Preoperative serum cortisone levels are associated with cognition in preschool-aged children with tetralogy of Fallot after corrective surgery: new evidence from human populations and mice.

BACKGROUND: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Children with TOF would be confronted with neurological impairment across their lifetime. Our study aimed to identify the risk factors for cerebral morphology changes and cognition in postoperative preschool-aged children with TOF. METHODS: We used mass spectrometry (MS) technology to assess the levels of serum metabolites, Wechsler preschool and primary scale of intelligence-Fourth edition (WPPSI-IV) index scores to evaluate neurodevelopmental levels and multimodal magnetic resonance imaging (MRI) to detect cortical morphological changes. RESULTS: Multiple linear regression showed that preoperative levels of serum cortisone were positively correlated with the gyrification index of the left inferior parietal gyrus in children with TOF and negatively related to their lower visual spaces index and nonverbal index. Meanwhile, preoperative SpO2 was negatively correlated with levels of serum cortisone after adjusting for all covariates. Furthermore, after intervening levels of cortisone in chronic hypoxic model mice, total brain volumes were reduced at both postnatal (P) 11.5 and P30 days. CONCLUSIONS: Our results suggest that preoperative serum cortisone levels could be used as a biomarker of neurodevelopmental impairment in children with TOF. Our study findings emphasized that preoperative levels of cortisone could influence cerebral development and cognition abilities in children with TOF.

Common alterations in plasma free amino acid profiles and gut microbiota-derived tryptophan metabolites of five types of cancer patients.

Amino acids not only play a vital role in the synthesis of biological molecules such as proteins in cancer malignant cells, they are also essential metabolites for immune cell activation and antitumor effects in the tumor microenvironment. The abnormal changes in amino acid metabolism are closely related to the occurrence and development of tumors and immunity. Intestinal microorganisms play an essential role in amino acid metabolism, and tryptophan and its intestinal microbial metabolites are typical representatives. However, it is known that the cyclic amino acid profile is affected by specific cancer types, so relevant studies mainly focus on one type of cancer and rarely study different cancer forms at the same time. The objective of this study was to examine the PFAA profile of five cancer patients and the characteristics of tryptophan intestinal microbial metabolites to determine whether there are general amino acid changes across tumors. Plasma samples were collected from esophageal (n = 53), lung (n = 73), colorectal (n = 94), gastric (n = 55), breast cancer (n = 25), and healthy control (HC) (n = 139) subjects. PFAA profile and tryptophan metabolites were measured, and their perioperative changes were examined using high-performance liquid chromatography. Univariate analysis revealed significant differences between cancer patients and HC. Furthermore, multivariate analysis discriminated cancer patients from HC. Regression diagnosis models were established for each cancer group using differential amino acids from univariate analysis. Receiver-operating characteristic analysis was applied to evaluate these diagnosis models. Finally, GABA, arginine, tryptophan, taurine, glutamic acid, and melatonin showed common alterations across all types of cancer patients. Metabolic pathway analysis shows that the most significant enrichment pathways were tryptophan, arginine, and proline metabolism. This study provides evidence that common alterations of the metabolites mentioned above suggest their role in the pathogenesis of each cancer patient. It was suggested that multivariate models based on PFAA profiles and tryptophan metabolites might be applicable in the screening of cancer patients.

Determination of aflatoxin B1 by novel nanofiber-packed solid-phase extraction coupled with a high performance liquid chromatography-fluorescence detector.

A novel analytical proposal based on nanofiber-packed solid-phase extraction coupled with high performance liquid chromatography-fluorescence detector (HPLC-FLD) has been successfully developed for determining aflatoxin B1 (AFB1) in foods. Four types of nanofibers, including polystyrene (PS) nanofibers, polypyrrole (PPY) nanofibers, polystyrene-acrylic resin (PS-AR) nanofibers, and polystyrene-polyvinyl pyrrolidone (PS-PVP) nanofibers, were fabricated by electrospinning and utilized to prepare a home-made extraction device. In this study, the factors of different fibers, namely, fiber dosage, pH of extraction solution, type of salt ion, concentration of salt ion, and volume of the eluent were optimized. Under optimized conditions, the method showed good linearity in the range of 0.1-40 ng mL-1 with a correlation coefficient greater than 0.999 and good inter-day accuracy (90.8-112.7% recovery) and precision (1.8-3.6% intra-day RSDs, 2.6% inter-day RSD), and the limit of detection (LOD) was 0.05 ng mL-1. Due to its cost-effective, time-saving, environmentally friendly, and simple performance, it has the potential to be utilized to determine aflatoxins in complicated matrices.

Determination of polyamines in urine via electrospun nanofibers-based solid-phase extraction coupled with GC-MS and application to gastric cancer patients.

The simultaneous determination of polyamines and their metabolites in urine samples was achieved by gas chromatography-mass spectrometry in the selected ion monitoring mode. After conjugating with the ion-pair reagent bis-2-ethylhexylphosphate in the aqueous phase, the polyamines in the samples were extracted with polystyrene nanofiber-based packed-fiber solid-phase extraction followed by a derivatization step using pentafluoropropionyl anhydride. With optimal conditions, all analytes were separated well. For analytes of putrescine, cadaverine, N-acetylputrescine, and N-acetylcadaverine, the linearity was good in the range of 0.05-500 µmol/L (R2  ≥ 0.993). While for spermidine, spermine, acetylspermidine, N8 -acetylspermidine, and N-acetylspermine, the linearity was good in the range of 0.5-500 µmol/L (R2  ≥ 0.990). The recoveries of three spiked concentrations (0.5, 5, 300 µmol/L) were 85.6%-108.4%, and relative standard deviations for intra- and interday were in the range of 2.9%-13.4% and 4.5%-15.1%, respectively. The method was successfully applied to the analysis of urine samples of gastric cancer patients. The results showed that the levels of most polyamines and N-acetylated polyamines from the patient group were significantly higher than those from the control group. The altered concentrations of the above-mentioned metabolites suggest their role in the pathogenesis of gastric cancer, and they should be further evaluated as potential markers of gastric cancer.

Rapid determination of seven synthetic dyes in casual snacks based on packed-fibers solid-phase extraction coupled with HPLC-DAD.

Based on packed-fiber solid-phase extraction and HPLC-DAD, a simple analytical method for the determination of seven synthetic dyes has been successfully developed. Polystyrene/polypyrrole (PS/PPy) fibers were obtained via electro-spinning of polystyrene skeletal nanofibers, followed by the oxidation with FeCl3 to trigger the polymerization of pyrrole and the deposition of polypyrrole coatings on PS fibrous skeleton fibers. The relationship between the extraction performance of the fibers and the electrospinning process at different humidities was investigated based on morphologic study and BET surface area. In the extraction process, purification, concentration, and desorption could be accomplished in one step. The established method exhibited good sensitivity, selectivity, reproducibility, and good efficiency for synthetic dyes in casual snacks (preserved fruit, flavored yogurt, and fruity hard candy) samples. With optimal conditions, the LODs (S/N = 3) were 2.4 to 21.09 ng mL-1, and linearities were acceptable in liquid matrix and solid matrices. The recoveries were 93.9-103.9%.

Simultaneous analysis of two urinary biomarkers of oxidative damage to DNA and RNA based on packed-fiber solid phase extraction coupled with high-performance liquid chromatography.

The determination of the concentrations of urinary biomarkers of oxidative damage to DNA and RNA is difficult due to the low content of targets and the complex matrix of urine. A method using polystyrene/polypyrrole (PS/PPY) electronspun nanofibers as the adsorbent was introduced to the routine urinary treatment and determination of 8-OHdG and 8-oxoG for the first time. And 2-aminoethyl diphenylborate (DPBA) solution was creatively used in the loading and rinsing steps in order to promote the retention of the analytes as well as remove impurities. Under optimal conditions, 8-OHdG, 8-oxoG and IS were separated very well and exhibited a good linearity in the range of 0.5-50 ng mL-1, with correlation coefficients of R2 > 0.996. Limits of detection (LOD) were 0.058 ng mL-1 and 0.093 ng mL-1, and limits of quantification (LOQ) were 0.195 ng mL-1 and 0.309 ng mL-1, respectively. The recoveries were 88.8-104.9%. The proposed method was so simple and economical that it had the potential to be applied to batch quantitative analysis of 8-OHdG and 8-oxoG in urine. And it was successfully applied to real urine samples of cancer patients.

Solid phase extraction with Polypyrrole nanofibers for simultaneously determination of three water-soluble vitamins in urine.

This paper put forward a prospective pre-cleanup method of packed-fiber solid phase extraction by using Polypyrrole (Ppy) electrospun nanofibers as the sorbent to simultaneously extract three water-soluble vitamins (i.e., folic acid, cyanocobalamin and riboflavin) in human urine. Primary extraction of target analytes was carried out by loading samples onto the column along with diphenylboronic acid 2-aminoethylester (DPBA) reagent, and then the column should be rinsed with DPBA solution for three times before eluting. The DPBA was innovatively applied as complexing reagent to retain as much of three analytes as possible on the column based on the multi interaction between three vitamins and the boronate affinity reagent, thus improving hydrophobicity of targets and adsorption efficiency through loading and rinsing steps. Under optimized conditions, sample concentration factor was five times with small amount of organic solvent consumed and recoveries between 84.9% to 125.4%, and the lowest detection limit (LOD) between 0.020 to 0.041 µg/mL were achieved. Finally, the urine samples from a group of healthy children were processed with the optimized method. It proved that the proposed method is applicable in the determination of urinary B-vitamins in big samples of people.

Simultaneous determination of five phthalate esters and bisphenol A in milk by packed-nanofiber solid-phase extraction coupled with gas chromatography and mass spectrometry.

A novel polystyrene/pyridine composite nanofiber was synthesized and utilized as the sorbent material for the solid-phase extraction of bisphenol A and five common phthalate esters in milk. The method of extraction integrated extraction and preconcentration of target analytes into a single step. Bisphenol A and five common phthalate esters were selected as target compounds for the development and evaluation of the method. The effects of operating parameters for nanofiber-based solid-phase extraction, such as selection and amount of sorbent, the volume fraction of perchlorate (precipitate protein), desorption solvent, volume of desorption solvent, and effect of salt addition were optimized. Under optimal conditions, higher extraction recoveries (89.6-118.0%) of the six compounds in milk spiked at three levels were obtained, and the satisfied relative standard deviation were ranged from 0.6 to 10.9%. The detection limits and quantification limits of the method ranged from 0.01 to 0.06 µg/L and 0.05 to 0.53 µg/L, respectively. Matrix effects were also verified and well controlled in the range of 91.3-109.3%. The new method gave better performance metrics than Chinese standard method and other published methods. Thus, the proposed method may be applied to the analysis of the phthalate esters and bisphenol A in complex matrixes.

Polystyrene nanofibers capped with copper nanoparticles for selective extraction of glutathione prior to its determination by HPLC.

Polystyrene nanofibers were coated with copper nanoparticles (CuNPs) by a combination of electrospinning and in-situ reduction of Cu(II) using sodium borohydride as the reductant. The CuNPs on the nanofibers were characterized by energy dispersive spectrometry, scanning electron microscopy and transmission electron microscopy. A cartridge was packed with the nanofibers which then were activated with methanol and water. Glutathione (GSH) is found to quantitatively adsorbed by the packed cartridge at pH 3.0, and then can be desorbed with aqueous 2-mercaptoethanol and detected, after derivatization with ortho-phthalaldehyde, via high performance liquid chromatography with fluorometric detection. Under optimized conditions, the method has a 1.1 ng·mL-1 detection limit and a response that is linear in the 10-1000 ng·mL-1 GSH concentration range. The recoveries of GSH from artificial urine spiked at three levels (80, 400 and 800 ng·mL-1) are in the range of 94.6-98.6% with relative standard deviations (RSD) of <4.5% (n = 5). The method was applied to assessing the differences in urinary GSH between high-risk infants and healthy infants. The results show that the levels of GSH of normal infants are significantly higher than those of high-risk infants (P < 0.05). Graphical abstract Schematic of the preparation of CuNP-assembled nanofibers and the mechanism of extracting glutathione (GSH). GSH can be extracted by this material based on a strong interaction between the sorbent and GSH. This is attributed to the formation of Cu-S bonds between Cu and -SH.

Packed-Nanofiber solid phase extraction coupled with gas chromatography-mass spectrometry for the determination of phthalate esters in urines from children.

In this paper, we developed a rapid and safe method based on packed-fiber solid-phase extraction (PFSPE) system coupled with gas chromatography-mass spectrometry for the determination of four phthalate esters (PAEs), diethyl-o-phthalate (DEP), dibutyl-o-phthalate (DBP), di (2-ethylhexyl) phathalate (DEHP), di-n-octyl phthalate (DNOP), in urine samples. The PAEs in urine samples (500µL) were rapidly cleaned up from urines using polystyrene (PS) nanofibers packed micro-columns fitted on a PFSPE pretreatment device, which can process up to 12 samples simultaneously in 5min. Under optimum conditions, satisfied recovery and relative standard deviation values (RSDs) were in the range of 80.4-111.7% and 1.5-10.9%, respectively. The limits of detection (LOD) and the limits of quantification (LOQ) were ranged from 0.1 to 0.5ngmL-1 and 0.5-2ngmL-1, respectively. The well controlled matrix effect was also evaluated by comparing the signal response of the pure PAEs standards dissolved in methanol with the signal response of PAEs in the urine matrix. This new method was successfully applied to determine four PAEs in urine samples of overweight and normal-weight children, and an association between phthalates in urines and obesity was observed. Thus, the method seems to be a useful tool for monitoring of the level of urinary phthalate esters and also to support an evidence for further reasearch of obesity.

Application of packed-fiber solid-phase extraction coupled with GC-MS for the determination of short-chain fatty acids in children's urine.

BACKGROUND: Autism spectrum disorder (ASD) is a complex disorder involving interactions between genetic, epigenetic and environmental factors. Gastrointestinal (GI) disorders are prevalent in the cohort of children with ASD and they have been recognized as a comorbid condition recently. It is of value to monitor GI issues in individuals, and to help further characterize factors that may contribute to GI disorders (in individuals with and without ASD). Due to the biological relevance of short-chain fatty acids (SCFAs) to GI disorders, it is important to develop a rapid and selective detection method capable of identifying and quantifying SCFAs in complex biological samples. Because of low concentration and hydrophilicity of SCFAs, the pretreatment of sample becomes the key step to detection method. We erected and verified a packed-fiber solid-phase extraction (PFSPE) based on Polypyrrole (PPY) nanofibers coupled with gas chromatography-mass spectrometry (GC-MS) to determine SCFAs in urine. The proposed method was applied to detect SCFAs in urine from children with and without ASD, and the results between the 2 groups was compared. METHODS: PFSPE method was utilized for the direct pretreatment of SCFAs in urine from children. The SCFAs extracted on nanofibers was subsequently eluted with hydrochloric acid ethanol solution and detected by GC-MS. RESULTS: Intraday and interday assay CVs were ≤10%, and the recoveries was 82.6%-110.5%. Limit of detection (LOD) and limit of quantification (LOQ) were 0.25-2.67ng/ml and 0.85-8.97ng/ml, respectively. The level of SCFAs in urine from children with ASD were significantly higher than that from control group. CONCLUSION: The proposed method improves the simplification of sample treatment and displays sufficient analytical sensitivity and selectivity. The assay offers a potential to monitor the SCFAs in urine in clinical and experimental investigation of ASD.

Selective extraction of catecholamines by packed fiber solid-phase using composite nanofibers composing of polymeric crown ether with polystyrene.

For the first time, electrospun composite nanofibers comprising polymeric crown ether with polystyrene (PCE-PS) have been used for the selective extraction of catecholamines - dopamine (DA), norepinephrine (NE) and epinephrine (E) - prior to their analysis by high-performance liquid chromatography-electrochemical detection. Using a minicartridge packed with PCE-PS composite nanofibers, the target compounds were extracted effectively from urine samples to which diphenylborinic acid 2-aminoethyl ester was added as a complexing reagent. The extracted catecholamines could be liberated from the fiber by the addition of acetic acid. A good linearity was observed for catecholamines in the range of 2.0-200 ng mL(-1) (NE, E and DA). The detection limits of catecholamines (signal-to-noise ratio = 3) were 0.5 ng mL(-1) (NE), 0.2 ng mL(-1) (E) and 0.2 ng mL(-1) (DA), respectively. Under the optimized conditions, the absolute recoveries of the above three catecholamines were 90.6% (NE), 88.5% (E) and 94.5% (DA). The repeatability of extraction performance was from 5.4 to 9.2% (expressed as relative standard deviation). Our results indicate that the proposed method could be used for the determination of NE, E and DA in urine.

Polypyrrole hollow fiber for solid phase extraction.

We have developed a solid-phase extraction method based on conductive polypyrrole (PPy) hollow fibers which were fabricated by electrospinning and in situ polymerization. The electrospun poly (e-caprolactone) (PCL) fibers were employed as templates for the in situ surface polymerization of PPy under mechanical stirring or ultrasonication to obtain burr-shaped or smooth fiber shells, respectively. Hollow PPy fibers, achieved by removing the PCL templates, were the ideal sorbents for solid phase extraction of polar compounds due to their inherent multi-functionalities. By using the hollow PPy fibers, two important neuroendocrine markers of behavioural disorders, 5-hydroxyindole-3-acetic acid and homovanillic acid, were successfully extracted. Under the optimized conditions, the absolute recoveries of the above two neuroendocrine markers were 90.7% and 92.4%, respectively, in human plasma. Due to its simplicity, selectivity and sensitivity, the method may be applied to quantitatively analyse the concentrations of polar species in complex matrix samples.