Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Protein kinase C  (2)
  • Springer  (2)
  • International Union of Crystallography (IUCr)
Collection
Publisher
  • Springer  (2)
  • International Union of Crystallography (IUCr)
Years
  • 1
    ISSN: 1432-0851
    Keywords: Key words Interleukin-2 receptor ; Protein kinase C ; Acute lymphoblastic leukemia ; Immunosuppression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Peripheral blood lymphocytes obtained from children with acute lymphoblastic leukemia (ALL) at onset were studied for the expression of interleukin-2 (IL-2) receptor α-chain (CD25) by two-color flow-cytometric analysis. Stimulated with anti-CD3 monoclonal antibody (mAb) alone, CD25 expression was significantly suppressed in CD4+ T cells from 27 of 48 (56.3%) cases and in CD8+ T cells from 29 of 48 (60.4%) cases. When stimulated with anti-CD3 mAb plus phorbol 12-myristate 13-acetate (PMA), CD25 expression was clearly restored in certain cases of ALL. When PMA plus ionomycin were used for stimulation of T cells, CD25 was inducible in a majority of cases. Interestingly CD25 expression upon anti-CD3 mAb stimulation was recovered after complete remission had been achieved. These observations suggest the presence in ALL children at onset of an in vitro defect in the signal transduction pathway of the T-cell-receptor/CD3 complex, resulting in inefficient CD25 expression. However, immune-staining analysis indicated that protein kinase C was normally translocated from the cytosol fraction to the cell membrane fraction. The mobilization of cytoplasmic free calcium is also normal.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2013
    Keywords: Key words Calcium transients ; Phorbol esters ; Protein kinase C ; Skeletal muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  By recording the calcium transients evoked by voltage-clamp depolarizing pulse with arsenazo III as a calcium indicator, it has been shown that 1 µmol/l phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) agonist, causes a transient potentiation and then a depression of the calcium transients of twitch muscle fibers in frogs. PDBu also produces an initial translocation and activation of PKC, which is followed by a down-regulation. To find out whether the effect of PDBu on the calcium transients depends on PKC, a correlated study of the effect of phorbol esters on calcium transients and PKC activity was performed. The calcium transients and PKC activity were similarly affected by PDBu in ordinary and cold-accommodated frogs, but the effects occurred more quickly in the latter. However, they still changed in parallel as in ordinary frogs. 1 or 10 µmol/l, 4-α-phorbol, a PKC-inactive analogue of phorbol ester, caused a partial depression of the calcium transients in cold-accommodated frogs, while PKC activity was not affected. Moreover, the transient potentiation of the calcium transients induced by 1 µmol/l PDBu could be antagonized by the PKC inhibitors 10 µmol/l chelerythrine chloride or 10 µmol/l polymyxin B (PMB). All these results suggest that: (1) the transient potentiation of calcium transients induced by PDBu is caused by activation of PKC; (2) phorbol ester can depress the calcium transients by a mechanism that is independent of PKC.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...