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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 35 (1992), S. 472-485 
    ISSN: 1432-1432
    Keywords: LINE-1 (L1) ; Peromyscus ; Repetitive elements ; Molecular drive
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two distinct members of the LINE-1 (L1) family in Peromyscus were characterized. The two clones, denoted L1Pm55 and L1Pm62, were 1.5 kb and 1.8 kb in length, respectively, and align to the identical region of the L1 sequence of Mus domesticus. Sequence similarity was on the order of 70% between L1Pm55 and L1Pm62, which approximates that between either Peromyscus sequence and Mus Ll. L1Pm62 represents a more prevalent subfamily than L1Pm55. L1Pm62 exists in about 500 copies per haploid genome, while L1Pm55 exists in about 100 copies. The existence of major and minor subpopulations of L1 within Peromyscus is in contrast to murine rodents and higher primates, where L1 copy number is on the order of 20,000 to 100,000, and where levels of intraspecific divergence among L1 elements are typically less than 15–20%. Additional Peromyscus clones are similarly divergent from both L1Pm62 and LIPm55, implying the existence of more than two distinct L1 subfamilies. The highly divergent L1 subfamilies in Peromyscus apparently have been evolving independently for more than 25 million years, preceding the divergence of cricetine and murine rodents. Investigations of the evolution of L1 within Peromyscus by restriction and Southern analysis was performed using species groups represented by the partially interfertile species pairs P. maniculatus-P. polionotus, P. leucopus-P. gossypinus, and P. truei-P. difficilis of the nominate subgenus and P. californicus of the Haplomylomys subgenus. Changes in L1 and species group taxonomic boundaries frequently coincided. The implications for phylogeny are discussed.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Monatsschrift Kinderheilkunde 145 (1997), S. 798-801 
    ISSN: 1433-0474
    Keywords: Schlüsselwörter Persistierender Ductus arteriosus (PDA) ; Katheterinterventioneller PDA-Verschluß ; Raskind-occluder ; Key words Patent ductus arteriosus (PDA) ; Transcatheter closure of PDA ; Rashkind occluder ; Front-loading-technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Transcatheter closure of patent ductus arteriosus Botalli (PDA) has become a routine procedure. Only PDA in low birth weight infants, and short and wide open PDA in small children could not be closed by means of catheter technology. Different transcatheter closure systems are available now. We report on a premature infant now 16 month old weighting 6,8 kg were surgery seemed inadvisable. After angiography a funnel- shaped PDA seemed to be suitable for closure by a Ductocclud spiral coil (PFM company). The spiral coil could not be set in place safely because meanwhile the pulmonary PDA month had widened after angiography. Transcatheter closure then was successful using a 17 mm Rashkind double umbrella (Bard company) in modified implantation technique with a 8 french introduction set, and special attention to avoid the isthmus of the aorta and pulmonary artery stenosis. Discussion: Ductal reactivity at an age of 16 months seems unusual. Even at this age one has to be aware of possibly dramatic changes of the shape of the ductus during examination. Experience with several transcatheter PDA-closure systems is necessary for the successful closure even in cases of unexpected changes of shape of PDA.
    Notes: Zusammenfassung Der katheterinterventionelle Verschluß eines persistierenden Ductus arteriosus Botalli (PDA) ist heute eine Routinemethode, für die eine ganze Reihe von verschiedenen Verschlußsystemen zur Verfügung steht. Eine Ausnahme für die Intervention stellen nur noch Frühgeborene und kleine Kinder mit kurzen, weit offenen Duktus dar. Wir berichten über ein 16 Monate altes, 6,8 kg schweres ehemaliges Frühgeborenes mit relativen Kontraindikationen zu einer Operation, bei dem nach Angiographie ein trichterförmiger Duktus zum Verschluß durch eine Ductocclud-Spirale (Fa. PFM) geeignet erschien. Die Spirale war jedoch nicht sicher zu plazieren, da sich die pulmonale Duktusmündung durch die mit der Intervention verbundenen Manipulationen zwischenzeitlich erheblich geweitet hatte. Der Verschluß des PDA gelang dann mit einem 17-mm-Rashkind-Doppelschirm (Fa. Bard) in modifizierter Implantationstechnik mit einer 8-Fr.-Schleuse unter besonderer Berücksichtigung der Schonung der Aortenisthmusregion und der Pulmonalarterienstrombahn. Diskussion: Die Empfindlichkeit des Duktusgewebes noch im Alter von 16 Monaten erscheint ungewöhnlich. Der Untersucher muß auch in diesem Alter auf drastische Änderungen der Duktusmorphologie vorbereitet sein. Bei entsprechender Erfahrung mit verschiedenen Verschlußsystemen kann die Intervention trotz „Duktusspiel” gelingen.
    Type of Medium: Electronic Resource
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  • 13
    facet.materialart.
    Unknown
    Woodstock, Md., etc : Periodicals Archive Online (PAO)
    Theological Studies. 52:4 (1991:Dec.) 775 
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  • 14
    facet.materialart.
    Unknown
    Baltimore, Md. : Periodicals Archive Online (PAO)
    Behavioral science. 25:4 (1980:July) 315 
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  • 15
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The histamine-receptor subtype mediated effects on action potentials of electrically driven and spontaneously active isolated sheep cardiac Purkinje fibres were investigated using H1-and H2-selective agonists and antagonists. In electrically stimulated Purkinje fibres histamine (3 μmol/l) increased action potential plateau height, decreased action potential duration at −60mV, and enhanced pacemaker activity. These effects were abolished by 30 μmol/l cimetidine (H2-selective antagonist), but not impaired by 0.3 μmol/l dimethindene (H1-selective antagonist). In spontaneously active Purkinje fibres, histamine (10 μmol/l) increased the spontaneous rate by 24%, the slope of diastolic depolarization by 45% and shortened the duration of the diastole at −60mV by 32% of the respective control measurements. These effects were blocked by 30 μmol/l cimetidine, but not by 0.3 μmol/l dimethindene. The concentration-response relationship of histamine was shifted to higher histamine concentrations by approximately 2 logarithmic units in the presence of 30 μmol/l cimetidine, but no displacement was found in the presence of 0.3 μmol/l dimetindene. The H2-selective agonist impromidine (0.001–0.3 μmol/l) has similar actions to histamine on spontaneously active Purkinje fibres, while the H1-selective agonist 2-(2-pyridyl-)ethylamine was ineffective. It is concluded that the pronounced stimulatory action of histamine on spontaneous activity in sheep cardiac Purkinje fibres is exclusively mediated by H2-receptors.
    Type of Medium: Electronic Resource
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  • 16
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The histamine-receptor-subtype-mediated effects on action potentials of electrically driven and spontaneously active isolated sheep cardiac Purkinje fibers were investigated using H1-and H2-selective agonists and antagonists. In electrically stimulated Purkinje fibers, histamine (3 μmol/l) increased the action potential plateau height, decreased the action potential duration measured at a repolarization level of −60 mV and enhanced the pacemaker activity. These effects were abolished by the H2-selective antagonist cimetidine (30 μmol/l), but were not impaired by the H1-selective antagonist dimetindene (0.3 μmol/l). In spontaneously active Purkinje fibers, histamine (10 μmol/l) increased the spontaneous rate by 24%, the slope of diastolic depolarization by 45% and shortened the duration of the diastole by 32% of the respective control measurements. These effects were blocked by 30 μmol/l cimetidine, but remained unchanged in the presence of 0.3 μmol/l dimetindene. Concentration-response curves of histamine were shifted to the right by approximately 2 logarithmic units in the presence of 30 μmol/l cimetidine, but were not influenced in the presence of 0.3 μmol/l dimetindene. The H2-selective agonist impromidine (0.001–0.3 μmol/l) had similar actions as histamine on spontaneously active Purkinje fibers, while the H1-selective agonist 2-(2-pyridyl-)ethylamine was ineffective. It is concluded that the pronounced stimulatory action of histamine on spontaneous activity in sheep cardiac Purkinje fibers is exclusively mediated by H2 receptors.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Herz-, Thorax- und Gefässchirurgie 12 (1998), S. 189-192 
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Echokardiographie – Chirurgie angeborener Herzfehler ; Key words Echocardiography – Surgery of congenital heart disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Purpose of this study was to evaluate the clinical utility of intraoperative echocardiography in the assessment of surgical repair of congenitally malformed hearts. In 235 of 508 patients who underwent cardiac surgery during a one year period transesophageal intraoperative echocardiography was performed. This was done to exclude residual ventricular septal defects or right ventricular outflow tract obstruction (n=84), to evaluate results of AV valve reconstruction (n=61), to assess ventricular function following arterial switch operation for complete transposition or in complex heart defects palliated by a Fontan-type procedure (n=50), to assess repair of left ventricular outflow obstruction (n=22) and for miscellaneous defects (n=18). Residual defects leading to immediate reoperation during the same surgical session were found in 4 patients (1.7%), minor residual defects not requiring reoperation were present in 6 patients (2.6%). In 2 patients with complete AV septal defect the left AV valves were only mildly regurgitant immediately after reconstruction but subsequent suture deshiscence required later reopoeration. Echocardiographic data were supplemented by direct pressure measurements in the ventricles and contrast injection into the left atrium. We conclude that intraoperative echocardiography can provide useful clinical informations, if its findings are interpreted in context with pressure measurements and contrast injections.
    Notes: Zusammenfassung Zweck dieser Studie war, den klinischen Nutzen der intraoperativen Echokardiographie bei Patienten mit angeborenen Herzfehlern zu untersuchen. Von 508 während des Zeitraumes eines Jahres durchgeführten Operationen bei angeborenen Herzfehlern wurde bei 235 (47%) eine intraoperative Echokardiographie durchgeführt. Die Indikationen waren Ausschluß von residuellen Ventrikelseptumdefekten und residuellen rechtsventrikulären Ausflußbahnobstruktionen (n=84), Evaluation von AV Klappenrekonstruktionen (n=61), vorwiegende Evaluation der Ventrikelfunktion nach arterieller Switchoperation bei kompletter Transposition oder bei Palliation komplexer Herzfehler durch eine Fontanoperation (n=50), Untersuchungen nach Operation einer linksventrikulären Ausflußbahnobstruktion (n=22), sowie sonstige Operationen (n=18). Residuelle Defekte, welche zu sofortiger Reoperation in der gleichen Sitzung Anlaß gaben, wurden bei 4 Patienten (1,7%) gefunden, unbedeutende residuelle Defekte, die keine Reoperation erforderlich machten bei 6 Patienten (2,6%). In 2 Fällen wurden bei korrigierten kompletten AV Septumdefekten unmittelbar postoperativ geringe Insuffizienzen der linken AV Klappe gesehen, welche später so an Schweregrad zunahmen, daß spätere Reoperationen notwendig wurden. Die durch die transösophageale Echokardiographie erhobenen Befunde wurden durch direkte blutige Druckmessungen und Kontrastinjektion in den linken Vorhof ergänzt. Wir schlußfolgern, daß die intraoperative Echokardiographie klinisch sinnvolle Informationen liefern kann, wenn die erhobenen Befunde im Kontext mit den oben aufgeführten anderen Messungen interpretiert werden.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Herz-, Thorax- und Gefässchirurgie 12 (1998), S. 221-225 
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Vorhofseptumdefekt – Interventioneller Verschluß– Echokardiographie ; Key words Atrial septal defect – transcatheter closure – echocardiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Surgical closure of atrial septal defects can nowadays be performed without preoperative cardiac catheterization. For a transcatheter closure, however, x-ray exposure has been indispensable. We report a closure of an atrial septal defect under transesophageal echocardiography without fluoroscopy. A nine year old girl with an 11 mm atrial septal defect centrally located in the oval fossa was elected for transcatheter closure. Doppler-echocardiographically estimated Qp/Qs was 1.7:1. Oxymetric Qp/Qs was 1.6:1. After sedation with midazolam and propofol a diagnostic and interventional catheterization was performed without fluoroscopy. Under transesophageal echocardiography, the defect was sized over the wire with a 5F balloon catheter. The distance to the right pulmonary veins was 10 mm, to the coronary sinus and to the mitral valve 8 mm, respectively. Under transesophageal echocardiography, an 11 mm Amplatzer Septal Occluder was placed into the defect. Complete closure was achieved and no complications were encountered. We conclude that in selected cases with an atrial septal defect located in the oval fossa and clear-cut echocardiographic findings, an Amplatzer Septal Occluder can be safely deployed under echocardiographic guidance alone.
    Notes: Zusammenfassung Der operative Verschluß eines Vorhofseptumdefekts (ASD) kann heutzutage ohne präoperative Katheteruntersuchung durchgeführt werden. Für den interventionellen Verschluß unter Durchleuchtung ist jedoch eine Strahlenexposition unvermeidbar. Wir berichten über einen interventionellen ASD-Verschluß allein unter transösophagealer Ultraschallkontrolle. Ein neun Jahre altes Mädchen mit einem 11 mm großen ASD vom Secundum-Typ wurde zum interventionellen ASD-Verschluß vorgestellt. Das Shuntvolumen über den Defekt wurde Doppler-echokardiographisch mit Qp/Qs=1,7:1 und oxymetrisch mit Qp/Qs=1,6:1 bestimmt. Unter Sedierung mit Midazolam und Propofol wurde sowohl die Katheterdiagnostik als auch die Intervention ohne Durchleuchtung durchgeführt. Die Defektgröße wurde unter transösophagealer Echokardiographie mit einem 5F Ballonkatheter ermittelt: Der Defekt war 11 mm groß, der Abstand zu den rechten Lungenvenen betrug 10 mm, zum Koronarsinus und zur Mitralklappe jeweils 8 mm. Unter transösophagealer Echokardiographie konnte komplikationslos ein 11 mm großer Amplatzer Septal Occluder in den Defekt plaziert werden. Es bestand kein Restshunt. Der hier berichtete Fall demonstriert, daß die Technik des interventionellen ASD-Verschlusses inzwischen so ausgereift ist, daß sowohl Diagnostik, Sizing als auch Implantation eines transvenös eingebrachten Amplatzer Septal Occluders ganz ohne Röntgenstrahlung möglich ist.
    Type of Medium: Electronic Resource
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  • 19
    ISSN: 1432-1238
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 357 (1998), S. 291-298 
    ISSN: 1432-1912
    Keywords: Key words Rat ventricular myocyte ; Voltage-clamp ; Transient outward current ; Action potential ; Tedisamil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Tedisamil has been described as a selective inhibitor of a fast inactivating transient outward current (ito,f) in rat ventricular myocytes. Because recent reports demonstrated the existence of a second slowly inactivating transient component (ito,s) we investigated ito,s and differentiated the effects of tedisamil on both transient outward current components and their influence on action potential duration. Standard electrophysiological techniques were used for whole cell recordings at 24–26° C from enzymatically isolated myocytes. Inhibition of ito,f by tedisamil was the result of an acceleration of inactivation at positive test potentials with a concentration for halfmaximal inhibition (EC50) of 4–7 μmol/l, which is confirmatory to reports from other investigators. Our new results show that ito,s is more sensitive to tedisamil with an EC50 of 0.5 μmol/l. Furthermore the pattern of ito,s inhibition is different compared with ito,f, because inactivation of ito,s is not accelerated by tedisamil. Instead the amplitude of the steady state inactivation curve of ito,s is attenuated which indicates a reduction of maximally available current. Ito,s was evaluated by three different methods as time-dependently inactivating current (7.5 s test pulse duration), voltage-dependently inactivated current and tedisamil-sensitive current. All approaches yield similar inactivation curves. The potential for halfmaximal inactivation of ito,s lies about 35 mV more negative than that for ito,f and the slope factor (K = –23 mV) is different to that of ito,f (K = –3 mV). Effectiveness of tedisamil-induced modulation of ito,f and ito,s on action potential repolarization was tested. Action potentials stimulated at 0.5 Hz were not prolonged by 1 μmol/l tedisamil (dominant ito,s block) at a repolarization level of 0 mV but prolonged to about 120% of control at –70 mV. This indicates that ito,f was sufficient to guarantee a regular early repolarization whereas decrease of ito,s delayed the final repolarization. In conclusion, the observation that tedisamil inhibits ito,f and ito,s differently supports the hypothesis that the two ito-components are related to two different channel populations expressed in rat ventricular myocytes.
    Type of Medium: Electronic Resource
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