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.

Context: A number of risk factors for chronic renal allograft rejection have been identified; in particular the number and severity of acute rejections, hypertension, hyperlipidemia, and insufficient immunosuppression.', 'In a retrospective case control study, all histologically confirmed cases of chronic rejection (n=45) that occurred between 1985 and 1993 among patients transplanted at Huddinge Hospital were compared with twice as many controls. Determinants such as donor age and sex, HLA-mismatch, cold ischemia time, recipient age and sex, body mass index, cause of renal disease, time undergoing dialysis, condition of blood vessels at surgery, time of onset, number of acute rejection episodes during the first 3 months, area under the serum creatinine versus time curve (AUC(Creatinine)), blood pressure, blood lipids, and cyclosporine concentrations at various times after the transplantation were also compared. Additional data were obtained from a questionnaire, concerning 79% of the cases and controls.', 'Cases and controls were similar with regard to most determinants, that is, blood pressure, blood lipids, and average cyclosporine concentrations. The main outstanding risk factor for chronic rejection was the time-averaged creatinine (AUC(Creatinine)) value between day 22 and 3 months after transplantation. The adjusted odds ratio for chronic rejection increased stepwise from 1.1 to 9.2, when AUC(Creatinine) increased from < 150 to >300 micromol/l. The number of acute rejection episodes and number of HLA-mismatches also had a significant effect on the risk of chronic rejection.
Answer: To reduce the risk of developing chronic rejection after renal transplantation acute rejection episodes during the first 3 months should be avoided as much as possible.
Is area under the serum creatinine time-curve a strong predictor of chronic renal allograft rejection?

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

Context: Liver resection is the only curative treatment offering a chance of long-term survival in patients with colorectal liver metastases (CRM). Recent data indicated that liver resection in patients with tumor progression while receiving chemotherapy was associated with poor outcome. The aim of the study was to identify risk factors for poor outcome in patients with pre-operative chemotherapy of CRM.', 'We analyzed 160 patients after liver resection for CRM with preoperative systemic. chemotherapy. Three groups of patients were identified: 44 patients (27.5%) had a tumor response, 20 (12.5%) showed stable disease, and 96 (60%) patients had tumor progression while on chemotherapy. Median follow-up was 2.4 years (range, 6 days-11.1 years). All available clinicopathologic variables possibly associated with outcome were evaluated.', 'Survival was 88%, 53%, and 37% at 1, 3, and 5 years. Noncurative resection, carcinoembryonic antigen levels >200 ng/ml, tumor grading, size of the largest tumor >5 cm, and number of metastases were associated with poor patient outcome. In the multivariate analysis, tumor free margin and tumor grading correlated with the outcome. Tumor progression while on chemotherapy had no influence on the long-term survival.
Answer: Liver resection offers a long-term survival benefit for patients with CRM, even when tumor growth proceeds during pre-operative chemotherapy.

Does nonresponse to pre-operative chemotherapy preclude long-term survival after liver resection in patients with colorectal liver metastases?