Efficacy of high-fidelity simulation debriefing on the performance of practicing anaesthetists in simulated scenarios.

BACKGROUND: Research into adverse events in hospitalized patients suggests that a significant number are preventable. The purpose of this randomized, controlled study was to determine if simulation-based debriefing improved performance of practicing anaesthetists managing high-fidelity simulation scenarios. METHODS: The anaesthetists were randomly allocated to Group A: simulation debriefing; Group B: home study; and Group C: no intervention and secondary randomization to one of two scenarios. Six to nine months later, subjects returned to manage the alternate scenario. Facilitators blinded to study group allocation completed the performance checklists (dichotomously scored checklist, DSC) and Global Rating Scale of Performance (GRS). Two non-expert raters were trained, and assessed all videotaped performances. RESULTS: Interim analysis indicated no difference between Groups B and C which were merged into one group. Seventy-four subjects were recruited, with 58 complete data sets available. There was no significant effect of group on pre-test scores. A significant improvement was seen between pre- and post-tests on the DSC in debriefed subjects (pre-test 66.8%, post-test 70.3%; F(1,57)=4.18, P=0.046). Both groups showed significant improvement in the GRS over time (F(1,57)=5.94, P=0.018), but no significant difference between the groups. CONCLUSIONS: We found a modest improvement in performance on a DSC in the debriefed group and overall improvement in both control and debriefed groups using a GRS. Whether this improvement translates into clinical practice has yet to be determined.

Metastasis in tongue from carcinoma of bronchus: a case report.

A case of carcinoma of the lung with a metastasis on the tongue is presented. The case is of interest because, although primary carcinomas of the tongue are fairly common accounting for 50 per cent of all oral carcinomas, metastatic tumour represents only one per cent of all malignant tumours of the oral cavity and of these only 0.2 per cent metastasize to the tongue.

High-fidelity patient simulation: validation of performance checklists.

BACKGROUND: Standardized scenarios can be used for performance assessments geared to the level of the learner. The purpose of this study was to validate checklists used for the assessments of medical students' performance using high-fidelity patient simulation. METHODS: Our undergraduate committee designed 10 scenarios based on curriculum objectives. Fifteen faculty members with undergraduate educational experience identified items considered appropriate for medical students' performance level and identified items that, if omitted, would negatively affect grades. Items endorsed by less than 20% of faculty were omitted. For remaining items, weighting was calculated according to faculty responses. Students managed at least one scenario during which their performance was videotaped. Two raters independently completed the checklists for three consecutive sessions to determine inter-rater reliability. Validity was determined using Cronbach's alpha with an alpha>or=0.6 and

Novel scintillation proximity assay for measuring membrane-associated steps of peptidoglycan biosynthesis in Escherichia coli.

We have developed a novel, high-throughput scintillation proximity assay to measure the membrane-associated steps (stages 2 and 3) of peptidoglycan synthesis in Escherichia coli. At least five enzymes are involved in these two stages, all of which are thought to be essential for the survival of the cell. The individual enzymes are difficult to assay since the substrates are lipidic and difficult to isolate in large quantities and analysis is done by paper chromatography. We have assayed all five enzymes in a single mixture by monitoring synthesis of cross-linked peptidoglycan, which is the final product of the pathway. E. coli membranes are incubated with the two sugar precursors, UDP-N-acetyl muramylpentapeptide and UDP-[(3)H]-N-acetylglucosamine. The radiolabel is incorporated into peptidoglycan, which is captured using wheat germ agglutinin-coated scintillation proximity assay beads. The assay monitors the activity of the translocase (MraY), the transferase (MurG), the lipid pyrophosphorylase, and the transglycosylase and transpeptidase activities of the penicillin-binding proteins. Vancomyin, tunicamycin, nisin, moenomycin, bacitracin, and penicillin inhibit the assay, and these inhibitors have been used to validate the assay. The search for new antimicrobial agents that act via the late stages of peptidoglycan biosynthesis can now be performed in high throughput in a microtiter plate.

Production of recombinant human bile salt stimulated lipase and its variant in Pichia pastoris.

hBSSL and its truncated variant hBSSL-C cDNA clones were expressed in Pichia pastoris using two different signal peptides, native signal peptide and invertase signal peptide, respectively, to facilitate secretion of the recombinant proteins into the culture medium. Both recombinant proteins were secreted into the culture medium to a level of 45-50 mg/liter in shake flask cultures. Native signal peptide of hBSSL was recognized in P. pastoris and was cleaved at the same site as in humans. The level of expression of the hBSSL gene was found to be dependent on the number of its copies integrated into the host chromosome. The multicopy transformant clone was found to be very stable. When grown and induced in a fermentor, the level of accumulation of the recombinant hBSSL in the culture medium improved from 50 mg/liter in shake flask cultures to 300 mg/liter. The recombinant hBSSL purified from the culture supernatant was found to be similar to the native hBSSL in its biochemical properties except for the lectin-binding profile.