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.

Q: Context: Transient tachypnea of the newborn (TTN) is a benign disorder with a variable clinical course that often leads to hospitalization. The aim of this study was to assess and validate the relationship between the serum cystatin C level and symptom duration in infants with TTN.', 'Forty newborns presenting with TTN and who had undergone serum cystatin C (Cys C) tests on the first day of admission to the Kyung Hee University Hospital (Seoul, Korea) from 2009 to 2013 were included. The serum Cys C level, creatinine (Cr) level, estimated glomerular filtration rate (eGFR), and tachypnea duration were correlated retrospectively.', 'The median gestation period was 37.8\xa0±\xa03.8 weeks and the mean birth weight was 3.2\xa0±\xa00.4\xa0kg. Tachypnea duration was 3.3\xa0±\xa02.0 days. Serum Cys C and Cr levels were 1.7\xa0±\xa00.2\xa0mg/L and 0.8\xa0±\xa01.2\xa0mg/dL, respectively. Tachypnea duration was significantly positively correlated with the serum levels of Cys C and significantly negatively correlated with Cys C-based eGFR (p\xa0=\xa00.016), but was not significantly correlated with the serum Cr level or Cr-based eGFR. When tachypnea duration was compared between infants with Cys C level <1.6\xa0mg/L (n\xa0=\xa015; Group A) and infants with Cys C level\xa0≥\xa01.6\xa0mg/L (n\xa0=\xa025; Group B), the symptom duration was significantly shorter in Group A infants (p\xa0=\xa00.011).
Answer: Tachypnea duration was shorter with higher Cys C-based eGFR in infants with TTN.

A: Does decreased Cystatin C-Estimated Glomerular Filtration Rate be Correlated with Prolonged Hospital Stay in Transient Tachypnea of Newborn Infants?
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Q: Context: Current staging for renal cancer (RC) does not directly rely on tumor size. We examined the increment in accuracy related to inclusion of pathologically determined tumor size in prediction of nodal metastases (N+), distant metastases (M+), and cancer-specific survival (CSS).', 'Partial or radical nephrectomy was performed in 2245 patients with clear cell histology. Pathologic stages were T1a in 566, T1b in 490, T2 in 303, T3 in 831, and T4 in 55 patients. Tumor size was 0.5-25 cm (mean, 6.8). Multivariate models relied on 1997 and 2002 TNM variables and addressed N+, M+ disease, and CCS. Their accuracy was compared according to either the presence or absence of tumor size.', 'In all univariate and multivariate models, tumor size was a statistically significant predictor of all outcomes (p< or =0.001). In all multivariate models, tumor size added between 3.7% and 0.8% to predictive accuracy of either 1997 or 2002 TNM categories.
Answer: Tumor size represents a highly significant, multivariate, and informative predictor of RC outcomes and may warrant inclusion in future TNM revisions.

A: Does tumor size improve the accuracy of TNM predictions in patients with renal cancer?
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Q: Context: In chronic renal failure leptin levels are elevated and BMD decreased, however, so far data about correlations between leptin and BMD in dialyzed patients are scarce. It has been suggested that leptin is a predictor of BMD in postmenopausal women. We examined the relationships between leptinemia, BMD and bone metabolism in HD and CAPD patients. We also assessed whether leptin is significant and independent predictor of BMD in dialyzed patients.', 'BMD was measured using dual energy X-ray absorptiometry (DEXA) at lumbar spine and femoral neck in 25 HD and 23 CAPD patients. Markers of bone turnover and leptin were studied using commercially available kits.', 'In femoral neck BMD was significantly higher in CAPD patients, without significant differences in BMD in lumbar spine. There was a negative correlation between BMD at the femoral neck and time on hemodialysis (r= -0.45, p < 0.05). In CAPD patients BMD at the lumbar spine correlated negatively with vitamin D3 (r= -0.54, p < 0.05), osteocalcin (r= 0.54, p < 0 .05), and positively with BMI (r= 0.63, p < 0.01). BMD at the femoral neck correlated positively with BMI (r= 0.59, p < 0.01), and negatively with osteocalcin (r= -0.63, p < 0.05) and time on CAPD (r= -0.52, p < 0.05). Leptin correlate only with cholesterol (r= 0.25, p < 0.05), TSH (r= 0.35, p < 0.01), ss(2) microglobulin (r= 0.32, p < 0.001) and BMD at the femoral neck (r= -0.23, p < 0.05)in all dialyzed (HD and CAPD) patients.
Answer: BMD depends on time of renal replacement therapy. Biochemical markers of bone metabolism poorly correlate with BMD and leptin in dialyzed patients. Leptin is not a predictor of BMD in dialyzed patients.

A:
Are bone mineral density and bone metabolism related to leptin in hemodialyzed and peritoneally dialyzed uremic patients?
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