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Sample records for ischemic canine myocardium

  1. Substrate use in ischemic and reperfused canine myocardium: quantitative considerations

    SciTech Connect

    Myears, D.W.; Sobel, B.E.; Bergmann, S.R.

    1987-07-01

    The patterns of use of substrate in reperfused myocardium are not yet well elucidated, and their delineation is essential for adequate interpretation of results of analyses performed after positron emission tomography with labeled substrates to differentiate normal from abnormal heart muscle. Accordingly, in open-chest, anesthetized dogs the authors measured glucose and fatty acid utilization in normal, ischemic, and reperfused myocardium and assessed the contributions of metabolism of each substrate to overall oxidative metabolism. Intracoronary (/sup 3/H)glucose and (/sup 14/C)palmitate were administered in five control dogs, eight dogs subjected to 1 h of coronary occlusion, and nine dogs subjected to reperfusion after 1 h of ischemia. Regional coronary venous blood samples were assayed sequentially. In reperfused myocardium, utilization of glucose was 103% greater than that in ischemic and 273% greater than in normal myocardium. Utilization of fatty acid during reperfusion, although greater than that in ischemic myocardium, was significantly less than that in normal myocardium despite restoration of flow to 80% of control values. Despite diminished net uptake of fatty acid, oxidation of fatty acid accounted for 63% of total oxygen consumption in reperfused myocardium. These studies indicate that canine myocardium reperfused after 1 h of ischemia exhibits enhanced uptake of glucose and impaired utilization of palmitate. Nevertheless, palmitate continues to comprise the substrate primarily utilized for oxidative metabolism.

  2. Neutrophil accumulation in ischemic canine myocardium. Insights into time course, distribution, and mechanism of localization during early reperfusion

    SciTech Connect

    Dreyer, W.J.; Michael, L.H.; West, M.S.; Smith, C.W.; Rothlein, R.; Rossen, R.D.; Anderson, D.C.; Entman, M.L. )

    1991-07-01

    The authors have previously demonstrated that chemotactic factors released from the ischemic canine myocardium peak early during reperfusion and that they elicit neutrophil adherence reactions in vitro that are dependent on the CD18 glycoprotein family. In this study they investigated the hypothesis that neutrophil localization in ischemic canine myocardium in vivo occurs over a similar time course during early reperfusion and involves a CD18-dependent mechanism. they concluded the circumflex coronary artery for 1 hour in acute, open-chest dogs, followed by reperfusion for 1, 2, 3, or 4 hours. Regional myocardial blood flow was determined using radiolabeled microspheres, and localization was traced using technetium-99m-labeled autologous neutrophils. In the first hour of reperfusion, neutrophil localization occurred preferentially within the subendocardial region and was inversely related to flow. Neutrophil localization diminished across the ischemic myocardium from endocardium to epicardium but remained negatively related to flow in the midmyocardial region. Regardless of flow, little neutrophil localization occurred in the subepicardial region. Neutrophil localization was greatest in the first hour of reperfusion and diminished thereafter. By 4 hours of reperfusion, the rate of localization was markedly attenuated relative to 1 hour. Dogs given anti-CD18 monoclonal antibody R15.7 (1 mg/kg i.v.) before occlusion underwent 1 hour of occlusion followed by 1 hour of reperfusion. When compared with 1-hour reperfusion controls, the R15.7-treated dogs demonstrated significant attenuation of neutrophil localization in the subendocardial region. These data support the concepts that rapid neutrophil localization during reperfusion occurs within regions of previous myocardial ischemia and that neutrophils preferentially localize within the subendocardial region.

  3. [Stunned myocardium after acute ischemic stroke].

    PubMed

    Varela, Daniel; Díaz, Fernanda; Hlavnicka, Alejandro; Wainsztein, Néstor; Leiguarda, Ramón

    2006-01-01

    The so-called stunned myocardium, defined as transitory myocardial contractile dysfunction, has been clearly demonstrated in diverse clinical situations. However, stunned myocardium related to ischemic stroke has been poorly identified. We describe two patients with diagnosis of acute ischemic stroke who developed eletrocardiographic changes, cardiac enzyme increasing levels and myocardial dysfunction secondary to abnormal cardiac wall motion. At the same time the patients developed acute lung injury with rapid resolution, perhaps as a consequence of neurocardiogenic components.

  4. Thallium-201 kinetics in nonischemic canine myocardium

    SciTech Connect

    Okada, R.D.; Jacobs, M.L.; Daggett, W.M.

    1982-01-01

    Myocardial thallium-201 (/sup 201/Tl) kinetics have not been precisely defined because reliable techniques to determine continuous activity in vivo have not been available. In this study, an implantable miniature cadmium telluride radiation detection device was inserted through the left ventricular apex, positioned against the endocardium, and used for continuous on-line monitoring of myocardial /sup 201/Tl activity for 260-810 minutes in 18 dogs. Blood was serially sampled and counted. Microsphere-determined myocardial blood flow was measured before administration of /sup 201/Tl and was not significantly different from that measured at the end of the experiment in 11 of 18 dogs. Thallium was administered intravenously. Myocardial and blood activity curves were analyzed using a nonlinear least-squares estimation of the decay constant lambda (min/sup -1/). The mean final blood lambda/sub 3/ was almost identical to the mean myocardial lambda. The data suggest that /sup 201/Tl washout after peak activity is reached in nonischemic myocardium is mono-exponential. The rate of /sup 201/Tl clearance from the myocardium is related to the rate of /sup 201/Tl clearance from the blood after i.v. administration of the tracer.

  5. Arachidonic acid metabolism in fibroblasts derived from canine myocardium

    SciTech Connect

    Weber, D.R.; Prescott, S.M.

    1986-03-05

    Canine fibroblasts from normal or healing infarcted myocardium were grown in culture. The cells were morphologically indistinguishable, but the doubling time of cells from healing myocardium was 39.6 +/- 3.5 hr whereas that of normals was 24 +/- 3.7 (n=5, p < .025). Fibroblasts incorporated (/sup 3/H)arachidonate (AA) into phospholipids. Calcium ionophore A23187 (10 ..mu..M) caused release and metabolism of (/sup 3/H) AA. A23187 or AA (10..mu..M) induced production of 6-keto PGF1..cap alpha.., PGE2, and a hydroxy metabolite of AA. RIA of 6-keto PGF1..cap alpha.. showed that subconfluent cells from healing myocardium produced 1202 +/- 354 pg/mg protein whereas that of normals was 551 +/- 222 (n=7, p < .025). Histamine and bradykinin also induced AA metabolism but were less potent. They examined the effect of AA released from deteriorating myocytes on AA metabolism by cultured fibroblasts. They confirmed that isolated myocytes labelled with (/sup 3/H)AA released but did not metabolize (/sup 3/H)AA. In coincubations, fibroblasts incorporated myocyte-derived AA. Subsequent stimulation of the fibroblasts with A23187 induced the synthesis of 6-keto PGF1..cap alpha.., PGE2 and a hydroxy metabolite. The fibroblast content of healing myocardium was 35-1000 times that of normal tissue (n=7). Thus even a moderate change in AA metabolism, amplified by the AA released from deteriorating myocytes, may be a significant physiologic or pathologic event.

  6. Protective effect of ischemic postconditioning against ischemia reperfusion-induced myocardium oxidative injury in IR rats.

    PubMed

    Zhang, Li; Ma, Jiangwei; Liu, Huajin

    2012-03-27

    Brief episodes of myocardial ischemia-reperfusion (IR) employed during reperfusion after a prolonged ischemic insult may attenuate the total ischemia-reperfusion injury. This phenomenon has been termed ischemic postconditioning. In the present study, we studied the possible effect of ischemic postconditioning on an ischemic reperfusion (IR)-induced myocardium oxidative injury in rat model. Results showed that ischemic postconditioning could improve arrhythmia cordis, reduce myocardium infarction and serum creatin kinase (CK), lactate dehydrogenase (LDH) and aspartate transaminase (AST) activities in IR rats. In addition, ischemic postconditioning could still decrease myocardium malondialdehyde (MDA) level, and increased myocardium Na+-K+-ATPase, Ca2+-Mg2+-ATPase, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) activities. It can be concluded that ischemic postconditioning possesses strong protective effects against ischemia reperfusion-induced myocardium oxidative injury in IR rats.

  7. Innate immune inflammatory response in the acutely ischemic myocardium.

    PubMed

    Deftereos, Spyridon; Angelidis, Christos; Bouras, Georgios; Raisakis, Konstantinos; Gerckens, Ulrich; Cleman, Michael W; Giannopoulos, Georgios

    2014-01-01

    The "holy grail" of modern interventional cardiology is the salvage of viable myocardial tissue in the distribution of an acutely occluded coronary artery. Thrombolysis and percutaneous coronary interventions, provided they can be delivered on time, can interrupt the occlusion and save tissue. At the same time restoring the patency of the coronary vessels and providing the ischemic myocardium with blood can cause additional tissue damage. A key element of ischemic and reperfusion injury and major determinant of the evolution of damage in the injured myocardium is the inflammatory response. The innate immune system initiates and directs this response which is a prerequisite for subsequent healing. The complement cascade is set in motion following the release of subcellular membrane constituents. Endogenous 'danger' signals known as danger-associated molecular patterns (DAMPs) released from ischemic and dying cells alert the innate immune system and activate several signal transduction pathways through interactions with the highly conserved Toll like receptors (TLRs). Reactive oxygen species (ROS) generation directly induces pro-inflammatory cascades and triggers formation of the inflammasome. The challenge lies into designing strategies that specifically block the inflammatory cascades responsible for tissue damage without affecting those concerned with tissue healing.

  8. Cellular compartmentation in ischemic myocardium: indirect analysis by electron probe

    SciTech Connect

    Walsh, L.G.; Tormey, J.M.

    1988-10-01

    Electron probe microanalysis (EPMA) was carried out directly on myocardial cells and on the myofibrils and the mitochondria within them. A third subcellular compartment, which contains sarcoplasmic reticulum (SR), was measured indirectly. The percent of the total cell calcium content that resides within this ''hidden'' compartment was calculated from cell data minus weighted myofibril and mitochondria data. This approach was applied to control, ischemic, and reperfused myocardium, and other elements were also quantified. We found that the calcium content of this third compartment is little changed during global ischemia but is markedly depleted after 5 min reperfusion. We conclude that these changes are ascribable to changes in SR function.

  9. Heat shock proteins, end effectors of myocardium ischemic preconditioning?

    PubMed Central

    Guisasola, María Concepcion; Desco, Maria del Mar; Gonzalez, Fernanda Silvana; Asensio, Fernando; Dulin, Elena; Suarez, Antonio; Garcia Barreno, Pedro

    2006-01-01

    The purpose of this study was to investigate (1) whether ischemia-reperfusion increased the content of heat shock protein 72 (Hsp72) transcripts and (2) whether myocardial content of Hsp72 is increased by ischemic preconditioning so that they can be considered as end effectors of preconditioning. Twelve male minipigs (8 protocol, 4 sham) were used, with the following ischemic preconditioning protocol: 3 ischemia and reperfusion 5-minute alternative cycles and last reperfusion cycle of 3 hours. Initial and final transmural biopsies (both in healthy and ischemic areas) were taken in all animals. Heat shock protein 72 messenger ribonucleic acid (mRNA) expression was measured by a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method using complementary DNA normalized against the housekeeping gene cyclophilin. The identification of heat shock protein 72 was performed by immunoblot. In our “classic” preconditioning model, we found no changes in mRNA hsp72 levels or heat shock protein 72 content in the myocardium after 3 hours of reperfusion. Our experimental model is valid and the experimental techniques are appropriate, but the induction of heat shock proteins 72 as end effectors of cardioprotection in ischemic preconditioning does not occur in the first hours after ischemia, but probably at least 24 hours after it, in the so-called “second protection window.” PMID:17009598

  10. Sustained nonoxidative glucose utilization and depletion of glycogen in reperfused canine myocardium

    SciTech Connect

    Schwaiger, M.; Neese, R.A.; Araujo, L.; Wyns, W.; Wisneski, J.A.; Sochor, H.; Swank, S.; Kulber, D.; Selin, C.; Phelps, M.

    1989-03-01

    Ischemically injured reperfused myocardium is characterized by increased 18F-fluorodeoxyglucose uptake as demonstrated by positron emission tomography. To elucidate the metabolic fate of exogenous glucose entering reperfused myocardium, D-(6-14C) glucose and L-(U-13C) lactate were used to determine glucose uptake, glucose oxidation and the contribution of exogenous glucose to lactate production. The pathologic model under investigation consisted of a 3 h balloon occlusion of the left anterior descending coronary artery followed by 24 h of reperfusion in canine myocardium. The extent and severity of myocardial injury after the ischemia and reperfusion were assessed by histochemical evaluation (triphenyltetrazolium chloride and periodic acid-Schiff stains). Thirteen intervention and four control dogs were studied. The glucose uptake in the occluded/reperfused area was significantly enhanced compared with that in control dogs (0.40 +/- 0.14 versus 0.15 +/- 0.10 mumol/ml, respectively). In addition, a significantly greater portion of the glucose extracted immediately entered glycolysis in the intervention group (75%) than in the control dogs (33%). The activity of the nonoxidative glycolytic pathway was markedly increased in the ischemically injured reperfused area, as evidenced by the four times greater lactate release in this area compared with the control value. The dual carbon-labeled isotopes showed that 57% of the exogenous glucose entering glycolysis was being converted to lactate. Exogenous glucose contributed to greater than 90% of the observed lactate production. This finding was confirmed by the histochemical finding of sustained glycogen depletion in the occlusion/reperfusion area. The average area of glycogen depletion (37%) significantly exceeded the average area of necrosis (17%).

  11. Ethanol Promotes Arteriogenesis and Restores Perfusion to Chronically Ischemic Myocardium

    PubMed Central

    Lassaletta, Antonio D.; Elmadhun, Nassrene Y.; Liu, Yuhong; Feng, Jun; Burgess, Thomas A.; Karlson, Nicholas W.; Laham, Roger J.; Sellke, Frank W.

    2014-01-01

    Background Moderate alcohol consumption is known to be cardioprotective as compared to either heavy drinking or complete abstinence. We assessed the hypothesis that ethanol supplementation would improve myocardial function in the setting of chronic ischemia. Methods and Results Sixteen male Yorkshire swine underwent placement of an ameroid constrictor to the left circumflex artery to induce chronic myocardial ischemia. Post-operatively animals were supplemented with either 90 ml of ethanol daily (50%/V, EtOH) or 80 g of sucrose of equal caloric value (SUC) serving as controls. Seven weeks after ameroid placement, arteriolar density (1.74 ± 0.210 vs. 3.11 ± 0.368 % area of arterioles per low-powered field in SUC vs. EtOH, p = 0.004), myocardial perfusion (ratio of blood flow to the at-risk myocardium compared to the normal ventricle during demand pacing was 0.585 ± 0.107 vs. 1.08 ± 0.138 for SUC vs. EtOH, p = 0.014), and microvascular reactivity were significantly increased in the ethanol-treated animals compared to controls in the at-risk myocardium. Analysis of VEGF and NOTCH pathway signaling suggested pro-neovascular and proliferative activity in the ischemic area. The average peak blood alcohol level in the treatment group was 40 ± 4 mg/dL consistent with levels of moderate drinking in humans. Conclusions Ethanol supplementation increased arteriolar density and significantly improved myocardial perfusion and endothelium-dependent vasorelaxation in chronically ischemic myocardium. These findings suggest that at moderate doses, ethanol directly promotes vasculogenesis and improves microvascular function resulting in significant improvements in myocardial perfusion in the setting of chronic ischemia. PMID:24030397

  12. Investigation of myocardial photodynamic revascularization method on ischemic rat myocardium model

    NASA Astrophysics Data System (ADS)

    Vasilchenko, S. Yu.; Stratonnikov, A. A.; Volkova, A. I.; Loschenov, V. B.; Sheptak, E. A.; Kharnas, S. S.

    2006-08-01

    Ischemic heart disease is one of the leading reasons of invalidisation and death rate of able-bodied citizens in the world. There are many various surgical and medicamentous methods of its treatment for today, however all these methods have restrictions in application. Our work was directed at initiation possibility clarification of ischemic myocardium revascularization by means of making necrosis with photodynamic therapy. The investigation was carried out in rats with the ischemia artificial made by means of left coronary artery ligation. Level of Photosense photosensitizer accumulation in ischemic and normal rat myocardium zones was defined. Myocardial photodynamic revascularization procedure of ischemic rat myocardium was carried out. Morphological analysis of the myocardium preparations showed the presence of active revascularization of ischemic myocardium after photodynamic therapy. The method of ischemia level estimation based on spectral optical definition of blood oxygen saturation was developed.

  13. Bioreducible Polymer-Transfected Skeletal Myoblasts for VEGF Delivery to Acutely Ischemic Myocardium

    PubMed Central

    McGinn, Arlo N.; Nam, Hye Yeong; Ou, Mei; Straub, Catherine M.; Hu, Norman; Yockman, James W.; Bull, David A.; Kim, Sung Wan

    2010-01-01

    Implantation of skeletal myoblasts to the heart has been investigated as a means to regenerate and protect the myocardium from damage after myocardial infarction. While several animal studies utilizing skeletal myoblasts have reported positive findings, results from clinical studies have been mixed. In this study we utilize a newly developed bioreducible polymer system to transfect skeletal myoblasts with a plasmid encoding vascular endothelial growth factor (VEGF) prior to implantation into acutely ischemic myocardium. VEGF has been demonstrated to promote revascularization of the myocardium following myocardial infarction. We report that implanting VEGF expressing skeletal myoblasts into acutely ischemic myocardium produces superior results compared to implantation of untransfected skeletal myoblasts. Skeletal myoblasts expressing secreted VEGF were able to restore cardiac function to non-diseased levels as measured by ejection fraction, to limit remodeling of the heart chamber as measured by end systolic and diastolic volumes, and to prevent myocardial wall thinning. Additionally, arteriole and capillary formation, retention of viable cardiomyocytes, and prevention of apoptosis was significantly improved by VEGF expressing skeletal myoblasts compared to untransfected myoblasts. This work demonstrates the feasibility of using bioreducible cationic polymers to create engineered skeletal myoblasts to treat acutely ischemic myocardium. PMID:20970850

  14. Myocardial clearance of technetium-99m-teboroxime in reperfused injured canine myocardium

    PubMed Central

    2014-01-01

    Background Recent technical developments using solid-state technology have enabled rapid image acquisition with single photon emission computed tomography (SPECT) and have led to a renewed interest in technetium-99m-teboroxime (Tc-99m-teboroxime) as a myocardial imaging agent. Tc-99m-teboroxime has demonstrated high myocardial extraction, linear myocardial uptake relative to flow even at high flow rates, rapid uptake and clearance kinetics, and differential clearance in the setting of ischemia. However, the myocardial clearance kinetics of Tc-99m-teboroxime in a model of myocardial injury has not been previously reported. Thus, the purposes of this study were to use a canine model of ischemia-reperfusion to (1) compare Tc-99m-teboroxime clearance kinetics in normal and ischemic-reperfused myocardium and (2) assess the utility of Tc-99m-teboroxime clearance kinetics in determining the severity of injury following ischemia-reperfusion. Methods Thirteen dogs underwent left circumflex coronary artery (LCx) occlusion for either 30 min (IR30, n = 6) or 120 min (IR120, n = 7), followed by reperfusion, and finally Tc-99m-teboroxime administration 120 min after reperfusion. Microsphere blood flows were determined at baseline, during occlusion, after reperfusion, and before euthanasia. Post-mortem, area at risk was determined using Evans blue dye, and viability was determined using triphenytetrazolium chloride (TTC) staining. The hearts were then subdivided into 24 pieces and Tc-99m activity was measured in a well counter. Results TTC-determined infarct area as a percentage of total left ventricular myocardium was 1.1% ± 0.3% for the IR30 group and 7.5% ± 2.9% for the IR120 group (p < 0.05). During coronary occlusion, both the IR30 and IR120 groups demonstrated decreases in percent wall thickening in the ischemia-reperfusion zone (IRZ) as compared with the normal zone (NZ). In the IR30 group, percent wall thickening in the IRZ recovered during the

  15. Variability and reproducibility of rubidium-82 kinetic parameters in the myocardium of the anesthetized canine

    SciTech Connect

    Coxson, P.G.; Brennan, K.M.; Huesman, R.H.

    1995-02-01

    Kinetic analysis of {sup 82}Rb (I) dynamic PET data produces quantitative measures which could be used to evaluate ischemic heart disease. These measures have the potential to generate objective comparisons of different patients or the same patient at different times. To achieve this potential, it is essential to determine the variability and reproducibility of the kinetic parameters. A total of 48 I dynamic PET datasets were acquired from two pure bred beagles. Each animal underwent eight I PET studies with essentially the same protocol for three successive weeks. Data were acquired with the Donner 600-Crystal Positron Tomograph (PET600). In each week, single-slice dynamic I PET datasets were collected with the animal at rest at three different gantry positions separated by 5 mm. Additional dataset were collected after dipyridamole infusion and after administration of aminophylline to induce a return to rest. A two-compartment kinetic model with correction for myocardial vasculature and spillover from the left ventricular blood pool was used to analyze the dynamic datasets. Model parameters for uptake (k{sub 1}), washout (k{sub 2}) and vascular fraction (f{sub v}) were estimated in 11-14 myocardial regions of interest (ROIs) using a weighted least-squares criterion. Statistical fluctuation due to the PET acquisition process was minimized by using a relatively high I dose (about 30 mCi) to take advantage of the high count rate capacity of the PET600. The variation in mean k{sub 1}, where the mean is taken over the myocardial ROIs was 10%-20% (Dog 1) and 15%-50% (Dog 2) among the rest studies conducted on the same data. Similar variation was evident in comparing studies in the same animal for different weeks. Spatial and temporal variation in estimates of the uptake rate (k{sub 1}) of I in the resting myocardium of the anesthetized canine are small in relation to the functional increase in k{sub 1}, following dipyridamole stress. 17 refs., 14 figs.

  16. Early Recovery of Regional Performance in Salvaged Ischemic Myocardium following Coronary Artery Occlusion in the Dog

    PubMed Central

    Darsee, John R.; Kloner, Robert A.; Braunwald, Eugene

    1981-01-01

    Although numerous agents have been shown experimentally to protect ischemic myocardium, a critical unanswered question is whether function is preserved in the salvaged tissue. Accordingly, 38 openchest dogs had measurements of percent segment length shortening (%SS) and velocity of segment length shortening either in midmyocardial or subepicardial and subendocardial ischemic segments before and after 60 min of left anterior descending coronary artery occlusion during 5 h of reperfusion; 10 additional dogs were subjected to 3 h of coronary occlusion followed by 72 h of reperfusion. 15 min after coronary artery occlusion, radiolabeled microspheres were injected into the left atrium for measurement of regional myocardial blood flow, and dogs were treated with 1 mg/kg i.v. (n = 23) of an anti-inflammatory drug, flurbiprofen or an equal volume of saline (n = 25). The ischemic myocardium-at-risk for necrosis was determined by injecting methylene blue dye into the left atrium with the coronary artery reoccluded at the end of the reperfusion period, slicing the left ventricle into thin transverse sections, and measuring the areas of each slice that were not perfused (pink unstained tissue) by methylene blue. The quantity of necrotic tissue in each transverse section was measured by planimetry after incubation of the slices in triphenyltetrazolium chloride, and by direct histological examination in dogs with 72 h of reperfusion. Regional myocardial blood flow of the ischemic segments between the ultrasonic dimension crystals was similar in treated (0.34±0.03 ml/min per g) and control dogs (0.35±0.03 ml/min per g). In saline-treated control dogs subjected to a l-h coronary occlusion, 17.9±1.8% of the myocardium-at-risk became necrotic but in flurbiprofen-treated dogs none of the tissue became necrotic. In saline-treated dogs passive lengthening of the previously ischemic segments persisted through 5 h of reperfusion in all three regions of myocardium after a 1-h coronary

  17. Demonstration of early ischemic injury in porcine right ventricular myocardium.

    PubMed Central

    Spinale, F. G.; Schulte, B. A.; Crawford, F. A.

    1989-01-01

    Past studies of acute canine right ventricular (RV) ischemia have failed to demonstrate early irreversible injury or decreased function; however, the dog has extensive collateral circulation that may attenuate RV myocardial injury. The aim of this study was to measure RV function using contrast ventriculography and assess myocardial injury by immunohistochemical evaluation of creatine kinase (CK), lactate dehydrogenase (LDH), and tropomyosin (TROP) as well as by electron microscopy after right coronary occlusion in 14 closed-chest pigs. Significant depression in RV ejection fraction and stroke volume index after 10 minutes and was observed (P less than 0.05). CK, LDH, and TROP were positive in control tissue with a diminution of CK and LDH staining along the subendocardium after 15 minutes of ischemia. Irreversible ultrastructural injury in conjunction with large losses of CK and LDH became evident after 30 minutes. Thus, in the pig, which has a coronary anatomy similar to humans, significant RV dysfunction and irreversible myocardial injury can be demonstrated after 15 to 30 minutes of ischemia. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:2923187

  18. Flow into ischemic myocardium and across coronary collateral vessels is modulated by a waterfall mechanism.

    PubMed

    Eng, C; Kirk, E S

    1984-07-01

    If a coronary artery is ligated and the distal end cannulated, blood flows retrograde from the cannula when vented to the atmosphere. By varying the height of the outflow tubing, and thereby changing the outflow pressure, pressure-flow relationships can be constructed. We used this technique in eight dogs to assess the characteristics of blood flow into ischemic myocardium. Above a back pressure of 10 mm Hg, increasing back pressure resulted in a decrease of retrograde blood flow. However, below a back pressure of about 10 mm Hg (10.7 +/- 2.7 mm Hg), alterations in back pressure did not result in changes in retrograde blood flow (back pressure-independent region). The transition at 10 mm Hg is interpreted as the critical waterfall pressure in ischemic myocardium. In another group of eight dogs, the ischemic bed was completely embolized with 25-micron sized microspheres to prevent RBF from entering the tissue as back pressure was raised. Pressure-flow relationships performed in this group revealed a back pressure-independent region that extended to approximately 20 mm Hg (23.0 +/- 2.5 mm Hg). This behavior of the pressure-flow relationship is consistent with a waterfall phenomenon on the collateral vessels. To the extent that collateral vessels in the dog are mainly epicardial in location, the findings suggest that extravascular pressures of 20 mm Hg can occur in the more superficial layers of the heart. In addition, the waterfall on the collaterals indicates that this mechanism can operate on nonvenous vessels. Our results suggest separate waterfall phenomena operating on the collateral vessels (20 mm Hg) and on the vessels in the ischemic myocardium (10 mm Hg).

  19. Beneficial actions of bevantolol on subendocardial blood flow and contractile function in ischemic myocardium.

    PubMed

    Gross, G J; Buck, J D; Warltier, D C; Hardman, H F

    1979-01-01

    The effect of a new cardioselective beta adrenergic antagonist, bevantolol (CI-775), on regional myocardial blood flow and contractile function distal to a severe flow-limiting stenosis of the left circumflex coronary artery was studied in open-chest dogs. Bevantolol (1 mg/kg, i.v.) or saline was administered 30 min after production of left circumflex stenosis sufficient to reduce resting coronary blood flow and contractile force approximately 40%. Regional myocardial blood flow and contractile force were measured with radiolabeled microspheres and Brodie-Walton strain gauge arches, respectively. No significant changes were observed in the saline-treated group. Following bevantolol treatment subendocardial blood flow (1.30 +/- 0.29 to 0.93 +/- 0.19 ml/min/g) and contractile force decreased (11.4 +/- 4.4%) significantly (p less than 0.05) in nonischemic myocardium. Subendocardial blood flow (0.59 +/- 0.14 to 0.81 +/- 0.14 ml/min/g) and contractile force increased (29.3 +/- 3.6%) significantly (p less than 0.05) in ischemic myocardium. These results suggest that bevantolol produces a favorable redistribution of flow to ischemic subendocardium. The increase in flow results in an improvement of contractile function in the ischemic region.

  20. Metabolic Syndrome Impairs Notch Signaling and Promotes Apoptosis in Chronically Ischemic Myocardium

    PubMed Central

    Elmadhun, Nassrene Y.; Sabe, Ashraf A.; Lassaletta, Antonio D.; Chu, Louis M.; Kondra, Katelyn; Sturek, Michael; Sellke, Frank W.

    2014-01-01

    Objective Impaired angiogenesis is a known consequence of metabolic syndrome (MetS), however, the mechanism is not fully understood. Recent studies have shown that the Notch signaling pathway is an integral component of cardiac angiogenesis. We tested in a clinically relevant swine model the effects of MetS on Notch and apoptosis signaling in chronically ischemic myocardium. Methods Ossabaw swine were fed either a regular diet (CTL, n=8) or a high-cholesterol diet (MetS, n=8) to induce MetS. An ameroid constrictor was placed to induce chronic myocardial ischemia. Eleven weeks later, animals underwent cardiac harvest of the ischemic myocardium. Results There was down-regulation of pro-angiogenesis proteins Notch2, Notch4, Jagged2, Ang1 and ENOS in the MetS group compared to CTL. There was also up-regulation of pro-apoptosis protein Caspase8, and down-regulation of anti-angiogenesis protein pFOX03, and pro-survival proteins pP38 and HSP90 in the MetS group. Cell death was increased in the MetS group compared to CTL. Both CTL and MetS groups had similar arteriolar count and capillary density, and Notch3 and Jagged1 were both similarly concentrated in the smooth muscle wall in both groups. Conclusions MetS in chronic myocardial ischemia significantly impairs Notch signaling by down regulating Notch receptors, ligands and pro-angiogenesis proteins. MetS also increases apoptosis signaling, decreases survival signaling and increases cell death in chronically ischemic myocardium. Although short-term angiogenesis appears unaffected in this model of early MetS, the molecular signals for angiogenesis are impaired, thus suggesting that inhibition of Notch signaling may underlie decreased angiogenesis in later stages of MetS. PMID:25037620

  1. The iron-regulatory peptide hepcidin is upregulated in the ischemic and in the remote myocardium after myocardial infarction.

    PubMed

    Simonis, Gregor; Mueller, Katrin; Schwarz, Peggy; Wiedemann, Stephan; Adler, Guido; Strasser, Ruth H; Kulaksiz, Hasan

    2010-09-01

    Recent evidence suggests that iron metabolism contributes to the ischemic damage after myocardial infarction. Hepcidin, a recently discovered peptide hormone, regulates iron uptake and metabolism, protecting the body from iron overload. In this study we analyzed the regulation of hepcidin in the heart and blood of rats after myocardial infarction. To induce a myocardial infarction in the rats, left anterior descending coronary artery ligation was performed. After 1-24h, biopsies from the ischemic and the non-ischemic myocardium were taken. In these biopsies, the mRNA levels and the protein expression of hepcidin were analyzed by quantitative RT-PCR and immunoblot analysis, respectively. In parallel, the serum levels of prohepcidin were measured by ELISA. Six hours after myocardial infarction, the hepcidin mRNA expression was temporally upregulated in the ischemic and in the non-ischemic myocardium. The upregulation was specific for hepcidin, since other iron-related genes (hemojuvelin, IREG-1) remained unchanged. Furthermore, the alteration of the hepcidin protein expression in the ischemic area was connected to the level of hepcidin in the serum of the infarcted rats, where hepcidin also raised up. Angiotensin receptor blockade with candesartan did not influence the mRNA regulation of hepcidin. Together, these data show a particular upregulation of the iron-regulatory peptide hepcidin in the ischemic and the non-ischemic myocardium after myocardial infarction. It is speculated that upregulation of hepcidin may reduce iron toxicity and thus infarct size expansion in an infarcted heart.

  2. Passive targeting of ischemic-reperfused myocardium with adenosine-loaded silica nanoparticles

    PubMed Central

    Galagudza, Michael; Korolev, Dmitry; Postnov, Viktor; Naumisheva, Elena; Grigorova, Yulia; Uskov, Ivan; Shlyakhto, Eugene

    2012-01-01

    Pharmacological agents suggested for infarct size limitation have serious side effects when used at cardioprotective doses which hinders their translation into clinical practice. The solution to the problem might be direct delivery of cardioprotective drugs into ischemic-reperfused myocardium. In this study, we explored the potential of silica nanoparticles for passive delivery of adenosine, a prototype cardioprotective agent, into ischemic-reperfused heart tissue. In addition, the biodegradation of silica nanoparticles was studied both in vitro and in vivo. Immobilization of adenosine on the surface of silica nanoparticles resulted in enhancement of adenosine-mediated infarct size limitation in the rat model. Furthermore, the hypotensive effect of adenosine was attenuated after its adsorption on silica nanoparticles. We conclude that silica nanoparticles are biocompatible materials that might potentially be used as carriers for heart-targeted drug delivery. PMID:22619519

  3. Molecular imaging of induced pluripotent stem cell immunogenicity with in vivo development in ischemic myocardium.

    PubMed

    Liu, Zhiqiang; Wen, Xinyu; Wang, Haibin; Zhou, Jin; Zhao, Mengge; Lin, Qiuxia; Wang, Yan; Li, Junjie; Li, Dexue; Du, Zhiyan; Yao, Anning; Cao, Feng; Wang, Changyong

    2013-01-01

    Whether differentiation of induced pluripotent stem cells (iPSCs) in ischemic myocardium enhances their immunogenicity, thereby increasing their chance for rejection, is unclear. Here, we dynamically demonstrated the immunogenicity and rejection of iPSCs in ischemic myocardium using bioluminescent imaging (BLI). Murine iPSCs were transduced with a tri-fusion (TF) reporter gene consisting of firefly luciferase-red fluorescent protein-truncated thymidine kinase (fluc-mrfp-tTK). Ascorbic acid (Vc) were used to induce iPSCs to differentiate into cardiomyocytes (CM). iPSCs and iPS-CMs were intramyocardially injected into immunocompetent or immunosuppressed allogenic murine with myocardial infarction. BLI was performed to track transplanted cells. Immune cell infiltration was evaluated by immunohistochemistry. Syngeneic iPSCs were also injected and evaluated. The results demonstrated that undifferentiated iPSCs survived and proliferated in allogenic immunocompetent recipients early post-transplantation, accompanying with mild immune cell infiltration. With in vivo differentiation, a progressive immune cell infiltration could be detected. While transplantation of allogenic iPSC-CMs were observed an acute rejection from receipts. In immune-suppressed recipients, the proliferation of iPSCs could be maintained and intramyocardial teratomas were formed. Transplantation of syngeneic iPSCs and iPSC-CMs were also observed progressive immune cell infiltration. This study demonstrated that iPSC immunogenicity increases with in vivo differentiation, which will increase their chance for rejection in iPSC-based therapy.

  4. Long-term preservation of ischemic myocardium in the dog by hyaluronidase.

    PubMed

    Kloner, R A; Braunwald, E; Maroko, P R

    1978-08-01

    The administration of hyaluronidase is a promising intervention to protect the ischemic myocardium in man, but evidence of the extent to which it may reduce the ultimate size of an infarct is not well-defined. Hence, open chest, anesthetized dogs were randomized into 10 control dogs which received saline and eight treated dogs which received three doses of hyaluronidase (500 NF units/kg I.V.) at 15 minutes, 2 hours and 24 hours after occlusion of the left anterior descending coronary artery (CAO). Regional myocardial blood flow (RMBF) assessed by the microsphere technique was measured 12 minutes after CAO. The chest was then closed and the dogs were allowed to recover. Twenty-one days after CAO, the hearts were excised, divided into 1 cm thick slices and incubated in triphenyl tetrazolium chloride. Infarct size was then determined by planimetry. The left ventricular myocardium was divided into multiple samples for RMBF analysis. In control dogs 23.2 +/- 2% of the left ventricle was infarcted, compared to only 9 +/- 2.8% (P less than 0.001) in hyaluronidase-treated dogs. RMBF in noninfarcted myocardium directly adjacent to the infarct was similar to that in the normal zone remote from the infarct in the control dogs; however, in the hyaluronidase-treated dogs, blood flow in the myocardium adjacent to the infarct was significantly reduced to 68% of normal (P less than 0.01) in the outer myocardial wall and to 86% of normal (P less than 0.02) in the inner myocardial wall, which indicates that this tissue, at least in some part, was in jeopardy, but was salvaged by hyaluronidase. Epicardial electrocardiographic data showed that three weeks after CAO, Q waves were less frequent and smaller in hyaluronidase compared to untreated dogs. Preservation of the frequency and magnitude of R waves was greater in the hyaluronidase-treated group at three weeks. We conclude that hyaluronidase resulted in long-term preservation of the ischemic myocardium.

  5. Ultrastructural and functional effects of lead poisoning on adult canine myocardium: assessment of thiamin treatment

    SciTech Connect

    Kincaid, N.G.

    1985-01-01

    The effects of lead (Pb) poisoning on the adult canine myocardium were assessed quantitatively using stereological techniques, functional testing, and blood analyses as well as qualitatively by morphological investigation. Relative measurements using stereological techniques compared the volume fractions of cellular components of the three groups. Blood was analyzed for lead, hemoglobin, hematocrit, total erythrocytes, total leukocytes, thiamin pyrophosphate (TPP), delta-aminolevulinic acid dehydratase activity (ALAD), and zinc protoporphyrin (ZPP). The major finding of the stereological analysis was the statistically significant increase of 3.2% in myofilament volume in the Pb treated group and the significant decrease in mitochondrial volume in both the Pb treated and Pb + B/sub 1/ treated groups. A statistically significant decrease in the mitochondria/myofilament volume ratio was found in the Pb treated, but no Pb + B/sub 1/ treated group. This may indicate either a protective effect of thiamin on mitochondria or a reduced compensatory need of the myocyte to increase myofilament volume.

  6. Spacial and temporal profiles of neutrophil accumulation in the reperfused ischemic myocardium

    SciTech Connect

    de Lorgeril, M.; Rousseau, G.; Basmadjian, A.; St-Jean, G.; Tran, D.C.; Latour, J.G. )

    1990-01-01

    To elucidate further the pathogenic role of neutrophils in evolving reperfused myocardial infarction, we investigated the dynamics of their accumulation and distribution in the ischemic myocardium. The left anterior descending coronary artery was occluded in dogs for 2 hours followed by reperfusion for 0, 3, 6, or 24 hours. 111In-labeled neutrophils were injected at the time of occlusion or after 16 hours of reperfusion. The area at risk was similar among groups. Infarct size expressed in percent of the area at risk was identical between groups reperfused for 6 (35.2 +/- 4.4%) or 24 (32.3 +/- 3.9%) hours but smaller (22.0 +/- 4.4%; p less than 0.05) after 3 hours of reperfusion. 111In-neutrophils accumulation quantified by scintigraphy correlated positively with infarct size (r = 0.64, p less than 0.005); accumulation rates (cells/h/cm2MI) were high during the first 3 (2288 +/- 754) and 6 hours (1953 +/- 463) but low (490 +/- 192) between 16 and 24 hours of reperfusion. Cells accumulating during reperfusion (12,566 +/- 2307 cells/g at 3 hours) were found within the borders of the necrotic area, and the cell counts (2420 +/- 724 cells/g, p less than 0.05) in the live tissue located within the area at risk after 3 hours of reperfusion were similar to those found in the subepicardium at the onset of reperfusion: (2240 +/- 571 cells/g). Only a few cells were detected in the normally perfused myocardium (67 +/- 33 cells/g). We conclude that reperfusion accumulation in the ischemic myocardium; the reaction takes place within 3-6 hours of reperfusion, a period of time where infarct size is growing by about 40%. These results support the concept that leukocytes may play a pathogenic role on infarct size in models with brief ischemia followed by reperfusion.

  7. In vivo mechanical study of helical cardiac pacing electrode interacting with canine myocardium

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangming; Ma, Nianke; Fan, Hualin; Niu, Guodong; Yang, Wei

    2007-06-01

    Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque time curves presente saw-tooth fashion. The maximum torque has a range of 0.3 1.9 N mm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.

  8. Remote Ischemic Postconditioning Ameliorates the Mesenchymal Stem Cells Engraftment in Reperfused Myocardium

    PubMed Central

    Jiang, Qin; Yu, Tao; Huang, Keli; Lu, Jing; Zhang, Hao; Hu, Shengshou

    2016-01-01

    Objectives Remote Ischemic postconditioning (RIPoC) is a cardioprotective strategy for alleviating the reperfusion injury. We hypothesized that RIPoC or ischemic postconditioning (IPoC) could protect the engrafted mesenchymal stem cells (MSCs) in reperfusion myocardium. Methods Female Sprague-Dawley rats were subject to 30 minutes of occlusion of left anterior descending (LAD). Ischemia reperfusion (IR) received reperfusion without interruption after ischemia. RIPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the limb at the onset of reperfusion. IPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the LAD at the same time. Male MSCs were intramyocardially administered after ischemia. Results Compared with that in IR group, ischemic myocardium in RIPoC+IPoC group, RIPoC group and IPoC group were found to have higher anti-oxidative stress and mitochondrial function level, lower lipid peroxidation and inflammational injury level, higher level of stromal cell derived factor-1 alpha and vascular endothelium growth factor gene expression at 3 days later. By immunohistochemical examination and quantitative polymerase chain reaction, more engrafted MSCs, better cardiac function and less cardiac fibrosis in RIPoC+IPoC group, RIPoC group and IPoC group were detected at 3 weeks after delivery. There were no significant differences between RIPoC and RIPoC+IPoC group. Conclusions Combination therapy using intramyocardial MSCs transplantation with RIPoC enhanced transplantation efficiency and cardiac function, and reduced cardiac fibrosis. These beneficial effects were mainly attributed to hospitable milieu for engrafted cells. IPoC could not render additional effect on MSCs engraftment elicited by RIPoC. PMID:26760781

  9. MRI monitoring of function, perfusion and viability in microembolized moderately ischemic myocardium.

    PubMed

    Do, Loi; Wilson, Mark W; Krug, Roland; Hetts, Steven W; Saeed, Maythem

    2015-08-01

    Assessment of microembolization after coronary interventions is clinically challenging, thus we longitudinally investigated microemboli effects on moderately ischemic myocardium using MRI and histopathology. Twenty-four pigs (8/group) were divided into: group I (no intervention), group II (45 min LAD occlusion) and group III (45 min LAD occlusion with microembolization). Cine, perfusion and delayed contrast enhanced MRI (DE-MRI), using 1.5T MRI, were used for assessment at 3 days and 5 weeks. Triphenyltetrazolium-chloride (TTC) and Masson-trichrome were used as gold standard references for macro and microscopic quantification of myocardial infarction (MI). Cine MRI showed differential increase in end systolic volume (1.3 ± 0.08 ml/kg group II and 1.6 ± 0.1 ml/kg group III) and decrease in ejection fraction (45 ± 2 and 36 ± 2%, respectively) compared with controls at 3 days (2.1 ± 0.1 ml ESV and 50 ± 1% EF, P < 0.05). At 5 weeks group III, but not II, showed persistent perfusion deficits, wall thinning in the LAD territory and compensatory hypertrophy in remote myocardium. DE-MRI MI at 3 days was significantly smaller in group II (3.3 ± 2.2 g) than III (9.8 ± 0.6 g), at 5 weeks, MI were smaller by 60% (1.3 ± 0.9 g) and 22% (7.7 ± 0.5 g), respectively. TTC MI was similar to DE-MRI in group II (1.6 ± 1.0 g) and III (9.2 ± 1.6 g), but not microscopy (2.8 ± 0.4 and 10.5 ± 1.5 g, respectively). The effects of moderate ischemia with and without microembolization on myocardium could be differentiated using multiple MRI sequences. MRI demonstrated that microemboli in moderately ischemic myocardium, but not solely ischemia, prolonged ventricular dysfunction, created perfusion deficits, poor infarct resorption and enhanced compensatory hypertrophy, while moderate ischemia alone caused minor LV changes.

  10. 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

  11. Subendocardial segment length shortening at lateral margins of ischemic myocardium in dogs

    SciTech Connect

    Gallagher, K.P.; Gerren, R.A.; Choy, M.; Stirling, M.C.; Dysko, R.C. )

    1987-10-01

    The lateral borders of an infarcted area are sharply delineated in terms of perfusion, but functional impairment extends a limited distance into adjacent nonischemic myocardium. To determine the distribution of functional impairment the authors arrayed three ultrasonic dimension gauges to measure two subendocardial segment lengths in series. The center crystal, placed at the perfusion boundary (PB) between left anterior descending and circumflex arteries, radiated ultrasound to receiver crystals 7-17 mm to either side of the PB. The locations of the functional measurements relative to the PB were determined with myocardial blood flow (tracer-labeled microsphere) maps constructed from multiple small tissue samples obtained circumferentially. On the ischemic side of the PB, dL decreased from 2.24 {plus minus} 0.54 to 0.42 {plus minus} 0.39 mm. By adding the data from the two segments in series, a combined measurement of dL across heterogeneously perfused myocardium was derived that decreased by 38% from control. The level of shortening represented an integral of normal and abnormal motion that was proportional to the mean reduction in blood flow ({minus}44%) in all of the muscle spanned by the crystals. They conclude that subendocardial segment lengths average shortening in the muscle they subtend when arrayed across the perfusion boundary.

  12. Study of possible mechanism of protective effect of phosphocreatine on ischemic myocardium

    SciTech Connect

    Preobrazhenskii, A.N.; Dzhavadov, S.A.; Saks, V.A.

    1986-10-20

    The accumulation of (/sup 32/P)phosphocreatine by control and isolated perfused ischemic rat hearts was studied. It was found that at phosphocreatine concentrations of 0.5-10 mM in the perfusing solution the rate of phosphocreatine accumulation was twice as high in hearts subjected to ischemia for 35 min as in the control hearts and constituted 182 nmoles/min/g dry weight tissue at a phosphocreatine concentrations in the perfusate of 10 mM. 5'-Nucleotidase and phosphatase activities were found in the crude plasma membrane fraction from rat hearts. The pH-dependence of the activity of these enzymes was studied. The 5'-nucleotidase activity decreased 4- to 5-fold with a drop in the pH from 8.0 to 6.0. The phosphatase activity of the preparations increased 2-fold with a drop in the pH from 8.0 to 6.0. The 5'-nucleotidase activity was inhibited by 10 mM phosphocreatine in the presence of 5 mM Mg/sup 2 +/, and the degree of the inhibition depended on the pH. Maximum inhibition by phosphocreatine (58%) was observed at pH 6.0. The inhibition of phosphatase by phosphocreatine did not depend on the pH and reached 20% in the presence of 10 mM phosphocreatine. Some possible mechanisms of the protective effect of phosphocreatine on an ischemic myocardium are discussed.

  13. Bone marrow and bone marrow derived mononuclear stem cells therapy for the chronically ischemic myocardium

    SciTech Connect

    Waksman, Ron; Baffour, Richard

    2003-09-01

    Bone marrow stem cells have been shown to differentiate into various phenotypes including cardiomyocytes, vascular endothelial cells and smooth muscle. Bone marrow stem cells are mobilized and home in to areas of injured myocardium where they are involved in tissue repair. In addition, bone marrow secretes multiple growth factors, which are essential for angiogenesis and arteriogenesis. In some patients, these processes are not enough to avert clinical symptoms of ischemic disease. Therefore, in vivo administration of an adequate number of stem cells would be a significant therapeutic advance. Unfractionated bone marrow derived mononuclear stem cells, which contain both hematopoietic and nonhematopoietic cells may be more appropriate for cell therapy. Studies in animal models suggest that implantation of different types of stem cells improve angiogenesis and arteriogenesis, tissue perfusion as well as left ventricular function. Several unanswered questions remain. For example, the optimal delivery approach, dosage and timing of the administration of cell therapy as well as durability of improvements need to be studied. Early clinical studies have demonstrated safety and feasibility of various cell therapies in ischemic disease. Randomized, double blind and placebo-controlled clinical trials need to be completed to determine the effectiveness of stem cell.

  14. Postischemic cardiac recovery in heme oxygenase-1 transgenic ischemic/reperfused mouse myocardium

    PubMed Central

    Juhasz, Bela; Varga, Balazs; Czompa, Attila; Bak, Istvan; Lekli, Istvan; Gesztelyi, Rudolf; Zsuga, Judit; Kemeny-Beke, Adam; Antal, Miklos; Szendrei, Levente; Tosaki, Arpad

    2011-01-01

    Abstract Heme oxygenase-1 (HO-1) transgenic mice (Tg) were created using a rat HO-1 genomic transgene. Transgene expression was detected by RT-PCR and Western blots in the left ventricle (LV), right ventricle (RV) and septum (S) in mouse hearts, and its function was demonstrated by the elevated HO enzyme activity. Tg and non-transgenic (NTg) mouse hearts were isolated and subjected to ischemia/reperfusion. Significant post-ischemic recovery in coronary flow (CF), aortic flow (AF), aortic pressure (AOP) and first derivative of AOP (AOPdp/dt) were detected in the HO-1 Tg group compared to the NTg values. In HO-1 Tg hearts treated with 50 μmol/kg of tin protoporphyrin IX (SnPPIX), an HO enzyme inhibitor, abolished the post-ischemic cardiac recovery. HO-1 related carbon monoxide (CO) production was detected in NTg, HO-1 Tg and HO-1 Tg + SnPPIX treated groups, and a substantial increase in CO production was observed in the HO-1 Tg hearts subjected to ischemia/reperfusion. Moreover, in ischemia/reperfusion-induced tissue Na+ and Ca2+ gains were reduced in HO-1 Tg group in comparison with the NTg and HO-1 Tg + SnPPIX treated groups; furthermore K+ loss was reduced in the HO-1 Tg group. The infarct size was markedly reduced from its NTg control value of 37 ± 4% to 20 ± 6% (P < 0.05) in the HO-1 Tg group, and was increased to 47 ± 5% (P < 0.05) in the HO-1 knockout (KO) hearts. Parallel to the infarct size reduction, the incidence of total and sustained ventricular fibrillation were also reduced from their NTg control values of 92% and 83% to 25% (P < 0.05) and 8% (P < 0.05) in the HO-1 Tg group, and were increased to 100% and 100% in HO-1 KO−/− hearts. Immunohistochemical staining of HO-1 was intensified in HO-1 Tg compared to the NTg myocardium. Thus, the HO-1 Tg mouse model suggests a valuable therapeutic approach in the treatment of ischemic myocardium. PMID:20716121

  15. Relationship between Tl-201, Tc-99m (Sn) pyrophosphate and F-18 2-deoxyglucose uptake in ischemically injured dog myocardium

    SciTech Connect

    Sochor, H.; Schwaiger, M.; Schelbert, H.R.; Huang, S.C.; Ellison, D.; Hansen, H.; Selin, C.; Parodi, O.; Phelps, M.E.

    1987-11-01

    We have previously demonstrated that enhanced glucose utilization in reperfused myocardium as assessed by F-18 2-deoxyglucose (FDG) and positron tomography predicts functional recovery. In this study, we compared segmental uptake of F-18 FDG with that of Tl-201 and Tc-99m (Sn) pyrophosphate (Tc-99m PPi) as conventional markers of tissue viability in seven dogs after a 3-hour intracoronary balloon occlusion and 20 hours of reperfusion. Myocardial blood flow was determined with microspheres. Regional retention fractions were calculated from tracer tissue concentrations, the arterial input function, and blood flow. Ischemic injury was assessed by triphenyltetrazolium chloride (TTC) staining and histologic analysis. At 24 hours, blood flow was 22% lower in reperfused than in control myocardium (p less than 0.05). Uptake of Tl-201 was related linearly to blood flow (r = 0.92), while glucose utilization and Tc-99m PPi were 2.9 (p less than 0.01) and 4.7 (p less than 0.05) times higher in reperfused than in control myocardium. Retention fractions of Tc-99m PPi increased with the degree of ischemic injury, while F-18 FDG uptake was highest in segments with mild cell injury. Thus, in ischemically injured myocardium, Tl-201 primarily reflects blood flow. F-18 FDG as a marker of glucose utilization identifies ischemically injured but viable tissue. The admixture of necrotic cells can be determined with Tc-99m PPi. Our results indicate that a dual tracer approach might best characterize the presence and extent of reversibly and of irreversibly injured tissue in a given myocardial region.

  16. Colloidal lanthanum as a marker for impaired plasma membrane permeability in ischemic dog myocardium.

    PubMed Central

    Hoffstein, S.; Gennaro, D. E.; Fox, A. C.; Hirsch, J.; Streuli, F.; Weissmann, G.

    1975-01-01

    Colloidal lanthanum salts have an average particle size of 40 degrees A; consequently, this electron-opaque marker remains extracellular and does not cross the intact plasma membrane. The affinity of lanthanum for calcium-binding sites on mitochondrial membranes makes it possible to demonstrate loss of plasma membrane integrity at the cellular level in ischemic myocardium. Biopsies were obtained from infarcted, marginal and normal areas 3 1/2 hours after ischemia was produced in 9 anesthetized closed-chest dogs by electrically induced thrombosis of the left anterior descending coronary artery. The tissue was immediately fixed in 4% glutaraldehyde and 0.1 M cacodylate buffer containing 1.3% La(NO3)3, pH 7.4, for 2 hours. In normal control tissue prepared this way the lanthanum tracer, as expected, was confirmed to the extracellular spaces, including, basement membranes, gap junctions and portions of the intercalated discs. Specimens taken near the center of frank infarctions all contained intracellular as well as extracellular lanthanum. Intracellular lanthanum could be seen evenly distributed around lipid droplets and in focal deposits around mitochondria. Only when mitochondria were disrupted did lanthanum gain access to internal sites on mitochondrial membranes. Areas marginal to the infarct contained cells in varying stages of degeneration including many that appeared normal by morphologic criteria alone. Intracellular lanthanum was present in many but not all of the marginal cells in which degenerative changes could be seen. Similarly a few of the cells that appeared morphologically normal contained intracellular lanthanum. The entry of lanthanum into some of these marginal cells and its exclusion from adjacent cells demonstrated that ischemic injury affects the permeability properties of the plasma membrane and independently of other intracellular morphologic changes and that lanthanum can be a sensitive indicator of such alteration in membrane permeability

  17. Effects of ischemic preconditioning on myocardium Caspase-3, SOCS-1, SOCS-3, TNF-α and IL-6 mRNA expression levels in myocardium IR rats.

    PubMed

    Ma, Jiangwei; Qiao, Zengyong; Xu, Biao

    2013-10-01

    The aim of this study was to characterise the effects of ischemic preconditioning (IP) on heart function parameters (ΔST and ΔT), activities of serum creatine kinase (CK), lactate dehydrogenase (LDH), and levels of serum nitric oxide (NO), malondialdehyde (MDA), and myocardium Caspase-3 mRNA, SOCS-1, SOCS-3, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) expression levels and Apoptosis index in myocardium IR rats. Results showed that ΔST and ΔST values in IP group were markedly lower than those in IR group. Compared with IR group, IP significantly (p < 0.01) decreased serum CK (0.83 ± 0.09 vs 1.36 ± 0.15), LDH (5613 ± 462 vs 7106 ± 492) activities and MDA (11.32 ± 1.05 vs 15.49 ± 1.26) level, increased the serum NO (86.39 ± 7.03 vs 53.77 ± 4.27) level in IR group. The IP induced a significant decreased in myocardium Caspase-3 mRNA (0.303 ± 0.021 vs 0.515 ± 0.022) gene expression (p < 0.01) compared to IR model group. The IP induced a significant decreased in myocardium SOCS-1 (0.241 ± 0.031 vs 0.596 ± 0.036), SOCS-3 (0.258 ± 0.031 vs 0.713 ± 0.057), TNF-α (0.137 ± 0.011 vs 0.427 ± 0.035) and IL-6 (0.314 ± 0.021 vs 0.719 ± 0.064) mRNA gene expression (p < 0.01) compared to IR model group. We conclude that IP is effective in the therapy of heart disease. These findings may have implications for the clinical development of preconditioning-based therapies for ischemic heart disease.

  18. Remote ischemic postconditioning enhances cell retention in the myocardium after intravenous administration of bone marrow mesenchymal stromal cells.

    PubMed

    Jiang, Qin; Song, Peng; Wang, Enshi; Li, Jun; Hu, Shengshou; Zhang, Hao

    2013-03-01

    Efficacy of intravenous administration of mesenchymal stromal cells (MSCs) for myocardial infarction (MI) is limited by low cell retention in the damaged myocardium. Previous studies indicated that remote ischemic conditioning could protect against ischemia-reperfusion-induced injury by release of various cytokines including stromal cell derived factor-1 alpha (SDF-1α). However, whether remote ischemic postconditioning (RIPostC) can also enhance the retention of infused cells in the myocardium by activating MSC homing is unclear. In this study, RIPostC was induced with 4cycles of 5min occlusion and reperfusion of the abdominal aorta in female Sprague-Dawley (SD) rats which underwent ligation of the coronary artery 1week previously. Cytokine levels in serum and myocardium were evaluated by enzyme-linked immunosorbent assay (ELISA) at 1, 6, 24 and 48h after RIPostC. Then, a total of 4×10(6) male MSCs were infused intravenously at 24h after RIPostC. The number of survived cells in the myocardium was evaluated by real-time polymerase chain reaction analysis for Y chromosome and the heart function was evaluated by echocardiography at 1month after cell infusion. Furthermore, 10μg/kg rabbit anti-rat CXCR4 polyclonal antibody was injected intraperitoneally to prove the role of SDF-1α for RIPostC. RIPostC induced an increase in SDF-1α in serum at 1h and enhanced SDF-1α transcription and protein synthesis in the myocardium at 24h after the procedure. 1month after cell transplantation, RIPostC significantly increased MSC myocardial retention by 79.1±12.3% and thereby contributed to enhanced cardiac function in comparison with cell transplantation without RIPostC. Furthermore, blockade with a CXCR4-specific antibody after RIPostC markedly attenuated the enhancement of therapeutic efficacy. We conclude that RIPostC activated SDF-1α expression and enhanced retention of the infused MSCs in the injured myocardium. Priming of the heart with RIPostC might be a novel

  19. Unique Transcriptional Profile of Sustained Ligand-Activated Preconditioning in Pre- and Post-Ischemic Myocardium

    PubMed Central

    Ashton, Kevin J.; Tupicoff, Amanda; Williams-Pritchard, Grant; Kiessling, Can J.; See Hoe, Louise E.; Headrick, John P.; Peart, Jason N.

    2013-01-01

    Background Opioidergic SLP (sustained ligand-activated preconditioning) induced by 3–5 days of opioid receptor (OR) agonism induces persistent protection against ischemia-reperfusion (I-R) injury in young and aged hearts, and is mechanistically distinct from conventional preconditioning responses. We thus applied unbiased gene-array interrogation to identify molecular effects of SLP in pre- and post-ischemic myocardium. Methodology/Principal Findings Male C57Bl/6 mice were implanted with 75 mg morphine or placebo pellets for 5 days. Resultant SLP did not modify cardiac function, and markedly reduced dysfunction and injury in perfused hearts subjected to 25 min ischemia/45 min reperfusion. Microarray analysis identified 14 up- and 86 down-regulated genes in normoxic hearts from SLP mice (≥1.3-fold change, FDR≤5%). Induced genes encoded sarcomeric/contractile proteins (Myh7, Mybpc3,Myom2,Des), natriuretic peptides (Nppa,Nppb) and stress-signaling elements (Csda,Ptgds). Highly repressed genes primarily encoded chemokines (Ccl2,Ccl4,Ccl7,Ccl9,Ccl13,Ccl3l3,Cxcl3), cytokines (Il1b,Il6,Tnf) and other proteins involved in inflammation/immunity (C3,Cd74,Cd83, Cd86,Hla-dbq1,Hla-drb1,Saa1,Selp,Serpina3), together with endoplasmic stress proteins (known: Dnajb1,Herpud1,Socs3; putative: Il6, Gadd45g,Rcan1) and transcriptional controllers (Egr2,Egr3, Fos,Hmox1,Nfkbid). Biological themes modified thus related to inflammation/immunity, together with cellular/cardiovascular movement and development. SLP also modified the transcriptional response to I-R (46 genes uniquely altered post-ischemia), which may influence later infarction/remodeling. This included up-regulated determinants of cellular resistance to oxidant (Mgst3,Gstm1,Gstm2) and other forms of stress (Xirp1,Ankrd1,Clu), and repression of stress-response genes (Hspa1a,Hspd1,Hsp90aa,Hsph1,Serpinh1) and Txnip. Conclusions Protection via SLP is associated with transcriptional repression of inflammation/immunity, up

  20. The effects of dipyridamole on blood flow and oxygen handling in the acutely ischaemic and normal canine myocardium

    PubMed Central

    Marshall, R. J.; Parratt, J. R.

    1973-01-01

    1. The effects of the intravenous administration of dipyridamole (0·25 mg/kg) were examined in a canine preparation that enabled simultaneous measurements to be made of blood flow in ischaemic and in essentially normal areas of the myocardium and also of oxygen handling (availability, consumption and extraction) in both these regions. 2. When administered to dogs anaesthetized with trichlorethylene 2-3 h after acute ligation of the descending branch of the left coronary artery, dipyridamole markedly increased blood flow in essentially normal regions (left circumflex flow) but failed to increase flow in the area supplied by the ligated vessel (measured by 133xenon clearance and by retrograde flow). In five of the six animals definite decreases in flow (` stealing ') were observed in the ischaemic region. These flow changes were related to the decreased trans-ventricular perfusion pressure (diastolic peripheral coronary pressure minus left ventricular end-diastolic pressure) and were accompanied by electrocardiographic evidence of increasingly severe myocardial ischaemia. The results support the suggestion that only increasing the perfusion gradient will usefully improve blood flow (and hence oxygen availability) to the acutely ischaemic myocardium. 3. Despite these effects on ischaemic muscle blood flow, the oxygen tension of the blood draining the infarcting muscle was markedly elevated. The conclusion is drawn that dipyridamole decreases the efficiency of the myocardial circulation by opening up vessels that do not take part in tissue exchange. PMID:4777702

  1. First report on application of diode laser for photocoagulation of canine myocardium

    NASA Astrophysics Data System (ADS)

    Ware, David L.; Motamedi, Massoud; Pohl, John; Bell, Brent A.; Boor, Paul

    1994-07-01

    Ventricular tachycardia (VT) is a rapid heart rhythm which is often life threatening. Several surgical and percutaneous ways to destroy the myocardium responsible for VT have been studied. It has been postulated that laser therapy may be ideal for this purpose because it can heat a large volume of tissue. Recent developments in diode lasers have prompted us to evaluate this source (810 nm) for photocoagulation of myocardial tissue. Its size, ease of maintenance, and cost make diode laser suitable for clinical practice in general, and for percutaneous photoablation in particular. Lesions were created in myocardium with contact irradiation using a 600 micron bare tipped optical fiber both in vitro and in vivo. Exposures of 2 to 3 W over 30 to 60 seconds created lesions with no or minimal char formations. In vivo lesions tended to be larger than in vitro, with better defined border zones. Animals tolerated laser irradiation well without significant ventricular ectopy. Diode laser irradiation is a promising means to percutaneously coagulate ventricular myocardium and for cure of VT. Further investigation of the dosimetry and healing response in both healthy and diseased myocardium is warranted.

  2. Two forms of spiral-wave reentry in an ionic model of ischemic ventricular myocardium

    NASA Astrophysics Data System (ADS)

    Xu, Aoxiang; Guevara, Michael R.

    1998-03-01

    It is well known that there is considerable spatial inhomogeneity in the electrical properties of heart muscle, and that the many interventions that increase this initial degree of inhomogeneity all make it easier to induce certain cardiac arrhythmias. We consider here the specific example of myocardial ischemia, which greatly increases the electrical heterogeneity of ventricular tissue, and often triggers life-threatening cardiac arrhythmias such as ventricular tachycardia and ventricular fibrillation. There is growing evidence that spiral-wave activity underlies these reentrant arrhythmias. We thus investigate whether spiral waves might be induced in a realistic model of inhomogeneous ventricular myocardium. We first modify the Luo and Rudy [Circ. Res. 68, 1501-1526 (1991)] ionic model of cardiac ventricular muscle so as to obtain maintained spiral-wave activity in a two-dimensional homogeneous sheet of ventricular muscle. Regional ischemia is simulated by raising the external potassium concentration ([K+]o) from its nominal value of 5.4 mM in a subsection of the sheet, thus creating a localized inhomogeneity. Spiral-wave activity is induced using a pacing protocol in which the pacing frequency is gradually increased. When [K+]o is sufficiently high in the abnormal area (e.g., 20 mM), there is complete block of propagation of the action potential into that area, resulting in a free end or wave break as the activation wave front encounters the abnormal area. As pacing continues, the free end of the activation wave front traveling in the normal area increasingly separates or detaches from the border between normal and abnormal tissue, eventually resulting in the formation of a maintained spiral wave, whose core lies entirely within an area of normal tissue lying outside of the abnormal area ("type I" spiral wave). At lower [K+]o (e.g., 10.5 mM) in the abnormal area, there is no longer complete block of propagation into the abnormal area; instead, there is partial

  3. Tissue Engineered, Hydrogel-Based Endothelial Progenitor Cell Therapy Robustly Revascularizes Ischemic Myocardium and Preserves Ventricular Function

    PubMed Central

    Atluri, Pavan; Miller, Jordan S; Emery, Robert J; Hung, George; Trubelja, Alen; Cohen, Jeffrey E; Lloyd, Kelsey; Han, Jason; Gaffey, Ann C; MacArthur, John W; Chen, Christopher S; Woo, Y Joseph

    2014-01-01

    Objective Cell based angiogenic therapy for ischemic heart failure has had limited clinical impact, likely related to very low cell retention (<1%) and dispersion. We developed a novel, tissue engineered, hydrogel based cell delivery strategy to overcome these limitations and provide prolonged regional retention of myocardial endothelial progenitor cells (EPC) at high cell dosage. Methods EPCs were isolated from Wistar Rats and encapsulated in fibrin gels. In vitro viability was quantified using a fluorescent live-dead stain of transgenic eGFP+ EPCs. EPC-laden constructs were implanted onto ischemic rat myocardium in a model of acute myocardial infarction (LAD ligation) for 4 weeks. Intramyocardial cell injection (IC, 2×106 EPCs), empty fibrin, and isolated LAD ligation groups served as controls. Hemodynamics were quantified using echocardiography, Doppler flow analysis, and intraventricular pressure-volume analysis. Vasculogenesis and ventricular geometry were quantified. EPC migration was analyzed by utilizing EPCs from transgenic eGFP+ rodents. Results EPCs demonstrated an overall 88.7% viability for all matrix and cell conditions investigated after 48 hours. Histologic assessment of 1-wk implants demonstrated significant migration of transgenic eGFP+ EPCs from the fibrin matrix to the infarcted myocardium as compared to IC (28±12.3 vs. 2.4±2.1cells/hpf, p=0.0001). We also observed a marked increase in vasculogenesis at the implant site. Significant improvements in ventricular hemodynamics and geometry were present following EPC-hydrogel therapy as compared to control. Conclusion We present a tissue engineered hydrogel-based EPC mediated therapy to enhance cell delivery, cell retention, vasculogenesis, and preservation of myocardial structure and function. PMID:25129603

  4. [The characteristics of the inotropic effects of Levosimendan on the isolated myocardium of patients with ischemic heart disease].

    PubMed

    Afanas'ev, S A; Timofeev, V Iu

    2000-01-01

    Effect of the new cardiotonic agent levosimendan on the inotropic response parameters of the isolated myocardium of patients suffering from ischemic heart disease (IHD) was studied in the 0.01-1.00 mumole/liter concentration range. The inotropic response was measured in an isometric mode (electric stimulation frequency, 0.5 Hz; temperature, 37 degrees C; perfusion rate, 10 ml/min). In the range of 0.01-0.1 mumole/liter, levosimendan preferentially increases the rate of stress growth (+dP/dt) and the relaxation time. At concentrations above 0.1 mumole/liter, levosimendan produces a pronounced increase (56%) in the amplitude of single contraction. The mechanogram exhibits the signs of Ca-overload, including the post-contraction wave. It is concluded that the inotropic action of levosimendan on the isolated myocardium of IHD patients is related predominantly to increasing calcium uptake from outside. This circumstance is apparently caused by the initially high calcium content in sarcoplasmic reticulum, which is an important feature of the entire intracellular homeostasis in cardiomyocytes during IHD.

  5. Kinetics of thallium-201 in reperfused canine myocardium after coronary artery occlusion

    SciTech Connect

    Okada, R.D.

    1984-05-01

    To study the kinetics of thallium-201 in nonsalvaged acutely infarcted myocardium and salvaged myocardium, the tracer was administered after experimental left anterior descending coronary artery reperfusion 2 hours after occlusion. In 19 dogs, thallium activity was then monitored for 4 hours in the reperfused anterior wall and normal posterior wall using miniature cadmium telluride radiation detectors. After sacrifice, 13 of the dogs were found to have an infarcted anterior wall by triphenyltetrazolium-chloride staining. In these dogs, mean (+/- standard deviation) fractional 4 hour thallium clearance was 0.33 +/- 0.08 for the infarct zone and 0.15 +/- 0.06 for the normal control zone (p less than 0.001). When computer-modeled, the clearance curve from the infarct zone was biexponential. The second exponential clearance curve from the infarct zone began 19.1 +/- 3.2 minutes after tracer administration, and was indistinguishable from the monoexponential clearance curve from the normal control zone. Thallium clearance from the blood pool was triexponential, the final exponential clearance curve being indistinguishable from the normal control zone clearance curve. Six dogs were found to have a salvaged noninfarcted anterior wall by triphenyltetrazolium-chloride staining. In these dogs, mean fractional 4 hour thallium clearance was 0.20 +/- 0.07 for the reperfused zone, and 0.19 +/- 0.08 for the normal control zone (p . NS). When computer-modeled, clearance curves for the reperfused and control zones were monoexponential. The monoexponential clearance curve for the salvaged reperfused zone was indistinguishable from the monoexponential clearance curve for normal myocardium.

  6. Blood flow, flow reserve, and glucose utilization in viable and nonviable myocardium in patients with ischemic cardiomyopathy

    PubMed Central

    Zhang, Xiaoli; Schindler, Thomas H.; Prior, John O.; Sayre, James; Dahlbom, Magnus; Huang, Sung-Cheng

    2016-01-01

    Purpose The aim of the study was to determine whether glucose uptake in viable myocardium of ischemic cardiomyopathy patients depends on rest myocardial blood flow (MBF) and the residual myocardial flow reserve (MFR). Methods Thirty-six patients with ischemic cardiomyopathy (left ventricular ejection fraction 25±10 %) were studied with 13N-ammonia and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty age-matched normals served as controls. Regional MBF was determined at rest and during dipyridamole hyperemia and regional FDG extraction was estimated from regional FDG to 13N-ammonia activity ratios. Results Rest MBF was reduced in viable (0.42±0.18 ml/min per g) and nonviable regions (0.32±0.09 ml/min per g) relative to remote regions (0.68±0.23 ml/min per g, p<0.001) and to normals (0.63±0.13 ml/min per g). Dipyridamole raised MBFs in controls, remote, viable, and nonviable regions. MBFs at rest (p<0.05) and stress (p<0.05) in viable regions were significantly higher than that in nonviable regions, while MFRs did not differ significantly (p>0.05). Compared to MFR in remote myocardium, MFRs in viable regions were similar (1.39±0.56 vs 1.70±0.45, p>0.05) but were significantly lower in nonviable regions (1.23±0.43, p<0.001). Moreover, the FDG and thus glucose extraction was higher in viable than in remote (1.40±0.14 vs 0.90±0.20, p<0.001) and in nonviable regions (1.13±0.21, p<0.001). The extraction of FDG in viable regions was independent of rest MBF but correlated inversely with MFRs (r=−0.424, p<0.05). No correlation between the FDG extraction and MFR was observed in nonviable regions. Conclusion As in the animal model, decreasing MFRs in viable myocardium are associated with increasing glucose extraction that likely reflects a metabolic adaptation of remodeling hibernating myocytes. PMID:23287994

  7. Fluorescence lifetime measurements of NADH and tryptophan in intact ischemic, intact rabbit myocardium

    NASA Astrophysics Data System (ADS)

    Hamburger, Adrian; Gryczynski, Zygmunt; Lakowicz, Joseph R.; Sommers, Keith

    1999-07-01

    Ischemia-reperfusion injury is the leading cause of early dysfunction following transplantation. Currently, there are no techniques available to accurately measure ischemic changes during organ storage. Therefore, the interest exists in developing non-invasive monitoring techniques. We used NADH and tryptophan as fluorescent markers, since both are intrinsic fluorophores and excellent indicators for levels of hypoxia and protein denaturation, respectively.

  8. Adenosine Stress and Rest T1 Mapping Can Differentiate Between Ischemic, Infarcted, Remote, and Normal Myocardium Without the Need for Gadolinium Contrast Agents

    PubMed Central

    Liu, Alexander; Wijesurendra, Rohan S.; Francis, Jane M.; Robson, Matthew D.; Neubauer, Stefan; Piechnik, Stefan K.; Ferreira, Vanessa M.

    2016-01-01

    Objectives The aim of this study was to evaluate the potential of T1 mapping at rest and during adenosine stress as a novel method for ischemia detection without the use of gadolinium contrast. Background In chronic coronary artery disease (CAD), accurate detection of ischemia is important because targeted revascularization improves clinical outcomes. Myocardial blood volume (MBV) may be a more comprehensive marker of ischemia than myocardial blood flow. T1 mapping using cardiac magnetic resonance (CMR) is highly sensitive to changes in myocardial water content, including MBV. We propose that T1 mapping at rest and during adenosine vasodilatory stress can detect MBV changes in normal and diseased myocardium in CAD. Methods Twenty normal controls (10 at 1.5-T; 10 at 3.0-T) and 10 CAD patients (1.5-T) underwent conventional CMR to assess for left ventricular function (cine), infarction (late gadolinium enhancement [LGE]) and ischemia (myocardial perfusion reserve index [MPRI] on first-pass perfusion imaging during adenosine stress). These were compared to novel pre-contrast stress/rest T1 mapping using the Shortened Modified Look-Locker Inversion recovery technique, which is heart rate independent. T1 values were derived for normal myocardium in controls and for infarcted, ischemic, and remote myocardium in CAD patients. Results Normal myocardium in controls (normal wall motion, MPRI, no LGE) showed normal resting T1 (954 ± 19 ms at 1.5-T; 1,189 ± 34 ms at 3.0-T) and significant positive T1 reactivity during adenosine stress compared to baseline (6.2 ± 0.5% at 1.5-T; 6.3 ± 1.1% at 3.0-T; all p < 0.0001). Infarcted myocardium showed the highest resting T1 of all tissue classes (1,442 ± 84 ms), without significant T1 reactivity (0.2 ± 1.5%). Ischemic myocardium showed elevated resting T1 compared to normal (987 ± 17 ms; p < 0.001) without significant T1 reactivity (0.2 ± 0.8%). Remote myocardium, although having comparable resting T1 to normal (955 ± 17 ms

  9. Stimulus-induced critical point. Mechanism for electrical initiation of reentry in normal canine myocardium.

    PubMed Central

    Frazier, D W; Wolf, P D; Wharton, J M; Tang, A S; Smith, W M; Ideker, R E

    1989-01-01

    The hypothesis was tested that the field of a premature (S2) stimulus, interacting with relatively refractory tissue, can create unidirectional block and reentry in the absence of nonuniform dispersion of recovery. Simultaneous recordings from a small region of normal right ventricular (RV) myocardium were made from 117 to 120 transmural or epicardial electrodes in 14 dogs. S1 pacing from a row of electrodes on one side of the mapped area generated parallel activation isochrones followed by uniform parallel isorecovery lines. Cathodal S2 shocks of 25 to 250 V lasting 3 ms were delivered from a mesh electrode along one side of the mapped area to scan the recovery period, creating isogradient electric field lines perpendicular to the isorecovery lines. Circus reentry was created following S2 stimulation; initial conduction was distant from the S2 site and spread towards more refractory tissue. Reentry was clockwise for right S1 (near the septum) with top S2 (near the pulmonary valve) and for left S1 with bottom S2; and counterclockwise for right S1 with bottom S2 and left S1 with top S2. The center of the reentrant circuit for all S2 voltages and coupling intervals occurred at potential gradients of 5.1 +/- 0.6 V/cm (mean +/- standard deviation) and at preshock intervals 1 +/- 3 ms longer than refractory periods determined locally for a 2 mA stimulus. Thus, when S2 field strengths and tissue refractoriness are uniformally dispersed at an angle to each other, circus reentry occurs around a "critical point" where an S2 field of approximately 5 V/cm intersects tissue approximately at the end of its refractory period. Images PMID:2921316

  10. Kinetics of a putative hypoxic tissue marker, Technetium-99m-nitroimidazole (BMS181321), in normoxic, hypoxic, ischemic and stunned myocardium

    SciTech Connect

    Kusuoka, Hideo; Hashimoto, Katsuji; Fukuchi, Kazuki

    1994-08-01

    This study focused on the kinetics of the newly developed {sup 99m}TTc-nitroimidazole, propyleneamine oxime-1,2-nitroimidazole (BMS181321) in the different setting of myocardial perfusion states and oxygenation levels, and compared the kinetics of BMS181321 with those of other technetium analogues. The kinetics of BMS181321 were evaluated in isolated perfused rat hearts. Technetium-99m-hexamethyl propyleneamine oxime (HMPAO) and a non-nitroimidazole-containing analogue of BMS 181321 (6-methyl propyleneamine oxime; PAO-6-Me) were used to compare their kinetics with those of BMS181321. BMS181321 cleared quickly from normoxic hearts and the retention in the myocardium 10 min after injection was 0.84% {plus_minus} 0.04% ID/g wet wt (mean {plus_minus} s.e.m.). In contrast, BMS181321 was retained after reperfusion when it was injected before ischemia; the uptake in the myocardium 10 min after reperfusion was significantly greater than in controls (23.9% {plus_minus} 3.9%ID/g wt, p<0.05). These results indicate that {sup 99m}Tc-BMS181321 is well trapped in ischemic myocardium and moderately trapped in hypoxic myocardium, but washed out quickly in stunned myocardium. The residence time influences the amount retained. 14 refs., 7 figs., 1 tab.

  11. Identification of ischemic and hibernating myocardium: feasibility of post-exercise F-18 deoxyglucose positron emission tomography

    SciTech Connect

    Marwick, T.H.; MacIntyre, W.J.; Salcedo, E.E.; Go, R.T.; Saha, G.; Beachler, A. )

    1991-02-01

    The identification of ischemic and hibernating myocardium facilitates the selection of patients most likely to benefit from revascularization. This study examined the feasibility of metabolic imaging, using post-exercise F-18 deoxyglucose positron emission tomography (FDG-PET) for the diagnosis of both ischemia and hibernation in 27 patients with known coronary anatomy. Normal post-exercise FDG uptake was defined in each patient by reference to normal resting perfusion and normal coronary supply. Abnormal elevation of FDG (ischemia or hibernation) was compared in 13 myocardial segments in each patient, with the results of dipyridamole stress perfusion imaging performed by rubidium-82 positron emission tomography (Rb-PET). Myocardial ischemia was diagnosed by either FDG-PET or Rb-PET in 34 segments subtended by significant local coronary stenoses. Increased FDG uptake was present in 32/34 (94%) and a reversible perfusion defect was identified by Rb-PET in 22/34 (65%, p less than .01). In 3 patients, ischemia was identified by metabolic imaging alone. In 16 patients with previous myocardial infarction, perfusion defects were present at rest in 89 regions, 30 of which (34%) demonstrated increased FDG uptake, consistent with the presence of hibernation. Increased post-exercise FDG uptake appears to be a sensitive indicator of ischemia and myocardial hibernation. Increased post-exercise FDG uptake, appears to be a sensitive indicator of ischemia and myocardial hibernation. This test may be useful in selecting post-infarction patients for revascularization.

  12. Modulation of ephrinB2 leads to increased angiogenesis in ischemic myocardium and endothelial cell proliferation

    SciTech Connect

    Mansson-Broberg, Agneta; Siddiqui, Anwar J.; Genander, Maria; Grinnemo, Karl-Henrik; Hao Xiaojin; Andersson, Agneta B.; Waerdell, Eva; Sylven, Christer Corbascio, Matthias

    2008-08-29

    Eph/ephrin signaling is pivotal in prenatal angiogenesis while its potential role in postnatal angiogenesis largely remains to be explored. Therefore its putative angiogenic and therapeutic effects were explored in endothelium and in myocardial ischemia. In culture of human aortic endothelial cells the fusion protein ephrinB2-Fc induced cell proliferation (p < 0.0005) and in the murine aortic ring model ephrinB2-Fc induced increased sprouting (p < 0.05). Myocardial infarction was induced by ligation of the left anterior descending artery in mouse. During the following 2 weeks mRNA of the receptor/ligand pair EphB4/ephrinB2 was expressed dichotomously (p < 0.05) and other Eph/ephrin pairs were expressed to a lesser degree. Twenty-four hours after intraperitoneal administration of ephrinB2-Fc it was detected in abundance throughout the myocardium along capillaries, showing signs of increased mitosis. After 4 weeks the capillary density was increased 28% in the periinfarcted area (p < 0.05) to a level not different from healthy regions of the heart where no change was observed. These results implicate that EphB4/ephrinB2 is an important signaling pathway in ischemic heart disease and its modulation may induce therapeutic angiogenesis.

  13. Cardiac progenitor-derived exosomes protect ischemic myocardium from acute ischemia/reperfusion injury

    SciTech Connect

    Chen, Lijuan; Wang, Yingjie; Pan, Yaohua; Zhang, Lan; Shen, Chengxing; Qin, Gangjian; Ashraf, Muhammad; Weintraub, Neal; Ma, Genshan; Tang, Yaoliang

    2013-02-15

    Highlights: ► Cardiac progenitor-derived (CPC) Exosomes protect H9C2 from apoptosis in vitro. ► CPC-exosomes protect cardiomyoyctes from MI/R induced apoptosis in vivo. ► CPC-exosomes were taken up by H9C2 with high efficiency using PKH26 labeling. ► miR-451, one of GATA4-responsive miRNA cluster, is enriched in CPC-exosomes. -- Abstract: Background: Cardiac progenitors (CPC) mediate cardioprotection via paracrine effects. To date, most of studies focused on secreted paracrine proteins. Here we investigated the CPC-derived-exosomes on protecting myocardium from acute ischemia/reperfusion (MI/R) injury. Methods and results: CPC were isolated from mouse heart using two-step protocol. Exosomes were purified from conditional medium, and confirmed by electron micrograph and Western blot using CD63 as a marker. qRT-PCR shows that CPC-exosomes have high level expression of GATA4-responsive-miR-451. Exosomes were ex vivo labeled with PKH26, We observed exosomes can be uptaken by H9C2 cardiomyoblasts with high efficiency after 12 h incubation. CPC-exosomes protect H9C2 from oxidative stress by inhibiting caspase 3/7 activation invitro. In vivo delivery of CPC-exosomes in an acute mouse myocardial ischemia/reperfusion model inhibited cardiomyocyte apoptosis by about 53% in comparison with PBS control (p < 0.05). Conclusion: Our results suggest, for the first time, the CPC-exosomes can be used as a therapeutic vehicle for cardioprotection, and highlights a new perspective for using non-cell exosomes for cardiac disease.

  14. Real-time monitoring of nitric oxide in ischemic myocardium using an NO-selective electrode calibrated by electron spin resonance.

    PubMed

    Takahashi, Shun-suke; Omori, Yoichi; Miyazaki, Hiroyuki; Yoshino, Fumihiko; Shoji, Hirofumi; Lee, Masaichi-Chang-il; Todoki, Kazuo; Kamibayashi, Masato; Murakami, Eiichi

    2003-11-21

    Using a Langendorff-perfused rat heart preparation and selective electrodes, we determined nitric oxide (NO) and oxygen levels in cardiac tissue. An NO-selective electrode that was calibrated by electron spin resonance (ESR) spectroscopy was inserted into the middle of the myocardium in the left ventricle. Simultaneously, we used an O2-selective electrode to measure the partial pressure of oxygen (pO2) in the perfusate, Krebs-Henseleit (K-H) solution, that was ejected from the heart. After 30 min of aerobic control perfusion, hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion. Under ischemic conditions, with a gradually decreasing pO2, NO detected by an NO-sensitive electrode within the myocardium was gradually increased. The maximum concentration increases in NO and decreases in pO2 during global ischemia were +10.200 +/- 1.223 microM and -58.608 +/- 4.123 mmHg, respectively. NO and pO2 levels both recovered to pre-ischemia baseline values when perfusion was restarted after global ischemia (reperfusion). The presence of Nomega-nitro-L-arginine methyl ester (L-NAME, 10 mM), a NOS inhibitor, prevented ischemia/reperfusion-induced changes in NO. This study shows that an NO-selective electrode that is calibrated by ESR can provide accurate, real-time monitoring of cardiac NO in normal and ischemic myocardium.

  15. Interleukin-8 gene induction in the myocardium after ischemia and reperfusion in vivo.

    PubMed Central

    Kukielka, G L; Smith, C W; LaRosa, G J; Manning, A M; Mendoza, L H; Daly, T J; Hughes, B J; Youker, K A; Hawkins, H K; Michael, L H

    1995-01-01

    Neutrophil adhesion and direct cytotoxicity for cardiac myocytes require chemotactic stimulation and are dependent upon CD18-ICAM-1 binding. To characterize the potential role of IL-8 in this interaction, canine IL-8 cDNA was cloned and the mature recombinant protein expressed in Escherichia coli BL21 cells. Recombinant canine IL-8 markedly increased adhesion of neutrophils to isolated canine cardiac myocytes. This adhesion resulted in direct cytotoxicity for cardiac myocytes. Both processes were specifically blocked by antibodies directed against CD18 and IL-8. In vivo, after 1 h of coronary occlusion, IL-8 mRNA was markedly and consistently induced in reperfused segments of myocardium. IL-8 mRNA was not induced in control (normally perfused) myocardial segments. Minimal amounts of IL-8 mRNA were detected after 3 or 4 h of ischemia without reperfusion. Highest levels of induction were evident in the most ischemic myocardial segments. IL-8 mRNA peaked in the first 3 h of reperfusion and persisted at high levels beyond 24 h. IL-8 staining was present in the inflammatory infiltrate near the border between necrotic and viable myocardium, as well as in small veins in the same area. These findings provide the first direct evidence for regulation of IL-8 in ischemic and reperfused canine myocardium and support the hypothesis that IL-8 participates in neutrophil-mediated myocardial injury. Images PMID:7814650

  16. Influence of propranolol on high energy phosphate and tissue acidosis in regional ischemic myocardium of pigs: assessment with arterial pressure and respiration gated in vivo 31-phosphorus magnetic resonance spectroscopy.

    PubMed

    Tanaka, M; Fujiwara, H; Ishida, M; Kida, M; Onodera, T; Wu, D J; Matsuda, M; Kawamura, A; Takemura, G; Kawai, C

    1989-08-01

    In an attempt to define the metabolic abnormalities of the ischemic myocardium, the changes in high energy phosphates, inorganic phosphate and intracellular pH were serially and quantitatively evaluated in ischemic porcine hearts having no collateral circulation, using arterial pressure and respiration gated in vivo 31P magnetic resonance spectroscopy. The protocol was also modified for propranolol pretreatment (0.6 mg/kg intravenously) to define its effect on the metabolism of ischemic myocardium. In the non-treated group, creatine phosphate was rapidly depleted by 10 minutes after ischemia; by 40 minutes, ATP and intracellular pH gradually decreased to 10 +/- 11% of control and to 5.90 +/- 0.26, respectively, and inorganic phosphate rose to 303 +/- 43% of control. In the propranolol treated group, the concentrations of creatine phosphate and ATP were higher, and those of inorganic phosphate and tissue pH were similar compared with controls during 40 minutes of ischemia. This suggests that the beneficial effect of propranolol on the ischemic myocardium is due to the preservation of ATP, an essential energy resource for numerous enzymatic reactions in viable myocardium.

  17. Effect of exercise training and myocardial infarction on force development and contractile kinetics in isolated canine myocardium.

    PubMed

    Canan, Benjamin D; Haizlip, Kaylan M; Xu, Ying; Monasky, Michelle M; Hiranandani, Nitisha; Milani-Nejad, Nima; Varian, Kenneth D; Slabaugh, Jessica L; Schultz, Eric J; Fedorov, Vadim V; Billman, George E; Janssen, Paul M L

    2016-04-15

    It is well known that moderate exercise training elicits a small increase in ventricular mass (i.e., a physiological hypertrophy) that has many beneficial effects on overall cardiac health. It is also well known that, when a myocardial infarction damages part of the heart, the remaining myocardium remodels to compensate for the loss of viable functioning myocardium. The effects of exercise training, myocardial infarction (MI), and their interaction on the contractile performance of the myocardium itself remain largely to be determined. The present study investigated the contractile properties and kinetics of right ventricular myocardium isolated from sedentary and exercise trained (10-12 wk progressively increasing treadmill running, begun 4 wk after MI induction) dogs with and without a left ventricular myocardial infarction. Exercise training increased force development, whereas MI decreased force development that was not improved by exercise training. Contractile kinetics were significantly slower in the trained dogs, whereas this impact of training was less or no longer present after MI. Length-dependent activation, both evaluated on contractile force and kinetics, was similar in all four groups. The control exercise-trained group exhibited a more positive force-frequency relationship compared with the sedentary control group while both sedentary and trained post-MI dogs had a more negative relationship. Last, the impact of the β-adrenergic receptor agonist isoproterenol resulted in a similar increase in force and acceleration of contractile kinetics in all groups. Thus, exercise training increased developed force but slowed contractile kinetics in control (noninfarcted animals), actions that were attenuated or completely absent in post-MI dogs.

  18. Fibrin patch-based insulin-like growth factor-1 gene-modified stem cell transplantation repairs ischemic myocardium

    PubMed Central

    Li, Jun; Zhu, Kai; Yang, Shan; Wang, Yulin; Guo, Changfa; Yin, Kanhua; Wang, Chunsheng

    2015-01-01

    Bone marrow mesenchymal stem cells (BMSCs), tissue-engineered cardiac patch, and therapeutic gene have all been proposed as promising therapy strategies for cardiac repair after myocardial infarction. In our study, BMSCs were modified with insulin-like growth factor-1 (IGF-1) gene, loaded into a fibrin patch, and then transplanted into a porcine model of ischemia/reperfusion (I/R) myocardium injury. The results demonstrated that IGF-1 gene overexpression could promote proliferation of endothelial cells and cardiomyocyte-like differentiation of BMSCs in vitro. Four weeks after transplantation of fibrin patch loaded with gene-modified BMSCs, IGF-1 overexpression could successfully promote angiogenesis, inhibit remodeling, increase grafted cell survival and reduce apoptosis. In conclusion, the integrated strategy, which combined fibrin patch with IGF-1 gene modified BMSCs, could promote the histological cardiac repair for a clinically relevant porcine model of I/R myocardium injury. PMID:25767192

  19. Early assessment of tissue viability with radioiodinated heptadecanoic acid in reperfused canine myocardium: Comparison with thallium-201

    SciTech Connect

    Chappuis, F.; Meier, B.; Belenger, J.; Blaeuenstein, P.L.; Lerch, R. )

    1990-04-01

    Myocardial scintigraphy with heptadecanoic acid labeled with iodine-123 (123I-HDA) may allow early noninvasive delineation of viable myocardium after reperfusion. In this study myocardial uptake of 123I-HDA was compared with that of thallium-201 in six closed-chest dogs after 5 hours of occlusion followed by 1 hour of reperfusion of the left anterior descending coronary artery. Myocardial blood flow was measured with microspheres, and myocardial viability was assessed by means of triphenyltetrazolium chloride staining. In viable areas of the reperfused region, 123I-HDA uptake, thallium-201 uptake, and myocardial blood flow were similar to those measured in the control circumflex region. However, in infarcted areas they were reduced to 48 +/- 2% (mean +/- SEM; p less than 0.001), 59 +/- 3% (p less than 0.001), and 74 +/- 5% (p less than 0.001) of control values, respectively. Results of multiple regression analysis showed that thallium-201 uptake primarily reflected the level of flow during reperfusion, whereas 123I-HDA uptake was dependent on both myocardial blood flow and viability. At each level of flow, 123I-HDA uptake was significantly lower in infarcted than in viable myocardium. By means of discriminant analysis, 123I-HDA uptake was found to be the single most important predictor of viability, whereas thallium-201 was only of limited importance. Myocardial 123I-HDA uptake greater than or equal to 71% or myocardial thallium-201 uptake greater than or equal to 73% best differentiated viable from infarcted myocardium. According to these criteria, 123I-HDA predicted myocardial viability with a sensitivity of 77%, a specificity of 84% and a predictive accuracy of 81%.

  20. The use of MMP2 antibody-conjugated cationic microbubble to target the ischemic myocardium, enhance Timp3 gene transfection and improve cardiac function.

    PubMed

    Yan, Ping; Chen, Ko-Jie; Wu, Jun; Sun, Lu; Sung, Hsing-Wen; Weisel, Richard D; Xie, Jun; Li, Ren-Ke

    2014-01-01

    The objective of this study was to synthesize a cationic microbubble (CMB) conjugated with an antibody against matrix metalloproteinase 2 (CMBMMP2) to increase microbubble accumulation and gene transfection in the infarcted myocardium and to restore ventricular function following an ischemic insult. We previously reported that our CMBs enhanced the efficiency of gene transfection following ultrasound-targeted microbubble destruction (UTMD) in rodent hearts. Therefore, we conjugated a thiolated MMP2 antibody to the PEG chains on the CMB surface, which was verified by fluorescent microscopy. Rats underwent ischemia/reperfusion injury 3 days prior to UTMD delivery of the control or Timp3 plasmid. The CMBMMP2 improved microbubble accumulation in the infarct region, with 57% more contrast intensity compared to the non-conjugated CMB. UTMD-mediated CMBMMP2 delivery of the Timp3 gene significantly increased TIMP3 protein levels in the infarct scar and border zone at 3 days post-UTMD compared to delivery by the non-conjugated CMB. Both MMP2 and MMP9 activity were reduced in the CMBMMP2Timp3 group, which resulted in smaller and thicker infarcts and improved cardiac function. UTMD therapy with this CMBMMP2 provides an efficient platform for the targeted delivery of factors intended to preserve ventricular structure and improve cardiac function after ischemic injury.

  1. [Ca²⁺] i-induced augmentation of the inward rectifier potassium current (IK1) in canine and human ventricular myocardium.

    PubMed

    Nagy, Norbert; Acsai, Károly; Kormos, Anita; Sebők, Zsuzsanna; Farkas, Attila S; Jost, Norbert; Nánási, Péter P; Papp, Julius Gy; Varró, András; Tóth, András

    2013-11-01

    The inward rectifier K⁺ current (IK1) plays an important role in terminal repolarization and stabilization of the resting potential in cardiac cells. Although IK1 was shown to be sensitive to changes in intracellular Ca²⁺ concentration ([Ca²⁺]i), the nature of this Ca²⁺ sensitivity-in spite of its deep influence on action potential morphology-is controversial. Therefore, we aimed to investigate the effects of a nonadrenergic rise in [Ca²⁺]i on the amplitude of IK1 in canine and human ventricular myocardium and its consequences on cardiac repolarization. IK1, defined as the current inhibited by 10 μM Ba²⁺, was significantly increased in isolated canine myocytes following a steady rise in [Ca²⁺]i. Enhanced IK1 was also observed when [Ca²⁺]i was not buffered by ethylene glycol tetraacetic acid, and [Ca²⁺]I transients were generated. This [Ca²⁺]i-dependent augmentation of IK1 was largely attenuated after inhibition of CaMKII by 1 μM KN-93. Elevation of [Ca²⁺]o in multicellular canine and human ventricular preparations resulted in shortening of action potentials and acceleration of terminal repolarization. High [Ca²⁺]o enhanced the action potential lengthening effect of the Ba(2+)-induced IK1 blockade and attenuated the prolongation of action potentials following a 0.3-μM dofetilide-induced IKr blockade. Blockade of IKs by 0.5 μM HMR-1556 had no significant effect on APD90 in either 2 mM or 4 mM [Ca²⁺]o. It is concluded that high [Ca²⁺]i leads to augmentation of the Ba²⁺-sensitive current in dogs and humans, regardless of the mechanism of the increase. This effect seems to be at least partially mediated by a CaMKII-dependent pathway and may provide an effective endogenous defense against cardiac arrhythmias induced by Ca²⁺ overload. PMID:23807312

  2. Molecular Strategy to Reduce In Vivo Collagen Barrier Promotes Entry of NCX1 Positive Inducible Pluripotent Stem Cells (iPSCNCX1+) into Ischemic (or Injured) Myocardium

    PubMed Central

    Millard, Ronald W.; Yu, Xi-Yong; Luther, Kristin; Xu, Meifeng; Zhao, Ting C.; Yang, Huang-Tian; Qi, Zhihua; LaSance, Kathleen; Ashraf, Muhammad; Wang, Yigang

    2013-01-01

    Objective The purpose of this study was to assess the effect of collagen composition on engraftment of progenitor cells within infarcted myocardium. Background We previously reported that intramyocardial penetration of stem/progenitor cells in epicardial patches was enhanced when collagen was reduced in hearts overexpressing adenylyl cyclase-6 (AC6). In this study we hypothesized an alternative strategy wherein overexpression of microRNA-29b (miR-29b), inhibiting mRNAs that encode cardiac fibroblast proteins involved in fibrosis, would similarly facilitate progenitor cell migration into infarcted rat myocardium. Methods In vitro: A tri-cell patch (Tri-P) consisting of cardiac sodium-calcium exchanger-1 (NCX1) positive iPSC (iPSCNCX1+), endothelial cells (EC), and mouse embryonic fibroblasts (MEF) was created, co-cultured, and seeded on isolated peritoneum. The expression of fibrosis-related genes was analyzed in cardiac fibroblasts (CFb) by qPCR and Western blot. In vivo: Nude rat hearts were administered mimic miRNA-29b (miR-29b), miRNA-29b inhibitor (Anti-29b), or negative mimic (Ctrl) before creation of an ischemically induced regional myocardial infarction (MI). The Tri-P was placed over the infarcted region 7 days later. Angiomyogenesis was analyzed by micro-CT imaging and immunofluorescent staining. Echocardiography was performed weekly. Results The number of green fluorescent protein positive (GFP+) cells, capillary density, and heart function were significantly increased in hearts overexpressing miR-29b as compared with Ctrl and Anti-29b groups. Conversely, down-regulation of miR-29b with anti-29b in vitro and in vivo induced interstitial fibrosis and cardiac remodeling. Conclusion Overexpression of miR-29b significantly reduced scar formation after MI and facilitated iPSCNCX1+ penetration from the cell patch into the infarcted area, resulting in restoration of heart function after MI. PMID:23990893

  3. Acute myocardial infarction associated with single vessel coronary artery disease: an analysis of clinical outcome and the prognostic importance of vessel patency and residual ischemic myocardium

    SciTech Connect

    Wilson, W.W.; Gibson, R.S.; Nygaard, T.W.; Craddock, G.B. Jr.; Watson, D.D.; Crampton, R.S.; Beller, G.A.

    1988-02-01

    The long-term outcome and the significance of residual ischemic myocardium, as assessed by predischarge exercise thallium scintigraphy and vessel patency, were studied in 97 patients with single vessel coronary artery disease by angiography 12 +/- 4 days after uncomplicated myocardial infarction. During a mean follow-up period of 39 +/- 17 months, no patients died, 6 (6%) had a recurrent nonfatal infarction and 25 (26%) experienced rapidly progressive angina requiring hospitalization. Although neither exercise-induced angina nor ST segment depression was predictive of a recurrent cardiac event, the mean number of infarct zone scan segments showing thallium redistribution (1.0 +/- 1.0 versus 0.5 +/- 0.8, p = 0.01) and the percent of patients with infarct zone redistribution (61 versus 39%, p = 0.05) were greater in those patients who experienced a late ischemic event. Kaplan-Meier analysis demonstrated a lower event-free survival rate in patients with redistribution (n = 45) than in those without redistribution (n = 52) (p = 0.019). Although no patient received immediate thrombolytic therapy, the infarct-related vessel was angiographically patent in 40 patients (41%). Vessel patency did not influence event-free survival, although a patent vessel, as compared with an occluded vessel, was associated with a greater prevalence of non-Q wave infarction (58 versus 21%, p less than 0.001), fewer persistent infarct zone thallium defects (1.2 +/- 1.1 versus 2.0 +/- 1.2, p = 0.001), more reversible infarct zone thallium defects (1.0 +/- 1.0 versus 0.5 +/- 0.9, p = 0.02) and a trend toward a higher left ventricular ejection fraction (53 +/- 10% versus 49 +/- 12%, p = 0.07).

  4. Protection of ischemic myocardium: comparison of effects of propranolol, bevantolol and N-dimethyl propranolol on infarct size following coronary artery occlusion in anesthetized dogs.

    PubMed

    Warltier, D C; Gross, G J; Jesmok, G J; Brooks, H L; Hardman, H F

    1980-01-01

    The relative extent of myocardial infarction produced by occlusion of the left anterior descendens coronary artery in anesthetized dogs was determined under control conditions or following treatment (4 h after ligation) with propranolol (1 mg/kg), bevantolol (3 mg/kg) or N-dimethyl propranolol (10 mg/kg). Doses of drugs were selected to provide similar reductions in heart rate, aortic blood pressure and contractility. Infarct size was estimated indirectly from levels of plasma creatine phosphokinase and measured histochemically by nitroblue tetrazolium stain. A significant ( p < 0.001) correlation between methods was found. Propranolol and bevantolol (beta adrenergic antagonists) produced a significant (p < 0.05) reduction (approximately 50% decrease) in infarct size, measured at 8 h following induction of ischemia, while N-dimemthyl propranolol (no beta antagonist activity) produced no effect. While all three agents produced similar hemodynamic actions and thereby reduced primary determinants of myocardial oxygen demand, only the beta blockers were able to afford protection of ischemic myocardium.

  5. Improvement in the relationship between flow to ischemic myocardium and the extent of necrosis with glycolytic intermediates that decrease blood oxygen affinity in dogs.

    PubMed

    Pantely, G A; Oyama, A A; Metcalfe, J; Lawson, M S; Welch, J E

    1981-08-01

    Reducing blood oxygen affinity may enhance myocardial oxygen delivery during ischemia. We evaluated this hypothesis in awake, previously instrumented dogs that received a 20 ml/kg infusion of a solution of dihydroxyacetone, phosphate, and pyruvate after acute occlusion of either the left anterior descending or circumflex coronary artery. This infusion reduced blood oxygen affinity (BOA) after 2 hours; the P50 increased from 29.9 +/- 0.7 torr (mean +/- SD) to 32.1 +/- 0.6 torr; P less than 0.01 (BOA group). Four dogs received 20 ml/kg of phosphate and pyruvate solution to assess volume effects (V group), and five dogs were controls (C group). The 2-hour P50 values in V and C were unchanged. Regional flow (15-mum spheres) reduction 2 hours postocclusion was compared to the percent tissue infarcted determined by histology 7-9 days after occlusion for multiple samples from the endocardial layer of the left ventricle. When flow was less than 40% of normal, V and C had 55% infarction while BOA had 37% (P less than 0.05); at flow less than 20% of normal, V and C had 79% infarction while BOA had 38% (P less than 0.001); and at less than 10% of normal, V and C 87% and 94% infarction, respectively, while BOA had 56% (P less than 0.001). Reducing blood oxygen affinity after coronary artery occlusion significantly decreased the extent of myocardial necrosis for the same degree of ischemia. Reducing BOA may increase oxygen delivery to ischemic myocardium when flow is restricted.

  6. A quantitative index of regional blood flow in canine myocardium derived noninvasively with N-13 ammonia and dynamic positron emission tomography

    SciTech Connect

    Nienaber, C.A.; Ratib, O.; Gambhir, S.S.; Krivokapich, J.; Huang, S.C.; Phelps, M.E.; Schelbert, H.R. )

    1991-01-01

    To derive a quantitative index of regional myocardial blood flow, the arterial input function of the flow tracer N-13 ammonia and the regional myocardial N-13 activity concentrations were noninvasively determined in 29 experiments in eight dogs. N-13 ammonia was administered intravenously and cross-sectional images were acquired dynamically using an ECAT III positron emission tomograph with an effective in-plane resolution of 13.46 mm full-width half-maximum. Time-activity curves were derived from the serial images by assigning regions of interest to the left ventricular myocardium and left ventricular blood pool. Tracer net extractions were estimated from the myocardial time-activity concentrations at various times after tracer injection and the integral of the arterial input function. Myocardial blood flow was altered by intravenous dipyridamole, morphine, propranolol and partial or complete occlusion of the left anterior descending coronary artery, and ranged from 9 to 860 ml/min per 100 g. Estimates of tracer net extractions were most accurate when determined from the myocardial N-13 activity concentrations at 60 s divided by the integral of the arterial input function to that time. These estimates correlated with regional myocardial blood flows determined independently by the microsphere technique by y = x (1 - 0.64(e-114/x); SEE = 22.9; r = 0.94). First pass extraction fractions of N-13 ammonia determined noninvasively with this approach declined with higher flows in a nonlinear fashion and were similar to those determined invasively by direct intracoronary N-13 ammonia injections. The findings indicate that an accurate index of regional myocardial blood flow can be obtained noninvasively by high temporal sampling of arterial and myocardial tracer activity concentrations with positron emission tomography.

  7. Protective effect of pretreatment with the calcium antagonist anipamil on the ischemic-reperfused rat myocardium: a phosphorus-31 nuclear magnetic resonance study

    SciTech Connect

    Kirkels, J.H.; Ruigrok, T.J.; Van Echteld, C.J.; Meijler, F.L.

    1988-05-01

    To assess whether the prophylactic administration of anipamil, a new calcium antagonist, protects the heart against the effects of ischemia and reperfusion, rats were injected intraperitoneally twice daily for 5 days with 5 mg/kg body weight of this drug. The heart was then isolated and perfused by the Langendorff technique. Phosphorus-31 nuclear magnetic resonance spectroscopy was used to monitor myocardial energy metabolism and intracellular pH during control perfusion and 30 min of total ischemia (37/sup 0/C), followed by 30 min of reperfusion. Pretreatment with anipamil altered neither left ventricular developed pressure under normoxic conditions nor the rate and extent of depletion of adenosine triphosphate (ATP) and creatine phosphate during ischemia. Intracellular acidification, however, was attenuated. On reperfusion, hearts from anipamil-pretreated animals recovered significantly better than untreated hearts with respect to replenishment of ATP and creatine phosphate stores, restitution of low levels of intracellular inorganic phosphate and recovery of left ventricular function and coronary flow. Intracellular pH recovered rapidly to preischemic levels, whereas in untreated hearts a complex intracellular inorganic phosphate peak indicated the existence of areas of different pH within the myocardium. It is concluded that anipamil pretreatment protects the heart against some of the deleterious effects of ischemia and reperfusion. Because this protection occurred in the absence of a negative inotropic effect during normoxia, it cannot be attributed to an energy-sparing effect during ischemia. Therefore, alternative mechanisms of action are to be considered.

  8. Adjunctive treatment with ticagrelor, but not clopidogrel, added to tPA enables sustained coronary artery recanalisation with recovery of myocardium perfusion in a canine coronary thrombosis model.

    PubMed

    Wang, Kai; Zhou, Xiaorong; Huang, Yanming; Khalil, Mazen; Wiktor, Dominik; van Giezen, J J J; Penn, Marc S

    2010-09-01

    Reperfusion therapy for myocardial infarction is limited by significant re-occlusion rates and less-than-optimal myocardial tissue perfusion. It was the objective of this study to assess and compare the effect of ticagrelor, the first reversibly binding oral P2Y12 receptor antagonist, with that of clopidogrel, in conjunction with thrombolytic therapy, on platelet aggregation, thrombus formation, and myocardial perfusion in a canine model. Thrombus formation was induced by electrolytic injury and blood flow was measured with a Doppler ultrasonic flowmeter. All animals received tissue plasminogen activator (tPA) (1 mg/kg over 20 min); 10 animals received clopidogrel (10 mg/kg IV bolus over 5 min), 10 animals received ticagrelor initiated with a 1-min bolus (75 microg/kg/min), followed by continuous infusion (10 microg/kg/min) for 2 h, and 10 animals received IV saline. Re-occlusion rate and cyclic flow variation decreased with ticagrelor compared to saline groups (p<0.05). Adenosine phosphate (ADP)-induced platelet aggregation decreased with ticagrelor (1.9% +/- 2.67) and clopidogrel (1.11% +/- 2.0) vs. saline (26.3% +/- 23.5, p<0.05) at the end of adjunctive therapy. Bleeding time increased in the clopidogrel compared to the ticagrelor group (p=0.01). Infarct size was reduced with ticagrelor compared to the clopidogrel and saline groups (p<0.05). Blood flow remained significantly below baseline values at 20 min after tPA administration in the saline and clopidogrel groups but not in the ticagrelor group. In conclusion, in a dog coronary thrombosis model, ticagrelor blocks ADP-induced platelet activation and aggregation; prevents platelet-mediated thrombosis; prolongs reperfusion time and reduces re-occlusion and cyclic flow variation; and significantly decreases infarct size and rapidly restores myocardial tissue perfusion. PMID:20694285

  9. Over-expression of HSPA12B protects mice against myocardium ischemic/reperfusion injury through a PPARγ-dependent PI3K/Akt/eNOS pathway

    PubMed Central

    Sun, Yanjun; Ye, Lincai; Jiang, Chuan; Jiang, Jun; Hong, Haifa; Qiu, Lisheng

    2015-01-01

    Acute myocardial ischemia/reperfusion (MIR) injury leads to severe arrhythmias and a high lethality. We aim to determine the effect of heat shock protein A12B (HSPA12B), a newly discovered member of the Hsp70 family, on heart injury parameters following MIR surgery. We used HSPA12B transgenic mice to determine its effects on heart function parameters, infarct size and cellular apoptosis following MIR surgery. Proinflammatory cytokines, oxidative products and anti-oxidative enzymes in the myocardium were measured to evaluate the anti-inflammatory and anti-oxidative effects of HSPA12B over-expression. The role of PPARs/eNOS/PI3k/Akt pathway was investigated using their inhibitors. The alteration of hemodynamic parameters, histopathological, apoptotic and infarct size caused by MIR was greatly attenuated in HSPA12B over-expressed mice. HSPA12B also greatly mitigated the inflammatory response, demonstrated by the decrease in the levels of IL-1β, IL-6, TNF-a and MPO. Anti-oxidative enzymes (SOD, Catalase and GPx) were restored by HSPA12B; oxidative products (8-OHdG, MDA and protein carbonyl) were decreased. HSPA12B activated the PPARγ-dependent eNOS/PI3k/Akt pathway, and the influence of HSPA12B on cardiac function was reversed by the inhibitors of eNOS, PPARγ, Akt and PI3K. Our results present a novel signaling mechanism that HSPA12B protects MIR injury through a PPARγ-dependent PI3K/Akt/eNOS pathway. PMID:26885270

  10. MR Assessment of Myocardial Perfusion, Viability, and Function after Intramyocardial Transfer of VM202, a New Plasmid Human Hepatocyte Growth Factor in Ischemic Swine Myocardium1

    PubMed Central

    Saeed, Maythem; Martin, Alastair; Ursell, Phillip; Do, Loi; Bucknor, Matt; Higgins, Charles B.; Saloner, David

    2008-01-01

    Purpose: VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling. Materials and Methods: The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days ± 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time. Results: In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg ± 0.12 to 1.73 mL/kg ± 0.10, P < .01) and end-systolic (1.33 mL/kg ± 0.07 to 0.92 mL/kg ± 0.08, P < .001) volumes and an increase in ejection fraction (38.2% ± 1.3 to 47.0% ± 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter ± 19 vs 119 per square millimeter ± 17, P < .05) and arterioles (21 per square millimeter ± 4 vs 3 per square millimeter ± 1, P < .001). Conclusion: Intramyocardial transfer of VM202 improved myocardial

  11. Double-nuclide study of the myocardium using 201Tl and 123I-labeled fatty acids in non-ischemic myocardial diseases.

    PubMed

    Knapp, W H; Vyska, K; Machulla, H J; Notohamiprodjo, G; Schmidt, U; Knust, E J; Gleichmann, U

    1988-06-01

    Metabolic impairment and perfusion abnormalities are known to occur in hypertensive heart disease (HHD) and in cardiomyopathies. Free fatty acid (FFA) extraction is severely inhibited in a number of pathobiochemical reactions. This parameter was assessed using the radiolabeled FFA analogue 123I-(p-iodo-phenyl-)-pentadecanoic acid (IPPA) and 201Tl as perfusion marker, both of them injected at maximal physical workload. The regional extraction fraction of IPPA (IPPA-EF) was estimated by relating the regional IPPA and 201Tl uptake to each other. In HHD (normal coronary arteries) with posterior wall thickness less than or equal to 12 mm IPPA-EF was 77 +/- 18% (SD) in septum and 92 +/- 17% in the posterolateral wall (N = 13), with thickness of greater than 12 mm 60 +/- 23% in septum and 61 +/- 20% in the posterolateral wall (N = 8) when compared with IPPA-EF in normal subjects (= 100%, N = 9). In hypertrophic cardiomyopathy (HCM) IPPA-EF averaged 51 +/- 20% in septum and 87 +/- 10% in the posterolateral wall (N = 11). In these patient groups no systematic regional changes in 201TI uptake were observed. In dilated cardiomyopathy (DCM) both IPPA-EF and 201Tl uptake showed distinct regional variations and a great interindividual variability with a mean IPPA-EF reduction of 12% (N = 9). Thus, IPPA uptake in primarily non-ischemic myocardial disease may already be compromised when 201Tl uptake is unchanged. The double-nuclide method for IPPA-EF determination allows to eliminate the influence of flow in FFA imaging and enhances the potential of scintigraphy in the differential diagnosis of HHD versus coronary artery disease. PMID:3405780

  12. Improved myocardium transducer

    NASA Technical Reports Server (NTRS)

    Culler, V. H.; Feldstein, C.; Lewis, G. W.

    1979-01-01

    Method of implanting myocardium transducer uses special indented pins that are caught and securely held by epicardial fibers. Pins are small enough to cause minimum of trauma to myocardium during implantation or removal.

  13. [Phenomenon of heart ischemic postconditioning].

    PubMed

    Maslov, L N; Mrochek, A G; Hanus, L; Pei, J -M; Zhang, Y; Wang, H; Naryzhnaia, N V

    2012-08-01

    Authors of review analyzed papers on problem of heart ischemic postconditioning. In the review, it was demonstrated that postconditioning decreased an infarct size, prevented cardiomyocytes apoptosis, improved cardiac contractility in reperfusion period, augmented cardiac tolerance to arrhythmogenic impact ofreperfusion, prevented neutrophil invasion into the reperfused heart, abolished reperfusion endothelial dysfunction and suppressed reperfusion oxidative stress in myocardium. PMID:23155619

  14. Canine Distemper

    MedlinePlus

    Although this brochure provides basic information about canine distemper, your veterinarian is always your best source of health information. Consult your veterinarian for more information about canine distemper and its prevention. ...

  15. Concentration of digoxin, methyldigoxin, digitoxin and ouabain in the myocardium of the dog following coronary occulsion.

    PubMed

    Kuhlmann, J; Kötter, V; von Leitner, E; Arbeiter, G; Schröder, R

    1975-01-01

    26 mongrel dogs were given a single dose of 0.03mg/kg tritium-labelled digoxin, beta-methyldigoxin, digitoxin or ouabain 2 hrs or 95 hrs following experimental coronary occlusion. Examination of the epicardial ECG was performed by moving from intact to ischemic or necrotic zones. 60 min after glycoside administration the animals were sacrificed and tissue samples from the marked heart muscles areas and from the skeletal muscle were analysed for glycoside content. The early glycoside uptake in acute ischemic or necrotic myocardium was diminished independently of the physicochemical properties of the glycoside. Significantly higher glycoside concentrations (ng/g wet weight) were measured in the injured myocardium 3 hrs after coronary occlusion than 96 hrs afterward (p less than 0.005). The values in acute ischemic myocardium varied considerably. This nonhomogeneity of glycoside uptake in the acute ischemic heart muscle may partly explain the increased sensitivity to glycosides in myocardial infarction. The decline of glycoside concentration correlates with the alterations in the epicardial ECG. The cardiac effects of cardenolides 60 min after intravenous administration was caused by the unchanged glycoside. In contrast to the myocardium, glycoside accumulation could not be found in the skeletal muscle. The concentrations of digoxin, beta-methyldigoxin and digitoxin in the skeletal muscle were significantly higher than the concentration of ouabain, which was rapidly eliminated via the urine.

  16. Evaluation of ischemic heart disease and viability by cardiac MRI.

    PubMed

    Bhatia, Mona

    2014-01-01

    In ischemic heart disease, cardiac MRI, besides being the gold standard for evaluation of quantitative ventricular function, enables evaluation of myocardial wall thickness, T2-weighted imaging for myocardial edema and infarct quantification and transmurality. Delayed hyperenhancement sequences are highly predictive of scar formation, being associated with myocyte necrosis. The extent and transmurality of delayed hyperenhancement has prognostic implications and is inversely proportional to the degree of functional recovery after acute myocardial infarction. A greater transmural extent of infarction (eg, hyperenhancement involving >50% of the wall thickness) can predict regions that are less likely to improve in function after therapy. The ultimate focus of MRI in ischemic heart disease is in diagnosis, quantification of myocardium at risk, salvageable myocardium, perfusion defects and differentiation of viable myocardium from non viable myocardium to enable prognostication.

  17. Ischemic Stroke

    MedlinePlus

    A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Ischemic stroke is the most common type. It is usually ... are at risk for having a more serious stroke. Symptoms of stroke are Sudden numbness or weakness ...

  18. Detection of viable myocardium using coronary angiography and ventriculography.

    PubMed

    Conti, C Richard

    2002-08-01

    In 2002, coronary angiography is the only way to assess precisely the combination of proximal stenoses, distal target vessels, collaterals, microcirculation, and TIMI antegrade flow. At the time of coronary angiography, global LV function is best determined using biplane ventriculography in order to correlate wall motion with coronary stenoses, distal target vessels, microcirculation, collaterals, and antegrade TIMI flow. This can be done under resting conditions after nitrates or after postextrasystolic potentiation. The absolute diagnosis of viability can only be made retrospectively. Large areas of ischemic viable myocardium should improve contraction after revascularization, decrease symptoms, and prolong survival.

  19. The Influence of Diabetes Mellitus in Myocardial Ischemic Preconditioning

    PubMed Central

    Rezende, Paulo Cury; Rahmi, Rosa Maria

    2016-01-01

    Ischemic preconditioning (IP) is a powerful mechanism of protection discovered in the heart in which ischemia paradoxically protects the myocardium against other ischemic insults. Many factors such as diseases and medications may influence IP expression. Although diabetes poses higher cardiovascular risk, the physiopathology underlying this condition is uncertain. Moreover, although diabetes is believed to alter intracellular pathways related to myocardial protective mechanisms, it is still controversial whether diabetes may interfere with ischemic preconditioning and whether this might influence clinical outcomes. This review article looks at published reports with animal models and humans that tried to evaluate the possible influence of diabetes in myocardial ischemic preconditioning.

  20. The Influence of Diabetes Mellitus in Myocardial Ischemic Preconditioning

    PubMed Central

    Rezende, Paulo Cury; Rahmi, Rosa Maria

    2016-01-01

    Ischemic preconditioning (IP) is a powerful mechanism of protection discovered in the heart in which ischemia paradoxically protects the myocardium against other ischemic insults. Many factors such as diseases and medications may influence IP expression. Although diabetes poses higher cardiovascular risk, the physiopathology underlying this condition is uncertain. Moreover, although diabetes is believed to alter intracellular pathways related to myocardial protective mechanisms, it is still controversial whether diabetes may interfere with ischemic preconditioning and whether this might influence clinical outcomes. This review article looks at published reports with animal models and humans that tried to evaluate the possible influence of diabetes in myocardial ischemic preconditioning. PMID:27656659

  1. Shock-induced arrhythmogenesis in the myocardium

    NASA Astrophysics Data System (ADS)

    Trayanova, Natalia; Eason, James

    2002-09-01

    The focus of this article is the investigation of the electrical behavior of the normal myocardium following the delivery of high-strength defibrillation shocks. To achieve its goal, the study employs a complex three-dimensional defibrillation model of a slice of the canine heart characterized with realistic geometry and fiber architecture. Defibrillation shocks of various strengths and electrode configurations are delivered to the model preparation in which a sustained ventricular tachycardia is induced. Instead of analyzing the post-shock electrical events as progressions of transmembrane potential maps, the study examines the evolution of the postshock phase singularities (PSs) which represent the organizing centers of reentry. The simulation results demonstrate that the shock induces numerous PSs the majority of which vanish before the reentrant wavefronts associated with them complete half of a single rotation. Failed shocks are characterized with one or more PSs that survive the initial period of PS annihilation to establish a new postshock arrhythmia. The increase in shock strength results in an overall decrease of the number of PSs that survive over 200 ms after the end of the shock; however, the exact behavior of the PSs is strongly dependent on the shock electrode configuration.

  2. Effect of theophylline on adenosine production in the canine myocardium

    SciTech Connect

    McKenzie, J.E.; Steffen, R.P.; Haddy, F.J.

    1987-01-01

    Adenosine is thought to participate in local regulation of coronary blood flow. However, competitive antagonists of adenosine fail to block myocardial active hyperemia. The authors examined the effect of locally administered theophylline on active hyperemia and myocardial adenosine production during intracoronary isoproterenol infusion in the dog heart. Isoproterenol decreased coronary resistance and increased myocardial adenosine production. Infusion of theophylline at a rate that attenuated the vasodilator response to exogenously administered adenosine failed to attenuate the increase in coronary blood flow produced by isoproterenol. However, theophylline plus isoproterenol production greater increases in myocardial adensine production than isoproterenol alone. The curves relating resistance and adenosine in the presence of theophylline fell to the right of those in the absence of theophylline. These findings suggest that the failure of theophylline to attenuate isoproterenol hyperemia in the dog heart results at least in part from an increase in adenosine concentration at the arteriole to a level beyond that blocked by this competitive antagonist and that adenosine may in fact play a role in isoproterenol-induced active hyperemia.

  3. Myocardial neutrophil accumulation during reperfusion after reversible or ischemic injury

    SciTech Connect

    Go, L.O.; Murry, C.E.; Richard, V.J.; Weischedel, G.R.; Jennings, R.B.; Reimer, K.A. )

    1988-11-01

    Recent studies suggest that polymorphonuclear leukocytes (PMNs) may cause additional myocyte injury during reperfusion of ischemic myocardium. The present study was done to investigate whether PMNs accumulate in myocardium during early reperfusion after reversible or irreversible ischemic injury. Open-chest anesthetized dogs underwent circumflex coronary occlusions for 12 min, 40 min, or 90 min, followed by 1 h of reperfusion. Autologous PMNs were radiolabeled with {sup 111}In and reinjected to quantitate myocardial PMN influx during reflow. {sup 125}I-labeled albumin was injected simultaneously to correct for {sup 111}In associated with plasma proteins in myocardial tissue. The number of PMNs was determined in the inner, middle, and outer one-third of nonischemic and ischemic-reperfused myocardium. In the 12-min group, 40% fewer PMNs were present in the reperfused than in the nonischemic control tissue. In contrast, in both the 40- and 90-min groups, PMN accumulation was two- to six-fold greater in the ischemic-reperfused than nonischemic myocardium, with a transmural gradient of PMN influx increasing from the outer to inner layers. Collateral blood flow, measured with radioactive microspheres, was not significantly different among the three groups. The failure of PMNs to accumulate during reperfusion after 12 min of ischemia does not support the hypothesis that PMNs contribute to postischemic dysfunction of reversibly injured myocytes. Whether PMNs cause cell death during early reperfusion after longer ischemic episodes remains unknown; however, the rapidity of PMN accumulation in the zones of predicted infarction is consistent with this possibility.

  4. Genetic modification of stem cells for improved therapy of the infarcted myocardium.

    PubMed

    Haider, Husnain Kh; Mustafa, Anique; Feng, Yuliang; Ashraf, Muhammad

    2011-10-01

    The conventional treatment modalities for ischemic heart disease only provide symptomatic relief to the patient without repairing and regenerating the damaged myocardium. Stem cell transplantation has emerged as a promising alternative therapeutic approach for cardiovascular diseases. Stem cells possess the potential of differentiation to adopt morphofunctional cardiac and vasculogenic phenotypes to repopulate the scar tissue and restore regional blood flow in the ischemic myocardium. These beneficial therapeutic effects make stem cell transplantation the method of choice for the treatment of ischemic heart disease. The efficacy of stem cell transplantation may be augmented by genetic manipulation of the cells prior to transplantation. Not only will insertion of therapeutic transgene(s) into the stem cells support the survival and differentiation of cells in the unfavorable microenvironment of the ischemic myocardium, but also the genetically manipulated stem cells will serve as a source of the transgene expression product in the heart for therapeutic benefits. We provide an overview of the extensively studied stem cell types for cardiac regeneration, the various methods in which these cells have been genetically manipulated and rationale of genetic modification of stem cells for use in regenerative cardiovascular therapeutics.

  5. C-reactive protein activates complement in infarcted human myocardium.

    PubMed

    Nijmeijer, Remco; Lagrand, Wim K; Lubbers, Yvonne T P; Visser, Cees A; Meijer, Chris J L M; Niessen, Hans W M; Hack, C Erik

    2003-07-01

    Circulating levels of C-reactive protein (CRP) constitute a cardiovascular risk marker. Immunohistochemical studies have revealed co-localization of CRP and activated complement in human infarcted myocardium suggesting CRP to enhance inflammation in ischemic myocardium by inducing local complement activation. The aim was to establish whether CRP activates complement in infarcted human myocardium and to assess the relationship between this activation and the duration of infarction. Myocardial tissue samples from 56 patients that had died from acute myocardial infarction were evaluated. Specimens were taken from infarcted as well as noninfarcted sites of the heart. CRP-mediated complement activation was assessed by immunohistochemistry and by measuring levels of complement, CRP, and CRP-complement complexes, specific markers for CRP-mediated activation, in homogenates of the heart. Infarctions of 12 hours to 5 days had significantly more extensive depositions of complement and CRP and contained significantly more CRP, activated complement, and CRP-complement complexes than infarctions that were less than 12 hours old. Levels of CRP complexes correlated significantly with CRP and complement concentrations in the infarctions, as well as with the extent of complement and CRP depositions as measured via immunohistochemistry. Specific activation products of CRP-mediated activation of complement are increased in infarcts of more than 12 hours in duration and correlate with the extent of complement depositions. Hence, CRP seems to enhance local inflammatory reactions ensuing in human myocardial infarcts of more than 12 hours duration.

  6. [The viable myocardium: metabolic, diagnostic and therapeutic aspects].

    PubMed

    Strozzi, C; Spisani, P

    1993-01-01

    The term stunned myocardium is used to indicate a reversible post-ischemic dysfunction of the ventricular mechanism which may persist for hours, days or weeks after the restoration of coronary flow following spontaneous or pharmacological thrombolysis, transluminal coronary angioplasty, aorto-coronary bypass and ischemic attacks. Hibernating myocardium is used to describe a depression of ventricular contractility in the presence of chronic hypoperfusion which may be reversed following revascularization as a result of aorto-coronary by-pass surgery. Three biochemical and physiopathological hypotheses are currently acknowledged to explain the phenomenon of stunning: the hypothesis of free oxygen radicals, the hypothesis related to an energy deficit and that involving a calcium overload. It is possible that oxydizing stress induced by free radicals may modify the activity of one or more sarcolemmic proteins which regulate the flow of calcium or other ions. Alterations in the transport and accumulation of calcium ions due to a Na+/Ca++ pump deficit and calcium-ATPase of the sarcoplasmatic reticle appear to be responsible for contractile dysfunction. The hypothesis concerning an energy deficit appears to be least probable since even if ATP levels are low the intracellular energy status does not appear to be a factor which limits mechanical function which may be stimulated in the absence of further variations in the content of highly energetic phosphates. There is also reduced myofibrillar creatinkinase activity. In hibernating myocardium the mechanical dysfunction is due to a metabolic and therefore contractile "down-regulation' with low myocardial energy and oxygen consumption to ensure the survival of chronically hypoperfused areas.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8233008

  7. Canine papillomaviruses.

    PubMed

    Lange, Christian E; Favrot, Claude

    2011-11-01

    Papillomaviruses can infect epithelia and induce proliferative disorders. Different types of canine papillomaviruses have been found to be associated with distinct pathologies including exophytic warts as in canine oral papillomatosis, endophytic warts, and pigmented plaques and, in some cases, squamous cell carcinomas. Virus infection is followed by a phase of subclinical infection before the onset of symptoms. A diagnosis can in some cases be made clinically but should be verified if there are any doubts. Most papillomas do regress spontaneously within a few months. Preventative vaccination is possible but not on the market.

  8. Regional myocardial shape and dimensions of the working isolated canine left ventricle

    NASA Technical Reports Server (NTRS)

    Ritman, E. L.; Tsuiki, K.; Donald, D.; Wood, E. H.

    1975-01-01

    The extent to which the dynamic shape and dimensions of the isolated left ventricular myocardial wall differ throughout the myocardium and how these differences are characteristic of the anatomic location was demonstrated. The use of a biplane X-ray technique and a metabolically-supported isolated canine left ventricle preparation provided an angiographically ideal means of measuring mechanical dynamics of the myocardium while the intact left ventricular myocardial structure and electrical activation pattern retains most of the in situ ventricular characteristics.

  9. Myocardial kinetics of fluorine-18 misonidazole: A marker of hypoxic myocardium

    SciTech Connect

    Shelton, M.E.; Dence, C.S.; Hwang, D.R.; Welch, M.J.; Bergmann, S.R.

    1989-03-01

    Fluoromisonidazole, a member of a class of compounds referred to as ''hypoxic sensitizers,'' accumulates in hypoxic, viable tumor cells. We hypothesized that it might therefore accumulate also in ischemic, but non-necrotic myocardium potentially salvageable by interventional therapy. To evaluate the myocardial kinetics of (18F)fluoromisonidazole (FM), 20 isolated perfused rabbit hearts were used to characterize the uptake and binding of tracer under control conditions (n = 6), or with ischemia (flow 10% of control, n = 5), hypoxia without low flow (control flow rates with hypoxic medium, n = 5), or with reperfusion (n = 4). Myocardial retention of tracer detected externally with gamma scintillation probes after 20 min of constant (18F)FM infusion followed by 20 min of washout with nonradioactive buffer was 41 +/- 7% and 46 +/- 8% of peak activity in hearts subjected to ischemia or hypoxia, respectively, and significantly higher than in hearts subjected to either control perfusion or to ischemia followed by reperfusion (18 +/- 6 and 16 +/- 5% of peak activity, respectively, p less than 0.01). The biologic half-time of retained tracer was 40 hr in all hearts indicating essentially irreversible binding. Based on these findings, we measured uptake of (18F)FM using positron emission tomography in five dogs subjected to acute coronary occlusion. Five to thirteen millicuries of tracer were injected within 3 hr of occlusion. Within 30 min after administration of tracer, 18F accumulation in ischemic myocardium was greater than that observed in normal myocardium. The results indicate that (18F)FM accumulates in ischemic myocardium in relation to diminished tissue oxygen content and not simply because of diminished flow. Thus, this class of compounds may be potentially useful to help identify hypoxic myocardium.

  10. Canine Parvovirus

    MedlinePlus

    Finally, do not let your puppy or adult dog to come into contact with the fecal waste of other dogs while walking or playing outdoors. Prompt and proper ... advisable as a way to limit spread of canine parvovirus infection as well as other diseases that ...

  11. Increased expression of Dock180 protein in the noninfarcted myocardium in rats.

    PubMed

    Liu, Xiao-Lan; Li, Gang; Wang, Zhi-Hua; Zhao, Wen-Ju; Wang, Li-Ping

    2013-03-01

    The integrin β1 subunit and its downstream molecule focal adhesion kinase have been identified as critical molecules for the inhibition of postinfarction cardiac remodeling, ischemic cardiomyopathy, and heart failure. However, as a component of the integrin pathway, it is still unclear whether Dock180 (dedicator of cytokinesis 1) protein is expressed in the noninfarcted myocardium of the peri-infarct zones. In this study, experimental myocardial infarction (MI) and sham-operation (sham) models were established in Sprague Dawley rats and the expression of Dock180 protein in the myocardium of the sham group and in the noninfarcted myocardium of the peri-infarct zones of the MI group was detected by Western blot technique. The Dock180 protein expression in the myocardium was as follows: postsham 24-hour group, 0.10 ± 0.04 (n = 8); post-MI 24-hour group, 0.13 ± 0.03 (n = 8); postsham 12-week group, 0.11 ± 0.05 (n = 8); and post-MI 12-week group 0.17 ± 0.04 (n = 8). The Dock180 protein expression in the myocardium in the post-MI 12-week group was significantly higher than that in the postsham 12-week group (p = 0.019), in the postsham 24-hour group (p = 0.004), and in the post-MI 24-hour group (p = 0.040). We conclude that Dock180 protein is expressed in the myocardium in rats. Furthermore, its expression is significantly increased in the noninfarcted myocardium of the peri-infarct zones.

  12. Canine neoplasia

    PubMed Central

    Prier, J. E.; Brodey, R. S.

    1963-01-01

    The authors review current knowledge of spontaneous neoplasms in the dog. The prevalence of certain types of canine tumour has been studied, and comparisons have been made with the occurrence of similar neoplasms in man. Where there are appropriate analogies between the two species, the dog with spontaneous tumours can be used for studies that are not practicable in man. Nutritional and morphological studies have been done on cells cultured from canine tumours. Some consistency has been demonstrated in the morphology of cultures of different tumours of the same type. Nutritional studies with the transmissible venereal sarcoma of the dog have shown the cells to be subject to a growth-repressing effect by SH-containing amino-acids. Attempts to transmit tumours to other dogs or other species have generally been unsuccessful. A transplantable tumour developed in a mouse injected with non-cellular material from a canine thyroid carcinoma, but it is not certain that the tumour was induced. Cell-culture studies have shown that some tumours yield a factor that is cytopathogenic for normal cells, but none has been shown capable of inducing neoplasms in vivo. ImagesFIG. 3FIG. 4FIG. 5FIG. 1FIG. 2FIG. 6 PMID:14058226

  13. 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.

  14. 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

  15. Canine lymphoma

    SciTech Connect

    Weller, R.E.

    1986-10-01

    Canine lymphoma has served as the ''workhorse'' for the development of veterinary oncology and as an important animal model for human non-Hodgkins lymphomas. Significant advances have been achieved in understanding the biological behavior of the disease and in its treatment. Although it is unlikely that a cure for lymphoma will be achieved, owners should be encouraged to treat their pets, provided they understand that only prolonged remissions and survivals are likely to result. Cooperative studies, employing large numbers of dogs, are needed to optimize and refine the classification scheme to provide a system with diagnostic and prognostic correlates and derive maximum benefit from therapeutic regimens. Such studies need to be prospective in nature, with a solid statistical base incorporated into their design. Rather than being content with what we have accomplished to date in treatment of canine lymphoma, the opportunity exists for the veterinary profession to make further significant contributions to the understanding and treatment of lymphoma in the dog. 10 refs., 4 tabs.

  16. Impact of Denervated Myocardium on Improving Risk Stratification for Sudden Cardiac Death

    PubMed Central

    Cain, Michael E.

    2014-01-01

    Between 184,000 and 462,000 Americans die suddenly each year. Fifty percent to 70% of these deaths are due to ventricular tachycardia/fibrillation (VT/VF). We tested whether hibernating myocardium or myocardial sympathetic denervation identifies patients at high-risk for developing VT/VF independently of ejection fraction (EF). Positron emission tomography (PET) was used to quantify myocardial sympathetic denervation (11C-meta-hydroxyephedrine [11C-HED]), perfusion (13N-ammonia), and viability (insulin-stimulated 18F-2-deoxyglucose [18FDG]) in patients with ischemic cardiomyopathy (EF < 35%) eligible for a primary prevention implantable cardioverter defibrillator (ICD). The primary end-point was sudden cardiac arrest (SCA) defined as arrhythmic death or ICD discharge for VT/VF > 240 bpm. Volumes of total denervated (P = .001) and viable denervated myocardium (11C-HED-18FDG mismatch, P = .03) predicted SCA, whereas hibernating and infarcted myocardium did not. Multivariate analysis identified four independent predictors of SCA: denervated myocardium > 37.6% of left ventricule (LV), LV end-diastolic volume > 98 mL/m2, creatinine level > 1.49 mg/dL, and no angiotensin- inhibition therapy. Denervated myocardium had a hazard ratio of 3.5 for SCA (10.3%/year vs. 3.0%/year, p=0.001). Absence of all four factors predicted low risk (44% of cohort; SCA <1%/y) whereas two or more factors identified subjects at high-risk (20% of cohort; SCA 12%/y). Denervated myocardium quantified using PET strongly predicts risk of SCA, and is independent of EF, infarct volume, and other clinical variables. PMID:25125727

  17. Impact of denervated myocardium on improving risk stratification for sudden cardiac death.

    PubMed

    Cain, Michael E

    2014-01-01

    Between 184,000 and 462,000 Americans die suddenly each year. Fifty percent to 70% of these deaths are due to ventricular tachycardia/fibrillation (VT/VF). We tested whether hibernating myocardium or myocardial sympathetic denervation identifies patients at high-risk for developing VT/VF independently of ejection fraction (EF). Positron emission tomography (PET) was used to quantify myocardial sympathetic denervation ((11)C-meta-hydroxyephedrine [(11)C-HED]), perfusion ((13)N-ammonia), and viability (insulin-stimulated (18)F-2-deoxyglucose [(18)FDG]) in patients with ischemic cardiomyopathy (EF < 35%) eligible for a primary prevention implantable cardioverter defibrillator (ICD). The primary end-point was sudden cardiac arrest (SCA) defined as arrhythmic death or ICD discharge for VT/VF > 240 bpm. Volumes of total denervated (P = .001) and viable denervated myocardium ((11)C-HED-(18)FDG mismatch, P = .03) predicted SCA, whereas hibernating and infarcted myocardium did not. Multivariate analysis identified four independent predictors of SCA: denervated myocardium > 37.6% of left ventricule (LV), LV end-diastolic volume > 98 mL/m(2), creatinine level > 1.49 mg/dL, and no angiotensin- inhibition therapy. Denervated myocardium had a hazard ratio of 3.5 for SCA (10.3%/year vs. 3.0%/year, p=0.001). Absence of all four factors predicted low risk (44% of cohort; SCA <1%/y) whereas two or more factors identified subjects at high-risk (20% of cohort; SCA 12%/y). Denervated myocardium quantified using PET strongly predicts risk of SCA, and is independent of EF, infarct volume, and other clinical variables.

  18. Neutrophil depletion suppresses In-labeled platelet accumulation in infarcted myocardium

    SciTech Connect

    Bednar, M.; Smith, B.; Pinto, A.; Mullane, K.M.

    1985-09-01

    Platelets and neutrophils accumulate rapidly in infarcted myocardium. Although antineutrophil agents reduce the size of the infarcted area, this is not observed with antiplatelet drugs. The possibility that myocardial ischemia-induced platelet deposition was secondary to a neutrophil-mediated event was assessed by injecting prostacyclin-washed autologous In-labeled platelets and measuring the amount of radioactivity in different regions of the heart following 90-min occlusion of the left anterior descending coronary artery followed by reperfusion for periods up to 5 h. Platelet deposition during the reperfusion phase was linear with time and similar to the time course of neutrophil accumulation. There was a transmural distribution of radioactivity across the myocardium where the ''zone'' between infarcted and risk regions, called the ''interface,'' greater than infarct greater than risk greater than normal. Neutropenia, had minimal effects on platelet aggregation ex vivo, but significantly reduced platelet accumulation in the ischemic myocardium following 5-h reperfusion and abolished the transmural platelet distribution. These results suggest that myocardial platelet deposition is secondary to a neutrophil-mediated event in this occlusion-reperfusion model of myocardial injury. Interactions between platelets and neutrophils at the site of tissue damage may influence the process of myocardial ischemic injury.

  19. In vivo delineation of myocardial hypoxia during coronary occlusion using fluorine-18 fluoromisonidazole and positron emission tomography: A potential approach for identification of jeopardized myocardium

    SciTech Connect

    Shelton, M.E.; Dence, C.S.; Hwang, D.R.; Herrero, P.; Welch, M.J.; Bergmann, S.R. )

    1990-08-01

    Previous studies have demonstrated that the positron-emitting fluorine-18 (18F)-labeled fluoromisonidazole is a specific tracer of myocardial hypoxia. Its fractional extraction is enhanced in ischemic or hypoxic myocardium but returns to baseline levels on reperfusion and recovery of normal function. Thus, this agent might be useful in delineating acutely hypoxic but potentially salvageable myocardium. Accordingly, to delineate the relation between the myocardial extraction of 18F-fluoromisonidazole after intravenous administration and the time of antecedent ischemia in vivo, uptake of tracer was measured with positron emission tomography and direct postmortem tissue analysis in 14 dogs in which tracer was administered within 3 h of coronary occlusion (a time associated with marked potential for salvage on reperfusion); in 4 dogs after 6 h of coronary occlusion (a time associated with minimal salvage of myocardium on reperfusion); and in 8 dogs after greater than 24 h of coronary occlusion (to delineate uptake in tissue that is irreversibly damaged). The residual fraction (that is, the amount of tracer extracted and retained in a region) in ischemic myocardium in the dogs in which 18F-fluoromisonidazole was administered within 3 h after occlusion averaged (+/- standard deviation) 23 +/- 18%, which was higher than the residual fraction in myocardium subjected to ischemia for either 6 or greater than 24 h before tracer administration (12 +/- 7% and 5 +/- 2%, respectively, p less than 0.01 for both). Retention of tracer in remote normal myocardium averaged 2 +/- 1%.

  20. Successful Nd:Yag Laser Photocoagulation Of Arrhythmogenic Myocardium: Potential Limitations Of Current Optical Delivery Systems.

    NASA Astrophysics Data System (ADS)

    Svenson, Robert H.; Marroum, Marie-Claire; Frank, Frank; Selle, Jay G.; Gallagher, John J.; Bou-Saba, George; Seifert, Kathleen T.; Linder, Kathy; Tatsis, George P.

    1987-04-01

    Canine myocardial lesions of predictable dimensions can be achieved with Nd:YAG laser photocoagulation. These lesions are well demarcated from surrounding normal tissue and heal with homogeneous scar formation. Intraoperative Nd:YAG laser photocoagulation successfully ablated 52 of 55 ventricular tachycardias in 17 patients. Histologic examination of tissues from these arrhythmogenic areas showed differences from lesions produced on canine epicardium. Lesions from the human cases were less predictable and not well circumscribed. These differences are felt to be due to optical inhomogeneities present in diseased, scarred human myocardium, geometric irregularities of the endocardial surface, anatomical constraints on tissue-fiber distance, and the angle of incidence of the beam with the tissue. Modifications of current delivery systems may overcome some of these limitations. Ablation of ventricular tachycardia arising deeper than 4.0 to 6.0 mm. from the irradiated surface may require interstitial probes coupled to the fiberoptic.

  1. Targeted drug delivery into reversibly injured myocardium with silica nanoparticles: surface functionalization, natural biodistribution, and acute toxicity

    PubMed Central

    Galagudza, Michael M; Korolev, Dmitry V; Sonin, Dmitry L; Postnov, Viktor N; Papayan, Garry V; Uskov, Ivan S; Belozertseva, Anastasia V; Shlyakhto, Eugene V

    2010-01-01

    The clinical outcome of patients with ischemic heart disease can be significantly improved with the implementation of targeted drug delivery into the ischemic myocardium. In this paper, we present our original findings relevant to the problem of therapeutic heart targeting with use of nanoparticles. Experimental approaches included fabrication of carbon and silica nanoparticles, their characterization and surface modification. The acute hemodynamic effects of nanoparticle formulation as well as nanoparticle biodistribution were studied in male Wistar rats. Carbon and silica nanoparticles are nontoxic materials that can be used as carriers for heart-targeted drug delivery. Concepts of passive and active targeting can be applied to the development of targeted drug delivery to the ischemic myocardial cells. Provided that ischemic heart-targeted drug delivery can be proved to be safe and efficient, the results of this research may contribute to the development of new technologies in the pharmaceutical industry. PMID:20463939

  2. Ischemic Colitis

    PubMed Central

    FitzGerald, James F.; Hernandez III, Luis O.

    2015-01-01

    Most clinicians associate ischemic colitis with elderly patients who have underlying cardiovascular comorbidities. While the majority of cases probably occur in this population, the disease can present in younger patients as a result of different risk factors, making the diagnosis challenging. While a majority of patients respond to medical management, surgery is required in approximately 20% of the cases and is associated with high morbidity and mortality. PMID:26034405

  3. Experimental Calcification of the Myocardium

    PubMed Central

    Bonucci, Ermanno; Sadun, Raffaele

    1973-01-01

    Focal areas of calcification are frequent in rat myocardium 30 and 60 days after administration of dihydrotachysterol. These areas are PAS-positive, stain deeply with alcian blue and show high affinity for colloidal iron. Calcification is almost completely confined to intracellular structures. Small clusters of needle-shaped crystals are first found in apparently undamaged mitochondria in undamaged myocardial cells. When all the mitochondria are calcified, the cell degenerates, and inorganic crystals are laid down in relationship with its myofilaments. In other myocardial cells, clusters of amorphous or finely granular inorganic substance are found in both mitochondria and myofibrils. Both structures show signs of advanced degeneration. Inorganic substance has only occasionally been found within the structures of the sarcoplasmic reticulum. These structures do not seem to be involved in myocardial calcification under the present experimental conditions. Calcification of myocardial cells gives rise to a cellular reaction. Many macrophagic cells surround the calcified areas, which are rapidly reabsorbed. The present results show that myocardial mitochondria are actively engaged in controlling the intracellular concentration and movement of calcium ions. Their role in the myocardial contraction-relaxation cycle and the possible mechanism of myocardial calcification are discussed. ImagesFig 14Fig 1Fig 2Fig 3Fig 4Fig 5Fig 6Fig 7Fig 8Fig 9Fig 10Fig 11Fig 12Fig 13 PMID:4197422

  4. Modeling the dispersion in electromechanically coupled myocardium

    PubMed Central

    Eriksson, Thomas S. E.; Prassl, Anton J.; Plank, Gernot; Holzapfel, Gerhard A.

    2014-01-01

    SUMMARY We present an approach to model the dispersion of fiber and sheet orientations in the myocardium. By utilizing structure parameters, an existing orthotropic and invariant-based constitutive model developed to describe the passive behavior of the myocardium is augmented. Two dispersion parameters are fitted to experimentally observed angular dispersion data of the myocardial tissue. Computations are performed on a unit myocardium tissue cube and on a slice of the left ventricle indicating that the dispersion parameter has an effect on the myocardial deformation and stress development. The use of fiber dispersions relating to a pathological myocardium had a rather big effect. The final example represents an ellipsoidal model of the left ventricle indicating the influence of fiber and sheet dispersions upon contraction over a cardiac cycle. Although only a minor shift in the pressure–volume (PV) loops between the cases with no dispersions and with fiber and sheet dispersions for a healthy myocardium was observed, a remarkably different behavior is obtained with a fiber dispersion relating to a diseased myocardium. In future simulations, this dispersion model for myocardial tissue may advantageously be used together with models of, for example, growth and remodeling of various cardiac diseases. PMID:23868817

  5. Characterization of pericardial and plasma ghrelin levels in patients with ischemic and non-ischemic heart disease.

    PubMed

    Sax, Balazs; Merkely, Béla; Túri, Katalin; Nagy, Andrea; Ahres, Abdelkrim; Hartyánszky, István; Hüttl, Tivadar; Szabolcs, Zoltán; Cseh, Károly; Kékesi, Violetta

    2013-09-10

    Ghrelin is an endocrine regulatory peptide with multiple functions including cardioprotective effects. It is produced in various tissues among others in the myocardium. Pericardial fluid has been proven to be a biologically active compartment of the heart that communicates with the myocardial interstitium. Thus, pericardial level of certain agents may reflect their concentration in the myocardium well. In our study we measured acylated (active) and total (acylated and non-acylated) pericardial and plasma ghrelin levels of patients with ischemic and non-ischemic heart disease. Pericardial fluid and plasma samples were obtained from patients with coronary artery disease (ISCH, n=54) or valvular heart disease (VHD, n=41) undergoing cardiac surgery. Acylated pericardial ghrelin concentrations were found to be significantly higher in patients with ischemic heart disease (ISCH vs. VHD, 32±3 vs. 16±2pg/ml, p<0.01), whereas plasma levels of the peptide showed no difference between patient groups. Pericardial-to-plasma ratio, an index abolishing systemic effects on local ghrelin level was also significantly higher in ISCH group for both acylated and total ghrelin. Plasma total ghrelin showed negative correlation to BMI, plasma insulin and insulin resistance index HOMA-A. Pericardial acylated and total ghrelin concentrations were negatively correlated with posterior wall thickness (R=-0.31, p<0.05 and R=-0.35, p<0.01, respectively). Plasma insulin concentration and HOMA-A showed significant negative correlation with pericardial ghrelin levels. In conclusion, increased pericardial active ghrelin content and higher pericardial-to-plasma ghrelin ratio were found in ischemic heart disease as compared to non-ischemic patients suggesting an increased ghrelin production of the chronically ischemic myocardium. According to our results, pericardial ghrelin content is negatively influenced by left ventricular hypertrophy and insulin resistance.

  6. [THE MECHANISMS OF ISCHEMIC MITRAL VALVE INSUFFICIENCY FORMATION].

    PubMed

    Rudenko, S A

    2015-07-01

    In clinic in the period from 2012 to 2014 in 142 patients were performed interventions on the mitral valve for coronary heart disease and ischemic mitral valve insufficiency (MVI). The majority of patients were able to work, its witness for social-economic significance of problem. The main reason of the ischemic MVI arised were the dilatation of mitral valve fibrousing and substitution of papillar muscles for left ventricle remodelling. Symmetrical deformation of mitral valve arised in most cases after anterior-septal myocardium infarction, left ventricle global remodelling and apical substitution of papillar muscles; asymmetrical ones--after posterior myocardial infarction for local left ventricle papillar muscles. PMID:26591216

  7. Canine hyperlipidaemia.

    PubMed

    Xenoulis, P G; Steiner, J M

    2015-10-01

    Hyperlipidaemia refers to an increased concentration of lipids in the blood. Hyperlipidaemia is common in dogs and has recently emerged as an important clinical condition that requires a systematic diagnostic approach and appropriate treatment. Hyperlipidaemia can be either primary or secondary to other diseases. Secondary hyperlipidaemia is the most common form in dogs, and it can be a result of endocrine disorders, pancreatitis, cholestasis, protein-losing nephropathy, obesity, as well as other conditions and the use of certain drugs. Primary hyperlipidaemia is less common in the general canine population but it can be very common within certain breeds. Hypertriglyceridaemia of Miniature Schnauzers is the most common form of primary hyperlipidaemia in dogs but other breeds are also affected. Possible complications of hyperlipidaemia in dogs include pancreatitis, liver disease, atherosclerosis, ocular disease and seizures. Management of primary hyperlipidaemia in dogs is achieved by administration of ultra low-fat diets with or without the administration of lipid lowering drugs such as omega-3 fatty acids, fibrates, niacin and statins. PMID:26456868

  8. Preparation of normal and ischemic myocardial tissue for scanning electron microscopy.

    PubMed

    Ashraf, M

    1982-01-01

    Normal and ischemic myocardium was prepared by slicing and cryofracture techniques for examination with the SEM. The tissues were dehydrated in ethanol and Freon 113 (slicing method) or were cryofractured in Freon 113 cooled with liquid nitrogen, followed by critical point drying and coating with gold and palladium. Some osmicated tissue pieces were treated with thiocarbohydrazide for examination without metal coating. Some hearts were infiltrated with silver particles and were examined with backscattered electron imaging technique (BSI). The cryofractured tissue provided the most useful and consistent surface features of the cell organelles with a minimum of mechanical disorder compared to other methods. Although the myocardium prepared by slicing method revealed the interior of the cells, it contained several frayed edges and loose myofibrils making interpretation of the ischemic myocardium difficult. The normal cells exhibited myofibrils covered by transverse tubules at the level of Z bands as confirmed by BSI using silver particles as an extracellular tracer and numerous oval to elongated mitochondria located between the myofibrils. An extensive network of tubules (sarcoplasmic reticulum) over the sarcomeres and nuclei were observed. The changes observed by SEM in the ischemic hearts were consistent with those seen in TEM. With prolonged coronary ligation the changes became obvious. The T-tubules were often broken and nuclei were distorted. The myofibrils were disorganized and formed homogeneous bands. These SEM studies suggest that myocardium prepared by cryofracture technique yields information on normal and ischemic cell structure consistent with data obtained by TEM. PMID:7167767

  9. Anisotropic Elastography for Local Passive Properties and Active Contractility of Myocardium from Dynamic Heart Imaging Sequence

    PubMed Central

    Wang, Ge; Sun, L. Z.

    2006-01-01

    Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters. PMID:23165032

  10. Exercise preconditioning of the myocardium.

    PubMed

    Kavazis, Andreas N

    2009-01-01

    Diseases of the heart (e.g. myocardial ischaemia reperfusion injury) remain the major cause of death in the industrialized world. Therefore, developing a pragmatic countermeasure to reduce myocardial ischaemia reperfusion injury is vital. In this regard, a plethora of evidence indicates that regular exercise can protect the heart during an ischaemia reperfusion insult (i.e. cardioprotection). This review summarizes studies indicating that both short-term (i.e. 1-5 days) and long-term (i.e. weeks to months) endurance exercise provides cardioprotection. Data are presented showing that exercise duration and exercise intensity are both important factors in achieving a cardioprotective phenotype. Importantly, it appears that the exercise duration of a single exercise session should last for 60 minutes and should be performed at about 75% maximum oxygen consumption in order to achieve exercise-induced cardioprotection. Furthermore, data are presented showing that exercise-induced cardioprotection against myocardial stunning can persist for at least 9 days after the cessation of exercise training, but is lost 18 days after exercise. This review also summarizes the exercise-induced adaptations that occur to the myocardium. In particular, extrinsic changes observed in human and animal models include neural, hormonal, humoral, vascular and reduced body fat. Other anatomical and biochemical/molecular changes that have been studied as putative mechanisms in exercise-induced cardioprotection include alterations in anatomic coronary arteries, induction of myocardial heat shock proteins, increased myocardial cyclooxygenase-2 activity, elevated endoplasmic reticulum stress proteins, nitric oxide production, improved function of sarcolemmal and/or mitochondrial adenosine triphosphate (ATP)-sensitive potassium channels and increased myocardial antioxidant capacity. However, the most compelling evidence for exercise-induced cardioprotection is the fact that exercise training

  11. Estimation of jeopardized left ventricular myocardium in symptomatic and silent ischemia as determined by iodine-123 phenylpentadecanoic acid rotational tomography

    SciTech Connect

    Kahn, J.K.; Pippin, J.J.; Akers, M.S.; Corbett, J.R.

    1989-03-01

    Whether patients with silent myocardial ischemia have a lesser mass of ischemic myocardium than patients with symptomatic ischemia is controversial. Forty-five patients with angiographic coronary artery disease (greater than or equal to 70% luminal diameter narrowing) were studied. All patients had ischemic patterns of myocardial uptake and clearance of the long-chain fatty acid perfusion/metabolic imaging agent iodine-123 phenylpentadecanoic acid after maximal exercise. Single-photon emission computed tomography was performed and 25 myocardial segments were analyzed using circumferential activity profile curves. The 21 patients with silent treadmill ischemia exercised longer than the 24 patients with painful treadmill ischemia (430 +/- 137 vs 337 +/- 96 seconds, p less than 0.01) and to a higher heart rate (138 +/- 21 vs 125 +/- 18 beats/min, p less than 0.05). Patients with treadmill silent ischemia had the same number of abnormally perfused myocardial segments as patients with painful treadmill ischemia (8.6 +/- 4.5 vs 6.5 +/- 4.1 segments, difference not significant) and the same number of reversibly ischemic myocardial segments (4.0 +/- 1.4 vs 4.2 +/- 3.0 segments, difference not significant). The angiographic severity and extent of coronary artery disease were similar in the 2 groups. Thus, in this selected group of patients, those with silent treadmill ischemia appear to have at least as great an extent of ischemic myocardium as patients with painful exertional ischemia.

  12. Ischemic preconditioning protects against ischemic brain injury

    PubMed Central

    Ma, Xiao-meng; Liu, Mei; Liu, Ying-ying; Ma, Li-li; Jiang, Ying; Chen, Xiao-hong

    2016-01-01

    In this study, we hypothesized that an increase in integrin αvβ3 and its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αvβ3, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αvβ3 and vascular endothelial growth factor levels in the brain following ischemia. PMID:27335560

  13. Localization of Impacted Canines

    PubMed Central

    Mehrotra, Praveen; Bhagchandani, Jitendra; Singh, Ashish; Garg, Aarti; Kumar, Snehi; Sharma, Ashish; Yadav, Harsh

    2015-01-01

    Impaction of maxillary canines is a frequently encountered clinical problem. The impaction of canine can be prevented in some situationsif the canine displacement is diagnosed in the early mixed dentition period and this would be extremely useful for the clinician. Hence,it is very important to focus on the means of early diagnosis and interception of this clinical situation. In the present article, the differentmodalities used to diagnose the impacted canine are reviewed with an insight into current 3-D modalities. PMID:25738100

  14. Imaging of the myocardium using (18)F-FDG-PET/MRI.

    PubMed

    Ferda, Jiří; Hromádka, Milan; Baxa, Jan

    2016-10-01

    The introduction of the integrated hybrid PET/MRI equipment creates the possibility to perform PET and MRI simultaneously. Depending on the clinical question, the metabolic conversion to glycolytic activity or beta-oxidation is performed before the application of FDG. Since FDG aids to evaluate the energetic metabolism of the myocytes and myocardial MRI reaches the imaging capabilities of perfusion and tissue characterization in the daily routine, FDG-PET/MRI looks to be a promising method of PET/MRI exploitation in cardiac imaging. When myocardial FDG uptake should be evaluated in association with the perfusion distribution, the cross-evaluation of FDG accumulation distribution and perfusion distribution pattern is necessary. The different scenarios may be used in the assessment of myocardium, the conversion to glycolytic activity is used in the imaging of the viable myocardium, but the glycolytic activity suppression might be used in the indications of the identification of injured myocardium by ischemia or inflammation. FDG-PET/MRI might aid to answer the clinical tasks according to the structure, current function and possibilities to improve the function in ischemic heart disease or to display the extent or activity of myocardial inflammation in sarcoidosis. The tight coupling between metabolism, perfusion and contractile function offers an opportunity for the simultaneous assessment of cardiac performance using one imaging modality. PMID:27470994

  15. Imaging of the myocardium using (18)F-FDG-PET/MRI.

    PubMed

    Ferda, Jiří; Hromádka, Milan; Baxa, Jan

    2016-10-01

    The introduction of the integrated hybrid PET/MRI equipment creates the possibility to perform PET and MRI simultaneously. Depending on the clinical question, the metabolic conversion to glycolytic activity or beta-oxidation is performed before the application of FDG. Since FDG aids to evaluate the energetic metabolism of the myocytes and myocardial MRI reaches the imaging capabilities of perfusion and tissue characterization in the daily routine, FDG-PET/MRI looks to be a promising method of PET/MRI exploitation in cardiac imaging. When myocardial FDG uptake should be evaluated in association with the perfusion distribution, the cross-evaluation of FDG accumulation distribution and perfusion distribution pattern is necessary. The different scenarios may be used in the assessment of myocardium, the conversion to glycolytic activity is used in the imaging of the viable myocardium, but the glycolytic activity suppression might be used in the indications of the identification of injured myocardium by ischemia or inflammation. FDG-PET/MRI might aid to answer the clinical tasks according to the structure, current function and possibilities to improve the function in ischemic heart disease or to display the extent or activity of myocardial inflammation in sarcoidosis. The tight coupling between metabolism, perfusion and contractile function offers an opportunity for the simultaneous assessment of cardiac performance using one imaging modality.

  16. Prolonged Cardiac Dysfunction After Intraparenchymal Hemorrhage and Neurogenic Stunned Myocardium.

    PubMed

    Krishnamoorthy, Vijay; Wilson, Thomas; Sharma, Deepak; Vavilala, Monica S

    2016-01-01

    Cardiac dysfunction occurring secondary to neurologic disease, termed neurogenic stunned myocardium, is an incompletely understood phenomenon that has been described after several distinct neurologic processes. We present a case of neurogenic stunned myocardium, discovered intraoperatively after anesthetic induction, in a patient who presented to our operating room with a recent intraparenchymal hemorrhage. We discuss the longitudinal cardiac functional course after neurogenic stunned myocardium. Finally, we discuss the pathophysiology of neurogenic stunned myocardium, as well as its implications for anesthesiologists caring for neurosurgical patients.

  17. Biochemical and subcellular distribution of arachidonic acid in rat myocardium

    SciTech Connect

    Miyazaki, Y.; Gross, R.W.; Sobel, B.E.; Saffitz, J.E. )

    1987-12-01

    Selective release of arachidonic acid from prelabeled phospholipid pools has been observed following exposure of neonatal rat cardiac myocytes to metabolic inhibitors in vitro and has been correlated temporally with the development of irreversible sarcolemmal damage. Hydrolysis of phospholipids with release of arachidonic acid may be an important mechanism in the pathogenesis of sarcolemmal damage induced by ischemia. To elucidate potential subcellular loci of arachidonic acid release in ischemic myocardium, the authors characterized the phospholipid composition of adult rat myocardial sarcolemma and delineated the biochemical and subcellular distribution of radiolabeled arachidonic acid in neonatal rat myocytes incubated with ({sup 3}H)-arachidonic acid for selected intervals. Radioactivity was located almost exclusively in mitochondria and internal cytoplasmic membranes (primarily sarcoplasmic reticulum), which collectively contained 90% of myocyte radioactivity. These results indicate that radiolabeled arachidonic acid released from prelabeled phospholipid pools on exposure of neonatal rat myocytes to oxidative inhibitors is derived from mitochondria and internal cell membranes. The diminutive labeling of the sarcolemma suggests that turnover of arachidonoyl phospholipids is slower in the sarcolemma than in other membranous organelles.

  18. Myocardium wall thickness transducer and measuring method

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H. (Inventor)

    1976-01-01

    A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described.

  19. Myocardial ischemic conditioning: Physiological aspects and clinical applications in cardiac surgery.

    PubMed

    Bousselmi, Radhouane; Lebbi, Mohamed Anis; Ferjani, Mustapha

    2014-04-01

    Ischemia-reperfusion is a major determinant of myocardial impairment in patients undergoing cardiac surgery. The main goal of research in cardioprotection is to develop effective techniques to avoid ischemia-reperfusion lesions. Myocardial ischemic conditioning is a powerful endogenous cardioprotective phenomenon. First described in animals in 1986, myocardial ischemic conditioning consists of applying increased tolerance of the myocardium to sustained ischemia by exposing it to brief episodes of ischemia-reperfusion. Several studies have sought to demonstrate its effective cardioprotective action in humans and to understand its underlying mechanisms. Myocardial ischemic conditioning has two forms: ischemic preconditioning (IPC) when the conditioning stimulus is applied before the index ischemia and ischemic postconditioning when the conditioning stimulus is applied after it. The cardioprotective action of ischemic conditioning was reproduced by applying the ischemia-reperfusion stimulus to organs remote from the heart. This non-invasive manner of applying ischemic conditioning has led to its application in clinical settings. Clinical trials for the different forms of ischemic conditioning were mainly developed in cardiac surgery. Many studies suggest that this phenomenon can represent an interesting adjuvant to classical cardioprotection during on-pump cardiac surgery. Ischemic conditioning was also tested in interventional cardiology with interesting results. Finally, advances made in the understanding of mechanisms that underlie the cardioprotective action of ischemic conditioning have paved the way to a new form of myocardial conditioning which is pharmacological conditioning.

  20. Collateral circulation as a marker of the presence of viable myocardium in patients with recent myocardial infarction

    SciTech Connect

    Fujita, M.; Ohno, A.; Wada, O.; Miwa, K.; Nozawa, T.; Yamanishi, K.; Sasayama, S. )

    1991-08-01

    The relationship between the presence of viable myocardium and the extent of coronary collateral circulation to the infarct area was evaluated in 20 patients with a recent anterior myocardial infarction who had complete obstruction of the left anterior descending coronary artery. The viability of myocardial tissue was assessed by exercise thallium-201 myocardial scintigraphy, and the collateral circulation was angiographically evaluated by means of a collateral index ranging from 0 to 3. Patients were divided into two groups according to the presence (group 1, n = 10) or absence (group 2, n = 10) of viable myocardium in the perfusion territory of the infarct-related artery. The collateral index in group 1 was 2.5 {plus minus} 0.5 (SD), which was significantly higher than the 0.7 {plus minus} 0.8 in group 2. These findings indicate that the presence of ischemic but viable myocardium is intimately related to the development of collateral circulation in patients with myocardial infarction, and the existence of well-developed collateral channels predicts the presence of viable myocardium in the infarct area.

  1. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction

    PubMed Central

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, 99mTc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of 99mTc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with 201Tl SPECT and 18F-FDG PET, then, proved that such prominent uptake of 99mTc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of 99mTc-IDA-D-[c(RGDfK)]2 was non-inferior to that of 18F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of 99mTc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that 99mTc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  2. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction.

    PubMed

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-06-10

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization.

  3. Identification of Angiogenesis Rich-Viable Myocardium using RGD Dimer based SPECT after Myocardial Infarction.

    PubMed

    Lee, Min Su; Park, Hyun Soo; Lee, Byung Chul; Jung, Jae Ho; Yoo, Jung Sun; Kim, Sang Eun

    2016-01-01

    Cardiac healing after myocardial ischemia is a complex biological process. Advances in understanding of wound healing response have paved the way for clinical testing of novel molecular imaging to improve clinical outcomes. A key factor for assessing myocardial viability after ischemic injury is the evaluation of angiogenesis accompanying increased expression of integrin αvβ3. Here, we describe the capability of an αvβ3 integrin-targeting SPECT agent, (99m)Tc-IDA-D-[c(RGDfK)]2, for identification of ischemic but viable myocardium, i.e., hibernating myocardium which is crucial to predict functional recovery after revascularization, the standard care of cardiovascular medicine. In vivo SPECT imaging of rat models with transient coronary occlusion showed significantly high uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 in the ischemic region. Comparative measurements with (201)Tl SPECT and (18)F-FDG PET, then, proved that such prominent uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 exactly matched the hallmark of hibernation, i.e., the perfusion-metabolism mismatch pattern. The uptake of (99m)Tc-IDA-D-[c(RGDfK)]2 was non-inferior to that of (18)F-FDG, confirmed by time-course variation analysis. Immunohistochemical characterization revealed that an intense signal of (99m)Tc-IDA-D-[c(RGDfK)]2 corresponded to the vibrant angiogenic events with elevated expression of αvβ3 integrin. Together, these results establish that (99m)Tc-IDA-D-[c(RGDfK)]2 SPECT can serve as a sensitive clinical measure for myocardial salvage to identify the patients who might benefit most from revascularization. PMID:27283041

  4. Evidence for role of epoxyeicosatrienoic acids in mediating ischemic preconditioning and postconditioning in dog

    PubMed Central

    Gross, Garrett J.; Gauthier, Kathryn M.; Moore, Jeannine; Campbell, William B.; Falck, John R.; Nithipatikom, Kasem

    2009-01-01

    Cytochrome P-450 (CYP) epoxygenases and their arachidonic acid (AA) metabolites, the epoxyeicosatrienoic acids (EETs), have been shown to produce marked reductions in infarct size (IS) in canine myocardium either given before an ischemic insult or at reperfusion similar to that produced in ischemic preconditioning (IPC) and postconditioning (POC) protocols. However, no studies have addressed the possibility that EETs serve a beneficial role in IPC or POC. We tested the hypothesis that EETs may play a role in these two phenomena by preconditioning dog hearts with one 5-min period of total coronary occlusion followed by 10 min of reperfusion before 60 min of occlusion and 3 h of reperfusion or by postconditioning with three 30-s periods of reperfusion interspersed with three 30-s periods of occlusion. To test for a role of EETs in IPC and POC, the selective EET antagonists 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE) or its derivative, 14,15-epoxyeicosa-5(Z)-enoic acid 2-[2-(3-hydroxy-propoxy)-ethoxy]-ethyl ester (14,15-EEZE-PEG), were administered 10 min before IPC, 5 min after IPC, or 5 min before POC. In a separate series, the selective EET synthesis inhibitor N-methylsulfonyl-6-(propargyloxyphenyl)hexanamide (MS-PPOH) was administered 10 min before IPC. Infarct size was determined by tetrazolium staining and coronary collateral blood flow at 30 min of occlusion and reperfusion flow at 3 h by radioactive microspheres. Both IPC and POC produced nearly equivalent reductions in IS expressed as a percentage of the area at risk (AAR) [Control 21.2 ± 1.2%, IPC 8.3 ± 2.2%, POC 10.1 ± 1.8% (P < 0.001)]. 14,15-EEZE, 14,15-EEZE-PEG, and MS-PPOH markedly attenuated the cardioprotective effects of IPC and POC (14,15-EEZE and 14,15-EEZE-PEG) at doses that had no effect on IS/AAR when given alone. These results suggest a unique role for endogenous EETs in both IPC and POC. PMID:19448143

  5. Backscatter and attenuation characterization of ventricular myocardium

    NASA Astrophysics Data System (ADS)

    Gibson, Allyson Ann

    2009-12-01

    This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

  6. Cardiac Magnetic Resonance Imaging in Ischemic Heart Disease

    PubMed Central

    Florian, A.; Jurcut, R.; Ginghina, C.; Bogaert, J.

    2011-01-01

    Cardiac magnetic resonance imaging (MRI) has emerged as a prime player in the clinical and preclinical detection of ischemic heart disease (IHD) as well in the prognosis assessment by offering a comprehensive approach for all spectrums of coronary artery disease (CAD) patients. The aim of this review is to provide the reader a state–of–the art on how the newest cardiac MRI techniques can be used to study IHD patients. In patients with suspected/stable CAD, functional and perfusion imaging both at rest and during vasodilatatory stress (adenosine, dypiridamole)/dobutamine stress can accurately depict ischemic myocardium secondary to significant coronary artery stenosis. In patients with acute MI, MRI is a robust tool for differentiating and sizing the jeopardized and the infarcted myocardium by using a combination of functional, edema, perfusion and Gd contrast imaging. Moreover, important prognostic factors like myocardial salvage, the presence of microvascular obstruction (MVO), post reperfusion myocardial hemorrhage, RV involvement and infarct related complications can be assessed in the same examination. In patients with chronic ischemic cardiomyopathy, the role of the MRI extends from diagnosis by means of Gadolinium contrast scar imaging to therapy and prognosis by functional assessment and viability testing with rest and dobutamine stress imaging. In all the circumstances mentioned, MRI derived information has been proven valuable in every day clinical decision making and prognosis assessment. Thus, MRI is becoming more and more an accepted alternative to other imaging modalities both in the acute and chronic setting. PMID:22514564

  7. Canine hearing loss management.

    PubMed

    Scheifele, Lesa; Clark, John Greer; Scheifele, Peter M

    2012-11-01

    Dog owners and handlers are naturally concerned when suspicion of hearing loss arises for their dogs. Questions frequently asked of the veterinarian center on warning signs of canine hearing loss and what can be done for the dog if hearing loss is confirmed. This article addresses warning signs of canine hearing loss, communication training and safety awareness issues, and the feasibility of hearing aid amplification for dogs.

  8. Magnetic Resonance Imaging of Non-ischemic Cardiomyopathies: A Pictorial Essay.

    PubMed

    Olivas-Chacon, Cristina I; Mullins, Carola; Stewart, Kevan; Akle, Nassim; Calleros, Jesus E; Ramos-Duran, Luis R

    2015-01-01

    Non-ischemic cardiomyopathies are defined as either primary or secondary diseases of the myocardium resulting in cardiac dysfunction. While primary cardiomyopathies are confined to the heart and can be genetic or acquired, secondary cardiomyopathies show involvement of the heart as a manifestation of an underlying systemic disease including metabolic, inflammatory, granulomatous, infectious, or autoimmune entities. Non-ischemic cardiomyopathies are currently classified as hypertrophic, dilated, restrictive, or unclassifiable, including left ventricular non-compaction. Cardiovascular Magnetic Resonance Imaging (CMRI) not only has the capability to assess cardiac morphology and function, but also the ability to detect edema, hemorrhage, fibrosis, and intramyocardial deposits, providing a valuable imaging tool in the characterization of non-ischemic cardiomyopathies. This pictorial essay shows some of the most important non-ischemic cardiomyopathies with an emphasis on magnetic resonance imaging features.

  9. Magnetic Resonance Imaging of Non-ischemic Cardiomyopathies: A Pictorial Essay

    PubMed Central

    Olivas-Chacon, Cristina I; Mullins, Carola; Stewart, Kevan; Akle, Nassim; Calleros, Jesus E; Ramos-Duran, Luis R

    2015-01-01

    Non-ischemic cardiomyopathies are defined as either primary or secondary diseases of the myocardium resulting in cardiac dysfunction. While primary cardiomyopathies are confined to the heart and can be genetic or acquired, secondary cardiomyopathies show involvement of the heart as a manifestation of an underlying systemic disease including metabolic, inflammatory, granulomatous, infectious, or autoimmune entities. Non-ischemic cardiomyopathies are currently classified as hypertrophic, dilated, restrictive, or unclassifiable, including left ventricular non-compaction. Cardiovascular Magnetic Resonance Imaging (CMRI) not only has the capability to assess cardiac morphology and function, but also the ability to detect edema, hemorrhage, fibrosis, and intramyocardial deposits, providing a valuable imaging tool in the characterization of non-ischemic cardiomyopathies. This pictorial essay shows some of the most important non-ischemic cardiomyopathies with an emphasis on magnetic resonance imaging features. PMID:26199786

  10. Ischemic optic neuropathy.

    PubMed

    Athappilly, Geetha; Pelak, Victoria S; Mandava, Naresh; Bennett, Jeffrey L

    2008-10-01

    Ischemic optic neuropathy is the most frequent cause of vision loss in middle age. Clinical and laboratory research studies have begun to clarify the natural history, clinical presentation, diagnostic criteria and pathogenesis of various ischemic nerve injuries. As a result, physicians are acquiring new tools to aid in the diagnosis and potential treatment of ischemic nerve injury. The aim of this review is to examine recent data on anterior and posterior ischemic optic neuropathy and to provide a framework for physicians to manage and counsel affected individuals. PMID:18826805

  11. Exploratory analysis of the spatio-temporal deformation of the myocardium during systole from tagged MRI.

    PubMed

    Clarysse, Patrick; Han, Meimei; Croisille, Pierre; Magnin, Isabelle E

    2002-11-01

    Myocardial contractile function is, with perfusion, one of the main affected factors in ischemic heart diseases. In this paper, we propose an original framework based on functional data analysis for the quantitative study of spatio-temporal parameters related to the myocardial contraction mechanics. The mechanical strains in the left-ventricular (LV) myocardium are computed from tagged magnetic resonance imaging cardiac sequences. A statistical functional model of the normal contractile function of the LV is build from the study of eight examinations on healthy subjects. We show that it is possible to detect abnormal strain patterns comparatively to this model, by generating distance maps at rest and under pharmacological stress. We demonstrate the consistency of the results for the circumferential deformation parameter on healthy and pathological data sets. PMID:12450363

  12. Noncompaction of the Ventricular Myocardium and Polycystic Kidney Disease: A Case Report.

    PubMed

    Fukino, Keiko; Ishiwata, Junpei; Shinohara, Hiroki; Oshima, Tsukasa; Kozaki, Tsunashi; Ikutomi, Masayasu; Amaki, Toshihiro; Nakamura, Fumitaka

    2016-06-01

    Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary disorders, characterized by the formation of multiple cysts in the kidneys and other organs, as well as noncystic manifestations such as cerebral aneurysm. The most common cardiovascular disorders associated with ADPKD include valvular abnormalities and aortic aneurysm. An association between ADPKD and impaired left ventricular function has occasionally been reported. We describe a 74-year-old woman with ADPKD and exertional dyspnea. Impaired left ventricular function resulting from noncompaction of the ventricular myocardium (NVM) and secondary left ventricular aneurysm were diagnosed. Cardiac sarcoidosis and ischemic heart disease were ruled out. Myocardial ischemia resulting from NVM was the presumptive cause of the ventricular aneurysm. To our knowledge, this is the first report of concurrent isolated NVM and left ventricular aneurysm in a patient with ADPKD. ADPKD and various cardiomyopathies, including NVM, are all reported to involve mutations of sarcomere genes, suggesting a possible link between the conditions. PMID:26873255

  13. Transient Ischemic Attack

    MedlinePlus

    Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  14. Synergistic effect of adipose-derived stem cell therapy and bone marrow progenitor recruitment in ischemic heart.

    PubMed

    Ii, Masaaki; Horii, Miki; Yokoyama, Ayumi; Shoji, Taro; Mifune, Yutaka; Kawamoto, Atsuhiko; Asahi, Michio; Asahara, Takayuki

    2011-04-01

    Human multipotent adipose-derived stem cells (hMADSCs) have recently been isolated featuring extensive expansion capacity ex vivo. We tested the hypothesis that hMADSC transplantation might contribute to cardiac functional recovery by its direct or indirect effect on myocardial infarction (MI). Nude rats were either transplanted with hMADSCs or PBS (control) in ischemic myocardium immediately following MI. Echocardiographical assessment of cardiac function after MI with hMADSCs showed significant improvement of each parameter compared to that with PBS. Histological analysis also showed significantly reduced infarct size and increased capillary density in peri-infarct myocardium by hMADSC treatment. However, remarkable transdifferentiation of hMADSCs into cardiac or vascular lineage cells was not observed. Despite the less transdifferentiation capacity, hMADSCs produced robust multiple pro-angiogenic growth factors and chemokines, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor-1α (SDF-1α). Specifically, hMADSC-derived SDF-1α had a crucial role for cooperative angiogenesis, with the paracrine effect of hMADSCs and Tie2-positive bone marrow (BM) progenitor recruitment in ischemic myocardium. hMADSCs exhibit a therapeutic effect on cardiac preservation following MI, with the production of VEGF, bFGF, and SDF-1α showing paracrine effects and endogenous BM stem/progenitor recruitment to ischemic myocardium rather than its direct contribution to tissue regeneration. PMID:21135814

  15. Metastatic Midgut Carcinoid in the Myocardium.

    PubMed

    Bukowczan, Jakub; Lois, Konstantinos B; Skinner, Jane; Petrides, George; James, Robert Andrew; Perros, Petros

    2015-09-01

    Metastasis of neuroendocrine tumor to the myocardium is rare. We present a case of 64-year-old woman, who presented initially with abdominal pain and large adnexal mass. The image-guided biopsy showed low-grade neuroendocrine tumor with Ki67 less than 2% within the ovarian tissue. CT staging revealed bilateral adnexal masses, liver metastases, and primary lesion in the terminal ileum. Octreoscan showed marked tracer uptake within the lower esophagus not related to obvious mass on CT scan; the echocardiography confirmed the presence of a 2.7 cm LV/LA mass. In this case, close correlation between ECHO and the octreoscan obviated need for myocardial biopsy. PMID:26164175

  16. Genetic Modification of Mesenchymal Stem Cells Overexpressing CCR1 Increases Cell Viability, Migration, Engraftment and Capillary Density in the Injured Myocardium

    PubMed Central

    Huang, Jing; Zhang, Zhiping; Guo, Jian; Ni, Aiguo; Deb, Arjun; Zhang, Lunan; Mirotsou, Maria; Pratt, Richard E; Dzau, Victor J

    2010-01-01

    Rationale Although mesenchymal stem cell (MSC) transplantation has been shown to promote cardiac repair in acute myocardial injury in vivo, its overall restorative capacity appears to be restricted mainly due to poor cell viability and low engraftment in the ischemic myocardium. Specific chemokines are upregulated in the infarcted myocardium. However the expression levels of the corresponding chemokine receptors (e.g. CCR1, CXCR2) in MSCs are very low. We hypothesized that this discordance may account for the poor MSC engraftment and survival. Objective To determine whether overexpression of CCR1 or CXCR2 chemokine receptors in MSCs augments their cell survival, migration and engraftment after injection in the infarcted myocardium. Methods and Results Overexpression of CCR1, but not CXCR2, dramatically increased chemokine-induced murine MSC migration and protected MSC from apoptosis in vitro. Moreover, when MSCs were injected intramyocardially one hour after coronary artery ligation, CCR1-MSCs accumulated in the infarcted myocardium at significantly higher levels than control-MSCs or CXCR2-MSCs three days post-myocardial infarction (MI). CCR1-MSC injected hearts exhibited a significant reduction in infarct size, reduced cardiomyocytes apoptosis and increased capillary density in injured myocardium three days post-MI. Furthermore, intramyocardial injection of CCR1-MSCs prevented cardiac remodeling and restored cardiac function 4 weeks post-MI. Conclusions Our results demonstrate the in vitro and in vivo salutary effects of genetic modification of stem cells. Specifically, overexpression of chemokine receptor enhances the migration, survival and engraftment of MSCs, and may provide a new therapeutic strategy for the injured myocardium. PMID:20378860

  17. [Structural and functional changes of myocardium in Chernobyl disaster clean-up workers with atrial fibrillation].

    PubMed

    Khomaziuk, I M; Habulavichene, Zh M; Khomaziuk, V A

    2011-01-01

    Particularities and clinical importance of the structural and functional changes of myocardium were estimated in Chernobyl disaster clean-up workers with atrial fibrillation (AF). We examined 122 men with AF, which was associated with ischemic heart disease and arterial hypertension. Paroxysmal AF was diagnosed in 42 patients, 80 patients had permanent AE Control group comprised 80 men without AF. Echocardiography and Doppler studies were performed using ultrasound scanner Aloka SSD-630 (Japan). Significant structural and functional changes of the heart were revealed already in paroxysmal AF and became more pronounced in permanent AF. Increased left atrial size, its ratio to left ventricular end diastolic diameter, diastolic dysfunction were important echocardiographic predictors of AF. Heart walls thickening was accompanied by disorders of myocardial relaxation, increase in myocardial mass led to ischemia, and together they promoted overload, dysfunction of atrium and development of AF. Obligatory echocardiographic examination of the Chernobyl disaster clean-up workers with ischemic heart disease and arterial hypertension is necessary for predicting AF early, ordering adequate therapy in proper time and improving prognosis.

  18. Cardioprotection Acquired Through Exercise: The Role of Ischemic Preconditioning

    PubMed Central

    Marongiu, Elisabetta; Crisafulli, Antonio

    2014-01-01

    A great bulk of evidence supports the concept that regular exercise training can reduce the incidence of coronary events and increase survival chances after myocardial infarction. These exercise-induced beneficial effects on the myocardium are reached by means of the reduction of several risk factors relating to cardiovascular disease, such as high cholesterol, hypertension, obesity etc. Furthermore, it has been demonstrated that exercise can reproduce the “ischemic preconditioning” (IP), which refers to the capacity of short periods of ischemia to render the myocardium more resistant to subsequent ischemic insult and to limit infarct size during prolonged ischemia. However, IP is a complex phenomenon which, along with infarct size reduction, can also provide protection against arrhythmia and myocardial stunning due to ischemia-reperfusion. Several clues demonstrate that preconditioning may be directly induced by exercise, thus inducing a protective phenotype at the heart level without the necessity of causing ischemia. Exercise appears to act as a physiological stress that induces beneficial myocardial adaptive responses at cellular level. The purpose of the present paper is to review the latest data on the role played by exercise in triggering myocardial preconditioning. PMID:24720421

  19. Cardioprotection acquired through exercise: the role of ischemic preconditioning.

    PubMed

    Marongiu, Elisabetta; Crisafulli, Antonio

    2014-11-01

    A great bulk of evidence supports the concept that regular exercise training can reduce the incidence of coronary events and increase survival chances after myocardial infarction. These exercise-induced beneficial effects on the myocardium are reached by means of the reduction of several risk factors relating to cardiovascular disease, such as high cholesterol, hypertension, obesity etc. Furthermore, it has been demonstrated that exercise can reproduce the "ischemic preconditioning" (IP), which refers to the capacity of short periods of ischemia to render the myocardium more resistant to subsequent ischemic insult and to limit infarct size during prolonged ischemia. However, IP is a complex phenomenon which, along with infarct size reduction, can also provide protection against arrhythmia and myocardial stunning due to ischemia-reperfusion. Several clues demonstrate that preconditioning may be directly induced by exercise, thus inducing a protective phenotype at the heart level without the necessity of causing ischemia. Exercise appears to act as a physiological stress that induces beneficial myocardial adaptive responses at cellular level. The purpose of the present paper is to review the latest data on the role played by exercise in triggering myocardial preconditioning.

  20. Exercise-induced expression of VEGF and salvation of myocardium in the early stage of myocardial infarction.

    PubMed

    Wu, Guifu; Rana, Jamal S; Wykrzykowska, Joanna; Du, Zhimin; Ke, Qingen; Kang, Peter; Li, Jian; Laham, Roger J

    2009-02-01

    The mechanism of exercise-induced benefit and angiogenesis in ischemic heart disease remains poorly defined. This study was designed to investigate the effects of exercise training on the expression of angiogenic factors and angiogenesis in the infarcted myocardium [myocarial infaction (MI)]. Sixty-three male FVB mice were used for study and were divided into subgroups to test the response to exercise: the time-dependent expression of angiogenic factors to exercise training in normal (group 1; n = 12) and infarcted myocardium (group 2; n = 15) and the exercise-induced angiogenic response in normal and infarcted myocardium (group 3; n = 20) as well as the impact of exercise preconditioning on infarcted myocardium (group 4; n = 26). Exercise training consisted of daily treadmill exercise for 1 h for 3 days. Expression of VEGF and its receptors Flt-1 and Flk-1 was upregulated by exercise training in mice with MI. Exercise-induced VEGF expression in the MI group was higher than that in the sham (control) group. Cell proliferation assessment showed a significantly higher (P < 0.05) number of bromodeoxyuridine-positive cells in post-MI mice in the exercise group as opposed to post-MI mice in the sedentary group. 2,3,5-Triphenyltetrazolium chloride staining revealed a profound difference in the size of MI (18.25 +/- 2.93%) in the exercise group versus the sedentary group (29.26 +/- 7.64%, P = 0.02). Moreover, exercise preconditioning before MI promoted VEGF expression at both mRNA and protein levels. In conclusion, activation of VEGF and its receptors occurs in the infarcted mice heart in response to exercise, which results in decreased infarct size and improved angiogenesis.

  1. Canine epilepsy genetics.

    PubMed

    Ekenstedt, Kari J; Patterson, Edward E; Mickelson, James R

    2012-02-01

    There has been much interest in utilizing the dog as a genetic model for common human diseases. Both dogs and humans suffer from naturally occurring epilepsies that share many clinical characteristics. Investigations of inherited human epilepsies have led to the discovery of several mutated genes involved in this disease; however, the vast majority of human epilepsies remain unexplained. Mouse models of epilepsy exist, including single-gene spontaneous and knockout models, but, similar to humans, other, polygenic models have been more difficult to discern. This appears to also be the case in canine epilepsy genetics. There are two forms of canine epilepsies for which gene mutations have been described to date: the progressive myoclonic epilepsies (PMEs) and idiopathic epilepsy (IE). Gene discovery in the PMEs has been more successful, with eight known genes; six of these are orthologous to corresponding human disorders, while two are novel genes that can now be used as candidates for human studies. Only one IE gene has been described in dogs, an LGI2 mutation in Lagotto Romagnolos with a focal, juvenile remitting epilepsy. This gene is also a novel candidate for human remitting childhood epilepsy studies. The majority of studies of dog breeds with IE, however, have either failed to identify any genes or loci of interest, or, as in complex mouse and human IEs, have identified multiple QTLs. There is still tremendous promise in the ongoing canine epilepsy studies, but if canine IEs prove to be as genetically complex as human and murine IEs, then deciphering the bases of these canine epilepsies will continue to be challenging.

  2. Vaccines for Canine Leishmaniasis

    PubMed Central

    Palatnik-de-Sousa, Clarisa B.

    2012-01-01

    Leishmaniasis is the third most important vector-borne disease worldwide. Visceral leishmaniasis (VL) is a severe and frequently lethal protozoan disease of increasing incidence and severity due to infected human and dog migration, new geographical distribution of the insect due to global warming, coinfection with immunosuppressive diseases, and poverty. The disease is an anthroponosis in India and Central Africa and a canid zoonosis (ZVL) in the Americas, the Middle East, Central Asia, China, and the Mediterranean. The ZVL epidemic has been controlled by one or more measures including the culling of infected dogs, treatment of human cases, and insecticidal treatment of homes and dogs. However, the use of vaccines is considered the most cost–effective control tool for human and canine disease. Since the severity of the disease is related to the generation of T-cell immunosuppression, effective vaccines should be capable of sustaining or enhancing the T-cell immunity. In this review we summarize the clinical and parasitological characteristics of ZVL with special focus on the cellular and humoral canine immune response and review state-of-the-art vaccine development against human and canine VL. Experimental vaccination against leishmaniasis has evolved from the practice of leishmanization with living parasites to vaccination with crude lysates, native parasite extracts to recombinant and DNA vaccination. Although more than 30 defined vaccines have been studied in laboratory models no human formulation has been licensed so far; however three second-generation canine vaccines have already been registered. As expected for a zoonotic disease, the recent preventive vaccination of dogs in Brazil has led to a reduction in the incidence of canine and human disease. The recent identification of several Leishmania proteins with T-cell epitopes anticipates development of a multiprotein vaccine that will be capable of protecting both humans and dogs against VL. PMID:22566950

  3. OCT imaging of myocardium extending to pulmonary vein

    NASA Astrophysics Data System (ADS)

    Li, Zhifang; Dickfeld, Timm; Tang, Qinggong; Wang, Bohan; Chen, Yu

    2016-02-01

    In this study, we propose to use optical coherence tomography to enable a direct visualization of myocardium extending into the pulmonary vein (PV). The results showed that there are obvious differences in the morphology of myocardium and fibrous tissue in the transition region of myocardial sleeve, which is in agreement with the histological analysis. In addition, the myocardial area in transition point has three layers in the depth of 1 mm, and the depth-resolved myocardial fiber show different orientation in the different layers. This characteristic was applied for segmentation of the structures of myocardium extending into PV.

  4. Can pulsed ultrasound increase tissue damage during ischemia? A study of the effects of ultrasound on infarcted and non-infarcted myocardium in anesthetized pigs

    PubMed Central

    Olivecrona, Göran K; Härdig, Bjarne Madsen; Roijer, Anders; Block, Mattias; Grins, Edgars; Persson, Hans W; Johansson, Leif; Olsson, Bertil

    2005-01-01

    Background The same mechanisms by which ultrasound enhances thrombolysis are described in connection with non-beneficial effects of ultrasound. The present safety study was therefore designed to explore effects of beneficial ultrasound characteristics on the infarcted and non-infarcted myocardium. Methods In an open chest porcine model (n = 17), myocardial infarction was induced by ligating a coronary diagonal branch. Pulsed ultrasound of frequency 1 MHz and intensity 0.1 W/cm2 (ISATA) was applied during one hour to both infarcted and non-infarcted myocardial tissue. These ultrasound characteristics are similar to those used in studies of ultrasound enhanced thrombolysis. Using blinded assessment technique, myocardial damage was rated according to histopathological criteria. Results Infarcted myocardium exhibited a significant increase in damage score compared to non-infarcted myocardium: 6.2 ± 2.0 vs. 4.3 ± 1.5 (mean ± standard deviation), (p = 0.004). In the infarcted myocardium, ultrasound exposure yielded a further significant increase of damage scores: 8.1 ± 1.7 vs. 6.2 ± 2.0 (p = 0.027). Conclusion Our results suggest an instantaneous additive effect on the ischemic damage in myocardial tissue when exposed to ultrasound of stated characteristics. The ultimate damage degree remains to be clarified. PMID:15831106

  5. X-ray microanalysis of calcium in ischemic myocardium: a new method of rapid freezing.

    PubMed

    Sybers, H D; Myre, C D; Myre, M V

    1983-01-01

    X-ray microanalysis of biological material is best accomplished on unfixed frozen tissue sectioned on a cryoultramicrotome. The need for ultra-rapid freezing to minimize ice crystal artifact has been well documented but is difficult to achieve without the use of potentially hazardous Isopentane or Freon 22 in liquid nitrogen slush. In the present study we employ a slurry of powdered graphite in liquid nitrogen to obtain rapid freezing of cardiac tissue. The results obtained were as good as those which are achieved with Freon 22 in liquid nitrogen, and subsequent cryoultramicrotomy produced thin sections relatively free of ice crystal artifact. Microanalysis revealed a slight increase in mitochondrial calcium as compared with cytoplasmic calcium in normal myocytes. Mitochondrial calcium concentration rose significantly after 30 min of ischemia while only a slight rise in cytoplasmic calcium occurred. These findings suggest that the techniques employed are adequate for detecting ion shifts which occur during ischemia and may be useful for determining the effects of therapeutic agents at the organellar level. PMID:6635573

  6. Impacted Canines: Our Clinical Experience

    PubMed Central

    Chawla, Sonia; Marya, Karan; Jhamb, Aakarsh; Bhatia, Hind Pal

    2011-01-01

    Background To discuss the management of impacted canines and the various approaches used for the same. Materials and methods The data of 33 cases, with 43 impacted canine teeth, seen and operated over a period of 3-year in Santosh Dental College and Hospital has been compiled. The diagnostic methods and treatment modalities undertaken are described and discussed. Results Canine impactions were more common in the maxilla as compared with mandible in our study, which was statistically significant. Impacted canine position was mostly palatal in maxilla and labial in mandible. Chi-square test yielded a p-value of 0.002 which shows that there is an association between arch and position. The treatment options used were surgical exposure and orthodontic repositioning, cyst enucleation with extraction of impacted canine and surgical removal of impacted canine. Conclusion Surgical exposure and orthodontic repositioning was successfully applied as first-line treatment for correcting ectopic positioned canine. In cases where exposure and subsequent orthodontic treatment was not indicated, the impacted canine was surgically removed to prevent future problems and surgical procedure was designed according to position of impacted canine.

  7. Spiral waves in a model of myocardium

    NASA Astrophysics Data System (ADS)

    Tyson, John J.; Keener, James P.

    1987-11-01

    Myocardial tissue is an excitable medium through which propagate waves of electrical stimulation and muscular contraction. In addition to radially expanding waves of neuromuscular activity characterizing the normal heartbeat, myocardial tissue may also support high frequency, rotating spiral waves of activity which are associated with cardiac pathologies (flutter and fibrillation). Recently Pertsov, Ermakova and Panfilov have presented a numerical study of rotating spiral waves in a two-dimensional excitable medium modeled on the FitzHugh-Nagumo equations, suitably modified to reflect the electrical properties of myocardium. We show that some of their principal numerical results can be reproduced in quantitative detail by a general theory of rotating spiral waves in excitable media. The critical ingredients of our theory are the dispersion of nonlinear plane waves and the effects of curvature on the propagation of wave fronts in two-dimensional media. The close comparison of our analytical results with numerical simulations of the full reaction-diffusion equations lends credence to our theoretical description of spiral waves in excitable media.

  8. [Alignment of malpositioned canines].

    PubMed

    Wagner, L

    1991-03-01

    This article presents a system for aligning impacted canines. The base of this system is the lingual arch, a rigid reaction unit of four teeth, molars and premolars. From this base unit an impacted canine can be extruded, moved distally, jumped over the occlusion and derotated by segment arches, coil springs and elastic ligatures. The efficiency of this appliance is due to the elimination of undesired reactive forces, the safe moving of teeth, the possibility of an exact force application and the simple manipulation; also the esthetic inconvenience is minimal. All this results in a better prognosis and an essentially shorter treatment time. This appliance can be used in the upper and the lower jaw. Schematic drawings and clinical examples demonstrate this method.

  9. Murine myocardium OCT imaging with a blood substitute

    NASA Astrophysics Data System (ADS)

    Kim, Jeehyun; Villard, Joseph W.; Lee, Ho; Feldman, Marc D.; Milner, Thomas E.

    2002-06-01

    Imaging of the in vivo murine myocardium using optical coherence tomography (OCT) is described. Application of conventional techniques (e.g. MRI, Ultrasound imaging) for imaging the murine myocardium is problematic because the wall thickness is less than 1.5mm (20g mouse), and the heart rate can be as high as six-hundred beats per minute. To acquire a real-time image of the murine myocardium, OCT can provide sufficient spatial resolution (10 micrometers ) and imaging speed (1000 A-Scans/s). Strong light scattering by blood in the heart causes significant light attenuation making delineation of the endocardium-chamber boundary problematic. By replacing whole blood in the mouse with an artificial blood substitute we demonstrate significant reduction of light scattering in the murine myocardium. The results indicate a significant reduction in light scattering as whole blood hematocrit is diminished below 5%. To measure thickness change of the myocardium during one cycle, a myocardium edge detection algorithm is developed and demonstrated.

  10. Control of canine distemper.

    PubMed

    Chappuis, G

    1995-05-01

    Control of canine distemper can realistically only be achieved by the use of vaccination. The types of vaccine in current use are described, together with some of the problems encountered such as interference by maternal antibodies, and usage in species other than dogs. Modified live viral vaccines, as used for more than thirty years, have proved very effective. Nevertheless there is scope for some improvement in vaccine efficacy and recent developments in genetic recombinant methods are described. PMID:8588329

  11. [Canine histoplasmosis in Japan].

    PubMed

    Sano, Ayako; Miyaji, Makoto

    2003-01-01

    Histoplasmosis is a fungal infection caused by Histoplasma capsulatum and is distributed a worldwide. Although the disease has been treated as an imported mycosis, some autochthonous human, 1 equine and 4 canine cases suggested that the disease is endemic. Histoplasmosis is classified depending on the variety of causative agent. Histoplasmosis farciminosi known as pseudofarcy, is manifested only in Perissodactyla where it invades lymph nodes and lymph ducts, and is recognized by isolation from horses. Historically, Japan was one of the endemic areas of pseudofarcy before World War II, and more than 20,000 cases were recorded in horses used by the military. Interestingly, Japanese canine histoplasmosis uniformly showed skin ulcers and granulomatous lesions on the skin without pulmonary or gastrointestinal involvement, both of which were very similar to pseudofarcy. It was diagnosed as histoplasmosis by the detection of internal transcribed spacer legions of rRNA gene of H. capsulatum from paraffin embedded tissue samples. Furthermore, the fungal isolate from the human case with no history of going abroad or immigrating was identified as H. capsulatum var. farciminosum by a gene sequence. These facts indicated that pseudofarcy is not only an infectious disease in horses, but also a zoonotic fungal infection. Japanese autochthonous canine histoplasmosis might be a heteroecism of pseudofarcy because of its likeness to the human case, the similarity of clinical manifestations and the historical background at this stage.

  12. [The intracellular metabolism of neutrophils under different forms of ischemic heart disease].

    PubMed

    Kratnov, A E

    2012-12-01

    The article deals with the results of study of the intracellular metabolism of neutrophils in 96 patients including 56 (58.3%) patients with ischemic heart disease. It is established that in patients with ischemic heart disease as compared with patients without ischemic heart disease occurs the increase of neutrophils producing of active forms of oxygen against the background of decrease of intracellular activity of catalase and increase of concentration of lactate in phagocytes. Under severing of ischemic heart disease from unstable stenocardia to cardiac infarction the activation of oxygen-depending metabolism of neutrophils conditioned by increase of concentration of immune complexes circulating in blood was not compensated by increasing of intracellular activity of enzymes of system of antioxidant defense. The maximum activation of NAD(F)N-oxidase of neutrophils (production of superoxide anion-radical) was detected in patients with cardiac infarction with Q-wave. This condition was accompanied by maximal increase of concentration of lactate in phagocytes up to twice higher exceed the level of indicators in patients without ischemic heart disease. It can be assumed that in conditions of acute hypoxia occurring under myocardium ischemia in patients with ischemic heart disease, the lactate production increases in neutrophils hence the triggering of development of intracellular acidosis, impact of oxygen-depending factors and phagocytes destruction.

  13. Regional myocardial shape and dimensions of the working isolated canine left ventricle

    NASA Technical Reports Server (NTRS)

    Ritman, E.; Tsuiki, K.; Donald, D.; Wood, E. H.

    1975-01-01

    Angiographic experiments were performed on isolated canine left ventricle preparations using donor dog to supply blood to the coronary circulation via a rotary pump to control coronary flow. The angiographic record was transferred from video tape to video disk for detailed uninterrupted sequential analysis at a frequency of 60 fields/sec. It is shown that the use of a biplane X-ray technique and a metabolically supported isolated canine left ventricle preparation provides an angiographically ideal means of measuring the mechanical dynamics of the myocardium while the intact left ventricular myocardial structure and electrical activation pattern retain most of the in situ ventricular characteristics. In particular, biplane X-ray angiography of the left ventricle can provide estimates of total ventricular function such as ejection fraction, stroke volume, and myocardial mass correct to within 15% under the angiographically ideal conditions of the preparation.

  14. Fatty acid uptake in normal human myocardium

    SciTech Connect

    Vyska, K.; Meyer, W.; Stremmel, W.; Notohamiprodjo, G.; Minami, K.; Machulla, H.J.; Gleichmann, U.; Meyer, H.; Koerfer, R. )

    1991-09-01

    Fatty acid binding protein has been found in rat aortic endothelial cell membrane. It has been identified to be a 40-kDa protein that corresponds to a 40-kDa fatty acid binding protein with high affinity for a variety of long chain fatty acids isolated from rat heart myocytes. It is proposed that this endothelial membrane fatty acid binding protein might mediate the myocardial uptake of fatty acids. For evaluation of this hypothesis in vivo, influx kinetics of tracer-labeled fatty acids was examined in 15 normal subjects by scintigraphic techniques. Variation of the plasma fatty acid concentration and plasma perfusion rate has been achieved by modulation of nutrition state and exercise conditions. The clinical results suggest that the myocardial fatty acid influx rate is saturable by increasing fatty acid plasma concentration as well as by increasing plasma flow. For analysis of these data, functional relations describing fatty acid transport from plasma into myocardial tissue in the presence and absence of an unstirred layer were developed. The fitting of these relations to experimental data indicate that the free fatty acid influx into myocardial tissue reveals the criteria of a reaction on a capillary surface in the vicinity of flowing plasma but not of a reaction in extravascular space or in an unstirred layer and that the fatty acid influx into normal myocardium is a saturable process that is characterized by the quantity corresponding to the Michaelis-Menten constant, Km, and the maximal velocity, Vmax, 0.24 {plus minus} 0.024 mumol/g and 0.37 {plus minus} 0.013 mumol/g(g.min), respectively. These data are compatible with a nondiffusional uptake process mediated by the initial interaction of fatty acids with the 40-kDa membrane fatty acid binding protein of cardiac endothelial cells.

  15. Enhanced Electrical Integration of Engineered Human Myocardium via Intramyocardial versus Epicardial Delivery in Infarcted Rat Hearts

    PubMed Central

    Gerbin, Kaytlyn A.; Yang, Xiulan; Murry, Charles E.; Coulombe, Kareen L. K.

    2015-01-01

    Cardiac tissue engineering is a promising approach to provide large-scale tissues for transplantation to regenerate the heart after ischemic injury, however, integration with the host myocardium will be required to achieve electromechanical benefits. To test the ability of engineered heart tissues to electrically integrate with the host, 10 million human embryonic stem cell (hESC)-derived cardiomyocytes were used to form either scaffold-free tissue patches implanted on the epicardium or micro-tissue particles (~1000 cells/particle) delivered by intramyocardial injection into the left ventricular wall of the ischemia/reperfusion injured athymic rat heart. Results were compared to intramyocardial injection of 10 million dispersed hESC-cardiomyocytes. Graft size was not significantly different between treatment groups and correlated inversely with infarct size. After implantation on the epicardial surface, hESC-cardiac tissue patches were electromechanically active, but they beat slowly and were not electrically coupled to the host at 4 weeks based on ex vivo fluorescent imaging of their graft-autonomous GCaMP3 calcium reporter. Histologically, scar tissue physically separated the patch graft and host myocardium. In contrast, following intramyocardial injection of micro-tissue particles and suspended cardiomyocytes, 100% of the grafts detected by fluorescent GCaMP3 imaging were electrically coupled to the host heart at spontaneous rate and could follow host pacing up to a maximum of 300–390 beats per minute (5–6.5 Hz). Gap junctions between intramyocardial graft and host tissue were identified histologically. The extensive coupling and rapid response rate of the human myocardial grafts after intramyocardial delivery suggest electrophysiological adaptation of hESC-derived cardiomyocytes to the rat heart’s pacemaking activity. These data support the use of the rat model for studying electromechanical integration of human cardiomyocytes, and they identify lack of

  16. Hibernating myocardium results in partial sympathetic denervation and nerve sprouting.

    PubMed

    Fernandez, Stanley F; Ovchinnikov, Vladislav; Canty, John M; Fallavollita, James A

    2013-01-15

    Hibernating myocardium due to chronic repetitive ischemia is associated with regional sympathetic nerve dysfunction and spontaneous arrhythmic death in the absence of infarction. Although inhomogeneity in regional sympathetic innervation is an acknowledged substrate for sudden death, the mechanism(s) responsible for these abnormalities in viable, dysfunctional myocardium (i.e., neural stunning vs. sympathetic denervation) and their association with nerve sprouting are unknown. Accordingly, markers of sympathetic nerve function and nerve sprouting were assessed in subendocardial tissue collected from chronically instrumented pigs with hibernating myocardium (n = 18) as well as sham-instrumented controls (n = 7). Hibernating myocardium exhibited evidence of partial sympathetic denervation compared with the normally perfused region and sham controls, with corresponding regional reductions in tyrosine hydroxylase protein (-32%, P < 0.001), norepinephrine uptake transport protein (-25%, P = 0.01), and tissue norepinephrine content (-45%, P < 0.001). Partial denervation induced nerve sprouting with regional increases in nerve growth factor precursor protein (31%, P = 0.01) and growth associated protein-43 (38%, P < 0.05). All of the changes in sympathetic nerve markers were similar in animals that developed sudden death (n = 9) compared with electively terminated pigs with hibernating myocardium (n = 9). In conclusion, sympathetic nerve dysfunction in hibernating myocardium is most consistent with partial sympathetic denervation and is associated with regional nerve sprouting. The extent of sympathetic remodeling is similar in animals that develop sudden death compared with survivors; this suggests that sympathetic remodeling in hibernating myocardium is not an independent trigger for sudden death. Nevertheless, sympathetic remodeling likely contributes to electrical instability in combination with other factors.

  17. Mechanism of antifibrillatory action of Org 7797 in regionally ischemic pig heart.

    PubMed

    Janse, M J; Wilms-Schopman, F; Opthof, T

    1990-04-01

    Org 7797 is effective against ventricular fibrillation (VF) induced during ischemia. In Langendorff-perfused pig hearts, application of three premature stimuli to nonischemic myocardium between 3 and 5 min after coronary occlusion always resulted in VF in the absence of drug. In no instance when Org 7797 was present (2-10 microM) could VF be induced, although sustained and nonsustained ventricular tachycardias (VTs) could still be initiated in about two thirds of treated hearts. We determined the effects of Org 7797 on wavelength in normal and ischemic myocardium during regular driving at a cycle length of 350 ms. Wavelength, the algebraic product of conduction velocity and refractory period, is considered a useful parameter in assessing efficacy of antiarrhythmic agents in preventing reentrant arrhythmias. Conduction velocity was obtained by analyzing the spread of activation under 121 unipolar electrodes (1 mm apart) placed around a central stimulus electrode. Refractory periods were determined with premature test stimuli at an intensity of twice diastolic threshold. Both in normal and ischemic myocardium Org 7797 (5-10 microM) produced a marked shortening of wavelength. This should predispose to reentry. However, Org 7797 prolonged the refractory period at the fastest possible driving rate from 154 to 247 ms and attenuated (5 microM) or prevented (10 microM) shortening of the refractory period during application of subsequent premature stimuli. The antifibrillatory effect of the drug may be explained by prolongation of wavelength at very short cycles.

  18. Absence of canine papillomavirus sequences in canine mammary tumours.

    PubMed

    Sardon, D; Blundell, R; Burrai, G P; Alberti, A; Tore, G; Passino, E Sanna; Antuofermo, E

    2015-01-01

    Human papillomaviruses (PVs) are found in human breast cancer tissue; however, it remains controversial as to whether these viruses play a role in the aetiology of this tumour. There has been minimal study of whether PVs are found in normal or abnormal mammary glands of animals. The present study investigated whether a PV sequence could be found in the mammary glands of 33 female dogs by rolling circle amplification and polymerase chain reaction. No PV DNA was found in normal or neoplastic canine mammary tissues, suggesting that canine PVs are probably not involved in the pathogenesis of canine mammary neoplasia. PMID:25435511

  19. [The use of metabolic therapy in the treatment of ischemic heart disease in hemodynamically formed insignificant aortic stenosis with chronic heart failure].

    PubMed

    Kuriata, A V; Karavanskaia, I L; Kushnir, Iu S

    2011-01-01

    Analysis of medical treatment was conducted with justified using of the metabolic component in a complex therapy of ischemic heart disease with chronic heart failure in hemodynamically formed insignificant aortic stenoses. The effect of metabolic correction is shown for pharmaceutical compounds Meldoniya in the form of Vasonat manufactured by "OlainFarm" (Latvia). Positive results of maintenance of systolic activity and prevention of diastolic dysfunction of myocardium were presented. The application of Vasonat in appropriate for the stabilization of adaptive properties of the myocardium and prophylaxis of the development of critical indicators of heart failure in this combined. PMID:22768738

  20. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  1. Noncompaction myocardium in association with type Ib glycogen storage disease.

    PubMed

    Goeppert, Benjamin; Lindner, Martin; Vogel, Monika Nadja; Warth, Arne; Stenzinger, Albrecht; Renner, Marcus; Schnabel, Philipp; Schirmacher, Peter; Autschbach, Frank; Weichert, Wilko

    2012-10-15

    Noncompaction myocardium is a rare disorder assumed to occur as an arrest of the compaction process during the normal development of the heart. Left ventricular noncompaction has been reported to be associated with a variety of cardiac and extracardiac, especially neuromuscular abnormalities. Moreover, it has been suggested that metabolic alterations could be responsible for the noncompaction. However, no association of noncompaction myocardium with type Ib glycogen storage disease (GSD) has been reported so far. Type Ib GSD is due to a defect of a transmembrane protein which results, similar to type Ia GSD, in hypoglycemia, a markedly enlarged liver and, additionally, in neutropenia, recurrent infections, and inflammatory bowel disease. Until now, no muscular or cardiac involvement has been described in type Ib GSD patients. The present case represents the first report of a noncompaction myocardium in a child with type Ib GSD who died of sudden clinical deterioration at the age of four.

  2. Hypokinesia of myocardium of perfused rat heart at different oxygenation of myoglobin and redox state of cytochrome

    NASA Astrophysics Data System (ADS)

    Frank, Klaus H.; Zuendorf, J.; Tauschek, D.; Kessler, Manfred D.

    2002-06-01

    Questions about development of hypo-kinetic zones in myocardium of patients suffering from severe coronary heart disease are discussed controversially among heart surgeons. We established a model for isolated and hemoglobin free perfusion of rat heart in which sufficient flow was established within all capillaries and thus existence of ischemic capillaries could be excluded. A definite diagnosis of tissue anoxia is only possible by optical measurements of the oxidation and the reduction (redox state) of the cytochrome oxidase of intact myocytes. Therefore, we used an EMPHO for this kind of measurements. Intracellular oxygenation of myoglobin oxygenation (MbO2) and redox state of cytochrome aa3, b and c were recorded in the outer wall of working, hypo-kinetic and a-kinetic myocardium. As a result of our investigations we were able to prove that by lowering at the venous end of capillaries tissue pO2 and myoglobin oxygenation stepwise below 5 mmHg and 50% of saturation respectively, a continuous decrease of myocardial contractility could be achieved.

  3. System of scale-selective tomography of myocardium birefringence

    NASA Astrophysics Data System (ADS)

    Ushenko, O. G.; Boichuk, T. M.; Bachinskiy, V. T.; Vanchuliak, O. Ya.; Minzer, O. P.; Ushenko, Yu. O.; Dubolazov, O. V.; Savich, V. O.

    2015-09-01

    This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections of the myocardium). The polarized structure of autofluorescence imaging layers of biological tissues was detected and investigated. Proposed the model of describing the formation of polarization inhomogeneous of autofluorescence imaging biological optically anisotropic layers. On this basis, analytically and experimentally tested to justify the method of laser polarimetry autofluorescent. Analyzed the effectiveness of this method in the postmortem diagnosis of infarction. The objective criteria (statistical moments) of differentiation of autofluorescent images of histological sections myocardium were defined. The operational characteristics (sensitivity, specificity, accuracy) of these technique were determined.

  4. 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

  5. Assessment of Retrograde Coronary Venous Infusion of Mesenchymal Stem Cells Combined with Basic Fibroblast Growth Factor in Canine Myocardial Infarction Using Strain Values Derived from Speckle-Tracking Echocardiography.

    PubMed

    Sun, Qi-Wei; Zhen, Lei; Wang, Qin; Sun, Yan; Yang, Jiao; Li, Yi-Jia; Li, Rong-Juan; Ma, Ning; Li, Zhi-An; Wang, Lu-Ya; Nie, Shao-Ping; Yang, Ya

    2016-01-01

    Speckle-tracking echocardiography was used to assess retrograde coronary venous infusion of mesenchymal stem cells (MSCs) combined with basic fibroblast growth factor (bFGF) in a canine model of acute myocardial infarction (AMI). AMI was induced by ligation of the left anterior descending coronary artery. Coronary venous retroperfusion was performed at 1 wk after AMI. Twenty-eight animals were randomized into four groups: saline, bFGF+saline, saline+MSCs and bFGF+MSCs. Echocardiography was performed before AMI, at 7 d post-AMI and 40 d after retroperfusion. Apoptotic cardiomyocytes in the border zone of the ischemic region were evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling. Vascular endothelial growth factor and factor VIII concentrations were measured by western blotting. The left ventricular end-systolic volume increased significantly, whereas the left ventricular ejection fraction and global and segmental strain values decreased significantly after AMI. After retroperfusion, the strain values of the infarct zone, but not conventional echocardiographic parameters, were significantly different between control and bFGF+MSC groups. Cardiomyocyte apoptosis decreased, whereas vascular endothelial growth factor and factor VIII concentrations were higher in the bFGF+MSC, bFGF and MSC groups. Cardiomyocyte apoptosis was well correlated with the strain values. Although retrograde coronary venous infusion of bFGF and MSCs promoted neo-vascularization of the infarcted myocardium and inhibited apoptosis, there was only a slight strain improvement without a substantial increase in global cardiac functions.

  6. Cardiac MRI and Ischemic Heart Disease: Role in Diagnosis and Risk Stratification.

    PubMed

    Sawlani, Rahul N; Collins, Jeremy D

    2016-05-01

    Cardiac magnetic resonance imaging (CMRI) has been under development for the past four decades and has more recently become an essential tool in the evaluation of ischemic heart disease (IHD). It is the reference standard for quantification of both right and left ventricular volume and function and, after landmark work published in the New England Journal of Medicine in 2000, has proven effective in identifying hibernating myocardium, or hypokinetic myocardium that will recover after revascularization. More recent literature continues to support both delayed enhancement imaging and CMRI stress perfusion as essential tools in evaluating IHD. This review will briefly address the basics of CMRI and the scientific literature supporting the use of CMRI in IHD. It will then address more recent clinical studies establishing the clinical utility of CMRI in IHD, followed by a discussion of future directions in CMRI. PMID:26980317

  7. Astrocyte-mediated ischemic tolerance.

    PubMed

    Hirayama, Yuri; Ikeda-Matsuo, Yuri; Notomi, Shoji; Enaida, Hiroshi; Kinouchi, Hiroyuki; Koizumi, Schuichi

    2015-03-01

    Preconditioning (PC) using a preceding sublethal ischemic insult is an attractive strategy for protecting neurons by inducing ischemic tolerance in the brain. Although the underlying molecular mechanisms have been extensively studied, almost all studies have focused on neurons. Here, using a middle cerebral artery occlusion model in mice, we show that astrocytes play an essential role in the induction of brain ischemic tolerance. PC caused activation of glial cells without producing any noticeable brain damage. The spatiotemporal pattern of astrocytic, but not microglial, activation correlated well with that of ischemic tolerance. Interestingly, such activation in astrocytes lasted at least 8 weeks. Importantly, inhibiting astrocytes with fluorocitrate abolished the induction of ischemic tolerance. To investigate the underlying mechanisms, we focused on the P2X7 receptor as a key molecule in astrocyte-mediated ischemic tolerance. P2X7 receptors were dramatically upregulated in activated astrocytes. PC-induced ischemic tolerance was abolished in P2X7 receptor knock-out mice. Moreover, our results suggest that hypoxia-inducible factor-1α, a well known mediator of ischemic tolerance, is involved in P2X7 receptor-mediated ischemic tolerance. Unlike previous reports focusing on neuron-based mechanisms, our results show that astrocytes play indispensable roles in inducing ischemic tolerance, and that upregulation of P2X7 receptors in astrocytes is essential. PMID:25740510

  8. Canine hypoadrenocorticism: Part I

    PubMed Central

    Klein, Susan C.; Peterson, Mark E.

    2010-01-01

    Hypoadrenocorticism (Addison’s disease) has been referred to as “the great pretender,” due to its ability to mimic other common diseases in the dog and thereby represent a diagnostic challenge. Naturally occurring hypoadrenocorticism is an uncommon canine disease. Young, female dogs are overrepresented. Hypoadrenocorticism typically results from immune-mediated destruction of all adrenocortical layers, resulting in deficiencies of min-eralocorticoids (aldosterone) and glucocorticoids (cortisol). A small number of dogs suffer from glucocorticoid deficiency only. Dogs suffering from hypoadrenocorticism may present in a variety of conditions, from a mildly ill dog to a shocky and recumbent dog. This review discusses etiology, pathophysiology, history, physical examination findings, and diagnostic findings in the Addisonian patient. A follow-up article (Part II) will discuss the definitive diagnosis and management strategies for these patients. PMID:20357943

  9. Engineering and visualization of bacteria for targeting infarcted myocardium.

    PubMed

    Le, Uyenchi N; Kim, Hyung-Seok; Kwon, Jin-Sook; Kim, Mi Yeon; Nguyen, Vu H; Jiang, Sheng Nan; Lee, Byeong-Il; Hong, Yeongjin; Shin, Myung Geun; Rhee, Joon Haeng; Bom, Hee-Seung; Ahn, Youngkeun; Gambhir, Sanjiv S; Choy, Hyon E; Min, Jung-Joon

    2011-05-01

    Optimization of the specific affinity of cardiac delivery vector could significantly improve the efficiency of gene/protein delivery, yet no cardiac vectors to date have sufficient target specificity for myocardial infarction (MI). In this study, we explored bacterial tropism for infarcted myocardium based on our previous observations that certain bacteria are capable of targeting the hypoxic regions in solid tumors. Out of several Escherichia coli or Salmonella typhimurium strains, the S. typhimurium defective in the synthesis of ppGpp (ΔppGpp S. typhimurium) revealed accumulation and selective proliferation in the infarcted myocardium without spillover to noncardiac tissue. The Salmonellae that were engineered to express a variant of Renilla luciferase gene (RLuc8), under the control of the E. coli arabinose operon promoter (P(BAD)), selectively targeted and delivered RLuc8 in the infarcted myocardium only upon injection of L-arabinose. An examination of the infarct size before and after infection, and estimations of C-reactive protein (CRP) and procalcitonin indicated that intravenous injection of ΔppGpp S. typhimurium did not induce serious local or systemic immune reactions. This current proof-of-principle study demonstrates for the first time the capacity of Salmonellae to target infarcted myocardium and to serve as a vehicle for the selective delivery of therapeutic agents in MI.

  10. From Molecules to Myofibers: Multiscale Imaging of the Myocardium

    PubMed Central

    Goergen, Craig J.

    2012-01-01

    Pathology in the heart can be examined at several scales, ranging from the molecular to the macroscopic. Traditionally, fluorescence-based techniques such as flow cytometry have been used to study the myocardium at the molecular, cellular, and microscopic levels. Recent advances in magnetic resonance imaging (MRI), however, have made it possible to image certain cellular and molecular events in the myocardium noninvasively in vivo. In addition, diffusion MRI has been used to image myocardial fiber architecture and microstructure in the intact heart. Diffusion MRI tractography, in particular, is providing novel insights into myocardial microsctructure in both health and disease. Recent developments have also been made in fluorescence imaging, making it possible to image fluorescent probes in the heart of small animals non-invasively in vivo. Moreover, techniques have been developed to perform in vivo fluorescence tomography of the mouse heart. These advances in MRI and fluorescence imaging allow events in the myocardium to be imaged at several scales linking molecular changes to alterations in microstructure and microstructural changes to gross function. A complete and integrated picture of pathophysiology in the myocardium is thus obtained. This multiscale approach has the potential to be of significant value not only in preclinical research but, ultimately, in the clinical arena as well. PMID:21643889

  11. Three-dimensional imaging of the myocardium with isotopes

    NASA Technical Reports Server (NTRS)

    Budinger, T. F.

    1975-01-01

    Three methods of imaging the three-dimensional distribution of isotopes in the myocardium are discussed. Three-dimensional imaging was examined using multiple Anger-camera views. Longitudinal tomographic images with compensation for blurring were studied. Transverse-section reconstruction using coincidence detection of annihilation gammas from positron emitting isotopes was investigated.

  12. Effects of ischemic preconditioning on ischemia/reperfusion-induced arrhythmias by upregulatation of connexin 43 expression

    PubMed Central

    2011-01-01

    Background The susceptibility of hypertrophied myocardium to ischemia-reperfusion injury is associated with increased risk of postoperative arrhythmias. We investigate the effects of ischemic preconditioning (IP) on post-ischemic reperfusion arrhythmias in hypertrophic rabbit hearts. Methods Thirty-three rabbit models of myocardial hypertrophy were randomly divided into three groups of 11 each: non-ischemia-reperfusion group (group A), ischemia-reperfusion group (group B), and ischemic preconditioning group (group C). Another ten healthy rabbits with normal myocardium served as the healthy control group. Rabbit models of myocardial hypertrophy were induced by abdominal aortic banding. Surface electrocardiogram (ECG) was recorded and Curtis-Ravingerova score was used for arrhythmia quantification. Connexin 43 (Cx43) expression was assessed by immunohistochemistry. Results Ratios of heart weight to body weight and left ventricular weight to body weight increase significantly in the three groups compared with the healthy control group (p < 0.05). Arrhythmia incidence in group C is significantly lower than group B (p < 0.05). Curtis-Ravingerova score in group C is lower than group B (p < 0.05). Cx43 expression area in group A is smaller by comparison with the healthy control group (p < 0.05). Cx43 expression area and fluorescence intensity in group B are reduced by 60.9% and 23.9%, respectively, compared with group A (p < 0.05). In group C, Cx43 expression area increases by 32.5% compared with group B (p < 0.05), and decreases by 54.8% compared with group A (p < 0.05). Conclusions The incidence of ischemia/reperfusion-induced arrhythmias in hypertrophic rabbit hearts decreases after IP, which plays an important protecting role on the electrophysiology of hypertrophied myocardium by up-regulating the expression of Cx43. PMID:21635761

  13. Melatonin-induced glycosaminoglycans augmentation in myocardium remote to infarction.

    PubMed

    Drobnik, J; Tosik, D; Piera, L; Szczepanowska, A; Olczak, S; Zielinska, A; Liberski, P P; Ciosek, J

    2013-12-01

    Elevated levels of collagen as well as transient increases of glycosaminoglycans (GAG) have been shown in the myocardium remote to the infarction. The aim of the study is to observe the effect of melatonin on the accumulation of collagen and GAG in the left ventricle wall, remote to the infarction. A second aim is to determine whether the effect of the pineal indole is mediated by the membrane melatonin receptors of heart fibroblasts. Rats with myocardial infarction induced by ligation of the left coronary artery were treated with melatonin at a dose of 60 μg/100 g b.w. or vehicle (2% ethanol in 0.9% NaCl). The results were compared with an untreated control. In the second part of the study, the fibroblasts from the non-infarcted part of myocardium were isolated and cultured. Melatonin at a range of concentrations from 10(-8) M to 10(-6) M was applied to the fibroblast cultures. In the final part of the study, the influence of luzindole (10(-6) M), the melatonin membrane receptor inhibitor, on melatonin-induced GAG augmentation was investigated. Both collagen and GAG content were measured in the experiment. Melatonin elevated GAG content in the myocardium remote to the infarcted heart. Collagen level was not changed by pineal indoleamine. Fibroblasts isolated from the myocardium varied in shape from fusiform to spindle-shaped. Moreover, the pineal hormone (10(-7)M and 10(-6)M) increased GAG accumulation in the fibroblast culture. Luzindole inhibited melatonin-induced elevation of GAG content at 10(-6)M. Melatonin increased GAG content in the myocardium remote to infarction. This effect was dependent on the direct influence of the pineal indole on the heart fibroblasts. The melatonin-induced GAG elevation is blocked by luzindole, the melatonin membrane receptors inhibitor, indicating a direct effect of this indole.

  14. Acute ischemic stroke update.

    PubMed

    Baldwin, Kathleen; Orr, Sean; Briand, Mary; Piazza, Carolyn; Veydt, Annita; McCoy, Stacey

    2010-05-01

    Stroke is the third most common cause of death in the United States and is the number one cause of long-term disability. Legislative mandates, largely the result of the American Heart Association, American Stroke Association, and Brain Attack Coalition working cooperatively, have resulted in nationwide standardization of care for patients who experience a stroke. Transport to a skilled facility that can provide optimal care, including immediate treatment to halt or reverse the damage caused by stroke, must occur swiftly. Admission to a certified stroke center is recommended for improving outcomes. Most strokes are ischemic in nature. Acute ischemic stroke is a heterogeneous group of vascular diseases, which makes targeted treatment challenging. To provide a thorough review of the literature since the 2007 acute ischemic stroke guidelines were developed, we performed a search of the MEDLINE database (January 1, 2004-July 1, 2009) for relevant English-language studies. Results (through July 1, 2009) from clinical trials included in the Internet Stroke Center registry were also accessed. Results from several pivotal studies have contributed to our knowledge of stroke. Additional data support the efficacy and safety of intravenous alteplase, the standard of care for acute ischemic stroke since 1995. Due to these study results, the American Stroke Association changed its recommendation to extend the time window for administration of intravenous alteplase from within 3 hours to 4.5 hours of symptom onset; this recommendation enables many more patients to receive the drug. Other findings included clinically useful biomarkers, the role of inflammation and infection, an expanded role for placement of intracranial stents, a reduced role for urgent carotid endarterectomy, alternative treatments for large-vessel disease, identification of nontraditional risk factors, including risk factors for women, and newly published pediatric stroke guidelines. In addition, new devices for

  15. Burn-induced subepicardial injury in frog heart: a simple model mimicking ST segment changes in ischemic heart disease

    PubMed Central

    KAZAMA, Itsuro

    2015-01-01

    To mimic ischemic heart disease in humans, several animal models have been created, mainly in rodents by surgically ligating their coronary arteries. In the present study, by simply inducing burn injuries on the bullfrog heart, we reproduced abnormal ST segment changes in the electrocardiogram (ECG), mimicking those observed in ischemic heart disease, such as acute myocardial infarction and angina pectoris. The “currents of injury” created by a voltage gradient between the intact and damaged areas of the myocardium, negatively deflected the ECG vector during the diastolic phase, making the ST segment appear elevated during the systolic phase. This frog model of heart injury would be suitable to explain the mechanisms of ST segment changes observed in ischemic heart disease. PMID:26346747

  16. The effect of a heparin-based coacervate of fibroblast growth factor-2 on scarring in the infarcted myocardium.

    PubMed

    Chu, Hunghao; Chen, Chien-Wen; Huard, Johnny; Wang, Yadong

    2013-02-01

    Effective delivery of exogenous angiogenic growth factors can provide a new therapy for ischemic diseases. However, clinical translation of growth factor therapies faces multiples challenges; the most significant one is the short half-life of the naked protein. We use heparin and a nontoxic polycation to form an injectable coacervate that protects growth factors and preserves their bioactivities. Here we report the effectiveness of fibroblast growth factor-2 (FGF2) coacervate in reducing scar burden in a mouse myocardial infarction model. The coacervate provides spatial and temporal control of the release of heparin-binding proteins. Coacervate treated animals show lower level of inflammation, fibrosis and cardiomyocyte death in the infarcted myocardium. Histological evaluation indicates that FGF2 coacervate significantly increases the number of endothelial and mural cells and results in stable capillaries and arterioles to at least 6 weeks post injection. Echocardiographic assessment shows that FGF2 coacervate promotes cardiac contractibility and inhibits ventricular dilation, suggesting that the improvement at the tissue level leads to better cardiac functions. On the contrary, identical dosage of free FGF2 shows no statistical difference from saline or vehicle control in histological or functional assessment. Overall, injection of FGF2 coacervate ameliorated the ischemic injury caused by myocardial infarction. The promising data in rodent warrant further examination of the potential of clinical translation of this technology.

  17. Expression of c-yes oncogene product in various animal tissues and spontaneous canine tumours.

    PubMed

    Rungsipipat, A; Tateyama, S; Yamaguchi, R; Uchida, K; Miyoshi, N

    1999-06-01

    An immunohistochemical study of various visceral organs of normal adult dogs, cats, pigs, horses, cows, and chickens (five of each species) and of 185 spontaneous canine tumours was carried out using paraffin wax sections and a commercially available antibody to the human c- yes oncogene product. Among the adult normal tissues of six animal species, epithelial cells of the proximal and distal renal tubules, the myocardium, hepatocytes, cerebellar Purkinje cells and adrenal cortical cells were positive for c- yes product. Among the foetal tissues of dogs and chickens, a positive reaction was observed on canine chorionic villi cells and chick yolk sac surface epithelium, and on epithelial cells of the renal tubules, hepatocytes and the myocardium. These findings suggest that the c- yes proto-oncogene may play a physiological role in the cell growth and metabolism of these adult and foetal tissues. Of the 185 tumours tested, 59 (31.9 per cent) expressed the c- yes oncogene product. The c- yes -positive tumours accounted for 44.4 per cent (12/27) of the skin tumours, 5.5 per cent (1/18) of the round cell tumours, 35. 7 per cent (10/28) of the soft tissue tumours, 21.4 per cent (3/14) of the testicular tumours, 29.1 per cent (23/79) of the mammary tumours, and 52.6 per cent (10/19) of the other tumours types. Expression of the c- yes oncogene appeared to be common in spontaneously arising canine tumours, and the degree of expression varied considerably by tumour type.

  18. Thallium 201 imaging and gated cardiac blood pool scans in patients with ischemic and idiopathic congestive cardiomyopathy. A clinical and pathologic study.

    PubMed

    Bulkley, B H; Hutchins, G M; Bailey, I; Strauss, H W; Pitt, B

    1977-05-01

    In ischemic cardiomyopathy (CM) fibrosis replaces large segments of myocardium, but in idiopathic congestive CM the myocardium contains only small foci of fibrosis or is morphologically normal. As coronary disease and myocardial infarction may be clinically silent, it is not always possible to distinguish ischemic from idiopathic congestive CM during life without cardiac catheterization. To determine whether noninvasive methods, thallium 201 myocardial (Tl) imaging and technetium 99m gated cardiac blood pool scans (GCBPS), could separate the entities, we evaluated radioisotope images of the heart in 13 patients with ischemic, and eight patients with idiopathic congestive CM, and 14 patients with normal hearts. Diagnosis was setablished by cardiac catherterization and/or autopsy in each of the 35 patients. The 14 normals could be readily distinguished from CM, and ischemic could be distinguished from idiopathic dilated CM in 20 of 21 patients. All patients with myocardiopathy showed hypokinetic and dilated left ventricles, but right ventricular dilatation was evident mainly in those with idiopathic CM. Tl images in the ischemic type had defects of greater than 40% of image circumference which corresponded to segmental wall motion abnormalities on GCBPS, whereas those with the idiopathic congestive form were homogeneous or had defects of less than 20% of image circumference. Autopsy studies in 7 of 35 patients correlated Tl defects of greater than 20% of circumference with transmural myocardial fibrosis. PMID:557377

  19. Risk Stratification for Sudden Cardiac Death In Patients With Non-ischemic Dilated Cardiomyopathy

    PubMed Central

    Shekha, Karthik; Ghosh, Joydeep; Thekkoott, Deepak; Greenberg, Yisachar

    2005-01-01

    Non ischemic dilated cardiomyopathy (NIDCM) is a disorder of myocardium. It has varying etiologies. Albeit the varying etiologies of this heart muscle disorder, it presents with symptoms of heart failure, and rarely as sudden cardiac death (SCD). Manifestations of this disorder are in many ways similar to its counterpart, ischemic dilated cardiomyopathy (IDCM). A proportion of patients with NIDCM carries a grave prognosis and is prone to sudden cardiac death from sustained ventricular arrhythmias. Identification of this subgroup of patients who carry the risk of sudden cardiac death despite adequate medical management is a challenge .Yet another method is a blanket treatment of patients with this disorder with anti arrhythmic medications or anti tachyarrhythmia devices like implantable cardioverter defibrillators (ICD). However this modality of treatment could be a costly exercise even for affluent economies. In this review we try to analyze the existing data of risk stratification of NIDCM and its clinical implications in practice. PMID:16943952

  20. Canine leishmaniosis in South America

    PubMed Central

    Dantas-Torres, Filipe

    2009-01-01

    Canine leishmaniosis is widespread in South America, where a number of Leishmania species have been isolated or molecularly characterised from dogs. Most cases of canine leishmaniosis are caused by Leishmania infantum (syn. Leishmania chagasi) and Leishmania braziliensis. The only well-established vector of Leishmania parasites to dogs in South America is Lutzomyia longipalpis, the main vector of L. infantum, but many other phlebotomine sandfly species might be involved. For quite some time, canine leishmaniosis has been regarded as a rural disease, but nowadays it is well-established in large urbanised areas. Serological investigations reveal that the prevalence of anti-Leishmania antibodies in dogs might reach more than 50%, being as high as 75% in highly endemic foci. Many aspects related to the epidemiology of canine leishmaniosis (e.g., factors increasing the risk disease development) in some South American countries other than Brazil are poorly understood and should be further studied. A better understanding of the epidemiology of canine leishmaniosis in South America would be helpful to design sustainable control and prevention strategies against Leishmania infection in both dogs and humans. PMID:19426440

  1. The Clinical Status of Stem Cell Therapy for Ischemic Cardiomyopathy

    PubMed Central

    Wang, Xianyun; Zhang, Jun; Zhang, Fan; Li, Jing; Li, Yaqi; Tan, Zirui; Hu, Jie; Qi, Yixin; Yan, Baoyong

    2015-01-01

    Ischemic cardiomyopathy (ICM) is becoming a leading cause of morbidity and mortality in the whole world. Stem cell-based therapy is emerging as a promising option for treatment of ICM. Several stem cell types including cardiac-derived stem cells (CSCs), bone marrow-derived stem cells, mesenchymal stem cells (MSCs), skeletal myoblasts (SMs), and CD34+ and CD 133+ stem cells have been applied in clinical researches. The clinical effect produced by stem cell administration in ICM mainly depends on the transdifferentiation and paracrine effect. One important issue is that low survival and residential rate of transferred stem cells in the infracted myocardium blocks the effective advances in cardiac improvement. Many other factors associated with the efficacy of cell replacement therapy for ICM mainly including the route of delivery, the type and number of stem cell infusion, the timing of injection, patient's physical condition, the particular microenvironment onto which the cells are delivered, and clinical condition remain to be addressed. Here we provide an overview of the pros and cons of these transferred cells and discuss the current state of their therapeutic potential. We believe that stem cell translation will be an ideal option for patients following ischemic heart disease in the future. PMID:26101528

  2. Protective effects of remote ischemic preconditioning in isolated rat hearts

    PubMed Central

    Teng, Xiao; Yuan, Xin; Tang, Yue; Shi, Jingqian

    2015-01-01

    To use Langendorff model to investigate whether remote ischemic preconditioning (RIPC) attenuates post-ischemic mechanical dysfunction on isolated rat heart and to explore possible mechanisms. SD rats were randomly divided into RIPC group, RIPC + norepinephrine (NE) depletion group, RIPC + pertussis toxin (PTX) pretreatment group, ischemia/reperfusion group without treatment (ischemia group) and time control (TC) group. RIPC was achieved through interrupted occlusion of anterior mesenteric artery. Then, Langendorff model was established using routine methods. Heart function was tested; immunohistochemistry and ELISA methods were used to detect various indices related to myocardial injury. Compared with ischemia group in which the hemodynamic parameters deteriorated significantly, heart function recovered to a certain degree among the RIPC, RIPC + NE depletion, and RIPC + PTX groups (P<0.05). More apoptotic nuclei were observed in ischemia group than in the other three groups (P<0.05); more apoptotic nuclei were detected in NE depletion and PTX groups than in RIPC group (P<0.05). While, there was no significant difference between NE depletion and PTX groups. In conclusion, RIPC protection on I/R myocardium extends to the period after hearts are isolated. NE and PTX-sensitive inhibitory G protein might have a role in the protection process. PMID:26550168

  3. Effect of levosimendan injection on oxidative stress of rat myocardium.

    PubMed

    Basel, Halil; Kavak, Servet; Demir, Halit; Meral, Ismail; Ekim, Hasan; Bektas, Hava

    2013-06-01

    This experiment was designed to investigate the effect of levosimendan injection on lipid peroxidation product malondialdehyde (MDA) and antioxidant glutathione (GSH) levels, and activities of antioxidant enzymes in myocardium of rats. Twenty male Wistar-albino rats were divided randomly into 2 study groups, each consisting of 10 rats. The animals in the first group were not treated with drug and served as control. It was found that the MDA and GSH levels decreased in levosimendan injected group. Superoxide dismutase, glutathione peroxidase, catalase and carbonic anhydrase enzyme activities were lower in levosimendan injected group than controls. It was concluded that lower tissue free radical level caused by levosimendan injection led to a lower antioxidant enzymes synthesis in the body and a decrease in the antioxidant enzyme activity and free radical scavenger level in myocardium of rat.

  4. Myocardium and BMP signaling are required for endocardial differentiation.

    PubMed

    Palencia-Desai, Sharina; Rost, Megan S; Schumacher, Jennifer A; Ton, Quynh V; Craig, Michael P; Baltrunaite, Kristina; Koenig, Andrew L; Wang, Jinhu; Poss, Kenneth D; Chi, Neil C; Stainier, Didier Y R; Sumanas, Saulius

    2015-07-01

    Endocardial and myocardial progenitors originate in distinct regions of the anterior lateral plate mesoderm and migrate to the midline where they coalesce to form the cardiac tube. Endocardial progenitors acquire a molecular identity distinct from other vascular endothelial cells and initiate expression of specific genes such as nfatc1. Yet the molecular pathways and tissue interactions involved in establishing endocardial identity are poorly understood. The endocardium develops in tight association with cardiomyocytes. To test for a potential role of the myocardium in endocardial morphogenesis, we used two different zebrafish models deficient in cardiomyocytes: the hand2 mutant and a myocardial-specific genetic ablation method. We show that in hand2 mutants endocardial progenitors migrate to the midline but fail to assemble into a cardiac cone and do not express markers of differentiated endocardium. Endocardial differentiation defects were rescued by myocardial but not endocardial-specific expression of hand2. In metronidazole-treated myl7:nitroreductase embryos, myocardial cells were targeted for apoptosis, which resulted in the loss of endocardial nfatc1 expression. However, endocardial cells were present and retained expression of general vascular endothelial markers. We further identified bone morphogenetic protein (BMP) as a candidate myocardium-derived signal required for endocardial differentiation. Chemical and genetic inhibition of BMP signaling at the tailbud stage resulted in severe inhibition of endocardial differentiation while there was little effect on myocardial development. Heat-shock-induced bmp2b expression rescued endocardial nfatc1 expression in hand2 mutants and in myocardium-depleted embryos. Our results indicate that the myocardium is crucial for endocardial morphogenesis and differentiation, and identify BMP as a signal involved in endocardial differentiation.

  5. Imaging acute ischemic stroke.

    PubMed

    González, R Gilberto; Schwamm, Lee H

    2016-01-01

    Acute ischemic stroke is common and often treatable, but treatment requires reliable information on the state of the brain that may be provided by modern neuroimaging. Critical information includes: the presence of hemorrhage; the site of arterial occlusion; the size of the early infarct "core"; and the size of underperfused, potentially threatened brain parenchyma, commonly referred to as the "penumbra." In this chapter we review the major determinants of outcomes in ischemic stroke patients, and the clinical value of various advanced computed tomography and magnetic resonance imaging methods that may provide key physiologic information in these patients. The focus is on major strokes due to occlusions of large arteries of the anterior circulation, the most common cause of a severe stroke syndrome. The current evidence-based approach to imaging the acute stroke patient at the Massachusetts General Hospital is presented, which is applicable for all stroke types. We conclude with new information on time and stroke evolution that imaging has revealed, and how it may open the possibilities of treating many more patients. PMID:27432672

  6. High expression of arachidonate 15-lipoxygenase and proinflammatory markers in human ischemic heart tissue

    SciTech Connect

    Magnusson, Lisa U.; Lundqvist, Annika; Asp, Julia; Synnergren, Jane; Johansson, Cecilia Thalen; Palmqvist, Lars; Jeppsson, Anders; Hulten, Lillemor Mattsson

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We found a 17-fold upregulation of ALOX15 in the ischemic heart. Black-Right-Pointing-Pointer Incubation of human muscle cells in hypoxia showed a 22-fold upregulation of ALOX15. Black-Right-Pointing-Pointer We observed increased levels of proinflammatory markers in ischemic heart tissue. Black-Right-Pointing-Pointer Suggesting a link between ischemia and inflammation in ischemic heart biopsies. -- Abstract: A common feature of the ischemic heart and atherosclerotic plaques is the presence of hypoxia (insufficient levels of oxygen in the tissue). Hypoxia has pronounced effects on almost every aspect of cell physiology, and the nuclear transcription factor hypoxia inducible factor-1{alpha} (HIF-1{alpha}) regulates adaptive responses to low concentrations of oxygen in mammalian cells. In our recent work, we observed that hypoxia increases the proinflammatory enzyme arachidonate 15-lipoxygenase (ALOX15B) in human carotid plaques. ALOX15 has recently been shown to be present in the human myocardium, but the effect of ischemia on its expression has not been investigated. Here we test the hypothesis that ischemia of the heart leads to increased expression of ALOX15, and found an almost 2-fold increase in HIF-1{alpha} mRNA expression and a 17-fold upregulation of ALOX15 mRNA expression in the ischemic heart biopsies from patients undergoing coronary bypass surgery compared with non ischemic heart tissue. To investigate the effect of low oxygen concentration on ALOX15 we incubated human vascular muscle cells in hypoxia and showed that expression of ALOX15 increased 22-fold compared with cells incubated in normoxic conditions. We also observed increased mRNA levels of proinflammatory markers in ischemic heart tissue compared with non-ischemic controls. In summary, we demonstrate increased ALOX15 in human ischemic heart biopsies. Furthermore we demonstrate that hypoxia increases ALOX15 in human muscle cells. Our results yield

  7. Intracoronary Delivery of Mitochondria to the Ischemic Heart for Cardioprotection.

    PubMed

    Cowan, Douglas B; Yao, Rouan; Akurathi, Vamsidhar; Snay, Erin R; Thedsanamoorthy, Jerusha K; Zurakowski, David; Ericsson, Maria; Friehs, Ingeborg; Wu, Yaotang; Levitsky, Sidney; Del Nido, Pedro J; Packard, Alan B; McCully, James D

    2016-01-01

    We have previously shown that transplantation of autologously derived, respiration-competent mitochondria by direct injection into the heart following transient ischemia and reperfusion enhances cell viability and contractile function. To increase the therapeutic potential of this approach, we investigated whether exogenous mitochondria can be effectively delivered through the coronary vasculature to protect the ischemic myocardium and studied the fate of these transplanted organelles in the heart. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and then reperfused for 10 minutes. Mitochondria were labeled with 18F-rhodamine 6G and iron oxide nanoparticles. The labeled mitochondria were either directly injected into the ischemic region or delivered by vascular perfusion through the coronary arteries at the onset of reperfusion. These hearts were used for positron emission tomography, microcomputed tomography, and magnetic resonance imaging with subsequent microscopic analyses of tissue sections to confirm the uptake and distribution of exogenous mitochondria. Injected mitochondria were localized near the site of delivery; while, vascular perfusion of mitochondria resulted in rapid and extensive dispersal throughout the heart. Both injected and perfused mitochondria were observed in interstitial spaces and were associated with blood vessels and cardiomyocytes. To determine the efficacy of vascular perfusion of mitochondria, an additional group of rabbit hearts were subjected to 30 minutes of regional ischemia and reperfused for 120 minutes. Immediately following regional ischemia, the hearts received unlabeled, autologous mitochondria delivered through the coronary arteries. Autologous mitochondria perfused through the coronary vasculature significantly decreased infarct size and significantly enhanced post-ischemic myocardial function. In conclusion, the delivery of mitochondria through the coronary arteries resulted in their rapid

  8. Intracoronary Delivery of Mitochondria to the Ischemic Heart for Cardioprotection

    PubMed Central

    Cowan, Douglas B.; Yao, Rouan; Akurathi, Vamsidhar; Snay, Erin R.; Thedsanamoorthy, Jerusha K.; Zurakowski, David; Ericsson, Maria; Friehs, Ingeborg; Wu, Yaotang; Levitsky, Sidney; del Nido, Pedro J.; Packard, Alan B.

    2016-01-01

    We have previously shown that transplantation of autologously derived, respiration-competent mitochondria by direct injection into the heart following transient ischemia and reperfusion enhances cell viability and contractile function. To increase the therapeutic potential of this approach, we investigated whether exogenous mitochondria can be effectively delivered through the coronary vasculature to protect the ischemic myocardium and studied the fate of these transplanted organelles in the heart. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and then reperfused for 10 minutes. Mitochondria were labeled with 18F-rhodamine 6G and iron oxide nanoparticles. The labeled mitochondria were either directly injected into the ischemic region or delivered by vascular perfusion through the coronary arteries at the onset of reperfusion. These hearts were used for positron emission tomography, microcomputed tomography, and magnetic resonance imaging with subsequent microscopic analyses of tissue sections to confirm the uptake and distribution of exogenous mitochondria. Injected mitochondria were localized near the site of delivery; while, vascular perfusion of mitochondria resulted in rapid and extensive dispersal throughout the heart. Both injected and perfused mitochondria were observed in interstitial spaces and were associated with blood vessels and cardiomyocytes. To determine the efficacy of vascular perfusion of mitochondria, an additional group of rabbit hearts were subjected to 30 minutes of regional ischemia and reperfused for 120 minutes. Immediately following regional ischemia, the hearts received unlabeled, autologous mitochondria delivered through the coronary arteries. Autologous mitochondria perfused through the coronary vasculature significantly decreased infarct size and significantly enhanced post-ischemic myocardial function. In conclusion, the delivery of mitochondria through the coronary arteries resulted in their rapid

  9. Direct effects of smoking on the heart: silent ischemic disturbances of coronary flow

    SciTech Connect

    Deanfield, J.E.; Shea, M.J.; Wilson, R.A.; Horlock, P.; de Landsheere, C.M.; Selwyn, A.P.

    1986-05-01

    Cigarette smoking is strongly associated with ischemic heart disease and acute coronary events. The effect of smoking a single cigarette on regional myocardial perfusion was studied in 13 chronic smokers with typical stable angina pectoris using positron emission tomography and rubidium-82 (/sup 82/Rb). Findings were compared with the effects of physical exercise. After exercise, 8 patients (61%) had angina, ST depression and abnormal regional myocardial perfusion. Uptake of /sup 82/Rb increased from 49 +/- 8 to 60 +/- 7 in remote myocardium, but decreased from 46 +/- 3 to 37 +/- 5 in an ischemic area. The remaining 5 patients (39%) had homogeneous increases in /sup 82/Rb uptake without angina or ST depression. After smoking, 6 of the 8 patients with positive exercise test responses had a decrease in /sup 82/Rb uptake, from 47 +/- 3 to 35 +/- 6 in the same segment of myocardium affected during exercise. However, in contrast to exercise, the events during smoking were largely silent. The absolute decreases in regional /sup 82/Rb uptake after smoking occurred at significantly lower levels of myocardial oxygen demand than after exercise. This suggests that an impairment of coronary blood supply is responsible. Thus, in smokers with coronary artery disease, each cigarette can cause profound silent disturbances of regional myocardial perfusion that are likely to occur frequently during daily life. Such repeated insults may represent an important mechanism linking smoking with coronary events.

  10. [Cerebrolysin for acute ischemic stroke].

    PubMed

    iganshina, L E; Abakumova, T R

    2013-01-01

    The review discusses existing evidence of benefits and risks of cerebrolysin--a mixture of low-molecular-weight peptides and amino acids derived from pigs' brain tissue with proposed neuroprotective and neurotrophic properties, for acute ischemic stroke. The review presents results of systematic search and analysis of randomised clinical trials comparing cerebrolysin with placebo in patients with acute ischemic stroke. Only one trial was selected as meeting quality criteria. No difference in death and adverse events between cerebrolysin and placebo was established. The authors conclude about insufficiency of evidence to evaluate the effect of cerebrolysin on survival and dependency in people with acute ischemic stroke.

  11. Remote Ischemic Conditioning

    PubMed Central

    Heusch, Gerd; Bøtker, Hans Erik; Przyklenk, Karin; Redington, Andrew; Yellon, Derek

    2014-01-01

    In remote ischemic conditioning (RIC) brief, reversible episodes of ischemia with reperfusion in one vascular bed, tissue or organ confer a global protective phenotype and render remote tissues and organs resistant to ischemia/reperfusion injury. The peripheral stimulus can be chemical, mechanical or electrical and involves activation of peripheral sensory nerves. The signal transfer to the heart or other organs is through neuronal and humoral communications. Protection can be transferred, even across species, with plasma-derived dialysate and involves nitric oxide, stromal derived factor-1α, microRNA-144, but also other, not yet identified factors. Intracardiac signal transduction involves: adenosine, bradykinin, cytokines, and chemokines, which activate specific receptors; intracellular kinases; and mitochondrial function. RIC by repeated brief inflation/deflation of a blood pressure cuff protects against endothelial dysfunction and myocardial injury in percutaneous coronary interventions, coronary artery bypass grafting and reperfused acute myocardial infarction. RIC is safe and effective, noninvasive, easily feasible and inexpensive. PMID:25593060

  12. Ischemic bowel disease

    PubMed Central

    Castelli, M. F.; Qizilbash, A. H.; Salem, S.; Fyshe, T. G.

    1974-01-01

    The clinical, radiologic and pathologic features of 25 cases of ischemic bowel disease are presented. The majority of patients presented with the triad of abdominal pain, diarrhea and vomiting. In 13 patients the diarrhea was associated with the passage of bright red blood per rectum. There were 10 cases of infarction, 11 of enterocolitis and 4 had resulted in stricture formation. In five cases of enterocolitis the lesion was transient; symptoms improved with conservative medical management and the radiologic findings returned to normal. Barium enema examination yielded abnormal findings in the majority of the cases in which it was performed. Plain films of the abdomen, however, were not helpful. The actual mortality in this group of patients was 44%, 80% in those with infarction of the bowel and 20% in the other two groups. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7 PMID:4419659

  13. Current developments in canine genetics.

    PubMed

    Marschall, Yvonne; Distl, Ottmar

    2010-01-01

    In recent years, canine genetics had made huge progress. In 1999 the first complete karyotype and ideogram of the dog was published. Several linkage and RH maps followed. Using these maps, sets of microsatellite markers for whole genome scans were compiled. In 2003 the sequencing of the DNA of a female Boxer began. Now the second version of the dog genome assembly has been put online, and recently, a microchip SNP array became available. Parallel to these developments, some causal mutations for different traits have been identified. Most of the identified mutations were responsible for monogenic canine hereditary diseases. With the tools available now, it is possible to use the advantages of the population structure of the various dog breeds to unravel complex genetic traits. Furthermore, the dog is a suitable model for the research of a large number of human hereditary diseases and particularly for cancer genetics, heart and neurodegenerative diseases. There are some examples where it was possible to benefit from the knowledge of canine genetics for human research. The search for quantitative trait loci (QTL), the testing of candidate genes and genome-wide association studies can now be performed in dogs. QTL for skeletal size variations and for canine hip dysplasia have been already identified and for these complex traits the responsible genes and their possible interactions can now be identified. PMID:20690545

  14. [Preparation of ATP-2Na loaded liposome and its effect on tissues energy state in myocardial ischemic mice].

    PubMed

    Pi, Feng-mei; Tu, Xi-de; Wu, Yue

    2010-10-01

    The aim of this study is to improve liposome encapsulation efficiency of water soluble drug ATP-2Na with hydrophobic ion pairing method, and evaluate its effect on tissues energy state in myocardial ischemia mice. Ion pair complex of ATP-2Na with HTAB was prepared first; then the liposomes were prepared by ethanol injection method. The size and zeta potential of ATP-2Na liposome were investigated. Its effect on tissues energy state in myocardium ischemia mice was evaluated by detecting ATP-2Na concentration in tissues and blood after injection in comparison to ATP-2Na solution. The diameters and zeta potential of ATP-2Na liposomes were (144.0 +/- 2.7) nm and (+16.2 +/- 1.6) mV, respectively. The encapsulation efficiency was (85.02 +/- 2.31) %. The in vitro drug release pattern from liposomes matches with Weibull equation. Compared with ATP-2Na solution, ATP-2Na liposome increased the ATP concentration of blood in myocardial ischemic mice very significantly; compared with blank, ATP-2Na liposome increased ATP content of myocardium and liver in myocaridal ischemic mice significantly, but ATP-2Na solution didn't show this effect. ATP-2Na liposome might have an advantage in improving tissue energy state on myocaridal ischemic animals.

  15. Pathophysiology of sudden cardiac death as demonstrated by molecular pathology of natriuretic peptides in the myocardium.

    PubMed

    Chen, Jian-Hua; Michiue, Tomomi; Ishikawa, Takaki; Maeda, Hitoshi

    2012-11-30

    Various heart diseases present with sudden death; however, it is difficult to interpret the severity of or difference in respective preexisting and terminal cardiac dysfunction based on conventional morphology. The present study investigated the cardiac pathophysiology employing quantitative mRNA measurement of atrial and brain natriuretic peptides (ANP and BNP) in the myocardium as markers of cardiac strain, using autopsy materials consisting of acute ischemic heart disease (AIHD, n=40) with/without the pathology of apparent myocardial necrosis (n=19/21), recurrent myocardial infarction (RMI, n=19), chronic congestive heart disease (CHD, n=11) and right ventricular cardiomyopathy (RVC, n=5), as well as hemopericardium (HP, n=11) due to myocardial infarction (n=5) and aortic rupture (n=6), and acute pulmonary thromboembolism (PTE, n=5). Cardiac death groups showed higher ANP and/or BNP mRNA expressions in the left ventricle than acute fatal bleeding (sharp instrumental injury; n=15) and/or mechanical asphyxiation (strangulation; n=10). AIHD and RMI cases had similar ANP and BNP mRNA expressions in bilateral ventricular walls, but their bilateral atrial levels were lower in RMI. RVC showed higher mRNA expressions of posterior left ventricular BNP, and right ventricular and bilateral atrial ANP and BNP. HP cases had lower BNP mRNA expression in the right ventricular wall, but PTE showed lower ANP and BNP mRNA expressions in the left ventricular wall; however, these mRNA expressions at other sites were similar to those of AIHD. CHD presented findings similar to those of AIHD, but the pericardial BNP level was significantly increased. These observations indicate characteristic molecular biological responses of myocardial natriuretic peptides in individual heart diseases and suggest the possible application of molecular pathology to demonstrate cardiac dysfunction even after death.

  16. Sildenafil Augments Early Protective Transcriptional Changes After Ischemia In Mouse Myocardium

    PubMed Central

    Vidavalur, Ramesh; Penumathsa, Suresh Varma; Thirunavukkarasu, Mahesh; Zhan, Lijun; Krueger, Winfried; Maulik, Nilanjana

    2009-01-01

    Recently, targeting cyclic-GMP specific phosphodiesterase-5 (PDE5) has attracted much interest in several cardiopulmonary diseases, in particular myocardial ischemia (MI). Although multiple mechanisms were postulated for these beneficial effects at cellular level, early transcriptional changes were unknown. The aim of present study was to examine gene expression profiles in response to MI after 24h of ischemia in murine model and compare transcriptional modulation by sildenafil, a popular phosphodiesterase 5 (PDE5) inhibitor. Mice were divided into four groups: Control sham (C), Sildenafil sham (S), Control MI (CMI) and Sildenafil MI (SMI). Sildenafil was given at a dose of 0.7 mg/kg intraperitoneally 30 minutes before LAD occlusion. cDNA microarray analysis of peri-infarct tissue was done using a custom cloneset and employing a looped dye swap design. Replicate signals were median averaged and normalized using LOWESS algorithm. R/MAANOVA analysis was used and false discovery rate corrected permutation p-values < 0.005 were employed as significance thresholds. 156 genes were identified as significantly regulated demonstrating fold difference >1.5 in atleast one of the four groups. 52 genes were significantly upregulated in SMI compared to CMI. For a randomly chosen subset of genes (9), microarray data were confirmed through real time RT-PCR. The differentially expressed genes could be classified into following groups based on their function: Phosphorylation/dephosphorylation, Apoptosis, differentiation, ATP binding. Our results suggest that sildenafil treatment might regulate early genetic reprogramming strategy for preservation of the ischemic myocardium. PMID:19013509

  17. Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury.

    PubMed

    Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

    2015-01-01

    Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury.

  18. Repeated sauna therapy attenuates ventricular remodeling after myocardial infarction in rats by increasing coronary vascularity of noninfarcted myocardium.

    PubMed

    Sobajima, Mitsuo; Nozawa, Takashi; Shida, Takuya; Ohori, Takashi; Suzuki, Takayuki; Matsuki, Akira; Inoue, Hiroshi

    2011-08-01

    Repeated sauna therapy (ST) increases endothelial nitric oxide synthase (eNOS) activity and improves cardiac function in heart failure as well as peripheral blood flow in ischemic limbs. The present study investigates whether ST can increase coronary vascularity and thus attenuate cardiac remodeling after myocardial infarction (MI). We induced MI by ligating the left coronary artery of Wistar rats. The rats were placed in a far-infrared dry sauna at 41°C for 15 min and then at 34°C for 20 min once daily for 4 wk. Cardiac hemodynamic, histopathological, and gene analyses were performed. Despite the similar sizes of MI between the ST and non-ST groups (51.4 ± 0.3 vs. 51.1 ± 0.2%), ST reduced left ventricular (LV) end-diastolic (9.7 ± 0.4 vs. 10.7 ± 0.5 mm, P < 0.01) and end-systolic (8.6 ± 0.5 vs. 9.6 ± 0.6 mm, P < 0.01) dimensions and attenuated MI-induced increases in LV end-diastolic pressure. Cross-sectional areas of cardiomyocytes were smaller in ST rats and associated with a significant reduction in myocardial atrial natriuretic peptide mRNA levels. Vascular density was reduced in the noninfarcted myocardium of non-ST rats, and the density of cells positive for CD31 and for α-smooth muscle actin was decreased. These decreases were attenuated in ST rats compared with non-ST rats and associated with increases in myocardial eNOS and vascular endothelial growth factor mRNA levels. In conclusion, ST attenuates cardiac remodeling after MI, at least in part, through improving coronary vascularity in the noninfarcted myocardium. Repeated ST might serve as a novel noninvasive therapy for patients with MI.

  19. Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury

    PubMed Central

    Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

    2015-01-01

    Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury. PMID:26103523

  20. Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury.

    PubMed

    Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

    2015-01-01

    Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury. PMID:26103523

  1. Noncompaction of the ventricular myocardium associated with mitral regurgitation and preserved ventricular systolic function.

    PubMed

    Ali, Sulafa Khalid M; Omran, Ahmed S; Najm, Hani; Godman, Michael J

    2004-01-01

    Noncompaction of the ventricular myocardium is an embryonic cardiomyopathy that is increasingly being recognized. Mitral regurgitation, when present, is usually a result of the associated left ventricular systolic dysfunction. We report 4 patients with noncompaction of the ventricular myocardium in whom ventricular systolic function was preserved. Mitral regurgitation was associated with changes in the mitral valve leaflets and an abnormal coaptation pattern. This association of noncompaction of the ventricular myocardium with mitral regurgitation has not, to our knowledge, been reported.

  2. [The effect of helium-neon laser radiation on the energy metabolic indices of the myocardium].

    PubMed

    Chizhov, G K; Koval'skaia, N I; Kozlov, V I

    1991-03-01

    It was shown in experiments on white rats, that intravenous and direct myocardium helium-neon laser irradiation leads to the some activation of lactate, glucose-6-phosphate, succinate and reduced NAD degydrogenases. During direct myocardium irradiation these changes are in a less degree. It is suggested that helium-neon laser irradiation displays some active influence on the energy metabolism enzymes of the myocardium, and the mechanisms of this action are discussed. PMID:2054512

  3. The Role of Uncoupling Protein 2 During Myocardial Dysfunction in a Canine Model of Endotoxin Shock.

    PubMed

    Wang, Xiaoting; Liu, Dawei; Chai, Wenzhao; Long, Yun; Su, Longxiang; Yang, Rongli

    2015-03-01

    To explore the role of uncoupling protein 2 (UCP2) during myocardial dysfunction in a canine model of endotoxin shock, 26 mongrel canines were randomly divided into the following four groups: A (control group; n = 6), B2 (shock after 2 h; n = 7), B4 (shock after 4 h; n = 7), and B6 (shock after 6 h; n = 6). Escherichia coli endotoxin was injected into the canines via the central vein, and hemodynamics were monitored. Energy metabolism, UCP2 mRNA and protein expression, and UCP2 localization were analyzed, and the correlation between energy metabolism changes, and UCP2 expression was determined. After the canine endotoxin shock model was successfully established, the expression of UCP2 mRNA and protein was found to increase, with later time points showing significant increases (P < 0.05). Immunofluorescence assays of UCP2 in heart tissue showed that UCP2 was localized in the cytoplasm, and its expression pattern was the same as that found in the mRNA and protein analyses. The energy metabolism results revealed that the ADP levels increased, but the ATP and phosphocreatine (PCr) levels and ATP/ADP and PCr/ATP ratios decreased in the model. In particular, the PCr/ATP ratio was significantly different from that of the control group 6 h after shock (P < 0.05). Furthermore, correlation analysis showed that the UCP2 protein and mRNA levels were negatively correlated with myocardial energy levels. In summary, decreased energy synthesis can occur in the myocardium during endotoxin shock, and UCP2 may play an important role in this process. The negative correlation between UCP2 expression and energy metabolism requires further study, as the results might contribute to the treatment of sepsis with heart failure.

  4. Immunopathological Features of Canine Myocarditis Associated with Leishmania infantum Infection.

    PubMed

    Costagliola, Alessandro; Piegari, Giuseppe; Otrocka-Domagala, Iwona; Ciccarelli, Davide; Iovane, Valentina; Oliva, Gaetano; Russo, Valeria; Rinaldi, Laura; Papparella, Serenella; Paciello, Orlando

    2016-01-01

    Myocarditis associated with infectious diseases may occur in dogs, including those caused by the protozoa Neospora caninum, Trypanosoma cruzi, Babesia canis, and Hepatozoon canis. However, although cardiac disease due to Leishmania infection has also been documented, the immunopathological features of myocarditis have not been reported so far. The aim of this study was to examine the types of cellular infiltrates and expression of MHC classes I and II in myocardial samples obtained at necropsy from 15 dogs with an established intravitam diagnosis of visceral leishmaniasis. Pathological features of myocardium were characterized by hyaline degeneration of cardiomyocytes, necrosis, and infiltration of mononuclear inflammatory cells consisting of lymphocytes and macrophages, sometimes with perivascular pattern; fibrosis was also present in various degrees. Immunophenotyping of inflammatory cells was performed by immunohistochemistry on cryostat sections obtained from the heart of the infected dogs. The predominant leukocyte population was CD8+ with a fewer number of CD4+ cells. Many cardiomyocytes expressed MHC classes I and II on the sarcolemma. Leishmania amastigote forms were not detected within macrophages or any other cell of the examined samples. Our study provided evidence that myocarditis in canine visceral leishmaniasis might be related to immunological alterations associated with Leishmania infection. PMID:27413751

  5. Immunopathological Features of Canine Myocarditis Associated with Leishmania infantum Infection

    PubMed Central

    Piegari, Giuseppe; Otrocka-Domagala, Iwona; Ciccarelli, Davide; Iovane, Valentina; Oliva, Gaetano; Russo, Valeria; Rinaldi, Laura; Papparella, Serenella; Paciello, Orlando

    2016-01-01

    Myocarditis associated with infectious diseases may occur in dogs, including those caused by the protozoa Neospora caninum, Trypanosoma cruzi, Babesia canis, and Hepatozoon canis. However, although cardiac disease due to Leishmania infection has also been documented, the immunopathological features of myocarditis have not been reported so far. The aim of this study was to examine the types of cellular infiltrates and expression of MHC classes I and II in myocardial samples obtained at necropsy from 15 dogs with an established intravitam diagnosis of visceral leishmaniasis. Pathological features of myocardium were characterized by hyaline degeneration of cardiomyocytes, necrosis, and infiltration of mononuclear inflammatory cells consisting of lymphocytes and macrophages, sometimes with perivascular pattern; fibrosis was also present in various degrees. Immunophenotyping of inflammatory cells was performed by immunohistochemistry on cryostat sections obtained from the heart of the infected dogs. The predominant leukocyte population was CD8+ with a fewer number of CD4+ cells. Many cardiomyocytes expressed MHC classes I and II on the sarcolemma. Leishmania amastigote forms were not detected within macrophages or any other cell of the examined samples. Our study provided evidence that myocarditis in canine visceral leishmaniasis might be related to immunological alterations associated with Leishmania infection. PMID:27413751

  6. Preterm Hypoxic–Ischemic Encephalopathy

    PubMed Central

    Gopagondanahalli, Krishna Revanna; Li, Jingang; Fahey, Michael C.; Hunt, Rod W.; Jenkin, Graham; Miller, Suzanne L.; Malhotra, Atul

    2016-01-01

    Hypoxic–ischemic encephalopathy (HIE) is a recognizable and defined clinical syndrome in term infants that results from a severe or prolonged hypoxic–ischemic episode before or during birth. However, in the preterm infant, defining hypoxic–ischemic injury (HII), its clinical course, monitoring, and outcomes remains complex. Few studies examine preterm HIE, and these are heterogeneous, with variable inclusion criteria and outcomes reported. We examine the available evidence that implies that the incidence of hypoxic–ischemic insult in preterm infants is probably higher than recognized and follows a more complex clinical course, with higher rates of adverse neurological outcomes, compared to term infants. This review aims to elucidate the causes and consequences of preterm hypoxia–ischemia, the subsequent clinical encephalopathy syndrome, diagnostic tools, and outcomes. Finally, we suggest a uniform definition for preterm HIE that may help in identifying infants most at risk of adverse outcomes and amenable to neuroprotective therapies. PMID:27812521

  7. The effects of exposure to electromagnetic field on rat myocardium.

    PubMed

    Kiray, Amac; Tayefi, Hamid; Kiray, Muge; Bagriyanik, Husnu Alper; Pekcetin, Cetin; Ergur, Bekir Ugur; Ozogul, Candan

    2013-06-01

    Exposure to electromagnetic fields (EMFs) causes increased adverse effects on biological systems. The aim of this study was to investigate the effects of EMF on heart tissue by biochemical and histomorphological evaluations in EMF-exposed adult rats. In this study, 28 male Wistar rats weighing 200-250 g were used. The rats were divided into two groups: sham group (n = 14) and EMF group (n = 14). Rats in sham group were exposed to same conditions as the EMF group except the exposure to EMF. Rats in EMF group were exposed to a 50-Hz EMF of 3 mT for 4 h/day and 7 days/week for 2 months. After 2 months of exposure, rats were killed; the hearts were excised and evaluated. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and caspase-3 immunohistochemistry were performed. In EMF-exposed group, levels of lipid peroxidation significantly increased and activities of superoxide dismutase and glutathione peroxidase decreased compared with sham group. The number of TUNEL-positive cells and caspase-3 immunoreactivity increased in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. In conclusion, the results show that the exposure to EMF causes oxidative stress, apoptosis and morphologic damage in myocardium of adult rats. The results of our study indicate that EMF-related changes in rat myocardium could be the result of increased oxidative stress. Further studies are needed to demonstrate whether the exposure to EMF can induce adverse effects on myocardium.

  8. Genetics of Human and Canine Dilated Cardiomyopathy

    PubMed Central

    Simpson, Siobhan; Edwards, Jennifer; Ferguson-Mignan, Thomas F. N.; Cobb, Malcolm; Mongan, Nigel P.; Rutland, Catrin S.

    2015-01-01

    Cardiovascular disease is a leading cause of death in both humans and dogs. Dilated cardiomyopathy (DCM) accounts for a large number of these cases, reported to be the third most common form of cardiac disease in humans and the second most common in dogs. In human studies of DCM there are more than 50 genetic loci associated with the disease. Despite canine DCM having similar disease progression to human DCM studies into the genetic basis of canine DCM lag far behind those of human DCM. In this review the aetiology, epidemiology, and clinical characteristics of canine DCM are examined, along with highlighting possible different subtypes of canine DCM and their potential relevance to human DCM. Finally the current position of genetic research into canine and human DCM, including the genetic loci, is identified and the reasons many studies may have failed to find a genetic association with canine DCM are reviewed. PMID:26266250

  9. Protection of the myocardium with high-energy solutions.

    PubMed

    Levitsky, S; Feinberg, H

    1975-07-01

    An approach to intraoperative protection of the myocardium is described that attempts to increase glucose utilization by infusion of high-energy solutions during aortic cross-clamping. Infusion of hypertonic glucose or glucose plus insulin prior to aortic cross-clamping has enhanced contractility and increased high-energy phosphate moieties in animals with induced ischemia. Recent pilot experiments in our laboratory suggest that infusions of creatine may result in increased production of creatine phosphate, which in turn induces phosphorylation of adenosine diphosphate to adenosine triphosphate, possibly enhancing myocardial contractility. The intraoperative clinical benefits of these infusions remain to be proved, however.

  10. Interdisciplinary approach to palatally impacted canine

    PubMed Central

    Goel, Ashish; Loomba, Anju; Goel, Poonam; Sharma, Naresh

    2010-01-01

    Interdisciplinary approach for the management of malocclusion provides a holistic approach of patient management. Prudent treatment planning is necessary to achieve the various treatment goals. The article highlights the salient features and various surgical and orthodontic considerations to approach cases with impacted canines. It is exemplified with a case in which a palatally impacted canine and a highly placed canine in the buccal vestibule have been surgically intervened and orthodontically extruded with sequential traction and aligned in the arch. PMID:22442552

  11. Mapping and ablation of trigger premature ventricular contractions in a case of electrical storm associated with ischemic cardiomyopathy.

    PubMed

    Okada, Taro; Yamada, Takumi; Murakami, Yoshimasa; Yoshida, Naoki; Ninomiya, Yuuichi; Toyama, Junji

    2007-03-01

    We report a case of polymorphic ventricular tachycardia and ventricular fibrillation (PVT/VF) storm associated with ischemic cardiomyopathy (ICM). The electrocardiogram (ECG) monitor revealed frequent premature ventricular contractions (PVCs) initiated PVT/VF. Electroanatomic mapping revealed the plausible origins of PVCs were located in the scar border zone at the posterior septum of the left ventricle. Purkinje-like potentials (PLPs) always preceded PVCs and a decremental property for the PLPs and infarcted myocardium junction was observed. Ablation at these sites eliminated both PVCs and PVT/VF.

  12. Recapitulating maladaptive, multiscale remodeling of failing myocardium on a chip.

    PubMed

    McCain, Megan L; Sheehy, Sean P; Grosberg, Anna; Goss, Josue A; Parker, Kevin Kit

    2013-06-11

    The lack of a robust pipeline of medical therapeutic agents for the treatment of heart disease may be partially attributed to the lack of in vitro models that recapitulate the essential structure-function relationships of healthy and diseased myocardium. We designed and built a system to mimic mechanical overload in vitro by applying cyclic stretch to engineered laminar ventricular tissue on a stretchable chip. To test our model, we quantified changes in gene expression, myocyte architecture, calcium handling, and contractile function and compared our results vs. several decades of animal studies and clinical observations. Cyclic stretch activated gene expression profiles characteristic of pathological remodeling, including decreased α- to β-myosin heavy chain ratios, and induced maladaptive changes to myocyte shape and sarcomere alignment. In stretched tissues, calcium transients resembled those reported in failing myocytes and peak systolic stress was significantly reduced. Our results suggest that failing myocardium, as defined genetically, structurally, and functionally, can be replicated in an in vitro microsystem by faithfully recapitulating the structural and mechanical microenvironment of the diseased heart.

  13. Effect of glucose on the distribution of iodine-123-IHA-16 between esterification and oxidation in canine myocardium

    SciTech Connect

    Arvieux, C.C.; Fagret, D.; Dubois, F.; Brichon, P.Y.; Mathieu, J.P.; Pilichowski, P.; Cuchet, P.; Comet, M. )

    1990-05-01

    To evaluate the effect of glucose perfusion on the myocardial metabolism of (123I)-16-iodo-9-hexadecenoic acid (IHA), the latter was injected intravenously into six fasting dogs perfused with a solution lacking glucose (controls) and seven fasting dogs perfused with glucose and insulin. The distribution of myocardial 123I among iodides, free IHA, and esterified IHA was measured in myocardial biopsy specimens. The increase in esterification and decrease in oxidation of IHA due to glucose were quantified using a compartmental mathematical model of myocardial IHA metabolism. Subsequently, in six control and six glucose-perfused dogs, cardiac radioactivity was measured with a scintillation camera for 1 hr following i.v. injection of IHA. Four different methods were used to analyze the myocardial time-activity curves and to calculate the distribution of IHA between oxidation and esterification. Results comparable to those provided by analysis of biopsy specimens can be obtained by considering the curve to be the sum of an exponential and a constant, or by analyzing it with a compartmental mathematical model.

  14. PlGF-MMP9-engineered iPS cells supported on a PEG-fibrinogen hydrogel scaffold possess an enhanced capacity to repair damaged myocardium.

    PubMed

    Bearzi, C; Gargioli, C; Baci, D; Fortunato, O; Shapira-Schweitzer, K; Kossover, O; Latronico, M V G; Seliktar, D; Condorelli, G; Rizzi, R

    2014-01-01

    Cell-based regenerative therapies are significantly improved by engineering allografts to express factors that increase vascularization and engraftment, such as placental growth factor (PlGF) and matrix metalloproteinase 9 (MMP9). Moreover, the seeding of therapeutic cells onto a suitable scaffold is of utmost importance for tissue regeneration. On these premises, we sought to assess the reparative potential of induced pluripotent stem (iPS) cells bioengineered to secrete PlGF or MMP9 and delivered to infarcted myocardium upon a poly(ethylene glycol)-fibrinogen scaffold. When assessing optimal stiffness of the PEG-fibrinogen (PF) scaffold, we found that the appearance of contracting cells after cardiogenic induction was accelerated on the support designed with an intermediate stiffness. Revascularization and hemodynamic parameters of infarcted mouse heart were significantly improved by injection into the infarct of this optimized PF scaffold seeded with both MiPS (iPS cells engineered to secrete MMP9) and PiPS (iPS cells engineered to secrete PlGF) cells as compared with nonengineered cells or PF alone. Importantly, allograft-derived cells and host myocardium were functionally integrated. Therefore, survival and integration of allografts in the ischemic heart can be significantly improved with the use of therapeutic cells bioengineered to secrete MMP9 and PlGF and encapsulated within an injectable PF hydrogel having an optimized stiffness.

  15. Canine histiocytic neoplasia: An overview

    PubMed Central

    Fulmer, Amanda K.; Mauldin, Glenna E.

    2007-01-01

    Canine histiocytic neoplasms include cutaneous histiocytoma, as well as localized and disseminated histiocytic sarcoma. These tumors have variable biologic behavior, although the malignant disorders often have a poor prognosis. Immunohistochemistry plays an essential role in differentiating histiocytic tumors from other neoplasias that may have similar histological appearances. This allows a definitive diagnosis to be established and provides a more accurate prediction of prognosis. This article reviews the biologic behavior, diagnosis, and treatment of histiocytic tumors in the dog. PMID:17987966

  16. Canine Blastomycosis in Southern Saskatchewan

    PubMed Central

    Harasen, Greg L.G.; Randall, James W.

    1986-01-01

    The incidence of canine blastomycosis in southern Saskatchewan is examined and three clinical cases are described. Nineteen cases of the disease have been diagnosed in southern Saskatchewan since April of 1981. Eight cases were diagnosed during a six month period from August 1985 to February 1986 in dogs residing in a small central area of Regina. The geographical and chronological clustering of cases suggests a local source of exposure to Blastomyces dermatitidis, not previously considered to be endemic to Saskatchewan. PMID:17422705

  17. Sewage surveillance reveals the presence of canine GVII norovirus and canine astrovirus in Uruguay.

    PubMed

    Lizasoain, A; Tort, L F L; García, M; Gómez, M M; Leite, J P G; Miagostovich, M P; Cristina, J; Berois, M; Colina, R; Victoria, Matías

    2015-11-01

    Canine norovirus (NoV) and astrovirus (AstV) were studied in 20 domestic sewage samples collected in two cities in Uruguay. Four samples were characterized as canine AstV after phylogenetic analysis clustering with strains detected in Italy and Brazil in 2008 and 2012, respectively. One sample was characterized as canine NoV and clustered with a strain detected in Hong Kong and recently classified as GVII. This study shows the occurrence of a canine NoV GVII strain for the first time in the American continent and also warns about possible zoonotic infection, since canine strains were detected in domestic sewage.

  18. Genome Sequence of Canine Herpesvirus

    PubMed Central

    Papageorgiou, Konstantinos V.; Suárez, Nicolás M.; Wilkie, Gavin S.; McDonald, Michael; Graham, Elizabeth M.; Davison, Andrew J.

    2016-01-01

    Canine herpesvirus is a widespread alphaherpesvirus that causes a fatal haemorrhagic disease of neonatal puppies. We have used high-throughput methods to determine the genome sequences of three viral strains (0194, V777 and V1154) isolated in the United Kingdom between 1985 and 2000. The sequences are very closely related to each other. The canine herpesvirus genome is estimated to be 125 kbp in size and consists of a unique long sequence (97.5 kbp) and a unique short sequence (7.7 kbp) that are each flanked by terminal and internal inverted repeats (38 bp and 10.0 kbp, respectively). The overall nucleotide composition is 31.6% G+C, which is the lowest among the completely sequenced alphaherpesviruses. The genome contains 76 open reading frames predicted to encode functional proteins, all of which have counterparts in other alphaherpesviruses. The availability of the sequences will facilitate future research on the diagnosis and treatment of canine herpesvirus-associated disease. PMID:27213534

  19. High b value DWI in evaluation of the hyperacute cerebral ischemia at 3T: A comparative study in an embolic canine stroke model

    PubMed Central

    Cheng, Qiguang; Xu, Xiaoquan; Zu, Qingquan; Lu, Shanshan; Yu, Jing; Liu, Xinglong; Wang, Bin; Shi, Haibin; Teng, Gaojun; Liu, Sheng

    2016-01-01

    Previous studies have indicated that the temporal change of relative diffusion weighted imaging (rDWI) signal intensity may help to determine the onset time of a stroke. Furthermore, several studies have indicated that high b value DWI offered improved detection rates for hyper-acute ischemic lesions compared with standard b value DWI. However, the temporal changes of the rDWI on high b value DWI remain unclear. Therefore, based on our embolic canine stroke model, we evaluated the temporal evolution of rDWI on high b value DWI, and further compared its diagnostic value in predicting the onset time of ischemic stroke with rDWI on standard b value DWI. Twelve canine MCAO models were established, and DWI was performed at 1, 2, 3, 4, 5 and 6 h after MCAO, with 3 b values of 1,000, 2,000 and 3,000. High b value DWI detected all ischemic lesions after 1 h, while standard b value did not detect the ischemic lesions in one dog at 1 h. With all three of the tested b values, rDWIs increased continuously within 6 h, while relative apparent diffusion coefficient (rADC) values rapidly decreased in 1 h, then became relatively stable. The area under the curve values for rDWI with b value of 1,000, 2,000 and 3,000, in predicting ischemic lesions within 3 h were 0.897, 0.929 and 0.938, while for rADC were 0.645, 0.583 and 0.599, respectively. Therefore, the results indicated that the rDWI was helpful in aging hyper-acute ischemic stroke, while rADC appeared not to be. High b value DWI had a higher detection rate for ischemic lesions and better predictive efficacy in determining the onset time of hyper-acute stroke. PMID:27446301

  20. Probability mapping of scarred myocardium using texture and intensity features in CMR images

    PubMed Central

    2013-01-01

    Background The myocardium exhibits heterogeneous nature due to scarring after Myocardial Infarction (MI). In Cardiac Magnetic Resonance (CMR) imaging, Late Gadolinium (LG) contrast agent enhances the intensity of scarred area in the myocardium. Methods In this paper, we propose a probability mapping technique using Texture and Intensity features to describe heterogeneous nature of the scarred myocardium in Cardiac Magnetic Resonance (CMR) images after Myocardial Infarction (MI). Scarred tissue and non-scarred tissue are represented with high and low probabilities, respectively. Intermediate values possibly indicate areas where the scarred and healthy tissues are interwoven. The probability map of scarred myocardium is calculated by using a probability function based on Bayes rule. Any set of features can be used in the probability function. Results In the present study, we demonstrate the use of two different types of features. One is based on the mean intensity of pixel and the other on underlying texture information of the scarred and non-scarred myocardium. Examples of probability maps computed using the mean intensity of pixel and the underlying texture information are presented. We hypothesize that the probability mapping of myocardium offers alternate visualization, possibly showing the details with physiological significance difficult to detect visually in the original CMR image. Conclusion The probability mapping obtained from the two features provides a way to define different cardiac segments which offer a way to identify areas in the myocardium of diagnostic importance (like core and border areas in scarred myocardium). PMID:24053280

  1. Quantification of fiber orientation in the canine atrial pacemaker complex using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ambrosi, Christina M.; Fedorov, Vadim V.; Schuessler, Richard B.; Rollins, Andrew M.; Efimov, Igor R.

    2012-07-01

    The atrial pacemaker complex is responsible for the initiation and early propagation of cardiac impulses. Optical coherence tomography (OCT), a nondestructive imaging modality with spatial resolutions of ˜1 to 15 μm, can be used to identify unique fiber orientation patterns in this region of the heart. Functionally characterized canine sinoatrial nodes (SAN) (n=7) were imaged using OCT up to ˜1 mm below the endocardial tissue surface. OCT images were directly compared to their corresponding histological sections. Fiber orientation patterns unique to the crista terminalis (CT), SAN, and surrounding atrial myocardium were identified with dominant average fiber angles of 89±12 deg, 110±16 deg, and 95±35 deg, respectively. Both the CT and surrounding atrial myocardium displayed predominantly unidirectionally based fiber orientation patterns within each specimen, whereas the SAN displayed an increased amount of fiber disarray manifested quantitatively as a significantly greater standard deviation in fiber angle distribution within specimens [33±7 deg versus 23±5 deg, atrium (p=0.02); 18±3 deg, CT (p=0.0003)]. We also identified unique, local patterns of fiber orientation specific to the functionally characterized block zone. We demonstrate the ability of OCT in detecting components of the atrial pacemaker complex which are intimately involved in both normal and abnormal cardiac conduction.

  2. Ischemic Stroke after Heart Transplantation

    PubMed Central

    Acampa, Maurizio; Lazzerini, Pietro Enea; Guideri, Francesca; Tassi, Rossana; Martini, Giuseppe

    2016-01-01

    Cerebrovascular complications after orthotopic heart transplantation (OHT) are more common in comparison with neurological sequelae subsequent to routine cardiac surgery. Ischemic stroke and transient ischemic attack (TIA) are more common (with an incidence of up to 13%) than intracranial hemorrhage (2.5%). Clinically, ischemic stroke is manifested by the appearance of focal neurologic deficits, although sometimes a stroke may be silent or manifests itself by the appearance of encephalopathy, reflecting a diffuse brain disorder. Ischemic stroke subtypes distribution in perioperative and postoperative period after OHT is very different from classical distribution, with different pathogenic mechanisms. Infact, ischemic stroke may be caused by less common and unusual mechanisms, linked to surgical procedures and to postoperative inflammation, peculiar to this group of patients. However, many strokes (40%) occur without a well-defined etiology (cryptogenic strokes). A silent atrial fibrillation (AF) may play a role in pathogenesis of these strokes and P wave dispersion may represent a predictor of AF. In OHT patients, P wave dispersion correlates with homocysteine plasma levels and hyperhomocysteinemia could play a role in the pathogenesis of these strokes with multiple mechanisms increasing the risk of AF. In conclusion, stroke after heart transplantation represents a complication with considerable impact not only on mortality but also on subsequent poor functional outcome. PMID:26915504

  3. Acute inflammatory reaction after myocardial ischemic injury and reperfusion. Development and use of a neutrophil-specific antibody.

    PubMed Central

    Hawkins, H. K.; Entman, M. L.; Zhu, J. Y.; Youker, K. A.; Berens, K.; Doré, M.; Smith, C. W.

    1996-01-01

    Reperfusion of the infarcted canine myocardium after 1 hour of ischemia is associated with an acute inflammatory infiltrate at the border of the infarct. In this paper, we demonstrate that early margination and emigration of neutrophils originate in thin-walled (approximately 5 micrometers) venous cisterns that average 200 micrometers in length and vary from 10 to 70 micrometers in width and show strong constitutive expression of both ICAM-1 and P-selectin; this class of vessels (venous cisterns) appears to be a unique feature in heart. A monoclonal antibody (SG8H6) with specificity for canine neutrophils was developed that allowed much more sensitive immunohistochemical detection of neutrophils in tissue and allowed us to follow tissue infiltration with time. Samples from 1 hour of reperfusion revealed dense margination and substantial emigration of neutrophils associated with the venous cisterns and collecting venules. By 2 hours, there was intense local emigration to the extravascular space between cardiac myocytes. By 3 hours, the infiltrate extended deeper into the infarct, and there was a continuous border zone of neutrophil infiltration that overlapped a region where intact cardiac myocytes strongly expressed ICAM-1 mRNA and extended into the necrotic tissue. At later times, neutrophil migration into infarcted tissue continued to progress. Neutrophil transmigration into reperfused myocardium is more extensive than previously described, and its extravascular distribution during early reperfusion is primarily in the viable border zone of the myocardium where myocyte ICAM-1 mRNA is found. These data are compatible with the hypothesis that extravascular neutrophils may participate in reperfusion injury. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8669481

  4. Observations on the effects of CO/sub 2/-laser on rat myocardium

    SciTech Connect

    Owen, E.R.; Canfield, P.; Bryant, K.; Hopwood, P.R.

    1984-01-01

    The effect of CO/sub 2/-laser burn on rat myocardium was studied to evaluate a hypothesis developed by Mirhoseini and Cayton that infarcted myocardium may be revascularized by establishing an alternative circulation from a ventricle to the coronary arteries by means of laser channels burned through the myocardium. The hearts of 22 rats were examined histologically for a period ranging from a few minutes to 50 days after CO/sub 2/ laser was applied to the myocardium. The laser initiated an intense inflammatory response in the myocardium adjacent to the target site. The authors believe that the inflammatory response, observed in this study to the Biophy-Las 80 surgical laser, must be reduced if laser is to be an effective means of myocardial revascularization.

  5. Molecular pathology of natriuretic peptides in the myocardium with special regard to fatal intoxication, hypothermia, and hyperthermia.

    PubMed

    Chen, Jian-Hua; Michiue, Tomomi; Ishikawa, Takaki; Maeda, Hitoshi

    2012-09-01

    The present study investigated the molecular pathology of atrial and brain natriuretic peptides (ANP and BNP) in the myocardium to evaluate terminal cardiac function in routine forensic casework with particular regard to fatal drug intoxication (n = 18; sedative-hypnotics, n = 10; methamphetamine, n = 8), hypothermia (cold exposure, n = 13), and hyperthermia (heatstroke, n = 10), compared with that in acute ischemic heart disease (AIHD, n = 35) and congestive heart disease (CHD, n = 11) as controls (total n = 87; within 48 h postmortem). Quantitative analyses of myocardial ANP and BNP messenger RNA demonstrated that their expressions in bilateral atrial and ventricular walls were high in methamphetamine intoxication and hypothermia, comparable to those in AIHD and CHD, but were low in sedative-hypnotic intoxication and hyperthermia. In pericardial fluid, both ANP and BNP levels were increased in hypothermia, while CHD cases had an elevated BNP level, and ANP level showed a tendency to increase in hyperthermia; however, immunohistochemistry showed no evident differences in myocardial ANP and BNP among the causes of death. These findings suggest terminal high cardiac strain in methamphetamine intoxication, decreased cardiac strain in sedative-hypnotic intoxication and hyperthermia (heatstroke), and persistent congestion in hypothermia (cold exposure).

  6. Rewarming Rate of the Myocardium During the Aortic Cross-Clamp Time: Variations with Different Levels of Body Hypothermia

    PubMed Central

    Juffé, Alberto; Burgos, Raul; Montero, Carlos Garcia; Tellez, Gaberiel; Prades, Gonzalo; Lloves, Eduardo; Figuera, Diego

    1985-01-01

    Twenty patients underwent elective cardiac valve replacement at 20° C of body hypothermia. Temperatures of the ventricles of both walls were monitored on 12 different sites. Distribution of myocardial temperature ranged between 24.3 and 29.3° C for patients of Group I before cardioplegia delivery and 13.2° C in the septum after cardioplegic infusion. Average temperatures for the anterior and posterior wall were 13.6 C and 15° C in the left ventricle and 14.7 and 15° C in the right ventricle. Myocardial temperatures ranged from 26 to 28.7° C for patients of Group II. After cardioplegic arrest, septal temperatures averaged 14.9° C. The recorded sites of the anterior and posterior left ventricle were 14.1 and 13.1° C. The effects of rewarming on the different myocardial areas occurred according to a logarithmic equation, which is faster in the first 10 minutes. The data suggest that the myocardium can be adequately protected with 25° C hypothermia when the cross-clamp period is shorter than 60 minutes. When longer ischemic periods are expected, myocardial protection is best accomplished with 20° C hypothermia. PMID:15227003

  7. Increased uptake of 18F-fluorodeoxyglucose in postischemic myocardium of patients with exercise-induced angina

    SciTech Connect

    Camici, P.; Araujo, L.I.; Spinks, T.; Lammertsma, A.A.; Kaski, J.C.; Shea, M.J.; Selwyn, A.P.; Jones, T.; Maseri, A.

    1986-07-01

    Regional myocardial perfusion and exogenous glucose uptake were assessed with rubidium-82 (82Rb) and 18F-2-fluoro-2-deoxyglucose (FDG) in 10 normal volunteers and 12 patients with coronary artery disease and stable angina pectoris by means of positron emission tomography. In patients at rest, the myocardial uptake of /sup 82/Rb and FDG did not differ significantly from that measured in normal subjects. The exercise test performed within the positron camera in eight patients produced typical chest pain and ischemic electrocardiographic changes in all. In each of the eight patients a region of reduced cation uptake was demonstrated in the /sup 82/Rb scan recorded at peak exercise, after which uptake of /sup 82/Rb returned to the control value 5 to 14 min after the end of the exercise. In these patients, FDG was injected in the recovery phase when all the variables that were altered during exercise, including regional myocardial /sup 82/Rb uptake, had returned to control values. In all but one patient, FDG accumulation in the regions of reduced /sup 82/Rb uptake during exercise was significantly higher than that in the nonischemic regions, i.e., the ones with a normal increment of /sup 82/Rb uptake on exercise. In the nonischemic areas, FDG uptake was not significantly different from that found in normal subjects after exercise. In conclusion, myocardial glucose transport and phosphorylation seem to be enhanced in the postischemic myocardium of patients with exercise-induced ischemia.

  8. Emodin-mediated protection from acute myocardial infarction via inhibition of inflammation and apoptosis in local ischemic myocardium.

    PubMed

    Wu, Yanxia; Tu, Xin; Lin, Guosheng; Xia, Hao; Huang, Hao; Wan, Jing; Cheng, Zhide; Liu, Mengyuan; Chen, Gao; Zhang, Haimou; Fu, Jinrong; Liu, Qian; Liu, Dong-Xu

    2007-10-13

    Acute myocardial infarction (AMI) is associated with inflammation and apoptosis. Emodin plays an anti-inflammatory role in several inflammatory diseases. Recent studies have demonstrated that emodin protects against myocardial ischemia/reperfusion injury. However, its mechanism underlying its effects remains unknown. In a murine model of AMI, based on ligation of the left coronary artery, administration of emodin reduced myocardial infarct size (MIS) in a dose-dependent manner. Emodin significantly suppressed TNF-alpha expression and NF-kappaB activation in the local myocardial infarction area. Treatment with emodin inhibited myocardial cell apoptosis by inhibiting caspase-3 activation. Therefore, these studies demonstrate that emodin protects against myocardial cell injury via suppression of local inflammation and apoptosis.

  9. Remote ischemic preconditioning for prevention of high-altitude diseases: fact or fiction?

    PubMed

    Berger, Marc Moritz; Macholz, Franziska; Mairbäurl, Heimo; Bärtsch, Peter

    2015-11-15

    Preconditioning refers to exposure to brief episodes of potentially adverse stimuli and protects against injury during subsequent exposures. This was first described in the heart, where episodes of ischemia/reperfusion render the myocardium resistant to subsequent ischemic injury, which is likely caused by reactive oxygen species (ROS) and proinflammatory processes. Protection of the heart was also found when preconditioning was performed in an organ different from the target, which is called remote ischemic preconditioning (RIPC). The mechanisms causing protection seem to include stimulation of nitric oxide (NO) synthase, increase in antioxidant enzymes, and downregulation of proinflammatory cytokines. These pathways are also thought to play a role in high-altitude diseases: high-altitude pulmonary edema (HAPE) is associated with decreased bioavailability of NO and increased generation of ROS, whereas mechanisms causing acute mountain sickness (AMS) and high-altitude cerebral edema (HACE) seem to involve cytotoxic effects by ROS and inflammation. Based on these apparent similarities between ischemic damage and AMS, HACE, and HAPE, it is reasonable to assume that RIPC might be protective and improve altitude tolerance. In studies addressing high-altitude/hypoxia tolerance, RIPC has been shown to decrease pulmonary arterial systolic pressure in normobaric hypoxia (13% O2) and at high altitude (4,342 m). Our own results indicate that RIPC transiently decreases the severity of AMS at 12% O2. Thus preliminary studies show some benefit, but clearly, further experiments to establish the efficacy and potential mechanism of RIPC are needed.

  10. Mechanistic molecular imaging of cardiac cell therapy for ischemic heart disease.

    PubMed

    Yu, Qiujun; Fan, Weiwei; Cao, Feng

    2013-10-01

    Cell-based myocardial regeneration has emerged as a promising therapeutic option for ischemic heart disease, though not yet at the level of routine clinical utility. Despite the encouraging results from initial preclinical studies that have demonstrated improved function and reduced infarct size of the ischemic myocardium following several candidate cell transplantation, the beneficial effects and molecular mechanisms of cardiac cell therapy are still unclear in clinical applications to date, and much remains to be optimized. To improve engraftment, accurate methods are required for tracking cell fate and quantifying functional outcome. In the present review, we summarized the current status and challenges of cardiac cell therapy for ischemic heart disease and discussed the strengths and limitations of currently available in vivo imaging techniques with special focus on the newly developed multimodality approaches for assessing the efficacy of engrafted donor cells. We also addressed the hurdles these imaging modalities are facing, including issues regarding immunogenicity and tumorigenicity of transplanted stem cells, and provided some the future perspectives on stem cell imaging.

  11. Dipeptidyl peptidase-4 inhibitors and the ischemic heart: Additional benefits beyond glycemic control.

    PubMed

    Chattipakorn, Nipon; Apaijai, Nattayaporn; Chattipakorn, Siriporn C

    2016-01-01

    Obese-insulin resistance and type 2 diabetes mellitus (T2DM) have become global health problems, and they are both associated with a higher risk of ischemic heart disease. Although reperfusion therapy is the treatment to increase blood supply to the ischemic myocardium, this intervention potentially causes cardiac tissue damage and instigates arrhythmias, processes known as reperfusion injury. Dipeptidyl peptidase 4 (DPP-4) inhibitors are glycemic control drugs commonly used in T2DM patients. Growing evidence from basic and clinical studies demonstrates that a DPP-4 inhibitor could exert cardioprotection and improve left ventricular function by reducing oxidative stress, apoptosis, and increasing reperfusion injury salvage kinase (RISK) activity. However, recent reports also showed potentially adverse cardiac events due to the use of a DPP-4 inhibitor. To investigate this disparity, future large clinical trials are essential in verifying whether DPP-4 inhibitors are beneficial beyond their glycemic control particularly for the ischemic heart in obese-insulin resistant subjects and T2DM patients.

  12. [Pregnancy and acute ischemic stroke].

    PubMed

    Bereczki, Dániel

    2016-05-15

    Pregnancy-related ischemic strokes play an important role in both maternal and fetal morbidity and mortality. Changes in hemostaseology and hemodynamics as well as risk factors related to or independent from pregnancy contribute to the increased stroke-risk during gestation and the puerperium. Potential teratogenic effects make diagnostics, acute therapy and prevention challenging. Because randomized, controlled trials are not available, a multicenter registry of patients with gestational stroke would be desirable. Until definite guidelines emerge, management of acute ischemic stroke during pregnancy remains individual, involving experts and weighing the risks and benefits.

  13. Growth differentiation factor 15 may protect the myocardium from no-reflow by inhibiting the inflammatory-like response that predominantly involves neutrophil infiltration

    PubMed Central

    ZHANG, MEI; PAN, KUNYING; LIU, QIANPING; ZHOU, XIN; JIANG, TIEMIN; LI, YUMING

    2016-01-01

    The aim of the current study was to investigate the time course of the expression of growth differentiation factor-15 (GDF-15) in rat ischemic myocardium with increasing durations of reperfusion, and to elucidate its physiopathological role in the no-reflow phenomenon. Wistar rats were randomly divided into ischemia reperfusion (I/R) and sham groups, and myocardial I/R was established by ligation of the left anterior descending coronary artery for 1 h followed by reperfusion for 2, 4, 6, 12, 24 h and 7 days whilst rats in the sham group were subjected to a sham operation. The expression levels of GDF-15 and ICAM-1 were measured, in addition to myeloperoxidase (MPO) activity. The myocardial anatomical no-reflow and infarction areas were assessed. The area at risk was not significantly different following various periods of reperfusion, while the infarct area and no-reflow area were significantly greater following 6 h of reperfusion (P<0.05). The mRNA and protein expression levels of GDF-15 were increased during the onset and development of no-reflow, and peaked following 24 h of reperfusion. MPO activity was reduced with increasing reperfusion duration, while ICAM-1 levels were increased. Hematoxylin and eosin staining demonstrated that myocardial neutrophil infiltration was significantly increased by I/R injury, in particular following 2, 4 and 6 h of reperfusion. GDF-15 expression levels were negatively correlated with MPO activity (r=−0.55, P<0.001), and the MPO activity was negatively correlated with the area of no-reflow (r=−0.46, P<0.01). By contrast, GDF-15 was significantly positively correlated with ICAM-1 levels (r=0.52, P<0.01), which additionally were demonstrated to be significantly positively associated with the size of the no-reflow area (r= 0.39, P<0.05). The current study demonstrated the time course effect of reperfusion on the expression of GDF-15 in the myocardial I/R rat model, with the shorter reperfusion times (6 h) resulting in

  14. Growth differentiation factor 15 may protect the myocardium from no‑reflow by inhibiting the inflammatory‑like response that predominantly involves neutrophil infiltration.

    PubMed

    Zhang, Mei; Pan, Kunying; Liu, Qianping; Zhou, Xin; Jiang, Tiemin; Li, Yuming

    2016-01-01

    The aim of the current study was to investigate the time course of the expression of growth differentiation factor‑15 (GDF‑15) in rat ischemic myocardium with increasing durations of reperfusion, and to elucidate its physiopathological role in the no‑reflow phenomenon. Wistar rats were randomly divided into ischemia reperfusion (I/R) and sham groups, and myocardial I/R was established by ligation of the left anterior descending coronary artery for 1 h followed by reperfusion for 2, 4, 6, 12, 24 h and 7 days whilst rats in the sham group were subjected to a sham operation. The expression levels of GDF‑15 and ICAM‑1 were measured, in addition to myeloperoxidase (MPO) activity. The myocardial anatomical no‑reflow and infarction areas were assessed. The area at risk was not significantly different following various periods of reperfusion, while the infarct area and no‑reflow area were significantly greater following 6 h of reperfusion (P<0.05). The mRNA and protein expression levels of GDF‑15 were increased during the onset and development of no‑reflow, and peaked following 24 h of reperfusion. MPO activity was reduced with increasing reperfusion duration, while ICAM‑1 levels were increased. Hematoxylin and eosin staining demonstrated that myocardial neutrophil infiltration was significantly increased by I/R injury, in particular following 2, 4 and 6 h of reperfusion. GDF‑15 expression levels were negatively correlated with MPO activity (r=‑0.55, P<0.001), and the MPO activity was negatively correlated with the area of no‑reflow (r=‑0.46, P<0.01). By contrast, GDF‑15 was significantly positively correlated with ICAM‑1 levels (r=0.52, P<0.01), which additionally were demonstrated to be significantly positively associated with the size of the no‑reflow area (r=0.39, P<0.05). The current study demonstrated the time course effect of reperfusion on the expression of GDF‑15 in the myocardial I/R rat model, with the shorter reperfusion

  15. Physical invariant strain energy function for passive myocardium.

    PubMed

    Shariff, M H B M

    2013-04-01

    Principal axis formulations are regularly used in isotropic elasticity, but they are not often used in dealing with anisotropic problems. In this paper, based on a principal axis technique, we develop a physical invariant orthotropic constitutive equation for incompressible solids, where it contains only a one variable (general) function. The corresponding strain energy function depends on six invariants that have immediate physical interpretation. These invariants are useful in facilitating an experiment to obtain a specific constitutive equation for a particular type of materials. The explicit appearance of the classical ground-state constants in the constitutive equation simplifies the calculation for their admissible values. A specific constitutive model is proposed for passive myocardium, and the model fits reasonably well with existing simple shear and biaxial experimental data. It is also able to predict a set of data from a simple shear experiment.

  16. An analysis of the cable properties of frog ventricular myocardium.

    PubMed Central

    Chapman, R A; Fry, C H

    1978-01-01

    1. The passive and active electrical parameters of frog ventricular myocardium have been measured. 2. The cytoplasmic resistivity has been determined by following changes in the resistance of a micro-electrode on penetration of a cell. 3. Unidimensional cable analysis using direct and alternating currents revealed the presence of a single time constant attributed to the surface membrane. 4. Longitudinal impedance measurements indicate that a second time constant is present in the intracellular pathway. 5. The results indicate that the resistance between cells is low so that action potentials can propagate from cell to cell by local circuits. 6. A three-dimensional cable analysis has also been carried out and compared to a simplified mathematical model which is presented in an Appendix and which closely approximates the experimental situation. PMID:309942

  17. Monolayered mesenchymal stem cells repair scarred myocardium after myocardial infarction.

    PubMed

    Miyahara, Yoshinori; Nagaya, Noritoshi; Kataoka, Masaharu; Yanagawa, Bobby; Tanaka, Koichi; Hao, Hiroyuki; Ishino, Kozo; Ishida, Hideyuki; Shimizu, Tatsuya; Kangawa, Kenji; Sano, Shunji; Okano, Teruo; Kitamura, Soichiro; Mori, Hidezo

    2006-04-01

    Mesenchymal stem cells are multipotent cells that can differentiate into cardiomyocytes and vascular endothelial cells. Here we show, using cell sheet technology, that monolayered mesenchymal stem cells have multipotent and self-propagating properties after transplantation into infarcted rat hearts. We cultured adipose tissue-derived mesenchymal stem cells characterized by flow cytometry using temperature-responsive culture dishes. Four weeks after coronary ligation, we transplanted the monolayered mesenchymal stem cells onto the scarred myocardium. After transplantation, the engrafted sheet gradually grew to form a thick stratum that included newly formed vessels, undifferentiated cells and few cardiomyocytes. The mesenchymal stem cell sheet also acted through paracrine pathways to trigger angiogenesis. Unlike a fibroblast cell sheet, the monolayered mesenchymal stem cells reversed wall thinning in the scar area and improved cardiac function in rats with myocardial infarction. Thus, transplantation of monolayered mesenchymal stem cells may be a new therapeutic strategy for cardiac tissue regeneration. PMID:16582917

  18. [Inappropriate preservation of myocardium by topical cooling with iced slush].

    PubMed

    Takeuchi, K; Takashima, K; Munakata, M; Ono, Y; Fukui, K; Suzuki, S; del Nido, P J

    1996-09-01

    Topical cooling with iced slush has been applied as a conventional myocardial preservation in open heart surgery. However, there might be several disadvantages due to topical cooling with iced slush which melted to be liquid, because of membrane integrity decreased during ischemia. To understand more detailed mechanism of deterioration for myocardium by immersion in some liquid during ischemia, we subjected isolated crystalloid perfused rabbit hearts to a 30 minute of ischemia with immersion in Krebs-Henseleit (K-H) solution (I), K-H+hexamethlyamiloride which was Na+/H+ channel blocker (II) and histidine containing cardioplegia (HBS) designed to accelerate anaerobic glycolysis by a proton buffering (III), followed by a 30 minute of reperfusion. These groups were compared to the hearts hanging in air during ischemia (control). Phosphocreatine (PCr), ATP and intracellular pH were measured by 31 PNMR in group I, II, III. Developed pressure (Dev P) and diastolic pressure (EDP) with a intracavitary balloon were also evaluated with monitoring of 2 mmHg diastolic contracture during ischemia. Dev P declined to 46%, 54% of preischemic value in group I and group II, respectively, although % recovery of control heart was 74% after ischemia-reperfusion process. Diastolic function was severely deteriorated in group I and II, as compared to control heart. ATP and intracellular pH showed a similar decline as PCr in group I and II which was not seen in group III during ischemia. HBS prevented the deterioration of PCr, ATP and intracellular pH during ischemia along with excellent recovery of myocardial function. We therefore conclude that 1) significant deterioration of myocardium occurs with ischemia if the heart preserved in Krebs-Heseleit solution and the mechanism of injury by immersion in liquid on the heart appears to be due to proton accumulation caused by intracellular acidification and loss of high energy phosphate. PMID:8911040

  19. A review of canine pseudocyesis.

    PubMed

    Gobello, C; de la Sota, R L; Goya, R G

    2001-12-01

    The purpose of this article is to review the most relevant features of the physiology, clinical signs, diagnosis, treatment and prevention of canine pseudocyesis (PSC). This is a physiological syndrome, characterized by clinical signs such as: nesting, weight gain, mammary enlargement, lactation and maternal behaviour, which appears in non-pregnant bitches at the end of metaoestrus. PSC is a frequent finding in domestic dogs. Although it is generally admitted that prolactin (PRL) plays a central role in the appearance of PSC, its precise aetiophysiology is not completely understood yet. A number of clinical studies suggest that at some point of metaoestrus circulating PRL levels rise in overtly pseudopregnant bitches. Individual differences in sensitivity to PRL as well as the existence of molecular variants of canine PRL with different bioactivity versus immunoreactivity ratios may help clarify the aetiopathology of PSC. Diagnosis of PSC is based on the presence of typical clinical signs in metaoestrous non-pregnant bitches. Considering that PSC is a self limiting physiological state, mild cases usually need no treatment. Discouraging maternal behaviour and sometimes fitting Elizabethan collars to prevent licking of the mammary glands may suffice in these cases. Sex steroids (oestrogens, progestins and androgens) have been traditionally used to treat PSC but the side-effects usually outweigh the benefits of these medications. Inhibition of PRL release by ergot derivatives [bromocriptine (10-100 microg/kg per day for 10-14 days], cabergoline (5 microg/kg per day during 5-10 days), metergoline (0.2 mg/kg per day during 8-10 days) has proved to be effective for the treatment of canine PSC. Although some of these ergot derivatives present some untoward side-effects, they are transient and can usually be managed. Predisposed bitches not intended for breeding should be spayed as ovariectomy is the only permanent preventive measure.

  20. Lasers in the treatment of ischemic heart disease in China

    NASA Astrophysics Data System (ADS)

    Zhang, Yongzhen; Chen, Mingzhe

    2000-10-01

    Myocardial revascularization by laser is a new treatment modality for chronic, severe, refractory angina in the patients with coronary heart disease that is not amenable to angioplasty (PTCA) or bypass surgery (CABG). Transmyocardial revascularization (TMR), typically requiring open thoracotomy, uses laser to create channels that would directly carry blood from left ventricular cavity into the ischemic myocardium. Current data indicate that TMR may provide these patients with improvement in angina severity, quality of life, and myocardial perfusion. The greatest potential future use of TMR is as an adjunct to CABG in patients with disease that prevents bypass grafting due to lack of distal targets or a conduit. Recently, as percutaneous (catheter-based) myocardial revascularization (PMR) has been developed with laser technology that permits the creation of channels from the endocardial surface of the left ventricle. The early results with PMR seem encouraging. Randomized clinical trial has demonstrated symptomatic improvement and increased exercise capacity. The risk: benefit ratio for PMR appears to be much more favorable than that for TMR. The mechanisms of action of them have not yet been clearly elucidated, and several theories have been proposed, including channel patency, angiogenesis, denervation, and placebo effect. The challenge of TMR/PMR is related to improvement of perioperative outcomes and long-term survival without worsening of left ventricular function. In future, it may be feasible to combine TMR/PMR with intramyocardial delivery of angiogenic growth factors to induce further new blood vessel formation.

  1. Applications of laser in ischemic heart disease in China

    NASA Astrophysics Data System (ADS)

    Chen, Mingzhe; Zhang, Yongzhen

    1999-09-01

    Current data demonstrate that laser coronary angioplasty is most useful in complex lesions not well suited for percutaneous transluminal coronary angioplasty (PTCA). It is not `stand-alone' procedure, and should be considered an adjunct to PTCA or stenting. To date, there are not data supporting reduction of restenosis. Direct myocardial revascularization (DMR), either transmyocardial revascularization (TMR) or percutaneous (catheter-based) myocardial revascularization (PMR), uses laser to create channels between ischemic myocardium and left ventricular cavity. Candidates include patients with chronic, severe, refractory angina and those unable to undergo angioplasty or bypass surgery because conduits or acceptable target vessels are lacking. Although the mechanisms of action of DMR have not yet been clearly elucidated, but several theories have been proposed, including channel patency, angiogenesis, and denervation. TMR, typically requiring open thoracotomy, is effective for improving myocardial perfusion and reducing angina. Pilot studies demonstrate that clinical application of PMR is feasible and safe and effective for decreasing angina. Late sequelae also remain to be determined. An ongoing randomized clinical trial is comparing PMR with conventional medical therapy in patients with severe, refractory angina and disease unamenable to angioplasty or bypass surgery.

  2. Genetic susceptibility to ischemic stroke

    PubMed Central

    Meschia, James F.; Worrall, Bradford B.; Rich, Stephen S.

    2014-01-01

    Clinicians who treat patients with stroke need to be aware of several single-gene disorders that have ischemic stroke as a major feature, including sickle cell disease, Fabry disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and retinal vasculopathy with cerebral leukodystrophy. The reported genome-wide association studies of ischemic stroke and several related phenotypes (for example, ischemic white matter disease) have shown that no single common genetic variant imparts major risk. Larger studies with samples numbering in the thousands are ongoing to identify common variants with smaller effects on risk. Pharmacogenomic studies have uncovered genetic determinants of response to warfarin, statins and clopidogrel. Despite increasing knowledge of stroke genetics, incorporating this new knowledge into clinical practice remains a challenge. The goals of this article are to review common single-gene disorders relevant to ischemic stroke, summarize the status of candidate gene and genome-wide studies aimed at discovering genetic stroke risk factors, and to briefly discuss pharmacogenomics related to stroke treatment. PMID:21629240

  3. Effect of gadolinium-DTPA on the magnetic relaxation times of normal and infarcted myocardium. [Dogs

    SciTech Connect

    Wesbey, G.E.; Higgins, C.B.; McNamara, M.T.; Engelstad, B.L.; Lipton, M.J.; Sievers, R.; Ehman, R.L.; Lovin, J.; Brasch, R.C.

    1984-10-01

    Acute myocardial infarctions were produced in 11 dogs by ligation of the left anterior descending coronary artery. Twenty-four hours after ligation Gd-DTPA was injected intravenously, followed by cardiectomy either 90 seconds (3 dogs) or 5 minutes (5 dogs) later. The remaining 3 dogs had cardiectomy without injection of Gd-DTPA at 24 hours after coronary occlusion. The 3 dogs that did not receive Gd-DTPA had longer T1 and T2 relaxation times in infarcted myocardium than in normal myocardium. The T1 and T2 relaxation times of normal myocardium at 90 seconds postinjection of Gd-DTPA were significantly shorter than those of the normal myocardium of animals that did not receive Gd-DTPA. At five minutes postinjection, significantly greater T1 shortening was exhibited in the infarcted myocardium compared with adjacent normal myocardium in the dogs injected with Gd-DTPA. Thus, Gd-DTPA has differential and time-varying effects on relaxation times of normal and infarcted myocardium.

  4. The alteration of interelemental ratios in myocardium under the congenital heart disease (SRXRF)

    NASA Astrophysics Data System (ADS)

    Trunova, V. A.; Zvereva, V. V.; Okuneva, G. N.; Levicheva, E. N.

    2007-05-01

    It is the myocardium that bears the basic functional loading during heart working, including muscle contractility and enzyme activity. The elemental concentrations in myocardium tissue of heart were determined by SRXRF technique. Our investigation is systematical: the elemental content in each compartment (left and right ventricles, left and right auricles) of hearts of healthy and diseased children (congenital heart diseases, transposition of main vessels (TMV)) was analyzed. The elemental distribution in myocardium of four heart chambers of human fetuses was also analyzed. Following elements were determined: S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr. It was revealed that the elemental concentrations in myocardium of both ventricles are almost constant in heart of fetuses and healthy children. The transition from pre-natal study (fetus) to post-natal study is accompanied by the redistribution of chemical elements in myocardium. The higher concentrations of S, Fe, Ca, Sr and Cu in myocardium of children are observed, the content of K, Br, Rb and especially Se is lower than in heart of fetuses. The elemental distribution in myocardium of children TMV is considerably different in comparison with the healthy children: the higher levels of Cu are observed. The content of Se is lower.

  5. [Blood supply of the compact and spongy myocardium of fish, amphibia and reptiles].

    PubMed

    Romenskiĭ, O Iu

    1978-07-01

    Coronal arteries were injected with lead carbonate suspension and with Indian ink and cleared preparations 150--300 mkm thick were made in 195 hearts of fish, amphibians and reptiles and studied roentgenographically. It was stated that in Chondrichthyes (shark, skate) and in Chondrostei (beluga, stellate sturgeon, sturgeon), as well as in alligator both compact and spongy myocardium of the cardiac ventricle possess blood vessels. In teleostei, amphibians and reptiles (except alligator) spongy myocardium is avascular and receives its nutrition from the ventricle. In view of the data on the presence of blood vessels in the spongy myocardium in some vertebrates, it is impossible to accept the theory suggested by Grant and Regnier according to which vessels in the heart walls appear only in connection with compactization of the myocardium. Vascularization of the spongy myocardium is closely connected with oxygen saturation of the blood flowing through the heart. When this saturation is not satisfactory, the spongy myocardium has blood vessels. In alligator, vascularization of the spongy myocardium is connected with the fact that the heart has four chambers and there are arterial and venous blood streams.

  6. [Four-week simulated weightlessness increases the expression of atrial natriuretic peptide in the myocardium].

    PubMed

    Zhang, Wen-Cheng; Lu, Yuan-Ming; Yang, Huai-Zhang; Xu, Peng-Tao; Chang, Hui; Yu, Zhi-Bin

    2013-04-25

    One of the major circulatory changes that occur in human during space flight and simulated weightlessness is a cerebral redistribution of body fluids, which is accompanied by an increase of blood volume in the upper body. Therefore, atrial myocardium should increase the secretion of atrial natriuretic peptide (ANP), but the researches lack common conclusion until now. The present study was to investigate the expression level of ANP in simulated weightlessness rats, and to confirm the changes of ANP by observing the associated proteins of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). The tail-suspended rat model was used to simulate weightlessness. Western blots were carried out to examine the expression levels of ANP and SNARE proteins in atrial and left ventricular myocardium. The results showed that ANP expression in atrial myocardium showed an increase in 4-week tail-suspended rats (SUS) compared with that in the synchronous control rats (CON). We only detected a trace amount of ANP in the left ventricular myocardium of the CON, but found an enhanced expression of ANP in left ventricular myocardium of the SUS. Expression of VAMP-1/2 (vesicle associated SNARE) increased significantly in both atrial and left ventricular myocardium in the SUS compared with that in the CON. There was no difference of the expression of syntaxin-4 (target compartment associated SNARE) between the CON and SUS, but the expression of SNAP-23 showed an increase in atrial myocardium of the SUS compared with that in the CON. Synip and Munc-18c as regulators of SNAREs did not show significant difference between the CON and SUS. These results suggest that the expression of ANP shows an increase in atrial and left ventricular myocardium of 4-week tail-suspended rats. Enhanced expression of VAMP-1/2 associated with ANP vesicles confirms the increased expression of ANP in atrial and left ventricular myocardium.

  7. Magnetic resonance imaging and multi-detector computed tomography assessment of extracellular compartment in ischemic and non-ischemic myocardial pathologies.

    PubMed

    Saeed, Maythem; Hetts, Steven W; Jablonowski, Robert; Wilson, Mark W

    2014-11-26

    Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume (ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular (approximately 10% of tissue volume), interstitium (approximately 15%) and intracellular (approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types I/III collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis (e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy (hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging (MRI) has the ability to characterize tissue proton relaxation times (T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI (DE-MRI) and multi-detector computed tomography (DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary

  8. Neuroinflammation in advanced canine glaucoma

    PubMed Central

    Jiang, Bing; Harper, Matthew M.; Kecova, Helga; Adamus, Grazyna; Kardon, Randy H.; Grozdanic, Sinisa D.

    2010-01-01

    Purpose The pathophysiological events that occur in advanced glaucoma are not well characterized. The principal purpose of this study is to characterize the gene expression changes that occur in advanced glaucoma. Methods Retinal RNA was obtained from canine eyes with advanced glaucoma as well as from healthy eyes. Global gene expression patterns were determined using oligonucleotide microarrays and confirmed by real-time PCR. The presence of tumor necrosis factor (TNF) and its receptors was evaluated by immunolabeling. Finally, we evaluated the presence of serum autoantibodies directed against retinal epitopes using western blot analyses. Results We identified over 500 genes with statistically significant changes in expression level in the glaucomatous retina. Decreased expression levels were detected for large number of functional groups, including synapse and synaptic transmission, cell adhesion, and calcium metabolism. Many of the molecules with decreased expression levels have been previously shown to be components of retinal ganglion cells. Genes with elevated expression in glaucoma are largely associated with inflammation, such as antigen presentation, protein degradation, and innate immunity. In contrast, expression of many other pro-inflammatory genes, such as interferons or interleukins, was not detected at abnormal levels. Conclusions This study characterizes the molecular events that occur in the canine retina with advanced glaucoma. Our data suggest that in the dog this stage of the disease is accompanied by pronounced retinal neuroinflammation. PMID:21042562

  9. Canine size, shape, and bending strength in primates and carnivores.

    PubMed

    Plavcan, J Michael; Ruff, Christopher B

    2008-05-01

    Anthropoid primates are well known for their highly sexually dimorphic canine teeth, with males possessing canines that are up to 400% taller than those of females. Primate canine dimorphism has been extensively documented, with a consensus that large male primate canines serve as weapons for intrasexual competition, and some evidence that large female canines in some species may likewise function as weapons. However, apart from speculation that very tall male canines may be relatively weak and that seed predators have strong canines, the functional significance of primate canine shape has not been explored. Because carnivore canine shape and size are associated with killing style, this group provides a useful comparative baseline for primates. We evaluate primate maxillary canine tooth size, shape and relative bending strength against body size, skull size, and behavioral and demographic measures of male competition and sexual selection, and compare them to those of carnivores. We demonstrate that, relative to skull length and body mass, primate male canines are on average as large as or larger than those of similar sized carnivores. The range of primate female canine sizes embraces that of carnivores. Male and female primate canines are generally as strong as or stronger than those of carnivores. Although we find that seed-eating primates have relatively strong canines, we find no clear relationship between male primate canine strength and demographic or behavioral estimates of male competition or sexual selection, in spite of a strong relationship between these measures and canine crown height. This suggests either that most primate canines are selected to be very strong regardless of variation in behavior, or that primate canine shape is inherently strong enough to accommodate changes in crown height without compromising canine function.

  10. White Matter Ischemic Changes in Hyperacute Ischemic Stroke

    PubMed Central

    Trouard, Theodore P; Lafleur, Scott R.; Krupinski, Elizabeth A.; Salamon, Noriko; Kidwell, Chelsea S.

    2015-01-01

    Background and Purpose— The purpose of this study was to evaluate changes in fractional anisotropy (FA), as measured by diffusion tensor imaging, of white matter (WM) infarction and hypoperfusion in patients with acute ischemic stroke using a quantitative voxel-based analysis. Methods— In this prospective study, diffusion tensor imaging and dynamic susceptibility contrast perfusion sequences were acquired in 21 patients with acute ischemic stroke who presented within 6 hours of symptom onset. The coregistered FA, apparent diffusion coefficient, and dynamic susceptibility contrast time to maximum (Tmax) maps were used for voxel-based quantification using a region of interest approach in the ipsilateral affected side and in the homologous contralateral WM. The regions of WM infarction versus hypoperfusion were segmented using a threshold method. Data were analyzed by regression and ANOVA. Results— There was an overall significant mean difference (P<0.001) for the apparent diffusion coefficient, Tmax, and FA values between the normal, hypoperfused, and infarcted WM. The mean±SD of FA was significantly higher (P<0.001) in hypoperfused WM (0.397±0.019) and lower (P<0.001) in infarcted WM (0.313±0.037) when compared with normal WM (0.360±0.020). Regression tree analysis of hypoperfused WM showed the largest mean FA difference at Tmax above versus below 5.4 s with a mean difference of 0.033 (P=0.0096). Conclusions— Diffusion tensor imaging-FA was decreased in regions of WM infarction and increased in hypoperfused WM in patients with hyperacute acute ischemic stroke. The significantly increased FA values in the hypoperfused WM with Tmax≥5.4 s are suggestive of early ischemic microstructural changes. PMID:25523053

  11. Protection from ischemic heart injury by a vigilant heme oxygenase-1 plasmid system.

    PubMed

    Tang, Yao Liang; Tang, Yi; Zhang, Y Clare; Qian, Keping; Shen, Leping; Phillips, M Ian

    2004-04-01

    Although human heme oxygenase-1 (hHO-1) could provide a useful approach for cellular protection in the ischemic heart, constitutive overexpression of hHO-1 may lead to unwanted side effects. To avoid this, we designed a hypoxia-regulated hHO-1 gene therapy system that can be switched on and off. This vigilant plasmid system is composed of myosin light chain-2v promoter and a gene switch that is based on an oxygen-dependent degradation domain from the hypoxia inducible factor-1-alpha. The vector can sense ischemia and switch on the hHO-1 gene system, specifically in the heart. In an in vivo experiment, the vigilant hHO-1 plasmid or saline was injected intramyocardially into myocardial infarction mice or sham operation mice. After gene transfer, expression of hHO-1 was only detected in the ischemic heart treated with vigilant hHO-1 plasmids. Masson trichrome staining showed significantly fewer fibrotic areas in vigilant hHO-1 plasmids-treated mice compared with saline control (43.0%+/-4.8% versus 62.5%+/-3.3%, P<0.01). The reduction of interstitial fibrosis is accompanied by an increase in myocardial hHO-1 expression in peri-infarct border areas, concomitant with higher Bcl-2 levels and lower Bax, Bak, and caspase 3 levels in the ischemic myocardium compared with saline control. By use of a cardiac catheter, heart from vigilant hHO-1 plasmids-treated mice showed improved recovery of contractile and diastolic performance after myocardial infarction compared with saline control. This study documents the beneficial regulation and therapeutic potential of vigilant plasmid-mediated hHO-1 gene transfer. This novel gene transfer strategy can provide cardiac-specific protection from future repeated bouts of ischemic injury.

  12. Bisoprolol improves perfusion of ischaemic myocardium in anaesthetized pigs.

    PubMed Central

    Sassen, L. M.; den Boer, M. O.; Rensen, R. J.; Saxena, P. R.; Verdouw, P. D.

    1988-01-01

    1. The ability of the cardioselective beta-adrenoceptor antagonist bisoprolol ((+/-)-1-[4-(2-isopropoxyethoxymethyl)-phenoxy]-3-isopropyl-amino -2-propanol hemifumarate, EMD 33512) to suppress isoprenaline-induced increases in heart rate and maximal rate of rise in left ventricular pressure (LVdP/dtmax) was studied in 6 anaesthetized pigs given 4 cumulative doses (16, 64, 256 and 1024 micrograms kg-1). Bisoprolol was about 2 times more effective in suppressing isoprenaline-induced increases in LVdP/dtmax than those in heart rate. 2. In 8 animals which had a partial stenosis of the left anterior descending coronary artery (LADCA), the effects of 3 consecutive doses (50, 200 and 750 micrograms kg-1) of bisoprolol were studied on systemic haemodynamics, regional myocardial perfusion and function. The effects of the drug were compared with those obtained in a group of 9 animals with LADCA stenosis which did not receive any treatment. 3. The lowest dose of bisoprolol (50 micrograms kg-1) increased perfusion of the ischaemic myocardium (which had been reduced from 123 +/- 20 ml min-1 100 g-1 to 42 +/- 11 ml min-1 100 g-1) by 21 +/- 10 ml min-1 100 g-1 (P less than 0.05). In particular the subendocardial layers, which were most severely affected by the stenosis (a decrease from 128 +/- 19 ml min-1 100 g-1 to 20 +/- 6 ml min-1 100 g-1) benefited from the administration of the drug (an increase of 30 +/- 10 ml min-1 100 g-1). Perfusion of the subepicardium was not significantly affected. With the higher dose only a minor additional improvement in perfusion of the ischaemic myocardium was observed. 4. The negative chronotropic response is the most likely factor leading to the improvement in perfusion. 5. Myocardial wall thickening, which decreased from 41 +/- 2% to 9 +/- 4% (P less than 0.05) due to the hypoperfusion, did not improve after administration of the drug. This lack of improvement may possibly be due to the duration of ischaemia before and the magnitude of the

  13. Regional left ventricular filling: Does it reflect diastolic abnormalities in contiguous areas of myocardium

    SciTech Connect

    Brown, E.J. Jr.; Idoine, J.; Swinford, R.D.; Pollack, W.M.; Lawson, W.E.; Shatkin, B.; Oster, Z.H.; Atkins, H.L.; Cohn, P.F.

    1989-02-01

    To test the hypothesis that regional left ventricular filling reflects diastolic changes in contiguous areas of myocardium, we performed radionuclide ventriculograms on normal subjects, patients with left anterior descending coronary artery disease, and patients with anteroseptal myocardial infarctions. We reasoned that because diastolic properties of the anteroseptal myocardium should be different in the three groups of patients, regional filling in the anteroseptal area of the left ventricle should also be different, if regional filling does, indeed, reflect diastolic changes in the adjacent myocardium. While anteroseptal regional filling in the normal subjects was different than regional filling in the two patient groups, the degree of filling abnormality was similar in patients with and without myocardial infarctions. Our results suggest that regional left ventricular filling is not exclusively determined by diastolic changes in contiguous areas of myocardium.

  14. Left ventricular dysfunction in ischemic heart disease: fundamental importance of the fibrous matrix.

    PubMed

    Swan, H J

    1994-05-01

    The contractile function of the myocardium is coordinated by a fibrous matrix of exquisite organization and complexity. In the normal heart, and apparently in physiological hypertrophy, this matrix is submicroscopic. In pathological states changes are frequent, and usually progressive. Thickening of the many elements of the fine structure is due to an increased synthesis of Type I collagen, This change, which affects the myocardium in a global manner, can be observed by light microscopy using special techniques. Perivascular fibrosis, with an increase in vascular smooth muscle, is accompanied by development of fibrous septa, with a decrease in diastolic compliance. These structural changes are believed to be due to increased activation of the renin-angiotensin-aldosterone system, and to be independent of the processes of myocyte hypertrophy. Reparative or replacement fibrosis is a separate process by means of which small and large areas of necrosis heal, with the development of coarse collagen structures, which lack a specific organizational pattern. Regarding ischemic heart disease, an increase in tissue collagenase is found in experimental myocardial "stunning" and in the very early phase of acute infarction. Absence of elements of the fibrous matrix allow for myocyte slippage, and--if the affected area is large--cardiac dilatation. If, subsequently, the necrosis becomes transmural, there is further disturbance of collagen due to both mechanical strain and continued autolysis, During healing collagen synthesis increases greatly to allow for reparative scarring in the available tissue matrix. In cases of infarction with moderate or severe initial dilatation, pathological hypertrophy of the spared myocardium is progressive, accounting for late heart failure and poor survival.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Etiology of maxillary canine impaction: a review.

    PubMed

    Becker, Adrian; Chaushu, Stella

    2015-10-01

    This article is a review that enumerates the causes of impaction of the maxillary permanent canines, including hard tissue obstructions, soft tissue lesions, and anomalies of neighboring teeth, and discusses the much-argued relationship between environmental and genetic factors. These phenomena have been shown in many investigations to accompany the diagnosis of canine impaction and have been presented as unrelated anomalous features, each of which is etiologically construed as genetic, including the aberrant canine itself. While in general the influence of genetics pervades the wider picture, a guidance theory proposes an alternative etiologic line of reasoning and interpretation of these studies, in which the same genetically determined anomalous features provide an abnormal milieu in which the canine is reared and from which it is guided in its misdirected and often abortive path of eruption. PMID:26432311

  16. Canine atopic dermatitis - what have we learned?

    PubMed

    Nuttall, Tim; Uri, Maarja; Halliwell, Richard

    2013-02-23

    Canine atopic dermatitis is a complex multifactorial disease. Here, Tim Nuttall, Maarja Uri and Richard Halliwell, representing three generations of veterinary dermatologists, describe the research underpinning our understanding of the condition and highlight its relevance to clinical practice.

  17. Coagulating activity of the blood, vascular wall, and myocardium under hypodynamia conditions

    NASA Technical Reports Server (NTRS)

    Petrovskiy, B. V. (Editor); Chazov, E. I. (Editor); Andreyev, S. V. (Editor)

    1980-01-01

    In order to study the effects of hypodynamia on the coagulating properties of the blood, vascular wall, and myocardium, chinchilla rabbits were kept for varying periods in special cages which restricted their movements. At the end of the experiment, blood samples were taken and the animals were sacrificed. Preparations were made from the myocardium venae cavae, and layers of the aorta. Two resultant interrelated and mutually conditioned syndromes were discovered: thrombohemorrhagic in the blood and hemorrago-thrombotic in the tissues.

  18. Remodeling of the myocardium in early trabeculation and cardiac valve formation; a role for TGFβ2.

    PubMed

    Kruithof, Boudewijn P T; Kruithof-De-Julio, Marianna; Poelmann, Robert E; Gittenberger-De-Groot, Adriana C; Gaussin, Vinciane; Goumans, Marie-José

    2013-01-01

    Trabeculation and the formation of the leaflets of the mitral and tricuspid valves both involve remodeling of the embryonic myocardium. The nature and possible connection of these myocardial remodeling processes, however, are unclear. Therefore, we examined the morphogenesis of the early ventricular and atrioventricular (AV) myocardium and report for the first time that the formation of the early trabeculae and the positioning of the valve primordia (endocardial cushions) into the ventricular lumen are part of one continuous myocardial remodeling process, which involves the dissociation of the myocardial layers. For the endocardial cushions, this process results in delamination from the AV myocardium. The AV myocardium that will harbor the right lateral cushion is the exception and becomes positioned in the ventricular lumen by folding of the right ventricle. As a consequence, remodeling of the left and right AV myocardium occurs differently with implications for the formation of the mural leaflets and annulus fibrosis. At both the right and left side, the valvular myocardium harbors a distinct molecular phenotype and its removal from the cardiac leaflets involves a second wave of delamination. Interestingly, in the TGFβ2-KO mouse, which is a known model for cushion and valve defects, remodeling of the early myocardium is disturbed as indicated by defective trabeculae formation, persistence of valvular myocardium, disturbed myocardial phenotypes and differential defects at left and right side of the AV canal. Based on these results we propose a new model clarifying early trabeculae formation and AV valve formation and provide new inroads for an enhanced understanding of congenital heart defects.

  19. Arterial ischemic stroke in HIV

    PubMed Central

    Bryer, Alan; Lucas, Sebastian; Stanley, Alan; Allain, Theresa J.; Joekes, Elizabeth; Emsley, Hedley; Turnbull, Ian; Downey, Colin; Toh, Cheng-Hock; Brown, Kevin; Brown, David; Ison, Catherine; Smith, Colin; Corbett, Elizabeth L.; Nath, Avindra; Heyderman, Robert S.; Connor, Myles D.; Solomon, Tom

    2016-01-01

    HIV infection, and potentially its treatment, increases the risk of an arterial ischemic stroke. Multiple etiologies and lack of clear case definitions inhibit progress in this field. Several etiologies, many treatable, are relevant to HIV-related stroke. To fully understand the mechanisms and the terminology used, a robust classification algorithm to help ascribe the various etiologies is needed. This consensus paper considers the strengths and limitations of current case definitions in the context of HIV infection. The case definitions for the major etiologies in HIV-related strokes were refined (e.g., varicella zoster vasculopathy and antiphospholipid syndrome) and in some instances new case definitions were described (e.g., HIV-associated vasculopathy). These case definitions provided a framework for an algorithm to help assign a final diagnosis, and help classify the subtypes of HIV etiology in ischemic stroke. PMID:27386505

  20. Uptake and distribution of a labeled fatty acid in a canine model of ischemia with and without reperfusion

    SciTech Connect

    Devous, M.D. Sr.

    1985-05-01

    The relationship between regional myocardial blood flow (RMBF) and the regional distribution of 15-(4-iodophenyl)-9-methyl pentadecanoic acid (9-MPDA) was studied in a canine model of myocardial ischemia with and without reperfusion. Group 1 dogs received 135 min of left anterior descending coronary artery (LAD) occlusion; Group 2 dogs received 90 min of LAD occlusion and 45 min of reflow; and Group 3 dogs received 90 min of LAD occlusion and 3.5 hr of reperfusion. All animals received 9-MPDA 15 min prior to sacrifice, and tracer microspheres prior to occlusion, 5 and 80 min after occlusion, 15 min after reperfusion, and 15 min before the end of reperfusion. In Group 1 (permanent ischemia), 9-MPDA distribution was closely correlated with RMBF both 5 and 80 min after occlusion. In Group 2, 9-MPDA uptake was most closely correlated with reperfusion RMBF rather than ischemic RMBF. However, in 1 animal with good reperfusion, 9-MPDA uptake was reduced and was correlated with ischemic blood flow measured 5 min after occlusion. In Group 3, 9-MPDA uptake was correlated with RMBF measured during the ischemic period and not with reperfusion RMBF. It appears that 9-MPDA uptake is determined by RMBF when flow is limited, or early in reperfusion. With prolonged reperfusion, 9-MPDA uptake is significantly reduced in the ischemic zone in the presence of normal flow. This finding implies that the uptake of this fatty acid during reperfusion is related to myocardial damage (myocardial metabolism.) and not to RMBF.

  1. [Nonsurgical endodontic treatment of an invaginated canine].

    PubMed

    Fernández Guerrero, F; Miñana Laliga, R; Bullon Fernandez, P

    1989-01-01

    We present a case of a maxillary canine with a dens invaginatus treated successfully. The patient had pain, swelling and a sinus tract coming from the inmature apex of the canine. The canals were enlarged and cleaned and the main canal was filled with Calcium Hydroxide to allow the root development. Seven months later, the patient was asymptomatic and the tooth was obturated with guttapercha. One year later it was confirm the success in the treatment.

  2. Proliferative histiocytic disorders of canine skin.

    PubMed

    Middleton, D J

    1997-06-01

    Proliferative histiocytic disorders of canine skin present a clinical spectrum from the innocuous self-limiting solitary dermal lesion of cutaneous histiocytoma, through the recurrent deep dermal nodules of cutaneous histiocytosis to the generally fatal condition of Bernese Mountain Dogs termed systemic histiocytosis, in which visceral involvement is commonly encountered. Immunocytochemical characterization of the constituent histiocytic cells and accompanying lymphoid infiltrate using canine species specific reagents has elucidated considerably the mechanism by which these conditions exhibit their various biologic behaviours.

  3. [Nonsurgical endodontic treatment of an invaginated canine].

    PubMed

    Fernández Guerrero, F; Miñana Laliga, R; Bullon Fernandez, P

    1989-01-01

    We present a case of a maxillary canine with a dens invaginatus treated successfully. The patient had pain, swelling and a sinus tract coming from the inmature apex of the canine. The canals were enlarged and cleaned and the main canal was filled with Calcium Hydroxide to allow the root development. Seven months later, the patient was asymptomatic and the tooth was obturated with guttapercha. One year later it was confirm the success in the treatment. PMID:2638021

  4. Probing myocardium biomechanics using quantitative optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

    2015-03-01

    We present a quantitative optical coherence elastographic method for noncontact assessment of the myocardium elasticity. The method is based on shear wave imaging optical coherence tomography (SWI-OCT), where a focused air-puff system is used to induce localized tissue deformation through a low-pressure short-duration air stream and a phase-sensitive OCT system is utilized to monitor the propagation of the induced tissue displacement with nanoscale sensitivity. The 1-D scanning of M-mode OCT imaging and the application of optical phase retrieval and mapping techniques enable the reconstruction and visualization of 2-D depth-resolved shear wave propagation in tissue with ultra-high frame rate. The feasibility of this method in quantitative elasticity measurement is demonstrated on tissue-mimicking phantoms with the estimated Young's modulus compared with uniaxial compression tests. We also performed pilot experiments on ex vivo mouse cardiac muscle tissues with normal and genetically altered cardiomyocytes. Our results indicate this noncontact quantitative optical coherence elastographic method can be a useful tool for the cardiac muscle research and studies.

  5. Robust left ventricular myocardium segmentation for multi-protocol MR

    NASA Astrophysics Data System (ADS)

    Groth, A.; Weese, J.; Lehmann, H.

    2012-02-01

    For a number of cardiac procedures like the treatments of ventricular tachycardia (VT), coronary artery disease (CAD) and heart failure (HF) both anatomical as well as vitality information about the left ventricular myocardium are required. To this end, two images for the anatomical and functional information, respectively, must be acquired and analyzed, e.g. using two different 3D MR protocols. To enable automatic analysis, a workflow has been proposed1 which allows to integrate the vitality information extracted from the functional image data into a patient-specific anatomical model generated from the anatomical image. However, in the proposed workflow the extraction of accurate vitality information from the functional image depends to a large extend on the accuracy of both the anatomical model and the mapping of the model to the functional image. In this paper we propose and evaluate methods for improving these two aspects. More specifically, on one hand we aim to improve the segmentation of the often low-contrast left ventricular epicardium in the anatomical 3D MR images by introducing a patient-specific shape-bias. On the other hand, we introduce a registration approach that facilitates the mapping of the anatomical model to images acquired by different protocols and modalities, such as functional 3D MR. The new methods are evaluated on clinical MR data, for which considerable improvements can be achieved.

  6. Using Gabor filter banks and temporal-spatial constraints to compute 3D myocardium strain.

    PubMed

    Chen, Ting; Axel, Leon

    2006-01-01

    In this paper, we describe a new approach for reconstructing 3D strains in the myocardium using tagged MR images. We first segment the myocardium using a 3D deformable model driven by image gradients and Gabor filter responses. Tags are automatically detected and tracked as deformable thin plates during systole and early diastole. To keep the tracking results more stable and consistent, we use a combination of gradient information, an intensity probabilistic model, the phase information, and a temporal-spatial smoothness constraint. Based on the tag deformation, we compute a dense displacement in the myocardium around both ventricles. The displacements in x-, y-, and z- directions are calculated separately and are combined to form the final displacement maps. We do not use the information outside the segmented surface of the myocardium to avoid displacement errors caused by noises, artifacts, and correlations between different regions in the myocardium. The strain in the myocardium during the heart cycle is derived from the displacement. This method accepts images of either a tag grid or separate horizontal and vertical tag lines as its input. Experimental results on phantom and real data demonstrate good performance of this method in calculating the myocardial strain.

  7. Hyperacute management of ischemic stroke.

    PubMed

    Song, Sarah

    2013-11-01

    Stroke is a devastating disease and currently the fourth leading cause of death in this country. Acute ischemic stroke is an emergency and requires effective triage, diagnosis, and critical management. The hyperacute management of ischemic stroke begins in the field, with recognition of stroke symptoms by emergency medical systems (EMS) personnel. The EMS is an important component to an effective stroke system of care, which also includes primary stroke centers, routing protocols for acute ischemic stroke, and telemedicine. Following the arrival of a potential stroke patient to the emergency room setting, patients should be stabilized and undergo assessment for potential intravenous alteplase (IV tPA) treatment. Assessments include diagnostic tests, neuroimaging, and standardized stroke evaluations. After these assessments have been performed, IV tPA, the only medication for acute stroke approved by the U.S. Food and Drug Administration, can be considered using a variety of inclusion and exclusion criteria. Previously time restrictions limited the usage of IV tPA to 3 hours, but this time window has now been extended for eligible candidates to 4.5 hours. The administration of IV tPA has specific requirements for monitoring and should be standardized via protocol across hospitals.

  8. [Ischemic cerebrovascular accidents in childhood].

    PubMed

    Pascual Pascual, S I; Pascual Castroviejo, I; Vélez, A

    1988-04-01

    Authors review 53 children, aged 0 to 14 years, affected with cerebrovascular ischemic strokes. Largest aetiological groups were: a) congenital heart disease, 16 patients; b) arteritis of unknown cause, 11; c) idiopathic arterial occlusion without arteritis images on angiography, 7; d) moyamoya disease, 6; and d) local or systemic infections, 5. The mode of onset was as completed stroke in 72% and stroke in evolution in 24%. After acute stage 17.6% of patients presented other definitive strokes, 11.7% suffered only transient ischemic strokes (TIA), and 4% reversible ischemic neurologic deficits (RIND). Mean follow-up was 4.36 years, 9.8% of patients died, 11.8% recovered completely and 52.9% improved after initial stroke. Poor global evolution was associated with heart disease (p less than 0.05) and with onset of strokes before age 2 (p less than 0.05). Most important sequelae, besides motor impairment, were epilepsy (49%) and mental retardation (50% got less than IQ 80). Late epilepsy was associated with seizures at onset (p less than 0.05). Clinical factors of adverse mental development were: a) seizures at onset, b) late epilepsy and c) stroke before age 2. 66% of cases had two or more arterial lesions in the same or in different arterial trees. Therefore, embolic and arteritic factors probably play an important role in infancy and childhood stroke. PMID:3400936

  9. Environmental contamination by canine geohelminths

    PubMed Central

    2014-01-01

    Intestinal nematodes affecting dogs, i.e. roundworms, hookworms and whipworms, have a relevant health-risk impact for animals and, for most of them, for human beings. Both dogs and humans are typically infected by ingesting infective stages, (i.e. larvated eggs or larvae) present in the environment. The existence of a high rate of soil and grass contamination with infective parasitic elements has been demonstrated worldwide in leisure, recreational, public and urban areas, i.e. parks, green areas, bicycle paths, city squares, playgrounds, sandpits, beaches. This review discusses the epidemiological and sanitary importance of faecal pollution with canine intestinal parasites in urban environments and the integrated approaches useful to minimize the risk of infection in different settings. PMID:24524656

  10. Environmental contamination by canine geohelminths.

    PubMed

    Traversa, Donato; Frangipane di Regalbono, Antonio; Di Cesare, Angela; La Torre, Francesco; Drake, Jason; Pietrobelli, Mario

    2014-01-01

    Intestinal nematodes affecting dogs, i.e. roundworms, hookworms and whipworms, have a relevant health-risk impact for animals and, for most of them, for human beings. Both dogs and humans are typically infected by ingesting infective stages, (i.e. larvated eggs or larvae) present in the environment. The existence of a high rate of soil and grass contamination with infective parasitic elements has been demonstrated worldwide in leisure, recreational, public and urban areas, i.e. parks, green areas, bicycle paths, city squares, playgrounds, sandpits, beaches. This review discusses the epidemiological and sanitary importance of faecal pollution with canine intestinal parasites in urban environments and the integrated approaches useful to minimize the risk of infection in different settings. PMID:24524656

  11. CANINE: a robotic mine dog

    NASA Astrophysics Data System (ADS)

    Stancil, Brian A.; Hyams, Jeffrey; Shelley, Jordan; Babu, Kartik; Badino, Hernán.; Bansal, Aayush; Huber, Daniel; Batavia, Parag

    2013-01-01

    Neya Systems, LLC competed in the CANINE program sponsored by the U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) which culminated in a competition held at Fort Benning as part of the 2012 Robotics Rodeo. As part of this program, we developed a robot with the capability to learn and recognize the appearance of target objects, conduct an area search amid distractor objects and obstacles, and relocate the target object in the same way that Mine dogs and Sentry dogs are used within military contexts for exploration and threat detection. Neya teamed with the Robotics Institute at Carnegie Mellon University to develop vision-based solutions for probabilistic target learning and recognition. In addition, we used a Mission Planning and Management System (MPMS) to orchestrate complex search and retrieval tasks using a general set of modular autonomous services relating to robot mobility, perception and grasping.

  12. Biomarkers in canine parvovirus enteritis.

    PubMed

    Schoeman, J P; Goddard, A; Leisewitz, A L

    2013-07-01

    Canine parvovirus (CPV) enteritis has, since its emergence in 1978, remained a common and important cause of morbidity and mortality in young dogs. The continued incidence of parvoviral enteritis is partly due to the virus' capability to evolve into more virulent and resistant variants with significant local gastrointestinal and systemic inflammatory sequelae. This paper reviews current knowledge on historical-, signalment-, and clinical factors as well as several haematological-, biochemical- and endocrine parameters that can be used as diagnostic and prognostic biomarkers in CPV enteritis. These factors include season of presentation, purebred nature, bodyweight, vomiting, leukopaenia, lymphopaenia, thrombocytopaenia, hypercoagulability, hypercortisolaemia, hypothyroxinaemia, hypoalbuminaemia, elevated C-reactive protein and tumour necrosis factor, hypocholesterolaemia and hypocitrullinaemia. Factors contributing to the manifestations of CPV infection are multiple with elements of host, pathogen, secondary infections, underlying stressors and environment affecting severity and outcome. The availability of several prognosticators has made identification of patients at high risk of death and their subsequent targeted management more rewarding.

  13. Age estimation from canine volumes.

    PubMed

    De Angelis, Danilo; Gaudio, Daniel; Guercini, Nicola; Cipriani, Filippo; Gibelli, Daniele; Caputi, Sergio; Cattaneo, Cristina

    2015-08-01

    Techniques for estimation of biological age are constantly evolving and are finding daily application in the forensic radiology field in cases concerning the estimation of the chronological age of a corpse in order to reconstruct the biological profile, or of a living subject, for example in cases of immigration of people without identity papers from a civil registry. The deposition of teeth secondary dentine and consequent decrease of pulp chamber in size are well known as aging phenomena, and they have been applied to the forensic context by the development of age estimation procedures, such as Kvaal-Solheim and Cameriere methods. The present study takes into consideration canines pulp chamber volume related to the entire teeth volume, with the aim of proposing new regression formulae for age estimation using 91 cone beam computerized scans and a freeware open-source software, in order to permit affordable reproducibility of volumes calculation.

  14. Canine Cytogenetics - From band to basepair

    PubMed Central

    Breen, Matthew

    2008-01-01

    Humans and dogs have coexisted for thousands of years, during which time we have developed a unique bond, centered on companionship. Along the way, we have developed purebred dog breeds in a manner that has resulted unfortunately in many of them being affected by serious genetic disorders, including cancers. With serendipity and irony the unique genetic architecture of the 21st Century genome of Man's best friend may ultimately provide many of the keys to unlock some of nature's most intriguing biological puzzles. Canine cytogenetics has advanced significantly over the past 10 years, spurred on largely by the surge of interest in the dog as a biomedical model for genetic disease and the availability of advanced genomics resources. As such the role of canine cytogenetics has moved rapidly from one that served initially to define the gross genomic organization of the canine genome and provide a reliable means to determine the chromosomal location of individual genes, to one that enabled the assembled sequence of the canine genome to be anchored to the karyotype. Canine cytogenetics now presents the biomedical research community with a means to assist in our search for a greater understanding of how genome architectures altered during speciation and in our search for genes associated with cancers that affect both dogs and humans. The cytogenetics ‘toolbox’ for the dog is now loaded. This review aims to provide a summary of some of the recent advancements in canine cytogenetics. PMID:18467825

  15. [The features of myocardial deformation of left ventricle in patients with ischemic heart disease defined by the two dimensional strain method].

    PubMed

    Galimskaia, V A; Donchenko, I A; Romanovskaia, E M; Oleĭnikov, V É

    2014-01-01

    Aim of this study was to assess qualitative and quantitative features of deformation parameters of left ventricular myocardium in patients with ischemic heart disease (IHD) with and without history of myocardial infarction (MI) using two-dimensional strain imaging. We examined 30 patients with clinical IHD with (group 1, n = 15) and without (group 2, n = 15) history of MI and 20 healthy volunteers. Compared with healthy subjects IHD patients of both groups had reduced longitudinal and circular myocardial deformation. There were no significant differences between patients with IHD and controls in parameters of radial, global, and regional deformation.

  16. Echocardiographic assessment of ischemic mitral regurgitation.

    PubMed

    Dudzinski, David M; Hung, Judy

    2014-01-01

    Ischemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction. Echocardiographic diagnosis and assessment of ischemic mitral regurgitation are critical to gauge its adverse effects on prognosis and to attempt to tailor rational treatment strategy. There is no single approach to the echocardiographic assessment of ischemic mitral regurgitation: standard echocardiographic measures of mitral regurgitation severity and of LV dysfunction are complemented by assessments of displacement of the papillary muscles and quantitative indices of mitral valve deformation. Development of novel approaches to understand mitral valve geometry by echocardiography may improve understanding of the mechanism, clinical trajectory, and reparability of ischemic mitral regurgitation.

  17. Structure and vascularization of the ventricular myocardium in Holocephali: their evolutionary significance.

    PubMed

    Durán, Ana C; López-Unzu, Miguel A; Rodríguez, Cristina; Fernández, Borja; Lorenzale, Miguel; Linares, Andrea; Salmerón, Francisca; Sans-Coma, Valentín

    2015-06-01

    It was generally assumed that the ventricle of the primitive vertebrate heart was composed of trabeculated, or spongy, myocardium, supplied by oxygen-poor luminal blood. In addition, it was presumed that the mixed ventricular myocardium, consisting of a compacta and a spongiosa, and its supply through coronary arteries appeared several times throughout fish evolution. Recent work has suggested, however, that a fully vascularized, mixed myocardium may be the primitive condition in gnathostomes. The present study of the heart ventricles of four holocephalan species aimed to clarify this controversy. Our observations showed that the ventricular myocardium of Chimaera monstrosa and Harriotta raleighana consists of a very thin compacta overlying a widespread spongiosa. The ventricle of Hydrolagus affinis is composed exclusively of trabeculated myocardium. In these three species there is a well-developed coronary artery system. The main coronary artery trunks run along the outflow tract, giving off subepicardial ventricular arteries. The trabeculae of the spongiosa are irrigated by branches of the subepicardial arteries and by penetrating arterial vessels arising directly from the main coronary trunks at the level of the conoventricular junction. The ventricle of Rhinochimaera atlantica has only spongy myocardium supplied by luminal blood. Small coronary arterial vessels are present in the subepicardium, but they do not enter the myocardial trabeculae. The present findings show for the first time that in a wild living vertebrate species, specifically H. affinis, an extensive coronary artery system supplying the whole cardiac ventricle exists in the absence of a well-developed compact ventricular myocardium. This is consistent with the notion derived from experimental work that myocardial cell proliferation and coronary vascular growth rely on distinct developmental programs. Our observations, together with data in the literature on elasmobranchs, support the view that

  18. Patency of heart blood vessels under photosensitization reaction shortly after intravenous injection of talaporfin sodium in canine model

    NASA Astrophysics Data System (ADS)

    Hamada, Risa; Matsuzaki, Ryota; Ogawa, Emiyu; Arai, Tsunenori

    2016-03-01

    In order to investigate patency of heart blood vessels by photosensitization reaction shortly after intravenous injection of talaporfin sodium, we performed in vitro endothelial cell lethality study and in vivo study of heart blood vessel patency in canine one week after photosensitization reaction. Cell lethality of human umbilical vein endothelial cells under different albumin concentrations corresponding with blood and interstice concentrations were employed and their lethality 2 hours after the reaction was measured by WST assay in vitro. Almost all cells survived by 40 J/cm2 photosensitization reaction with blood albumin concentration. Laser diffuser made of plastic optical fiber with 70 mm in length was used in vivo. Red diode laser of 664nm wavelength was emitted from this diffuser with 17.1-42.9 mW/cm in 10 minutes. We estimated the fluence rate distribution by a ray-trace simulator using pre-measured optical coefficients of myocardium tissue, μa 0.12 mm-1 and μs' 0.36 mm-1. Almost all blood vessels were patent in every irradiation conditions in canine heart. Coronary artery and vein up to 1 mm diameter were patent in typical myocardium sample with 25.7 mW/cm. We estimated fluence rate distribution of this sample and found that blood vessels were patent even fluence rate over 40 J/cm2. This in vivo study could be explained by the result of in vitro study. We suggest that this blood vessel patency after our particular photosensitization reaction might be because of few photosensitizer uptake in the blood endothelial cells and/or reduced oxidation damage by thick albumin concentration in blood.

  19. Pioglitazone after Ischemic Stroke or Transient Ischemic Attack

    PubMed Central

    Kernan, W.N.; Viscoli, C.M.; Furie, K.L.; Young, L.H.; Inzucchi, S.E.; Gorman, M.; Guarino, P.D.; Lovejoy, A.M.; Peduzzi, P.N.; Conwit, R.; Brass, L.M.; Schwartz, G.G.; Adams, H.P.; Berger, L.; Carolei, A.; Clark, W.; Coull, B.; Ford, G.A.; Kleindorfer, D.; O’Leary, J.R.; Parsons, M.W.; Ringleb, P.; Sen, S.; Spence, J.D.; Tanne, D.; Wang, D.; Winder, T.R.

    2016-01-01

    BACKGROUND Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease. METHODS In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction. RESULTS By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P = 0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; P<0.001). There was no significant between-group difference in all-cause mortality (hazard ratio, 0.93; 95% CI, 0.73 to 1.17; P = 0.52). Pioglitazone was associated with a greater frequency of weight gain exceeding 4.5 kg than was placebo (52.2% vs. 33.7%, P<0.001), edema (35.6% vs. 24.9%, P<0.001), and bone fracture requiring surgery or hospitalization (5.1% vs. 3.2%, P = 0.003). CONCLUSIONS In this trial involving patients without diabetes who had insulin resistance along with a recent history of ischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of

  20. Pyruvate-dependent preconditioning and cardioprotection in murine myocardium.

    PubMed

    Flood, Amanda; Hack, Benjamin D; Headrick, John P

    2003-03-01

    1. Whether pyruvate inhibits or can actually initiate myocardial preconditioning is unclear and whether pyruvate provides protection via its action as a 'cosubstrate' with glucose or via alternative mechanisms also remains controversial. We examined effects of a high concentration of pyruvate (10 mmol/L) alone or with 15 mmol/L glucose in mouse hearts subjected to 20 min ischaemia and 30 min reperfusion. 2. Provision of 10 mmol/L pyruvate alone or as a cosubstrate markedly reduced ischaemic contracture and enhanced postischaemic recovery. Time to contracture was increased from approximately 3 min to over 8 min, peak contracture was reduced from 90 mmHg to less than 60 mmHg and postischaemic pressure development was also improved. Effects on contracture were independent of the presence of pyruvate during ischaemia and improved postischaemic recovery was evident with pre-ischaemic pyruvate perfusion. 3. Cardioprotection did not require the presence of pyruvate during ischaemia or reperfusion and effects of pyruvate pretreatment could be mimicked by pretreatment with 1 mmol/L dichloroacetate (DCA), an activator of pyruvate dehydrogenase. 4. Myocardial adenosine efflux and Ca2+ content were elevated (by 215 and 65%, respectively) following pretreatment with pyruvate, potentially triggering a preconditioned state. A role for adenosine A1 receptors is supported by lack of added protection with pyruvate in hearts transgenically overexpressing adenosine A1 receptors. 5. Collectively, these observations demonstrate that pre-ischaemic treatment with pyruvate or DCA provides a beneficial preconditioning-like effect in ischaemic and postischaemic myocardium. The response appears unrelated to glycolytic inhibition, but may be mediated via transient changes in adenosine levels and/or cellular Ca2+.

  1. Luteolin Limits Infarct Size and Improves Cardiac Function after Myocardium Ischemia/Reperfusion Injury in Diabetic Rats

    PubMed Central

    Gao, Haokao; Li, Jiayi; Shen, Min; Cao, Feng; Wang, Haichang

    2012-01-01

    Background The present study was to investigate the effects and mechanism of Luteolin on myocardial infarct size, cardiac function and cardiomyocyte apoptosis in diabetic rats with myocardial ischemia/reperfusion (I/R) injury. Methodology/Principal Findings Diabetic rats underwent 30 minutes of ischemia followed by 3 h of reperfusion. Animals were pretreated with or without Luteolin before coronary artery ligation. The severity of myocardial I/R induced LDH release, arrhythmia, infarct size, cardiac function impairment, cardiomyocyte apoptosis were compared. Western blot analysis was performed to elucidate the target proteins of Luteolin. The inflammatory cytokine production were also examined in ischemic myocardium underwent I/R injury. Our results revealed that Luteolin administration significantly reduced LDH release, decreased the incidence of arrhythmia, attenuated myocardial infarct size, enhanced left ventricular ejection fraction and decreased myocardial apoptotic death compared with I/R group. Western blot analysis showed that Luteolin treatment up-regulated anti-apoptotic proteins FGFR2 and LIF expression, increased BAD phosphorylation while decreased the ratio of Bax to Bcl-2. Luteolin treatment also inhibited MPO expression and inflammatory cytokine production including IL-6, IL-1a and TNF-a. Moreover, co-administration of wortmannin and Luteolin abolished the beneficial effects of Luteolin. Conclusions/Significance This study indicates that Luteolin preserves cardiac function, reduces infarct size and cardiomyocyte apoptotic rate after I/R injury in diabetic rats. Luteolin exerts its action by up-regulating of anti-apoptotic proteins FGFR2 and LIF expression, activating PI3K/Akt pathway while increasing BAD phosphorylation and decreasing ratio of Bax to Bcl-2. PMID:22432030

  2. Serological detection of infection with canine distemper virus, canine parvovirus and canine adenovirus in communal dogs from Zimbabwe.

    PubMed

    McRee, Anna; Wilkes, Rebecca P; Dawson, Jessica; Parry, Roger; Foggin, Chris; Adams, Hayley; Odoi, Agricola; Kennedy, Melissa A

    2014-01-01

    Domestic dogs are common amongst communities in sub-Saharan Africa and may serve as important reservoirs for infectious agents that may cause diseases in wildlife. Two agents of concern are canine parvovirus (CPV) and canine distemper virus (CDV), which may infect and cause disease in large carnivore species such as African wild dogs and African lions, respectively. The impact of domestic dogs and their diseases on wildlife conservation is increasing in Zimbabwe, necessitating thorough assessment and implementation of control measures. In this study, domestic dogs in north-western Zimbabwe were evaluated for antibodies to CDV, CPV, and canine adenovirus (CAV). These dogs were communal and had no vaccination history. Two hundred and twenty-five blood samples were collected and tested using a commercial enzyme-linked immunosorbent assay (ELISA) for antibodies to CPV, CDV, and CAV. Of these dogs, 75 (34%) had detectable antibodies to CDV, whilst 191 (84%) had antibodies to CPV. Antibodies to canine adenovirus were present in 28 (13%) dogs. Canine parvovirus had high prevalence in all six geographic areas tested. These results indicate that CPV is circulating widely amongst domestic dogs in the region. In addition, CDV is present at high levels. Both pathogens can infect wildlife species. Efforts for conservation of large carnivores in Zimbabwe must address the role of domestic dogs in disease transmission. PMID:25686382

  3. Serological detection of infection with canine distemper virus, canine parvovirus and canine adenovirus in communal dogs from Zimbabwe.

    PubMed

    McRee, Anna; Wilkes, Rebecca P; Dawson, Jessica; Parry, Roger; Foggin, Chris; Adams, Hayley; Odoi, Agricola; Kennedy, Melissa A

    2014-01-01

    Domestic dogs are common amongst communities in sub-Saharan Africa and may serve as important reservoirs for infectious agents that may cause diseases in wildlife. Two agents of concern are canine parvovirus (CPV) and canine distemper virus (CDV), which may infect and cause disease in large carnivore species such as African wild dogs and African lions, respectively. The impact of domestic dogs and their diseases on wildlife conservation is increasing in Zimbabwe, necessitating thorough assessment and implementation of control measures. In this study, domestic dogs in north-western Zimbabwe were evaluated for antibodies to CDV, CPV, and canine adenovirus (CAV). These dogs were communal and had no vaccination history. Two hundred and twenty-five blood samples were collected and tested using a commercial enzyme-linked immunosorbent assay (ELISA) for antibodies to CPV, CDV, and CAV. Of these dogs, 75 (34%) had detectable antibodies to CDV, whilst 191 (84%) had antibodies to CPV. Antibodies to canine adenovirus were present in 28 (13%) dogs. Canine parvovirus had high prevalence in all six geographic areas tested. These results indicate that CPV is circulating widely amongst domestic dogs in the region. In addition, CDV is present at high levels. Both pathogens can infect wildlife species. Efforts for conservation of large carnivores in Zimbabwe must address the role of domestic dogs in disease transmission.

  4. Distinct microRNA expression signatures in human right atrial and ventricular myocardium.

    PubMed

    Zhang, Yangyang; Wang, Xiaowei; Xu, Xiaohan; Wang, Jun; Liu, Xiang; Chen, Yijiang

    2012-12-01

    Human atrial and ventricular myocardium has distinct structure and physiology. MicroRNAs (miRNAs) are the central players in the regulation of gene expression, participating in many physiological processes. A comprehensive knowledge of miRNA expression in the human heart is essential for the understanding of myocardial function. The aim of this study was to compare the miRNA signature in human right atrial and ventricular myocardium. Agilent human miRNA arrays were used to indicate the miRNA expression signatures of the right atrial (n = 8) and ventricular (n = 9) myocardium of healthy individuals. Quantitative reverse transcription-polymerase chain reactions (qRT-PCRs) were used to validate the array results. DIANA-mirPath was used to incorporate the miRNAs into pathways. MiRNA arrays showed that 169 miRNAs were expressed at different levels in human right atrial and ventricular myocardium. The unsupervised hierarchical clustering analysis based on the 169 dysregulated miRNAs showed that miRNA expression categorized two well-defined clusters that corresponded to human right atrial and ventricular myocardium. The qRT-PCR results correlated well with the microarray data. Bioinformatic analysis indicated the potential miRNA targets and molecular pathways. This study indicates that distinct miRNA expression signatures in human right atrial and ventricular myocardium. The findings provide a novel understanding of the molecular differences between human atrial and ventricular myocardium and may establish a framework for an anatomically detailed evaluation of cardiac function regulation.

  5. Diagnostic and prognostic value of 3D NOGA mapping in ischemic heart disease.

    PubMed

    Gyöngyösi, Mariann; Dib, Nabil

    2011-07-01

    The three-dimensional NOGA(®) (Biologics Delivery Systems, a Johnson & Johnson company, Irwindale, CA, USA) electromechanical mapping system simultaneously registers the electrical and mechanical activities of the left ventricle, enabling online assessment of myocardial viability. The system distinguishes between viable, nonviable, stunned, and hibernating myocardium and can assess wall motion. The evaluation of the electrophysiological state of the tissue by NOGA(®) mapping has been validated by comparing the electroanatomical voltage and local linear shortening maps obtained with this technique with several noninvasive diagnostic tests. Bipolar signal analysis and determination of the existence and degree of transmural infarctions are also possible with NOGA(®). Immediately after percutaneous coronary intervention, an increased electromechanical discordance between voltage and local linear shortening maps indicates procedure-induced stunning that is caused by repetitive ischemia or microvascular compromise. Catheter-based direct intramyocardial injection of cells or gene constructs by NOGA(®) reduces the likelihood of systemic toxicity of the injected substance, resulting in minimal washout, limited exposure of nontarget organs, and precise localization to ischemic and peri-ischemic myocardial regions in patients with chronic myocardial ischemia. In addition, direct intramyocardial injection enables the treatment of chronic myocardial infarction by provoking a chemotactic signal at the injection-injury site that contributes to cell engraftment. By measuring the electrical activation pattern in delayed-motion areas, NOGA(®) might also be useful to predict response to cardiac resynchronization therapy. PMID:21587214

  6. Role of platelet-activating factor in polymorphonuclear neutrophil recruitment in reperfused ischemic rabbit heart.

    PubMed

    Montrucchio, G; Alloatti, G; Mariano, F; Comino, A; Cacace, G; Polloni, R; De Filippi, P G; Emanuelli, G; Camussi, G

    1993-02-01

    This study investigated the role of platelet-activating factor in the recruitment of polymorphonuclear neutrophils (PMN) in a rabbit model of cardiac ischemia and reperfusion. The accumulation of PMN was evaluated 2 and 24 hours after removal of 40 minutes of coronary occlusion by morphometric analysis and 111In-labeled PMN infiltration. The administration of two structurally unrelated platelet-activating factor-receptor antagonists (SDZ 63-675, 5 mg/kg body weight, and WEB 2170, 5 mg/kg body weight) before reperfusion significantly reduced the accumulation of PMN, as well as the hemodynamic alterations and the size of necrotic area. Two hours after reperfusion, the percentage of increase of 111In-labeled PMN in transmural central ischemic zone was significantly reduced in rabbits pretreated with SDZ 63-675 (51.4 +/- 7.9) or WEB 2170 (32.4 +/- 8.8) with respect to untreated rabbits (107.6 +/- 13.5). The morphometric analysis of myocardial sections confirmed the reduction of PMN infiltration at 2 hours and demonstrated that at 24 hours the phenomenon was even more significant. In addition, SDZ 63-675 and WEB 2170 prevented early transient bradycardia and hypotension and reduced the infarct size, judged by staining with tetrazolium at 2 and 24 hours after reperfusion, and by histological examination at 24 hours. These results suggest that platelet-activating factor is involved in the accumulation of PMN in the reperfused ischemic myocardium and contributes to the evolution of myocardial injury.

  7. Remote Ischemic Conditioning: Its Benefits and Limitations.

    PubMed

    Kloner, Robert A

    2016-03-01

    This editorial describes benefits and limitations of remote ischemic conditioning. Remote ischemic conditioning was shown to reduce myocardial intact size in at least 4 sizeable clinical trials of acute myocardial infarction. It was not effective in recent studies of cardiac surgery. Reasons for these differences are discussed.

  8. Cerebral ischemic stroke: is gender important?

    PubMed Central

    Gibson, Claire L

    2013-01-01

    Cerebral stroke continues to be a major cause of death and the leading cause of long-term disability in developed countries. Evidence reviewed here suggests that gender influences various aspects of the clinical spectrum of ischemic stroke, in terms of influencing how a patients present with ischemic stroke through to how they respond to treatment. In addition, this review focuses on discussing the various pathologic mechanisms of ischemic stroke that may differ according to gender and compares how intrinsic and hormonal mechanisms may account for such gender differences. All clinical trials to date investigating putative neuroprotective treatments for ischemic stroke have failed, and it may be that our understanding of the injury cascade initiated after ischemic injury is incomplete. Revealing aspects of the pathophysiological consequences of ischemic stroke that are gender specific may enable gender relevant and effective neuroprotective strategies to be identified. Thus, it is possible to conclude that gender does, in fact, have an important role in ischemic stroke and must be factored into experimental and clinical investigations of ischemic stroke. PMID:23756694

  9. Booster effect of canine distemper, canine parvovirus infection and infectious canine hepatitis combination vaccine in domesticated adult dogs.

    PubMed

    Taguchi, Masayuki; Namikawa, Kazuhiko; Maruo, Takuya; Orito, Kensuke; Lynch, Jonathan; Tsuchiya, Ryo; Sahara, Hiroeki

    2012-08-01

    Domesticated adult dogs with antibody titer classified as below 'high' to one or more of canine distemper virus (CDV), canine parvovirus type-2 (CPV-2) and canine adenovirus type-1 (CAdV-1) were then given an additional inoculation, and the effectiveness of this booster evaluated 2 months later. Consequently, CDV and CAdV-1 antibody titer experienced a significant increase, but the same effect was not observed in the antibody titer of CPV-2. These findings suggest that with additional inoculation, a booster effect may be expected in increasing antibody titers for CDV and CAdV-1, but it is unlikely to give an increase in CPV-2 antibody titer.

  10. Orthodontic Traction of Impacted Canine Using Cantilever

    PubMed Central

    Gonçalves, João Roberto; Cassano, Daniel Serra; Bianchi, Jonas

    2016-01-01

    The impaction of the maxillary canines causes relevant aesthetic and functional problems. The multidisciplinary approach to the proper planning and execution of orthodontic traction of the element in question is essential. Many strategies are cited in the literature; among them is the good biomechanical control in order to avoid possible side effects. The aim of this paper is to present a case report in which a superior canine impacted by palatine was pulled out with the aid of the cantilever on the Segmented Arch Technique (SAT) concept. A 14.7-year-old female patient appeared at clinic complaining about the absence of the upper right permanent canine. The proposed treatment prioritized the traction of the upper right canine without changing the occlusion and aesthetics. For this, it only installed the upper fixed appliance (Roth with slot 0.018), opting for SAT in order to minimize unwanted side effects. The use of cantilever to the traction of the upper right canine has enabled an efficient and predictable outcome, because it is of statically determined mechanics. PMID:27800192

  11. Epidemiologic study of canine blastomycosis in Wisconsin.

    PubMed

    Archer, J R; Trainer, D O; Schell, R F

    1987-05-15

    An epidemiologic study was designed to investigate the increasing number of cases of canine blastomycosis being reported in Wisconsin. From January 1980 through July 1982, 200 cases of canine blastomycosis from 39 Wisconsin counties were examined to assess epidemiologic and environmental aspects of this disease. Based on a survey of 176 dog owners, principal disease characteristics for canine blastomycosis were anorexia, lethargy, shortness of breath, chronic cough, and weight loss. The greatest number of cases of canine blastomycosis was in the northwest, north central, northeast, central, and southeast regions of Wisconsin. The northeast and central regions were determined to be new enzootic areas. Sporting breeds accounted for the largest percentage of cases among the various breeds of dogs in Wisconsin. Most of the affected dogs were 3 years old or younger and there was no apparent sexual predilection. Canine blastomycosis was diagnosed more frequently from late spring through late fall. Enzootic areas, except for the southeast region of Wisconsin, were located where the soil was sandy and acid. The results of this study suggested a possible association of enzootic areas with waterways, especially impoundments.

  12. Early changes in contractility and coronary blood flow in the normal areas of the ischemic porcine heart.

    PubMed

    Pashkow, F; Holland, R; Brooks, H

    1977-03-01

    The regional responses of normal myocardium distant from an ischemic area were studied during acute anterior descending occlusion in the open-chest chloralose-anesthetized pig. Three markers of regional response in both normal and ischemic areas were used: surface ECG electrode, a force gauge in series with left ventricular outer wall fibers, and coronary blood inflow to each region as determined by electromagnetic cuff-probes. Following brief anterior descending artery occlusion (120 sec)., a characteristic rapid decline in contractile force and evolution of TQ-ST segment changes was observed in the ischemic area. In contrast, in the distant area increases in contractil force (p less than 0.001) and coronary blood flow (p less than 0.002) occurred. These distant responses were essentially obliterated following transection and cannulation of the artery supplying this region (p less than 0.05). The findings are consistent with a reflex neurovascular mechanism operating within the intact heart. This reflex is rapidly activated in order to maintain adequate levels of cardiac performance despite sudden loss of functional myocardial mass.

  13. [The application of hemoreologic indicators in prognosis of complications of acute myocardium infarction].

    PubMed

    Pakhrova, O A; Kudriashova, M V; Grineva, M R; Mishina, I E

    2015-02-01

    The sampling of 60 patients with acute myocardium infarction underwent a complex study of hemoreologic indicators with purpose to establish predictors of development of early complications of diseases to substantiate additions to algorithm of examination and to differentiate treatment regimens. It is established that under acute myocardium infarction the blood viscosity increases on low velocity of shifting and plasma. Also, the process of aggregation of erythrocytes increases and number of normocytes decreases without significant alterations of blood viscosity on high velocity of shift and capacity of erythrocytes to be distorted. At the same time, the mentioned above alterations in patients with acute myocardium infarction does not result in decreasing of effectiveness oftransportation of oxygen to tissues. Against the background of development the hemoreologic disorders have more apparent character and result in progressive decreasing of tissue perfusion. The most significant prognostic indicator concerning complications of acute myocardium infarction is a time parameter of increment of aggregation of erythrocytes surpassing 2.80 in 89% of patients with complications. The expedience of inclusion of detection of reologic blood indicators fir their subsequent correction in the complex of examination ofpatients with acute myocardium infarction.

  14. Epidemiologic features of canine hypothyroidism.

    PubMed

    Milne, K L; Hayes, H M

    1981-01-01

    This study investigates the epidemiologic features of 3,206 dogs diagnosed with hypothyroidism (including myxedema) from 1.1 million dogs seen at 15 veterinary teaching hospitals between March, 1964 and June, 1978. Nine breeds found to be at high-risk for hypothyroidism were: golden retrievers, Doberman pinschers, dachshunds, Shetland sheepdogs, Irish setters, Pomeranians, miniature schnauzers, cocker spaniels, and Airedales. Two breed with a significant deficit of risk were German shepherds and mixed breed (mongrel) dogs. Age risk was greatest among younger dogs of high-risk breeds, further suggesting a genetic component to the etiology of this disease. In contrast, low-risk dogs had increasing relative risk through nine years of age. Spayed female dogs displayed a significantly higher risk when compared to intact females. Though not statistically significant, male castrated dogs had 30% more hypothyroidism compared to their intact counterparts. Among the case series were 91 endocrine and hormone-related neoplasms and 198 other endocrine-related disorders. Further studies linking canine hypothyroidism to other conditions, particularly cancer, could provide valuable insight into human disease experience.

  15. Chronic skeletal muscle ischemia preserves coronary flow in the ischemic rat heart.

    PubMed

    Varnavas, Varnavas C; Kontaras, Konstantinos; Glava, Chryssoula; Maniotis, Christos D; Koutouzis, Michael; Baltogiannis, Giannis G; Papalois, Apostolos; Kolettis, Theofilos M; Kyriakides, Zenon S

    2011-10-01

    Chronic skeletal muscle ischemia confers cytoprotection to the ventricular myocardium during infarction, but the underlying mechanisms remain unclear. Although neovascularization in the left ventricular myocardium has been proposed as a possible mechanism, the functional capacity of such vessels has not been studied. We examined the effects of chronic limb ischemia on infarct size, coronary blood flow, and left ventricular function after ischemia-reperfusion. Hindlimb ischemia was induced in 65 Wistar rats by excision of the left femoral artery, whereas 65 rats were sham operated. After 4 wk, myocardial infarction was generated by permanent coronary artery ligation. Infarct size was measured 24 h postligation. Left ventricular function was evaluated in isolated hearts after ischemia-reperfusion, 4 wk after limb ischemia. Neovascularization was assessed by immunohistochemistry, and coronary flow was measured under maximum vasodilatation at different perfusion pressures before and after coronary ligation. Infarct size was smaller after limb ischemia compared with controls (24.4 ± 8.1% vs. 46.2 ± 9.5% of the ventricle and 47.6 ± 8.7% vs. 80.1 ± 9.3% of the ischemic area, respectively). Indexes of left ventricular function at the end of reperfusion (divided by baseline values) were improved after limb ischemia (developed pressure: 0.68 ± 0.06 vs. 0.59 ± 0.05, P = 0.008; maximum +dP/dt: 0.70 ± 0.08 vs. 0.59 ± 0.04, P = 0.004; and maximum -dP/dt: 0.86 ± 0.14 vs. 0.72 ± 0.10, P = 0.041). Coronary vessel density was markedly higher (P = 0.00021) in limb ischemic rats. In contrast to controls (F = 5.65, P = 0.00182), where coronary flow decreased, it remained unchanged (F = 1.36, P = 0.28) after ligation in limb ischemic rats. In conclusion, chronic hindlimb ischemia decreases infarct size and attenuates left ventricular dysfunction by increasing coronary collateral vessel density and blood flow.

  16. Hyperspectral imaging of ischemic wounds

    NASA Astrophysics Data System (ADS)

    Gnyawali, Surya C.; Elgharably, Haytham; Melvin, James; Huang, Kun; Bergdall, Valerie; Allen, David W.; Hwang, Jeeseong; Litorja, Maritoni; Shirley, Eric; Sen, Chandan K.; Xu, Ronald

    2012-03-01

    Optical imaging has the potential to achieve high spatial resolution and high functional sensitivity in wound assessment. However, clinical acceptance of many optical imaging devices is hampered by poor reproducibility, low accuracy, and lack of biological interpretation. We developed an in vivo model of ischemic flap for non-contact assessment of wound tissue functional parameters and spectral characteristics. The model was created by elevating the bipedicle skin flaps of a domestic pig from the underlying vascular bed and inhibiting graft bed reperfusion by a silastic sheet. Hyperspectral imaging was carried out on the ischemic flap model and compared with transcutaneous oxygen tension and perfusion measurements at different positions of the wound. Hyperspectral images have also been captured continuously during a post-occlusive reactive hyperemia (PORH) procedure. Tissue spectral characteristics obtained by hyperspectral imaging correlated well with cutaneous tissue oxygen tension, blood perfusion, and microscopic changes of tissue morphology. Our experiments not only demonstrated the technical feasibility for quantitative assessment of chronic wound but also provided a potential digital phantom platform for quantitative characterization and calibration of medical optical devices.

  17. Ischemic preconditioning and clinical scenarios

    PubMed Central

    Narayanan, Srinivasan V.; Dave, Kunjan R.; Perez-Pinzon, Miguel A.

    2013-01-01

    Purpose of review Ischemic preconditioning (IPC) is gaining attention as a novel neuroprotective therapy and could provide an improved mechanistic understanding of tolerance to cerebral ischemia. The purpose of this article is to review the recent work in the field of IPC and its applications to clinical scenarios. Recent findings The cellular signaling pathways that are activated following IPC are now better understood and have enabled investigators to identify several IPC mimetics. Most of these studies were performed in rodents, and efficacy of these mimetics remains to be evaluated in human patients. Additionally, remote ischemic preconditioning (RIPC) may have higher translational value than IPC. Repeated cycles of temporary ischemia in a remote organ can activate protective pathways in the target organ, including the heart and brain. Clinical trials are underway to test the efficacy of RIPC in protecting brain against subarachnoid hemorrhage. Summary IPC, RIPC, and IPC mimetics have the potential to be therapeutic in various clinical scenarios. Further understanding of IPC-induced neuroprotection pathways and utilization of clinically relevant animal models are necessary to increase the translational potential of IPC in the near future. PMID:23197083

  18. Peroxisomal Biogenesis in Ischemic Brain

    PubMed Central

    Young, Jennifer M.; Nelson, Jonathan W.; Cheng, Jian; Zhang, Wenri; Mader, Sarah; Davis, Catherine M.; Morrison, Richard S.

    2015-01-01

    Abstract Aims: Peroxisomes are highly adaptable and dynamic organelles, adjusting their size, number, and enzyme composition to changing environmental and metabolic demands. We determined whether peroxisomes respond to ischemia, and whether peroxisomal biogenesis is an adaptive response to cerebral ischemia. Results: Focal cerebral ischemia induced peroxisomal biogenesis in peri-infarct neurons, which was associated with a corresponding increase in peroxisomal antioxidant enzyme catalase. Peroxisomal biogenesis was also observed in primary cultured cortical neurons subjected to ischemic insult induced by oxygen-glucose deprivation (OGD). A catalase inhibitor increased OGD-induced neuronal death. Moreover, preventing peroxisomal proliferation by knocking down dynamin-related protein 1 (Drp1) exacerbated neuronal death induced by OGD, whereas enhancing peroxisomal biogenesis pharmacologically using a peroxisome proliferator-activated receptor-alpha agonist protected against neuronal death induced by OGD. Innovation: This is the first documentation of ischemia-induced peroxisomal biogenesis in mammalian brain using a combined in vivo and in vitro approach, electron microscopy, high-resolution laser-scanning confocal microscopy, and super-resolution structured illumination microscopy. Conclusion: Our findings suggest that neurons respond to ischemic injury by increasing peroxisome biogenesis, which serves a protective function, likely mediated by enhanced antioxidant capacity of neurons. Antioxid. Redox Signal. 22, 109–120. PMID:25226217

  19. SERCA overexpression reduces hydroxyl radical injury in murine myocardium.

    PubMed

    Hiranandani, Nitisha; Bupha-Intr, Tepmanas; Janssen, Paul M L

    2006-12-01

    Hydroxyl radicals (*OH) are involved in the pathogenesis of ischemia-reperfusion injury and are observed in clinical situations, including acute heart failure, stroke, and myocardial infarction. Acute transient exposure to *OH causes an intracellular Ca(2+) overload and leads to impaired contractility. We investigated whether upregulation of sarcoplasmic reticulum Ca(2+)-ATPase function (SERCA) can attenuate *OH-induced dysfunction. Small, contracting right ventricular papillary muscles from wild-type (WT) SERCA1a-overexpressing (transgenic, TG) and SERCA2a heterogeneous knockout (HET) mice were directly exposed to *OH. This brief 2-min exposure led to a transient elevation of diastolic force (F(dia)) and depression of developed force (F(dev)). In WT mice, F(dia) increased to 485 +/- 49% and F(dev) decreased to 11 +/- 3%. In sharp contrast, in TG mice F(dia) increased only to 241 +/- 17%, whereas F(dev) decreased only to 51 +/- 5% (P < 0.05 vs. WT). In HET mice, F(dia) rose more than WT (to 597 +/- 20%, P < 0.05), whereas F(dev) was reduced in a similar amount. After approximately 45 min after *OH exposure, a new steady state was reached: F(dev) returned to 37 +/- 6% and 32 +/- 6%, whereas F(dia) came back to 238 +/- 28% and 292 +/- 17% in WT and HET mice, respectively. In contrast, the sustained dysfunction was significantly less in TG mice: F(dia) and F(dev) returned to 144 +/- 20% and 67 +/- 6%, respectively. Before exposure to *OH, there is decrease in phospholamban (PLB) phosphorylation at Ser16 (pPLBSer16) and PLB phosphorylation at Thr17 (pPLBThr17) in TG mice and an increase in pPLBSer16 and pPLBThr17 in HET mice versus WT. After exposure to *OH there is decrease in pPLBSer16 in WT, TG, and HET mice but no significant change in the level of pPLBThr17 in any group. The results indicate that SERCA overexpression can reduce the *OH-induced contractile dysfunction in murine myocardium, whereas a reduced SR Ca(2+)-ATPase activity aggravates this injury. Loss of

  20. LAZAROID U-74500A FOR WARM ISCHEMIA AND REPERFUSION INJURY OF THE CANINE SMALL INTESTINE

    PubMed Central

    Tanaka, Hiromu; Zhu, Yue; Zhang, Shimin; Ishizaki, Naoki; Jin, Maeng Bong; Azuma, Takashi; Lee, Randall; Starzl, Thomas E.; Todo, Satoru

    2009-01-01

    BACKGROUND Although lazaroids have been shown to protect various organs from ischemia/reperfusion injury, results obtained in the small intestine have been conflicting. STUDY DESIGN The canine small intestine was made totally ischemic for 2 hours by occluding the superior mesenteric artery and the superior mesenteric vein with interruption of the mesenteric collateral vessels. A lazaroid compound, U74500A, or a citrate vehicle was given intravenously to each of the six animals for 30 minutes before intestinal ischemia. Intestinal tissue blood flow, lipid peroxidation, neutrophil infiltration, adenine nucleotides and their catabolites, and histologic changes after reperfusion were determined. RESULTS Lazaroid treatment attenuated decline of the mucosal and serosal blood flow after reperfusion. Accumulation of lipid peroxidation products and neutrophils in mucosal tissues was markedly inhibited by the treatment. Postischemic energy resynthesis was also augmented by lazaroid. Morphologically, mucosal architectures were better preserved with lazaroid treatment after reperfusion, and recovered to normal by postoperative day 3 in the treated group and by post-operative day 7 in control animals. CONCLUSIONS Lazaroids protect the canine small intestine from ischemia/reperfusion injury by inhibiting lipid peroxidation and neutrophil infiltration. Dogs are tolerant of 2-hour normothermic complete intestinal ischemia. PMID:9100685

  1. Canine rabies ecology in southern Africa.

    PubMed

    Bingham, John

    2005-09-01

    Rabies is a widespread disease in African domestic dogs and certain wild canine populations. Canine rabies became established in Africa during the 20th century, coinciding with ecologic changes that favored its emergence in canids. I present a conceptual and terminologic framework for understanding rabies ecology in African canids. The framework is underpinned by 2 distinct concepts: maintenance and persistence. Maintenance encompasses the notion of indefinite transmission of infection within a local population and depends on an average transmission ratio > or =1. Maintenance in all local populations is inherently unstable, and the disease frequently becomes extinct. Persistence, the notion of long-term continuity, depends on the presence of rabies in > or =1 local population within the canine metapopulation at any time. The implications for understanding rabies ecology and control are reviewed, as are previous studies on rabies ecology in African canids.

  2. [Structural-metabolic characteristics of the myocardium in acute hemorrhage and hyperbaric oxygenation].

    PubMed

    Berkutskaia, T S; Bykov, E G; Leonov, A N

    1975-01-01

    Histochemical and pathomorphological changes in the myocardium in acute loss of blood and hyperbaric oxygenation were investigated in experiments on 130 white rats. It was established that acute loss of blood brought about an activation of phosphorylase, a decrease in the content of glycogen, an inhibition of the activity of cytochrome oxidase and succinic dehydrogenase in the myocardium. Foci of dystrophy were formed in the subendocaridal zone of the two ventricles and septum. Oxygenobarotherapy contributed to normalization of the level of activity of enzymes, preservation of glycogen, reduced the extent of manifestation of dystrophic changes in myocardiocytes. Hyperbaric oxygenation of healthy animals led to changes in the enzymatic activity in the myocardium. Dystrophic changes were noted in individual myocardiocytes. The data obtained testify to a direct influence of oxygen on metabolism of the myocardial cells.

  3. Oncolytic Virotherapy of Canine and Feline Cancer

    PubMed Central

    Gentschev, Ivaylo; Patil, Sandeep S.; Petrov, Ivan; Cappello, Joseph; Adelfinger, Marion; Szalay, Aladar A.

    2014-01-01

    Cancer is the leading cause of disease-related death in companion animals such as dogs and cats. Despite recent progress in the diagnosis and treatment of advanced canine and feline cancer, overall patient treatment outcome has not been substantially improved. Virotherapy using oncolytic viruses is one promising new strategy for cancer therapy. Oncolytic viruses (OVs) preferentially infect and lyse cancer cells, without causing excessive damage to surrounding healthy tissue, and initiate tumor-specific immunity. The current review describes the use of different oncolytic viruses for cancer therapy and their application to canine and feline cancer. PMID:24841386

  4. Dens invaginatus (dilated odontome) in mandibular canine

    PubMed Central

    Halawar, Sangamesh S; Satyakiran, GVV; Krishnanand, PS; Prashanth, R

    2014-01-01

    Dens invaginatus is a developmental malformation of teeth related to shape of the teeth. Affected teeth show a deep infolding of enamel and dentin starting from the tip of the cusps and may extend deep into the root. It results from the invagination of the enamel organ into the dental papilla before calcification has occurred. Teeth most affected are maxillary lateral incisors. The presence of dens invaginatus in mandibular canine is extremely rare. The tooth was symptomatic in that it was mobile and was oriented horizontally. This article presents a case of symptomatic dens invaginatus in mandibular canine. PMID:25364169

  5. Medical Treatment of Primary Canine Glaucoma.

    PubMed

    Alario, Anthony F; Strong, Travis D; Pizzirani, Stefano

    2015-11-01

    Glaucoma is a painful and often blinding group of ocular diseases for which there is no cure. Although the definition of glaucoma is rapidly evolving, elevated intraocular pressure (IOP) remains the most consistent risk factor of glaucoma in the canine patient. Therapy should be aimed at neuroprotection. The mainstay of therapy focuses on reducing IOP and maintaining a visual and comfortable eye. This article discusses the most current ocular hypotensive agents, focusing on their basic pharmacology, efficacy at lowering IOP, and recommended use in the treatment of idiopathic canine glaucoma.

  6. Tubular vimentin metaplasia in canine nephropathies.

    PubMed

    Vilafranca, M; Domingo, M; Ferrer, L

    1994-09-01

    The expression of the intermediate filament vimentin was examined immunocytochemically in 17 cases of histologically confirmed primary canine nephropathy, and compared with its expression in normal canine kidney. In normal renal tissue, the expression of vimentin was restricted to glomerular elements, but in all cases of chronic interstitial nephritis it extended to the cortical tubular epithelia, and was correlated with the degree of tubulo-interstitial damage. Three of four cases of renal cell carcinoma had vimentin reactivity in neoplastic cells. In only one case of familial renal disease was vimentin expressed in scattered epithelial cells of the cortical tubules.

  7. Cardiac Ventricular HIFU: Convergence of Experiment and Theory in the Canine Model

    NASA Astrophysics Data System (ADS)

    Muratore, Robert; Abe, Yukio; Homma, Shunichi; Bernardi, Richard; Kalisz, Andrew; Feleppa, Ernest J.

    2007-05-01

    OBJECTIVE: HIFU is a promising technique for treating cardiac ventricular diseases such as sustained ventricular tachycardia. Ablations can potentially destroy arrhythmogenic foci and block reentrant circuits. Towards this end, we have learned to control HIFU lesions in the canine model in vivo. METHODS: Experiment — Thoracotomies were performed on anesthetized dogs, following IACUC guidelines. In this open-chest configuration, a polyethylene water-filled bag was coupled to the myocardium with degassed ultrasound gel. The transducer was lowered into the water. Ventricular locations were targeted and insonified with multiple 200-ms HIFU bursts of 60-W acoustic power; the bursts were triggered with the electrocardiogram QRS complex. The therapeutic transducer was a 35-mm focal length, 33-mm diameter PZT annular array, excited at 5.25 MHz. Its -3dB focal region dimensions were 2.5 mm axially and 0.3 mm transversely. A confocal diagnostic transducer was used for aiming and for recording backscattered radiofrequency ultrasound data. Theory — A comprehensive acoustic model has been developed. Individual modules numerically simulate physical processes such as ultrasound beam propagation, energy transfer, and heat flow within tissue. One set of modules simulates HIFU ablation in moving tissue. Tissue motion was obtained from digitized B-mode videos of transverse cross sections of a beating canine heart. Epicardial and endocardial surface positions were extracted from the video frames. Additional simulations of static tissue compared linear and nonlinear propagation models. RESULTS: Significant agreement between simulated and measured lesion sizes and between linear and nonlinear propagation models was demonstrated.

  8. A Study of Transmigrated Canine in an Indian Population

    PubMed Central

    Sharma, Gaurav; Nagpal, Archna

    2014-01-01

    Aim. The purpose of this study was to investigate the prevalence of transmigrated canines in a north Indian population and association with gender, side, associated pathologies, and dental anomalies. Subjects and methods. The prospective study consisted of panoramic radiographs of 3000 patients from two dental colleges in north India. The panoramic radiographs were screened for radiographically identified position of the transmigrated tooth, retained canine, and other coexisting dental anomalies. Results. The overall prevalence of transmigrated canines (15 mandibular and 5 maxillary) was 0.66%. The prevalence of mandibular transmigrated canine was 0.5% and maxillary transmigrated canine was 0.16%. All the transmigrated canines were unilateral. The age range was 15–53 years (average age 24.1 years) and there were 12 males (60%) and 8 females (40%). Type 1 mandibular canine transmigration was the commonest type found in our study (10 cases), followed by types 2 and 4 (2 cases each) and 1 case of type 5 transmigration. Conclusion. The prevalence of transmigrated canines in the north Indian population was 0.66% and no gender predilection was evident. The transmigrated canines have a low complication rate (10.0%) and no correlation with other dental anomalies was found. Type 3 canine is the rarest form of mandibular canine transmigration. PMID:27433532

  9. VEGF-C/VEGFR-3 pathway promotes myocyte hypertrophy and survival in the infarcted myocardium

    PubMed Central

    Zhao, Tieqiang; Zhao, Wenyuan; Meng, Weixin; Liu, Chang; Chen, Yuanjian; Gerling, Ivan C; Weber, Karl T; Bhattacharya, Syamal K; Kumar, Rahul; Sun, Yao

    2015-01-01

    Background: Numerous studies have shown that in addition to angio/lymphangiogenesis, the VEGF family is involved in other cellular actions. We have recently reported that enhanced VEGF-C and VEGFR-3 in the infarcted rat myocardium, suggesting the paracrine/autocrine function of VEGF-C on cardiac remodeling. The current study was designed to test the hypothesis that VEGF-C regulates cardiomyocyte growth and survival in the infarcted myocardium. Methods and results: Gene profiling and VEGFR-3 expression of cardiomyocytes were assessed by laser capture microdissection/microarray and immunohistochemistry in the normal and infarcted myocardium. The effect of VEGF-C on myocyte hypertrophy and apoptosis during normoxia and hypoxia was detected by RT-PCR and western blotting in cultured rat neonatal cardiomyocytes. VEGFR-3 was minimally expressed in cardiomyocytes of the normal and noninfarcted myocardium, while markedly elevated in the surviving cardiomyocytes of the infarcted myocardium and border zone. Genes altered in the surviving cardiomyocytes were associated with the networks regulating cellular growth and survival. VEGF-C significantly increased the expression of atrial natriuretic factor (ANP), brain natriuretic factor (BNP), and β-myosin heavy chain (MHC), markers of hypertrophy, in neonatal cardiomyocytes. Hypoxia caused neonatal cardiomyocyte atrophy, which was prevented by VEGF-C treatment. Hypoxia significantly enhanced apoptotic mediators, including cleaved caspase 3, 8, and 9, and Bax in neonatal cardiomyocytes, which were abolished by VEGF-C treatment. Conclusion: Our findings indicate that VEGF-C/VEGFR-3 pathway exerts a beneficial role in the infarcted myocardium by promoting compensatory cardiomyocyte hypertrophy and survival. PMID:26064438

  10. Analysis of Mitochondrial Proteins in the Surviving Myocardium after Ischemia Identifies Mitochondrial Pyruvate Carrier Expression as Possible Mediator of Tissue Viability.

    PubMed

    Fernández-Caggiano, Mariana; Prysyazhna, Oleksandra; Barallobre-Barreiro, Javier; CalviñoSantos, Ramón; Aldama López, Guillermo; Generosa Crespo-Leiro, Maria; Eaton, Philip; Doménech, Nieves

    2016-01-01

    The endogenous mechanisms contributing to tissue survival following myocardial infarction are not fully understood. We investigated the alterations in the mitochondrial proteome after ischemia-reperfusion (I/R) and its possible implications on cell survival. Mitochondrial proteomic analysis of cardiac tissue from an in vivo porcine I/R model found that surviving tissue in the peri-infarct border zone showed increased expression of several proteins. Notably, these included subunits of the mitochondrial pyruvate carrier (MPC), namely MPC1 and MPC2. Western blot, immunohistochemistry, and mRNA analysis corroborated the elevated expression of MPC in the surviving tissue. Furthermore, MPC1 and MPC2 protein levels were found to be markedly elevated in the myocardium of ischemic cardiomyopathy patients. These findings led to the hypothesis that increased MPC expression is cardioprotective due to enhancement of mitochondrial pyruvate uptake in the energy-starved heart following I/R. To test this, isolated mouse hearts perfused with a modified Krebs buffer (containing glucose, pyruvate, and octanoate as metabolic substrates) were subjected to I/R with or without the MPC transport inhibitor UK5099. UK5099 increased myocardial infarction and attenuated post-ischemic recovery of left ventricular end-diastolic pressure. However, aerobically perfused control hearts that were exposed to UK5099 did not modulate contractile function, although pyruvate uptake was blocked as evidenced by increased cytosolic lactate and pyruvate levels. Our findings indicate that increased expression of MPC leads to enhanced uptake and utilization of pyruvate during I/R. We propose this as a putative endogenous mechanism that promotes myocardial survival to limit infarct size.

  11. Canine parvovirus enteritis, canine distemper, and major histocompatibility complex genetic variation in Mexican wolves.

    PubMed

    Hedrick, Philip W; Lee, Rhonda N; Buchanan, Colleen

    2003-10-01

    The endangered Mexican wolf (Canis lupus baileyi) was recently reintroduced into Arizona and New Mexico (USA). In 1999 and 2000, pups from three litters that were part of the reintroduction program died of either canine parvovirus or canine distemper. Overall, half (seven of 14) of the pups died of either canine parvovirus or canine distemper. The parents and their litters were analyzed for variation at the class II major histocompatibility complex (MHC) gene DRB1. Similar MHC genes are related to disease resistance in other species. All six of the surviving pups genotyped for the MHC gene were heterozygous while five of the pups that died were heterozygous and one was homozygous. Resistance to pathogens is an important aspect of the management and long-term survival of endangered taxa, such as the Mexican wolf.

  12. Characteristics of Misclassified CT Perfusion Ischemic Core in Patients with Acute Ischemic Stroke

    PubMed Central

    Geuskens, Ralph R. E. G.; Borst, Jordi; Lucas, Marit; Boers, A. M. Merel; Berkhemer, Olvert A.; Roos, Yvo B. W. E. M.; van Walderveen, Marianne A. A.; Jenniskens, Sjoerd F. M.; van Zwam, Wim H.; Dippel, Diederik W. J.; Majoie, Charles B. L. M.; Marquering, Henk A.

    2015-01-01

    Background CT perfusion (CTP) is used to estimate the extent of ischemic core and penumbra in patients with acute ischemic stroke. CTP reliability, however, is limited. This study aims to identify regions misclassified as ischemic core on CTP, using infarct on follow-up noncontrast CT. We aim to assess differences in volumetric and perfusion characteristics in these regions compared to areas that ended up as infarct on follow-up. Materials and Methods This study included 35 patients with >100 mm brain coverage CTP. CTP processing was performed using Philips software (IntelliSpace 7.0). Final infarct was automatically segmented on follow-up noncontrast CT and used as reference. CTP and follow-up noncontrast CT image data were registered. This allowed classification of ischemic lesion agreement (core on CTP: rMTT≥145%, aCBV<2.0 ml/100g and infarct on follow-up noncontrast CT) and misclassified ischemic core (core on CTP, not identified on follow-up noncontrast CT) regions. False discovery ratio (FDR), defined as misclassified ischemic core volume divided by total CTP ischemic core volume, was calculated. Absolute and relative CTP parameters (CBV, CBF, and MTT) were calculated for both misclassified CTP ischemic core and ischemic lesion agreement regions and compared using paired rank-sum tests. Results Median total CTP ischemic core volume was 49.7ml (IQR:29.9ml-132ml); median misclassified ischemic core volume was 30.4ml (IQR:20.9ml-77.0ml). Median FDR between patients was 62% (IQR:49%-80%). Median relative mean transit time was 243% (IQR:198%-289%) and 342% (IQR:249%-432%) for misclassified and ischemic lesion agreement regions, respectively. Median absolute cerebral blood volume was 1.59 (IQR:1.43–1.79) ml/100g (P<0.01) and 1.38 (IQR:1.15–1.49) ml/100g (P<0.01) for misclassified ischemic core and ischemic lesion agreement, respectively. All CTP parameter values differed significantly. Conclusion For all patients a considerable region of the CTP ischemic core

  13. [Effect of allergic damage on plastic metabolism of the myocardium in rabbits].

    PubMed

    Grozdova, M D; Starostina, L K

    1975-12-01

    The plastic metabolism of the myocardium in rabbits was studied after varying periods of allergic damage induced by repeated injections of normal horse serum. An accelerated decompostion of the myofibril proteins was demomstrated to occur during the acute phase. During the reparation phase, an activation of the protein synthesis in the myocardium occurred. The newly synthesized myofibril proteins had a longer turnover in the tissues, than under normal conditions. The turnover time of the mitochondrial proteins did not differ from the normal one. PMID:1223362

  14. Statistical and fractal analysis of autofluorescent myocardium images in posthumous diagnostics of acute coronary insufficiency

    NASA Astrophysics Data System (ADS)

    Boichuk, T. M.; Bachinskiy, V. T.; Vanchuliak, O. Ya.; Minzer, O. P.; Garazdiuk, M.; Motrich, A. V.

    2014-08-01

    This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections of the myocardium). The polarized structure of autofluorescence imaging layers of biological tissues was detected and investigated. Proposed the model of describing the formation of polarization inhomogeneous of autofluorescence imaging biological optically anisotropic layers. On this basis, analytically and experimentally tested to justify the method of laser polarimetry autofluorescent. Analyzed the effectiveness of this method in the postmortem diagnosis of infarction. The objective criteria (statistical moments) of differentiation of autofluorescent images of histological sections myocardium were defined. The operational characteristics (sensitivity, specificity, accuracy) of these technique were determined.

  15. Scale-selective analysis of myocardium polarization images in problems of diagnostic of necrotic changes

    NASA Astrophysics Data System (ADS)

    Ushenko, O. G.; Dubolazov, O. V.; Ushenko, Yu. O.; Gorsky, M. P.

    2015-11-01

    This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections of the myocardium). The polarized structure of autofluorescence imaging layers of biological tissues was detected and investigated. Proposed the model of describing the formation of polarization inhomogeneous of autofluorescence imaging biological optically anisotropic layers. On this basis, analytically and experimentally tested to justify the method of laser polarimetry autofluorescent. Analyzed the effectiveness of of this method in the postmortem diagnosis of infarction. The objective criteria (statistical moments) of differentiation of autofluorescent images of histological sections myocardium were defined. The operational characteristics (sensitivity, specificity, accuracy) of these technique were determined.

  16. [Protein fractions and their enzyme activity in rat myocardium after a 22-hour space flight].

    PubMed

    Gaevskaia, M S; Veresotskaia, N A; Kolganova, N S; Kolchina, E V; Kurkina, L M

    1976-01-01

    No significant changes in the content of sarcoplasmatic and myofibrillar proteins were found in the myocardium of rats that made a 22-day flight onboard the biosatellite. On the 2nd and 26th postflight days the activity of aspartate and alanine aminotransferases of sarcoplasmatic proteins was increased and the total activity of lactate dehydrogenase and its isoenzyme spectrum remained unchanged. On the 2nd postflight day the ATPase activity of myosin of the myocardium was substantially lowered and on the 26th postflight day it returned to the normal. This decline in the ATPase activity of myosin can be regarded as an adaptive reaction to weightlessness.

  17. Canine adenovirus downstream processing protocol.

    PubMed

    Puig, Meritxell; Piedra, Jose; Miravet, Susana; Segura, María Mercedes

    2014-01-01

    Adenovirus vectors are efficient gene delivery tools. A major caveat with vectors derived from common human adenovirus serotypes is that most adults are likely to have been exposed to the wild-type virus and exhibit active immunity against the vectors. This preexisting immunity limits their clinical success. Strategies to circumvent this problem include the use of nonhuman adenovirus vectors. Vectors derived from canine adenovirus type 2 (CAV-2) are among the best-studied representatives. CAV-2 vectors are particularly attractive for the treatment of neurodegenerative disorders. In addition, CAV-2 vectors have shown great promise as oncolytic agents in virotherapy approaches and as vectors for recombinant vaccines. The rising interest in CAV-2 vectors calls for the development of scalable GMP compliant production and purification strategies. A detailed protocol describing a complete scalable downstream processing strategy for CAV-2 vectors is reported here. Clarification of CAV-2 particles is achieved by microfiltration. CAV-2 particles are subsequently concentrated and partially purified by ultrafiltration-diafiltration. A Benzonase(®) digestion step is carried out between ultrafiltration and diafiltration operations to eliminate contaminating nucleic acids. Chromatography purification is accomplished in two consecutive steps. CAV-2 particles are first captured and concentrated on a propyl hydrophobic interaction chromatography column followed by a polishing step using DEAE anion exchange monoliths. Using this protocol, high-quality CAV-2 vector preparations containing low levels of contamination with empty viral capsids and other inactive vector forms are typically obtained. The complete process yield was estimated to be 38-45 %. PMID:24132487

  18. Ischemic perinatal stroke: challenge and opportunities.

    PubMed

    Raju, Tonse N K

    2008-08-01

    The second highest risk group for developing a cerebral stroke is the perinatal period, generally defined as 20 weeks of gestation through 28th postnatal day of age. In this commentary, a brief overview of ischemic perinatal strokes is presented. Ischemic perinatal stroke (IPS) occurs at a rate of 1 : 2300 to 1 : 5000 births, accounting for 30% of children with hemiplegic cerebral palsy (CP). Thus, IPS is the most common known cause for CP [1-3]. Although they occur frequently, much remains to be studied about perinatal strokes in general and the ischemic variety in particular. PMID:18705894

  19. Evaluation of global longitudinal strain of left ventricle and regional longitudinal strain in the region of left ventricular leads predicts the response to cardiac resynchronization therapy in patients with ischemic heart failure.

    PubMed

    Ma, Chun-Yan; Liu, Shuang; Yang, Jun; Tang, Li; Zhang, Li-Ming; Li, Nan; Yu, Bo

    2014-09-01

    Myocardium viability in ischemic heart failure (HF) may affect the effect of cardiac resynchronization therapy (CRT). We hypothesized that longitudinal strain of 2D-STE, which reflects myocardium viability, can predict the response to CRT in patients with ischemic HF. 2D-STE was performed in 42 patients with HF, 1 week before and 1 year after CRT. GLS, RLS, and the LV synchrony index (SI), defined as the difference in timing to peak radial strain between LV anterior septal and posterior wall in LV short axis view, were calculated. A decrease in the LV end-systolic volume (LVESV) value of ≥ 15 % 1 year after CRT was defined as response to CRT. Twenty-nine patients responded to CRT (CRT-R group), while 13 patients did not respond and were assigned as CRT-NR group. Pre-CRT RLS and GLS were higher, while SI is lower, in CRT-R patients compared with CRT-NR group (p < 0.001). The ROC curve revealed that RLS of -11.5 % predicted response to CRT with sensitivity of 80.0 % and specificity of 77.9 % (AUC = 0.84, p < 0.001). Further, GLS of -13 % predicted response to CRT with sensitivity of 73.0 % and specificity of 73.4 % (AUC = 0.79, p < 0.001). In conclusion, LV dyssynchrony, GLS, and RLS calculated by 2D-STE can predict long-term response to CRT in patients with ischemic HF.

  20. Lysis of human tumor cell lines by canine complement plus monoclonal antiganglioside antibodies or natural canine xenoantibodies.

    PubMed

    Helfand, S C; Hank, J A; Gan, J; Sondel, P M

    1996-01-10

    Because certain antiganglioside monoclonal antibodies can facilitate antibody-dependent cellular cytotoxicity against GD2+ ganglioside-bearing human and canine tumor cells, we wished to determine if clinically relevant antiganglioside monoclonal antibodies (Mabs) could also fix canine complement to lyse tumor cells in vitro. Using flow cytometry, human tumor cell lines (M21 melanoma and OHS osteosarcoma) were shown to highly express ganglioside GD2 and, to a lesser degree, GD3. In 51Cr release assays, M21 cells were lysed with canine serum, as a source of complement, plus either Mab 14.G2a or its mouse-human chimera, ch 14.18, specific for GD2. Heating canine serum abrogated its lytic activity and addition of rabbit complement reconstituted M21 lysis. Similar results were obtained with M21 cells when Mab R24 (against GD3) and canine serum were used. OHS cells were also lysed with canine serum plus Mab 14.G2a and lytic activity was abolished by heating canine serum but reconstituted with rabbit complement. Alone, canine serum or Mabs were not lytic to M21 or OHS cells. Conversely, human neuroblastoma (LAN-5) and K562 erythroleukemia cells were lysed by canine serum alone which was shown by flow cytometry to contain naturally occurring canine IgM antibodies that bound LAN-5 and K562 cells. The lytic activity of canine serum for LAN-5 or K562 cells was abolished by heating and restored by addition of either human or rabbit complement. Thus, human tumor cell lines can be lysed with antiganglioside Mabs through fixation and activation of canine complement-dependent lytic pathways. Canine xenoantibodies also mediate complement-dependent cytotoxicity of some human tumor cell lines. Together, these results are significant because they demonstrate an antitumor effect of the canine immune system which is of potential importance for cancer immunotherapy in a promising animal model.

  1. Experimental Forelimb Allotransplantation in Canine Model.

    PubMed

    Hong, Sa-Hyeok; Eun, Seok-Chan

    2016-01-01

    As reconstructive transplantation is gaining popularity as a viable alternative for upper limb amputees, it is becoming increasingly important for plastic surgeons to renew surgical skills and knowledge of this area. Forelimb allotransplantation research has been performed previously in rodent and swine models. However, preclinical canine forelimb allotransplantation studies are lacking in the literature. The purpose of this paper is to provide an overview of the surgical skills necessary to successfully perform forelimb transplantation in canines as a means to prepare for clinical application. A total of 18 transplantation operations on canines were performed. The recipient limb was shortened at the one-third proximal forearm level. The operation was performed in the following order: bones (two reconstructive plates), muscles and tendons (separately sutured), nerves (median, ulnar, and radial nerve), arteries (two), and veins (two). The total mean time of transplantation was 5 hours ± 30 minutes. All of the animals that received transplantation were treated with FK-506 (tacrolimus, 2 mg/kg) for 7 days after surgery. Most allografts survived with perfect viability without vascular problems during the early postoperative period. The canine forelimb allotransplantation model is well qualified to be a suitable training model for standard transplantation and future research work. PMID:27597952

  2. Experimental Forelimb Allotransplantation in Canine Model

    PubMed Central

    2016-01-01

    As reconstructive transplantation is gaining popularity as a viable alternative for upper limb amputees, it is becoming increasingly important for plastic surgeons to renew surgical skills and knowledge of this area. Forelimb allotransplantation research has been performed previously in rodent and swine models. However, preclinical canine forelimb allotransplantation studies are lacking in the literature. The purpose of this paper is to provide an overview of the surgical skills necessary to successfully perform forelimb transplantation in canines as a means to prepare for clinical application. A total of 18 transplantation operations on canines were performed. The recipient limb was shortened at the one-third proximal forearm level. The operation was performed in the following order: bones (two reconstructive plates), muscles and tendons (separately sutured), nerves (median, ulnar, and radial nerve), arteries (two), and veins (two). The total mean time of transplantation was 5 hours ± 30 minutes. All of the animals that received transplantation were treated with FK-506 (tacrolimus, 2 mg/kg) for 7 days after surgery. Most allografts survived with perfect viability without vascular problems during the early postoperative period. The canine forelimb allotransplantation model is well qualified to be a suitable training model for standard transplantation and future research work. PMID:27597952

  3. Canine models of human rare disorders

    PubMed Central

    Hytönen, Marjo K.

    2016-01-01

    ABSTRACT Millions of children worldwide are born with rare and debilitating developmental disorders each year. Although an increasing number of these conditions are being recognized at the molecular level, the characterization of the underlying pathophysiology remains a grand challenge. This is often due to the lack of appropriate patient material or relevant animal models. Dogs are coming to the rescue as physiologically relevant large animal models. Hundreds of spontaneous genetic conditions have been described in dogs, most with close counterparts to human rare disorders. Our recent examples include the canine models of human Caffey (SLC37A2), van den Ende-Gupta (SCARF2) and Raine (FAM20C) syndromes. These studies demonstrate the pathophysiological similarity of human and canine syndromes, and suggest that joint efforts to characterize both human and canine rare diseases could provide additional benefits to the advancement of the field of rare diseases. Besides revealing new candidate genes, canine models allow access to experimental resources such as cells, tissues and even live animals for research and intervention purposes. PMID:27803843

  4. Canine retraction with J hook headgear.

    PubMed

    Ayala Perez, C; de Alba, J A; Caputo, A A; Chaconas, S J

    1980-11-01

    Several methods have been described for accomplishing distal movement of canines without losing posterior anchorage. An accepted method in canine retraction is the use of headgear with J hooks. Since it incorporates extraoral anchorage, it is most effective in maximum-anchorage cases. It was the purpose of this study to analyze the distribution of force transmitted to the alveolus and surrounding structures by means of photoelastic visualization, utilizing J hook headgear for maxillary canine retraction. A three-dimensional model representing a human skull was used. This model was constructed with different birefringent materials to simulate bone, teeth, and periodontal membranes. Three different vectors of force were applied representing high-, medium-, and low-pull headgear, which were placed at angles of 40, 20, and 0 degrees to the occlusal plane. The photoelastic analysis was made by means of a circular-transmission polariscope arrangement, and the photoelastic data were recorded photographically. The stress areas created by the three different vectors of force were associated with various degrees of canine tipping. This effect was greater with the low-pull force component than with the medium-pull traction. The high-pull headgear produced the least tipping tendency, being closer to a bodily movemment effect. Further, stresses were transmitted to deeper structures of the simulated facial bones; these regions were the frontozygomatic, zygomaticomaxillary, and zygomaticotemporal sutures.

  5. Canine notoedric mange: a case report.

    PubMed

    Leone, Federico

    2007-04-01

    Notoedric mange is a cutaneous ectoparasitic disease of cats caused by Notoedres cati, a mite belonging to the Sarcoptidae family. The disease occurs in felids, occasionally in other mammals and in humans. The canine form, even if cited by some authors, has never been documented. This report describes for the first time a case of notoedric mange in a dog.

  6. Immune-mediated canine and feline keratitis.

    PubMed

    Andrew, Stacy E

    2008-03-01

    Although the normal cornea is devoid of vasculature and lymphatics, there are still several immune-mediated corneal conditions that can occur in dogs and cats. An overview of corneal immunology is presented. Diseases of dogs, including chronic superficial keratitis, superficial punctate keratitis, and canine adenovirus endotheliitis, as well as feline diseases, including eosinophilic keratitis and herpesvirus-related conditions, are discussed.

  7. Seroprevalence of Canine Distemper Virus in Cats

    PubMed Central

    Ikeda, Yasuhiro; Nakamura, Kazuya; Miyazawa, Takayuki; Chen, Ming-Chu; Kuo, Tzong-Fu; Lin, James A.; Mikami, Takeshi; Kai, Chieko; Takahashi, Eiji

    2001-01-01

    A seroepidemiological survey of canine distemper virus (CDV) infection in Asian felids revealed that the prevalence of antibodies varied depending on region and, in some cases, exposure to dogs. The serologic pattern in cats with antibodies indicated that they had likely been exposed to field strains rather than typical CDV vaccine strains. PMID:11329473

  8. Infectious canine hepatitis associated with prednisone treatment.

    PubMed

    Wong, Valerie M; Marche, Candace; Simko, Elemir

    2012-11-01

    An 11-week-old, female Alaskan husky dog housed outdoors in the Yukon, Canada, was diagnosed with infectious canine hepatitis. The predisposing factors in this puppy for such a rare disease included inappropriate vaccination program, potential contact with endemic wildlife, and immunosuppression due to prednisone treatment.

  9. [Ischemic heart disease and arterial hypertention as risk factors of surgical treatment of patients with infrarenal segment of aortic aneurysm].

    PubMed

    Iaitskiĭ, N A; Bedrov, A Ia; Maslevtsov, D V; Tsvetkova, E A; Moiseev, A A

    2013-01-01

    A retrospective analysis of the data of 188 patients with the infrarenal segment of the aortic aneurysm (ISAA) showed, that ischemic heart disease and arterial hypertension were diagnosed practically in all patients--175 (93.0%) and 177 (94.1%) patients respectively. A decreased retractor function of the myocardium was noted in 88 (46.8%) of patients. According to the findings of echocardiography 134 (71.3%) patients had the arterial hypertension of third degree. For the assessment of the influence of the accompanying cardiac pathology on the results of planned surgical treatment and systematization of postoperative cardiac complications the classification, which was proposed by R. B. Rutherford et al. and modified by A. V. Pokrovsky et al. was used. The obtained data point at a direct proportional relationship between the degree of the initial cardiac status, frequency and severity of postoperative cardiac complications in patients after resection of ISAA in 1.6-2.3 times.

  10. Molecular Mechanisms of Renal Ischemic Conditioning Strategies.

    PubMed

    Kierulf-Lassen, Casper; Nieuwenhuijs-Moeke, Gertrude J; Krogstrup, Nicoline V; Oltean, Mihai; Jespersen, Bente; Dor, Frank J M F

    2015-01-01

    Ischemia-reperfusion injury is the leading cause of acute kidney injury in a variety of clinical settings such as renal transplantation and hypovolemic and/or septic shock. Strategies to reduce ischemia-reperfusion injury are obviously clinically relevant. Ischemic conditioning is an inherent part of the renal defense mechanism against ischemia and can be triggered by short periods of intermittent ischemia and reperfusion. Understanding the signaling transduction pathways of renal ischemic conditioning can promote further clinical translation and pharmacological advancements in this era. This review summarizes research on the molecular mechanisms underlying both local and remote ischemic pre-, per- and postconditioning of the kidney. The different types of conditioning strategies in the kidney recruit similar powerful pro-survival mechanisms. Likewise, renal ischemic conditioning mobilizes many of the same protective signaling pathways as in other organs, but differences are recognized. PMID:26330099

  11. Novel therapeutic strategies for ischemic heart disease.

    PubMed

    Perricone, Adam J; Vander Heide, Richard S

    2014-11-01

    Despite significant advances in the physician's ability to initiate myocardial reperfusion and salvage heart tissue, ischemic heart disease remains one of the leading causes of death in the United States. Consequently, alternative therapeutic strategies have been intensively investigated, especially methods of enhancing the heart's resistance to ischemic cell death - so called "cardioprotective" interventions. However, although a great deal has been learned regarding the methods and mechanisms of cardioprotective interventions, an efficacious therapy has yet to be successfully implemented in the clinical arena. This review discusses the current understanding of cardioprotection in the context of ischemic heart disease pathophysiology, highlighting those elements of ischemic heart disease pathophysiology that have received less attention as potential targets of cardioprotective intervention.

  12. Mandibular canine dimensions as an aid in gender estimation

    PubMed Central

    Rajarathnam, Basetty Neelakantam; David, Maria Priscilla; Indira, Annamalai Ponnuswamy

    2016-01-01

    Background: All humans have an identity in life; compassionate societies require this identity to be recognized even after death. Objectives: To measure the dimensions of the mandibular canine and assess the usefulness of the mandibular canine as an aid in gender estimation. Materials and Methods: The study population comprised 200 subjects inclusive of 100 males and 100 females with an age range of 18–25 years. Measurements made in mm at the contact point were of mesiodistal width of the right and left canines and intercanine distance both intraorally and on casts, and the mandibular canine index (MCI) was calculated. The obtained data were subjected to t-test/Mann-Whitney test and discriminant function analysis. Results: All parameters of mandibular canines, namely, intercanine distance, canine width, and canine index were greater in males compared to females suggesting significant sexual dimorphism of mandibular canines. On subjecting the data to discriminant function analysis, it classified sex correctly in 73% of the samples. Conclusion: The result of our study establishes the existence of significant sexual dimorphism in mandibular canines. We can therefore, recommend the use of mandibular canine dimensions as an applicable and additional method for gender determination in human identification. PMID:27555724

  13. Histopathologic studies of ischemic optic neuropathy.

    PubMed Central

    Knox, D L; Kerrison, J B; Green, W R

    2000-01-01

    PURPOSE: To define the histopathologic features of eyes in which a pathologic diagnosis of ischemic optic neuropathy had been made in the years 1951 through 1998. METHODS: The following data were documented: age of patient, race, sex, source of tissue, cause of death, clinical history, interval from loss of vision to death, enucleation, exenteration, and biopsy. The histopathologic criteria for diagnosis of ischemic optic neuropathy were the presence of localized ischemic edema, cavernous degeneration, or an area of atrophy located superior or inferior in the optic nerve. Cases with history of abrupt loss of vision were combined with reports from the literature to construct a time table of histopathologic features and associated conditions. RESULTS: Ischemic optic neuropathy was present in 193 eyes. There were 88 females and 65 males. The average age was 71.6 years. Ischemic edema without (early) and with (later) gitter macrophages was present in 26 (13.5%). Cavernous degeneration was present in 69 nerves (36%). Mucopolysaccharide (MPS) was present in 37 cavernous lesions 1 month or longer after loss of vision. Cavernous lesions were seen in 3 eyes in which peripapillary retinal nerve fiber layer hemorrhage had been observed prior to death. Atrophic lesions, the most common pattern, were observed in 133 optic nerves (66.8%). More than 1 ischemic lesion was seen in 38 optic nerves (19.7%). Bilateral ischemic lesions were seen in 50 (35.2%) of 142 paired eyes. CONCLUSIONS: Ischemic optic nerve lesions are initially acellular and later show macrophage infiltration. Cavernous lesions with MPS are present 4 weeks or longer after vision loss. The location of MPS posteriorly and along the internal margin suggests that MPS is produced at the edges of lesions. Progressive vision loss in ischemic optic neuropathy may be secondary to compression of intact nerve from ischemic edema and cavernous swelling, or a second ischemic lesion. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5

  14. Alternans and higher-order rhythms in an ionic model of a sheet of ischemic ventricular muscle

    NASA Astrophysics Data System (ADS)

    Arce, Humberto; Xu, Aoxiang; González, Hortensia; Guevara, Michael R.

    2000-06-01

    Life-threatening arrhythmias such as ventricular tachycardia and fibrillation often occur during acute myocardial ischemia. During the first few minutes following coronary occlusion, there is a gradual rise in the extracellular concentration of potassium ions ([K+]0) within ischemic tissue. This elevation of [K+]0 is one of the main causes of the electrophysiological changes produced by ischemia, and has been implicated in inducing arrhythmias. We investigate an ionic model of a 3 cm×3 cm sheet of normal ventricular myocardium containing an ischemic zone, simulated by elevating [K+]0 within a centrally-placed 1 cm×1 cm area of the sheet. As [K+]0 is gradually raised within the ischemic zone from the normal value of 5.4 mM, conduction first slows within the ischemic zone and then, at higher [K+]0, an arc of block develops within that area. The area distal to the arc of block is activated in a delayed fashion by a retrogradely moving wavefront originating from the distal edge of the ischemic zone. With a further increase in [K+]0, the point eventually comes where a very small increase in [K+]0 (0.01 mM) results in the abrupt transition from a global period-1 rhythm to a global period-2 rhythm in the sheet. In the peripheral part of the ischemic zone and in the normal area surrounding it, there is an alternation of action potential duration, producing a 2:2 response. Within the core of the ischemic zone, there is an alternation between an action potential and a maintained small-amplitude response (˜30 mV in height). With a further increase of [K+]0, the maintained small-amplitude response turns into a decrementing subthreshold response, so that there is 2:1 block in the central part of the ischemic zone. A still further increase of [K+]0 leads to a transition in the sheet from a global period-2 to a period-4 rhythm, and then to period-6 and period-8 rhythms, and finally to a complete block of propagation within the ischemic core. When the size of the sheet is

  15. Adiposity and ischemic and hemorrhagic stroke

    PubMed Central

    Kroll, Mary E.; Green, Jane; Beral, Valerie; Sudlow, Cathie L.M.; Brown, Anna; Kirichek, Oksana; Price, Alison; Yang, TienYu Owen

    2016-01-01

    Objective: To compare associations of body mass index (BMI) with ischemic stroke and hemorrhagic stroke risk, and to review the worldwide evidence. Methods: We recruited 1.3 million previously stroke-free UK women between 1996 and 2001 (mean age 57 years [SD 5]) and followed them by record linkage for hospital admissions and deaths. We used Cox regression to estimate adjusted relative risks for ischemic and hemorrhagic (intracerebral or subarachnoid hemorrhage) stroke in relation to BMI. We conducted a meta-analysis of published findings from prospective studies on these associations. Results: During an average follow-up of 11.7 years, there were 20,549 first strokes, of which 9,993 were specified as ischemic and 5,852 as hemorrhagic. Increased BMI was associated with an increased risk of ischemic stroke (relative risk 1.21 per 5 kg/m2 BMI, 95% confidence interval 1.18–1.23, p < 0.0001) but a decreased risk of hemorrhagic stroke (relative risk 0.89 per 5 kg/m2 BMI, 0.86–0.92, p < 0.0001). The BMI-associated trends for ischemic and hemorrhagic stroke were significantly different (heterogeneity: p < 0.0001) but were not significantly different for intracerebral hemorrhage (n = 2,790) and subarachnoid hemorrhage (n = 3,062) (heterogeneity: p = 0.5). Published data from prospective studies showed consistently greater BMI-associated relative risks for ischemic than hemorrhagic stroke with most evidence (prior to this study) coming from Asian populations. Conclusions: In UK women, higher BMI is associated with increased risk of ischemic stroke but decreased risk of hemorrhagic stroke. The totality of the available published evidence suggests that BMI-associated risks are greater for ischemic than for hemorrhagic stroke. PMID:27605176

  16. Chinese Herbal Products for Ischemic Stroke.

    PubMed

    Hung, I-Ling; Hung, Yu-Chiang; Wang, Lin-Yi; Hsu, Sheng-Feng; Chen, Hsuan-Ju; Tseng, Ying-Jung; Kuo, Chun-En; Hu, Wen-Long; Li, Tsai-Chung

    2015-01-01

    Traditional Chinese herbal products (CHPs) have been described in ancient medicine systems as treatments for various stroke-associated ailments. This study is aimed to investigate the prescription patterns and combinations of CHPs for ischemic stroke in Taiwan. Prescriptions of CHPs for ischemic stroke were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan. Every prescription with a leading diagnosis of ischemic stroke made during 2000-2010 was analyzed. Descriptive statistics were applied to the pattern of co-prescriptions. Multiple logistic regression models were used to assess demographic and risk factors that are correlated with CHP use. The dataset of inpatient claims data contained information on 15,896 subjects who experienced ischemic stroke from 2000 to 2010. There was an average of 5.82 CHPs in a single prescription for subjects with ischemic stroke. Bu-yang-huan-wu-tang (BYHWT) (40.32%) was by far the most frequently prescribed formula CHP for ischemic stroke, and the most commonly used combination of two-formula-CHP was BYHWT with Shu-jin-huo-xue-tang (SJHXT) (4.40%). Dan Shen (16.50%) was the most commonly used single CHP for ischemic stroke, and the most commonly used combination of two single CHPs was Shi Chang Pua with Yuan Zhi (4.79%). We found that BYHWT and Dan Shen were the most frequently prescribed formula and single CHP for ischemic stroke, respectively. These results provide information about individualized therapy and may contribute to further pharmacologic experiments and clinical trials. PMID:26477801

  17. The sinus venosus myocardium contributes to the atrioventricular canal: potential role during atrioventricular node development?

    PubMed

    Kelder, Tim P; Vicente-Steijn, Rebecca; Harryvan, Tom J; Kosmidis, Georgios; Gittenberger-de Groot, Adriana C; Poelmann, Rob E; Schalij, Martin J; DeRuiter, Marco C; Jongbloed, Monique R M

    2015-06-01

    The presence of distinct electrophysiological pathways within the atrioventricular node (AVN) is a prerequisite for atrioventricular nodal reentrant tachycardia to occur. In this study, the different cell contributions that may account for the anatomical and functional heterogeneity of the AVN were investigated. To study the temporal development of the AVN, the expression pattern of ISL1, expressed in cardiac progenitor cells, was studied in sequential stages performing co-staining with myocardial markers (TNNI2 and NKX2-5) and HCN4 (cardiac conduction system marker). An ISL1+/TNNI2+/HCN4+ continuity between the myocardium of the sinus venosus and atrioventricular canal was identified in the region of the putative AVN, which showed a pacemaker-like phenotype based on single cell patch-clamp experiments. Furthermore, qPCR analysis showed that even during early development, different cell populations can be identified in the region of the putative AVN. Fate mapping was performed by in ovo vital dye microinjection. Embryos were harvested and analysed 24 and 48 hrs post-injection. These experiments showed incorporation of sinus venosus myocardium in the posterior region of the atrioventricular canal. The myocardium of the sinus venosus contributes to the atrioventricular canal. It is postulated that the myocardium of the sinus venosus contributes to nodal extensions or transitional cells of the AVN since these cells are located in the posterior region of the AVN. This finding may help to understand the origin of atrioventricular nodal reentrant tachycardia.

  18. Effects of dietary magnesium deficiency on thallium-201 kinetics and distribution in rat myocardium: concise communication

    SciTech Connect

    Llaurado, J.G.; Madden, J.A.; Smith, G.A.

    1983-05-01

    Kinetics and distribution of TI-201 were studied in myocardium of rats with chronic dietary induced Mg deficiency. Rats were fed the Mg-deficient diet for 30 days and were then injected intravenously with 0.2 mCi of TI-201. Comparable control animals were fed a standard laboratory diet. One-half hour after injection, rats were killed and a segment of myocardium was washed with nonradioactive Krebs solution in a special chamber. Radioactivity in the tissue was recorded continuously for 1 hr. A three-compartment model (extracellular, main intracellular, and subcellular) was found to describe adequately the kinetics of TI-201. In myocardium of Mg-deficient animals, significant changes in values of transport rate constants and compartment sizes for TI-201 indicated a moderate decrease in extracellular compartment and a threefold enlargement in subcellular compartment (presumably mitochondrial) at the expense of the main intracellular compartment, which underwent a marked reduction. Bulk TI-201 uptake in myocardium of Mg-deficient rats was unchanged. The findings are interpreted as being consistent with mitochondrial alterations reported in Mg-deficient animals. Clinical implications are discussed.

  19. Isolated noncompaction of the myocardium: multiplane transesophageal echocardiography diagnosis in an adult.

    PubMed

    Maltagliati, A; Pepi, M

    2000-11-01

    We describe a case of isolated noncompaction of the myocardium in a 66-year-old patient. Peculiar anatomic features of this disease were clearly suspected on transthoracic echocardiography and precisely recognized through transesophageal echocardiography. The role of transthoracic and transesophageal echocardiography in the detection of this rare disease is described in this report.

  20. A murine experimental model for the mechanical behaviour of viable right-ventricular myocardium

    PubMed Central

    Valdez-Jasso, Daniela; Simon, Marc A; Champion, Hunter C; Sacks, Michael S

    2012-01-01

    Although right-ventricular function is an important determinant of cardio-pulmonary performance in health and disease, right ventricular myocardium mechanical behaviour has received relatively little attention. We present a novel experimental method for quantifying the mechanical behaviour of transmurally intact, viable right-ventricular myocardium. Seven murine right ventricular free wall (RVFW) specimens were isolated and biaxial mechanical behaviour measured, along with quantification of the local transmural myofibre and collagen fibre architecture. We developed a complementary strain energy function based method to capture the average biomechanical response. Overall, murine RVFW revealed distinct mechanical anisotropy. The preferential alignment of the myofibres and collagen fibres to the apex-to-outflow-tract direction was consistent with this also being the mechanically stiffer axis. We also observed that the myofibre and collagen fibre orientations were remarkably uniform throughout the entire RVFW thickness. Thus, our findings indicate a close correspondence between the tissue microstructure and biomechanical behaviour of the RVFW myocardium, and are a first step towards elucidating the structure–function of non-contracted murine RVFW myocardium in health and disease. PMID:22848044

  1. Collaborative processing to extract myocardium from a sequence of two-dimensional echocardiograms

    NASA Astrophysics Data System (ADS)

    Revankar, Shriram V.; Sher, David B.; Rosenthal, Steven

    1991-06-01

    Echocardiography is an important clinical method for identification and assessment of the entire spectrum of cardiac diseases. Visual assessment of the echocardiograms is tedious and subjective, but on the other hand, owing to the poor quality of the data, the automatic techniques are unreliable. One can minimize these drawbacks through collaborative processing. The authors describe a collaborative method to extract the myocardium from a sequence of two-dimensional echocardiograms. Initially, a morphologically adaptive thresholding scheme generates a rough estimate of the myocardium, and then a collaborative scheme refines the estimate. The threshold is computed at each pixel as a function of the local morphology and a default threshold. The points that have echodensities greater than the threshold form a rough estimate of the myocardium. This is collaboratively refined in accordance with the corrections specified by the operator, through mouse gestures. The gestures are mapped on to an image processing scheme that decides the precise boundaries of the intended regions that are to be added to or deleted from the estimated myocardium.

  2. Scrib:Rac1 interactions are required for the morphogenesis of the ventricular myocardium

    PubMed Central

    Boczonadi, Veronika; Gillespie, Rachel; Keenan, Iain; Ramsbottom, Simon A.; Donald-Wilson, Charlotte; Al Nazer, Mariana; Humbert, Patrick; Schwarz, Robert J.; Chaudhry, Bill; Henderson, Deborah J.

    2014-01-01

    Aims The organization and maturation of ventricular cardiomyocytes from the embryonic to the adult form is crucial for normal cardiac function. We have shown that a polarity protein, Scrib, may be involved in regulating the early stages of this process. Our goal was to establish whether Scrib plays a cell autonomous role in the ventricular myocardium, and whether this involves well-known polarity pathways. Methods and results Deletion of Scrib in cardiac precursors utilizing Scribflox mice together with the Nkx2.5-Cre driver resulted in disruption of the cytoarchitecture of the forming trabeculae and ventricular septal defects. Although the majority of mice lacking Scrib in the myocardium survived to adulthood, they developed marked cardiac fibrosis. Scrib did not physically interact with the planar cell polarity (PCP) protein, Vangl2, in early cardiomyocytes as it does in other tissues, suggesting that the anomalies did not result from disruption of PCP signalling. However, Scrib interacted with Rac1 physically in embryonic cardiomyocytes and genetically to result in ventricular abnormalities, suggesting that this interaction is crucial for the development of the early myocardium. Conclusions The Scrib–Rac1 interaction plays a crucial role in the organization of developing cardiomyocytes and formation of the ventricular myocardium. Thus, we have identified a novel signalling pathway in the early, functioning, heart muscle. These data also show that the foetus can recover from relatively severe abnormalities in prenatal ventricular development, although cardiac fibrosis can be a long-term consequence. PMID:25139745

  3. Atrial BNP endocrine function during chronic unloading of the normal canine heart.

    PubMed

    Lisy, Ondrej; Redfield, Margaret M; Schirger, John A; Burnett, John C

    2005-01-01

    The goal of the study was to define the effect of chronic unloading of the normal heart on atrial endocrine function with a focus on brain natriuretic peptide (BNP), specifically addressing the role of load and neurohumoral stimulation. Although produced primarily by atrial myocardium in the normal heart, controversy persists with regard to load-dependent vs. neurohumoral mechanisms controlling atrial BNP synthesis and storage. We used a unique canine model of chronic unloading of the heart produced by thoracic inferior vena caval constriction (TIVCC), which also resulted in activation of plasma endothelin (ET-1), ANG II, and norepinephrine (NE), known activators of BNP synthesis, compared with sham. TIVCC was produced by banding of the inferior vena cava for 10 days (n = 6), whereas in control (n = 5) the band was not constricted (sham). In a third group (n = 7), the band was released on day 11, thus acutely reloading the heart. Chronic TIVCC decreased cardiac output and right atrial pressure with a decrease in atrial mass index consistent with atrial atrophy. Atrial BNP mRNA decreased compared with sham. Immunoelectron microscopy revealed an increase in BNP in atrial granules consistent with increased storage. Acute reloading increased cardiac filling pressures and resulted in an increase in plasma BNP. We conclude that chronic unloading of the normal heart results in atrial atrophic remodeling and in suppression of atrial BNP mRNA despite intense stimulation by ET, ANG II, and NE, underscoring the primacy of load in the control of atrial endocrine function and structure.

  4. Atrial Electromechanical Cycle Length Mapping in Paced Canine Hearts In Vivo

    PubMed Central

    Costet, Alexandre; Bunting, Ethan; Grondin, Julien; Gambhir, Alok; Konofagou, Elisa E.

    2015-01-01

    Atrial arrhythmias affect millions of people worldwide. Characterization and study of arrhythmias in the atria in the clinic is currently performed point-by-point using mapping catheters capable of generating maps of the electrical activation rate or cycle length. In this paper, we describe a new ultrasound-based mapping technique called Electromechanical Cycle Length Mapping (ECLM) capable of estimating the electromechanical activation rate, or cycle length, i.e., the rate of the mechanical activation of the myocardium which follows the electrical activation. ECLM relies on frequency analysis of the incremental strain within the atria and can be performed in a single acquisition. ECLM was validated in a canine model paced from the left atrial appendage, against pacing rates within the reported range of cycle lengths previously measured during atrial arrhythmias such as atrial fibrillation. Correlation between the global estimated electromechanical cycle lengths and pacing rates was shown to be excellent (slope = 0.983, intercept = 3.91, r2=0.9999). The effect of the number of cardiac cycles on the performance of ECLM was also investigated and the reproducibility of ECLM was demonstrated (error between consecutive acquisitions for all pacing rates: 6.3 ± 4.3 %). These findings indicate the potential of ECLM for non-invasively characterizing atrial arrhythmias and, provide feedback on the treatment planning of catheter ablation procedures in the clinic. PMID:26168174

  5. [Ocular ischemic syndrome--a case report].

    PubMed

    Zemba, M; Avram, Corina Ioana; Ochinciuc, Uliana; Stamate, Alina Cristina; Camburu, Raluca Lăcrămioara

    2013-01-01

    Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started. PMID:24386788

  6. [Ocular ischemic syndrome--a case report].

    PubMed

    Zemba, M; Avram, Corina Ioana; Ochinciuc, Uliana; Stamate, Alina Cristina; Camburu, Raluca Lăcrămioara

    2013-01-01

    Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started.

  7. Decline of Phosphotransfer and Substrate Supply Metabolic Circuits Hinders ATP Cycling in Aging Myocardium.

    PubMed

    Nemutlu, Emirhan; Gupta, Anu; Zhang, Song; Viqar, Maria; Holmuhamedov, Ekhson; Terzic, Andre; Jahangir, Arshad; Dzeja, Petras

    2015-01-01

    Integration of mitochondria with cytosolic ATP-consuming/ATP-sensing and substrate supply processes is critical for muscle bioenergetics and electrical activity. Whether age-dependent muscle weakness and increased electrical instability depends on perturbations in cellular energetic circuits is unknown. To define energetic remodeling of aged atrial myocardium we tracked dynamics of ATP synthesis-utilization, substrate supply, and phosphotransfer circuits through adenylate kinase (AK), creatine kinase (CK), and glycolytic/glycogenolytic pathways using 18O stable isotope-based phosphometabolomic technology. Samples of intact atrial myocardium from adult and aged rats were subjected to 18O-labeling procedure at resting basal state, and analyzed using the 18O-assisted HPLC-GC/MS technique. Characteristics for aging atria were lower inorganic phosphate Pi[18O], γ-ATP[18O], β-ADP[18O], and creatine phosphate CrP[18O] 18O-labeling rates indicating diminished ATP utilization-synthesis and AK and CK phosphotransfer fluxes. Shift in dynamics of glycolytic phosphotransfer was reflected in the diminished G6P[18O] turnover with relatively constant glycogenolytic flux or G1P[18O] 18O-labeling. Labeling of G3P[18O], an indicator of G3P-shuttle activity and substrate supply to mitochondria, was depressed in aged myocardium. Aged atrial myocardium displayed reduced incorporation of 18O into second (18O2), third (18O3), and fourth (18O4) positions of Pi[18O] and a lower Pi[18O]/γ-ATP[18 O]-labeling ratio, indicating delayed energetic communication and ATP cycling between mitochondria and cellular ATPases. Adrenergic stress alleviated diminished CK flux, AK catalyzed β-ATP turnover and energetic communication in aging atria. Thus, 18O-assisted phosphometabolomics uncovered simultaneous phosphotransfer through AK, CK, and glycolytic pathways and G3P substrate shuttle deficits hindering energetic communication and ATP cycling, which may underlie energetic vulnerability of aging

  8. [Separate evaluation of beta-methyl fatty acid uptake and perfusion in rat myocardium].

    PubMed

    Taniguchi, M; Bunkou, H; Nakajima, K; Taki, J; Muramori, A; Matsunari, I; Nambu, I; Shiirei, Y; Tonami, N; Hisada, K

    1989-12-01

    The kinetics and distribution of I-125 beta-methyl iodophenyl pentadecanoic acid (BMIPP) in rat's heart were studied for separate evaluation of perfusion and metabolism. Tl-201 and BMIPP were simultaneously injected. The experimental groups consisted of control (C), glucose (G) and sodium lactate loaded group (L). In C, myocardial uptake at 5 minutes after BMIPP injection was 3.60% ID/g and remained constant up to 60 minutes. The myocardium/lung ratio (2.44) and the myocardium/muscle ratio (4.55) of BMIPP were almost equal to those of Tl-201. But myocardium/liver ratio was low (1.31). In G, myocardial uptake of BMIPP (1.94 +/- 0.36% ID/g) and g-BMIPP/Tl (0.31 +/- 0.03) at 15 minutes after injection were significantly decreased (p less than 0.001) than those of C (3.16 +/- 0.18% ID/g and 0.48 +/- 0.05). In L. myocardial perfusion was decreased and g-BMIPP/Tl (0.73 +/- 0.14) was significantly higher (p less than 0.01) than those of C. Coefficient of variance of the density within a myocardium, and the ratio of inner to outer layer of myocardium (I/O ratio) were calculated from autoradiogram by videodensitometry. The myocardial distribution of BMIPP was more inhomogeneous, and the I/O ratio was lower than that of Tl-201, although these were not specific for metabolic interventions. In conclusion BMIPP is suitable for SPECT imaging and dual nuclide imaging by BMIPP and Tl-201 will provide informations about myocardial fatty acid metabolism and perfusion. PMID:2622083

  9. Decline of Phosphotransfer and Substrate Supply Metabolic Circuits Hinders ATP Cycling in Aging Myocardium.

    PubMed

    Nemutlu, Emirhan; Gupta, Anu; Zhang, Song; Viqar, Maria; Holmuhamedov, Ekhson; Terzic, Andre; Jahangir, Arshad; Dzeja, Petras

    2015-01-01

    Integration of mitochondria with cytosolic ATP-consuming/ATP-sensing and substrate supply processes is critical for muscle bioenergetics and electrical activity. Whether age-dependent muscle weakness and increased electrical instability depends on perturbations in cellular energetic circuits is unknown. To define energetic remodeling of aged atrial myocardium we tracked dynamics of ATP synthesis-utilization, substrate supply, and phosphotransfer circuits through adenylate kinase (AK), creatine kinase (CK), and glycolytic/glycogenolytic pathways using 18O stable isotope-based phosphometabolomic technology. Samples of intact atrial myocardium from adult and aged rats were subjected to 18O-labeling procedure at resting basal state, and analyzed using the 18O-assisted HPLC-GC/MS technique. Characteristics for aging atria were lower inorganic phosphate Pi[18O], γ-ATP[18O], β-ADP[18O], and creatine phosphate CrP[18O] 18O-labeling rates indicating diminished ATP utilization-synthesis and AK and CK phosphotransfer fluxes. Shift in dynamics of glycolytic phosphotransfer was reflected in the diminished G6P[18O] turnover with relatively constant glycogenolytic flux or G1P[18O] 18O-labeling. Labeling of G3P[18O], an indicator of G3P-shuttle activity and substrate supply to mitochondria, was depressed in aged myocardium. Aged atrial myocardium displayed reduced incorporation of 18O into second (18O2), third (18O3), and fourth (18O4) positions of Pi[18O] and a lower Pi[18O]/γ-ATP[18 O]-labeling ratio, indicating delayed energetic communication and ATP cycling between mitochondria and cellular ATPases. Adrenergic stress alleviated diminished CK flux, AK catalyzed β-ATP turnover and energetic communication in aging atria. Thus, 18O-assisted phosphometabolomics uncovered simultaneous phosphotransfer through AK, CK, and glycolytic pathways and G3P substrate shuttle deficits hindering energetic communication and ATP cycling, which may underlie energetic vulnerability of aging

  10. Reduced expression of CRHR2 and Sp-1 in myocardium of ovariectomized rats is improved by exercise training.

    PubMed

    Tang, Zhiping; Wang, Yujun; Zhu, Xiaoyan; Ni, Xin; Cong, Binhai; Lu, Jianqiang

    2015-01-01

    Exercise training has been looked on as a non-pharmacologic approach to treating ovariectomy (OVX)-induced dysfunctions. In this study, we investigated whether chronic exercise impacts on expression of urocortins (UCNs) and corticotropin-releasing hormone receptor type 2 (CRHR2) in myocardium of OVX rats. Bilateral OVX or sham-operation was performed under anesthesia. Both groups were then divided into two subgroups, with or without treadmill training for 8 weeks. It was found that OVX as well as exercise did not affect the mRNA levels of UCN, UCN2 and UCN3 in myocardium. OVX caused down-regulation of CRHR2 in myocardium. Exercise training reversed the OVX-induced reduction of CRHR2, but had no influence on CRHR2 level in sham rats. OVX resulted in a decrease in estrogen receptor α (ERα) expression in myocardium, which was restored by exercise. Moreover, exercise training also reversed OVX-induced down-regulation of specific protein-1 (Sp-1) expression in myocardium. CRHR2 expression level correlated with Sp-1 and ERα level in myocardium. These results indicate that exercise training can restore the CRHR2 level in myocardium of OVX rats, which is associated with ERα and Sp-1 expression.

  11. [CHANGES BLOOD GAS AND OF FREE RADICAL OXIDATION OF LIPIDS IN THE MYOCARDIUM DURING ADAPTATION TO PHYSICAL STRESS].

    PubMed

    Balykin, M V; Sagidova, S A; Zharkov, A V

    2015-09-01

    The article considers the changes of gas composition, acid-base blood balance, lipid peroxidation processes, and activity of the antioxidant defense system in rat myocardium in the course of adaptation to physical activity (swimming). It has been found out that during the first five days physical activity is accompanied by hypoxia, acidotic blood changes, and increase of lipid peroxidation processes in myocardium. Adaptation to swimming activity (15-30 days) leads to hypoxic and acidotic blood changes, and increases antioxidant defense system in myocardium.

  12. [Catecholamines and their metabolic enzymes in the rat myocardium after a flight on the Kosmos-936 biosatellite].

    PubMed

    Kwetncanski, R; Tigranian, R A; Torda, T

    1982-01-01

    In the myocardium of the weightless and centrifuged rats flown for 18.5 days onboard the biosatellite Cosmos-936 the catecholamine concentration and activity of enzymes involved in their synthesis and degradation--dopamine-beta-hydroxylase, monoamine oxidase and catechol-O-methyl transferase--were measured. The catecholamine concentration in the myocardium of both flight groups significantly increased, and the enzyme activity did not change. These results suggest that an exposure to space flight increases the catecholamine concentration and exerts no effect on their synthesis and degradation in the rat myocardium.

  13. Deterioration of baroreflex by transient global cerebral ischemia: its correlation with the degree of ischemia or post-ischemic hypoperfusion in the medulla oblongata.

    PubMed

    Kurihara, J; Sahara, T; Kato, H

    1989-12-01

    In a canine model of transient global cerebral ischemia, the correlation between the decrease in baroreflex sensitivity (BRS) following 5-min ischemia and the degree of ischemia or post-ischemic hypoperfusion was investigated. Although the medulla oblongata and the cerebral cortex suffered a similar degree of ischemia, the extent of post-ischemic decrease in BRS was inversely correlated with the residual blood flow during ischemia in the medulla, but not with that in the cerebral cortex. A similar degree of post-ischemic hypoperfusion occurred in the medulla and the cerebral cortex. However, the extent of decrease in BRS was not correlated with the degree of hypoperfusion, and the cortical EEG was not significantly affected. These results suggest that the decrease in BRS may be due to the functional damage in the medulla and that the selective decrease in BRS without concomitant impairment of the EEG cannot be ascribed to the regional difference in the degree of ischemia or post-ischemic hypoperfusion. PMID:2615041

  14. Exenatide exerts a PKA-dependent positive inotropic effect in human atrial myocardium: GLP-1R mediated effects in human myocardium.

    PubMed

    Wallner, Markus; Kolesnik, Ewald; Ablasser, Klemens; Khafaga, Mounir; Wakula, Paulina; Ljubojevic, Senka; Thon-Gutschi, Eva Maria; Sourij, Harald; Kapl, Martin; Edmunds, Nicholas J; Kuzmiski, J Brent; Griffith, David A; Knez, Igor; Pieske, Burkert; von Lewinski, Dirk

    2015-12-01

    Glucagon-like peptide-1 receptor (GLP-1R) agonists are a rapidly growing class of drugs developed for treating type-2 diabetes mellitus. Patients with diabetes carry an up to 5-fold greater mortality risk compared to non-diabetic patients, mainly as a result of cardiovascular diseases. Although beneficial cardiovascular effects have been reported, exact mechanisms of GLP-1R-agonist action in the heart, especially in human myocardium, are poorly understood. The effects of GLP-1R-agonists (exenatide, GLP-1(7-36)NH2, PF-06446009, PF-06446667) on cardiac contractility were tested in non-failing atrial and ventricular trabeculae from 72 patients. The GLP-1(7-36)NH2 metabolite, GLP-1(9-36)NH2, was also examined. In electrically stimulated trabeculae, the effects of compounds on isometric force were measured in the absence and presence of pharmacological inhibitors of signal transduction pathways. The role of β-arrestin signaling was examined using a β-arrestin partial agonist, PF-06446667. Expression levels were tested by immunoblots. Translocation of GLP-1R downstream molecular targets, Epac2, GLUT-1 and GLUT-4, were assessed by fluorescence microscopy. All tested GLP-1R-agonists significantly increased developed force in human atrial trabeculae, whereas GLP-1(9-36)NH2 had no effect. Exendin(9-39)NH2, a GLP-1R-antagonist, and H-89 blunted the inotropic effect of exenatide. In addition, exenatide increased PKA-dependent phosphorylation of phospholamban (PLB), GLUT-1 and Epac2 translocation, but not GLUT-4 translocation. Exenatide failed to enhance contractility in ventricular myocardium. Quantitative real-time PCR (qRT-PCR) revealed a significant higher GLP-1R expression in the atrium compared to ventricle. Exenatide increased contractility in a dose-dependent manner via GLP-1R/cAMP/PKA pathway and induced GLUT-1 and Epac2 translocation in human atrial myocardium, but had no effect in ventricular myocardium. Therapeutic use of GLP-1R-agonists may therefore impart

  15. Rhabdomyolysis as a complication of canine babesiosis.

    PubMed

    Jacobson, L S; Lobetti, R G

    1996-06-01

    Rhabdomyolysis was diagnosed in two dogs with babesiosis. The first animal presented with muscle pain and caramel-coloured urine, and had markedly elevated serum myoglobin and muscle enzymes. Acute renal failure complicated the clinical picture. The second dog exhibited muscle pain and tremors, together with neurological signs and pulmonary oedema, and died soon after admission. Muscle necrosis and haemorrhage were found at necropsy. In human malaria, a disease clinically similar to canine babesiosis, rhabdomyolysis is unusual, but clinically silent muscle damage appears to be common. Likewise, biochemical evidence of muscle damage is readily found in experimental bovine babesiosis. Muscle enzymes were mildly elevated in three dogs with severe babesiosis and pigmenturia but there was no obvious muscle damage, indicating that this might also apply to canine babesiosis. The pathogenesis of infection-associated rhabdomyolysis and acute renal failure remains unclear, but inflammatory cytokines and nitric oxide could play an important role. PMID:8965483

  16. Characterization of pantropic canine coronavirus from Brazil.

    PubMed

    Pinto, Luciane D; Barros, Iracema N; Budaszewski, Renata F; Weber, Matheus N; Mata, Helena; Antunes, Jéssica R; Boabaid, Fabiana M; Wouters, Angélica T B; Driemeier, David; Brandão, Paulo E; Canal, Cláudio W

    2014-12-01

    Characterization of canine coronavirus (CCoV) strains currently in circulation is essential for understanding viral evolution. The aim of this study was to determine the presence of pantropic CCoV type IIa in tissue samples from five puppies that died in Southern Brazil as a result of severe gastroenteritis. Reverse-transcriptase PCR was used to generate amplicons for sequence analysis. Phylogenetic analysis of the CCoV-IIa strains indicated that they were similar to those found in other countries, suggesting a common ancestor of these Brazilian isolates. This is the first report of pantropic CCoV-II in puppies from Latin America and our findings highlight that CCoV should be included as a differential diagnosis when dogs present with clinical signs and lesions typically seen with canine parvovirus infection.

  17. Cryptosporidium muris in a Texas canine population.

    PubMed

    Lupo, Philip J; Langer-Curry, Rebecca C; Robinson, Mary; Okhuysen, Pablo C; Chappell, Cynthia L

    2008-06-01

    Molecular technology has led to the discovery of previously unrecognized Cryptosporidium species in new hosts, such as C. canis in humans. The notion that dogs may transmit Cryptosporidium species to humans has significant public health implications, and additional studies are merited. The purpose of this study was to examine a group of kenneled dogs to determine the prevalence of Cryptosporidium species infection and to identify parasite species. Prevalence of active infection was 71%. Six positive samples were analyzed by polymerase chain reaction amplification of the 18S ribosomal RNA gene followed by restriction fragment length polymorphism analysis to identify the Cryptosporidium species. Restriction digest patterns identified C. muris as the infecting species in all six dogs; species identity was confirmed by genetic sequencing. To our knowledge, this is the first report of a naturally occurring C. muris infection in a canine host. The finding of C. muris in asymptomatic canines supports the notion of dogs as potential sources of human infection.

  18. Identification of link proteins in canine synovial cell cultures and canine articular cartilage

    PubMed Central

    1985-01-01

    Link proteins are glycoproteins in cartilage that are involved in the stabilization of aggregates of proteoglycans and hyaluronic acid. We have identified link proteins in synovial cell cultures form normal canine synovium using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunofluorescence, and immunolocation with specific antibodies by electrophoretic transfer. We have also found evidence for the synthesis of link proteins in these cultures by fluorography of radiolabeled synovial cell extracts. We have identified a 70,000 mol-wt protein in canine synovial cell culture extracts that has antigenic cross-reactivity with the 48,000-mol-wt link protein. Three link proteins were identified in normal canine articular cartilage. These results indicate that link proteins are more widely distributed in connective tissues than previously recognized and may have biological functions other than aggregate stabilization. PMID:3980578

  19. Serologic investigations of canine parvovirus and canine distemper in relation to wolf (Canis lupus) pup mortalities.

    PubMed

    Johnson, M R; Boyd, D K; Pletscher, D H

    1994-04-01

    Twenty-one serum samples from 18 wolves (Canis lupus) were collected from 1985 to 1990 from northwestern Montana (USA) and southeastern British Columbia, Canada, and evaluated for antibodies to canine parvovirus (CPV), canine distemper (CD), infectious canine hepatitis, and Lyme disease; we found prevalences of 13 (65%) of 19, five (29%) of 17, seven (36%) of 19, and 0 of 20 wolves for these diseases, respectively. Pups died or disappeared in three of the eight packs studied. In these three packs, adult pack members had CPV titers > or = 1,600 or CD titers > or = 1,250. In packs that successfully raised pups, CPV and CD titers were low. We propose that CPV or CD may have caused some pup mortalities. PMID:8028116

  20. Generation of E3-deleted canine adenoviruses expressing canine parvovirus capsid by homologous recombination in bacteria.

    PubMed

    Morrison, Mark D; Reid, Dorothy; Onions, David; Spibey, Norman; Nicolson, Lesley

    2002-02-01

    E3-deleted canine adenovirus type 1 (CAV-1) was generated by homologous recombination in bacterial cells, using an antibiotic resistance marker to facilitate the recovery of recombinants. This marker was flanked by unique restriction endonuclease sites, which allowed its subsequent removal and the insertion of cassettes expressing the canine parvovirus capsid at the E3 locus. Infectious virus was recovered following transfection of canine cells and capsid expression was observed by RT-PCR from one of the virus constructs. A second construct, containing a different promoter, showed delayed growth and genome instability which, based on the size difference between these inserts, suggests a maximum packaging size of 106 to 109% wild-type genome size for CAV-1. PMID:11853396

  1. Quantification of Shear Deformations and Corresponding Stresses in the Biaxially Tested Human Myocardium.

    PubMed

    Sommer, Gerhard; Haspinger, Daniel Ch; Andrä, Michaela; Sacherer, Michael; Viertler, Christian; Regitnig, Peter; Holzapfel, Gerhard A

    2015-10-01

    One goal of cardiac research is to perform numerical simulations to describe/reproduce the mechanoelectrical function of the human myocardium in health and disease. Such simulations are based on a complex combination of mathematical models describing the passive mechanical behavior of the myocardium and its electrophysiology, i.e., the activation of cardiac muscle cells. The problem in developing adequate constitutive models is the shortage of experimental data suitable for detailed parameter estimation in specific functional forms. A combination of shear and biaxial extension tests with different loading protocols on different specimen orientations is necessary to capture adequately the direction-dependent (orthotropic) response of the myocardium. In most experimental animal studies, where planar biaxial extension tests on the myocardium have been conducted, the generated shear stresses were neither considered nor discussed. Hence, in this study a method is presented which allows the quantification of shear deformations and related stresses. It demonstrates an approach for experimenters as to how the generation of these shear stresses can be minimized during mechanical testing. Experimental results on 14 passive human myocardial specimens, obtained from nine human hearts, show the efficiency of this newly developed method. Moreover, the influence of the clamping technique of the specimen, i.e., the load transmission between the testing device and the tissue, on the stress response is determined by testing an isotropic material (Latex). We identified that the force transmission between the testing device and the specimen by means of hooks and cords does not influence the performed experiments. We further showed that in-plane shear stresses definitely exist in biaxially tested human ventricular myocardium, but can be reduced to a minimum by preparing the specimens in an appropriate manner. Moreover, we showed whether shear stresses can be neglected when performing

  2. Remote detection of explosives using trained canines

    SciTech Connect

    Smith, J.C.

    1983-03-01

    Use of dogs is a search method which combines high probability of detection, speed of search, and low cost. It was concluded that the canine could be used for explosive screening of personnel, but that it was imperative that the dog be in a position remote from employees and employee traffic. A study was made of the design of booths and air flow for this purpose. Results of tests and conclusions are given and discussed. (DLC)

  3. Treatment of canine scabies with milbemycin oxime.

    PubMed

    Miller, W H; de Jaham, C; Scott, D W; Cayatte, S M; Bagladi, M S; Buerger, R G

    1996-04-01

    The purpose of this study was to determine the efficacy of orally administered milbemycin oxime in the treatment of canine scabies. Forty dogs were treated. Mean drug dosage for all dogs was approximately 2 mg/kg body weight. Twenty-seven dogs received 3 doses separated by 7 d, and 13 dogs received 2 doses separated by 14 d. All dogs were clinically normal following treatment and no adverse reactions were detected.

  4. Treatment of canine scabies with milbemycin oxime.

    PubMed Central

    Miller, W H; de Jaham, C; Scott, D W; Cayatte, S M; Bagladi, M S; Buerger, R G

    1996-01-01

    The purpose of this study was to determine the efficacy of orally administered milbemycin oxime in the treatment of canine scabies. Forty dogs were treated. Mean drug dosage for all dogs was approximately 2 mg/kg body weight. Twenty-seven dogs received 3 doses separated by 7 d, and 13 dogs received 2 doses separated by 14 d. All dogs were clinically normal following treatment and no adverse reactions were detected. PMID:8801016

  5. Lipomatous infiltration of the canine salivary gland.

    PubMed

    Brown, P J; Lucke, V M; Sozmen, M; Whitbread, T J; Wyatt, J M

    1997-06-01

    Benign connective tumours of the canine salivary glands are rare. This report describes lipomatous infiltration of parotid or submandibular salivary glands in seven dogs in which the glands were enlarged as a result of infiltration by fat cells; they appeared to have been successfully treated by local excision. The precise cause of the lipomatous infiltration in the dogs is unclear but different causes of similar lesions in humans are discussed.

  6. Clusterin: a protective mediator for ischemic cardiomyocytes?

    PubMed

    Krijnen, P A J; Cillessen, S A G M; Manoe, R; Muller, A; Visser, C A; Meijer, C J L M; Musters, R J P; Hack, C E; Aarden, L A; Niessen, H W M

    2005-11-01

    We examined the relationship between clusterin and activated complement in human heart infarction and evaluated the effect of this protein on ischemic rat neonatal cardiomyoblasts (H9c2) and isolated adult ventricular rat cardiomyocytes as in vitro models of acute myocardial infarction. Clusterin protects cells by inhibiting complement and colocalizes with complement on jeopardized human cardiomyocytes after infarction. The distribution of clusterin and complement factor C3d was evaluated in the infarcted human heart. We also analyzed the protein expression of clusterin in ischemic H9c2 cells. The binding of endogenous and purified human clusterin on H9c2 cells was analyzed by flow cytometry. Furthermore, the effect of clusterin on the viability of ischemically challenged H9c2 cells and isolated adult ventricular rat cardiomyocytes was analyzed. In human myocardial infarcts, clusterin was found on scattered, morphologically viable cardiomyocytes within the infarcted area that were negative for complement. In H9c2 cells, clusterin was rapidly expressed after ischemia. Its expression was reduced after reperfusion. Clusterin bound to single annexin V-positive or annexin V and propidium iodide-positive H9c2 cells. Clusterin inhibited ischemia-induced death in H9c2 cells as well as in isolated adult ventricular rat cardiomyocytes in the absence of complement. We conclude that ischemia induces the upregulation of clusterin in ischemically challenged, but viable, cardiomyocytes. Our data suggest that clusterin protects cardiomyocytes against ischemic cell death via a complement-independent pathway.

  7. [Experimental model of ocular ischemic diseases].

    PubMed

    Kiseleva, T N; Chudin, A V

    2014-01-01

    The review presents the most common methods of modeling of retinal ischemia in vitro (chemical ischemia with iodoacetic acid, incubation of the retinal pigment epithelium cells with oligomycin, deprivation of oxygen and glucose) and in vivo (a model with increased intraocular pressure, cerebral artery occlusion, chronic ligation of the carotid arteries, photocoagulation of the retinal vessels, occlusion of the central retinal artery, endothelin-1 administration). Modeling ischemic injury in rats is the most frequently used method in studies, because the blood supply of their eyes is similar to blood flow in the human eyes. Each method has its own advantages and disadvantages. Application of methods depends on the purpose of the experimental study. Currently model of ocular ischemic disease can be obtained easily by injecting vasoconstrictive drug endothelin-1. It is the most widely used method of high intraocular pressure induced ocular ischemic damage similar to glaucoma, occlusion of central retinal artery or ophthalmic artery in human. The development of experimental models of ocular ischemic diseases and detailed investigation of mechanisms of impairment of microcirculation are useful for improve the efficiency of diagnostic and treatment of ischemic diseases of retina and optic nerve. PMID:25971134

  8. Hypothermia for hypoxic–ischemic encephalopathy

    PubMed Central

    Cotten, C Michael; Shankaran, Seetha

    2010-01-01

    Moderate to severe hypoxic–ischemic injury in newborn infants, manifested as encephalopathy immediately or within hours after birth, is associated with a high risk of either death or a lifetime with disability. In recent multicenter clinical trials, hypothermia initiated within the first 6 postnatal hours has emerged as a therapy that reduces the risk of death or impairment among infants with hypoxic–ischemic encephalopathy. Prior to hypothermia, no therapies directly targeting neonatal encephalopathy secondary to hypoxic–ischemic injury had convincing evidence of efficacy. Hypothermia therapy is now becoming increasingly available at tertiary centers. Despite the deserved enthusiasm for hypothermia, obstetric and neonatology caregivers, as well as society at large, must be reminded that in the clinical trials more than 40% of cooled infants died or survived with impairment. Although hypothermia is an evidence-based therapy, additional discoveries are needed to further improve outcome after HIE. In this article, we briefly present the epidemiology of neonatal encephalopathy due to hypoxic–ischemic injury, describe the rationale for the use of hypothermia therapy for hypoxic–ischemic encephalopathy, and present results of the clinical trials that have demonstrated the efficacy of hypothermia. We also present findings noted during and after these trials that will guide care and direct research for this devastating problem. PMID:20625441

  9. Increasing Incidence of Canine Leptospirosis in Switzerland

    PubMed Central

    Major, Andrea; Schweighauser, Ariane; Francey, Thierry

    2014-01-01

    A marked increase in canine leptospirosis was observed in Switzerland over 10 years with a peak incidence of 28.1 diagnosed cases/100,000 dogs/year in the most affected canton. With 95% affected dogs living at altitudes <800 m, the disease presented a seasonal pattern associated with temperature (r2 0.73) and rainfall (r2 0.39), >90% cases being diagnosed between May and October. The increasing yearly incidence however was only weakly correlated with climatic data including number of summer (r2 0.25) or rainy days (r2 0.38). Serovars Australis and Bratislava showed the highest seropositivity rates with 70.5% and 69.1%, respectively. Main clinical manifestations included renal (99.6%), pulmonary (76.7%), hepatic (26.0%), and hemorrhagic syndromes (18.2%), leading to a high mortality rate (43.3%). Similar to the human disease, liver involvement had the strongest association with negative outcome (OR 16.3). Based on these data, canine leptospirosis presents similar features and severity as the human infection for which it therefore can be considered a model. Its re-emergence in a temperate country with very high incidence rates in canines should thus be viewed as a warning and emphasize the need for increased awareness in other species. PMID:25032740

  10. Increasing incidence of canine leptospirosis in Switzerland.

    PubMed

    Major, Andrea; Schweighauser, Ariane; Francey, Thierry

    2014-07-01

    A marked increase in canine leptospirosis was observed in Switzerland over 10 years with a peak incidence of 28.1 diagnosed cases/100,000 dogs/year in the most affected canton. With 95% affected dogs living at altitudes <800 m, the disease presented a seasonal pattern associated with temperature (r2 0.73) and rainfall (r2 0.39), >90% cases being diagnosed between May and October. The increasing yearly incidence however was only weakly correlated with climatic data including number of summer (r2 0.25) or rainy days (r2 0.38). Serovars Australis and Bratislava showed the highest seropositivity rates with 70.5% and 69.1%, respectively. Main clinical manifestations included renal (99.6%), pulmonary (76.7%), hepatic (26.0%), and hemorrhagic syndromes (18.2%), leading to a high mortality rate (43.3%). Similar to the human disease, liver involvement had the strongest association with negative outcome (OR 16.3). Based on these data, canine leptospirosis presents similar features and severity as the human infection for which it therefore can be considered a model. Its re-emergence in a temperate country with very high incidence rates in canines should thus be viewed as a warning and emphasize the need for increased awareness in other species. PMID:25032740

  11. Cytodiagnostics of canine lymphomas - possibilities and limitations.

    PubMed

    Sapierzyński, R; Kliczkowska-Klarowicz, K; Jankowska, U; Jagielski, D

    2016-01-01

    Malignant lymphomas are one of the most common malignant tumours occurring in dogs. The basic method of lymphoma diagnosis in human, as well as in canine oncology is histopathology supported by immunohistochemistry. It was suggested that in veterinary medicine excisional biopsy of lymph node and histopathology should be considered only where the cytologic diagnosis is equivocal or needs to be confirmed. There are at least three basic reasons for which cytological examination ought to be accepted as a sufficient and reliable diagnostic method for lymphoma in dogs. Firstly, most dog owners consider the fine-needle biopsy as an acceptable non-harmful method of sample collection. Secondly, an increasing number of studies recommend cytology as an accurate test for diagnosing and subtyping canine lymphoma. Finally, the vast majority of canine lymphoma subtypes belong to 4-5 categories characterized by a typical cytological picture. Immunocytochemical staining of cytological smears gives new diagnostic possibilities, such as detection of markers better characterizing given growth or a potential goal for target therapy in individual cases (for example inhibitors of platelet-derived growth factor). PMID:27487521

  12. Identification of canine helper T-cell epitopes from the fusion protein of canine distemper virus

    PubMed Central

    Ghosh, Souravi; Walker, John; Jackson, David C

    2001-01-01

    The fusion protein of canine distemper virus (CDV-F), a 662 amino-acid envelope protein, was used as the target molecule for identification of canine T helper (Th) epitopes. A library of 94 peptides, each 17 residues in length overlapping by 10 residues and covering the entire sequence of CDV-F, was screened using a lymphocyte proliferation assay with peripheral blood mononuclear cells (PBMC) obtained from dogs inoculated with canine distemper virus (CDV) vaccine. Initially we observed low and inconsistent proliferation of PBMC in response to these peptides, even when using cells obtained from dogs that had received multiple doses of CDV. Subsequently, the use of expanded cell populations derived by in vitro stimulation of canine PBMC with pools of peptides allowed the identification of a number of putative canine Th-epitopes within the protein sequence of CDV-F. There were two major clusters of Th-epitopes identified close to the cleavage site of the F0 fusion protein, while some others were scattered in both the F1 and F2 fragments of the protein. Some of these peptides, in particular peptide 35 (p35), were stimulatory in dogs of different breeds and ages. The identification of such promiscuous canine Th-epitopes encouraged us to assemble p35 in tandem with luteinising hormone releasing hormone (LHRH) a 10 amino-acid residue synthetic peptide representing a B-cell epitope which alone induces no antibody in dogs. The totally synthetic immunogen was able to induce the production of very high titres of antibodies against LHRH in all dogs tested. These results indicate that p35 could be an ideal candidate for use as a Th-epitope for use in outbred dogs. PMID:11576221

  13. [Echocardiographic evaluation of ischemic cardiopathy].

    PubMed

    Asin Cardiel, E; Yuste, P; Señor, J; Palma, J; Martínez-Bordiu, C

    1976-01-01

    We studied a group of patients with ischemic heart disease divided into two groups: Group I coronary insufficiency. Group II myocardial infaction. We centered the work on the following aspects: analysis of the contractility; evaluation of the movement of the ventricular wall and of the septum; movement of the mitral valve; diagnosis of ventricular dyskinesias, akinesias, and hypokinesias. The patients in group I did not show significant alterations in the values of the ejection fraction and speed of circunferential shortening. The mean values of these parimeters are significantly less than the group of patients with infarcts, and 41% of these patients have EF less than 50% and Vcf less than 0.9. We did not find a correlation between these perimeters and the localization of the infarct. The velocity of the posterior ventricular wall was disminished in both groups of patients. The amplitude of movement of the posterior wall was reduced in the group of patients with infarctions. These parimeters were more altered in the posterior infarcts than in those with anterior localization and they are more an index of the state of the posterior wall than of the ventricular contractility considered overall, contary to mitral descriptions. In 3 cases of acute infarct we found paradoxical movement of the septum, which normalized itself in one patient in 6 months. In 6 other patients with old infarct we observed localized dyskinesias of the septum and of the free wall of the left ventricle. The mitral valve appears altered in a great proportion of coronary patients the most notorious characteristics being: a decrease in the EF pendent; an increase of the F index. These findings are considered in relation with the ventricular pressures and with the degree of distensibility of the left ventricle.

  14. Granulocyte-colony stimulating factor therapy to induce neovascularization in ischemic heart disease.

    PubMed

    Ripa, Rasmus Sejersten

    2012-03-01

    Cell based therapy for ischemic heart disease has the potential to reduce post infarct heart failure and chronic ischemia. Treatment with granulocyte-colony stimulating factor (G-CSF) mobilizes cells from the bone marrow to the peripheral blood. Some of these cells are putative stem or progenitor cells. G-CSF is injected subcutaneously. This therapy is intuitively attractive compared to other cell based techniques since repeated catheterizations and ex vivo cell purification and expansion are avoided. Previous preclinical and early clinical trials have indicated that treatment with G-CSF leads to improved myocardial perfusion and function in acute or chronic ischemic heart disease. The hypothesis of this thesis is that patient with ischemic heart disease will benefit from G-CSF therapy. We examined this hypothesis in two clinical trials with G-CSF treatment to patients with either acute myocardial infarction or severe chronic ischemic heart disease. In addition, we assed a number of factors that could potentially affect the effect of cell based therapy. Finally, we intended to develop a method for in vivo cell tracking in the heart. Our research showed that subcutaneous G-CSF along with gene therapy do not improve myocardial function in patients with chronic ischemia despite a large increase in circulation bone marrow-derived cells. Also, neither angina pectoris nor exercise capacity was improved compared to placebo treatment. We could not identify differences in angiogenic factors or bone marrow-derived cells in the blood that could explain the neutral effect of G-CSF. Next, we examined G-CSF as adjunctive therapy following ST segment elevation myocardial infarction. We did not find any effect of G-CSF neither on the primary endpoint--regional myocardial function--nor on left ventricular ejection fraction (secondary endpoint) compared to placebo treatment. In subsequent analyses, we found significant differences in the types of cells mobilized from the bone marrow

  15. Type II secretory phospholipase A2 binds to ischemic flip-flopped cardiomyocytes and subsequently induces cell death.

    PubMed

    Nijmeijer, R; Willemsen, M; Meijer, C J L M; Visser, C A; Verheijen, R H; Gottlieb, R A; Hack, C E; Niessen, H W M

    2003-11-01

    Type II secretory phospholipase A2 (sPLA2) is a cardiovascular risk factor. We recently found depositions of sPLA2 in the necrotic center of infarcted human myocardium and normally appearing cardiomyocytes adjacent to the border zone. The consequences of binding of sPLA2 to ischemic cardiomyocytes are not known. To explore a potential effect of sPLA2 on ischemic cardiomyocytes at a cellular level we used an in vitro model. The cardiomyocyte cell line H9c2 or adult cardiomyocytes were isolated from rabbits that were incubated with sPLA2 in the presence of metabolic inhibitors to mimic ischemia-reperfusion conditions. Cell viability was established with the use of annexin V and propidium iodide or 7-aminoactinomycin D. Metabolic inhibition induced an increase of the number of flip-flopped cells, including a population that did not stain with propidium iodide and that was caspase-3 negative. sPLA2 bound to the flip-flopped cells, including those negative for caspase-3. sPLA2 binding induced cell death in these latter cells. In addition, sPLA2 potentiated the binding of C-reactive protein (CRP) to these cells. We conclude that by binding to flip-flopped cardiomyocytes, including those that are caspase-3 negative and presumably reversibly injured, sPLA2 may induce cell death and tag these cells with CRP.

  16. Mechanism of ischemic contracture in ferret hearts: relative roles of [Ca2+]i elevation and ATP depletion.

    PubMed

    Koretsune, Y; Marban, E

    1990-01-01

    When coronary perfusion is interrupted, the diastolic force generated by the myocardium first falls but eventually increases. The delayed rise in force, ischemic contracture, has been attributed either to ATP depletion or to elevation of the intracellular free calcium concentration ([Ca2+]i). To distinguish between these possibilities, we measured [Ca2+]i and ATP concentration [( ATP]) in ferret hearts using nuclear magnetic resonance (NMR) spectroscopy. Mean time-average [Ca2+]i and [ATP] equaled 0.25 microM and 2.7 mumol/g wet wt, respectively, under control perfusion conditions. [Ca2+]i increased and [ATP] fell during total global ischemia. Although [Ca2+]i exceeded the usual systolic levels of 1.7 microM within 20-25 min of ischemia and reached a steady level between 2 and 3 microM by 30-35 min, force only began to rise after 40 min. In contrast, the time required for [ATP] to fall to less than 10% of control levels coincided closely with the onset of contracture. Ischemia in the presence of iodoacetate, an inhibitor of glycolysis, led to a precipitous fall in [ATP] and a concomitant rise in force, both of which preceded any elevation of [Ca2+]i. Thus changes in [Ca2+]i are neither sufficient nor necessary for the initiation of ischemic contracture. We conclude that ATP depletion is primary and that the rise in resting force reflects the formation of rigor cross bridges.

  17. Cardiac magnetic resonance determinants of functional mitral regurgitation in ischemic and non ischemic left ventricular dysfunction.

    PubMed

    Fernández-Golfín, Covadonga; De Agustin, Alberto; Manzano, M Carmen; Bustos, Ana; Sánchez, Tibisay; Pérez de Isla, Leopoldo; Fuentes, Manuel; Macaya, Carlos; Zamorano, José

    2011-04-01

    Functional mitral regurgitation (FMR) is frequent in left ventricular (LV) dilatation/dysfunction. Echocardiographic predictors of FMR are known. However, cardiac magnetic resonance (CMR) predictors of FMR have not been fully addressed. The aim of the study was to evaluate CMR mitral valve (MV) parameters associated with FMR in ischemic and non ischemic LV dysfunction. 80 patients with LV ejection fraction below 45% and/or left ventricular dilatation of ischemic and non ischemic etiology were included. Cine-MR images (steady state free-precession) were acquired in a short-axis and 4 chambers views where MV evaluation was performed. Delayed enhancement was performed as well. Significant FMR was established as more than mild MR according to the echocardiographic report. Mean age was 59 years, males 79%. FMR was detected in 20 patients (25%) Significant differences were noted in LV functional parameters and in most MV parameters according to the presence of significant FMR. However, differences were noted between ischemic and non ischemic groups. In the first, differences in most MV parameters remained significant while in the non ischemic, only systolic and diastolic interpapillary muscle distance (1.60 vs. 2.19 cm, P = 0.001; 2. 51 vs. 3.04, P = 0.008) were predictors of FMR. FMR is associated with a more severe LV dilatation/dysfunction in the overall population. CMR MV parameters are associated with the presence of significant FMR and are different between ischemic and non ischemic patients. CMR evaluation of these patients may help in risk stratification as well as in surgical candidate selection.

  18. Spectroscopic Monitoring of Kidney Tissue Ischemic Injury

    SciTech Connect

    Demos, S G; Fitzgerald, J T; Michalopoulou, A P; Troppmann, C

    2004-03-11

    Noninvasive evaluation of tissue viability of donor kidneys used for transplantation is an issue that current technology is not able to address. In this work, we explore optical spectroscopy for its potential to assess the degree of ischemic damage in kidney tissue. We hypothesized that ischemic damage to kidney tissue will give rise to changes in its optical properties which in turn may be used to asses the degree of tissue injury. The experimental results demonstrate that the autofluorescence intensity of the injured kidney is decreasing as a function of time exposed to ischemic injury. Changes were also observed in the NIR light scattering intensities most probably arising from changes due to injury and death of the tissue.

  19. Resilience in Patients with Ischemic Heart Disease

    PubMed Central

    de Lemos, Conceição Maria Martins; Moraes, David William; Pellanda, Lucia Campos

    2016-01-01

    Background Resilience is a psychosocial factor associated with clinical outcomes in chronic diseases. The relationship between this protective factor and certain diseases, such heart diseases, is still under-explored. Objective The present study sought to investigate the frequency of resilience in individuals with ischemic heart disease. Method This was a cross-sectional study with 133 patients of both genders, aged between 35 and 65 years, treated at Rio Grande do Sul Cardiology Institute - Cardiology University Foundation, with a diagnosis of ischemic heart disease during the study period. Sixty-seven patients had a history of acute myocardial infarction. The individuals were interviewed and evaluated by the Wagnild & Young resilience scale and a sociodemographic questionnaire. Results Eighty-one percent of patients were classified as resilient according to the scale. Conclusion In the sample studied, resilience was identified in high proportion among patients with ischemic heart disease. PMID:26815312

  20. Cerebrovascular arteriopathy (arteriosclerosis) and ischemic childhood stroke.

    PubMed

    Daniels, S R; Bates, S; Lukin, R R; Benton, C; Third, J; Glueck, C J

    1982-01-01

    The aim of this report is to describe the intracranial cerebrovascular abnormalities and clinical status of 8 children who had familial lipoprotein disorders and evidence of thromboembolic cerebrovascular disease. Six of the 8 children had low levels of plasma high density lipoprotein cholesterol, two had high triglyceride levels, and all came from kindreds characterized by familial lipoprotein abnormalities and premature cardio- and/or cerebrovascular atherosclerosis. Vascular occlusion, irregularities of the arterial lumen, beading, tortuosity, and evidence of collateralization were consistently noted. We speculate that cerebrovascular arteriosclerosis in pediatric ischemic stroke victims who have familial lipoprotein abnormalities may be related to lipoprotein-mediated endothelial damage and thrombosis formation, or to the failure to restore endothelial cells' integrity following damage. The apparent association of lipoproteins and strokes in children and their families merits further exploration, particularly when assessing cerebral angiograms in pediatric ischemic stroke victims. In children with unexplained ischemic cerebrovascular accidents, the diagnostic possibility of occlusive arteriosclerosis with thrombosis must be entertained.

  1. [Vascular brain lesions and ischemic heart disease].

    PubMed

    Levin, G Z

    1979-01-01

    The role of essential hypertension in the pathogenesis of cerebral vessel disorders (not only hemorrhagic, but also ischemic) is greater than in the pathogenesis of the heart ischemic disease. An analysis of the evidences left by ancient doctors, when compared with statistical data of our time, gives one grounds to believe that cerebral hemorrhages have been a rather common disease, at least, since the time of the antique civilization of Greece and Rome, whereas ischemic heart disease has become a widespread disease among the population of the developed countries only in our time. This makes it possible to assume that the role of essential hypertension and that of atherosclerosis are not equal in the "diseases of civilization", if the diseases of today's developed society are meant.

  2. The association of migraine with ischemic stroke.

    PubMed

    Kurth, Tobias

    2010-03-01

    Migraine is a common, chronic-intermittent primary headache disorder affecting mostly women. The migraine pathophysiology involves both the neuronal and vascular systems, and in some patients, transient neurologic symptoms occur, which are known as migraine aura. A large body of literature supports an association between migraine and ischemic stroke, which is apparent mostly in young women with migraine with aura. Further increased risks have been observed particularly in smokers and women who use oral contraceptives. The vast majority of individual studies, as well as a recent meta-analysis, did not find an association between migraine without aura and ischemic stroke. Although there are several hypotheses about potential biological mechanisms linking migraine with aura to ischemic stroke, the precise causes remain unclear. Because the absolute risk of stroke is considerably low in patients with migraine, the vast majority of migraine patients will not experience a stroke event because of the migraine.

  3. Segmentation of scarred and non-scarred myocardium in LG enhanced CMR images using intensity-based textural analysis.

    PubMed

    Kotu, Lasya Priya; Engan, Kjersti; Eftestøl, Trygve; Ørn, Stein; Woie, Leik

    2011-01-01

    The Late Gadolinium (LG) enhancement in Cardiac Magnetic Resonance (CMR) imaging is used to increase the intensity of scarred area in myocardium for thorough examination. Automatic segmentation of scar is important because scar size is largely responsible in changing the size, shape and functioning of left ventricle and it is a preliminary step required in exploring the information present in scar. We have proposed a new technique to segment scar (infarct region) from non-scarred myocardium using intensity-based texture analysis. Our new technique uses dictionary-based texture features and dc-values to segment scarred and non-scarred myocardium using Maximum Likelihood Estimator (MLE) based Bayes classification. Texture analysis aided with intensity values gives better segmentation of scar from myocardium with high sensitivity and specificity values in comparison to manual segmentation by expert cardiologists.

  4. Enhanced infarct myocardium repair mediated by thermosensitive copolymer hydrogel-based stem cell transplantation

    PubMed Central

    Xia, Yu; Zhu, Kai; Lai, Hao; Lang, Meidong; Xiao, Yan; Lian, Sheng

    2015-01-01

    Mesenchymal stem cell (MSC) transplantation by intramyocardial injection has been proposed as a promising therapy strategy for cardiac repair after myocardium infarction. However, low retention and survival of grafted MSCs hinder its further application. In this study, copolymer with N-isopropylacrylamide/acrylic acid/2-hydroxylethyl methacrylate-poly(ɛ-caprolactone) ratio of 88:9.6:2.4 was bioconjugated with type I collagen to construct a novel injectable thermosensitive hydrogel. The injectable and biocompatible hydrogel-mediated MSC transplantation could enhance the grafted cell survival in the myocardium, which contributed to the increased neovascularization, decreased interstitial fibrosis, and ultimately improved heart function to a significantly greater degree than regular MSC transplantation. We suggest that this novel hydrogel has the potential for future stem cell transplantation. PMID:25432986

  5. [CHANGES IN THE METABOLISM IN THE MYOCARDIUM OF RATS WITH ARTERIAL HYPERTENSION].

    PubMed

    Dovgan, R S; Zagorodnyi, M I

    2015-01-01

    In the myocardium of the rats with arterial hypertension marked increase in the amount of unsaturated fatty acids and polyunsaturated fatty acids. Reducing the concentration of palmitic acid and increased levels of arachidonic acid is considered as one of the factors that lead to the development of energy deficit and oxidative stress. In rats, with hypertension myocardial lactate concentration increases in the cytoplasmic fraction and reducing the amount of ATP. The level in the cytoplasmic and mitochondrial fractions above benchmarks, indicating about the change of antioxidant systems of the body In the cytoplasm and mitochondria of cardiomyocytes of the rats with arterial hypertension marked decrease in the activity of antioxidant enzymes: NO-synthase, catalase, glutathione reductase, which causes metabolic changes of the myocardium. PMID:27491168

  6. [Hibernating and stunned myocardium. Pathogenetic mechanisms during and after myocardial ischemia].

    PubMed

    Carella, Giovanni; Mazzone, Marinella; Forte, Paola; Buccelletti, Francesco; Portale, Grazia

    2002-10-01

    In this paper the Authors consider the concept of stunning/hibernating myocardium, analizing the most recent articles and reviews in literature, until April 2002 (database PubMed). Dysfunctional segments with normal perfusion and normal glucose utilization are considered to be "stunned", and dysfunctional segments with reduced perfusion and preserved glucose utilization are considered to be "hibernated". Together with the two major hypothesis (generation of oxygen-derived free radicals and transient calcium overload) in developing of dysfunctional myocardium after ischaemia, recent studies have demonstrated an important role in down-regulation of beta-adrenergic receptors both in the stunned and in the hibernated segments. Moreover, the increase of negatively inotropic cytokines TNF-alpha and NOS2 has been observed in dysfunctional segments. The number of copies of mRNA has been quantified by reverse transcription-polymerase chain reaction (reverse-PCR).

  7. A structurally based viscoelastic model for passive myocardium in finite deformation

    NASA Astrophysics Data System (ADS)

    Shen, Jing Jin

    2016-09-01

    This paper discusses the finite-deformation viscoelastic modeling for passive myocardium tissue. The formulations established can also be applied to model other fiber-reinforced soft tissue. Based on the morphological structure of the myocardium, a specific free-energy function is constructed to reflect its orthotropicity. After deriving the stress-strain relationships in the simple shear deformation, a genetic algorithm is used to optimally estimate the material parameters of the myocardial constitutive equation. The results show that the proposed myocardial model can well fit the shear experimental data. To validate the viscoelastic model, it is used to predict the creep and the dynamic responses of a cylindrical model of the left ventricle. Upon comparing the results calculated by the proven myocardial elastic model with those by the viscoelastic model, the merits of the latter are discussed.

  8. Age-dependent changes in expression of alpha/sub 1/-adrenergic receptors in rat myocardium

    SciTech Connect

    Schaffer, W.; Williams, R.S.

    1986-07-16

    The expression of alpha/sub 1/-adrenergic receptors within ventricular myocardium of rats ranging in age from 21 days of fetal life to 24 months after birth was measured from (/sup 125/I) 2-(..beta.. hydroxy phenyl) ethylaminomethyl tetralone binding isotherms. No difference was observed in binding affinity between any of the age groups studied. The number of alpha/sub 1/-adrenergic receptors was found to be 60-120% higher in membranes from fetal or immature rats up to 25 days of age when compared with adult animals. The increased expression of alpha/sub 1/-adrenergic receptors in the developing heart relative to that observed in adult heart is consistent with the hypothesis that alpha/sub 1/-adrenergic receptor stimulation may modulate protein synthesis and growth in mammalian myocardium.

  9. Motion estimation and compensation for coronary artery and myocardium in cardiac CT

    NASA Astrophysics Data System (ADS)

    Tang, Qiulin; Matthews, James; Razeto, Marco; Linde, Jesper J.; Nakanishi, Satoru

    2015-03-01

    Motion blurring is still a challenge for cardiac CT imaging. A new motion estimation (ME) and motion compensation method is developed for cardiac CT. The proposed method estimates motion of entire heart, and then applies motion compensation. Therefore, the proposed method reduces motion artifacts not only in coronary artery region as most other methods did, but also reduces motion blurring in myocardium region. In motion compensated reconstruction, we use the Fourier transfer method proposed by Pack et al to obtain a series of partial images, and then warp and sum together to obtain final motion compensated images. The robustness and performance of the proposed method was verified with data from 10 patients and improvements in sharpness of both coronary arteries and myocardium were obtained.

  10. Second harmonic generation imaging of the collagen in myocardium for atrial fibrillation diagnosis

    NASA Astrophysics Data System (ADS)

    Tsai, Ming-Rung; Chiou, Yu-We; Sun, Chi-Kuang

    2009-02-01

    Myocardial fibrosis, a common sequela of cardiac hypertrophy, has been shown to be associated with arrhythmias in experimental models. Some research has indicated that myocardial fibrosis plays an important role in predisposing patients to atrial fibrillation. Second harmonic generation (SHG) is an optically nonlinear coherent process to image the collagen network. In this presentation, we observe the SHG images of the collagen matrix in atrial myocardium and we analyzed of collagen fibers arrangement by using Fourier-transform analysis. Moreover, comparing the SHG images of the collagen fibers in atrial myocardium between normal sinus rhythm (NSR) and atrial fibrillation (AF), our result indicated that it is possible to realize the relation between myocardial fibrosis and AF.

  11. Myoblasts transplanted into rat infarcted myocardium are functionally isolated from their host

    PubMed Central

    Léobon, Bertrand; Garcin, Isabelle; Menasché, Philippe; Vilquin, Jean-Thomas; Audinat, Etienne; Charpak, Serge

    2003-01-01

    Survival and differentiation of myogenic cells grafted into infarcted myocardium have raised the hope that cell transplantation becomes a new therapy for cardiovascular diseases. The approach was further supported by transplantation of skeletal myoblasts, which was shown to improve cardiac performance in several animal species. Despite the success of myoblast transplantation and its recent trial in human, the mechanism responsible for the functional improvement remains unclear. Here, we used intracellular recordings coupled to video and fluorescence microscopy to establish whether myoblasts, genetically labeled with enhanced GFP and transplanted into rat infarcted myocardium, retain excitable and contractile properties, and participate actively to cardiac function. Our results indicate that grafted myoblasts differentiate into peculiar hyperexcitable myotubes with a contractile activity fully independent of neighboring cardiomyocytes. We conclude that mechanisms other than electromechanical coupling between grafted and host cells are involved in the improvement of cardiac function. PMID:12805561

  12. Role of platelet-activating factor in polymorphonuclear neutrophil recruitment in reperfused ischemic rabbit heart.

    PubMed Central

    Montrucchio, G.; Alloatti, G.; Mariano, F.; Comino, A.; Cacace, G.; Polloni, R.; De Filippi, P. G.; Emanuelli, G.; Camussi, G.

    1993-01-01

    This study investigated the role of platelet-activating factor in the recruitment of polymorphonuclear neutrophils (PMN) in a rabbit model of cardiac ischemia and reperfusion. The accumulation of PMN was evaluated 2 and 24 hours after removal of 40 minutes of coronary occlusion by morphometric analysis and 111In-labeled PMN infiltration. The administration of two structurally unrelated platelet-activating factor-receptor antagonists (SDZ 63-675, 5 mg/kg body weight, and WEB 2170, 5 mg/kg body weight) before reperfusion significantly reduced the accumulation of PMN, as well as the hemodynamic alterations and the size of necrotic area. Two hours after reperfusion, the percentage of increase of 111In-labeled PMN in transmural central ischemic zone was significantly reduced in rabbits pretreated with SDZ 63-675 (51.4 +/- 7.9) or WEB 2170 (32.4 +/- 8.8) with respect to untreated rabbits (107.6 +/- 13.5). The morphometric analysis of myocardial sections confirmed the reduction of PMN infiltration at 2 hours and demonstrated that at 24 hours the phenomenon was even more significant. In addition, SDZ 63-675 and WEB 2170 prevented early transient bradycardia and hypotension and reduced the infarct size, judged by staining with tetrazolium at 2 and 24 hours after reperfusion, and by histological examination at 24 hours. These results suggest that platelet-activating factor is involved in the accumulation of PMN in the reperfused ischemic myocardium and contributes to the evolution of myocardial injury. Images Figure 5 Figure 6 PMID:8434642

  13. Cardioprotection by systemic dosing of thymosin beta four following ischemic myocardial injury

    PubMed Central

    Bao, Weike; Ballard, Victoria L.; Needle, Saul; Hoang, Bao; Lenhard, Stephen C.; Tunstead, James R.; Jucker, Beat M.; Willette, Robert N.; Pipes, G. Teg

    2013-01-01

    Thymosin beta 4 (Tβ4) was previously shown to reduce infarct size and improve contractile performance in chronic myocardial ischemic injury via two phases of action: an acute phase, just after injury, when Tβ4 preserves ischemic myocardium via antiapoptotic or anti-inflammatory mechanisms; and a chronic phase, when Tβ4 activates the growth of vascular or cardiac progenitor cells. In order to differentiate between the effects of Tβ4 during the acute and during the chronic phases, and also in order to obtain detailed hemodynamic and biomarker data on the effects of Tβ4 treatment suitable for use in clinical studies, we tested Tβ4 in a rat model of chronic myocardial ischemia using two dosing regimens: short term dosing (Tβ4 administered only during the first 3 days following injury), and long term dosing (Tβ4 administered during the first 3 days following injury and also every third day until the end of the study). Tβ4 administered throughout the study reduced infarct size and resulted in significant improvements in hemodynamic performance; however, chamber volumes and ejection fractions were not significantly improved. Tβ4 administered only during the first 3 days following injury tended to reduce infarct size, chamber volumes and improve hemodynamic performance. Plasma biomarkers of myocyte injury were significantly reduced by Tβ4 treatment during the acute injury period, and plasma ANP levels were significantly reduced in both dosing groups. Surprisingly, neither acute nor chronic Tβ4 treatment significantly increased blood vessel density in peri-infarct regions. These results suggest the following: repeated dosing may be required to achieve clinically measureable improvements in cardiac function post-myocardial infarction (MI); improvement in cardiac function may be observed in the absence of a high degree of angiogenesis; and that plasma biomarkers of cardiac function and myocardial injury are sensitive pharmacodynamic biomarkers of the effects of T

  14. Myocardial regeneration by activation of multipotent cardiac stem cells in ischemic heart failure

    NASA Astrophysics Data System (ADS)

    Urbanek, Konrad; Torella, Daniele; Sheikh, Farooq; de Angelis, Antonella; Nurzynska, Daria; Silvestri, Furio; Beltrami, C. Alberto; Bussani, Rossana; Beltrami, Antonio P.; Quaini, Federico; Bolli, Roberto; Leri, Annarosa; Kajstura, Jan; Anversa, Piero

    2005-06-01

    In this study, we tested whether the human heart possesses a cardiac stem cell (CSC) pool that promotes regeneration after infarction. For this purpose, CSC growth and senescence were measured in 20 hearts with acute infarcts, 20 hearts with end-stage postinfarction cardiomyopathy, and 12 control hearts. CSC number increased markedly in acute and, to a lesser extent, in chronic infarcts. CSC growth correlated with the increase in telomerase-competent dividing CSCs from 1.5% in controls to 28% in acute infarcts and 14% in chronic infarcts. The CSC mitotic index increased 29-fold in acute and 14-fold in chronic infarcts. CSCs committed to the myocyte, smooth muscle, and endothelial cell lineages increased 85-fold in acute infarcts and 25-fold in chronic infarcts. However, p16INK4a-p53-positive senescent CSCs also increased and were 10%, 18%, and 40% in controls, acute infarcts, and chronic infarcts, respectively. Old CSCs had short telomeres and apoptosis involved 0.3%, 3.8%, and 9.6% of CSCs in controls, acute infarcts, and chronic infarcts, respectively. These variables reduced the number of functionally competent CSCs from 26,000/cm3 of viable myocardium in acute to 7,000/cm3 in chronic infarcts, respectively. In seven acute infarcts, foci of spontaneous myocardial regeneration that did not involve cell fusion were identified. In conclusion, the human heart possesses a CSC compartment, and CSC activation occurs in response to ischemic injury. The loss of functionally competent CSCs in chronic ischemic cardiomyopathy may underlie the progressive functional deterioration and the onset of terminal failure. cardiac progenitor cells | human heart | myocardial infarction

  15. Drug Delivery to the Ischemic Brain

    PubMed Central

    Thompson, Brandon J.; Ronaldson, Patrick T.

    2014-01-01

    Cerebral ischemia occurs when blood flow to the brain is insufficient to meet metabolic demand. This can result from cerebral artery occlusion that interrupts blood flow, limits CNS supply of oxygen and glucose, and causes an infarction/ischemic stroke. Ischemia initiates a cascade of molecular events inneurons and cerebrovascular endothelial cells including energy depletion, dissipation of ion gradients, calcium overload, excitotoxicity, oxidative stress, and accumulation of ions and fluid. Blood-brain barrier (BBB) disruption is associated with cerebral ischemia and leads to vasogenic edema, a primary cause of stroke-associated mortality. To date, only a single drug has received US Food and Drug Administration (FDA) approval for acute ischemic stroke treatment, recombinant tissue plasminogen activator (rt-PA). While rt-PA therapy restores perfusion to ischemic brain, considerable tissue damage occurs when cerebral blood flow is re-established. Therefore, there is a critical need for novel therapeutic approaches that can “rescue” salvageable brain tissue and/or protect BBB integrity during ischemic stroke. One class of drugs that may enable neural cell rescue following cerebral ischemia/reperfusion injury is the HMG-CoA reductase inhibitors (i.e., statins). Understanding potential CNS drug delivery pathways for statins is critical to their utility in ischemic stroke. Here, we review molecular pathways associated with cerebral ischemia and novel approaches for delivering drugs to treat ischemic disease. Specifically, we discuss utility of endogenous BBB drug uptake transporters such as organic anion transporting polypeptides (OATPs/Oatps) and nanotechnology-based carriers for optimization of CNS drug delivery. Overall, this chapter highlights state-of-the-art technologies that may improve pharmacotherapy of cerebral ischemia. PMID:25307217

  16. Implantation of a Novel Allogeneic Mesenchymal Precursor Cell Type in Patients with Ischemic Cardiomyopathy Undergoing Coronary Artery Bypass Grafting: an Open Label Phase IIa Trial.

    PubMed

    Anastasiadis, Kyriakos; Antonitsis, Polychronis; Westaby, Stephen; Reginald, Ajan; Sultan, Sabena; Doumas, Argirios; Efthimiadis, George; Evans, Martin John

    2016-06-01

    Heart failure is a life-limiting condition affecting over 40 million patients worldwide. Ischemic cardiomyopathy (ICM) is the most common cause. This study investigates in situ cardiac regeneration utilizing precision delivery of a novel mesenchymal precursor cell type (iMP) during coronary artery bypass surgery (CABG) in patients with ischemic cardiomyopathy (LVEF < 40 %). The phase IIa safety study was designed to enroll 11 patients. Preoperative scintigraphy imaging (SPECT) was used to identify hibernating myocardium not suitable for conventional myocardial revascularization for iMP implantation. iMP cells were implanted intramyocardially in predefined viable peri-infarct areas that showed poor perfusion, which could not be grafted due to poor target vessel quality. Postoperatively, SPECT was then used to identify changes in scar area. Intramyocardial implantation of iMP cells with CABG was safe with preliminary evidence of efficacy of improved myocardial contractility and perfusion of nonrevascularized territories resulting in a significant reduction in left ventricular scar area at 12 months after treatment. Clinical improvement was associated with a significant improvement in quality of life at 6 months posttreatment in all patients. The results suggest the potential for in situ myocardial regeneration in ischemic heart failure by delivery of iMP cells. PMID:27037806

  17. Effect of ethanol and the catalase inhibitor aminotriazole on lipid peroxidation in the rat myocardium

    SciTech Connect

    Panchenko, L.F.; Pirozhkov, S.V.; Popova, S.V.; Antonenkov, V.D.

    1987-09-01

    The authors study the effect of chronic administration of ethanol and aminotriazole on the level of lipid peroxidation in the ray myocardium. The action of natural and artificial antioxidants on alcohol-induced lipid peroxidation also was studied. To determine the level of chemiluminescence, 1 ml of a sample of nuclear free homogenate or of the total fraction of particles was introduced for radioactivity measurement. After incubation the spontaneous weak luminescence was measured.

  18. Influence of mechanical ventilation and sepsis on redox balance in diaphragm, myocardium, limb muscles, and lungs.

    PubMed

    Chacon-Cabrera, Alba; Rojas, Yeny; Martínez-Caro, Leticia; Vila-Ubach, Monica; Nin, Nicolas; Ferruelo, Antonio; Esteban, Andrés; Lorente, José A; Barreiro, Esther

    2014-12-01

    Mechanical ventilation (MV), using high tidal volumes (V(T)), causes lung (ventilator-induced lung injury [VILI]) and distant organ injury. Additionally, sepsis is characterized by increased oxidative stress. We tested whether MV is associated with enhanced oxidative stress in sepsis, the commonest underlying condition in clinical acute lung injury. Protein carbonylation and nitration, antioxidants, and inflammation (immunoblotting) were evaluated in diaphragm, gastrocnemius, soleus, myocardium, and lungs of nonseptic and septic (cecal ligation and puncture 24 hours before MV) rats undergoing MV (n = 7 per group) for 150 minutes using 3 different strategies (low V(T) [V(T) = 9 mL/kg], moderate V(T) [V(T) = 15 mL/kg], and high V(T) [V(T) = 25 mL/kg]) and in nonventilated control animals. Compared with nonventilated control animals, in septic and nonseptic rodents (1) diaphragms, limb muscles, and myocardium of high-V(T) rats exhibited a decrease in protein oxidation and nitration levels, (2) antioxidant levels followed a specific fiber-type distribution in slow- and fast-twitch muscles, (3) tumor necrosis factor α (TNF-α) levels were higher in respiratory and limb muscles, whereas no differences were observed in myocardium, and (4) in lungs, protein oxidation was increased, antioxidants were rather decreased, and TNF-α remained unmodified. In this model of VILI, oxidative stress does not occur in distant organs or skeletal muscles of rodents after several hours of MV with moderate-to-high V(T), whereas protein oxidation levels were increased in the lungs of the animals. Inflammatory events were moderately expressed in skeletal muscles and lungs of the MV rats. Concomitant sepsis did not strongly affect the MV-induced effects on muscles, myocardium, or lungs in the rodents.

  19. Imaging necrotic myocardium: Detection with 99mTc-pyrophosphate and radiolabeled antimyosin

    SciTech Connect

    Khaw, B.A.; Haber, E. )

    1989-08-01

    The major value of hot-spot imaging of the myocardium is its ability to define areas of necrosis rather than areas of diminished blood flow or cellular function. Applications of hot-spot imaging include the diagnosis and quantitation of myocardial infarction, myocarditis, and cardiac transplant rejection. The two agents in clinical use, 99mTc-Pyrophosphate and radiolabeled antimyosin, are discussed. 52 references.

  20. Regulation of acetylation restores proteolytic function of diseased myocardium in mouse and human.

    PubMed

    Wang, Ding; Fang, Caiyun; Zong, Nobel C; Liem, David A; Cadeiras, Martin; Scruggs, Sarah B; Yu, Hongxiu; Kim, Allen K; Yang, Pengyuan; Deng, Mario; Lu, Haojie; Ping, Peipei

    2013-12-01

    Proteasome complexes play essential roles in maintaining cellular protein homeostasis and serve fundamental roles in cardiac function under normal and pathological conditions. A functional detriment in proteasomal activities has been recognized as a major contributor to the progression of cardiovascular diseases. Therefore, approaches to restore proteolytic function within the setting of the diseased myocardium would be of great clinical significance. In this study, we discovered that the cardiac proteasomal activity could be regulated by acetylation. Histone deacetylase (HDAC) inhibitors (suberoylanilide hydroxamic acid and sodium valproate) enhanced the acetylation of 20S proteasome subunits in the myocardium and led to an elevation of proteolytic capacity. This regulatory paradigm was present in both healthy and acutely ischemia/reperfusion (I/R) injured murine hearts, and HDAC inhibition in vitro restored proteolytic capacities to baseline sham levels in injured hearts. This mechanism of regulation was also viable in failing human myocardium. With 20S proteasomal complexes purified from murine myocardium treated with HDAC inhibitors in vivo, we confirmed that acetylation of 20S subunits directly, at least in part, presents a molecular explanation for the improvement in function. Furthermore, using high-resolution LC-MS/MS, we unraveled the first cardiac 20S acetylome, which identified the acetylation of nine N-termini and seven internal lysine residues. Acetylation on four lysine residues and four N-termini on cardiac proteasomes were novel discoveries of this study. In addition, the acetylation of five lysine residues was inducible via HDAC inhibition, which correlated with the enhancement of 20S proteasomal activity. Taken as a whole, our investigation unveiled a novel mechanism of proteasomal function regulation in vivo and established a new strategy for the potential rescue of compromised proteolytic function in the failing heart using HDAC inhibitors.

  1. Effects of myocardial infarction on the distribution and transport of nutrients and oxygen in porcine myocardium.

    PubMed

    Davis, Bryce H; Morimoto, Yoshihisa; Sample, Chris; Olbrich, Kevin; Leddy, Holly A; Guilak, Farshid; Taylor, Doris A

    2012-10-01

    One of the primary limitations of cell therapy for myocardial infarction is the low survival of transplanted cells, with a loss of up to 80% of cells within 3 days of delivery. The aims of this study were to investigate the distribution of nutrients and oxygen in infarcted myocardium and to quantify how macromolecular transport properties might affect cell survival. Transmural myocardial infarction was created by controlled cryoablation in pigs. At 30 days post-infarction, oxygen and metabolite levels were measured in the peripheral skeletal muscle, normal myocardium, the infarct border zone, and the infarct interior. The diffusion coefficients of fluorescein or FITC-labeled dextran (0.3-70 kD) were measured in these tissues using fluorescence recovery after photobleaching. The vascular density was measured via endogenous alkaline phosphatase staining. To examine the influence of these infarct conditions on cells therapeutically used in vivo, skeletal myoblast survival and differentiation were studied in vitro under the oxygen and glucose concentrations measured in the infarct tissue. Glucose and oxygen concentrations, along with vascular density were significantly reduced in infarct when compared to the uninjured myocardium and infarct border zone, although the degree of decrease differed. The diffusivity of molecules smaller than 40 kD was significantly higher in infarct center and border zone as compared to uninjured heart. Skeletal myoblast differentiation and survival were decreased stepwise from control to hypoxia, starvation, and ischemia conditions. Although oxygen, glucose, and vascular density were significantly reduced in infarcted myocardium, the rate of macromolecular diffusion was significantly increased, suggesting that diffusive transport may not be inhibited in infarct tissue, and thus the supply of nutrients to transplanted cells may be possible. in vitro studies mimicking infarct conditions suggest that increasing nutrients available to

  2. Wave propagation simulation in normal and infarcted myocardium: computational and modelling issues.

    PubMed

    Maglaveras, N; Van Capelle, F J; De Bakker, J M

    1998-01-01

    Simulation of propagating action potentials (PAP) in normal and abnormal myocardium is used for the understanding of mechanisms responsible for eliciting dangerous arrhythmias. One- and two-dimensional models dealing with PAP properties are reviewed in this paper viewed both from the computational and mathematical aspects. These models are used for linking theoretical and experimental results. The discontinuous nature of the PAP is demonstrated through the combination of experimental and theoretically derived results. In particular it can be shown that for increased intracellular coupling resistance the PAP upstroke phase properties (Vmax, dV/dtmax and tau foot) change considerably, and in some cases non-monotonically with increased coupling resistance. It is shown that tau foot) is a parameter that is very sensitive to the cell's distance to the stimulus site, the stimulus strength and the coupling resistance. In particular it can be shown that in a one-dimensional structure the tau foot value can increase dramatically for lower coupling resistance values near the stimulus site and subsequently can be reduced as we move to distances larger than five resting length constants from the stimulus site. The tau foot variability is reduced with increased coupling resistance, rendering the lower coupling resistance structures, under abnormal excitation sequences, more vulnerable to conduction block and arrhythmias. Using the theory of discontinuous propagation of the PAP in the myocardium it is demonstrated that for specific abnormal situations in the myocardium, such as infarcted tissue, one- and two-dimensional models can reliably simulate propagation characteristics and explain complex phenomena such as propagation at bifurcation sites and mechanisms of block and re-entry. In conclusion it is shown that applied mathematics and informatics can help in elucidating electrophysiologically complex mechanisms such as arrhythmias and conduction disturbances in the myocardium

  3. Function of remote non-infarcted myocardium after STEMI: analysis with cardiovascular magnetic resonance.

    PubMed

    Husser, Oliver; Chaustre, Fabian; Sanchis, Juan; Nunez, Julio; Monmeneu, Jose V; Lopez-Lereu, Maria P; Bonanad, Clara; Gomez, Cristina; Oltra, Ricardo; Llacer, Angel; Riegger, Günter A J; Chorro, Francisco J; Bodi, Vicente

    2012-12-01

    To evaluate remote myocardial function after ST-elevation myocardial infarction (STEMI) and the impact of infarct size (IS) using cardiovascular magnetic resonance (CMR). 161 patients and 15 controls underwent CMR at 1st week and 6th month after STEMI. Using the 17-segments model, segments were categorized into infarcted, adjacent and remote myocardium. Relative systolic wall thickening (SWT, %) was assessed using the centerline method. IS (% of left ventricular mass) was determined in late enhancement imaging. Overall, in remote myocardium, SWT was comparable (83 ± 32) to controls (77 ± 25, P = .5) and did not increase significantly (P = .2) at the 6th month (88 ± 35, P = .3 vs. control). When IS was categorized into tertiles (<13.6%, (n = 49), 13.7-28.2%, (n = 60), >28.2%, (n = 52)), SWT in the remote area at the 1st week was not different from controls, regardless of infarct size (p between .2 and .8 for all tertiles). At 6 months, SWT was larger compared to controls only in small infarctions (98 ± 34 vs. 77 ± 25, P = .03). In medium and large infarctions there was no difference in SWT of the remote area compared to controls (87 ± 33 and 79 ± 34, P = .3 and P = .09) and there was no significant increase at 6 months (P between .2 and .9). In remote myocardium there was no difference in contractility compared to controls after STEMI. After 6 month a slight hypercontractility can only be observed in small infarctions. In medium and large infarctions no difference of SWT in remote myocardium compared to controls can be observed.

  4. Effect of hyperbaric oxygenation on carbohydrate metabolism protein synthesis in the myocardium during sustained hypodynamia

    NASA Technical Reports Server (NTRS)

    Makarov, G. A.

    1980-01-01

    Glycolysis and the intensity of protein synthesis were studied in 140 white male rats in subcellular fractions of the myocardium during 45 day hypodynamia and hyperbaric oxygenation. Hypodynamia increased: (1) the amount of lactic acids; (2) the amount of pyruvic acid; (3) the lactate/pyruvate coefficient; and (4) the activities of aldolase and lactate dehydrogenase. Hyperbaric oxygenation was found to have a favorable metabolic effect on the animals with hypodynamia.

  5. Cardiac Expression of Skeletal Muscle Sodium Channels Increases Longitudinal Conduction Velocity in the Canine One Week Myocardial Infarction

    PubMed Central

    Coronel, Ruben; Lau, David H; Sosunov, Eugene A; Janse, Michiel J; Danilo, Peter; Anyukhovsky, Evgeny P; Wilms-Schopman, Francien JG; Opthof, Tobias; Shlapakova, Iryna N; Ozgen, Nazira; Prestia, Kevin; Kryukova, Yelena; Cohen, Ira S.; Robinson, Richard B; Rosen, Michael R

    2013-01-01

    Background Skeletal muscle sodium channel (Nav1.4) expression in border zone myocardium increases action potential upstroke velocity in depolarized isolated tissue. Because resting membrane potential in the 1 week canine infarct is reduced, we hypothesized that conduction velocity (CV) is greater in Nav1.4 dogs compared to control dogs. Objective To measure CV in the infarct border zone border in dogs with and without Nav1.4 expression. Methods Adenovirus was injected in the infarct border zone in 34 dogs. The adenovirus incorporated the Nav1.4- and a green fluorescent protein (GFP) gene (Nav1.4 group, n=16) or only GFP (n=18). After 1 week, upstroke velocity and CV were measured by sequential microelectrode recordings at 4 and 7 mM [K+] in superfused epicardial slabs. High density in vivo epicardial activation mapping was performed in a subgroup (8 Nav1.4, 6 GFP) at 3–4 locations in the border zone. Microscopy and antibody staining confirmed GFP or Nav1.4 expression. Results Infarct sizes were similar between groups (30.6+/−3 % of LV mass, mean+/−SEM). Longitudinal CV was greater in Nav1.4- than in GFP- sites (58.5+/−1.8 vs 53.3+/−1.2 cm/s, 20 and 15 sites, respectively, p<0.05). Transverse CV was not different between the groups. In tissue slabs dV/dtmax was higher and CV was greater in Nav1.4 than in control at 7 mM [K+] (P<0.05). Immunohistochemical Nav1.4 staining was seen at the longitudinal ends of the myocytes. Conclusion Nav1.4 channels in myocardium surviving 1 week infarction increases longitudinal but not transverse CV, consistent with the increased dV/dtmax and with the cellular localization of Nav1.4. PMID:20385252

  6. Neural Stem Cells and Ischemic Brain

    PubMed Central

    Zhang, Zhenggang; Chopp, Michael

    2016-01-01

    Stroke activates neural stem cells in the ventricular-subventricular zone (V/SVZ) of the lateral ventricle, which increases neuroblasts and oligodendrocyte progenitor cells (OPCs). Within the ischemic brain, neural stem cells, neuroblasts and OPCs appear to actively communicate with cerebral endothelial cells and other brain parenchymal cells to mediate ischemic brain repair; however, stroke-induced neurogenesis unlikely plays any significant roles in neuronal replacement. In this mini-review, we will discuss recent findings how intercellular communications between stroke-induced neurogenesis and oligodendrogenesis and brain parenchymal cells could potentially facilitate brain repair processes. PMID:27488979

  7. Ischemic Gastropathic Ulcer Mimics Gastric Cancer

    PubMed Central

    Daher, Saleh; Lahav, Ziv; Rmeileh, Ayman Abu; Mizrahi, Meir

    2016-01-01

    Gastric ulcer due to mesenteric ischemia is a rare clinical finding. As a result, few reports of ischemic gastric ulcers have been reported in the literature. The diagnosis of ischemic gastropathy is seldom considered in patients presenting with abdominal pain and gastric ulcers. In this case report, we describe a patient with increasing abdominal pain, weight loss, and gastric ulcers, who underwent extensive medical evaluation and whose symptoms were resistant to medical interventions. Finally he was diagnosed with chronic mesenteric ischemia, and his clinical and endoscopic abnormalities resolved after surgical revascularization of both the superior mesenteric artery and the celiac trunk. PMID:27579191

  8. Unsupervised 4D myocardium segmentation with a Markov Random Field based deformable model.

    PubMed

    Cordero-Grande, L; Vegas-Sánchez-Ferrero, G; Casaseca-de-la-Higuera, P; San-Román-Calvar, J Alberto; Revilla-Orodea, Ana; Martín-Fernández, M; Alberola-López, C

    2011-06-01

    A stochastic deformable model is proposed for the segmentation of the myocardium in Magnetic Resonance Imaging. The segmentation is posed as a probabilistic optimization problem in which the optimal time-dependent surface is obtained for the myocardium of the heart in a discrete space of locations built upon simple geometric assumptions. For this purpose, first, the left ventricle is detected by a set of image analysis tools gathered from the literature. Then, the segmentation solution is obtained by the Maximization of the Posterior Marginals for the myocardium location in a Markov Random Field framework which optimally integrates temporal-spatial smoothness with intensity and gradient related features in an unsupervised way by the Maximum Likelihood estimation of the parameters of the field. This scheme provides a flexible and robust segmentation method which has been able to generate results comparable to manually segmented images for some derived cardiac function parameters in a set of 43 patients affected in different degrees by an Acute Myocardial Infarction.

  9. Ghrelin protects infarcted myocardium by induction of autophagy and AMP-activated protein kinase pathway.

    PubMed

    Yuan, Ming-Jie; Kong, Bin; Wang, Tao; Wang, Xin; Huang, He; Maghsoudi, Taneen

    2016-08-01

    The majority of studies have reported that enhancing autophagy in the myocardium is cardioprotective. Here, we tested the hypothesis that ghrelin, a growth hormone-releasing peptide, will protect infarcted myocardium by inducing of autophagy. Myocardial infarction was induced in mice by left coronary artery ligation the surviving mice 24 h after surgical were started on 2 week treatments with one of the following: vehicle, acylated ghrelin(50 mg/kg per day) or acylated ghrelin plus 3-MA(an autophagy inhibitor, 15 mg/kg, per day). We found that ghrelin significantly improved the cardiac function, and autophagy was enhanced by elevated LC3-II/LC-I ratio and mRNA expression of autophagy related protein. In vitro, cultured neonatal rat ventricular cardiomyocytes were subjected to simulate ischemia/reperfusion, 3-MA significantly attenuated ghrelin-induced autophagy, which was associated with activated AMP-activated protein kinase (AMPK) signal pathway. Moreover, ghrelin reduced cell death, and RNAi-mediated knockdown of autophagy protein 5 (Atg5) partly abolished ghrelin's cardioprotective effect. It is the first time to demonstrate that the cardioprotective effect of ghrelin on ischemia myocardium in part through regulating of autophagy signal pathway. PMID:27235554

  10. The endoderm and myocardium join forces to drive early heart tube assembly.

    PubMed

    Aleksandrova, Anastasiia; Czirok, Andras; Kosa, Edina; Galkin, Oleksandr; Cheuvront, Tracey J; Rongish, Brenda J

    2015-08-01

    Formation of the muscular layer of the heart, the myocardium, involves the medial movement of bilateral progenitor fields; driven primarily by shortening of the endoderm during foregut formation. Using a combination of time-lapse imaging, microsurgical perturbations and computational modeling, we show that the speed of the medial-ward movement of the myocardial progenitors is similar, but not identical to that of the adjacent endoderm. Further, the extracellular matrix microenvironment separating the two germ layers also moves with the myocardium, indicating that collective tissue motion and not cell migration drives tubular heart assembly. Importantly, as myocardial cells approach the midline, they perform distinct anterior-directed movements relative to the endoderm. Based on the analysis of microincision experiments and computational models, we propose two characteristic, autonomous morphogenetic activities within the early myocardium: 1) an active contraction of the medial portion of the heart field and 2) curling- the tendency of the unconstrained myocardial tissue to form a spherical surface with a concave ventral side. In the intact embryo, these deformations are constrained by the endoderm and the adjacent mesoderm, nevertheless the corresponding mechanical stresses contribute to the proper positioning of myocardial primordia.

  11. Differentiation of viable and nonviable myocardium after acute reperfusion using serial thallium-201 imaging

    SciTech Connect

    Okada, R.D.; Boucher, C.A.

    1987-02-01

    This study was performed to determine if differences in regional myocardial thallium clearance rates could differentiate salvaged from nonsalvaged myocardium after reperfusion. Twenty-one dogs underwent 2 hours of left anterior descending coronary artery ligation followed by reperfusion. Thallium was administered 5 minutes later and serial images were acquired over 3 hours. Of the 21 dogs, 15 had infarctions of which nine had initially reduced anterior wall thallium activity (group 1) and six had normal or increased activity (group 2). Six dogs did not have an infarction (group 3). All group 1 dogs demonstrated reduced clearance rates in the anterior wall (T1/2 = 15.0 +/- 4.7 hours, SD) compared to the posterior wall (T1/2 = 9.0 +/- 4.4 hours; p less than 0.001). Group 2 dogs demonstrated increased clearance rates in the anterior wall (T1/2 = 5.7 +/- 2.0 hours) compared to the posterior wall (T1/2 = 10.5 +/- 4.6 hours; p less than 0.001). Group 3 dogs demonstrated no difference in clearance rates. In conclusion, although thallium uptake is frequently reduced in nonsalvaged myocardium, tracer uptake can be normal or increased if perfusion has been completely restored. However, an increased clearance rate from the reperfused zone compared to the normal zone is a reliable indicator of nonsalvaged myocardium, despite normal initial thallium uptake.

  12. Activation of neutrophils in the microvasculature of the ischaemic and reperfused myocardium.

    PubMed

    Tillmanns, H; Neumann, F J; Tiefenbacher, C; Dorigo, O; Parekh, N; Waas, W; Zimmermann, R; Steinhausen, M; Kuebler, W

    1993-11-01

    In 11 rats, the microcirculation of the repeatedly ischaemic (stunned) left ventricular myocardium was studied using in vivo fluorescence microscopy. Stunning was provoked by six subsequent 10 min ligations of the left anterior descending coronary artery, each of them followed by a 20 min reperfusion period. In the stunned myocardium showing hypokinetic wall motion, myocardial blood flow dropped by 55%; in this region, leukocytes often appeared in slow-flow capillaries plugging capillary branches. Closely linking to leukocyte adherence, a rise of microvascular permeability was documented by extravascular clouds of fluorescent dextran. After nifedipine treatment, in ischaemic regions marked dilatation of larger A1 and A2 arterioles was noted, in addition to the ischaemia-induced dilatation of smaller A3 and A4 arterioles. Furthermore nifedipine and nisoldipine reduced the number of adherent leukocytes in post-capillary venules and capillaries of the repeatedly ischaemic myocardium. In 12 patients with coronary one-vessel disease and without previous transmural myocardial infarction, elective coronary angioplasty (PTCA) was performed (balloon inflation for 2 min). After elective PTCA of the LAD, a significant rise in the proportion of activated neutrophils was noted. After elective 2 min PTCA of the LAD, coronary sinus blood samples showed a marked rise of FMLC stimulated superoxide anion production, whereas passive deformability decreased considerably. Furthermore, an increase in chemotactic activity in coronary sinus blood samples was observed.

  13. Functional Differences in Engineered Myocardium from Embryonic Stem Cell-Derived versus Neonatal Cardiomyocytes

    PubMed Central

    Feinberg, Adam W.; Ripplinger, Crystal M.; van der Meer, Peter; Sheehy, Sean P.; Domian, Ibrahim; Chien, Kenneth R.; Parker, Kevin Kit

    2013-01-01

    Summary Stem cell-derived cardiomyocytes represent unique tools for cell- and tissue-based regenerative therapies, drug discovery and safety, and studies of fundamental heart-failure mechanisms. However, the degree to which stem cell-derived cardiomyocytes compare to mature cardiomyocytes is often debated. We reasoned that physiological metrics of engineered cardiac tissues offer a means of comparison. We built laminar myocardium engineered from cardiomyocytes that were differentiated from mouse embryonic stem cell-derived cardiac progenitors or harvested directly from neonatal mouse ventricles, and compared their anatomy and physiology in vitro. Tissues assembled from progenitor-derived myocytes and neonate myocytes demonstrated similar cytoskeletal architectures but different gap junction organization and electromechanical properties. Progenitor-derived myocardium had significantly less contractile stress and slower longitudinal conduction velocity than neonate-derived myocardium, indicating that the developmental state of the cardiomyocytes affects the electromechanical function of the resultant engineered tissue. These data suggest a need to establish performance metrics for future stem cell applications. PMID:24286027

  14. Polarization birefringence measurements for characterizing the myocardium, including healthy, infarcted, and stem-cell-regenerated tissues

    NASA Astrophysics Data System (ADS)

    Wood, Michael F. G.; Ghosh, Nirmalya; Wallenburg, Marika A.; Li, Shu-Hong; Weisel, Richard D.; Wilson, Brian C.; Li, Ren-Ke; Vitkin, I. Alex

    2010-07-01

    Myocardial infarction leads to structural remodeling of the myocardium, in particular to the loss of cardiomyocytes due to necrosis and an increase in collagen with scar formation. Stem cell regenerative treatments have been shown to alter this remodeling process, resulting in improved cardiac function. As healthy myocardial tissue is highly fibrous and anisotropic, it exhibits optical linear birefringence due to the different refractive indices parallel and perpendicular to the fibers. Accordingly, changes in myocardial structure associated with infarction and treatment-induced remodeling will alter the anisotropy exhibited by the tissue. Polarization-based linear birefringence is measured on the myocardium of adult rat hearts after myocardial infarction and compared with hearts that had received mesenchymal stem cell treatment. Both point measurement and imaging data show a decrease in birefringence in the region of infarction, with a partial rebound back toward the healthy values following regenerative treatment with stem cells. These results demonstrate the ability of optical polarimetry to characterize the micro-organizational state of the myocardium via its measured anisotropy, and the potential of this approach for monitoring regenerative treatments of myocardial infarction.

  15. [An improved method for microdialysis study of noradrenaline level in rat myocardium].

    PubMed

    Gilinskiĭ, M A; Faĭbushevich, A A; Lunte, C E

    1998-01-01

    A level of myocardial norepinephrine (NE) is considered as one of the meaningful parameters in the estimation of myocardium functioning. Long lasting changes of myocardial NE appear to be not only a sequence of pathologic processes in myocardium, but could also be a factor responsible for some diseases. An improved microdialysis sampling technique with HPLC-ED analysis was developed to measure in vivo NE content in a rat myocardial interstitium. Linear polyacrylonitryl 5 mm probes were flushed with methanol while being immersed in water. In vitro NE recovery with the flow rate of perfusate was found at the level 67.9 + 0.4%. Probes were implanted into the rat myocardium under the general anaesthesia. Myocardial dialysate was collected during 20 min into plastic vials, containing 10 microliters of 0.1 M perchloric acid. Low noise, high sensitivity dual electrochemical detection was used for the determination of NE amount in the samples. Overall sensitivity threshold was found about 0.3 pg of NE in 20 microliters. Steady state concentration of NE in myocardial dialysate was found 54 + 7 pg/ml. 20 min before cardiac arrest the concentration of NE in myocardial dialysate was found to be increased 4-5 times. 40 min after cardiac arrest further increase in NE content was registered up to 1-4 ng per ml of perfusate. It is suggested that the method will be useful for routine study of myocardial NE.

  16. Elastase Deficiency Phenotype of Pseudomonas aeruginosa Canine Otitis Externa Isolates

    PubMed Central

    Petermann, Shana R.; Doetkott, Curt; Rust, Lynn

    2001-01-01

    Pseudomonas aeruginosa veterinary isolates were assayed for elastase and total matrix protease activity. The elastase activity of canine ear isolates was much less than that of strain PAO1 and that of all other veterinary isolates (P < 0.0001). The results indicate that canine ear isolates have a distinct elastase phenotype. PMID:11329471

  17. Displacement of maxillary canines after facemask treatment: a case report.

    PubMed

    Oz, Aslihan Zeynep; Taner, Tülin

    2014-01-01

    The aim of case report is to present the displacement of maxillary canines after orthopedic treatment. A 9 year-old male patient with Class III malocclusion had treated by facemask treatment combination with rapid maxillary expansion and orthopedic changes were obtained. After two years, palatally impactions of maxillary canines were observed.

  18. First detection of canine parvovirus type 2c in Brazil

    PubMed Central

    Streck, André Felipe; de Souza, Carine Kunzler; Gonçalves, Karla Rathje; Zang, Luciana; Pinto, Luciane Dubina; Canal, Cláudio Wageck

    2009-01-01

    The presence of canine parvovirus type 2 (CPV-2), 2a and 2b has been described in Brazil, however, the type 2c had not been reported until now. In the current study, seven out of nine samples from dogs with diarrhea were characterized as CPV-2c, indicating that this virus is already circulating in the Brazilian canine population. PMID:24031389

  19. Canine evolution in sabretoothed carnivores: natural selection or sexual selection?

    PubMed

    Randau, Marcela; Carbone, Chris; Turvey, Samuel T

    2013-01-01

    The remarkable elongated upper canines of extinct sabretoothed carnivorous mammals have been the subject of considerable speculation on their adaptive function, but the absence of living analogues prevents any direct inference about their evolution. We analysed scaling relationships of the upper canines of 20 sabretoothed feliform carnivores (Nimravidae, Barbourofelidae, Machairodontinae), representing both dirk-toothed and scimitar-toothed sabretooth ecomorphs, and 33 non-sabretoothed felids in relation to body size in order to characterize and identify the evolutionary processes driving their development, using the scaling relationships of carnassial teeth in both groups as a control. Carnassials display isometric allometry in both sabretooths and non-sabretooths, supporting their close relationship with meat-slicing, whereas the upper canines of both groups display positive allometry with body size. Whereas there is no statistical difference in allometry of upper canine height between dirk-toothed and scimitar-toothed sabretooth ecomorphs, the significantly stronger positive allometry of upper canine height shown by sabretooths as a whole compared to non-sabretooths reveals that different processes drove canine evolution in these groups. Although sabretoothed canines must still have been effective for prey capture and processing by hypercarnivorous predators, canine morphology in these extinct carnivores was likely to have been driven to a greater extent by sexual selection than in non-sabretooths. Scaling relationships therefore indicate the probable importance of sexual selection in the evolution of the hypertrophied sabretooth anterior dentition.

  20. Impaired translocation and activation of mitochondrial Akt1 mitigated mitochondrial oxidative phosphorylation Complex V activity in diabetic myocardium.

    PubMed

    Yang, Jia-Ying; Deng, Wu; Chen, Yumay; Fan, Weiwei; Baldwin, Kenneth M; Jope, Richard S; Wallace, Douglas C; Wang, Ping H

    2013-06-01

    Insulin can translocate Akt to mitochondria in cardiac muscle. The goals of this study were to define sub-mitochondrial localization of the translocated Akt, to dissect the effects of insulin on Akt isoform translocation, and to determine the direct effect of mitochondrial Akt activation on Complex V activity in normal and diabetic myocardium. The translocated Akt sequentially localized to the mitochondrial intermembrane space, inner membrane, and matrix. To confirm Akt translocation, in vitro import assay showed rapid entry of Akt into mitochondria. Akt isoforms were differentially regulated by insulin stimulation, only Akt1 translocated into mitochondria. In the insulin-resistant Type 2 diabetes model, Akt1 translocation was blunted. Mitochondrial activation of Akt1 increased Complex V activity by 24% in normal myocardium in vivo and restored Complex V activity in diabetic myocardium. Basal mitochondrial Complex V activity was lower by 22% in the Akt1(-/-) myocardium. Insulin-stimulated Complex V activity was not impaired in the Akt1(-/-) myocardium, due to compensatory translocation of Akt2 to mitochondria. Akt1 is the primary isoform that relayed insulin signaling to mitochondria and modulated mitochondrial Complex V activity. Activation of mitochondrial Akt1 enhanced ATP production and increased phosphocreatine in cardiac muscle cells. Dysregulation of this signal pathway might impair mitochondrial bioenergetics in diabetic myocardium.

  1. Cyclooxygenase-2 (COX-2) expression in canine intracranial meningiomas.

    PubMed

    Rossmeisl, J H; Robertson, J L; Zimmerman, K L; Higgins, M A; Geiger, D A

    2009-09-01

    Meningiomas are the most common canine intracranial tumour. Neurologic disability and death from treatment failure remain problematic despite current surgical and radiotherapeutic treatments for canine intracranial meningiomas. Cyclooxygenase-2 (COX-2) over-expression has been demonstrated in multiple canine malignancies, and COX-2 inhibitory treatment strategies have been shown to have both preventative and therapeutic effects in spontaneous and experimental models of cancer. The purpose of this study was to evaluate COX-2 expression in canine intracranial meningiomas. Immunohistochemical and Western blot (WB) analyses showed COX-2 expression in multiple tissues of the normal canine brain, and 87% (21/24) of intracranial meningiomas studied were immunoreactive to COX-2. No significant associations between COX-2 immunoreactivity and tumour grade were identified. Further studies are required to elucidate the physiologic roles of constitutive COX-2 expression in the central nervous system as well as its participation in meningioma tumourigenesis. PMID:19691646

  2. Apicotomy: surgical management of maxillary dilacerated or ankylosed canines.

    PubMed

    Araújo, Eustáquio A; Araújo, Cristiana V; Tanaka, Orlando M

    2013-12-01

    This clinical article reports a technique, apicotomy, for managing dilacerated or ankylosed canines. The records of 3 patients successfully treated with apicotomy are presented. Orthodontists observe clinically significant incidences of impacted maxillary canines in their daily practices. Several procedures have been described to bring an ankylosed, impacted tooth into occlusion. Luxation is the most widely used solution, but there are risks involved with that approach, and the success rate is low. Surgical repositioning has also been used, but morbidity is high, and the aggressiveness of the procedure might also contraindicate it. Ankylosis might be related to the anatomic position of the canine's root apex and its adjacent anatomic structures. Apicotomy is a guided fracture of a canine root apex, followed by its orthodontic traction. It is a conservative surgical alternative for treating impacted canines with dilacerations or apical root ankylosis.

  3. Morphology and immunoreactivity of canine and feline extramedullary plasmacytomas.

    PubMed

    Mikiewicz, M; Otrocka-Domagała, I; Paździor-Czapula, K; Gesek, M

    2016-01-01

    The aim of the study was the evaluation of morphology and immunophenotype of canine (19 cases) and feline (7 cases) extramedullary plasmacytomas. Tumours, located in skin, oral cavity and spleen were surgically excised, fixed and processed for histopathology and immunohistochemistry (CD79α, CD18, proliferating cell nuclear antigen, metallothionein). Histologically, tumours were classified into mature, cleaved, asynchronous, polymorphous blastic, hyalin, or monomorphous blastic type. All evaluated tumours showed cytoplasmic expression of CD79α antigen. The expression of CD18 was observed in canine cutaneous and splenic tumours. In canine tumours expression of metallothionein was low to moderate, while in feline plasmacytomas - absent or low. In canine tumours, the mitotic index and proliferating cell nuclear antigen index were positively correlated with the expression of metallothionein. In feline tumours no correlation between mitotic index, proliferating cell nuclear antigen and metallothionein was found. This is the first study describing expression of metallothionein in canine and feline extramedullary plasmacytoma. PMID:27487508

  4. Apicotomy: surgical management of maxillary dilacerated or ankylosed canines.

    PubMed

    Araújo, Eustáquio A; Araújo, Cristiana V; Tanaka, Orlando M

    2013-12-01

    This clinical article reports a technique, apicotomy, for managing dilacerated or ankylosed canines. The records of 3 patients successfully treated with apicotomy are presented. Orthodontists observe clinically significant incidences of impacted maxillary canines in their daily practices. Several procedures have been described to bring an ankylosed, impacted tooth into occlusion. Luxation is the most widely used solution, but there are risks involved with that approach, and the success rate is low. Surgical repositioning has also been used, but morbidity is high, and the aggressiveness of the procedure might also contraindicate it. Ankylosis might be related to the anatomic position of the canine's root apex and its adjacent anatomic structures. Apicotomy is a guided fracture of a canine root apex, followed by its orthodontic traction. It is a conservative surgical alternative for treating impacted canines with dilacerations or apical root ankylosis. PMID:24286914

  5. Recombinant canine distemper virus serves as bivalent live vaccine against rabies and canine distemper.

    PubMed

    Wang, Xijun; Feng, Na; Ge, Jinying; Shuai, Lei; Peng, Liyan; Gao, Yuwei; Yang, Songtao; Xia, Xianzhu; Bu, Zhigao

    2012-07-20

    Effective, safe, and affordable rabies vaccines are still being sought. Attenuated live vaccine has been widely used to protect carnivores from canine distemper. In this study, we generated a recombinant canine distemper virus (CDV) vaccine strain, rCDV-RVG, expressing the rabies virus glycoprotein (RVG) by using reverse genetics. The recombinant virus rCDV-RVG retained growth properties similar to those of vector CDV in Vero cell culture. Animal studies demonstrated that rCDV-RVG was safe in mice and dogs. Mice inoculated intracerebrally or intramuscularly with rCDV-RVG showed no apparent signs of disease and developed a strong rabies virus (RABV) neutralizing antibody response, which completely protected mice from challenge with a lethal dose of street virus. Canine studies showed that vaccination with rCDV-RVG induced strong and long-lasting virus neutralizing antibody responses to RABV and CDV. This is the first study demonstrating that recombinant CDV has the potential to serve as bivalent live vaccine against rabies and canine distemper in animals. PMID:22698451

  6. G-CSF administration after myocardial infarction in mice attenuates late ischemic cardiomyopathy by enhanced arteriogenesis.

    PubMed

    Deindl, Elisabeth; Zaruba, Marc-Michael; Brunner, Stefan; Huber, Bruno; Mehl, Ursula; Assmann, Gerald; Hoefer, Imo E; Mueller-Hoecker, Josef; Franz, Wolfgang-Michael

    2006-05-01

    Granulocyte-colony stimulating factor (G-CSF) has been shown to improve cardiac function after myocardial infarction (MI) by bone marrow cell mobilization and by protecting cardiomyocytes from apoptotic cell death. However, its role in collateral artery growth (arteriogenesis) has not been elucidated. Here, we investigated the effect of G-CSF on arteriolar growth and cardiac function in a murine MI model. Mice were treated with G-CSF (100 microg/kg/day) directly after MI for 5 consecutive days. G-CSF application resulted in a significant increase of circulating mononuclear cells expressing stem cell markers. Arterioles in the border zone of infarcted myocardium showed an increased expression of ICAM-1 accompanied by an accumulation of bone marrow derived cells and a pronounced proliferation of endothelial and smooth muscle cells. Histology of G-CSF treated mice revealed a lower amount of granulation tissue (67.8 vs. 84.4%) associated with a subsequent reduction in free LV wall thinning and scar extension (23.1 vs. 30.8% of LV). Furthermore, G-CSF treated animals showed a significant improvement of post-MI survival (68.8 vs. 46.2%). Pressure-volume relations revealed a partially restored myocardial function at day 30 (EF: 32.5 vs. 17.2%). Our results demonstrate that G-CSF administration after MI stimulates arteriogenesis and attenuates ischemic cardiomyopathy after MI.

  7. Mesenchymal stem cell delivery strategies to promote cardiac regeneration following ischemic injury.

    PubMed

    Russo, Valerio; Young, Stuart; Hamilton, Andrew; Amsden, Brian G; Flynn, Lauren E

    2014-04-01

    Myocardial infarction (MI) is one of the leading causes of mortality worldwide and is associated with irreversible cardiomyocyte death and pathological remodeling of cardiac tissue. In the past 15 years, several animal models have been developed for pre-clinical testing to assess the potential of stem cells for functional tissue regeneration and the attenuation of left ventricular remodeling. The promising results obtained in terms of improved cardiac function, neo-angiogenesis and reduction in infarct size have motivated the initiation of clinical trials in humans. Despite the potential, the results of these studies have highlighted that the effective delivery and retention of viable cells within the heart remain significant challenges that have limited the therapeutic efficacy of cell-based therapies for treating the ischemic myocardium. In this review, we discuss key elements for designing clinically translatable cell-delivery approaches to promote myocardial regeneration. Key topics addressed include cell selection, with a focus on mesenchymal stem cells derived from the bone marrow (bMSCs) and adipose tissue (ASCs), including a discussion of their potential mechanisms of action. Natural and synthetic biomaterials that have been investigated as injectable cell delivery vehicles for cardiac applications are critically reviewed, including an analysis of the role of the biomaterials themselves in the therapeutic scheme. PMID:24560461

  8. An overview of antithrombotics in ischemic stroke.

    PubMed

    Schweickert, Patricia A; Gaughen, John R; Kreitel, Elizabeth M; Shephard, Timothy J; Solenski, Nina J; Jensen, Mary E

    2016-06-19

    The use of antithrombotic medications is an important component of ischemic stroke treatment and prevention. This article reviews the evidence for best practices for antithrombotic use in stroke with focused discussion on the specific agents used to treat and prevent stroke. PMID:27153001

  9. Gene Therapy For Ischemic Heart Disease

    PubMed Central

    Lavu, Madhav; Gundewar, Susheel; Lefer, David J.

    2010-01-01

    Current pharmacologic therapy for ischemic heart disease suffers multiple limitations such as compliance issues and side effects of medications. Revascularization procedures often end with need for repeat procedures. Patients remain symptomatic despite maximal medical therapy. Gene therapy offers an attractive alternative to current pharmacologic therapies and may be beneficial in refractory disease. Gene therapy with isoforms of growth factors such as VEGF, FGF and HGF induces angiogenesis, decreases apoptosis and leads to protection in the ischemic heart. Stem cell therapy augmented with gene therapy used for myogenesis has proven to be beneficial in numerous animal models of myocardial ischemia. Gene therapy coding for antioxidants, eNOS, HSP, mitogen-activated protein kinase and numerous other anti apoptotic proteins have demonstrated significant cardioprotection in animal models. Clinical trials have demonstrated safety in humans apart from symptomatic and objective improvements in cardiac function. Current research efforts are aimed at refining various gene transfection techniques and regulation of gene expression in vivo in the heart and circulation to improve clinical outcomes in patients that suffer from ischemic heart disease. In this review article we will attempt to summarize the current state of both preclinical and clinical studies of gene therapy to combat myocardial ischemic disease. PMID:20600100

  10. Systemic corticosteroids in nonarteritic ischemic optic neuropathy

    PubMed Central

    Al-Zubidi, Nagham; Zhang, Jason; Spitze, Arielle; Lee, Andrew G

    2014-01-01

    Nonarteritic ischemic optic neuropathy (NAION) is one of the most prevalent optic nerve disorders seen in ophthalmic practice. The role of corticosteroid therapy in NAION remains a highly controversial area of debate in ophthalmology. This brief review will provide an overview of the current clinical evidence on this topic as well as some comment on the medical debate. PMID:25449939

  11. Extraglandular and intraglandular vascularization of canine prostate.

    PubMed

    Stefanov, Miroslav

    2004-03-01

    The literature on the vascularization of the canine prostate is reviewed and the clinical significance of prostate morphology is described. Scanning Electron Microscopy (SEM), combined with improved corrosion casting methods, reveal new morphological details that promise better diagnostics and treatment but also require expansion of clinical nomenclature. A proposal is made for including two previously unnamed veins in Nomina Anatomica Veterinaria (NAV). The canine prostate has two lobes with independent vascularization. Each lobe is supplied through the left and right a. prostatica, respectively. The a. prostatica sprouts three small vessels (cranial, middle, and caudal) towards the prostate gland. A. prostatica is a small-size artery whose wall structure is similar to the arteries of the muscular type. V. prostatica is a small-size valved vein. The canine prostate has capsular, parenchymal, and urethral vascular zones. The surface vessels of the capsule are predominantly veins and the diameter of arterial vessels is larger than that of the veins. The trabecular vessels are of two types: direct and branched. The prostate parenchyma is supplied by branches of the trabecular vessels. The periacinary capillaries are fenestrated and form a net in a circular pattern. The processes of the myoepithelial cells embrace both the acins and the periacinar capillaries. In the prostate ductal system. there are spermatozoa. The prostatic part of the urethra is supplied by an independent branch of a. prostatica. The prostatic urethral part is drained by v. prostatica, the vein of the urethral bulb and the ventral prostate veins. M. urethralis begins as early as the urethral prostatic part. The greater part of the white muscle fibers in m. urethralis suggest an enhanced anaerobic metabolism.

  12. Definition, Classification, and Pathophysiology of Canine Glaucoma.

    PubMed

    Pizzirani, Stefano

    2015-11-01

    Glaucoma is a common ocular condition in humans and dogs leading to optic nerve degeneration and irreversible blindness. Primary glaucoma is a group of spontaneous heterogeneous diseases. Multiple factors are involved in its pathogenesis and these factors vary across human ethnic groups and canine breeds, so the clinical phenotypes are numerous and their classification can be challenging and remain superficial. Aging and oxidative stress are major triggers for the manifestation of disease. Multiple, intertwined inflammatory and biochemical cascades eventually alter cellular and extracellular physiology in the optic nerve and trabecular meshwork and lead to vision loss.

  13. Definition, Classification, and Pathophysiology of Canine Glaucoma.

    PubMed

    Pizzirani, Stefano

    2015-11-01

    Glaucoma is a common ocular condition in humans and dogs leading to optic nerve degeneration and irreversible blindness. Primary glaucoma is a group of spontaneous heterogeneous diseases. Multiple factors are involved in its pathogenesis and these factors vary across human ethnic groups and canine breeds, so the clinical phenotypes are numerous and their classification can be challenging and remain superficial. Aging and oxidative stress are major triggers for the manifestation of disease. Multiple, intertwined inflammatory and biochemical cascades eventually alter cellular and extracellular physiology in the optic nerve and trabecular meshwork and lead to vision loss. PMID:26456751

  14. Cytogenetic investigations in four canine lymphomas.

    PubMed

    Winkler, Susanne; Murua Escobar, Hugo; Reimann-Berg, Nicola; Bullerdiek, Jörn; Nolte, Ingo

    2005-01-01

    Four cases of canine lymphoma are presented, including histological examination and cytogenetic investigation. The first case showed a derivative chromosome 13, the second case showed a clonal trisomy 8 and the third case showed a complex karyotype with a clonal trisomy 13 and additional clonal trisomies of the chromosomes 20, 30 and 37, as well as a non-clonal tetrasomy 9. Case four showed a single trisomy 2. Comparing these results with human hematopoietic malignancies, there are notable similarities between both species. PMID:16309190

  15. Canine distemper epizootic in Everglades mink.

    PubMed

    Cunningham, M W; Shindle, D B; Allison, A B; Terrell, S P; Mead, D G; Owen, M

    2009-10-01

    Four free-ranging mink, Neovison vison, collected between June and September 2004 in the Fakahatchee Strand Preserve State Park (FSPSP, Florida, USA), were examined for canine distemper virus (CDV) infection. Microscopic lesions and viral inclusions consistent with CDV infection were observed in three mink. Virus isolation and reverse transcription-polymerase chain reaction performed on all mink were positive for CDV. Anecdotal records of mink observations in FSPSP suggest a postepizootic decline in the mink population followed by an apparent recovery. We recommend further research to assess the status of the Everglades mink and the impact of CDV on this and other American mink populations in Florida. PMID:19901388

  16. Lactoferrin in canine sera: a pyometra study.

    PubMed

    Bartoskova, A; Adlerova, L; Kudlackova, H; Leva, L; Vitasek, R; Faldyna, M

    2009-07-01

    The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non-pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action. PMID:19754566

  17. The genetics of canine skull shape variation.

    PubMed

    Schoenebeck, Jeffrey J; Ostrander, Elaine A

    2013-02-01

    A dog's craniofacial diversity is the result of continual human intervention in natural selection, a process that began tens of thousands of years ago. To date, we know little of the genetic underpinnings and developmental mechanisms that make dog skulls so morphologically plastic. In this Perspectives, we discuss the origins of dog skull shapes in terms of history and biology and highlight recent advances in understanding the genetics of canine skull shapes. Of particular interest are those molecular genetic changes that are associated with the development of distinct breeds.

  18. Cerebrospinal fluid may mediate CNS ischemic injury

    PubMed Central

    Wang, Yanming F; Gwathmey, Judith K; Zhang, Guorong; Soriano, Sulpicio G; He, Shunli; Wang, Yanguang

    2005-01-01

    Background The central nervous system (CNS) is extremely vulnerable to ischemic injury. The details underlying this susceptibility are not completely understood. Since the CNS is surrounded by cerebrospinal fluid (CSF) that contains a low concentration of plasma protein, we examined the effect of changing the CSF in the evolution of CNS injury during ischemic insult. Methods Lumbar spinal cord ischemia was induced in rabbits by cross-clamping the descending abdominal aorta for 1 h, 2 h or 3 h followed by 7 d of reperfusion. Prior to ischemia, rabbits were subjected to the following procedures; 1) CSF depletion, 2) CSF replenishment at 0 mmHg intracranial pressure (ICP), and 3) replacement of CSF with 8% albumin- or 1% gelatin-modified artificial CSF, respectively. Motor function of the hind limbs and histopathological changes of the spinal cord were scored. Post-ischemic microcirculation of the spinal cord was visualized by fluorescein isothiocyanate (FITC) albumin. Results The severity of histopathological damage paralleled the neurological deficit scores. Paraplegia and associated histopathological changes were accompanied by a clear post-ischemic deficit in blood perfusion. Spinal cord ischemia for 1 h resulted in permanent paraplegia in the control group. Depletion of the CSF significantly prevented paraplegia. CSF replenishment with the ICP reduced to 0 mmHg, did not prevent paraplegia. Replacement of CSF with albumin- or gelatin-modified artificial CSF prevented paraplegia in rabbits even when the ICP was maintained at 10–15 mmHg. Conclusion We conclude that the presence of normal CSF may contribute to the vulnerability of the spinal cord to ischemic injury. Depletion of the CSF or replacement of the CSF with an albumin- or gelatin-modified artificial CSF can be neuroprotective. PMID:16174300

  19. Sarcolemmal Ca(2+)-entry through L-type Ca(2+) channels controls the profile of Ca(2+)-activated Cl(-) current in canine ventricular myocytes.

    PubMed

    Horváth, Balázs; Váczi, Krisztina; Hegyi, Bence; Gönczi, Mónika; Dienes, Beatrix; Kistamás, Kornél; Bányász, Tamás; Magyar, János; Baczkó, István; Varró, András; Seprényi, György; Csernoch, László; Nánási, Péter P; Szentandrássy, Norbert

    2016-08-01

    Ca(2+)-activated Cl(-) current (ICl(Ca)) mediated by TMEM16A and/or Bestrophin-3 may contribute to cardiac arrhythmias. The true profile of ICl(Ca) during an actual ventricular action potential (AP), however, is poorly understood. We aimed to study the profile of ICl(Ca) systematically under physiological conditions (normal Ca(2+) cycling and AP voltage-clamp) as well as in conditions designed to change [Ca(2+)]i. The expression of TMEM16A and/or Bestrophin-3 in canine and human left ventricular myocytes was examined. The possible spatial distribution of these proteins and their co-localization with Cav1.2 was also studied. The profile of ICl(Ca), identified as a 9-anthracene carboxylic acid-sensitive current under AP voltage-clamp conditions, contained an early fast outward and a late inward component, overlapping early and terminal repolarizations, respectively. Both components were moderately reduced by ryanodine, while fully abolished by BAPTA, but not EGTA. [Ca(2+)]i was monitored using Fura-2-AM. Setting [Ca(2+)]i to the systolic level measured in the bulk cytoplasm (1.1μM) decreased ICl(Ca), while application of Bay K8644, isoproterenol, and faster stimulation rates increased the amplitude of ICl(Ca). Ca(2+)-entry through L-type Ca(2+) channels was essential for activation of ICl(Ca). TMEM16A and Bestrophin-3 showed strong co-localization with one another and also with Cav1.2 channels, when assessed using immunolabeling and confocal microscopy in both canine myocytes and human ventricular myocardium. Activation of ICl(Ca) in canine ventricular cells requires Ca(2+)-entry through neighboring L-type Ca(2+) channels and is only augmented by SR Ca(2+)-release. Substantial activation of ICl(Ca) requires high Ca(2+) concentration in the dyadic clefts which can be effectively buffered by BAPTA, but not EGTA. PMID:27189885

  20. In-vivo assessment of normal T1 values of the right-ventricular myocardium by cardiac MRI.

    PubMed

    Kawel-Boehm, N; Dellas Buser, T; Greiser, A; Bieri, O; Bremerich, J; Santini, F

    2014-02-01

    To test feasibility of myocardial T1 mapping of the right ventricle (RV) at systole when myocardium is more compact and to determine the most appropriate imaging plane. 20 healthy volunteers (11 men; 33 ± 8 years) were imaged on a 1.5T scanner (MAGNETOM Avanto, Siemens AG, Erlangen, Germany). A modified look-locker inversion-recovery sequence was acquired at mid-ventricular short axis (SAX), as horizontal long-axis view and as transversal view at systole (mean trigger time 363 ± 37 ms). Myocardial T1 time of the left-ventricular and RV myocardium was measured within a region of interest (ROI) on generated T1-maps. The most appropriate imaging plane for the RV was determined by the ability to draw a ROI including the largest amount of myocardium without including adjacent tissue or blood. At systole, when myocardium is thicker, measurements of the RV myocardium were feasible in 18/20 subjects. Average size of the ROI was 0.42 ± 0.28 cm(2). In 10/18 subjects, short axis was the most appropriate imaging plane to obtain measurements (p = 0.034). Average T1 time of the RV myocardium was 1,016 ± 61 ms, and average T1 of the left-ventricular (LV) was 956 ± 25 ms (p < 0.001). T1 mapping of the RV myocardium is feasible during systole in the majority of healthy subjects but with a small ROI only. SAX plane was the optimal imaging plane in the majority of subjects. Native myocardial T1 time of the RV is significantly longer compared to the LV, which might be explained by the naturally higher collagen content of the RV.

  1. Upper canine inclination influences the aesthetics of a smile.

    PubMed

    Bothung, C; Fischer, K; Schiffer, H; Springer, I; Wolfart, S

    2015-02-01

    This current study investigated which angle of canine inclination (angle between canine tooth axis (CA-line) and the line between the lateral canthus and the ipsilateral labial angle (EM-line)) is perceived to be most attractive in a smile. The second objective was to determine whether laymen and dental experts share the same opinion. A Q-sort assessment was performed with 48 posed smile photographs to obtain two models of neutral facial attractiveness. Two sets of images (1 male model set, 1 female model set), each containing seven images with incrementally altered canine and posterior teeth inclinations, were generated. The images were ranked for attractiveness by three groups (61 laymen, 59 orthodontists, 60 dentists). The images with 0° inclination, that is CA-line (maxillary canine axis) parallel to EM-line (the line formed by the lateral canthus and the ipsilateral corner of the mouth) (male model set: 54·4%; female model set: 38·9%), or -5° (inward) inclination (male model set: 20%; female model set: 29·4%) were perceived to be most attractive within each set. Images showing inward canine inclinations were regarded to be more attractive than those with outward inclinations. Dental experts and laymen were in accordance with the aesthetics. Smiles were perceived to be most attractive when the upper canine tooth axis was parallel to the EM-line. In reconstructive or orthodontic therapy, it is thus important to incline canines more inwardly than outwardly.

  2. Stem Cell-Associated Marker Expression in Canine Hair Follicles.

    PubMed

    Gerhards, Nora M; Sayar, Beyza S; Origgi, Francesco C; Galichet, Arnaud; Müller, Eliane J; Welle, Monika M; Wiener, Dominique J

    2016-03-01

    Functional hair follicle (HF) stem cells (SCs) are crucial to maintain the constant recurring growth of hair. In mice and humans, SC subpopulations with different biomarker expression profiles have been identified in discrete anatomic compartments of the HF. The rare studies investigating canine HF SCs have shown similarities in biomarker expression profiles to that of mouse and human SCs. The aim of our study was to broaden the current repertoire of SC-associated markers and their expression patterns in the dog. We combined analyses on the expression levels of CD34, K15, Sox9, CD200, Nestin, LGR5 and LGR6 in canine skin using RT-qPCR, the corresponding proteins in dog skin lysates, and their expression patterns in canine HFs using immunohistochemistry. Using validated antibodies, we were able to define the location of CD34, Sox9, Keratin15, LGR5 and Nestin in canine HFs and confirm that all tested biomarkers are expressed in canine skin. Our results show similarities between the expression profile of canine, human and mouse HF SC markers. This repertoire of biomarkers will allow us to conduct functional studies and investigate alterations in the canine SC compartment of different diseases, like alopecia or skin cancer with the possibility to extend relevant findings to human patients.

  3. The Incidence of Impacted Maxillary Canines in a Kosovar Population

    PubMed Central

    Gashi, Ali; Kamberi, Blerim; Ademi-Abdyli, Resmije; Perjuci, Ferijale; Sahatçiu-Gashi, Arjeta

    2014-01-01

    Aim. The purpose of this study was to investigate the incidence of impacted maxillary canines in a Kosovar population. Materials and Methods. The study consisted of a retrospective analysis of the records of 8101 patients treated in the University Dentistry Clinical Center of Kosovo between August 2001 and February 2004. The chi-squared test was used to examine potential differences in the distribution of impacted maxillary canines stratified by gender, age, location (left or right), and position. P < 0.05 was accepted as statistically significant. Results. It was found that the incidence of impacted maxillary canines was 1.62%. Of the 131 impacted maxillary canines, 101 were in female patients and 30 were in male patients, a statistically significant difference. Ages were in the range of 9 to >20 years, with a mean age of 24.38 ± 8.09 years. Of these subjects, 99 (75.57%) had unilaterally impacted maxillary canines, while 32 (24.43%) had bilateral impactions, a statistically significant difference (P < 0.00002). Impacted canines in 92 subjects (70.2%) were palatally placed, and 18 (13.7%) were labially placed. This difference was also statistically significant (P < 0.00001). Conclusion. The incidence of impacted maxillary canines in the sample Kosovar population was 1.62%, which is comparable to the findings from previous studies. PMID:27355063

  4. Cone-beam computed tomography findings of impacted upper canines

    PubMed Central

    Bastos, Luana Costa; Oliveira-Santos, Christiano; da Silva, Silvio José Albergaria; Neves, Frederico Sampaio; Campos, Paulo Sérgio Flores

    2014-01-01

    Purpose To describe the features of impacted upper canines and their relationship with adjacent structures through three-dimensional cone-beam computed tomography (CBCT) images. Materials and Methods Using the CBCT scans of 79 upper impacted canines, we evaluated the following parameters: gender, unilateral/bilateral occurrence, location, presence and degree of root resorption of adjacent teeth (mild, moderate, or severe), root dilaceration, dental follicle width, and presence of other associated local conditions. Results Most of the impacted canines were observed in females (56 cases), unilaterally (51 cases), and at a palatine location (53 cases). Root resorption in adjacent teeth and root dilaceration were observed in 55 and 47 impacted canines, respectively. In most of the cases, the width of the dental follicle of the canine was normal; it was abnormally wide in 20 cases. A statistically significant association was observed for all variables, except for root dilaceration (p=0.115) and the side of impaction (p=0.260). Conclusion Root resorption of adjacent teeth was present in most cases of canine impaction, mostly affecting adjacent lateral incisors to a mild degree. A wide dental follicle of impacted canines was not associated with a higher incidence of external root resorption of adjacent teeth. PMID:25473636

  5. Rapid maxillary canine retraction by dental distraction: A clinical study

    PubMed Central

    Koteswara Prasad, N. K.; Chitharanjan, Arun; Kailasam, Vignesh

    2014-01-01

    Aim: The aim of this clinical study was to perform rapid maxillary canine retraction through distraction of the periodontal ligament and investigate the rate and amount of canine retraction, amount of anchor loss, the nature of tooth movement achieved, and radiographic changes in the periodontal ligament region during and after canine distraction. Materials and Methods: This study was conducted on 10 distractions ranging in age from 14 years to 25 years who needed canine retraction and first premolar extraction in the maxillary arch. Ten canine distractions were carried out with custom-made, tooth-borne intra-oral distraction device. Results: The results indicate that the periodontal ligament can be distracted just like the mid-palatal suture in rapid palatal expansion and the maxillary canines are retracted rapidly into the first premolar extraction space at the rate of about 2.53 mm/week. Conclusion: Though this study indicates that the periodontal ligament can be distracted to elicit rapid tooth movement, the long-term effects of canine distraction are not well known and need close monitoring. PMID:25298710

  6. Stem Cell-Associated Marker Expression in Canine Hair Follicles.

    PubMed

    Gerhards, Nora M; Sayar, Beyza S; Origgi, Francesco C; Galichet, Arnaud; Müller, Eliane J; Welle, Monika M; Wiener, Dominique J

    2016-03-01

    Functional hair follicle (HF) stem cells (SCs) are crucial to maintain the constant recurring growth of hair. In mice and humans, SC subpopulations with different biomarker expression profiles have been identified in discrete anatomic compartments of the HF. The rare studies investigating canine HF SCs have shown similarities in biomarker expression profiles to that of mouse and human SCs. The aim of our study was to broaden the current repertoire of SC-associated markers and their expression patterns in the dog. We combined analyses on the expression levels of CD34, K15, Sox9, CD200, Nestin, LGR5 and LGR6 in canine skin using RT-qPCR, the corresponding proteins in dog skin lysates, and their expression patterns in canine HFs using immunohistochemistry. Using validated antibodies, we were able to define the location of CD34, Sox9, Keratin15, LGR5 and Nestin in canine HFs and confirm that all tested biomarkers are expressed in canine skin. Our results show similarities between the expression profile of canine, human and mouse HF SC markers. This repertoire of biomarkers will allow us to conduct functional studies and investigate alterations in the canine SC compartment of different diseases, like alopecia or skin cancer with the possibility to extend relevant findings to human patients. PMID:26739040

  7. Calcium secretion in canine tracheal mucosa

    SciTech Connect

    Al-Bazzaz, F.J.; Jayaram, T.

    1985-10-01

    Calcium (Ca) affects many cellular functions of the respiratory tract mucosa and might alter the viscoelastic properties of mucus. To evaluate Ca homeostasis in a respiratory epithelium we investigated transport of Ca by the canine tracheal mucosa. Mucosal tissues were mounted in Ussing-type chambers and bathed with Krebs-Henseleit solution at 37 degrees C. Unidirectional fluxes of 45Ca were determined in tissues that were matched by conductance and short-circuit current (SCC). Under short-circuit conditions there was a significant net Ca secretion of 1.82 +/- 0.36 neq . cm-2 . h-1 (mean +/- SE). Under open-circuit conditions, where the spontaneous transepithelial potential difference could attract Ca toward the lumen, net Ca secretion increased significantly to 4.40 +/- 1.14 compared with 1.54 +/- 1.17 neq . cm-2 . h-1 when the preparation was short-circuited. Addition of a metabolic inhibitor, 2,4-dinitrophenol (2 mM in the mucosal bath), decreased tissue conductance and SCC and slightly decreased the unidirectional movement of Ca from submucosa to lumen. Submucosal epinephrine (10 microM) significantly enhanced Ca secretion by 2.0 +/- 0.63 neq . cm-2 . h-1. Submucosal ouabain (0.1 mM) failed to inhibit Ca secretion. The data suggest that canine tracheal mucosa secretes Ca; this secretory process is augmented by epinephrine or by the presence of a transepithelial potential difference as found under in vivo conditions.

  8. Canine Models for Copper Homeostasis Disorders

    PubMed Central

    Wu, Xiaoyan; Leegwater, Peter A. J.; Fieten, Hille

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted. PMID:26861285

  9. Canine Models for Copper Homeostasis Disorders.

    PubMed

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-02-04

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

  10. Immunology and pathogenesis of canine demodicosis.

    PubMed

    Ferrer, Lluis; Ravera, Ivan; Silbermayr, Katja

    2014-10-01

    Demodex mites colonized the hair follicles and sebaceous glands of mammals millions of years ago and have remained relatively unchanged in this protected ecologic niche since then. The host immune system detects and tolerates their presence. Toll-like receptor-2 of keratinocytes has been demonstrated to recognize mite chitin and to elicit an innate immune response. The subsequent acquired immune response is poorly understood at present, but there is experimental and clinical evidence that this is the main mechanism in the control of mite proliferation. A transgenic mouse model (STAT(-/-) /CD28(-/-) ) has demonstrated that the immune response is complex, probably involving both cellular and humoral mechanisms and requiring the role of co-stimulatory molecules (CD28). It is known that a genetic predisposition for developing canine juvenile generalized demodicosis exists; however, the primary defect leading to the disease remains unknown. Once the mite proliferation is advanced, dogs show a phenotype that is similar to the T-cell exhaustion characterized by low interleukin-2 production and high interleukin-10 and transforming growth factor-β production by lymphocytes, as described in other viral and parasitic diseases. Acaricidal treatment (macrocyclic lactones) decreases the antigenic load and reverses T-cell exhaustion, leading to a clinical cure. Although in recent years there have been significant advances in the management and understanding of this important and complex canine disease, more research in areas such as the aetiology of the genetic predisposition and the immune control of the mite populations is clearly needed.

  11. Gene expression pattern in canine mammary osteosarcoma.

    PubMed

    Pawłowski, K M; Majewska, A; Szyszko, K; Dolka, I; Motyl, T; Król, M

    2011-01-01

    Canine mammary sarcomas are usually very aggressive and easily metastasize. Unfortunately the biology of this type of tumor is not well known because they are a very rare type of tumors. The aim of this study was to find differences in gene expression patterns in canine mammary osteosarcomas (malignant) versus osteomas (benign) using DNA microarrays. Our microarray experiment showed that 11 genes were up-regulated in osteosarcoma in comparison to osteoma whereas 36 genes were down-regulated. Among the up-regulated genes were: PDK1, EXT1, and EIF4H which are involved in AKT/PI3K and GLI/Hedgehog pathways. These genes play an important role in cell biology (cancer cell proliferation) and may be essential in osteosarcoma formation and development. Analyzing the down-regulated genes, the most interesting seemed to be HSPB8 and SEPP1. HSPB8 is a small heat shock protein that plays an important role in cell cycle regulation, apoptosis, and breast carcinogenesis. Also SEPP1 may play a role in carcinogenesis, as its down-regulation may induce oxidative stress possibly resulting in carcinogenesis. The preliminary results of the present study indicate that the up-regulation of three genes EXT1, EIF4H, and PDK1 may play an essential role in osteosarcoma formation, development and proliferation. In our opinion the cross-talk between GLI/Hedgehog and PI3K/AKT pathways may be a key factor to increase tumor proliferation and malignancy. PMID:21528706

  12. Molecular epidemiology of canine histoplasmosis in Japan.

    PubMed

    Murata, Yoshiteru; Sano, Ayako; Ueda, Yachiyo; Inomata, Tomo; Takayama, Akiko; Poonwan, Nateewan; Nanthawan, Mekha; Mikami, Yuzuru; Miyaji, Makoto; Nishimura, Kazuko; Kamei, Katsuhiko

    2007-05-01

    A recent case of canine histoplasmosis, the first confirmed case of disseminated infection accompanied by carcinoma in Japan, was diagnosed by clinical characteristics, histopathological examination, chest radiographs, ocular fundoscopy and molecular biological data. The clinical manifestations were not limited to cutaneous symptoms but were referable to disseminated infection, similar to human autochthonous cases. The partial sequences of the internal transcribed spacer (ITS1/2) regions of the ribosomal DNA genes of this and other Japanese canine histoplasmosis strains were 99-100% identical to the sequence AB211551 derived from a human isolate in Thailand, and showed a close relationship to the sequences derived from Japanese autochthonous systemic and cutaneous human cases. The phylogenetic analysis of 97 sequences of the ITS1/2 region disclosed six genotypes. The genotypes derived from Japanese autochthonous human and dog cases belonged to the cluster consisting of Histoplasma capsulatum var. capsulatum and H. capsulatum var. farciminosum sequences, indicating that these varieties might cause not only cutaneous but also systemic histoplasmosis, regardless of their host species. The current status of the 3 varieties of Histoplasma capsulatum according to the host species remains a subject of further investigation. PMID:17464845

  13. Canine hematopoiesis in a model of combined injury

    SciTech Connect

    MacVittie, T.J.; Monroy, R.L.; Fink, M.; Gruber, D.F.; Patchen, M.L.

    1983-04-29

    The development of a large animal model for CI within the context of a nuclear disaster required that we describe, experimentally, the essential features of the radiobiology of acute effects in the canine. The large-animal model is also appropriate for assessing the immunologic, pharmacologic, and surgical modes of intervention of following CI. The canine model of CI at the AFRRI has stressed three developmental aspects: (a) establishing the radiobiology of the canine hemopoietic system, (b) choosing a relevant model for peritoneal sepsis, and (c) identifying several choices for physical trauma. This paper stresses the relevance of the first aspect, the radiation-induced suppression and recovery of the hemopoietic system.

  14. Canine Pluripotent Stem Cells: Are They Ready for Clinical Applications?

    PubMed

    Betts, Dean H; Tobias, Ian C

    2015-01-01

    The derivation of canine embryonic stem cells and generation of canine-induced pluripotent stem cells are significant achievements that have unlocked the potential for developing novel cell-based disease models, drug discovery platforms, and transplantation therapies in the dog. A progression from concept to cure in this clinically relevant companion animal will not only help our canine patients but also help advance human regenerative medicine. Nevertheless, many issues remain to be resolved before pluripotent cells can be used clinically in a safe and reproducible manner. PMID:26664969

  15. [Identification of viable myocardium in ischemic heart disease with severe left ventricular contractile dysfunction: comparison of myocardial scintigraphy with 99mTc-sestamabi and with 201-thallium].

    PubMed

    Brandao, S; Cagnac, R; Roncalli, J; Lotterie, J A; Elbaz, M; Richez, F; Galinier, M; Carrie, D; Alibelli-Chemarin, M J

    2005-06-01

    The aim of this study was to compare quantitatively uptake of 99mTc-Sestamibi at rest and that of late redistribution of 201Tl in the same patients with severe ischaemic left ventricular dysfunction, and to correlate the uptake of the tracer to regional ventricular dysfunction studied by ECG grated 99Tc-Sestamini. A double isotope myocardial scintigraphy, 201 Thallium at rest/redistribution and 99Tc-Sestamibi at rest and on exercise, was performed in 28 patients with severe postinfarction ischaemic cardiomyopathy (EF= 29 +/- 4%). Quantitative analysis for each patient and each isotope were performed with respect to the number of hits expressed in percentage of the activity of a normal zone in 17 circumferential profiles distributed in 4 zones, that is to say in 476 segments. A score allowed counting of viable and non-viable segments and evaluation of contractile function of the 17 segments with respect to wall motion and systolic thickening. Total concordance of global uptake of the two isotopes was observed in 430 of the 476 segments (90.3%) (r= 0.814, p< 0.0001), but the 99mTc-Sestamibi uptake was less than 201 Th (71 +/- 23% vs 73 +/- 21%, p= 0.0001). With respect to left ventricular wall motion, uptake of 99mTc-Sestamibi was greater than that of 201Tl in normal or hypokinetic segments but less in akinetic and dyskinetic segments. The difference between the two isotopes was most marked in segments with very severe contractile dysfunction. The authors conclude that the uptake of 99mTc-Sestamibi is correlated with that of late distribution of 201Tl when left ventricular contraction is not too poor and should no longer be considered as only a marker of perfusion but can also be useful in the investigation of myocardial viability.

  16. Relationship of functional recovery to scar contraction after myocardial infarction in the canine left ventricle

    SciTech Connect

    Choong, C.Y.; Gibbons, E.F.; Hogan, R.D.; Franklin, T.D.; Nolting, M.; Mann, D.L.; Weyman, A.E.

    1989-04-01

    We have previously reported that regional wall motion abnormalities in a canine model of acute myocardial infarction may show substantial improvement in the first 6 weeks after infarction. To determine whether the mechanism of this improvement in function is the result of scar contraction within the infarct, we studied the relationship between changes in regional wall motion defined by cross-sectional echocardiography and the regional concentration of radioactive microspheres injected immediately before coronary occlusion and sampled 6 weeks after occlusion. Eight dogs underwent serial echocardiographic and microsphere blood flow measurements immediately before and 30 minutes, 48 hours, 1 week, 3 weeks, and 6 weeks after ligation of the left anterior descending or the left circumflex coronary artery. Wall motion and blood flow were measured in the short-axis section of the left ventricle at the level of the midpapillary muscle in each 10-degree radial segment around the circumference of the ventricle. Infarct histology was assessed at 6 weeks by means of the same radial coordinate system. Control data were collected in a similar manner from four dogs that underwent sham operations and had no histologic evidence of infarction. In all of the animals with infarcts, but not in the sham animals, the calculated preocclusion endocardial and epicardial blood flow values in the histologic infarct zone (252 +/- 44 and 168 +/- 17 ml/min/100 gm, respectively, mean +/- SEM) were significantly higher than those in the normal opposite wall (endocardial: 106 +/- 3 ml/min/100 gm, p less than 0.01); epicardial: 108 +/- 3 ml/min/100 gm, p less than 0.01. The location and circumferential extent of myocardium showing this elevation of preocclusion blood flow correlated well (r = 0.93, p less than 0.001) with the location and circumferential extent of the histologic infarct.

  17. Kinetics of canine dental calculus crystallization: an in vitro study on the influence of inorganic components of canine saliva.

    PubMed

    Borah, Ballav M; Halter, Timothy J; Xie, Baoquan; Henneman, Zachary J; Siudzinski, Thomas R; Harris, Stephen; Elliott, Matthew; Nancollas, George H

    2014-07-01

    This work identifies carbonated hydroxyapatite (CAP) as the primary component of canine dental calculus, and corrects the long held belief that canine dental calculus is primarily CaCO3 (calcite). CAP is known to be the principal crystalline component of human dental calculus, suggesting that there are previously unknown similarities in the calcification that occurs in these two unique oral environments. In vitro kinetic experiments mimicking the inorganic components of canine saliva have examined the mechanisms of dental calculus formation. The solutions were prepared so as to mimic the inorganic components of canine saliva; phosphate, carbonate, and magnesium ion concentrations were varied individually to investigate the roll of these ions in controlling the nature of the phases that is nucleated. To date, the inorganic components of the canine oral systems have not been investigated at concentrations that mimic those in vivo. The mineral composition of the synthetic calculi grown under these conditions closely resembled samples excised from canines. This finding adds new information about calculus formation in humans and canines, and their sensitivity to chemicals used to treat these conditions. PMID:24776659

  18. Intracoronary thallium 201 scintigraphy as an immediate predictor of salvaged myocardium following intracoronary lysis

    SciTech Connect

    Krebber, H.J.; Schofer, J.; Mathey, D.; Montz, R.; Kalmar, P.; Rodewald, G.

    1984-01-01

    Since February of 1980, 157 patients who had had symptoms of acute myocardial infarction for less than 3 hours underwent intracoronary lysis. Forty-six patients required early aorta-coronary revascularization. However, operation was believed to be indicated only when intracoronary lysis was successful and myocardium was salvaged. Since left ventricular angiography proved unreliable in assessing the viability of the myocardium in the acute stage, starting in March of 1981 intracoronary thallium 201 scintiscans were obtained in 23 patients before and after intracoronary lysis. Patients in whom there was a significant reduction in the initial /sup 201/Th defect were considered ideal candidates for operation (Group 3). Patients with poor or unimproved /sup 201/Th uptake after successful intracoronary lysis were treated medically (Group 2), as were patients in whom intracoronary lysis was unsuccessful (Group 1). In order to validate this new approach, a comparison was made of the change in the regional wall motion of the ''infarcted area,'' as shown in the early and follow-up left ventricular angiograms in all three groups. In the acute stage, the mean regional ejection fraction was 19.9% in Group 1, 19.1% in Group 2, and 20.1% in Group 3. Only in Group 3 was there a significant increase in regional ejection fraction to a mean of 51%. The mean ejection fraction obtained at follow-up in Groups 1 and 2 was 16.5% and 17.3%, respectively. From these findings, it was concluded that /sup 201/Th scintigraphy is a valuable predictor of the salvageability of myocardium immediately following intracoronary lysis. To date, it has been the most valuable tool in assessing those patients suitable for early coronary revascularization.

  19. Nonoxidative ethanol metabolism in rabbit myocardium: purification to homogeneity of fatty acyl ethyl ester synthase

    SciTech Connect

    Mogelson, S.; Lange, L.G.

    1984-08-28

    Fatty acyl ethyl esters arise from an esterification of free fatty acids with ethanol in the absence of ATP and coenzyme A. This study was designed to purify the enzyme(s) in rabbit myocardium that catalyze(s) this reaction. Enzyme activity in homogenates of myocardium, as assayed by the rate of synthesis of ethyl (/sup 14/C)oleate from 0.4 mM (/sup 14/C)oleic acid and 0.2 M ethanol, was 31 nmol/ (g x h), and was recovered in the 48400g supernatant. This soluble ethyl ester synthase activity bound to DEAE-cellulose at pH 8, and elution with a NaCl gradient (0-0.25 M0 separated two enzyme activities accounting for 13 and 87% of recovered synthase activity. The major enzyme activity was purified over 5000-fold to homogeneity. Gel electrophoresis showed a single polypeptide with M/sub r/ 26,000, and gel permeation chromatography under nondenaturing conditions indicated a M/sub r/ of 50,000 for the active enzyme. Kinetic analyses indicated that greatest rates of synthesis were observed with unsaturated octadecanoic fatty acid substrates. K/sub m/'s for these fatty acids were essentially identical and equal to 0.2 mM; substrate specificity resulted from varying K/sub m/'s for methanol, ethanol, 1-propanol, and 1-butanol, while V/sub max/ was constant at approximately 1.5 nmol/(mg x s). The amino acid analysis of this synthase distinguishes it from typical cholesterol esterases. When the enzyme is maximally active with respect to ethyl ester synthesis, it does not hydrolyze cholesterol oleate. Fatty acid ethyl esters are synthesized in myocardium primarily by a soluble dimeric enzyme comprised of two nearly identical subunits which esterifies free fatty acids with ethanol to produce a nonoxidative metabolite.

  20. Effects of acute and chronic uremia on active cation transport in rat myocardium

    SciTech Connect

    Druml, W.; Kelly, R.A.; England, B.K.; O'Hara, D.S.; Mitch, W.E. )

    1990-12-01

    As abnormalities of active cation transport could contribute to the genesis of uremic cardiomyopathy, we investigated myocardial sodium pump function in rats with acute renal failure (ARF) and with a model of experimental chronic renal failure (CRF) that has metabolic similarities to advanced chronic uremia in humans. CRF rats were hypertensive and had left ventricular hypertrophy (33% higher heart:body weight ratio; P less than 0.01) at four weeks compared to pair-fed sham-operated rats. Importantly, both ouabain- and furosemide-sensitive 86Rb uptake rates were unchanged in left ventricular myocardial slices from CRF, and the intracellular sodium concentration was not different from that of control rats even though skeletal muscle sodium was increased, as we found previously. Insulin-stimulated, ouabain-sensitive 86Rb influx was also preserved. There also were no abnormalities in myocardium cation transport in rats with ARF. However, (3H)ouabain binding was decreased 45% in CRF rats (P less than 0.01); it was unchanged in acute uremia. Decreased ouabain binding in chronic uremia was due entirely to fewer low affinity (3H)ouabain binding sites (the binding affinity for ouabain was unaffected). We conclude that in chronic, (but not acute) renal failure, sodium pump number is reduced in myocardium but intracellular sodium is unchanged and active cation flux rates are maintained. These results emphasize that in rats with chronic uremia, intracellular sodium homeostasis is preserved in myocardium, despite the presence of marked abnormalities of active cation transport in skeletal muscle that are characteristic of chronic uremia.

  1. Anisotropic physical properties of myocardium characterized by ultrasonic measurements of backscatter, attenuation, and velocity

    NASA Astrophysics Data System (ADS)

    Baldwin, Steven L.

    The goal of elucidating the physical mechanisms underlying the propagation of ultrasonic waves in anisotropic soft tissue such as myocardium has posed an interesting and largely unsolved problem in the field of physics for the past 30 years. In part because of the vast complexity of the system being studied, progress towards understanding and modeling the mechanisms that underlie observed acoustic parameters may first require the guidance of careful experiment. Knowledge of the causes of observed ultrasonic properties in soft tissue including attenuation, speed of sound, and backscatter, and how those properties are altered with specific pathophysiologies, may lead to new noninvasive approaches to the diagnosis of disease. The primary aim of this Dissertation is to contribute to an understanding of the physics that underlies the mechanisms responsible for the observed interaction of ultrasound with myocardium. To this end, through-transmission and backscatter measurements were performed by varying acoustic properties as a function of angle of insonification relative to the predominant myofiber direction and by altering the material properties of myocardium by increased protein cross-linking induced by chemical fixation as an extreme form of changes that may occur in certain pathologies such as diabetes. Techniques to estimate acoustic parameters from backscatter were broadened and challenges to implementing these techniques in vivo were addressed. Provided that specific challenges identified in this Dissertation can be overcome, techniques to estimate attenuation from ultrasonic backscatter show promise as a means to investigate the physical interaction of ultrasound with anisotropic biological media in vivo. This Dissertation represents a step towards understanding the physics of the interaction of ultrasonic waves with anisotropic biological media.

  2. The effects of prenatal and neonatal exposure to electromagnetic fields on infant rat myocardium

    PubMed Central

    Tayefi, Hamid; Kiray, Amac; Ergur, Bekir Ugur; Bagriyanik, Husnu Alper; Pekcetin, Cetin; Fidan, Mustafa; Ozogul, Candan

    2010-01-01

    Introduction Electromagnetic fields (EMF) have adverse effects as a result of widespread use of electromagnetic energy on biological systems. The aim of this study was to investigate the effects of prenatal exposure to EMF on rat myocardium by biochemical and histopathological evaluations. Material and methods In this study, 10 pregnant Wistar rats were used. Half of the pregnant rats were exposed to EMF of 3 mT, and the other half to sham conditions during gestation. After parturition, rat pups in the 5 EMF-exposed litters from birth until postnatal day 20 were exposed to EMF of 3 mT for 4 h/day (EMF-exposed group, n = 30). Rat pups in sham litters from birth until postnatal day 20 were exposed to sham conditions (sham group, n= 20). Results In the EMF-exposed group, lipid peroxidation levels significantly increased compared to sham. Superoxide dismutase activities decreased significantly in the EMF-exposed group compared to sham. TUNEL staining showed that the number of TUNEL-positive cells increased significantly in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. Conclusions In conclusion, the results show that prenatal exposure to EMF causes oxidative stress, apoptosis and morphological pathology in myocardium of rat pups. The results of our study indicate a probable role of free radicals in the adverse effects of prenatal exposure to EMF. Further studies are needed to demonstrate whether the EMF exposure can induce adverse effects on the myocardium. PMID:22427754

  3. Validation of a commercially available automated canine-specific immunoturbidimetric method for measuring canine C-reactive protein

    PubMed Central

    Hillström, Anna; Hagman, Ragnvi; Tvedten, Harold; Kjelgaard-Hansen, Mads

    2014-01-01

    Background Measurement of C-reactive protein (CRP) is used for diagnosing and monitoring systemic inflammatory disease in canine patients. An automated human immunoturbidimetric assay has been validated for measuring canine CRP, but cross-reactivity with canine CRP is unpredictable. Objective The purpose of the study was to validate a new automated canine-specific immunoturbidimetric CRP method (Gentian cCRP). Methods Studies of imprecision, accuracy, prozone effect, interference, limit of quantification, and stability under different storage conditions were performed. The new method was compared with a human CRP assay previously validated for canine CRP determination. Samples from 40 healthy dogs were analyzed to establish a reference interval. Results Total imprecision was < 2.4% for 4 tested serum pools analyzed twice daily over 10 days. The method was linear under dilution, and no prozone effect was detected at a concentration of 1200 mg/L. Recovery after spiking serum with purified canine CRP at 2 different concentrations was 123% and 116%, respectively. No interference from hemoglobin or triglycerides (10 g/L) was detected. CRP was stable for 14 days at 4°C and 22°C. In the method comparison study, there was good agreement between the validated human CRP assay and the new canine-specific assay. Healthy dogs had CRP concentrations that were less than the limit of quantification of the Gentian cCRP method (6.8 mg/L). Conclusions The new canine-specific immunoturbidimetric CRP assay is a reliable and rapid method for measuring canine CRP, suitable for clinical use due to the option for an automated assay. PMID:24798319

  4. [Intramural chronotopography of depolarization of myocardium of heart ventricles of pig (Sus scrofa domesticus)].

    PubMed

    Gulyaeva, A S; Roshchecskaya, I M; Roshchevsky, M P

    2014-01-01

    Sequence of depolarization of myocardium of pig heart ventricles was studied by the method of multichannel synchronous cardioelectrotopography. There is established formation of areas of early depolarization in subendocardium of interventricular septum and in the base of left ventricle papillary muscles; of multiple foci--in the depth of walls; of areas of late depolarization--in subepicardium of the left ventricle dorsolateral side. As compared with other species of ungulate animals (reindeer and sheep, in pig heart ventricles, differences are revealed in locations of early and late depolarization, a breakdown of the excitation wave into subepicardium.

  5. Regional Stress-Induced Ischemia in Non-fibrotic Hypertrophied Myocardium in Young HCM Patients.

    PubMed

    Jablonowski, Robert; Fernlund, Eva; Aletras, Anthony H; Engblom, Henrik; Heiberg, Einar; Liuba, Petru; Arheden, Håkan; Carlsson, Marcus

    2015-12-01

    The relationship between hypertrophy, perfusion abnormalities and fibrosis is unknown in young patients with hypertrophic cardiomyopathy (HCM). Since mounting evidence suggests causal relationship between myocardial ischemia and major adverse cardiac events, we sought to investigate whether (1) regional myocardial perfusion is decreased in young HCM patients and in individuals at risk of HCM, and (2) hypoperfused areas are larger than areas with fibrosis. HCM patients (n = 12), HCM-risk subjects (n = 15) and controls (n = 9) were imaged on a 1.5 T MRI scanner. Myocardial hypertrophy was assessed on cine images. Perfusion images were acquired during adenosine hyperemia and at rest. Maximum upslope ratios of perfusion (stress/rest) were used for semiquantitative analysis. Fibrosis was assessed by late gadolinium enhancement (LGE). Results are presented as median and range. Perfusion in HCM-risk subjects and in non-hypertrophied segments in HCM patients showed no difference compared to controls (P = ns). Hypertrophic segments in HCM patients without LGE showed decreased perfusion compared to segments without hypertrophy [1.5 (1.1-2.3) vs. 2.0 (1.8-2.6), P < 0.001], and hypertrophic segments with LGE showed even lower perfusion using a segmental analysis [0.9 (0.6-1.8), P < 0.05]. The extent of hypoperfused myocardium in HCM patients during adenosine exceeded the extent of fibrosis on LGE [20 (0-48) vs. 4 (0-7) % slice area, P < 0.05] and hypoperfused areas at rest (P < 0.001). Regional perfusion is decreased in hypertrophied compared to non-hypertrophied myocardium and is lowest in fibrotic myocardium in young HCM patients but does not discriminate HCM-risk subjects from controls. The stress-induced hypoperfused regions exceed regions with LGE, indicating that hypoperfusion precedes fibrosis and may be a more sensitive marker of diseased myocardium in HCM.

  6. Effects of hypodynamia on the hemocoagulative properties of the vascular wall and myocardium

    NASA Technical Reports Server (NTRS)

    Inchina, V. I.

    1980-01-01

    The hemocoagulative properties of the aorta (laminar), myocardium, hollow veins, and fibrinolytic capacity of tissues were studied in 14 rabbits subjected to 7 days of restricted mobility and compared to those of 10 control animals. Two tables of results show that, as a result of hypodynamia, the thromboplastic activity of the inner and middle layers of the aorta together with the destruction of endothelium increases the hemocoagulative potential and creates the threat of thrombogenesis. There is also an increase in fibrin-stabilizing activity for all tissues.

  7. Two-dimensional strain combined with adenosine stress echocardiography assessment of viable myocardium.

    PubMed

    Fang, Ling-Ling; Zhang, Ping-Yang; Wang, Chong; Wang, Li-Ming; Ma, Xiao-Wu; Shi, Hong-Wei; Feng, Xue-Hong

    2011-03-01

    The objective of this study was to explore a new method for the identification of viable myocardium by means of two-dimensional (2D) strain imaging combined with adenosine stress echocardiography. A total of 15 anesthetized open-chest healthy mongrel dogs underwent left anterior descending coronary artery occlusion for 90 min followed by 120-min reperfusion. Adenosine was infused at 140 μg kg(-1) min(-1) over a period of 6 min. Images were acquired at baseline (when pericardial cradle was made), after reperfusion (when reperfusion finished) and after adenosine administration (while administration stopped). Measurements of the regional peak-systolic strain in radial, circumferential, and longitudinal motion on anterior wall and anterior septum were, respectively, performed under different conditions. The dogs were killed after the echocardiographic studies finished and then the area of infracted myocardium was defined by triphenyltetrazolium chloride histology. A segment with equal or less than 50% area of infracted myocardium was considered to be viable. As a result, 37 regions were viable whereas 53 were non-viable among 90 regions in 15 dogs. At baseline, there was no significant difference in peak-systolic radial strain (Rs), circumferential strain (Cs), and longitudinal strain (Ls) between the viable and non-viable groups. After reperfusion, Rs, Cs, and Ls in absolute value decreased compared to those at baseline in both groups, although there was no significant difference between these groups. Rs and Ls increased after adenosine administration compared to reperfusion (p < 0.01; p < 0.05) in viable group while there were no changes in non-viable group. Compared with non-viable group Rs, Cs and Ls in viable group increased significantly (p < 0.01; 0.05) after adenosine administration. There was a negative correlation between Rs and infarct size (r = -0.72). Cs and Ls correlated well with infarct size, respectively (r = 0.40; 0.67). A change of Rs more than 13

  8. Viscoelastic properties of pressure overload hypertrophied myocardium: effect of serine protease treatment

    NASA Technical Reports Server (NTRS)

    Stroud, Jason D.; Baicu, Catalin F.; Barnes, Mary A.; Spinale, Francis G.; Zile, Michael R.

    2002-01-01

    To determine whether and to what extent one component of the extracellular matrix, fibrillar collagen, contributes causally to abnormalities in viscoelasticity, collagen was acutely degraded by activation of endogenous matrix metalloproteinases (MMPs) with the serine protease plasmin. Papillary muscles were isolated from normal cats and cats with right ventricular pressure overload hypertrophy (POH) induced by pulmonary artery banding. Plasmin treatment caused MMP activation, collagen degradation, decreased the elastic stiffness constant, and decreased the viscosity constant in both normal and POH muscles. Thus, whereas many mechanisms may contribute to the abnormalities in myocardial viscoelasticity in the POH myocardium, changes in fibrillar collagen appear to play a predominant role.

  9. [Intramural chronotopography of depolarization of myocardium of heart ventricles of pig (Sus scrofa domesticus)].

    PubMed

    2014-01-01

    Sequence of depolarization of myocardium of pig heart ventricles was studied by the method of multichannel synchronous cardioelectrotopography. There is established formation of areas of early depolarization in subendocardium of interventricular septum and in the base of left ventricle papillary muscles; of multiple foci--in the depth of walls; of areas of late depolarization--in subepicardium of the left ventricle dorsolateral side. As compared with other species of ungulate animals (reindeer and sheep, in pig heart ventricles, differences are revealed in locations of early and late depolarization, a breakdown of the excitation wave into subepicardium. PMID:25508945

  10. [Intramural chronotopography of depolarization of myocardium of heart ventricles of pig (Sus scrofa domesticus)].

    PubMed

    Gulyaeva, A S; Roshchecskaya, I M; Roshchevsky, M P

    2014-01-01

    Sequence of depolarization of myocardium of pig heart ventricles was studied by the method of multichannel synchronous cardioelectrotopography. There is established formation of areas of early depolarization in subendocardium of interventricular septum and in the base of left ventricle papillary muscles; of multiple foci--in the depth of walls; of areas of late depolarization--in subepicardium of the left ventricle dorsolateral side. As compared with other species of ungulate animals (reindeer and sheep, in pig heart ventricles, differences are revealed in locations of early and late depolarization, a breakdown of the excitation wave into subepicardium. PMID:25486814

  11. Arrangements of multiple images of human myocardium for information for the surgeon during open heart surgery

    NASA Astrophysics Data System (ADS)

    Kessler, Manfred D.; Cristea, Paul D.; Hiller, Michael; Trinks, Tobias

    2002-06-01

    The feasibility to obtain visualized information of myocardium by imaging is a new dimension. However, during heart surgery the surgeon does not need all data of images continuously. Therefore, development of strategies able to reduce flux of information transiently in between images might become important. Arrangements of images in 3-dimensional structures can produce better outlines. Images often contain information of several parameters. Therefore, a selection of important parts of the pictures might be helpful. Optical sensors will have the ability to detect dangerous situations in tissues which can release optical or acoustic signals.

  12. Effect of Ischemia on the Canine Large Bowel: A Comparison with the Small Intestine1

    PubMed Central

    Takeyoshi, Izumi; Zhang, Shimin; Nakamura, Kenjiro; Ikoma, Akira; Zhu, Yue; Starzl, Thomas E.; Todo, Satoru

    2010-01-01

    Mucosal injury caused by ischemia and reperfusion has been well documented with the small intestine, but little is known about the colon. In the present study, the effect of warm and cold ischemia on the canine colon was studied and compared to that on the small intestine. After in situ flushing, the small intestine and the colon from six beagle dogs were removed and stored for 0.5, 1.5, and 3 hr at 37°C (warm ischemia) or for 1, 6, 12, 24, 36, and 48 hr at 4°C (cold ischemia). Electrophysiology, permeability, biochemistry, and histopathology of the specimens at each ischemic period and after reperfusion in the Ussing chamber were determined. Warm and cold ischemia induced duration-dependent suppression of electrophysiology in both organs, but the colonic mucosa retained higher activity of absorptive enterocytes and cryptic cells than the small intestine. Only the colon showed increased permeability of FITC-conjugated Dextran from the mucosal surface to the submucosal layer after prolonged ischemia. Changes in adenine nucleotides and purine catabolites were not markedly different between the organs. Histopathologic abnormalities during ischemia and after reperfusion were more serious with the small intestine than with the colon. Compared to warm ischemia, hypothermia lessened or delayed these morphofunctional derangements in both organs, which became universally worsened after reperfusion. Colonic mucosa receives morphofunctional derangements from ischemia and reperfusion, but the severity of the damage was much less severe in the colon than in the small intestine. PMID:8606507

  13. Beneficial effect of medicinal plants on the contractility of post-hypoxic isolated guinea pig atria - Potential implications for the treatment of ischemic-reperfusion injury.

    PubMed

    Bipat, Robbert; Toelsie, Jerry R; Magali, Indira; Soekhoe, Rubaina; Stender, Karin; Wangsawirana, Angelique; Oedairadjsingh, Krishan; Pawirodihardjo, Jennifer; Mans, Dennis R A

    2016-08-01

    Context Ischemic-reperfusion injury is accompanied by a decreased contractility of the myocardium. Positive-inotropic agents have proven useful for treating this condition but may exert serious side-effects. Objective In this study, aqueous preparations from Abelmoschus esculentus L. Moench (Malvaceae), Annona muricata L. (Annonaceae), Bixa orellana L. (Bixaceae), Cecropia peltata L. (Moraceae), Erythrina fusca Lour. (Fabaceae), Psidium guajava L. (Myrtaceae) and Terminalia catappa L. (Combretaceae) were evaluated for their ability to improve the decreased contractility of isolated guinea pig atria after hypoxic stress. Materials and methods Guinea pig atria isolated in Ringer-Locke buffer gassed with 100% O2 at 30 °C were exposed for 5 min to hypoxia, then allowed to recover in oxygenated buffer alone or containing a single plant extract (0.001-1 mg/mL). The contractility (g/s) and beating frequency (beats/min), as well as troponin C contents of the bathing solution (ng/mL), were determined and expressed as means ± SDs. Results The extracts of A. muricata, B. orellana, C. peltata and T. catappa caused an increase in the contractility compared to untreated atria of 340 ± 102%, 151 ± 13%, 141 ± 14% and 238 ± 44%, respectively. However, the latter two preparations increased the troponin C contents of the bathing solution to 36 ± 11 and 69 ± 33, compared to the value of 11 ± 3 ng/mL found with untreated atria. Conclusions Preparations from A. muricata and B. orellana may possess positive-inotropic properties which may improve the contractility of the post-hypoxic myocardium. Studies to assess their usefulness in ischemic-reperfusion injury are warranted.

  14. Beneficial effect of medicinal plants on the contractility of post-hypoxic isolated guinea pig atria - Potential implications for the treatment of ischemic-reperfusion injury.

    PubMed

    Bipat, Robbert; Toelsie, Jerry R; Magali, Indira; Soekhoe, Rubaina; Stender, Karin; Wangsawirana, Angelique; Oedairadjsingh, Krishan; Pawirodihardjo, Jennifer; Mans, Dennis R A

    2016-08-01

    Context Ischemic-reperfusion injury is accompanied by a decreased contractility of the myocardium. Positive-inotropic agents have proven useful for treating this condition but may exert serious side-effects. Objective In this study, aqueous preparations from Abelmoschus esculentus L. Moench (Malvaceae), Annona muricata L. (Annonaceae), Bixa orellana L. (Bixaceae), Cecropia peltata L. (Moraceae), Erythrina fusca Lour. (Fabaceae), Psidium guajava L. (Myrtaceae) and Terminalia catappa L. (Combretaceae) were evaluated for their ability to improve the decreased contractility of isolated guinea pig atria after hypoxic stress. Materials and methods Guinea pig atria isolated in Ringer-Locke buffer gassed with 100% O2 at 30 °C were exposed for 5 min to hypoxia, then allowed to recover in oxygenated buffer alone or containing a single plant extract (0.001-1 mg/mL). The contractility (g/s) and beating frequency (beats/min), as well as troponin C contents of the bathing solution (ng/mL), were determined and expressed as means ± SDs. Results The extracts of A. muricata, B. orellana, C. peltata and T. catappa caused an increase in the contractility compared to untreated atria of 340 ± 102%, 151 ± 13%, 141 ± 14% and 238 ± 44%, respectively. However, the latter two preparations increased the troponin C contents of the bathing solution to 36 ± 11 and 69 ± 33, compared to the value of 11 ± 3 ng/mL found with untreated atria. Conclusions Preparations from A. muricata and B. orellana may possess positive-inotropic properties which may improve the contractility of the post-hypoxic myocardium. Studies to assess their usefulness in ischemic-reperfusion injury are warranted. PMID:26730936

  15. Role of thioredoxin-1 in ischemic preconditioning, postconditioning and aged ischemic hearts.

    PubMed

    D'Annunzio, Veronica; Perez, Virginia; Boveris, Alberto; Gelpi, Ricardo J; Poderoso, Juan J

    2016-07-01

    Thioredoxin is one of the most important cellular antioxidant systems known to date, and is responsible of maintaining the reduced state of the intracellular space. Trx-1 is a small cytosolic protein whose transcription is induced by stress. Therefore it is possible that this antioxidant plays a protective role against the oxidative stress caused by an increase of reactive oxygen species concentration, as occurs during the reperfusion after an ischemic episode. However, in addition to its antioxidant properties, it is able to activate other cytoplasmic and nuclear mediators that confer cardioprotection. It is remarkable that Trx-1 also participates in myocardial protection mechanisms such as ischemic preconditioning and postconditioning, activating proteins related to cellular survival. In this sense, it has been shown that Trx-1 inhibition abolished the preconditioning cardioprotective effect, evidenced through apoptosis and infarct size. Furthermore, ischemic postconditioning preserves Trx-1 content at reperfusion, after ischemia. However, comorbidities such as aging can modify this powerful cellular defense leading to decrease cardioprotection. Even ischemic preconditioning and postconditioning protocols performed in aged animal models failed to decrease infarct size. Therefore, the lack of success of antioxidants therapies to treat ischemic heart disease could be solved, at least in part, avoiding the damage of Trx system. PMID:26987940

  16. Spectroscopic imaging and spatial localization using adiabatic pulses and applications to detect transmural metabolite distribution in the canine heart.

    PubMed

    Robitaille, P M; Merkle, H; Sublett, E; Hendrich, K; Lew, B; Path, G; From, A H; Bache, R J; Garwood, M; Uğurbil, K

    1989-04-01

    Adiabatic pulses have been employed in spectroscopic imaging and relaxation rate measurements at 4.7 T to demonstrate the feasibility of obtaining spectroscopic data from the complete sensitive volume of a surface coil using the surface coil as a transmitter and receiver. With conventional B1 sensitive pulses, spectroscopic localization or imaging techniques, such as chemical-shift imaging, yield resonance intensities that are distorted severely as a function of space, and maximal signal is detected from a small region within the complete sensitive volume of the coil. With adiabatic pulses, however, this problem is eliminated completely. In addition, a new method of spatial localization is introduced. This method, referred to as FLAX-ISIS, is a derivative of longitudinally modulated Fourier series window and ISIS approaches and utilizes adiabatic inversion and excitation pulses. The method allows construction of localized spectra for multiple regions along the surface coil axis by postacquisition data manipulation of a single set of free induction decays. These techniques were applied to the study of the myocardium using an implanted surface coil in an instrumented closed-chest canine model and in an open-chest preparation. The results demonstrate that one-dimensional techniques are adequate for transmural detection of metabolites provided signal origin is restricted to a column perpendicular to the left ventricle wall. PMID:2755331

  17. Aspirin resistant patients with recent ischemic stroke.

    PubMed

    Castilla-Guerra, L; Navas-Alcántara, M S; Fernández-Moreno, M C

    2014-04-01

    Some patients with a recent ischemic stroke who are being treated with aspirin as an antiaggregant suffer a new ischemic stroke. These patients (15-25%) have been called unresponsive to aspirin or aspirin resistant. The aspirin-resistant patients have a four-time greater risk of suffering a stroke. Furthermore, these strokes are generally more severe, with increased infarct volume and greater risk of recurrence. There is currently no ideal laboratory test to detect the resistance to the antiaggregant effect of aspirin. The study of resistance to aspirin would only be indicated in selected cases. In these patients, one should first rule out any "pseudo-resistance" to aspirin (lack of compliance, concomitant treatments that interfere with the action of the aspirin). PMID:24211052

  18. Isolated naratriptan-associated ischemic colitis

    PubMed Central

    Nissan, George; Chaudhry, Priyanka; Rangasamy, Priya; Mudrovich, Steven

    2016-01-01

    We report a 41-year-old woman who developed histology- and colonoscopy-proven ischemic colitis with the use of naratriptan not exceeding the maximum 2 doses a day and 3 days per week and without a known medical or cardiovascular history. By exclusion of other causes of colonic ischemia, naratriptan was considered the sole causal agent. Discontinuation of naratriptan resulted in a complete clinical recovery. To date, our patient is the youngest known patient to develop ischemic colitis on isolated naratriptan in the setting of no known medical risk factors or predisposing medical condition. Even though triptans are commonly used for the abortive treatment of migraine headaches, such a reported side effect is rare; however, careful assessment and individual patient-based treatment is advised.

  19. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text.

  20. [Ischemic cholangiopathy induced by extended burns].

    PubMed

    Cohen, Laurence; Angot, Emilie; Goria, Odile; Koning, Edith; François, Arnaud; Sabourin, Jean-Christophe

    2013-04-01

    Ischemic cholangiopathy is a recently described entity occurring mainly after hepatic grafts. Very few cases after intensive care unit (ICU) for extended burn injury were reported. We report the case of a 73-year-old woman consulting in an hepatology unit, for a jaundice appearing during a hospitalisation in an intensive care unit and increasing from her leaving from ICU, where she was treated for an extended burn injury. She had no pre-existing biological features of biliary disease. Biological tests were normal. Magnetic resonance imaging acquisitions of biliary tracts pointed out severe stenosing lesions of diffuse cholangiopathy concerning intrahepatic biliary tract, mainly peri-hilar. Biopsie from the liver confirmed the diagnosis, showing a biliary cirrhosis with bile infarcts. This case is the fourth case of ischemic cholangiopathy after extended burn injury, concerning a patient without a prior history of hepatic or biliary illness and appearing after hospitalisation in intensive care unit.

  1. Isolated naratriptan-associated ischemic colitis

    PubMed Central

    Nissan, George; Chaudhry, Priyanka; Rangasamy, Priya; Mudrovich, Steven

    2016-01-01

    We report a 41-year-old woman who developed histology- and colonoscopy-proven ischemic colitis with the use of naratriptan not exceeding the maximum 2 doses a day and 3 days per week and without a known medical or cardiovascular history. By exclusion of other causes of colonic ischemia, naratriptan was considered the sole causal agent. Discontinuation of naratriptan resulted in a complete clinical recovery. To date, our patient is the youngest known patient to develop ischemic colitis on isolated naratriptan in the setting of no known medical risk factors or predisposing medical condition. Even though triptans are commonly used for the abortive treatment of migraine headaches, such a reported side effect is rare; however, careful assessment and individual patient-based treatment is advised. PMID:27695179

  2. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text. PMID:27333757

  3. Ischemic Colitis in an Endurance Runner

    PubMed Central

    Grames, Chase; Berry-Cabán, Cristóbal S.

    2012-01-01

    A 20-year-old female running the Marine Corps Marathon developed diarrhea at mile 12. After finishing the race she noted that she was covered in bloody stool. A local emergency department suspected ischemic colitis. After discharge, her primary care physician instructed her to discontinue the use of all nonsteroidal anti-inflammatory drugs. Her symptoms resolved and she returned to running without any complications. This paper describes the pathophysiology, diagnostic approach, and management options. PMID:23091744

  4. The myocardium.

    PubMed

    Langer, G A; Frank, J S; Brady, A J

    1976-01-01

    A comparison of some of the mechanical properties of cardiac with other types of muscle has been made, showing that, except for the speed of some responses, cardiac muscle is similar to other types of muscle. Furthermore, the techniques used in both living and glycerol-extracted insect fibrillar and vertebrate skeletal muscle are applicable to heart muscle, where the focus of the technique is now on cross-bridge mechanics and energetics. It is particularly encouraging to see many well known phenomena such as inactivation with shortening, stress related increases in active force, and the Fenn effect begin to find some more specific relation to cross-bridge mechanical and chemical activity. The high compliance of cardiac preparations still clouds the interpretation of data obtained from whole muscle preparations; however, the reduced compliance of glycerol-extracted cardiac muscle offers some hope of obviating some series compliance. Indeed, the correspondence in mechanical responses of living and glycerol-extracted preparations shows that glycerol preparations are of great utility since the time dependence of activation also can be removed in these studies. A more complete analysis of muscle models, in which the cross-bridge contribution to muscle elasticity is more realistically evaluated, should help in relating muscle measurements to cross-bridge activity. Furthermore, studies on both living and glycerol-extracted cardiac muscle, particularly if sarcomere length can be controlled, offer new hope of closing the perpetual gap in our understanding of cardiac muscle physiology relative to skeletal muscle.

  5. Restoration of canine disocclusion by using etched porcelain onlays.

    PubMed

    Glaser, C G; Nagy, W W

    1991-03-01

    The restoration of a progressive delayed disocclusion on periodontally healthy canines by etched porcelain onlays has been presented as a suitable treatment alternative to interrupt bruxism and reverse destructive occlusal neuroses.

  6. Periodontal ligament distraction: A simplified approach for rapid canine retraction

    PubMed Central

    Prabhat, K. C.; Maheshwari, Sandhya; Gupta, N. D.; Verma, Sanjeev K.; Goyal, Lata

    2012-01-01

    Distraction osteogenesis is a method of inducing new bone formation by applying mechanical strains on preexisting bone. The process of osteogenesis in the periodontal ligament during orthodontic tooth movement is similar to the osteogenesis in the midpalatal suture during rapid palatal expansion. A new concept of “distracting the periodontal ligament” is proposed to elicit rapid canine retraction in two weeks. At the time of first premolar extraction, the interseptal bone distal to the canine was undermined with a bone bur, grooving vertically inside the extraction socket along the buccal and lingual sides and extending obliquely toward the socket base. Then, a tooth-borne, custom-made, intraoral distraction device was placed to distract the canine distally into the extraction space. It was activated 0.5 mm/day, immediately after the extraction. Canine was distracted 6.5 mm into the extraction space within two weeks. PMID:22628978

  7. Death of a wild wolf from canine parvovirus enteritis

    USGS Publications Warehouse

    Mech, L.D.; Kurtz, H.J.; Goyal, S.

    1997-01-01

    A 9-mo-old female wolf (Canis lupus) in the Superior National Forest of Minnesota (USA) died from a canine parvovirus (CPV) infection. This is the first direct evidence that this infection effects free-ranging wild wolves.

  8. Management of Class II malocclusion with ectopic maxillary canines

    PubMed Central

    Mascarenhas, Rohan; Parveen, Shahista; Ansari, Tariq Aziz

    2015-01-01

    Correction of Class II relationship, deep bite and ectopically erupting canines is an orthodontic challenge for the clinician. A 13-year-old male patient presented with Class II malocclusion, ectopically erupting canines, and cross bite with maxillary left lateral incisor. He was treated with a combination of Headgear, Forsus™ fatigue resistant device [FFRD] with fixed mechanotherapy for the management of space deficiency and correction of Class II malocclusions. Headgear was used to distalize upper first molars and also to prevent further downward and forward growth of the maxilla. Then Forsus™ FFRD was used for the advancement of the mandible. The molar and canine relationship were corrected from a Class II to a Class I. The objectives were to establish good occlusion and enable eruption of unerupted canines. All these objectives were achieved and remained stable. PMID:26097371

  9. Bilateral agenesis of maxillary permanent canines: Review of the literature

    PubMed Central

    Borzabadi-Farahani, Ali

    2015-01-01

    Oligodontia, or agenesis of six or more teeth, excluding third molars, which involves canine agenesis is rare, and restorative management can be challenging. Bilateral agenesis of a permanent canine in the general population often indicates a several missing adult teeth. The most common sign of it is the primary canine retention beyond its exfoliation age. The multistage restorative management includes the early diagnosis, excluding associated medical problems as well as assessment of patient's malocclusion and facial skeletal pattern, life span of deciduous teeth, possibility of premolar substitution, minimum required number of prosthetic units, patient's preferences, and the cost of treatment. A 10-year-old boy with bilateral agenesis of maxillary permanent canines is described. Some thoughts on the multidisciplinary restorative management of this case are discussed. PMID:25657989

  10. Cytotoxic Effects of Loperamide Hydrochloride on Canine Cancer Cells

    PubMed Central

    REGAN, Rebecca Cohen; GOGAL, Robert Michael; BARBER, James Perry; TUCKFIELD, Richard Cary; HOWERTH, Elizabeth Wynne; LAWRENCE, Jessica Ann

    2014-01-01

    Loperamide is a peripheral opiate agonist that can cause apoptosis and G2/M arrest in human cancer cell lines and may sensitize cells to chemotherapy. The objectives of this study were to investigate the effects of loperamide on viability, apoptosis and cell cycle kinetics in canine cancer cells and to establish whether the drug sensitizes cells to doxorubicin. Cell viability was assessed using Alamar Blue. Cell death and cell cycle were studied using flow cytometry with 7-Aminoactinomycin-D (7-AAD) and propidium iodide (PI), respectively. Loperamide decreased cell viability in a dose-dependent fashion and was most effective against canine osteosarcoma cells. In all cell lines, it induced a dose and time dependent apoptosis and resulted in accumulation in G0/G1. When co-incubated with doxorubicin, loperamide induced a synergistic cell kill in canine carcinoma cells. Investigation is warranted into the role of loperamide in the treatment of canine cancer. PMID:25649936

  11. [Isolation of canine rotavirus and study of its immunobiological properties].

    PubMed

    Ramishvili, L G; Maglakelidze, D A; Labadze, T N

    2001-01-01

    Canine rotavirus was isolated in MA104 roller culture of rhesus macaque cells. Two passages in gnotobiotic puppies and two in colostrum-free puppies resulted in isolation of strain P of canine rotavirus. After 20 passages in MA104 culture the virus was adapted to MDCK culture. Optimal conditions for accumulation of canine rotavirus and its antigen (9.01 g TCD50/ml) in MDCK culture are trypsin pretreatment of the virus inoculate in the final concentration of 50 mcg/ml for 30 min at 37 degrees C, presence of trypsin (10 mcg/ml) in the maintenance medium, multiplicity of infection 0.1 TCD50/ml, and incubation in roller culture at 37 degrees C during 24-30 h. After 60 passages in cell culture, canine rotavirus completely lost its virulence for colostrum-free puppies but retained antigenic activity and induced manifest seroconversion in infected. PMID:11449799

  12. White matter injury in ischemic stroke.

    PubMed

    Wang, Yuan; Liu, Gang; Hong, Dandan; Chen, Fenghua; Ji, Xunming; Cao, Guodong

    2016-06-01

    Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions. PMID:27090751

  13. Endovascular treatment of acute ischemic stroke.

    PubMed

    Leslie-Mazwi, Thabele; Rabinov, James; Hirsch, Joshua A

    2016-01-01

    Endovascular thrombectomy is an effective treatment for major acute ischemic stroke syndromes caused by major anterior circulation artery occlusions (commonly referred to as large vessel occlusion) and is superior to intravenous thrombolysis and medical management. Treatment should occur as quickly as is reasonably possible. All patients with moderate to severe symptoms (National Institutes of Health stroke scale >8) and a treatable occlusion should be considered. The use of neuroimaging is critical to exclude hemorrhage and large ischemic cores. Very shortly after stroke onset (<3 hours) computed tomography (CT) and CT angiography provide sufficient information to proceed; diffusion magnetic resonance imaging (MRI) is less reliable during this early stage. After 3 hours from onset diffusion MRI is the most reliable method to define ischemic core size and should be used in centers that can offer it rapidly. Recanalization is highly effective with a stentriever or using a direct aspiration technique, with the patient awake or under conscious sedation rather than general anesthesia, if it may be performed safely. After thrombectomy the patient should be admitted to an intensive care setting and inpatient rehabilitation undertaken as soon as feasible. Patient outcomes should be assessed at 3 months, preferably using the modified Rankin score. PMID:27430469

  14. White matter injury in ischemic stroke.

    PubMed

    Wang, Yuan; Liu, Gang; Hong, Dandan; Chen, Fenghua; Ji, Xunming; Cao, Guodong

    2016-06-01

    Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions.

  15. Neurovascular Regulation in the Ischemic Brain

    PubMed Central

    Jackman, Katherine

    2015-01-01

    Abstract Significance: The brain has high energetic requirements and is therefore highly dependent on adequate cerebral blood supply. To compensate for dangerous fluctuations in cerebral perfusion, the circulation of the brain has evolved intrinsic safeguarding measures. Recent Advances and Critical Issues: The vascular network of the brain incorporates a high degree of redundancy, allowing the redirection and redistribution of blood flow in the event of vascular occlusion. Furthermore, active responses such as cerebral autoregulation, which acts to maintain constant cerebral blood flow in response to changing blood pressure, and functional hyperemia, which couples blood supply with synaptic activity, allow the brain to maintain adequate cerebral perfusion in the face of varying supply or demand. In the presence of stroke risk factors, such as hypertension and diabetes, these protective processes are impaired and the susceptibility of the brain to ischemic injury is increased. One potential mechanism for the increased injury is that collateral flow arising from the normally perfused brain and supplying blood flow to the ischemic region is suppressed, resulting in more severe ischemia. Future Directions: Approaches to support collateral flow may ameliorate the outcome of focal cerebral ischemia by rescuing cerebral perfusion in potentially viable regions of the ischemic territory. Antioxid. Redox Signal. 22, 149–160. PMID:24328757

  16. Cardioprotection by remote ischemic conditioning: Mechanisms and clinical evidences

    PubMed Central

    Aimo, Alberto; Borrelli, Chiara; Giannoni, Alberto; Pastormerlo, Luigi Emilio; Barison, Andrea; Mirizzi, Gianluca; Emdin, Michele; Passino, Claudio

    2015-01-01

    In remote ischemic conditioning (RIC), several cycles of ischemia and reperfusion render distant organ and tissues more resistant to the ischemia-reperfusion injury. The intermittent ischemia can be applied before the ischemic insult in the target site (remote ischemic preconditioning), during the ischemic insult (remote ischemic perconditioning) or at the onset of reperfusion (remote ischemic postconditioning). The mechanisms of RIC have not been completely defined yet; however, these mechanisms must be represented by the release of humoral mediators and/or the activation of a neural reflex. RIC has been discovered in the heart, and has been arising great enthusiasm in the cardiovascular field. Its efficacy has been evaluated in many clinical trials, which provided controversial results. Our incomplete comprehension of the mechanisms underlying the RIC could be impairing the design of clinical trials and the interpretation of their results. In the present review we summarize current knowledge about RIC pathophysiology and the data about its cardioprotective efficacy. PMID:26516416

  17. Management of an Unusual Maxillary Canine: A Rare Entity

    PubMed Central

    Muppalla, Jaya Nagendra Krishna; Kavuda, Krishnamurthy; Punna, Rajani; Vanapatla, Amulya

    2015-01-01

    Clinicians need to have intimate knowledge and thorough understanding of both pulp chamber and root canal anatomy. They should be aware of possibility of anatomical variations in the root canal system during endodontic treatment. Maxillary canines usually have single root and root canal but rarely may have single root with two root canals. This case describes a lengthier maxillary canine with two root canals. PMID:26779354

  18. Recent epidemiological status of canine viral enteric infections and Giardia infection in Japan.

    PubMed

    Mochizuki, M; Hashimoto, M; Ishida, T

    2001-05-01

    Epidemiology of canine enteric infections was studied. Rectal swabs collected from 95 dogs presented at animal hospitals during a period from January to June of 2000 were examined for enteric pathogens, including viruses and Giardia lamblia (G. lamblia). Most frequently detected in both diarrheal and normal feces were canine coronavirus (55.4%) and G. lamblia (48.2%). Canine parvovirus type 2 (CPV-2) was specifically associated with diarrheal cases and CPV-2b was the predominant antigenic type. Although canine rotavirus, canine adenovirus, and canine distemper virus were also detected in a small number of diarrheal cases, no evidence for calicivirus infection was obtained. PMID:11411507

  19. Transmigration of mandibular canine: report of four cases and review of literature.

    PubMed

    Sharma, Gaurav; Nagpal, Archna

    2011-01-01

    Transmigration of canine is a rare phenomenon. The prevalence of transmigration of mandibular canine has been found to be only 0.14%-0.31%. The treatment of impacted transmigrated canine is very complicated if it is diagnosed at a later stage. We report 4 cases of transmigration of mandibular canine and review the literature regarding the etiology and treatment. Panoramic radiograph should be taken during the mixed dentition period if the mandibular canine has not erupted from more than one year from its normal chronological age of eruption as intraoral periapical radiograph examination will not always detect an impacted or transmigrated canine. PMID:22570797

  20. Three-year serologic immunity against canine parvovirus type 2 and canine adenovirus type 2 in dogs vaccinated with a canine combination vaccine.

    PubMed

    Larson, L J; Schultz, R D

    2007-01-01

    A group of client-owned dogs and a group of dogs at a commercial kennel were evaluated for duration of antibody responses against canine parvovirus type 2 (CPV-2) and canine adenovirus type 1 (CAV-1) after receiving a combination vaccine containing recombinant canarypox-vectored canine distemper virus (CDV) and modified-live CPV-2, CAV-2, and canine parainfluenza virus, with (C6) or without (C4) two serovars of Leptospira (Recombitek C4 or C6, Merial). Duration of antibody, which correlates with protective immunity, was found to be at least 36 months in both groups. Recombitek combination vaccines can confidently be given every 3 years with assurance of protection in immunocompetent dogs against CPV-2 and CAV-1 as well as CDV. This allows this combination vaccine, like other, similar modified- live virus combination products containing CDV, CAV-2, and CPV-2, to be administered in accordance with the recommendations of the American Animal Hospital Association Canine Vaccine Task Force. PMID:18183549