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: To study the prevalence and age dependency of senile plaques (SP) and neurofibrillary tangles (NFT), the brain changes characteristic of Alzheimer disease (AD), and their association with apolipoprotein E (APOE) genotypes in a community-dwelling normal population.', 'This neuropathological study used both silver staining and A beta immunohistochemistry in brain tissue microarrays, including SP coverage and NFT counts from frontal cortex and hippocampus, and APOE genotyping, and was performed on a consecutive prospective series of 603 subjects (aged between 0 and 97 years) of an unselected population living outside of institutions. Cases were subjected to autopsy following sudden or unexpected out-of-hospital death, covering 22.1% of the mortality of Tampere, Finland and its surroundings. None died of AD, although 22 (3.7%) were demented and 10 (1.7%) had memory problems.', 'Of the series, 30.8% had SP, and 42.1% had NFT; these occurred more commonly among females and showed a strong relationship with age. Both changes had already appeared at around 30 years of age, reaching an occurrence of almost 100% in the oldest. SP were more frequent in APOE epsilon 4-carriers compared with noncarriers in every age group except the oldest (>90 years). The difference was most evident during the ages 50 to 59 years, where 40.7% of epsilon 4-carriers had SP, compared with 8.2% in noncarriers (odds ratio, 8.39; 95% confidence interval, 2.55-27.62). The difference in NFT prevalence between APOE genotypes was not statistically significant in any age group.
Answer: The brain changes associated with AD may already begin developing early in middle age, especially among APOE epsilon 4 carriers.

Ex Output:
Does apolipoprotein E-dependent accumulation of Alzheimer disease-related lesions begin in middle age?


Ex Input:
Context: The ability to achieve significant donor engraftment without fully myeloablative conditioning has revolutionized allogeneic stem cell transplantation. These nonmyeloablative approaches may allow extension of this potentially curative modality to an increasing number of patients including those with non-malignant diseases. Although a number of regimens have been explored, the optimal means of conditioning has not been determined.', 'We previously demonstrated that rapamycin (RAPA) has the ability to promote T-cell tolerance even in the presence of costimulation. In the current study, we examine the ability of rapamycin or the calcineurin inhibitor cyclosporine A (CSA) to promote chimerism in a murine haploidentical bone marrow transplantation model. Mice were conditioned with 300 cGy and received either RAPA at 3 mg/kg/day IP, CSA at 20 mg/kg/day IP, or no immunosuppression starting on the day before the transplant and continued for 4 weeks.', 'There was no apparent toxicity, and animals maintained normal blood counts throughout. More importantly, long-term macrochimerism was observed only in the RAPA-treated group.
Answer: These results establish a simple, nontoxic, irradiation-based regimen that facilitates engraftment without ablation. This strategy may prove useful in nonmalignant disorders such as hemoglobinopathies in which moderate levels of donor chimerism could prove curative.

Ex Output:
Does low-dose radiation plus rapamycin promote long-term bone marrow chimerism?


Ex Input:
Context: Helicobacter pylori infection is now accepted as the most common cause of chronic active gastritis and peptic ulcer disease. The etiologies of many infectious diseases have been attributed to specific or clonal strains of bacterial pathogens. Polymerase chain reaction (PCR) amplification of DNA between repetitive DNA sequences, REP elements (REP-PCR), has been utilized to generate DNA fingerprints to examine similarity among strains within a bacterial species.', 'Genomic DNA from H. pylori isolates obtained from 70 individuals (39 duodenal ulcers and 31 simple gastritis) was PCR-amplified using consensus probes to repetitive DNA elements. The H. pylori DNA fingerprints were analyzed for similarity and correlated with disease presentation using the NTSYS-pc computer program.', 'Each H. pylori strain had a distinct DNA fingerprint except for two pairs. Single-colony DNA fingerprints of H. pylori from the same patient were identical, suggesting that each patient harbors a single strain. Computer-assisted cluster analysis of the REP-PCR DNA fingerprints showed two large clusters of isolates, one associated with simple gastritis and the other with duodenal ulcer disease.
Answer: Cluster analysis of REP-PCR DNA fingerprints of H. pylori strains suggests that duodenal ulcer isolates, as a group, are more similar to one another and different from gastritis isolates. These results suggest that disease-specific strains may exist.

Ex Output:

Does cluster analysis of Helicobacter pylori genomic DNA fingerprints suggest gastroduodenal disease-specific associations?