The phyogenetic principles of mma: A hypothetical biostratigraphic model

Two erectoid hominids from Sarstedt prompted a detailed examination of the course of the impressions of the Arteria meningea media and their characteristics within the line of hominidae

Vier Monate unter den Revolutionären in Livland : Selbsterlebtes

http://www.ester.ee/record=b4009991*es

Ueber die Ausscheidung des Strychnins : Inaugural-Dissertation zur Erlangung des Grades eines Doctors der Medicin

http://tartu.ester.ee/record=b2448006~S1*es

Die Reform der livländischen Credit-Societät und der Bauer-Rentenbank im Interesse des Gehorchsland-Verkaufes

http://www.ester.ee/record=b4457496*es

"Internationale Frauenuniversität – Technik und Kultur" (ifu) an der Universität Hannover 15. Juli bis 15. Oktober 2000 : Werkstattbericht

Mehr als 900Frauen aus über 115 Ländern versammelten sich in den Sommermonaten 2000 an der „Internationalen Frauenuniversität - Technik und Kultur" (ifu), um zu den Bereichen Migration, Körper, Information, Wasser, Stadt und Arbeit gesellschafts-und geschlechtsrelevante Themen zu diskutieren und in Projekten umzusetzen

Characterisation of development and electrophysiological mechanisms underlying rhythmicity of the avian lymph heart

Despite significant advances in tissue engineering such as the use of scaffolds, bioreactors and pluripotent stem cells, effective cardiac tissue engineering for therapeutic purposes has remained a largely intractable challenge. For this area to capitalise on such advances, a novel approach may be to unravel the physiological mechanisms underlying the development of tissues that exhibit rhythmic contraction yet do not originate from the cardiac lineage. Considerable attention has been focused on the physiology of the avian lymph heart, a discrete organ with skeletal muscle origins yet which displays pacemaker properties normally only found in the heart. A functional lymph heart is essential for avian survival and growth in ovo. The histological nature of the lymph heart is similar to skeletal muscle although molecular and bioelectrical characterisation during development to assess mechanisms that contribute towards lymph heart contractile rhythmicity have not been undertaken. A better understanding of these processes may provide exploitable insights for therapeutic rhythmically contractile tissue engineering approaches in this area of significant unmet clinical need. Here, using molecular and electrophysiological approaches, we describe the molecular development of the lymph heart to understand how this skeletal muscle becomes fully functional during discrete in ovo stages of development. Our results show that the lymph heart does not follow the normal transitional programme of myogenesis as documented in most skeletal muscle, but instead develops through a concurrent programme of precursor expansion, commitment to myogenesis and functional differentiation which offers a mechanistic explanation for its rapid development. Extracellular electrophysiological field potential recordings revealed that the peak-to-peak amplitude of electrically evoked local field potentials elicited from isolated lymph heart were significantly reduced by treatment with carbachol; an effect that could be fully reversed by atropine. Moreover, nifedipine and cyclopiazonic acid both significantly reduced peak-to-peak local field potential amplitude. Optical recordings of lymph heart showed that the organ’s rhythmicity can be blocked by the HCN channel blocker, ZD7288; an effect also associated with a significant reduction in peak-to-peak local field potential amplitude. Additionally, we also show that isoforms of HCN channels are expressed in avian lymph heart. These results demonstrate that cholinergic signalling and L-type Ca2+ channels are important in excitation and contraction coupling, while HCN channels contribute to maintenance of lymph heart rhythmicity

Die Grundlagen des Livl. Boden-Credits

Autors uzrādīts teksta beigās

Haeckel's Theses. A Protest: with Editorial Reply

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