OBJECTIVETo improve the method of indirubin in serum by HPLC and apply to pharmacokinetics in rats.

METHODChromatographic separation was conducted on an C18 column (4.6 mm x 250 mm, 5 microm), using a mixture of methanol-water (75:25) as mobile phase at a flow rate of 1.0 mL min(-1) with UV detection at 289 nm, the column temperature was at 35 degrees C and ethinyl estradiol was used as an internal standard. Rats were administered i. v. bolus of indirubin in doses of 2.0 and 4.0 mg x kg(-1) through a jugular vein catheter, respectively. Serial blood samples (about 100 microL) were individually collected at 2, 5, 10, 20, 30, 60, 90, 120, 180 min after administration, and the concentrations of indirubin determined were in rat serum by HPLC. The pharmacokinetic parameters were calculated with the Winnonlin 5.0 software.

RESULTThe calibration curve for indirubin was linear ( R2 = 0.9996) in the range of 0.031-2.48 mg x L(-1) and the limit of detection (LOD) was 31 microg x L(-1). The average recovery of indirubin in rat serum was more than 98% and the relative standard deviations of intra-day and inter-day were both less than 10%. The pharmacokinetics of Indirubin in rats was fitted to two-compartment model.

CONCLUSIONThe method is simple and accurate with a high sensitivity and a good repeatability, and it can be applied to the evaluation of pharmacokinetic parameters of indirubin in rats and blood concentration of indirubin in clinical controlling.

Animals ; Chromatography, High Pressure Liquid ; methods ; Indoles ; blood ; pharmacokinetics ; Male ; Rats ; Rats, Wistar

Objective:To analyze the clinical features and etiological results of neonatal central nervous system(CNS) infection and provide basis for optimization of pathogen detection strategy for CNS infection.Methods:We collected the clinical and laboratory data of hospitalized neonates with clinical diagnosis of CNS infection in the neonatal department at Hebei Provincial Children′s Hospital, from January 1, 2020 to August 31, 2021.The clinical manifestations of the enrolled neonates, as well as the cerebrospinal fluid(CSF)pathogens detected by conventional and molecular biological detection techniques were analyzed.Laboratory characteristics of different kinds of pathogen were compared.Results:A total of 101 eligible neonates were enrolled.The median gestational age was 38.8(36.2, 39.6)weeks, with a prematurity rate 26.7%.There were 68 boys.The median age of onset was 9(2, 14)days.Blood culture was positive in 19(18.8%) cases, including 17 cases of bacteria and two cases of fungus.Positive findings were found in CSF specimens of 33(32.7%)cases by various methods including 13 bacteria, 19 viruses and one fungi.Streptococcus group B and Escherichia coli were the first two bacteria in CSF.Enterovirus was the most common virus in CSF.In terms of detection methods of CSF pathogens, seven cases(7/101, 6.9%) were detected by CSF culture, two cases(2/21, 9.5%)by smear, 22 cases(22/45, 48.9%)by single-virus targeted/multiplex polymerase chain reaction and four cases(4/7, 57.1%)by metagenomic next-generation sequencing.The CSF white blood cell counts, protein levels and blood C-reactive protein levels were higher in the cases with bacteria/fungi detection from CNS infection than in those with virus detection( P<0.05). Almost all neonates(98/101, 97.0%)were clinically cured or significantly improved before discharge.Two neonates were discharged against medical advice and one neonate was transferred to the other hospital after clinical improvement. Conclusion:Combined use of conventional and molecular biological detection techniques can significantly improve the etiological positive rate of neonatal CNS infection.Viral infection is not rare in the neonatal population.Our study demonstrated the spectrum of organism causing neonatal CNS infection, which provided a basis for the optimization of pathogen detection strategy.