instruction:
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.
question:
Results from GOG 178 showed a prolongation of progression-free survival (PFS) with the immediate use of chemotherapy (CT) following a complete clinical response (CR) in patients with stage III-IV ovarian cancer. We wanted to evaluate our strategy of reserving second line (2nd line) chemotherapy to the time of clinical recurrence by determining PFS intervals following first, second, and third line agents and to compare these finding to results of GOG 178.', 'We conducted a retrospective parallel study to GOG 178 using identical criteria for PFS definitions. Patients (pts) with stage III-IV cancer achieving a CR following surgery and five to eight cycles of platinum-based CT were identified. Patients not obtaining a CR and those with a CR who underwent second look surgery were excluded. Rather than immediately beginning consolidation CT after CR, second line agents were started at recurrence and were followed by a third line when pts progressed. Clinical-pathologic characteristics were abstracted, and time intervals including time to recurrence, time to use of second line CT, time to use of third line (3rd line) CT, and survival were recorded. Time intervals were studied by Kaplan-Meier method.', 'Of 217 reviewed pts (1991-2001), 59 eligible pts were identified. Forty-nine patients had stage III disease and ten had stage IV. At completion of surgery, 44 were optimally debulked. With a median follow-up of 51 months, the median PFS (from CR) of all patients was 20 months. At 5 years, 36% of pts remain disease-free, and 66% of pts are alive. Twenty-three pts have not received second line agents, and thirty-six have received them. For all pts, the median time from CR to start of second line chemotherapy was 21 months, and the median time to start of third line agents was 43 months. Recurrences occurred after 6 months from completion of first line (1st line) therapy in 87% of cases and after 12 months in 50%.
answer:
Is timing n't everything : an analysis of when to start salvage chemotherapy in ovarian cancer?


question:
The role of Kdr (VEGFR-2/Flk-1) in vascular formation has been well described, but the role of Flt1 (VEGFR-1) is not well studied and is generally considered as a decoy receptor for trapping VEGF.', 'The effects of VEGFR1/2 kinase inhibitor (VRI) and calycosin on Flt1 tyrosine kinase (TK) activity were evaluated by molecular docking, enzymatic inhibition assay, protein co-immunoprecipitation and siRNA gene knock-down analysis in HUVECs. Toxicities of the chemicals were examined using HUVECs viability. Their effects on angiogenesis and vessel formation were furthered studied in HUVECs in vitro and Tg(fli-1:EGFP) zebrafish in vivo. The gene and protein expression of VEGF and VEGF receptors were investigated by quantitative RT-PCR and Western blot.', 'VRI strongly inhibited physiological functions of both VEGF receptors and suppressed endothelial cell survival. This resulted in blood vessel loss in zebrafish embryos. Interestingly, calycosin co-treatment impeded VRI-induced blood vessel loss. Docking and kinase inhibition assay revealed that calycosin competed with VRI for the tyrosine kinase domain of Flt1 without affecting ATP binding. On the contrary, calycosin did not affect the interaction between VRI and Kdr-TK. Consistent with these results, calycosin counteracted the inhibition of Flt1-TK and PI3K phosphorylation induced by VRI in HUVECs. Further studies in vitro and in vivo showed that the minimizing effect of calycosin on VRI-mediated endothelial cytotoxicity was blocked by wortmannin (a PI3K inhibitor). The impeding effect of calycosin on VRI-induced blood vessel loss was absent in zebrafish embryos injected with Flt1 MO.
answer:
Is basal Flt1 tyrosine kinase activity a positive regulator of endothelial survival and vascularization during zebrafish embryogenesis?


question:
Carrot allergy is caused by primary sensitization to birch pollen. Continuous carrot exposure results in additional Dau c 1-specific allergic responses. Thus, immunotherapy with birch pollen may not improve the food allergy.', 'Evaluation of mutation and oligomerization of the major carrot allergen, Dau c 1, in regard to alteration of antibody binding capacities, structure, and the ability to induce blocking IgG antibodies.', 'Measurement of IgE reactivities to monomers, dimers of wild-type and mutant Dau c 1.0104 and Dau c 1.0201, and Dau c 1.0104 trimer, their ability to induce blocking antibodies in mice, and their allergenic potency by histamine release.', 'The reactivity of human IgE to the mutant dimer was reduced on average by 81%. Sera of immunized Balb/c mice showed specific IgG similar to the human IgE antibody response; Dau c 1.01 was more antigenic than Dau c 1.02. Both wild-type and mutant Dau c 1 variants induced cross-reacting IgG, which blocked binding of human IgE. The mutants were more antigenic than the wild-type forms, and the dimers induced higher IgG responses in mice than the monomers. The results of the histamine release experiments corroborated the findings of the antibody binding studies.
answer:

Is allergenicity and antigenicity of wild-type and mutant , monomeric , and dimeric carrot major allergen Dau c 1 : destruction of conformation , not oligomerization , the roadmap to save allergen vaccines?