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.

Example Input: Context: Pandemic strains of HIV-1 (group M) encode a total of nine structural (gag, pol, env), regulatory (rev, tat) and accessory (vif, vpr, vpu, nef) genes. However, some subtype A and C viruses exhibit an unusual gene arrangement in which the first exon of rev (rev1) and the vpu gene are placed in the same open reading frame. Although this rev1-vpu gene fusion is present in a considerable fraction of HIV-1 strains, its functional significance is unknown.', 'Examining infectious molecular clones (IMCs) of HIV-1 that encode the rev1-vpu polymorphism, we show that a fusion protein is expressed in infected cells. Due to the splicing pattern of viral mRNA, however, these same IMCs also express a regular Vpu protein, which is produced at much higher levels. To investigate the function of the fusion gene, we characterized isogenic IMC pairs differing only in their ability to express a Rev1-Vpu protein. Analysis in transfected HEK293T and infected CD4+ T cells showed that all of these viruses were equally active in known Vpu functions, such as down-modulation of CD4 or counteraction of tetherin. Furthermore, the polymorphism did not affect Vpu-mediated inhibition of NF-B activation or Rev-dependent nuclear export of incompletely spliced viral mRNAs. There was also no evidence for enhanced replication of Rev1-Vpu expressing viruses in primary PBMCs or ex vivo infected human lymphoid tissues. Finally, the frequency of HIV-1 quasispecies members that encoded a rev1-vpu fusion gene did not change in HIV-1 infected individuals over time.
Answer: Expression of a rev1-vpu fusion gene does not affect regular Rev and Vpu functions or alter HIV-1 replication in primary target cells. Since there is no evidence for increased replication fitness of rev1-vpu encoding viruses, this polymorphism likely emerged in the context of other mutations within and/or outside the rev1-vpu intergenic region, and may have a neutral phenotype.
Example Output: Does a Naturally Occurring rev1-vpu Fusion Gene Confer a Fitness Advantage to HIV-1?

Example Input: Context: Gastric lipase is an important enzyme for dietary triglyceride digestion in normal subjects. Its regulation is unknown, as is the relation between the quantity and activity of the enzyme.', 'In a dose-response study we investigated the effect of low doses of pentagastrin (less than 1000 ng/kg/h) on the output of gastric lipase measured by a kinetic assay and an enzyme-linked immunosorbent assay (ELISA).', 'In five healthy volunteers stepwise intravenous pentagastrin infusions of 0, 50, 100, 500, and 1000 ng/kg/h resulted in a stepwise increase in the lipase output, as measured with ELISA. However, the lipolytic activity, measured with a kinetic assay, decreased as the pH of the gastric contents decreased.
Answer: We conclude that secretion of the gastric lipase is stimulated by pentagastrin, but the simultaneous secretion of acid counteracts the lipolytic activity of the enzyme when food is not present.
Example Output: Do low doses of pentagastrin stimulate gastric lipase secretion in man?

Example Input: Context: Tissue-plasminogen activator (tPA) demonstrated beneficial effects on peritoneal adhesion formation; however, its short half-life limits its continual fibrinolytic effect. Therefore, we delivered adenovirus encoding tPA to prevent adhesions.', 'Rats were subjected to peritoneal injury and assigned to two protocols. In de novo adhesion protocol, adenovirus encoding human tPA gene (Ad-htPA) was instilled after peritoneal injury in group 1 (n = 22), whereas group 2 received phosphate-buffered saline (PBS) (n = 24). In recurrent adhesion protocol, group 1 (n = 15) received the same Ad-htPA dose after adhesiolysis and group 2 (n = 13) received PBS. Adhesion severity was scored 1 week after ad-htPA instillation. Adhesions were analyzed for htPA mRNA by reverse transcription-polymerase chain reaction and levels of htPA, and fibrinolytic inhibitors PAI-1, TIMP-1, and TGF-beta1 were measured using enzyme-linked immunosorbent assay.', 'htPA mRNA and protein were only expressed in adhesions from treated groups. A reduction in adhesion scores (P < .01) and in fibrinolytic inhibitors (P < .001) occurred in the treatment groups. Also, negative correlation was found (r = -.69, P < .01) between adhesion scores and htPA protein, but a positive correlation was found (r = .90, P < .01) between adhesion score and fibrinolytic inhibitors. No bleeding or wound complications were encountered.
Answer: Administration of adenovector encoding htPA is safe and decreased de novo and recurrent peritoneal adhesions.
Example Output:
Does adenovirus-mediated overexpression of human tissue plasminogen activator prevent peritoneal adhesion formation/reformation in rats?