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.

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.
Are von Hippel-Lindau disease-associated hemangioblastomas derived from embryologic multipotent cells?

Granulocyte-colony stimulating factor (G-CSF) is used for the mobilization of bone marrow and endothelial progenitor cells, though G-CSF-induced inflammation may cause endothelial dysfunction. We examined the effects of G-CSF on endothelium, C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-alpha) and anti-inflammatory cytokines namely interleukin 10 (IL-10).', 'We studied 60 women with breast cancer, who were randomized to either subcutaneous G-CSF (5 microg/kg), o.d. for 5 days after adjuvant chemotherapy (n = 40) or placebo (n = 20).', 'We measured flow-mediated dilatation (FMD%) of the brachial artery by ultrasonography, CRP, TNF-alpha, IL-10 and the ratio TNF-alpha/ IL-10 blood levels before, 2-h and 5-days after the G-CSF or placebo treatment.', 'There was a greater increase of FMD, IL-10 and reduction of TNF-alpha/ IL-10, 2 h and 5 days after the G-CSF treatment compared to placebo. Although, CRP and TNF-alpha were higher, TNF-alpha/IL-10 was lower at the end of G-CSF treatment compared to placebo. Improvement of FMD was related to changes of IL-10 and TNF-alpha/IL-10.
Is treatment with granulocyte colony stimulating factor associated with improvement in endothelial function?

To determine the extent of genetic variation among internationally collected HIV-1 isolates, to analyse phylogenetic relationships and the geographic distribution of different variants.', 'Phylogenetic comparison of 70 HIV-1 isolates collected in 15 countries on four continents.', 'To sequence the complete gag genome of HIV-1 isolates, build multiple sequence alignments and construct phylogenetic trees using distance matrix methods and maximum parsimony algorithms.', 'Phylogenetic tree analysis identified seven distinct genotypes. The seven genotypes were evident by both distance matrix methods and maximum parsimony analysis, and were strongly supported by bootstrap resampling of the data. The intra-genotypic gag distances averaged 7%, whereas the inter-genotypic distances averaged 14%. The geographic distribution of variants was complex. Some genotypes have apparently migrated to several continents and many areas harbor a mixture of genotypes. Related variants may cluster in certain areas, particularly isolates from a single city collected over a short time.

Does phylogenetic analysis of gag genes from 70 international HIV-1 isolates provide evidence for multiple genotypes?