Canadian Association of University Surgeons annual symposium: Continuity of care: Toronto, Ontario, Sep. 6, 2007.

This 2007 symposium of the Canadian Association of University Surgeons brought together surgeons from a number of jurisdictions to discuss the challenges and opportunities that reduced physician work hours will bring to the care of the surgical patient. Dr. Brian Taylor, president of the association, underscored the need to find a balance between the benefits of diminished workloads/work hours and the loss of continuity of care. He opined that Canada needs to learn from our European colleagues' experience. Dr. Per-Olof Nyström, professor of surgery, presented the modern Swedish model of surgical care, which had to be developed as a consequence of the European Union's legal restrictions on the amount of time an individual surgeon may work. Sweden employs a team-based shared-care model driven by the individual surgeon's expertise rather than the "village factory" model of the multiskilled, multitasking approach of surgical care more prevalent in Canada. Dr. Chris de Gara, secretary treasurer of the association, presented the evidence base for (and against) work-hour restrictions and how well-designed systems can ensure effective continuity of care. Dr. Stewart Hamilton illustrated how one such system for the delivery of the emergency general surgical services has evolved at the University of Alberta Hospital, which demonstrated its effectiveness in providing quality surgical continuity of care. Dr. Debrah Wirtzfeld underscored the importance of trainee lifestyle and how modern Web-based technologies can ensure reduced errors with the implementation of a "sign-out" system.

Electron donor-driven bacterial and archaeal community patterns along forest ring edges in Ontario, Canada.

Forest rings are 50-1600 m diameter circular structures found in boreal forests around the globe. They are believed to be chemically reducing chimney features, having an accumulation of reduced species in the middle of the ring and oxidation processes occurring at the ring's edges. It has been suggested that microorganisms could be responsible for charge transfer from the inside to the outside of the ring. To explore this, we focused on the changes in bacterial and archaeal communities in the ring edges of two forest rings, the 'Bean' and the 'Thorn North' ring, in proximity to each other in Ontario, Canada. The drier samples from the methane-sourced Bean ring were characterized by the abundance of bacteria from the classes Deltaproteobacteria and Gemmatimonadetes. Geobacter spp. and methanotrophs, such as Candidatus Methylomirabilis and Methylobacter, were highly abundant in these samples. The Thorn North ring, centred on an H2 S accumulation in groundwater, had wetter samples and its communities were dominated by the classes Alphaproteobacteria and Anaerolineae. This ring's microbial communities showed an overall higher microbial diversity supported by higher available free energy. For both rings, the species diversity was highest near the borders of the 20-30 m broad ring edges.

Contaminated operating room boots: the potential for infection.

BACKGROUND: Dirty operating room boots, often contaminated with blood and other infected material, are not only a source of discontent among surgeons and other surgical personnel, but they also pose a potential risk of transmission of viral or bacterial diseases to the wearer and cleaner of the boots. METHOD: Operating room boots were examined for the presence of blood by visual inspection; the presence or absence of blood was confirmed by a specific biochemical test. Bacterial isolation and quantification from boots were performed with conventional methodology. RESULTS: In this study, a spot check revealed that 44% of all operating room boots tested were contaminated with blood and that the majority were contaminated with bacteria. Sixty-three percent of surgeons using the facility had blood-contaminated boots, and a significant number of boots belonging to other surgical personnel were also contaminated with blood and bacteria normally associated with skin microbiota or the environment. Comfort shoes with perforations on their upper surface and plastic boots commonly found in operating rooms were most heavily contaminated, whereas Wellington boots and clogs had less contamination. CONCLUSION: The present practice of manual cleaning of boots is unsatisfactory, and it is recommended that boots be washed in automatic washing machines.

Cigarette smoking and bladder cancer: an epidemiological inquiry in West Yorkshire.

Results are given of a case-control study on bladder cancer in West Yorkshire. The aim of the study was to assess what risks exist for cigarette smoking in the United Kingdom and also to investigate if a dose response effect was present. The study shows for the first time in the United Kingdom a positive but weak relationship between cigarette smoking and bladder cancer. Close examination of the data with regard to this effect shows that a complex set of relationships result when the quantity smoked and the period of smoking are taken into account. A dose response effect is weakly demonstrated when a medium quantity of cigarettes are smoked but it is not present at all in those who smoked most cigarettes for the longest periods. No risk appears to exist for those who have smoked only filter cigarettes. The results are contrasted with similar studies and the significance of the observations are discussed.

Telomerase activity in malignant and benign bladder conditions.

This study investigated whether the enzyme telomerase is active in bladder tumours, whether there is any correlation between activity and grade, and whether the enzyme is expressed in non-malignant conditions. Fifty-two patients undergoing cystoscopy or TURBT at a district general hospital were included, 25 with current bladder tumours, 13 with previous but no current tumours, and 14 with non-malignant pathology. Specimens were analysed by the telomerase repeat amplification protocol (TRAP assay), a highly-sensitive polymerase chain reaction (PCR)-based assay, and a commercially-available ELISA kit. Telomerase activity was detected in 80% of bladder tumours, more frequently in moderate- or poorly-differentiated (93%) than well-differentiated (56%) tumours. Activity was not uniform across individual tumours. Telomerase was also frequently (61%) detected in inflammatory lesions found in patients being followed up for previous bladder tumours, and in two (14%) patients with benign pathologies. In conclusion, telomerase was frequently but not uniformly detected in bladder tumours; its presence was not specific to malignancy. There is a possible correlation between tumour grade and telomerase activity.

A population-based study of tumor-node relationship, resection margins, and surgeon volume on gastric cancer survival.

BACKGROUND: Gastric cancer surgery literature is conflicting. Two European level I randomized controlled trials refute Asian lesser level evidence promoting more radical resections. Population-based study evidence is undefined. METHODS: Using this study design we examined the overall survival, the tumor-node relationship, margins, and surgeon volume on gastric cancer survival in a Canadian province. RESULTS: Between 1991 and 1997, 577 (71 +/- 13 years 60% male) gastric adenocarcinomas were diagnosed in Northern Alberta (population 1.7 million). Respectively, median survival in months for stage I (n = 67) was 77, stage II (n = 55) 75, stage III (n = 155) 12, stage IV (n = 235) 3, and 65 unstaged (n = 65) 4. Five-year survival for T1N0 (n = 28) was 68% versus T1N1 (n = 7) 71% (P = 0.80); for T2N0 (n = 29) 58% versus T2N1 (n = 19) 58% versus T2N3 (n = 7) 29% (P = 0.08); for T3N0 (n = 33) 57%, versus T3N1 (n = 98) 9% versus T3N2 (n = 47) 0% versus T3N3 (n = 8) 0% (P < 0.0001). Median gastrectomy survival (months) in stage III was 15 months margin negative versus 8 months margin positive versus 6 bypass and 5 for no surgery (P = 0.0004). In stage IV it was margin positive 8 versus margin negative 6 (nonsignificant), bypass 3 versus no surgery 2. Five-year survival for surgeons doing fewer than 20 gastrectomies (n = 196 patients) was 29% (median 1.4 years) versus 35% (median 2.3 years; n = 72 patients) for surgeons doing 20 or more (n = 4; P = 0.325). CONCLUSIONS: From these population data we conclude that (1) few patients present with "curable" gastric cancer, (2) node negative or small gastric cancer survival is not influenced by nodal stage, (3) positive margin resection survival is better than bypass or no surgery in stage IV but not stage III disease, and (4) surgeon volume does not appear to influence patient survival.

Metabolic effects of prostatectomy.

Transurethral resection syndrome (TURS), complicating transurethral resection of the prostate (TURP) has been ascribed to hyponatraemia but reports have indicated that hyperammonaemia following metabolism of glycine can be the main cause. Prospective data has been collected on 96 prostatectomy patients (82 TURP and 14 retropubic). The retropubic group showed no significant postoperative change in the serum sodium or plasma ammonia. Of the TURP group, no TURS occurred although hyponatraemia was noted in 32 patients. The weight of prostate resected, the volume of glycine used, the time taken and the plasma ammonia levels were not significantly different in the normonatraemic or hyponatraemic groups. In severely hyponatraemic patients (13 out of 32 with a 10 mmol/l, or greater, decrease in serum sodium) there was a significant rise (P less than 0.05) in plasma ammonia, 1 or 4 h post TURP, which had decreased by 24 h. There was a highly significant increase in serum glycine level in the hyponatraemic compared with the normonatraemic group (P less than 0.001). There was no correlation between serum glycine and plasma ammonia levels in the normonatraemic or hyponatraemic group. There were nine patients with post TURP plasma ammonia levels greater than 100 mumol/l (mean 254) who experienced no mental confusion: six of these patients were hyponatraemic. The weight of prostate resected (mean 26 g), volume of glycine used (mean 181) and operation time (mean 39 min) were all relatively low. Subsequently, TURS has occurred in a patient, with severe hyponatraemia and hyperglycinaemia but no hyperammonaemia. This study shows that hyperammonaemia does not always correlate with hyponatraemia or hyperglycinaemia, and high plasma ammonia levels can occur in the absence of TURS.

Lymphovascular invasion is associated with poor survival in gastric cancer: an application of gene-expression and tissue array techniques.

OBJECTIVES: To examine a population-based cohort for the association between clinicopathologic predictors of survival and immunohistochemical markers (IHC), and to assess changes in gene expression that are associated with lymphovascular invasion (LVI). SUMMARY BACKGROUND DATA: LVI has been associated with poor survival and aggressive tumor behavior. The molecular changes responsible for the behavior of gastric cancer have yet to be determined. Characterization of IHC markers and gene expression profiles may identify molecular alterations governing tumor behavior. METHODS: : Clinicopathologic and survival data of 114 patients were reviewed. Archival specimens were used to construct a multitumor tissue array that was subjected to IHC of selected protein targets. Correlation of IHC with tumor thickness (T status), LVI and prognosis was studied. Microarray analysis of fresh gastric cancer tissue was conducted to examine the gene expression profile with respect to LVI. RESULTS: In a multivariate analysis, nodal status (N), metastasis (M), and LVI were independent predictors of survival. LVI was associated with a 5-year survival of 13.9% versus 55.9% in patients in whom it was absent. LVI correlated with advancing T status (P = 0.001) and N status (P < 0.001). IHC staining of cyclooxygenase-2 (COX-2) correlated with T status, tumor grade, lymph node positivity, and IHC staining of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Microarray analyses suggested differential expression of oligophrenin-1 (OPHN1) and ribophorin-II (RPNII) with respect to LVI. CONCLUSION: LVI was an independent predictor of survival in gastric cancer. Expression of COX-2 may facilitate tumor invasion through MMP-2 and MMP-9 activation. OPHN1 and RPN II appeared to be differentially expressed in gastric cancers exhibiting LVI. The reported function of OPHN1 and RPN II makes these gene products promising candidates for future studies involving LVI in gastric cancer.

Gastric adenocarcinoma: review and considerations for future directions.

OBJECTIVE: This update reviews the epidemiology and surgical management, and the controversies of gastric adenocarcinoma. We provide the relevance of outcome data to surgical decision-making and discuss the application of gene-expression analysis to clinical practice. SUMMARY BACKGROUND DATA: Gastric cancer mortality rates have remained relatively unchanged over the past 30 years, and gastric cancer continues to be one of the leading causes of cancer-related death. Well-conducted studies have stimulated changes to surgical decision-making and technique. Microarray studies linked to predictive outcome models are poised to advance our understanding of the biologic behavior of gastric cancer and improve surgical management and outcome. METHODS: We performed a review of the English gastric adenocarcinoma medical literature (1980-2003). This review included epidemiology, pathology and staging, surgical management, issues and controversies in management, prognostic variables, and the application of outcome models to gastric cancer. The results of DNA microarray analysis in various cancers and its predictive abilities in gastric cancer are considered. RESULTS: Prognostic studies have provided valuable data to better the understanding of gastric cancer. These studies have contributed to improved surgical technique, more accurate pathologic characterization, and the identification of clinically useful prognostic markers. The application of microarray analysis linked to predictive models will provide a molecular understanding of the biology driving gastric cancer. CONCLUSIONS: Predictive models generate important information allowing a logical evolution in the surgical and pathologic understanding and therapy for gastric cancer. However, a greater understanding of the molecular changes associated with gastric cancer is needed to guide surgical and medical therapy.

Role of P-glycoprotein in chemoresistant superficial bladder tumours.

OBJECTIVE: The drug resistance at cellular level is mediated by P-glycoprotein (P-G), which is variably expressed in bladder tumours. The effect of intravesical chemotherapy on P-G status was studied in chemoresistant and recurrent superficial tumours which progressed to metastasis or needed further treatment. METHODS: Archival histological materials of 14 patients who received intravesical epirubicin for recurrent superficial transitional cell carcinoma of the bladder were studied for the presence of P-G using monoclonal antibody JSB-1. RESULTS: Four patients showed complete absence of P-G following chemotherapy although only 2 patients were recurrence-free. In 4 patients with extravesical metastasis, there was no evidence of increased P-G expression. CONCLUSIONS: The P-glycoprotein expression is not related to histological grading or clinical progression of bladder tumours.

Does the use of stained maggots present a risk of bladder cancer to coarse fishermen?

A case-control study in West Yorkshire has been used to investigate possible risks of bladder cancer amongst those fishermen who used azo-based dyestuffs to stain maggots or who purchased ready coloured maggots. No risks have been found, although the confidence limits of the estimates are wide. These data refer to exposures over ten years ago and it is possible recent changes in fishing practice, if they have occurred, are not yet assessable due to the long mean latency seen in bladder cancer when exposure to carcinogens is not great. This paper does not suggest the general use of these substances is without hazard, merely that no risk is associated with the study group and that the chemicals under study are not a major cause of bladder cancer.