Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 130 (1970), S. 330-344 
    ISSN: 1432-0568
    Keywords: Cholinesterase ; Liver development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Im Stadium 12–14 besitzt das präsumptive Leberentoderm bei der Ausbildung der primären Leberdivertikel und der Leberbucht ChE-Aktivität (Abb. 2-4). 2. Im Stadium 15 wird die Leberanlage vom Darm durch die Einziehung der visceralen Seitenplatten zwischen Darmentoderm und Leberentoderm abgeschnürt. Dabei enthält das Entoderm keine ChE, während die visceralen Seitenplatten stark reagieren (Abb. 5 und 6). 3. Im Stadium 16 tritt im präsumptiven Lebermesenchym eine ChE-Aktivität auf. In die Maschen des positiven Mesenchyms wachsen die negativen entodermalen Leberzellbälkchen ein (Abb. 7). 4. Im Stadium 18 erfolgt die weitere Abschnürung der Leberanlage durch die Formierung des engen primitiven Duodenums. Dabei zeigt das Darmentoderm eine kräftige ChE-Aktivität, während das Leberentoderm weiterhin negativ bleibt (Abb. 8). 5. Wie in anderen Organanlagen ist die ChE-Aktivität bei der Entwicklung der Leberanlage mit Gestaltungsbewegungen der reagierenden Zellen korreliert.
    Notes: Summary 1. In stages 12–14, when the primary liver diverticula are formed, the presumptive liver endoderm exhibits cholinesterase activity (Figs. 2-4). 2. In stage 15 the liver anlage is separated from the foregut by the visceral mesodermal layers bulging in between gut endoderm and liver endoderm. During this process the endoderm has no ChE activity, whereas the visceral mesodermal layers react strongly (Figs. 5 and 6). 3. In stage 16 ChE activity appears in the presumptive liver mesenchyme. The liver cords which are ChE negativ penetrate into the reacting mesenchymal network (Fig. 7). 4. In stage 18 a further separation of the liver anlage is accomplished by the formation of the primitive duodenum. Now the gut endoderm shows strong ChE activity, while the liver endoderm remains negative (Fig. 8). 5. As in the development of other organs ChE activity is correlated with morphogenetic movements of the reacting cells in the formation of the liver.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 201 (2000), S. 27-37 
    ISSN: 1432-0568
    Keywords: Key words Melanoma ; Cell movement ; Time lapse video microscopy ; Muscarinic receptors ; Choline acetyltransferase ; Cholinesterase ; SK-mel 28 cells ; Acetylcholine ; Carbachol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  In a previous immunohistochemical study we observed muscarinic acetylcholine receptors in primary and metastatic human melanomas, which were not present in normal skin melanocytes. In the present study we demonstrated the endogenous expression of muscarinic receptors, of choline acetyltransferase and of cholinesterase activity in the human melanoma cell line SK-mel 28. We tested the effect of muscarinic agonists on cellular movements of the melanoma cells in a perfusion chamber by digital video time-lapse microscopy. Within 3 to 10 min after onset of muscarinic perfusion cell body contractions and retraction of cell processes of more than 5 µm occurred in about 30% of the melanoma cells. The effect disappeared after addition of atropine. The proportion of reacting cells corresponded to the endogenous expression of muscarinic receptors revealed by immunocytochemistry with the monoclonal antibody M35. The experiments indicate the presence of an autocrine muscarinic cholinergic system in the melanoma cells and demonstrate a direct link between muscarinic receptors and the contractile apparatus. Melanocytes are derived from neural crest cells that express cholinesterase activity and muscarinic receptors during their migratory phase in the embryo. Therefore, re-expression of the muscarinic cholinergic system in tumour cells may be involved in invasive growth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...