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.
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Question: Context: Macroprolactinemia is a frequent finding in hyperprolactinemic individuals, usually without clinical impact. Data on biological activity of macroprolactin (bbPRL) are controversial and mostly based on a heterologous rat Nb2 cell bioassay. Biological activity of bbPRL observed in vitro but not in vivo may be due to its high molecular weight, preventing its passage through capillary barrier. Alternatively, bbPRL bioactivity may differ depending on the prolactin (PRL) receptor (PRLR) species specificity.', 'The objective of the study was to characterize the bioactivity of bbPRL in a homologous bioassay: Ba/F-3 cells stably expressing the human PRLR.', "Chromatography-purified bbPRL from macroprolactinemic individuals (group I, n = 18) and monomeric PRL from hyperprolactinemic patients without macroprolactinemia (group II, n = 5) were tested in Nb2 and Ba/F-LLP bioassays. Both groups were followed up at the neuroendocrinology outpatients' clinic.", 'Biological activity of bbPRL presented in the two bioassays was measured.', 'In group I, no patient had hypogonadism. Mean ratio bioactivity to immunoactivity of bbPRL in the Nb2 assay was 0.69. There was no dose-response in 15 of the 18 samples tested in Ba/F-LLP assay. In group II, three patients had galactorrhea and all five had hypogonadism. Mean ratio bioactivity to immunoactivity of monomeric PRL samples was 1.35 in Nb2 and 0.91 in Ba/F-LLP assay.
Answer: Whereas both bioassays achieve similar results with respect to monomeric PRL activity, our results indicate that the activity displayed by bbPRL toward the rat receptor may be inappropriate because it is not observed in the human PRLR-mediated assay, consistent with the apparent absence of bioactivity in vivo.

Answer: Does human macroprolactin display low biological activity via its homologous receptor in a new sensitive bioassay?


Question: Context: The Tonnis radiographic classification of developmental dysplasia of the hip (DDH) has been used as a prognostic indicator for patients with walking-age DDH. The International Hip Dysplasia Institute (IHDI) classification, a new radiographic classification system, has been proposed to be more reliable by its creators. We sought to validate its reliability using independent observers, to compare it to the Tonnis method, and to assess its prognostic significance in a large cohort of patients.', 'A consecutive series of walking-age DDH patients were examined radiographically and classified by the Tonnis and IHDI schemes by 3 independent observers. Interobserver agreement was determined using the Kappa method. Clinical data were collected on patients with regard to success of closed reduction, need for later pelvic osteotomy, and presence of subsequent radiographic avascular necrosis (AVN). The prognostic value of the Tonnis and IHDI classifications to predict these clinical outcomes was determined.', 'A total of 287 hips were available for analysis of the classification schemes. In total, 235 hips underwent attempted closed reduction and were eligible for analysis of successful closed reduction, and 131 hips had >4-year follow-up and were utilized for analysis of late pelvic osteotomy and AVN. Both classifications showed excellent interobserver reliability and in general, there was nonstatistically significant better reliability for the IHDI versus the Tonnis classification. In multivariate analysis, both IHDI and Tonnis classifications were found to be predictive of successful closed reduction and need for late pelvic osteotomy. Both methods showed trends toward being predictive of AVN rate, without statistical significance.
Answer: The IHDI classification is subjectively more facile to use and has excellent interrelater agreement for classifying the radiographic severity of DDH. It is also reliable in predicting success of closed reduction and need for late pelvic osteotomy.

Answer: Is a New Radiographic Classification System for Developmental Hip Dysplasia Reliable and Predictive of Successful Closed Reduction and Late Pelvic Osteotomy?


Question: Context: Intraflagellar transport (IFT) is a motility process operating between the ciliary/flagellar (interchangeable terms) membrane and the microtubular axoneme of motile and sensory cilia. Multipolypeptide IFT particles, composed of complexes A and B, carry flagellar precursors to their assembly site at the flagellar tip (anterograde) powered by kinesin, and turnover products from the tip back to the cytoplasm (retrograde) driven by cytoplasmic dynein. IFT is essential for the assembly and maintenance of almost all eukaryotic cilia and flagella, and mutations affecting either the IFT motors or the IFT particle polypeptides result in the inability to assemble normal flagella or in defects in the sensory functions of cilia.', 'We found that the IFT complex B polypeptide, IFT27, is a Rab-like small G protein. Reduction of the level of IFT27 by RNA interference reduces the levels of other complex A and B proteins, suggesting that this protein is instrumental in maintaining the stability of both IFT complexes. Furthermore, in addition to its role in flagellar assembly, IFT27 is unique among IFT polypeptides in that its partial knockdown results in defects in cytokinesis and elongation of the cell cycle and a more complete knockdown is lethal.
Answer: IFT27, a small G protein, is one of a growing number of flagellar proteins that are now known to have a role in cell-cycle control.

Answer:
Is intraflagellar transport protein 27 a small G protein involved in cell-cycle control?