Given a passage, 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.

Input: Consider Input: The cancer stem cell model links neoplastic cells with normal stem cell biology, but little is known on how normal stem cells are transformed into cancer stem cells.', 'To investigate the processes underlying the transformation of normal stem cells we developed in vitro a cancer stem cell model from human amniotic and chorionic placenta membranes. In this model we studied the expression of specific stem cell molecules by flow cytometry, and genes, by real time RT-PCR. Microscopy immunfluorescence was employed to investigate the proliferative and differentiation patterns. Fluorescence microscopy and FACS were employed to investigate the proliferative and differentiation patterns. To evaluate the tumorigenic potential of our model we injected the cells into NOD.CB17-Prkdcscid/NCrHsd mice.', 'Normal human stem cells from amniotic and chorionic placenta membranes were converted into neural cell lineages, under specific conditions, to form secondary neurospheres with a capacity for self-renewal. After extensive in vitro culture, these cells underwent spontaneous transformations and acquired a neuroblastoma (NB)-like phenotype with an elevated proliferative potential that is comparable to established neuroblastoma cell lines. The ability of these cells to transform their phenotype was evidenced by increased clonogenic ability in vitro; by augmented expression level of certain proliferation- and transformation-related genes (e.g., CCNA2, MYCN, ENPP2, GRIA3, and KIT); by the presence of multinucleated and hyperdiploid cells. We further demonstrated that the transformed phenotype is an NB by measuring the expression of NB-specific markers, disialoganglioside GD2 and N-Myc proteins.

Output: Are human placenta-derived neurospheres susceptible to transformation after extensive in vitro expansion?


Input: Consider Input: Multiple intercostal recordings were supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate electrocardiogram (ECG) criterion for differentiating between left and right OT-VA origins.', 'We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular OT (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10). Superior and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, transition zone (TZ) index, R/S amplitude ratio, and R-wave duration ratio were measured in the regular, superior, and inferior precordial leads.', 'The combined TZ index, TZ index inferior was significantly smaller, while the V2 inferior transition ratio was significantly larger for ACC origins than RVOT origins (P < 0.05). The area under the curve for the combined TZ index by a receiver operating characteristic analysis was 0.974, which was significantly larger than other parameters. A cutoff value ≤0.25 predicted an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0.

Output: Does multiple Intercostal Space Electrocardiogram allow Accurate Localization of Outflow Tract Ventricular Arrhythmia Origin?


Input: Consider Input: To propose a methodology for characterizing proficiency in sputum smear microscopy for acid-fast bacilli (AFB) in the diagnosis of tuberculosis and to determine the number of microscopies necessary to establish this proficiency, as well as the quality of the transcription of results, the causes of the discrepancies in the readings (rater or microscope used), and the criterion for classification of microscopy results that poses the most difficulty in characterizing proficiency.', 'Four hundred sputum smear microscopies for the diagnosis of tuberculosis were analyzed through double-blind readings by six professionals who usually read/supervise microscopies performed in public health care facilities. The sample was stratified to obtain, at least, a reliability of 90% in the double-blind readings, an alpha error of 5%, and a precision of 3%. The results were analyzed using observed reliability and the kappa index.', 'Thirteen errors (0.27%) were found in the transcription of results. Reliability increased when the three distinct categories of positive results (AFB+, AFB++, and AFB+++) were grouped or when inconclusive results were excluded from the analysis. The quantification of the bacterial load was the classification criterion that posed the most difficulty in establishing proficiency. Using higher quality microscopes increased reliability. Reliability values stabilized only from the reading of 75 microscopies onward.


Output: Does methodology for characterizing proficiency in interpreting sputum smear microscopy result in the diagnosis of tuberculosis?