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.

[Q]: Context: Acute kidney injury (AKI) is an established indicator of all-cause mortality in a coronary care unit (CCU), and evaluating the risks of renal dysfunction can guide treatment decisions. In this study we used the Society of Thoracic Surgeons (STS) score to predict the incidence of AKI in CCU patients who had not undergone coronary artery bypass surgery (CABG) after a cardiac angiogram.', 'The study cohort comprised 126 patients diagnosed with 2 or 3 coronary vessels disease who did not receive CABG during their hospital course. This study was performed in the CCU of a tertiary referral university hospital between September 2012 and August 2013. The STS score was evaluated with adjustment in all patients and the outcomes of the risk of mortality, morbidity, or mortality and renal failure were selected for predicting assessment. Furthermore, the performance of the STS scores was compared with that of other scoring systems.', 'A total of 28.5% (36 of 126) of the patients had AKI of varying severity. For predicting AKI, the STS renal failure score was excellent, with areas under the receiver operating characteristic curve of 0.851 ± 0.039, p < 0.001. When compared with other scoring systems, the STS renal failure score demonstrated the highest discriminatory power, the most favorable Youden index, and the highest overall correctness of prediction.\Question: Do society of Thoracic Surgeons score predicts kidney injury in patients not undergoing bypass surgery?
[A]: The STS score is an effective tool for predicting AKI in patients with coronary artery disease who have not undergone CABG. Frequent monitoring of serum creatinine level or early application of AKI biomarkers are warranted for STS renal failure 5.7% or greater.


[Q]: Context: Therapeutic and prophylactic vena cava filters (VCFs) are used to prevent pulmonary embolism. Concerns exist over placing a permanent filter in a young trauma patient. Recently, retrievable VCFs have become available. One such filter is the OptEase, which has a recommended time of removal of up to 23 days after insertion. Data supporting this recommendation are sparse. Many trauma patients will need filters for more than 2 weeks, and there are no data evaluating the safety of removal after extended time periods. The purpose of this study was to determine the safety, feasibility, and reaction of the vena cava when removing the OptEase retrievable VCF at different time intervals.', 'Twenty Yorkshire cross pigs (80-113 kg) underwent general anesthesia with tiletamine and zolazepam. Filters were placed in the infrarenal vena cava (VC) through the femoral vein under fluoroscopic guidance. Animals were then divided into four groups. In group 1, filters were removed at 14 days; in group 2, at 30 days; in group 3, at 60 days; and in group 4, at 90 days. Removal was attempted using a snare-and-sheath technique through the femoral vein. Animals with successful filter removal were allowed to recover; then, the animals underwent autopsy (gross and microscopic VC examination) 2 months later. Animals with unsuccessful filter removal underwent autopsy immediately after attempted removal. Venacavograms were taken at filter insertion, at removal, and before autopsy to evaluate any VC abnormalities.', 'Successful removal of the filter in all five pigs (100%) was reliably performed only in the 14-day group. In this group, the initial VC transverse diameter was 19.4 +/- 0.8 mm and was significantly reduced to 9.8 +/- 1.1 mm (p < 0.05) immediately after removal. Sixty days later, before autopsy, VC diameter had increased to 15.3 +/- 1.9 mm, which was significantly larger than at removal (p < 0.05) but not different from the initial value. In the 30-day group, removal was successful in only one of five animals. Although removal was successful in the one pig, autopsy at 2 months postremoval revealed total occlusion of the VC. Filters could not be removed from 60- and 90-day groups. At autopsy, the VCF struts were embedded or protruded through the VC wall. Microscopic examination of the VC revealed significant scarring underneath and between the struts.\Question: Is removal of the OptEase retrievable vena cava filter feasible after extended time periods because of filter protrusion through the vena cava?
[A]: Removal of the retrievable OptEase VCF may be successfully performed up to 14 days after insertion. Strut protrusion through the VC wall prohibited successful and safe removal at extended time intervals.


[Q]: Context: Obstructive uropathy is a significant clinical problem that results in apoptotic renal cell death and progressive renal fibrosis. A number of different inflammatory mediators have been implicated in the pathophysiology of obstruction induced renal injury including tumor necrosis factor-alpha (TNF)-alpha. The cellular source of obstruction induced renal TNF-alpha production and its relationship to renal inflammatory cell infiltration remain unknown.', 'Male Sprague-Dawley rats were anesthetized and exposed to varying lengths of unilateral ureteral obstruction vs sham operation. The kidneys were harvested following renal injury and evaluated for TNF-alpha mRNA expression (reverse transcriptase polymerase chain reaction), TNF-alpha protein production (enzyme-linked immunosorbent assay), TNF-alpha cellular localization (immunohistochemistry) and leukocyte infiltration (leukocyte staining).', 'Renal TNF-alpha mRNA expression and protein production peaked following 3 days of ureteral obstruction (54 +/- 5% vs sham 22 +/- 9% of glyceraldehyde-3-phosphate dehydrogenase mRNA, p <0.05 and 204 +/- 13 vs sham 84 +/- 9 pg/ml, p <0.05, respectively). TNF-alpha production localized primarily to renal cortical tubular cells following obstruction and the time point of maximal TNF-alpha production (3 days of obstruction) were not associated with a significant renal inflammatory cell infiltrate.\Question: Does unilateral ureteral obstruction induce renal tubular cell production of tumor necrosis factor-alpha independent of inflammatory cell infiltration?
[A]:
TNF-alpha is produced by the renal cortical tubular cells in response to ureteral obstruction and independent of a significant inflammatory cell infiltrate. Identification of the cellular source of TNF-alpha expression during renal obstruction may have therapeutic implications for the targeted inhibition of TNF-alpha production and potential amelioration of obstructive renal injury.