Control of c-fos expression in STC-1 cells by peptidomimetic stimuli.

Enteroendocrine cells respond to nutrient and non-nutrient stimuli in the gut lumen. The intestinal hormone cholecystokinin (CCK) is secreted in response to luminal fatty acids, amino acids, peptides and proteins. The peptidomimetic cephalosporins have been reported to provide model, stable, compounds with similar secretagogue activity to peptide. Putative luminal stimuli also influence transcriptional activity in enteroendocrine cells, but the mechanisms are uncertain. In the present study we have investigated the control of c-fos expression in STC-1 cells (an enteroendocrine cell line). Peptidomimetics stimulated calcium-dependent release of CCK, and increased intracellular calcium, phosphorylation of p42/44 mitogen-activated protein kinase (MAP kinase) and c-fos mRNA abundance. Hypotonic stress also increased p42/44 MAP kinase phosphorylation and c-fos mRNA, but not CCK release. The increase in c-fos mRNA was strikingly potentiated by peptidomimetics in hypotonic medium. Increased c-fos expression, but not CCK release, was suppressed by the MAP kinase (MEK) inhibitor PD98059, and by the tyrosine kinase inhibitor genistein. We conclude that in STC-1 cells, peptidomimetics act through the p42/44 MAP kinase pathway to increase c-fos expression but not exocytosis. Moreover, a putative non-nutritive stimulus, hypotonic stress, may interact with this pathway to enhance c-fos expression, independently of hormone release.

Audit in orthodontic practice: how well do we communicate with our referring practitioners?

A questionnaire survey of 102 dental practitioners who refer patients to our specialist practice was undertaken to determine how satisfied they were with our current communication methods. Eighty-five replies were received (83 per cent). Seventy-two per cent felt that they were kept sufficiently informed about treatment decisions and progress. Almost all the practitioners were satisfied with our current extraction letter arrangements and with our practice of referring patients requiring oral surgery procedures directly to a local oral surgeon. Forty-six per cent of respondents noted a lapse in attendance by some patients undergoing active orthodontic treatment and 40 per cent requested more information regarding our waiting list. In general, 34 per cent of our referring practitioners felt that our communication methods could be improved to some degree, and a number of suggested improvements were made. Additional information was also obtained on referral patterns and the practitioners' own involvement with providing orthodontic treatment.

A removable appliance for the three-dimensional movement of ectopic maxillary canines.

A removable appliance design has been described which is useful in the traction of ectopic canine teeth and is capable of exerting forces in all planes of space, thus optimizing the potential to achieve a stable and aesthetically pleasing result. It does not substitute for the finesse of a fixed appliance, but is a useful tool for when a fixed appliance is not acceptable to the patient. The appliance is cheap to construct, easy to adjust and keep clean, and is well tolerated by patients.