Quantification of subclasses of human colonic myenteric neurons by immunoreactivity to Hu, choline acetyltransferase and nitric oxide synthase.

An accurate method to count human enteric neurons is essential to develop a comprehensive account of the classes of nerve cells responsible for gut function and dysfunction. The majority of cells in the enteric nervous system utilize acetyl choline, or nitric oxide, or a combination of these, as neurotransmitters. Antisera raised against the RNA-binding protein Hu, were used to identify nerve cell bodies in whole mounts of the myenteric plexus of human colon, and then were utilized to analyse cells immunoreactive for combinations of choline acetyltransferase and nitric oxide synthase. Antisera to Hu provided a reliable means to count apparently all enteric nerve cell bodies, revealing 10% more cell bodies than labelling with neuron specific enolase, and no labelling of glial cells as revealed by S100. ChAT+/NOS- neurons accounted for 48% (+/-3%) of myenteric neurons and ChAT-/NOS+ neurons accounted for 43% (+/-2.5%). ChAT+/NOS+ neurons comprised 4% (+/-0.5) of the total number of neurons, and a novel class of small ChAT-/NOS- neurons, making up 5% (+/-0.9%) of all cells, was described for the first time.

Management of an unexpected appendiceal neoplasm.

BACKGROUND: Appendiceal neoplasms are rare and most present unexpectedly as acute appendicitis. The classification and management are confusing, and there are few substantial reports in the literature. METHODS: A systematic literature review was performed to access relevant publications on the presentation, pathology and management of appendiceal tumours. RESULTS: Appendiceal tumours account for 0.4 to 1 per cent of all gastrointestinal tract malignancies and are found in 0.7 to 1.7 per cent of appendicectomy specimens. Carcinoid tumours are most common. Most are cured by simple appendicectomy if the tumour is less than 2 cm in size and does not involve the resection margin or mesoappendix. Epithelial tumours may present with, or in time develop, pseudomyxoma peritonei, the optimal management of which involves complete tumour resection and intraperitoneal chemotherapy, usually available only in specialized centres. CONCLUSION: Suggested algorithms for the management of unexpected appendiceal tumours are provided. Recommendations are made for follow-up of patients with a perforated appendiceal epithelial tumour.