Pathological changes in rat model of urinary calculus induced by melamine / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate melamine-induced pathological changes in the kidney.</p><p><b>METHOD</b>Wistar rats were fed with a diet containing 0, 1% and 2% melamine for 15 weeks. After melamine feeding was stopped, various outcome measures were observed for 4 weeks.</p><p><b>RESULT</b>Rats fed with melamine showed reduced caloric intake, slower weight gain and impaired renal function. The blood urea nitrogen of group A and B [(13.23 ± 5.10) mmol/L and (18.30 ± 5.90) mmol/L, respectively] and serum creatinine levels of group B [(19.90 ± 2.90) mmol/L] were higher than that of group C [(8.23 ± 2.30) mmol/L and (10.04 ± 1.73) mmol/L](P < 0.01, respectively). Additionally, the kidney coefficients of group A and B were higher than that of group C (P < 0.01, respectively). Crystals, tubular ectasia and interstitial inflammation and fibrosis were found in the kidneys of melamine fed rats. Four weeks after discontinuation of feeding with melamine-contained diet, the caloric intake and weight of the rats increased, the coefficients of the kidney decreased, and the blood urea nitrogen of group A and B [(17.96 ± 2.04) mmol/L and (19.20 ± 3.36) mmol/L, respectively] and serum creatinine levels of group B [(24.20 ± 5.28) mmol/L], which became worse than 4 weeks before (P < 0.01;P < 0.05, respectively), and were still higher than that of group C [(8.30 ± 1.79) mmol/L and (9.87 ± 2.71) mmol/L, P < 0.01, respectively]. Crystals remained inside the kidney, changes in the renal interstitium did not improve.</p><p><b>CONCLUSION</b>(1) Melamine-induced urinary calculus rat model can be established by feeding 3-week old male Wistar rats with a diet containing 2% melamine for 15 weeks. The main constituent of the urinary calculus was melamine (> 90%), with a little uric acid and traces of cyanuric acid. (2) Melamine damaged the renal function, formed renal crystals, and led to the pathological changes of kidneys. All the influences seemed to be dose-depended and was related with the obstruction of the crystals or calculus in the kidney. (3) The renal function and the pathological changes did not improve 4 weeks after discontinuation of feeding with melamine-contained diet.</p>

Diagnosis and treatment of melamine-associated urinary calculus complicated with acute renal failure in infants and young children / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Infants in some areas of China developed urinary lithiasis after being fed with powdered milk that was tainted with melamine in 2008 and very small proportion of the infants developed acute renal failure caused by urinary tract calculus obstruction. The aim of this article was to summarize clinical characteristics, diagnosis and treatment of infants with urinary calculus and acute renal failure developed after being fed with melamine tainted formula milk.</p><p><b>METHODS</b>Data of infant patients with urinary calculus and acute renal failure due to melamine tainted formula milk admitted to the Beijing Children's Hospital Affiliated to the Capital Medical University and the Xuzhou Children's Hospital in 2008 were used to analyze the epidemiological characteristics, clinical manifestations, imaging features as well as effects of 4 types of therapies.</p><p><b>RESULTS</b>All the 34 infants with urinary calculus were complicated with acute renal failure, their blood urea nitrogen (BUN) was (24.1+/-8.2) mmol/L and creatinine (Cr) was (384.2+/-201.2) micromol/L. The chemical analysis on the urinary calculus sampled from 15 of the infants showed that the calculus contained melamine and acidum uricum. The time needed for the four types of therapies for returning Cr to normal was (3.5+/-1.9) days for cystoscopy group, (2.7+/-1.1) days for lithotomy group, (3.8+/-2.3) days for dialysis group, and (2.7+/-1.6) days for medical treatment group, which had no statistically significant difference (P=0.508). Renal failure of all the 34 infants was relieved within 1 to 7 days, averaging (3.00+/-1.78) days.</p><p><b>CONCLUSIONS</b>Melamine tainted formula milk may cause urinary calculus and obstructive acute renal failure. It is suggested that firstly the patients with urinary calculus complicated with acute renal failure should be treated with dialysis or medication to correct electrolyte disturbance, in particular hyperkalemia, and then relieve the obstruction with available medical and surgical methods as soon as possible. It was observed that the short-term prognosis was satisfactory.</p>

Melamine related urinary calculus and acute renal failure in infants / 中华儿科杂志

<p><b>OBJECTIVE</b>To summarize clinical characteristics, diagnosis and treatment of infants with urinary calculus and acute renal failure developed after being fed with melamine tainted formula milk.</p><p><b>METHODS</b>Data of infant patients with urinary calculus and acute renal failure due to melamine tainted formula milk admitted to the Beijing Children's Hospital affiliated to the Capital Medical University and the Xuzhou Children's Hospital in 2008 were used to analyze the epidemiological characteristics, clinical manifestations, image features as well as effects of 4 types of therapies.</p><p><b>RESULTS</b>All the 34 infants with urinary calculus were complicated with acute renal failure, their blood urea nitrogen (BUN) was (24.1 +/- 8.2) mmol/L and creatinine (Cr) was (384.2 +/- 201.2) micromol/L. The chemical analysis on the urinary calculus sampled from 14 of the infants showed that the calculus contained melamine and acidum uricum. The time needed for the four types of therapies for returning Cr to normal was (3.5 +/- 1.9) d for cystoscopy group, (2.7 +/- 1.1) d for lithotomy group, (3.8 +/- 2.3) d for dialysis group, and (2.7 +/- 1.6) d for medical treatment group, which had no statistically significant difference (P = 0.508). Renal failure of all the 34 infants was relieved within 1 to 7 days, averaging (3.0 +/- 1.8) d.</p><p><b>CONCLUSION</b>Melamine tainted formula milk may cause urinary calculus and obstructive acute renal failure. It is suggested that firstly the patients with urinary calculus complicated with acute renal failure should be treated with dialysis or medication to correct electrolyte disturbances, in particular hyperkalemia, and then relieve the obstruction with available medical and surgical methods as soon as possible. It is observed that the short term prognosis is satisfactory.</p>