Objective:To develop and validate a liquid chromatography-tandem mass spectrometry method for determining levofloxacin in plasma sample from pediatric patients.Method:This is a prospective, observational study. The clinical residual plasma samples from healthy individuals for physical examination in Children's Hospital Affiliated to Zhengzhou University were collected as blank matrix. Plasma samples from five pediatric patients who did not receive levofloxacin or ciprofloxacin in the department of Respiration were collected for methodological evaluation. In addition, 34 clinical plasma samples from 22 pediatric patients (9 males and 13 females; mean age (8.1±3.7) years) using levofloxacin was collected, and their plasma concentrations were determined. Using ciprofloxacin as the internal standard, levofloxacin in plasma samples was quantified by liquid chromatography-tandem mass spectrometry following protein precipitation using acetonitrile. A C18 column (Shim-pac GIST-HP C18, 2.1 mm×100 mm, 3 μm) and mobile phase composed of water (containing 0.1% formic acid) and acetonitrile (containing 0.1% formic acid) with gradient elution at a flow rate of 0.4 ml/min were used to separate levofloxacin. The column temperature was 40 ℃, injection volume was 1 μl and the total analysis time was 9 min. Levofloxacin and ciprofloxacin were ionized with an ESI source in positive ion mode and detected in multiple reaction monitoring (MRM) mode. The detected ions of levofloxacin and ciprofloxacin were m/z 362.10→318.1 and 332.15→231.05, respectively. The method′s specificity, sensitivity, linearity, precision, accuracy, recovery rate, stability, matrix effect, and carry-over were validated. All statistical analyses were performed with SPSS statistical software (version 17.0). The normality of the data was detected by the K-S test. A P<0.05 was considered statistically significant for two tailed tests. Results:The LC-MS/MS method showed a good linearity within the range of 0.062 5-20 mg/L, with the lower detection limit of levofloxacin of 0.062 5 mg/L. The calibration curve for levofloxacin was Y=0.093X+0.010 ( R2>0.99). Under different quality control levels, the accuracy ranged from 92.57% to 104.39%, and the intra-day and inter-day imprecision ranged from 2.32% to 9.35%. These values were not affected by the normal matrix, 5% hemolysis matrix and 15% hyperlipidemia matrix. Furthermore, the levofloxacin plasma samples were stable in the short term. A total of 34 plasma samples from 22 patients were collected and analyzed. Only 2 plasma samples were below the lower limit of quantification, while the other plasma concentrations of levofloxacin were ranged from 0.091 to 6.755 mg/L. Cmax was (5.52 ± 1.09) mg/L. Conclusion:The LC-MS/MS method meets the requirements of the reference method and requires a small sample size (50 μl), making it suitable for the determination of levofloxacin in plasma from pediatric patients.

ObjectiveTo investigate the role of endoplasmic reticulum stress genes in the prognosis of pancreatic cancer， and to establish a prognostic prediction model based on the prognostic markers for pancreatic cancer. MethodsTranscriptome sequencing data were downloaded from TCGA and GTEx databases， and MsigDB website was used to obtain endoplasmic reticulum stress genes. A univariate Cox regression analysis was performed to obtain the genes associated with the prognosis of pancreatic cancer， and a consensus clustering analysis was used to construct the molecular typing of pancreatic cancer， while the differentially expressed genes between the two subgroups were obtained. A Lasso regression analysis was used to obtain the core genes associated with the prognosis of pancreatic cancer， which were used to construct a prognostic prediction model for pancreatic cancer. Related datasets were obtained from the GEO database to validate the predictive performance of the model. The CIBERSORT analysis was used to investigate the correlation between risk score and immune infiltration. Quantitative real-time PCR was used to measure the expression of genes in pancreatic cancer tissue and cell lines. The independent-samples t test was used for comparison of continuous data between two groups， and the chi-square test was used for comparison of categorical data between groups. Survival was compared using Log-rank test. The predictive value of the model was evaluated by evaluating the area under the ROC curve. ResultsThe endoplasmic reticulum stress genes CEBPB， MARCKS， PMAIP1， and UBXN10 were independent risk factors for the prognosis of pancreatic cancer， and based on the expression characteristics of these genes， the TCGA pancreatic cancer cohort was divided into two subgroups， i.e.， cluster A and cluster B， while the cluster A patients had a significantly shorter overall survival time than the cluster B patients （P<0.01）. The Lasso regression analysis obtained 5 core genes from the differentially expressed genes affecting the prognosis of pancreatic cancer， and the risk scoring system was established as risk score=0.156×CDA+0.135×AHNAK2+0.020×RHOV+0.095×LY6D+0.054×SPRR1B. The ROC curve analysis showed that this model had good overall predictive performance， with the area under the ROC curve of 0.731 at 1 year， 0.712 at 3 years， and 0.686 at 5 years， and the low-risk group based on this model had a significantly longer overall survival time than the high-risk group （χ²=11.733， P=0.001）. The model showed good predictive performance in the external dataset GSE57495. Quantitative real-time PCR results showed that the expression levels of CDA， AHNAK2， RHOV， LY6D， and SPRR1B in 40 pancreatic cancer tissue samples were significantly upregulated compared with those in normal adjacent tissue samples （t=2.529， 2.458， 3.314， 3.583， and 5.082， all P<0.05）. ConclusionThe expression characteristics of CDA， AHNAK2， RHOV， LY6D， and SPRR1B can be used to predict the prognosis of pancreatic cancer， and the high expression levels of these genes are associated with the poor prognosis of pancreatic cancer patients.

OBJECTIVE: To investigate the effect of vitamin D3 on polarization of monocyte macrophages induced by serum from patients with ankylosing spondylitis (AS). METHODS: Twenty AS naïve patients and 20 healthy controls from Wenzhou People's Hospital during January 2016 and December 2017 were enrolled. The macrophages were differentiated from THP1 cells induced by phorbol 12-myristate 13-acetate (PMA), and then co-cultured with the serum from healthy subjects (control group) or AS patients. Vitamin D3 was added in the medium mixed with serum from AS patients. Flow cytometry was used to analyze the ratio of CD68 and CD206 positive cells, and RT-PCR was performed to detect the mRNA expression of inducible nitric oxide synthase(iNOS) and arginase-1(Arg-1). RESULTS: THP1 cells could be polarized into mononuclear-macrophages with the induction of PMA. The proportion of CD206 positive cells in AS-serum group was lower than that in the control group (=9.434, <0.05), while the proportion of CD68 positive cells was higher than that in the control group (=43.920, <0.05). The proportion of CD206 positive cells in vitamin D3 group was higher than that in AS-serum group (=8.895, <0.05), while the proportion of CD68 positive cells was lower than that in AS-serum group (=9.089, <0.05). mRNA expression of Arg-1 in AS-serum group was lower than that in the control group (=8.899, <0.05), while mRNA expression of iNOS was higher than that in the control group (=3.656, <0.05). mRNA expression of Arg-1 in vitamin D3 group was higher than that in AS-serum group (=6.219, <0.05), while mRNA expression of iNOS was lower than that in AS-serum group (=5.876, <0.05). CONCLUSIONS Vitamin D3 can regulate the polarization of mononuclear macrophages for immunoregulation in patients with AS.
Adjuvants, Immunologic ; pharmacology ; Cell Differentiation ; drug effects ; Cholecalciferol ; pharmacology ; Humans ; Monocytes ; drug effects ; Spondylitis, Ankylosing ; blood ; physiopathology