Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Ex Input:
Context: Early metastasis in node-negative breast cancer indicates that breast cancer cells obviously can bypass the lymph nodes and disseminate directly hematogenous to distant organs. For this purpose, we evaluated the prognostic value of blood-borne, HER2-positive circulating tumor cells (CTC) in the peripheral blood from 42 breast cancer patients with a median follow-up of 95 months.', 'Cells were isolated by the patented combined buoyant density gradient and immunomagnetic separation procedure and analyzed by immunocytochemistry.', 'We detected one to eight CTCs in the peripheral blood of 17 of 35 patients (48.6%) presenting no overt metastasis. As a positive control, 7 of 7 (100%) patients with metastatic disease presented positive. Healthy persons and patients (n = 32) operated for nonmalignant diseases presented negative for CTCs. The presence and frequency of HER2-positive CTCs correlated with a significantly decreased disease-free survival (P < 0.005) and overall survival (P < 0.05). Interestingly, in 12 patients with HER2-positive CTCs, the primary tumor was negative for HER2 as assessed by immunohistochemical score and fluorescence in situ hybridization.
Answer: This study provides some evidence of a prognostic effect of HER2-positive CTCs in stage I to III breast cancer. Future studies have to determine the outcome of patients treated with HER2-targeting therapies with respect to HER2-positive CTC levels because it is not unlikely that high levels of HER2-positive CTCs reflect the activity of the tumor and may predict response to trastuzumab.

Ex Output:
Do hER2-positive circulating tumor cells indicate poor clinical outcome in stage I to III breast cancer patients?

Ex Input:
Context: Preconditioning neurons with noninjurious hypoxia (hypoxic preconditioning, HPC) or the anesthetic isoflurane (APC) induces tolerance of severe ischemic stress. The mechanisms of both types of preconditioning in the hippocampus require moderate increases in intracellular Ca and activation of protein kinase signaling. The authors hypothesized that the expression of signal transduction genes would be similar after APC and HPC.', 'Hippocampal slice cultures prepared from 9-day-old rats were preconditioned with hypoxia (5 min of 95% nitrogen/5% carbon dioxide) or 1% isoflurane in air/5% carbon dioxide for 1 h. A day later, cultures were subjected to 10 min oxygen and glucose deprivation (simulated ischemia). Intracellular Ca, measured in CA1 neurons at the completion of preconditioning, and cell death in CA1, CA3, and dentate regions was assessed 48 h after simulated ischemia. Message RNA encoding 119 signal transduction genes was quantified with rat complimentary DNA microarrays from pre-oxygen-glucose deprivation samples.', 'Both APC and HPC increased intracellular Ca approximately 50 nm and decreased CA1, CA3, and dentate neuron death by about 50% after simulated ischemia. Many signaling genes were increased after preconditioning, with hypoxia increasing more apoptosis/survival genes (8 of 10) than isoflurane (0 of 10). In contrast, isoflurane increased more cell cycle/development/growth genes than did hypoxia (8 of 14 genes, vs. 1 of 14).
Answer: Despite sharing similar upstream signaling and neuroprotective outcomes, the genomic response to APC and HPC is different. Increased expression of antiapoptosis genes after HPC and cell development genes after APC has implications both for neuroprotection and long-term effects of anesthetics.

Ex Output:
Does expression of signal transduction genes differ after hypoxic or isoflurane preconditioning of rat hippocampal slice cultures?

Ex Input:
Context: Bariatric surgery is associated with cognitive benefits, but the nature of such gains may be variable across demographically and clinically diverse persons. Older adults achieve less weight loss and resolution of fewer medical co-morbidities after surgery compared to younger patients and are also at heightened risk for nutritional deficiencies. However, no study has examined the influence of age on cognitive improvements after bariatric surgery. The objective of this study was to determine the effects of age on cognitive function postbariatric surgery.', 'A total of 95 participants enrolled in the Longitudinal Assessment for Bariatric Surgery completed a computerized cognitive test battery before bariatric surgery and at 12-weeks and 12-months postoperatively.', 'Baseline cognitive impairments were common. Significant improvements were found in attention/executive function and memory abilities 12-weeks and 12-months after surgery. Age was not associated with baseline cognitive test performance. Separate multivariable regression analyses controlling for baseline attention/executive function and memory also showed that age was not a significant predictor of 12-week or 12-month performances in these domains (P>.05 for all).
Answer: The present study provides preliminary evidence suggesting that older age does not preclude postbariatric surgery cognitive benefits. Prospective studies in more age diverse samples (i.e., up to 70 yr) are needed to determine whether bariatric surgery can reduce risk of age-related neurologic conditions like Alzheimer's disease and stroke.

Ex Output:
Does older age limit postbariatric surgery cognitive benefits : a preliminary investigation?