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:
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:
P53 is a key protein which controls cell cycle arrest and apoptosis in response to DNA damage. Auto-antibodies against p53 have been detected in some cancer patients and also in patients with autoimmune diseases. In these patients, the main cause of anti-p53 antibody occurrence was considered to be increased intracellular p53 protein in cancer cells and autoreactive lymphocytes, respectively. Intracellular p53 also increases with cardiomyocyte apoptosis during heart failure and autoreactive lymphocytes play a role in the course of idiopathic dilated cardiomyopathy (IDC) and ischemic cardiomyopathy (ICM). Based on these observations, we hypothesized that anti-p53 antibody response may also occur in patients with heart failure due to ICM and IDC.', 'The aim of this study was to evaluate anti-p53 antibodies in the serum of patients with heart failure due to IDC and ICM.', '70 eligible patients with heart failure and severe left ventricular systolic dysfunction (mean fractional shortening 12.03 +/- 3.93%) were included in the study. The aetiology of heart failure was IDC in 26 patients and ICM in 44 patients, according to the angiographic and echocardiographic findings.', 'Anti-p53 antibodies were not detected in any of the patients.
answer:
Do serum anti-p53 antibodies occur in patients with heart failure due to idiopathic dilated and ischemic cardiomyopathies?

question:
Pathological complete remission (pCR) of estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer is rarely achieved after neoadjuvant chemotherapy (NAC). In addition, the prognostic value of pCR for this breast cancer subtype is limited. We explored whether response evaluation by magnetic resonance imaging (MRI) is associated with recurrence-free survival after NAC in ER-positive/HER2-negative breast cancer.', 'MRI examinations were performed in 272 women with ER-positive/HER2-negative breast cancer before, during and after NAC. MRI interpretation included lesion morphology at baseline, changes in morphology and size, and contrast uptake kinetics. These MRI features, clinical characteristics and final pathology were correlated with recurrence-free survival.', 'The median follow up time was 41 months. There were 35 women with events, including 19 breast-cancer-related deaths. On multivariable analysis, age younger than 50 years (hazard ratio (HR)=2.55, 95 % confidence interval (CI) 1.3, 5.02, p=0.007), radiological complete response after NAC (HR=14.11, CI 1.81, 1818; p=0.006) and smaller diameters of washout/plateau enhancement at MRI after NAC (HR=1.02, CI 1.00, 1.04, p=0.036) were independently associated with best recurrence-free survival. Pathological response was not significant; HR=2.12, CI 0.86, 4.64, p=0.096.
answer:
Is survival associated with complete response on MRI after neoadjuvant chemotherapy in ER-positive HER2-negative breast cancer?