Min Zhang

Min Zhang, YiRan Wu, ZhaoXu Lu, MeiYan Song, XiaoLan Huang, LaLa Mi, Jian Yang, Xiaodai Cui. Clin Psychopharmacol Neurosci 2023;21:240-51. https://doi.org/10.9758/cpn.2023.21.2.240

Several observational studies have reported associations between low levels of fat-soluble vitamins (A, D and E) and the incidence of pneumonia. Whether infection affects or negatively regulates serum vitamin levels remains controversial. Our aims were to develop and validate a simple-pretreatment and fast method to determine the serum levels of selected fat-soluble vitamins, namely vitamin A (retinol), vitamin D (25-OH-D₃, 25-OH-D₂, and 3-epi-25-OH-D₃), and vitamin E (α-tocopherol), in children suffering from pneumonia during the acute phase and after inflammatory marker recovery. The sample preparation procedure involving protein precipitation and filtration was finished in one step, and separation took 8 min per sample. The calibrations were linear, with R² > 0.99. Both the intra-run (n = 6) and inter-run (n = 3) precision (relative standard deviation, RSD%) values were below 14.61%. The spiked recoveries at 3 concentrations ranged from 80.97 to 111.91%. Accuracies were calibrated using both National Institute of Standards and Technology serum (NIST 968f) and external quality assurance (EQA) samples offered by the National Center of Clinical Laboratories of China, and the relative error (RE%) values ranged from −13.17% to 12.53%. Clinical sample analysis revealed that infection did alter the serum retinol concentration and it did not alter the 25-OH-D and α-tocopherol levels in young children with pneumonia.

Background: Reference intervals (RIs) are normal ranges of clinical indicators established from healthy subjects, and comparing test results with RIs is the first step for clinicians in differentiating between healthy and diseased subjects. Capillary blood is widely used in complete blood count (CBC) tests in children; however, capillary blood‐based RIs for the CBC parameters are still lacking for all pediatric populations. The aim of this study was to establish capillary blood‐based RIs for the CBC parameters in children aged 3 months to 18 years in Beijing.Methods: A total of 6799 capillary blood specimens from children were collected, including 3832 males and 2967 females aged 3 months to 18 years, and CBC parameters were analyzed. Data analysis, RI calculations, and 90% confidence interval (CI) calculations were performed according to CLSI C28‐A3 guidelines.Results: Capillary blood RIs for 22 CBC parameters were established in children aged 3 months to 18 years. The levels of most red blood cell‐related parameters increased with age and were generally higher in males than in females. White blood cell counts were relatively stable, with no obvious upward or downward trends from 3 months to 18 years of age. Platelet levels decreased within the first year and tended to be stable thereafter. Further validation with 458 healthy children illustrated that the verified results were within the established RIs with a 90%‐100% proportion.Conclusion: We established capillary blood RIs for 22 CBC parameters in children across a broad age range in Beijing.

Neural tube defects (NTDs) are serious congenital malformations. Excessive maternal homocysteine (Hcy) increases the risk of NTDs, while its mechanism remains elusive. Here we report the role of histone homocysteinylation in neural tube closure (NTC). A total of 39 histone homocysteinylation sites are identified in samples from human embryonic brain tissue using mass spectrometry. Elevated levels of histone KHcy and H3K79Hcy are detected at increased cellular Hcy levels in human fetal brains. Using ChIP-seq and RNA-seq assays, we demonstrate that an increase in H3K79Hcy level down-regulates the expression of selected NTC-related genes including Cecr2, Smarca4, and Dnmt3b. In human NTDs brain tissues, decrease in expression of CECR2, SMARCA4, and DNMT3B is also detected along with high levels of Hcy and H3K79Hcy. Our results suggest that higher levels of Hcy contribute to the onset of NTDs through up-regulation of histone H3K79Hcy, leading to abnormal expressions of selected NTC-related genes.

Background: Neural tube defects are a group of severe neurological birth defects with one-carbon metabolism disturbance. The lack of information available on the distribution of one-carbon metabolites in lesion tissues precludes further elucidation of the pathogenesis of NTDs. Our aims were to develop and validate a simple and robust method for one-carbon related amino acid measurements in both intracellular and extracellular bio-samples and apply this method to NTD tissues for risk metabolite screening. Method: A simultaneous test for nine amino acids (homocysteine, S-adenosylhomocysteine, serine, histidine, methionine, cystathionine, cysteine, glycine, and tryptophan) in both intracellular and extracellular matrices was developed using liquid chromatography tandem mass spectrometry in a multiple reaction monitoring mode. Three kinds of tissues from folate deficient and NTD-affected embryos and controls in a NTD high-risk area were analyzed using this method. Results: Method recoveries ranged from 87.10% to 118.85% and accuracy (relative error, RE%) ranged from −14.96% to 13.96%. Calibration curves were linear (R² > 0.99). The within-run and between-run precision were both lower than 15%. Reproducibility CV% ranged from 0.29% to 13.37% in low, medium and high concentration standard spiked plasma, HEK-293 cells, and brain, lung, heart tissues. NTD brain tissue showed significantly high concentration of homocysteine and cystathionine, and low concentration of histidine, glycine, methionine and tryptophan. Conclusion: This high-throughput method is reliable and accurate for simultaneous determination of one-carbon amino acid metabolites in both intracellular and extracellular bio-samples.