Sphingolipid metabolism was examined in guinea-pig airway smooth muscle cells stimulated by platelet-derived growth factor (PDGF) and 4β-phorbol 12- myristate 13-acetate (PMA), as mitogens and bradykinin (BK) as non-mitogen. Stimulation of the cells by PMA and PDGF for 60 min. at 37°C induced the following changes in sphingolipid metabolites: in cells prelabeled with PH] palmitate, a 1.2 f...

After a 2-hr incubation with soluble immune response suppressor (SIRS), product of concanavalin A-activated murine T cells, macrophages release factor, M phi-derived factor (M phi-SF), which nonspecifically suppresses responses in vitro. The mechanism(s) action phi-SF and range cell types affected by have been investigated. suppressed antibody to background levels if added at culture initiation...

Thrombosis, especially arterial, develops by mediation of platelets, adhering to collagen fibers at areas of endothelial cell damage. At this phase, platelet activation leads them to secrete factors [ADP, Fibrinogen, von Willebrand Factor (vWF), Fibronectin, Factor XIII] capable of promoting cell aggregation/adhesion and coagulation, inducing vasoconstriction (thromboxane A2) and acting as mito...

The production of interleukin 2 (IL-2) gamma interferon, IL-4, tumor necrosis factor alpha (TNF-alpha), TNF-beta, IL-5, and IL-10 in vitro by peripheral blood mononuclear cells cultured from healthy immunocompetent subjects after mitogen stimulation was determined. The mitogens used were concanavalin A, phytohemagglutinin, pokeweed mitogen, and Staphylococcus aureus Cowen. The results obtained ...

rIL-4 inhibits the production of IFN-gamma by PBMC stimulated with mitogens or allogeneic cells. The suppression is observed at the protein and at the mRNA level; it is dose and time dependent, and it is abolished by a neutralizing mAb to IL-4. It is suggested that the balance between the production of IL-4 and IFN-gamma may be significantly influenced by the chronological order of activation o...

The in vivo effects of fructus Schizandrae and radix Eleutherococci combined extracts on various parameters of lymphocyte activity in Balb/c mice were studied. Feeding mice 300, 600 or 1200 μg of the extracts per day for 7 d, produced the activation of chemokinetic activity of spleen lymphocytes, enhancement of proliferative response of splenocytes and blood lymphocytes to mitogens, stimulation...

Platelets have multiple functions beyond their roles in thrombosis and hemostasis. Platelets support liver regeneration, which is required after partial hepatectomy and acute or chronic liver injury. Although it is widely assumed that platelets stimulate liver regeneration by local excretion of mitogens stored within platelet granules, definitive evidence for this is lacking, and alternative me...