313 research outputs found
Aspects of Myocardial Protection and Cardioplegia in Clinical Comparison
No full textKonzepte zur thorakalen Organpräservation beherbergen eine Reihe von
physikalischen wie chemischen Beschaffenheiten, die einzeln wie in ihrer
Gesamtkomposition auf Herz und Lunge einwirken. Die vorliegende
Habilitationsschrift präsentiert Untersuchungen an cardioplegischen Konzepten
zum Einfluß der Temperatur, des Hämatokrits, des Kalziums, der Zugabe von
L-Arginin, sowie an der Richtung und Route einer Perfusion mit Präserva-
tionslösung auf die Protektion der Lunge im Rahmen der Organgewinnung zur
Lungen-transplantation, sowie an der Geometrie des linken Ventrikels auf die
Kontraktilität des Herzens und eine klinische Vergleichsstudie zweier
cardioplegischer Konzepte an Notfall-Patienten mit Ischämie-belasteten Herzen,
die operativ revaskularisiert werden. Der gut steuerbare Herzstillstand, die
verläßliche Wiederbelebung des Herzschlags sowie die Cardioprotektion der
Myozyten und der Endothelzellen vor Ischämie und den Konse-quenzen der
Reperfusion und Reoxygenation nach Hypoxie bestimmen maßgeblich die Güte einer
Cardioplegie. Normothermie erlaubt die Aufrechterhaltung des zellulären
Stoffwechsels und ermöglicht metabolische Reparaturmechanismen unter Ausschluß
einer Ischämie oder Hypoxie. Hy-pothermie reduziert den Stoffwechsel, senkt
den Sauerstoffbedarf der Zellen und kann vor den Folgen einer Ischämie
schützen. In einer Versuchsanordnung konnten wir zeigen, daß die
kontinuierliche Coronarperfusion mit kaltem Blut eine anhaltende Cardioplegie
er-möglicht und eine gute Cardioprotektion bewirkt. Der Hämatokrit wird
maßgeblich durch den Gehalt an Hämoglobin bestimmt (ausgenom-men die
onkologisch-maligne veränderte Blutzusammensetzung). Hämoglobin transpor-tiert
den Großteil des Sauerstoffs im Blutstrom und ist eine der Säulen der
Pufferkapazität des Blutes. An der Extrakorporalen Zirkulation wird eine
möglichst geringe Hämodilution angestrebt mit dem Ziel den Hämatokrit nicht
abfallen zu lassen. In einer Versuchsanord-nung konnten wir zeigen, daß bei
kontinuierlicher artifizieller Coronarperfusion mit Blut-cardioplegie sich ein
niedriger Hämatokrit von 20 – 25 % als vorteilhaft erweist zur Plegie und
Versorgung des Herzens, ein hoher Hämatokrit von 40 – 45 % dagegen als
schädlich mit Einbuße der cardialen Funktion und Bildung eines cardialen
Ödems. Der zytoplasmatische Gehalt an Kalzium zusammen mit anderen
Elektrolyten bewirkt Kontraktion und Relaxation der Cardiomyozyten. Die
zytoplasmatische Überladung mit Kalzium entsteht in der Aetiologie vieler
Noxen wie der Ischämie-Reperfusion und der Hy-poxie-Reoxygenation. Als Folge
können eine temporäre Hyperkontraktur, ein „stunning“ oder „stone-heart“
entstehen. In einer Versuchsanordnung konnten wir zeigen, daß sich eine
Hypokalzämie in der Phase der Reoxygenation nach Hypoxie als vorteilhaft
erweist zur Minderung des Hypoxie-Reoxygenationsschadens an Herz und Lunge mit
verbesser-ter Herzfunktion und Reduktion des erhöhten Gefäßwiderstandes in der
pulmonalvaskulä-ren Strombahn. Die Zugabe von Aminosäuren zur
blutcardioplegischen Lösung erhöht deren Protektions-wirkung. So unterstützen
Glutamat und Aspartat in der Blutcardioplegie die metabolische und
funktionelle Erholung des Cardiomyozyten von einer Ischämie-Reperfusion. In
einer Versuchsanordnung mit cardialer Ischämie, Reperfusion und Protektion
durch Blutcardio-plegie konnten wir zeigen, daß die Funktion des Endothels
hiervon ausgenommen ist. Die Zugabe von L-Arginin zu Blut oder
Blutcardioplegie in der Phase der Reperfusion nach Ischämie schützt
Cardiomyozyten und Endothelzellen und verbessert ihre metabolische wie
funktionelle Rekonvaleszens. Der Organpräservation kommt entscheidender
Einfluß auf den Erfolg der Lungentrans-plantation zu mit initialem
Gasaustausch, Heilung der Bronchusanastomosen und Verhin-derung der
Entwicklung einer Bronchiolitis obliterans. Für eine gute Organpräservation
ist die vollständige Perfusion des Lungenparenchyms und Bronchialgewebes mit
der Präser-vationslösung wichtig. Als Gefäßbett bieten sich die
pulmonalarterielle, pulmonalvenöse und die bronchialarterielle Strombahn. In
einer Versuchsanordnung mit unterschiedlichen Perfusionsrouten konnten wir
zeigen, daß die retrograde Perfusionsroute über die Pulmo-nalvenen zu einer
besseren Perfusion des Lungen- und Bronchialgewebes führt als die antegrade
über die Pulmonalarterien, und daß Atelektasen die Perfusion des Lungenpar-
enchyms beeinträchtigen. Die Geometrie des linken Ventrikels beeinflußt dessen
Pumpfunktion. Die Vergrößerung des linken Ventrikels durch Dilatation oder
Ausbildung eines Aneurysmas führt zu einer sphärischen Distension. In einer
Versuchsanordnung konnten wir zeigen, daß eine sphä-rische Distension die
Elastizität und Kontraktilität des linken Ventrikels beeinträchtigt, und die
anschließende Aufhebung der sphärischen Distension und Rückführung in eine
ellip-tische Modellierung mit physiologischem Ventrikeldiameter die
linksventrikuläre Elastizität und Kontraktilität verbessert. In einer
klinischen Vergleichsstudie wurde die protektive Wirkung zweier
cardioplegischer Konzepte überprüft. Notfall-Patienten mit Ischämie-belasteten
Herzen wurden für die ope-rative Revaskularisierung randomisiert für die
kristalloide Cardioplegie mit Kirsch/HAES oder die Blutcardioplegie nach
Buckberg. Mit beiden Konzepten der Cardioplegie, der kri-stalloiden
Cardioplegie nach Kirsch/HAES sowie der Blutcardioplegie nach Buckberg, lie-
ßen sich die zu operierenden Herzen zuverlässig stillstehen und relaxieren.
Patienten nach Blutcardioplegie boten bessere cardiale Verlaufsparameter wie
in der regionalen Kontraktilität, der Enzymexpression sowie Ischämiezeichen im
EKG. Dieser Unterschied wurde vor allem bei Patienten im cardiogenen Schock
deutlich. Die Wahl der Cardioplegie hatte allerdings nur einen undeutlichen
Einfluß auf den klinischen Verlauf: die Mortalität, die Verweildauer auf der
Intensivstation sowie die Anzahl der Tage der künstlichen Beat-mung waren in
beiden Gruppen der Cardioplegie ohne signifikanten Unterschied mit Ten-denz
der schnelleren Rekonvaleszenz in der Gruppe der Blutcardioplegie. Patienten
der Blutcardioplegie-Gruppe ohne Schocksymptomatik erforderten signifikant
weniger Kreis-laufunterstützung durch Katecholamine und eine intraaortale
Ballonpumpe. Auch wurden nach Blutcardioplegie signifikant weniger
Fremdbluteinheiten transfundiert.Concepts for thoracic organ preservation involve a number of physical and
chemical entities which act individually and in combination on the heart and
lungs. This professorial dissertation presents evaluations of different
cardioplegic concepts and examines the influence of temperature, hematocrit,
calcium and the addition of L-arginin, as well as the direction and route of
delivery of the preservation solution, on the protection of the lungs when
organs are harvested for transplantation. It also considers the geometry of
the left ventricle and its influence on the contractility of the heart and
presents a clinical study comparing two cardioplegic concepts applied in
patients suffering from cardiac ischemia with emergency indication for rapid
coronary bypass revascularization. A good cardioplegic concept is
characterized by precise control of cardiac arrest, reliable re-instigation of
the heartbeat and effective cardioprotection of the myocytes and endothelial
cells from ischemia and the consequences of reperfusion and reoxygenation
subsequent to hypoxemia. Normothermia without ischemia or hypoxemia allows the
continuation of cellular metabolism and facilitates metabolic repair
mechanisms. Hypothermia reduces the metabolism, decreases the oxygen
requirement of cells and can protect the heart against the consequences of
ischemia. In an experimental study we were able to demonstrate that continuous
coronary perfusion with cold blood results in ongoing cardioplegic arrest and
achieves good cardiac protection. The hematocrit is mainly defined by the
amount of hemoglobin (except when the blood is altered by oncologically
malignant composition). Hemoglobin transports the largest proportion of oxygen
in the blood stream and is one of the pillars of the puffer capacity of the
blood. On extracorporeal circulation as little hemodilution as possible is
important, with the aim of not decreasing the hematocrit. In our experimental
study we demonstrated that a low hematocrit of 20–25 % during continuous
artificial coronary perfusion nourishes the myocardium and is advantageous for
cardioplegic arrest, in opposition to a high hematocrit of 40–45 %, which
impairs cardiac function and promotes the development of cardiac edema. The
cytoplasmatic content of calcium in combination with the other electrolytes
enables the undulating contraction and relaxation of the cardiomyocytes.
Cytoplasmatic overloading with calcium is the result in the etiology of
cellular injury of many causes such as ischemia/reperfusion and reoxygenation
after hypoxemia. This can lead to temporary hypercontraction, the development
of stunning, or the formation of a stone heart. We demonstrated experimentally
that hypocalcemia during reoxygenation following hypoxemia is advantageous in
curbing damage to the heart and lungs, resulting in improved cardiac function
and reduction of increased vascular resistance in the pulmonary vascular bed.
The addition of amino acids to a blood cardioplegic solution augments its
protective power. In particular glutamate and aspartate as contents of a blood
cardioplegic solution support the metabolic and functional recovery of
cardiomyocytes from ischemia/reperfusion. In an experimental study concerning
cardiac ischemia, reperfusion and protection by blood cardioplegia we
identified a gap in the protection for the endothelium. The addition of
L-arginin to blood or to blood cardioplegia during the phase of reperfusion
subsequent to ischemia protects cardiomyocytes and endothelial cells and
improves their metabolic and functional recovery. Measures for organ
preservation mainly determine the success of lung transplantation with regard
to initial gas exchange, healing of the bronchus anastomoses and inhibition of
the development of bronchiolitis obliterans. In order to achieve good organ
preservation, complete perfusion of the lung parenchyma and bronchial tissue
with the preservation solution is important. As vascular bed the pulmonary
arteries, the pulmonary veins and the bronchial arteries are available. In an
experimental study with different routes of delivery we demonstrated that the
retrograde route of perfusion via the pulmonary veins leads to better
perfusion of the lung and bronchial tissue than the antegrade route via the
pulmonary arteries, and that atelectasis impairs perfusion of the lung
parenchyma. The geometry of the left ventricle influences its pumping
function. Enlargement of the left ventricle due to dilatation or the
development of an aneurysm leads to spherical distension. In a further
experimental study we demonstrated that spherical distension reduces the
elasticity and contractility of the left ventricle, and that the subsequent
reversal of the spherical distension and the restoration of an elliptical
shape, with physiological diameter of the ventricle, improves the left
ventricular elasticity and contractility. In a comparative clinical study the
protective power of two different cardioplegic concepts was investigated.
Patients with the indication for emergency coronary revascularization due to
ischemic jeopardization of the heart were randomly divided into two groups in
which different cardioplegic concepts were applied. One group of patients was
operated on using crystalloid cardioplegia with Kirsch/HAES solution and the
second group with blood cardioplegia following Buckberg’s concept. Both
cardioplegic concepts were efficient in making the hearts stop beating and
relax. Patients who received Buckberg’s blood cardioplegia performed better
postoperatively than those with Kirsch/HAES solution in terms of regional
contractility, expression of cardiac enzymes and signals for ischemia on the
electrocardiogram. This difference was larger for patients in cardiogenic
shock. The choice of cardioplegia did not show a sharp difference in clinical
outcome between the two groups of patients: mortality, duration of intensive
care unit stay and the number of days on mechanical ventilation were without
significant differences between the two groups, but with a tendency towards
faster recovery in the group operated on using Buckberg’s blood cardioplegia.
Patients of the Buckberg’s blood cardioplegia group without signs of cardiac
shock required significantly less hemodynamic support with catecholamines and
intraaortic balloon counterpulsation. Also, significantly fewer blood
transfusions were administered after Buckberg’s blood cardioplegia
Observations upon Peloponnesus and Greek islands made in 1829, by Rufus Anderson, one of the Secretaries of the American Board of Commisioners for foreign Missions. Boston: published by Crocker and Brewster, 47, Washington st. New-York: Jonathan Leavitt,
No full textAppendix.Introduction.Dedication: by the author to the members of the members of the prudential Committee of the American Board of Commissioners for foreign Missions.Content description: Detailed contentsIllustration: 2 (Maps ,)Pagination: pp8+334p+2ppVolumes: 1Text Genre:Prose / JournalIllustration: 2 (χάρτες ,
“A Conversation Between Kip Jones and Patricia Leavy: Arts-Based Research, Performative Social Science and Working on the Margins.”
No full textThis paper reports a conversation between international pioneers in Arts-Based Research and Performative Social Science, Patricia Leavy and Kip Jones. They begin by delineating the differences between research and/or dissemination that use tools from the Arts in their production. Leavy turns to her fiction writing as an example, while Jones discusses the making of his research-based short film, Rufus Stone. The conversation then turns to how these novel approaches have changed the way in which they work and these efforts in relation to the academy. The concept of “audience” is raised. Both then give examples of taking alternative routes in their career paths and funding for this kind of work. Jones specifically talks about using creativity in all our approaches, including small-scale projects that rely on creativity rather than money. He suggests being creative in the ways in which we write for publication and present our work to other academics. Leavy ends the conversation by discussing taking risks and walking through fear. Jones recommends not working in silos, but letting all parts of our lives influence our outputs
Molly Rufus
No full textImage submitted by author for Poetry Spotlighthttps://digitalcommons.odu.edu/vapoets-images/1033/thumbnail.jp
Detection of Gender Differences in Incomplete Revascularization after Coronary Artery Bypass Surgery Varies with Classification Technique
No full textOertelt-Prigione S, Kendel F, Kaltenbach M, Hetzer R, Regitz-Zagrosek V, Baretti R. Detection of Gender Differences in Incomplete Revascularization after Coronary Artery Bypass Surgery Varies with Classification Technique. BioMed Research International. 2013;2013: 108475
The Book of Fables
No full textHere is a simple, landscape-formatted, canvas-spined book about 9¼ x 8¼ with nearly identical front and back covers. The pattern is the same for fourteen of the fifteen fables presented. Texts with a monochrome splash of color behind them stand on the left facing a full-page black design against a single different color on the right. The exception is at the centerfold, which combines text and illustration on both pages and uses background color for both. All of the book's illustrations are signed Rufus Morris. The last adds 41. In TH, the distance is five miles and the stakes are five pounds. In The Tortoise and the Eagle, the eagle realizes in mid-air that he has been lied to about the reward of jewels and he exacts his revenge by sticking his talons into the soft parts of the tortoise's body. I find this version strange. Story and image for The Fox and the Wolf do not match: the story is about a cave, and the picture is about a well! There is of course also a well-known fable that involves a well. I think that the translator literally got onto a different page from the illustrator! In FK, the frogs ask for a king who would make them live a little honester. The most dramatic of the illustrations depicts desperation in The Old Man and Death.Edited by Edric Vredenbur
Vacation Days in Greece.
No full textPreface: author]Dedication: His SonContent description: TitleIllustration: 18 (Maps ,Views ,antiquities ,)Pagination: PP8+240PVolumes: 1Text Genre:ProseIllustration: 18 (χάρτες ,τοπία ,αρχαιότητες ,
Rufus E. Clement Records
No full textDr. Rufus Early Clement, the sixth President of Atlanta University, was the longest serving president in the history of the institution. While president, Clement served on the American Council on Education, the United Negro College Fund, and was appointed by President Dwight D. Eisenhower to the United Service Organization. Clement served as president until his death in 1967. Materials consists of correspondence and reports from organizations such as Gammon Theological Seminary, the United Negro College Fund, National Education Association, Carnegie Research Fund, General Education Board, Harmon Foundation, National Association for the Advancement of Colored People, Atlanta Urban League, Southern Regional Council, Southern Conference for Human Welfare, Georgia Department of Education, and the United States Veterans Administration.
At the AUC Robert W. Woodruff Library we are always striving to improve our digital collections. We welcome additional information about people, places, or events depicted in any of the works in this collection. To submit information, please contact us at [email protected]
Axiological Constants of Milan Rufus’ Poetic Creation
No full textAxiological Constants of Milan Rufus’ Poetic Creation. – Since the mid-twentieth century, Milan Rufus has been part of the most important poets of the Slovak literature. The author understands the full-valuable existence of a literary work as conditioned by a constant intermingling of the aesthetic and ethical moments. In the work of this poet, there are several constants, which are inter alia characterized by the fact that they are based on the spiritual heritage of the Slovak culture and literature. Author looks on the society through Axiology, where home, family and God are dominant. In his poetry, home representing values are extended even to the political and national values, which are displayed with the term of homeland and the term of patriotism. For Milan Rufus the family as the most intimate community does not only represent the starting point, but also the aim of all human effort. The work of this poet is full of sensitive messages, prayers and thanksgiving, which is particularly reflected in the spiritual richness and integrity of his poems
Vision in the rufus snake eel, Ophichthus rufus : adaptive mechanisms for a burrowing life-style
No full text8 pages, 8 figuresA unique retinal topography was found in the rufus snake eel, Ophichthus rufus, a burrowing fish that shows a preference for nocturnal habits. The cells in the ganglion-cell layer formed a high-density semicircular band that covered the dorso-rostral, temporal and ventro- rostral areas of the retina. Three regions of high acuity were identified in the ventro-temporal, ventrorostral and dorsal regions of the retina. This is the first time that multiple specialisations have been found in a benthic deep-water fish. The ventro-temporal and ventro- rostral visual axes were found at 48 and 54 from the retinal centre, subtending the dorsal field of view, while the dorsal axis was at 66 , subtending the ventral field of view. These characteristics may represent an adaptation to identify the mouth of the muddy burrows in which this species hides or where it looks for food. O. rufus has a duplex retina with numerous slender rod photoreceptors arranged in banks of four layers. This morphology is typical of deep-sea teleosts with a high visual sensitivity, which is useful in a dim-light environment. A few tiny cones were also present, probably enhancing acuity during the eel’s daily activity. The retina of O. rufus also possessed a well developed vascularisation, possibly to overcome the hypoxic conditions that may be found in the burrow. The characteristics of the retina of the rufus snake eel indicate singular visual capabilities that are discussed in relation to the burrowing life-style and to what is known of feeding habits of this fishThe author is especially grateful to M. Rufino and to L. Gil de Sola for providing the material during the MEDITS 2000 cruise, and to S. Lluch for helping in the retinal blood-vessel identification. The technicians of the Unidad Te´cnica de Microscopı´a Electro´ nica of the Barcelona University kindly prepared and processed the samples for the transmission electron microscope. The photographs of Fig. 1 belong to the UE project DGXIV-no. 96-063. Dr. R. Villanueva greatly improved the manuscript with his accurate criticism. Finally, the author would like to thank Dr. Rodgers for kindly reviewing the final English version, and two anonymous reviewers for their valuable comments on the manuscript. All the experiments comply with the current law (5/1995) of SpainPeer reviewe
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