TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: To determine whether the number and location of positive surgical margins (PSMs) in radical prostatectomy (RP) surgical specimens affect biochemical recurrence (BCR) rates.', 'The locations of PSMs were recorded for 1308 consecutive men who underwent RP between October 2000 and December 2006. BCR was defined as three consecutive prostate-specific antigen (PSA) level rises with the peak level >or=0.15 ng/mL. Multivariate regression analyses were used to identify preoperative predictors of PSMs and BCR. The estimated 5-year risk of BCR was calculated using the Kaplan-Meier method.', 'In all, 128 (9.8%) men had one or more PSMs. The mean body mass index, mean preoperative serum PSA level, the distributions of clinical stage and biopsy Gleason scores, and the presence or absence of biopsy perineural invasion were significantly different between men with or with no PSMs. In multivariate analysis, baseline serum PSA level, Gleason score and perineural invasion were independent preoperative predictors of PSMs. The 5-year actuarial BCR rates were dependent on the site of the PSM (P = 0.035) and not the number of PSMs (P = 0.18). The rank order of estimated 5-year BCR rates according to the site of PSMs were base > anterior > posterolateral > apex approximately posterior.\Question: Does site of positive surgical margins influence biochemical recurrence after radical prostatectomy?

SOLUTION: About half of the men with PSMs in the RP surgical specimen in our prospective series did not develop BCR. The risk of BCR was dependent on the site and not the number of PSMs. Adjuvant therapy should be considered in cases with anterior and basilar PSMs due to the very high risk of BCR.

PROBLEM: Context: Different apoptosis pathways activate caspase-3. In a study involving 27 patients with traumatic brain injury (TBI), higher caspase-3 levels were found in contusion brain tissue resected from non-survivors than from survivors. The objective of this study was to determine whether there is an association in TBI patients between serum caspase-3 levels (thus using an easier, quicker, less expensive and less invasive procedure) and mortality, in a larger series of patients.', 'We carried out a prospective, observational and multicenter study in six Spanish Hospital Intensive Care Units including 112 patients with severe TBI. All had Glasgow Coma Scale (GCS) scores lower than 9. Patients with an Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Blood samples were collected on day 1 of TBI to measure serum caspas-3 levels. The endpoint was 30-day mortality.', 'We found that non-surviving patients (n = 31) showed higher (p = 0.003) serum caspase-3 levels compared to survivors (n = 81). Kaplan-Meier survival analysis showed a higher risk of death in TBI patients with serum caspase-3 levels >0.20 ng/mL than in patients with lower concentrations (Hazard Ratio = 3.15; 95% CI = 1.40 to 7.08; P < 0.001). Multiple logistic regression analysis showed that serum caspase-3 levels > 0.20 ng/mL were associated with mortality at 30 days in TBI patients controlling for Marshall CT classification, age and GCS (Odds ratio = 7.99; 95% CI = 2.116 to 36.744; P = 0.001).\Question: Are serum caspase-3 levels and mortality associated in patients with severe traumatic brain injury?

SOLUTION: The association between serum caspase-3 levels and mortality in TBI patients was the major novel finding of our study.

PROBLEM: Context: The combination of hepatic ischemia and cholestasis, both identified as risk factors for oxidative stress, potentially enhances postischemic reperfusion (I/R) injury. Preoperative biliary drainage relieves oxidative stress and therefore seems a worthwhile intervention in cholestatic patients undergoing major liver resection.', 'To assess the effect of biliary decompression on I/R injury in a reversible bile duct ligation (BDL) model in the rat.', 'Male Wistar rats were randomized into 3 groups. The first group underwent 30 minutes of partial liver ischemia after 7 days BDL; the second group underwent internal drainage (ID) after 7 days BDL and after 5 days, were subjected to partial liver ischemia. The last group (control animals) underwent 2 sham laparotomies and subsequent ischemia. Inflammatory response (interleukin [IL]-6, IL-10, GRO/KC, and interferon-gamma), hepatic damage and oxidative stress were assessed during 24 hours of reperfusion.', 'Cholestatic rats, as compared with the ID and control groups, showed significantly increased I/R injury as determined by transaminase release, histologic injury score and neutrophil infiltration. Plasma IL-6, IL-10, and GRO/KC (a CXC chemokine) were significantly increased in the BDL group (P < .05 vs control and ID). Moreover, the hepatic antioxidant capacity was strongly decreased in the BDL group (P < .01 vs control and ID). No significant differences for most parameters were seen in the ID group as compared to the control group.\Question: Does biliary drainage attenuate postischemic reperfusion injury in the cholestatic rat liver?

SOLUTION:
The cholestatic rat is more susceptible to postischemic liver injury and these injurious effects were significantly attenuated by biliary decompression.