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Biomedical subjects

F Falcioni

Publications and source records attributed to F Falcioni.

21 records · Page 2Linked to original sources

Functionally distinct human T-lymphocyte clones sharing potent suppressive activity on immunoglobulin secretion.

T-lymphocyte clones derived from populations sensitized to alloantigens in vitro were tested for their regulatory effects on pokeweed mitogen-stimulated immunoglobulin (Ig) secretion. Clones with natural killer (NK)-like cytotoxicity and/or suppressive activity for lymphoproliferative (LP) responses potently inhibited Ig secretion. Moreover, certain alloproliferative T4+ interleukin-2 (IL-2)-secreting 'helper' clones shared this strong suppressive activity on Ig secretion. The remaining clones enhanced, rather than suppressed, Ig production. Inhibition by all types of suppressive clones appeared not to be restricted by MHC products, since allogeneic HLA-mismatched donors were suppressed as efficiently as the autologous donor. Suppression was radioresistant, and was apparently not caused by absorption of IL-2, or cytotoxicity of the clones. Suppression was still detectable at plateau levels when cloned cells were added as late as 96 hr after the initiation of the cultures, suggesting an inhibitory mechanism divorced from early B-cell activation events. Thus, T-lymphocyte clones with distinct different functional activities share similar profound suppressive effects on Ig secretion in vitro.

Clone Cells↗

Influence of TPA (12-O-tetradodecanoyl-phorbol-13-acetate) on human B lymphocyte function.

The effect of the tumour-promoting agent TPA (12-0-tetra-dodecanoyl-phorbol-13-acetate) on the proliferation and Ig secretion response of blood and tonsil lymphocytes was investigated and compared to that of the T-cell-dependent polyclonal activators pokeweed mitogen (PWM) and group A streptococcal cell membranes (A-ScM) or the T-cell-independent B cell mitogen Staphylococcus aureus Cowan I (SAC) and a T-cell-independent B cell activator Klebsiella pneumoniae (Klebs M). In blood mononuclear cells (MNC), a rather weak, monocyte-dependent DNA synthetic response was observed after exposure to TPA, in comparison to PWM, A-ScM or SAC. Whereas highly purified B cells did not respond to TPA, purified T cells proliferated to a similar degree as unseparated MNC; moreover, the addition of T to B lymphocytes enhanced proliferation rates proportionally to the number of T cells added. This suggests that TPA acts as a polyclonal T cell activator (PTA) for human blood and tonsil cells. Similarly, TPA induced only small amounts of Ig secretion in blood and in tonsil MNC, as determined by an ELISA assay, and no significant Ig secretion in highly purified B cells. The rather weak B cell differentiation response was not due to a monocyte suppressor effect, since partially monocyte-depleted MNC or B cells responded similarly to the non-depleted cells. Thus, TPA cannot be considered as an alternative to other B cells stimulators, both with regard to DNA synthesis and Ig secretion.

B-Lymphocytes↗

[Investigation of drug users reported to the juvenile court of Rome].

After illustrating the new set of rules in matter of stupefacient and psychotropic drugs, introduced in Italy on December 1975, and the duties assigned by the law to the judicial power, the findings are set forth here of an investigation carried out on 40 youths whose addiction to the use of drugs had been reported to the juvenile court of Rome up to April 30, 1977. Anamnestic, social, judicial and clinical data on such subjects were obtained. Even with the obvious reservations resulting from the extremely small sample, some findings are observed that appear to be significant: a considerable portion of the minors addicted to the use of drugs was the recipient of other interventions by the juvenile court in the civil, administrative and criminal sphere; for the males, the prevailing anamnestetic and social data correspond to the characteristics of the other subjects, with whom the court usually deals at the "re-educational" or criminal level, while, with regard to females, the picture is remarkably different. The use of heroin seems to be wide-spread among the males, where also prevail previous hospitalizations caused by the use of drugs. The Authors advocate a new and more extensive verification, to be carried out after a period of time.

Adolescent↗