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
    ISSN: 1432-0533
    Keywords: Ischemia ; Hippocampus ; Resistant neurons ; Recirculation time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphology of the hippocampus of Mongolian gerbils was investigated by light and electron microscopy after 5-min forebrain ischemia and survival times of up to 10 months. After 3 weeks recirculation only 5.8% of pyramidal neurons of the CA1 (cornu ammonis 1) sector had survived but the thickness of the inner and outer hippocampal layers did not change. After recirculation times of 6 and 10 months the number of surviving neurons declined no further but all layers of the CA1 subfield shrank markedly. Ultrastructurally, many but not all surviving CA1 neurons were altered. After 3 weeks both “dark” and “pale” type neurons were present, while after 6 and 10 months only the “pale” type of injury persisted. Axonal enlargements and myelin breakdown were observed at all survival times up to 10 months of recirculation. The astrocytes of CA1 sector contained numerous glial fibrils which were most pronounced after the longer recirculation times. The stratum radiatum presented intact presynaptic terminals densely packed with an abundance of clear vesicles even after survival of 10 months. Initially, morphologically damaged postsynaptic structures were still attached to these terminals but they disappeared after longer recirculation times. However, even after 10 months some intact synapses were observed involving dendrites which probably originated from surviving CA1 neurons. In CA3 sector and dentate gyrus no ultrastructural changes occurred at any survival time. The close association of surviving CA1 neurons with intact presynaptic terminals and reactive glial cells may be of importance for the development of epileptogenic foci which are characteristic of this particular brain region.
    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
    Archives of dermatological research 269 (1980), S. 281-290 
    ISSN: 1432-069X
    Keywords: Dihydrotestosterone (DHT) ; Sebaceous gland lipogenesis ; Topical progesterone ; Testosterone metabolism ; Dihydrotestosteron ; Talgdrüsenlipogenese ; lokale Applikation von Progesteron ; Testosteronstoffwechsel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Effekt von Progesteron auf den 14C-Testosteronstoff-wechsel und auf die 14C-Lipidsynthese wurde an zwei Talgdrüsenmodellen der Hamsterflanke und des Rattenohres untersucht. Die einseitige lokale Applikation von Progesteron auf die weibliche Hamsterflanke, die mit Testosteronpropionat vorbehandelt war, brachte eine lokal begrenzte Hemmung sowohl der in vitro 14C-Lipogenese als auch der in vitro Konversion von 14C-Testosteron zu 5α-reduzierten Metaboliten. Lokal aufgebrachtes Progesteron hemmte nicht die in vitro 14C-Lipogenese beim männlichen Hamsterflankenorgan. In vitro zugesetztes Progesteron hemmte die 14C-Lipogenese und den 14C-Testosteron-stoffwechsel bei der Talgdrüse des männlichen Rattenohres. Diese Resultate unterstützten die Hypothese, daß die Hemmung der Lipogenese der Talgdrüse durch Progesteron eine Folge seines hemmenden Effekts auf den Testosteron-stoffwechsel ist. Diese Vorstellung gibt eine wohl gültige Erklärung für die klinischen Ergebnisse, die mit Progesteron durch andere Untersucher erstellt wurden.
    Notes: Summary The effect of progesterone on 14C-testosterone metabolism and on 14C-lipid synthesis was studied in two animal sebaceous gland models, hamster flank organ and rat ear skin. Unilateral topical application of progesterone to the female hamster flank organ topically treated with testosterone propionate resulted in localized inhibition of both in vitro 14C-lipogenesis and in vitro conversion of 14C-testosterone to 5α-reduced radio-metabolites. Topical progesterone did not inhibit in vitro 14C-lipogenesis in the male hamster flank organ. Progesterone added in vitro inhibited 14C-lipogenesis and 14C-testosterone metabolism in male rat ear sebaceous glands. These results lend support to the hypothesis that inhibition of sebaceous gland lipogenesis by progesterone is a consequence of its inhibitory effect on testosterone metabolism. Such a rationale provides a valid explanation for the clinical findings with progesterone reported by other investigators.
    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...