TASK DEFINITION: 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.
PROBLEM: Context: After formation of the linear heart tube a chamber-specific program of gene expression becomes active that underlies the formation of the chamber myocardium. To assess whether this program is recapitulated in in vitro differentiated embryonic stem cells, we performed qualitative and quantitative analyses of cardiogenesis in vivo and in vitro.', 'Gene expression profiles were made by in situ hybridisation and real-time PCR and electrophysiological profiles by patch clamp analyses of cardiomyocytes derived from time series of differentiating HM1 mouse embryonic stem cells and from embryonic and adult mouse hearts.', 'In embryoid bodies the in situ patterns of expression of alpha-myosin heavy chain, myosin light chain 2a and sarcoendoplasmic reticulum calcium ATPase 2a were similar to that of the heart muscle-specific marker gene cardiac troponin I. Myosin light chain 2v was expressed in part of the cardiac troponin I-expressing area, indicating heterogeneity within the cardiac cell population. Atrial natriuretic factor expression, indicative of the chamber-type program, could only very occasionally be detected by in situ hybridisation. Quantitative reverse transcriptase PCR showed that all cardiac genes, most notably atrial natriuretic factor, were expressed at relatively low levels, similar to those in embryonic hearts at embryonic day 8.75-9. Analysis of the electrophysiological characteristics of embryonic stem cell-derived cardiomyocytes showed an increase of the upstroke velocity and a shorter duration of the action potential during prolonged differentiation in vitro. When embryonic mouse heart compartments of embryonic day 12.5 were used as a reference, the electrophysiological characteristics of a substantial part of the embryonic stem cell-derived cardiomyocytes were most reminiscent to those observed in the embryonic outflow tract.
Answer: Together, these data suggest that most cardiomyocytes acquired by differentiation of embryonic stem cells maintain a phenotype reminiscent of that of the cardiomyocytes of the primary heart tube, and hardly any myocytes develop a chamber myocardial phenotype.

SOLUTION: Do cardiomyocytes derived from embryonic stem cells resemble cardiomyocytes of the embryonic heart tube?

PROBLEM: Context: To describe the common locations of active trigger points (TrPs) in the temporalis muscle and their referred pain patterns in chronic tension type headache (CTTH), and to determine if pressure sensitivity maps of this muscle can be used to describe the spatial distribution of active TrPs.', 'Forty women with CTTH were included. An electronic pressure algometer was used to assess pressure pain thresholds (PPT) from 9 points over each temporalis muscle: 3 points in the anterior, medial and posterior part, respectively. Both muscles were examined for the presence of active TrPs over each of the 9 points. The referred pain pattern of each active TrP was assessed.', 'Two-way analysis of variance detected significant differences in mean PPT levels between the measurement points (F=30.3; P<0.001), but not between sides (F=2.1; P=0.2). PPT scores decreased from the posterior to the anterior column (P<0.001). No differences were found in the number of active TrPs (F=0.3; P=0.9) between the dominant side the nondominant side. Significant differences were found in the distribution of the active TrPs (chi2=12.2; P<0.001): active TrPs were mostly found in the anterior column and in the middle of the muscle belly. The analysis of variance did not detect significant differences in the referred pain pattern between active TrPs (F=1.1, P=0.4). The topographical pressure pain sensitivity maps showed the distinct distribution of the TrPs indicated by locations with low PPTs.
Answer: Multiple active TrPs in the temporalis muscle were found, particularly in the anterior column and in the middle of the muscle belly. Bilateral posterior to anterior decreased distribution of PPTs in the temporalis muscle in women with CTTH was found. The locations of active TrPs in the temporalis muscle corresponded well to the muscle areas with lower PPT, supporting the relationship between multiple active muscle TrPs and topographical pressure sensitivity maps in the temporalis muscle in women with CTTH.

SOLUTION: Are multiple active myofascial trigger points and pressure pain sensitivity maps in the temporalis muscle related in women with chronic tension type headache?

PROBLEM: Context: Although evidence suggests that antiretroviral (ARV) regimens containing nonnucleoside reverse transcriptase inhibitors (NNRTIs) are superior to single-protease inhibitor (PI)-based regimens at suppressing viral load, it is unclear how much of the improved viral suppression is due to intrinsic drug potency versus higher levels of adherence to simpler regimens. We therefore examined adherence and viral suppression in NNRTI and single-PI regimens in a cohort of largely ARV-experienced participants by using objective measures of adherence.', "Participants were recruited from the Research on Access to Care in the Homeless (REACH) Cohort and were included in the study if they were on single-PI-based or NNRTI-based highly active antiretroviral therapy (HAART) regimens for at least 3 months prior to study entry. Adherence was measured by unannounced pill counts at the participant's usual place of residence. The primary outcome was suppression of HIV viral RNA to <50 copies/mL.", 'Among 109 individuals who were followed for a median of 8.7 months, the odds of virologic suppression were approximately 8 times higher (p < .01) for participants on NNRTI-based regimens (n = 53) compared with those using single-PI-based regimens (n = 56) when controlling for adherence, as well as other potential confounders in a multivariable analysis. The only other independent predictors of viral suppression in multivariable modeling were ARV adherence (p < .01), CD4 nadir (p = .02), and continuous months on current regimen prior to the start of adherence monitoring (p < .01). There was no significant difference in adherence by unannounced pill counts in participants receiving NNRTI- versus single-PI-containing regimens.
Answer: A higher proportion of individuals using NNRTI-based regimens had viral suppression when compared to those taking single-PI-containing regimens, and this association was not confounded by higher levels of adherence. These results suggest that improved viral suppression on NNRTI regimens compared to single-PI regimens is more closely associated with regimen potency than higher levels of adherence.

SOLUTION:
Are higher rates of viral suppression with nonnucleoside reverse transcriptase inhibitors compared to single protease inhibitors explained by better adherence?