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.

Q: Context: Intrathecal magnesium sulfate coinfusion with morphine increases antinociception in normal rats; however, because magnesium also delays the onset of tolerance, it is not clear whether this additional antinociception is a result of potentiated analgesia or tolerance abatement. We examined the antinociceptive interaction of intrathecal (IT) bolus magnesium sulfate and morphine in morphine naive rats and those with mechanical allodynia after a surgical incision. After intrathecal catheter implantation, rats were given preinjections of magnesium or saline, followed by injections of morphine or saline. In morphine naive rats, IT bolus magnesium sulfate 281 and 375 microg followed by IT morphine 0.25 or 0.5 nmol enhanced peak antinociception and area under the response versus time curve two-to-three-fold in the tail-flick test as compared with morphine alone. Likewise, in rats with incisional pain, IT bolus magnesium sulfate 188 and 375 microg followed by morphine 0.5 nmol reduced mechanical allodynia, whereas morphine 0.5 nmol alone did not. This study suggests that IT magnesium sulfate potentiates morphine at a spinal site of action.\Question: Does magnesium sulfate potentiate morphine antinociception at the spinal level?

A: Magnesium sulfate potentiates morphine analgesia when coadministered intrathecally in normal rats, and in an animal model of mechanical allodynia after a surgical incision. These results suggest that intrathecal administration of magnesium sulfate may be a useful adjunct to spinal morphine analgesia.
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Q: 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?

A: 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.
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Q: Context: A prominent feature of many human cancers is oncogene-driven activation of the DNA damage response (DDR) during early tumorigenesis. It has been shown previously that noninvasive imaging of the phosphorylated histone H2A variant H2AX, H2AX, a DNA damage signaling protein, is possible using (111)In-labeled anti-H2AX antibody conjugated to the cell-penetrating peptide transactivator of transcription (TAT). The purpose of this study was to investigate whether (111)In-anti-H2AX-TAT detects the DDR during mammary oncogenesis in BALB-neuT mice.', 'Mammary fat pads from BALB-neuT and wild-type mice (age, 40-106 d) were immunostained for H2AX. (111)In-anti-H2AX-TAT or a control probe was administered intravenously to BALB-neuT mice. SPECT was performed weekly and compared with tumor detection using palpation and dynamic contrast-enhanced MR imaging.', 'H2AX expression was elevated in hyperplastic lesions in the mammary fat pads of BALB-neuT mice aged 76-106 d, compared with normal fat pads from younger mice and carcinomas from older mice (13.5 1.2 H2AX foci/cell vs. 5.2 1.5 [P < 0.05] and 3.4 1.1 [P < 0.001], respectively). Serial SPECT imaging revealed a 2.5-fold increase in (111)In-anti-H2AX-TAT accumulation in the mammary fat pads of mice aged 76-106 d, compared with control probe (P = 0.01). The median time to detection of neoplastic lesions by (111)In-anti-H2AX-TAT (defined as >5% injected dose per gram of tissue) was 96 d, compared with 120 and 131 d for dynamic contrast-enhanced MR imaging and palpation, respectively (P < 0.001).\Question: Does imaging DNA damage allow detection of preneoplasia in the BALB-neuT model of breast cancer?

A:
DDR imaging using (111)In-anti-H2AX-TAT identified mammary tumors significantly earlier than MR imaging. Imaging the DDR holds promise for the detection of preneoplasia and as a technique for screening cancer-prone individuals.
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