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 Q]: Context: Brain structures underlying posttraumatic stress disorder (PTSD) have been a focus of imaging studies, but associations between treatment outcome and alterations in brain structures remain largely unexamined. We longitudinally examined the relation of structural changes in the rostral anterior cingulate cortex (rACC), a previously identified key region in the PTSD fear network, to outcome of prolonged exposure (PE) treatment.', 'The sample included 78 adults (53 women): 41 patients with PTSD and 37 trauma-exposed healthy volunteers (TE-HCs). Patients underwent a 10-week course of PE treatment and completed pre- and posttreatment assessments and magnetic resonance imaging (MRI) structural scans. TE-HCs also underwent assessment and MRI at baseline and 10 weeks later. PE remitters (n\xa0=\xa011), nonremitters (n\xa0=\xa014), and TE-HCs, were compared at baseline on demographic and clinical characteristics and ACC structure. Remitters, nonremitters, and TE-HCs were compared for pre- to posttreatment clinical and structural ACC change, controlling for potential confounding variables.', 'There were no baseline differences in structure between PTSD and TE-HCs or remitters and nonremitters. Following treatment, PTSD remitters exhibited cortical thinning and volume decrease in the left rACC compared with PTSD nonremitters and TE-HCs.
Answer: These results, while in need of replication, suggest that PE treatment for PTSD, by extinguishing maladaptive trauma associations, may promote synaptic plasticity and structure change in rACC. Future research should explore possible underlying mechanisms.
[EX A]: Does pTSD REMISSION AFTER PROLONGED EXPOSURE TREATMENT be ASSOCIATED WITH ANTERIOR CINGULATE CORTEX THINNING AND VOLUME REDUCTION?

[EX Q]: Context: Critical size defects (CSDs) of bone are defined as defects that do not heal spontaneously to new bone during the lifetime of an adult individual. In contrast, immature animals are capable to heal defects of identical size. It was our hypothesis that age-related paracrine effects are relevant for this difference in regeneration.', 'The pooled supernatant of primary rat calvarial osteoblast-like cell cultures (POBC) derived from prenatal or postnatal donors was concentrated and applied into CSDs of adult recipient organisms (n = 10). In addition, the supernatant of POBC derived from prenatal donors was pooled and purified by reverse-phase chromatography. Each pre-purified fraction was tested in a proliferation indicating bioassay. Peptide fractions containing proliferative activities were re-chromatographed and re-tested in a bioassay. Finally, a proliferative activity was purified, identified by sequence analysis and applied into CSDs of adult recipients.', 'The application of POBC derived from prenatal donors resulted in osseous regeneration of a CSD in adult recipients, while the supernatant of postnatal donors had much smaller effects. The morphologic features resembled the spontaneous osseous healing of calvarial defects of the same size in immature organisms. The polypeptide "tissue inhibitor of metalloproteinases type II"(TIMP-2) was isolated from the supernatant of cultures of POBC derived from prenatal donors by measuring the induction of their proliferation. Additionally, the application of human TIMP-2 injected into calvarial CSDs of adult organisms resulted in osseous healing.
Answer: We conclude that one component responsible for the healing effect of CSDs of POBC supernatants derived from prenatal donors is TIMP-2.
[EX A]: Is tissue inhibitor of metalloproteinases II ( TIMP-2 ) an osteoanabolic factor in vitro and in vivo?

[EX Q]: Context: Prospective cohort.', 'Elbow stiffness is the most common adverse event after isolated radial head fractures.', 'To assess the effect of coaching on elbow motion during the same office visit in patients with such fractures.', 'We enrolled 49 adult patients with minimally displaced radial head fractures, within 14 days of injury. After diagnosis, we measured demographics, catastrophic thinking, health anxiety, symptoms of depression, upper extremity-specific symptoms and disability, pain, and elbow and wrist motion. The patient was taught to apply an effective stretch in spite of the pain to limit stiffness, and elbow motion was measured again.', 'With the exception of radial deviation and pronation, motion measures improved slightly but significantly on average immediately after coaching. Elbow flexion improved from 79% (110° ± 22°) of the uninjured side to 88% (122° ± 18°) after coaching (P\xa0<\xa0.001); elbow extension improved from 71% (29° ± 14°) to 78% (22° ± 15°) (P\xa0=\xa0.0012).
Answer: Instruction that stretching exercises are healthy even when painful resulted in immediate improvements in motion. Prospective studies comparing different strategies for coaching patients regarding painful stretches might help clarify the optimal approach.
[EX A]:
Does coaching of patients with an isolated minimally displaced fracture of the radial head immediately increase range of motion?