Analysis of serum metabolism in premature infants before and after feeding using GC-MS and the relationship with necrotizing enterocolitis.

Preterm birth and enteral feeding are two main factors leading to necrotizing enterocolitis (NEC). The metabolomics of preterm infants before and after feeding can provide a basis for the prediction of NEC. Using the method of cross-sectional study, the mode was established with the serum samples of 19 premature infants at birth and after feeding as the control group. The serum was analyzed using GC-MS. Chemometric analysis includes principal component analysis, partial least squares-discriminant analysis, and orthogonal partial least squares-discriminant analysis. Spectral separation of serum metabolites occurred in premature infants before and after feeding. The levels of xylose, d-talose, phosphoglycolic acid, maleimide, l-gulonolactone, maleic acid, ß-hydroxypyruvate, itaconic acid, and pantothenic acid in the serum of premature infants after feeding were significant in both multidimensional and single-dimensional modes (variable importance in projection >2, P < 0.01). There was a moderate correlation between total bilirubin and l-gulonolactone and ß-hydroxypyruvate (0.8 > r > 0.5). Maleimide, maleic acid, and itaconic acid have diagnostic value (area under the curve >0.9). The results indicated that serum metabolism of preterm infants changes significantly after feeding. Some metabolites have potential value in predicting NEC.

Intestinal tract and parenteral multi-organ sequential pathological injury caused by necrotizing enterocolitis.

BACKGROUND: To explore the relationship between the pathological changes of the colon, terminal ileum, lung, liver and kidney, and the changes of Bax, PCNA and PAF in a rat model of NEC. METHODS: One hundred and forty neonatal SD rats were randomly divided into NEC group and control group (70 in each group). NEC group was given hypoxia, cold stimulation and artificial feeding twice a day for 3 consecutive days. The control group was only fed normally. After modeling, From the 1st day to the 7th day, 10 rats were sampled in each group for pathological examination of colon, terminal ileum, lung, liver and kidney tissue. The levels of Bax, PCNA and PAF were investigated by immunohistochemistry. RESULTS: Compared with the normal group, in the NEC group, on the 1st day, the colon, terminal ileum, lung, liver and kidney showed inflammatory damage. On the 5th day, the inflammatory injury was reduced. The inflammation disappeared on the 7th day. There were differences in the time of apoptosis in the intestine. In the intestine, the proliferation of PCNA was weak at first and then strong. Bax in liver and kidney showed marked apoptosis and apoptosis time increased in the lung. The expression of PCNA increased in lung, liver and kidney, and the expression of PAF increased in lung and liver. CONCLUSIONS: NEC can lead to secondary injury of different degrees in colon, terminal ileum, lung, liver and kidney, and the degree and time of injury and repair were different. In general, organ repair played a leading role on the 4th day after modeling.

[Serum metabolomics of preterm and full-term infants based on gas chromatography-mass spectrometry].

OBJECTIVE: To study the features of serum metabolites in preterm infants based on gas chromatography-mass spectrometry (GC-MS), and to find differentially expressed metabolites in the serum of preterm infants. METHODS: Serum samples were collected from 19 preterm infants and 20 full-term infants before feeding. GC-MS was used to measure metabolic profiles, and the metabolic features of 397 serum metabolites in preterm infants were analyzed. RESULTS: There was a significant difference in serum metabolic features between the preterm and full-term infants before feeding. There were significant differences between the full-term and preterm infants in the levels of metabolites such as O-phosphonothreonine, digicitrin, tannic acid, and fructose-1,6-diphosphate (P<0.01), suggesting that the above differentially expressed metabolites were highly differentiated between the preterm and full-term infants. Most differentially expressed metabolites were involved in the metabolic pathways such as ABC transporters, ß-alanine and pyrimidines and were correlated with some clinical parameters (albumin and total bilirubin) (P<0.05). CONCLUSIONS: There is a significant difference in serum metabolites between preterm and full-term infants before feeding. Metabolomics plays an important role in improving metabolic disorders and exploring metabolism-related diseases in preterm infants.

Gas chromatography-mass spectrometry based serum metabolic analysis for premature infants and the relationship with necrotizing enterocolitis: a cross-sectional study.

BACKGROUND: Preterm birth and feeding are the most important pathogenic factors of neonatal necrotizing enterocolitis (NEC). Metabonomic has been widely used in the diagnosis and treatment of other diseases, but there is no research on the related diseases of premature infants. Compared with full-term infants, the metabolism of preterm infants has its own specificity, so it can easily lead to NEC and other digestive tract inflammatory diseases. Metabonomic may be applied to the diagnosis of preterm related diseases, such as NEC. METHODS: The model was established with premature infant serum samples from 19 premature infants in our hospital, which was compared with the full-term infant control group. Serum was analyzed by gas chromatography-mass spectrometry (GC-MS), coupled with the analysis of serum metabolic characteristics. The variable important in projection, P value and Pearson correlation coefficient of samples were analyzed by using SIMCA, SPSS and other multivariate statistical analysis software. RESULTS: Compared to the term infants, premature infants had significantly higher levels of luteolin, and lower levels of xylose, O-succinyl-L-homoserine and lauric acid in the serum. There were some correlations among several different metabolites and clinically related indices (albumin, total bilirubin) for premature birth related diseases. CONCLUSIONS: There are metabolic alterations in the serum of premature infants, which make contribution to the diagnosis of NEC.

A novel H(2)O(2) amperometric biosensor based on gold nanoparticles/self-doped polyaniline nanofibers.

A new kind of gold nanoparticles/self-doped polyaniline nanofibers (Au/SPAN) with grooves has been prepared for the immobilization of horseradish peroxidase (HRP) on the surface of glassy carbon electrode (GCE). The ratio of gold in the composite nanofibers was up to 64%, which could promote the conductivity and biocompatibility of SPAN and increase the immobilized amount of HRP molecules greatly. The electrode exhibits enhanced electrocatalytic activity in the reduction of H(2)O(2) in the presence of the mediator hydroquinone (HQ). The effects of concentration of HQ, solution pH and the working potential on the current response of the modified electrode toward H(2)O(2) were optimized to obtain the maximal sensitivity. The proposed biosensor exhibited a good linear response in the range from 10 to 2000 µM with a detection limit of 1.6 µM (S/N=3) under the optimum conditions. The response showed Michaelis-Menten behavior at larger H(2)O(2) concentrations, and the apparent Michaelis-Menten constant K(m) was estimated to be 2.21 mM. The detection of H(2)O(2) concentration in real sample showed acceptable accuracy with the traditional potassium permanganate titration.