TASK DEFINITION: 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.
PROBLEM: Context: Monitoring renal function is crucial in children undergoing chemotherapy. To date, a combination of routine serum creatinine (SCR) monitoring with occasional determination of creatinine clearance ratio (CCR) is widely used as clinical standard for this purpose. Both methods have their limitations regarding diagnostic value (SCR) or practicability (CCR), especially in young children. Diagnostic alternatives, such as glomerular filtration rate (GFR) estimation formulas have not been proved to be superior. The aim of the study was to evaluate whether serum cystatin C (CysC) may have a diagnostic impact on pediatric patients.', 'CysC, SCR, several GFR estimation formulas (Counahan-Barratt, Ghazali-Barratt, Schwartz, Shull, Traub), and CCR were studied in 80 pediatric cancer patients (age range: 0.17-17.9 years) during their chemotherapy. Special attention was given to children under the age of 3 in whom accurate urine collection for CCR is difficult.', 'All parameters correlated similarly well with CCR. Total accuracy was 66% and 67% for CysC and SCR, respectively. In very young children (<3 years), correlation with CCR was for CysC r = -0.74 with an area under the curve (AUC) of 0.646, and for SCR r = -0.27 with AUC = 0.594. Total accuracy was 60% for CysC, 50% for SCR.\Question: Is serum cystatin C a suitable marker for routine monitoring of renal function in pediatric cancer patients , especially of very young age?

SOLUTION: CysC represents a suitable marker for monitoring renal function in pediatric cancer patients. In young children (<3 years), CysC may have a better diagnostic value than SCR. Future studies should show if CysC can improve renal monitoring by replacing SCR, especially in very young children.

PROBLEM: Context: To describe technical challenges encountered using the Ovation endograft for abdominal aortic aneurysms and suggest tips and maneuvers for successful management.', "Deployment of the Ovation's unsupported main body is often associated with the anteroposterior arrangement of the limb gates instead of the usual side-by-side configuration, rendering contralateral catheterization challenging. Successful catheterization of the contralateral limb can be confirmed by lateral deviation of the ipsilateral stiff guidewire caused by balloon inflation within the contralateral limb. Moreover, failure to cannulate the contralateral limb gate due to persistent impingement of the guidewire or compromise of the inflated rings can be overcome using the transbrachial antegrade approach.\Question: Does technical challenge encountered during deployment of the ovation abdominal aortic stent-graft system?

SOLUTION: Awareness of certain aspects associated with the use of the Ovation device and adoption of the adjunctive techniques herein described helps the interventionist avoid unexpected challenges or manage technical difficulties to maximize the device's safety and effectiveness.

PROBLEM: Context: Vitamin D is associated with a number of inflammatory diseases and plays a significant role in regulating bone metabolism. Serum calcifediol was demonstrated to be potentially associated with periodontal disease. The purpose of this study was to evaluate whether an association exists between plasma calcifediol concentrations and aggressive periodontitis (AgP) and whether plasma levels of bone-related biomarkers (osteocalcin, alkaline phosphatase, calcium, and phosphorus) regulated by vitamin D are related to AgP.', 'Sixty-six patients with generalized AgP, 52 patients with chronic periodontitis, and 60 healthy controls were included in this study. Periodontal examination consisted of probing depth, attachment loss, and bleeding index measurements. Hematic calcifediol and bone-related biomarker levels were detected using radioimmunity assay kits or a biochemical analyzer.', 'Plasma calcifediol levels in patients with AgP were higher than those of healthy controls (29.28 versus 21.60 nmol/l; P <0.05) and were statistically significantly correlated with bleeding index (r = 0.321; P <0.05). Plasma osteocalcin concentrations in patients with AgP were higher than those of healthy controls (0.90 versus 0.70 ng/ml; P <0.05). Serum inorganic phosphorus values of both periodontitis groups were lower than those of healthy controls (1.06 +/- 0.18 mmol/l and 1.10 +/- 0.15 mmol/l versus 1.26 +/- 0.17 mmol/l; P <0.05).\Question: Is elevated plasma calcifediol associated with aggressive periodontitis?

SOLUTION:
Plasma calcifediol levels might be associated with periodontal inflammation.