In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: The aim of this study was to examine the efficacy and surgical success rates of amniotic membrane (AM) transplantation performed for corneal perforation closure using a novel technique.', 'This study included 6 eyes from 6 patients with corneal perforation who had received AM transplantation between May 2011 and April 2012. The AM was collected from human placenta shortly after cesarean section. In surgery, the AM was folded into pleats and used to plug the wound using 10-0 nylon suture. The wound was then covered with an AM seal. After reepithelialization and AM scarring, sutures were removed.', 'All 6 patients had successful wound closure with 1 surgery. One patient underwent optical keratoplasty later, and 1 patient required combined preserved sclera transplantation. The absolute value of astigmatism decreased to <3.50 diopters (D) 3 months after surgery and to <3.00 D 6 months after surgery in patients with peripheral AM transplants. The visual acuity gradually improved over the first 3 months after surgery, and visual acuity gains were maintained at the 6-month postoperative mark.\Question: Do '' Pleats fold '' technique of amniotic membrane transplantation for management of corneal perforations?
[EX A]: The AM transplantation procedure may be an effective option for treating corneal perforations when the wound is circular or irregular, except for incised wounds. Our "Pleats Fold" AM transplantation technique can achieve definite closure and effectively repair wounds of various sizes. Postoperative astigmatic values were acceptable. Therefore, we recommend this procedure for repairing lesions <3 mm in diameter that do not involve the central cornea and that are infection free.

[EX Q]: Context: Dynamic pelvic magnetic resonance imaging (DP-MRI) offers a comprehensive evaluation of pelvic organ structure in addition to functional information regarding evacuation. Opportunity to apply this technology can be limited due to regional lack of availability. Ideally, clues from standard anorectal testing could predict abnormalities on DP-MRI, leading to its efficient use. The aim of this study is to determine whether high-resolution anorectal manometry (HR-ARM) correlates with findings on DP-MRI.', "This is a retrospective study of HR-ARM performed on patients with constipation who also underwent DP-MRI. Studies were reviewed for significant findings including posterior pelvic organ prolapse, rectocele>3cm, rectal intussusception, and anorectal angle. Statistical analysis was performed using Pearson's correlation coefficient, Student's t-test, and Fisher's exact test.", 'Twenty-three patients undergoing HR-ARM (age range 25-78) also underwent DP-MRI. All were female; 76% were Caucasian. Twenty had significant structural findings: small pelvic prolapse (n=2), moderate pelvic prolapse (n=10), large pelvic prolapse (n=9), rectocele (n=8), or rectal intussusception (n=3). Only intrarectal pressure on HR-ARM weakly correlated with size of rectocele (r=0.46; P=0.03) and degree of pelvic organ prolapse (r=0.48; P=0.02). The remainder of the HR-ARM parameters did not significantly correlate with DP-MRI findings. Patients with dyssynergy were not more likely to have rectoceles>3cm (44.4% versus 35.7%; P=0.5) or large prolapses (44.4% versus 50%, P=1.0), compared with those without dyssynergy, on HR-ARM.\Question: Are high-resolution anorectal manometry and dynamic pelvic magnetic resonance imaging complementary technologies?
[EX A]: We were unable to find a correlation between HR-ARM findings and structural pelvic defects on DP-MRI. Therefore, these two technologies provide complementary information in the evaluation of defecatory dysfunction.

[EX Q]: Context: The role of CXCR4 in bone marrow localization of neuroblastoma cells has been recently proposed. The aim of this study was to investigate the expression and chemotactic functionality of CXCR4 in human metastatic neuroblastoma cells isolated from the bone marrow and, for comparison, in a panel of neuroblastoma cell lines.', 'CXCR4 expression and chemotactic functionality were investigated in metastatic neuroblastoma cells isolated from patient bone marrow and in neuroblastoma cell lines. The former cells were isolated as CD45- or GD2+ cells by immunomagnetic bead manipulation. Chemotactic assays were done in a transwell system. Regulator of G protein signaling expression was investigated by reverse transcription-PCR.', 'Metastatic neuroblastoma cells consistently expressed CXCR4, which was also detected in 5 of 10 neuroblastoma cell lines. CXCL12 did not stimulate the chemotaxis of primary tumor cells or cell lines in either normoxia or hypoxia, irrespective of CXCR4 up-regulation detected under the latter condition. Accordingly, neuroblastoma cells failed to modulate filamentous actin and to activate mitogen-activated protein kinase upon treatment with CXCL12. RGS16 mRNA was consistently expressed in primary tumor cells and cell lines, but its down-regulation by RNA interference did not restore CXCR4 chemotactic functionality.\Question: Does cXCL12 attract CXCR4+ human metastatic neuroblastoma cells : clinical implications?
[EX A]:
These results show unambiguously that CXCR4 expressed in human metastatic neuroblastoma cells is not functional and do not support the clinical use of CXCR4 antagonists to prevent neuroblastoma metastasis.