A case of carcinoma rete testis: histomorphological, immunohistochemical and ultrastructural findings and review of literature.

A 72-year-old man presenting with a secondary hydrocoel underwent orchidectomy. Gross examination revealed a tumor arising in the region of the rete testis, which on histopathology proved to be a papillary adenocarcinoma. The patient did not have evidence of any other neoplasia elsewhere in the body. The lesion fulfilled the anatomic criteria elucidated by Nochomovitz et al to be labelled as adenocarcinoma of Rete testis. Electron microscopy revealed characteristic nuclear infoldings and microtubules with two different arrangements. The tubules were either seen to form concentric circles or were in irregular groups with filaments interspersed. The lesion on immunohistochemistry was negative for germ cell markers AFP and HCG, and was positive for cytokeratin and epithelial membrane antigen. A review of literature is also presented.

Autoinhibition and desensitization of serotonergic responses in guinea pig ileum.

The present study was undertaken to investigate the autoinhibition and desensitization of 5-hydroxytryptamine (5-HT) using another agonist MK-212 on guinea pig ileum. 5-HT and MK-212 produced dose dependent contractions of guinea pig ileum. The responses to MK-212 were reduced in the presence of 5-HT and vice versa. Neither 5-HT nor MK-212 produced any change in the responses to histamine, acetylcholine or KCl. Increase in Ca++ in bathing fluid reversed the desensitization produced by MK-212 or 5-HT. Our data suggest that 5-HT and MK-212 produce desensitization which is specific for serotonergic receptors and possibly involves Ca++ ions.