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Biomedical subjects

Brian Fong

Publications and source records attributed to Brian Fong.

4 recordsLinked to original sources

Effect of preoperative delay on survival in patients with bladder cancer undergoing cystectomy in Quebec: a population based study.

PURPOSE: In Canada there is growing concern that waiting time for cancer surgery has been increasing. We used population based data to estimate the average PD for RC in Quebec and assess whether delayed surgery has a negative impact on long-term survival. MATERIALS AND METHODS: We used the provincial billing database of the maladie du Quebec to identify all patients with bladder cancer 18 years or older who underwent RAMQ from 1990 to 2002. PD was calculated as the time elapsed between the most recent transurethral resection and the date of RC. Patients were categorized according to PD tertiles into 3 groups, namely 1) 20 or less, 2) 21 to 47 and (C) 48 days or greater. Cox proportional hazards models were used to assess the effect of PD on overall survival, while adjusting for patient and provider factors. RESULTS: During the study period 1,592 radical cystectomies were performed. Overall median PD was 33 days (95% CI 30 to 35). Median PD increased from 23 days in 1990 to 50 in 2002. After adjusting for calendar year, and patient and provider variables there were no significant differences in survival among the 3 delay categories. However, patients subject to greater than 12 weeks of delay were at 20% greater risk for dying (95% CI 1.0 to 1.5, p = 0.051). CONCLUSIONS: In line with previous reports PD greater than 12 weeks seems to be associated with a worse long-term prognosis.

Adult↗

Patellar tracking during simulated quadriceps contraction.

The current study compared patella tracking during simulated concentric and eccentric quadriceps contractions in 12 knees from cadavers using a three-dimensional electromagnetic tracking system. The patella shifted (translated) and tilted medially during approximately the initial 22 degrees tibiofemoral flexion. The patella then shifted and tilted laterally for the remaining arc of tibiofemoral flexion (90 degrees). At 90 degrees tibiofemoral flexion, the patella had an orientation of lateral patella shift and lateral patella tilt. Patella shift was significantly more lateral between 40 degrees and 70 degrees tibiofemoral flexion during concentric quadriceps action than during eccentric contraction. Patella tilt was significantly more lateral between 45 degrees and 55 degrees tibiofemoral flexion during concentric quadriceps contraction than during eccentric action. No other significant differences were seen between the quadriceps contraction conditions. The current study supports the hypothesis that patellar instability is most likely a result of various anatomic and physiologic factors causing a failure of the extensor mechanism to deliver the patella into the femoral sulcus and that a patellar dislocation rarely would occur in a normal knee.

Biomechanical Phenomena↗

On the Use of Pattern Fluorescence Photobleaching Recovery with Modulation Detection to Obtain Colloidal Size Distributions.

Fluorescence photobleaching recovery, long a staple tool of complex fluid experimentation, is discussed as a method for size characterization of colloidal particles. Specific comparisons are made to dynamic light scattering, which is often used for sizing particles despite some important limitations. The capabilities of fluorescence photobleaching recovery for size determination are demonstrated for aggregating core-shell silica-polypeptide composite particles suspended in polar organic solvents. Copyright 2001 Academic Press.

Journal Article↗