Development of an ex vivo model of pig kidney perfused with human lymphocytes. Analysis of xenogeneic cellular reactions.

Background: Because of the explosive nature and the extremely rapid process of hyperacute rejection (HAR), significant infiltration of the xenograft by immunocompetent cells is not observed, and the role and the mechanism of action of cell-mediated rejection in discordant xenografts are therefore still under discussion.

Method: We developed an experimental approach using pig kidneys perfused with human peripheral blood lymphocytes (PBL) in which the immunologic barrier of hyperacute rejection was excluded and which mimics the in vivo situation.

Results: PBL retention in the kidney was evaluated at 20-minute intervals for 3 hours.

Unusual endocervical polypoid tumor with endocrine cells: an immunohistochemical and ultrastructural analysis.

Light microscopic, immunohistochemical, and ultrastructural features of an unusual polypoid tumor of endocervix are reported. Numerous polypeptide hormone and amine-producing endocrine cells were disclosed. Main conventional characteristics were the architectural growth pattern, with infolding glands giving rise to small secondary glands, the hypermucinous benign-appearing epithelium of endocervical type, and, possibly, the stromal smooth muscle.

Isolation and characterization of syncytiotrophoblast plasma membrane from human placenta.

Human full-term syncytiotrophoblast plasma membranes isolated by mechanical procedures (sieving and ultrasonic disintegration), purified by phase centrifugation, form a single band of 1.052 +/- 0.002 g/ml density in percoll gradient.