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.

Input: Consider 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.

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

Input: Consider Input: Context: Histologic evidence of the comparative neurotoxicity of lidocaine, mepivacaine, and prilocaine is incomplete. We compared the intrathecal neurotoxicity in rats among these 3 drugs based on morphologic and neurofunctional findings.', 'Rats (n=169) randomly received 0.12 microL/g of 0%, 2%, 5%, 7.5%, 10%, or 20% lidocaine, mepivacaine, or prilocaine or 25% glucose dissolved in distilled water via a chronically implanted intrathecal catheter. The effect of the agents on neurofunction was evaluated by movement of the hind limb (behavior test) and by sensory threshold (paw-stimulation test). The L1 spinal cord, the posterior and anterior roots, and the cauda equina were removed en bloc 5 days later and examined by light and electron microscopy.', 'A significant decrease in sensory threshold or irreversible hind-limb limitation was observed only in rats receiving 20% lidocaine. Morphologic abnormalities characterized by axonal degeneration were observed in rats receiving > or =7.5% lidocaine, 20% mepivacaine, and 20% prilocaine, at the posterior white matter and the proximal portion of the posterior root just at the entrance into the spinal cord. The incidence of lesions was significantly higher in rats receiving lidocaine than mepivacaine and prilocaine.
Answer: It is suggested that intrathecal mepivacaine and prilocaine are less neurotoxic than highly concentrated lidocaine in a rat intrathecal model.

Output: Are intrathecal mepivacaine and prilocaine less neurotoxic than lidocaine in a rat intrathecal model?

Input: Consider Input: Context: Plague is a severe, highly communicable bacterial disease caused by Yersinia pestis. It is still endemic in more than 20 countries worldwide. Although known as a devastating disease for centuries, laboratory confirmation of clinical suspected cases is still problematic. No standardized and internationally approved test system is commercially available. The aim of this study was the introduction and evaluation of a combination of immunomagnetic separation and flow cytometry for the serodiagnosis of human plague.', 'Paramagnetic polystyrene beads were coated with purified F1 capsular antigen (F1 CA) and reacted with sera from plague patients, from 26 laboratory personnel vaccinated against plague and from 102 healthy blood donors (HBD). After incubation with fluorescein isothiocyanate-conjugated anti-human rabbit IgG, particle-associated fluorescence was detected by flow cytometry.', 'Anti-F1 CA antibodies could be demonstrated in all patients with bacteriologically confirmed plague and in 22 sera (84.6%) from vaccinees. Only one serum in the HBD group showed a weakly positive reaction. The total assay time was less than 2 h.
Answer: Compared with a recently published combination of an anti-F1 CA enzyme-linked immunosorbent assay (ELISA) and immunoblot, the new assay showed the same sensitivity as the ELISA and almost the same specificity (99.0 versus 100%) as the immunoblot. Allowing a rapid, reliable, and quantitative analysis, immunomagnetic separation combined with flow cytometry might replace both conventional immunoassays.
Output: Do serodiagnosis of human plague by a combination of immunomagnetic separation and flow cytometry?