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An interferon-gamma (IFN-gamma)-inducing molecule (OK-PSA) has been purified from OK-432 by an affinity chromatographic technique performed on cyanogen bromide-activated Sepharose 4B-bound TS-2 monoclonal antibody, which neutralizes IFN-gamma-inducing activity of OK-432. OK-PSA has striking anti-tumor activity in vivo and in vitro. In the current study, the liposomes were used to improve the delivery of the agent (OK-PSA) to effector cells and to increase the therapeutic effect. Significantly less OK-PSA encapsulated into liposomes (Lipo-OK-PSA) than OK-PSA alone (1/100 or less of OK-PSA alone) was required to induce IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), TNF-beta, interleukin-1 beta (IL-1 beta), natural killer, and lymphokine-activated killer activities by human peripheral blood mononuclear cells and mouse spleen cells. Furthermore, higher levels of these activities were detected in peripheral blood mononuclear cells and mouse spleen cells treated with Lipo-OK-PSA than in those treated with OK-PSA. All of these activities induced by Lipo-OK-PSA were almost completely neutralized by anti-asialo-GM1 antibody and complement (p < 0.001). In in vivo experiments, Lipo-OK-PSA elicited striking anti-tumor activity on syngeneic Meth-A tumor-bearing and colon 26-bearing BALB/c mice and on salivary gland tumor-bearing nude mice far better than did OK-PSA. Furthermore, high levels of natural killer and lymphokine-activated killer activities and a significant increase in the number of cells positive for asialo-GM1, IFN-gamma, TNF-alpha, or IL-1 beta were detected in the spleen cells derived from the animals given Lipo-OK-PSA compared with those given saline. These findings clearly indicate that OK-PSA plays an important role in the anti-tumor efficiency of OK-432, and that, for the most part, liposome encapsulation of this molecule markedly accelerates its effect mediated by asialo-GM1-positive cells (mainly natural killer cells).

It has been found by PCR-SSCP analysis and direct DNA sequencing that a human salivary adenosquamous carcinoma-forming cell line, TYS, has a mutant p53 gene at codon 281Asp--His. When TYS cells were treated with a differentiation-inducing agent, vesnarinone, cellular proliferation was significantly inhibited on the basis of MTT assay. In addition, it has been found by Northern blotting and/or immunoblotting that expression of p21WAF1 and transforming growth factor-beta (TGF-beta) is up-regulated by treating TYS cells with vesnarinone. TGF-beta 1 alone also induced p21WAF1 expression in TYS cells. Moreover, it has been shown by ELISA that the treatment of TYS cells with vesnarinone results in the enhanced generation of latent TGF-beta 1. The expression of TGF-beta receptor (T beta R), including T beta R-I, T beta R-II and T beta R-III, on TYS cells was detected by affinity cross-linking using 125I-TGF-beta 1 and addition of active TGF-beta 1 into serum-free culture medium inhibited the growth of TYS cells in a concentration-dependent manner. These findings suggest that vesnarinone might directly induce expression of p21WAF1 gene in TYS cells, the product of which may be associated with the inhibition of cell growth and induce differentiation.

A case of osseous choristoma in the buccal mucosa of a 9 -year-old girl is described. In the literature only 11 cases have been reported previously. The lesion measured 8.5×8.5mm and was removed under local anesthesia.Histologically, the lesion consisted of a well circumscribed mass of dense lamellar bone, surrouded by a thin layer of fibrous connective tissue. The excised area of bum' mucosa healed and was free of recurrence after 5 months.