Improving staging accuracy in colon and rectal cancer by sentinel lymph node mapping: a comparative study.

AIM: To compare the predictive value of sentinel lymph node (SN) mapping between patients with colon and rectal cancer. PATIENTS AND METHODS: An ex vivo SN procedure was performed in 100 patients with colon and 32 patients with rectal cancer. If the sentinel node was negative, immunohistochemical analyses using two different antibodies against cytokeratins (Cam5.2 and CK 20) and one antibody against BerEp-4 were performed to detect occult tumour cells. Isolated tumour cells (<0.2mm) were discriminated from micrometastases (0.2-2mm). RESULTS: An SN was identified in 117 patients (89%), and accurately predicted nodal status in 106 patients (accuracy 91%). Both sensitivity and negative predictive value were higher in colon carcinomas than in rectal carcinomas (83% versus 57%, p=0.06 and 93% versus 65%, p=0.002 respectively). In patients with extensive lymph node metastases the SN procedures were less successful. Eleven of the 13 unsuccessful SN procedures were performed in patients with rectal cancer who had pre-operative radiotherapy. After immunohistochemical analysis 21 of the 73 N0 patients had occult tumour cells in their SN; eight patients had micrometastases and 13 patients had isolated tumour cells. CONCLUSION: SN mapping accurately predicts nodal status in patients with colonic cancer. Immunohistochemical analysis demonstrates micrometastatic disease in eight out of 73 N0 patients, with a true upstaging rate of 11%. SN mapping is less reliable in patients with rectal cancer after pre-operative radiotherapy.

Successful treatment of fulminant pneumococcal sepsis with recombinant tissue plasminogen activator.

This case report describes a patient with a rapidly progressive pneumococcal septic shock and purpura fulminans. Despite maximal conventional treatment, the patient developed progressive multiple organ failure with imminent necrosis of the extremities. This extremely rare, but often fatal, disease responded dramatically to the infusion of recombinant tissue plasminogen activator.

Chronic experimental colitis induced by dextran sulphate sodium (DSS) is characterized by Th1 and Th2 cytokines.

Oral administration of DSS has been reported to induce an acute and chronic colitis in mice. The aim of our study was to evaluate if the chronic phase of DSS-induced colitis was characterized by a Th1/Th2 response and how this would relate to mucosal regeneration. Swiss Webster mice were fed 5% DSS in their drinking water for 7 days, followed by 2-5 weeks consumption of water. Control mice received only water. The animals were killed at 3 and 6 weeks after induction. Their colons were isolated for histology and immunohistochemistry, using specific MoAbs for T and B cells, macrophages, interferon-gamma (IFN-gamma), IL-4 and IL-5. Colons were scored for inflammation, damage and regeneration. Two weeks after stopping DSS the colonic epithelium had only partially healed. Total colitis scores were still increased, especially in the distal colon, which was due to more inflammation, damage and less regeneration. In areas of incomplete colonic healing the basal parts of the lamina propria contained macrophages and CD4+ T cells. These CD4+ T cells showed a focal increase of IFN-gamma and IL-4 staining compared with control animals. These findings were still observed 5 weeks after stopping DSS in some mice, albeit less extensive. Chronic DSS-induced colitis is characterized by focal epithelial regeneration and a Th1 as well as Th2 cytokine profile. We postulate that chronic immune activation mediated by both populations of Th cells can interfere with colonic healing and can play a role in the pathogenesis of chronic colitis.