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.

[Q]: To determine the origin of the neoplastic cell in central nervous system (CNS) hemangioblastomas in von Hippel-Lindau disease (VHL) and its role in tumor formation and distribution, we characterized and differentiated neoplastic cells from hemangioblastomas removed from VHL patients.', 'A total of 31 CNS hemangioblastomas from 25 VHL patients were resected and analyzed. Tumor cells from the hemangioblastomas were characterized, grown, and differentiated into multiple lineages. Resected hemangioblastomas were located in the cerebellum (11 tumors), brainstem (five tumors), and spinal cord (15 tumors). Consistent with an embryologically derived hemangioblast, the neoplastic cells demonstrated coexpression of the mesodermal markers brachyury, Flk-1 (vascular endothelial growth factor-2), and stem cell leukemia (Scl). The neoplastic cells also expressed hematopoietic stem cell antigens and receptors including CD133, CD34, c-kit, Scl, erythropoietin, and erythropoietin receptor. Under specific microenvironments, neoplastic cells (hemangioblasts) were expanded and differentiated into erythrocytic, granulocytic, and endothelial progenitors. Deletion of the wild-type VHL allele in the hematopoietic and endothelial progeny confirmed their neoplastic origin.
[A]: Are von Hippel-Lindau disease-associated hemangioblastomas derived from embryologic multipotent cells?

[Q]: Traditionally cerebellar functions are thought to be related to control of tone, posture, gait, and coordination of skilled motor activity. However, there is an increasing body of evidence implicating the cerebellum in cognition, language, memory, and motor learning. Preterm infants are at increased risk of neurodevelopmental delay, cognitive dysfunction, and behavioral and emotional disturbances. The role of the cerebellum in these adverse outcomes is unclear.', 'The objective of this study was to determine whether absolute cerebellar volumes differ between term-equivalent preterm infants and term-born control infants and to assess whether cerebellar volume is influenced by any possible antenatal, perinatal, and postnatal factors.', 'The study compared the MR imaging cerebellar volume by using a manual quantification program of 113 preterm infants at term-equivalent age and 15 term-born control infants.', 'The median cerebellar volume of preterm at term-equivalent age was 25.4 cm3 and that of term-born control infants was 26.9 cm3. On initial analysis, there was a significant median difference of 2.0 cm3 (95% CI, 1.2 cm3 to 2.7 cm3) (2-sided P < .0001). However multiple regression analysis of perinatal variables showed that only infants with supratentorial lesions (P = .003) were significantly associated with the reduction in cerebellar volumes. The median cerebellar volumes were the following: supratentorial lesions, 18.9 cm3; no supratentorial lesions, 26.1 cm3; and term infants, 26.9 cm3 (analysis of variance, P < .0001). Hence, there was no significant difference in cerebellar volumes of preterm infants at term-equivalent age in the absence of supratentorial lesions. The median vermal volumes were 0.7 cm3 and were significantly related to cerebellar volumes both in preterm infants with and without lesions and in term-control infants.
[A]: Are smaller cerebellar volumes in very preterm infants at term-equivalent age associated with the presence of supratentorial lesions?

[Q]: In the previous work, we correlated epidermal hyperplasia with increased epidermal absorption in the 250-400 nm region. During a recent review of that work, the apparent formation of a chromophore, with absorption slightly longer than 400 nm, in the epidermis of irradiated animals was noted. In this study, we have extended the transmission measurement to include the 250-800 nm region.', 'Age-matched Skh-1 hairless mice were separated into three groups. One group was irradiated with 6.3 J/cm(2) (0.9 minimal erythemal dose; MED) of solar simulating ultraviolet radiation (SSUVR) five times/week for 2 weeks, then increased to 1.1 MED (7.1 J/cm(2)) for two additional weeks (20-day group). A second 10-day group, added halfway through the protocol, was irradiated with 0.9 MED five times/week for 2 weeks. The control group received no UV irradiation. Routine H&E staining and epidermal absorption spectral analysis were carried out on biopsy specimens from each animal.', 'This work confirms the development or enhancement of a visible chromophore with a maximum absorption at ca 412 nm. This peak appears to be radiation dose dependent. It can be discerned in both the groups, albeit more prominently in the 20-day animals. The absorption is sufficiently strong to impart a yellow to reddish appearance to skin viewed in full spectrum visible light.
[A]:
Does modest in vivo exposure to solar wavelengths induce a visible absorbing chromophore in Skh-1 mouse epidermis?