No abstract

A proteolytically released fragment of collagen XIX, termed a matricryptin, promotes the assembly of inhibitory nerve terminals through integrin receptors.

A peroxidase-antiperoxidase technique for S-100 protein has been applied to 68 salivary glands. These included 17 pleomorphic adenomas, seven adenoid cystic carcinomas, 23 adenolymphomas and a number of other neoplasms. In addition, five specimens of myoepithelial sialadenitis ('benign lymphoepithelial lesion') and five normal parotid glands were included. Consistent results were obtained, myoepithelial cells and cells in myxoid and chondroid areas in pleomorphic adenomas staining intensely. In adenoid cystic carcinoma, on the other hand, there was no staining. The adenolymphomas possessed intensely S-100 protein-positive cells in the interfollicular lymphoid areas; these were probably interdigitating reticulum cells. In addition, branching structures, probably corresponding to Langerhans' cells, were observed in the epithelium of adenolymphomas.

SUMMARY Twenty five specimens of branchial cyst from the same number of patients have been examined. On staining with haematoxylin and eosin a consistent finding was that the mural lymphoid follicles were always aligned with their mantle zones towards the luminal epithelium. With conventional staining lymphatic sinuses were noted in 17 of the specimens, but with immunohistochemical staining these structures were apparent in 23 cysts. Their frequent occurrence in branchial cysts supports the theory that these lesions are derived from epithelial inclusions in lymph nodes. Immunohistochemical techniques for a range of other markers, using polyclonal and monoclonal antisera, showed a distribution of lymphoid and non-lymphoid tissue elements, as seen in lymph nodes and, for example, palatine tonsils. The lining luminal epithelium also shared many features in common with the crypt epithelium of tonsils. 28 February 1985 antigens: K and X immunoglobulin light chains; y, a, ,t, 8, and e immunoglobulin heavy chains; factor VIII related antigen; muramidase; a,-antitrypsin; and S-100 protein. The primary antisera used were polyclonal; they were raised in rabbits and obtained commercially from Mercia Brocades, Weybridge, Surrey, UK. The primary antisera were applied at suitable titres for 20 min after trypsinisation and blocking of endogenous peroxidase with the hydrochloric acid and methanol technique. After a thorough wash swine antirabbit antiserum was applied for 20 min; this was followed by another wash in Tris buffer at pH 7-6. Rabbit PAP was then applied for a further 20 min, followed by a final wash in buffer. The peroxidase was visualised by the usual 3,3'-diaminobenzidine (DAB) reaction, and the sections were counterstained in haematoxylin, washed, dehydrated, cleared, and mounted in synthetic medium.In addition, polyclonal antisera to cathepsin B, cathepsin G, and leucocyte elastase were applied. These were raised in sheep and generously supplied by the

SUMMARY A polyclonal antiserum, produced in sheep and reactive against purified human leucocyte elastase, has been applied to paraffin sections from a range of human tissues by means of the indirect immunoperoxidase method. Striking and consistent results have been obtained. Normal or inflammatory granulocytes were intensely positive, the reaction being "blocked" by pure elastase. Activity was not seen in other sites, including histiocytic reticulum and lymphoid cells, although some weaker reaction was present in gastric and ileal lining epithelium. Strong reactivity was also seen in the cells of acute and chronic myeloid leukaemia and in extramedullary haemopoiesis. The advantages of this technique are compared with those for muramidase (lysozyme), a,-antitrypsin, and naphthol-AS-D-chloroacetate esterase.