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M J Halonen

Publications and source records attributed to M J Halonen.

4 recordsLinked to original sources
PubMed1998

Fas receptor expression on asthmatic eosinophils.

Activation of the Fas receptor (Fas; CD95) on eosinophils induces apoptosis and may play a role in controlling eosinophil number in blood and tissue. To determine whether Fas expression on eosinophils is different between asthmatics and non-asthmatics, eosinophils were isolated from the peripheral blood using a three-step procedure of dextran sedimentation, ficoll hypaque separation and negative selection with anti-CD16 monoclonal antibody bound to magnetic beads. Fas expression was quantified by flow cytometry. Fas expression and the percentage of eosinophils expressing Fas were not different between asthmatics (n=9) and non-asthmatics (n=14).

Adolescent↗
PubMed1994

Antiallergic activity of tylogenin, a novel steroidal compound from Tylophora sylvatica.

Tylogenin, a steroidal aglycone generated by acid hydrolysis from two seasonal glycosides occurring in Tylophora sylvatica, inhibits IgE-induced basophil mediator release for allergic reactions. In the rabbit basophil-dependent serotonin release (BDSR) assay system, the inhibitory activity of tylogenin (geom mean IC50 = 39 microM) was significantly (P < 0.05) greater than that of its parent glycosides, tylophoroside (geom mean IC50 263 microM) and acetyltylophoroside (geom mean IC50 331 microM), and that of dexamethasone (geom mean IC50 = 912 microM). The activity of tylogenin was found to increase with the incubation time. In the human leukocyte-dependent histamine release (LDHR) test model, the glycosides had only a minimal activity. In contrast, tylogenin, with a geom mean IC50 = 49 microM, exerted a significantly (P < 0.05) greater potency than dexamethasone (IC50 = 257 microM). These results suggest that tylogenin could represent a new class of antiallergic agents.

4-Butyrolactone↗