Epidermoid cyst of an accessory spleen at the pancreatic tail: diagnostic value of MRI.

We report a rare case of an epidermoid cyst in an accessory spleen at the pancreatic tail. Only 12 cases have been reported. Among the different diagnostic modalities, magnetic resonance imaging was most useful for the differential diagnosis. Precise imaging of the cyst wall and its comparison with the surrounding organs are essential.

Immunological function of adhesive glycoprotein from rat ascites hepatoma cells: production of macrophage chemotactic lymphokine.

As previously described, a cell surface-associated adhesive glycoprotein capable of inducing not only aggregation of hepatoma cells but also adhesiveness was separated from differentiated rat ascites hepatoma AH136B cells (forming cell islands in vivo) and highly purified by chromatography. The factor functioned as a mitogenic lectin on rat T lymphocytes. Undifferentiated rat ascites hepatoma AH109A cells (present as single cells in vivo) were unable to synthesize the factor. Distinct macrophage chemotactic activity was released in vitro from rat lymphocytes stimulated by this factor; it was detected in culture supernatant stimulated by 1 microgram/ml of the factor, becoming maximal by 10 micrograms/ml. The activity became detectable in 6 hr after stimulation, reaching its peak in 24 hr. Production of this type of chemotactic lymphokine was suppressed by puromycin (2.0 micrograms/ml). It was heat-stable, nondialysable, stable for freeze-thawing and had an approximate molecular weight of 12,500 on gel filtration; it was derived from nylon wool-non-adherent cells (T lymphocytes). AH136B tumour after subcutaneous transplantation was clearly small in size but the skin site was characterized by marked macrophage and lymphocyte reactions; AH109A tumour after similar transplantation was much larger in size but the cell reaction in the skin site was apparently less marked, suggesting an involvement of the lymphokine in the mediation of macrophage reaction in the tumour site.

Lymphocyte chemotaxis in inflammation. VI. Lyt phenotype analysis of effector cells responsible for producing murine lymphocyte chemotactic factor.

Murine lymphocyte chemotactic factor (LCF) was demonstrated in various culture fluids of C3H/HeN lymphoid cells stimulated with specific soluble protein antigen, mitogen or alloantigenic cells. Further experiments, using monoclonal anti-Thy 1.2, anti-Lyt 1.1 and anti-Lyt 2.1 antibodies for negative selection with complement (C), were carried out to characterize the effector-cell populations responsible for producing LCF after these stimuli. Treatment of sensitized lymph node (LN) cells with either anti-Thy 1.2, or anti-Lyt 1.1 and C resulted in an almost complete elimination of the capacity to produce LCF after dinitrophenylated-ovalbumin-stimulation. In addition, spleen cells treated with these antibodies and C before stimulation with either alloantigen (irradiated C57BL/6 spleen cells or concanavalin A [Con A]) yielded almost the same results as those for LN cells. In contrast, depletion of Lyt cells, under conditions which fully abrogated the generation of cytotoxic T cells in primary mixed-lymphocyte culture (MLC) and the cytotoxic activity of the cells generated in MLC, had little or no ability to eliminate LCF production in either system. It was thus suggested that Lyt 1+2- T-cell subpopulations were primarily responsible for LCF production after stimulation with either specific protein antigen, alloantigen, or Con A.