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.

Ex Input:
Context: We developed an algorithm that prospectively defines when to excise the neurovascular bundles during radical retropubic prostatectomy with the goal of maximizing the performance of nerve sparing procedures while minimizing positive surgical margins.', 'From January 1 to December 31, 2000 a single surgeon performed 272 radical retropubic prostatectomies and 263 were performed from January 1 to December 31, 2001. A single pathologist analyzed all specimens with positive margins. There were no prospectively defined criteria to guide decisions regarding excision of the neurovascular bundles in the 2000 study cohort. Gleason score, percent tumor volume and perineural invasion were independently analyzed in the biopsy specimens according to the site of origin (right versus left side) for the 2001 group only. The ipsilateral neurovascular bundle was excised for Gleason 6 or less tumors when there were 50% or greater tumor volume in the biopsy specimen and perineural invasion, for Gleason 7 tumors when there was 30% or greater tumor volume, or perineural invasion and for Gleason 8 to 10 tumors when there was 10% or greater tumor volume, or perineural invasion.', 'There were no statistically significant differences between the 2000 and 2001 groups in regard to preoperative prostate specific antigen, clinical and pathological stage, biopsy Gleason score and percent tumor volume in the surgical specimen. There was a statistically significant decrease in the incidence of positive margins between the 2000 and 2001 groups (14% versus 8%, p = 0.027). The lower positive margin rate was not achieved because of a tendency to excise more neurovascular bundles since a significantly greater percent of neurovascular bundles was preserved in the 2001 group. The sensitivity, specificity, positive and negative predictive values, and accuracy of our algorithm were 18%, 93%, 28%, 89% and 84%, respectively. In sides of the prostate with extraprostatic extension ipsilateral wide excision of the neurovascular bundle was associated with positive margins in 33% of cases compared with 22% when the neurovascular bundle was preserved (p = 0.42).\Question: Does the New York University nerve sparing algorithm decrease the rate of positive surgical margins following radical retropubic prostatectomy?

Ex Output:
The New York University nerve sparing algorithm prospectively defines when to excise the neurovascular bundle based on Gleason score, perineural invasion and tumor volume in the biopsy specimen. Use of this algorithm decreases positive surgical margin rates, while significantly increasing the preservation of neurovascular bundles.

Ex Input:
Context: Intrathecal adenosine is antinociceptive under conditions of central sensitization, but not in response to acute stimuli in normals. The reasons for this selective circumstance of action remain unclear, but some evidence links adenosine's antinociceptive effects to release of norepinephrine by terminals in the spinal cord. The purpose of this study was to test whether spinal adenosine induces norepinephrine release selectively in settings of hypersensitivity.", 'Rats randomly assigned to spinal nerve ligation, sham operation, or no operation were anesthetized. A microdialysis fiber was implanted in the spinal cord dorsal horn at the L5-L6 level and perfused with artificial cerebrospinal fluid. After washout and a baseline sample period, adenosine at various concentrations was infused through the fiber for 150 min, and samples were collected every 15 min.', "In ligated, but not in sham or normal animals, adenosine perfusion increased norepinephrine in spinal cord microdialysates in a concentration-dependent manner. The effects of adenosine plateaued after 75 min and remained stable until the end of the experiment. Intravenous injection of selective adenosine A1 and A2 receptor antagonists revealed that adenosine's effect on spinal norepinephrine release was A1 receptor mediated.\Question: Does intraspinal adenosine induce spinal cord norepinephrine release in spinal nerve-ligated rats but not in normal or sham controls?

Ex Output:
This is the first study to provide direct evidence that adenosine is able to release norepinephrine in spinal cord dorsal horns in living animals. However, this effect was only seen in animals after spinal nerve ligation. These data are consistent with behavioral studies demonstrating that adenosine's antinociceptive effects in rats after spinal nerve ligation is totally dependent on intact spinal noradrenergic terminals and can be blocked by spinal alpha 2-adrenergic receptor antagonists.

Ex Input:
Context: It has been contended that, during cardiopulmonary bypass at 27 degrees C, pH-stat management decreases cerebral metabolic rate for oxygen (CMRO2) more than alpha-stat management. In contrast, other studies have not found CMRO2 to differ between techniques. Using each animal as its own control, the authors assessed the effect of alpha-stat versus pH-stat management of CMRO2, cerebral blood flow (CBF), and brain oxygen extraction during cardiopulmonary bypass at 27 degrees C.', 'Fourteen New Zealand White rabbits, anesthetized with fentanyl and diazepam, underwent cardiopulmonary bypass at 27 degrees C (membrane oxygenator, centrifugal pump, and bifemoral arterial perfusion). Group 1 animals (n = 7) had alpha-stat management for the initial 65-70 min of bypass, and were then changed to pH-stat management for the remaining 30 min of bypass. Group 2 animals (n = 7) had pH-stat management for the initial 65-70 min of bypass, and were then changed to alpha-stat management for the remaining 30 min. Measurement of CBF (radiolabeled microspheres), CMRO2 (CBF x brain arterial-venous oxygen content difference), brain temperature, systemic hemodynamics, and arterial blood gases were made in each animal under both alpha-stat and pH-stat conditions.', 'CMRO2 did not differ between alpha-stat and pH-stat conditions (1.4 +/- 0.3 ml.100 g-1.min-1; median +/- quartile deviation), and was independent of order of determination. Changes in CBF between alpha-stat and pH-stat conditions were associated with proportional opposite changes in cerebral oxygen extraction. Cerebral blood flow was significantly greater with pH-stat management than with alpha-stat management (37 +/- 5 vs. 30 +/- 3 ml.100 g-1.min-1, respectively). The CBF response to changing PaCO2 was significantly greater when going from alpha-stat to pH-stat conditions (group 1) than in the reverse order (group 2).\Question: Does hypothermic acid-base management affect cerebral metabolic rate for oxygen at 27 degrees C. A study during cardiopulmonary bypass in rabbits?

Ex Output:
During cardiopulmonary bypass at 27 degrees C, hypothermic acid-base management has no measurable effect on CMRO2. CMRO2 was neither extraction limited nor dependent on either PaCO2, CBF, or hemoglobin oxygen affinity differences between alpha-stat and pH-stat management. Cerebral blood flow responses to changing CMRO2 depend on the "starting" conditions, with alpha-stat management appearing to better preserve CBF reactivity than pH-stat management.