[New permanent expandable prosthesis for the treatment of urethral stenosis]

The paper presents our initial experience in the treatment of urethral stenosis through implantation of a "Wallstent" self expanding resident prosthesis. A total of eleven prosthesis were placed in 10 patients with excellent results, from a clinical, urodynamic, radiological and endoscopic point of view, in 9 of them after 5 months. We believe that this kind of prosthesis can be a valid alternative to other established therapeutic options in the management of urethral stenosis. Long-term monitoring, however, will be necessary in order to corroborate the excellent results obtained in this short/medium-term observation.

Localization of endogenous galactoside-binding lectin during morphogenesis of Xenopus laevis

A monoclonal antibody has been produced against Xenopus laevis galactoside-binding neural-crest-stage lectin. This antibody inhibits lectin-mediated hemagglutination. Using this antibody in conjunction with immunohistochemical techniques, lectin deposition has been studied in embryos and tadpoles at different stages of morphogenesis, from initial neural crest migration, up to the formation of a swimming tadpole. Lectin levels change during development in different regions of the embryo and tadpole, decreasing in migratory cells, and increasing in sites where cells become more adhesive to one another. The results suggest that galactoside-binding lectins may be an important class of cellular adhesion molecules during these stages of development.

Role of antigen-presenting cells in the cytotoxic T-cell response to minor histocompatibility antigens (MIHA). I. In vitro function of cells pulsed with MIHA in vivo

Although antigen-presenting cells (APC) appear to be able to process minor histocompatibility antigens (MIHA) expressed on allogeneic cells and present them in association with intrinsic H-2 of the APC in vivo, this does not occur in vitro. This could be due to fundamentally different mechanisms of antigen handling by APC in vitro, or it could represent compromised APC function. In order to distinguish these possibilities, we designed a system in which BALB/c spleen cells are transferred into an MIHA-disparate irradiated host and allowed to reside for 2-3 days; the spleen cells of the repopulated host are removed and used as stimulator cells for the CTL response of primed BALB/c responder cells to DBA/2 MIHA. These cells are referred to as in vivo-pulsed APC (IVP-APC). Donor BALB/c cells are able to pick up DBA/2 MIHA after a passage in DBA/2 hosts and efficiently present MIHA to primed CTL precursors to generate DBA/2-specific CTL. The donor cell type able to pick up and present MIHA is present in spleen but not thymus or bone marrow, is Thy-1.2 negative, Ia+, and nylon wool-adherent. Its stimulatory capacity is as efficient on a per cell basis as that of DBA/2 spleen cells. The generation of IVP-APC requires repopulation of the irradiated host, which must express MIHA foreign to the BALB/c donor cells. When we attempted to generate IVP-APC in H-2 incompatible hosts, we found that, although the IVP-APC could present H-2 antigens, they were unable to present MIHA in association with intrinsic APC H-2 antigens. Use of intra-H-2 recombinant strains as host mice indicated that compatibility of donor and host at the KI region of H-2 was essential for the generation of IVP-APC able to present apparently unprocessed MIHA to primed BALB/c responder cells. Thus, we were unable to reproduce the antigen-processing function of APC encountering antigen in situ using an adoptive transfer method of pulsing APC with MIHA in vivo. In addition, we suggest that our results may impose constraints on the formulation of models to account for the association of MIHA with H-2 antigens.