The present study investigated the activity and cellular localization of individual isoenzymes of nitric oxide synthase (NOS) using immunohistochemistry and the [3H]citrulline assay in normal colorectal epithelia and neoplastic tissue. Intracellular localization of isoenzymes of NOS was detectable by immunohistochemistry in normal epithelial cells. Colorectal adenocarcinomas had a marked reduction of both Inducible NOS (iNOS) and constitutive NOS (cNOS) expression. Expression of iNOS was completely absent in tumour cells (P < 0.0001), while cNOS was reduced in 66% and absent in 34% of tumours studied when compared with controls (P < 0.0001). NOS activity using the [3H]citrulline assay was detectable in normal epithelium and was found to be reduced in tumours (P < 0.001). In addition, colonic adenomas had reduced INOS but not cNOS expression when compared with controls (P < 0.003 and P = 0.39 respectively). We conclude that NOS is present and active within the epithelium of the normal colon, with localization of the individual isoenzymes. Furthermore, there was loss of activity and expression of individual isoenzymes in colonic neoplasms.

In patients with suppurative or perforated appendicitis, the rate of intra-abdominal abscess is equivalent between groups treated with peritoneal irrigation and suction alone.

At the current institution NEAT success has been guarded, likely secondary to availability of inpatient beds. The implementation of NEAT appears to have reduced emergency waiting times. These early results suggest concurrent a detrimental effect on IPLOS; however, some of this effect may be a result of a large increase in short stay admissions.