Six-year prospective analysis of the rectal bleeding clinic at the Queen Elizabeth Hospital, Adelaide, South Australia.

BACKGROUND: One-stop rectal bleeding clinics (RBC) are designed to diagnose and treat colorectal diseases that present with rectal bleeding. The Queen Elizabeth Hospital RBC is an open access clinic and is unique in South Australia. It offers flexible sigmoidoscopy and facilities for treating common anorectal conditions. METHODS: Data of all patients presenting to the RBC were prospectively recorded into a database. Data were collected on the patient details, presentation, medical history, physical examination, treatment and intended follow-up. RESULTS: A total of 1539 cases was seen in the clinic between March 2000 and February 2006. Flexible sigmoidoscopy was carried out in 1145 cases (75.03%). Banding or injection of haemorrhoids was carried out in 383 cases. A total of 590 patients was referred for colonoscopy and of these, 27 were diagnosed with colorectal adenocarcinoma or squamous cell cancer of the anus. Most of these patients were more than 50 years old (26 of 27; 96.30%) and had associated symptoms, such as weight loss or altered bowel habit with their rectal bleeding (23 of 27; 85.19%). CONCLUSION: Rectal bleeding clinics can facilitate early diagnosis of colorectal malignancy and can also provide a 'one-stop shop' for treating benign anorectal conditions.

Transcriptional regulation of nanog by OCT4 and SOX2.

Nanog, Sox2, and Oct4 are transcription factors all essential to maintaining the pluripotent embryonic stem cell phenotype. Through a cooperative interaction, Sox2 and Oct4 have previously been described to drive pluripotent-specific expression of a number of genes. We now extend the list of Sox2-Oct4 target genes to include Nanog. Within the Nanog proximal promoter, we identify a composite sox-oct cis-regulatory element essential for Nanog pluripotent transcription. This element is conserved over 250 million years of cumulative evolution within the eutherian mammals. A Nanog proximal promoter-EGFP (enhanced green fluorescent protein) reporter transgene recapitulates endogenous Nanog mRNA expression in embryonic stem cells and their differentiated derivatives. Sox2 and Oct4 interaction with the Nanog promoter was confirmed through mutagenesis and in vitro binding assays. Electrophoretic mobility shift assays indicate that the Sox2-Oct4 heterodimer forms more efficiently on the composite element within Nanog than the similar element within Fgf4. Using chromatin immunoprecipitation, we show that Oct4 and Sox2 bind to the Nanog promoter in living mouse and human embryonic stem cells. Furthermore, by specific knockdown of Oct4 and Sox2 mRNA by RNA interference in embryonic stem cells, we provide genetic evidence for a link between Oct4, Sox2, and the Nanog promoter. These studies extend the understanding of the pluripotent genetic regulatory network within which the Sox2-Oct4 complex are at the top of the regulatory hierarchy.