mobilize because of capillary forces (against prevailing viscous forces) or gravitational forces, which is in the direction of prevailing viscous forces for the experiments presented here.

  18. Predictive Factors of Hospital Mortality Due to Myocardial Infarction: A Multilevel Analysis of Iran's National Data

    PubMed Central

    Ahmadi, Ali; Soori, Hamid; Mehrabi, Yadollah; Etemad, Koorosh; Sajjadi, Homeira; Sadeghi, Mehraban

    2015-01-01

    Background: Regarding failure to establish the statistical presuppositions for analysis of the data by conventional approaches, hierarchical structure of the data as well as the effect of higher-level variables, this study was conducted to determine the factors independently associated with hospital mortality due to myocardial infarction (MI) in Iran using a multilevel analysis. Methods: This study was a national, hospital-based, and cross-sectional study. In this study, the data of 20750 new MI patients between April, 2012 and March, 2013 in Iran were used. The hospital mortality due to MI was considered as the dependent variable. The demographic data, clinical and behavioral risk factors at the individual level and environmental data were gathered. Multilevel logistic regression models with Stata software were used to analyze the data. Results: Within 1-year of study, the frequency (%) of hospital mortality within 30 days of admission was derived 2511 (12.1%) patients. The adjusted odds ratio (OR) of mortality with (95% confidence interval [CI]) was derived 2.07 (95% CI: 1.5–2.8) for right bundle branch block, 1.5 (95% CI: 1.3–1.7) for ST-segment elevation MI, 1.3 (95% CI: 1.1–1.4) for female gender, and 1.2 (95% CI: 1.1–1.3) for humidity, all of which were considered as risk factors of mortality. But, OR of mortality was 0.7 for precipitation (95% CI: 0.7–0.8) and 0.5 for angioplasty (95% CI: 0.4–0.6) were considered as protective factors of mortality. Conclusions: Individual risk factors had independent effects on the hospital mortality due to MI. Variables in the province level had no significant effect on the outcome of MI. Increasing access and quality to treatment could reduce the mortality due to MI. PMID:26730342

  19. Acute Myocardial Infarction Due to Spontaneous Dissection of the Right Coronary Artery in a Young Male

    SciTech Connect

    Papadopoulos, Dimitris P. Moyssakis, Ioannis; Perakis, Alexandros; Athanasiou, Andreas; Anagnostopoulou, Sophia; Benos, Ioannis; Votteas, Vassilios E.

    2004-09-15

    Spontaneous coronary artery dissection is a rare cause of acute myocardial infarction. We report a case of a 33-year-old male who presented with an acute inferior myocardial infarction. Coronary arteriography performed 3 hours after the episode revealed a dissection involving the middle segment of right coronary artery. Because of a spiral form of dissection and the TIMI 3 flow grade, our patient was treated medically and repeat coronary angiography 6 months later was decided.

  20. Prenatal methamphetamine differentially alters myocardial sensitivity to ischemic injury in male and female adult hearts.

    PubMed

    Rorabaugh, Boyd R; Seeley, Sarah L; Bui, Albert D; Sprague, Lisanne; D'Souza, Manoranjan S

    2016-02-15

    Methamphetamine is one of the most common illicit drugs abused during pregnancy. The neurological effects of prenatal methamphetamine are well known. However, few studies have investigated the potential effects of prenatal methamphetamine on adult cardiovascular function. Previous work demonstrated that prenatal cocaine exposure increases sensitivity of the adult heart to ischemic injury. Methamphetamine and cocaine have different mechanisms of action, but both drugs exert their effects by increasing dopaminergic and adrenergic receptor stimulation. Thus the goal of this study was to determine whether prenatal methamphetamine also worsens ischemic injury in the adult heart. Pregnant rats were injected with methamphetamine (5 mg·kg(-1)·day(-1)) or saline throughout pregnancy. When pups reached 8 wk of age, their hearts were subjected to ischemia and reperfusion by means of a Langendorff isolated heart system. Prenatal methamphetamine had no significant effect on infarct size, preischemic contractile function, or postischemic recovery of contractile function in male hearts. However, methamphetamine-treated female hearts exhibited significantly larger infarcts and significantly elevated end-diastolic pressure during recovery from ischemia. Methamphetamine significantly reduced protein kinase Cε expression and Akt phosphorylation in female hearts but had no effect on these cardioprotective proteins in male hearts. These data indicate that prenatal methamphetamine differentially affects male and female sensitivity to myocardial ischemic injury and alters cardioprotective signaling proteins in the adult heart. PMID:26683901

  1. Hydrologic property alterations due to elevated temperatures at Yucca Mountain

    SciTech Connect

    Flint, A.L.; Nash, M.H.; Nash, M.S.

    1994-12-31

    Yucca Mountain is currently being evaluated as a potential site for a high level nuclear waste repository. The pre-emplacement hydrologic properties of the rock are important in determining the suitability of the site; however, post emplacement thermal loads and associated drying may permanently alter the character of the rock. A preliminary study was undertaken to determine the effects of elevated temperatures on hydrologic properties of the welded Topopah Spring member of the Paintbrush Tuff and a zeolitic, nonwelded tuff from the Tuffaceous Beds of Calico Hills. Rock outcrop samples were collected and dried in the laboratory at different temperatures (up to 400 degrees C). Hydrologic and physical properties -were tested before and after each of the drying cycles.

  2. Intraventricular flow alterations due to dyssynchronous wall motion

    NASA Astrophysics Data System (ADS)

    Pope, Audrey M.; Lai, Hong Kuan; Samaee, Milad; Santhanakrishnan, Arvind

    2015-11-01

    Roughly 30% of patients with systolic heart failure suffer from left ventricular dyssynchrony (LVD), in which mechanical discoordination of the ventricle walls leads to poor hemodynamics and suboptimal cardiac function. There is currently no clear mechanistic understanding of how abnormalities in septal-lateral (SL) wall motion affects left ventricle (LV) function, which is needed to improve the treatment of LVD using cardiac resynchronization therapy. We use an experimental flow phantom with an LV physical model to study mechanistic effects of SL wall motion delay on LV function. To simulate mechanical LVD, two rigid shafts were coupled to two segments (apical and mid sections) along the septal wall of the LV model. Flow through the LV model was driven using a piston pump, and stepper motors coupled to the above shafts were used to locally perturb the septal wall segments relative to the pump motion. 2D PIV was used to examine the intraventricular flow through the LV physical model. Alterations to SL delay results in a reduction in the kinetic energy (KE) of the flow field compared to synchronous SL motion. The effect of varying SL motion delay from 0% (synchronous) to 100% (out-of-phase) on KE and viscous dissipation will be presented. This research was supported by the Oklahoma Center for Advancement of Science and Technology (HR14-022).

  3. Concentrated Ambient Particles Alter Myocardial Blood Flow during Acute Ischemia in Conscious Canines

    PubMed Central

    Bartoli, Carlo R.; Wellenius, Gregory A.; Coull, Brent A.; Akiyama, Ichiro; Diaz, Edgar A.; Lawrence, Joy; Okabe, Kazunori; Verrier, Richard L.; Godleski, John J.

    2009-01-01

    Background Experimental and observational studies have demonstrated that short-term exposure to ambient particulate matter (PM) exacerbates myocardial ischemia. Objectives We conducted this study to investigate the effects of concentrated ambient particles (CAPs) on myocardial blood flow during myocardial ischemia in chronically instrumented conscious canines. Methods Eleven canines were instrumented with a balloon occluder around the left anterior descending coronary artery and catheters for determination of myocardial blood flow using fluorescent microspheres. Telemetric electrocardiographic and blood pressure monitoring was available for four of these animals. After recovery, we exposed animals by inhalation to 5 hr of either filtered air or CAPs (mean concentration ± SD, 349.0 ± 282.6 μg/m3) in a crossover protocol. We determined myocardial blood flow during a 5-min coronary artery occlusion immediately after each exposure. Data were analyzed using mixed models for repeated measures. The primary analysis was based on four canines that completed the protocol. Results CAPs exposure decreased total myocardial blood flow during coronary artery occlusion by 0.12 mL/min/g (p < 0.001) and was accompanied by a 13% (p < 0.001) increase in coronary vascular resistance. Rate–pressure product, an index of myocardial oxygen demand, did not differ by exposure (p = 0.90). CAPs effects on myocardial blood flow were significantly more pronounced in myocardium within or near the ischemic zone versus more remote myocardium (p interaction < 0.001). Conclusions These results suggest that PM exacerbates myocardial ischemia by increased coronary vascular resistance and decreased myocardial perfusion. Further studies are needed to elucidate the mechanism of these effects. PMID:19337504

  4. Acute myocardial infarction due to left anterior descending coronary artery dissection after blunt chest trauma.

    PubMed

    Oghlakian, Gerard; Maldjian, Pierre; Kaluski, Edo; Saric, Muhamed

    2010-03-01

    Cardiac complications of chest trauma range from arrhythmias to valvular avulsions to myocardial contusion, rupture, and rarely myocardial infarction. We describe a case of a young patient with blunt chest trauma after a motor vehicle accident in whom the diagnosis of myocardial infarction was established a week later because no electrocardiogram or cardiac biomarkers were obtained on presentation. Retrospective review of contrast-enhanced computed tomography (CT) of the chest done on presentation demonstrated a perfusion defect in the distribution of the left anterior descending artery (LAD). Subsequent coronary angiography demonstrated dissection in the proximal LAD. Our case illustrates the importance of electrocardiography and contrast-enhanced chest CT in initial evaluation of patients with blunt chest trauma and suspected injury to the coronary arteries. PMID:19214607

  5. Catecholamines and myocardial contractile function during hypodynamia and with an altered thyroid hormone balance

    NASA Technical Reports Server (NTRS)

    Pruss, G. M.; Kuznetsov, V. I.; Zhilinskaya, A. A.

    1980-01-01

    The dynamics of catecholamine content and myocardial contractile function during hypodynamia were studied in 109 white rats whose motor activity was severely restricted for up to 30 days. During the first five days myocardial catecholamine content, contractile function, and physical load tolerance decreased. Small doses of thyroidin counteracted this tendency. After 15 days, noradrenalin content and other indices approached normal levels and, after 30 days, were the same as control levels, although cardiac functional reserve was decreased. Thyroidin administration after 15 days had no noticeable effect. A detailed table shows changes in 17 indices of myocardial contractile function during hypodynamia.

  6. Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome)

    PubMed Central

    Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Ítalo Bruno dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

    2013-01-01

    Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concentrations were increased. Acute myocardial infarction without ST segment elevation was suspected, and coronary angiography was immediately performed, which showed severe diffuse left ventricular hypokinesia, medial-apical systolic ballooning, and a lack of significant coronary injury. The patient was referred to the intensive care unit and was successfully treated with supportive therapy. As this case shows, Takotsubo syndrome might simulate the clinical manifestations of acute myocardial infarction, and coronary angiography is necessary to distinguish between both myocardial infarction and myocardial infarction in the acute stage. The present patient progressed with spontaneous resolution of the ventricular dysfunction without any sequelae. PMID:23887762

  7. Lingual Haematoma due to Tenecteplase in a Patient with Acute Myocardial Infarction

    PubMed Central

    Bal, Muhlis; Salturk, Ziya; Ateş, Ahmet Hakan; Yağcı, Serkan; Coşkun Bal, Gökçen

    2013-01-01

    The use of intravenous thrombolytic agents has revolutionised the treatment of acute myocardial infarction. However, the improvement in mortality rate achieved with these drugs is tempered by the risk of serious bleeding complications, including intracranial haemorrhage. Tenecteplase is a genetically engineered mutant tissue plasminogen activator. Haemorrhagic complications of tissue plasminogen activator (tPA) are well known. Compared to other tPAs, tenecteplase use leads to lower rates of bleeding complications. Here, we report a case of unusual site of spontaneous bleeding, intralingual haematoma during tenecteplase therapy following acute myocardial infarction, which caused significant upper airway obstruction and required tracheotomy to maintain the patient's airway. Clinical dilemmas related to securing the airway or reversing the effects of tissue plasminogen activator are discussed. PMID:23862086

  8. Targeted Regional Injection of Biocomposite Microspheres Alters Post Myocardial Infarction Remodeling and Matrix Proteolytic Pathways

    PubMed Central

    Dixon, Jennifer A.; Gorman, Robert C.; Stroud, Robert E.; Mukherjee, Rupak; Meyer, Evan C.; Baker, Nathaniel L.; Morita, Masato; Hamamoto, Hirotsugu; Ryan, Liam P.; Gorman, Joseph H.; Spinale, Francis G.

    2011-01-01

    Background While localized delivery of biocomposite materials, such as calcium hydroxyapatite (CHAM), have been demonstrated to potentially attenuate adverse LV remodeling post-myocardial infarction (MI), the underlying biological mechanisms for this effect remain unclear. This study tested the hypothesis that targeted CHAM injections would alter proteolytic pathways (matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs)), and be associated with parameters of post-MI LV remodeling. Methods and Results MI was induced in adult sheep followed by 20 targeted injections of a total volume of 1.3 mL (n=6) or 2.6 mL of CHAM (n=5), or saline (n=13), and LV end-diastolic volume (EDV) and MMP/TIMP profiles in the MI region were measured at 8 weeks post-MI. LV EDV decreased with 2.6 mL CHAM vs MI Only (105.4±7.5 vs 80.6±4.2 respectively, p<0.05) but not with 1.3 mL CHAM (94.5±5.0, p=0.32). However, MI thickness increased by 2-fold in both CHAM groups compared to MI Only (p<0.05). MMP-13 increased 40-fold in the MI Only group (p<0.05) but fell by over 6-fold in both CHAM groups (p<0.05). MMP-7 increased approximately 1.5-fold in the MI Only group (p<0.05) but decreased to referent control values in both CHAM groups in the MI region (p<0.05). Collagen content was reduced by approximately 30% in the CHAM groups compared to MI Only (p<0.05). Conclusions Differential effects on LV remodeling and MMP/TIMP profiles occurred with CHAM. Thus, targeted injections of a biocomposite material can favorably affect the post-MI remodeling process and therefore holds promise as a treatment strategy in and of itself, or as a matrix with potentially synergistic effects with localized pharmacologic or cellular therapies. PMID:21911817

  9. Time dependent alterations of serum matrix metalloproteinase-1 and metalloproteinase-1 tissue inhibitor after successful reperfusion of acute myocardial infarction.

    PubMed Central

    Hirohata, S.; Kusachi, S.; Murakami, M.; Murakami, T.; Sano, I.; Watanabe, T.; Komatsubara, I.; Kondo, J.; Tsuji, T.

    1997-01-01

    OBJECTIVE: To test the hypothesis that changes in serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitors of metalloproteinase-1 (TIMP-1) after acute myocardial infarction reflect extracellular matrix remodelling and the infarct healing process. PATIENTS: 13 consecutive patients with their first acute myocardial infarction who underwent successful reperfusion. METHODS: Blood was sampled on the day of admission, and on days 2, 3, 4, 5, 7, 14, and 28. Serum MMP-1 and TIMP-1 were measured by one step sandwich enzyme immunoassay. Left ventricular volume indices were determined by left ventriculography performed four weeks after the infarct. RESULTS: Serum concentrations of both MMP-1 and TIMP-1 changed over time. The average serum MMP-1 was more than 1 SD below the mean control values during the initial four days, increased thereafter, reaching a peak concentration around day 14, and then returned to the middle control range. Negative correlations with left ventricular end systolic volume index and positive correlations with left ventricular ejection fraction were obtained for serum MMP-1 on day 5, when it began to rise, and for the magnitude of rise in MMP-1 on day 5 compared to admission. Serum TIMP-1 at admission was more than 1 SD below the mean control value, and increased gradually thereafter, reaching a peak on around day 14. Negative correlations with left ventricular end systolic volume index and positive correlations with left ventricular ejection fraction were obtained for serum TIMP-1 on days 5 and 7, and for the magnitude of rise in TIMP-1 on days 5 and 7 compared to admission. CONCLUSIONS: Both MMP-1 and TIMP-1 showed significant time dependent alteration after acute myocardial infarction. Thus MMP-1 and TIMP-1 may provide useful information in evaluating the healing process as it affects left ventricular remodelling after acute myocardial infarction. PMID:9391291

  10. Diabetes-Induced Alterations in the Extracellular Matrix and Their Impact on Myocardial Function

    PubMed Central

    Law, Brittany; Fowlkes, Vennece; Goldsmith, Jack G.; Carver, Wayne; Goldsmith, Edie C.

    2014-01-01

    Diabetes is an increasing public health problem that is expected to escalate in the future due to the growing incidence of obesity in the western world.While this disease is well known for its devastating effects on the kidneys and vascular system, diabetic individuals can develop cardiac dysfunction, termed diabetic cardiomyopathy, in the absence of other cardiovascular risk factors such as hypertension or atherosclerosis. While much effort has gone into understanding the effects of elevated glucose or altered insulin sensitivity on cellular components within the heart, significant changes in the cardiac extracellular matrix (ECM) have also been noted. In this review article we highlight what is currently known regarding the effects diabetes has on both the expression and chemical modification of proteins within the ECM and how the fibrotic response often observed as a consequence of this disease can contribute to reduced cardiac function. PMID:22221857

  11. [Cardiac Angiosarcoma with Acute Myocardial Infarction due to Tumor Embolism;Report of a Case].

    PubMed

    Date, Yusuke; Miyazu, Katsuyuki; Ikeda, Masahiro

    2016-09-01

    We report the case of a 28-year-old man with a rare angiosarcoma complicated by acute myocardial infarction secondary to tumor embolism. He was transported to our emergency unit because of sudden onset of chest pain. The echocardiography showed a 42×60 mm mass in the left ventricle, and the coronary angiography showed embolic occlusion of the proximal left anterior descending and circumflex arteries. Emergent surgical removal of the mass was attempted under cardiopulmonary bypass, concomitant with double coronary artery bypass grafting and mitral valve replacement with a mechanical prosthesis. However, complete tumor excision was impossible. The postoperative pathological examination revealed undifferentiated angiosarcoma. Twenty days after the operation, the patient suffered acute cerebral hemorrhage from a metastatic tumor in the brain. He died at 37 days after the initial cardiac surgery. PMID:27586319

  12. Acute myocardial infarction due to coronary thrombosis caused by blunt chest trauma.

    PubMed

    Treuth, Gregory M; Baibars, Motaz; Alraiyes, Abdul Hamid; Alraies, M Chadi

    2014-01-01

    A 65-year-old man presented to the emergency department following an anterior chest trauma. He had significant chest pain and chest X-ray was significant for revealed multiple rib fractures and negative. CT scan of the chest ruled out pulmonary embolism or aortic dissection. However, few hours later he developed hypotension requiring admission to medical intensive care unit and intravenous vasopressors. Further workup showed ST elevation myocardial infarction involving the anterior ECG leads. Emergent coronary angiography was performed with intervention to the mid-left anterior descending occlusion. Cardiogenic shock resolved and patient was discharged few days later. One-year follow-up with echocardiogram showed stable ischaemic cardiomyopathy with improved left ventricular ejection fraction to 50%. PMID:24769662

  13. Acute Myocardial Infarction in a Young Lady due to Vitamin B12 Deficiency Induced Hyperhomocysteinemia

    PubMed Central

    Shamkani, Warkaa Al; Jafar, Nagham Saeed; Narayanan, Sunil Roy; Rajappan, Anil Kumar

    2015-01-01

    Hyper-homocysteinemia is a risk factor for coronary artery disease in young patients. A 32 years old female without any conventional risk factors except obesity presented with acute anterior wall myocardial infarction (MI). Her echocardiography showed anterior wall hypokinesia with moderate left ventricular dysfunction. Angiography showed tight stenosis of the proximal left anterior descending (LAD) and borderline lesion in left circumflex coronary artery (LCX). She underwent percutaneous coronary intervention (PCI) to LAD with good result. Her blood tests showed low vitamin B12, folate and serum iron levels and elevated serum homocysteine level. She was given folic acid and vitamin B12 and her homocysteine levels normalized. This case demonstrates that hyperhomocysteinemia caused by nutritional deficiency of vitamin co factors may lead to MI. Hyperhomocysteinemia should be considered in the evalauation of young people with MI, especially those without conventional risk factors. PMID:25838876

  14. Myocardial Reloading after Extracorporeal Membrane Oxygenation Alters Substrate Metabolism While Promoting Protein Synthesis

    SciTech Connect

    Kajimoto, Masaki; Priddy, Colleen M.; Ledee, Dolena; Xu, Chun; Isern, Nancy G.; Olson, Aaron; Des Rosiers, Christine; Portman, Michael A.

    2013-08-19

    Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after ECMO remains high.Cardiac substrate and amino acid requirements upon weaning are unknown and may impact recovery. We assessed the hypothesis that ventricular reloading modulates both substrate entry into the citric acid cycle (CAC) and myocardial protein synthesis. Fourteen immature piglets (7.8-15.6 kg) were separated into 2 groups based on ventricular loading status: 8 hour-ECMO (UNLOAD) and post-wean from ECMO (RELOAD). We infused [2-13C]-pyruvate as an oxidative substrate and [13C6]-L-leucine, as a tracer of amino acid oxidation and protein synthesis into the coronary artery. RELOAD showed marked elevations in myocardial oxygen consumption above baseline and UNLOAD. Pyruvate uptake was markedly increased though RELOAD decreased pyruvate contribution to oxidative CAC metabolism.RELOAD also increased absolute concentrations of all CAC intermediates, while maintaining or increasing 13C-molar percent enrichment. RELOAD also significantly increased cardiac fractional protein synthesis rates by >70% over UNLOAD. Conclusions: RELOAD produced high energy metabolic requirement and rebound protein synthesis. Relative pyruvate decarboxylation decreased with RELOAD while promoting anaplerotic pyruvate carboxylation and amino acid incorporation into protein rather than to the CAC for oxidation. These perturbations may serve as therapeutic targets to improve contractile function after ECMO.

  15. 7-oxo-PGI2 induced late protective action from arrhythmias due to local myocardial ischemia.

    PubMed

    Udvary, E; Végh, A; Szekeres, L

    1991-01-01

    In our earlier experiments administration of the stable PGI2 analogue: 7-oxo-PGI2-ephedrine salt to dogs resulted in a late appearing and long-lasting protection from coronary ligation induced ischemia and subsequent postocclusion and reperfusion arrhythmias. Objective of the present study was to evaluate the extent and duration of antiischemic and antiarrhythmic action induced by a single dose 50 micrograms/kg i.m. 7-oxo-PGI2 in dogs subjected to myocardial ischemia evoked by left anterior descending coronary (LAD) ligation at different intervals (2, 6, 24, 48, 72 hours and 2 weeks) after treatment. In the 2 weeks prolonged treatment group treatment started with 50 micrograms/kg i.m. dose, followed every third day by administration of 25 micrograms/kg 7-oxo-PGI2. After anesthesia and thoracotomy the electrophysiological parameters (SCL, CSNRT, AFRP, VFRP and A-V ERP) were determined by means of computer controlled programmed electrical stimulation. Then the animals were subjected to LAD occlusion for 25 min and subsequent reperfusion. 7-oxo-PGI2 pretreatment considerably protected against myocardial ischemia, i.e. there was a marked reduction in ST-segment elevation, the number of ES and the incidence of VF. The maximal antiischemic action and the most striking reduction in ventricular arrhythmias could be observed 48 hours after a single dose of 7-oxo-PGI2 and also after prolonged treatment of two weeks. In this latter group CSNRT showed the most expressed prolongation, however, AFRP and to lesser degree VFRP was also prolonged. PMID:2029655

  16. Alterations in myocardial energy metabolism induced by the anti-cancer drug doxorubicin.

    PubMed

    Tokarska-Schlattner, Malgorzata; Wallimann, Theo; Schlattner, Uwe

    2006-09-01

    Doxorubicin and other anthracyclines are among the most potent chemotherapeutic drugs for the treatment of acute leukaemia, lymphomas and different types of solid tumours such as breast, liver and lung cancers. Their clinical use is, however, limited by the risk of severe cardiotoxicity, which can lead to irreversible congestive heart failure. There is increasing evidence that essential components of myocardial energy metabolism are among the highly sensitive and early targets of doxorubicin-induced damage. Here we review doxorubicin-induced detrimental changes in cardiac energetics, with an emphasis on the emerging importance of defects in energy-transferring and -signalling systems, like creatine kinase and AMP-activated protein kinase. PMID:16945832

  17. The Frequency and Significance of Silent Myocardial Ischemia Due to Hyoscine Butylbromide Use in Peripheral Angiography

    SciTech Connect

    Maher, Richard; Phillips-Hughes, Jane; Banning, Adrian; Boardman, Philip

    1999-09-15

    Purpose: Hyoscine-N-butylbromide (HB) is an anticholinergic drug used in digital subtraction angiography of the aortoiliac region because it decreases bowel gas movement artifact. HB also causes an increase in heart rate. We investigated whether this could cause silent myocardial ischemia (SMI) in susceptible patients during peripheral angiography. Methods: Thirty-six patients undergoing peripheral angiography were randomized into two groups, with 17 patients receiving 20 mg HB intraarterially during the angiogram and 19 patients receiving no drug. All patients were fitted with a Holter monitor that recorded the electrocardiogram before, during, and after the angiogram. Heart rate trends and ST segments were then analyzed. Results: Patients given HB had a statistically significant rise in heart rate compared with the control group. Although the difference was not statistically significant, two (12%) patients receiving HB had procedural ST depression compared with none in the control group. Pre- and postprocedural episodes of ST depression were common, occurring in 41% of patients receiving HB and 37% of patients receiving no drug, and were associated with an increase in heart rate. Conclusion: The infrequent episodes of procedural SMI, potentially caused by the positive chronotropic effects of HB, are probably insignificant when compared with the high frequency of SMI episodes occurring outside the procedure.

  18. Sudden death of a child from myocardial infarction due to arteritis of the left coronary trunk.

    PubMed

    Takahashi, Shirushi; Takada, Aya; Saito, Kazuyuki; Hara, Masaaki; Yoneyama, Katsumi; Nakanishi, Hiroaki; Takahashi, Kei; Moriya, Takuya; Funayama, Masato

    2015-01-01

    An eight-year-old Japanese boy developed abdominal pain, followed by convulsion and loss of consciousness. He was taken to an emergency room but could not be resuscitated. At autopsy, the left main coronary trunk (LMT) demonstrated an increase in caliber with severe luminal narrowing, and the left anterior descending branch (LAD) subsequent to the LMT showed severe stenosis. Microscopically, the intima of the LMT demonstrated severe fibrosis and infiltration of lymphocytes and histiocytes suggesting vasculitis, and the small lumen was occupied by a fresh thrombus. The LAD showed significant intimal thickening with strong lymphocytic inflammation at the edge of the thickening. The left ventricle showed widespread myocardial infarction in the recovery stage. There were no findings of atherosclerosis, vasculitis or fibrocellular changes in the ascending aorta or intravisceral arteries other than the LMT and the LAD under investigation. The increase in the caliber of the LMT and the limitation of arteritis to the LMT and the subsequent branch suggested Kawasaki disease (KD), but it was atypical that the patient had no clinical history consistent with KD. The present case showed no findings suggesting classical polyarteritis nodosa (cPAN) at the acute or scar stage in the other vessels being investigated, and cPAN in childhood is rare compared to KD. A nonspecific inflammatory reaction (single organ vasculitis, SOV) was also considered as a possible cause, but it is difficult to determine whether the cause of the coronary stenosis in the present case was SOV because the sampling of arteries was insufficient. If forensic pathologists make unusual findings suggesting vasculitis at autopsy, the collection of a sufficient number of vessels of various sizes is warranted. PMID:25239164

  19. Evidence Report: Risk of Crew Adverse Health Event Due to Altered Immune Response

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Sams, Clarence F.

    2013-01-01

    The Risk of Crew Adverse Health Event Due to Altered Immune Response is identified by the National Aeronautics and Space Administration (NASA) Human Research Program (HRP) as a recognized risk to human health and performance in space. The HRP Program Requirements Document (PRD) defines these risks. This Evidence Report provides a summary of the evidence that has been used to identify and characterize this risk. It is known that human immune function is altered in- and post-flight, but it is unclear at present if such alterations lead to increased susceptibility to disease. Reactivation of latent viruses has been documented in crewmembers, although this reactivation has not been directly correlated with immune changes or with observed diseases. As described in this report, further research is required to better characterize the relationships between altered immune response and susceptibility to disease during and after spaceflight. This is particularly important for future deep-space exploration missions.

  20. Myocardial MiR-30 downregulation triggered by doxorubicin drives alterations in β-adrenergic signaling and enhances apoptosis.

    PubMed

    Roca-Alonso, L; Castellano, L; Mills, A; Dabrowska, A F; Sikkel, M B; Pellegrino, L; Jacob, J; Frampton, A E; Krell, J; Coombes, R C; Harding, S E; Lyon, A R; Stebbing, J

    2015-01-01

    The use of anthracyclines such as doxorubicin (DOX) has improved outcome in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-associated cardiotoxicity is frequently irreversible and typically progresses to heart failure (HF) but our understanding of molecular mechanisms underlying this and essential for development of cardioprotective strategies remains largely obscure. As microRNAs (miRNAs) have been shown to play potent regulatory roles in both cardiovascular disease and cancer, we investigated miRNA changes in DOX-induced HF and the alteration of cellular processes downstream. Myocardial miRNA profiling was performed after DOX-induced injury, either via acute application to isolated cardiomyocytes or via chronic exposure in vivo, and compared with miRNA profiles from remodeled hearts following myocardial infarction. The miR-30 family was downregulated in all three models. We describe here that miR-30 act regulating the β-adrenergic pathway, where preferential β1- and β2-adrenoceptor (β1AR and β2AR) direct inhibition is combined with Giα-2 targeting for fine-tuning. Importantly, we show that miR-30 also target the pro-apoptotic gene BNIP3L/NIX. In aggregate, we demonstrate that high miR-30 levels are protective against DOX toxicity and correlate this in turn with lower reactive oxygen species generation. In addition, we identify GATA-6 as a mediator of DOX-associated reductions in miR-30 expression. In conclusion, we describe that DOX causes acute and sustained miR-30 downregulation in cardiomyocytes via GATA-6. miR-30 overexpression protects cardiac cells from DOX-induced apoptosis, and its maintenance represents a potential cardioprotective and anti-tumorigenic strategy for anthracyclines. PMID:25950484

  1. Spontaneous alterations in left ventricular regional wall motion after acute myocardial infarction.

    PubMed

    Shen, W F; Cui, L Q; Wang, M H; Gong, L S; Lesbre, J P

    1990-12-01

    For assessing the relationship between the left ventricular (LV) wall motion abnormalities and the status of residual flow to the infarcted region, the extent of coronary artery disease and one-year outcome, 60 patients with a first transmural, Q-wave myocardial infarction (MI) underwent serial echocardiographic examinations. The abnormal wall motion (AWM) score was calculated, and the cardiac events (death, reinfarction, severe ventricular arrhythmia or congestive heart failure) after discharge were recorded. The AWM score of the infarcted area was higher in patients with total occlusion than in those with subtotal occlusion (anterior MI: 14.6 +/- 2.4 vs 7.2 +/- 2.1; inferior MI: 9.7 +/- 2.1 vs 5.1 +/-1.2, all P less than 0.01). Regional wall motion of the noninfarcted area was preserved in patients with single vessel disease but decreased in those with multivessel disease. In patients who developed cardiac events in follow-up period a higher AWM (16.4 +/- 3.7) was found than in those who did not (8.9 +/- 3.1, P less than 0.05). A score of greater than 13 had a strong prediction of cardiac events after acute MI, with a sensitivity of 81%, specificity of 94% and positive predictive accuracy of 88%. PMID:2127245

  2. ALTERATIONS IN THE PERMEABILITY OF NEUROSPORA CRASSA DUE TO POLYENE ANTIBIOTICS

    PubMed Central

    Kinsky, Stephen C.

    1961-01-01

    Kinsky, Stephen C. (Washington University, St. Louis, Mo.). Alterations in the permeability of Neurospora crassa due to polyene antibiotics. J. Bacteriol. 82:889–897. 1961.—Thirty-three antibiotics and synthetic fungicides were examined for their effect on the growth and morphology of Neurospora crassa. Only the polyene antibiotics (nystatin, amphotericin B, and filipin) caused a decrease in the dry weight of mycelial mats, which was accompanied by the appearance of cytoplasmic constituents in the medium. The influence of polyene concentration, incubation time, mycelial age, various metabolic inhibitors, pH, and media composition on this phenomenon are described. The present evidence indicates that the polyenes exert their primarily fungicidal effect by an alteration of permeability, probably due to direct action on the membrane of sensitive organisms. PMID:14456208

  3. Altered myocardial metabolic adaptation to increased fatty acid availability in cardiomyocyte-specific CLOCK mutant mice.

    PubMed

    Peliciari-Garcia, Rodrigo A; Goel, Mehak; Aristorenas, Jonathan A; Shah, Krishna; He, Lan; Yang, Qinglin; Shalev, Anath; Bailey, Shannon M; Prabhu, Sumanth D; Chatham, John C; Gamble, Karen L; Young, Martin E

    2016-10-01

    A mismatch between fatty acid availability and utilization leads to cellular/organ dysfunction during cardiometabolic disease states (e.g., obesity, diabetes mellitus). This can precipitate cardiac dysfunction. The heart adapts to increased fatty acid availability at transcriptional, translational, post-translational and metabolic levels, thereby attenuating cardiomyopathy development. We have previously reported that the cardiomyocyte circadian clock regulates transcriptional responsiveness of the heart to acute increases in fatty acid availability (e.g., short-term fasting). The purpose of the present study was to investigate whether the cardiomyocyte circadian clock plays a role in adaptation of the heart to chronic elevations in fatty acid availability. Fatty acid availability was increased in cardiomyocyte-specific CLOCK mutant (CCM) and wild-type (WT) littermate mice for 9weeks in time-of-day-independent (streptozotocin (STZ) induced diabetes) and dependent (high fat diet meal feeding) manners. Indices of myocardial metabolic adaptation (e.g., substrate reliance perturbations) to STZ-induced diabetes and high fat meal feeding were found to be dependent on genotype. Various transcriptional and post-translational mechanisms were investigated, revealing that Cte1 mRNA induction in the heart during STZ-induced diabetes is attenuated in CCM hearts. At the functional level, time-of-day-dependent high fat meal feeding tended to influence cardiac function to a greater extent in WT versus CCM mice. Collectively, these data suggest that CLOCK (a circadian clock component) is important for metabolic adaption of the heart to prolonged elevations in fatty acid availability. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26721420

  4. Comprehensive analysis of myocardial infarction due to left circumflex artery occlusion: comparison with infarction due to right coronary artery and left anterior descending artery occlusion

    SciTech Connect

    Huey, B.L.; Beller, G.A.; Kaiser, D.L.; Gibson, R.S.

    1988-11-01

    Forty consecutive patients with creatine kinase-MB confirmed myocardial infarction due to circumflex artery occlusion (Group 1) were prospectively evaluated and compared with 107 patients with infarction due to right coronary artery occlusion (Group 2) and 94 with left anterior descending artery occlusion (Group 3). All 241 patients underwent exercise thallium-201 scintigraphy, radionuclide ventriculography, 24 h Holter electrocardiographic (ECG) monitoring and coronary arteriography before hospital discharge and were followed up for 39 +/- 18 months. There were no significant differences among the three infarct groups in age, gender, number of risk factors, prevalence and type of prior infarction, Norris index, Killip class and frequency of in-hospital complications. Acute ST segment elevation was present in only 48% of patients in Group 1 versus 71 and 72% in Groups 2 and 3, respectively (p = 0.012), and 38% of patients with a circumflex artery-related infarct had no significant ST changes (that is, elevation or depression) on admission (versus 21 and 20% for patients in Groups 2 and 3, respectively) (p = 0.001). Abnormal R waves in lead V1 were more common in Group 1 than in Group 2 (p less than 0.003) as was ST elevation in leads I, aVL and V4 to V6 (p less than or equal to 0.048). These differences in ECG findings between Group 1 and 2 patients correlated with a significantly higher prevalence of posterior and lateral wall asynergy in the group with a circumflex artery-related infarct. Infarct size based on peak creatine kinase levels and multiple radionuclide variables was intermediate in Group 1 compared with that in Group 2 (smallest) and Group 3 (largest). During long-term follow-up, the probability of recurrent cardiac events was similar in the three infarct groups.

  5. Image reconstruction in higher dimensions: myocardial perfusion imaging of tracer dynamics with cardiac motion due to deformation and respiration

    DOE PAGESBeta

    Shrestha, Uttam M.; Seo, Youngho; Botvinick, Elias H.; Gullberg, Grant T.

    2015-10-09

    Myocardial perfusion imaging (MPI) using slow rotating large field of view cameras requires spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration. In vivo, MPI contains additional degrees of freedom involving unavoidable motion of the heart due to quasiperiodic beating and the effects of respiration, which can severely degrade the quality of the images. This work develops a technique for a single photon emission computed tomography (SPECT) that reconstructs the distribution of the radiotracer concentration in the myocardium using a tensor product of different sets of basis functions that approximately describe the spatiotemporal variationmore » of the radiotracer concentration and the motion of the heart. In this study the temporal B-spline basis functions are chosen to reflect the dynamics of the radiotracer, while the intrinsic deformation and the extrinsic motion of the heart are described by a product of a discrete set of Gaussian basis functions. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it deforms due to cardiac beating, and is displaced due to respiratory motion. We find these results are compared with the conventional 4D-spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. The higher dimensional reconstruction method proposed here improves bias, yet the signal-to-noise ratio (SNR) decreases slightly due to redistribution of the counts over the cardiac-respiratory gates. Additionally, there is a trade-off between the number of gates and the number of projections per gate to achieve high contrast images.« less

  6. Image Reconstruction in Higher Dimensions: Myocardial Perfusion Imaging of Tracer Dynamics with Cardiac Motion Due to Deformation and Respiration

    PubMed Central

    Shrestha, Uttam M.; Seo, Youngho; Botvinick, Elias H.; Gullberg, Grant T.

    2015-01-01

    Myocardial perfusion imaging (MPI) using slow rotating large field of view cameras requires spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration. In vivo, MPI contains additional degrees of freedom involving unavoidable motion of the heart due to quasiperiodic beating and the effects of respiration, which can severely degrade the quality of the images. This work develops a technique for a single photon emission computed tomography (SPECT) that reconstructs the distribution of the radiotracer concentration in the myocardium using a tensor product of different sets of basis functions that approximately describe the spatiotemporal variation of the radiotracer concentration and the motion of the heart. In this study the temporal B-spline basis functions are chosen to reflect the dynamics of the radiotracer, while the intrinsic deformation and the extrinsic motion of the heart are described by a product of a discrete set of Gaussian basis functions. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it deforms due to cardiac beating, and is displaced due to respiratory motion. These results are compared with the conventional 4D-spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. The higher dimensional reconstruction method proposed here improves bias, yet the signal-to-noise ratio (SNR) decreases due to redistribution of the counts over the cardiac-respiratory gates. However, there is a trade-off between the number of gates and the number of projections per gate to achieve high contrast images. PMID:26450115

  7. Image reconstruction in higher dimensions: myocardial perfusion imaging of tracer dynamics with cardiac motion due to deformation and respiration

    SciTech Connect

    Shrestha, Uttam M.; Seo, Youngho; Botvinick, Elias H.; Gullberg, Grant T.

    2015-10-09

    Myocardial perfusion imaging (MPI) using slow rotating large field of view cameras requires spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration. In vivo, MPI contains additional degrees of freedom involving unavoidable motion of the heart due to quasiperiodic beating and the effects of respiration, which can severely degrade the quality of the images. This work develops a technique for a single photon emission computed tomography (SPECT) that reconstructs the distribution of the radiotracer concentration in the myocardium using a tensor product of different sets of basis functions that approximately describe the spatiotemporal variation of the radiotracer concentration and the motion of the heart. In this study the temporal B-spline basis functions are chosen to reflect the dynamics of the radiotracer, while the intrinsic deformation and the extrinsic motion of the heart are described by a product of a discrete set of Gaussian basis functions. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it deforms due to cardiac beating, and is displaced due to respiratory motion. We find these results are compared with the conventional 4D-spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. The higher dimensional reconstruction method proposed here improves bias, yet the signal-to-noise ratio (SNR) decreases slightly due to redistribution of the counts over the cardiac-respiratory gates. Additionally, there is a trade-off between the number of gates and the number of projections per gate to achieve high contrast images.

  8. Image reconstruction in higher dimensions: myocardial perfusion imaging of tracer dynamics with cardiac motion due to deformation and respiration

    NASA Astrophysics Data System (ADS)

    Shrestha, Uttam M.; Seo, Youngho; Botvinick, Elias H.; Gullberg, Grant T.

    2015-11-01

    Myocardial perfusion imaging (MPI) using slow rotating large field of view cameras requires spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration. In vivo, MPI contains additional degrees of freedom involving unavoidable motion of the heart due to quasiperiodic beating and the effects of respiration, which can severely degrade the quality of the images. This work develops a technique for a single photon emission computed tomography (SPECT) that reconstructs the distribution of the radiotracer concentration in the myocardium using a tensor product of different sets of basis functions that approximately describe the spatiotemporal variation of the radiotracer concentration and the motion of the heart. In this study the temporal B-spline basis functions are chosen to reflect the dynamics of the radiotracer, while the intrinsic deformation and the extrinsic motion of the heart are described by a product of a discrete set of Gaussian basis functions. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it deforms due to cardiac beating, and is displaced due to respiratory motion. These results are compared with the conventional 4D-spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. The higher dimensional reconstruction method proposed here improves bias, yet the signal-to-noise ratio (SNR) decreases slightly due to redistribution of the counts over the cardiac-respiratory gates. Additionally, there is a trade-off between the number of gates and the number of projections per gate to achieve high contrast images.

  9. Image reconstruction in higher dimensions: myocardial perfusion imaging of tracer dynamics with cardiac motion due to deformation and respiration.

    PubMed

    Shrestha, Uttam M; Seo, Youngho; Botvinick, Elias H; Gullberg, Grant T

    2015-11-01

    Myocardial perfusion imaging (MPI) using slow rotating large field of view cameras requires spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration. In vivo, MPI contains additional degrees of freedom involving unavoidable motion of the heart due to quasiperiodic beating and the effects of respiration, which can severely degrade the quality of the images. This work develops a technique for a single photon emission computed tomography (SPECT) that reconstructs the distribution of the radiotracer concentration in the myocardium using a tensor product of different sets of basis functions that approximately describe the spatiotemporal variation of the radiotracer concentration and the motion of the heart. In this study the temporal B-spline basis functions are chosen to reflect the dynamics of the radiotracer, while the intrinsic deformation and the extrinsic motion of the heart are described by a product of a discrete set of Gaussian basis functions. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it deforms due to cardiac beating, and is displaced due to respiratory motion. These results are compared with the conventional 4D-spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. The higher dimensional reconstruction method proposed here improves bias, yet the signal-to-noise ratio (SNR) decreases slightly due to redistribution of the counts over the cardiac-respiratory gates. Additionally, there is a trade-off between the number of gates and the number of projections per gate to achieve high contrast images. PMID:26450115

  10. Altered oxido-reductive state in the diabetic heart: loss of cardioprotection due to protein disulfide isomerase.

    PubMed

    Toldo, Stefano; Boccellino, Mariarosaria; Rinaldi, Barbara; Seropian, Ignacio M; Mezzaroma, Eleonora; Severino, Anna; Quagliuolo, Lucio; Van Tassell, Benjamin W; Marfella, Raffaele; Paolisso, Giuseppe; Rossi, Francesco; Natarajan, Ramesh; Voelkel, Norbert; Abbate, Antonio; Crea, Filippo; Baldi, Alfonso

    2011-01-01

    Diabetes is associated with an increased risk of heart failure, in part explained by endoplasmic reticulum stress and apoptosis. Protein disulfide isomerase (PDI) prevents stressed cardiomyocytes apoptosis. We hypothesized that diabetes impairs PDI function by an alteration in its oxido-reductive state. Myocardial biopsies harvested from the anterolateral left ventricular wall from diabetic (n = 7) and nondiabetic (n = 8) patients were used to assess PDI expression and cardiomyocyte death. A mouse model of diabetes (streptozotocin injection, 130 mg/mL) was used to study PDI expression and its redox state after ischemia/reperfusion injury induced by 30-min occlusion of the left anterior coronary artery followed by reperfusion. Transthoracic echocardiography was performed to assess cardiac remodeling after 1 wk. Western blot analysis was used to analyze PDI expression, and methoxy-polyethyleneglycol-maleimide was used to assess its redox state. Dehydroascorbate (DHA) administration was used to restore the PDI redox state. Diabetic patients had a greater number of transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells than nondiabetic patients despite a greater myocardial PDI expression suggesting altered PDI function. Diabetic mice had a worse postinfarction remodeling associated with an altered PDI redox state. DHA treatment restored functional PDI redox state and ameliorated post-myocardial infarction remodeling. An increase in PDI levels with a paradoxical decrease of its active form occurs in the diabetic heart after ischemia and may explain the lack of protective effects of PDI in diabetes. Restoration of PDI redox state prevents adverse remodeling. The potential significance of these findings deserves to be validated in a clinical setting. PMID:21637911

  11. Memory deficits due to brain injury: unique PET findings and dream alterations.

    PubMed

    Nishida, Masaki; Nariai, Tadashi; Hiura, Mikio; Ishii, Kenji; Nishikawa, Toru

    2011-01-01

    The authors herein report the case of a young male with memory deficits due to a traumatic head injury, who presented with sleep-related symptoms such as hypersomnia and dream alterations. Although MRI and polysomnography showed no abnormalities, (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and (11)C flumazenil (FMZ)-PET revealed findings consistent with cerebral damage to the affected temporal region. The memory deficit of the patient gradually improved in parallel with the relief of the sleep-related symptoms. FDG-PET showed considerable improvement in glucose metabolism when he had recovered, however, evidence of neural loss remained in the FMZ-PET findings. PMID:22674950

  12. Memory deficits due to brain injury: unique PET findings and dream alterations

    PubMed Central

    Nishida, Masaki; Nariai, Tadashi; Hiura, Mikio; Ishii, Kenji; Nishikawa, Toru

    2011-01-01

    The authors herein report the case of a young male with memory deficits due to a traumatic head injury, who presented with sleep-related symptoms such as hypersomnia and dream alterations. Although MRI and polysomnography showed no abnormalities, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and 11C flumazenil (FMZ)-PET revealed findings consistent with cerebral damage to the affected temporal region. The memory deficit of the patient gradually improved in parallel with the relief of the sleep-related symptoms. FDG-PET showed considerable improvement in glucose metabolism when he had recovered, however, evidence of neural loss remained in the FMZ-PET findings. PMID:22674950

  13. A hypoxic episode during cardiogenesis downregulates the adenosinergic system and alters the myocardial anoxic tolerance.

    PubMed

    Robin, Elodie; Marcillac, Fabrice; Raddatz, Eric

    2015-04-01

    To what extent hypoxia alters the adenosine (ADO) system and impacts on cardiac function during embryogenesis is not known. Ectonucleoside triphosphate diphosphohydrolase (CD39), ecto-5'-nucleotidase (CD73), adenosine kinase (AdK), adenosine deaminase (ADA), equilibrative (ENT1,3,4), and concentrative (CNT3) transporters and ADO receptors A1, A2A, A2B, and A3 constitute the adenosinergic system. During the first 4 days of development chick embryos were exposed in ovo to normoxia followed or not followed by 6 h hypoxia. ADO and glycogen content and mRNA expression of the genes were determined in the atria, ventricle, and outflow tract of the normoxic (N) and hypoxic (H) hearts. Electrocardiogram and ventricular shortening of the N and H hearts were recorded ex vivo throughout anoxia/reoxygenation ± ADO. Under basal conditions, CD39, CD73, ADK, ADA, ENT1,3,4, CNT3, and ADO receptors were differentially expressed in the atria, ventricle, and outflow tract. In H hearts ADO level doubled, glycogen decreased, and mRNA expression of all the investigated genes was downregulated by hypoxia, except for A2A and A3 receptors. The most rapid and marked downregulation was found for ADA in atria. H hearts were arrhythmic and more vulnerable to anoxia-reoxygenation than N hearts. Despite downregulation of the genes, exposure of isolated hearts to ADO 1) preserved glycogen through activation of A1 receptor and Akt-GSK3β-GS pathway, 2) prolonged activity and improved conduction under anoxia, and 3) restored QT interval in H hearts. Thus hypoxia-induced downregulation of the adenosinergic system can be regarded as a coping response, limiting the detrimental accumulation of ADO without interfering with ADO signaling. PMID:25632022

  14. Subdaily Hydrologic Alteration due to Hydropower Operations in the Bio-Bio river in Southern Chile

    NASA Astrophysics Data System (ADS)

    Olivares, M. A.; Fernandez, M.; Benavides, C.; Palma, R.

    2012-12-01

    Hydropower plants can inexpensively respond to short-term changes in power demand. This can cause fluctuating operations at a subdaily scale. This work includes an assessment of the degree of subdaily hydrologic alteration (SDHA) due to operation two reservoir hydropower plants in the Bio-Bio river in southern Chile. Alternative operational constraints in the form of minimum instream flows (MIFs) and maximum ramping rates (MRRs) were defined and included into an economic dispatch model for hydrothermal scheduling with hourly stages and a weekly horizon. The model minimizes weekly total costs -including thermal production costs, failure costs, and expected future cost of water- over the entire grid (Chile's Central Interconnected System). Subdaily hydrologic alteration was assessed by computing a set of indicators compiled by Zimmerman et al. (2010). These indicators are obtained from hourly time series for 24-hour periods. Assessment of SDHA was based on a comparison of the indicador values obtained for actual recent operations to those obtained for a natural subdaily flow regime derived from hydrologic techniques and flow gage records. Results showed that current operations cause a downstream subdaily flow regime which deviates significatly from its natural counterpart. In other words, hydropower operations cause a significant degree of subdaily hydrologic alteration in the Bio-Bio river. Environmental constraints were imposed to the downstream reservoir operations. MIFs constraints took values between 30% and 60% of historical monthly average flows, whereas MRRs were set to values between 14 m3/s/hour and 68 m3/s/hour. Results indicate that both types of constraints improve the indicators of subdaily hydrologic alteration. However, under MIF constraints alone, improvement is only observed during some seasons in the year. MRR constraints improve the indicators all year round. Additionally, it was observed that the effect of environmental constraints on the

  15. Alterations in the Osteocyte Lacunar-Canalicular Microenvironment due to Estrogen Deficiency

    PubMed Central

    Sharma, Divya; Ciani, Cesare; Ramirez Marin, Paula A.; Levy, Jessica D.; Doty, Stephen B.; Fritton, Susannah P.

    2012-01-01

    While reduced estrogen levels have been shown to increase bone turnover and induce bone loss, there has been little analysis of the effects of diminished estrogen levels on the lacunar-canalicular porosity that houses the osteocytes. Alterations in the osteocyte lacunar-canalicular microenvironment may affect the osteocyte’s ability to sense and translate mechanical signals, possibly contributing to bone degradation during osteoporosis. To investigate whether reduced estrogen levels affect the osteocyte microenvironment, this study used high-resolution microscopy techniques to assess the lacunar-canalicular microstructure in the rat ovariectomy (OVX) model of postmenopausal osteoporosis. Confocal microscopy analyses indicated that OVX rats had a larger effective lacunar-canalicular porosity surrounding osteocytes in both cortical and cancellous bone from the proximal tibial metaphysis, with little change in cortical bone from the diaphysis or cancellous bone from the epiphysis. The increase in the effective lacunar-canalicular porosity in the tibial metaphysis was not due to changes in osteocyte lacunar density, lacunar size, or the number of canaliculi per lacuna. Instead, the effective canalicular size measured using a small molecular weight tracer was larger in OVX rats compared to controls. Further analysis using scanning and transmission electron microscopy demonstrated that the larger effective canalicular size in the estrogen-deficient state was due to nanostructural matrix-mineral level differences like loose collagen surrounding osteocyte canaliculi. These matrix-mineral differences were also found in osteocyte lacunae in OVX, but the small surface changes did not significantly increase the effective lacunar size. The alterations in the lacunar-canalicular surface mineral or matrix environment appear to make OVX bone tissue more permeable to small molecules, potentially altering interstitial fluid flow around osteocytes during mechanical loading. PMID

  16. Myocardial Infarction-Associated Transcript, a Long Noncoding RNA, Is Overexpressed During Dilated Cardiomyopathy Due to Chronic Chagas Disease.

    PubMed

    Frade, Amanda Farage; Laugier, Laurie; Ferreira, Ludmila Rodrigues Pinto; Baron, Monique Andrade; Benvenuti, Luiz Alberto; Teixeira, Priscila Camillo; Navarro, Isabela Cunha; Cabantous, Sandrine; Ferreira, Frederico Moraes; da Silva Cândido, Darlan; Gaiotto, Fabio Antônio; Bacal, Fernando; Pomerantzeff, Pablo; Santos, Ronaldo Honorato Barros; Kalil, Jorge; Cunha-Neto, Edecio; Chevillard, Christophe

    2016-07-01

    Long noncoding RNAs (lncRNAs) modulate gene expression at the epigenetic, transcriptional, and posttranscriptional levels. Dysregulation of the lncRNA known as myocardial infarction-associated transcript (MIAT) has been associated with myocardial infarction. Chagas disease causes a severe inflammatory dilated chronic cardiomyopathy (CCC). We investigated the role of MIAT in CCC. A whole-transcriptome analysis of heart biopsy specimens and formalin-fixed, paraffin-embedded samples revealed that MIAT was overexpressed in patients with CCC, compared with subjects with noninflammatory dilated cardiomyopathy and controls. These results were confirmed in a mouse model. Results suggest that MIAT is a specific biomarker of CCC. PMID:26951817

  17. A protocol design for studying alterations of pharmacokinetic parameters due to pregnancy.

    PubMed

    Philipson, A

    1980-01-01

    A study protocol is described by means of which useful and pertinent information on possible alterations of pharmacokinetic parameters due to pregnancy can be investigated. Whenever any drug is prescribed to a pregnant woman for medical reasons, pharmacokinetic data for that drug can be obtained by determination of drug levels in urine, plasma or serum, or other possible tissues. The same data should later be obtained for an identical dose of the same drug given to the same woman after pregnancy. By comparing pharmacokinetic parameters in the same woman during pregnancy and after--when she serves as her own nonpregnant control--clinically and statistically significant differences may be discovered with a comparatively small patient material. As in each case the drug that is studied is prescribed for medical reasons, this protocol involves no undue risks for the pregnant woman or the fetus. PMID:7445992

  18. Structural alterations of the coronary arterial wall are associated with myocardial flow heterogeneity in type 2 diabetes mellitus

    PubMed Central

    Schindler, Thomas H.; Facta, Alvaro D.; Prior, John O.; Cadenas, Jerson; Zhang, Xiao-Li; Li, Yanjie; Sayre, James; Goldin, Jonathan

    2016-01-01

    Purpose To determine the relationship between carotid intima–media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). Methods In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined with electron beam tomography (EBT). Global and regional MBF was determined in milliliters per gram per minute with 13N-ammonia and positron emission tomography (PET) at rest, during cold pressor testing (CPT), and during adenosine (ADO) stimulation. Results There was neither a relationship between carotid IMT and CAC (r=0.10, p=0.32) nor between carotid IMT and coronary circulatory function in response to CPT and during ADO (r=−0.18, p=0.25 and r=0.10, p=0.54, respectively). In 33 individuals, EBT detected CAC with a mean Agatston-derived calcium score of 44±18. There was a significant difference in regional MBFs between territories with and without CAC at rest and during ADO-stimulated hyperemia (0.69±0.24 vs. 0.74±0.23 and 1.82±0.50 vs. 1.95±0.51 ml/g/min; p≤0.05, respectively) and also during CPT in DM but less pronounced (0.81±0.24 vs. 0.83±0.23 ml/g/min; p=ns). The increase in CAC was paralleled with a progressive regional decrease in resting as well as in CPT- and ADO-related MBFs (r=−0.36, p≤0.014; r=−0.46, p≤0.007; and r=−0.33, p≤0.041, respectively). Conclusions The absence of any correlation between carotid IMT and coronary circulatory function in type 2 DM suggests different features and stages of early atherosclerosis in the peripheral and coronary circulation. PET-measured MBF heterogeneity at rest and during vasomotor stress may reflect downstream fluid dynamic effects of coronary artery disease (CAD)-related early structural alterations of the arterial wall. PMID:18704406

  19. ST Segment Elevation Myocardial Infarction Due to Severe Ostial Left Main Stem Stenosis in a Patient with Syphilitic Aortitis.

    PubMed

    Predescu, L M; Zarma, L; Platon, P; Postu, M; Bucsa, A; Croitoru, M; Prodan, B; Chioncel, O; Deleanu, D

    2016-01-01

    Cardiovascular manifestations of tertiary syphilis infections are uncommon, but represent an important cause of mortality and morbidity. Syphilitic aortitis is characterized by aortic regurgitation, dilatation of ascending aorta and ostial coronary artery lesions. We report a case of 36 years old man admitted to our hospital for acute anterior ST segment elevation myocardial infarction complicated with cardiogenic shock (hypotension 75/50 mmHg). Transthoracic echocardiography revealed a dilated left ventricle with severe systolic dysfunction (ejection fraction = 25%), severe mitral regurgitation, moderate aortic regurgitation and mildly dilated ascending aorta. Coronary angiography showed a severe ostial lesion of left main coronary artery which was treated by urgent stent implantation and an intra-aortic contrapulsation balloon was implanted. Blood tests for syphilitic infection were positive. The patient was discharged with treatment including benzathine penicillin. In our case, we present an acute manifestation of a syphilitic ostial left main stenosis treated by primary percutaneous coronary intervention in acute myocardial infarction. Long term follow-up of the patient is crucial as a result of potential rapid in-stent restenosis caused by continuous infection of the ascending aorta. This case is particular because it shows that syphilitic aortitis can be diagnosed in acute settings, like ST segment elevation myocardial infarction. PMID:27141575

  20. Hesperidin blunts streptozotocin-isoproternol induced myocardial toxicity in rats by altering of PPAR-γ receptor.

    PubMed

    Agrawal, Yogeeta O; Sharma, Pankaj Kumar; Shrivastava, Birendra; Arya, Dharamvir Singh; Goyal, Sameer N

    2014-08-01

    Hesperidin has been shown to possess cardioprotective and anti-diabetic potential. Hitherto, its molecular mechanism on isoproterenol (ISO)-induced myocardial dysfunction in diabetes is still not explored. Hence, for the first time we sought to investigate whether hesperidin exerts any beneficial effect on the pathophysiology of myocardial infarction (MI) in diabetes through the PPAR-γ pathway by assessing a variety of indices e.g., apoptosis, hemodynamic, biochemical and histoarchitectural changes. Diabetes was induced by a single dose of STZ (50 mg/kg IP). Diabetic rats received either hesperidin (100 mg/kg/day orally), the PPAR-γ antagonist GW9662 (1 mg/kg/day IP), or both for 14 days with concurrent administration of ISO (85 mg/kg SC) on days 13 and 14. ISO-STZ rats resulted in severe myocardial dysfunction (decreased ±LVdP/dt and increased LVEDP). In addition, augmented myocardial thiobarbituric acid-reactive substances and serum troponin-I with a concomitant decrease in level of glutathione and activities of catalase, superoxide dismutase antioxidants with cardiac injury biomarkers creatine kinase-MB isoenzyme, lactate dehydrogenase were seen. Morphological studies of the ISO-STZ challenged myocardium exhibited severe necrosis, edema and inflammatory changes. In Western blot analysis, Bcl-2 and PPAR-γ expression were decreased where as Bax expression was significantly increased, suggesting role of apoptosis in myocardial dysfunction. Interestingly, hesperidin treatment positively modulated these parameters as validated by improved hemodynamic and left ventricular functions, fortified endogenous anti-oxidant defence system and improved structural integrity of the myocardium. However, significant effects were lowered in animals treated with hesperidin plus GW9662. Moreover, down-regulated PPAR-γ and Bcl-2 expressions in myocardial infarcted diabetic hearts were increased by hesperidin treatment. Hence, for the first time the present study suggests that

  1. Protection against Myocardial Ischemia-Reperfusion Injury at Onset of Type 2 Diabetes in Zucker Diabetic Fatty Rats Is Associated with Altered Glucose Oxidation

    PubMed Central

    Povlsen, Jonas Agerlund; Løfgren, Bo; Dalgas, Christian; Birkler, Rune Isak Dupont; Johannsen, Mogens; Støttrup, Nicolaj Brejnholt; Bøtker, Hans Erik

    2013-01-01

    Background Inhibition of glucose oxidation during initial reperfusion confers protection against ischemia-reperfusion (IR) injury in the heart. Mitochondrial metabolism is altered with progression of type 2 diabetes (T2DM). We hypothesized that the metabolic alterations present at onset of T2DM induce cardioprotection by metabolic shutdown during IR, and that chronic alterations seen in late T2DM cause increased IR injury. Methods Isolated perfused hearts from 6 (prediabetic), 12 (onset of T2DM) and 24 (late T2DM) weeks old male Zucker diabetic fatty rats (ZDF) and their age-matched heterozygote controls were subjected to 40 min ischemia/120 min reperfusion. IR injury was assessed by TTC-staining. Myocardial glucose metabolism was evaluated by glucose tracer kinetics (glucose uptake-, glycolysis- and glucose oxidation rates), myocardial microdialysis (metabolomics) and tissue glycogen measurements. Results T2DM altered the development in sensitivity towards IR injury compared to controls. At late diabetes ZDF hearts suffered increased damage, while injury was decreased at onset of T2DM. Coincident with cardioprotection, oxidation of exogenous glucose was decreased during the initial and normalized after 5 minutes of reperfusion. Metabolomic analysis of citric acid cycle intermediates demonstrated that cardioprotection was associated with a reversible shutdown of mitochondrial glucose metabolism during ischemia and early reperfusion at onset of but not at late type 2 diabetes. Conclusions The metabolic alterations of type 2 diabetes are associated with protection against IR injury at onset but detrimental effects in late diabetes mellitus consistent with progressive dysfunction of glucose oxidation. These findings may explain the variable efficacy of cardioprotective interventions in individuals with type 2 diabetes. PMID:23704975

  2. Hyperoxia causes oxygen free radical-mediated membrane injury and alters myocardial function and hemodynamics in the newborn.

    PubMed

    Bandali, K S; Belanger, M P; Wittnich, C

    2004-08-01

    Newborn children can be exposed to high oxygen levels (hyperoxia) for hours to days during their medical and/or surgical management, and they also can have poor myocardial function and hemodynamics. Whether hyperoxia alone can compromise myocardial function and hemodynamics in the newborn and whether this is associated with oxygen free radical release that overwhelms naturally occurring antioxidant enzymes leading to myocardial membrane injury was the focus of this study. Yorkshire piglets were anesthetized with pentobarbital sodium (65 mg/kg), intubated, and ventilated to normoxia. Once normal blood gases were confirmed, animals were randomly allocated to either 5 h of normoxia [arterial Po(2) (Pa(O(2))) = 83 +/- 5 mmHg, n = 4] or hyperoxia (Pa(O(2)) = 422 +/- 33 mmHg, n = 6), and myocardial functional and hemodynamic assessments were made hourly. Left ventricular (LV) biopsies were taken for measurements of antioxidant enzyme activities [superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT)] and malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) as an indicator of oxygen free radical-mediated membrane injury. Hyperoxic piglets suffered significant reductions in contractility (P < 0.05), systolic blood pressure (P < 0.03), and mean arterial blood pressure (P < 0.05). Significant increases were seen in heart rate (P < 0.05), whereas a significant 11% (P < 0.05) and 61% (P < 0.001) reduction was seen in LV SOD and GPx activities, respectively, after 5 h of hyperoxia. Finally, MDA and 4-HNE levels were significantly elevated by 45% and 38% (P < 0.001 and P = 0.02), respectively, in piglets exposed to hyperoxia. Thus, in the newborn, hyperoxia triggers oxygen free radical-mediated membrane injury together with an inability of the newborn heart to upregulate its antioxidant enzyme defenses while impairing myocardial function and hemodynamics. PMID:15277198

  3. Prognostic significance of ST-T segment alterations in patients with non-Q wave myocardial infarction.

    PubMed Central

    Ramires, J. A.; Serrano, C. V.; Solimene, M. C.; Moffa, P. J.; Caramelli, B.; Pileggi, F.

    1996-01-01

    OBJECTIVE: To determine whether, among patients with non-Q wave myocardial infarction, the characteristics of the segment ST-T shifts at presentation in the diagnostic electrocardiogram can identify those with more severe coronary artery disease and predict a poor clinical outcome. DESIGN: Prospective controlled clinical trial. SETTING: Primary referral medical centre. PATIENTS: 93 patients (mean (SD) 62.0 (7.5) years) were studied: 41 with non-Q wave myocardial infarction and T wave inversion and 52 with ST segment depression. Cardiac events and mortality rates were assessed over 42 months. Age, sex, risk factors, creatinine kinase MB isoenzyme peak, and left ventricular function were comparable. RESULTS: 31 patients with T wave inversion myocardial infarction (94.6%) had total occlusion of the infarct related artery, compared with 12 patients with ST segment depression myocardial infarction (26.7%) (P < 0.05). When compared with patients with T wave inversion, patients with ST segment depression had a higher incidence of cardiac events during the first month and in the 41 subsequent months: 9.6% and 30.8% v 0% (P < 0.01) and 9.8% (P < 0.02), respectively. For the same observation periods, the mortality rates in patients with T wave inversion were 4.9% and 7.3%, and in patients with ST segment depression they were 5.8% and 9.6%, respectively. CONCLUSION: These data suggest that during a non-Q wave myocardial infarction the presence of ST segment depression is related to higher rates of short and long term cardiac events when compared with T wave inversion--possibly because of a higher incidence of residual stenosis of the infarct related artery. PMID:8697161

  4. Alterations in myocardial perfusion during exercise after isosorbide dinitrate infusion in patients with coronary disease: assessment by thallium-201 scintigraphy

    SciTech Connect

    Tono, I.; Satoh, S.; Kanaya, T.; Komatani, A.; Takahashi, K.; Tsuiki, K.; Yasui, S.

    1986-03-01

    We studied the effect of intravenous isosorbide dinitrate (ISDN) on myocardial perfusion of patients with coronary artery disease, by using exercise thallium-201 (TI-201) myocardial scintigraphy. A control study was conducted initially to assess regional myocardial perfusion rate. Left ventricular myocardium was divided into six parts: anterior, lateral, apical, inferior, posterior, and septal segments. The segmental myocardial perfusion was characterized according to TI-201 initial uptake index (IUI) of relative distribution and redistribution index (RDI) of TI-201 washout. The normal limit of IUI and RDI was established from the data of 17 persons with normal coronary arteries, and then the IUI less than or equal to 84% and the RDI greater than or equal to 1.12 was defined as abnormal. Based on IUI and RDI, each segment was characterized into three types: A type = IUI less than or equal to 84%, RDI greater than or equal to 1.12; B type = IUI less than or equal to 84%, RDI less than 1.12; and C type = IUI greater than 84%, RDI less than 1.12. ISDN was given as a dose of 0.1 mg/kg/hr, and then treadmill testing was repeated for the same duration of exercise time using the same protocol as in the control period. The segments of A type showed a significant improvement in IUI and RDI after receiving ISDN infusion, while the B and C type segments showed no change. It was also shown that the improvement of IUI and RDI of the A type segments was not as marked in multivessel disease as in cases of single-vessel disease.

  5. DETECTING STREAM INVERTEBRATE COMMUNITY ALTERATION DUE TO MID TO LOW LEVELS OF WATERSHED LANDSCAPE MODIFICATION

    EPA Science Inventory

    As part of an investigation into the effects of watershed landscape alteration on stream ecosystems, quantitative invertebrate samples were collected from riffles in 26 second and third order south shore Lake Superior streams. Nonmetric multidimensional scaling (NMDS) ordination ...

  6. Alteration of Dentin-Enamel Mechanical Properties Due to Dental Whitening Treatments

    PubMed Central

    Zimmerman, B.; Datko, L.; Cupelli, M.; Alapati, S.; Dean, D.; Kennedy, M.

    2010-01-01

    The mechanical properties of dentin and enamel affect the reliability and wear properties of a tooth. This study investigated the influence of clinical dental treatments and procedures, such as whitening treatments or etching prior to restorative procedures. Both autoclaved and non-autoclaved teeth were studied in order to allow for both comparison with published values and improved clinical relevance. Nanoindentation analysis with the Oliver-Pharr model provided elastic modulus and hardness across the dentin-enamel junction (DEJ). Large increases were observed in the elastic modulus of enamel in teeth that had been autoclaved (52.0GPa versus 113.4GPa), while smaller increases were observed in the dentin (17.9GPa versus 27.9GPa). Likewise, there was an increase in the hardness of enamel (2.0GPa versus 4.3GPa) and dentin (0.5GPa versus 0.7GPa) with autoclaving. These changes suggested that the range of elastic modulus and hardness values previously reported in literature may be partially due to the sterilization procedures. Treatment of the exterior of non-autoclaved teeth with Crest Whitestrips™, Opalescence™ or UltraEtch™ caused changes in the mechanical properties of both the enamel and dentin. Those treated with Crest Whitestrips™ showed a reduction in the elastic modulus of enamel (55.3GPa to 32.7GPa) and increase in the elastic modulus of dentin (17.2GPa to 24.3GPa). Opalescence™ treatments did not significantly affect the enamel properties, but did result in a decrease in modulus of dentin (18.5GPa to 15.1GPa). Additionally, as expected, UltraEtch™ treatment decreased the modulus and hardness of enamel (48.7GPa to 38.0GPa and 1.9GPa to 1.5GPa, respectively) and dentin (21.4GPa to 15.0GPa and 1.9GPa to 1.5GPa, respectively). Changes in the mechanical properties were linked to altered protein concentration within the tooth, as evidenced by fluorescence microscopy and Fourier transform infrared spectroscopy. PMID:20346902

  7. Are Amygdalar Volume Alterations in Children with Tourette Syndrome Due to ADHD Comorbidity?

    ERIC Educational Resources Information Center

    Ludolph, Andrea G.; Pinkhardt, Elmar H.; van Elst, Ludger Tebartz; Libal, Gerhard; Ludolph, Albert C.; Fegert, Jorg M.; Kassubek, Jan

    2008-01-01

    Recent studies have shown that changes in the basal ganglia circuitry and limbic loops may play an important role both in Tourette syndrome (TS) and attention-deficit-hyperactivity disorder (ADHD). This study aimed to investigate in vivo possible morphological alterations of the amygdala as a key component of the limbic system. Amygdalar and total…

  8. Altered host cell-bacteria interaction due to nanoparticle interaction with a bacterial biofilm.

    PubMed

    Raftery, Tara D; Lindler, Heidi; McNealy, Tamara L

    2013-02-01

    Nanoparticle (NP) use in everyday applications creates the potential for NPs to enter the environment where, in aquatic systems, they are likely to settle on substrates and interact with microbial communities. Legionella pneumophila biofilms are found as part of microbial communities in both natural and man-made environments, especially in man-made cooling systems. The bacterium is the causative agent of Legionnaires' disease. Legionella requires a host cell for replication in the environment, and amoebae commonly serve as this host cell. Our previous work demonstrated significant changes in Legionella biofilm morphology after exposure to 0.7 μg/L gold NPs (AuNPs). Here, we investigate how these morphology changes alter host-bacteria interactions using Acanthamoeba polyphaga as a model. Host-bacteria-NP interactions are affected by NP characteristics. Biofilms exposed to 4- and 18-nm, citrate-capped, spherical AuNPs significantly altered the grazing ability of A. polyphaga, which was not observed in biofilms exposed to 24-nm polystyrene beads. Uptake and replication of NP-exposed planktonic L. pneumophila within A. polyphaga were not altered regardless of NP size or core chemistry. Nanomaterial effects on the interaction of benthic organisms and bacteria may be directly or, as shown here, indirectly dependent on bacterial morphology. NP contamination therefore may alter interactions in a normal ecosystem function. PMID:23052925

  9. Expression of phospholipase D isozymes in scar and viable tissue in congestive heart failure due to myocardial infarction.

    PubMed

    Dent, Melissa R; Singal, Tushi; Dhalla, Naranjan S; Tappia, Paramjit S

    2004-01-01

    The phospholipase D (PLD) associated with the cardiac sarcolemmal (SL) membrane hydrolyses phosphatidylcholine to produce phosphatidic acid, an important phospholipid signaling molecule known to influence cardiac function. The present study was undertaken to examine PLD isozyme mRNA expression, protein contents and activities in congestive heart failure (CHF) subsequent to myocardial infarction (MI). MI was induced in rats by occlusion of the left anterior descending coronary artery. At 8 weeks after the surgical procedure, hemodynamic assessment revealed that these experimental rats were at a moderate stage of CHF. Semi-quantitative reverse transcriptase-polymerase chain reaction revealed that PLD1 and PLD2 mRNA amounts were unchanged in viable left ventricular (LV) tissue of the failing heart. Furthermore, this technique demonstrated the presence of PLD1 and PLD2 mRNA in the scar tissue. While SL PLD1 and PLD2 protein contents were elevated in the viable LV tissue of the failing heart, SL PLD1 activity was significantly decreased, whereas SL PLD2 activity was significantly increased. On the other hand, although PLD1 protein was undetectable, PLD2 protein and activity were detected in the scar tissue. Our findings suggest that differential changes in PLD isozymes may contribute to the pathophysiology of CHF and may also be involved in the processes of scar remodeling. PMID:15601581

  10. New therapeutic approach to heart failure due to myocardial infarction based on targeting growth hormone-releasing hormone receptor

    PubMed Central

    Schally, Andrew V.; Takeuchi, Lauro M.; Popovics, Petra; Jaszberenyi, Miklos; Vidaurre, Irving; Zarandi, Marta; Cai, Ren-Zhi; Block, Norman L.; Hare, Joshua M.; Rick, Ferenc G.

    2015-01-01

    Background We previously showed that growth hormone-releasing hormone (GHRH) agonists are cardioprotective following myocardial infarction (MI). Here, our aim was to evaluate the in vitro and in vivo activities of highly potent new GHRH agonists, and elucidate their mechanisms of action in promoting cardiac repair. Methods and Results H9c2 cells were cultured in serum-free medium, mimicking nutritional deprivation. GHRH agonists decreased calcium influx and significantly improved cell survival. Rats with cardiac infarction were treated with GHRH agonists or placebo for four weeks. MI size was reduced by selected GHRH agonists (JI-38, MR-356, MR-409); this accompanied an increased number of cardiac c-kit+ cells, cellular mitotic divisions, and vascular density. One week post-MI, MR-409 significantly reduced plasma levels of IL-2, IL-6, IL-10 and TNF-α compared to placebo. Gene expression studies revealed favorable outcomes of MR-409 treatment partially result from inhibitory activity on pro-apoptotic molecules and pro-fibrotic systems, and by elevation of bone morphogenetic proteins. Conclusions Treatment with GHRH agonists appears to reduce the inflammatory responses post-MI and may consequently improve mechanisms of healing and cardiac remod eling by regulating pathways involved in fibrosis, apoptosis and cardiac repair. Patients with cardiac dysfunction could benefit from treatment with novel GHRH agonists. PMID:25797248

  11. Moderate ischemic mitral regurgitation after postero-lateral myocardial infarction in sheep alters left ventricular shear but not normal strain in the infarct and infarct borderzone

    PubMed Central

    Ge, Liang; Wu, Yife; Soleimani, Mehrdad; Khazalpour, Michael; Takaba, Kiyoaki; Tartibi, Mehrzad; Zhang, Zhihong; Acevedo-Bolton, Gabriel; Saloner, David A.; Wallace, Arthur W.; Mishra, Rakesh; Grossi, Eugene A.; Guccione, Julius M.; Ratcliffe, Mark B.

    2016-01-01

    Background Chronic ischemic mitral regurgitation (CIMR: MR) is associated with poor outcome. Left ventricular (LV) strain after postero-lateral myocardial infarction (MI) may drive LV remodeling. Although moderate CIMR has been previously shown to effect LV remodeling, the effect of CIMR on LV strain after postero-lateral MI remains unknown. We tested the hypothesis that moderate CIMR alters LV strain after postero-lateral MI. Methods/Results Postero-lateral MI was created in 10 sheep. Cardiac MRI with tags was performed 2 weeks before and 2, 8 and 16 weeks after MI. LV and right ventricular (RV) volumes were measured and regurgitant volume indexed to body surface area (BSA; RegurgVolume Index) calculated as the difference between LV and RV stroke volumes / BSA. Three-dimensional strain was calculated. Circumferential (Ecc)and longitudinal (Ell) strains were reduced in the infarct proper, MI borderzone (BZ) and remote myocardium 16 weeks after MI. In addition, radial circumferential (Erc) and radial longitudinal (Erl) shear strains were reduced in remote myocardium but increased in the infarct and BZ 16 weeks after MI. Of all strain components, however, only Erc was effected by RegurgVolume Index (p=0.0005). There was no statistically significant effect of RegurgVolume Index on Ecc, Ell, Erl, or circumferential longitudinal shear strain (Ecl). Conclusions Moderate CIMR alters radial circumferential shear strain after postero-lateral MI in the sheep. Further studies are needed to determine the effect of shear strain on myocyte hypertrophy and the effect of mitral repair on myocardial strain. PMID:26857634

  12. Cardiac contractile dysfunction during mild coronary flow reductions is due to an altered calcium-pressure relationship in rat hearts.

    PubMed Central

    Figueredo, V M; Brandes, R; Weiner, M W; Massie, B M; Camacho, S A

    1992-01-01

    Coronary artery stenosis or occlusion results in reduced coronary flow and myocardial contractile depression. At severe flow reductions, increased inorganic phosphate (Pi) and intracellular acidosis clearly play a role in contractile depression. However, during milder flow reductions the mechanism(s) underlying contractile depression are less clear. Previous perfused heart studies demonstrated no change of Pi or pH during mild flow reductions, suggesting that changes of intravascular pressure (garden hose effect) may be the mediator of this contractile depression. Others have reported conflicting results regarding another possible mediator of contractility, the cytosolic free calcium (Cai). To examine the respective roles of Cai, Pi, pH, and vascular pressure in regulating contractility during mild flow reductions, Indo-1 calcium fluorescence and 31P magnetic resonance spectroscopy measurements were performed on Langendorff-perfused rat hearts. Cai and diastolic calcium levels did not change during flow reductions to 50% of control. Pi demonstrated a close relationship with developed pressure and significantly increased from 2.5 +/- 0.3 to 4.2 +/- 0.4 mumol/g dry weight during a 25% flow reduction. pH was unchanged until a 50% flow reduction. Increasing vascular pressure to superphysiological levels resulted in further increases of developed pressure, with no change in Cai. These findings are consistent with the hypothesis that during mild coronary flow reductions, contractile depression is mediated by an altered relationship between Cai and pressure, rather than by decreased Cai. Furthermore, increased Pi and decreased intravascular pressure may be responsible for this altered calcium-pressure relationship during mild coronary flow reductions. PMID:1430205

  13. Imaging alterations due to squamous metaplasia in intracranial neurenteric cysts: A report of two cases.

    PubMed

    Watanabe, Nobuyuki; Akasaki, Yasuharu; Fujigasaki, Junko; Mori, Ryosuke; Aizawa, Daisuke; Ikeuchi, Satoshi; Murayama, Yuichi

    2016-06-01

    Intracranial neurenteric cysts are rare congenital abnormalities with a broad imaging spectrum, and therefore are occasionally mistaken for other common intracranial cysts such as epidermoid and arachnoid cysts. We report two cases of neurenteric cysts in the posterior cranial fossa that were initially mistaken for other types of cysts. They exhibited signal intensity alterations in magnetic resonance imaging with significant volume expansion during their long-term observation. Both cases received surgical treatment because of clinical deterioration. Histologically, the cysts were lined by flattened or cuboidal epithelium, occasionally showing squamous metaplasia. Xanthogranulomatous inflammation and accumulation of cholesterol clefts, dry keratin and proteinaceous substance were observed in the cysts. These findings may indicate that chronic inflammation in neurenteric cysts induces squamous metaplasia, keratinization and high proteinaceous content, and causes MRI signal intensity alterations and volume expansion. We propose that MRI signal intensity alterations in neurenteric cysts may be a warning sign of their volume expansions, and thus require closer follow-up imaging and eventually surgical treatment. PMID:27009777

  14. Risk of Crew Adverse Health Event Due to Altered Immune Response

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Kunz, Hawley; Sams, Clarence F.

    2015-01-01

    Determining the effect of space travel on the human immune system has proven to be extremely challenging. Limited opportunities for in-flight studies, varying mission durations, technical and logistical obstacles, small subject numbers, and a broad range of potential assays have contributed to this problem. Additionally, the inherent complexity of the immune system, with its vast array of cell populations, sub-populations, diverse regulatory molecules, and broad interactions with other physiological systems, makes determining precise variables to measure very difficult. There is also the challenge of determining the clinical significance of any observed immune alterations. Will such a change lead to disease, or is it a transient subclinical observation related to short-term stress? The effect of this problem may be observed by scanning publications associated with immunity and spaceflight, which began to appear during the 1970s. Although individually they are each valid studies, the comprehensive literature to date suffers from widely varying sampling methods and assay techniques, low subject counts, and sometimes a disparate focus on narrow aspects of immunity. The most clinically relevant data are derived from in-flight human studies, which have demonstrated altered cell-mediated immunity and reactivation of latent herpes viruses. Much more data are available from post-flight testing of humans, with clear evidence of altered cytokine production patterns, altered leukocyte distribution, continued latent viral reactivation, and evidence of dramatically altered virus-specific immunity. It is unknown if post-flight assessments relate to the in-flight condition or are a response to landing stress and readaptation. In-flight culture of cells has clearly demonstrated that immune cells are gravity-sensitive and display altered functional characteristics. It is unknown if these data are related to in vivo immune cell function or are an artifact of microgravity culture

  15. Alteration of interleaflet coupling due to compounds displaying rapid translocation in lipid membranes

    PubMed Central

    Reigada, Ramon

    2016-01-01

    The spatial coincidence of lipid domains at both layers of the cell membrane is expected to play an important role in many cellular functions. Competition between the surface interleaflet tension and a line hydrophobic mismatch penalty are conjectured to determine the transversal behavior of laterally heterogeneous lipid membranes. Here, by a combination of molecular dynamics simulations, a continuum field theory and kinetic equations, I demonstrate that the presence of small, rapidly translocating molecules residing in the lipid bilayer may alter its transversal behavior by favoring the spatial coincidence of similar lipid phases. PMID:27596355

  16. Alteration of interleaflet coupling due to compounds displaying rapid translocation in lipid membranes.

    PubMed

    Reigada, Ramon

    2016-01-01

    The spatial coincidence of lipid domains at both layers of the cell membrane is expected to play an important role in many cellular functions. Competition between the surface interleaflet tension and a line hydrophobic mismatch penalty are conjectured to determine the transversal behavior of laterally heterogeneous lipid membranes. Here, by a combination of molecular dynamics simulations, a continuum field theory and kinetic equations, I demonstrate that the presence of small, rapidly translocating molecules residing in the lipid bilayer may alter its transversal behavior by favoring the spatial coincidence of similar lipid phases. PMID:27596355

  17. Reciprocal white matter alterations due to 16p11.2 chromosomal deletions versus duplications.

    PubMed

    Chang, Yi Shin; Owen, Julia P; Pojman, Nicholas J; Thieu, Tony; Bukshpun, Polina; Wakahiro, Mari L J; Marco, Elysa J; Berman, Jeffrey I; Spiro, John E; Chung, Wendy K; Buckner, Randy L; Roberts, Timothy P L; Nagarajan, Srikantan S; Sherr, Elliott H; Mukherjee, Pratik

    2016-08-01

    Copy number variants at the 16p11.2 chromosomal locus are associated with several neuropsychiatric disorders, including autism, schizophrenia, bipolar disorder, attention-deficit hyperactivity disorder, and speech and language disorders. A gene dosage dependence has been suggested, with 16p11.2 deletion carriers demonstrating higher body mass index and head circumference, and 16p11.2 duplication carriers demonstrating lower body mass index and head circumference. Here, we use diffusion tensor imaging to elucidate this reciprocal relationship in white matter organization, showing widespread increases of fractional anisotropy throughout the supratentorial white matter in pediatric deletion carriers and, in contrast, extensive decreases of white matter fractional anisotropy in pediatric and adult duplication carriers. We find associations of these white matter alterations with cognitive and behavioral impairments. We further demonstrate the value of imaging metrics for characterizing the copy number variant phenotype by employing linear discriminant analysis to predict the gene dosage status of the study subjects. These results show an effect of 16p11.2 gene dosage on white matter microstructure, and further suggest that opposite changes in diffusion tensor imaging metrics can lead to similar cognitive and behavioral deficits. Given the large effect sizes found in this study, our results support the view that specific genetic variations are more strongly associated with specific brain alterations than are shared neuropsychiatric diagnoses. Hum Brain Mapp 37:2833-2848, 2016. © 2016 Wiley Periodicals, Inc. PMID:27219475

  18. Degeneration of Dopaminergic Neurons Due to Metabolic Alterations and Parkinson’s Disease

    PubMed Central

    Song, Juhyun; Kim, Jongpil

    2016-01-01

    The rates of metabolic diseases, such as type 2 diabetes mellitus (T2DM), obesity, and cardiovascular disease (CVD), markedly increase with age. In recent years, studies have reported an association between metabolic changes and various pathophysiological mechanisms in the central nervous system (CNS) in patients with metabolic diseases. Oxidative stress and hyperglycemia in metabolic diseases lead to adverse neurophysiological phenomena, including neuronal loss, synaptic dysfunction, and improper insulin signaling, resulting in Parkinson’s disease (PD). In addition, several lines of evidence suggest that alterations of CNS environments by metabolic changes influence the dopamine neuronal loss, eventually affecting the pathogenesis of PD. Thus, we reviewed recent findings relating to degeneration of dopaminergic neurons during metabolic diseases. We highlight the fact that using a metabolic approach to manipulate degeneration of dopaminergic neurons can serve as a therapeutic strategy to attenuate pathology of PD. PMID:27065205

  19. Detection of time-varying harmonic amplitude alterations due to spectral interpolations between musical instrument tones.

    PubMed

    Horner, Andrew B; Beauchamp, James W; So, Richard H Y

    2009-01-01

    Gradated spectral interpolations between musical instrument tone pairs were used to investigate discrimination as a function of time-averaged spectral difference. All possible nonidentical pairs taken from a collection of eight musical instrument sounds consisting of bassoon, clarinet, flute, horn, oboe, saxophone, trumpet, and violin were tested. For each pair, several tones were generated with different balances between the primary and secondary instruments, where the balance was fixed across the duration of each tone. Among primary instruments it was found that changes to horn and bassoon [corrected] were most easily discriminable, while changes to saxophone and trumpet timbres were least discriminable. Among secondary instruments, the clarinet had the strongest effect on discrimination, whereas the bassoon had the least effect. For primary instruments, strong negative correlations were found between discrimination and their spectral incoherences, suggesting that the presence of dynamic spectral variations tends to increase the difficulty of detecting time-varying alterations such as spectral interpolation. PMID:19173434

  20. Pathological alterations due to motile Aeromonas infection in red swordtail fish (Xiphophorus helleri).

    PubMed

    Bunnajirakul, S; Pavasutthipaisit, S; Steinhagen, D

    2015-01-01

    A herd of red swordtail fish (Xiphophorus helleri) was reared in outdoor concrete ponds and suffered from occasional mortality. Moribund fishes showing abdominal dropsy and fin rots were sent for diagnosis. Gross necropsy findings showed enlargement of liver, spleen, and kidney in concurrence with congestion, and a severe accumulation of peritoneal fluid. Histopathological findings revealed an alteration of hepatocytes, with a severe diffuse accumulation of fat vacuoles in the cytoplasm. In the trunk kidney, severe accumulation of mononuclear cells together with cloudy swelling of the renal tubular epithelium was observed. From internal organs of the fish motile Aeromonas spp. were identified. The pathological findings might be associated with a long-term infection of affected fish fostered by common stressors such as improper feeding and poor pond environment condition (water temperature). Effective therapeutic measures comprised an advancement of keeping conditions and appropriate feeding to improve the health status in combination with the application of antibiotic substances. PMID:26527040

  1. Alteration of IGFBP-1 in soccer players due to intensive training.

    PubMed

    Lagundžin, Dragana; Vucić, Vesna; Glibetić, Marija; Nedić, Olgica

    2013-10-01

    Physical activity is accompanied by the changes in Insulin-like Growth Factor I (IGF-I)/IGF-Binding Protein 1 (IGFBP-1) axis. Inconsistent results concerning IGF-I and IGFBP-1 levels were reported. In this study we have raised some questions on the events that occur at the molecular level of the exercise-related IGFBP-1 changes. We have examined the fragmentation pattern of IGFBP-1, IGFBP-1 protease activity, interaction between IGFBP-1 and alpha2-macroglobulin (α2M), and possible existence of minor structural changes of IGFBP-1 in professional soccer players. Athletes had significantly greater amounts of fragmented IGFBP-1, whereas no difference was found in the amount of intact IGFBP-1 compared with controls. An increased activity of matrix metalloprotease-9 (MMP-9) was detected in athletes, causing IGFBP-1 degradation down to the fragment of 9 kDa as the major one. The amount of α2M, which protects IGFBP-1 from proteolysis, or the amount of IGFBP-1/α2M complexes was unaltered. Finally, we have examined whether IGFBP-1 isolated from soccer players exhibited altered reactivity with several chemical surfaces used in surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS). Different reactivity was detected with anion and cation exchangers, suggesting existence of at least one sequence within IGFBP-1, whose ionization pattern was not equal in athletes and controls. Differences in spectra obtained with ion exchanges may reflect differences in IGFBP-1 phosphorylation. Physiological implications of the events described in this study on the IGF-I availability are, at this time, unknown. It can be hypothesized that IGFBP-1 proteolysis leads to altered distribution of IGF-I among IGFBPs, which may affect the final IGF-associated response. PMID:23535908

  2. Alterations in myocardial metabolism and function at rest in stable angina pectoris: relations with the amount of exercise-induced thallium-201 perfusion defect

    SciTech Connect

    De Kock, M.; Melin, J.A.; Pouleur, H.; Rousseau, M.F.

    1986-01-01

    The relation between the amount of exercise-induced ischemia and alterations in left ventricular (LV) function and metabolism at rest was studied in 18 coronary patients with stable angina pectoris. An ischemic defect area score was computed from quantitative exercise thallium-201 (Tl-201) scintigraphy; this estimation of the amount of ischemic myocardium was used to classify the patients in group I (n = 8; score less than 15%, mean 6.7 +/- 2.5%) and II (n = 10; score greater than 15%; mean 27.2 +/- 8.9%). Hemodynamics and metabolism were studied in basal state. No patient had anginal pain during the study, and the extent of angiographic coronary artery disease (CAD) was comparable in the two groups. Heart rate, aortic pressure, coronary blood flow, and myocardial oxygen uptake were also similar in both groups. However, ejection fraction was reduced in group II (51 +/- 13 vs 63 +/- 5%; p less than 0.01) and LV relaxation was impaired as shown by the increase in time-constant of isovolumic pressure fall (55 +/- 16 vs 44 +/- 6 ms in group I; p less than 0.05); the LV end-diastolic pressure was also increased in group II (19 +/- 8 vs 10 +/- 4 mmHg in group l; p less than 0.05). Furthermore, in group II, myocardial lactate uptake was reduced (4 +/- 19 vs 30 +/- 29 mumole/min in group I; p less than 0.01) and the productions of alanine and glutamine were augmented (-7.5 +/- 4.4 vs -4.6 +/- 1.6 mumole/min in group I; p less than 0.05).

  3. Long-term prognosis of patients with acute myocardial infarction due to unprotected left main coronary artery disease: a single-centre experience over 14 years

    PubMed Central

    Xu, Li; Sun, Hao; Wang, Le-Feng; Yang, Xin-Chun; Li, Kui-Bao; Zhang, Da-Peng; Wang, Hong-Shi; Li, Wei-Ming

    2016-01-01

    INTRODUCTION Acute myocardial infarction (AMI) due to unprotected left main coronary artery (ULMCA) disease is clinically catastrophic although it has a low incidence. Studies on the long-term prognosis of these patients are rare. METHODS From January 1999 to September 2013, 55 patients whose infarct-related artery was the ULMCA were enrolled. Clinical, angiographic and interventional data was collected. Short-term and long-term clinical follow-up results as well as prognostic determinants during hospitalisation and follow-up were analysed. RESULTS Cardiogenic shock (CS) occurred in 30 (54.5%) patients. During hospitalisation, 22 (40.0%) patients died. Multivariate logistic regression analysis showed that CS (odds ratio [OR] 5.86; p = 0.03), collateral circulation of Grade 2 or 3 (OR 0.14; p = 0.02) and final flow of thrombolysis in myocardial infarction (TIMI) Grade 3 (OR 0.05; p = 0.03) correlated with death during hospitalisation. 33 patients survived to discharge; another seven patients died during the follow-up period of 44.6 ± 31.3 (median 60, range 0.67–117.00) months. The overall mortality rate was 52.7% (n = 29). Kaplan-Meier analysis showed that the total cumulative survival rate was 30.7%. Cox multivariate regression analysis showed that CS during hospitalisation was the only predictor of overall mortality (hazard ratio 4.07, 95% confidence interval 1.40–11.83; p = 0.01). CONCLUSION AMI caused by ULMCA lesions is complicated by high incidence of CS and mortality. CS, poor collateral blood flow and failure to restore final flow of TIMI Grade 3 correlated with death during hospitalisation. CS is the only predictor of long-term overall mortality. PMID:27439434

  4. Sap flow is Underestimated by Thermal Dissipation Sensors due to Alterations of Wood Anatomy

    NASA Astrophysics Data System (ADS)

    Marañón-Jiménez, S.; Wiedemann, A.; van den Bulcke, J.; Cuntz, M.; Rebmann, C.; Steppe, K.

    2014-12-01

    The thermal dissipation technique (TD) is one of the most commonly adopted methods for sap flow measurements. However, underestimations of up to 60% of the tree transpiration have been reported with this technique, although the causes are not certainly known. The insertion of TD sensors within the stems causes damage of the wood tissue and subsequent healing reactions, changing wood anatomy and likely the sap flow path. However, the anatomical changes in response to the insertion of sap flow sensors and the effects on the measured flow have not been assessed yet. In this study, we investigate the alteration of vessel anatomy on wounds formed around TD sensors. Our main objectives were to elucidate the anatomical causes of sap flow underestimation for ring-porous and diffuse-porous species, and relate these changes to sap flow underestimations. Successive sets of TD probes were installed in early, mid and end of the growing season in Fagus sylvatica (diffuse-porous) and Quercus petraea (ring-porous) trees. They were logged after the growing season and additional sets of sensors were installed in the logged stems with presumably no healing reaction. The wood tissue surrounding each sensor was then excised and analysed by X-ray computed microtomography (X-ray micro CT). This technique allowed the quantification of vessel anatomical characteristics and the reconstruction of the 3-D internal microstructure of the xylem vessels so that extension and shape of the altered area could be determined. Gels and tyloses clogged the conductive vessels around the sensors in both beech and oak. The extension of the affected area was larger for beech although these anatomical changes led to similar sap flow underestimations in both species. The higher vessel size in oak may explain this result and, therefore, larger sap flow underestimation per area of affected conductive tissue. The wound healing reaction likely occurred within the first weeks after sensor installation, which

  5. Lysosomotropic agents selectively target chronic lymphocytic leukemia cells due to altered sphingolipid metabolism.

    PubMed

    Dielschneider, R F; Eisenstat, H; Mi, S; Curtis, J M; Xiao, W; Johnston, J B; Gibson, S B

    2016-06-01

    Lysosome membrane permeabilization (LMP) mediates cell death in a variety of cancer cells. However, little is known about lysosomes and LMP in chronic lymphocytic leukemia (CLL). Owing to drug resistance and toxicity in CLL patients, better treatment strategies are required. Our results show that CLL cells were sensitive to the lysosomotropic agent siramesine. Furthermore, this drug was more effective in CLL cells, regardless of prognostic factors, compared with normal B cells. Siramesine caused LMP, lipid peroxidation and transcription factor EB nuclear translocation followed by mitochondrial membrane potential loss and reactive oxygen species release. Siramesine-induced cell death was blocked by lipid antioxidants, but not by soluble antioxidants or protease inhibitors. To determine whether CLL cells had altered lysosomes, we investigated sphingolipid metabolism as the lysosome is a hub for lipid metabolism. We found that CLL cells had more lysosomes, increased sphingosine-1-phosphate phosphatase 1 (SPP1) expression, and increased levels of sphingosine compared with normal B cells. Raising sphingosine levels increased LMP and cell death in CLL cells, but not in normal B cells. Together, these results show that excess sphingosine in CLL cells could contribute to their sensitivity toward LMP. Thus, targeting the lysosome could be a novel therapeutic strategy in CLL. PMID:26859075

  6. An invasive macrophyte alters sediment chemistry due to suppression of a native isoetid.

    PubMed

    Urban, Rebecca A; Titus, John E; Zhu, Wei-Xing

    2006-06-01

    The submersed macrophyte Utricularia inflata (inflated bladderwort) is a recent invader of Adirondack Mountain lakes (NY, USA). A 15-week greenhouse experiment and a 7-week field experiment were conducted to test the hypothesis that this rootless species fundamentally changes sediment chemistry through its suppression of the native short-statured species, Eriocaulon aquaticum. E. aquaticum has an extensive root system that releases oxygen into the sediment. In greenhouse conditions, E. aquaticum raised the porewater redox potential of otherwise bare sediment from 25 to 324 mV, lowered the sediment porewater pH from 5.7 to 4.6, and depleted the dissolved inorganic carbon and ammonium concentrations in the sediment porewater by 68.4 and 96.0%, respectively (P<0.001 for all four parameters). A cover of U. inflata over E. aquaticum, however, greatly reduced the latter's effect on redox potential (P<0.001), dissolved solutes (P<0.001), and pH (P<0.05). E. aquaticum biomass increased during the greenhouse experiment in the absence of U. inflata, but decreased in its presence (P<0.001). Redox and growth rate results from the field experiment paralleled those from the greenhouse experiment. Our data suggest that U. inflata may change nutrient cycling in Adirondack lake ecosystems by reducing the growth of native isoetid macrophytes, such as E. aquaticum, and consequently altering key features of sediment chemistry. PMID:16518632

  7. Spatial and Temporal Alterations on Carbon and Water Cycles Due to Grazing

    NASA Astrophysics Data System (ADS)

    Maksimowicz, M. M.; Brunsell, N. A.; Ham, J. M.

    2009-05-01

    Grasslands are vital in the carbon cycle, as large amounts of carbon are stored in the soils of the prairie. As climate change affects the carbon cycle, it is essential for the agricultural communities to understand the impacts of these changes on farming practices such as grazing and meat production. The objective of this study is to determine the effect of grazing on the carbon cycle by characterizing the surface boundary layer of both a grazed field and an ungrazed field. Data were collected from open path eddy covariance systems over Rannells Flint Hills Prairie Preserve in north-central Kansas, one over an ungrazed field and one over a grazed field. Cospectra of fluxes of CO2, heat, water, and momentum for July 2007 were compared to assess the size of eddies contributing energy to each field. For CO2, the cospectra for both the ungrazed and the ungrazed field were similar. For all of the other fluxes, lower frequency eddies contributed more energy in the grazed field than the ungrazed field. By using a footprint model, the contributing source areas were determined for fluxes from May through October of 2007. The grazed field had a larger distance of contribution in both stable and unstable atmospheric conditions. Implications of this study include the alterations on fields and impacts on the carbon and water cycles as a result of grazing.

  8. The Asthenosphere Melting Regimes Alteration due to Changing Conditions of Upper Mantle

    NASA Astrophysics Data System (ADS)

    Perepechko, Y. V.; Sharapov, V. N.; Sorokin, K., Jr.

    2014-12-01

    Analyzed in the article are different asthenosphere magma generation regimes above the upper mantle hot spots as thermodynamic and geometric parameters of the upper mantle and the conditions on its boundaries vary. The two-layer mantle model is applied to consider the formation of decompression melting areas. The thickness of metasomatically altered lithospheric mantle is determined by the mantle substance rheology and the location of the upper boundary of asthenosphere. We also take into consideration the principal solid state phase transitions by using the mantle substance state equation. The sizes and distribution of hot spots as well as their maximal temperature were defined by the thermodynamic conditions of the perovskite transition existence. The numerical analysis results demonstrate the manifestation of three main mantle dynamics modes; the conditions necessary to form the partial melting zones are not reached; some melting areas with the 30 to 65 Ma existence time do occur; the melting areas that are formed exist permanently. The permanently existing asthenosphere zones are marked by quasiperiodical variation in thickness and the degree of melting. The typical temperatures of a hot spot sharing these modes are the 1740°С and 2020°С correspondingly. The originally presupposed heating degree and the temperature ratio of the upper mantle do influence the decompression melting degree substantially and - to a lesser extent - they influence the size of melting zones. The primary evolution of the second mode is described by the development of a complex system of asthenosphere zones that lead to the occurrence of additional convectional cells dividing the partial melting zone. The variation in the rheological properties of the mantle substance also contributes to the manifestation of the complex structure of asthenosphere zone. The work was made with support of the Russian Foundation for Basic Research grant #12-05-00625.

  9. Molecular cause and functional impact of altered synaptic lipid signaling due to a prg-1 gene SNP.

    PubMed

    Vogt, Johannes; Yang, Jenq-Wei; Mobascher, Arian; Cheng, Jin; Li, Yunbo; Liu, Xingfeng; Baumgart, Jan; Thalman, Carine; Kirischuk, Sergei; Unichenko, Petr; Horta, Guilherme; Radyushkin, Konstantin; Stroh, Albrecht; Richers, Sebastian; Sahragard, Nassim; Distler, Ute; Tenzer, Stefan; Qiao, Lianyong; Lieb, Klaus; Tüscher, Oliver; Binder, Harald; Ferreiros, Nerea; Tegeder, Irmgard; Morris, Andrew J; Gropa, Sergiu; Nürnberg, Peter; Toliat, Mohammad R; Winterer, Georg; Luhmann, Heiko J; Huai, Jisen; Nitsch, Robert

    2016-01-01

    Loss of plasticity-related gene 1 (PRG-1), which regulates synaptic phospholipid signaling, leads to hyperexcitability via increased glutamate release altering excitation/inhibition (E/I) balance in cortical networks. A recently reported SNP in prg-1 (R345T/mutPRG-1) affects ~5 million European and US citizens in a monoallelic variant. Our studies show that this mutation leads to a loss-of-PRG-1 function at the synapse due to its inability to control lysophosphatidic acid (LPA) levels via a cellular uptake mechanism which appears to depend on proper glycosylation altered by this SNP. PRG-1(+/-) mice, which are animal correlates of human PRG-1(+/mut) carriers, showed an altered cortical network function and stress-related behavioral changes indicating altered resilience against psychiatric disorders. These could be reversed by modulation of phospholipid signaling via pharmacological inhibition of the LPA-synthesizing molecule autotaxin. In line, EEG recordings in a human population-based cohort revealed an E/I balance shift in monoallelic mutPRG-1 carriers and an impaired sensory gating, which is regarded as an endophenotype of stress-related mental disorders. Intervention into bioactive lipid signaling is thus a promising strategy to interfere with glutamate-dependent symptoms in psychiatric diseases. PMID:26671989

  10. Myocardial ischemia due to compression of an unruptured thoracic aortic aneurysm in a patient with Marfan syndrome.

    PubMed

    Minami, Hiroya; Asada, Tatsuro; Gan, Kunio; Abe, Koichiro; Izumi, Satoshi

    2007-06-01

    We report a 33-year-old woman who had a 60-mm thoracic aneurysm of the ascending aorta with Marfan syndrome and effort angina due to compression of the right coronary artery (RCA) by the aneurysm. Surgery was performed using the Bentall procedure and a coronary artery bypass graft to the RCA. Postoperatively, coronary angiography showed that the coronary flow of the RCA was restored by removing the aneurysmal compression. The patient was discharged without angina on postoperative day 21. PMID:17642279

  11. Immunohistochemical detection of early myocardial damage in two sudden deaths due to intentional butane inhalation. Two case reports with review of literature.

    PubMed

    Novosel, Irena; Kovačić, Zdravko; Gusić, Stjepan; Batelja, Lovorka; Nestić, Marina; Seiwerth, Sven; Skavić, Josip

    2011-04-01

    The abuse of household and other commercially available products containing volatile organic solvents is underrecognized. Not infrequently intentional butane inhalation results in high morbidity and mortality. A fatal outcome of butane abuse can be caused by asphyxia, cardiac arrhythmia or trauma. The reported number of cases in which death was the consequence of pure butane inhalation is limited, and in most cases a mixture of propellants was involved. This report covers two cases of sudden death due to the sniffing of a cigarette lighter refill containing butane. Autopsy was followed by toxicological, pathohistological and immunohistochemical analysis. Butane gas was confirmed in samples of blood, urine, brain and lungs by the gas chromatography method - "headspace" technique. Histology showed almost identical changes in the lungs and heart in both cases. The morphology of heart damage on standard H/E stains was of special interest because it displayed all the characteristics of chronic and acute myocardial hypoxia found in the absence of atherosclerotic heart disease. In order to confirm early cardiac death caused by asphyxia due to butane inhalation a panel of immunohistochemical agents was used: Myoglobin, Desmin, Fibronectin, Fibrinogen and CC9. PMID:21420651

  12. Correcting oral contraceptive pharmacokinetic alterations due to obesity. A randomized controlled trial

    PubMed Central

    Edelman, Alison B; Cherala, Ganesh; Munar, Myrna Y.; McInnis, Martha; Stanczyk, Frank Z.; Jensen, Jeffrey T

    2014-01-01

    Objective To determine if increasing the hormone dose or eliminating the hormone-free interval improves key pharmacokinetic (PK) alterations caused by obesity during oral contraceptive (OC) use. Study design Obese (BMI ≥ 30 kg/m2), ovulatory, otherwise healthy, women received an OC containing 20 mcg ethinyl estradiol (EE)/100 mcg levonorgestrel (LNG) dosed cyclically (21 days active pills with 7-day placebo week) for two cycles and then were randomized for two additional cycles to: Continuous Cycling [CC, a dose neutral arm using the same OC with no hormone-free interval] or Increased Dose [ID, a dose escalation arm using an OC containing 30 mcg EE/150 mcg LNG cyclically]. During Cycle 2, 3, and 4, outpatient visits were performed to assess maximum serum concentration (Cmax), area under the curve (AUC0-∞), and time to steady state as well as pharmacodynamics. These key PK parameters were calculated and compared within groups between baseline and treatment cycles. Results A total of 31 women enrolled and completed the study (CC group n = 16; ID group n = 15). Demographics were similar between groups [mean BMI: CC 38kg/m2 (SD 5.1), ID 41kg/m2 (SD 7.6)]. At baseline, the key LNG PK parameters were no different between groups; average time to reach steady-state was 12 days in both groups; Cmax were CC: 3.82 ± 1.28 ng/mL and ID: 3.13 ± 0.87 ng/mL; and AUC0-∞ were CC: 267 ± 115 hr*ng/mL and ID: 199±75 hr*ng/mL. Following randomization, the CC group maintained steady-state serum levels whereas the ID group had a significantly higher Cmax (p< 0.001) but again required 12 days to achieve steady-state. However, AUC was not significantly different between CC (412 ± 255 hr*ng/mL) and ID (283 ± 130 hr*ng/mL). Forty-five percent (14/31) of the study population had evidence of an active follicle-like structure prior to randomization and afterwards this decreased to 9% (3/31). Conclusion Both increasing the OC dose and continuous dosing appear to counteract the impact

  13. Alterations in tissue glutathione and angiotensin converting enzyme due to inhalation of diesel engine exhaust

    SciTech Connect

    Chaudhari, A.; Dutta, S.

    1982-02-01

    Quantitative changes in reduced glutathione (GSH) and angiotensin converting enzyme (ACE) of lung and extrapulmonary tissues were determined following exposure of laboratory animals to diesel engine exhaust (DEE). Exposure of male rats and guinea pigs to DEE containing 750 ..mu..g particulates per cubic meter for 1 wk did not cause any changes in GSH levels of lung, liver, and heart compared to control values. Rats were then exposed for various time periods to 6 mg/m/sup 3/ DEE. Two weeks of exposure produced statistically significant increases of 21 and 7% in GSH levels of lung and liver, respectively, but no change in the heart. Following 4 wk of exposure, lung showed a 14% increase and heat an 11% increase in GSH level. Furthermore, rats exposed for 4 wk to DEE did not show any particular susceptibility toward the GSH-depleting effect of acetaminophen as compared to controls. A significant depletion (15%) of hepatic GSH was observed after 8 wk of exposure, while lung was still showing an increase of 18% in GSH and heart was unaffected. Time-dependent increases of 18 and 33% in serum ACE activity were noted after 4 and 8 wk of exposure. Pulmonary ACE activity did not decrease until after 8 wk, and then to a small extent (7%). The observed increases in GSH may have been related to the presence of NO/sub 2/ in the DEE. On the other hand, the depletion of hepatic GSH suggests production of electrophillic compounds due to an induction of metabolic activity of liver. The change in serum ACE activity may be due to time-requiring perturbations in the pulmonary endothelial cells.

  14. Alteration of Fractured Rocks Due to Coupled Chemical and Mechanical Processes: High-Resolution Simulations and Experimental Observations

    NASA Astrophysics Data System (ADS)

    Ameli, Pasha

    Engineering activities such as enhanced geothermal energy production and improved oil recovery techniques are heavily dependent on the permeability of the subsurface, while others such as CO2 sequestration and nuclear waste disposal rely on the efficiency of rock formations as transport barriers. In either case fractures provide the main pathways for fluid flow and transport, especially in rocks with lower matrix porosity. Laboratory experiments aimed at quantifying the chemo-mechanical responses of fractures have shown a range of results, some of which contradict simple conceptual models. For example, under conditions favoring mineral dissolution, where one would expect an overall increase in permeability, experiments show that permeability increases under some conditions and decreases under others. Recent experiments have attempted to link these core-scale observations to the relevant small-scale processes occurring within fractures. Results suggest that the loss of mechanical strength in asperities due to chemical alteration may cause non-uniform deformation and alteration of fracture apertures. However, due to the lack of direct micro-scale measurements of the coupled chemical and mechanical processes that lead to alteration of contacting fracture surfaces, our ability to predict the long-term evolution of fractures is still limited. To explore the processes that control permeability evolution, I developed a computational model that uses micro-scale surface roughness and explicitly couples dissolution and elastic deformation to calculate local alterations in fracture aperture under chemical and mechanical stresses. A depth-averaged algorithm of fracture flow is used to model reactive transport and chemical alteration of the fracture surfaces. Then, I deform the resulting altered fracture-surfaces using an algorithm that calculates the elastic deformation. The results of the model are compared with flow-through experiments conducted on fractured limestone. The

  15. Alterations in rat brain polyphosphoinositide metabolism due to acute ethanol administration.

    PubMed

    Chandrasekhar, R; Huang, H M; Sun, G Y

    1988-04-01

    The effects of acute ethanol administration on the polyphosphoinositide metabolism of rat brain cerebral cortex were examined. Intracerebral injections of [gamma-32P]ATP proved to be an effective in vivo method to prelabel brain phospholipids, especially the polyphosphoinositides. High acute doses of ethanol (8 or 6 g/kg b.wt.) administered by gavage significantly inhibited the breakdown of polyphosphoinositides as judged by an elevation in the concentration as well as the labeling of these compounds. Concomitantly, there was a significant reduction in the level of diacylglycerols. Low acute doses of ethanol (2 g/kg b.wt.) did not seem to have any effects on the basal levels or labeling of these compounds. The changes in polyphosphoinositide labeling due to ethanol intoxication were reverted to near control values when animals regained their righting reflex (approximately 4 hr). These studies demonstrate that, under normal conditions, polyphosphoinositides and diacylglycerols are maintained in a dynamic equilibrium and that acute doses of ethanol can suppress the signal transduction process and disturb this equilibrium. PMID:2834532

  16. Adaptation to altered balance conditions in unilateral amputees due to atherosclerosis: a randomized controlled study

    PubMed Central

    2011-01-01

    Background Amputation impairs the ability to balance. We examined adaptation strategies in balance following dysvascularity-induced unilateral tibial amputation in skilled prosthetic users (SPU) and first fitted amputees (FFA) (N = 28). Methods Excursions of center of pressure (COP) were determined during 20 s quiet standing using a stabilometry system with eyes-open on both legs or on the non-affected leg(s). Main measures: COP trajectories and time functions; distribution of reaction forces between the two legs; inclination angles obtained through second order regression analysis using stabilogram data. Results FFA vs SPU demonstrated 27.8% greater postural sway in bilateral stance (p = 0.0004). Postural sway area was smaller in FFA standing on the non-affected leg compared with SPU (p = 0.028). The slope of the regression line indicating postural stability was nearly identical in FFA and SPU and the direction of regression line was opposite for the left and right leg amputees. Conclusion Of the two adaptation strategies in balance, the first appears before amputation due to pain and fatigue in the affected leg. This strategy appears in the form of reduced postural sway while standing on the non-affected leg. The second adaptation occurs during rehabilitation and regular use of the prosthesis resulting in normal weightbearing associated with reduced postural sway on two legs and return to the normal postural stability on one leg. PMID:21619618

  17. Alteration of the oxygen-dependent reactivity of de novo Due Ferri proteins.

    PubMed

    Reig, Amanda J; Pires, Marcos M; Snyder, Rae Ana; Wu, Yibing; Jo, Hyunil; Kulp, Daniel W; Butch, Susan E; Calhoun, Jennifer R; Szyperski, Thomas; Szyperski, Thomas G; Solomon, Edward I; DeGrado, William F

    2012-11-01

    De novo proteins provide a unique opportunity to investigate the structure-function relationships of metalloproteins in a minimal, well-defined and controlled scaffold. Here, we describe the rational programming of function in a de novo designed di-iron carboxylate protein from the Due Ferri family. Originally created to catalyse the O(2)-dependent, two-electron oxidation of hydroquinones, the protein was reprogrammed to catalyse the selective N-hydroxylation of arylamines by remodelling the substrate access cavity and introducing a critical third His ligand to the metal-binding cavity. Additional second- and third-shell modifications were required to stabilize the His ligand in the core of the protein. These structural changes resulted in at least a 10(6)-fold increase in the relative rate between the arylamine N-hydroxylation and hydroquinone oxidation reactions. This result highlights the potential for using de novo proteins as scaffolds for future investigations of the geometric and electronic factors that influence the catalytic tuning of di-iron active sites. PMID:23089864

  18. The Kutta-Zhukovsky Lift Theorem revisited: Alteration due to the Viscous Wake

    NASA Astrophysics Data System (ADS)

    Schmitz, Sven

    2011-11-01

    The circulation theory of lift comprised in the classical Kutta-Zhukovsky Lift Theorem forms the foundation of modern aerodynamic wing theory. The theorem has been applied ever since in lifting-line models of aircraft and rotary wings. Reynolds numbers larger than one million support its validity, yet the effect of a viscous wake on a change in the functional relationship between lift and circulation is not taken into account in standard lifting-line analyses. A discrepancy in circulation of more than six percent in comparison to the classical Kutta-Zhukovsky Lift Theorem has been demonstrated by the author (Schmitz & Chattot, Computers & Fluids, 36) for moderately separated flow around a wind turbine airfoil by means of a control volume analysis governed by the Navier-Stokes equations. The present work extends the previous analysis to general three-dimensional flow around a lifting body. An analytical expression is presented that extends the classical Kutta-Zhukovsky Lift Theorem by adding terms to the theorem due to chord- and spanwise vorticity transport. An integrated solution for induced drag is given that has not been documented in previous literature on the subject. The generalized theorem will find future application and quantification in actuator-line methods used to predict wind farm wake interactions with Atmospheric Boundary Layer flow.

  19. An Altered Pattern of Myocardial Histopathological and Molecular Changes Underlies the Different Characteristics of Type-1 and Type-2 Diabetic Cardiac Dysfunction

    PubMed Central

    Radovits, Tamás; Korkmaz, Sevil; Mátyás, Csaba; Oláh, Attila; Páli, Szabolcs; Zubarevich, Alina; Gwanmesia, Patricia Neh; Li, Shiliang; Loganathan, Sivakkanan; Barnucz, Enikő; Merkely, Béla; Szabó, Gábor

    2015-01-01

    Increasing evidence suggests that both types of diabetes mellitus (DM) lead to cardiac structural and functional changes. In this study we investigated and compared functional characteristics and underlying subcellular pathological features in rat models of type-1 and type-2 diabetic cardiomyopathy. Type-1 DM was induced by streptozotocin. For type-2 DM, Zucker Diabetic Fatty (ZDF) rats were used. Left ventricular pressure-volume analysis was performed to assess cardiac function. Myocardial nitrotyrosine immunohistochemistry, TUNEL assay, hematoxylin-eosin, and Masson's trichrome staining were performed. mRNA and protein expression were quantified by qRT-PCR and Western blot. Marked systolic dysfunction in type-1 DM was associated with severe nitrooxidative stress, apoptosis, and fibrosis. These pathological features were less pronounced or absent, while cardiomyocyte hypertrophy was comparable in type-2 DM, which was associated with unaltered systolic function and increased diastolic stiffness. mRNA-expression of hypertrophy markers c-fos, c-jun, and β-MHC, as well as pro-apoptotic caspase-12, was elevated in type-1, while it remained unaltered or only slightly increased in type-2 DM. Expression of the profibrotic TGF-β1 was upregulated in type-1 and showed a decrease in type-2 DM. We compared type-1 and type-2 diabetic cardiomyopathy in standard rat models and described an altered pattern of key pathophysiological features in the diabetic heart and corresponding functional consequences. PMID:25629059

  20. Altered combustion characteristics of metallized energetics due to stable secondary material inclusion

    NASA Astrophysics Data System (ADS)

    Terry, Brandon C.

    Though metals and metalloids have been widely considered as reactive fuels, the ability to tune their ignition and combustion characteristics remains challenging. One means to accomplish this may be through low-level inclusion of secondary materials into the metallized fuel. While there are several potential methods to stably introduce secondary inclusion materials, this work focuses on the use of mechanical activation (MA) and metal alloys. Recent work has shown that low-level inclusion of fluoropolymers into aluminum particles can have a substantial effect on their combustion characteristics. The reflected shock ignition of mechanically activated aluminum/polytetrafluoroethylene (MA Al/PTFE) is compared to a physical mixture (PM) of Al/PTFE, neat spherical aluminum, and flake aluminum. It was found that the powders with higher specific surface areas ignited faster than the spherical particles of the same size, and had ignition delay times comparable to agglomerates of aluminum particles that were two orders of magnitude smaller in size. Flake aluminum powder had the same ignition delay as MA Al/PTFE, indicating that any initial aluminum/fluoropolymer reactions did not yield an earlier onset of aluminum oxidation. However, MA Al/PTFE did have a shorter total burn time. The PM of Al/PTFE powder had a shorter ignition delay than neat spherical aluminum due to the rapid decomposition of PTFE into reactive fluorocarbon compounds, but the subsequent fluorocarbon reactions also created a secondary luminosity profile that significantly increased the total burn time of the system. The explosive shock ignition of aluminum and aluminum-silicon eutectic alloy compacts was evaluated with and without polymer inclusions. A statistical analysis was completed, investigating the effects of: detonation train orientation (into or not into a hard surface); the high explosive driver; whether the metal/polymer system is mechanically activated; particle size; particle morphology

  1. Reverse and pseudo redistribution of thallium-201 in healed myocardial infarction and normal and negative thallium-201 washout in ischemia due to background oversubtraction

    SciTech Connect

    Lear, J.L.; Raff, U.; Jain, R.

    1988-09-15

    While the interpolative background subtraction used in quantitative planar thallium scanning can significantly overestimate the background overlying the heart, the effects of background oversubtraction on quantitative analysis have not been well defined. A mathematical model that relates myocardial washout determined using interpolative background subtraction to true myocardial washout is presented. The model was validated using phantoms and applied to myocardial and pulmonary thallium kinetic data in 100 patients, 85 with and 15 without coronary artery disease. The model showed that when using interpolative background subtraction, measured washout equals true washout in normally perfused myocardium; however, depending on the relation between myocardial and pulmonary thallium clearance, myocardial washout in ischemic regions and areas of infarction can be substantially over- or underestimated. Based on generally accepted quantitative criteria, this incorrect washout determination can at times lead to misdiagnosis of infarction as ischemia and ischemia as normally perfused tissue. It can also cause both ''reverse redistribution'' and ''pseudo redistribution'' of thallium in myocardial infarction in the absence of a physiologic basis.

  2. Illustrating a new approach to estimating potential reduction in fish species richness due to flow alteration on a global scale

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Yanagawa, A.; Khajuria, A.; Sui, P.; Iwasaki, Y.; Hirano, K.; Mahendran, R.; Koirala, S.; Hirabayashi, Y.; Yoshimura, C.; Kanae, S.

    2013-06-01

    Changes in river discharge due to human activities and climate change would affect the sustainability of freshwater ecosystem. In order to globally assess the future status of freshwater ecosystem under regime shifts in river discharge, global-scale hydrological simulations need to be connected with a model to estimate the soundness of freshwater ecosystem. However, the explicit combination of those two on a global scale is still in its infancy. A couple of statistical models are introduced here to link flow regimes to fish species richness (FSR): one based on a linear relationship between FSR and mean river discharge, and the other based on a relationship between FSR and ecologically relevant flow indices involving other several flow characteristics as well as mean river discharge. The former one has been sometimes used in global simulation studies, but the latter one is newly introduced here in the context of global simulation. These statistical models for estimating FSR were combined with a set of global river discharge simulations to evaluate the potential impact of flow alterations due to climate change on FSR changes. Generally, future reductions in FSR by the latter method are larger and much more scattered rather than by the former method. In arid regions, both models provide reductions in FSR because mean discharge is projected to decrease from past to future, although the magnitude of reduction in FSR is different. On the other hand, large reductions in FSR only by the latter model are detected in heavy-snow regions due to the increases of mean discharge and frequency of low and high flows. Although we need further research to conclude which is more relevant, this study demonstrates that the new model could show a considerably different behavior in assessing the global impact of flow alteration on freshwater ecosystem change.

  3. Reduced Mitochondrial Function in Human Huntington Disease Lymphoblasts is Not Due to Alterations in Cardiolipin Metabolism or Mitochondrial Supercomplex Assembly.

    PubMed

    Mejia, Edgard M; Chau, Sarah; Sparagna, Genevieve C; Sipione, Simonetta; Hatch, Grant M

    2016-05-01

    Huntington's Disease (HD) is an autosomal dominant disease that occurs as a result of expansion of the trinucleotide repeat CAG (glutamine) on the HTT gene. HD patients exhibit various forms of mitochondrial dysfunction within neurons and peripheral tissues. Cardiolipin (Ptd2Gro) is a polyglycerophospholipid found exclusively in mitochondria and is important for maintaining mitochondrial function. We examined if altered Ptd2Gro metabolism was involved in the mitochondrial dysfunction associated with HD. Mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis were markedly diminished in Epstein-Barr virus transformed HD lymphoblasts compared to controls (CTRL). Mitochondrial supercomplex formation and Complex I activity within these supercomplexes did not vary between HD patients with different length of CAG repeats and appeared unaltered compared to CTRL. In contrast, in vitro Complex I enzyme activity in mitochondrial enriched samples was reduced in HD lymphoblasts compared to CTRL. The total cellular pool size of Ptd2Gro and its synthesis/remodeling from [(3)H]acetate/[(14)C]oleate were unaltered in HD lymphoblasts compared to CTRL. In addition, the molecular species of Ptd2Gro were essentially unaltered in HD lymphoblasts compared to CTRL. We conclude that compared to CTRL lymphoblasts, HD lymphoblasts display impaired mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis with any pathological CAG repeat length, but this is not due to alterations in Ptd2Gro metabolism. We suggest that HD patient lymphoblasts may be a useful model to study defective energy metabolism that does not involve alterations in Ptd2Gro metabolism. PMID:26846325

  4. Illustrating a new global-scale approach to estimating potential reduction in fish species richness due to flow alteration

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Yanagawa, A.; Iwasaki, Y.; Sui, P.; Koirala, S.; Hirano, K.; Khajuria, A.; Mahendran, R.; Hirabayashi, Y.; Yoshimura, C.; Kanae, S.

    2014-02-01

    Changes in river discharge due to human activities and climate change would affect the sustainability of freshwater ecosystems. To globally assess how changes in river discharge will affect the future status of freshwater ecosystems, global-scale hydrological simulations need to be connected with a model to estimate the durability of freshwater ecosystems. However, the development of this specific modelling combination for the global scale is still in its infancy. In this study, two statistical methods are introduced to link flow regimes to fish species richness (FSR): one is based on a linear relationship between FSR and mean river discharge (hereafter, FSR-MAD method), and the other is based on a multi-linear relationship between FSR and ecologically relevant flow indices involving several other flow characteristics and mean river discharge (FSR-FLVAR method). The FSR-MAD method has been used previously in global simulation studies. The FSR-FLVAR method is newly introduced here. These statistical methods for estimating FSR were combined with a set of global river discharge simulations to evaluate the potential impact of climate-change-induced flow alterations on FSR changes. Generally, future reductions in FSR with the FSR-FLVAR method are greater and much more scattered than with the FSR-MAD method. In arid regions, both methods indicate reductions in FSR because mean discharge is projected to decrease from past to future, although the magnitude of reductions in FSR is different between the two methods. In contrast, in heavy-snow regions a large reduction in FSR is shown by the FSR-FLVAR method due to increases in the frequency of low and high flows. Although further research is clearly needed to conclude which method is more appropriate, this study demonstrates that the FSR-FLVAR method could produce considerably different results when assessing the global role of flow alterations in changing freshwater ecosystems.

  5. Modeling of the relationship between the environmental air pollution, clinical risk factors, and hospital mortality due to myocardial infarction in Isfahan, Iran

    PubMed Central

    Sadeghi, Mehraban; Ahmadi, Ali; Baradaran, Azar; Masoudipoor, Neda; Frouzandeh, Soleiman

    2015-01-01

    Background: This study aimed to determine the relationship between the environmental factor, clinical risk factors, and individual variables with mortality due to acute myocardial infarction (MI) in Isfahan. Materials and Methods: This cross-sectional study was performed between April 2012 and March 2013. The data on the patients’ mortality due to MI in Isfahan were obtained from the MI National Registry. The international classification system (ICD10: I21-I22) was used to diagnose MI. The air quality indicators and environmental variables were used to measure the air pollution. Multilevel logistic regression in the Stata software was used to determine the factors associated with mortality in patients and odds ratios (ORs) were calculated. Results: Six hundred eleven patients with MI were studied during 1-year. 444 (72.2%) patients were male and the rest were female. 4.7% of the patients died due to MI. The mean age at MI incidence was 62.2 ± 13 years. Of the air pollution parameters, PM10 had the maximum mean concentration (49.113 ppm), followed by NOX, NO, NO2, CO, SO2, and O3. The adjusted OR of mortality was derived 2.07 (95% CI: 1.5-2.85) for right bundle branch block, 1.5 (95% CI: 1.3-1.7) for ST-segment elevation MI, 1.84 (95% CI: 1.13-3) for age, 1.06 (95% CI: 1.01-1.20) for CO, 1.1 (95% CI: 1.03-1.30) for O3, and 1.04 (95% CI: 1.01-1.4) for SO2, all of which were considered as the risk factors of mortality. However, OR of mortality was 0.79 for precipitation (95% CI: 0.74-0.84) and 0.52 for angioplasty (95% CI: 0.4-0.68) were considered as protective factors of mortality. The individual characteristics including age, history of MI in the immediate family, hypertension, and diabetes were significantly associated with mortality from MI. The indices of air pollution including SO2, CO, O3, and environmental factors such as the precipitation and temperature were the determinants of mortality in patients with MI. Conclusion: With regards to the factors

  6. Proinflammatory and Th1 cytokine alterations following ultraviolet radiation enhancement of disease due to influenza infection in mice.

    PubMed

    Ryan, Lisa K; Copeland, Lisa R; Daniels, Mary J; Costa, Elisabeth R; Selgrade, Mary Jane K

    2002-05-01

    Exposure of rodents to immunosuppressive agents such as ozone, dioxin, or ultraviolet radiation (UVR) leads to increased morbidity and mortality following influenza virus infection. However, these adverse effects are not related to the suppression of virus-specific immune responses. Our laboratory showed that UVR increased the morbidity, mortality, and pathogenesis of influenza virus without affecting protective immunity to the virus, as measured by resistance to reinfection, suggesting that UVR and other immunosuppressive pollutants such as dioxin and ozone may exacerbate early responses that contribute to the pathogenesis of a primary viral infection. In the present study, we examined the mechanism of UVR-enhanced mortality in the absence of effects on virus-specific immunity and tested the hypothesis that modulation of cytokine levels was associated with increased deaths and body weight loss. BALB/c mice were exposed to 8.2 kJ/m(2) UVR and were infected 3 days later with a sublethal influenza virus infection (LD(40) of mouse-adapted Hong Kong influenza A/68, H(3)N(2)). Influx of inflammatory cells, proinflammatory cytokines, and cytokines produced by T-helper lymphocytes (Th1 and Th2) were measured in lung homogenates (LH) as well as in bronchoalveolar lavage fluid (BAL). UVR preexposure decreased the influenza-induced lymphocytic influx 5 days after infection, but did not alter macrophage and neutrophil influx into the lung, or increase virus titers significantly. Although interferon (IFN)-gamma, total interleukin (IL)-12, IL-6, and TNF-alpha were altered in mice that received UVR exposure prior to infection, no clear association was made that correlated with the UVR-induced increase in body weight loss and mortality due to influenza infection. PMID:11961220

  7. Sphingolipid Therapy in Myocardial Ischemia-Reperfusion Injury

    PubMed Central

    Gundewar, Susheel; Lefer, David J.

    2009-01-01

    Sphingolipids are known to play a significant physiological role in cell growth, cell differentiation, and critical signal transduction pathways. Recent studies have demonstrated a significant role of sphingolipids and their metabolites in the pathogenesis of myocardial ischemia-reperfusion injury. Our laboratory has investigated the cytoprotective effects of N,N,N-Trimethylsphingosine chloride (TMS), a stable N-methylated synthetic sphingolipid analogue on myocardial and hepatic ischemia reperfusion injury in clinically relevant in vivo murine models of ischemia-reperfusion injury. TMS administered intravenously at the onset of ischemia reduced myocardial infarct size in the wild-type and obese (ob/ob) mice. Following myocardial I/R, there was an improvement in cardiac function in the wild-type mice. Additionally, TMS also decreased serum liver enzymes following hepatic I/R in wild-type mice. The cytoprotective effects did not extend to the ob/ob mice following hepatic I/R or to the db/db mice following both myocardial and hepatic I/R. Our data suggests that although TMS is cytoprotective following I/R in normal animals, the cytoprotective actions of TMS are largely attenuated in obese and diabetic animals which may be due to altered signaling mechanisms in these animal models. Here we review the therapeutic role of TMS and other sphingolipids in the pathogenesis of myocardial ischemia reperfusion injury and their possible mechanisms of cardioprotection. PMID:17928150

  8. Hydrogeochemical alteration of groundwater due to a CO2 injection test into a shallow aquifer in Northeast Germany

    NASA Astrophysics Data System (ADS)

    Dethlefsen, Frank; Peter, Anita; Hornbruch, Götz; Lamert, Hendrik; Garbe-Schönberg, Dieter; Beyer, Matthias; Dietrich, Peter; Dahmke, Andreas

    2014-05-01

    The accidental release of CO2 into potable aquifers, for instance as a consequence of a leakage out of a CO2 store site, can endanger drinking water resources due to the induced geochemical processes. A 10-day CO2 injection experiment into a shallow aquifer was carried out in Wittstock (Northeast Germany) in order to investigate the geochemical impact of a CO2 influx into such an aquifer and to test different monitoring methods. Information regarding the site investigation, the injection procedure monitoring setup, and first geochemical monitoring results are described in [1]. Apart from the utilization of the test results to evaluate monitoring approaches [2], further findings are presented on the evaluation of the geophysical monitoring [3], and the monitoring of stable carbon isotopes [4]. This part of the study focuses of the hydrogeochemical alteration of groundwater due to the CO2 injection test. As a consequence of the CO2 injection, major cations were released, i.e. concentrations increased, whereas major anion concentrations - beside bicarbonate - decreased, probably due to increased anion sorption capacity at variably charged exchange sites of minerals. Trace element concentrations increased as well significantly, whereas the relative concentration increase was far larger than the relative concentration increase of major cations. Furthermore, geochemical reactions show significant spatial heterogeneity, i.e. some elements such as Cr, Cu, Pb either increased in concentration or remained at stable concentrations with increasing TIC at different wells. Statistical analyses of regression coefficients confirm the different spatial reaction patterns at different wells. Concentration time series at single wells give evidence, that the trace element release is pH dependent, i.e. trace elements such as Zn, Ni, Co are released at pH of around 6.2-6.6, whereas other trace elements like As, Cd, Cu are released at pH of 5.6-6.4. [1] Peter, A., et al., Investigation of

  9. A bypass case due to an acute inferior myocardial infarction caused by vascular occlusion of the left subclavian artery and left anterior descending artery.

    PubMed

    Altas, Yakup; Ulugg, Ali Veysel

    2016-01-01

    ST segment elevation is the most common electrocardiographic finding in acute myocardial infarction. ST elevation in chest leads generally represents left anterior descending artery occlusion, while elevation in DII and III, and aVF represents right coronary and circumflex artery occlusion. A female patient aged 66 years was admitted to our emergency service with ST elevation in leads DIII and aVF. A diagnosis of acute inferior myocardial infarction was made. The patient's history included coronary artery bypass graft involving the left internal mammary artery to the left anterior descending coronary artery and aorta to the right coronary artery. The patient was taken to the cardiac catheterization laboratory for primary percutaneous coronary intervention and a lesion in the left anterior descending artery was identified. Additionally, the left subclavian artery was totally occluded. Following intervention to the lesion, the patient was discharged on day 4 of admission. PMID:27555777

  10. A bypass case due to an acute inferior myocardial infarction caused by vascular occlusion of the left subclavian artery and left anterior descending artery

    PubMed Central

    Altas, Yakup; Ulugg, Ali Veysel

    2016-01-01

    ST segment elevation is the most common electrocardiographic finding in acute myocardial infarction. ST elevation in chest leads generally represents left anterior descending artery occlusion, while elevation in DII and III, and aVF represents right coronary and circumflex artery occlusion. A female patient aged 66 years was admitted to our emergency service with ST elevation in leads DIII and aVF. A diagnosis of acute inferior myocardial infarction was made. The patient’s history included coronary artery bypass graft involving the left internal mammary artery to the left anterior descending coronary artery and aorta to the right coronary artery. The patient was taken to the cardiac catheterization laboratory for primary percutaneous coronary intervention and a lesion in the left anterior descending artery was identified. Additionally, the left subclavian artery was totally occluded. Following intervention to the lesion, the patient was discharged on day 4 of admission. PMID:27555777

  11. Fetal rat metabonome alteration by prenatal caffeine ingestion probably due to the increased circulatory glucocorticoid level and altered peripheral glucose and lipid metabolic pathways

    SciTech Connect

    Liu, Yansong; Xu, Dan; Feng, Jianghua; Kou, Hao; Liang, Gai; Yu, Hong; He, Xiaohua; Zhang, Baifang; Chen, Liaobin; Magdalou, Jacques; Wang, Hui

    2012-07-15

    The aims of this study were to clarify the metabonome alteration in fetal rats after prenatal caffeine ingestion and to explore the underlying mechanism pertaining to the increased fetal circulatory glucocorticoid (GC). Pregnant Wistar rats were daily intragastrically administered with different doses of caffeine (0, 20, 60 and 180 mg/kg) from gestational days (GD) 11 to 20. Metabonome of fetal plasma and amniotic fluid on GD20 were analyzed by {sup 1}H nuclear magnetic resonance-based metabonomics. Gene and protein expressions involved in the GC metabolism, glucose and lipid metabolic pathways in fetal liver and gastrocnemius were measured by real-time RT-PCR and immunohistochemistry. Fetal plasma metabonome were significantly altered by caffeine, which presents as the elevated α- and β‐glucose, reduced multiple lipid contents, varied apolipoprotein contents and increased levels of a number of amino acids. The metabonome of amniotic fluids showed a similar change as that in fetal plasma. Furthermore, the expressions of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD-2) were decreased, while the level of blood GC and the expressions of 11β-HSD-1 and glucocorticoid receptor (GR) were increased in fetal liver and gastrocnemius. Meanwhile, the expressions of insulin-like growth factor 1 (IGF-1), IGF-1 receptor and insulin receptor were decreased, while the expressions of adiponectin receptor 2, leptin receptors and AMP-activated protein kinase α2 were increased after caffeine treatment. Prenatal caffeine ingestion characteristically change the fetal metabonome, which is probably attributed to the alterations of glucose and lipid metabolic pathways induced by increased circulatory GC, activated GC metabolism and enhanced GR expression in peripheral metabolic tissues. -- Highlights: ► Prenatal caffeine ingestion altered the metabonome of IUGR fetal rats. ► Caffeine altered the glucose and lipid metabolic pathways of IUGR fetal rats. ► Prenatal caffeine

  12. Time-Course of Alterations in Myocardial Glucose Utilization in the Zucker Diabetic Fatty (ZDF) Rat with Correlation to Gene Expression of Glucose Transporters: A Small Animal PET Investigation

    PubMed Central

    Shoghi, Kooresh I.; Gropler, Robert J.; Sharp, Terry; Herrero, Pilar; Fettig, Nicole; Su, Yi; Mitra, Mayurranjan S.; Kovacs, Attila; Finck, Brian N.; Welch, Michael J.

    2010-01-01

    Objective Diabetic cardiomyopathy is associated with abnormalities in glucose metabolism. We evaluated myocardial glucose metabolism in a rodent model of Type 2 Diabetes (T2D), namely the Zucker Diabetic Rat (ZDF), and validated PET measures of glucose uptake against gene and protein expression of glucose transporters. Methods Six lean and ZDF rat underwent small animal PET imaging at the age of 14 weeks and at the age of 19 weeks. The imaging protocol consisted of a 60-minute dynamic acquisition with 18FDG (0.5–0.8mCi). Dynamic images were reconstructed using filtered back projection (FBP) with a 2.5 zoom on the heart and 40 frames per imaging session. PET measures of myocardial glucose uptake rate (MGUp) and utilization were determined with an input function derived by the Hybrid Image- Blood Sampling (HIBS) algorithm on recovery-corrected anterolateral myocardial regions of interest. Following the PET imaging session at week 19, hearts were extracted for gene and protein expression analysis of GLUT1 and GLUT4. The dependence of MGUp on gene expression of GLUT1 and GLUT4 was characterized by multiple-regression analysis. Results Compared to lean littermate control rats, MGUp was significantly depressed in ZDF rats at both week 14 and week 19 (P<0.006). Moreover, lean rats at week 19 displayed significantly higher MGUp than week 14 (P=0.007). Consistent with diminished MGUp, gene expression of GLUT4 was significantly (P=0.004) lower in ZDF rats. Finally, MGUp significantly (P=0.0003) correlated with gene expression of GLUT4. Conclusions Using small animal PET, we confirmed alterations in myocardial glucose utilization and validated PET measure of MGUp against gene and protein expression of glucose transporters in the diabetic heart of an animal model of T2D. PMID:18632819

  13. Reduced ability to release adenosine by diabetic rat cardiac fibroblasts due to altered expression of nucleoside transporters

    PubMed Central

    Podgorska, Marzena; Kocbuch, Katarzyna; Grden, Marzena; Szutowicz, Andrzej; Pawelczyk, Tadeusz

    2006-01-01

    Adenosine produced by cardiac cells is known to attenuate the proliferation of cardiac fibroblasts (CFs), inhibit collagen synthesis, and protect the myocardium against ischaemic and reperfusion injury. Diabetic patients' hearts exhibit ventricular hypertrophy and demonstrate reduced tolerance to hypoxia or ischaemia. In this study, we characterize the effects of glucose and insulin on processes that determine the release of adenosine from CFs. We showed that during ATP depletion, rat CFs cultured in the absence of insulin release significantly less adenosine compared to cells grown in the presence of insulin. Moreover, under both conditions the quantity of released adenosine depends on glucose concentration. We demonstrate that this is due to altered expression of nucleoside transporters. High glucose (25 mm) induced 85% decrease in nucleoside transporter ENT1 mRNA levels. Decrease of the insulin level below 10−11m resulted in over 3-fold increase in the nucleoside transporter CNT2 mRNA content. Measurements of adenosine transport in CFs cultured in the presence of 5 mm glucose and 10 nm insulin showed that the bidirectional equilibrative adenosine transport accounted for 70% of the overall adenosine uptake. However, cells grown in the presence of high glucose (25 mm) demonstrated 65% decrease of the bidirectional equilibrative adenosine transport. Experiments on CFs cultured in the absence of insulin showed that the unidirectional Na+-dependent adenosine uptake rose in these cells more than 4-fold. These results indicate that the development of diabetes may result in an increased uptake of interstitial adenosine by CFs, and reduction of the ability of these cells to release adenosine during ATP deprivation. PMID:16873415

  14. Declines in Soil pH due to Anthropogenic Nitrogen Inputs Alter Buffering and Exchange Reactions in Tropical Forest Soils

    NASA Astrophysics Data System (ADS)

    Lohse, K. A.

    2003-12-01

    Anthropogenic nitrogen (N) inputs may alter tropical soil buffering and exchange reactions that have important implications for nutrient cycling, forest productivity, and downstream ecosystems. In contrast to relatively young temperate soils that are typically buffered from N inputs by base cation reactions, aluminum reactions may serve to buffer highly weathered tropical soils and result in immediate increases in aluminum mobility and toxicity. Increased nitrate losses due to chronic N inputs may also deplete residual base cations in already weathered base cation-poor soils, further acidify soils, and thereby reduce nitrate mobility through pH-dependent anion exchange reactions. To test these hypotheses, I determined soil pH and cation and anion exchange capacity (CEC and AEC) and measured base cation and aluminum soil solution losses following first-time and long-term experimental N additions from two Hawaiian tropical forest soils, a 300 year old Andisol and a 4.1 million year old Oxisol. I found that elevated base cation losses accompanied increased nitrate losses after first time N additions to the young Andisol whereas immediate and large aluminum losses were associated with increased nitrate losses from the Oxisol. In the long-term, base cation and aluminum losses increased in proportion to nitrate losses. Long-term N additions at both sites resulted in significant declines in soil pH, decreased CEC and increased AEC. These results suggest that even chronic N inputs resulting in small but elevated nitrate losses may deplete residual base cations, increase mobility and toxicity of aluminum, and potentially lead to declines in forest productivity and acidification of downstream ecosystems. These findings also suggest that AEC may provide a long-term mechanism to delay nitrate losses in tropical forests with significant variable charge that are experiencing chronic anthropogenic N inputs.

  15. Alteration of the Carbon and Nitrogen Isotopic Composition in the Martian Surface Rocks Due to Cosmic Ray Exposure

    NASA Technical Reports Server (NTRS)

    Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

    2014-01-01

    C-13/C-12 and N-15/N-14 isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce C-13 and N-15 isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both C-13 and N-15 due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" C-13/C-12 ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in N-15/N-14 ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (N-15/N-14). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

  16. Illustrating a New Global-scale Approach to Estimating Potential Reduction in Fish Species Richness due to Flow Alteration

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Sayaka; Yanagawa, Aki; Iwasaki, Yuichi; Sui, Pengzhe; Koirala, Sujan; Khajuria, Anupam; Hirano, Kazunari; Mahendran, Roobavannan; Hirabayashi, Yukiko; Yoshimura, Chihiro; Kanae, Shinjiro

    2014-05-01

    Changes in river discharge due to human activities and climate change would affect the sustainability of freshwater ecosystems. To globally assess how changes in river discharge will affect the future status of freshwater ecosystems, global-scale hydrological simulations need to be connected with a model to estimate the durability of freshwater ecosystems. However, the development of this specific modelling combination for the global scale is still in its infancy. In this study, two statistical methods are introduced to link flow regimes to fish species richness (FSR): one is based on a linear relationship between FSR and mean river discharge (hereafter, FSR-MAD method), and the other is based on a multi-linear relationship between FSR and ecologically relevant flow indices involving several other flow characteristics and mean river discharge (FSR-FLVAR method). The FSR-MAD method has been used previously in global simulation studies. The FSR-FLVAR method is newly introduced here. These statistical methods for estimating FSR were combined with a set of state-of-art global river discharge simulations using latest outputs of 11 coupled atmosphere-ocean general circulation models to evaluate the potential impact of climate- change-induced flow alterations on FSR changes. Generally, future reductions in FSR with the FSR-FLVAR method are greater and much more scattered than those with the FSR-MAD method. In arid regions, both methods indicate reductions in FSR because mean discharge is projected to decrease in the future, although the magnitude of reductions in FSR is different between the two methods. In contrast, in heavy-snow regions a large reduction in FSR is shown by the FSR-FLVAR method due to increases in the frequency of low and high flows. Although we cannot determine only by this study which this prediction is more reliable, it can be argued that efforts to take plural ecologically relevant flow indices into account would lead to more appropriate methods for

  17. Myocardial Tissue Doppler Velocity in Child Growth

    PubMed Central

    Choi, Sun-Ha; Kim, Nam Kyun; Jung, Jo Won; Choi, Jae Young

    2016-01-01

    Background In adults, tissue Doppler imaging (TDI) is a recommended component of routine echocardiography. However, TDI velocities are less accepted in pediatrics, due to their strong variability and age dependence in children. This study examines the distribution of myocardial tissue Doppler velocities in healthy children to assess the effect of age with cardiac growth on the various echocardiographic measurements. Methods Total 144 healthy children were enrolled in this study. They were recruited from the pediatric outpatient clinic for routine well-child visits. The statistical relationships between age and TDI values were analyzed. Also, the statistical relationships between body surface area (BSA) and TDI values, left ventricle end-diastolic dimension (LVEDD) and TDI values were analyzed. Also, we conducted multivariate analysis of cardiac growth parameters such as, age, BSA, LVEDD and TDI velocity data. Results All of the age, BSA, and LVEDD had positive correlations with deceleration time (DT), pressure half-time (PHT), peak early diastolic myocardial velocity, peak systolic myocardial velocity, and had negative correlations with peak late diastolic velocity (A) and the ratio of trans-mitral inflow velocity to early diastolic velocity of mitral annulus (E/E'). In the multivariate analysis, all of the age, BSA, and LVEDD had positive correlations with DT, PHT, and negative correlations with A and E/E'. Conclusion The cardiac growth parameters related alterations of E/E' may suggest that diastolic myocardial velocities are cardiac growth dependent, and diastolic function has positive correlation with cardiac growth in pediatric group. This cardiac growth related myocardial functional variation would be important for assessment of cardiac involvement either in healthy and sick child. PMID:27081443

  18. A Coupled Biosphere-Atmosphere Climate Model Suitable for Studies of Climatic Change Due to Land Surface Alterations.

    NASA Astrophysics Data System (ADS)

    Varejão-Silva, Mário Adelmo; Franchito, Sergio H.; Brahmananda Rao, Vadlamudi

    1998-07-01

    A biosphere model based on BATS (Biosphere-Atmosphere Transfer Scheme) is coupled to a primitive equation global statistical-dynamical model in order to study the climatic impact due to land surface alterations. The fraction of the earth's surface covered by each vegetation type according to BATS is obtained for each latitude belt. In the control experiment, the mean annual zonally averaged climate is well simulated when compared with observations. Deforestation and desertification experiments are performed. In the deforestation experiment, the evergreen broadleaf tree in the Amazonian region is substituted by short grass; in the desertification experiment the semidesert, and the tall grass and deciduous shrubs are substituted by desert and semidesert in the African continent, respectively.The results show that in both the experiments there is a reduction in evapotranspiration and precipitation in the perturbed region and an increase in the soil surface temperature, the temperature of the foliage air layer, and the foliage temperature. Also, the latent heat flux decreased in the perturbed cases relative to the control case. To partially compensate for the decrease in latent heating, sensible heat flux increased in the perturbed cases compared with the control case. The changes in the deforestation case are greater in the latitude belt centered at 5°S, where in most part the Amazonian forest is situated. Otherwise, the changes in the desertification are greater in the latitude belt centered at 15°N. When there is also degradation of the African tropical forest (substitution of evergreen broadleaf trees by short grass), the greatest changes occur southward from that region (in the latitude belt centered at 5°N), and the magnitude of the changes are also increased. This shows the important role of the modification of tropical forest when there is degradation of the vegetation in the African region from 20°N to 0°°.The results regarding the changes in the

  19. Myocardial diseases of animals.

    PubMed Central

    Van Vleet, J. F.; Ferrans, V. J.

    1986-01-01

    In this review we have attempted a comprehensive compilation of the cardiac morphologic changes that occur in spontaneous and experimental myocardial diseases of animals. Our coverage addresses diseases of mammals and birds and includes these diseases found in both domesticated and wild animals. A similar review of the myocardial diseases in this broad range of animal species has not been attempted previously. We have summarized and illustrated the gross, microscopic, and ultrastructural alterations for these myocardial diseases; and, whenever possible, we have reviewed their biochemical pathogenesis. We have arranged the myocardial diseases for presentation and discussion according to an etiologic classification with seven categories. These include a group of idiopathic or primary cardiomyopathies recognized in man (hypertrophic, dilated, and restrictive types) and a large group of secondary cardiomyopathies with known causes, such as inherited tendency; nutritional deficiency; toxicity; physical injury and shock; endocrine disorders, and myocarditides of viral, bacterial, and protozoal causation. Considerable overlap exists between each of the etiologic groups in the spectrum of pathologic alterations seen in the myocardium. These include various degenerative changes, myocyte necrosis, and inflammatory lesions. However, some diseases show rather characteristic myocardial alterations such as vacuolar degeneration in anthracycline cardiotoxicity, myofibrillar lysis in furazolidone cardiotoxicity, calcification in calcinosis of mice, glycogen accumulation in the glycogenoses, lipofuscinosis in cattle, fatty degeneration in erucic acid cardiotoxicity, myofiber disarray in hypertrophic cardiomyopathy, and lymphocytic inflammation with inclusion bodies in canine parvoviral myocarditis. The myocardial diseases represent the largest group in the spectrum of spontaneous cardiac diseases of animals. Pericardial and endocardial diseases and congential cardiac diseases are

  20. The altered expression profile of microRNAs in cardiopulmonary bypass canine models and the effects of mir-499 on myocardial ischemic reperfusion injury

    PubMed Central

    2013-01-01

    Background MicroRNAs were enrolled in various cardiovascular disease especially ischemic heart diseases, but the microRNA changes during myocardial ischemia reperfusion injury underwent cardiopulmonary bypass are still unknown. This study screens the microRNA differences in CPB canines and evaluates the relationship of microRNAs with myocardial ischemia reperfusion injury. Methods 13 healthy canines received CPB with 60 minutes of aortic clamping and cardioplegic arrest, followed by 90 minutes reperfusion. Left ventricular myocardial samples, blood samples and hemodynamic data were taken at different time points. We performed microRNAs microarray experiments upon the left ventricle myocardium tissue of canines before CPB and after reperfusion for 90 minutes by pooling 3 tissue samples together and used qRT-PCR for confirmation. Results Statistically significant difference was found in mir-499 level before CPB and after reperfusion (T1 vs. T4, p = 0.041). We further examined the mir-499 levels by using qRT-PCR in all 13 canines at 4 different time points (T1 vs. T4, p = 0.029). Mir-499 expression was negatively correlated with cardiac troponin T (cTnT) and creatine kinase- MB (CK-MB) levels of canines in all time points samples (r = 0.469, p < 0.001 and r = 0.273, p = 0.050 respectively). Moreover, higher mir-499 expression level was associated with higher dP/dtmax at 25 minutes and 90 minutes after reperfusion. Conclusion Myocardial ischemic reperfusion injury with cardiopulmonary bypass results in declining level of mir-499 expression in left ventricle myocardium of canines, suggesting mir-499 would be a potential therapeutic target in cardiac protection during open heart surgery. PMID:23800236

  1. Myocardial Bridge

    MedlinePlus

    ... artery. See also on this site: Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated August ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  2. Myocardial ischemia due to a type IV dual LAD with the long LAD arising from the right sinus of valsalva: a case report and literature review.

    PubMed

    Gao, Xiangyu; Li, Hongwei; Chen, Hui

    2015-01-01

    We herein report the case of a 60-year-old man who presented with chest discomfort. Coronary angiography demonstrated that the short left anterior descending artery (LAD) arose from the left main coronary artery and the long LAD from the right coronary sinus of Valsalva, which was confirmed by 64-slice multidetector computed tomography coronary angiography. Single-photon emission computed tomography revealed a significant, almost irreversible degree of hypoperfusion in the anterior wall of the left ventricle, thus indicating that the short LAD was associated with myocardial ischemia and severe atherosclerotic lesions. Therefore, SPECT showed that the myocardium was largely necrotic, and we did not perform angioplasty for the short LAD. PMID:26466699

  3. Myocardial infarction resulting from coronary artery dissection in an adolescent with Ehlers-Danlos syndrome type IV due to a type III collagen mutation.

    PubMed Central

    Adès, L. C.; Waltham, R. D.; Chiodo, A. A.; Bateman, J. F.

    1995-01-01

    Ehlers-Danlos syndrome encompasses a group of inherited disorders of connective tissue, some of which are characterised by abnormalities of collagen metabolism. The chromosomal location, identified genes and biochemical defects, inheritance pattern, and clinical features for the various known subtypes are outlined. Prenatal diagnosis is possible for types IV, VI, VIIA1, and VIIA2. An unusual presentation of type IV Ehlers-Danlos syndrome in a 16 year old boy with an anterior myocardial infarction resulting from dissection of the left anterior descending coronary artery is reported here. A clinical diagnosis of type IV Ehlers-Danlos syndrome was made subsequently and confirmed by the reduced production, impaired secretion, and abnormally slow electrophoretic migration of type III collagen, indicating an underlying mutation in the COL3A1 gene. This patient represents the first case of type IV Ehlers-Danlos syndrome with symptomatic coronary artery dissection. Images PMID:7546986

  4. Blastocyst implantation failure in mice due to "nonreceptive endometrium": endometrial alterations by Hibiscus rosa-sinensis leaf extract.

    PubMed

    Nivsarkar, Manish; Patel, Manoj; Padh, Harish; Bapu, Cherian; Shrivastava, Neeta

    2005-03-01

    Many plants are known to possess antifertility activity. However, limited attempts have been made to scientifically evaluate these claims. Hibiscus rosa-sinensis flowers have been shown to possess antifertility and abortifacient activity. In this report, antiimplantation activity of water extract of leaves of H. rosa-sinensis was investigated. Pregnant female mice were dosed with extract (100 mg/kg body weight) from days 1 to 6 of pregnancy. No implantation sites were observed in treated animals when they were surgically opened on day 15 of pregnancy. Biochemical and biophysical alterations were observed in the endometrium in treated animals, especially on day 5, at 4:40 a.m., the day of implantation. A sharp increase in superoxide anion radical and a sharp fall in superoxide dismutase (SOD) activity, as seen in the endometrium from control animals, were altered in treated animals. The extract also exhibited antiestrogenic activity, as judged by increase in uterine weight. The physiological alterations induced by water extract of H. rosa-sinensis are discussed. PMID:15722074

  5. Bentonite alteration due to thermal-hydro-chemical processes during the early thermal period in a nuclear waste repository

    SciTech Connect

    Xu, T.; Senger, R.; Finsterle, S.

    2011-02-01

    After closure of an underground nuclear waste repository, the decay of radionuclides will raise temperature in the repository, and the bentonite buffer will resaturate by water inflow from the surrounding host rock. The perturbations from these thermal and hydrological processes are expected to dissipate within hundreds to a few thousand years. Here, we investigate coupled thermal-hydro-chemical processes and their effects on the short-term performance of a potential nuclear waste repository located in a clay formation. Using a simplified geometric configuration and abstracted hydraulic parameters of the clayey formation, we examine geochemical processes, coupled with thermo-hydrologic phenomena, and potential changes in porosity near the waste container during the early thermal period. The developed models were used for evaluating the mineral alterations and potential changes in porosity of the buffer, which can affect the repository performance. The results indicate that mineral alteration and associated changes in porosity induced by early thermal and hydrological processes are relatively small and are expected to not significantly affect flow and transport properties. Chlorite precipitation was obtained in all simulation cases. A maximum of one percent volume fraction of chlorite could be formed, whose process may reduce swelling and sorption capacity of bentonite clay, affecting the performance of the repository. llitisation process was not obtained from the present simulations.

  6. Altered joint tribology in osteoarthritis: Reduced lubricin synthesis due to the inflammatory process. New horizons for therapeutic approaches.

    PubMed

    Szychlinska, M A; Leonardi, R; Al-Qahtani, M; Mobasheri, A; Musumeci, G

    2016-06-01

    Osteoarthritis (OA) is the most common form of joint disease. This review aimed to consolidate the current evidence that implicates the inflammatory process in the attenuation of synovial lubrication and joint tissue homeostasis in OA. Moreover, with these findings, we propose some evidence for novel therapeutic strategies for preventing and/or treating this complex disorder. The studies reviewed support that inflammatory mediators participate in the onset and progression of OA after joint injury. The flow of pro-inflammatory cytokines following an acute injury seems to be directly associated with altered lubricating ability in the joint tissue. The latter is associated with reduced level of lubricin, one of the major joint lubricants. Future research should focus on the development of new therapies that attenuate the inflammatory process and restore lubricin synthesis and function. This approach could support joint tribology and synovial lubrication leading to improved joint function and pain relief. PMID:27118399

  7. Alterations in the coupling functions between cortical and cardio-respiratory oscillations due to anaesthesia with propofol and sevoflurane.

    PubMed

    Stankovski, Tomislav; Petkoski, Spase; Raeder, Johan; Smith, Andrew F; McClintock, Peter V E; Stefanovska, Aneta

    2016-05-13

    The precise mechanisms underlying general anaesthesia pose important and still open questions. To address them, we have studied anaesthesia induced by the widely used (intravenous) propofol and (inhalational) sevoflurane anaesthetics, computing cross-frequency coupling functions between neuronal, cardiac and respiratory oscillations in order to determine their mutual interactions. The phase domain coupling function reveals the form of the function defining the mechanism of an interaction, as well as its coupling strength. Using a method based on dynamical Bayesian inference, we have thus identified and analysed the coupling functions for six relationships. By quantitative assessment of the forms and strengths of the couplings, we have revealed how these relationships are altered by anaesthesia, also showing that some of them are differently affected by propofol and sevoflurane. These findings, together with the novel coupling function analysis, offer a new direction in the assessment of general anaesthesia and neurophysiological interactions, in general. PMID:27045000

  8. Alterations in the coupling functions between cortical and cardio-respiratory oscillations due to anaesthesia with propofol and sevoflurane

    PubMed Central

    Petkoski, Spase; Raeder, Johan; Smith, Andrew F.; McClintock, Peter V. E.; Stefanovska, Aneta

    2016-01-01

    The precise mechanisms underlying general anaesthesia pose important and still open questions. To address them, we have studied anaesthesia induced by the widely used (intravenous) propofol and (inhalational) sevoflurane anaesthetics, computing cross-frequency coupling functions between neuronal, cardiac and respiratory oscillations in order to determine their mutual interactions. The phase domain coupling function reveals the form of the function defining the mechanism of an interaction, as well as its coupling strength. Using a method based on dynamical Bayesian inference, we have thus identified and analysed the coupling functions for six relationships. By quantitative assessment of the forms and strengths of the couplings, we have revealed how these relationships are altered by anaesthesia, also showing that some of them are differently affected by propofol and sevoflurane. These findings, together with the novel coupling function analysis, offer a new direction in the assessment of general anaesthesia and neurophysiological interactions, in general. PMID:27045000

  9. Wave Propagation of Myocardial Stretch: Correlation with Myocardial Stiffness

    PubMed Central

    Pislaru, Cristina; Pellikka, Patricia A.; Pislaru, Sorin V.

    2015-01-01

    The mechanism of flow propagation during diastole in the left ventricle (LV) has been well described. Little is known about the associated waves propagating along the heart wall s. These waves may have a mechanism similar to pulse wave propagation in arteries. The major goal of the study was to evaluate the effect of myocardial stiffness and preload on this wave transmission. Methods Longitudinal late diastolic deformation and wave speed (Vp) of myocardial stretch in the anterior LV wall were measured using sonomicrometry in sixteen pigs. Animals with normal and altered myocardial stiffness (acute myocardial infarction) were studied with and without preload alterations. Elastic modulus estimated from Vp (EVP; Moens-Korteweg equation) was compared to incremental elastic modulus obtained from exponential end -diastolic stress-strain relation (ESS). Myocardial distensibility and α-and β-coefficients of stress-strain relations were calculated. Results Vp was higher at reperfusion compared to baseline (2.6±1.3 m/s vs. 1.3±0.4 m/s; p=0.005) and best correlated with ESS (r 2=0.80, p<0.0001), β-coefficient (r2=0.78, p<0.0001), distensibility (r2=0.47, p=0.005), and wall thickness/diameter ratio (r2=0.42, p=0.009). Elastic moduli (EVP and ESS) were strongly correlated (r2=0.83, p<0.0001). Increasing preload increased Vp and EVP and decreased distensibility. At multivariate analysis, ESS, wall thickness, and end-diastolic and systolic LV pressures were independent predictors of Vp (r2model=0.83, p<0.0001). Conclusions The main determinants of wave propagation of longitudinal myocardial stretch were myocardial stiffness and LV geometry and pressure. This local wave speed could potentially be measured noninvasively by echocardiography. PMID:25193091

  10. Metabolic alterations due to caloric restriction and every other day feeding in normal and growth hormone receptor knockout mice.

    PubMed

    Westbrook, Reyhan; Bonkowski, Michael S; Arum, Oge; Strader, April D; Bartke, Andrzej

    2014-01-01

    Mutations causing decreased somatotrophic signaling are known to increase insulin sensitivity and extend life span in mammals. Caloric restriction and every other day (EOD) dietary regimens are associated with similar improvements to insulin signaling and longevity in normal mice; however, these interventions fail to increase insulin sensitivity or life span in growth hormone receptor knockout (GHRKO) mice. To investigate the interactions of the GHRKO mutation with caloric restriction and EOD dietary interventions, we measured changes in the metabolic parameters oxygen consumption (VO2) and respiratory quotient produced by either long-term caloric restriction or EOD in male GHRKO and normal mice. GHRKO mice had increased VO2, which was unaltered by diet. In normal mice, EOD diet caused a significant reduction in VO2 compared with ad libitum (AL) mice during fed and fasted conditions. In normal mice, caloric restriction increased both the range of VO2 and the difference in minimum VO2 between fed and fasted states, whereas EOD diet caused a relatively static VO2 pattern under fed and fasted states. No diet significantly altered the range of VO2 of GHRKO mice under fed conditions. This provides further evidence that longevity-conferring diets cause major metabolic changes in normal mice, but not in GHRKO mice. PMID:23833202

  11. Altered Hematopoiesis in Mice Lacking DNA Polymerase μ Is Due to Inefficient Double-Strand Break Repair

    PubMed Central

    Lucas, Daniel; Escudero, Beatriz; Ligos, José Manuel; Segovia, Jose Carlos; Estrada, Juan Camilo; Terrados, Gloria; Blanco, Luis; Samper, Enrique; Bernad, Antonio

    2009-01-01

    Polymerase mu (Polμ) is an error-prone, DNA-directed DNA polymerase that participates in non-homologous end-joining (NHEJ) repair. In vivo, Polμ deficiency results in impaired Vκ-Jκ recombination and altered somatic hypermutation and centroblast development. In Polμ−/− mice, hematopoietic development was defective in several peripheral and bone marrow (BM) cell populations, with about a 40% decrease in BM cell number that affected several hematopoietic lineages. Hematopoietic progenitors were reduced both in number and in expansion potential. The observed phenotype correlates with a reduced efficiency in DNA double-strand break (DSB) repair in hematopoietic tissue. Whole-body γ-irradiation revealed that Polμ also plays a role in DSB repair in non-hematopoietic tissues. Our results show that Polμ function is required for physiological hematopoietic development with an important role in maintaining early progenitor cell homeostasis and genetic stability in hematopoietic and non-hematopoietic tissues. PMID:19229323

  12. Quantitative Assessment of Altered Rectal Mucosal Permeability Due to Rectally Applied Nonoxynol-9, Biopsy, and Simulated Intercourse

    PubMed Central

    Fuchs, Edward J.; Grohskopf, Lisa A.; Lee, Linda A.; Bakshi, Rahul P.; Hendrix, Craig W.

    2013-01-01

    Background. Microbicide toxicity may reduce the efficacy of topical preexposure prophylaxis for human immunodeficiency virus (HIV) transmission. Noninvasive quantitative measures of microbicide toxicity would usefully inform microbicide development. Methods. Ten subjects received 3 one-time interventions: 5 mL of Normosol-R fluid alone (negative control), 5 mL of 2% nonoxynol-9 (N-9) gel, and 5 mL of Normosol-R with coital simulation and sigmoidoscopic biopsy (CS + BX). Each dose of N-9 and Normosol-R contained 500 µCi of 99mtechnetium–diethylene triamine pentaacetic acid. Plasma and urine radioactivity was assessed over 24 hours. Results. The plasma radioisotope concentration peaked 1 hour after N-9 dosing. The mean maximum radioisotope concentration after N-9 receipt was 12.0 times (95% confidence interval [CI], 6.8–21.0) and 8.4 times (95% CI, 5.2–13.5) the mean concentration after Normosol-R control receipt and CS + BX receipt, respectively; paired differences persisted for 24 hours. After N-9 dosing, the urine isotope level was 3.6 times (95% CI, 1.1–11.4) the level observed 8 hours after Normosol-R control receipt and 4.0 times (95% CI, 1.4–11.4) the level observed 4 hours after CS + BX receipt. Permeability after CS + BX receipt was greater than that after Normosol-R control receipt in 0–2-hour urine specimens only (mean permeability, 2.4; 95% CI, 1.0–5.8) but was not greater in blood. Conclusions. Plasma sampling after rectal radioisotope administration provided quantitative estimates of altered mucosal permeability after chemical and mechanical stresses. Permeability testing may provide a useful noninvasive adjunct to assess the mucosal effects of candidate microbicides. Clinical Trials Registration. NCT00389311. PMID:23325915

  13. Cardiac and aortic structural alterations due to surgically-induced menopause associated with renovascular hypertension in rats.

    PubMed

    Mendonça, Leonardo de Souza; Fernandes-Santos, Caroline; Mandarim-de-Lacerda, Carlos Alberto

    2007-08-01

    Menopause and hypertension independently alter cardiovascular remodelling, but little is known about their effect on left ventricular and aortic wall remodelling. Eight-weeks-old Wistar rats were divided into four groups of six animals each: Sham group, OVX group (ovariectomized rats), 2K1C (two-kidneys, one-clip rats) and OVX + 2K1C group and kept until 19 weeks. Blood pressure (BP) increased 12% in OVX group, 35% in 2K1C and OVX + 2K1C groups compared with sham group. Vaginal cytology showed Sham and 2K1C rats cycling normally, whereas OVX and OVX + 2K1C rats were persistently in dioestrus or proestrus. At euthanasia, left ventricle (LV) and thoracic aorta were removed and analysed (immunohistochemistry and stereology). LV mass/tibia length ratio and cross-sectional area of cardiomyocytes increased in all groups except Sham. The intramyocardial vascularization reduced 30% in comparison with Sham group, with no difference among OVX, 2K1C and OVX + 2K1C groups. The cardiac interstitium increased more than 45% in both 2K1C and OVX + 2K1C groups compared with Sham, but there was no significant difference between Sham and OVX groups. Nuclei number of LV cardiomyocyte diminished in OVX group, followed by 2K1C group and OVX + 2K1C group, with no difference between the 2K1C and the OVX + 2K1C groups. There was positive immunostaining for angiotensin II AT1 receptor in smooth muscle cell layer of aortic tunica media in all groups. These results show that both ovariectomy and renovascular hypertension enhance BP as a single stimulus and therefore produce adverse cardiac remodelling. However, renovascular hypertension exerts a far greater influence than surgically-induced menopause in this parameter. PMID:17696911

  14. A higher aspect ratio enhanced bioaccumulation and altered immune responses due to intravenously-injected aluminum oxide nanoparticles.

    PubMed

    Park, Eun-Jung; Kim, Soo Nam; Kang, Min-Sung; Lee, Byoung-Seok; Yoon, Cheolho; Jeong, Uiseok; Kim, Younghun; Lee, Gwang-Hee; Kim, Dong-Wan; Kim, Jong Sung

    2016-07-01

    Aluminum oxide nanoparticles (AlO NP) have been widely utilized in a variety of areas, including in the optical, biomedical and electronic fields and in the overall development of nanotechnologies. However, their toxicological profiles are still not fully developed. This study compared the distribution and immunotoxicity of two rod-types of AlO NP. As reported previously, the two types of AlO NP had different aspect ratios (long-type: 6.2 ± 0.6, short-type: 2.1 ± 0.4), but the size and surface charge were very similar. On Day 14 after a single intravenous (IV) injection (1.25 or 5 mg/kg), both AlO NP accumulated primarily in the liver and spleen and altered the levels of redox response-related elements. The accumulated level was higher in mice exposed to the long-type AlO NP compared to the short-type. Additionally, it was noted that the levels of IL-1β, IL-8 and MCP-1 were enhanced in the blood of mice exposed to both types of AlO NP and the percentages of neutrophils and monocytes among all white blood cells were increased only in mice injected with the long-type AlO NP (5 mg/kg). In addition, as compared to the control, co-expression of CD80 and CD86 (necessary for antigen presentation) on splenocytes together with a decreased expression of chemotaxis-related marker (CD195) was attenuated by exposure to the AlO NP, especially the long-type. Taken together, the data suggest that accumulation following a single IV injection with rod-types of AlO NP is strengthened by a high aspect ratio and, subsequently, this accumulation has the potential to influence immune functions in an exposed host. PMID:27042761

  15. Geomorphic Framework to assess changes to aquatic habitat due to flow regulation and channel and floodplain alteration, Cedar River, Washington

    USGS Publications Warehouse

    Gendaszek, Andrew S.; Magirl, Christopher S.; Czuba, Christiana R.; Konrad, Christopher P.; Little, Rand

    2010-01-01

    Flow regulation, bank armoring, and floodplain alteration since the early 20th century have contributed to significant changes in the hydrologic regime and geomorphic processes of the Cedar River in Washington State. The Cedar River originates in the Cascade Range, provides drinking water to the Seattle metropolitan area, and supports several populations of anadromous salmonids. Flow regulation currently has limited influence on the magnitude, duration, and timing of high-flow events, which affect the incubation of salmonids as well as the production and maintenance of their habitat. Unlike structural changes to the channel and floodplain, flow regulation may be modified in the short-term to improve the viability of salmon populations. An understanding of the effects of flow regulation on those populations must be discerned over a range of scales from individual floods that affect the size of individual year classes to decadal high flow regime that influences the amount and quality of channel and off-channel habitat available for spawning and rearing. We present estimates of reach-scale sediment budgets and changes to channel morphology derived from historical orthoimagery, specific gage analyses at four long-term streamflow-gaging stations to quantify trends in aggradation, and hydrologic statistics of the magnitude and duration of peak streamflows. These data suggest a gradient of channel types from unconfined, sediment-rich segments to confined, sediment-poor segments that are likely to have distinct responses to high flows. Particle-size distribution data and longitudinal water surface and streambed profiles for the 56 km downstream of Chester Morse Lake measured in 2010 show the spatial extent of preferred salmonid habitat along the Cedar River. These historical and current data constitute a geomorphic framework to help assess different river management scenarios for salmonid habitat and population viability. PDF version of a presentation on changes to aquatic

  16. Inhibition of tomato (Solanum lycopersicum L.) root growth by cyanamide is due to altered cell division, phytohormone balance and expansin gene expression.

    PubMed

    Soltys, Dorota; Rudzińska-Langwald, Anna; Gniazdowska, Agnieszka; Wiśniewska, Anita; Bogatek, Renata

    2012-11-01

    Cyanamide (CA) has been reported as a natural compound produced by hairy vetch (Vicia villosa Roth.) and it was shown also to be an allelochemical, responsible for strong allelopathic potential in this species. CA phytotoxicity has been demonstrated on various plant species, but to date little is known about its mode of action at cellular level. Treatment of tomato (Solanum lycopersicum L.) roots with CA (1.2 mM) resulted in inhibition of growth accompanied by alterations in cell division, and imbalance of plant hormone (ethylene and auxin) homeostasis. Moreover, the phytotoxic effect of CA was also manifested by modifications in expansin gene expression, especially in expansins responsible for cell wall remodeling after the cytokinesis (LeEXPA9, LeEXPA18). Based on these results the phytotoxic activity of CA on growth of roots of tomato seedlings is likely due to alterations associated with cell division. PMID:22847024

  17. Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

    PubMed Central

    Zhou, Tingyang; Chuang, Chia-Chen; Zuo, Li

    2015-01-01

    Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body's antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury. PMID:26509170

  18. Myocardial reverse remodeling: how far can we rewind?

    PubMed

    Rodrigues, Patrícia G; Leite-Moreira, Adelino F; Falcão-Pires, Inês

    2016-06-01

    Heart failure (HF) is a systemic disease that can be divided into HF with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). HFpEF accounts for over 50% of all HF patients and is typically associated with high prevalence of several comorbidities, including hypertension, diabetes mellitus, pulmonary hypertension, obesity, and atrial fibrillation. Myocardial remodeling occurs both in HFrEF and HFpEF and it involves changes in cardiac structure, myocardial composition, and myocyte deformation and multiple biochemical and molecular alterations that impact heart function and its reserve capacity. Understanding the features of myocardial remodeling has become a major objective for limiting or reversing its progression, the latter known as reverse remodeling (RR). Research on HFrEF RR process is broader and has delivered effective therapeutic strategies, which have been employed for some decades. However, the RR process in HFpEF is less clear partly due to the lack of information on HFpEF pathophysiology and to the long list of failed standard HF therapeutics strategies in these patient's outcomes. Nevertheless, new proteins, protein-protein interactions, and signaling pathways are being explored as potential new targets for HFpEF remodeling and RR. Here, we review recent translational and clinical research in HFpEF myocardial remodeling to provide an overview on the most important features of RR, comparing HFpEF with HFrEF conditions. PMID:26993225

  19. Adipose stem cell sheets improved cardiac function in the rat myocardial infarction, but did not alter cardiac contractile responses to β-adrenergic stimulation.

    PubMed

    Otsuki, Yuki; Nakamura, Yoshinobu; Harada, Shingo; Yamamoto, Yasutaka; Ogino, Kazuhide; Morikawa, Kumi; Ninomiya, Haruaki; Miyagawa, Shigeru; Sawa, Yoshiki; Hisatome, Ichiro; Nishimura, Motonobu

    2015-01-01

    Adipose stem cells (ASCs) are a source of regenerative cells available for autologous transplantation to hearts. We compared protective actions of ASC sheets on rat myocardial infarction (MI) in comparison with those of skeletal myoblast cell sheets. Their effects on infarcted hearts were evaluated by biological, histochemical as well as physiological analyses. ASC sheets secreted higher concentrations of angiogenic factors (HGF, VEGF, and bFGF; P < 0.05) under normoxic and hypoxic conditions than those of myoblast cell sheets, associated with reduction of cell apoptosis (P < 0.05). Like myoblast cell sheets, ASC sheets improved cardiac function (P < 0.05) and decreased the plasma level of ANP (P < 0.05) in MI hearts. ASC sheets restored cardiac remodeling characterized by fibrosis, cardiac hypertrophy and impaired angiogenesis (P < 0.05), which was associated with increases in angiogenic factors (P < 0.05). In isolated perfused rat hearts, ASC sheets improved both systolic and diastolic functions, which was comparable to cardiac functions of myoblast cell sheets, while both cell sheets failed to restore cardiac contractile response to either isoproterenol, pimobendan or dibutyryl cAMP. These results indicated that ASC sheets improved cardiac function and remodeling of MI hearts mediated by their paracrine action and this improvement was comparable to those by myoblast cell sheets. PMID:25749147

  20. 2013 Immune Risk Standing Review Panel Evidence Review for: The Risk of Crew Adverse Health Event Due to Altered Immune Response

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2014-01-01

    The 2013 Immune Risk Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on February 3-4, 2014. The SRP reviewed the new Evidence Report for the Risk of Crew Adverse Health Event Due to Altered Immune Response (from here on referred to as the 2013 Immune Evidence Report), as well as the Research Plan for this Risk that is in the current version of the Human Research Program’s (HRP) Integrated Research Plan (IRP).

  1. Altered myocardial perfusion in patients with angina pectoris or silent ischemia during exercise as assessed by quantitative thallium-201 single-photon emission computed tomography

    SciTech Connect

    Mahmarian, J.J.; Pratt, C.M.; Cocanougher, M.K.; Verani, M.S. )

    1990-10-01

    The extent of abnormally perfused myocardium was compared in patients with and without chest pain during treadmill exercise from a large, relatively low-risk consecutive patient population (n = 356) referred for quantitative thallium-201 single-photon emission computed tomography (SPECT). All patients had concurrent coronary angiography. Patients were excluded if they had prior coronary angioplasty or bypass surgery. Tomographic images were assessed visually and from computer-generated polar maps. Chest pain during exercise was as frequent in patients with normal coronary arteries (12%) as in those with significant (greater than 50% stenosis) coronary artery disease (CAD) (14%). In the 219 patients with significant CAD, silent ischemia was fivefold more common than symptomatic ischemia (83% versus 17%, p = 0.0001). However, there were no differences in the extent, severity, or distribution of coronary stenoses in patients with silent or symptomatic ischemia. Our major observation was that the extent of quantified SPECT perfusion defects was nearly identical in patients with (20.9 +/- 15.9%) and without (20.5 +/- 15.6%) exertional chest pain. The sensitivity for detecting the presence of CAD was significantly improved with quantitative SPECT compared with stress electrocardiography (87% versus 65%, p = 0.0001). Although scintigraphic and electrocardiographic evidence of exercise-induced ischemia were comparable in patients with chest pain (67% versus 73%, respectively; p = NS), SPECT was superior to stress electrocardiography for detecting silent myocardial ischemia. The majority of patients in this study with CAD who developed ischemia during exercise testing were asymptomatic, although they exhibited an angiographic profile and extent of abnormally perfused myocardium similar to those of patients with symptomatic ischemia.

  2. Protective effects of Labisia pumila var. alata on biochemical and histopathological alterations of cardiac muscle cells in isoproterenol-induced myocardial infarction rats.

    PubMed

    Dianita, Roza; Jantan, Ibrahim; Amran, Athirah Z; Jalil, Juriyati

    2015-01-01

    The study was designed to evaluate the cardioprotective effects of the standardized aqueous and 80% ethanol extracts of Labisia pumila var. alata (LPva) in isoproterenol (ISO)-induced myocardial infarction (MI) in rats. The extracts were administered to Wistar rats orally for 28 days with three doses (100, 200 and 400 mg/kg of body weight) prior to ISO (85 mg/kg)-induced MI in two doses on day 29 and 30. The sera and hearts were collected for biochemical and histopathological analysis after the rats were sacrificed 48 h after the first induction. The main components of the extracts, gallic acid, alkylresorcinols and flavonoids were identified and quantitatively analyzed in the extracts by using a validated reversed phase HPLC method. The extracts showed significant protective effects as pretreated rats showed a significant dose-dependent decrease (p < 0.05) in cardiac enzyme activities, i.e., cardiac troponin I (cTnI), creatine kinase MB isoenzyme (CK-MB), lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate transaminase (AST), when compared with ISO-control rats. There were significant rises (p < 0.05) in the activity of oxidase enzymes, i.e., glutathione peroxide (GPx), catalase (CAT) and superoxide dismutase (SOD) of the pretreated rats, when compared with ISO-control group. Histopathological examination showed an improvement in membrane cell integrity in pre-treated rats compared to untreated rats. The major components of LPva extracts can be used as their biomarkers and contributed to the cardioprotective effects against ISO-induced MI rats. PMID:25786162

  3. Gender Differences in Non-Ischemic Myocardial Remodeling: Are They Due to Estrogen Modulation of Cardiac Mast Cells and/or Membrane Type 1 Matrix Metalloproteinase

    PubMed Central

    Janicki, Joseph S.; Spinale, Francis G.; Levick, Scott P.

    2013-01-01

    SUMMARY This review is focused on gender differences in cardiac remodeling secondary to sustained increases in cardiac volume (VO) and generated pressure (PO). Estrogen has been shown to favorably alter the course of VO-induced remodeling. That is, the VO-induced increased extracellular matrix proteolytic activity and mast cell degranulation responsible for the adverse cardiac remodeling in males and ovariectomized rodents do not occur in intact premenopausal females. While less is known regarding the mechanisms responsible for female cardioprotection in PO-induced stress, gender differences in remodeling have been reported indicating the ability of premenopausal females to adequately compensate. In view of the fact that, in male mice with PO, mast cells have been shown to play a role in the adverse remodeling suggests favorable estrogen modification of mast cell phenotype may also be responsible for cardioprotection in females with PO. Thus, while evidence is accumulating regarding premenopausal females being cardioprotected; there remains the need for in-depth studies to identify critical downstream molecular targets that are under the regulation of estrogen and relevant to cardiac remodeling. Such studies would result in the development of therapy which provides cardioprotection while avoiding the adverse effects of systemic estrogen delivery. PMID:23417570

  4. [Vectorcardiographic diagnosis of the myocardial inactivatable zone].

    PubMed

    de Micheli, A; Medrano, G A

    1989-01-01

    Clinical importance of the vectorcardiographic exploration (distant and spatial) of the myocardial electrical phenomenon is emphasized. This technique constitutes a useful integration of electrocardiographic exploration (near and analytical). The more characteristic morphological and chronological changes due to an inactivatable area are discussed in the light of ventricular myocardial depolarization. Some typical vectorcardiographic features corresponding to the presence of a myocardial inactivatable zone are presented. The utility of the complementary elements which vectorcardiography can bring to electrocardiography is emphasized. Both of these procedures integrate a rational exploration of electrical activity of the myocardium, the solid base of prognostic and therapeutic decisions in cases of myocardial infarction. PMID:2669657

  5. A Mouse Model Suggests Two Mechanisms for Thyroid Alterations in Infantile Cystinosis: Decreased Thyroglobulin Synthesis Due to Endoplasmic Reticulum Stress/Unfolded Protein Response and Impaired Lysosomal Processing

    PubMed Central

    Gaide Chevronnay, H. P.; Janssens, V.; Van Der Smissen, P.; Liao, X. H.; Abid, Y.; Nevo, N.; Antignac, C.; Refetoff, S.; Cherqui, S.; Pierreux, C. E.

    2015-01-01

    Thyroid hormones are released from thyroglobulin (Tg) in lysosomes, which are impaired in infantile/nephropathic cystinosis. Cystinosis is a lysosomal cystine storage disease due to defective cystine exporter, cystinosin. Cystinotic children develop subclinical and then overt hypothyroidism. Why hypothyroidism is the most frequent and earliest endocrine complication of cystinosis is unknown. We here defined early alterations in Ctns−/− mice thyroid and identified subcellular and molecular mechanisms. At 9 months, T4 and T3 plasma levels were normal and TSH was moderately increased (∼4-fold). By histology, hyperplasia and hypertrophy of most follicles preceded colloid exhaustion. Increased immunolabeling for thyrocyte proliferation and apoptotic shedding indicated accelerated cell turnover. Electron microscopy revealed endoplasmic reticulum (ER) dilation, apical lamellipodia indicating macropinocytic colloid uptake, and lysosomal cystine crystals. Tg accumulation in dilated ER contrasted with mRNA down-regulation. Increased expression of ER chaperones, glucose-regulated protein of 78 kDa and protein disulfide isomerase, associated with alternative X-box binding protein-1 splicing, revealed unfolded protein response (UPR) activation by ER stress. Decreased Tg mRNA and ER stress suggested reduced Tg synthesis. Coordinated increase of UPR markers, activating transcription factor-4 and C/EBP homologous protein, linked ER stress to apoptosis. Hormonogenic cathepsins were not altered, but lysosome-associated membrane protein-1 immunolabeling disclosed enlarged vesicles containing iodo-Tg and impaired lysosomal fusion. Isopycnic fractionation showed iodo-Tg accumulation in denser lysosomes, suggesting defective lysosomal processing and hormone release. In conclusion, Ctns−/− mice showed the following alterations: 1) compensated primary hypothyroidism and accelerated thyrocyte turnover; 2) impaired Tg production linked to ER stress/UPR response; and 3) altered

  6. Antiplatelet efficacy of P2Y12 inhibitors (prasugrel, ticagrelor, clopidogrel) in patients treated with mild therapeutic hypothermia after cardiac arrest due to acute myocardial infarction.

    PubMed

    Bednar, Frantisek; Kroupa, Josef; Ondrakova, Martina; Osmancik, Pavel; Kopa, Milos; Motovska, Zuzana

    2016-05-01

    Survivors after cardiac arrest (CA) due to AMI undergo PCI and then receive dual antiplatelet therapy. Mild therapeutic hypothermia (MTH) is recommended for unconscious patients after CA to improve neurological outcomes. MTH can attenuate the effectiveness of P2Y12 inhibitors by reducing gastrointestinal absorption and metabolic activation. The combined effect of these conditions on the efficacy of P2Y12 inhibitors is unknown. We compared the antiplatelet efficacies of new P2Y12 inhibitors in AMI patients after CA treated with MTH. Forty patients after CA for AMI treated with MTH and received one P2Y12 inhibitor (clopidogrel, prasugrel or ticagrelor) were enrolled in a prospective observational single-center study. Platelet inhibition was measured by VASP (PRI) on days 1, 2, and 3 after drug administration. In-hospital clinical data and 1-year survival data were obtained. The proportion of patients with ineffective platelet inhibition (PRI > 50 %, high on-treatment platelet reactivity) for clopidogrel, prasugrel, and ticagrelor was 77 vs. 19 vs. 1 % on day 1; 77 vs. 17 vs. 0 % on day 2; and 85 vs. 6 vs. 0 % on day 3 (P < 0.001). The platelet inhibition was significantly worse in clopidogrel group than in prasugrel or ticagrelor group. Prasugrel and ticagrelor are very effective for platelet inhibition in patients treated with MTH after CA due to AMI, but clopidogrel is not. Using prasugrel or ticagrelor seems to be a more suitable option in this high-risk group of acute patients. PMID:26340851

  7. Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight

    NASA Technical Reports Server (NTRS)

    Bloomberg, Jacob J.; Reschke, Millard F.; Clement, Gilles R.; Mulavara, Ajitkumar P.; Taylor, Laura C..

    2015-01-01

    Control of vehicles and other complex systems is a high-level integrative function of the central nervous system (CNS). It requires well-functioning subsystem performance, including good visual acuity, eye-hand coordination, spatial and geographic orientation perception, and cognitive function. Evidence from space flight research demonstrates that the function of each of these subsystems is altered by removing gravity, a fundamental orientation reference, which is sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, posture, navigation, and coordination of movements. The available evidence also shows that the degree of alteration of each subsystem depends on a number of crew- and mission-related factors. There is only limited operational evidence that these alterations cause functional impacts on mission-critical vehicle (or complex system) control capabilities. Furthermore, while much of the operational performance data collected during space flight has not been available for independent analysis, those that have been reviewed are somewhat equivocal owing to uncontrolled (and/or unmeasured) environmental and/or engineering factors. Whether this can be improved by further analysis of previously inaccessible operational data or by development of new operational research protocols remains to be seen. The true operational risks will be estimable only after we have filled the knowledge gaps and when we can accurately assess integrated performance in off-nominal operational settings (Paloski et al. 2008). Thus, our current understanding of the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight is limited primarily to extrapolation of scientific research findings, and, since there are limited ground-based analogs of the sensorimotor and vestibular changes associated with space flight, observation of their functional

  8. Prognostic Significance of Imaging Myocardial Sympathetic Innervation.

    PubMed

    Malhotra, Saurabh; Fernandez, Stanley F; Fallavollita, James A; Canty, John M

    2015-08-01

    There has been a longstanding interest in understanding whether the presence of inhomogeneity in myocardial sympathetic innervation can predict patients at risk of sudden cardiac arrest from lethal ventricular arrhythmias. The advent of radiolabeled norepinephrine analogs has allowed this to be imaged in patients with ischemic and non-ischemic cardiomyopathy using single, photon emission computed tomography (SPECT) and positron emission tomography (PET). Several observational studies have demonstrated that globally elevated myocardial sympathetic tone (as reflected by reduced myocardial norepinephrine analog uptake) can predict composite cardiac end-points including total cardiovascular mortality. More recent studies have indicated that quantifying the extent of regional denervation can predict the risk of lethal ventricular arrhythmias and sudden cardiac death. This review will summarize our current understanding of the prognostic significance of altered myocardial sympathetic innervation. PMID:26087899

  9. Doxorubicin In Vivo Rapidly Alters Expression and Translation of Myocardial Electron Transport Chain Genes, Leads to ATP Loss and Caspase 3 Activation

    PubMed Central

    Pointon, Amy V.; Walker, Tracy M.; Phillips, Kate M.; Luo, Jinli; Riley, Joan; Zhang, Shu-Dong; Parry, Joel D.; Lyon, Jonathan J.; Marczylo, Emma L.; Gant, Timothy W.

    2010-01-01

    Background Doxorubicin is one of the most effective anti-cancer drugs but its use is limited by cumulative cardiotoxicity that restricts lifetime dose. Redox damage is one of the most accepted mechanisms of toxicity, but not fully substantiated. Moreover doxorubicin is not an efficient redox cycling compound due to its low redox potential. Here we used genomic and chemical systems approaches in vivo to investigate the mechanisms of doxorubicin cardiotoxicity, and specifically test the hypothesis of redox cycling mediated cardiotoxicity. Methodology/Principal Findings Mice were treated with an acute dose of either doxorubicin (DOX) (15 mg/kg) or 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (25 mg/kg). DMNQ is a more efficient redox cycling agent than DOX but unlike DOX has limited ability to inhibit gene transcription and DNA replication. This allowed specific testing of the redox hypothesis for cardiotoxicity. An acute dose was used to avoid pathophysiological effects in the genomic analysis. However similar data were obtained with a chronic model, but are not specifically presented. All data are deposited in the Gene Expression Omnibus (GEO). Pathway and biochemical analysis of cardiac global gene transcription and mRNA translation data derived at time points from 5 min after an acute exposure in vivo showed a pronounced effect on electron transport chain activity. This led to loss of ATP, increased AMPK expression, mitochondrial genome amplification and activation of caspase 3. No data gathered with either compound indicated general redox damage, though site specific redox damage in mitochondria cannot be entirely discounted. Conclusions/Significance These data indicate the major mechanism of doxorubicin cardiotoxicity is via damage or inhibition of the electron transport chain and not general redox stress. There is a rapid response at transcriptional and translational level of many of the genes coding for proteins of the electron transport chain complexes. Still

  10. Age-associated impairement in endpoint accuracy of goal-directed contractions performed with two fingers is due to altered activation of the synergistic muscles.

    PubMed

    Chen, Yen-Ting; Pinto Neto, Osmar; de Miranda Marzullo, Ana Carolina; Kennedy, Deanna M; Fox, Emily J; Christou, Evangelos A

    2012-07-01

    The purpose of this study was to determine whether older adults compared with young adults exhibit impaired end-point accuracy during a two-finger task due to altered activation of the contributing synergistic muscles. Nine young (21.3 years ± 1.6 years, 4 men) and 9 older (73.1 years ± 6.4 years, 5 men) were instructed to accurately match the center of a target with concurrent abduction of the index and little fingers (synergistic two-finger task). The target comprised of 20% MVC and 200 ms. Visual feedback of the force trajectory and target was provided 1s after each trial. Subjects completed 40 trials and the last 10 were used for analysis. Endpoint accuracy was quantified as the normalized deviation from the target in terms of peak force (peak force error), time-to-peak force (time-to-peak force error), and a combination of the two (overall error). Motor output variability was quantified as the standard deviation and coefficient of variation (CV) of peak force and time to peak force. The neural activation of the involved synergist muscles (first dorsal interosseus (FDI) and abductor digiti minimi (ADM)) was quantified with the electromyography (EMG) amplitude (root mean square) and its frequency structure (wavelet analysis). Older adults exhibited significantly greater peak force (46.7 ± 10% vs. 24.9 ± 3.2%) and overall endpoint error (68.5 ± 9.7% vs. 41.7 ± 4.3%), whereas the time to peak force error was similar for the two age groups. Older adults also exerted greater peak force variability than young adults, as quantified by the CV of peak force (34.3 ± 3.5% vs. 24.1 ± 2.3%). The greater peak force error in older adults was associated with changes in the activation of the ADM muscle but not the FDI. Specifically, greater peak force error was associated with greater power from 13-30 Hz and lesser power from 30-60 Hz. These results, therefore, suggest that older adults compared with young adults exhibit impaired endpoint force accuracy during a two

  11. 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. PMID:26732686

  12. 2013 Immune Risk Standing Review Panel Research Plan Review for: The Risk of Crew Adverse Health Event Due to Altered Immune Response

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2014-01-01

    The 2013 Immune Risk Standing Review Panel (from here on referred to as the SRP) participated in a meeting with representatives from the Human Research Program (HRP) Human Health Countermeasures (HHC) Element and HRP management on February 3-4, 2014 in Houston, TX to review the updated Research Plan for the Risk of Crew Adverse Health Event Due to Altered Immune Response in the HRP Integrated Research Plan. The SRP is impressed with the work the immune discipline has done since the 2012 SRP review and agrees with the new wording of the Gaps, no longer questions, now statements. The SRP also likes the addition of adding targets for closing the Gaps, but it is not clear how they got to some of the interim stages (interval percentages). A major concern that the SRP has mentioned since the initial 2009 SRP meeting is that there is still not enough emphasis on the interdisciplinary aspect of the immune risk associated with other risks (i.e., nutrition, radiation, etc.). The SRP recommends that a "translational SRP" or advisory group be developed that is composed of members from all of the HRP SRPs. The SRP also thinks that the immune discipline should consider a more systems biology approach. Lastly, the SRP is concerned that the risks observed in research from low Earth orbit (LEO) missions may not accurately reflect all the risks of longer duration flight beyond LEO. Also, there does not seem to be a concern for immune responses that may occur when someone is in space longer than six months, for example, a Mars mission would take three years. The absence of disease in past and current flight scenarios does not mean the risk may not be there in future flight settings.

  13. Myocardial imaging. Coxsackie myocarditis

    SciTech Connect

    Wells, R.G.; Ruskin, J.A.; Sty, J.R.

    1986-09-01

    A 3-week-old male neonate with heart failure associated with Coxsackie virus infection was imaged with Tc-99m PYP and TI-201. The abnormal imaging pattern suggested myocardial infarction. Autopsy findings indicated that the cause was myocardial necrosis secondary to an acute inflammatory process. Causes of abnormal myocardial uptake of Tc-99m PYP in pediatrics include infarction, myocarditis, cardiomyopathy, bacterial endocarditis, and trauma. Myocardial imaging cannot provide a specific cause diagnosis. Causes of myocardial infarction in pediatrics are listed in Table 1.

  14. Determinants of myocardial conduction velocity: implications for arrhythmogenesis

    PubMed Central

    King, James H.; Huang, Christopher L.-H.; Fraser, James A.

    2013-01-01

    Slowed myocardial conduction velocity (θ) is associated with an increased risk of re-entrant excitation, predisposing to cardiac arrhythmia. θ is determined by the ion channel and physical properties of cardiac myocytes and by their interconnections. Thus, θ is closely related to the maximum rate of action potential (AP) depolarization [(dV/dt)max], as determined by the fast Na+ current (INa); the axial resistance (ra) to local circuit current flow between cells; their membrane capacitances (cm); and to the geometrical relationship between successive myocytes within cardiac tissue. These determinants are altered by a wide range of pathophysiological conditions. Firstly, INa is reduced by the impaired Na+ channel function that arises clinically during heart failure, ischemia, tachycardia, and following treatment with class I antiarrhythmic drugs. Such reductions also arise as a consequence of mutations in SCN5A such as those occurring in Lenègre disease, Brugada syndrome (BrS), sick sinus syndrome, and atrial fibrillation (AF). Secondly, ra, may be increased due to gap junction decoupling following ischemia, ventricular hypertrophy, and heart failure, or as a result of mutations in CJA5 found in idiopathic AF and atrial standstill. Finally, either ra or cm could potentially be altered by fibrotic change through the resultant decoupling of myocyte–myocyte connections and coupling of myocytes with fibroblasts. Such changes are observed in myocardial infarction and cardiomyopathy or following mutations in MHC403 and SCN5A resulting in hypertrophic cardiomyopathy (HCM) or Lenègre disease, respectively. This review defines and quantifies the determinants of θ and summarizes experimental evidence that links changes in these determinants with reduced myocardial θ and arrhythmogenesis. It thereby identifies the diverse pathophysiological conditions in which abnormal θ may contribute to arrhythmia. PMID:23825462

  15. Thermoinducible filamentation in Escherichia coli due to an altered RNA polymerase beta subunit is suppressed by high levels of ppGpp.

    PubMed Central

    Vinella, D; D'Ari, R

    1994-01-01

    The Escherichia coli strain known as GC2553, FB8, UTH1038, or K12S (Luria), considered an F- lambda- wild-type strain, is shown here to carry a cryptic mutation, ftsR1, causing nonlethal filamentation during exponential growth in Luria-Bertani (LB) broth at 42 degrees C and the inability to grow in salt-free LB broth at 42 degrees C. The ftsR1 mutation is completely suppressed in genetic backgrounds which increase RelA-dependent synthesis of the nucleotide ppGpp, i.e., argS201 (Mecr) and alaS21 (Mecr) mutations, affecting aminoacyl-tRNA synthetases, or the presence of a plac-relA' plasmid. These backgrounds also confer resistance in LB broth to the beta-lactam mecillinam, an antibiotic which specifically inhibits penicillin-binding protein 2 and, in wild-type cells, causes an indirect block in cell division. Furthermore, the ftsR1 mutant (but not an isogenic ftsR+ strain) is sensitive to mecillinam in minimal glucose medium at 37 degrees C. Since the division block caused by mecillinam can be overcome by overproduction of the cell division protein FtsZ, we tested the effect of plasmid pZAQ (carrying the ftsZ, ftsA, and ftsQ genes) on the ftsR1 mutant; it suppressed the filamentation in LB broth and the mecillinam sensitivity on minimal glucose medium at 37 degrees C but not the growth defect in salt-free LB broth at 42 degrees C. Genetic analysis indicated that the full phenotype of the ftsR1 mutant is due to a single mutation in the rpoB gene (90 min), coding for the beta subunit of RNA polymerase; we call this allele rpoB369(Fts). We propose that the rpoB369(Fts) mutation alters the specificity of the polymerase and that the mutant enzyme can recover normal activity in the presence of high salt concentrations or via interaction with the nucleotide ppGpp. PMID:8106339

  16. A large pseudoaneurysm of the left cardiac ventricle in a 57-year-old patient after urgent coronary artery bypass grafting and surgical mitral valve replacement due to acute myocardial infarction.

    PubMed

    Wieczorek, Joanna; Mizia-Stec, Katarzyna; Rybicka-Musialik, Anna; Janusiewicz, Piotr; Malinowski, Marcin; Deja, Marek A

    2014-12-01

    We present a rare case of a left ventricular pseudoaneurysm in a patient after inferior wall myocardial infarction. The infarction was complicated with acute mitral insufficiency, pulmonary edema, and cardiogenic shock. Urgent surgical mitral valve replacement and coronary artery bypass grafting were performed. After several months, the patient was hospitalized again because of deterioration of exercise tolerance and symptoms of acute congestive heart failure. A large pseudoaneurysm of the left ventricle was recognized and successfully treated surgically. PMID:26336464

  17. A large pseudoaneurysm of the left cardiac ventricle in a 57-year-old patient after urgent coronary artery bypass grafting and surgical mitral valve replacement due to acute myocardial infarction

    PubMed Central

    Mizia-Stec, Katarzyna; Rybicka-Musialik, Anna; Janusiewicz, Piotr; Malinowski, Marcin; Deja, Marek A.

    2014-01-01

    We present a rare case of a left ventricular pseudoaneurysm in a patient after inferior wall myocardial infarction. The infarction was complicated with acute mitral insufficiency, pulmonary edema, and cardiogenic shock. Urgent surgical mitral valve replacement and coronary artery bypass grafting were performed. After several months, the patient was hospitalized again because of deterioration of exercise tolerance and symptoms of acute congestive heart failure. A large pseudoaneurysm of the left ventricle was recognized and successfully treated surgically. PMID:26336464

  18. Invasion of a semi-arid shrubland by annual grasses increases autotrophic and heterotrophic soil respiration rates due to altered soil moisture and temperature patterns

    NASA Astrophysics Data System (ADS)

    Mauritz, M.; Hale, I.; Lipson, D.

    2010-12-01

    Shrub <-> grassland conversions are a globally occurring phenomenon altering habitat structure, quality and nutrient cycling. Grasses and shrubs differ in their above and belowground biomass allocation, root architecture, phenology, litter quality and quantity. Conversion affects soil microbial communities, soil moisture and temperature and carbon (C) allocation patterns. However, the effect of conversion on C storage is regionally variable and there is no consistent direction of change. In Southern California invasion by annual grasses is a major threat to native shrub communities and it has been proposed that grass invasion increases NPP and ecosystem C storage (Wolkovich et al, 2009). In order to better understand how this shrub <-> grassland conversion changes ecosystem C storage it is important to understand the partitioning of soil respiration into autotrophic and heterotrophic components. Respiration was measured in plots under shrubs and grasses from February when it was cold and wet to July when it was hot and dry, capturing seasonal transitions in temperature and water availability. Roots were excluded under shrubs and grasses with root exclusion cores to quantify heterotrophic respiration. Using total soil respiration (Rt) = autotrophic respiration (root) (Ra)+ heterotrophic respiration (microbial) (Rh) the components contributing to total soil respiration can be evaluated. Respiration, soil moisture and temperature were measured daily at four hour intervals using Licor 8100 automated chamber measurements. Throughout the measurement period, Rt under grasses exceeded Rt under shrubs. Higher Rt levels under grasses were mainly due to higher Ra in grasses rather than changes in Rh. On average grass Ra was almost double shrub Ra. Higher grass respiration levels are partially explained by differences in soil moisture and temperature between shrubs and grasses. Respiration rates responded similarly to seasonal transitions regardless of treatment although Ra

  19. Calpain inhibition preserves myocardial structure and function following myocardial infarction.

    PubMed

    Mani, Santhosh K; Balasubramanian, Sundaravadivel; Zavadzkas, Juozas A; Jeffords, Laura B; Rivers, William T; Zile, Michael R; Mukherjee, Rupak; Spinale, Francis G; Kuppuswamy, Dhandapani

    2009-11-01

    Cardiac pathology, such as myocardial infarction (MI), activates intracellular proteases that often trigger programmed cell death and contribute to maladaptive changes in myocardial structure and function. To test whether inhibition of calpain, a Ca(2+)-dependent cysteine protease, would prevent these changes, we used a mouse MI model. Calpeptin, an aldehydic inhibitor of calpain, was intravenously administered at 0.5 mg/kg body wt before MI induction and then at the same dose subcutaneously once per day. Both calpeptin-treated (n = 6) and untreated (n = 6) MI mice were used to study changes in myocardial structure and function after 4 days of MI, where end-diastolic volume (EDV) and left ventricular ejection fraction (EF) were measured by echocardiography. Calpain activation and programmed cell death were measured by immunohistochemistry, Western blotting, and TdT-mediated dUTP nick-end labeling (TUNEL). In MI mice, calpeptin treatment resulted in a significant improvement in EF [EF decreased from 67 + or - 2% pre-MI to 30 + or - 4% with MI only vs. 41 + or - 2% with MI + calpeptin] and attenuated the increase in EDV [EDV increased from 42 + or - 2 microl pre-MI to 73 + or - 4 microl with MI only vs. 55 + or - 4 microl with MI + calpeptin]. Furthermore, calpeptin treatment resulted in marked reduction in calpain- and caspase-3-associated changes and TUNEL staining. These studies indicate that calpain contributes to MI-induced alterations in myocardial structure and function and that it could be a potential therapeutic target in treating MI patients. PMID:19734364

  20. Effect of Curcuma longa and Ocimum sanctum on myocardial apoptosis in experimentally induced myocardial ischemic-reperfusion injury

    PubMed Central

    Mohanty, Ipseeta; Arya, Dharamvir Singh; Gupta, Suresh Kumar

    2006-01-01

    Background In the present investigation, the effect of Curcuma longa (Cl) and Ocimum sanctum (Os) on myocardial apoptosis and cardiac function was studied in an ischemia and reperfusion (I-R) model of myocardial injury. Methods Wistar albino rats were divided into four groups and orally fed saline once daily (sham, control IR) or Cl (100 mg/kg; Cl-IR) or Os (75 mg/kg; Os-IR) respectively for 1 month. On the 31st day, in the rats of the control IR, Cl-IR and Os-IR groups LAD occlusion was undertaken for 45 min, and reperfusion was allowed for 1 h. The hemodynamic parameters{mean arterial pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular peak positive (+) LVdP/dt (rate of pressure development) and negative (-) LVdP/dt (rate of pressure decline)} were monitored at pre-set points throughout the experimental duration and subsequently, the animals were sacrificed for immunohistopathological (Bax, Bcl-2 protein expression & TUNEL positivity) and histopathological studies. Results Chronic treatment with Cl significantly reduced TUNEL positivity (p < 0.05), Bax protein (p < 0.001) and upregulated Bcl-2 (p < 0.001) expression in comparison to control IR group. In addition, Cl demonstrated mitigating effects on several myocardial injury induced hemodynamic {(+)LVdP/dt, (-) LVdP/dt & LVEDP} and histopathological perturbations. Chronic Os treatment resulted in modest modulation of the hemodynamic alterations (MAP, LVEDP) but failed to demonstrate any significant antiapoptotic effects and prevent the histopathological alterations as compared to control IR group. Conclusion In the present study, significant cardioprotection and functional recovery demonstrated by Cl may be attributed to its anti-apoptotic property. In contrast to Os, Cl may attenuate cell death due to apoptosis and prevent the impairment of cardiac performance. PMID:16504000

  1. Idiopathic calcified myocardial mass

    PubMed Central

    Patterson, David; Gibson, Derek; Gomes, Ricardo; McDonald, Lawson; Olsen, Eckhardt; Parker, John; Ross, Donald

    1974-01-01

    Patterson, D., Gibson, D., Gomes, R., McDonald, L., Olsen, E., Parker, J., and Ross, D. (1974).Thorax,29, 589-594. Idiopathic calcified myocardial mass. Myocardial calcification can be subdivided into three groups—metastatic, dystrophic or an extension inwards from the pericardium. This case in which the calcified myocardial mass was initially delineated by radiography and by echocardiography and subsequently removed does not fit into any subdivision and has been termed idiopathic. Images PMID:4279467

  2. Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space Flight

    NASA Technical Reports Server (NTRS)

    Bloomberg, Jacob J.; Reschke, Millard F.; Clément, Gilles R.; Mulavara, Ajitkumar P.; Taylor, Laura C.

    2016-01-01

    We examine the various dimensions of the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight by reviewing the research and operational evidence demonstrating sensorimotor performance decrements during and after space flight. These sensorimotor performance decrements might affect vehicle and complex system control, including decreased visual acuity, eye-hand coordination, spatial and geographic orientation perception, and cognitive function. Sensorimotor performance decrements might also affect the ability to egress and walk away from the vehicle in case of an emergency or an extravehicular activity on a planetary surface. We also review the countermeasures that have been tested, including medication, prevention techniques and training exercises, physical rehabilitation, and mechanical devices. Furthermore, we identify the current knowledge and mitigation gaps that must be filled through further research and/or data mining efforts before the risk can be fully mitigated. We conclude that the true operational risks associated with the impacts of adaptive sensorimotor changes on mobility and crew abilities to control vehicles and other complex systems will only be estimable after the gaps have been filled and we have been able to accurately assess integrated performance in off-nominal operational settings. A large body of sensorimotor research data obtained from space flight experiments over the past half-century demonstrates significant decrements in oculomotor control, eye-hand coordination, spatial orientation, posture\\locomotor control and cognition during space flight missions. While these changes are most severe during and after G-transitions, the most crucial time for many critical operational tasks (e.g., landing and egress), only limited information is available to assess the operational impacts of these changes. Some of the operational observations are

  3. Discrete Microstructural Cues for the Attenuation of Fibrosis Following Myocardial Infarction

    PubMed Central

    Pinney, James R.; Du, Kim; Ayala, Perla; Fang, Qizhi; Sievers, Rich; Chew, Patrick; Delrosario, Lawrence; Lee, Randall J.; Desai, Tejal A.

    2014-01-01

    Chronic fibrosis caused by acute myocardial infarction (MI) leads to increased morbidity and mortality due to cardiac dysfunction. We have developed a therapeutic materials strategy that aims to mitigate myocardial fibrosis by utilizing injectable polymeric microstructures to mechanically alter the microenvironment. Polymeric microstructures were fabricated using photolithographic techniques and studied in a three-dimensional culture model of the fibrotic environment and by direct injection into the infarct zone of adult rats. Here, we show dose-dependent down-regulation of expression of genes associated with the mechanical fibrotic response in the presence of microstructures. Injection of this microstructured material into the infarct zone decreased levels of collagen and TGF-β, increased elastin deposition and vascularization in the infarcted region, and improved functional outcomes after six weeks. Our results demonstrate the efficacy of these discrete anti-fibrotic microstructures and suggest a potential therapeutic materials approach for combatting pathologic fibrosis. PMID:25047625

  4. [Myocardial responses to ischemia].

    PubMed

    Borisenko, V G; Gubareva, E A; Kade, A Kh

    2010-01-01

    The paper details the types of a myocardial response to impaired blood flow, such as myocardial stunning, hibernation, ischemic preconditioning, warm-up phenomenon, ischemic postconditioning, remodeling, and infarction. According to the pathogenesis, the authors identify several types of myocardial dysfunction in transient ischemic attack--uptake, delivery; and a mixed one. It is concluded the myocardial response to damage depends on a combination of influencing factors, a number of pathophysiological processes starting in the acute phase of ischemia achieve its peak in the late period. PMID:20564927

  5. [Myocardial viability, its importance for the therapeutic decision].

    PubMed

    Alexánderson, Erick; Ricalde, Alejandro; Meave, Aloha

    2005-01-01

    Myocardial viability detection is essential in patients with history of myocardial infarction whom develop ventricular dysfunction. Its detection influences the therapeutic decisions and the prognosis. Medical therapy in patients with ventricular dysfunction due to myocardial infarction and myocardial viability has been associated with higher morbidity and mortality rates than revascularization therapy, as well as improvements in the systolic function. Several imaging techniques used in the recognition of myocardial viability are available; these techniques are based on the assessment of the ventricular motion posterior to inotropic agents stimulation or on the demonstration of metabolic activity at the dysfunctional regions. In this study, some important aspects of each technique are reviewed, doing special emphasis in the utility of the Positron Emission Tomography (PET) which has been considered as the "gold standard" in the detection of myocardial viability. PMID:15909735

  6. Altered responsiveness to 5-HT at the crayfish neuromuscular junction due to chronic p-CPA and m-CPP treatment.

    PubMed

    Cooper, R L; Chase, R J; Tabor, J

    2001-10-19

    Serotonin (5-HT) levels in the hemolymph of crustaceans has been implied to alter aggressiveness which influences social interactions. The activation of IP3 as a second messenger cascade within crayfish motor neurons in response to application of 5-HT, suggests that the 5-HT receptor subtypes on the motor neurons are analogous to the vertebrate 5-HT2A receptors. Based on evidence in other systems, it would be expected that chronically sustained 5-HT levels in aggressive individuals would result in a compensatory negative feed-back regulation and/or that target tissues would diminish their sensitivity to high levels of circulating, free 5-HT. We addressed the issue of up- and down-regulation in the sensitivity of the responsiveness to exogenously applied 5-HT at the NMJs of crayfish in which the animals have altered endogenous 5-HT levels. Injections of the 5-HT1 and 5-HT2 vertebrate receptor agonist, 1-(3-Chlorophenyl) piperazine dihydrochloride (m-CPP), for 1 week resulted in a decreased responsiveness to application of 5-HT. The compound p-chlorophenylalanine (p-CPA) blocks the enzymatic synthesis of 5-HT and following 7 days of p-CPA injections, a super-sensitivity to exogenous application of 5-HT for both tonic and phasic neuromuscular junctions (NMJs) was observed. However, acute applications of p-CPA and m-CPP, followed by extensive saline washing, did not reveal any altered receptivity to 5-HT application. PMID:11597601

  7. Myocardial infarction size: measurement and modification

    PubMed Central

    Cairns, John A.

    1977-01-01

    The majority of in-hospital deaths from acute myocardial infarction occur as a result of the “power failure” syndrome (severe congestive heart failure and cardiogenic shock), which results from extensive loss of myocardium. The death of myocardial cells is sequential over many hours. Surrounding the central zone of necrosis in an acute myocardial infarction is a zone of ischemic myocardium whose fate might be altered by interventions during the early phase of the infarction. ST-segment mapping, serial measurement of the serum concentration of creatine phosphokinase and myocardial imaging by means of radionuclides are being developed for the noninvasive assessment of infarct size in animals and humans. A number of interventions appear to limit infarct size in animals. There have been relatively few studies in humans to date, but preliminary results suggest that infarct size might be limited by certain interventions. The research has provided important practical benefits in terms of understanding the course of acute myocardial infarction and the potential effects of conventional therapies. For the present, interventions designed to limit infarct size remain in the realm of clinical research; routine clinical use would be inappropriate. PMID:69481

  8. Does cancer start in the womb? altered mammary gland development and predisposition to breast cancer due to in utero exposure to endocrine disruptors.

    PubMed

    Soto, Ana M; Brisken, Cathrin; Schaeberle, Cheryl; Sonnenschein, Carlos

    2013-06-01

    We are now witnessing a resurgence of theories of development and carcinogenesis in which the environment is again being accepted as a major player in phenotype determination. Perturbations in the fetal environment predispose an individual to disease that only becomes apparent in adulthood. For example, gestational exposure to diethylstilbestrol resulted in clear cell carcinoma of the vagina and breast cancer. In this review the effects of the endocrine disruptor bisphenol-A (BPA) on mammary development and tumorigenesis in rodents is used as a paradigmatic example of how altered prenatal mammary development may lead to breast cancer in humans who are also widely exposed to it through plastic goods, food and drink packaging, and thermal paper receipts. Changes in the stroma and its extracellular matrix led to altered ductal morphogenesis. Additionally, gestational and lactational exposure to BPA increased the sensitivity of rats and mice to mammotropic hormones during puberty and beyond, thus suggesting a plausible explanation for the increased incidence of breast cancer. PMID:23702822

  9. Alterations of physiology and gene expression due to long-term magnesium-deficiency differ between leaves and roots of Citrus reticulata.

    PubMed

    Jin, Xiao-Lin; Ma, Cui-Lan; Yang, Lin-Tong; Chen, Li-Song

    2016-07-01

    Seedlings of Ponkan (Citrus reticulata) were irrigated with nutrient solution containing 0 (Mg-deficiency) or 1mM MgSO4 (control) every two day for 16 weeks. Thereafter, we examined magnesium (Mg)-deficiency-induced changes in leaf and root gas exchange, total soluble proteins and gene expression. Mg-deficiency lowered leaf CO2 assimilation, and increased leaf dark respiration. However, Mg-deficient roots had lower respiration. Total soluble protein level was not significantly altered by Mg-deficiency in roots, but was lower in Mg-deficient leaves than in controls. Using cDNA-AFLP, we obtained 70 and 71 differentially expressed genes from leaves and roots. These genes mainly functioned in signal transduction, stress response, carbohydrate and energy metabolism, cell transport, cell wall and cytoskeleton metabolism, nucleic acid, and protein metabolisms. Lipid metabolism (Ca(2+) signals)-related Mg-deficiency-responsive genes were isolated only from roots (leaves). Although little difference existed in the number of Mg-deficiency-responsive genes between them both, most of these genes only presented in Mg-deficient leaves or roots, and only four genes were shared by them both. Our data clearly demonstrated that Mg-deficiency-induced alterations of physiology and gene expression greatly differed between leaves and roots. In addition, we focused our discussion on the causes for photosynthetic decline in Mg-deficient leaves and the responses of roots to Mg-deficiency. PMID:27163764

  10. Identification of Temporal and Region-Specific Myocardial Gene Expression Patterns in Response to Infarction in Swine

    PubMed Central

    Nonell, Lara; Puigdecanet, Eulàlia; Astier, Laura; Solé, Francesc; Bayes-Genis, Antoni

    2013-01-01

    Molecular mechanisms associated with pathophysiological changes in ventricular remodelling due to myocardial infarction (MI) remain poorly understood. We analyzed changes in gene expression by microarray technology in porcine myocardial tissue at 1, 4, and 6 weeks post-MI. MI was induced by coronary artery ligation in 9 female pigs (30–40 kg). Animals were randomly sacrificed at 1, 4, or 6 weeks post-MI (n = 3 per group) and 3 healthy animals were also included as control group. Total RNA from myocardial samples was hybridized to GeneChip® Porcine Genome Arrays. Functional analysis was obtained with the Ingenuity Pathway Analysis (IPA) online tool. Validation of microarray data was performed by quantitative real-time PCR (qRT-PCR). More than 8,000 different probe sets showed altered expression in the remodelling myocardium at 1, 4, or 6 weeks post-MI. Ninety-seven percent of altered transcripts were detected in the infarct core and 255 probe sets were differentially expressed in the remote myocardium. Functional analysis revealed 28 genes de-regulated in the remote myocardial region in at least one of the three temporal analyzed stages, including genes associated with heart failure (HF), systemic sclerosis and coronary artery disease. In the infarct core tissue, eight major time-dependent gene expression patterns were recognized among 4,221 probe sets commonly altered over time. Altered gene expression of ACVR2B, BID, BMP2, BMPR1A, LMNA, NFKBIA, SMAD1, TGFB3, TNFRSF1A, and TP53 were further validated. The clustering of similar expression patterns for gene products with related function revealed molecular footprints, some of them described for the first time, which elucidate changes in biological processes at different stages after MI. PMID:23372767

  11. Myocardial infarction--fusion or confusion?

    PubMed

    Ardhanari, Sivakumar; Shah, Ashok J; Thakur, Ranjan K

    2009-09-01

    A patient with a dualchamber pacemaker with dynamic atrioventricular delay (AVD) experienced acute substernal chest pain. The rhythm strip in the ambulance showed intermittent ST elevation in the inferior leads. An emergent cardiac catheterization revealed nonobstructive coronary artery disease. Rate-responsive dual-chamber pacing with dynamic AVD was responsible for varying devvgrees of ventricular fusion due to competition with the patient's normal conduction. Intermittent ST elevation, evident only during ventricular fusion should have suggested secondary ventricular repolarization and not myocardial injury, but concomitant chest pain and inconspicuous bipolar pacing artifacts added to the confusion. Ventricular pacing may not only mask acute ST-T changes due to myocardial injury, but can also mimic acute myocardial infarction. PMID:19726827

  12. Combretastatin A4 disodium phosphate-induced myocardial injury

    PubMed Central

    Tochinai, Ryota; Nagata, Yuriko; Ando, Minoru; Hata, Chie; Suzuki, Tomo; Asakawa, Naoyuki; Yoshizawa, Kazuhiko; Uchida, Kazumi; Kado, Shoichi; Kobayashi, Toshihide; Kaneko, Kimiyuki; Kuwahara, Masayoshi

    2016-01-01

    Histopathological and electrocardiographic features of myocardial lesions induced by combretastatin A4 disodium phosphate (CA4DP) were evaluated, and the relation between myocardial lesions and vascular changes and the direct toxic effect of CA4DP on cardiomyocytes were discussed. We induced myocardial lesions by administration of CA4DP to rats and evaluated myocardial damage by histopathologic examination and electrocardiography. We evaluated blood pressure (BP) of CA4DP-treated rats and effects of CA4DP on cellular impedance-based contractility of human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs). The results revealed multifocal myocardial necrosis with a predilection for the interventricular septum and subendocardial regions of the apex of the left ventricular wall, injury of capillaries, morphological change of the ST junction, and QT interval prolongation. The histopathological profile of myocardial lesions suggested that CA4DP induced a lack of myocardial blood flow. CA4DP increased the diastolic BP and showed direct effects on hiPS-CMs. These results suggest that CA4DP induces dysfunction of small arteries and capillaries and has direct toxicity in cardiomyocytes. Therefore, it is thought that CA4DP induced capillary and myocardial injury due to collapse of the microcirculation in the myocardium. Moreover, the direct toxic effect of CA4DP on cardiomyocytes induced myocardial lesions in a coordinated manner.

  13. Combretastatin A4 disodium phosphate-induced myocardial injury.

    PubMed

    Tochinai, Ryota; Nagata, Yuriko; Ando, Minoru; Hata, Chie; Suzuki, Tomo; Asakawa, Naoyuki; Yoshizawa, Kazuhiko; Uchida, Kazumi; Kado, Shoichi; Kobayashi, Toshihide; Kaneko, Kimiyuki; Kuwahara, Masayoshi

    2016-07-01

    Histopathological and electrocardiographic features of myocardial lesions induced by combretastatin A4 disodium phosphate (CA4DP) were evaluated, and the relation between myocardial lesions and vascular changes and the direct toxic effect of CA4DP on cardiomyocytes were discussed. We induced myocardial lesions by administration of CA4DP to rats and evaluated myocardial damage by histopathologic examination and electrocardiography. We evaluated blood pressure (BP) of CA4DP-treated rats and effects of CA4DP on cellular impedance-based contractility of human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs). The results revealed multifocal myocardial necrosis with a predilection for the interventricular septum and subendocardial regions of the apex of the left ventricular wall, injury of capillaries, morphological change of the ST junction, and QT interval prolongation. The histopathological profile of myocardial lesions suggested that CA4DP induced a lack of myocardial blood flow. CA4DP increased the diastolic BP and showed direct effects on hiPS-CMs. These results suggest that CA4DP induces dysfunction of small arteries and capillaries and has direct toxicity in cardiomyocytes. Therefore, it is thought that CA4DP induced capillary and myocardial injury due to collapse of the microcirculation in the myocardium. Moreover, the direct toxic effect of CA4DP on cardiomyocytes induced myocardial lesions in a coordinated manner. PMID:27559241

  14. Shifts in the climate space of temperate cyprinid fishes due to climate change are coupled with altered body sizes and growth rates.

    PubMed

    Ruiz-Navarro, Ana; Gillingham, Phillipa K; Britton, J Robert

    2016-09-01

    Predictions of species responses to climate change often focus on distribution shifts, although responses can also include shifts in body sizes and population demographics. Here, shifts in the distributional ranges ('climate space'), body sizes (as maximum theoretical body sizes, L∞) and growth rates (as rate at which L∞ is reached, K) were predicted for five fishes of the Cyprinidae family in a temperate region over eight climate change projections. Great Britain was the model area, and the model species were Rutilus rutilus, Leuciscus leuciscus, Squalius cephalus, Gobio gobio and Abramis brama. Ensemble models predicted that the species' climate spaces would shift in all modelled projections, with the most drastic changes occurring under high emissions; all range centroids shifted in a north-westerly direction. Predicted climate space expanded for R. rutilus and A. brama, contracted for S. cephalus, and for L. leuciscus and G. gobio, expanded under low-emission scenarios but contracted under high emissions, suggesting the presence of some climate-distribution thresholds. For R. rutilus, A. brama, S. cephalus and G. gobio, shifts in their climate space were coupled with predicted shifts to significantly smaller maximum body sizes and/or faster growth rates, aligning strongly to aspects of temperature-body size theory. These predicted shifts in L∞ and K had considerable consequences for size-at-age per species, suggesting substantial alterations in population age structures and abundances. Thus, when predicting climate change outcomes for species, outputs that couple shifts in climate space with altered body sizes and growth rates provide considerable insights into the population and community consequences, especially for species that cannot easily track their thermal niches. PMID:26824727

  15. Potential alteration of fjordal circulation due to a large floating structure—Numerical investigation with application to Hood Canal basin in Puget Sound

    SciTech Connect

    Khangaonkar, Tarang; Wang, Taiping

    2013-01-02

    Circulation in typical fjords is characterized by a shallow brackish layer at the surface over a deep long and narrow saltwater column. This surface layer is responsible for the outflow of water from the fjord, is easily disrupted by external forces, such as wind, and is influenced by freshwater inflow. In this paper, we postulate that the stability of fjordal circulation may also be vulnerable to impacts from anthropogenic alterations, such as floating structures, that could constrict the mixing and transport in the upper layers of the water column. The potential for alteration of circulation in Hood Canal, a silled-fjord located inside Puget Sound, Washington, has been examined. Using classical analytical treatments along the lines formulated by Hansen and Rattray [1965], Rattray [1967], Dyer [1973] and more recently, MacCready [2004], we develop a solution applicable to a range of estuary classifications varying from a partially mixed estuary regime to classical fjord conditions. Both estuary types exist in the Puget Sound system, and we compare our analytical solution with observed data. The analysis is based on an exponential variation of eddy viscosity with depth, and it has been extended further with modifications of the free surface boundary conditions to develop a solution representing the presence of a floating bridge at the estuary/fjord entrance. The model results show that tidally averaged mean circulation under the influence of such a constraint could reduce by as much as 30 to 50 percent. The overall water quality of fjords and narrow estuaries is dependent on net circulation and flushing. A potential decrease in residual flow or a corresponding increase in residence time of this magnitude merits further study.

  16. Myocardial Bridging: An Up-to-Date Review

    PubMed Central

    Lee, Michael S.; Chen, Cheng-Han

    2016-01-01

    Myocardial bridging is a congenital anomaly in which a segment of a coronary artery takes a “tunneled” intramuscular course under a “bridge” of overlying myocardium. This causes vessel compression in systole, resulting in hemodynamic changes that may be associated with angina, myocardial ischemia, acute coronary syndrome, left ventricular dysfunction, arrhythmias, and even sudden cardiac death. While described on autopsy for centuries, technological advances such as coronary computed tomography angiography and intravascular ultrasound have contributed greatly to our understanding of the anatomic, hemodynamic, and pathophysiological consequences of systolic compression. Atherosclerosis preferentially develops immediately proximal to the bridged segment, likely due to alterations in shear stress, while the compressed segment itself is often spared. First-line therapy of symptomatic bridging remains medical treatment with beta-blockers and non-dihydropyridine calcium-channel blockers, and nitrates are contraindicated. Surgical myotomy, intracoronary stenting, and coronary artery bypass graft surgery have been used for refractory symptoms, but long-term outcomes remain uncertain. Further research is required to better define the patient population that would derive the greatest benefit from surgical and percutaneous intervention. PMID:25999138

  17. Myocardial Bridging: An Up-to-Date Review.

    PubMed

    Lee, Michael S; Chen, Cheng-Han

    2015-11-01

    Myocardial bridging is a congenital anomaly in which a segment of a coronary artery takes a "tunneled" intramuscular course under a "bridge" of overlying myocardium. This causes vessel compression in systole, resulting in hemodynamic changes that may be associated with angina, myocardial ischemia, acute coronary syndrome, left ventricular dysfunction, arrhythmias, and even sudden cardiac death. While described on autopsy for centuries, technological advances such as coronary computed tomography angiography and intravascular ultrasound have contributed greatly to our understanding of the anatomic, hemodynamic, and pathophysiological consequences of systolic compression. Atherosclerosis preferentially develops immediately proximal to the bridged segment, likely due to alterations in shear stress, while the compressed segment itself is often spared. First-line therapy of symptomatic bridging remains medical treatment with beta-blockers and non-dihydropyridine calcium-channel blockers, and nitrates are contraindicated. Surgical myotomy, intracoronary stenting, and coronary artery bypass graft surgery have been used for refractory symptoms, but long-term outcomes remain uncertain. Further research is required to better define the patient population that would derive the greatest benefit from surgical and percutaneous intervention. PMID:25999138

  18. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography. [Dogs

    SciTech Connect

    Schelbert, H.R.; Phelps, M.E.

    1980-06-01

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (/sup 13/N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique.

  19. Transient myocardial ischaemia after acute myocardial infarction.

    PubMed Central

    Currie, P; Saltissi, S

    1990-01-01

    The prevalence and characteristics of transient myocardial ischaemia were studied in 203 patients with recent acute myocardial infarction by both early (6.4 days) and late (38 days) ambulatory monitoring of the ST segment. Transient ST segment depression was much commoner during late (32% patients) than early (14%) monitoring. Most transient ischaemia (greater than 85% episodes) was silent and 80% of patients had only silent episodes. During late monitoring painful ST depression was accompanied by greater ST depression and tended to occur at a higher heart rate. Late transient ischaemia showed a diurnal distribution, occurred at a higher initial heart rate, and was more often accompanied by a further increase in heart rate than early ischaemia. Thus in the first 2 months after myocardial infarction transient ischaemia became increasingly common and more closely associated with increased myocardial oxygen demand. Because transient ischaemic episodes during early and late ambulatory monitoring have dissimilar characteristics they may also have different pathophysiologies and prognostic implications. PMID:2245108

  20. Mechanisms for altered carnitine content in hypertrophied rat hearts

    SciTech Connect

    Reibel, D.K.; O'Rourke, B.; Foster, K.A.

    1987-03-01

    Carnitine levels are reduced in hypertrophied hearts of rats subjected to aortic constriction (banding) and evaluated in hypertrophied hearts of spontaneously hypertensive rats (SHR). In an attempt to determine the mechanisms for these alterations, L-(/sup 14/C)carnitine transport was examined in isolated perfused hearts. Total carnitine uptake was significantly reduced by approx.20% in hypertrophied hearts of banded rats at all perfusate carnitine concentrations employed. The reduction in total uptake was due to a 40% reduction in carrier-mediated carnitine uptake with no difference in uptake by diffusion. In contrast, carnitine uptake was not altered in isolated hypertrophied hearts of SHR. However, serum carnitine levels were elevated in SHR, which could result in increased myocardial carnitine uptake in vivo. The data suggest that altered carnitine content in hypertrophied hearts of aortic-banded rats is due to an alteration in the carrier-mediated carnitine transport system in the myocardium. However, altered carnitine content in hypertrophied hearts of SHR is not due to a change in the carnitine transport system per se but may rather be due to a change in serum carnitine levels.

  1. Bioenergetic Insufficiencies Due to Metabolic Alterations Regulated by the Inhibitory Receptor PD-1 Are an Early Driver of CD8(+) T Cell Exhaustion.

    PubMed

    Bengsch, Bertram; Johnson, Andy L; Kurachi, Makoto; Odorizzi, Pamela M; Pauken, Kristen E; Attanasio, John; Stelekati, Erietta; McLane, Laura M; Paley, Michael A; Delgoffe, Greg M; Wherry, E John

    2016-08-16

    Dynamic reprogramming of metabolism is essential for T cell effector function and memory formation. However, the regulation of metabolism in exhausted CD8(+) T (Tex) cells is poorly understood. We found that during the first week of chronic lymphocytic choriomeningitis virus (LCMV) infection, before severe dysfunction develops, virus-specific CD8(+) T cells were already unable to match the bioenergetics of effector T cells generated during acute infection. Suppression of T cell bioenergetics involved restricted glucose uptake and use, despite persisting mechanistic target of rapamycin (mTOR) signaling and upregulation of many anabolic pathways. PD-1 regulated early glycolytic and mitochondrial alterations and repressed transcriptional coactivator PGC-1α. Improving bioenergetics by overexpression of PGC-1α enhanced function in developing Tex cells. Therapeutic reinvigoration by anti-PD-L1 reprogrammed metabolism in a subset of Tex cells. These data highlight a key metabolic control event early in exhaustion and suggest that manipulating glycolytic and mitochondrial metabolism might enhance checkpoint blockade outcomes. PMID:27496729

  2. Altered sphingolipid metabolism in multidrug-resistant ovarian cancer cells is due to uncoupling of glycolipid biosynthesis in the Golgi apparatus.

    PubMed

    Veldman, Robert Jan; Klappe, Karin; Hinrichs, John; Hummel, Ina; van der Schaaf, Gieta; Sietsma, Hannie; Kok, Jan Willem

    2002-07-01

    Multidrug-resistant tumor cells display enhanced levels of glucosylceramide. In this study, we investigated how this relates to the overall sphingolipid composition of multidrug-resistant ovarian carcinoma cells and which mechanisms are responsible for adapted sphingolipid metabolism. We found in multidrug-resistant cells substantially lower levels of lactosylceramide and gangliosides in sharp contrast to glucosylceramide, galactosylceramide, and sphingomyelin levels. This indicates a block in the glycolipid biosynthetic pathway at the level of lactosylceramide formation, with concomitant accumulation of glucosylceramide. A series of observations exclude regulation at the enzyme level as the underlying mechanism. First, reduced lactosylceramide formation occurred only in intact resistant cells whereas cell-free activity of lactosylceramide synthase was higher compared with the parental cells. Second, the level of lactosylceramide synthase gene expression was equal in both phenotypes. Third, glucosylceramide synthase (mRNA and protein) expression and activity were equal or lower in resistant cells. Based on the kinetics of sphingolipid metabolism, the observation that brefeldin A does not restore lactosylceramide synthesis, and altered localization of lactosylceramide synthase fused to green fluorescent protein, we conclude that lactosylceramide biosynthesis is highly uncoupled from glucosylceramide biosynthesis in the Golgi apparatus of resistant cells. PMID:12039850

  3. Excitatory synapses are stronger in the hippocampus of Rett syndrome mice due to altered synaptic trafficking of AMPA-type glutamate receptors.

    PubMed

    Li, Wei; Xu, Xin; Pozzo-Miller, Lucas

    2016-03-15

    Deficits in long-term potentiation (LTP) at central excitatory synapses are thought to contribute to cognitive impairments in neurodevelopmental disorders associated with intellectual disability and autism. Using the methyl-CpG-binding protein 2 (Mecp2) knockout (KO) mouse model of Rett syndrome, we show that naïve excitatory synapses onto hippocampal pyramidal neurons of symptomatic mice have all of the hallmarks of potentiated synapses. Stronger Mecp2 KO synapses failed to undergo LTP after either theta-burst afferent stimulation or pairing afferent stimulation with postsynaptic depolarization. On the other hand, basal synaptic strength and LTP were not affected in slices from younger presymptomatic Mecp2 KO mice. Furthermore, spine synapses in pyramidal neurons from symptomatic Mecp2 KO are larger and do not grow in size or incorporate GluA1 subunits after electrical or chemical LTP. Our data suggest that LTP is occluded in Mecp2 KO mice by already potentiated synapses. The higher surface levels of GluA1-containing receptors are consistent with altered expression levels of proteins involved in AMPA receptor trafficking, suggesting previously unidentified targets for therapeutic intervention for Rett syndrome and other MECP2-related disorders. PMID:26929363

  4. Is the atherosclerotic phenotype of preeclamptic placentas due to altered lipoprotein concentrations and placental lipoprotein receptors? Role of a small-for-gestational-age phenotype

    PubMed Central

    Hentschke, Marta R.; Poli-de-Figueiredo, Carlos E.; Pinheiro da Costa, Bartira E.; Kurlak, Lesia O.; Williams, Paula J.; Mistry, Hiten D.

    2013-01-01

    Atherosis of spiral arteries in uteroplacental beds from preeclamptic women resemble those of atherosclerosis, characterized by increased plasma lipids and lipoproteins. We hypothesized that: 1) lipoprotein receptors/transporters in the placenta would be upregulated in preeclampsia, associated with increased maternal and fetal lipoprotein concentrations; and 2) expression of these would be reduced in preeclamptic placentae from women delivering small-for-gestational-age (SGA) infants. Placental biopsies and maternal and umbilical serum samples were taken from 27 normotensive and 24 preeclamptic women. Maternal/umbilical cord serum LDL, HDL, total cholesterol, and triglycerides were measured. Placental mRNA expression of lipoprotein receptors/transporters were quantified using quantitative RT-PCR. Protein localization/expression of LDL receptor-related protein 1 (LRP-1) in the preeclamptic placentae with/without SGA was measured by immunohistochemistry. Placental mRNA expression of all genes except paraoxonase-1 (PON-1), microsomal triglyceride transfer protein (MTTP), and protein disulfide isomerase family A member 2 (PDIA2) were observed. No differences for any lipoprotein receptors/transporters were found between groups; however, in the preeclamptic group placental LRP-1 expression was lower in SGA delivering mothers (n = 7; P = 0.036). LRP-1 protein was localized around fetal vessels and Hofbauer cells. This is the first detailed study of maternal/fetal lipoprotein concentrations and placental lipoprotein receptor mRNA expression in normotensive and preeclamptic pregnancies. These findings do not support a role of altered lipid metabolism in preeclampsia, but may be involved in fetal growth. PMID:23898049

  5. Channel widening due to urbanization and a major flood can alter bed particle organization and bed stability in an urban boulder-bed channel

    NASA Astrophysics Data System (ADS)

    Prestegaard, K. L.; Behrns, K.; Blanchet, Z.; Hankin, E.

    2007-12-01

    The Anacostia River is a tributary of the Potomac River north of Washington D.C. that has become progressively more urbanized in the past 50 years. Bankfull discharge and bankfull width in the Anacostia have increased by 3- 4x in the past 50 years. Nearby watersheds of similar size and geology, but without significant urbanization, contain threshold gravel-bed streams. The Anacostia, however, is not a threshold channel; it exhibits break-up of boulder-bed channels in upstream reaches and significant gravel bar formation in downstream reaches. These gravel bars have grown and migrated considerably in the past 10-15 years, contributing significantly to local channel widening that can be twice that of adjacent reaches. The purpose of this study is to determine bedload transport rates and grain size distributions and their relationship to discharge, bed organization and sediment supply. Bed mobility data come from both bedload transport measurements and measurements of channel bed changes. Channel bed changes were obtained from a) repeated channel cross section surveys, b) surface and subsurface size distributions, and c) bed particle organization measurements (measurements of location of particles within reaches). These measurements were made prior to and after the floods of 2006, which equalled the largest floods on record for most parts of the Anacostia River. In some boulder bed reaches, boulders were removed from the center of the channel and deposited along and on the channel banks. The mid-channel boulders were replaced by sheets of gravel and cobbles, significantly altering the bed mobility of the channels.

  6. Myocardial infarction and marijuana.

    PubMed

    Charles, R; Holt, S; Kirkham, N

    1979-04-01

    Myocardial infarction in the virtual absence of risk factors occurred in a 25-year old man shortly after smoking a cigarette containing marijuana. Subsequent coronary arteriography was normal. PMID:466984

  7. 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

  8. Gsα activity is reduced in erythrocyte membranes of patients with psedohypoparathyroidism due to epigenetic alterations at the GNAS locus.

    PubMed

    Zazo, Celia; Thiele, Susanne; Martín, Cesar; Fernandez-Rebollo, Eduardo; Martinez-Indart, Lorea; Werner, Ralf; Garin, Intza; Hiort, Olaf; Perez de Nanclares, Guiomar

    2011-08-01

    In pseudohypoparathyroidism (PHP), PTH resistance results from impairment of signal transduction of G protein-coupled receptors caused by a deficiency of the Gsα-cAMP signaling cascade due to diminished Gsα activity in maternally imprinted tissues. In PHP-Ia, inactivating mutations of the GNAS gene lead to haploinsufficiency in some tissues with biallelic expression, so in addition to PHP, Albright's hereditary osteodystrophy (AHO) is also present. In PHP-Ib, caused by methylation defects at the GNAS locus, diminished Gsα activity was thought to be limited to maternally imprinted tissues, such as the renal proximal tubule and the thyroid, leading to a lack of AHO. Recently, we demonstrated methylation defects in patients with AHO signs, indicating a connection between epigenetic changes and AHO. Our objective was to determine Gsα activity in erythrocyte membranes in patients with epigenetic defects at the GNAS locus compared to normal controls and patients with inactivating GNAS mutations. Gsα activity and expression, mutation of the GNAS locus, and methylation status were studied in patients with PHP and mild signs of AHO (PHP-Ia: 12; PHP-Ib: 17, of which 8 had some features of AHO). Then, we statistically compared the Gsα activity of the different PHP subtypes. Patients with methylation defects at the GNAS locus show a significant decrease in erythrocyte Gsα activity compared to normal controls (PHP-Ib versus controls, p < .001). This was significantly lower in patients with AHO signs (PHP-Ib + mild-AHO versus PHP-Ib, p < .05). Our research shows that PHP-Ia and PHP-Ib classification is not only overlapped genetically, as reported, but also in terms of Gsα activity. Reduced expression of GNAS due to methylation defects could downregulate Gsα activity in other tissues beyond those described and could also be causative of AHO. PMID:21351142

  9. Molecular and cellular mechanisms of myocardial stunning.

    PubMed

    Bolli, R; Marbán, E

    1999-04-01

    The past two decades have witnessed an explosive growth of knowledge regarding postischemic myocardial dysfunction or myocardial "stunning." The purpose of this review is to summarize current information regarding the pathophysiology and pathogenesis of this phenomenon. Myocardial stunning should not be regarded as a single entity but rather as a "syndrome" that has been observed in a wide variety of experimental settings, which include the following: 1) stunning after a single, completely reversible episode of regional ischemia in vivo; 2) stunning after multiple, completely reversible episodes of regional ischemia in vivo; 3) stunning after a partly reversible episode of regional ischemia in vivo (subendocardial infarction); 4) stunning after global ischemia in vitro; 5) stunning after global ischemia in vivo; and 6) stunning after exercise-induced ischemia (high-flow ischemia). Whether these settings share a common mechanism is unknown. Although the pathogenesis of myocardial stunning has not been definitively established, the two major hypotheses are that it is caused by the generation of oxygen-derived free radicals (oxyradical hypothesis) and by a transient calcium overload (calcium hypothesis) on reperfusion. The final lesion responsible for the contractile depression appears to be a decreased responsiveness of contractile filaments to calcium. Recent evidence suggests that calcium overload may activate calpains, resulting in selective proteolysis of myofibrils; the time required for resynthesis of damaged proteins would explain in part the delayed recovery of function in stunned myocardium. The oxyradical and calcium hypotheses are not mutually exclusive and are likely to represent different facets of the same pathophysiological cascade. For example, increased free radical formation could cause cellular calcium overload, which would damage the contractile apparatus of the myocytes. Free radical generation could also directly alter contractile filaments in a

  10. Value of positive myocardial infarction imaging in coronary care units.

    PubMed Central

    Joseph, S P; Pereira-Prestes, A V; Ell, P J; Donaldson, R; Somerville, W; Emanuel, R W

    1979-01-01

    Positive myocardial imaging was undertaken on 120 unselected patients admitted to a coronary care unit with clinical suspicion of acute myocardial infarction. Multipurpose mobile gamma-cameras were used for serial imaging after administration of 99mtechnetium-labelled imidodiphosphonate, a low-cost radiopharmaceutical that is 97% specific for myocardial necrosis, with myocardial uptake and blood clearance most suitable for myocardial imaging. The sensitivty of detection was 94% for patients whose infarction was unequivocal on the ECG; when the presence of raised enzyme concentrations was also used as a criterion for myocardial necrosis, the overall sensitivity for all 120 patients remained 94%. In 73 patients (61%), whose ECGs were unhelpful or difficult to interpret, scintigraphy allowed infarction to be diagnosed in 11 (15%) and to be excluded in five (7%). In 32 (44%) of this group whose ECGs were totally uninterpretable due to previous myocardial damage or disorders of electrical activation, scintigraphy provided confirmation of a diagnosis that otherwise rested only on whether enzyme concentrations were raised. Myocardial imaging is thus a useful technique that permits more definite diagnosis in patients for whom ECG and enzyme data are uncertain. PMID:761017

  11. Myocardial Noncompaction Presenting With Myocardial Bridge

    PubMed Central

    Shen, Yuechun; Li, Xinchun; Lu, Dongfeng; Xiao, Aiyi; Li, Jun

    2015-01-01

    Abstract Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown. We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium. The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable. This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies. PMID:26356695

  12. [Energy metabolism and myocardial function in myocardiodystrophy].

    PubMed

    Temirova, K V; Kurlygina, L A; Zavodskaia, I S; Novikova, N A

    1976-09-01

    A total of 92 patients with chronic tonsilitis and cardiovascular changes were subjected to clinical observations, ECG analysis, potassium and nitroglycerine tests, and studies of the lactic acid level and creatinekinase activity as indces of myocardial metabolism. The examinations were conducted prior to and following tonsillectomy. In a majority of patients a correlation was revealed between the degree of ECG changes and the serum lactic acid level, as well as between the ECG improvement and a reduction of the lactic acid level following tonsillectomy. Three stages of tonsillogenic myocardiodystrophy were distinguished. The obtained data indicate the rationale of the used tests for the evaluation of the myocardial meabolism alterations and of the efficacy of treatment of chronic tonsillitis patients. PMID:1011536

  13. Transient myocardial ischaemia after acute myocardial infarction does not induce ventricular arrhythmias.

    PubMed Central

    Currie, P; Saltissi, S

    1993-01-01

    OBJECTIVE--To see whether transient myocardial ischaemia on ambulatory monitoring after myocardial infarction is associated with ventricular arrhythmias. DESIGN--A prospective study. SETTING--The coronary care unit, general medical wards, and cardiorespiratory department of a major teaching hospital. PATIENTS--203 consecutive patients without specific exclusion criteria admitted with acute myocardial infarction. INTERVENTIONS--24 hour ambulatory electrocardiographic monitoring for ventricular arrhythmias and ST depression both early (mean 6.3 days after infarction, n = 201) and late (mean 38 days, n = 177). MAIN OUTCOME MEASURES--Episodes of myocardial ischaemia were identified during ambulatory monitoring by transient ST depression of > or = 1.0 mm lasting for > or = 30 s. Ventricular arrhythmias were single extrasystoles, couplets, or ventricular tachycardia. RESULTS--All ventricular arrhythmias were significantly more frequent in late than early monitoring. The arrhythmias included couplets (in 83/174 (48%) v 49/200 (25%) of patients, p = 0.0000028) and ventricular tachycardia (29/174 (17%) v 15/199 (8%), p = 0.0064). Patients with ST depression (29 early; 56 late), compared with those without ischaemia, did not experience a significant increase in single extrasystoles, couplets (31% v 23% early; 47% v 48% late), or ventricular tachycardia (3% v 8% early; 18% v 16% late). Even patients with frequent (> or = 3 episodes), and deep (> or = 1.5 mm) or prolonged (> or = 20 min) ST depression had no increase in arrhythmias. CONCLUSIONS--Ventricular arrhythmias after myocardial infarction are not associated with transient myocardial ischaemia during daily activities. This study does not support the belief that to abolish silent ischaemia would reduce the incidence of sudden death due to uncontrollable ventricular arrhythmias after myocardial infarction. PMID:8489860

  14. BEHAVIORAL ALTERATIONS DUE TO DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Several experiments examining the effects of diesel exhaust on the behavior of rats are reported. Animals were exposed either as adults or neonates. The spontaneous locomotor activity (SLA), measured in standard running wheel cages, of adult rats exposed for 8 h/day, 7 days/week ...

  15. Obesity does not Lead to Imbalance Between Myocardial Phospholamban Phosphorylation and Dephosphorylation

    PubMed Central

    Freire, Paula Paccielli; Alves, Carlos Augusto Barnabe; de Deus, Adriana Fernandes; Leopoldo, Ana Paula Lima; Leopoldo, André Soares; da Silva, Danielle Cristina Tomaz; de Tomasi, Loreta Casquel; Campos, Dijon Henrique Salomé; Cicogna, Antonio Carlos

    2014-01-01

    Background The activation of the beta-adrenergic system promotes G protein stimulation that, via cyclic adenosine monophosphate (cAMP), alters the structure of protein kinase A (PKA) and leads to phospholamban (PLB) phosphorylation. This protein participates in the system that controls intracellular calcium in muscle cells, and it is the primary regulator of sarcoplasmic reticulum calcium pump activity. In obesity, the beta-adrenergic system is activated by the influence of increased leptin, therefore, resulting in higher myocardial phospholamban phosphorylation via cAMP-PKA. Objective To investigate the involvement of proteins which regulate the degree of PLB phosphorylation due to beta-adrenergic activation in obesity. In the present study, we hypothesized that there is an imbalance between phospholamban phosphorylation and dephosphorylation, with prevalence of protein phosphorylation. Methods Male Wistar rats were randomly distributed into two groups: control (n = 14), fed with normocaloric diet; and obese (n = 13), fed with a cycle of four unsaturated high-fat diets. Obesity was determined by the adiposity index, and protein expressions of phosphatase 1 (PP-1), PKA, PLB, phosphorylated phospholamban at serine16 (PPLB-Ser16) were assessed by Western blot. Results Obesity caused glucose intolerance, hyperinsulinemia, hypertriglyceridemia, hyperleptinemia and did not alter the protein expression of PKA, PP-1, PLB, PPLB-Ser16. Conclusion Obesity does not promote an imbalance between myocardial PLB phosphorylation and dephosphorylation via beta-adrenergic system. PMID:25120084

  16. Bovine myocardial epithelial inclusions.

    PubMed

    Baker, D C; Schmidt, S P; Langheinrich, K A; Cannon, L; Smart, R A

    1993-01-01

    Light microscopic, histochemical, immunohistochemical, and ultrastructural methods were used to examine myocardial epithelial masses in the hearts of ten cattle. The tissues consisted of paraffin-embedded or formalin-fixed samples from eight hearts that were being inspected in slaughter houses and from two hearts from calves that died of septicemia. The ages of the cattle ranged from 4 days to 12 years; the breeds were unspecified for all but one Hereford female and the two Holstein calves; and there were three males, four females, and three steers. The masses in these cases were compared with similar appearing lesions found in other animal species. The lesions in the bovine hearts were single to multiple, well circumscribed, found in the left ventricle wall, and composed of squamous to cuboidal epithelial cells that formed tubular, ductular, and acinar structures with lumens that were void or filled with amorphous protein globules. Electron microscopic examination revealed epithelial cells that had sparse apical microvilli, tight apical intercellular junctions, perinuclear bundles of filaments, and rare cilia. Almost half of the bovine epithelial masses (4/9) had occasional diastase-resistant periodic acid-Schiff-positive granules in their cytoplasm, and few had hyaluronidase-resistant alcian blue-positive granules (2/9) or colloidal iron-positive granules (1/9). All myocardial masses had abundant collagen surrounding the tubular and acinar structures, and 2/9 had elastin fibers as well. None of the myocardial masses had Churukian-Schenk or Fontana Masson's silver staining granules in epithelial cells. Immunohistochemically, all bovine myocardial tumors stained positively for cytokeratin (8/8), and occasional masses stained positively for vimentin (3/8) or carcinoembryonic antigen (3/8). None of the masses stained positively for desmin. The myocardial epithelial tumors most likely represent endodermal rests of tissue misplaced during organogenesis. PMID:7680178

  17. 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

  18. Studies the alterations of biochemical and mineral contents in bone tissue of mus musculus due to aluminum toxicity and the protective action of desferrioxamine and deferiprone by FTIR, ICP-OES, SEM and XRD techniques

    NASA Astrophysics Data System (ADS)

    Sivakumar, S.; Khatiwada, Chandra Prasad; Sivasubramanian, J.

    The present study has attempt to analyze the changes in the biochemical and mineral contents of aluminum intoxicated bone and determine the protective action of desferrioxamine (DFO) and deferiprone (DFP) by using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), and scanning electron microscopy (SEM) techniques for four groups of animals such as control (Group I), aluminum intoxicated (Group II), Al + DFP (Group III) and Al + DFO + DFP (Group IV) treated groups respectively. The FTIR spectra of the aluminum intoxicated bone showed significant alteration in the biochemical constituents. The bands ratio at I1400/I877 significantly decreased from control to aluminum, but enhanced it by Al + DFP to Al + DFO + DFP treated bone tissue for treatments of 16 weeks. This result suggests that DFO and DFP are the carbonate inhibitor, recovered from chronic growth of bone diseases and pathologies. The alteration of proteins profile indicated by Amide I and Amide II, where peak area values decreased from control to aluminum respectively, but enhanced by treated with DFP (p.o.) and DFO + DFP (i.p.) respectively. The XRD analysis showed a decrease in crystallinity due to aluminum toxicity. Further, the Ca, Mg, and P contents of the aluminum exposed bone were less than those of the control group, and enhanced by treatments with DFO and DFP. The concentrations of trace elements were found by ICP-OES. Therefore, present study suggests that due to aluminum toxicity severe loss of bone minerals, decrease in the biochemical constituents and changes in the surface morphology.

  19. Diagnostic approaches for diabetic cardiomyopathy and myocardial fibrosis

    PubMed Central

    Maya, Lisandro; Villarreal, Francisco J.

    2009-01-01

    In diabetes mellitus, alterations in cardiac structure/function in the absence of ischemic heart disease, hypertension or other cardiac pathologies is termed diabetic cardiomyopathy. In the United States, the prevalence of diabetes mellitus continues to rise and the disease currently affects about 8% of the general population. Hence, it is imperative the use of appropriate diagnostic strategies for diabetic cardiomyopathy, which may help correctly identify the disease at early stages and implement suitable corrective therapies. Currently, there is no single diagnostic method for the identification of diabetic cardiomyopathy. Diabetic cardiomyopathy is known to induce changes in cardiac structure such as, myocardial hypertrophy, fibrosis and fat droplet deposition. Early changes in cardiac function are typically manifested as abnormal diastolic function that with time leads to loss of contractile function. Echocardiography based methods currently stands as the preferred diagnostic approach for diabetic cardiomyopathy, due to its wide availability and economical use. In addition to conventional techniques, magnetic resonance imaging and spectroscopy along with contrast agents are now leading new approaches in the diagnosis of myocardial fibrosis, and cardiac and hepatic metabolic changes. These strategies can be complemented with serum biomarkers so they can offer a clear picture as to diabetes-induced changes in cardiac structure/function even at very early stages of the disease. This review article intends to provide a summary of experimental and routine tools currently available to diagnose diabetic cardiomyopathy induced changes in cardiac structure/function. These tools can be reliably used in either experimental models of diabetes or for clinical applications. PMID:19595694

  20. Acute myocardial infarction and sudden death in Sioux Indians.

    PubMed Central

    Hrabovsky, S L; Welty, T K; Coulehan, J L

    1989-01-01

    While some Indian tribes have low rates of acute myocardial infarction, Northern Plains Indians, including the Sioux, have rates of morbidity and mortality from acute myocardial infarction higher than those reported for the United States population in general. In a review of diagnosed cases of acute myocardial infarction over a 3-year period in 2 hospitals serving predominantly Sioux Indians, 8% of cases were found misclassified, and 22% failed to meet rigorous diagnostic criteria, although the patients did indeed have ischemic heart disease. Patients had high frequencies of complications and risk factors and a fatality rate of 16% within a month of admission. Sudden deaths likely due to ischemic heart disease but in persons not diagnosed as having acute myocardial infarction by chart review occurred 3 times more frequently than deaths occurring within a month of clinical diagnosis. PMID:2735047

  1. Acute myocardial infarction.

    PubMed

    Rischpler, Christoph

    2016-09-01

    Inflammatory processes after myocardial infarction have gained major interest in recent cardiovascular research. It is believed that not only the degree of cell recruitment to the heart plays a pivotal role in the quality of wound healing after myocardial infarction, but also the balance between different types or even subtypes of cells. It is also this balance which is thought to control key processes in tissue repair, such as apoptosis and neoangiogenesis. In this paper, we aim to review imaging strategies (with a special focus on nuclear molecular imaging strategies) that target cells and processes involved in postischemic inflammation and that have a high potential to be translated into clinic or that are already being used and evaluated in humans. PMID:27225319

  2. [Mortality of myocardial infarction].

    PubMed

    Bonnefoy, E; Kirkorian, G

    2011-12-01

    Coronary disease is a major cause of death and disability. From 1975 to 2000, coronary mortality was reduced by half. Better treatments and reduction of risk factors are the main causes. This phenomenon is observed in most developed countries, but mortality from coronary heart disease continues to increase in developing countries. In-hospital mortality of ST elevation myocardial infarction (STEMI) is in the range of 7 to 10% in registries. In infarction without ST segment elevation (NSTEMI), in-hospital mortality is around 5%. More recent studies found a similar in-hospital mortality for STEMI and NSTEMI. Because of patient selection and monitoring, mortality in clinical trials is much lower. After adjustment for the extent of coronary disease, age, risk factors, history of myocardial infarction, the excess mortality observed in women is fading. Many clinical, biological and laboratory parameters are associated with mortality in myocardial infarction. They refer to the immediate risk of death (ventricular rhythm disturbances, shock…), the extent of infarction (number of leads with ST elevation on the ECG, release of biomarkers, ejection fraction…), the presence of heart failure, the failure of reperfusion and the patient's baseline risk (age, renal function…). Risk scores, and more specifically the GRACE risk score, synthesize these different markers to predict the risk of death in a given patient. However, their use for the treatment of myocardial only concerns NSTEMI. Only a limited number of mechanical or pharmacological interventions reduces mortality of heart attack. The main benefits are observed with reperfusion by thrombolysis or primary angioplasty in STEMI, aspirin, heparin, beta-blockers, angiotensin converting enzyme inhibitors. Some medications such as bivalirudin and fondaparinux reduce mortality by decreasing the incidence of hemorrhagic complications. The guidelines classify interventions according to their benefit and especially their ability

  3. Early manifestation of alteration in cardiac function in dystrophin deficient mdx mouse using 3D CMR tagging

    PubMed Central

    Li, Wei; Liu, Wei; Zhong, Jia; Yu, Xin

    2009-01-01

    Background Duchenne muscular dystrophy (DMD) is caused by the absence of the cytoskeletal protein, dystrophin. In DMD patients, dilated cardiomyopathy leading to heart failure may occur during adolescence. However, early cardiac dysfunction is frequently undetected due to physical inactivity and generalized debilitation. The objective of this study is to determine the time course of cardiac functional alterations in mdx mouse, a mouse model of DMD, by evaluating regional ventricular function with CMR tagging. Methods In vivo myocardial function was evaluated by 3D CMR tagging in mdx mice at early (2 months), middle (7 months) and late (10 months) stages of disease development. Global cardiac function, regional myocardial wall strains, and ventricular torsion were quantified. Myocardial lesions were assessed with Masson's trichrome staining. Results Global contractile indexes were similar between mdx and C57BL/6 mice in each age group. Histology analysis showed that young mdx mice were free of myocardial lesions. Interstitial fibrosis was present in 7 month mdx mice, with further development into patches or transmural lesions at 10 months of age. As a result, 10 month mdx mice showed significantly reduced regional strain and torsion. However, young mdx mice showed an unexpected increase in regional strain and torsion, while 7 month mdx mice displayed similar regional ventricular function as the controls. Conclusion Despite normal global ventricular function, CMR tagging detected a biphasic change in myocardial wall strain and torsion, with an initial increase at young age followed by progressive decrease at older ages. These results suggest that CMR tagging can provide more sensitive measures of functional alterations than global functional indexes in dystrophin-related cardiomyopathies. PMID:19849858

  4. Hearts deficient in both Mfn1 and Mfn2 are protected against acute myocardial infarction.

    PubMed

    Hall, A R; Burke, N; Dongworth, R K; Kalkhoran, S B; Dyson, A; Vicencio, J M; Dorn Ii, G W; Yellon, D M; Hausenloy, D J

    2016-01-01

    Mitochondria alter their shape by undergoing cycles of fusion and fission. Changes in mitochondrial morphology impact on the cellular response to stress, and their interactions with other organelles such as the sarcoplasmic reticulum (SR). Inhibiting mitochondrial fission can protect the heart against acute ischemia/reperfusion (I/R) injury. However, the role of the mitochondrial fusion proteins, Mfn1 and Mfn2, in the response of the adult heart to acute I/R injury is not clear, and is investigated in this study. To determine the effect of combined Mfn1/Mfn2 ablation on the susceptibility to acute myocardial I/R injury, cardiac-specific ablation of both Mfn1 and Mfn2 (DKO) was initiated in mice aged 4-6 weeks, leading to knockout of both these proteins in 8-10-week-old animals. This resulted in fragmented mitochondria (electron microscopy), decreased mitochondrial respiratory function (respirometry), and impaired myocardial contractile function (echocardiography). In DKO mice subjected to in vivo regional myocardial ischemia (30 min) followed by 24 h reperfusion, myocardial infarct size (IS, expressed as a % of the area-at-risk) was reduced by 46% compared with wild-type (WT) hearts. In addition, mitochondria from DKO animals had decreased MPTP opening susceptibility (assessed by Ca(2+)-induced mitochondrial swelling), compared with WT hearts. Mfn2 is a key mediator of mitochondrial/SR tethering, and accordingly, the loss of Mfn2 in DKO hearts reduced the number of interactions measured between these organelles (quantified by proximal ligation assay), attenuated mitochondrial calcium overload (Rhod2 confocal microscopy), and decreased reactive oxygen species production (DCF confocal microscopy) in response to acute I/R injury. No differences in isolated mitochondrial ROS emissions (Amplex Red) were detected in response to Ca(2+) and Antimycin A, further implicating disruption of mitochondria/SR tethering as the protective mechanism. In summary, despite apparent

  5. Hearts deficient in both Mfn1 and Mfn2 are protected against acute myocardial infarction

    PubMed Central

    Hall, A R; Burke, N; Dongworth, R K; Kalkhoran, S B; Dyson, A; Vicencio, J M; Dorn II, G W; Yellon, D M; Hausenloy, D J

    2016-01-01

    Mitochondria alter their shape by undergoing cycles of fusion and fission. Changes in mitochondrial morphology impact on the cellular response to stress, and their interactions with other organelles such as the sarcoplasmic reticulum (SR). Inhibiting mitochondrial fission can protect the heart against acute ischemia/reperfusion (I/R) injury. However, the role of the mitochondrial fusion proteins, Mfn1 and Mfn2, in the response of the adult heart to acute I/R injury is not clear, and is investigated in this study. To determine the effect of combined Mfn1/Mfn2 ablation on the susceptibility to acute myocardial I/R injury, cardiac-specific ablation of both Mfn1 and Mfn2 (DKO) was initiated in mice aged 4–6 weeks, leading to knockout of both these proteins in 8–10-week-old animals. This resulted in fragmented mitochondria (electron microscopy), decreased mitochondrial respiratory function (respirometry), and impaired myocardial contractile function (echocardiography). In DKO mice subjected to in vivo regional myocardial ischemia (30 min) followed by 24 h reperfusion, myocardial infarct size (IS, expressed as a % of the area-at-risk) was reduced by 46% compared with wild-type (WT) hearts. In addition, mitochondria from DKO animals had decreased MPTP opening susceptibility (assessed by Ca2+-induced mitochondrial swelling), compared with WT hearts. Mfn2 is a key mediator of mitochondrial/SR tethering, and accordingly, the loss of Mfn2 in DKO hearts reduced the number of interactions measured between these organelles (quantified by proximal ligation assay), attenuated mitochondrial calcium overload (Rhod2 confocal microscopy), and decreased reactive oxygen species production (DCF confocal microscopy) in response to acute I/R injury. No differences in isolated mitochondrial ROS emissions (Amplex Red) were detected in response to Ca2+ and Antimycin A, further implicating disruption of mitochondria/SR tethering as the protective mechanism. In summary, despite apparent

  6. Cardioprotection against experimental myocardial ischemic injury using cornin.

    PubMed

    Xu, Y; Xu, Y; Luan, H; Jiang, Y; Tian, X; Zhang, S

    2016-02-01

    Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv) protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt. PMID:26871971

  7. Cardioprotection against experimental myocardial ischemic injury using cornin

    PubMed Central

    Xu, Y.; Xu, Y.; Luan, H.; Jiang, Y.; Tian, X.; Zhang, S.

    2016-01-01

    Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv) protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt. PMID:26871971

  8. Quantitation of myocardial fatty acid metabolism using PET

    SciTech Connect

    Bergmann, S.R.; Weinheimer, C.J.; Markham, J.; Herrero, P.

    1996-10-01

    Abnormalities of fatty acid metabolism in the heart presage contractile dysfunction and arrhythmias. This study was performed to determine whether myocardial fatty acid metabolism could be quantified noninvasively using PET and 1-{sup 11}C-palmitate. Anesthetized dogs were studied during control conditions; during administration of dobutamine; after oxfenicine; and during infusion of glucose. Dynamic PET data after administration of 1-{sup 11}C-palmitate were fitted to a four-compartment mathematical model. Modeled rates of palmitate utilization correlated closely with directly measured myocardial palmitate and total long-chain fatty acid utilization (r = 0.93 and 0.96, respectively, p < 0.001 for each) over a wide range of arterial fatty acid levels and altered patterns of myocardial substrate use (fatty acid extraction fraction ranging from 1% to 56%, glucose extraction fraction from 1% to 16% and myocardial fatty acid utilization from 1 to 484 nmole/g/min). The percent of fatty acid undergoing oxidation could also be measured. The results demonstrate the ability to quantify myocardial fatty acid utilization with PET. The approach is readily applicable for the determination of fatty acid metabolism noninvasively in patients. 37 refs., 5 figs., 4 tabs.

  9. Diurnal variations in myocardial metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heart is challenged by a plethora of extracellular stimuli over the course of a normal day, each of which distinctly influences myocardial contractile function. It is therefore not surprising that myocardial metabolism also oscillates in a time-of-day dependent manner. What is becoming increasin...

  10. Dipyridamole thallium-201 myocardial scintigraphy

    SciTech Connect

    Not Available

    1988-09-01

    Thallium-201 (/sup 201/Tl) myocardial scintigraphy is a sensitive technique for detecting coronary artery disease. Standardized exercise testing is the most common method for inducing myocardial stress for /sup 201/Tl imaging. Unfortunately, a significant number of patients are unable to undergo adequate treadmill or bicycle exercise. In these patients, pharmacologic stress with dipyridamole provides a safe, efficacious, and reliable alternative.

  11. Noninvasive estimation of regional myocardial oxygen consumption by positron emission tomography with carbon-11 acetate in patients with myocardial infarction

    SciTech Connect

    Walsh, M.N.; Geltman, E.M.; Brown, M.A.; Henes, C.G.; Weinheimer, C.J.; Sobel, B.E.; Bergmann, S.R. )

    1989-11-01

    We previously demonstrated in experimental studies that myocardial oxygen consumption (MVO2) can be estimated noninvasively with positron emission tomography (PET) from analysis of the myocardial turnover rate constant (k) after administration of carbon-11 (11C) acetate. To determine regional k in healthy human subjects and to estimate alterations in MVO2 accompanying myocardial ischemia, we administered (11C)acetate to five healthy human volunteers and to six patients with myocardial infarction. Extraction of (11C)acetate by the myocardium was avid and clearance from the blood-pool rapid yielding myocardial images of excellent quality. Regional k was homogeneous in myocardium of healthy volunteers (coefficient variation = 11%). In patients, k in regions remote from the area of infarction was not different from values in myocardium of healthy human volunteers (0.061 +/- 0.025 compared with 0.057 +/- 0.008 min-1). In contrast, MVO2 in the center of the infarct region was only 6% of that in remote regions (p less than 0.01). In four patients studied within 48 hr of infarction and again more than seven days after the acute event, regional k and MVO2 did not change. The approach developed should facilitate evaluation of the efficacy of interventions designed to enhance recovery of jeopardized myocardium and permit estimation of regional MVO2 and metabolic reserve underlying cardiac disease of diverse etiologies.

  12. Spiral MR myocardial tagging.

    PubMed

    Ryf, Salome; Kissinger, Kraig V; Spiegel, Marcus A; Börnert, Peter; Manning, Warren J; Boesiger, Peter; Stuber, Matthias

    2004-02-01

    In the present study, complementary spatial modulation of magnetization (CSPAMM) myocardial tagging was extended with an interleaved spiral imaging sequence. The use of a spiral sequence enables the acquisition of grid-tagged images with a tagline distance as low as 4 mm in a single breath-hold. Alternatively, a high temporal resolution of 77 frames per second was obtained with 8-mm grid spacing. Ten healthy adult subjects were studied. With this new approach, high-quality images can be obtained and the tags persist throughout the entire cardiac cycle. PMID:14755646

  13. Assessment of myocardial viability.

    PubMed

    Travin, Mark I; Bergmann, Steven R

    2005-01-01

    The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress

  14. Impact of high-fat, low-carbohydrate diet on myocardial substrate oxidation, insulin sensitivity, and cardiac function after ischemia-reperfusion.

    PubMed

    Liu, Jian; Wang, Peipei; Douglas, Samuel L; Tate, Joshua M; Sham, Simon; Lloyd, Steven G

    2016-07-01

    High-fat, low-carbohydrate Diet (HFLCD) impairs the myocardial response to ischemia-reperfusion, but the underlying mechanisms remain elusive. We sought to determine the magnitude of diet-induced alterations in intrinsic properties of the myocardium (including insulin sensitivity and substrate oxidation) and circulating substrate and insulin differences resulting from diet, leading to this impaired response. Rats were fed HFLCD (60% kcal from fat/30% protein/10% carbohydrate) or control diet (CONT) (16%/19%/65%) for 2 wk. Isolated hearts underwent global low-flow ischemia followed by reperfusion (I/R). Carbon-13 NMR spectroscopy was used to determine myocardial substrate TCA cycle entry. Myocardial insulin sensitivity was assessed as dose-response of Akt phosphorylation. There was a significant effect of HFLCD and I/R with both these factors leading to an increase in free fatty acid (FFA) oxidation and a decrease in carbohydrate or ketone oxidation. Following I/R, HFLCD led to decreased ketone and increased FFA oxidation; the recovery of left ventricular (LV) function was decreased in HFLCD and was negatively correlated with FFA oxidation and positively associated with ketone oxidation. HFLCD also resulted in reduced insulin sensitivity. Under physiologic ranges, there were no direct effects of buffer insulin and ketone levels on oxidation of any substrate and recovery of cardiac function after I/R. An insulin-ketone interaction exists for myocardial substrate oxidation characteristics. We conclude that the impaired recovery of function after ischemia-reperfusion with HFLCD is largely due to intrinsic diet effects on myocardial properties, rather than to diet effect on circulating insulin or substrate levels. PMID:27199129

  15. Effect of alpha 1-adrenergic blockade on myocardial blood flow during exercise after myocardial infarction.

    PubMed

    Herzog, C A; Dai, X Z; Bache, R J

    1991-08-01

    The effect of alpha 1-adrenergic blockade with prazosin on myocardial blood flow at rest and during two levels of treadmill exercise was assessed in 16 chronically instrumented dogs 9-14 days after myocardial infarction had been produced by occlusion of the left circumflex coronary artery. During resting conditions prazosin did not alter mean myocardial blood flow or the subendocardial-to-subepicardial flow ratio in either normally perfused or collateral-dependent myocardium. However, during exercise at comparable external work loads and comparable rate-pressure products, prazosin significantly increased blood flow to normally perfused (27% increase at the second level of exercise, P less than 0.001) and collateral-dependent myocardium (35% increase at the second level of exercise, P less than 0.001) compared with control. In addition, prazosin caused a small but significant decrease in the subendocardial-to-subepicardial flow ratio in both normal (1.27 +/- 0.04 to 1.19 +/- 0.04; P less than 0.01) and collateral-dependent myocardium (0.57 +/- 0.11 to 0.52 +/- 0.11; P less than 0.01) compared with control, reflecting a disproportionally greater increase in subepicardial flow in response to alpha 1-adrenergic blockade. These data demonstrate that alpha 1-adrenergic vasoconstriction inhibits coronary vasodilation during exercise, even in areas of collateral-dependent myocardium relatively early after coronary artery occlusion. PMID:1678929

  16. Valsartan after myocardial infarction.

    PubMed

    Güleç, Sadi

    2014-12-01

    One of the important problems of the patients undergoing acute myocardial infarction (MI) is early development of heart failure. It has been revealed in various studies that renin-angiotensin-aldosterone system (RAAS) has a significant role in this process. The studies conducted with angiotensin converting enzyme (ACE) inhibitors have resulted in decreased mortality rate. Another RAAS blocker which was discovered about ten years later than other ACE inhibitors in historical process is angiotensin receptor blockers (ARB) inhibiting the efficiency of angiotensin 2 by binding to angiotensin 1 receptor. Valsartan is one of the molecules of this group, which has higher number of large-scale randomized clinical studies. In this review, following presentation of a general overview on heart failure after acute MI, the efficiency of ARBs in this patient group will be discussed. This discussion will mostly emphasize the construction, outcomes and clinical importance of VALIANT (VALsartan In Acute myocardial iNfarcTion), which is the study on valsartan after acute MI heart failure. PMID:25604205

  17. Trauma Induced Myocardial Infarction

    PubMed Central

    Lolay, Georges A.; Abdel-Latef, Ahmed K.

    2016-01-01

    Chest Trauma in athletes is a common health problem. However, myocardial infarction secondary to coronary dissection in the setting of blunt chest trauma is extremely rare. We report a case of acute inferior wall myocardial infarction following blunt chest trauma. A 32-year-old male with no relevant medical problems was transferred to our medical center for retrosternal chest pain after being elbowed in the chest during a soccer game. Few seconds later, he started experiencing sharp retrosternal chest pain that was severe to that point where he called the emergency medical service. Upon arrival to the Trauma department patient was still complaining of chest pain. ECG demonstrated ST segment elevation in the inferior leads with reciprocal changes in the lateral leads all consistent with active ischemia. After rolling out Aortic dissection, patient was loaded with ASA, ticagerlor, heparin and was emergently taken to the cardiac catheterization lab. Coronary angiography demonstrated 100% thrombotic occlusion in the distal right coronary artery with TIMI 0 flow distally. After thrombus aspiration, a focal dissection was noted on the angiogram that was successfully stented. Two days after admission patient was discharged home. Echocardiography prior to discharge showed inferior wall akinesis, normal right ventricular systolic function and normal overall ejection fraction. PMID:26490501

  18. Mass spectrometry for the measurement of intramyocardial gas tensions: methodology and application to the study of myocardial ischemia.

    PubMed

    Khuri, S F; O'Riordan, J; Flaherty, J T; Brawley, R K; Donahoo, J S; Gott, V L

    1975-01-01

    The methodology for use of the mass spectrometer for the measurement of intramyocardial gas tensions in the canine preparation is described. Baseling studies were carried out initially in 36 animals, and control levels for myocardial oxygen tension and myocardial carbon dioxide tension were 19 mm Hg (S.D. 6 mm Hg) and 43 mm Hg (S.D. 10 mm Hg), respectively. Myocardial oxygen tension was not altered significantly by varying the arterial oxygen tension between 65 and 300 mm Hg. However, myocardial carbon dioxide tension increased linearly with increased arterial carbon dioxide tension. In 15 dogs placed on total cardiopulmonary bypass, a perfusion pressure 40-60 mm lower than the control mean arterial pressure resulted in myocardial ischemia with a decrease in myocardial oxygen tension and an increase in myocardial carbon dioxide tension. A subsequent increase in perfusion pressure to control levels resulted in resolution of ischemia and return of myocardial oxygen and carbon dioxide tensions to their control level. In another series of open-chest dogs on cardiopulmonary bypass, a proximal constriction applied to the left coronary circumflex artery resulted in a marked decrease in myocardial oxygen tensions and a marked increase in myocardial carbon dioxide tensions in the region supplied by the constricted vessel. In yet another series of open-chest dogs, it was found that incremental decreases in coronary flow established by constriction of the circumflex artery resulted in an exponential increase in both myocardial carbon dioxide tensions and ST-segment elevation as determined by a 25-gauge multi-contact plunge electrode placed in the posterior left ventricular wall. It appears that mass spectrometry techniques for evaluating myocardial ischemia have several advantages over myocardial biopsy techniques for assay of ATP and lactate, and also over the technique of coronary sinus lactate determination. PMID:1209001

  19. Computational Modeling of the Effects of Myocardial Infarction on Left Ventricular Hemodynamics

    NASA Astrophysics Data System (ADS)

    Vedula, Vijay; Seo, Jung Hee; Mittal, Rajat; Fortini, Stefania; Querzoli, Giorgio

    2012-11-01

    Most in-vivo and modeling studies on myocardial infarction and ischemia have been directed towards understanding the left ventricular wall mechanics including stress-strain behavior, end systolic pressure-volume correlations, ejection fraction and stroke work. Fewer studies have focused on the alterations in the intraventricular blood flow behavior due to local infarctions. Changes in the motion of the endocardium can cause local circulation and stagnation regions; these increase the blood cell residence time in the left ventricle and may eventually be implicated in thrombus formation. In the present study, we investigate the effects of myocardial infarction on the ventricular hemodynamics in simple models of the left ventricle using an immersed-boundary flow solver. Apart from the Eulerian flow features such as vorticity and velocity flow fields, pressure distribution, shear stress, viscous dissipation and pump work, we also examine the Lagrangian dynamics of the flow to gain insights into the effect of flow dynamics on thrombus formation. The study is preceded by a comprehensive validation study which is based on an in-vitro experimental model of the left ventricle and this study is also described. This research is supported by the U.S. National Science Foundation through (NSF) CDI-Type II grant IOS-1124804. Computational resources for some of the simulations were also provided in part through the NSF grant NSF-OCI-108849.

  20. ECG phenomena: pseudopreexcitation and repolarization disturbances resembling ST-elevation myocardial infarction caused by an intraatrial rhabdomyoma in a newborn.

    PubMed

    Paech, Christian; Gebauer, Roman Antonin

    2014-01-01

    As is known from other reports, a rhabdomyoma or tumor metastasis may alter intracardiac electrical conduction, producing electrical phenomena like pseudopreexcitation or repolarization disturbances resembling ST-elevation myocardial infarction or Brugada's syndrome. We present a newborn with a giant atrial rhabdomyoma and additionally multiple ventricular rhabdomyomas. He presented with several electrocardiogram (ECG) phenomena due to tumor-caused atrial depolarization and repolarization disturbances. Except from the cardiac tumors, the physical status was within normal range. Initial ECG showed a rapid atrial tachycardia with a ventricular rate of 230 bpm, which was terminated by electrical cardioversion. Afterwards, the ECG showed atrial rhythm with frequent atrial premature contractions and deformation of the PR interval with large, broad P waves and loss of discret PR segment, imposing as pseudopreexcitation. The following QRS complex was normal, with seemingly abnormal ventricular repolarization resembeling ST-elevation myocardial infarction. The atrial tumor was resected with consequent vast atrial reconstruction using patch plastic. The ventricular tumors were left without manipulation. After surgery, pseudopreexcitation and repolarization abnormalities vanished entirely and an alternans between sinus rhythm and ectopic atrial rhythm was present. These phenomena were supposably caused by isolated atrial depolarization disturbances due to tumor-caused heterogenous endocardial activation. The seemingly abnormal ventricular repolarization is probably due to repolarization of the atrial mass, superimposed on the ventricular repolarization. Recognizably, the QRS complex before and after surgical resection of the rhabdomyoma is identical, underlining the atrial origin of the repolarization abnormalities before surgery. PMID:23663513

  1. Myocardial perfusion as assessed by thallium-201 scintigraphy during the discontinuation of mechanical ventilation in ventilator-dependent patients

    SciTech Connect

    Hurford, W.E.; Lynch, K.E.; Strauss, H.W.; Lowenstein, E.; Zapol, W.M. )

    1991-06-01

    Patients who cannot be separated from mechanical ventilation (MV) after an episode of acute respiratory failure often have coexisting coronary artery disease. The authors hypothesized that increased left ventricular (LV) wall stress during periods of spontaneous ventilation (SV) could alter myocardial perfusion in these patients. Using thallium-201 (201TI) myocardial scintigraphy, the authors studied the occurrence of myocardial perfusion abnormalities during periods of SV in 15 MV-dependent patients (nine women, six men; aged 71 {plus minus} 7 yr, mean {plus minus} SD). Fourteen of these patients were studied once with 201TI myocardial scintigraphy during intermittent mechanical ventilation (IMV) and again on another day, after at least 10 min of SV through a T-piece. One patient was studied during SV only. Thirteen of 14 of the patients (93%) studied during MV had abnormal patterns of initial myocardial 201TI uptake, but only 1 patient demonstrated redistribution of 201TI on delayed images. The remainder of the abnormalities observed during MV were fixed defects. SV produced significant alterations of myocardial 201TI distribution or transient LV dilation, or both, in 7 of the 15 patients (47%). Four patients demonstrated new regional decreases of LV myocardial thallium concentration with redistribution of the isotope on delayed images. The patient studied only during SV also had myocardial 201TI defects with redistribution. Five patients (3 also having areas of 201TI redistribution) had transient LV dilation during SV.

  2. Immunological results in myocardial diseases.

    PubMed Central

    Bolte, H. D.; Schultheiss, P.

    1978-01-01

    Immunological studies have shown new diagnostically important changes in alcoholic and viral myocarditis, as well as in congestive cardiomyopathy. Increased heart size correlated with the degree of congestive heart failure, as well as with negative immunofluorescence and an increased IgA concentration in the serum. These findings may serve as a diagnostic aid in patients with myocardial disease due to alcohol abuse. Viral heart disease is characterized by a variety of symptoms and nuclear antibodies (IgM) can be of help in the differential diagnosis. Heart muscle tissue of patients with congestive cardiomyopathy preferentially binds IgG and IgA. In addition to the other changes these findings are of diagnostic importance. It seems likely that results similar to those obtained for humoral antibodies in congestive cardiomyopathy will apply in the correlation of the haemodynamic status of the patients. The pathophysiological implication of these findings is not clear at present, but the evolution of congestive cardiomyopathy appears to be associated with binding of immunoglobulin to the myocardium, as well as with humoral antiheart antibodies. PMID:704517

  3. An unusual myocardial infarction

    PubMed Central

    Di Michele, Sara; Mirabelli, Francesca; Mankad, Sunil

    2014-01-01

    Summary We present a 74-year-old male with a chondrosarcoma, who presented with chest pain. The history, electrocardiogram (ECG), and biomarkers established the diagnosis of myocardial infarction (MI); angiography did not show coronary atherosclerosis and, both initial transthoracic echocardiogram and chest computed tomography (CT), did not demonstrate any cardiac abnormalities. A second echocardiogram following a routine ECG showed presence of a mass involving the right ventricle and the cardiac apex that was confirmed by chest CT scan. We underline the importance of considering cardiac tumors in the clinical arena of MI management. Learning points Cardiac tumors cause ECG changes similar to ischemic heart diseases.Keep in mind cardiac tumors when performing transthoracic echocardiogram (TTE) in the setting of suspected MI.TTE is the technique of choice in detecting cardiac tumors. PMID:26693309

  4. Masquerades of myocardial infarction.

    PubMed Central

    Bean, W. B.

    1976-01-01

    I summarize these observations in Figure 1. It represents every person in a hypothetical population who has myocardial infarction. A large but unknown number, some believe almost half, never get help. Mobile coronary care units are reducing this group, but so far only a little. When the diagnosis is not understood the disease is not recognized. Then come discovery and popularization. Hereafter masquerades hide some cases and the diagnosis is missed. Somewhere fairly early the diagnostic fad leads to false positive diagnosis. As new techniques are discovered, perfected and mastered, false positive errors and masquerades leading to oversights diminish but still exist. All the skill and technical virtuosity in the world will not be applied if we do not think of the disease. When we think of it, even obscure cases may be resolved easily. PMID:960416

  5. Acute myocardial infarction complicating subarachnoid haemorrhage

    PubMed Central

    van der Velden, L.B.J.; Otterspoor, L.C.; Schultze Kool, L.J.; Biessels, G.J.; Verheugt, F.W.A.

    2009-01-01

    An acute myocardial infarction is a rare complication of a subarachnoid haemorrhage. The combination of these two conditions imposes important treatment dilemmas. We describe two patients with this combination of life-threatening conditions. Patient 1 was treated with emergency percutaneous coronary intervention followed by clipping of the anterior communicating artery aneurysm. Six months after discharge the patient's memory and orientation had almost completely recovered. Patient 2 was treated with aspirin until coiling of the aneurysm could be performed. After successful coiling low-molecular-weight heparin was added. One week later the patient died due to a free wall rupture. (Neth Heart J 2009;17:284-7.19789696) PMID:19789696

  6. Importance of markers in Tc-99m pyrophosphate myocardial images

    SciTech Connect

    Vasavada, P.J.; Micklos, T.J.; Nishiyama, H.

    1985-02-01

    A false-positive Tc-99m PYP myocardial scan may result due to gastric activity from the breakdown of radiopharmaceuticals and accumulation of Tc-99m pertechnetate in gastric cells. Importance of anatomic landmarks during early blood pool images is emphasized to prevent this error.

  7. Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

    PubMed Central

    Cosyns, Bernard; Droogmans, Steven; Hernot, Sophie; Degaillier, Céline; Garbar, Christian; Weytjens, Caroline; Roosens, Bram; Schoors, Danny; Lahoutte, Tony; Franken, Philippe R; Van Camp, Guy

    2008-01-01

    The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. We prospectively studied 40 Wistar rats. Diabetes was induced by intravenous streptozotocin in 20 rats. All rats underwent baseline and stress (dipyridamole: 20 mg/kg) high power intermittent imaging in short axis view under anaesthesia baseline and after six months. Myocardial blood flow was determined and compared at rest and after dipyridamole in both populations. The myocardial blood flow reserve was calculated and compared in the 2 groups. Parameters of left ventricular function were determined from the M-mode tracings and histological examination was performed in all rats at the end of the study. At six months, myocardial blood flow reserve was significantly lower in diabetic rats compared to controls (3.09 ± 0.98 vs. 1.28 ± 0.67 ml min-1 g-1; p < 0.05). There were also a significant decrease in left ventricular function and a decreased capillary surface area and diameter at histology in the diabetic group. In this animal study, diabetes induced a functional alteration of the coronary microcirculation, as demonstrated by contrast echocardiography, a decrease in capillary density and of the cardiac systolic function. These findings may offer new insights into the underlying mechanisms of diabetes cardiomyopathy. PMID:18764943

  8. Acute myocardial infarction and myocardial ischemia-reperfusion injury: a comparison

    PubMed Central

    Hashmi, Satwat; Al-Salam, Suhail

    2015-01-01

    Myocardial infarction (MI) denotes the death of cardiac myocytes due to extended ischemia. Myocardial reperfusion is the restoration of coronary blood flow after a period of coronary occlusion. Reperfusion has the potential to salvage ischemic myocardium but paradoxically can cause injury, a phenomenon called as ‘reperfusion injury’ (IR). Standard histologic, immunohistochemical and Elisa techniques were used to study the histopathologic, oxidative, apoptotic and inflammatory changes in MI and IR. The IL-6 levels in the LV of the MI group were significantly raised as compared to the IR group (P=0.0008). Plasma IL-6 was also significantly increased in the MI group as compared to the IR group (P=0.031). MI model was also associated with increase in the neutrophil polymorphs number in the infarction related myocardium as compared to the re-perfused myocardium. A significant increase in troponin I level in the MI group as compared to the IR group is also seen (P=0.0001). Our IR model showed enhanced pro-apoptotic mediators like cleaved caspase-3 (P=0.005) and cytochrome c in the myocardium as compared to the MI model. In conclusion, myocardial damage in MI is mainly due to ischemic necrosis and inflammatory mechanisms while apoptosis is the main mechanism of cell death in IR in addition to limited ischemic necrosis. PMID:26464621

  9. 2015 Sensorimotor Risk Standing Review Panel Evidence and Status Review For: the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2015-01-01

    The 2015 Sensorimotor Risk Standing Review Panel (from here on referred to as the SRP) participated in a WebEx/teleconference with members of the Human Health Countermeasures (HHC) Element, representatives from the Human Research Program (HRP), NASA Headquarters, and NASA Research and Education Support Services (NRESS) on December 17, 2015 (list of participants is in Section VI of this report). The SRP reviewed the new Evidence Report for the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight (from here on referred to as the 2015 Sensorimotor Evidence Report), and also received a status review of the Risk. The opening section of the 2015 Sensorimotor Evidence Report provides written descriptions of various incidents that have occurred during space missions. In most of these incidents, the main underlying contributing factors are not easy to identify unambiguously. For example, in section 1.9, a number of falls occurred while astronauts were walking on the moon. It is not clear to the SRP, however, why they fell. It is only possible to extrapolate from likely specific psychophysical or physiological abnormalities, but how these abnormalities were determined, and how they were directly responsible for the falls is unclear to the SRP. Section 2.1.2 on proprioception is very interesting, but the functional significance of the abnormalities detected is not clear. The SRP sees this as a problem throughout the report: a mapping between the component abnormalities identified and the holistic behaviors that are most relevant, for example, controlling the vehicle, and locomotion during egress, is generally lacking. The SRP thinks the cognitive section is too strongly focused on vestibular functioning. The SRP questions the notion that the main cognitive effects are mainly attributable to reversible vestibular changes induced by spaceflight. The SRP thinks that there can also

  10. [Painless anterior acute myocardial infarction in a transplanted heart].

    PubMed

    Poyet, R; Capilla, E; Tortat, A V; Brocq, F X; Pons, F; Kerebel, S; Jego, C; Cellarier, G R

    2015-11-01

    Cardiac allograft vasculopathy is the major determinant of long-term survival in patients after heart transplantation. Clinical presentations are congestive heart failure, ventricular arrhythmias and sudden cardiac death. Acute coronary syndrome is a rare presentation of cardiac allograft vasculopathy due to myocardial denervation. We present the case of a 31-year-old patient, who had undergone heart transplantation 6 months earlier and who developed a painless anterior myocardial infarction revealed by syncope. He was successfully treated by percutaneous coronary intervention with drug eluting stent implantation. PMID:26472502

  11. Acute myocardial infarction in young adults: causes and management

    PubMed Central

    Osula, S; Bell, G; Hornung, R

    2002-01-01

    The case report in this review illustrates an acute myocardial infarction in a young adult probably due to arterial thrombosis that can be attributed to a hypercoagulable state resulting from the nephrotic syndrome. Although rare, acute myocardial infarction should be considered in young adults presenting with chest pain. A detailed clinical history may help to identify the aetiology, and guide subsequent management, but diagnostic coronary angiography is essential. Careful risk factor modification and treatment of the underlying cause should reduce the incidence of recurrent cardiac events. PMID:11796868

  12. 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

  13. PET/CT Imaging in Mouse Models of Myocardial Ischemia

    PubMed Central

    Gargiulo, Sara; Greco, Adelaide; Gramanzini, Matteo; Petretta, Maria Piera; Ferro, Adele; Larobina, Michele; Panico, Mariarosaria; Brunetti, Arturo; Cuocolo, Alberto

    2012-01-01

    Different species have been used to reproduce myocardial infarction models but in the last years mice became the animals of choice for the analysis of several diseases, due to their short life cycle and the possibility of genetic manipulation. Many techniques are currently used for cardiovascular imaging in mice, including X-ray computed tomography (CT), high-resolution ultrasound, magnetic resonance imaging, and nuclear medicine procedures. Cardiac positron emission tomography (PET) allows to examine noninvasively, on a molecular level and with high sensitivity, regional changes in myocardial perfusion, metabolism, apoptosis, inflammation, and gene expression or to measure changes in anatomical and functional parameters in heart diseases. Currently hybrid PET/CT scanners for small laboratory animals are available, where CT adds high-resolution anatomical information. This paper reviews mouse models of myocardial infarction and discusses the applications of dedicated PET/CT systems technology, including animal preparation, anesthesia, radiotracers, and images postprocessing. PMID:22505813

  14. PET/CT imaging in mouse models of myocardial ischemia.

    PubMed

    Gargiulo, Sara; Greco, Adelaide; Gramanzini, Matteo; Petretta, Maria Piera; Ferro, Adele; Larobina, Michele; Panico, Mariarosaria; Brunetti, Arturo; Cuocolo, Alberto

    2012-01-01

    Different species have been used to reproduce myocardial infarction models but in the last years mice became the animals of choice for the analysis of several diseases, due to their short life cycle and the possibility of genetic manipulation. Many techniques are currently used for cardiovascular imaging in mice, including X-ray computed tomography (CT), high-resolution ultrasound, magnetic resonance imaging, and nuclear medicine procedures. Cardiac positron emission tomography (PET) allows to examine noninvasively, on a molecular level and with high sensitivity, regional changes in myocardial perfusion, metabolism, apoptosis, inflammation, and gene expression or to measure changes in anatomical and functional parameters in heart diseases. Currently hybrid PET/CT scanners for small laboratory animals are available, where CT adds high-resolution anatomical information. This paper reviews mouse models of myocardial infarction and discusses the applications of dedicated PET/CT systems technology, including animal preparation, anesthesia, radiotracers, and images postprocessing. PMID:22505813

  15. Amphetamine Containing Dietary Supplements and Acute Myocardial Infarction.

    PubMed

    Perez-Downes, Julio; Hritani, Abdulwahab; Baldeo, Candice; Antoun, Patrick

    2016-01-01

    Weight loss is one of the most researched and marketed topics in American society. Dietary regimens, medications that claim to boost the metabolism, and the constant pressure to fit into society all play a role in our patient's choices regarding new dietary products. One of the products that are well known to suppress appetite and cause weight loss is amphetamines. While these medications suppress appetite, most people are not aware of the detrimental side effects of amphetamines, including hypertension, tachycardia, arrhythmias, and in certain instances acute myocardial infarction. Here we present the uncommon entity of an acute myocardial infarction due to chronic use of an amphetamine containing dietary supplement in conjunction with an exercise regimen. Our case brings to light further awareness regarding use of amphetamines. Clinicians should have a high index of suspicion of use of these substances when young patients with no risk factors for coronary artery disease present with acute arrhythmias, heart failure, and myocardial infarctions. PMID:27516911

  16. Amphetamine Containing Dietary Supplements and Acute Myocardial Infarction

    PubMed Central

    Hritani, Abdulwahab; Antoun, Patrick

    2016-01-01

    Weight loss is one of the most researched and marketed topics in American society. Dietary regimens, medications that claim to boost the metabolism, and the constant pressure to fit into society all play a role in our patient's choices regarding new dietary products. One of the products that are well known to suppress appetite and cause weight loss is amphetamines. While these medications suppress appetite, most people are not aware of the detrimental side effects of amphetamines, including hypertension, tachycardia, arrhythmias, and in certain instances acute myocardial infarction. Here we present the uncommon entity of an acute myocardial infarction due to chronic use of an amphetamine containing dietary supplement in conjunction with an exercise regimen. Our case brings to light further awareness regarding use of amphetamines. Clinicians should have a high index of suspicion of use of these substances when young patients with no risk factors for coronary artery disease present with acute arrhythmias, heart failure, and myocardial infarctions. PMID:27516911

  17. Diminished synthesis of subunit a (ATP6) and altered function of ATP synthase and cytochrome c oxidase due to the mtDNA 2 bp microdeletion of TA at positions 9205 and 9206.

    PubMed

    Jesina, Pavel; Tesarová, Markéta; Fornůsková, Daniela; Vojtísková, Alena; Pecina, Petr; Kaplanová, Vilma; Hansíková, Hana; Zeman, Jirí; Houstek, Josef

    2004-11-01

    Dysfunction of mitochondrial ATPase (F1F(o)-ATP synthase) due to missense mutations in ATP6 [mtDNA (mitochondrial DNA)-encoded subunit a] is a frequent cause of severe mitochondrial encephalomyopathies. We have investigated a rare mtDNA mutation, i.e. a 2 bp deletion of TA at positions 9205 and 9206 (9205DeltaTA), which affects the STOP codon of the ATP6 gene and the cleavage site between the RNAs for ATP6 and COX3 (cytochrome c oxidase 3). The mutation was present at increasing load in a three-generation family (in blood: 16%/82%/>98%). In the affected boy with severe encephalopathy, a homoplasmic mutation was present in blood, fibroblasts and muscle. The fibroblasts from the patient showed normal aurovertin-sensitive ATPase hydrolytic activity, a 70% decrease in ATP synthesis and an 85% decrease in COX activity. ADP-stimulated respiration and the ADP-induced decrease in the mitochondrial membrane potential at state 4 were decreased by 50%. The content of subunit a was decreased 10-fold compared with other ATPase subunits, and [35S]-methionine labelling showed a 9-fold decrease in subunit a biosynthesis. The content of COX subunits 1, 4 and 6c was decreased by 30-60%. Northern Blot and quantitative real-time reverse transcription-PCR analysis further demonstrated that the primary ATP6--COX3 transcript is cleaved to the ATP6 and COX3 mRNAs 2-3-fold less efficiently. Structural studies by Blue-Native and two-dimensional electrophoresis revealed an altered pattern of COX assembly and instability of the ATPase complex, which dissociated into subcomplexes. The results indicate that the 9205DeltaTA mutation prevents the synthesis of ATPase subunit a, and causes the formation of incomplete ATPase complexes that are capable of ATP hydrolysis but not ATP synthesis. The mutation also affects the biogenesis of COX, which is present in a decreased amount in cells from affected individuals. PMID:15265003

  18. Diminished synthesis of subunit a (ATP6) and altered function of ATP synthase and cytochrome c oxidase due to the mtDNA 2 bp microdeletion of TA at positions 9205 and 9206

    PubMed Central

    2004-01-01

    Dysfunction of mitochondrial ATPase (F1Fo-ATP synthase) due to missense mutations in ATP6 [mtDNA (mitochondrial DNA)-encoded subunit a] is a frequent cause of severe mitochondrial encephalomyopathies. We have investigated a rare mtDNA mutation, i.e. a 2 bp deletion of TA at positions 9205 and 9206 (9205ΔTA), which affects the STOP codon of the ATP6 gene and the cleavage site between the RNAs for ATP6 and COX3 (cytochrome c oxidase 3). The mutation was present at increasing load in a three-generation family (in blood: 16%/82%/>98%). In the affected boy with severe encephalopathy, a homoplasmic mutation was present in blood, fibroblasts and muscle. The fibroblasts from the patient showed normal aurovertin-sensitive ATPase hydrolytic activity, a 70% decrease in ATP synthesis and an 85% decrease in COX activity. ADP-stimulated respiration and the ADP-induced decrease in the mitochondrial membrane potential at state 4 were decreased by 50%. The content of subunit a was decreased 10-fold compared with other ATPase subunits, and [35S]-methionine labelling showed a 9-fold decrease in subunit a biosynthesis. The content of COX subunits 1, 4 and 6c was decreased by 30–60%. Northern Blot and quantitative real-time reverse transcription–PCR analysis further demonstrated that the primary ATP6 – COX3 transcript is cleaved to the ATP6 and COX3 mRNAs 2–3-fold less efficiently. Structural studies by Blue-Native and two-dimensional electrophoresis revealed an altered pattern of COX assembly and instability of the ATPase complex, which dissociated into subcomplexes. The results indicate that the 9205ΔTA mutation prevents the synthesis of ATPase subunit a, and causes the formation of incomplete ATPase complexes that are capable of ATP hydrolysis but not ATP synthesis. The mutation also affects the biogenesis of COX, which is present in a decreased amount in cells from affected individuals. PMID:15265003

  19. [A comprehensive analysis of incidence of myocardial infarction in Vladikavkaz depending on solar and geomagnetic activity].

    PubMed

    Botoeva, N K; Khetarugova, l G; Rapoport, S I

    2013-01-01

    The data on myocardial infarction morbidity in Vladikavkaz for 2007-2010 were analysed with reference to solar and geomagnetic activity. Time series of morbidity in men and women were constructed and their seasonal constituent was distinguished. It was found that the number of myocardial infarctions increases on day with enhanced geomagnetic activity especially among subjects aged 50-69 years. Regression analysis of the relationship between the number of sunspots and myocardial infarctions yielded the equation of piecewise linear regression showing that 42% of the cases were due to the changes in the number of sunspots. Medium strength negative correlation was found between the number of myocardial infarctions and the recurrence index of Bz-component of the interplanetary magnetic field. It suggests an important role of chaotic dynamics of external factors in the development of myocardial infarction. PMID:25696947

  20. Bronchogenic Carcinoma with Cardiac Invasion Simulating Acute Myocardial Infarction

    PubMed Central

    Das, Anirban; Das, Sibes K.; Pandit, Sudipta; Karmakar, Rathindra Nath

    2016-01-01

    Cardiac metastases in bronchogenic carcinoma may occur due to retrograde lymphatic spread or by hematogenous dissemination of tumour cells, but direct invasion of heart by adjacent malignant lung mass is very uncommon. Pericardium is frequently involved in direct cardiac invasion by adjacent lung cancer. Pericardial effusion, pericarditis, and tamponade are common and life threatening presentation in such cases. But direct invasion of myocardium and endocardium is very uncommon. Left atrial endocardium is most commonly involved in such cases due to anatomical contiguity with pulmonary hilum through pulmonary veins, and in most cases left atrial involvement is asymptomatic. But myocardial compression and invasion by adjacent lung mass may result in myocardial ischemia and may present with retrosternal, oppressive chest pain which clinically may simulate with the acute myocardial infarction (AMI). As a result, it leads to misdiagnosis and delayed diagnosis of lung cancer. Here we report a case of non-small-cell carcinoma of right lung which was presented with asymptomatic invasion in left atrium and retrosternal chest pain simulating AMI due to myocardial compression by adjacent lung mass, in a seventy-four-year-old male smoker. PMID:27042370

  1. Myocardial Salvaging Effects of Berberine in Experimental Diabetes Co-Existing with Myocardial Infarction

    PubMed Central

    Borde, Manjusha K.; Mohanty, Ipseeta Ray; Maheshwari, Ujwala; Deshmukh, Y.A.

    2016-01-01

    Introduction Berberine, an isoquinoline alkaloid isolated from the Berberis aristata, has been shown to display a wide array of pharmacological activities (hypoglycaemic and hypolipidemic). Aim The present study was designed to investigate whether these pharmacological properties translate into the cardioprotective effects of Berberine in the setting of diabetes mellitus. Materials and Methods Necessary approval from the Institutional Animal Ethics Committee was taken for the study. Experimental diabetes was produced with single dose of Streptozotocin (STZ): 45mg/kg ip and myocardial infarction was induced by administering Isoproterenol (ISP): 85mg/kg, sc to rats on 35th & 36th day. After the confirmation of diabetes on 7th day (>200mg/dl), Berberine (100 mg/kg) was administered orally to experimental rats from day 8 and continued for 30 days thereafter. Various anti-diabetic (Glucose, HbA1c), cardioprotective (CPK-MB), metabolic (lipid profile), safety {liver function (SGPT, kidney function (Creatinine)} and histopathological indices of injury were evaluated in Healthy Control, Diabetic Control and Berberine treated groups. Results Administration of STZ-ISP resulted in a significant decrease in body weight (p<0.001), diabetic changes (increase in blood glucose, HbA1c), cardiac injury (leakage of myocardial CPK-MB), altered lipid profile, SGPT, creatinine levels (p<0.001) in the diabetic control group rats as compared to healthy control. Berberine treatment demonstrated significant antidiabetic as well as myocardial salvaging effects as indicated by restoration of blood glucose, HbA1c and CPK-MB levels (p<0.001) compared to diabetic control group. In addition, Berberine favourably modulated the lipid parameters (total cholesterol, triglycerides, HDL, LDL). Subsequent to ISP challenge, histopathological assessment of heart, pancreas and biochemical indices of injury confirmed the cardioprotective effects of Berberine in setting of diabetes. In addition, Berberine

  2. 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

  3. Postmortem mRNA Expression Patterns in Left Ventricular Myocardial Tissues and Their Implications for Forensic Diagnosis of Sudden Cardiac Death

    PubMed Central

    Son, Gi Hoon; Park, Seong Hwan; Kim, Yunmi; Kim, Ji Yeon; Kim, Jin Wook; Chung, Sooyoung; Kim, Yu-Hoon; Kim, Hyun; Hwang, Juck-Joon; Seo, Joong-Seok

    2014-01-01

    Sudden cardiac death (SCD), which is primarily caused by lethal heart disorders resulting in structural and arrhythmogenic abnormalities, is one of the prevalent modes of death in most developed countries. Myocardial ischemia, mainly due to coronary artery disease, is the most common type of heart disease leading to SCD. However, postmortem diagnosis of SCD is frequently complicated by obscure histological evidence. Here, we show that certain mRNA species, namely those encoding hemoglobin A1/2 and B (Hba1/2 and Hbb, respectively) as well as pyruvate dehydrogenase kinase 4 (Pdk4), exhibit distinct postmortem expression patterns in the left ventricular free wall of SCD subjects when compared with their expression patterns in the corresponding tissues from control subjects with non-cardiac causes of death. Hba1/2 and Hbb mRNA expression levels were higher in ischemic SCD cases with acute myocardial infarction or ischemic heart disease without recent infarction, and even in cardiac death subjects without apparent pathological signs of heart injuries, than control subjects. By contrast, Pdk4 mRNA was expressed at lower levels in SCD subjects. In conclusion, we found that altered myocardial Hba1/2, Hbb, and Pdk4 mRNA expression patterns can be employed as molecular signatures of fatal cardiac dysfunction to forensically implicate SCD as the primary cause of death. PMID:24642708

  4. 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. PMID:15546824

  5. Lidocaine Enhances Contractile Function of Ischemic Myocardial Regions in Mouse Model of Sustained Myocardial Ischemia

    PubMed Central

    Kania, Gabriela; Osto, Elena; Jakob, Philipp; Krasniqi, Nazmi; Beck-Schimmer, Beatrice; Blyszczuk, Przemyslaw; Eriksson, Urs

    2016-01-01

    Rationale Perioperative myocardial ischemia is common in high-risk patients. The use of interventional revascularisation or even thrombolysis is limited in this patient subset due to exceedingly high bleeding risks. Blockade of voltage-gated sodium channels (VGSC) with lidocaine had been suggested to reduce infarct size and cardiomyocyte cell death in ischemia/reperfusion models. However, the impact of lidocaine on cardiac function during sustained ischemia still remains unclear. Methods Sustained myocardial ischemia was induced by ligation of the left anterior descending artery in 12–16 weeks old male BALB/c mice. Subcutaneous lidocaine (30 mg/kg) was used to block VGSC. Cardiac function was quantified at baseline and at 72h by conventional and speckle-tracking based echocardiography to allow high-sensitivity in vivo phenotyping. Infarct size and cardiomyocyte cell death were assessed post mortem histologically and indirectly using troponin measurements. Results Ischemia strongly impaired both, global systolic and diastolic function, which were partially rescued in lidocaine treated in mice. No differences regarding infarct size and cardiomyocyte cell death were observed. Mechanistically, and as shown with speckle-tracking analysis, lidocaine specifically improves residual contractility in the ischemic but not in the remote, non-ischemic myocardium. Conclusion VGSC blockade with lidocaine rescues function of ischemic myocardium as a potential bridging to revascularisation in the setting of perioperative myocardial ischemia. PMID:27140425

  6. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  7. Experimental myocardial infarction

    PubMed Central

    Hood, William B.; Bianco, Jesus A.; Kumar, Raj; Whiting, Richard B.

    1970-01-01

    Compliance of the infarcted left ventricle was studied in dogs 3-5 days after occlusion of the left anterior descending coronary artery. Compliance was assessed from postmortem pressure-volume curves and from pressure-length measurements (mercury-in-silastic segment length gauges) made both in vivo and postmortem. Postmortem pressure-volume curves showed reduced compliance compared to sham-operated animals. Postmortem pressure-length curves of infarcted and adjacent normal myocardium indicated that the diminished total compliance could be attributed to an increase in stiffness of the infarcted area. This was confirmed by in vivo end-diastolic pressure-length changes produced by transient aortic occlusion. The infarcted area was akinetic, showing neither contraction nor aneurysmal bulging. In addition, anesthetized dogs with infarcts, when compared with sham-operated animals, had similar left ventricular end-diastolic volumes (indicator dilution method), but higher left ventricular end-diastolic pressures. Taken with previous observations, which show that systolic aneurysmal bulging is uniformly present at the onset of ischemia, these results indicate that stiffening of the ischemic myocardium occurs during the first 5 days after infarction, and show that elevation of left ventricular filling pressure does not necessarily signify ventricular dilatation. The results also suggest a mechanism whereby ventricular performance may improve during recovery from acute myocardial infarction. Images PMID:4914678

  8. Recombinant human neuregulin-1β is protective against radiation-induced myocardial cell injury.

    PubMed

    Zhou, Qiang; Hu, Wenbing; Fei, Xinxiong; Huang, Xuqun; Chen, Xi; Zhao, Deqing; Huang, Jun; Jiang, Lan; Wang, Gangsheng

    2016-07-01

    The aim of the present study was to investigate the role of recombinant human neuregulin-1β (rhNRG-1β) in the repair of the radiation-induced damage of myocardial cells and the underlying mechanism. Rats were divided into the radiotherapy alone group, the rhNRG-1β group (radiotherapy with rhNRG‑1β treatment) and the Herceptin group (radiotherapy with Herceptin treatment), and their myocardial cells were analyzed. The morphology of the myocardial cells was observed under an optical microscope, and the expression of γ‑H2AX and p53 was analyzed using immunohistochemistry and western blot analysis. Damage to the myocardial cells was identified in the three groups following radiation treatment, which was identified by cell swelling and altered morphology. The integrated optical density values of γ‑H2AX in the radiotherapy alone, rhNRG‑1β and Herceptin groups were 50.96±5.548, 27.63±10.61 and 76.12±2.084, respectively. The OD of the radiotherapy alone group was significantly higher than that of the rhNRG‑1β treated group (P<0.0001), and the value of the Herceptin group was significantly higher than that of the radiotherapy alone group (P<0.0001). The p53 level in the rhNRG‑1β group was less than that of the radiotherapy alone group (P<0.001), and was higher in the Herceptin group compared with the radiotherapy alone group (P<0.0001). Thus, rhNRG‑1β can ameliorate radiotherapy-induced myocardial cell injury, predominantly by enhancing myocardial cell DNA repair, inhibiting cell apoptosis and improving myocardial function. The results of this study in myocardial cells suggest that patients with thoracic cancer may benefit from treatment with rhNRG‑1β for the repair of the radiation-induced damage of myocardial cells. PMID:27150576

  9. Myocardial perfusion imaging for detection of silent myocardial ischemia

    SciTech Connect

    Beller, G.A.

    1988-04-21

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references.

  10. 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

  11. How reliable is myocardial imaging in the diagnosis of acute myocardial infarction

    SciTech Connect

    Willerson, J.T.

    1983-01-01

    Myocardial scintigraphic techniques available presently allow a sensitive and relatively specific diagnosis of acute myocardial infarction when they are used correctly, although every technique has definite limitations. Small myocardial infarcts (less than 3 gm.) may be missed, and there are temporal limitations in the usefulness of the scintigraphic techniques. The development of tomographic methodology that may be used with single-photon radionuclide emitters (including technetium and /sup 201/Tl will allow the detection of relatively small abnormalities in myocardial perfusion and regions of myocardial infarction and will help to provide a more objective interpretation of the myocardial scintigrams. The use of overlay techniques allowing simultaneous assessment of myocardial perfusion, infarct-avid imaging, and radionuclide ventriculograms will provide insight into the relevant aspects of the extent of myocardial damage, the relationship of damage to myocardial perfusion, and the functional impact of myocardial infarction on ventricular performance.

  12. Myocardial Infarction: Symptoms and Treatments.

    PubMed

    Lu, Lei; Liu, Min; Sun, RongRong; Zheng, Yi; Zhang, Peiying

    2015-07-01

    Myocardial infarction (MI) is a term used for an event of heart attack which is due to formation of plaques in the interior walls of the arteries resulting in reduced blood flow to the heart and injuring heart muscles because of lack of oxygen supply. The symptoms of MI include chest pain, which travels from left arm to neck, shortness of breath, sweating, nausea, vomiting, abnormal heart beating, anxiety, fatigue, weakness, stress, depression, and other factors. The immediate treatment of MI include, taking aspirin, which prevents blood from clotting, and nitro-glycerin to treat chest pain and oxygen. The heart attack can be prevented by taking an earlier action to lower those risks by controlling diet, fat, cholesterol, salt, smoking, nicotine, alcohol, drugs, monitoring of blood pressure every week, doing exercise every day, and loosing body weight. The treatment of MI includes, aspirin tablets, and to dissolve arterial blockage injection of thrombolytic or clot dissolving drugs such as tissue plasminogen activator, streptokinase or urokinase in blood within 3 h of the onset of a heart attack. The painkillers such as morphine or meperidine can be administered to relieve pain. Nitroglycerin and antihypertensive drugs such as beta-blockers, ACE inhibitors or calcium channel blockers may also be used to lower blood pressure and to improve the oxygen demand of heart. The ECG, coronary angiography and X-ray of heart and blood vessels can be performed to observe the narrowing of coronary arteries. In this article the causes, symptoms and treatments of MI are described. PMID:25638347

  13. Multifunctional MR monitoring of the healing process after myocardial infarction.

    PubMed

    Bönner, Florian; Jacoby, Christoph; Temme, Sebastian; Borg, Nadine; Ding, Zhaoping; Schrader, Jürgen; Flögel, Ulrich

    2014-01-01

    Healing of the myocardium after infarction comprises a variety of local adaptive processes which contribute to the functional outcome after the insult. Therefore, we aimed to establish a setting for concomitant assessment of regional alterations in contractile function, morphology, and immunological state to gain prognostic information on cardiac recovery after infarction. For this, mice were subjected to myocardial ischemia/reperfusion (I/R) and monitored for 28 days by cine MRI, T2 mapping, late gadolinium enhancement (LGE), and (19)F MRI. T2 values were calculated from gated multi-echo sequences. (19)F-loaded nanoparticles were injected intravenously for labelling circulating monocytes and making them detectable by (19)F MRI. In-house developed software was used for regional analysis of cine loops, T2 maps, LGE, and (19)F images to correlate local wall movement, tissue damage as well as monocyte recruitment over up to 200 sectors covering the left ventricle. This enabled us to evaluate simultaneously zonal cardiac necrosis, oedema, and inflammation patterns together with sectional fractional shortening (FS) and global myocardial function. Oedema, indicated by a rise in T2, showed a slightly better correlation with FS than LGE. Regional T2 values increased from 19 ms to above 30 ms after I/R. In the course of the healing process oedema resolved within 28 days, while myocardial function recovered. Infiltrating monocytes could be quantitatively tracked by (19)F MRI, as validated by flow cytometry. Furthermore, (19)F MRI proved to yield valuable insight on the outcome of myocardial infarction in a transgenic mouse model. In conclusion, our approach permits a comprehensive surveillance of key processes involved in myocardial healing providing independent and complementary information for individual prognosis. PMID:25098936

  14. Pathophysiology of technetium-99m stannous pyrophosphate and thallium-201 scintigraphy of acute anterior myocardial infarcts in dogs.

    PubMed Central

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

    1976-01-01

    In 17 dogs with acute myocardial infarcts produced by ligation of the proximal left anterior descending coronary artery, a comparative study was made of myocardial scintigrams obtained with technetium-99m stannous pyrophosphate (99mTc-PYP) and thallium-201 (201T1), tissue levels of 99mTc-PYP and 201T1 uptake, histopathologic alterations, and regional myocardial perfusion measured with radioactive microspheres. 9 of the 10 hearts examined histologically had transmural infarcts with outer peripheral, inner peripheral, and central zones characterized by distinctive histopathologic features. A progressive reduction in myocardial blood flow was demonstrated between normal myocardium and the centers of the infarcts, and correlated well with progressive reduction in 201T1 upatke in the same regions. Marked 99mTc-PYP concentration occurred in areas with partial to homogeneous myocardial necrosis and residual perfusion located in the outer peripheral regions of the infarcts. The latter areas also were characterized by the presence of muscle cell calcification. The patterns of distribution of 99mTc-PYP and 201T1 explained the filling defects on 201T1 myocardial scintigrams and the doughnut patterns on 99mTc-PYP myocardial scintigrams in dogs with transmural infarcts. One dog with a subendocardial infarct had a small homogeneous area of activity on the 99mTc-PYP myocardial scintigram, and showed marked uptake of 99mTc-PYP in subendocardial areas of extensive necrosis and calcification still receiving some coronary perfusion. Thus, the data indicate that the status of regional myocardial perfusion is a key determinant for the occurrence of distinctive patterns of myocardial necrosis and for the scintigraphic detection of acute myocardial infarcts with 99mTc-PYP and 201T1. Images PMID:180053

  15. Myocardial infarction following bee sting.

    PubMed

    Puvanalingam, A; Karpagam, P; Sundar, C; Venkatesan, S; Ragunanthanan

    2014-08-01

    Bee stings are commonly encountered worldwide. Various manifestations after bee sting have been described. Local reactions are common. Unusually, manifestations like vomiting, diarrhoea, dyspnoea, generalised oedema, acute renal failure, hypotension and collapse may occur. Rarely vasculitis, serum sickness, neuritis and encephalitis have been described which generally develop days to weeks after a sting. Acute coronary syndromes after hymenoptera stings and other environmental exposures are referred to as the Kounis syndrome or allergic myocardial ischaemia and infarction. We report a 60 year old male who developed myocardial infarction after multiple bee stings over his body. PMID:25856951

  16. Influence of microvascular dysfunction on regional myocardial deformation post-acute myocardial infarction: insights from a novel angiographic index for assessing myocardial tissue-level reperfusion.

    PubMed

    He, Ben; Ding, Song; Qiao, Zhiqing; Gao, Lincheng; Wang, Wei; Ge, Heng; Shen, Xuedong; Pu, Jun

    2016-05-01

    To investigate the impact of microvascular dysfunction assessed by angiography on myocardial deformation assessed by two-dimensional speckle-tracking echocardiography in ST-segment elevation myocardial infarction (STEMI). A total of 121 STEMI patients who received primary percutaneous coronary intervention were included. Thrombolysis in myocardial infarction, Myocardial Perfusion Frame Count (TMPFC), a novel angiographic method to assess myocardial perfusion, was used to evaluate microvascular dysfunction. Two-dimensional speckle-tracking echocardiography was performed at 3-7 days after reperfusion. The infarction related regional longitudinal (RLS) strains as well as circumferential (RCS) and radial (RRS) ones, along with global longitudinal, circumferential (GCS), and radial (GRS) strains were measured. Patients with microvascular dysfunction had decreased peak amplitude of RLS (p = 0.012), RCS (p < 0.001), RRS (p = 0.012) at the regional level and decreased peak amplitude of GCS (p = 0.005), GRS (p = 0.012) at the global level. The RCS to RLS and RCS to RRS ratios were significantly different between patients without than with microvascular dysfunction (1.28 ± 0.31 vs. 1.07 ± 0.47, p = 0.027 and 0.69 ± 0.33 vs. 0.56 ± 0.28, p = 0.047). Receiver operator characteristics curves identified a cutoff value of 94 frames for TMPFC to differentiate between normal and abnormal wall motion score index in the sub-acute phase of STEMI (AUC = 0.72; p < 0.001). In the sub-acute phase of STEMI, the presence of microvascular dysfunction in infarcted tissue relates to reduced global and regional myocardial deformation. RCS alterations were more significant than RLS and RRS between patients with than without microvascular dysfunction. TMPFC was useful to predict left ventricular systolic dysfunction in the sub-acute phase of STEMI. PMID:26803498

  17. Thallium-201 myocardial scintigraphy in acute myocardial infarction and ischemia

    SciTech Connect

    Wackers, F.J.

    1982-04-01

    Thallium-201 scintigraphy provides a sensitive and reliable method of detecting acute myocardial infarction and ischemia when imaging is performed with understanding of the temporal characteristics and accuracy of the technique. The results of scintigraphy are related to the time interval between onset of symptoms and time of imaging. During the first 6 hr after chest pain almost all patients with acute myocardial infarction and approximately 50% of the patients with unstable angina will demonstrate /sup 201/TI pefusion defects. Delayed imaging at 2-4 hr will permit distinction between ischemia and infarction. In patients with acute myocardial infarction, the size of the perfusion defect accurately reflects the extent of the infarcted and/or jeopardized myocardium, which may be used for prognostic stratification. In view of the characteristics of /sup 201/TI scintigraphy, the most practical application of this technique is in patients in whom myocardial infarction has to be ruled out, and for early recognition of patients at high risk for complications.

  18. Modulation of cardiac metabolism during myocardial ischemia.

    PubMed

    Chagas, Antonio C P; Dourado, Paulo M M; Galvão, Tatiana de Fátima Gonçalves

    2008-01-01

    Metabolic modulation during myocardial ischemia is possible by the use of specific drugs, which may induce a shift from free fatty acid towards predominantly glucose utilization by the myocardium to increase ATP generation per unit oxygen consumption. Three agents (trimetazidine, ranolazine, and perhexiline) have well-documented anti-ischaemic effects. However, perhexiline, the most potent agent currently available, requires plasma-level monitoring to avoid hepato-neuro-toxicity. Besides, the long-term safety of trimetazidine and ranolazine has yet to be established. In addition to their effect in ischemia, the potential use of these drugs in chronic heart failure is gaining recognition as clinical and experimental data are showing the improvement of myocardial function following treatment with several of them, even in the absence of ischemia. Future applications for this line of treatment is promising and deserves additional research. In particular, large, randomised, controlled trials investigating the effects of these agents on mortality and hospitalization rates due to coronary artery disease are needed. PMID:18991673

  19. [The early ergometric test after myocardial revascularization].

    PubMed

    Mazzucco, G; Conti, M; Biagioli, F; Delpero, P; Del Ponte, S; Gelato, D

    1991-09-01

    Ergometric tests (ET) were used to study 900 patients undergoing surgical myocardial revascularisation during the period between January 1983 and December 1989. ET was carried out without medical therapy between the 30th and 35th day post surgery. The test was positive in 193 subjects (21%); in 42 of the latter (5% of the total and 229 of positive subjects) symptoms of effort angina were found to persist. ET was negative in 557 patients (62%); 150 subjects (17%), although not positive, did not attain a sufficient heart rate to enable a 100% negative diagnosis to be made. No major complication was observed. Maximal short-term ET is a reliable and safe test for checking the efficacy of myocardial revascularisation and to assess functional recovery. In view of the relatively high percentage of positive tests due to ischemia but with the complete absence of symptoms, the authors affirm that the mere onset of anginous symptoms alone cannot be considered indicative of the success of cardiosurgery. PMID:1787892

  20. Myocardial tissue engineering using electrospun nanofiber composites

    PubMed Central

    Kim, Pyung-Hwan; Cho, Je-Yoel

    2016-01-01

    Emerging trends for cardiac tissue engineering are focused on increasing the biocompatibility and tissue regeneration ability of artificial heart tissue by incorporating various cell sources and bioactive molecules. Although primary cardiomyocytes can be successfully implanted, clinical applications are restricted due to their low survival rates and poor proliferation. To develop successful cardiovascular tissue regeneration systems, new technologies must be introduced to improve myocardial regeneration. Electrospinning is a simple, versatile technique for fabricating nanofibers. Here, we discuss various biodegradable polymers (natural, synthetic, and combinatorial polymers) that can be used for fiber fabrication. We also describe a series of fiber modification methods that can increase cell survival, proliferation, and migration and provide supporting mechanical properties by mimicking micro-environment structures, such as the extracellular matrix (ECM). In addition, the applications and types of nanofiber-based scaffolds for myocardial regeneration are described. Finally, fusion research methods combined with stem cells and scaffolds to improve biocompatibility are discussed. [BMB Reports 2016; 49(1): 26-36] PMID:26497579

  1. Coupled agent-based and finite-element models for predicting scar structure following myocardial infarction.

    PubMed

    Rouillard, Andrew D; Holmes, Jeffrey W

    2014-08-01

    Following myocardial infarction, damaged muscle is gradually replaced by collagenous scar tissue. The structural and mechanical properties of the scar are critical determinants of heart function, as well as the risk of serious post-infarction complications such as infarct rupture, infarct expansion, and progression to dilated heart failure. A number of therapeutic approaches currently under development aim to alter infarct mechanics in order to reduce complications, such as implantation of mechanical restraint devices, polymer injection, and peri-infarct pacing. Because mechanical stimuli regulate scar remodeling, the long-term consequences of therapies that alter infarct mechanics must be carefully considered. Computational models have the potential to greatly improve our ability to understand and predict how such therapies alter heart structure, mechanics, and function over time. Toward this end, we developed a straightforward method for coupling an agent-based model of scar formation to a finite-element model of tissue mechanics, creating a multi-scale model that captures the dynamic interplay between mechanical loading, scar deformation, and scar material properties. The agent-based component of the coupled model predicts how fibroblasts integrate local chemical, structural, and mechanical cues as they deposit and remodel collagen, while the finite-element component predicts local mechanics at any time point given the current collagen fiber structure and applied loads. We used the coupled model to explore the balance between increasing stiffness due to collagen deposition and increasing wall stress due to infarct thinning and left ventricular dilation during the normal time course of healing in myocardial infarcts, as well as the negative feedback between strain anisotropy and the structural anisotropy it promotes in healing scar. The coupled model reproduced the observed evolution of both collagen fiber structure and regional deformation following coronary

  2. Upregulation of cardiac NOS due to endotoxemia and vagal overactivity contributes to the hypotensive effect of chronic ethanol in female rats.

    PubMed

    El-Mas, Mahmoud M; Fan, Ming; Abdel-Rahman, Abdel A

    2011-01-10

    We previously reported that chronic ethanol lowers blood pressure in female rats. In this study, hemodynamic, biochemical, and immunoblot analyses were performed to investigate: (i) the roles of cardiac contractility and autonomic activity in the hypotensive action of ethanol, and (ii) whether endotoxemia-induced upregulation of cardiac and/or vascular nitric oxide synthase (NOS) isoforms underlies the hypotensive and cardiac effects of ethanol. Telemetric monitoring of blood pressure, heart rate, and myocardial contractility (dP/dt(max)) was performed in female rats receiving liquid diet with or without ethanol (5% w/v, 13weeks). Autonomic control was assessed by frequency domain analysis of interbeat intervals (IBI) and systolic blood pressure (SBP). Compared with pair-fed controls, ethanol caused sustained reductions in blood pressure, heart rate, and+dP/dt(max). Ethanol feeding increased the spectral power of high-frequency band (IBI(HF), 0.75-3Hz) and decreased the low-frequency band (IBI(LF), 0.25-0.75Hz) and IBI(LF/HF) ratio, suggesting increased cardiac parasympathetic dominance. In contrast, vascular tone was not affected by ethanol because SBP spectral bands and plasma norepinephrine remained unchanged. Myocardial expressions of eNOS and its upstream regulators, phosphatidylinositol 3-kinase (PI3K) and Akt, and plasma endotoxin and nitrite/nitrate were increased by ethanol. Myocardial iNOS was also increased by ethanol whereas nNOS remained unchanged and aortic levels of all NOS isoforms were not altered by ethanol. These findings suggest that facilitation of myocardial PI3K/Akt/eNOS and iNOS pathways, due possibly to ethanol-induced endotoxemia and/or increased cardiac parasympathetic dominance, might constitute a cellular mechanism for the reduced myocardial contractility and hypotension caused by ethanol in female rats. PMID:20970417

  3. Upregulation of cardiac NOS due to endotoxemia and vagal overactivity contribute to the hypotensive effect of chronic ethanol in female rats

    PubMed Central

    El-Mas, Mahmoud M.; Fan, Ming; Abdel-Rahman, Abdel A.

    2010-01-01

    We previously reported that chronic ethanol lowers blood pressure in female rats. In this study, hemodynamic, biochemical, and immunoblot analyses were performed to investigate: (i) the roles of cardiac contractility and autonomic activity in the hypotensive action of ethanol, and (ii) whether endotoxemia-induced upregulation of cardiac and/or vascular nitric oxide synthase (NOS) isoforms underlies the hypotensive and cardiac effects of ethanol. Telemetric monitoring of blood pressure, heart rate, and myocardial contractility (dP/dtmax) was performed in female rats receiving liquid diet with or without ethanol (5% w/v, 13 weeks). Autonomic control was assessed by frequency domain analysis of interbeat intervals (IBI) and systolic blood pressure (SBP). Compared with pair-fed controls, ethanol caused sustained reductions in blood pressure, heart rate, and +dP/dtmax. Ethanol feeding increased the spectral power of high-frequency band (IBIHF, 0.75–3 Hz) and decreased the low-frequency band (IBILF, 0.25–0.75 Hz) and IBILF/HF ratio, suggesting increased cardiac parasympathetic dominance. In contrast, vascular tone was not affected by ethanol because SBP spectral bands and plasma norepinephrine remained unchanged. Myocardial expressions of eNOS and its upstream regulators, phosphatidylinositol 3-kinase(PI3K) and Akt, and plasma endotoxin and nitrite/nitrate were increased by ethanol. Myocardial iNOS was also increased by ethanol whereas nNOS remained unchanged and aortic levels of all NOS isoforms were not altered by ethanol. These findings suggest that facilitation of myocardial PI3K/Akt/eNOS and iNOS pathways, due possibly to ethanol-induced endotoxemia and/or increased cardiac parasympathetic dominance, might constitute a cellular mechanism for the reduced myocardial contractility and hypotension caused by ethanol in female rats. PMID:20970417

  4. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  5. Lipid, Oxidative and Inflammatory Profile and Alterations in the Enzymes Paraoxonase and Butyrylcholinesterase in Plasma of Patients with Homocystinuria Due CBS Deficiency: The Vitamin B12 and Folic Acid Importance.

    PubMed

    Vanzin, Camila Simioni; Mescka, Caroline Paula; Donida, Bruna; Hammerschimidt, Tatiane Grazieli; Ribas, Graziela S; Kolling, Janaína; Scherer, Emilene B; Vilarinho, Laura; Nogueira, Célia; Coitinho, Adriana Simon; Wajner, Moacir; Wyse, Angela T S; Vargas, Carmen Regla

    2015-08-01

    Cystathionine-β-synthase (CBS) deficiency is the main cause of homocystinuria. Homocysteine (Hcy), methionine, and other metabolites of Hcy accumulate in the body of affected patients. Despite the fact that thromboembolism represents the major cause of morbidity in CBS-deficient patients, the mechanisms of cardiovascular alterations found in homocystinuria remain unclear. In this work, we evaluated the lipid and inflammatory profile, oxidative protein damage, and the activities of the enzymes paraoxonase (PON1) and butyrylcholinesterase (BuChE) in plasma of CBS-deficient patients at diagnosis and during the treatment (protein-restricted diet supplemented with pyridoxine, folic acid, betaine, and vitamin B12). We also investigated the effect of folic acid and vitamin B12 on these parameters. We found a significant decrease in HDL cholesterol and apolipoprotein A1 (ApoA-1) levels, as well as in PON1 activity in both untreated and treated CBS-deficient patients when compared to controls. BuChE activity and IL-6 levels were significantly increased in not treated patients. Furthermore, significant positive correlations between PON1 activity and sulphydryl groups and between IL-6 levels and carbonyl content were verified. Moreover, vitamin B12 was positively correlated with PON1 and ApoA-1 levels, while folic acid was inversely correlated with total Hcy concentration, demonstrating the importance of this treatment. Our results also demonstrated that CBS-deficient patients presented important alterations in biochemical parameters, possibly caused by the metabolites of Hcy, as well as by oxidative stress, and that the adequate adherence to the treatment is essential to revert or prevent these alterations. PMID:25805165

  6. Acute myocardial infarction

    PubMed Central

    Domes, Trustin; Szafran, Olga; Bilous, Cheryl; Olson, Odell; Spooner, G. Richard

    2006-01-01

    OBJECTIVE To assess the quality of care of acute myocardial infarction (AMI) in a rural health region. DESIGN Clinical audit employing multiple explicit criteria of care elements for emergency department and in-hospital AMI management. The audit was conducted using retrospective chart review. SETTING Twelve acute care health centres and hospitals in the East Central Health Region, a rural health region in Alberta, where medical and surgical services are provided almost entirely by family physicians. PARTICIPANTS Hospital inpatients with a confirmed discharge diagnosis of AMI (ICD-9-CM codes 410.xx) during the period April 1, 2001, to March 31, 2002, were included (177 confirmed cases). MAIN OUTCOME MEASURES Quality of AMI care was assessed using guidelines from the American College of Cardiology and the American Heart Association and the Canadian Cardiovascular Outcomes Research Team and Canadian Cardiovascular Society. Quality of care indicators at three stages of patient care were assessed: at initial recognition and AMI management in the emergency department, during in-hospital AMI management, and at preparation for discharge from hospital. RESULTS In the emergency department, the quality of care was high for most procedural and therapeutic audit elements, with the exception of rapid electrocardiography, urinalysis, and provision of nitroglycerin and morphine. Average door-to-needle time for thrombolysis was 102.5 minutes. The quality of in-hospital care was high for most elements, but low for nitroglycerin and angiotensin-converting enzyme (ACE) inhibitors, daily electrocardiography, and counseling regarding smoking cessation and diet. Few patients received counseling for lifestyle changes at hospital discharge. Male and younger patients were treated more aggressively than female and older patients. Sites that used care protocols achieved better results in initial AMI management than sites that did not. Stress testing was not readily available in the rural

  7. Myocardial contusion following nonfatal blunt chest trauma

    SciTech Connect

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

    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 fraction determinations are the most reliable aids in diagnosis of myocardial contusion following blunt chest trauma.

  8. Myocardial Energy Substrate Metabolism in Heart Failure : from Pathways to Therapeutic Targets.

    PubMed

    Fukushima, Arata; Milner, Kenneth; Gupta, Abhishek; Lopaschuk, Gary D

    2015-01-01

    Despite recent advances in therapy, heart failure remains a major cause of mortality and morbidity and is a growing healthcare burden worldwide. Alterations in myocardial energy substrate metabolism are a hallmark of heart failure, and are associated with an energy deficit in the failing heart. Previous studies have shown that a metabolic shift from mitochondrial oxidative metabolism to glycolysis, as well as an uncoupling between glycolysis and glucose oxidation, plays a crucial role in the development of cardiac inefficiency and functional impairment in heart failure. Therefore, optimizing energy substrate utilization, particularly by increasing mitochondrial glucose oxidation, can be a potentially promising approach to decrease the severity of heart failure by improving mechanical cardiac efficiency. One approach to stimulating myocardial glucose oxidation is to inhibit fatty acid oxidation. This review will overview the physiological regulation of both myocardial fatty acid and glucose oxidation in the heart, and will discuss what alterations in myocardial energy substrate metabolism occur in the failing heart. Furthermore, lysine acetylation has been recently identified as a novel post-translational pathway by which mitochondrial enzymes involved in all aspects of cardiac energy metabolism can be regulated. Thus, we will also discuss the effect of acetylation of metabolic enzymes on myocardial energy substrate preference in the settings of heart failure. Finally, we will focus on pharmacological interventions that target enzymes involved in fatty acid uptake, fatty acid oxidation, transcriptional regulation of fatty acid oxidation, and glucose oxidation to treat heart failure. PMID:26166604

  9. Spousal Adjustment to Myocardial Infarction.

    ERIC Educational Resources Information Center

    Ziglar, Elisa J.

    This paper reviews the literature on the stresses and coping strategies of spouses of patients with myocardial infarction (MI). It attempts to identify specific problem areas of adjustment for the spouse and to explore the effects of spousal adjustment on patient recovery. Chapter one provides an overview of the importance in examining the…

  10. [Sewer gas induced myocardial toxicity].

    PubMed

    Antonelli, Dante; Sabanchiev, Avi; Rosner, Ehud; Turgeman, Yoav

    2014-07-01

    We report the case of a 19 year-old worker who collapsed after acute exposure to sewer gas. He rapidly developed cardiorespiratory failure with electrocardiographic, echocardiographic and laboratory findings of myocardial involvement. The mainstay of the therapy was mainly supportive treatment with a successful outcome. PMID:25189024

  11. Thrombolysis for Acute Myocardial Infarction

    PubMed Central

    Webb, John; Thompson, Christopher

    1992-01-01

    Thrombolysis has an important role in the management of acute myocardial infarction. Early treatment can markedly reduce mortality and morbidity. This new standard of care requires knowledge of accepted indications and contraindications for thrombolysis as well as familiarity with available agents and regimens. ImagesFigure 3 PMID:21221398

  12. Assessment, significance and mechanism of ventricular electrical instability after myocardial infarction.

    PubMed

    Richards, David A B; Denniss, A Robert

    2007-06-01

    The mechanism of reentrant tachycardia was established nearly a century ago, but the relationships between myocardial infarction and predisposition to sudden death were not unravelled until much later. In the latter half of the twentieth century many studies sought to ascertain what variables were predictive of death following myocardial infarction. Approximately one half of all deaths during the year following myocardial infarction are sudden and due to ventricular tachycardia (VT) or ventricular fibrillation (VF). We aimed to utilise non-invasive signal-averaging, along with programmed electrical stimulation of the heart, to determine whether one could predict spontaneous ventricular tachycardia and sudden death late after myocardial infarction. The sensitivity of ventricular electrical instablility (inducible ventricular tachycardia or fibrillation) as a predictor of instantaneous death or spontaneous VT was 86%, and the specificity was 83%. When other variables (delayed ventricular activation at signal-averaging, ejection fraction at gated heart pool scan, ventricular ectopic activity at ambulatory monitoring and exercise testing) were taken into account, inducible VT at electrophysiological study was the single best predictor of spontaneous VT and sudden cardiac death after myocardial infarction. The Westmead studies of Uther et al. in the decade or so from 1980 established programmed stimulation as the best predictor of sudden death after myocardial infarction. Subsequent studies by others have demonstrated a survival advantage of defibrillator implantation in patients with low ejection fraction (and inducible ventricular tachycardia) after myocardial infarction. PMID:17446130

  13. Adenosine as an Adjunct Therapy in ST Elevation Myocardial Infarction Patients: Myth or Truth?

    PubMed

    Kassimis, George; Davlouros, Periklis; Patel, Niket; De Maria, Gianluigi; Kallistratos, Manolis S; Kharbanda, Rajesh K; Manolis, Athanasios J; Alexopoulos, Dimitrios; Banning, Adrian P

    2015-10-01

    Early reperfusion represents the key strategy in ST elevation myocardial infarction. However, reperfusion may induce myocardial damage due to the reperfusion myocardial injury, compromising the full potential of reperfusion therapy and accounting for unfavourable results in high risk patients. Adenosine seems to attenuate ischemia reperfusion injury, and thus represents a promising therapeutic option for treating such patients. However, previous randomized clinical trials have collectively failed to demonstrate whether adenosine can effectively reduce measures of myocardial injury and improve clinical outcome, despite its good basic evidence. The failure of such trials to show a real beneficial action may be in part related to specific factors other than adenosine's clinical efficacy. The purpose of this review is to explain the rationale for the use of adenosine as an adjunctive pharmacological cardio-protective agent following reperfusion of the ischemic myocardium, to address the weakness of previous trials and to summarize the current state of knowledge regarding the effect of adenosine administration on reperfusion myocardial injury in patients with myocardial infarction. Although some preclinical and clinical studies point towards the beneficial role of adenosine in the prevention and treatment of no-reflow phenomenon in myocardial infarction, many unanswered questions still remain, including the optimal clinical indication, mode, dosage, duration and timing of application, and the exact mechanisms leading to potential benefits. Clarifying these issues will depend on further properly designed, adequately powered and well conducted clinical trials, which will probably provide us with the definite answers. PMID:26150100

  14. Aqueous extract of Saussurea lappa root ameliorate oxidative myocardial injury induced by isoproterenol in rats

    PubMed Central

    Saleem, T. S. Mohamed; Lokanath, N.; Prasanthi, A.; Madhavi, M.; Mallika, G.; Vishnu, M. N.

    2013-01-01

    Saussurea lappa Clarke (Compositae), is commonly known as Kushta. In Ayurvedha, it is mentioned that the aqueous extract of the root S. lappa was used for treatment of angina pectoris. The present study was designed to investigate the cardioprotective effect of aqueous extract of root of S. lappa against isoproterenol induced myocardial injury. Myocardial injury in rat was induced by the administration of isoproterenol at a dose of 85 mg/kg, i.p., The rats were pretreated with the aqueous extract of S. lappa (AESL) in three different doses (100, 200 and 300 mg/kg, p.o.) through the oral route. Isoproterenol alone-treated rats showed increased serum concentration of lactate dehydrogenase (LDH), creatinine kinase (CK), and aspartate transaminase (AST), increased myocardial thiobarbituric acid reactive substances (TBARS) level, and decreased myocardial glutathione (GSH) level due to myocardial damage produced by isoproterenol. This is further conformed by histopathological changes. Chronic oral administration of AESL in three different doses significantly restored the level of myocardial LDH, CK, AST, TBARS, and GSH. The extract effect was compared with the reference standard α-tocopherol which also offered similar protection in biochemical and histopathological changes. The overall beneficial effect which was observed with the dose of 200 mg/kg indicated that AESL produced significant dose-dependent activity against isoproterenol induced myocardial injury. PMID:23833749

  15. [Gallium-67 myocardial imaging for the detection of adriamycin cardiomyopathy].

    PubMed

    Morozumi, T; Ishida, Y; Tani, A; Inui, M; Hori, M; Kitabatake, A; Kamada, T; Kondo, H; Kozuka, T; Kimura, K

    1990-05-01

    To detect Adriamycin cardiomyopathy, radionuclide myocardial imagings with Tl-201, Tc-99m pyrophosphate, I-123 metaiodobenzylguanidine and Ga-67 were performed in a 49 year-old-woman receiving Adriamycin (a total dose of 230 mg/m2) for the treatment of breast cancer. This patient demonstrated symptoms of congestive heart failure 2 months after the last intravenous administration. At the period of performing the radionuclide studies, echocardiographic LV ejection fraction (EF) was 22%. Despite severe deterioration of cardiac function, Tl-201 SPECT demonstrated no defect and Tc-99m pyrophosphate (PYP) SPECT demonstrated no positive finding. I-123 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated no regional defect. However, I-123 MIBG washout rate during 4 hours was markedly enhanced, probably reflecting abnormalities of norepinephrine kinetics due to the progression of heart failure. Compared to these pharmaceuticals, Ga-67 was diffusely accumulated in the heart. Then, 5 months after the first study, when LV EF improved to 30% and congestive symptoms disappeared probably owing to beta-blockade therapy, myocardial accumulation of Ga-67 markedly reduced. It has been reported that Ga-67 accumulates in malignant tumor cells and leukocytes. Since, in Adriamycin cardiomyopathy, myocardial accumulation of leukocytes with myocardial fibrotic changes have been histologically demonstrated, the results of Ga-67 scintigraphy may reflect the accumulation of leukocytes. Thus, this case indicates that Ga-67 scintigraphy is advantageous for detecting Adriamycin cardiomyopathy and may be more useful than Tl-201 and Tc-99m PYP scintigraphies. PMID:2395231

  16. Antioxidant enzymes attenuate myocardial stunning in the conscious dog

    SciTech Connect

    Triana, J.F.; Unisa, A.; Bolli, R. )

    1990-02-26

    Several studies have shown that postischemic myocardial dysfunction (myocardial stunning) is attenuated by antioxidants, implying a pathogenetic role of oxy-radicals in this phenomenon. However, since all these studies have been performed in open-chest preparations, artifacts due to anesthesia, trauma, and other nonphysiologic conditions cannot be excluded. Accordingly, chronically instrumented dogs underwent a 15-minute occlusion (o) of the left anterior descending artery followed by reperfusion. Dogs received i.v. either saline or superoxide dismutase (SOD) plus catalase (CAT) (16,000 U/kg and 55,000 U/kg, respectively, over 1 hour starting 15 minutes before O). Regional myocardial function was assessed as systolic wall thickening (WTh) using a pulsed Doppler probe. WTh after reperfusion was significantly greater in treated dogs, and this difference could not be ascribed to differences in collateral flow or hemodynamics. The authors conclude that SOD plus catalase attenuate myocardial stunning in the conscious dog, indicating that oxy-radicals play a pathogenetic role in this phenomenon under physiologic conditions.

  17. DNA ALTERATIONS

    EPA Science Inventory

    The exposure of an organism to genotoxic chemicals may induce a cascade of genetic events. nitially, structural alterations to DNA are formed. ext, the DNA damage is processed and subsequently expressed in mutant gene products. inally, diseases result from the genetic damage. he ...

  18. Recovery of regional myocardial dysfunction after successful coronary angioplasty early after a non-Q wave myocardial infarction

    SciTech Connect

    Suryapranata, H.; Serruys, P.W.; Beatt, K.; De Feyter, P.J.; van den Brand, M.; Roelandt, J. )

    1990-08-01

    More aggressive therapy has been suggested for patients who have a non-Q wave myocardial infarction (MI) because of the frequency of subsequent unstable angina, recurrent MI, and high mortality rate compared to patients with Q wave MI. The present study was undertaken to investigate the effect of coronary angioplasty on regional myocardial function of the infarct zone in patients with angina early after a non-Q wave MI. The study population consisted of 36 patients undergoing successful coronary angioplasty within 30 days of a non-Q wave MI, in whom sequential left ventricular angiograms of adequate quality were obtained before the initial procedure and at follow-up angiography. The global ejection fraction increased significantly from 60 +/- 9% to 67 +/- 6% (p = 0.0003). This significant increase in the global ejection fraction was primarily due to a significant improvement in the regional myocardial function of the infarct zone. The results of the present study show not only that ischemic attacks early after a non-Q wave MI may lead to prolonged regional myocardial dysfunction but more important that this depressed myocardium has the potential to achieve normal contraction after successful coronary angioplasty.

  19. Myocardial Structural and Biological Anomalies Induced by High Fat Diet in Psammomys obesus Gerbils

    PubMed Central

    Sahraoui, Abdelhamid; Dewachter, Céline; de Medina, Geoffrey; Naeije, Robert

    2016-01-01

    Background Psammomys obesus gerbils are particularly prone to develop diabetes and obesity after brief period of abundant food intake. A hypercaloric high fat diet has been shown to affect cardiac function. Here, we sought to determine whether a short period of high fat feeding might alter myocardial structure and expression of calcium handling proteins in this particular strain of gerbils. Methods Twenty Psammomys obesus gerbils were randomly assigned to receive a normal plant diet (controls) or a high fat diet. At baseline and 16-week later, body weight, plasma biochemical parameters (including lipid and carbohydrate levels) were evaluated. Myocardial samples were collected for pathobiological evaluation. Results Sixteen-week high fat dieting resulted in body weight gain and hyperlipidemia, while levels of carbohydrates remained unchanged. At myocardial level, high fat diet induced structural disorganization, including cardiomyocyte hypertrophy, lipid accumulation, interstitial and perivascular fibrosis and increased number of infiltrating neutrophils. Myocardial expressions of pro-apoptotic Bax-to-Bcl-2 ratio, pro-inflammatory cytokines [interleukin (IL)-1β and tumor necrosis factor (TNF)-α], intercellular (ICAM1) and vascular adhesion molecules (VCAM1) increased, while gene encoding cardiac muscle protein, the alpha myosin heavy polypeptide (MYH6), was downregulated. Myocardial expressions of sarco(endo)plasmic calcium-ATPase (SERCA2) and voltage-dependent calcium channel (Cacna1c) decreased, while protein kinase A (PKA) and calcium-calmodulin-dependent protein kinase (CaMK2D) expressions increased. Myocardial expressions of ryanodine receptor, phospholamban and sodium/calcium exchanger (Slc8a1) did not change. Conclusions We conclude that a relative short period of high fat diet in Psammomys obesus results in severe alterations of cardiac structure, activation of inflammatory and apoptotic processes, and altered expression of calcium-cycling determinants

  20. The PPAR-α activator fenofibrate fails to provide myocardial protection in ischemia and reperfusion in pigs

    PubMed Central

    Xu, Ya; Lu, Li; Greyson, Clifford; Rizeq, Mona; Nunley, Karin; Wyatt, Beata; Bristow, Michael R.; Long, Carlin S.; Schwartz, Gregory G.

    2010-01-01

    Rodent studies suggest that peroxisome proliferator-activated receptor-α (PPAR-α) activation reduces myocardial ischemia-reperfusion (I/R) injury and infarct size; however, effects of PPAR-α activation in large animal models of myocardial I/R are unknown. We determined whether chronic treatment with the PPAR-α activator fenofibrate affects myocardial I/R injury in pigs. Domestic farm pigs were assigned to treatment with fenofibrate 50 mg·kg−1 ·day−1 orally or no drug treatment, and either a low-fat (4% by weight) or a high-fat (20% by weight) diet. After 4 wk, 66 pigs underwent 90 min low-flow regional myocardial ischemia and 120 min reperfusion under anesthetized open-chest conditions, resulting in myocardial stunning. The high-fat group received an infusion of triglyceride emulsion and heparin during this terminal experiment to maintain elevated arterial free fatty acid (FFA) levels. An additional 21 pigs underwent 60 min no-flow ischemia and 180 min reperfusion, resulting in myocardial infarction. Plasma concentration of fenofibric acid was similar to the EC50 for activation of PPAR-α in vitro and to maximal concentrations achieved in clinical use. Myocardial expression of PPAR-α mRNA was prominent but unaffected by fenofibrate treatment. Fenofibrate increased expression of carnitine palmitoyltransferase (CPT)-I mRNA in liver and decreased arterial FFA and lactate concentrations (each P < 0.01). However, fenofibrate did not affect myocardial CPT-I expression, substrate uptake, lipid accumulation, or contractile function during low-flow I/R in either the low- or high-fat group, nor did it affect myocardial infarct size. Despite expression of PPAR-α in porcine myocardium and effects of fenofibrate on systemic metabolism, treatment with this PPAR-α activator does not alter myocardial metabolic or contractile responses to I/R in pigs. PMID:16339839

  1. [Family experiences post-acute myocardial infarction].

    PubMed

    Garcia, Raquel Pötter; Budó, Maria de Lourdes Denardin; Simon, Bruna Sodré; Wünsch, Simone; Oliveira, Stefanie Griebeler; Barbosa, Mariane da Silva

    2013-09-01

    This study aimed to describe the family experiences post-infarction. Qualitative, descriptive and exploratory research, carried out with six families of post-infarction patients. Data collection was conducted in families' homes, in the period of February to May of 2012, through observation and interviews with the family. The software Atlas Ti 6.2 was used to code the interviews and the data were explored with thematic analysis. Two categories emerged "Difficult times": immediate consequence of acute myocardial infarction for the families; and "We reeducate ourselves--we can adapt ourselves": current experience of families. The immediate post-infarction experience is permeated by several feelings, with the need for families to adapt to fit into the needs. The current experience shows changes in families due to the disease. The family is the main responsible for the care giving, although Nursing should exchange and share knowledge. PMID:24344600

  2. Acute myocardial infarction in the obstetric patient

    PubMed Central

    Firoz, Tabassum; Magee, Laura A

    2012-01-01

    Acute myocardial infraction (AMI) in the obstetric patient is a rare event, although the incidence is rising due to advancing maternal age and pre-existing cardiac risk factors and medical co-morbidities. While atherosclerotic disease is the leading cause of AMI, coronary artery dissection is an important consideration in pregnancy and in the postpartum period. The physiological changes of pregnancy as well as pregnancy-specific risk factors can predispose the obstetric patient to AMI. Diagnosis of AMI can be challenging as symptoms may be atypical. Furthermore, diagnostic tests must be interpreted in the context of pregnancy. While the overall management of the obstetric patient with AMI is similar to that outside of pregnancy, drug therapy requires modification as some medications may be contraindicated in pregnancy and breastfeeding. There is limited information about prognosis and risk stratification but it is anticipated that future studies will address this issue.

  3. Caffeine reduces myocardial blood flow during exercise.

    PubMed

    Higgins, John P; Babu, Kavita M

    2013-08-01

    Caffeine consumption has been receiving increased interest from both the medical and lay press, especially given the increased amounts now available in energy products. Acute ingestion of caffeine usually increases cardiac work; however, caffeine impairs the expected proportional increase in myocardial blood flow to match this increased work of the heart, most notably during exercise. This appears to be mainly due to caffeine's effect on blocking adenosine-induced vasodilatation in the coronary arteries in normal healthy subjects. This review summarizes the available medical literature specifically relating to pure caffeine tablet ingestion and reduced exercise coronary blood flow, and suggests possible mechanisms. Further studies are needed to evaluate this effect for other common caffeine-delivery systems, including coffee, energy beverages, and energy gels, which are often used for exercise performance enhancement, especially in teenagers and young athletes. PMID:23764265

  4. Quantification of regional myocardial wall motion by cardiovascular magnetic resonance

    PubMed Central

    Jiang, Kai

    2014-01-01

    Cardiovascular magnetic resonance (CMR) is a versatile tool that also allows comprehensive and accurate measurement of both global and regional myocardial contraction. Quantification of regional wall motion parameters, such as strain, strain rate, twist and torsion, has been shown to be more sensitive to early-stage functional alterations. Since the invention of CMR tagging by magnetization saturation in 1988, several CMR techniques have been developed to enable the measurement of regional myocardial wall motion, including myocardial tissue tagging, phase contrast mapping, displacement encoding with stimulated echoes (DENSE), and strain encoded (SENC) imaging. These techniques have been developed with their own advantages and limitations. In this review, two widely used and closely related CMR techniques, i.e., tissue tagging and DENSE, will be discussed from the perspective of pulse sequence development and image-processing techniques. The clinical and preclinical applications of tissue tagging and DENSE in assessing wall motion mechanics in both normal and diseased hearts, including coronary artery diseases, hypertrophic cardiomyopathy, aortic stenosis, and Duchenne muscular dystrophies, will be discussed. PMID:25392821

  5. [Efficacy of various antioxidants in experimental ischemia and myocardial infarct in the rat].

    PubMed

    Poliukhovich, G S; Vasil'eva, L P; Maslova, G T; Boboriko, T L; Speranskiĭ, S D

    1991-01-01

    Complex of vitamins E and C showed the most effective antinecrotic action in rats with simulated myocardial infarction in series of antioxidants studied: ascorbate, alpha-tocopherol, quercetine, derivatives of o-benzoquinone OBQ2 and OBQ3. Stabilization of lipid peroxidation in cardiomyocytes, increase in biomembranes stability and absence of distinct alterations in the antioxidative enzymatic system were found in rats with ischemia and myocardial infarction after treatment with the complex. Protective effect of the vitamins E and C complex was realised via antiradical mechanism. PMID:1750212

  6. Factors in myocardial "perfusion" imaging with ultrafast MRI and Gd-DTPA administration.

    PubMed

    Burstein, D; Taratuta, E; Manning, W J

    1991-08-01

    Ultrafast magnetic resonance imaging (MRI) and first pass observation of an interstitial contrast agent are currently being used to study myocardial perfusion. Image intensity, however, is a function of several parameters, including the delivery of the contrast agent to the interstitium (coronary flow rate and diffusion into the interstitium) and the relaxation properties of the tissue (contrast agent concentration, proton exchange rates, and relative intra- and extracellular volume fractions). In this study, image intensity during gadopentetate dimeglumine (Gd-DTPA) administration with T1-weighted ultrafast MR imaging was assessed in an isolated heart preparation. With increasing Gd-DTPA concentration, the steady-state myocardial image intensity increased but the time to reach steady state remained unchanged, resulting in an increased slope of image intensity change. A range of physiologic perfusion pressures (and resulting coronary flow rates) had insignificant effects on kinetics of Gd-DTPA wash-in or steady-state image intensity, suggesting that diffusion of Gd-DTPA into the interstitium is the rate limiting step in image intensity change with this preparation. Following global ischemia and reperfusion, transmural differences in the slope of image intensity change were apparent. However, the altered steady-state image intensity (due to postischemic edema) makes interpretation of this finding difficult. The studies described here demonstrate that although Gd-DTPA administration combined with ultrafast imaging may be a sensitive indicator of perfusion abnormalities, factors other than perfusion will affect image intensity. Extensive studies will be required before image intensity with this protocol is fully understood. PMID:1775055

  7. Electrotonic remodeling following myocardial infarction in dogs susceptible and resistant to sudden cardiac death.

    PubMed

    Del Rio, Carlos L; McConnell, Patrick I; Kukielka, Monica; Dzwonczyk, Roger; Clymer, Bradley D; Howie, Michael B; Billman, George E

    2008-02-01

    Passive electrical remodeling following myocardial infarction (MI) is well established. These changes can alter electrotonic loading and trigger the remodeling of repolarization currents, a potential mechanism for ventricular fibrillation (VF). However, little is known about the role of passive electrical markers as tools to identify VF susceptibility post-MI. This study investigated electrotonic remodeling in the post-MI ventricle, as measured by myocardial electrical impedance (MEI), in animals prone to and resistant to VF. MI was induced in dogs by a two-stage left anterior descending (LAD) coronary artery ligation. Before infarction, MEI electrodes were placed in remote (left circumflex, LCX) and infarcted (LAD) myocardium. MEI was measured in awake animals 1, 2, 7, and 21 days post-MI. Subsequently, VF susceptibility was tested by a 2-min LCX occlusion during exercise; 12 animals developed VF (susceptible, S) and 12 did not (resistant, R). The healing infarct had lower MEI than the normal myocardium. This difference was stable by day 2 post-MI (287 +/- 32 Omega vs. 425 +/- 62 Omega, P < 0.05). Significant differences were observed between resistant and susceptible animals 7 days post-MI; susceptible dogs had a wider electrotonic gradient between remote and infarcted myocardium (R: 89 +/- 60 Omega vs. S: 180 +/- 37 Omega). This difference increased over time in susceptible animals (252 +/- 53 Omega at 21 days) due to post-MI impedance changes on the remote myocardium. These data suggest that early electrotonic changes post-MI could be used to assess later arrhythmia susceptibility. In addition, passive-electrical changes could be a mechanism driving active-electrical remodeling post-MI, thereby facilitating the induction of arrhythmias. PMID:18048585

  8. Urinary amino acid alterations in 3-year-old children with neurodevelopmental effects due to perinatal dioxin exposure in Vietnam: a nested case-control study for neurobiomarker discovery.

    PubMed

    Nishijo, Muneko; Tai, Pham The; Anh, Nguyen Thi Nguyet; Nghi, Tran Ngoc; Nakagawa, Hideaki; Van Luong, Hoang; Anh, Tran Hai; Morikawa, Yuko; Waseda, Tomoo; Kido, Teruhiko; Nishijo, Hisao

    2015-01-01

    In our previous study of 3-year-old children in a dioxin contamination hot spot in Vietnam, the high total dioxin toxic equivalent (TEQ-PCDDs/Fs)-exposed group during the perinatal period displayed lower Bayley III neurodevelopmental scores, whereas the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed group displayed increased autistic traits. In autistic children, urinary amino acid profiles have revealed metabolic alterations in the amino acids that serve as neurotransmitters in the developing brain. Therefore, our present study aimed to investigate the use of alterations in urinary amino acid excretion as biomarkers of dioxin exposure-induced neurodevelopmental deficits in highly exposed 3-year-old children in Vietnam. A nested case-control study of urinary analyses was performed for 26 children who were selected from 111 3-year-old children whose perinatal dioxin exposure levels and neurodevelopmental status were examined in follow-up surveys conducted in a dioxin contaminated hot spot. We compared urinary amino acid levels between the following 4 groups: (1) a high TEQ-PCDDs/Fs and high TCDD-exposed group; (2) a high TEQ-PCDDs/Fs but low TCDD-exposed group; (3) a low TEQ-PCDDs/Fs exposed and poorly developed group; and (4) a low TEQ-PCDDs/Fs exposed and well-developed group. Urinary levels of histidine and tryptophan were significantly decreased in the high TEQ-PCDDs/Fs and high TCDD group, as well as in the high TEQ-PCDDs/Fs but low TCDD group, compared with the low TEQ-PCDDs/Fs and well-developed group. However, the ratio of histidine to glycine was significantly lower only in the high TEQ-PCDDs/Fs and high TCDD group. Furthermore, urinary histidine levels and the ratio of histidine to glycine were significantly correlated with neurodevelopmental scores, particularly for language and fine motor skills. These results indicate that urinary histidine is specifically associated with dioxin exposure-induced neurodevelopmental deficits, suggesting that

  9. Urinary Amino Acid Alterations in 3-Year-Old Children with Neurodevelopmental Effects due to Perinatal Dioxin Exposure in Vietnam: A Nested Case-Control Study for Neurobiomarker Discovery

    PubMed Central

    Nishijo, Muneko; Tai, Pham The; Anh, Nguyen Thi Nguyet; Nghi, Tran Ngoc; Nakagawa, Hideaki; Van Luong, Hoang; Anh, Tran Hai; Morikawa, Yuko; Waseda, Tomoo; Kido, Teruhiko; Nishijo, Hisao

    2015-01-01

    In our previous study of 3-year-old children in a dioxin contamination hot spot in Vietnam, the high total dioxin toxic equivalent (TEQ-PCDDs/Fs)-exposed group during the perinatal period displayed lower Bayley III neurodevelopmental scores, whereas the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed group displayed increased autistic traits. In autistic children, urinary amino acid profiles have revealed metabolic alterations in the amino acids that serve as neurotransmitters in the developing brain. Therefore, our present study aimed to investigate the use of alterations in urinary amino acid excretion as biomarkers of dioxin exposure-induced neurodevelopmental deficits in highly exposed 3-year-old children in Vietnam. A nested case-control study of urinary analyses was performed for 26 children who were selected from 111 3-year-old children whose perinatal dioxin exposure levels and neurodevelopmental status were examined in follow-up surveys conducted in a dioxin contaminated hot spot. We compared urinary amino acid levels between the following 4 groups: (1) a high TEQ-PCDDs/Fs and high TCDD-exposed group; (2) a high TEQ-PCDDs/Fs but low TCDD-exposed group; (3) a low TEQ-PCDDs/Fs exposed and poorly developed group; and (4) a low TEQ-PCDDs/Fs exposed and well-developed group. Urinary levels of histidine and tryptophan were significantly decreased in the high TEQ-PCDDs/Fs and high TCDD group, as well as in the high TEQ-PCDDs/Fs but low TCDD group, compared with the low TEQ-PCDDs/Fs and well-developed group. However, the ratio of histidine to glycine was significantly lower only in the high TEQ-PCDDs/Fs and high TCDD group. Furthermore, urinary histidine levels and the ratio of histidine to glycine were significantly correlated with neurodevelopmental scores, particularly for language and fine motor skills. These results indicate that urinary histidine is specifically associated with dioxin exposure-induced neurodevelopmental deficits, suggesting that

  10. In vivo induction of antioxidant response and oxidative stress associated with genotoxicity and histopathological alteration in two commercial fish species due to heavy metals exposure in northern India (Kali) river.

    PubMed

    Fatima, Mahino; Usmani, Nazura; Firdaus, Fakiha; Zafeer, Mohammad Faraz; Ahmad, Shafeeque; Akhtar, Kafil; Dawar Husain, S M; Ahmad, Mir Hilal; Anis, Ehraz; Mobarak Hossain, M

    2015-01-01

    Heavy metals can significantly bioaccumulate in fish tissues. The step wise mechanism of heavy metal toxicities on fish health is still limited. The present study assessed the tissue-specific antioxidant response and oxidative stress biomarkers of commercially important fish species namely, Channa striatus and Heteropneustes fossilis inhabiting Kali River of northern India where heavy-metal load is beyond the World Health Organisation - maximum permissible limits. Heavy metals chromium (Cr), nickel (Ni), lead (Pb) and cadmium (Cd) were elevated in both fish species compared to recommended values of the Federal Environmental Protection Agency (FEPA), 1999 for edible fishes. Reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CATA) activities in all tissues (brachial, neural, renal and hepatic) were altered. Cellular lipid and protein compromisation in both fishes induced by heavy metals was determined by lipid peroxidation (LPO) and protein carbonylation (PC) assays. Micronucleus (MN) test of erythrocytes and comet assay of liver cells confirmed genotoxicity. Histopathology of the liver, kidney and brain of affected fishes was distorted significantly with its reference fishes thereby affecting the quality and quantity of these fish stocks. This raises a serious concern as these fishes are consumed by the local population which would ultimately affect human health. PMID:26191657

  11. Translation of Methodology Used In Human Myocardial Imaging to a Sheep Model of Acute Myocardial Infarction

    PubMed Central

    Bailey, Elizabeth A; Bailey, Dale L; Hunyor, Stephen; Ladd, Leigh; Bautovich, George J

    2013-01-01

    Introduction: Pre-clinical investigation of stem cells for repairing damaged myocardium predominantly uses rodents, however large animals have cardiac circulation closely resembling the human heart. The aim of this study was to evaluate whether SPECT/CT myocardial perfusion imaging (MPI) could be used for assessing sheep myocardium following an acute myocardial infarction (MI) and response to intervention. Methods: Eighteen sheep were enrolled in a pilot study to evaluate [99mTc]-sestamibi MPI at baseline, post-MI and after therapy. Modifications to the standard MPI protocols were developed. All data was reconstructed with OSEM using CT-derived attenuation and scatter correction. Standard analyses were performed and inter-observer agreement was measured using Kappa (κ). Power determined the sample sizes needed to show statistically significant changes due to intervention. Results: Ten sheep completed the full protocol. Data processed was performed with pre-existing hardware and software used in human MPI scanning. No improvement in perfusion was seen in the control group, however improvements of 15%-35% were seen after intra-myocardial stem cell administration. Inter-observer agreement was excellent (К=0.89). Using a target power of 0.9, 28 sheep were required to detect a 10-12% change in perfusion. Conclusion: This study demonstrates the suitability of large animal models for imaging with standard MPI protocols and its feasibility with a manageable number of animals. These protocols could be translated into humans to study the efficacy of stem cell therapy in heart regeneration and repair.

  12. 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

  13. Perioperative myocardial ischemia reperfusion injury.

    PubMed

    Shernan, Stanton K

    2003-09-01

    Myocardial I-R injury contributes to adverse cardiovascular outcomes after cardiac surgery. The pathogenesis of I-R injury is complex and involves the activation, coordination, and amplification of several systemic and local proinflammatory pathways (Fig. 4). Treatment and prevention of perioperative morbidity associated with myocardial I-R will ultimately require a multifocal approach. Combining preoperative risk stratification (co-morbidity and surgical complexity), minimizing initiating factors predisposing to SIRS, limiting ischemia duration, and administering appropriate immunotherapy directed toward systemic and local proinflammatory mediators of I-R injury, should all be considered. In addition, the role of the genetic-environmental interactions in the pathogenesis of cardiovascular disease is also being examined. Thus, in the near future, preoperative screening for polymorphisms of certain inflammatory and coagulation genes should inevitably help reduce morbidity by permitting the identification of high-risk cardiac surgical patients and introducing the opportunity for gene therapy or pharmacogenetic intervention [42,64]. PMID:14562561

  14. 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

  15. Acute care of myocardial infarction.

    PubMed Central

    Gutman, M. B.; Lee, T. F.; Gin, K.; Ho, K.

    1996-01-01

    Patients with acute myocardial infarct (AMI) need rapid diagnosis and prompt initiation of thrombolytic therapy. Patients with suspected cardiac ischemia must receive a coordinated team response by the emergency room staff including rapid electrocardiographic analysis and a quick but thorough history and physical examination to diagnose AMI. Thrombolysis and adjunct therapies should be administered promptly when indicated. The choice of thrombolytics is predicated by the location of the infarct. PMID:8754702

  16. Myocardial Infarction in the Elderly

    PubMed Central

    Carro, Amelia; Kaski, Juan Carlos

    2011-01-01

    Advances in pharmacological treatment and effective early myocardial revascularization have –in recent years- led to improved clinical outcomes in patients with acute myocardial infarction (AMI). However, it has been suggested that compared to younger subjects, elderly AMI patients are less likely to receive evidence-based treatment, including myocardial revascularization therapy. Several reasons have been postulated to explain this trend, including uncertainty regarding the true benefits of the interventions commonly used in this setting as well as increased risk mainly associated with comorbidities. The diagnosis, management, and post-hospitalization care of elderly patients presenting with an acute coronary syndrome pose many difficulties at present. A complex interplay of variables such as comorbidities, functional and socioeconomic status, side effects associated with multiple drug administration, and individual biologic variability, all contribute to creating a complex clinical scenario. In this complex setting, clinicians are often required to extrapolate evidence-based results obtained in cardiovascular trials from which older patients are often, implicitly or explicitly, excluded. This article reviews current recommendations regarding management of AMI in the elderly. PMID:22396870

  17. Green tea extract given before regional myocardial ischemia-reperfusion in rats improves myocardial contractility by attenuating calcium overload.

    PubMed

    Liou, Ying-Ming; Hsieh, Shih-Rong; Wu, Tsu-Juey; Chen, Jan-Yow

    2010-11-01

    There is evidence for a negative correlation between green tea consumption and cardiovascular diseases. The aim of the present study was to examine whether green tea extract (GTE) given before regional myocardial ischemia could improve depression of myocardial contractility by preventing cytosolic Ca(2+) overload. Regional ischemia-reperfusion (IR) was induced in rats by ligating the left anterior descending branch for 20 min, then releasing the ligature. Ligation induced ventricular arrhythmias in rats without GTE pretreatment, but decreased arrhythmogenesis was seen in rats pretreated 30 min earlier with GTE (400 mg/kg). During reperfusion, arrhythmias only occurred during the initial 5 min, and GTE pretreatment had no effect. After overnight recovery, serum cTnI levels were greatly increased in control post-IR rats but only slightly elevated in GTE-pretreated post-IR rats. Myocardial contractility measured by echocardiography was still depressed after 3 days in control post-IR rats, but not in GTE-pretreated post-IR rats. No myocardial ischemic injury was seen in post-IR rats with or without GTE pretreatment. Using freshly isolated single heart myocytes, GTE was found to attenuate the post-IR injury-associated cytosolic Ca(2+) overload and modulate changes in the levels and distribution of myofibril, adherens junction, and gap junction proteins. In summary, GTE pretreatment protects cardiomyocytes from IR injury by preventing cytosolic Ca(2+) overload, myofibril disruption, and alterations in adherens and gap junction protein expression and distribution. PMID:20922441

  18. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  19. Myocardial ischaemia during tracheal intubation and extubation.

    PubMed

    Edwards, N D; Alford, A M; Dobson, P M; Peacock, J E; Reilly, C S

    1994-10-01

    The incidence of myocardial ischaemia during tracheal intubation and extubation was compared using ambulatory ECG monitoring in 60 patients undergoing a variety of different surgical operations. Seven patients had myocardial ischaemia after tracheal intubation and seven patients during tracheal extubation. The patients who developed myocardial ischaemia during tracheal extubation had significantly greater rate-pressure products immediately before tracheal extubation (P < 0.05) and 1 min after tracheal extubation (P < 0.01) compared with those patients who did not develop myocardial ischaemia during extubation. PMID:7999498

  20. Myocardial perfusion scintigraphy: the evidence.

    PubMed

    Underwood, S R; Anagnostopoulos, C; Cerqueira, M; Ell, P J; Flint, E J; Harbinson, M; Kelion, A D; Al-Mohammad, A; Prvulovich, E M; Shaw, L J; Tweddel, A C

    2004-02-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  1. EMPOWERING ADULT STEM CELLS FOR MYOCARDIAL REGENERATION

    PubMed Central

    Mohsin, Sadia; Siddiqi, Sailay; Collins, Brett; Sussman, Mark A.

    2012-01-01

    Treatment strategies for heart failure remain a high priority for ongoing research due to the profound unmet need in clinical disease coupled with lack of significant translational progress. The underlying issue is the same whether the cause is acute damage, chronic stress from disease, or aging: progressive loss of functional cardiomyocytes and diminished hemodynamic output. To stave off cardiomyocyte losses, a number of strategic approaches have been embraced in recent years involving both molecular and cellular approaches to augment myocardial structure and performance. Resultant excitement surrounding regenerative medicine in the heart has been tempered by realizations that reparative processes in the heart are insufficient to restore damaged myocardium to normal functional capacity and that cellular cardiomyoplasty is hampered by poor survival, proliferation, engraftment and differentiation of the donated population. To overcome these limitations, a combination of molecular and cellular approaches needs to be adopted involving use of genetic engineering to enhance resistance to cell death and increase regenerative capacity. This review will highlight biological properties of approached to potentiate stem cell-mediated regeneration to promote enhanced myocardial regeneration, persistence of donated cells, and long lasting tissue repair. Optimizing cell delivery and harnessing the power of survival signaling cascades for ex vivo genetic modification of stem cells prior to reintroduction into the patient will be critical to enhance the efficacy of cellular cardiomyoplasty. Once this goal is achieved, then cell-based therapy has great promise for treatment of heart failure to combat the loss of cardiac structure and function associated with acute damage, chronic disease or aging. PMID:22158649

  2. Polycythemia vera presenting as acute myocardial infarction: An unusual presentation

    PubMed Central

    Bahbahani, Hussain; Aljenaee, Khaled; Bella, Abdelhaleem

    2014-01-01

    Acute myocardial infarction (AMI) is usually seen in the setting of atherosclerosis and its associated risk factors. Myocardial infarction in the young poses a particular challenge, as the disease is less likely, due to atherosclerosis. We report the case of a 37-year-old female patient who presented with ST segment elevation anterolateral AMI. The only abnormality on routine blood investigation was raised hemoglobin and hematocrit. After further testing, she was diagnosed according to the World Health Organization (WHO) criteria with polycythemia vera. This case illustrates the importance of recognizing polycythemia vera as an important cause of thrombosis, which can present initially as AMI, and to emphasize the early recognition of the disease in order to initiate appropriate management strategies. PMID:25544823

  3. Fatal myocardial fibrosis in an aged chimpanzee (Pan troglodytes).

    PubMed

    Baldessari, Audrey; Snyder, Jessica; Ahrens, Joel; Murnane, Robert

    2013-01-01

    A 36-year-old male chimpanzee (Pan troglodytes) assigned to a life-long sign language communication project presented for sudden death. No other clinical or clinical pathological abnormalities were noted and given the signalment, death due to cardiac failure was suspected. Necropsy findings revealed moderate cardiomegaly and other chronic age-related findings including focal renal tubular cystic dilation and gingival hyperplasia. Histologic evaluation of the heart revealed interstitial fibrosing cardiomyopathy characterized by severe interstitial myocardial fibrosis replacing and separating myofibers within all chambers of the heart, especially the left ventricle, interventricular septum and subvalvular areas. This case report represents an additional case of sudden death associated with interstitial myocardial fibrosis in a chimpanzee. This process has been previously cited as the most common cause of sudden death in aged chimpanzees. PMID:23762500

  4. Multimodality imaging in the assessment of myocardial viability

    PubMed Central

    Partington, Sara L.; Kwong, Raymond Y.

    2014-01-01

    The prevalence of heart failure due to coronary artery disease continues to increase, and it portends a worse prognosis than non-ischemic cardiomyopathy. Revascularization improves prognosis in these high-risk patients who have evidence of viability; therefore, optimal assessment of myocardial viability remains essential. Multiple imaging modalities exist for differentiating viable myocardium from scar in territories with contractile dysfunction. Given the multiple modalities available, choosing the best modality for a specific patient can be a daunting task. In this review, the physiology of myocardial hibernation and stunning will be reviewed. All the current methods available for assessing viability including echocardiography, cardiac magnetic resonance imaging, nuclear imaging with single photon emission tomography and positron emission tomography imaging and cardiac computed tomography will be reviewed. The effectiveness of the various techniques will be compared, and the limitations of the current literature will be discussed. PMID:21069458

  5. Acute myocardial infarction during pregnancy: A clinical checkmate

    PubMed Central

    Jaiswal, Abhishek; Rashid, Mahjabeen; Balek, Mark; Park, Chong

    2013-01-01

    Acute myocardial infarction (AMI) in pregnancy is associated with high morbidity and mortality. Management of these patients can be challenging as little is known about the optimal management strategy. Medications routinely used may have harmful effects on the pregnancy outcome. In addition, AMI could occur in the absence of atherosclerotic disease. We describe optimal management strategy by eliciting the management of a 45-year-old female with ST segment elevation myocardial infarction. We recommend early use of coronary angiography to define the pathology in such cases. Radial artery assess should be preferred. Pregnant patients with AMI due to atherosclerotic disease should be given a 325 mg of aspirin and 600 mg of clopidogrel and either balloon angioplasty or bare metal stent should be used for revascularization. Percutaneous coronary intervention with heparin is preferred over bivalirudin and later should be reserved for patients with severe heparin allergy. PMID:23993012

  6. Intestinal Microbial Metabolites Are Linked to Severity of Myocardial Infarction in Rats.

    PubMed

    Lam, Vy; Su, Jidong; Hsu, Anna; Gross, Garrett J; Salzman, Nita H; Baker, John E

    2016-01-01

    Intestinal microbiota determine severity of myocardial infarction in rats. We determined whether low molecular weight metabolites derived from intestinal microbiota and transported to the systemic circulation are linked to severity of myocardial infarction. Plasma from rats treated for seven days with the non-absorbed antibiotic vancomycin or a mixture of streptomycin, neomycin, polymyxin B and bacitracin was analyzed using mass spectrometry-based metabolite profiling platforms. Antibiotic-induced changes in the abundance of individual groups of intestinal microbiota dramatically altered the host's metabolism. Hierarchical clustering of dissimilarities separated the levels of 284 identified metabolites from treated vs. untreated rats; 193 were altered by the antibiotic treatments with a tendency towards decreased metabolite levels. Catabolism of the aromatic amino acids phenylalanine, tryptophan and tyrosine was the most affected pathway comprising 33 affected metabolites. Both antibiotic treatments decreased the severity of an induced myocardial infarction in vivo by 27% and 29%, respectively. We then determined whether microbial metabolites of the amino acids phenylalanine, tryptophan and tyrosine were linked to decreased severity of myocardial infarction. Vancomycin-treated rats were administered amino acid metabolites prior to ischemia/reperfusion studies. Oral or intravenous pretreatment of rats with these amino acid metabolites abolished the decrease in infarct size conferred by vancomycin. Inhibition of JAK-2 (AG-490, 10 μM), Src kinase (PP1, 20 μM), Akt/PI3 kinase (Wortmannin, 100 nM), p44/42 MAPK (PD98059, 10 μM), p38 MAPK (SB203580, 10 μM), or KATP channels (glibenclamide, 3 μM) abolished cardioprotection by vancomycin, indicating microbial metabolites are interacting with cell surface receptors to transduce their signals through Src kinase, cell survival pathways and KATP channels. These inhibitors have no effect on myocardial infarct size in

  7. Paricalcitol attenuates lipopolysaccharide-induced myocardial inflammation by regulating the NF-κB signaling pathway.

    PubMed

    Lee, Ae Sin; Jung, Yu Jin; Thanh, Tùng Nguyễn; Lee, Sik; Kim, Won; Kang, Kyung Pyo; Park, Sung Kwang

    2016-04-01

    Vitamin D deficiency is associated with an increased risk of cardiovascular disease, diabetes, colon and breast cancer, infectious diseases and allergies. Vascular alterations are an important pathophysiological mechanism of sepsis. Experimental data suggest that paricalcitol, a vitamin D2 analogue, exerts beneficial effects on renal inflammation and fibrosis. In the present study, we aimed to investigate the effects of paricalcitol on lipopolysaccharide (LPS)-induced myocardial inflammation and to elucidate the underlying mechanisms. We used primary cultured human umbilical vein endothelial cells for in vitro experiments, in which stimulation with tumor necrosis factor (TNF)-α was used to induce endothelial cell inflammation. For in vivo experiments, myocardial inflammation was induced by an intraperitoneal injection of 15 mg/kg LPS into C57BL6 mice pre-treated with or without 0.2 µg/kg paricalcitol. Treatment with paricalcitol suppressed the TNF-α-induced increase in the protein expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and fractalkine in endothelial cells. Treatment with paricalcitol also decreased the TNF-α-induced nuclear factor (NF)-κB binding activity. In a mouse model of LPS-induced myocardial inflammation, pre-treatment with paricalcitol prevented the LPS-induced increase in the expression of myocardial ICAM-1, phosphorylated p65 and myocardial TNF-α. Pre-treatment with paricalcitol also alleviated endotoxemia‑induced microvascular leakage in the myocardium. The findings of our study suggest that paricalcitol exerts a protective effect against LPS-induced myocardial inflammation by regulating the expression of cell adhesion molecules and TNF-α, and by improving myocardial permeability. PMID:26954764

  8. Paricalcitol attenuates lipopolysaccharide-induced myocardial inflammation by regulating the NF-κB signaling pathway

    PubMed Central

    LEE, AE SIN; JUNG, YU JIN; THANH, TÙNG NGUYỄN; LEE, SIK; KIM, WON; KANG, KYUNG PYO; PARK, SUNG KWANG

    2016-01-01

    Vitamin D deficiency is associated with an increased risk of cardiovascular disease, diabetes, colon and breast cancer, infectious diseases and allergies. Vascular alterations are an important pathophysiological mechanism of sepsis. Experimental data suggest that paricalcitol, a vitamin D2 analogue, exerts beneficial effects on renal inflammation and fibrosis. In the present study, we aimed to investigate the effects of paricalcitol on lipopolysaccharide (LPS)-induced myocardial inflammation and to elucidate the underlying mechanisms. We used primary cultured human umbilical vein endothelial cells for in vitro experiments, in which stimulation with tumor necrosis factor (TNF)-α was used to induce endothelial cell inflammation. For in vivo experiments, myocardial inflammation was induced by an intraperitoneal injection of 15 mg/kg LPS into C57BL6 mice pre-treated with or without 0.2 µg/kg paricalcitol. Treatment with paricalcitol suppressed the TNF-α-induced increase in the protein expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and fractalkine in endothelial cells. Treatment with paricalcitol also decreased the TNF-α-induced nuclear factor (NF)-κB binding activity. In a mouse model of LPS-induced myocardial inflammation, pre-treatment with paricalcitol prevented the LPS-induced increase in the expression of myocardial ICAM-1, phosphorylated p65 and myocardial TNF-α. Pre-treatment with paricalcitol also alleviated endotoxemia-induced microvascular leakage in the myocardium. The findings of our study suggest that paricalcitol exerts a protective effect against LPS-induced myocardial inflammation by regulating the expression of cell adhesion molecules and TNF-α, and by improving myocardial permeability. PMID:26954764

  9. Myocardial dysfunction and cardiovascular disease in type 2 diabetes.

    PubMed

    Ofstad, Anne Pernille

    2016-07-01

    Type 2 diabetes mellitus (T2DM) is strongly associated with increased risk of myocardial dysfunction and cardiovascular disease (CVD), two separate conditions which often co-exist and influence each other's course. The prevalence of myocardial dysfunction may be as high as 75% in T2DM populations but is often overlooked due to the initial asymptomatic nature of the disease, complicating co-morbidities such as coronary artery disease (CAD) and obesity, and the lack of consensus on diagnostic criteria. More sensitive echocardiographic applications are furthermore needed to improve detection of early subclinical changes in myocardial function which do not affect conventional echocardiographic parameters. The pathophysiology of the diabetic myocardial dysfunction is not fully elucidated, but involves hyperglycemia and high levels of free fatty acids. It evolves over several years and increases the risk of developing overt HF, and is suggested to at least in part account for the worse outcome seen in T2DM individuals after cardiac events. CAD and stroke are the most frequent CV manifestations among T2DM patients and relate to a large degree to the accelerated atherosclerosis driven by inflammation. Diagnosing CAD is challenging due to the lower sensitivity inherent in the diagnostic tests and there is thus a need for new biomarkers to improve prediction and detection of CAD. It seems that a multi-factorial approach (i.e. targeting several CV risk factors simultaneously) is superior to a strict glucose lowering strategy in reducing risk for macrovascular events, and recent research may even support an effect also on HF outcomes. PMID:27071642

  10. Altered fingerprints: analysis and detection.

    PubMed

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K

    2012-03-01

    The widespread deployment of Automated Fingerprint Identification Systems (AFIS) in law enforcement and border control applications has heightened the need for ensuring that these systems are not compromised. While several issues related to fingerprint system security have been investigated, including the use of fake fingerprints for masquerading identity, the problem of fingerprint alteration or obfuscation has received very little attention. Fingerprint obfuscation refers to the deliberate alteration of the fingerprint pattern by an individual for the purpose of masking his identity. Several cases of fingerprint obfuscation have been reported in the press. Fingerprint image quality assessment software (e.g., NFIQ) cannot always detect altered fingerprints since the implicit image quality due to alteration may not change significantly. The main contributions of this paper are: 1) compiling case studies of incidents where individuals were found to have altered their fingerprints for circumventing AFIS, 2) investigating the impact of fingerprint alteration on the accuracy of a commercial fingerprint matcher, 3) classifying the alterations into three major categories and suggesting possible countermeasures, 4) developing a technique to automatically detect altered fingerprints based on analyzing orientation field and minutiae distribution, and 5) evaluating the proposed technique and the NFIQ algorithm on a large database of altered fingerprints provided by a law enforcement agency. Experimental results show the feasibility of the proposed approach in detecting altered fingerprints and highlight the need to further pursue this problem. PMID:21808092

  11. Do antioxidant vitamins reduce infarct size following acute myocardial ischemia/reperfusion?

    PubMed

    Bellows, S D; Hale, S L; Simkhovich, B Z; Kay, G L; Kloner, R A

    1995-02-01

    There is controversy concerning the ability of antioxidant vitamins to reduce myocardial infarct size. We sought to determine whether a brief prophylactic treatment of vitamin C or vitamin C plus Trolox (a water-soluble form of vitamin E) could reduce myocardial infarct size in an experimental model. We used an anesthetized open-chest rabbit model in which a branch of the circumflex coronary artery was ligated for 30 minutes followed by 4 hours of reperfusion. Experiments were performed in a randomized and blinded fashion. An IV injection of normal saline pH balanced to 7.4 (control group n = 15), vitamin C (150 mg/kg, n = 14), or vitamin C plus Trolox (150 mg/kg plus 100 mg/kg, respectively, n = 15) was administered prior to coronary occlusion. Collateral blood flow during coronary occlusion was measured by radioactive microspheres, myocardial risk zone (AR) was assessed by blue dye injection, and myocardial infarct size (AN) was assessed by triphenyltetrazolium chloride staining. All rabbits received comparable ischemic insult: Collateral blood flow and AR were similar among all three groups. Infarct size, measured as a percent of AR, did not differ significantly among the controls (21%), vitamin C (29%), or the vitamin C plus Trolox (18%) groups. Therefore, in this ischemia/reperfusion model, antioxidant vitamins did not alter myocardial infarct size. PMID:7540423

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

    SciTech Connect

    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. Almost 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.

  13. 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

  14. Myocardial ischaemia in infancy and childhood

    PubMed Central

    Berry, C. L.

    1967-01-01

    Examination of 135 consecutive necropsy specimens has shown that ischaemic myocardial injury is not uncommon in infancy and childhood. The extent of the myocardial change has been assessed by a technique of staining with acid fuchsin, first described by Selye (1958). The significance of the findings is discussed. Images PMID:4163355

  15. Diosmin exhibits anti-hyperlipidemic effects in isoproterenol induced myocardial infarcted rats.

    PubMed

    Queenthy, S Sharmila; John, Babu

    2013-10-15

    The aim of the present study was to evaluate the protective effects of diosmin on experimentally induced myocardial infarcted rats. Diosmin (5 and 10mg/kg body weight) was administered orally as pretreatment daily for a period of 10 days. Then isoproterenol (100mg/kg) was injected subcutaneously into rats at an interval of 24h for 2 days (on 11th and 12th day). Isoproterenol-induced myocardial infarcted rats showed significant changes in electrocardiogram and an increase in the levels of cardiac markers, compared with normal rats. Additionally, increased plasma lipid peroxidation products and altered lipid metabolism in the plasma were observed in the isoproterenol-induced myocardial infarcted rats. Pretreatment with diosmin (5 and 10mg/kg body weight) minimized the electrocardiographic changes, decreased the levels of serum cardiac marker enzymes reduced plasma lipid peroxidation and minimized the alterations in the lipid metabolism of isoproterenol-induced myocardial infarcted rats. Also, diosmin inhibited the enhanced activity of liver HMG CoA reductase. The in vitro study revealed the free radical scavenging activity of diosmin. The free radical scavenging and anti-hyperlipidaemic effects are the reasons for the cardioprotective effects of diosmin. PMID:24036254

  16. Myocardial perfusion SPECT in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery.

    PubMed

    Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga

    2014-04-01

    Pediatric myocardial perfusion imaging (MPI) is not a routine investigation in an Indian setting due to under referrals and logistic problems. However, MPI is a frequently performed and established modality of investigation in adults for the identification of myocardial ischemia and viability. We report myocardial perfusion scintigraphy in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery. Adenosine stress MPI revealed a large infarct involving anterior segment with moderate reversible ischemia of the lateral left ventricular segment. Coronary angiogram later confirmed left main coronary artery ostial occlusion with retrograde collateral supply from dilated right coronary artery. PMID:24761067

  17. Risk stratification after myocardial infarction. Clinical overview

    SciTech Connect

    O'Rourke, R.A. )

    1991-09-01

    Many patients with an acute myocardial infarction can be stratified into subgroups that are at high risk for morbidity and mortality on the basis of clinical characteristics that indicate recurrent myocardial ischemia, persistent left ventricular dysfunction, and/or recurrent cardiac arrhythmias. In patients with uncomplicated myocardial infarction the assessment of symptoms, physical findings, and ECG changes during predischarge exercise testing often identifies patients at increased risk for further cardiac events. Because of the suboptimum sensitivity and specificity of the exercise ECG for detecting myocardial ischemia, myocardial perfusion imaging with 201Tl and/or assessment of global and segmental ventricular function by two-dimensional echocardiography or radionuclide cineangiography during or immediately after exercise are often added to the predischarge risk stratification.

  18. [Ischemic myocardial metabolism and antianginal drugs].

    PubMed

    Ichihara, K

    1986-12-01

    The effect of several kinds of antianginal drugs: nitrates, coronary vasodilators, beta-adrenergic blocking agents and calcium entry blocking agents on the myocardial metabolism and myocardial acidosis during ischemia was studied in the dog heart in vivo. Ischemia was induced by ligating the left anterior descending coronary artery. Ischemia accelerated anaerobic metabolism in the myocardium, in which glycogen breakdown, accumulation of glycolytic intermediates, loss of high energy phosphate and tissue acidosis occurred. Nitroglycerin, beta-adrenergic blocking agents such as propranolol, and some calcium entry blocking agents such as diltiazem and flunarizine prevented the myocardial metabolism from shifting to an anaerobic metabolism in spite of ischemia. However, coronary vasodilators and the dihydropyridine type of calcium entry blocking agents were not capable of reducing changes in the myocardial metabolism and myocardial acidosis during ischemia. The author makes a point in the present review that all the drugs which dilate coronary artery are not always effective on the ischemic myocardium. PMID:3549484

  19. [Fibrinolysis in acute myocardial infarct].

    PubMed

    Bleifeld, W

    1987-10-24

    Fibrinolysis has opened up a new avenue in the treatment of acute myocardial infarction (AMI). In principle, the rate of reperfusion depends on the type of compound used, the mode of administration and the time between onset of symptoms and the beginning of treatment. With intracoronary streptokinase the reperfusion rate is of the order of 85%. Intravenous urokinase administered as a bolus results in a reopening rate of 50-60%; a similar rate of reperfusion is achieved with rt-PA as infusion, while i.v. streptokinase produces about 50% reopened coronary vessels. The final infarct size is decreased in 70% of patients if fibrinolysis is initiated within 2.5 hours after the onset of symptoms and followed by reopening of the occluded vessel. This results in a lowering of in-hospital mortality, which in various studies is of the order of 45-60%.- Bearing in mind the contraindications, fibrinolysis should be initiated within 3 hours. Hemodynamic improvement by a decrease of infarct size may also be achieved beyond 3 hours in large anterior myocardial infarctions and in posterior infarctions with cardiogenic shock. Early initiation of thrombolysis is of major importance in improving left ventricular function and lowering mortality following acute myocardial infarction. Therefore, prehospital thrombolytic therapy should be considered. - In the postinfarction phase coronary angiography is indicated in patients with angina at rest, stable angina of ECG signs of ischemia. In this situation transfer to a specialized cardiology division for possible percutaneous transluminal angioplasty is indicated. - Reocclusion after successful thrombolysis occurs in 20-30%, and it is therefore important to avoid reinfarction to improve the long term prognosis after AMI.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3321420

  20. Myocardial protection with mild hypothermia.

    PubMed

    Tissier, Renaud; Ghaleh, Bijan; Cohen, Michael V; Downey, James M; Berdeaux, Alain

    2012-05-01

    Mild hypothermia, 32-35° C, is very potent at reducing myocardial infarct size in rabbits, dogs, sheep, pigs, and rats. The benefit is directly related to reduction in normothermic ischaemic time, supporting the relevance of early and rapid cooling. The cardioprotective effect of mild hypothermia is not limited to its recognized reduction of infarct size, but also results in conservation of post-ischaemic contractile function, prevention of no-reflow or microvascular obstruction, and ultimately attenuation of left ventricular remodelling. The mechanism of the anti-infarct effect does not appear to be related to diminished energy utilization and metabolic preservation, but rather to survival signalling that involves either the extracellular signal-regulated kinases and/or the Akt/phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Initial clinical trials of hypothermia in patients with ST-segment elevation myocardial infarction were disappointing, probably because cooling was too slow to shorten normothermic ischaemic time appreciably. New approaches to more rapid cooling have recently been described and may soon be available for clinical use. Alternatively, it may be possible to pharmacologically mimic the protection provided by cooling soon after the onset of ischaemia with an activator of mild hypothermia signalling, e.g. extracellular signal-regulated kinase activator, that could be given by emergency medical personnel. Finally, the protection afforded by cooling can be added to that of pre- and post-conditioning because their mechanisms differ. Thus, myocardial salvage might be greatly increased by rapidly cooling patients as soon as possible and then giving a pharmacological post-conditioning agent immediately prior to reperfusion. PMID:22131353

  1. Solar activity and myocardial infarction.

    PubMed

    Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

    1983-01-01

    The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism. PMID:6851574

  2. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines. PMID:26548984

  3. Sum of effects of myocardial ischemia followed by electrically induced tachycardia on myocardial function

    PubMed Central

    Díez, José Luis; Hernándiz, Amparo; Cosín-Aguilar, Juan; Aguilar, Amparo; Portolés, Manuel

    2013-01-01

    Background The alteration of contractile function after tachyarrhythmia ceases is influenced by the type of prior ischemia (acute coronary syndrome or ischemia inherent in a coronary revascularization procedure). We aimed to analyze cardiac dysfunction in an acute experimental model of supraphysiological heart rate preceded by different durations and types of ischemia. Material/Methods Twenty-four pigs were included in: (S1) series of ventricular pacing; (S2, A and B) series with 10 or 20 min, respectively, of coronary occlusion previous to ventricular pacing; S3 with 20 brief, repeated ischemia/reperfusion processes prior to ventricular pacing and; (S4) control series. Overall cardiac function parameters and regional myocardial contractility at the apex and base of the left ventricle were recorded, as were oxidative stress markers (glutathione and lipid peroxide serum levels). Left ventricular pacing at 60% over baseline heart rate was performed for 2 h followed by 1 h of recovery. Results High ventricular pacing rates preceded by short, repeated periods of coronary ischemia/reperfusion resulted in worse impairment of overall cardiac and regional function that continued to be altered 1 h after tachycardia ceased. There was significant reduction of stroke volume (26.9±5.3 basal vs. 16±6.2 ml; p<0.05), LVP; dP/dt and LAD flow (13.1±1.5 basal vs. 8.4±1.6 ml/min; p<0.05); the base contractility remained altered when recovering compared to baseline (base SF: 5.6±2.8 vs. 2.2±0.7%; p<0.05); and LPO levels were higher than less aggressive series at the end of recovery. Conclusions Ischemia and tachycardia accumulate their effects, with increased cardiac involvement depending on the type of ischemia. PMID:23722244

  4. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  5. Myocardial Perfusion: Characteristics of Distal Intramyocardial Arteriolar Trees.

    PubMed

    Zamir, Mair; Vercnocke, Andrew J; Edwards, Phillip K; Anderson, Jill L; Jorgensen, Steven M; Ritman, Erik L

    2015-11-01

    A combination of experimental, theoretical, and imaging methodologies is used to examine the hierarchical structure and function of intramyocardial arteriolar trees in porcine hearts to provide a window onto a region of myocardial microvasculature which has been difficult to fully explore so far. A total of 66 microvascular trees from 6 isolated myocardial specimens were analyzed, with a cumulative number of 2438 arteriolar branches greater than or equal to 40 μm lumen diameter. The distribution of flow rates within each tree was derived from an assumed power law relationship for that tree between the diameter of vessel segments and flow rates that are consistent with that power law and subject to conservation of mass along hierarchical structure of the tree. The results indicate that the power law index increases at levels of arteriolar vasculature closer to the capillary level, consistent with a concomitant decrease in shear stress acting on endothelial tissue. These results resolve a long standing predicament which could not be resolved previously because of lack of data about the 3D, interconnected, arterioles. In the context of myocardial perfusion, the results indicate that the coefficient of variation of flow rate in pre-capillary distal arterioles is high, suggesting that heterogeneity of flow rate in these arterioles is not entirely random but may be due at least in part to active control. PMID:25952363

  6. Mechanics of the left ventricular myocardial interstitium: effects of acute and chronic myocardial edema.

    PubMed

    Desai, Ketaki V; Laine, Glen A; Stewart, Randolph H; Cox, Charles S; Quick, Christopher M; Allen, Steven J; Fischer, Uwe M

    2008-06-01

    Myocardial interstitial edema forms as a result of several disease states and clinical interventions. Acute myocardial interstitial edema is associated with compromised systolic and diastolic cardiac function and increased stiffness of the left ventricular chamber. Formation of chronic myocardial interstitial edema results in deposition of interstitial collagen, which causes interstitial fibrosis. To assess the effect of myocardial interstitial edema on the mechanical properties of the left ventricle and the myocardial interstitium, we induced acute and chronic interstitial edema in dogs. Acute myocardial edema was generated by coronary sinus pressure elevation, while chronic myocardial edema was generated by chronic pulmonary artery banding. The pressure-volume relationships of the left ventricular myocardial interstitium and left ventricular chamber for control animals were compared with acutely and chronically edematous animals. Collagen content of nonedematous and chronically edematous animals was also compared. Generating acute myocardial interstitial edema resulted in decreased left ventricular chamber compliance compared with nonedematous animals. With chronic edema, the primary form of collagen changed from type I to III. Left ventricular chamber compliance in animals made chronically edematous was significantly higher than nonedematous animals. The change in primary collagen type secondary to chronic left ventricular myocardial interstitial edema provides direct evidence for structural remodeling. The resulting functional adaptation allows the chronically edematous heart to maintain left ventricular chamber compliance when challenged with acute edema, thus preserving cardiac function over a wide range of interstitial fluid pressures. PMID:18375722

  7. Altered heart proteome in fructose-fed Fisher 344 rats exposed to bisphenol A.

    PubMed

    Ljunggren, S A; Iggland, M; Rönn, M; Lind, L; Lind, P M; Karlsson, H

    2016-03-10

    Bisphenol A (BPA), is an artificial estrogen initially produced for medical purposes but is today widely used in polycarbonate plastics and epoxy resins. Exposure-related reproductive disorders have been found, but recently it has also been suggested that BPA may be involved in obesity, diabetes, myocardial hypertrophy and myocardial infarction in humans. To mimic a modern lifestyle, female rats were fed with fructose or fructose plus BPA (0.25mg/L drinking water). The myocardial left ventricle proteome of water controls, fructose-fed and fructose-fed plus BPA supplemented rats was explored. The proteome was investigated using nano-liquid chromatography tandem mass spectrometry and two-dimensional gel electrophoresis followed by matrix assisted laser desorption/ionization mass spectrometry identification. In total, 41 proteins were significantly altered by BPA exposure compared to water or fructose controls. Principal component analysis and cellular process enrichment analysis of altered proteins suggested increased fatty acid transport and oxidation, increased ROS generation and altered structural integrity of the myocardial left ventricle in the fructose-fed BPA-exposed rats, indicating unfavorable effects on the myocardium. In conclusion, BPA exposure in the rats induces major alterations in the myocardial proteome. PMID:26930160

  8. Targeting myocardial substrate metabolism in heart failure: potential for new therapies

    PubMed Central

    Ardehali, Hossein; Sabbah, Hani N.; Burke, Michael A.; Sarma, Satyam; Liu, Peter P.; Cleland, John G.F.; Maggioni, Aldo; Fonarow, Gregg C.; Abel, E. Dale; Campia, Umberto; Gheorghiade, Mihai

    2012-01-01

    The incidence and prevalence of heart failure have increased significantly over the past few decades. Available data suggest that patients with heart failure independent of the aetiology have viable but dysfunctional myocardium that is potentially salvageable. Although a great deal of research effort has focused on characterizing the molecular basis of heart failure, cardiac metabolism in this disorder remains an understudied discipline. It is known that many aspects of cardiomyocyte energetics are altered in heart failure. These include a shift from fatty acid to glucose as a preferred substrate and a decline in the levels of ATP. Despite these demonstrated changes, there are currently no approved drugs that target metabolic enzymes or proteins in heart failure. This is partly due to our limited knowledge of the mechanisms and pathways that regulate cardiac metabolism. Better characterization of these pathways may potentially lead to new therapies for heart failure. Targeting myocardial energetics in the viable and potentially salvageable tissue may be particularly effective in the treatment of heart failure. Here, we will review metabolic changes that occur in fatty acid and glucose metabolism and AMP-activated kinase in heart failure. We propose that cardiac energetics should be considered as a potential target for therapy in heart failure and more research should be done in this area. PMID:22253453

  9. Cell therapy for myocardial infarction.

    PubMed

    Kwon, Yoo-Wook; Yang, Han-Mo; Cho, Hyun-Jai

    2010-05-01

    Ischemic heart disease, particularly acute myocardial infarction (MI), is the worldwide health care problem and the leading cause of morbidity and mortality. The fundamental treatment of MI remains a major unmet medical need. Although recent tremendous advances have been made in the treatment for acute MI such as percutaneous coronary intervention (PCI) and medical and surgical therapies, myocardial cell loss after ischemia and subsequent, adverse cardiac remodeling and heart failure are demanding for new therapeutic strategy. Since the first experimental studies of adult stem cell therapy into the ischemic heart were performed in the early 1990s, the identification and potential application of stem and/or progenitor cells has triggered attempts to regenerate damaged heart tissue and cell-based therapy is a promising option for treatment of MI. In this review, we would like to discuss the pathogenesis of acute MI, current standard treatments and their limitation, clinical results of recent stem or progenitor cell therapy which have shown a favorable safety profile with modest improvement in cardiac function, and putative mechanisms of benefits. PMID:24855535

  10. Circadian influences on myocardial infarction.

    PubMed

    Virag, Jitka A I; Lust, Robert M

    2014-01-01

    Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  11. Circadian influences on myocardial infarction

    PubMed Central

    Virag, Jitka A. I.; Lust, Robert M.

    2014-01-01

    Components of circadian rhythm maintenance, or “clock genes,” are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations. PMID:25400588

  12. [Acute myocardial infarction during sport].

    PubMed

    Fujiwara, M; Asakuma, S; Nakamura, K; Nakamura, T; Yasutomi, N; Iwasaki, T

    1995-10-01

    Thirty patients with acute myocardial infarction which occurred during sport were investigated to identify the type of sport, prodromata, situations at the onset of disease, habit of exercise, preceding medical evaluation, coronary risk factors, and coronary angiographic findings. Infarction occurred during golf in 12 patients, bowling in 4, gateball in 4, jogging or running in 5, baseball in 2, and tennis or table tennis in 3. The majority of the patients were playing ball games. Twenty-seven patients were men (90%) and 3 were women (10%). All patients had played the same kind of sport for several years. Twenty-four patients had one or more coronary risk factors, and especially 18 patients smoked cigarettes. Nine patients had experienced anterior chest pain but only two patients had received medical evaluation. Coronary angiography was performed in 25 patients (83.3%), revealing single-vessel disease in 14, two-vessel disease in 6, three-vessel disease in 4, and disease of all left main coronary trunks in 1. The acute episode of infarction occurred mainly in spring or fall. Many patients with acute myocardial infarction occurring during sport participate in sports of low or moderate dynamic and low static exercises which are generally regarded safe. Many patients had enjoyed their sports regularly for a long time. Though many patients had coronary risk factors, only a few had received a medical check before their heart attack. PMID:7500263

  13. Intracardiac Myocardial Elastography in canines and humans in vivo

    PubMed Central

    Grondin, Julien; Wan, Elaine; Gambhir, Alok; Garan, Hasan; Konofagou, Elisa E.

    2014-01-01

    Intracardiac echocardiography (ICE) is a useful imaging modality which is used during radiofrequency (RF) ablation procedures to help identify anatomical structures. Utilizing ICE in adjunct with myocardial elastography (ME) can provide additional information on the mechanical properties of cardiac tissue and provide information on mechanical changes due to ablation. The objective of this study was to demonstrate that ICE can be used at high frame rate using a diverging beam transmit sequence to image myocardial strain and differentiate myocardial tissue properties before, during and after ablation for a clinical ablation procedure. In this feasibility study, three normal canines and eight patients with atrial fibrillation (AF) were studied in vivo. A 5.8-MHz ICE transducer was used to image the heart with a diverging beam transmit method achieving 1200 frames per second (fps). Cumulative axial displacement estimation was performed using 1-D cross-correlation with a window size of 2.7mm and 95% overlap. Axial cumulative strains were estimated in left atrium (LA) and right atrium (RA) using a least-squares estimator with a kernel of 2mm on the axial displacements. In the canine case, radial thickening was detected in the lateral wall and in the interatrial septum during LA emptying. For AF patients, mean absolute strain in the ablated region was lower (6.7±3.1%) than before the ablation (17.4±9.3%) in LA at end LA emptying. In the cavotricuspid isthmus (CTI) region, mean absolute strain magnitude at end RA emptying was found to be higher during ablation (43.0±18.1%) compared to after ablation (33.7±15.8%). Myocardial strains in the LA of an AF patient were approximately 2.6 times lower in the ablated region than before ablation. This initial feasibility may suggest ME as a new imaging modality to be used in adjunct with ICE in RF ablation guidance and lesion monitoring. PMID:25643083

  14. Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

    SciTech Connect

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Nitenberg, A.; Venot, A.; Guerin, F.; Degeorges, M.; Roucayrol, J.C.

    1986-05-29

    Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined.

  15. Effect of doxorubicin on (at-I-131) heptadecanoic acid myocardial scintigraphy and echocardiography in dogs

    SciTech Connect

    Styles, C.B.; Noujaim, A.A.; Jugdutt, B.I.; Sykes, T.R.; Bain, G.O.; Shnitka, T.L.; Hooper, H.R.

    1983-11-01

    The effects of serial treatment with doxorubicin on dynamic myocardidal scintigraphy with (at-I-131) heptadecanoic acid (I-131 HA), and on global left-ventricular function determined echocardiographically, were studied in a group of nine mongrel dogs. Total extractable myocaridal lipid was compared postmortem between a group of control dogs and doxorubicin-treated dogs. A significant and then progressive fall in global LV function was observed at a cumulative doxorubicin dose of 4 mg/kg. A significant increase in the myocaridal t/sub 1/2/ of the I-131 HA was observed only at a higher cumulative dose, 10 mg/kg. No significant alteration in total extractable myocardial lipids was observed between control dogs and those treated with doxorubicin. The findings suggest that the changes leading to an alteration of myocardial dynamic imaging with I-131 HA are not the initiating factor in doxorubicin cardiotoxicity.

  16. Echocardiographic analysis with a two-dimensional strain of chronic myocardial ischemia induced with ameroid constrictor in the pig.

    PubMed

    Caillaud, Dominique; Calderon, Joachim; Réant, Patricia; Lafitte, Stéphane; Dos Santos, Pierre; Couffinhal, Thierry; Roques, Xavier; Barandon, Laurent

    2010-05-01

    Despite much progress in the medical management of myocardial ischemia, several problems remain and experimental models help to improve our understanding of the pathophysiology involved in this domain. The ameroid constrictor model is the most widely used to create ischemia but evaluation of patent ischemia is still under debate. In the present study, we describe the potential of a two-dimensional (2D) strain for experimentally evaluating myocardial ischemia in the pig. An ameroid constrictor was placed around the circumflex artery in 30 pigs. Angiography showed 90% stenosis at one and two months. Left ventricular function was moderately altered and associated with mitral valve insufficiency in 30% of cases. Longitudinal and circumference strains were dramatically modified in the ischemic inferior-lateral zone compared to the healthy anterior zone (P<0.01) at one and two months. We correlated these results to myocardial ischemia by using contrast echocardiography, which showed a significant reduction in myocardial perfusion in the ischemic zone compared to the uninjured area, and by using histological analysis. We showed that evaluation of the 2D strain could be an interesting approach for assessing myocardial ischemia after ameroid constrictor implantation. The 2D strain represents a useful tool for the evaluation of experimental models of myocardial ischemia. PMID:20139196

  17. The role of neutrophils in myocardial ischemia-reperfusion injury.

    PubMed

    Jordan, J E; Zhao, Z Q; Vinten-Johansen, J

    1999-09-01

    Reperfusion of ischemic myocardium is necessary to salvage tissue from eventual death. However, reperfusion after even brief periods of ischemia is associated with pathologic changes that represent either an acceleration of processes initiated during ischemia per se, or new pathophysiological changes that were initiated after reperfusion. This 'reperfusion injury' shares many characteristics with inflammatory responses in the myocardium. Neutrophils feature prominently in this inflammatory component of postischemic injury. Ischemia-reperfusion prompts a release of oxygen free radicals, cytokines and other proinflammatory mediators that activate both the neutrophils and the coronary vascular endothelium. Activation of these cell types promotes the expression of adhesion molecules on both the neutrophils and endothelium, which recruits neutrophils to the surface of the endothelium and initiate a specific cascade of cell-cell interactions, leading first to adherence of neutrophils to the vascular endothelium, followed later by transendothelial migration and direct interaction with myocytes. This specific series of events is a prerequisite to the phenotypic expression of reperfusion injury, including endothelial dysfunction, microvascular collapse and blood flow defects, myocardial infarction and apoptosis. Pharmacologic therapy can target the various components in this critical series of events. Effective targets for these pharmacologic agents include: (a) inhibiting the release or accumulation of proinflammatory mediators, (b) altering neutrophil or endothelial cell activation and (c) attenuating adhesion molecule expression on endothelium, neutrophils and myocytes. Monoclonal antibodies to adhesion molecules (P-selectin, L-selectin, CD11, CD18), complement fragments and receptors attenuate neutrophil-mediated injury (vascular injury, infarction), but clinical application may encounter limitations due to antigen-antibody reactions with the peptides. Humanized

  18. Use of thallium 201 myocardial imaging to exclude myocardial infarction after dissection in congenital coarctation of the aorta

    SciTech Connect

    Halon, D.A.; Weiss, A.T.; Tzivoni, D.; Atlan, H.; Gotsman, M.S.

    1981-10-01

    The use of a mobile gamma camera with thallium 201 myocardial imaging is described to exclude myocardial infarction in a patient admitted to the coronary care unit in shock and with clinical, enzyme, and ECG changes consistent with infarction. The patient suffered from acute aortic dissection associated with congenital coarctation of the aorta. The myocardial scan excluded transmural myocardial injury.

  19. Cardioplegia and myocardial preservation during cardiopulmonary bypass.

    PubMed

    Engelman, R M; Levitsky, S; O'Donoghue, M J; Auvil, J

    1978-09-01

    A standard experimental protocol was developed to explore the role of hypothermia and potassium cardioplegia in myocardial preservation during 120 minutes of ischemic arrest followed by 30 minutes of reperfusion. Seven different experimental groups of six animals each were evaluated using an in-vivo pig heart preparation. Hypothermic arrest without cardioplegia and cardioplegic arrest at normothermia were each compared to hypothermic cardioplegia. In addition, the use of an asanguineous hypothermic coronary perfusate without cardioplegia was compared to both multidose cardioplegia and single-dose cardioplegia followed by the same asanguineous perfusate. The parameters measured included: myocardial contractility and compliance, myocardial blood flow, endocardial/epicardial blood flow ratio, and electron microscopic studies. Myocardial preservation was inadequate with hypothermic arrest alone (without cardioplegia; and with cardioplegia at normothermia. In both experimental groups, myocardial contractility and compliance were so depressed that the) could not be accurately measured following ischemia and reperfusion while coronary blood flow remained significantly elevated. Preservation was improved but still inadequate following myocardial washout with a normokalemic or hypokalemic perfusate and following single dose cardioplegia plus myocardial washout. In the latter four groups, contractility ranged from 42 to 78% of control, and there was a decrease in compliance of 16 to 78%. Adequate preservation was found only after hypothermia and multidose potassium (35 mEq/L) cardioplegia. In this group, contractility was 129 +/- 13% of control and compliance increased by 21 +/- 24% compared to that of the control. PMID:14740689

  20. [Myocardial infarction and thromboembolism during pregnancy].

    PubMed

    Härtel, Dirk; Sorges, Eckhard; Carlsson, Jörg; Römer, Volker; Tebbe, Ulrich

    2003-05-01

    Acute myocardial infarction is a very rare event during pregnancy and bears the problem of misdiagnosis. However, about 150 cases have been published worldwide with a preponderance of anterior wall infarcts. With more women delaying childbearing until an older age and increasing prevalence of smoking in young women, it can be expected that all forms of coronary artery disease--including acute myocardial infarction--will be seen more often in the future. Among the causes of coronary artery occlusion in pregnancy are (1) rupture of very small coronary artery plaques triggered by different events, e.g., hypertension; (2) plain coronary artery disease; (3) dissection of coronary arteries; (4) coronary artery spasms with/without arterial thrombosis. Prompt diagnosis and immediate therapy are necessary to lower the high mortality of mother and fetus. The gold standard in the therapy of acute myocardial infarction during pregnancy is immediate coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) with or without stent implantation. Application of thrombolytics (recombinant tissue plasminogen activator [rt-PA], r-PA, streptokinase [SK], urokinase [UK]) has been reported in single patients but should be limited to cases where acute PTCA is not available and where the infarct occurs before the 14th week of pregnancy because of possible embryopathy. If the patient is in the last 10 weeks of pregnancy, anticipation of delivery should be part of the medical planning. Consultation with an obstetrician must be obtained as soon as the patient enters the hospital. Besides bleeding complications, venous thrombosis with pulmonary embolism is among the most common causes of death during pregnancy. Pregnancy-related changes in physiology - increase in the resistance to flow from the lower extremities to the heart - and congenital coagulation abnormalities are most important to be recognized. This leads to the fact that superficial and deep venous thromboses

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

    ClinicalTrials.gov

    2016-01-25

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

  2. Electrocardiograms corresponding to the development of myocardial infarction in anesthetized WHHLMI rabbits (Oryctolagus cuniculus), an animal model for familial hypercholesterolemia.

    PubMed

    Kobayashi, Tsutomu; Ito, Takashi; Yamada, Satoshi; Kuniyoshi, Nobue; Shiomi, Masashi

    2012-10-01

    The aim of this study was to determine whether features indicative of myocardial ischemia occur in the electrocardiograms (ECG) in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for human familial hypercholesterolemia. ECG were recorded in 110 anesthetized WHHLMI rabbits (age, 10 to 39 mo) by using unipolar and bipolar limb leads with or without chest leads. We noted the following electrocardiographic changes: T wave inversion (37.4%), ST segment depression (31.8%), deep Q wave (16.3%), reduced R wave amplitude (7.3%), ST segment elevation (2.7%), and high T wave (1.8%). These ECG changes resembled those in human patients with coronary heart disease. Histopathologic examination revealed that the left ventricular wall showed acute myocardial lesions, including loss of cross-striations, vacuolar degeneration, coagulation necrosis of cardiac myocytes, and edema between myofibrils, in addition to chronic myocardial lesions such as myocardial fibrosis. The coronary arteries that caused these ECG changes were severely stenosed due to atherosclerotic lesions. Ischemic ECG changes corresponded to the locations of the myocardial lesions. Normal ECG waveforms were similar between WHHLMI rabbits and humans, in contrast to the large differences between rabbits and mice or rats. In conclusion, ischemic ECG changes in WHHLMI rabbits reflect the location of myocardial lesions, making this model useful for studying coronary heart disease. PMID:23114045

  3. Adaptation of myocardial blood flow to increased metabolic demand is not dependent on endothelial vasodilators in the rat heart.

    PubMed Central

    Tiefenbacher, C. P.; Tillmanns, H.; Niroomand, F.; Zimmermann, R.; Kübler, W.

    1997-01-01

    OBJECTIVE: To investigate the role of endothelial vasodilating factors in adaptation of myocardial blood flow to increased metabolic demands. DESIGN: Alterations in the effects of endothelium dependent (acetylcholine) and independent (sodium nitroprusside) vasodilators and the beta 1 receptor agonist dobutamine were studied after inhibition of endothelium derived relaxing factor (EDRF) with L-NG-nitro-arginine methyl ester (L-NAME), prostanoid synthesis with indomethacin, and ATP sensitive potassium channels with glibenclamide. EXPERIMENTAL ANIMALS: Female Wistar rats, in situ perfused heart. MAIN OUTCOME MEASURES: Myocardial blood flow (H2 clearance); systolic fractional thickening (pulsed Doppler); mean arterial blood pressure. RESULTS: L-NAME reduced myocardial blood flow by 58 (12)% (mean (SD), P < 0.001) and systolic thickening fraction (FT) by 36 (9)% (P < 0.05). These effects were significantly reversed by administration of L-arginine but not D-arginine. Pretreatment with L-NAME inhibited the increase in myocardial blood flow caused by acetylcholine (control: +42 (9)%; L-NAME: -29 (7)%, P < 0.001) but did not affect the increase in myocardial blood flow caused by sodium nitroprusside (control: +44 (5)%; L-NAME: +34 (10)%, NS). Pretreatment with L-NAME did not change the effect of dobutamine on myocardial blood flow (+61 (3)%) and FT (+32 (8)%) compared with baseline values (P < 0.001). Neither pretreatment with indomethacin nor with glibenclamide reduced the dobutamine induced increase in myocardial blood flow. CONCLUSIONS: Inhibition of EDRF, prostanoid synthesis, and ATP sensitive potassium channels did not reduce the vasodilator reserve during increased metabolic demands induced by beta 1 adrenergic stimulation. Therefore, adaptation of myocardial blood flow to increased metabolic demands is independent of endothelial relaxing factors in the rat heart. PMID:9068398

  4. Drastic alteration of diffusioosmosis due to steric effects.

    PubMed

    Hoshyargar, Vahid; Ashrafizadeh, Seyed Nezameddin; Sadeghi, Arman

    2015-11-21

    The inclusion of the ionic size (steric) effects into the steady and locally developed diffusioosmotic flow inside a uniformly charged slit microchannel through a theoretical analysis is the subject of this study. The results indicate essential quantitative and qualitative distinctions between the steric effects on classical electrokinetic phenomena like electroosmosis and on diffusioosmosis. For example, although the steric effect on electroosmotic flow is always unfavorable, it may have a positive influence on diffusioosmosis and even double the mean velocity under certain conditions. Moreover, finite ionic sizes can even change the flow direction with a tendency to increase the chance of flow toward higher concentrations. Another interesting finding is that, unlike electroosmosis, the steric effects on diffusioosmotic flow do not vanish even when the EDL is very thin. The main quantitative difference between the ionic size effects on diffusioosmosis and the other electrokinetic phenomena is the critical zeta potential above which these effects become important which is here found to be only about several tens of millivolts. The more sensitivity of diffusioosmosis to the steric effects and also the above-mentioned surprisingly different trends are attributed to the induced electric field which may drastically get influenced by the steric factor. PMID:26465606

  5. Alterations in bone forming cells due to reduced weight bearing

    NASA Technical Reports Server (NTRS)

    Doty, S. B.; Morey-Holton, E.

    1984-01-01

    A reduction in new bone formation occurred as a result of space flight (Cosmos 1129) and in the suspended animal model of Morey-Holton (1979, 1980). The results indicate that alkaline phosphatase activity of the bone-forming cells is also reduced under these conditions, and the cells in the diaphysis are more affected than those in the metaphyseal region. In addition, these cells show (1) reduced proline incorporation into bone matrix, and (2) increased intracellular lysosomal activity. A change in the cytoskeleton could be the common factor in explaining these results. This suggestion is futher supported by the previous observations that colchicine injections result in decreased osteoblastic function.

  6. Anatomical alterations due to polyploidy in cassava, Manihot esculenta Crantz.

    PubMed

    Nassar, Nagib M A; Graciano-Ribeiro, D; Fernandes, S D C; Araujo, P C

    2008-01-01

    Information on anatomical structure is needed by breeders working on improvement for drought tolerance. For studying the effect of polyploidy on cassava anatomy and its significance to tolerance to drought, we induced a polyploidy type of a selected clone (UnB 530) by applying an aqueous solution of 0.2% colchicine on lateral buds for a period of 12 h. The stem identified as tetraploid was propagated to produce the whole plant. Free-hand cross-sections of the median portion between stem internodes were made. They were clarified using 50% sodium hypochlorite solution, stained with 1% safranin-alcian blue, passed through an ethanol series and butyl acetate and mounted in synthetic resin. The tetraploid type showed more prismatic and druse crystals in the cortical parenchyma, and its pericycle fibers had thicker walls. The secondary xylem of tetraploid types was wider than diploid ones, having thinner walls and less starch. PMID:18551393

  7. Alterations in gray matter volume due to unilateral hearing loss

    PubMed Central

    Wang, Xingchao; Xu, Pengfei; Li, Peng; Wang, Zhenmin; Zhao, Fu; Gao, Zhixian; Xu, Lei; Luo, Yue-jia; Fan, Jin; Liu, Pinan

    2016-01-01

    Although extensive research on neural plasticity resulting from hearing deprivation has been conducted, the direct influence of compromised audition on the auditory cortex and the potential impact of long durations of incomplete sensory stimulation on the adult cortex are still not fully understood. In this study, using voxel-based morphometry, we evaluated gray matter (GM) volume changes that may be associated with reduced hearing ability and the duration of hearing impairment in 42 unilateral hearing loss (UHL) patients with acoustic neuromas compared to 24 normal controls. We found significant GM volume increases in the somatosensory and motor systems and GM volume decreases in the auditory (i.e., Heschl’s gyrus) and visual systems (i.e., the calcarine cortex) in UHL patients. The GM volume decreases in the primary auditory cortex (i.e., superior temporal gyrus and Heschl’s gyrus) correlated with reduced hearing ability. Meanwhile, the GM volume decreases in structures involving high-level cognitive control functions (i.e., dorsolateral prefrontal cortex and anterior cingulate cortex) correlated positively with hearing loss duration. Our findings demonstrated that the severity and duration of UHL may contribute to the dissociated morphology of auditory and high-level neural structures, providing insight into the brain’s plasticity related to chronic, persistent partial sensory loss. PMID:27174521

  8. Alterations in the Serum Glycome due to Metastatic Prostate Cancer

    PubMed Central

    Kyselova, Zuzana; Mechref, Yehia; Bataineh, Mohammad M. Al; Dobrolecki, Lacey E.; Hickey, Robert J.; Vinson, Jake; Sweeney, Christopher J.; Novotny, Milos V.

    2013-01-01

    Glycomic profiles derived from human blood sera of 10 healthy males were compared to those from 24 prostate cancer patients. The profiles were acquired using MALDI-MS of permethylated N-glycans released from 10-μl sample aliquots. Quantitative permethylation was attained using solid-phase permethylation. Principal component analysis of the glycomic profiles revealed significant differences among the two sets, allowing their distinct clustering. The first principal component distinguished the 24 prostate cancer patients from the healthy individuals. It was determined that fucosylation of glycan structures is generally higher in cancer samples (ANOVA test p-value of 0.0006). Although more than 50 N-glycan structures were determined, twelve glycan structures, of which six were fucosylated, were significantly different between the two sample sets. Significant differences were confirmed through two independent statistical tests (ANOVA and ROC analyses). Ten of these structures had a significantly higher relative intensities in the case of the cancer samples, while the other two were less abundant in the cancer samples. All 12 structures were statistically significant, as suggested by their very low ANOVA scores (< 0.001) and ROC analysis, with area under the curve values close to 1 or zero. Accordingly, these structures can be considered as cancer–specific glycans and potential prostate cancer biomarkers. Therefore, serum glycomic profiling appears worthy of further investigation to define its role in cancer early detection and prognostication. PMID:17432893

  9. Alterations of Cloud Microphysics Due to Cloud Processed CCN

    NASA Astrophysics Data System (ADS)

    Hudson, J. G.; Tabor, S. S.; Noble, S. R., Jr.

    2015-12-01

    High-resolution CCN spectra have revealed bimodality (Hudson et al. 2015) similar to aerosol size spectra (e.g., Hoppel et al. 1985). Bimodality is caused by chemical and physical cloud processes that increase mass or hygroscopicity of only CCN that produced activated cloud droplets. Bimodality is categorized by relative CCN concentrations (NCCN) within the two modes, Nu-Np; i.e., NCCN within the higher critical supersaturation, Sc, mode that did not undergo cloud processing minus NCCN within the lower Sc mode that was cloud processed. Lower, especially negative, Nu-Np designates greater processing. The table shows regressions between Nu-Np and characteristics of clouds nearest the CCN measurements. ICE-T MASE parameter R SL R SL Nc 0.17 93.24 -0.26 98.65 MD -0.31 99.69 0.33 99.78 σ -0.27 99.04 0.48 100.00 Ld -0.31 99.61 0.38 99.96 Table. Correlation coefficients, R, and one-tailed significance levels in percent, SL, for Nu-Np with microphysics of the clouds closest to each CCN measurement, 75 ICE-T and 74 MASE cases. Nc is cloud droplet concentration, MD is cloud droplet mean diameter, σ is standard deviation of cloud droplet spectra, Ldis drizzle drop LWC. Two aircraft field campaigns, Ice in Clouds Experiment-Tropical (ICE-T) and Marine Stratus/Stratocumulus Experiment (MASE) show opposite R signs because coalescence dominated cloud processing in low altitude ICE-T cumuli whereas chemical transformations predominated in MASE low altitude polluted stratus. Coalescence reduces Nc and NCCN, which thus increases MD, and σ, which promote Ld. Chemical transformations, e.g., SO2 to SO4, increase CCN hygroscopicity, thus reducing Sc, but not affecting Nc or NCCN. Lower Sc CCN are capable of producing greater Nc in subsequent cloud cycles, which leads to lower MD and σ which reduce Ld (figure). These observations are consistent with cloud droplet growth models for the higher vertical wind (W) of cumuli and lower W of stratus. Coalescence thus reduces the indirect aerosol effect (IAE) with a positive feedback that further enhances coalescence and drizzle. Chemical cloud processing enhances both components of IAE; 1st IAE by greater droplet surface area, 2ndIAE by suppressing drizzle and thus increasing cloudiness. Hoppel, Fitzgerald and Larson: JGR 90, 2365-79 Hudson, Noble and Tabor: JGRA 120, 3436-52

  10. Alterations in gray matter volume due to unilateral hearing loss.

    PubMed

    Wang, Xingchao; Xu, Pengfei; Li, Peng; Wang, Zhenmin; Zhao, Fu; Gao, Zhixian; Xu, Lei; Luo, Yue-Jia; Fan, Jin; Liu, Pinan

    2016-01-01

    Although extensive research on neural plasticity resulting from hearing deprivation has been conducted, the direct influence of compromised audition on the auditory cortex and the potential impact of long durations of incomplete sensory stimulation on the adult cortex are still not fully understood. In this study, using voxel-based morphometry, we evaluated gray matter (GM) volume changes that may be associated with reduced hearing ability and the duration of hearing impairment in 42 unilateral hearing loss (UHL) patients with acoustic neuromas compared to 24 normal controls. We found significant GM volume increases in the somatosensory and motor systems and GM volume decreases in the auditory (i.e., Heschl's gyrus) and visual systems (i.e., the calcarine cortex) in UHL patients. The GM volume decreases in the primary auditory cortex (i.e., superior temporal gyrus and Heschl's gyrus) correlated with reduced hearing ability. Meanwhile, the GM volume decreases in structures involving high-level cognitive control functions (i.e., dorsolateral prefrontal cortex and anterior cingulate cortex) correlated positively with hearing loss duration. Our findings demonstrated that the severity and duration of UHL may contribute to the dissociated morphology of auditory and high-level neural structures, providing insight into the brain's plasticity related to chronic, persistent partial sensory loss. PMID:27174521

  11. Compensatory changes in Ca(2+) and myocardial O(2) consumption in beta-tropomyosin transgenic hearts.

    PubMed

    MacGowan, G A; Du, C; Wieczorek, D F; Koretsky, A P

    2001-12-01

    Transgenic mice overexpressing beta-tropomyosin have increased myofilament Ca(2+) sensitivity that we hypothesized would result in altered relationships among pressure and heart rates, intracellular Ca(2+), and myocardial O(2) consumption. In perfused hearts from transgenic mice there was a marked negative force-frequency response between 6 and 10 Hz with a 30 +/- 3% reduction in peak-positive first derivative of pressure development over time (dP/dt) compared with 14 +/- 2% in wild-type mice (P < 0.001). At 8 Hz systolic pressures were normal, though peak systolic intracellular Ca(2+) was significantly reduced in transgenic mice versus wild type (726 +/- 61 vs. 936 +/- 67 nM, P < 0.05) indicating an alteration in the pressure-Ca(2+) relationship. Over a wide range of positive and negative inotropic interventions there were normal developed pressures, though marked elevations in myocardial O(2) consumption (15-54%). Because pressures are normal and intracellular Ca(2+) decreased and myocardial O(2) consumption increased, this suggests that these abnormalities are at least in part compensatory mechanisms to the altered myofilament function. PMID:11709421

  12. Constitutive properties of hypertrophied myocardium: cellular contribution to changes in myocardial stiffness

    NASA Technical Reports Server (NTRS)

    Harris, Todd S.; Baicu, Catalin F.; Conrad, Chester H.; Koide, Masaaki; Buckley, J. Michael; Barnes, Mary; Cooper, George 4th; Zile, Michael R.

    2002-01-01

    Recent studies have suggested that pressure overload hypertrophy (POH) alters the viscoelastic properties of individual cardiocytes when studied in isolation. However, whether these changes in cardiocyte properties contribute causally to changes in the material properties of the cardiac muscle as a whole is unknown. Accordingly, a selective, isolated, acute change in cardiocyte constitutive properties was imposed in an in vitro system capable of measuring the resultant effect on the material properties of the composite cardiac muscle. POH caused an increase in both myocardial elastic stiffness, from 20.5 +/- 1.3 to 28.4 +/- 1.8, and viscous damping, from 15.2 +/- 1.1 to 19.8 +/- 1.5 s (normal vs. POH, P < 0.05), respectively. Recent studies have shown that cardiocyte constitutive properties could be acutely altered by depolymerizing the microtubules with colchicine. Colchicine caused a significant decrease in the viscous damping in POH muscles (19.8 +/- 1.5 s at baseline vs. 14.7 +/- 1.3 s after colchicine, P < 0.05). Therefore, myocardial material properties can be altered by selectively changing the constitutive properties of one element within this muscle tissue, the cardiocyte. Changes in the constitutive properties of the cardiocytes themselves contribute to the abnormalities in myocardial stiffness and viscosity that develop during POH.

  13. Oxygen surrounding the heart during ischemic conservation determines the myocardial injury during reperfusion.

    PubMed

    Feng, Yansheng; Bopassa, Jean Chrisostome

    2015-01-01

    There is discrepancy regarding the duration of reperfusion required using 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) staining to assess myocardial infarction in an isolated, perfused heart model. Several investigators prefer long-term reperfusion (120 minutes) to determine myocardial injury, while others have used a shorter duration (30-40 minutes). We investigated whether oxygen surrounding the myocardium during ischemia plays a critical role in the installation of myocardial infarction during reperfusion. Mice hearts were perfused with a Langendorff apparatus using Krebs Henseleit (KH) buffer oxygenated with 95% O2 plus 5% CO2 at 37°C. Hearts were either immersed in KH or suspended in air during 18 minutes of global ischemia in a normothermic, water-jacketed chamber. Hearts then were reperfused for 40, 60, or 90 minutes. We found that hearts immersed in KH had decreased recovery of function and increased myocardial infarct size, reaching a steady-state level after 40 minutes of reperfusion. In contrast, hearts suspended in air approached steady-state after 90 minutes of reperfusion. Thus, mitochondrial reactive oxygen species (ROS) production was much lower in air-maintained hearts than in KH-immersed hearts. To investigate whether an increase in oxygen surrounding the myocardium during ischemia might cause further damage, we bubbled the KH solution with nitrogen (KH+N2) rather than oxygen (KH+O2). With this alteration, recovery of cardiac function was improved and myocardial infarct size and mitochondrial ROS production were reduced compared with hearts immersed in KH+O2. In conclusion, short-term (40 minutes) reperfusion is sufficient to reach steady-state myocardial infarct size when hearts are immersed in physiologic solution during ischemia; however, a longer duration of reperfusion (90 minutes) is required if hearts are suspended in air. Thus, oxygen surrounding the heart during ischemia determines the extent of myocardium injury during reperfusion

  14. Effects of heart rate on myocardial thallium-201 uptake and clearance

    SciTech Connect

    Nordrehaug, J.E.; Danielsen, R.; Vik-Mo, H. )

    1989-12-01

    The effects of heart rate on the myocardial uptake and clearance of {sup 201}Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of predicted maximal heart rate. The mean of three views initial myocardial {sup 201}Tl uptake was higher at maximal than at both 80% and 60% of predicted maximal heart rate, being 81% (p less than 0.01) and 60% (p less than 0.01) of maximal activity, respectively. The myocardial activity in the delayed images was identical. There was a linear relationship between heart rate and the initial myocardial activity, r = 0.86 (p less than 0.001). The mean (range) {sup 201}Tl clearance was 58% (51-65), 47% (34-56), and 34% (22-49) (all differences p less than 0.01), respectively. Concordance among the three individual views in estimating clearance was best for the highest exercise level. There was a linear relationship between heart rate and clearance, r = 0.80 (p less than 0.001). Clearance was altered by only 1.67 x 10%/heart bpm (0.024 hr/heart beat). Clearance in the liver, spleen and lungs increased at submaximal exercise levels. Thus, a linear relationship between heart rate and clearance is the result of changes in the initial exercise myocardial {sup 201}Tl activity. Submaximal exercise may reduce reproducibility of clearance estimation, and the change of myocardial clearance with heart rate seems less than previously suggested.

  15. Effect of beam hardening on transmural myocardial perfusion quantification in myocardial CT imaging

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    The detection of subendocardial ischemia exhibiting an abnormal transmural perfusion gradient (TPG) may help identify ischemic conditions due to micro-vascular dysfunction. We evaluated the effect of beam hardening (BH) artifacts on TPG quantification using myocardial CT perfusion (CTP). We used a prototype spectral detector CT scanner (Philips Healthcare) to acquire dynamic myocardial CTP scans in a porcine ischemia model with partial occlusion of the left anterior descending (LAD) coronary artery guided by pressure wire-derived fractional flow reserve (FFR) measurements. Conventional 120 kVp and 70 keV projection-based mono-energetic images were reconstructed from the same projection data and used to compute myocardial blood flow (MBF) using the Johnson-Wilson model. Under moderate LAD occlusion (FFR~0.7), we used three 5 mm short axis slices and divided the myocardium into three LAD segments and three remote segments. For each slice and each segment, we characterized TPG as the mean "endo-to-epi" transmural flow ratio (TFR). BH-induced hypoenhancement on the ischemic anterior wall at 120 kVp resulted in significantly lower mean TFR value as compared to the 70 keV TFR value (0.29+/-0.01 vs. 0.55+/-0.01 p<1e-05). No significant difference was measured between 120 kVp and 70 keV mean TFR values on segments moderately affected or unaffected by BH. In the entire ischemic LAD territory, 120 kVp mean endocardial flow was significantly reduced as compared to mean epicardial flow (15.80+/-10.98 vs. 40.85+/-23.44 ml/min/100g; p<1e-04). At 70 keV, BH was effectively minimized resulting in mean endocardial MBF of 40.85+/-15.3407 ml/min/100g vs. 74.09+/-5.07 ml/min/100g (p=0.0054) in the epicardium. We also found that BH artifact in the conventional 120 kVp images resulted in falsely reduced MBF measurements even under non-ischemic conditions.

  16. 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. PMID:26053731

  17. Quantification of Regional Myocardial Oxygenation by Magnetic Resonance Imaging: Validation with Positron Emission Tomography

    PubMed Central

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

    2011-01-01

    Background A comprehensive evaluation of myocardial ischemia requires measures of both oxygen supply and demand. Positron emission tomography (PET) is currently the gold standard for such evaluations, but its use is limited due to its ionizing radiation, limited availability, and high cost. A cardiac magnetic resonance imaging (MRI) method was developed for assessing myocardial oxygenation. The purpose of this study was to evaluate and validate this technique compared to PET during pharmacologic stress in a canine model of coronary artery stenosis. Methods and Results Twenty-one beagles and small mongrel dogs without coronary artery stenosis (controls), or with moderate to severe acute coronary artery stenosis underwent MRI and PET imaging at rest and during dipyridamole vasodilation or dobutamine stress to induce a wide range of changes in cardiac perfusion and oxygenation. MRI first-pass perfusion imaging was performed to quantify myocardial blood flow (MBF) and volume (MBV). The MRI blood-oxygen-level-dependent (BOLD) technique was used to determine the myocardial oxygen extraction fraction (OEF) during pharmacologic hyperemia. Myocardial oxygen consumption (MVO2) was determined by Fick’s law. In the same dogs, 15O-water and 11C-acetate were used to measure MBF and MVO2, respectively, by PET. Regional assessments were performed for both MR and PET. MRI data correlated nicely with PET values for MBF (R2 = 0.79, P < 0.001), MVO2 (R2 = 0.74, P < 0.001), and OEF (R2 = 0.66, P < 0.01). Conclusions Cardiac MRI methods may provide an alternative to radionuclide imaging in settings of myocardial ischemia. Our newly developed quantitative MRI oxygenation imaging technique may be a valuable non-invasive tool to directly evaluate myocardial energetics and efficiency. PMID:19933371

  18. Ventricular Aneurysm Following Myocardial Infarction

    PubMed Central

    Walters, M. B.

    1966-01-01

    Cineradiographic examination appears to be the best method for the study of cardiac pulsations. Fifty consecutive patients, who had sustained transmural myocardial infarction at least six months previously, were studied by this technique. Thirty-six had some abnormality of pulsation and eight had dynamic ventricular aneurysm. Six of the eight had suffered severe infarct. Functional recovery in those with aneurysm was not as complete as in the rest of the group. Two made a poor functional recovery, two a fair recovery, and four a moderately good recovery. Clinically, there were no systemic emboli in the patients with dynamic aneurysms. Five of the 50 had persistent ST-segment elevation and “coving” of the T waves; three of these patients had aneurysms. There was no good correlation between the electrocardiographic site of the infarct and the site of the abnormal pulsation. ImagesFig. 1 PMID:5928534

  19. Myocardial infarction in young adults

    PubMed Central

    Egred, M; Viswanathan, G; Davis, G

    2005-01-01

    Although myocardial infarction (MI) mainly occurs in patients older than 45, young men or women can suffer MI. Fortunately, its incidence is not common in patients younger than 45 years. However, the disease carries a significant morbidity, psychological effects, and financial constraints for the person and the family when it occurs at a young age. The causes of MI among patients aged less than 45 can be divided into four groups: (1) atheromatous coronary artery disease; (2) non-atheromatous coronary artery disease; (2) hyper-coagulable states; (4) MI related to substance misuse. There is a considerable overlap between all the groups. This article reviews the literature and highlights the practical issues involved in the management of young adults with MI. PMID:16344295

  20. [Myocardial pyrophosphate uptake in cardiac amyloidosis: report of case].

    PubMed

    Redondo, Francisca; González, Patricio; Ramírez, Alfredo

    2002-03-01

    We report a previously healthy 73 years old woman, who was hospitalised with increasing dyspnea and signs of congestive heart failure. Echocardiography showed a normal left ventricular cavity with increased echogenicity of its walls and severe pulmonary hypertension. A lung ventilation/perfusion scintigraphy concluded that there was a low probability for pulmonary embolism. Coronary angiography was normal. A restrictive cardiomyopathy due to amyloid deposits was suspected. Myocardial pyrophosphate scintigraphy showed intense pyrophosphate uptake in the left ventricle wall. An abdominal fat tissue biopsy was positive for amyloid deposits. PMID:12043375

  1. Valsartan preconditioning protects against myocardial ischemia-reperfusion injury through TLR4/NF-kappaB signaling pathway.

    PubMed

    Yang, Jian; Jiang, Hong; Yang, Jun; Ding, Jia-Wang; Chen, Li-Hua; Li, Song; Zhang, Xiao-Dong

    2009-10-01

    Toll-like receptor 4 (TLR4) activation has been implicated in the pathogenesis of myocardial ischemia/reperfusion (I/R) injury. The activated TLR4 is capable of activating a variety of proinflammatory mediators, such as tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6). Valsartan as a kind of Angiotensin II type 1 receptor blockers is gradually used for the treatment of ischemic heart disease depending on its anti-inflammation function. Therefore, we hypothesized that valsartan protects against myocardial I/R injury by suppressing TLR4 activation. We constructed the rat model of myocardial I/R injury. The rats were pretreated with valsartan for 2 weeks, and then subjected to 30 min ischemia and 2 h reperfusion. TLR4 and Nuclear factor kappa-B (NF-kappaB) levels were detected by quantitative real-time PCR and western blot. In order to evaluate myocardial damage, the myocardial infarct size, histopathologic changes, and the release of myocardial enzymes, proinflammation cytokines and Angiotensin II were analyzed by triphenyl tetrazolium chloride (TTC) staining, light microscopy, and enzyme-linked immunosorbent assay (ELISA), respectively. Valsartan preconditioning inhibited TLR4 and NF-kappaB expressions concomitant with an improvement in myocardial injury, such as smaller infarct size, fewer release of myocardial enzymes, and proinflammation mediators. These findings suggest that valsartan plays a pivotal role in the protective effects on myocardial I/R injury. This protection mechanism is possibly due to its anti-inflammation function via TLR4/NF-kappaB signaling pathway. PMID:19370315

  2. Lay Public's Knowledge and Decisions in Response to Symptoms of Acute Myocardial Infarction

    ERIC Educational Resources Information Center

    Cytryn, Kayla N.; Yoskowitz, Nicole A.; Cimino, James J.; Patel, Vimla L.

    2009-01-01

    Despite public health initiatives targeting rapid action in response to symptoms of myocardial infarction (MI), people continue to delay in going to a hospital when experiencing these symptoms due to lack of recognition as cardiac-related. The objective of this research was to characterize lay individuals' knowledge of symptoms of acute myocardial…

  3. A novel method of clot extraction using a FilterWire EX in acute myocardial infarction.

    PubMed

    Aqel, Raed A; Gupta, Ritesh; Zoghbi, Gilbert J

    2007-04-01

    We describe a novel approach for the use of a FilterWire EX distal protection device as a snaring device for clot extraction in a patient who sustained acute ST-elevation myocardial infarction due to occlusion of the right coronary artery. PMID:17404414

  4. [Acute myocardial infarction in the postoperative period following pneumonectomy].

    PubMed

    López Alvarez, S; Bonome González, C; Izquierdo Villarroya, B; Barbeito Vilariño, M J; Etxainz Alvarez, A; Alvarez Refojo, F

    2002-11-01

    A 72-year-old man, smoker, with insuline-dependent diabetes and dislipemia underwent left pneumonectomy. Several episodes of intraoperative hemodynamic instability associated with electrocardiographic ST segment alterations were attributed to surgical manipulation; ischemia was not suspected. Cardiorespiratory failure, related to extensive anterior infarction, developed a few minutes after admission to the postoperative intensive care unit (PICU). Cardiopulmonary resuscitation and mechanical ventilation were required. The patient responded to treatment with beta blockers, platelet antiaggregants and statins. Tube was removed a few hours later and the patient was discharged from the PICU on the fifth day. Pneumonectomy has a high rate of morbidity and mortality, with complications mainly arising in the lung and heart. Risk from anesthesia is considered to be great in this procedure, and for that reason it is essential to identify intraoperative myocardial ischemia so that it can be treated aggressively. In patients at high cardiovascular risk who undergo lung resection, intraoperative episodes of myocardial ischemia are associated with a high incidence of postoperative miocardial infarction. Therefore, careful postoperative monitoring is needed and measures should be taken to prevent angina. Early extubation should be avoided. PMID:12516493

  5. Myocyte repolarization modulates myocardial function in aging dogs.

    PubMed

    Sorrentino, Andrea; Signore, Sergio; Qanud, Khaled; Borghetti, Giulia; Meo, Marianna; Cannata, Antonio; Zhou, Yu; Wybieralska, Ewa; Luciani, Marco; Kannappan, Ramaswamy; Zhang, Eric; Matsuda, Alex; Webster, Andrew; Cimini, Maria; Kertowidjojo, Elizabeth; D'Alessandro, David A; Wunimenghe, Oriyanhan; Michler, Robert E; Royer, Christopher; Goichberg, Polina; Leri, Annarosa; Barrett, Edward G; Anversa, Piero; Hintze, Thomas H; Rota, Marcello

    2016-04-01

    Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions. PMID:26801307

  6. Effect of prophylactic digitalization on the development of myocardial hypertrophy.

    PubMed

    Cutilletta, A F; Rudnik, M; Arcilla, R A; Straube, R

    1977-11-01

    The effect of prophylactic digitalization on the development of left ventricular hypertrophy was studied in adult rats. Digitoxin, 0.1 mg/100 g body wt or solvent was given daily for 1 wk prior to either aortic constriction or sham operation and was continued until the animals were killed, either 1 or 4 wk after surgery. A hemodynamic study was done in those animals killed 1 wk after surgery; hearts of all animals were examined for evidence of myocardial hypertrophy. Constriction of the ascending aorta had no significant effect on cardiac output but did reduce peak flow velocity and flow acceleration. An increase in left ventricular mass, RNA, and hydroxyproline was found in the animals with aortic constriction. Digitoxin treatment did not alter peak flow velocity or flow acceleration, but did significantly increase isovolumic (dP/dt)P-1. Digitoxin had no effect on body weight, heart weight, RNA, or hydroxyproline in either the sham-operated animals or in the animals with aortic constriction. Therefore, despite plasma digitoxin levels sufficient to affect myocardial contractility, left ventricular hypertrophy still developed after aortic constriction. PMID:144440

  7. [Thrombolytic treatment of acute myocardial infarct. 1].

    PubMed

    Soares-Costa, J T; Soares-Costa, T J; Gabriel, H M

    1998-05-01

    I-Rationale of thrombolytic therapy in acute myocardial infarction (AMI). II-Thrombolytic drugs. III-Effects of thrombolytic therapy on mortality. IV-Studies comparing the effects of various thrombolytic agents on mortality. PMID:9951051

  8. Imaging of myocardial fatty acid oxidation.

    PubMed

    Mather, Kieren J; DeGrado, Timothy R

    2016-10-01

    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 non-invasive 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. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26923433

  9. Repetitive Myocardial Infarctions Secondary to Delirium Tremens

    PubMed Central

    Schwartzberg, David; Shiroff, Adam

    2014-01-01

    Delirium tremens develops in a minority of patients undergoing acute alcohol withdrawal; however, that minority is vulnerable to significant morbidity and mortality. Historically, benzodiazepines are given intravenously to control withdrawal symptoms, although occasionally a more substantial medication is needed to prevent the devastating effects of delirium tremens, that is, propofol. We report a trauma patient who required propofol sedation for delirium tremens that was refractory to benzodiazepine treatment. Extubed prematurely, he suffered a non-ST segment myocardial infarction followed by an ST segment myocardial infarction requiring multiple interventions by cardiology. We hypothesize that his myocardial ischemia was secondary to an increased myocardial oxygen demand that occurred during his stress-induced catecholamine surge during the time he was undertreated for delirium tremens. This advocates for the use of propofol for refractory benzodiazepine treatment of delirium tremens and adds to the literature on the instability patients experience during withdrawal. PMID:25197580

  10. Repetitive myocardial infarctions secondary to delirium tremens.

    PubMed

    Schwartzberg, David; Shiroff, Adam

    2014-01-01

    Delirium tremens develops in a minority of patients undergoing acute alcohol withdrawal; however, that minority is vulnerable to significant morbidity and mortality. Historically, benzodiazepines are given intravenously to control withdrawal symptoms, although occasionally a more substantial medication is needed to prevent the devastating effects of delirium tremens, that is, propofol. We report a trauma patient who required propofol sedation for delirium tremens that was refractory to benzodiazepine treatment. Extubed prematurely, he suffered a non-ST segment myocardial infarction followed by an ST segment myocardial infarction requiring multiple interventions by cardiology. We hypothesize that his myocardial ischemia was secondary to an increased myocardial oxygen demand that occurred during his stress-induced catecholamine surge during the time he was undertreated for delirium tremens. This advocates for the use of propofol for refractory benzodiazepine treatment of delirium tremens and adds to the literature on the instability patients experience during withdrawal. PMID:25197580

  11. Myocardial hypoperfusion on conventional contrast computed tomography.

    PubMed

    Ching, Shing; Chung, Tak Shun

    2015-10-01

    Non–electrocardiogram (ECG)–gated contrast computed tomography (CT) is commonly performed to exclude aortic dissection in chest pain patients. Besides evaluating the aorta for dissection flap, attention should be paid to the myocardium for areas of hypoenhancement that may suggest ischemia. Current models of multidetector CT enable assessment of myocardial perfusion with minimal motion artifact even without ECG gating. Transmural hypoenhancement with preserved wall thickness in a coronary distribution is highly specific for acute myocardial infarction. We report 2 cases of acute chest pain with initial nondiagnostic studies that underwent CT aortogram to exclude dissection. Instead, the CT showed myocardial hypoenhancement in left anterior descending artery territory. Myocardial hypoenhancement occurred before ST-segment elevation on ECG, suggesting that recognition of this important finding may lead to earlier revascularization decisions. PMID:26321167

  12. [Further understanding on myocardial damage in the early stage post severe burn and its clinical significance].

    PubMed

    Huang, Y S

    2016-05-20

    A series of studies demonstrated that myocardial damage and cardiac dysfunction occurs immediately following severe burn, even before significant reduction in blood volume due to increased capillary permeability. Such myocardial damage and cardiac dysfunction leads to cardiac deficiency, and it is a precipitating factor for burn shock and ischemic/hypoxic injury. In recent years, many experimental and clinical studies elucidated the pathogenesis and confirmed the clinical importance of prevention and treatment of"shock heart"in the early stage post severe burn. PMID:27188482

  13. Applying the results of large clinical trials in the management of acute myocardial infarction.

    PubMed Central

    Sweeney, J P; Schwartz, G G

    1996-01-01

    Mortality from acute myocardial infarction has declined in recent years, largely due to the widespread application of new pharmacologic and mechanical interventions that have been tested in large, prospective, randomized clinical trials. For practicing generalists, we review the key data from such trials that have shaped the current management of patients with acute myocardial infarction. We discuss the roles of thrombolytic therapy, coronary angioplasty, nitrates, beta- and calcium channel blockers, angiotensin-converting-enzyme inhibitors, magnesium, and antiarrhythmic and antithrombotic agents. In addition, we highlight critical unanswered questions in the management of this disorder. PMID:8775936

  14. Rheolytic therapy combined with intragraft abciximab for treatment in acute myocardial infarction.

    PubMed

    Vallakati, Ajay; Mastrine, Lou; Ayzenberg, Sergey

    2013-02-01

    After coronary artery bypass graft (CABG) surgery, patients can present with challenging lesions in the setting of acute coronary syndrome, particularly with high clot burden. Techniques including thrombectomy and local delivery of glycoprotein IIb/IIIa inhibitors have been utilized for these saphenous venous graft lesions. We report a case involving a post-CABG patient presenting with an acute ST-segment elevation myocardial infarction due to great clot burden in his bypass graft and successful restoration of thrombolysis in myocardial infarction (TIMI) grade 3 flow after rheolytic thrombectomy followed by localized IIb/IIIa administration. PMID:23388236

  15. [The latest treatments for myocardial infarction].

    PubMed

    Leclercq, Florence

    2015-03-01

    Ischemic heart disease and its main complication, myocardial infarction, remain the leading cause of death after the age of forty in developed countries. Myocardial infarction is the consequence of a sudden obstruction of a coronary artery by a thrombus. Thrombolysis and coronary angioplasty are the two emergency coronary artery revascularisation techniques. A medication-based treatment and adapted lifestyle aim to prevent repeat infarction. PMID:26040139

  16. Myocardial perfusion imaging with 201Tl.

    PubMed

    Pagnanelli, Robert A; Basso, Danny A

    2010-03-01

    The object of this review is to provide information about (201)Tl-thallous chloride in radionuclide myocardial perfusion imaging. This technique has experienced a recent resurgence because of the shortage of (99m)Tc. After reading this article, the technologist will be able to describe the properties and uptake mechanism of (201)Tl, the procedure for myocardial perfusion imaging with this agent, and the advantages and disadvantages of thallium, compared with the technetium agents. PMID:20159930

  17. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-11-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  18. Investigation of ischemia modified albumin, oxidant and antioxidant markers in acute myocardial infarction

    PubMed Central

    Hazini, Ahmet; Işıldak, İbrahim; Alpdağtaş, Saadet; Önül, Abdullah; Şenel, Ünal; Kocaman, Tuba; Dur, Ali; Iraz, Mustafa; Uyarel, Hüseyin

    2015-01-01

    Introduction Acute myocardial infarction (AMI) is still one of the most common causes of death worldwide. In recent years, for diagnosis of myocardial ischemia, a new parameter, called ischemia modified albumin (IMA), which is thought to be more advantageous than common methods, has been researched. Aim In this study, systematic analysis of parameters considered to be related to myocardial ischemia has been performed, comparing between control and myocardial ischemia groups. Material and methods We selected 40 patients with AMI and 25 healthy controls for this study. Ischemia modified albumin levels, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) antioxidant enzyme activities and non-enzymatic antioxidants such as retinol, α-tocopherol, β-carotene and ascorbic acid levels were investigated in both groups. Glutathione (GSH) and malondialdehyde (MDA) levels, which are indicators of oxidative stress, were compared between patient and control groups. Results Ischemia modified albumin levels were found significantly higher in the AMI diagnosed group when compared with controls. The MDA level was elevated in the patient group, whereas the GSH level was decreased. SOD, GPx and CAT enzyme levels were decreased in the patient group, where it could be presumed that oxidative stress causes the cardiovascular diseases. Conclusions Due to the increased oxidative stress, non-enzymatic and enzymatic antioxidant capacity was affected. Systematic investigation of parameters related to myocardial infarction has been performed, and it is believed that such parameters can contribute to protection and early diagnosis of AMI and understanding the mechanism of development of the disease. PMID:26677379

  19. Myocardial perfusion of infarcted and normal myocardium in propofol-anesthetized minipigs using (82)Rubidium PET.

    PubMed

    Rasmussen, Thomas; Follin, Bjarke; Kastrup, Jens; Christensen, Thomas Emil; Hammelev, Karsten Pharao; Kjær, Andreas; Hasbak, Philip

    2016-06-01

    Cardiac Rubidium-82 ((82)Rb) positron-emission-tomography (PET) is a good method for quantification of myocardial blood flow in man. Quantification of myocardial blood flow in animals to evaluate new treatment strategies or to understand underlying disease is also of great interest but raises some challenges. Animals, which have been anesthetized during PET acquisition, might react differently to used stress medications, and therefore difficulties might exist while evaluating the resulting PET images using standard software packages from commercial vendors optimized for human hearts. Furthermore propofol, used for anesthesia, can influence myocardial perfusion and coronary flow reserve due to its vasorelaxant effect, and interactions might exist between propofol and used stress agents, potentially affecting the result of the examination. We present cardiac (82)Rb-PET studies performed in propofol-anesthetized minipigs with normal and infarcted myocardium stressed with both adenosine and dipyridamole. Despite the mentioned challenges, we were able to trace the small minipig heart with software designed for human cardiac PET and to achieve blood flow measurements comparable with results in humans with both adenosine and dipyridamole. We found dipyridamole to be a superior stress agent for this experimental setup. Finally, we were able to clearly identify the myocardial perfusion defect after an induced myocardial infarction. PMID:26931633

  20. Relationship between myocardial bridging and coronary arteriosclerosis.

    PubMed

    Sun, Jian Ling; Huang, Wei Min; Guo, Ji Hong; Li, Xiao Ying; Ma, Xian Lin; Wang, Chong Yu

    2013-04-01

    The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis. PMID:23076634

  1. Computational modeling of acute myocardial infarction.

    PubMed

    Sáez, P; Kuhl, E

    2016-01-01

    Myocardial infarction, commonly known as heart attack, is caused by reduced blood supply and damages the heart muscle because of a lack of oxygen. Myocardial infarction initiates a cascade of biochemical and mechanical events. In the early stages, cardiomyocytes death, wall thinning, collagen degradation, and ventricular dilation are the immediate consequences of myocardial infarction. In the later stages, collagenous scar formation in the infarcted zone and hypertrophy of the non-infarcted zone are auto-regulatory mechanisms to partly correct for these events. Here we propose a computational model for the short-term adaptation after myocardial infarction using the continuum theory of multiplicative growth. Our model captures the effects of cell death initiating wall thinning, and collagen degradation initiating ventricular dilation. Our simulations agree well with clinical observations in early myocardial infarction. They represent a first step toward simulating the progression of myocardial infarction with the ultimate goal to predict the propensity toward heart failure as a function of infarct intensity, location, and size. PMID:26583449

  2. Myocardial Sleeve Tissues in Surgical Lung Specimens.

    PubMed

    Yoshida, Akihiko; Kamata, Tsugumasa; Iwasa, Takeshi; Watanabe, Shun-ichi; Tsuta, Koji

    2015-10-01

    Left atrial myocardial extensions over the pulmonary veins (PVs), known as myocardial sleeves, are present in the physiological anatomy of most individuals. Although this structure has recently received clinical attention as a major origin of paroxysmal atrial fibrillation (AF), it has not been documented in surgical specimens. Here, we examine incidentally identified myocardial sleeve tissue in routinely processed lung resection specimens to determine its incidence and diagnostic implications. Among 694 lung resection specimens with evaluable PV margins, myocardial sleeve tissue was identified in 26 cases (3.7%). The tissue was located within the adventitia of the PVs, mostly in margin preparations, and existed outside the pericardium in the majority of cases. Carcinoma infiltration of the sleeves was evident in 6 cases. No heart injuries were observed, and no tumors invaded the heart. Preoperative electrocardiography showed sinus rhythm in all cases, whereas postoperative monitoring revealed sinus rhythm in all patients except one who showed AF and flutter. Myocardial sleeve tissue is an underrecognized incidental finding in lung resection specimens, and it is not indicative of heart injury. Cancer infiltration into this tissue indicates neither heart invasion nor, by itself, invasion into the pericardium. Although surgical transection of the myocardial sleeve did not evoke immediate arrhythmia in most cases, the overall influence of this procedure on the postsurgical risk of AF remains to be determined in further studies involving extensive rhythm assessment. PMID:26099012

  3. 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

  4. Age-related changes of myocardial ATP supply and demand mechanisms

    PubMed Central

    Yaniv, Yael; Juhaszova, Magdalena; Sollott, Steven J.

    2013-01-01

    In advanced age, the resting myocardial oxygen consumption (M V̇O2) and cardiac work (CW) in the rat remain intact. However, M V̇O2, CW and cardiac efficiency achieved at high demand are decreased with age, compared to maximal values in the young. Whether this deterioration is due to decrease in myocardial ATP demand, ATP supply, or the control mechanisms that match them, remains controversial. Here we discuss evolving perspectives of age-related changes of myocardial ATP supply and demand mechanisms, and critique experimental models used to investigate aging. Specifically, we evaluate experimental data collected at the level of isolated mitochondria, tissue, or organism, and discuss how mitochondrial energetic mechanisms change in advanced age, both at basal and high energy demand levels. PMID:23845538

  5. Intravenous methylphenidate: an unusual way to provoke ST-elevation myocardial infarction.

    PubMed

    Hay, Emile; Shklovski, Vitaly; Blaer, Yossef; Shlakhover, Vladimir; Katz, Amos

    2015-02-01

    Acute ST-T elevation is a sign of myocardial ischemia or infarction usually due to coronary artery atherosclerosis or coronary spasm. Coronary spasm may be spontaneous or can occur as a result of a drug that causes arterial spam. Ritalin, Novartis Pharmaceut. Corporation, USA (methylphenidate hydrochloride), a dopamine reuptake inhibitor,is an oral drug used to treat attention-deficit/hyperactivity disorder and narcolepsy. Sudden deaths, stroke, and myocardial infarction have been reported in adults taking stimulant drugs at usual dose for attention-deficit/hyperactivity disorder [1]. This drug is not supplied as solution for injection [2]. We report here, what we believe to be, the first case report of a 40-year-old male patient who was admitted for acute chest pain and ST-elevation myocardial infarction after intravenous self-injection of Ritalin. His coronary angiogram demonstrated nonobstructive coronary disease. PMID:25200508

  6. Incomplete myocardial rupture after coronary embolism of an isolated single coronary artery.

    PubMed

    Pindado, Javier; Marcos-Alberca, Pedro; Rey, Manuel; Rábago, Rosa; de Diego, Carlos; Ibáñez, Borja; Córdoba, Manuel; Farré, Jerónimo

    2005-01-01

    An 82-year-old female was admitted to the coronary care unit with an anterior wall myocardial infarction and cardiogenic shock. She was in chronic atrial fibrillation without oral anticoagulation. Coronary angiography showed occlusion of the left main coronary artery which originated together with a normal right coronary artery from the right sinus of Valsalva. The advanced age, the presence of chronic atrial fibrillation not anticoagulated and the normal appearance of the remaining coronary arteries suggested a thromboembolic origin. Transthoracic echocardiography showed an abrupt interruption of the myocardial wall, in the apical portion of the interventricular septum, not communicating with the pericardial sac or right ventricular cavity suggesting the presence of an incomplete contained rupture of the myocardial wall at this location. She died in cardiogenic shock due to the extensive left ventricular damage. PMID:15664557

  7. Assessment of myocardial perfusion in patients after the arterial switch operation

    SciTech Connect

    Vogel, M.; Smallhorn, J.F.; Gilday, D.; Benson, L.N.; Ash, J.; Williams, W.G.; Freedom, R.M. )

    1991-02-01

    In 21 patients who had undergone the arterial switch operation, the adequacy of myocardial perfusion was evaluated by thallium-201 computed scintigraphy 2.6 +/- 2 (0.3-7) yr after surgery. Fourteen patients had undergone the arterial switch procedure after pulmonary artery banding and seven as a primary repair. Isoproterenol stress increased the heart rate by at least 55%. Tomographic imaging was performed at peak stress and 3 hr later in the reperfusion phase. Nine patients had perfusion defects. The perfusion defects were located at the left ventricular apex in four (with extension to the inferolateral wall in one), left ventricular anterolateral wall in two, ventricular septum in one, left ventricular inferior wall in one, and right ventricular free wall in one. Some of these defects could be due to myocardial damage at the time of surgery, but these results also raise concern about long-term adequacy of myocardial perfusion following the arterial switch procedure.

  8. Cardiac Motion Analysis Using High-Speed Video Images in a Rat Model for Myocardial Infarction

    NASA Astrophysics Data System (ADS)

    Ishii, Idaku; Okuda, Toshikazu; Nie, Yuman; Takaki, Takeshi; Orito, Kensuke; Tanaka, Akane; Matsuda, Hiroshi

    In this study, we performed a cardiac motion analysis by using 1000-frames per second (fps) stereo images to capture the three-dimensional motion of small color markers in a rat heart. This method of recording cardiac motion could quantify the rate of change in the myocardial area, which indicated localized myocardial activity of rhythmic expansion and contraction. We analyzed the three-dimensional motion distributions in a rat model for myocardial infarction, in which the heart rate was 4 times/s or more. In the analysis, we spatiotemporally quantified the characteristic cardiac motion in ischemic heart diseases and found that infarction due to ischemia in the rat heart was spread around the left ventricle.

  9. Traumatic myocardial infarction in a young athletic patient after a football game.

    PubMed

    Fanari, Zaher; Hadid, Mazen; Hammami, Sumaya; Qureshi, Wasif A

    2014-07-01

    Myocardial injury from blunt chest trauma can result from either direct contusion or coronary artery injury due to acute coronary syndrome or coronary dissection. Although rare, blunt chest trauma is one of the non-atherosclerotic mechanisms leading to acute myocardial infarction (MI) in patients younger than 45 years. We are reporting a case of a 36-year-old athletic man who presented with infero-lateral ST elevation MI secondary to a thrombotic occlusion of right coronary artery after a blunt chest trauma. Early recognition of myocardial infarction in patients presenting with chest trauma and differentiating it from other causes of chest pain in this setting is critical in guiding the diagnosis and management of this rare, but potentially fatal complication. PMID:25244725

  10. Acute Myocardial Infarction following a possible direct intravenous bite of Russell’s viper (Daboia russelli)

    PubMed Central

    2012-01-01

    Background Russell’s viper (Daboia russelli) bites lead to high morbidity and mortality in South Asia. Although variety of clinical manifestations is reported in viper bite victims, myocardial ischemic events are rare. Case presentation We report a unique case of inferior wall ST elevation myocardial infarction due to a Russell’s viper bite over a vein with possible direct intravenous envenoming, in a young male with no past history or family history suggestive of ischemic cardiac disease, from Sri Lanka. In addition, the possible mechanisms of myocardial ischemia in snake bite victims are also briefly discussed. Conclusion Importance of the awareness of physicians on the rare, yet fatal manifestations of snake envenoming is highlighted. PMID:22971617

  11. Myocardial Microcirculation and Mitochondrial Energetics in the Isolated Rat Heart.

    PubMed

    Ashruf, J F; Ince, C

    2016-01-01

    Normal functioning of myocardium requires adequate oxygenation, which in turn is dependent on an adequate microcirculation. NADH-fluorimetry enables a direct evaluation of the adequacy of tissue oxygenation while the measurement of quenching of Pd-porphyrine (PpIX) phosphorescence enables quantitative measurement of microvascular pO2. Combination of these two techniques provides information about the relation between microvascular oxygen content and parenchymal oxygen availability in Langendorff hearts. In normal myocardium there is heterogeneity at the microcirculatory level resulting in the existence of microcirculatory weak units, originating at the capillary level, which reoxygenate the slowest upon reoxygenation after an episode of ischemia. Sepsis and myocardial hypertrophia alter the pattern of oxygen transport whereby the microcirculation is disturbed at the arteriolar/arterial level. NADH fluorimetry also reveals a disturbance of mitochondrial oxygen availability in sepsis. Furthermore it is shown that these techniques can also be applied to various organs and tissues in vivo. PMID:26782208

  12. Reduced coronary flow and resistance reserve in primary scleroderma myocardial disease

    SciTech Connect

    Nitenberg, A.; Foult, J.M.; Kahan, A.; Perennec, J.; Devaux, J.Y.; Menkes, C.J.; Amor, B.

    1986-08-01

    The maximum coronary vasodilator capacity after intravenous dipyridamole (0.14 mg X kg-1 X min-1 X 4 minutes) was studied in seven patients with primary scleroderma myocardial disease and compared to that of seven control subjects. Hemodynamic data and left ventricular angiographic data were not different in the two groups. The coronary flow reserve was evaluated by the dipyridamole/basal coronary sinus blood flow ratio (D/B CSBF) and the coronary resistance reserve by the dipyridamole/basal coronary resistance ratio (D/B CR). Coronary reserve was greatly impaired in the group with primary scleroderma myocardial disease: D/B CSBF was lower than in the control group (2.54 +/- 1.37 vs 4.01 +/- 0.56, respectively; p less than 0.05) and D/B CR was higher than in the control group (0.47 +/- 0.25 vs 0.23 +/- 0.04, respectively; p less than 0.05). Such a decreased coronary flow and resistance reserve in patients with primary scleroderma myocardial disease was not explained by an alteration of left ventricular function. It may be an important contributing factor in the pathogenesis of primary scleroderma myocardial disease.

  13. [Prevention of myocardial ischemia. Study following aortocoronary bypass operation with the calcium antagonist diltiazem].

    PubMed

    Lischke, V; Probst, S; Behne, M; Dieterich, H A

    1995-02-01

    The incidence of postoperative myocardial infarction (MI) is proportional to the incidence of myocardial ischaemic episodes. Therefore, the prevention of such episodes is of great clinical importance. METHODS. In 90 patients undergoing coronary artery bypass grafting (CABG), perioperative i.v. treatment with either nitroglycerin (NTG), diltiazem (DIL), or the combination of DIL/NTG was used until arrival in the intensive care unit. Myocardial ischaemic episodes were monitored with an automatic ECG-ST-trend analyser (Marquette 7010). RESULTS. Significantly less ischaemic episodes were seen in the DIL group (6.7%) compared to the NTG group (13.2%) or DIL/NTG group (13.5%). Furthermore, significantly less ischaemic episodes were associated with relevant haemodynamic alterations in the DIL group (58.1%) compared to the NTG (89.1%) or DIL/NTG group (80.0%). Increases in heart rate were markedly reduced in the DIL group. DISCUSSION. DIL results in marked haemodynamic stabilisation during CABG, especially in the period immediately after extra-corporeal circulation. This might serve as an explanation for the significant reduction in ischaemic episodes in the DIL group compared to the other two groups. Therefore, perioperative prevention of myocardial ischaemia with the calcium antagonist DIL seems to be favourable in patients during CABG. PMID:7702188

  14. Apelin-13 protects against myocardial infarction-induced myocardial fibrosis.

    PubMed

    Zhang, Xuemin; Hu, Wenyu; Feng, Feng; Xu, Jian; Wu, Fang

    2016-06-01

    Myocardial infarction is a serious health threat. Apelin is an endogenous ligand of angiotensin II receptor-like 1 (APJ) and the apelin/APJ system is associated with various types of heart disease. However, whether apelin protects against myocardial infarction‑induced myocardial fibrosis remains unclear. The present study aimed to investigate the function of apelin‑13 during myocardial infarction‑induced myocardial fibrosis, and to determine the mechanism underlying the effects of apelin‑13. Apelin‑13 was demonstrated to improve left ventricular function and results of hematoxylin and eosin staining, Masson's trichrome staining and western blotting showed that apelin‑13 attenuated myocardial fibrosis. Further mechanistic investigation was performed by enzyme‑linked immunosorbent assay, western blotting and electrophoretic mobility shift assay. The results demonstrated that apelin‑13 inhibited the activation of nuclear factor (NF)‑κB signaling in vitro and in vivo. To the best of our knowledge, the present study was the first to demonstrate that apelin‑13 may attenuate myocardial infarction‑induced myocardial fibrosis, and that this protective function may be mediated by inhibition of NF‑κB signaling. The present study suggests a theoretical basis for the effects of apelin‑13 and provides insight into the potential clinical application of apelin-13. PMID:27109054

  15. Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction

    SciTech Connect

    Berman, D.S.; Kiat, H.; Maddahi, J.; Shah, P.K.

    1989-07-18

    Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.

  16. Incidence of acute myocardial infarction in patients with exercise-induced silent myocardial ischemia

    SciTech Connect

    Assey, M.E.; Walters, G.L.; Hendrix, G.H.; Carabello, B.A.; Usher, B.W.; Spann, J.F. Jr.

    1987-03-01

    Fifty-five patients with angiographically proved coronary artery disease (CAD) underwent Bruce protocol exercise stress testing with thallium-201 imaging. Twenty-seven patients (group I) showed myocardial hypoperfusion without angina pectoris during stress, which normalized at rest, and 28 patients (group II) had a similar pattern of reversible myocardial hypoperfusion but also had angina during stress. Patients were followed for at least 30 months. Six patients in group I had an acute myocardial infarction (AMI), 3 of whom died, and only 1 patient in group II had an AMI (p = 0.05), and did not die. Silent myocardial ischemia uncovered during exercise stress thallium testing may predispose to subsequent AMI. The presence of silent myocardial ischemia identified in this manner is of prognostic value, independent of angiographic variables such as extent of CAD and left ventricular ejection fraction.

  17. Prompt recognition and percutaneous coronary intervention leads to favorable myocardial recovery after ST-segment elevation myocardial infarction secondary to acute promyelocytic leukemia: pediatric case report.

    PubMed

    Thomas, Tamara O; Ramachandran, Preeti; Jefferies, John L; Beekman, Robert H; Hor, Kan; Lorts, Angela

    2013-01-01

    Acute myocardial infarction (AMI) is extremely rare in children, and unlike the adult disease, the etiology of the infarction is rarely due to atherosclerotic coronary disease. This unique reported case involved a 15-year-old boy with severe chest pain who presented with an ST-segment-elevation myocardial infarction secondary to in situ thrombus formation in the left anterior descending (LAD) coronary artery. The initial electrocardiogram (ECG) had a Q-wave pattern in V6 and ST depression in the inferior leads with ST-segment elevation in reciprocal leads. The cardiac enzymes and routine labs showed evidence of myocardial damage. The boy was urgently taken to the cardiac catheterization laboratory for percutaneous coronary intervention, where complete occlusion of the LAD was found and successfully stented. Eventually, a peripheral blood smear showed pancytopenia with 38 % hypergranular blast-like cells consistent with acute myeloid leukemia (AML), and chemotherapy with all-transretinoic acid was implemented. This first pediatric case report of an AML-associated AMI emphasizes the benefit resulting from expedient reperfusion of the ischemic myocardium by quick reestablishment of coronary perfusion. It also emphasizes the limitations of existing noninvasive technologies in detecting myocardial viability. PMID:23263162

  18. [Occupational stress and myocardial infarction].

    PubMed

    Consoli, Silla M

    2015-01-01

    Besides the best-known role of depressed mood, occupational stress deserves to be taken as a coronary risk factor. There are two basic models to define occupational stress: Karasek's model (high job psychological demands associated with low decision latitude, or even low social support at work) and Siegrist's model (imbalance between efforts and rewards received). The combination of the two models better reflects the coronary risk than each model alone. Occupational stress appears both as a risk factor and a prognostic factor after the occurrence of myocardial infarction. The relevance of the models is best in men or in younger age subjects. In women, role conflicts (occupational/domestic), the existence of excessive "intrinsic" efforts (job over investment) and association with marital stress provide more specific information. Burnout, particularly among health professionals, and bullying at work are also linked to cardiovascular risk. Occupational stress is a collective indicator of health at work, valuable to the employer. At an individual level, it can lead to therapeutic preventive approaches. PMID:26150284

  19. Molecular genetics of myocardial infarction

    PubMed Central

    Ichihara, Sahoko; Nishida, Tamotsu

    2008-01-01

    Abstract Myocardial infarction (MI) is an important clinical problem because of its large contribution to mortality. The main causal and treatable risk factors for MI include hypertension, hypercholesterolemia or dyslipidemia, diabetes mellitus, and smoking. In addition to these risk factors, recent studies have shown the importance of genetic factors and interactions between multiple genes and environmental factors. Disease prevention is an important strategy for reducing the overall burden of MI, with the identification of markers for disease risk being key both for risk prediction and for potential intervention to lower the chance of future events. Although genetic linkage analyses of families and sib-pairs as well as candidate gene and genome-wide association studies have implicated several loci and candidate genes in predisposition to coronary heart disease (CHD) or MI, the genes that contribute to genetic susceptibility to these conditions remain to be identified definitively. In this review, we summarize both candidate loci for CHD or MI identified by linkage analyses and candidate genes examined by association studies. We also review in more detail studies that have revealed the association with MI or CHD of polymorphisms in MTHFR, LPL, and APOE by the candidate gene approach and those in LTA and at chromosomal region 9p21.3 by genome-wide scans. Such studies may provide insight into the function of implicated genes as well as into the role of genetic factors in the development of CHD and MI. PMID:18704761

  20. Echocardiographic assessment of myocardial ischemia

    PubMed Central

    Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-01-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  1. Echocardiographic assessment of myocardial ischemia.

    PubMed

    Leischik, Roman; Dworrak, Birgit; Sanchis-Gomar, Fabian; Lucia, Alejandro; Buck, Thomas; Erbel, Raimund

    2016-07-01

    Over the last 60 years, echocardiography has emerged as a dominant and indispensable technique for the detection and assessment of coronary heart disease (CHD). In this review, we will describe and discuss this powerful tool of cardiology, especially in the hands of an experienced user, with a focus on myocardial ischemia. Technical development is still on-going, and various new ultrasound techniques have been established in the field of echocardiography in the last several years, including tissue Doppler imaging (TDI), contrast echocardiography, three-dimensional echocardiography (3DE), and speckle tracking echocardiography (i.e., strain/strain rate-echocardiography). High-end equipment with harmonic imaging, high frame rates and the opportunity to adjust mechanical indices has improved imaging quality. Like all new techniques, these techniques must first be subjected to comprehensive scientific assessment, and appropriate training that accounts for physical and physiological limits should be provided. These limits will constantly be redefined as echocardiographic techniques continue to change, which will present new challenges for the further development of ultrasound technology. PMID:27500160

  2. The Electrophysiologic Cardiac Ventricular Substrate in Patients after Myocardial Infarction: Noninvasive Characterization with ECG Imaging (ECGI)

    PubMed Central

    Cuculich, Phillip S.; Zhang, Junjie; Wang, Yong; Desouza, Kavit A.; Vijayakumar, Ramya; Woodard, Pamela K.; Rudy, Yoram

    2012-01-01

    Objectives To noninvasively image the electophysiologic substrate of human ventricles after myocardial infarction and define its characteristics. Background Ventricular infarct border zone is characterized by abnormal cellular electrophsyiology and altered structural architecture and is a key contributor to arrhythmogenesis. The ability to noninvasively image its electrical characteristics could contribute to understanding of mechanisms and to risk-stratification for ventricular arrhythmia. Methods Electrocardiographic Imaging (ECGI), a noninvasive functional electrophysiologic imaging modality, was performed during sinus rhythm in 24 subjects with infarct-related myocardial scar. The abnormal electrophysiologic substrate on the epicardial aspect of the scar was identified and its location, size, and morphology were compared to the anatomic scar imaged by other noninvasive modalities. Results ECGI constructs epicardial electrograms which have characteristics of reduced amplitude (low voltage) and fractionation. ECGI co-localizes the epicardial electrical scar to the anatomic scar with a high degree of accuracy (sensitivity 89%, specificity 85%). In nearly all subjects, sinus rhythm activation patterns were affected by the presence of myocardial scar. Late potentials could be identified and were almost always within ventricular scar. Conclusions ECGI accurately identifies areas of anatomic scar and complements standard anatomic imaging by providing scar - related electrophysiologic characteristics of low voltages, altered sinus rhythm activation, electrogram fragmentation and presence of late potentials. PMID:22018301

  3. Alterations in carbohydrate metabolism and its regulation in PPARalpha null mouse hearts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although a shift from fatty acids (FAs) to carbohydrates (CHOs) is considered beneficial for the diseased heart, it is unclear why subjects with FA beta-oxidation defects are prone to cardiac decompensation under stress conditions. The present study investigated potential alterations in the myocardi...

  4. Contemporary perspective on endogenous myocardial regeneration

    PubMed Central

    Milasinovic, Dejan; Mohl, Werner

    2015-01-01

    Considering the complex nature of the adult heart, it is no wonder that innate regenerative processes, while maintaining adequate cardiac function, fall short in myocardial jeopardy. In spite of these enchaining limitations, cardiac rejuvenation occurs as well as restricted regeneration. In this review, the background as well as potential mechanisms of endogenous myocardial regeneration are summarized. We present and analyze the available evidence in three subsequent steps. First, we examine the experimental research data that provide insights into the mechanisms and origins of the replicating cardiac myocytes, including cell populations referred to as cardiac progenitor cells (i.e., c-kit+ cells). Second, we describe the role of clinical settings such as acute or chronic myocardial ischemia, as initiators of pathways of endogenous myocardial regeneration. Third, the hitherto conducted clinical studies that examined different approaches of initiating endogenous myocardial regeneration in failing human hearts are analyzed. In conclusion, we present the evidence in support of the notion that regaining cardiac function beyond cellular replacement of dysfunctional myocardium via initiation of innate regenerative pathways could create a new perspective and a paradigm change in heart failure therapeutics. Reinitiating cardiac morphogenesis by reintroducing developmental pathways in the adult failing heart might provide a feasible way of tissue regeneration. Based on our hypothesis “embryonic recall”, we present first supporting evidence on regenerative impulses in the myocardium, as induced by developmental processes. PMID:26131310

  5. Postmortem diagnosis of acute myocardial infarction in patients with acute respiratory failure - demographics, etiologic and pulmonary histologic analysis

    PubMed Central

    de Matos Soeiro, Alexandre; Ruppert, Aline D; Canzian, Mauro; Capelozzi, Vera L; Serrano, Carlos V

    2012-01-01

    OBJECTIVES: Acute respiratory failure is present in 5% of patients with acute myocardial infarction and is responsible for 20% to 30% of the fatal post-acute myocardial infarction. The role of inflammation associated with pulmonary edema as a cause of acute respiratory failure post-acute myocardial infarction remains to be determined. We aimed to describe the demographics, etiologic data and histological pulmonary findings obtained through autopsies of patients who died during the period from 1990 to 2008 due to acute respiratory failure with no diagnosis of acute myocardial infarction during life. METHODS: This study considers 4,223 autopsies of patients who died of acute respiratory failure that was not preceded by any particular diagnosis while they were alive. The diagnosis of acute myocardial infarction was given in 218 (4.63%) patients. The age, sex and major associated diseases were recorded for each patient. Pulmonary histopathology was categorized as follows: diffuse alveolar damage, pulmonary edema, alveolar hemorrhage and lymphoplasmacytic interstitial pneumonia. The odds ratio of acute myocardial infarction associated with specific histopathology was determined by logistic regression. RESULTS: In total, 147 men were included in the study. The mean age at the time of death was 64 years. Pulmonary histopathology revealed pulmonary edema as well as the presence of diffuse alveolar damage in 72.9% of patients. Bacterial bronchopneumonia was present in 11.9% of patients, systemic arterial hypertension in 10.1% and dilated cardiomyopathy in 6.9%. A multivariate analysis demonstrated a significant positive association between acute myocardial infarction with diffuse alveolar damage and pulmonary edema. CONCLUSIONS: For the first time, we demonstrated that in autopsies of patients with acute respiratory failure as the cause of death, 5% were diagnosed with acute myocardial infarction. Pulmonary histology revealed a significant inflammatory response, which has

  6. Impaired Insulin Signaling Accelerates Cardiac Mitochondrial Dysfunction After Myocardial Infarction

    PubMed Central

    Sena, Sandra; Hu, Ping; Zhang, Dongfang; Wang, Xiaohui; Wayment, Benjamin; Olsen, Curtis; Avelar, Erick; Abel, E. Dale; Litwin, Sheldon E

    2009-01-01

    Diabetes increases mortality and accelerates left ventricular (LV) dysfunction following myocardial infarction (MI). This study sought to determine the impact of impaired myocardial insulin signaling, in the absence of diabetes, on the development of LV dysfunction following MI. Mice with cardiomyocyte-restricted knock out of the insulin receptor (CIRKO) and wild type (WT) mice were subjected to proximal left coronary artery ligation (MI) and followed for 14 days. Despite equivalent infarct size, mortality was increased in CIRKO-MI vs. WT-MI mice (68 % vs. 40 %, respectively). In surviving mice, LV ejection fraction and dP/dt were reduced by > 40% in CIRKO-MI vs. WT-MI. Relative to shams, isometric developed tension in LV papillary muscles increased in WT-MI but not in CIRKO-MI. Time to peak tension and relaxation times were prolonged in CIRKO-MI vs. WT-MI suggesting impaired, load-independent myocardial contractile function. To elucidate mechanisms for impaired LV contractility, mitochondrial function was examined in permeabilized cardiac fibers. Whereas maximal ADP-stimulated mitochondrial O2 consumption rates (VADP) with palmitoyl carnitine were unchanged in WT-MI mice relative to sham-operated animals, VADP was significantly reduced in CIRKO-MI (13.17 ± 0.94 vs. 9.14 ± 0.88 nmol O2/min/mgdw, p<0.05). Relative to WT-MI, expression levels of GLUT4, PPAR-α, SERCA2, and the FA-Oxidation genes MCAD, LCAD, CPT2 and the electron transfer flavoprotein ETFDH were repressed in CIRKO-MI. Thus reduced insulin action in cardiac myocytes accelerates post-MI LV dysfunction, due in part to a rapid decline in mitochondrial FA oxidative capacity, which combined with limited glucose transport capacity may reduce substrate utilization and availability. PMID:19249310

  7. Enhanced IL-17 signalling following myocardial ischaemia/reperfusion injury

    PubMed Central

    Barry, Seán P.; Ounzain, Samir; McCormick, James; Scarabelli, Tiziano M.; Chen-Scarabelli, Carol; Saravolatz, Louis I.I.; Faggian, Giuseppe; Mazzucco, Alessandro; Suzuki, Hisanori; Thiemermann, Christoph; Knight, Richard A.; Latchman, David S.; Stephanou, Anastasis

    2013-01-01

    Background IL-17A and IL-17F are pro-inflammatory cytokines which induce the expression of several cytokines, chemokines and matrix metalloproteinases (MMPs) in target cells. IL-17 cytokines have recently attracted huge interest due to their pathogenic role in diseases such as arthritis and inflammatory bowel disease although a role for IL-17 cytokines in myocardial infarction (MI) has not previously been described. Methods In vivo MI was performed by coronary artery occlusion in the absence or presence of a neutralizing IL-17 antibody for blocking IL-17 actions in vivo. IL-17 signaling was also assessed in isolated primary cardiomyocytes by Western blot, mRNA expression and immunostaining. Results Expression of IL-17A, IL-17F and the IL-17 receptor (IL-17RA) were all increased following MI. Expression of several IL-17 target genes, including Cxcl1, Cxcl2, IL-1β, iNOS and IL-6 was also upregulated following MI. In addition, IL-17A promoted the expression of Cxcl1 and IL-6 in isolated cardiomyocytes in a MAPK and PI(3)K-dependent manner. IL-17A and ischaemia/reperfusion (I/R) injury were found to have an additive effect on Cxcl1 expression, suggesting that IL-17 may enhance myocardial neutrophil recruitment during MI. Moreover, protein levels of both IL-17R and IL-17A were enhanced following in vivo MI. Finally, blocking IL-17 signaling in vivo reduced the levels of apoptotic cell death markers following in vivo MI. Conclusions These data imply that the expression of IL-17 cytokines and their receptor are elevated during myocardial I/R injury and may play a fundamental role in post infarct inflammatory and apoptotic responses. PMID:22030025

  8. Depression Increases Sympathetic Activity and Exacerbates Myocardial Remodeling after Myocardial Infarction: Evidence from an Animal Experiment

    PubMed Central

    Liu, Tao; Yuan, Xiaoran; Ruan, Bing; Sun, Lifang; Tang, Yanhong; Yang, Bo; Hu, Dan; Huang, Congxin

    2014-01-01

    Depression is an independent risk factor for cardiovascular events and mortality in patients with myocardial infarction (MI). Excessive sympathetic activation and serious myocardial remodeling may contribute to this association. The aim of this study was to discuss the effect of depression on sympathetic activity and myocardial remodeling after MI. Wild-type (WT) rats were divided into a sham group (Sham), a myocardial infarction group (MI), a depression group (D), and a myocardial infarction plus depression group (MI+D). Compared with controls, the MI+D animals displayed depression-like behaviors and attenuated body weight gain. The evaluation of sympathetic activity showed an increased level in plasma concentrations of epinephrine and norepinephrine and higher expression of myocardial tyrosine hydroxylase in the MI+D group than the control groups (p<0.05 for all). Cardiac function and morphologic analyses revealed a decreased fractional shortening accompanied by increased left ventricular dimensions, thinning myocardium wall, and reduced collagen repair in the MI+D group compared with the MI group (p<0.05 for all). Frequent premature ventricular contractions, prolonged QT duration and ventricular repolarization duration, shorted effective refractory period, and increased susceptibility to ventricular arrhythmia were displayed in MI+D rats. These results indicate that sympathetic hyperactivation and exacerbated myocardial remodeling may be a plausible mechanism linking depression to an adverse prognosis after MI. PMID:25036781

  9. Spontaneous changes in /sup 201/Tl myocardial perfusion imaging after myocardial infarction

    SciTech Connect

    Buda, A.J.; Dubbin, J.D.; MacDonald, I.L.; Strauss, H.D.; Orr, S.A.; Meindok, H.

    1982-12-01

    To examine regional myocardial perfusion after myocardial infarction, 26 patients underwent exercise electrocardiographic testing with /sup 201/Tl myocardial perfusion imaging 3 weeks and 3 months after infarction. At 3 weeks, 9 of 26 patients (35%) had myocardial ischemia by exercise electrocardiographic testing, whereas 18 of 26 (69%) had ischemia by /sup 201/Tl imaging. The /sup 201/Tl scintigrams were scored by dividing each image, in 3 views, into 5 segments, using a 5-point scoring scheme. The exercise /sup 201/Tl score was 44.3 +/- 1.2 and increased to 47.3 +/- 1.2 in the redistribution study (p less than 0.001). Three months after infarction, although there was a significantly greater rate-pressure product which would predict a larger ischemic defect and a decrease in the stress /sup 201/Tl score, the stress score was improved (48.3 +/- 1.1, p less than 0.001). The redistribution score was similar, that is, 48.9 +/- 1.0. The improvement in /sup 201/Tl myocardial perfusion was associated with a loss of stress-induced ischemia in 8 patients (30%). These results indicate that spontaneous improvements in /sup 201/Tl myocardial perfusion imaging may occur after myocardial infarction.

  10. Role of myocardial perfusion imaging in evaluating thrombolytic therapy for acute myocardial infarction

    SciTech Connect

    Beller, G.A.

    1987-03-01

    Myocardial thallium-201 scintigraphy is being increasingly employed as a method for assessing the efficacy of coronary reperfusion in acute myocardial infarction. New thallium uptake after intracoronary tracer administration after successful recanalization indicates that nutrient blood flow has been successfully restored. One may also presume that some myocardial salvage occurred if thallium administered in this manner is transported intracellularly by myocytes with intact sarcolemmal membranes. However, if one injects thallium by way of the intracoronary route immediately after reperfusion, the initial uptake of thallium in reperfused myocardium may predominantly represent hyperemic flow and regional thallium counts measured may not be proportional to the mass of viable myocytes. When thallium is injected intravenously during the occlusion phase the degree of redistribution after thrombolysis is proportional to the degree of flow restoration and myocardial viability. When thallium is injected for the first time intravenously immediately after reperfusion, an overestimation of myocardial salvage may occur because of excess thallium uptake in the infarct zone consequent to significant hyperemia. Another approach to myocardial thallium scintigraphy in patients undergoing thrombolytic therapy is to administer two separate intravenous injections before and 24 hours or later after treatment. Finally, patients with acute myocardial infarction who receive intravenous thrombolytic therapy are candidates for predischarge exercise thallium-201 scintigraphy for risk stratification and detection of residual ischemia.

  11. 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

  12. Aortocoronary graft flow and reactive hyperaemia in relation to postoperative myocardial infarction.

    PubMed Central

    Skotnicki, S; Vonk, J; Sleegers, T; Dercksen, S; Linssen, G; Lacquet, L; Kuijpers, P

    1976-01-01

    Blood flow through aortocoronary venous grafts and its response to a brief period of arterial occlusion--reactive hyperaemia--were studied in relation to the development of postoperative myocardial infarction. In 40 patients with intractable angina due to obstructive coronary artery disease, 72 aortocoronary venous grafts were constructed. In 18% of the grafts there was no response to the flow to temporary occlusion, due to absence of reactive hyperaemia. In the remaining grafts the flow increased from 17% to 26%. In 17-5% of the patients postoperative myocardial infarction was diagnosed. No relation could be established between this control flow through aortocoronary grafts and postoperative myocardial infarction. A significant difference was found in the magnitude of the reactive hyperaemia following occlusion of the graft between patients who developed myocardial infarction (13-0%) and those who did not (26-8%). Some of our observations suggest that the myocardium is in a state of reactive hyperaemia after coronary surgery. With certain technical precautions the flow changes caused by reactive hyperaemia can be used as an indicator of the result to be expected from bypass surgery. PMID:781900

  13. Adenosine enhances myocardial glucose uptake only in the presence of insulin.

    PubMed

    Law, W R; McLane, M P

    1991-09-01

    Better understood in other tissues, the effects of adenosine on insulin-stimulated glucose uptake in the heart are poorly understood. Under pentobarbital anesthesia, we instrumented mongrel dogs to obtain general hemodynamics (blood pressure and heart rate), and arterial and coronary sinus blood samples for measuring oxygen and glucose concentrations. An electromagnetic blood flow probe around the circumflex coronary artery allowed determinations of blood flow, and calculation of substrate uptake by the heart (Fick principle). Somatostatin (SRIF) was infused intravenously (0.8 micrograms/kg/min) along with 0, 0.5, 1.0, 5.0, or 10 mU/kg/min regular insulin, and variable quantities of glucose to maintain euglycemia. Concomitant with the SRIF, insulin, and glucose infusions, adenosine was infused in logarithmically increasing rates (0, 0.01, 0.1, 1.0, 10 or 100 mumol/min) for 30 minutes each into the main left coronary arteries. Insulin infusions increased myocardial glucose uptake in a dose-dependent manner. The heart displayed exquisite sensitivity to insulin, with an ED50 of approximately 14 microU/mL (serum insulin). Adenosine infusions in the absence of insulin (SRIF infusion) increased coronary blood flow, but did not alter myocardial glucose uptake. In the presence of insulin, adenosine increased the maximal value for glucose uptake without changing sensitivity to insulin. These results indicate that adenosine enhances myocardial responsiveness to insulin, with respect to glucose uptake, independent of changes in blood flow. Since glucose can be used for anaerobic metabolism, and adenosine levels are known to increase under situations in which myocardial oxygenation is inadequate, these data have serious implications for conditions such as myocardial ischemia or hypoxia, when glycolytic substrate availability is vital. PMID:1680214

  14. Hypothesis tests for hydrologic alteration

    NASA Astrophysics Data System (ADS)

    Kroll, Charles N.; Croteau, Kelly E.; Vogel, Richard M.

    2015-11-01

    Hydrologic systems can be altered by anthropogenic and climatic influences. While there are a number of statistical frameworks for describing and evaluating the extent of hydrologic alteration, here we present a new framework for assessing whether statistically significant hydrologic alteration has occurred, or whether the shift in the hydrologic regime is consistent with the natural variability of the system. Four hypothesis tests based on shifts of flow duration curves (FDCs) are developed and tested using three different experimental designs based on different strategies for resampling of annual FDCs. The four hypothesis tests examined are the Kolmogorov-Smirnov (KS), Kuiper (K), confidence interval (CI), and ecosurplus and ecodeficit (Eco). Here 117 streamflow sites that have potentially undergone hydrologic alteration due to reservoir construction are examined. 20 years of pre-reservoir record is used to develop the critical value of the test statistic for type I errors of 5% and 10%, while 10 years of post-alteration record is used to examine the power of each test. The best experimental design, based on calculating the mean annual FDC from an exhaustive jackknife resampling regime, provided a larger number of unique values of each test statistic and properly reproduced type I errors. Of the four tests, the CI test consistently had the highest power, while the K test had the second highest power; KS and Eco always had the lowest power. The power of the CI test appeared related to the storage ratio of the reservoir, a rough measure of the hydrologic alteration of the system.

  15. [Ventricular Septal Perforation after Inferior Myocardial Infarction].

    PubMed

    Sato, Hisashi; Nakayama, Yoshihiro; Tanaka, Hideya; Takahashi, Baku

    2016-07-01

    We report a rare case of ventricular septal perforation (VSP) after inferior myocardial infarction. Surgical repair of VSP after inferior infarction is technically difficult because of its anatomical location. An 81-year-old female presented with dyspnea on the 8th day after percutaneous coronary intervention for acute inferior myocardial infarction. Echocardiography revealed a ventricular septal perforation. Urgent operation was performed. There was a VSP around the base of the ventricular septum. The myocardial infarction extended to the adjacent muscle of the mitral valve annulus. Two bovine pericardial patches were used in the left ventricular cavity. The patches were sewn on the mitral valve annulus which was the only normal tissue in the region. The 1st patch was used to close the VSP directly, and the 2nd patch was sutured to the normal myocardium to exclude the infracted area. No residual shunt flow was observed. The postoperative course was uneventful. PMID:27365060

  16. Action of acetylstrophanthidin on experimental myocardial infarction.

    NASA Technical Reports Server (NTRS)

    Nola, G. T.; Pope, S. E.; Harrison, D. C.

    1972-01-01

    An experimental animal model with acute myocardial infarction of a size insufficient to produce profound heart failure or shock was used to study the effects of acute infarction on digitalis tolerance and the hemodynamic changes produced by moderate and large doses of acetylstrophanthidin. With acute myocardial infarction, digitalis toxic arrhythmias could be precipitated with significantly lower doses of digitalis than in animals without myocardial infarction. There was no precise correlation between the size of infarction and the toxic dose of glycoside. Coronary artery ligation produced a stable but relatively depressed circulatory state, as evidenced by lowered cardiac output and stroke volume and elevated systemic vascular resistance and left atrial mean pressure. When digitalis was infused, the following significant changes were observed at nontoxic doses: (1) elevation of aortic and left ventricular pressures; (2) further decline in cardiac output; and (3) decreased left atrial mean pressure.

  17. [Recurrent myocardial infarctions: specific changes in biomarkers and in myocardial remodeling (case-control study)].

    PubMed

    Volkova, E G; Malykhina, O P; Levashov, S Iu

    2007-01-01

    Basing on a case-control study (n=81) with the use of standard methods of myocardial infarction verification, examination of hemogram, troponin T, C-reactive protein, echocardiography data it was established that markers of myocardial infarction (troponin T level) and inflammation (C reactive protein level, lymphopenia) during recurrent infarctions are less pronounced than during first infarctions. Remodeling in recurrent infarctions had the following specific characteristics: increase of left ventricular end diastolic dimension, myocardial mass index, diastolic dysfunction and stroke volume with unchanged ejection fraction. PMID:18260891

  18. Myocardial disarray in Noonan syndrome

    PubMed Central

    Burch, Michael; Mann, Jessica M; Sharland, Michael; Shinebourne, Elliot A; Patton, Michael A; McKenna, William J

    1992-01-01

    Objective—To characterise the histopathology of the left ventricular hypertrophy commonly associated with Noonan syndrome by assessing the extent of myocyte disarray and therefore to define one aspect of the relation between this disease and idiopathic hypertrophic cardiomyopathy. Design—Blinded histological analysis. Setting—Hospital medical school. Patients—Six hearts of children with the Noonan phenotype and isolated ventricular hypertrophy were compared with age and sex matched controls. Methods—Histological analysis was performed with an image analyser under light microscopy. Representative sections from the entire left ventricular free wall were examined. Results were expressed as the percentage of fields showing disarray related to the number of fields evaluated: 100 fields were examined for each patient. Results—In the patients with Noonan syndrome myocardial disarray was present in the ventricular septum in 24 (5·7)% (mean (SD)) of fields and in the free wall in 22·2 (6·8)%. In the controls disarray was present in the septum in 3·8 (2·3)% of fields and in the free wall in 2·4 (2·8)%. In both regions the extent of disarray was significantly greater in patients with Noonan syndrome (p < 0·0005; 95% confidence interval 14 to 26·3 for the septum: p < 0·005, 95% confidence interval 11·4 to 28·2 for the free wall). Conclusions—The ventricular hypertrophy associated with Noonan syndrome is histologically similar to hypertrophic cardiomyopathy but whether the two diseases are the expression of the same genetic defect remains to be determined. PMID:1467053

  19. Correlated Alteration Effects in CM Carbonaceous Chondrites

    NASA Astrophysics Data System (ADS)

    Zolensky, Michael E.; Browning, Lauren B.; McSween, Harry Y., Jr.

    1996-01-01

    Three parameters are proposed to determine the relative extent of alteration in CM chondrites. The mineralogic alteration index monitors the relative progress of coupled substitutions in the progressive alteration of cronstedtite to Mg-serpentine, and increases with increasing alteration. To calculate values of this index, an algorithm has been developed to estimate the average matrix phyllosilicate composition in individual CM chondrites. The second parameter is the volume percent of isolated matrix silicates, which decreases with progressive alteration due to mineral hydration. Finally, the volume percent of chondrule alteration monitors the extent of chondrule phyllosilicate production, and increases as alteration proceeds. These parameters define the first CM alteration scale that-relies on multiple indicators of progressive alteration. The following relative order of increasing alteration is established by this model: Murchison less than or equal to Bells less than Pollen less than or equal to Murray less than Mighei less than Nogoya less than Cold Bokkeveld. Bulk delta18O values generally increase with progressive alteration, providing additional support for this sequence. The relative degree of aqueous processing Cochabamba and Boriskino experienced is less precisely constrained, although both fall near the middle of this sequence. A comparison between the mineralogic alteration index and literature values of the whole-rock chemistry of CM chondrites reveals several correlations. For example, a positive, nearly linear correlation between bulk H content and progressive CM alteration suggests an approximately constant production rate of new phyllosilicates relative to the mineralogical transition from cronstedtite to Mg-serpentine. Furthermore, the abundance of trapped planetary Ar-36 decreases systematically in progressively altered CM chondrites, suggesting the wholesale destruction of primary noble gas carrier phase(s) by aqueous reactions. Multiple

  20. Asymptomatic myocardial ischemia following cold provocation

    SciTech Connect

    Shea, M.J.; Deanfield, J.E.; deLandsheere, C.M.; Wilson, R.A.; Kensett, M.; Selwyn, A.P.

    1987-09-01

    Cold is thought to provoke angina in patients with coronary disease either by an increase in myocardial demand or an increase in coronary vascular resistance. We investigated and compared the effects of cold pressor stimulation and symptom-limited supine bicycle exercise on regional myocardial perfusion in 35 patients with stable angina and coronary disease and in 10 normal subjects. Regional myocardial perfusion was assessed with positron emission tomography and rubidium-82. Following cold pressor stimulation 24 of 35 patients demonstrated significant abnormalities of regional myocardial perfusion with reduced cation uptake in affected regions of myocardium: 52 +/- 9 to 43 +/- 9 (p less than 0.001 vs normal subjects). Among these 24 patients only nine developed ST depression and only seven had angina. In contrast, 29 of 35 patients underwent supine exercise, and abnormal regional myocardial perfusion occurred in all 29, with a reduction in cation intake from 48 +/- 10 to 43 +/- 14 (p less than 0.001 vs normal subjects). Angina was present in 27 of 29 and ST depression in 25 of 29. Although the absolute decrease in cation uptake was somewhat greater following cold as opposed to exercise, the peak heart rate after cold was significantly lower than that after exercise (82 +/- 12 vs 108 +/- 16 bpm, p less than 0.05). Peak systolic blood pressures after cold and exercise were similar (159 +/- 24 vs 158 +/- 28). Thus, cold produces much more frequent asymptomatic disturbances of regional myocardial perfusion in patients with stable angina and coronary disease than is suggested by pain or ECG changes.

  1. Intestinal Microbial Metabolites Are Linked to Severity of Myocardial Infarction in Rats

    PubMed Central

    Lam, Vy; Su, Jidong; Hsu, Anna; Gross, Garrett J.; Salzman, Nita H.

    2016-01-01

    Intestinal microbiota determine severity of myocardial infarction in rats. We determined whether low molecular weight metabolites derived from intestinal microbiota and transported to the systemic circulation are linked to severity of myocardial infarction. Plasma from rats treated for seven days with the non-absorbed antibiotic vancomycin or a mixture of streptomycin, neomycin, polymyxin B and bacitracin was analyzed using mass spectrometry-based metabolite profiling platforms. Antibiotic-induced changes in the abundance of individual groups of intestinal microbiota dramatically altered the host’s metabolism. Hierarchical clustering of dissimilarities separated the levels of 284 identified metabolites from treated vs. untreated rats; 193 were altered by the antibiotic treatments with a tendency towards decreased metabolite levels. Catabolism of the aromatic amino acids phenylalanine, tryptophan and tyrosine was the most affected pathway comprising 33 affected metabolites. Both antibiotic treatments decreased the severity of an induced myocardial infarction in vivo by 27% and 29%, respectively. We then determined whether microbial metabolites of the amino acids phenylalanine, tryptophan and tyrosine were linked to decreased severity of myocardial infarction. Vancomycin-treated rats were administered amino acid metabolites prior to ischemia/reperfusion studies. Oral or intravenous pretreatment of rats with these amino acid metabolites abolished the decrease in infarct size conferred by vancomycin. Inhibition of JAK-2 (AG-490, 10 μM), Src kinase (PP1, 20 μM), Akt/PI3 kinase (Wortmannin, 100 nM), p44/42 MAPK (PD98059, 10 μM), p38 MAPK (SB203580, 10 μM), or KATP channels (glibenclamide, 3 μM) abolished cardioprotection by vancomycin, indicating microbial metabolites are interacting with cell surface receptors to transduce their signals through Src kinase, cell survival pathways and KATP channels. These inhibitors have no effect on myocardial infarct size in

  2. The role of CD36 in the regulation of myocardial lipid metabolism.

    PubMed

    Kim, Ty T; Dyck, Jason R B

    2016-10-01

    Since the heart has one of the highest energy requirements of all organs in the body, it requires a constant and plentiful supply of fuel to function properly. Mitochondrial oxidation of lipids provides a major source of ATP for the heart, and the cellular processes that regulate lipid uptake and utilization are important contributors to maintaining proper myocardial energetic status. Although numerous proteins are coordinately regulated in order to ensure proper fatty acid utilization in the cardiomyocyte, a key first step in this process is the entry of fatty acids into the cell. An important protein involved in the transport of fatty acids into the cardiomyocyte is the plasma membrane-associated protein known as fatty acid translocase (FAT; also known as CD36). While multiple proteins are involved in facilitating fatty acid uptake in the heart, CD36 accounts for approximately 50-70% of the total fatty acid taken up in cardiomyocytes. As such, myocardial metabolism of fatty acids may depend upon proper CD36 function. Consistent with this, changes in CD36 levels/function have been implicated in the alteration of myocardial metabolism in the pathophysiology of certain cardiovascular diseases. As such, a better understanding of the role and function of CD36 in the heart may provide important insights for the development of new treatments for specific cardiovascular diseases. Herein, we review the role of CD36 in myocardial lipid metabolism in the healthy heart and describe how CD36-mediated alterations in lipid metabolism may contribute to cardiovascular disease. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26995462

  3. Recurrent myocardial infarction with patent coronary arteries.

    PubMed Central

    Haywood, L. J.; Khan, A. H.; Bornheimer, J.; Finck, E.; Tatter, D.

    1997-01-01

    Two separate episodes of severe chest pain occurred several years apart in a 25-year-old male patient with typical clinical findings of acute myocardial infarction with each episode. Cardiac catheterization following the second infarction confirmed the presence of myocardial dysfunction with apical akinesis and dyskinesis. Both coronary arteries were radiologically patent; however, there was evidence of probable recanalization of the right coronary artery. Several months later, the patient developed flank pain, hematuria, progressive renal failure, and cardiac decompensation, and died with intractable arrhythmias. At autopsy, a large apical mitral thrombosis was found and was the presumptive source of multiple systemic emboli. Images Figure 3 Figure 4 PMID:9195802

  4. Hemodialysis-Induced Myocardial Stunning: A Review.

    PubMed

    Brown, Maxine; Burrows, LaVonne; Pruett, Timothy; Burrows, Thaddeus

    2015-01-01

    Patients on hemodialysis have a high incidence of cardiac morbidity and mortality, and echocardiographic evidence of hemodialysis-related myocardial stunning supports a potential link between the hemodialysis treatment itself and cardiac sequelae. Fluid removal rates exceeding 13 mL/kg/hour during hemodialysis have been implicated in the development of myocardial stunning. Providers caring for patients on chronic hemodialysis might improve patient outcomes by the use of modified treatment monitoring methods, alternative dialysis delivery methods, and enhanced patient education regarding risks of excessive interdialytic weight gains. PMID:26290919

  5. Altered States of Consciousness and Alcohol.

    ERIC Educational Resources Information Center

    Jones, Ben Morgan; And Others

    This document contains the reports of research at a symposium on "Altered States of Consciousness and Alcohol." The participants primarily agreed that alcohol induces an altered state of consciousness similar to other drugs, but that this phenomenon has not been explicitly stated due to the current interest in newer and more novel drugs. The…

  6. Depressed expression of MuRF1 and MAFbx in areas remote of recent myocardial infarction: a mechanism contributing to myocardial remodeling?

    PubMed

    Conraads, Viviane M; Vrints, Christiaan J; Rodrigus, Inez E; Hoymans, Vicky Y; Van Craenenbroeck, Emeline M; Bosmans, Johan; Claeys, Marc J; Van Herck, Paul; Linke, Axel; Schuler, Gerhard; Adams, Volker

    2010-03-01

    Ventricular remodeling following myocardial infarction (MI) includes myocardial hypertrophy, a process requiring increased protein synthesis and sarcomere assembly. The anti-hypertrophic effect of MuRF1/MafBx, both muscle-specific E3-ubiquitin ligases, has been demonstrated in animal experiments and in cultured cardiomyocytes. We assessed MuRF1/MAFbx expression in myocardium remote of recently (<2 weeks) infarcted regions (MI), compared with patients undergoing coronary artery bypass surgery, with normal systolic function and without previous infarction (control or Con). Left ventricular myocardial biopsies were obtained from the contralateral normal zone in MI (n = 14) patients and from the Con (n = 12) group. MuRF-1/MAFbx expression was assessed using RT-PCR and Western blot (WB). In addition, the myocardial expression of TNF-alpha was measured (RT-PCR) and troponin I, beta-myosin and phosphorylated Akt/Akt (pAkt/Akt) were quantified (WB). MuRF1 and MAFbx expression (mRNA and protein level) were significantly reduced in biopsies from MI patients. TNF-alpha was significantly higher in MI and exhibited a negative correlation with MuRF1 and MAFbx. The expression of troponin I and cardiomyocyte size were increased in MI in comparison to Con, whereas beta-myosin expression was not altered. When compared with Con, pAkt/Akt was elevated. The results of the present study suggest that the atrogenes MuRF1/MAFbx are involved in regulating the hypertrophic response, characteristic of the early post-infarction remodeling phase. Reduced expression of MuRF1 and MAFbx in the myocardium might permit hypertrophy, which is supported by the elevation of troponin I. A regulatory role of TNF-alpha needs to be confirmed in further experiments. PMID:19859778

  7. Imaging of cocaine-induced global and regional myocardial ischemia

    SciTech Connect

    Oster, Z.H.; Som, P.; Wang, G.J.; Weber, D.A. )

    1991-08-01

    Severe and often fatal cardiac complications have been reported in cocaine users with narrowed coronary arteries caused by atherosclerosis as well as in young adults with normal coronaries. The authors have found that in normal dogs cocaine induces severe temporary hypoperfusion of the left ventricle as indicated by a significantly lower 201Tl concentration compared to the baseline state. The most significant decrease in uptake occurred 5 min after injection and was more pronounced in the septal and apical segments. Following intravenous administration of cocaine, instead of gradual disappearance of 201Tl from the left ventricle, there was continuous increase in 201Tl concentration in the left ventricle. These imaging experiments indicate that the deleterious effects of cocaine on the heart are probably due to spasm of the coronaries and decreased myocardial perfusion. Since spasm of the large subpericardial vessels does not seem to explain the magnitude of the increased coronary resistance and decreased coronary flow after cocaine as described in the literature, it is suggested that microvascular spasm of smaller vessels plays a major role in the temporary decrease in perfusion. The data may also suggest that severe temporary myocardial ischemia is probably the initiating factor for the cardiac complications induced by cocaine.

  8. Myocardial Cell Pattern on Piezoelectric Nanofiber Mats for Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Liu, X.; Wang, X.; Zhao, H.; Du, Y.

    2014-11-01

    The paper presents in vitro contractile myocardial cell pattern on piezoelectric nanofiber mats with applications in energy harvesting. The cell-based energy harvester consists of myocardial cell sheet and a PDMS substrate with a PVDF nanofiber mat on. Experimentally, cultured on specifically distributed nanofiber mats, neonatal rat ventricular cardiomyocytes are characterized with the related morphology and contraction. Previously, we have come up with the concept of energy harvesting from heart beating using piezoelectric material. A bio-hybrid energy harvester combined living cardiomyocytes, PDMS polymer substrate and piezoelectric PVDF film with the electrical output of peak current 87.5nA and peak voltage 92.3mV. However, the thickness of the cardiomyocyte cultured on a two-dimensional substrate is much less than that of the piezoelectric film. The Micro Contact Printing (μCP) method used in cell pattern on the PDMS thin film has tough requirement for the film surface. As such, in this paper we fabricated nanofiber-constructed PDMS thin film to realize cell pattern due to PVDF nanofibers with better piezoelectricity and microstructures of nanofiber mats guiding cell distribution. Living cardiomyocytes patterned on those distributed piezoelectric nanofibers with the result of the same distribution as the nanofiber pattern.

  9. Current stem cell delivery methods for myocardial repair.

    PubMed

    Sheng, Calvin C; Zhou, Li; Hao, Jijun

    2013-01-01

    Heart failure commonly results from an irreparable damage due to cardiovascular diseases (CVDs), the leading cause of morbidity and mortality in the United States. In recent years, the rapid advancements in stem cell research have garnered much praise for paving the way to novel therapies in reversing myocardial injuries. Cell types currently investigated for cellular delivery include embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and adult stem cell lineages such as skeletal myoblasts, bone-marrow-derived stem cells (BMSCs), mesenchymal stem cells (MSCs), and cardiac stem cells (CSCs). To engraft these cells into patients' damaged myocardium, a variety of approaches (intramyocardial, transendocardial, transcoronary, venous, intravenous, intracoronary artery and retrograde venous administrations and bioengineered tissue transplantation) have been developed and explored. In this paper, we will discuss the pros and cons of these delivery modalities, the current state of their therapeutic potentials, and a multifaceted evaluation of their reported clinical feasibility, safety, and efficacy. While the issues of optimal delivery approach, the best progenitor stem cell type, the most effective dose, and timing of administration remain to be addressed, we are highly optimistic that stem cell therapy will provide a clinically viable option for myocardial regeneration. PMID:23509740

  10. Current Stem Cell Delivery Methods for Myocardial Repair

    PubMed Central

    Sheng, Calvin C.; Zhou, Li; Hao, Jijun

    2013-01-01

    Heart failure commonly results from an irreparable damage due to cardiovascular diseases (CVDs), the leading cause of morbidity and mortality in the United States. In recent years, the rapid advancements in stem cell research have garnered much praise for paving the way to novel therapies in reversing myocardial injuries. Cell types currently investigated for cellular delivery include embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and adult stem cell lineages such as skeletal myoblasts, bone-marrow-derived stem cells (BMSCs), mesenchymal stem cells (MSCs), and cardiac stem cells (CSCs). To engraft these cells into patients' damaged myocardium, a variety of approaches (intramyocardial, transendocardial, transcoronary, venous, intravenous, intracoronary artery and retrograde venous administrations and bioengineered tissue transplantation) have been developed and explored. In this paper, we will discuss the pros and cons of these delivery modalities, the current state of their therapeutic potentials, and a multifaceted evaluation of their reported clinical feasibility, safety, and efficacy. While the issues of optimal delivery approach, the best progenitor stem cell type, the most effective dose, and timing of administration remain to be addressed, we are highly optimistic that stem cell therapy will provide a clinically viable option for myocardial regeneration. PMID:23509740

  11. Myocardial Remodeling: Cellular and Extracellular Events and Targets

    PubMed Central

    Dixon, Jennifer A.; Spinale, Francis G.

    2011-01-01

    The focus of this review is on translational studies utilizing large-animal models and clinical studies that provide fundamental insight into cellular and extracellular pathways contributing to post–myocardial infarction (MI) left ventricle (LV) remodeling. Specifically, both large-animal and clinical studies have examined the potential role of endogenous and exogenous stem cells to alter the course of LV remodeling. Interestingly, there have been alterations in LV remodeling with stem cell treatment despite a lack of long-term cell engraftment. The translation of the full potential of stem cell treatments to clinical studies has yet to be realized. The modulation of proteolytic pathways that contribute to the post-MI remodeling process has also been examined. On the basis of recent large-animal studies, there appears to be a relationship between stem cell treatment post-MI and the modification of proteolytic pathways, generating the hypothesis that stem cells leave an echo effect that moderates LV remodeling. PMID:21314431

  12. Abnormal Myocardial Blood Flow Reserve Observed in Cardiac Amyloidosis

    PubMed Central

    Nel, Karen; Senior, Roxy; Greaves, Kim

    2016-01-01

    We performed real-time myocardial contrast echocardiography on a patient with cardiac amyloidosis and previous normal coronary angiography presenting with atypical chest pain to assess myocardial blood flow reserve (MBFR). Myocardial contrast echocardiography was performed and flash microbubble destruction and replenishment analysis was used to calculate myocardial blood flow. Dipyridamole was used to achieve hyperemia. MBFR was derived from the ratio of peak myocardial blood flow at hyperemia and rest. The results show a marked reduction in MBFR in our patient. Previous reports of luminal obstruction of intramyocardial rather than epicardial vessels by amyloid deposition may be causing microvascular dysfunction. PMID:27081447

  13. Global myocardial strain assessment by different imaging modalities to predict outcomes after ST-elevation myocardial infarction: A systematic review

    PubMed Central

    Shetye, Abhishek; Nazir, Sheraz A; Squire, Iain B; McCann, Gerald P

    2015-01-01

    AIM: To conduct a systematic review relating myocardial strain assessed by different imaging modalities for prognostication following ST-elevation myocardial infarction (STEMI). METHODS: An online literature search was performed in PubMed and OVID® electronic databases to identify any studies that assessed global myocardial strain parameters using speckle-tracking echocardiography (STE) and/or cardiac magnetic resonance imaging (CMR) techniques [either myocardial tagging or feature tracking (FT) software] in an acute STEMI cohort (days 0-14 post-event) to predict prognosis [either development of major adverse cardiac events (MACE)] or adverse left ventricular (LV) remodelling at follow-up (≥ 6 mo for MACE, ≥ 3 mo for remodelling). Search was restricted to studies within the last 20 years. All studies that matched the pre-defined search criteria were reviewed and their results interpreted. Due to considerable heterogeneity between studies, meta-analysis was not performed. RESULTS: A total of seven studies (n = 7) were identified that matched the search criteria. All studies used STE to evaluate strain parameters - five (n = 5) assessed global longitudinal strain (GLS) (n = 5), one assessed GLS rate (GLS-R) (n = 1) and one assessed both (n = 1). Three studies showed that GLS independently predicted the development of adverse LV remodelling by multivariate analysis - odds ratio between 1.19 (CI: 1.04-1.37, P < 0.05) and 10 (CI: 6.7-14, P < 0.001) depending on the study. Four studies showed that GLS predicted the development of MACE - hazard ratio (HR) between 1.1 (CI: 1-1.1, P = 0.006) and 2.34 (1.10-4.97, P < 0.05). One paper found that GLS-R could significantly predict MACE - HR 18 (10-35, P < 0.001) - whilst another showed it did not. GLS < -10.85% had sensitivity/specificity of 89.7%/91% respectively for predicting the development of remodelling whilst GLS < -13% could predict the development of MACE with sensitivity/specificity of 100%/89% respectively. No

  14. 32 CFR 310.33 - New and altered record systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alterations. (ii) Increases in numbers of individuals due to normal growth are not considered alterations... significantly the scope of population covered (for example, expansion of a system of records covering a...

  15. 32 CFR 310.33 - New and altered record systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alterations. (ii) Increases in numbers of individuals due to normal growth are not considered alterations... significantly the scope of population covered (for example, expansion of a system of records covering a...

  16. Relationship between post-cardiac arrest myocardial oxidative stress and myocardial dysfunction in the rat

    PubMed Central

    2014-01-01

    Background Reperfusion after resuscitation from cardiac arrest (CA) is an event that increases reactive oxygen species production leading to oxidative stress. More specifically, myocardial oxidative stress may play a role in the severity of post-CA myocardial dysfunction. This study investigated the relationship between myocardial oxidative stress and post-CA myocardial injury and dysfunction in a rat model of CA and cardiopulmonary resuscitation (CPR). Ventricular fibrillation was induced in 26 rats and was untreated for 6 min. CPR, including mechanical chest compression, ventilation, and epinephrine, was then initiated and continued for additional 6 min prior to defibrillations. Resuscitated animals were sacrificed at two h (n = 9), 4 h (n = 6) and 72 h (n = 8) following resuscitation, and plasma collected for assessment of: high sensitivity cardiac troponin T (hs-cTnT), as marker of myocardial injury; isoprostanes (IsoP), as marker of lipid peroxidation; and 8-hydroxyguanosine (8-OHG), as marker of DNA oxidative damage. Hearts were also harvested for measurement of tissue IsoP and 8-OHG. Myocardial function was assessed by echocardiography at the corresponding time points. Additional 8 rats were not subjected to CA and served as baseline controls. Results Compared to baseline, left ventricular ejection fraction (LVEF) was reduced at 2 and 4 h following resuscitation (p < 0.01), while it was similar at 72 h. Inversely, plasma hs-cTnT increased, compared to baseline, at 2 and 4 h post-CA (p < 0.01), and then recovered at 72 h. Similarly, plasma and myocardial tissue IsoP and 8-OHG levels increased at 2 and 4 h post-resuscitation (p < 0.01 vs. baseline), while returned to baseline 72 h later. Myocardial IsoP were directly related to hs-cTnT levels (r = 0.760, p < 0.01) and inversely related to LVEF (r = -0.770, p < 0.01). Myocardial 8-OHG were also directly related to hs-cTnT levels (r = 0.409, p < 0.05) and

  17. Myofilament dysfunction contributes to impaired myocardial contraction in the infarct border zone

    PubMed Central

    Shimkunas, Rafael; Makwana, Om; Spaulding, Kimberly; Bazargan, Mona; Khazalpour, Michael; Takaba, Kiyoaki; Soleimani, Mehrdad; Myagmar, Bat-Erdene; Lovett, David H.; Simpson, Paul C.; Ratcliffe, Mark B.

    2014-01-01

    After myocardial infarction, a poorly contracting nonischemic border zone forms adjacent to the infarct. The cause of border zone dysfunction is unclear. The goal of this study was to determine the myofilament mechanisms involved in postinfarction border zone dysfunction. Two weeks after anteroapical infarction of sheep hearts, we studied in vitro isometric and isotonic contractions of demembranated myocardium from the infarct border zone and a zone remote from the infarct. Maximal force development (Fmax) of the border zone myocardium was reduced by 31 ± 2% versus the remote zone myocardium (n = 6/group, P < 0.0001). Decreased border zone Fmax was not due to a reduced content of contractile material, as assessed histologically, and from myosin content. Furthermore, decreased border zone Fmax did not involve altered cross-bridge kinetics, as assessed by muscle shortening velocity and force development kinetics. Decreased border zone Fmax was associated with decreased cross-bridge formation, as assessed from muscle stiffness in the absence of ATP where cross-bridge formation should be maximized (rigor stiffness was reduced 34 ± 6%, n = 5, P = 0.011 vs. the remote zone). Furthermore, the border zone myocardium had significantly reduced phosphorylation of myosin essential light chain (ELC; 41 ± 10%, n = 4, P < 0.05). However, for animals treated with doxycycline, an inhibitor of matrix metalloproteinases, rigor stiffness and ELC phosphorylation were not reduced in the border zone myocardium, suggesting that doxycycline had a protective effect. In conclusion, myofilament dysfunction contributes to postinfarction border zone dysfunction, myofilament dysfunction involves impaired cross-bridge formation and decreased ELC phosphorylation, and matrix metalloproteinase inhibition may be beneficial for limiting postinfarct border zone dysfunction. PMID:25128171

  18. Conjugated linoleic acid and nitrite attenuate mitochondrial dysfunction during myocardial ischemia.

    PubMed

    Van Hoose, Patrick M; Kelm, Natia Qipshidze; Piell, Kellianne M; Cole, Marsha P

    2016-08-01

    Cardiovascular health is influenced by dietary composition and the western diet is composed of varying types/amounts of fat. Conjugated linoleic acid (cLA) is an abundant dietary unsaturated fatty acid associated with health benefits but its biological signaling is not well understood. Nitrite is enriched in vegetables within the diet and can impact signaling of unsaturated fatty acids; however, its role on cLA signaling is not well understood. Elucidating how nitrite may impact the biological signaling of cLA is important due to the dietary consumption of both cLA and nitrite in the western diet. Since co-administration of cLA and nitrite results in cardioprotection during myocardial infarction (MI), it was hypothesized that cLA and nitrite may affect cardiac mitochondrial respiratory function and complex activity in MI. C57BL/6J mice were treated with cLA and nitrite for either 10 or 13days, where MI was induced on day 3. Following treatment, respiration and complex activity were measured. Among the major findings of this study, cLA treatment (10days) decreases state 3 respiration in vivo. Following MI, nitrite alone and in combination with cLA attenuates increased state 3 respiration and decreases hydrogen peroxide levels. Further, nitrite and cLA co-treatment attenuates increased complex III activity after MI. These results suggest that cLA, nitrite and the combination significantly alter cardiac mitochondrial respiratory and electron transport chain activity in vivo and following MI. Overall, the daily consumption of cLA and nitrite in the diet can have diverse cardiovascular implications, some of which occur at the mitochondrial level. PMID:27156147

  19. Myocardial fibrosis in nonhuman primate with pressure overload hypertrophy.

    PubMed

    Pick, R; Janicki, J S; Weber, K T

    1989-11-01

    Characteristics of pressure overload hypertrophy are known to include an accumulation of collagen (or fibrosis) and a biochemical remodeling of fibrillar type I and III collagens. The corresponding structural nature of myocardial fibrosis is less clear. This light morphologic study was undertaken to address this issue in the hypertrophied left ventricle of the nonhuman primate with experimental hypertension. For this purpose, the picrosirius red technique and polarization microscopy were used to examine the myocardium during the evolutionary, early, and late phases of established hypertrophy corresponding to 4, 35, and 88 weeks of experimental hypertension. Evidence of increased thin perimysial fiber formation, together with collagen fiber disruption and edema at 4 weeks of hypertrophy, was found when the chamber volume to left ventricular mass ratio was reduced. After 35 weeks, when this ratio was again normal, a greater number of intermuscular spaces contained both thick and thin perimysial fibers. In addition to this interstitial fibrosis, a reactive fibrosis consisting of a meshwork of thick and thin perimysial fibers was seen extending over muscle fibers. Finally, at 88 weeks, this fibrous meshwork had encircled muscle and there now was evidence of cell necrosis. The accompanying replacement fibrosis consisted of yet another distinctive orthogonal grid of thick and thin collagen fibers. Thus, a continuum of fibrillar collagen remodeling was seen in pressure overload hypertrophy in the nonhuman primate myocardium. Structurally distinct patterns of myocardial fibrosis were recognized based on the alignment of perimysial fibers with muscle that may explain the cellular remodeling and altered mechanical behavior of the concentrically hypertrophied myocardium. PMID:2530905

  20. Myocardial Function and Lipid Metabolism in the Chronic Alcoholic Animal

    PubMed Central

    Regan, Timothy J.; Khan, Mohammad I.; Ettinger, Philip O.; Haider, Bunyad; Lyons, Michael M.; Oldewurtel, Henry A.; Weber, Marilyn

    1974-01-01

    In view of the variables that obscure the pathogenesis of cardiomyopathy, a study was undertaken in mongrel dogs fed ethanol as 36% of calories for up to 22 mo. Both the experimental and control groups maintained body weight, hematocrit, plasma vitamin, and protein levels. Left ventricular function was evaluated in the intact anesthetized dog using indicator dilution for end-diastolic and stroke volume determinations. During increased afterload with angiotensin, the ethanol group exhibited a larger rise of end-diastolic pressure (P<0.01), whereas end-diastolic and stroke volume responses were significantly less than in controls. Preload increments with saline elicited a significantly higher end-diastolic pressure rise in the ethanol group (P<0.01). No hypertrophy, inflammation, or fibrosis was present and it was postulated that the enhanced diastolic stiffness was related to accumulation of Alcian Blue-positive material in the ventricular interstitium. To evaluate myocardial lipid metabolism, [1-14C]oleic acid was infused systemically. Plasma specific activity and myocardial lipid uptake were similar in both groups. There was a significantly increased incorporation of label into triglyceride, associated with a reduced 14CO2 production, considered the basis for a twofold increment of triglyceride content. In addition, diminished incorporation of [14C]oleic acid into phospholipid was observed accompanied by morphologic abnormalities of cardiac cell membranes. Potassium loss and sodium gain, like the lipid alteration, was more prominent in the subendocardium. Thus, chronic ethanol ingestion in this animal model is associated with abnormalities of ventricular function without evident malnutrition, analogous to the preclinical malfunction described in the human alcoholic. Images PMID:4368946

  1. Myocardial Ischemia: Lack of Coronary Blood Flow or Myocardial Oxygen Supply/Demand Imbalance?

    PubMed

    Heusch, Gerd

    2016-07-01

    Regional myocardial blood flow and contractile function in ischemic myocardium are well matched, and there is no evidence for an oxygen supply/demand imbalance. Thus, myocardial ischemia is lack of coronary blood flow with electric, functional, metabolic, and structural consequences for the myocardium. All therapeutic interventions must aim to improve blood flow to ischemic myocardium as much and as quickly as possible. PMID:27390331

  2. 131Cs myocardial scintigraphy. Application to assessment of anterior myocardial infarction.

    PubMed Central

    Burguet, W; Merchie, G; Kulbertus, H

    1975-01-01

    Earlier studies have indicated that caesium-131 is a good myocardial scanning agent for the demonstration of anterior infarcts. One hundred and ten patients with documented anterior myocardial infarction were studied by 131Cs myocardial scintigraphy. An anterior area of decreased uptake of caesium was noted in all but 3 subjects whose necrotic zone was likely to be of small dimensions. In 20 cases, the scintigram showed a definite, sometimes very large, cold area whereas the electrocardiogram failed to display any diagnostic feature of myocardial necrosis. In most of the latter instances, the electrocardiographic diagnosis was obscured by the presence of intraventricular conduction disturbances. In order to visualize the intracardiac cavities, the 131Cs investigation was usually completed by a 113mIn scintigram, which allowed recognition of a parietal aneurysm in 12 of the 18 patients with extensive anterior lesions. In each case, an index of necrosis was computed from planimetric measurements of the infarcted area as compared to the total left ventricular surfact in both the anteroposterior and left anterior oblique projections. This index was shown to correlate with the incidence of major complications developing after the acute episode of coronary occlusion. The sensitivity, specificity, and accuracy of the method are briefly discussed. It is felt that myocardial scintigraphy represents a sound approach to the semiquantitative assessment of anterior myocardial infarction; the clinical usefulness of the technique seems sufficiently demonstrated to prompt further research in this field. Images PMID:1191417

  3. Myocardial energy production and consumption remain balanced during positive inotropic stimulation when coronary flow is restricted to basal rates in rabbit heart.

    PubMed Central

    Marshall, R C; Nash, W W; Bersohn, M M; Wong, G A

    1987-01-01

    The effect on myocardial energy balance of increasing oxygen demand without altering basal myocardial perfusion rate was assessed in isolated, isovolumic, retrograde blood perfused rabbit hearts. Myocardial energy requirements were increased with paired stimulation. The capacity of rapid paired stimulation to increase mechanical energy consumption was demonstrated in the presence of increased perfusion with the rate X pressure product and oxygen consumption increasing 86 and 148%, respectively, compared with control values. In contrast, rapid paired stimulation under constant, basal flow conditions did not alter the rate X pressure product, while oxygen extraction and consumption increased only 40% relative to control. Myocardial ATP, creatine-phosphate, and lactate content were identical under control and constant flow-paired stimulation conditions. The results of this study indicate that no detectable energy imbalance was produced by rapid paired stimulation with flow held constant at basal rates. These results suggest that the myocardium does not increase mechanical energy expenditure in response to inotropic or rate stimulation in the presence of restricted flow reserve and are inconsistent with the concept of "demand-induced" or "relative" myocardial ischemia. PMID:3654976

  4. Cardiac MRI evaluation of myocardial disease.

    PubMed

    Captur, Gabriella; Manisty, Charlotte; Moon, James C

    2016-09-15

    Cardiovascular magnetic resonance (CMR) is a key imaging technique for cardiac phenotyping with a major clinical role. It can assess advanced aspects of cardiac structure and function, scar burden and other myocardial tissue characteristics but there is new information that can now be derived. This can fill many of the gaps in our knowledge with the potential to change thinking, disease classifications and definitions as well as patient care. Established techniques such as the late gadolinium enhancement technique are now embedded in clinical care. New techniques are coming through. Myocardial tissue characterisation techniques, particularly myocardial mapping can precisely measure tissue magnetisation-T1, T2, T2* and also the extracellular volume. These change in disease. Key biological pathways are now open for scrutiny including focal fibrosis (scar) and diffuse fibrosis, inflammation, metabolism and infiltration. Other new areas to engage in where major insights are growing include detailed assessments of myocardial mechanics and performance, spectroscopy and hyperpolarised CMR. In spite of the advances, challenges remain, particularly surrounding utilisation, technical development to improve accuracy, reproducibility and deliverability, and the role of multidisciplinary research to understand the detailed pathological basis of the MR signal changes. Collectively, these new developments are galvanising CMR uptake and having a major translational impact on healthcare globally and it is steadily becoming key imaging tool. PMID:27354273

  5. Myocardial ischemic protection in natural mammalian hibernation

    PubMed Central

    Yan, Lin; Kudej, Raymond K.; Vatner, Dorothy E.

    2015-01-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation. PMID:25613166

  6. Thrombolytic therapy in acute myocardial infarction.

    PubMed

    Woo, K S; White, H D

    1994-07-01

    Thrombolytic therapy has revolutionized the treatment of acute myocardial infarction by reducing mortality and preserving left ventricular function. It is relatively safe and cost-effective. However, it is currently underused in most countries. Patients in whom thrombolysis is indicated include those with ST elevation on the electrocardiogram or bundle branch block pattern who present within 12 hours of myocardial infarction; the indications should be widened to include the elderly, patients who have undergone nontraumatic cardiopulmonary resuscitation, and women during menstruation. The risk-benefit ratio should be assessed for the individual patient. Prehospital thrombolytic treatment has been shown to be feasible with the support of well-trained staff and resuscitation equipment, and may be cost-effective in communities with time delays before hospitalization greater than 1 hour. The most important strategy is to shorten the "door to needle" time in hospital. The importance of full infarct-related artery flow (Thrombolysis in Myocardial Infarction [TIMI] grade 3 flow) for preservation of ventricular function and survival has been documented in the second Thrombolysis Trial of Eminase in Acute Myocardial Infarction (TEAM 2) and the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) studies. Aspirin and heparin are beneficial adjunctive regimens to thrombolytic therapy but optimal epicardial reperfusion is achieved in only about half of patients. Improved thrombolytic, adjunctive antiplatelet, and antithrombotic regimens are required to achieve early full reperfusion, which is crucial to improve survival and quality of life. PMID:7919592

  7. Myocardial protection: what the anesthesiologist does.

    PubMed

    Merin, R G

    1990-09-01

    The role of the anesthesiologist in myocardial protection is to optimize myocardial oxygen balance during the perioperative period. Nonpharmacological steps that can be taken to achieve this revolve around maintaining a satisfactory hemoglobin concentration and oxyhemoglobin saturation through maximizing ventilation. In addition, alkalosis and hypothermia should be prevented since they cause a left shift of the oxyhemoglobin dissociation curve, thus interfering with tissue oxygen delivery. Hypocarbia increases coronary vascular resistance. Blood volume must be adequate with an optimal hemoglobin concentration. Pharmacological measures should also be used, and it is important to continue through the perioperative period any previously administered cardioactive drugs. Furthermore, in the prebypass period, tachycardia may not be controlled by anesthetics; unless the tachycardia is paroxysmal, beta blockers are the drugs of choice. Depending on the cause, diastolic hypotension also needs to be treated either with volume, vasoconstrictors, or inotropes. Likewise, major hypertension can produce increased demand and, again depending on the cause, either anesthetics, vasodilators, beta blockers, or calcium blockers may be useful. Finally, myocardial ischemia without obvious cause probably should be treated with nitroglycerin or calcium blockers. During surgery, the effect of the anesthetic drugs on myocardial oxygen balance is important. PMID:2133851

  8. Myocardial infarction complicated by ventricular septal rupture.

    PubMed

    Sahjian, Michael; Ventriglia, Rich; Bolton, Lauri

    2012-01-01

    Transporting patients with an ST segment elevation myocardial infarction (STEMI) is a fairly common practice for most critical care transport teams. When a STEMI is complicated by ventricular septal rupture, the care can become more challenging, especially if the rupture is not yet diagnosed. This article describes such a transport and reviews the pathophysiology of the process along with treatment options. PMID:22225564

  9. Decreased selenium levels in acute myocardial infarction

    SciTech Connect

    Kok, F.J.; Hofman, A.; Witteman, J.C.M.; de Bruijn, A.M.; Kruyssen, D.H.C.M.; de Bruin, M.; Valkenburg, H.A. )

    1989-02-24

    To study the association between selenium status and the risk of myocardial infarction, the authors compared plasma, erythrocyte, and toenail selenium levels and the activity of erythrocyte glutathione peroxidase among 84 patients with acute myocardial infarction and 84 population controls. Mean concentrations of all selenium measurements were lower in cases than controls. The differences were statistically significant, except for the plasma selenium level. A positive trend in the risk of acute myocardial infarction from high to low toenail selenium levels was observed, which persisted after adjustment for other risk factors for myocardial infarction. In contrast, erythrocyte glutathione peroxidase activity was significantly higher in cases than controls. Because toenail selenium level reflects blood levels up to one year before sampling, these findings suggest that a low selenium status was present before the infarction and, thus, may be of etiologic relevance. The higher glutathione peroxidase activity in the cases may be interpreted as a defense against increased oxidant stress either preceding or following the acute event.

  10. Rehabilitation of Patients Following Myocardial Infarction.

    ERIC Educational Resources Information Center

    Blumenthal, James A.; Emery, Charles F.

    1988-01-01

    Examines three behavioral strategies in cardiac rehabilitation (CR) for formal treatment for physical and psychosocial sequelae of myocardial infarction (MI): exercise therapy, Type A modification, and nonspecific psychological therapies. Concludes CR improves the quality of life among post-MI patients, but does not prolong life or significantly…

  11. Myocardial ischemic protection in natural mammalian hibernation.

    PubMed

    Yan, Lin; Kudej, Raymond K; Vatner, Dorothy E; Vatner, Stephen F

    2015-03-01

    Hibernating myocardium is an important clinical syndrome protecting the heart with chronic myocardial ischemia, named for its assumed resemblance to hibernating mammals in winter. However, the effects of myocardial ischemic protection have never been studied in true mammalian hibernation, which is a unique strategy for surviving extreme winter environmental stress. The goal of this investigation was to test the hypothesis that ischemic stress may also be protected in woodchucks as they hibernate in winter. Myocardial infarction was induced by coronary occlusion followed by reperfusion in naturally hibernating woodchucks in winter with and without hibernation and in summer, when not hibernating. The ischemic area at risk was similar among groups. Myocardial infarction was significantly less in woodchucks in winter, whether hibernating or not, compared with summer, and was similar to that resulting after ischemic preconditioning. Whereas several genes were up or downregulated in both hibernating woodchuck and with ischemic preconditioning, one mechanism was unique to hibernation, i.e., activation of cAMP-response element binding protein (CREB). When CREB was upregulated in summer, it induced protection similar to that observed in the woodchuck heart in winter. The cardioprotection in hibernation was also mediated by endothelial nitric oxide synthase, rather than inducible nitric oxide synthase. Thus, the hibernating woodchuck heart is a novel model to study cardioprotection for two major reasons: (1) powerful cardioprotection occurs naturally in winter months in the absence of any preconditioning stimuli, and (2) it resembles ischemic preconditioning, but with novel mechanisms, making this model potentially useful for clinical translation. PMID:25613166

  12. Thrombus aspiration in acute myocardial infarction.

    PubMed

    Mahmoud, Karim D; Zijlstra, Felix

    2016-07-01

    The success of primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is often hampered by incomplete microvascular myocardial reperfusion owing to distal embolization of thrombus resulting in microvascular obstruction. To address this problem, thrombus aspiration devices have been developed that can be used to evacuate coronary thrombus either manually or mechanically. Thrombus aspiration has the potential to reduce the local thrombus load, minimize the need for balloon predilatation, facilitate direct stenting, prevent distal embolization, and ultimately improve myocardial reperfusion. Furthermore, thrombus aspiration has enabled us to study coronary thrombus in vivo, and has facilitated recognition of distinct mechanisms of coronary thrombosis. Clinical trials focusing on manual thrombus aspiration in primary PCI have generally shown improved myocardial reperfusion. However, in two large trials powered for clinical end points, no reduction in 1-year mortality or other adverse clinical events was observed with the use of this strategy. Moreover, one of these trials showed a marginally increased risk of stroke. Consequently, current guidelines do not recommend routine use of thrombus aspiration. Future studies should focus on the identification of subgroups of patients with STEMI who might derive benefit from manual thrombus aspiration, and establish the effect of operator performance on the efficacy and safety of the procedure. PMID:26961064

  13. Perceived Neighborhood Social Cohesion and Myocardial Infarction

    PubMed Central

    Kim, Eric S.; Hawes, Armani M.; Smith, Jacqui

    2015-01-01

    Background The main strategy for alleviating heart disease has been to target individuals and encourage them to change their health behaviors. Though important, emphasis on individuals has diverted focus and responsibility away from neighborhood characteristics, which also strongly influence people’s behaviors. Although a growing body of research has repeatedly demonstrated strong associations between neighborhood characteristics and cardiovascular health, it has typically focused on negative neighborhood characteristics. Only a few studies have examined the potential health enhancing effects of positive neighborhood characteristics, such as perceived neighborhood social cohesion. Methods Using multiple logistic regression models, we tested whether higher perceived neighborhood social cohesion was associated with lower incidence of myocardial infarction. Prospective data from the Health and Retirement Study—a nationally representative panel study of American adults over the age of 50—were used to analyze 5,276 participants with no history of heart disease. Respondents were tracked for four years and analyses adjusted for relevant sociodemographic, behavioral, biological, and psychosocial factors. Results In a model that adjusted for age, gender, race, marital status, education, and total wealth, each standard deviation increase in perceived neighborhood social cohesion was associated with a 22% reduced odds of myocardial infarction (OR = 0.78, 95% CI, 0.63–0.94. The association between perceived neighborhood social cohesion and myocardial infarction remained even after adjusting for behavioral, biological, and psychosocial covariates. Conclusions Higher perceived neighborhood social cohesion may have a protective effect against myocardial infarction. PMID:25135074

  14. Circadian rhythms in myocardial metabolism and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Circadian rhythms in myocardial function and dysfunction are firmly established in both animal models and humans. For example, the incidence of arrhythmias and sudden cardiac death increases when organisms awaken. Such observations have classically been explained by circadian rhythms in neurohumoral...

  15. [Prehospital thrombolytic therapy in acute myocardial infarction].

    PubMed

    Carlsson, J; Schuster, H P; Tebbe, U

    1997-10-01

    The extent of myocardial damage occurring during acute myocardial infarction is time dependent, and there is abundant evidence from most clinical trials that mortality reduction is greatest in patients treated early with thrombolytic agents, although beneficial effects have been shown with treatment initiated up to 12 h after onset of symptoms. All studies on prehospital thrombolysis have conclusively shown the practicability and safety of patient selection and administration of the thrombolytic agent. The accuracy of diagnosis in the prehospital setting was comparable to trials of in-hospital thrombolysis, e.g., in the Myocardial Infarction Triage and Intervention Project (MITI) 98% of the patients enrolled had subsequent evidence of acute myocardial infarction. With regard to time savings, all randomized studies showed positive results. The smallest time gain was observed in the MITI trial: prehospital-treated patients received thrombolytic therapy an average of 33 min earlier than those treated in hospital. In the European Myocardial Infarction Project (EMIP) the difference in time between prehospital and hospital treatment was a median of 55 min. However, none of these trials was able to show a significant short-term mortality difference between the two groups. Only a meta analysis of five randomized studies with a combined median time gain of about 60 min showed a significant 17% reduction in short-term mortality for patients who received thrombolytic therapy in the prehospital phase. In the Grampian Region Early Anistreplase Trial (GREAT), a study performed in a more rural area than other studies, the time gain by prehospital initiation of thrombolysis was a median of 130 min. GREAT was the only study to date reporting a significant mortality benefit for prehospital-treated patients after 3 months and 1 year. In conclusion, prehospital thrombolysis is feasible and safe. Patients with acute myocardial infarction can be correctly identified and treated with

  16. A framework to measure myocardial extracellular volume fraction using dual-phase low dose CT images

    SciTech Connect

    Liu, Yixun; Summers, Ronald M.; Yao, Jianhua; Liu, Songtao; Sibley, Christopher T.; Bluemke, David A.; Nacif, Marcelo S.

    2013-10-15

    Purpose: Myocardial extracellular volume fraction (ECVF) is a surrogate imaging biomarker of diffuse myocardial fibrosis, a hallmark of pathologic ventricular remodeling. Low dose cardiac CT is emerging as a promising modality to detect diffuse interstitial myocardial fibrosis due to its fast acquisition and low radiation; however, the insufficient contrast in the low dose CT images poses great challenge to measure ECVF from the image. Methods: To deal with this difficulty, the authors present a complete ECVF measurement framework including a point-guided myocardial modeling, a deformable model-based myocardium segmentation, nonrigid registration of pre- and post-CT, and ECVF calculation. Results: The proposed method was evaluated on 20 patients by two observers. Compared to the manually delineated reference segmentations, the accuracy of our segmentation in terms of true positive volume fraction (TPVF), false positive volume fraction (FPVF), and average surface distance (ASD), were 92.18% ± 3.52%, 0.31% ± 0.10%, 0.69 ± 0.14 mm, respectively. The interobserver variability measured by concordance correlation coefficient regarding TPVF, FPVF, and ASD were 0.95, 0.90, 0.94, respectively, demonstrating excellent agreement. Bland-Altman method showed 95% limits of agreement between ECVF at CT and ECVF at MR. Conclusions: The proposed framework demonstrates its efficiency, accuracy, and noninvasiveness in ECVF measurement and dramatically advances the ECVF at cardiac CT toward its clinical use.

  17. [Myocardial involvement in diabetic patients evaluated by exercise thallium-201 scintigraphy and cardiac catheterization].

    PubMed

    Mizuno, S; Genda, A; Nakayama, A; Igarashi, Y; Takeda, R

    1985-06-01

    To evaluate myocardial involvement in diabetes mellitus, we studied 39 patients with negative double-Master's test and without hypertension by exercise thallium-201 (T1-201) myocardial scintigraphy using a bicycle ergometer. Among the 39 patients, 12 (30.8%) showed filling defects in the scintigrams (positive cases), including eight with stress-induced defects and four with fixed defects. The positive cases had higher scores of diabetic complications (3.6 +/- 2.4 vs 2.1 +/- 1.8; p less than 0.05) and longer durations of diabetes as compared with those of the negative cases. The frequency of insulin therapy was also greater in the positive cases. Eleven patients (5 positive and 6 negative cases) who underwent cardiac catheterization had no significant stenotic lesions of their coronary arteries. However, all of the positive cases showed abnormal wall motion, mainly hypokinesis, by left ventriculography (LVG). The abnormalities of the LVG corresponded to the findings of the scintigrams (i.e. filling defects and decrease in washout ratios by circumferential profile analysis). These results suggest that in some diabetics myocardial involvement exists in the early stage without overt cardiac disease and exercise T1-201 scintigraphy is useful in detecting pre-clinical cardiomyopathy. Cardiomyopathy in diabetics seems to be due to disturbances of the myocardial microcirculation. PMID:4093624

  18. Prediction of coronary plaque location on arteries having myocardial bridge, using finite element models.

    PubMed

    Nikolić, Dalibor; Radović, Miloš; Aleksandrić, Srđan; Tomašević, Miloje; Filipović, Nenad

    2014-11-01

    This study was performed to evaluate the influences of the myocardial bridges on the plaque initializations and progression in the coronary arteries. The wall structure is changed due to the plaque presence, which could be the reason for multiple heart malfunctions. Using simplified parametric finite element model (FE model) of the coronary artery having myocardial bridge and analyzing different mechanical parameters from blood circulation through the artery (wall shear stress, oscillatory shear index, residence time), we investigated the prediction of "the best" position for plaque progression. We chose six patients from the angiography records and used data from DICOM images to generate FE models with our software tools for FE preprocessing, solving and post-processing. We found a good correlation between real positions of the plaque and the ones that we predicted to develop at the proximal part of the myocardial bridges with wall shear stress, oscillatory shear index and residence time. This computer model could be additional predictive tool for everyday clinical examination of the patient with myocardial bridge. PMID:25139775

  19. Prediction of myocardial damage depth induced by extracellular photosensitization reaction using fluorescence measurement in vivo

    NASA Astrophysics Data System (ADS)

    Takahashi, M.; Ogawa, E.; Nakamura, T.; Kawakami, H.; Machida, N.; Yajima, M.; Kurotsu, M.; Ito, A.; Kimura, T.; Arai, T.

    2014-03-01

    We experimentally studied the correlation between myocardial damage depth due to the extracellular photosensitization reaction (PR) using talaporfin sodium and fluorescence-fall amount (FA), which is calculated from the measured backscattering fluorescence intensity via a manipulatable 7 Fr. laser catheter during the PR operation in vivo to establish treatment depth predictor for a non-thermal tachyarrhythmia treatment. The PR was performed to left and/or right ventricle in the open-chest canine heart. The laser irradiation of 663+/-2 nm in wavelength via the laser catheter was operated 15 min after the intravenous administration of talaporfin sodium with concentration of 36.2+/-8.0 μg/ml in plasma. The irradiation was operated with irradiance of 5, 10, 20 W/cm2, and duration of 5, 10, 20 s. Backscattering fluorescence of 710+/-2 nm in wavelength was measured via the laser catheter during the PR. The FA was calculated multiplying the irradiation duration by the fluorescence-fall, which is subtraction of the fluorescence intensity at the kickoff and end of the irradiation. The canine heart was extracted 1 week after the PR and HE stained specimen was histologically evaluated. The correlation of the myocardial damage depth and FA was investigated. We found that FA obtained a logarithmic relation to the myocardial damage depth. We think that the FA might be available to predict the PR induced myocardial damage depth for the application of tachyarrhythmia treatment under catheterization in vivo.

  20. Cardioprotective effect of insulin-like growth factor I in myocardial ischemia followed by reperfusion.

    PubMed Central

    Buerke, M; Murohara, T; Skurk, C; Nuss, C; Tomaselli, K; Lefer, A M

    1995-01-01

    In the present study, the cardioprotective effects of insulin-like growth factor I (IGF-I) were examined in a murine model of myocardial ischemia reperfusion (i.e., 20 min + 24 hr). IGF-I (1-10 micrograms per rat) administered 1 hr prior to ischemia significantly attenuated myocardial injury (i.e., creatine kinase loss) compared to vehicle (P < 0.001). In addition, cardiac myeloperoxidase activity, an index of neutrophil accumulation, in the ischemic area was significantly attenuated by IGF-I (P < 0.001). This protective effect of IGF-I was not observed with des-(1-3)-IGF-I. Immunohistochemical analysis of ischemic-reperfused myocardial tissue demonstrated markedly increased DNA fragmentation due to programmed cell death (i.e., apoptosis) compared to nonischemic myocardium. Furthermore, IGF-I significantly attenuated the incidence of myocyte apoptosis after myocardial ischemia and reperfusion. Therefore, IGF-I appears to be an effective agent for preserving ischemic myocardium from reperfusion injury and protects via two different mechanisms--inhibition of polymorphonuclear leukocyte-induced cardiac necrosis and inhibition of reperfusion-induced apoptosis of cardiac myocytes. Images Fig. 5 PMID:7644533

  1. [Altered states of consciousness].

    PubMed

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed. PMID:15810684

  2. Compatibility of Astragalus and Salvia extract inhibits myocardial fibrosis and ventricular remodeling by regulation of protein kinase D1 protein

    PubMed Central

    Mao, Bingyu; Nuan, Liu; Yang, Lei; Zeng, Xiaotao

    2015-01-01

    Aims: This study is to determine the effect of astragalus and salvia extract on the alteration of myocardium in a rat model of myocardial infarction. Methods: A total of 40 male Sprague-Dawley rats were randomly divided into the sham-operated group, the control group, the Astragalus group, the Salvia group, and the compatibility of Astragalus and Salvia and group. The cardiac functions were determined at 8 weeks after treatment. Hematoxylin-eosin staining was performed to observe the morphology and arrangement of cardiomyocytes. Masson’s trichrome staining was performed to investigate the distribution of myocardial interstitial collagen. Immunohistochemical staining was performed to determine the expression ofprotein kinase D1 in myocardial tissues. Results: In the sham-operated group, the Astragalus group, the Salvia group, and the compatibility of Astragalus and Salvia group, the left ventricular systolic pressure and the maximum rate of left ventricular pressure were significantly increased while the left ventricular end diastolic pressure were significantly decreased when compared with those in the control group (P < 0.05). Normal morphology and arrangement of cardiomyocytes were maintained in the compatibility of Astragalus and Salvia group. Contents of collagen fibers in myocardial tissues were decreased in the compatibility of Astragalus and Salvia group (P < 0.05). Expression levels of protein kinase D1 were significantly decreased in cardiomyocytes of the compatibility of Astragalus and Salvia group. Conclusions: Compatibility of Astragalus and Salvia extract may inhibit myocardial fibrosis and ventricular remodeling by regulation of protein kinase D1 protein in a rat model of myocardial infarction. PMID:26064267

  3. The Role of Oxidative Stress in Myocardial Ischemia and Reperfusion Injury and Remodeling: Revisited

    PubMed Central

    Kurian, Gino A.; Rajagopal, Rashmi; Vedantham, Srinivasan; Rajesh, Mohanraj

    2016-01-01

    Oxidative and reductive stress are dual dynamic phases experienced by the cells undergoing adaptation towards endogenous or exogenous noxious stimulus. The former arises due to the imbalance between the reactive oxygen species production and antioxidant defenses, while the latter is due to the aberrant increase in the reducing equivalents. Mitochondrial malfunction is the common denominator arising from the aberrant functioning of the rheostat that maintains the homeostasis between oxidative and reductive stress. Recent experimental evidences suggest that the maladaptation during oxidative stress could play a pivotal role in the pathophysiology of major cardiovascular diseases such as myocardial infraction, atherosclerosis, and diabetic cardiovascular complications. In this review we have discussed the role of oxidative and reductive stress pathways in the pathogenesis of myocardial ischemia/reperfusion injury and diabetic cardiomyopathy (DCM). Furthermore, we have provided impetus for the development of subcellular organelle targeted antioxidant drug therapy for thwarting the deterioration of the failing myocardium in the aforementioned cardiovascular conditions. PMID:27313825

  4. The Role of Oxidative Stress in Myocardial Ischemia and Reperfusion Injury and Remodeling: Revisited.

    PubMed

    Kurian, Gino A; Rajagopal, Rashmi; Vedantham, Srinivasan; Rajesh, Mohanraj

    2016-01-01

    Oxidative and reductive stress are dual dynamic phases experienced by the cells undergoing adaptation towards endogenous or exogenous noxious stimulus. The former arises due to the imbalance between the reactive oxygen species production and antioxidant defenses, while the latter is due to the aberrant increase in the reducing equivalents. Mitochondrial malfunction is the common denominator arising from the aberrant functioning of the rheostat that maintains the homeostasis between oxidative and reductive stress. Recent experimental evidences suggest that the maladaptation during oxidative stress could play a pivotal role in the pathophysiology of major cardiovascular diseases such as myocardial infraction, atherosclerosis, and diabetic cardiovascular complications. In this review we have discussed the role of oxidative and reductive stress pathways in the pathogenesis of myocardial ischemia/reperfusion injury and diabetic cardiomyopathy (DCM). Furthermore, we have provided impetus for the development of subcellular organelle targeted antioxidant drug therapy for thwarting the deterioration of the failing myocardium in the aforementioned cardiovascular conditions. PMID:27313825

  5. Control of intraoperative hypertension with isoflurane in patients with coronary artery disease: effects on regional myocardial blood flow and metabolism.

    PubMed

    Sahlman, L; Milocco, I; Appelgren, L; William-Olsson, G; Ricksten, S E

    1989-02-01

    The effect of isoflurane on regional myocardial metabolism and blood flow, when used as an adjunct to fentanyl-nitrous oxide anesthesia, to control intraoperative hypertension was investigated. Twenty-two patients with two- or three-vessel coronary artery disease with an ejection fraction greater than 0.5 and on beta-blockers up to the morning of surgery were studied during elective coronary artery by-pass grafting. Systemic and pulmonary hemodynamics, and regional (great cardiac vein, GCVF) myocardial blood flow and myocardial metabolic parameters were measured. In 10 patients, both GCVF and global (coronary sinus, CSF) myocardial blood flows were recorded. Measurements were made 1) after induction of anesthesia but prior to skin incision, 2) during sternotomy, and 3) during isoflurane administration after its use to reduce arterial pressure to the presternotomy level. The increase in systemic arterial pressure during sternotomy was due to an increase in systemic vascular resistance accompanied by increases in heart rate, pulmonary capillary wedge pressure, (PCWP) regional myocardial oxygen consumption and extraction, GCVF and total coronary vascular resistance. Isoflurane reduced systemic arterial pressure but not PCWP, to presternotomy levels within 6.9 +/- 0.7 minutes at an end-tidal concentration of 1.5 +/- 0.2%. Isoflurane induced a pronounced systemic and coronary vasodilatation and increases in cardiac index, heart rate and regional myocardial oxygen extraction while the GCVF/CSF ratio remained unchanged. While mean regional--MLE% values were not effected by sternotomy, in two patients myocardial lactate production was seen during sternotomy but not during isoflurane. In another two patients, isoflurane induced lactate production.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2783640

  6. BOTH ENDOGENOUS AND EXOGENOUS TESTOSTERONE DECREASE MYOCARDIAL STAT3 ACTIVATION AND SOCS3 EXPRESSION FOLLOWING ACUTE ISCHEMIA AND REPERFUSION

    PubMed Central

    Wang, Meijing; Wang, Yue; Abarbanell, Aaron; Tan, Jiangjing; Weil, Brent; Herrmann, Jeremy; Meldrum, Daniel R.

    2009-01-01

    Background Signal transducer and activator of transduction 3 (STAT3) pathway has been shown to be cardioprotective. We observed decreased STAT3/suppressor of cytokine signaling 3 (SOCS3) in male hearts, which was associated with worse post-ischemic myocardial function compared to females. However, it is unclear whether this down-regulation of myocardial STAT3/SOCS3 is due to testosterone in males. We hypothesized that following ischemia/reperfusion (I/R): 1) endogenous testosterone decreases myocardial STAT3 and SOCS3 in males; 2) administration of exogenous testosterone reduces myocardial STAT3/SOCS3 in female and castrated male hearts. Methods To study this, hearts from I/R injury (Langendorff) were homogenized and assessed for phosphorylated-STAT3 (p-STAT3), total-STAT3 (T-STAT3), SOCS3 and GAPDH by western blot. Groups: age-matched adult males, females, castrated males, males with androgen receptor blocker-flutamide implantation, females and castrated males with chronic (3-week) 5alpha-dihydrotestosterone (DHT) release pellet implantation or acute (5-minute) testosterone infusion (ATI) prior to ischemia (n=5–9/group). Results Castration or flutamide treatment significantly increased SOCS3 expression in male hearts after I/R. However, only castration increased myocardial STAT3 activation. Notably, DHT replacement or ATI markedly decreased myocardial STAT3/SOCS3 in castrated males and females subjected to I/R. Conclusion These results suggest that endogenous and exogenous testosterone decrease myocardial STAT3 activation and SOCS3 expression following I/R. This represents the initial demonstration of testosterone-downregulated STAT3/SOCS3 signaling in myocardium. PMID:19628067

  7. Reperfusion strategies in ST-segment elevation myocardial infarction.

    PubMed

    Stiermaier, T; Desch, S; Schuler, G; Thiele, H; Eitel, I

    2013-08-01

    ST-elevation myocardial infarction (STEMI) is a major cause of morbidity and mortality worldwide. Emergent reperfusion of the infarct related artery is the cornerstone of STEMI treatment in order to salvage myocardium and improve cardiovascular outcome. Basically, reperfusion strategies include fibrinolysis, primary percutaneous coronary intervention (PCI) or the combination of both methods. Clinical studies indicate that primary PCI is superior to fibrinolytic therapy when performed rapidly at experienced centers. However, physicians are often faced with the decision to either accept PCI-related delays due to transfer or to administer fibrinolysis immediately. A well structured regional system of STEMI care helps to select the appropriate reperfusion strategy and guarantee timely restoration of coronary blood flow. This article reviews the evidence behind the respective reperfusion therapies and summarizes current guidelines for STEMI management. PMID:24008602

  8. Noncompaction and embolic myocardial infarction: the importance of oral anticoagulation.

    PubMed

    Pulignano, Giovanni; Tinti, Maria Denitza; Tolone, Stefano; Musto, Carmine; De Lio, Lucia; Pino, Paolo Giuseppe; Minardi, Giovanni; Violini, Roberto; Uguccioni, Massimo

    2015-01-01

    Left ventricular noncompaction (LVNC) is characterized by left ventricular (LV) hypertrabeculations and is associated with heart failure, arrhythmias and embolism. We report the case of a 67-year-old LVNC patient, under oral anticoagulation (OAC) therapy for apical thrombosis. After she discontinued OAC, the thrombus involved almost the whole of the left ventricle; in a few months her condition worsened, requiring hospitalization, and despite heparin infusion she experienced myocardial infarction (MI), caused by embolic occlusion of the left anterior descending artery. Although infrequent as a complication of LVNC, and usually attributable to microvascular dysfunction, in this case MI seems due to coronary thromboembolism from dislodged thrombotic material in the left ventricle. PMID:26162290

  9. Type 2 myocardial infarction: the chimaera of cardiology?

    PubMed

    Collinson, Paul; Lindahl, Bertil

    2015-11-01

    The term type 2 myocardial infarction first appeared as part of the universal definition of myocardial infarction. It was introduced to cover a group of patients who had elevation of cardiac troponin but did not meet the traditional criteria for acute myocardial infarction although they were considered to have an underlying ischaemic aetiology for the myocardial damage observed. Since first inception, the term type 2 myocardial infarction has always been vague. Although attempts have been made to produce a systematic definition of what constitutes a type 2 myocardial infarction, it has been more often characterised by what it is not rather than what it is. Clinical studies that have used type 2 myocardial infarction as a diagnostic criterion have produced disparate incidence figures. The range of associated clinical conditions differs from study to study. Additionally, there are no agreed or evidence-based treatment strategies for type 2 myocardial infarction. The authors believe that the term type 2 myocardial infarction is confusing and not evidence-based. They consider that there is good reason to stop using this term and consider instead the concept of secondary myocardial injury that relates to the underlying pathophysiology of the primary clinical condition. PMID:26220812

  10. Oligophrenin1 protects mice against myocardial ischemia and reperfusion injury by modulating inflammation and myocardial apoptosis.

    PubMed

    Niermann, Christina; Gorressen, Simone; Klier, Meike; Gowert, Nina S; Billuart, Pierre; Kelm, Malte; Merx, Marc W; Elvers, Margitta

    2016-08-01

    The Rho family of small GTPases has been analyzed in cardiac physiology and pathophysiology including myocardial infarction (MI) in the last years. Contradictory results show either a protective or a declined effect of RhoA and the RhoA effector Rho-associated protein kinase (ROCK) in myocardial ischemia and reperfusion injury that is associated with cardiomyocyte survival and caspase-3 activation. Cardiac-specific deletion of Rac1 reduced ischemia reperfusion injury in diabetic hearts, whereas cardiomyocyte specific overexpression of active Rac1 predisposes the heart to increased myocardial injury with enhanced contractile dysfunction. GTPase-activating proteins (GAPs) control the activation of Rho proteins through stimulation of GTP hydrolysis. However, the impact of GAPs in myocardial ischemia and reperfusion injury remains elusive. Here we analyzed the role of oligophrenin1 (OPHN1), a RhoGAP with Bin/Amphiphysin/Rvs (BAR) domain known to regulate the activity of RhoA, Rac1 and Cdc42 in MI. The expression of Ophn1, RhoA and Rac1 is strongly upregulated 24h after myocardial ischemia. Loss of OPHN1 induced enhanced activity of Rho effector molecules leading to elevated cardiomyocyte apoptosis and increased migration of inflammatory cells into the infarct border zone of OPHN1 deficient mice. Consequently, echocardiography 24h after myocardial ischemia revealed declined left ventricle function in OPHN1 deficient mice. Our results indicate that OPHN1 mediated regulation of RhoA, Rac1 and Cdc42 is crucial for the preservation of cardiac function after myocardial injury. PMID:27117132

  11. Thymoquinone Protects against Myocardial Ischemic Injury by Mitigating Oxidative Stress and Inflammation

    PubMed Central

    Ojha, Shreesh; Azimullah, Sheikh; Mohanraj, Rajesh; Sharma, Charu; Yasin, Javed; Arya, Dharamvir S.; Adem, Abdu

    2015-01-01

    The present study was aimed at investigating the cardioprotective activity of thymoquinone (TMQ), an active principle of the herb, Nigella sativa, which is used for the management of various diseases. The present study examined the cardioprotective effect of TMQ in isoproterenol- (ISP-) induced myocardial infarction in rats. Myocardial infarction was induced by two subcutaneous injections of ISP (85 mg/kg) at an interval of 24 hr. TMQ (20 mg/kg) was administered orally for 21 days. ISP-treated rats showed depletion of antioxidants and marker enzymes from myocardium along with lipid peroxidation and enhanced levels of proinflammatory cytokines. ISP also induced histopathological alterations in myocardium. Treatment with TMQ prevented the depletion of endogenous antioxidants and myocyte injury marker enzymes and inhibited lipid peroxidation as well as reducing the levels of proinflammatory cytokines. TMQ pretreatment also reduced myonecrosis, edema, and infiltration of inflammatory cells and showed preservation of cardiomyocytes histoarchitecture. The present study results demonstrate that TMQ exerts cardioprotective effect by mitigating oxidative stress, augmenting endogenous antioxidants, and maintaining structural integrity. The results of the present study indicate that TMQ may serve as an excellent agent alone or as adjuvant to prevent the onset and progression of myocardial injury. PMID:26101531

  12. Ischemic myocardial disease as an example of a thrombotic event. A historical note.

    PubMed

    Martins e Silva, J

    2006-05-01

    The definition of myocardial ischemia as a clinical entity of thrombotic etiology was established in 1912 by James Herrick. His proposal was based on the work of William Heberden, who in 1772 defined the clinical profile of angina pectoris, and the observations of Edward Jenner about a century later on intracoronary thrombosis in patients who had died with such symptoms. On the basis of these results, Jenner and Caleb Parry proposed that the main cause of angina were alterations in the coronary arteries, while Marshall Hall, in 1842, attributed sudden death in these patients to interruption of the coronary circulation. The discovery of a common cause for angina pectoris and myocardial infarction, inducing a reduction or interruption of oxygen supply to myocardial tissue, the atherosclerotic etiology of intracoronary lesions, and the importance of plaque fissuring in the sudden formation of intracoronary thrombi, were successive milestones in our understanding in the 20th century, the culmination of the process of meticulous observation begun many years before. PMID:16910161

  13. Oxygen cycling to improve survival of stem cells for myocardial repair: A review.

    PubMed

    Dall, Christopher; Khan, Mahmood; Chen, Chun-An; Angelos, Mark G

    2016-05-15

    Heart disease represents the leading cause of death among Americans. There is currently no clinical treatment to regenerate viable myocardium following myocardial infarction, and patients may suffer progressive deterioration and decreased myocardial function from the effects of remodeling of the necrotic myocardium. New therapeutic strategies hold promise for patients who suffer from ischemic heart disease by directly addressing the restoration of functional myocardium following death of cardiomyocytes. Therapeutic stem cell transplantation has shown modest benefit in clinical human trials with decreased fibrosis and increased functional myocardium. Moreover, autologous transplantation holds the potential to implement these therapies while avoiding the immunomodulation concerns of heart transplantation. Despite these benefits, stem cell therapy has been characterized by poor survival and low engraftment of injected stem cells. The hypoxic tissue environment of the ischemic/infracting myocardium impedes stem cell survival and engraftment in myocardial tissue. Hypoxic preconditioning has been suggested as a viable strategy to increase hypoxic tolerance of stem cells. A number of in vivo and in vitro studies have demonstrated improved stem cell viability by altering stem cell secretion of protein signals and up-regulation of numerous paracrine signaling pathways that affect inflammatory, survival, and angiogenic signaling pathways. This review will discuss both the mechanisms of hypoxic preconditioning as well as the effects of hypoxic preconditioning in different cell and animal models, examining the pitfalls in current research and the next steps into potentially implementing this methodology in clinical research trials. PMID:27091653

  14. N-13 ammonia as an indicator of myocardial blood flow. [Dogs

    SciTech Connect

    Schelbert, H.R.; Phelps, M.E.; Huang, S.C.; MacDonald, N.S.; Hansen, H.; Selin, C.; Kuhl, D.E.

    1981-06-01

    We have characterized N-13 ammonia as a myocardial blood flow imaging agent suitable for positron-emission computed tomography. However, the mechanisms of uptake and retention of this agent in myocardium are not known, and effects of altered metabolism were not considered. Therefore, we studied the uptake and retention of N-13 ammonia in myocardium under various hemodynamic and metabolic conditions in open-chest dogs. N-13 ammonia was extracted nearly 100% during its initial capillary transit, followed by metabolic trapping that competed with flow-dependent back diffusion. At control flows, the first capillary transit extraction fraction (E) of N-13 ammonia averaged 0.82 +- 0.06. Inhibition of glutamine synthetase with L-methionine sulfoximine impaired metabolic trapping of N-13 ammonia and implicates te glutamic acid-glutamine reaction as the primary mechanism for ammonia fixation. Blood flow and metabolic trapping are the primary determinants of myocardial uptake and retention of N-13 ammonia. The relative constancy of metabolic trapping over a wide range of hemodynamic and metabolic conditions demonstrates the value of N-13 ammonia as a myocardial blood flow imaging agent.

  15. Myocardial Hypertrophy and Its Role in Heart Failure with Preserved Ejection Fraction

    PubMed Central

    Heinzel, Frank R.; Hohendanner, Felix; Jin, Ge; Sedej, Simon; Edelmann, Frank

    2015-01-01

    Left ventricular hypertrophy (LVH) is the most common myocardial structural abnormality associated with heart failure with preserved ejection fraction (HFpEF). LVH is driven by neurohumoral activation, increased mechanical load and cytokines associated with arterial hypertension, chronic kidney disease, diabetes and other co-morbidities. Here we discuss the experimental and clinical evidence that links LVH to diastolic dysfunction and qualifies LVH as one diagnostic marker for HFpEF. Mechanisms leading to diastolic dysfunction in LVH are incompletely understood but may include extracellular matrix changes, vascular dysfunction as well as altered cardiomyocyte mechano-elastical properties. Beating cardiomyocytes from HFpEF patients have not yet been studied, but we and others have shown increased Ca2+ turnover and impaired relaxation in cardiomyocytes from hypertrophied hearts. Structural myocardial remodeling can lead to heterogeneity in regional myocardial contractile function, which contributes to diastolic dysfunction in HFpEF. In the clinical setting of patients with compound co-morbidities, diastolic dysfunction may occur independently of LVH. This may be one explanation why current approaches to reduce LVH have not been effective to improve symptoms and prognosis in HFpEF. Exercise training on the other hand, in clinical trials improved exercise tolerance and diastolic function but did not reduce LVH. Thus, current clinical evidence does not support regression of LVH as a surrogate marker for (short-term) improvement of HFpEF. PMID:26183480

  16. Coronary artery perforation in a patient with STEMI and a myocardial bridge: an increased risk for coronary artery perforation?

    PubMed

    Becher, Tobias; Baumann, Stefan; Huseynov, Aydin; Behnes, Michael; Borggrefe, Martin; Akin, Ibrahim

    2015-06-01

    We present the case of a patient with ST-elevation myocardial infarction (STEMI) due to subtotal occlusion of the left anterior descending coronary artery caused by an atherosclerotic lesion and a myocardial bridge (MB). Stenting of the MB caused coronary artery perforation resulting in a fistula to the right ventricle that was closed by implantation of a PTFE-covered stent. Follow-up coronary angiography showed persistent shunting, which was sealed by inflation of a high-pressure balloon over the site of extravasation guided by intravascular ultrasound. Additionally, we provide a short review of cases with coronary artery perforation after stenting of an MB. PMID:25842348

  17. Iodine-123 N-methyl-4-iododexetimide: a new radioligand for single-photon emission tomographic imaging of myocardial muscarinic receptors.

    PubMed

    Hicks, R J; Kassiou, M; Eu, P; Katsifis, A G; Garra, M; Power, J; Najdovski, L; Lambrecht, R M

    1995-04-01

    Cardiac muscarinic receptor ligands suitable for positron emission tomography have previously been characterised. Attempts to develop radioligands of these receptors suitable for single-photon emission tomographic (SPET) imaging have not been successful due to high lung retention and high non-specific binding of previously investigated potential tracers. The purpose of this study was to evaluate the biodistribution and in vivo imaging characteristics of a new radiopharmaceutical, [123I]N-methyl-4-iododexetimide. Biodistribution studies performed in rats showed high cardiac uptake (2.4% ID/g) 10 min after injection with a heart to lung activity ratio of 5:1. Specificity and stereoselectivity of cardiac binding were demonstrated using blocking experiments in rats. Dynamic imaging studies in anaesthetised greyhounds demonstrated rapid and high myocardial uptake and low lung binding with stable heart to lung activity ratios of > 2.5:1 between 10 and 30 min, making SPECT imaging feasible. Administration of an excess of an unlabelled muscarinic antagonist, methyl-quinuclidinyl benzylate rapidly displaced myocardial activity to background levels and the pharmacologically inactive enantiomer, [123I]N-methyl-4-iodolevetimide, had no detectable cardiac uptake, indicating specific and stereoselective muscarinic receptor binding. SPET revealed higher activity in the inferior than in the anterior wall, this being consistent with previously described regional variation of cardiac parasympathetic innervation. [123I]N-methyl-4-iododexetimide shows promise as an imaging agent for muscarinic receptor distribution in the heart and may be helpful in evaluating diverse cardiac diseases associated with altered muscarinic receptor function, including heart failure and diabetic heart disease. PMID:7607265

  18. Effects of intracoronary melatonin on ischemia-reperfusion injury in ST-elevation myocardial infarction.

    PubMed

    Ekeløf, Sarah V; Halladin, Natalie L; Jensen, Svend E; Zaremba, Tomas; Aarøe, Jens; Kjærgaard, Benedict; Simonsen, Carsten W; Rosenberg, Jacob; Gögenur, Ismail

    2016-01-01

    Acute coronary occlusion is effectively treated by primary percutaneous coronary intervention. However, myocardial ischemia-reperfusion injury is at the moment an unavoidable consequence of the procedure. Oxidative stress is central in the development of ischemia-reperfusion injury. Melatonin, an endogenous hormone, acts through antioxidant mechanisms and could potentially minimize the myocardial injury. The aim of the experimental study was to examine the cardioprotective effects of melatonin in a porcine closed-chest reperfused infarction model. A total of 20 landrace pigs were randomized to a dosage of 200 mg (0.4 mg/mL) melatonin or placebo (saline). The intervention was administered intracoronary and intravenous. Infarct size, area at risk and microvascular obstruction were determined ex vivo by cardiovascular magnetic resonance imaging. Myocardial salvage index was calculated. The plasma levels of high-sensitive troponin T were assessed repeatedly. The experimenters were blinded with regard to treatment regimen. Melatonin did not significantly increase myocardial salvage index compared with placebo [melatonin 21.8% (16.1; 24.8) vs. placebo 20.2% (16.9; 27.0), p = 1.00]. The extent of microvascular obstruction was similar between the groups [melatonin 3.8% (2.7; 7.1) vs. placebo 3.7% (1.3; 7.7), p = 0.96]. The area under the curve for high-sensitive troponin T release was insignificantly reduced by 32% in the melatonin group [AUC melatonin 12,343.9 (6,889.2; 20,147.4) ng h/L vs. AUC placebo 18,285.3 (5,180.4; 23,716.8) ng h/L, p = 0.82]. Combined intracoronary and intravenous treatment with melatonin did not reduce myocardial reperfusion injury. The lack of a positive effect could be due to an ineffective dose of melatonin, a type II error or the timing of administration. PMID:25319673

  19. Thoracic epidural anesthesia improves functional recovery from myocardial stunning in conscious dogs.

    PubMed

    Rolf, N; Van de Velde, M; Wouters, P F; Möllhoff, T; Weber, T P; Van Aken, H K

    1996-11-01

    The effects of thoracic epidural anesthesia (TEA) on the contractile performance of ischemic and postischemic myocardium have not been well investigated. The purpose of this investigation was to examine the effects of TEA on severity and duration of myocardial stunning in an experimental model for sublethal acute myocardial ischemia. Seven dogs were chronically instrumented for measurement of heart rate (HR), left atrial (LAP), aortic and left ventricular pressure (LVP), LV dP/dtmax' and myocardial wall-thickening fraction (WTF). An occluder around the left anterior descending artery (LAD) allowed induction of reversible LAD ischemia. TEA was performed with lidocaine 4 mg/kg through a chronically implanted epidural catheter at the second thoracic level. Regional myocardial blood flow was determined with colored microspheres. Two experiments were performed in a cross-over design on separate days: Experiment 1, induction of 10 min of LAD ischemia without TEA; and Experiment 2, induction of 10 min of LAD ischemia with TEA. WTF was measured at baseline (BL) and predetermined time points until complete recovery from ischemic dysfunction occurred. LAD ischemia caused a significant decrease of LAD-WTF with (-28% +/- 5.1% versus BL) and without TEA (-15.5% +/- 5.3% versus BL). After 3 h of reperfusion, WTF as percent of BL values was significantly higher with TEA (P < 0.001). BL values of WTF were reached after 24 h with TEA and after more than 48 h without TEA (P < 0.05). There were no significant differences for mean arterial pressure (MAP), heart rate (HR), LVP, LAP, and LVdP/dtmax between the groups during ischemia and reperfusion. In nonischemic myocardium TEA caused an increase of subendocardial blood flow. During ischemia neither the subendocardial/subepicardial nor the occluded/ normal zone blood flow was affected by TEA. TEA attenuates myocardial stunning in conscious dogs. This finding is consistent with data regarding a reduction of infarct size due