Expression of Cathepsin B and L antigen and activity is associated with early colorectal cancer progression.

Cathepsin B and Cathepsin L are cysteine proteases important in the process of invasion and metastasis. The aim of our study was to assay antigen and activity levels of these enzymes and to correlate these with established clinical and pathological prognostic parameters including patient survival. 99 patients undergoing operations for colorectal cancer were included in this study. We quantitated cathepsin B and L levels in matched normal mucosa and cancer samples using an enzyme-linked immunosorbent assay (ELISA) and specific activity assays and expressed the results as tumour/normal ratios. Significant correlations were found between tumour/normal cathepsin B and L antigen and activity ratios. Cathepsin B and L tumour/normal activity ratios were greater than 1 in early stage disease and there were gradual reductions in cathepsin B (P = 0.02) and L (P = 0.03) activity ratios with advancing tumour stage. Survival of patients with potentially curative disease was inversely related to both cathepsin B (P = 0.007) and L (P = 0.001) activity ratio, in addition to cathepsin L antigen ratio (P = 0.008). Our findings suggest that cysteine proteases play an important role in colorectal cancer progression.

Tracheal intubating conditions using propofol and remifentanil target-controlled infusions.

Using target-controlled infusions (TCI) we aimed to determine the most appropriate dose of remifentanil required for intubation, using a steady effect-site concentration of propofol and without the use of neuromuscular blocking drugs. Sixty ASA III patients presenting for elective surgery were randomly allocated to one of three groups. Anaesthesia was induced in all patients using a target-controlled infusion of propofol 6.5 microg x ml(-1). This was reduced to 3 microg x ml(-1) after 1 min. Each group received a different TCI of remifentanil, 19, 15 or 11 ng x ml(-1), which was reduced to 10, 8 or 6 ng x ml(-1), respectively, after 1 min. Laryngoscopy and intubation were attempted at 4 min. Laryngoscopy and ease of intubation were assessed using a standard scoring system. Intubation was considered satisfactory in 75% of patients in groups 1 and 2 and 35% of patients in group 3. Intubation was successful in 20/20, 19/20 and 15/20 patients in groups 1, 2 and 3, respectively. Pulse oximetry, heart rate and noninvasive arterial pressure were measured pre-induction, and at intervals until after laryngoscopy and intubation. Mean arterial pressure (MAP) and heart rate decreased following induction of anaesthesia in all groups, which was statistically significant. Following laryngoscopy, MAP and heart rate increased, but were significantly less than the corresponding baseline values.