ABSTRACT
A method of LC-QTOF/MS combining with chemical synthesis has been used to determine the structures of three novel bile acids from bear bile powder. Reference substances of tauroursodeoxycholic acid and taurochenodeoxycholic acid were oxidized by pyridinium chlorochromate. The products were analyzed by LC-QTOF/MS. Total 4 products including 3 isomers were predicted and identified according to the PCC oxidation theory and LC-QTOF/MS results. Bear bile powder samples were dissolved by methanol and analyzed by LC-QTOF/MS. Three unknown peaks were found and identified as 2-[[(3beta, 5beta)-3-hydroxy-7, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, 2-[[(5beta)-3, 7, 24-trioxocholan-24-yl]amino]-ethanesulfonic acid and 2-[[(5beta, 7beta)-7-hydroxy-3, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, separately, by matching their results with that of oxidation products above.
ABSTRACT
Objective To assess the prognosis and effect on renal function of pediatric urolithiasis caused by melamine-contaminated milk powder (PUMMP) in a long-term follow-up.Methods One hundred and two of 8335 children (≤ 6-year-old) with history of consuming melamine-contaminated milk powder screened in our hospital were followed up for eighteen months after diagnosis. Urinary system ultrasonography, urinalysis, urinary microprotein profiles [microalbumin (ALBU), immunoglobulin G (IgG), and N-acetyl-β-D-glucosidase (NAG)], urinary melamine and cyanuric acid were examined in the first visit and at the end of follow-up. Results Follow-up was completed in 91 children and the stone was excreted in 82 children (90.1%).Stones less than 5 mm in diameter were most vulnerable to discharge, and stones larger than 10 mm could not be expelled without interventions. At the end of follow-up, no melamine or cyanuric acid was found in the urine samples of 74 patients. Urinalysis showed that incidences of proteinuria, microscopic hematuria and leukocyturia were 0%, 5.1% and 2.0%, which were significant different from those in the first visit (Pproteinutria=0.123, Phemnatuna=0.038 and Pleukocyhuris=0.005).Urinary microprotein profiles revealed that some children whose urinalysis was normal still presented glomerular and renal tubular injury and the abnormal rates were 8.8% and 12.1%respectively. The glomerular injury was mainly related to persistent stone, male and younger.Conclusions 90.1% of children with PUMMP passes urinary stones at the end of follow-up.Stone size is the major risk factor of discharge. No melamine or cyanuric acid is found in the urine of children. After eighteen months, glomerular and renal tubular injury is still found in some patients. Further follow-up is necessary.