TASK DEFINITION: Given a passage with a context and an answer, 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.
PROBLEM: Context: Pedicle subtraction osteotomy (PSO) is one of the surgical options for treating alignment disorders of the fused spine (due to post-surgical fusion or related to arthritis). It enables satisfactory sagittal realignment and improved function due to economic sagittal balance. The aim of this study was to analyze clinical and radiological results of PSO after a minimum follow-up of 2\xa0years and demonstrate the benefit of sub-group analysis as a function of pelvic incidence (PI).', 'A descriptive prospective single center study of 63 patients presenting with spinal global malalignment who underwent correction by PSO. Function was assessed by the Oswestry disability index (ODI), a visual analog scale of lumbar pain (VAS) and a SF-36 questionnaire. Radiographic analyses of pre- and post-operative pelvic-spinal parameters were performed on X-rays obtained by EOS(®) imaging after 3D modeling. Global analysis and analysis of sub-groups as a function of pelvic incidence were performed and the full balance integrated index (FBI) was calculated.', 'this series showed a marked clinical improvement and significant progress of functional scores. Global post-operative radiological analysis showed a significant improvement in all pelvic and spinal parameters. The mean correction obtained after PSO was 31.7°\xa0±\xa08.4°, hence global improvement of lumbar lordosis of 22°. The sagittal vertical angle (SVA) decreased from +9\xa0cm before surgery to +4.3\xa0cm after surgery. Sub-group analysis demonstrated greater improvement in pelvic tilt, sacral slope and spinal parameters of patients with a small or moderate pelvic incidence; all had an FBI index\xa0<10°. Most of the pelvic and spinal parameters of patients with a large pelvic incidence were insufficiently corrected and they had an FBI index\xa0>10°
Answer: PSO is a surgical procedure enabling correction of multiplane rigid spinal deformities that require major sagittal correction. It was seen to be highly effective in patients with a small or moderate pelvic incidence (PI <60°) but was sometimes less effective in patients with large pelvic incidence due to insufficient lordosis correction. Clinical results were highly correlated with the value of the FBI index.

SOLUTION: Are clinical and radiological outcomes of lumbar posterior subtraction osteotomies correlated to pelvic incidence and FBI index : Prospective series of 63 cases?

PROBLEM: Context: The aim of this study was to visualize early stage prostate cancer (Cap) in a clinical setting. In previous studies, the results of magnetic resonance imaging (MRI) for screening Cap have rarely been confirmed by well-designed multisite prostate biopsy.', 'The prostate glands of 90 men with elevated prostate-specific antigen (PSA) were imaged by dynamic contrast-enhanced MRI (DCE-MRI) before transrectal ultrasound-guided 14-cores prostate biopsy. Each core was divided into three subcore fractions (total of 42 fractions) to generate a histological localization diagram, which was compared with localization-visualized DCE-MRI.', "The detection rate of Cap in 57 patients with PSA < 10.0 ng/ml was 36.8% as determined by the initial biopsy. DCE-MRI uncovered 92.9% of the clinically significant Caps and its specificity was 96.2% for the first biopsy session. One case with positive DCE-MRI and a negative primary biopsy was positive with additional biopsies. All of 26 DCE-MRI positive cases had significant Cap, and two of eight patients with histological Cap and negative or equivocal imaging had significant cancer. In total, 9 of 20 cases with DCE-MRI stage T2 underwent radical prostatectomy. All of them had organ-confined disease, although 33-77% (mean 63%) of them were expected to be rated T3 or higher by Partin's table.
Answer: DCE-MRI can identify early stage Cap with high sensitivity and specificity, and can predict the histological grade to some extent. DCE-MRI prior to biopsy should be applied to younger patients with surgical indications. Otherwise, we recommend the definitive diagnosis of Cap by utilizing DCE-MRI alone.

SOLUTION: Is dynamic contrast-enhanced magnetic resonance imaging ( DCE-MRI ) a useful modality for the precise detection and staging of early prostate cancer?

PROBLEM: Context: We tested for the presence of erythropoietin receptor (Epo-R) in human skeletal muscle and alterations in gene expression after prolonged use of an erythropoiesis-stimulating agent (ESA).', 'Nine healthy men were treated with ESA for 10 weeks (darbepoietin alfa). Muscle biopsies were collected before and after treatment. Alterations in gene expression were evaluated by gene array. Western blot and PCR analysis were used to test for Epo-R presence in human skeletal muscle.', 'Very low Epo-R mRNA levels were found, but a new and sensitive antibody did not identify Epo-R protein in human skeletal muscle. The between-subject variation in skeletal muscle gene expression was greater than that observed in response to prolonged ESA treatment.
Answer: Erythropoietin is unlikely to exert direct effects in human skeletal muscle due to a lack of Epo-R protein. Furthermore, prolonged ESA treatment does not seem to exert either direct or indirect effects on skeletal muscle gene expression.

SOLUTION:
Does prolonged erythropoietin treatment impact gene expression in human skeletal muscle?