An upstream signaling gene calmodulin regulates the synthesis of insect wax via activating fatty acid biosynthesis pathway.

Insect wax accumulates on the surface of insect cuticle, which acts as an important protective barrier against rain, ultraviolet light radiation, pathogens, etc. The waxing behavior, wax composition and molecular mechanism underling wax biosynthesis are unclear in dustywings. Herein, the current study determined the vital developmental stage for waxing behavior in dustywings, examined the components of waxy secretions, and identified key regulatory genes for wax biosynthesis. The wax glands were mainly located on the thorax and abdomen of dustywing adults. The adults spread the waxy secretions over their entire body surface. The metabolomics analysis identified 32 lipids and lipid-like molecules, 15 organic acids and derivatives, 7 benzenoids, etc. as the main components of waxy secretions. The fatty acids represented the largest proportion of the category of lipid and lipid-like molecules. The conjoint analysis of metabolomics and transcriptomics identified two crucial genes fatty acyl-CoA reductase (CsFAR) and calmodulin (CsCaM) for wax biosynthesis. The down-regulation of these genes via nanocarrier-mediated RNA interference technology significantly reduced the amount of wax particles. Notably, the RNAi of CsCaM apparently suppressed the expression of most genes in fatty acid biosynthesis pathway, indicating the CsCaM might act as a main upstream regulator of fatty acid biosynthesis pathway.

Optimization of Busulfan Dosing Regimen in Pediatric Patients Using a Population Pharmacokinetic Model Incorporating GST Mutations.

PURPOSE: The aim of this study was to develop a novel busulfan dosing regimen, based on a population pharmacokinetic (PPK) model in Chinese children, and to achieve better area under the concentration-time curve (AUC) targeting. PATIENTS AND METHODS: We collected busulfan concentration-time samples from 69 children who received intravenous busulfan prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT). A population pharmacokinetic model for busulfan was developed by nonlinear mixed effect modelling and was validated by an external dataset (n=14). A novel busulfan dosing regimen was developed through simulated patients, and has been verified on real patients. Limited sampling strategy (LSS) was established by Bayesian forecasting. Mean absolute prediction error (MAPE) and relative root mean Squared error (rRMSE) were calculated to evaluate predictive accuracy. RESULTS: A one-compartment model with first-order elimination best described the data. GSTA1 genotypes, body surface area (BSA) and aspartate aminotransferase (AST) were found to be significant covariates of Bu clearance, and BSA had significant impact of the volume of distribution. Moreover, two equations were obtained for recommended dose regimens: dose (mg)=34.14×BSA (m2)+3.75 (for GSTA1 *A/*A), Dose (mg)=30.99×BSA (m2)+3.21 (for GSTA1 *A/*B). We also presented a piecewise dosage based on BSA categories for each GSTA1 mutation. A two-point LSS, two hours and four hours after dosing, behaved well with acceptable prediction precision (rRMSE=1.026%, MAPE=6.55%). CONCLUSION: We recommend a GSTA1-BSA and BSA-based dosing (Q6 h) based on a PPK model for personalizing busulfan therapy in pediatric population. Additionally, an optimal LSS (C2h and C4h) provides convenience for therapeutic drug monitoring (TDM) in the future.

A rapid HPLC-MS/MS method for determining busulfan in hemolytic samples from children with hematopoietic stem cell transplantation.

A rapid and sensitive method for the quantitative detection of busulfan (BU) in children's hemolytic samples by HPLC-tandem mass spectrometry (MS/MS) was established. In this study, the sample preparation procedure involved a one-step protein precipitation with acetonitrile (ACN) solution, and the HPLC-MS/MS method used Hypersil GOLD C18 . The mobile phase consisted of 10 mM ammonium acetate solution (containing 0.1% formic acid) and ACN with a flow rate of 0.4 mL/min. Multiple reaction monitoring modes were used for quantitative analysis and the ion pairs of BU and BU-d8 were m/z 263.9 → 150.9 and 272.0 → 159.0, respectively. BU had a good linearity in the range of 0.01-10 µg mL-1 . The intra- and inter-day relative error was between -7.21% and 8.26%, and the coefficient of variation was less than 12.64%. The average extraction recovery rate in plasma samples was 99.76% ± 6.53%, and the matrix in normal plasma and hemolyzed plasma had no significant effect on the detection results. Normal and hemolytic samples could maintain good stability at 4, 25 and -40°C. As a result, this method is particularly suitable for determining BU in hemolytic samples from children with hematopoietic stem cell transplantation (HSCT), and this study provides the methodological basis for further research on the pharmacokinetics of BU in children with HSCT.

Busulfan systemic exposure and its relationship with efficacy and safety in hematopoietic stem cell transplantation in children: a meta-analysis.

BACKGROUND: Busulfan (Bu) is a key component of several conditioning regimens used before hematopoietic stem cell transplantation (HSCT). However, the optimum systemic exposure (expressed as the area under the concentration-time curve [AUC]) of Bu for clinical outcome in children is controversial. METHODS: Research on pertinent literature was carried out at PubMed, EMBASE, Web of science, the Cochrane Library and ClinicalTrials.gov. Observational studies were included, which compared clinical outcomes above and below the area under the concentration-time curve (AUC) cut-off value, which we set as 800, 900, 1000, 1125, 1350, and 1500 µM × min. The primary efficacy outcome was notable in the rate of graft failure. In the safety outcomes, incidents of veno-occlusive disease (VOD) were recorded, as well as other adverse events. RESULTS: Thirteen studies involving 548 pediatric patients (aged 0.3-18 years) were included. Pooled results showed that, compared with the mean Bu AUC (i.e., the average value of AUC measured multiple times for each patient) of > 900 µM × min, the mean AUC value of < 900 µM × min significantly increased the incidence of graft failure (RR = 3.666, 95% CI: 1.419, 9.467). The incidence of VOD was significantly decreased with the mean AUC < 1350 µM × min (RR = 0.370, 95% CI: 0.205-0.666) and < 1500 µM × min (RR = 0.409, 95% CI: 0182-0.920). CONCLUSIONS: In children, Bu mean AUC above the cut-off value of 900 µM × min (after every 6-h dosing) was associated with decreased rates of graft failure, while the cut-off value of 1350 µM × min were associated with increased risk of VOD, particularly for the patients without VOD prophylaxis therapy. Further well-designed prospective and multi centric randomized controlled trials with larger sample size are necessary before putting our result into clinical practices.

Exploring the drug-induced anemia signals in children using electronic medical records.

Objectives: The objectives were to identify drugs related with anemia in children and evaluate the novelty of these correlations. Methods: The authors established a two-step method for detecting the relationship between drugs and anemia using electronic medical records (EMRs), which were obtained from 247,136 patients in Beijing Children's Hospital between 2007 and 2017. The authors extracted potential drugs by mining cases for hemoglobin abnormalities from the EMR and then performed a retrospective cohort study to correlate them with anemia by calculating the matched odds ratios and 95% confidence interval using unconditional logistic regression analysis. Results: In total, nine positive drug-anemia associations were identified. Among them, the correlations of drugs fluconazole (OR 3.95; 95%CI: 2.65-5.87) and cefathiamidine (OR 3.49; 95%CI: 2.94-4.15) with anemia were considered new signals in both children and adults. Three associations of drugs, vancomycin, cefoperazone-sulbactam and ibuprofen, with anemia were considered new signals in children. Conclusion: The authors detected nine signals of drug-induced anemia, including two new signals in children and adults and three new signals in children. This study could serve as a model for using EMR and automatic mining to monitor adverse drug reaction signals in the pediatric population.

Model-Based Meta-Analysis in Ankylosing Spondylitis: A Quantitative Comparison of Biologics and Small Targeted Molecules.

Information on the comparative efficacy is important for drug development as well as drug therapy. Up to now, the relative efficacy of approved biologics and many agents under investigation in ankylosing spondylitis (AS) are still unclear. The objective of this study was to quantify the relative efficacy and time course of various treatments measured by the Ankylosing Spondylitis Assessment Study group response criteria 20 scores (ASAS20), change from baseline in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI). There were 34 double-blinded trials of 10 biologics and small molecules encompassing 5,339 patients with AS were included in this analysis. Three mathematical models with nonparametric placebo estimations were used to describe the longitudinal profile for the above three efficacy measures. The results detected significant differences among included treatments, and infliximab and golimumab were found to have the highest efficacy in given dosage regimens across all measures.

Selective protection of nigral dopaminergic neurons by echinacoside in a rat model of Parkinson disease induced by rotenone.

OBJECTIVE: To observe the protective effects of echinacoside on rotenone-induced damages in rats. METHODS: Healthy male Sprague-Dawley rats, weighing from 200 to 220 g, were randomly divided into five groups with 20 rats in each group: control group, rotenone group and echinacoside groups of low, medium and high doses (20, 40 and 80 mg/(kg·d)). Rats in the rotenone group were injected intraperitoneally for four weeks with rotenone (2.75 mg/(kg·d)), dissolved into dimethyl sulfoxide; rats in the control group were injected intraperitoneally with dimethyl sulfoxide daily, and rats in the echinacoside groups received daily intraperitoneal injection of rotenone along with echinacoside gastric perfusion for four weeks. Modified neurological severity score was used to evaluate neurobehavior of the animals; dopaminergic neurons in substantia nigra were observed by immunochemical method and dopamine concentration in striatum was determined by a fluorescence spectrophotometer. Biomarkers of liver and kidney damage were also measured. RESULTS: In the rotenone group, the rats suffered from severe neurological disability (P<0.01), and the number of dopaminergic neurons in substantia nigra and dopamine concentration in striatum were decreased (P<0.05) compared with the normal control group; levels of the biomarkers for evaluating liver and kidney damage were increased (P<0.05). In the echinacoside groups, the neurological disability and the loss of dopaminergic neurons in substantia nigra were suppressed and dopamine concentrations in striatum were increased (P<0.05), but the liver and kidney damage was not improved (P>0.05). CONCLUSION: Rotenone causes severe damages to dopaminergic neurons, liver and kidney in rats and echinacoside selectively reverses dopaminergic neuronal injury.