Objective: To detect relationship between expression of erythropoietin (EPO) and erythropoietin receptor (EPOR) on kidney and kidney lesion in children with acute kidney injury (AKI).Methods: Thirty-eights children with AKI who involved in the study. The patient population comprised 29 boys and 9 girls. The children with thin basement membrane nephropathy were as control in the study. The expression of EPO and EPOR on kidney in AKI children were examined by immunity histochemistry method. The renal tubulointerstitium histopathologic lesion was shown by the counting score. The correlations between EPO and EPOR expression levels and histopathologic lesion degrees in renal tubulointerstitium were studied in children with AKI. Results Thirty-eight children with AKI were divided into mild patients ( AKI 1 and AKI 2) and serious patients (AKI 3). The levels of EPO expression in AKI children kidney were (6.52±2.12)%, (3.02±0.79)%, and (1.62±0.18)% (P< 0.01), respectively, in control group, mild patients, serious patients. The levels of EPOR expression in AKI children kidney were 40.46±8.42)%, 64.78±16.38)%, 62.36±15.67)% (P< 0.01), respectively, in control group, mild patients, serious patients. There were negative correlation between EPO expression and histopathologic lesion degrees in kidney (r=-0.872, P< 0.01). There were positive correlation between EPOR expression and histopathologic lesion degrees in kidney (r=0.772, P< 0.01). Conclusion:The level of EPO secretion was decreased, but the expression of EPOR was increased in AKI children kidney, which suggested that using extraneous EPO may help to renal repair of AKI children.

Objective:To investigate the effect of illness on preterm infant's hypothalamus-putituary-adrenal axis, we measured the concentration of cortisol, aldosterone and ACTH.Methods: Ninety preterm infants were divided into two groups: gestational age (GA) ≥ 34weeks' and GA< 34weeks'. We measured serum cortisol, aldosterone and ACTH within 72 hours after birth, day 7 and day 14. Results:(1) The serum cortisol concentration on severe illness was higher than that on mild illness. GA≥34weeks', the cortisol concentration on severe illness infants was significantly higher than mild ill infants within 72 hours (t=-2.263, P=0.029). GA< 34 weeks', the cortisol concentration on severe illness infants was significantly higher on the day 14 (t=-2.913, P=0.006).(2) The cortisol concentration was significantly decreased on the day 7 and day 14 than that within 72 hours in the GA≥34weeks' (F = 4.679, p = 0.012); (3) The cortisol concentration on death infants was significant higher than that on survivors on the day 14.(4) When the cortisol concentration was above the 75 th , the incidence of mechanical ventilation therapy, glucose metabolism disorder, gastrointestinal hemorrhage, severe periventricular -intraventricular hemorrhage and brain leukomacia, chronic lung disease, and mortality rate were increased strikingly. Conclusions:The preterm infant already has the ability to response stimuli by regulating cortisol secretion. The cortisol concentration is correlated with the severity of the disease, complications and prognosis.