The starting point of this work is the description of a microsurgical technique designed to carry out termino-terminal arterial anastomosis in rats. The technique is based on the intussusception of the afferent vessel of the anastomosis in the efferent vessel, both of which are fixed by a horizontal U-shaped stitch. Of the twelve cases which make up this series, haemorrhage appeared in two, and a postanastomotic aneurysm developed in one. The lack of complications both before and after operating, even in the long term, in the balance of the cases (75%), together with the simple and quick procedure of this kind of anastomosis, makes this technique a possible alternative to the classical techniques of vascular microanastomosis in experimental surgery.

Anastomosis, Surgical↗

PubMedDate not supplied

Characteristics of cellular structures derived by tissue culture of pre-implantation blastocysts of the pig.

Tissue mechanically dissociated from blastocysts of the pig around the time of implantation were found to produce, in culture, free-floating multicellular spheroids (trophospheres) and adherent monolayer cells. Ultrastructurally the two cellular layers of the trophospheres were very similar to those of the blastocyst but the trophosphere outer layer characteristically contained very large mitochondria with a vastly expanded matrix and few cristae. Similar mitochondria were also found in the monolayer cells. Using a monoclonal antibody specific for pig trophectoderm, it was found that about 20% of the monolayer cells, and some of the spheroids expressed this trophectodermal antigen. In the latter case the antigen was present only on the surface facing the medium. The spheroids were fluid-filled and occasionally grew inside each other. The monolayer cells were predominantly uninuclear but did form a number of binucleate cells and in older cultures the occasional cell with many nuclei could be seen. The spheroids and the monolayer cells had similar glycoprotein profiles indicating that they were composed of similar cell populations. A glycoprotein of apparent molecular weight 68,000 observed in both spheres and monolayers may represent pig placental alkaline phosphatase. Both trophospheres and monolayer cells were observed to interconvert steroid precursors. It is apparent that the trophospheres share many features of the blastocyst and may thus represent a valuable model system similar to those described in other species for the investigation of their biochemical physiological and immunological properties.

Animals↗

PubMedDate not supplied