A rapid and simple HPLC-MS/MS method for the therapeutic drug monitoring of six special-grade antimicrobials in pediatric patients.

Meropenem, linezolid, fluconazole, voriconazole, posaconazole, and vancomycin are six important antimicrobials used for severe infections in critically ill patients listed in special-grade antimicrobials in China. The six antimicrobials' highly variable pharmacodynamics and pharmacokinetics in critically ill pediatric patients present significant challenges to clinicians in ensuring optimal therapeutic targets. Therefore, therapeutic drug monitoring of these antimicrobials in human plasma is necessary to obtain their plasma concentration. A rapid, simple, and sample-saving high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed, which could simultaneously determine all six antimicrobials. It required only 10 µL of plasma and a one-step protein precipitation process. Chromatographic separation was achieved on a reversed-phase column (C18, 30 × 2.1 mm, 2.6 µm) via gradient elution using water and acetonitrile containing 0.1 % formic acid as mobile phase. The injection volume was 2 µL, and the total run time was only 2.5 min. Detection was done using a Triple Quad™ 4500MD tandem mass spectrometer coupled with an electrospray ionization (ESI) source in positive mode. The calibration curves ranged from 0.5 to 64 µg/mL for meropenem and fluconazole, 0.2-25.6 µg/mL for linezolid and voriconazole, 0.1-12.8 µg/mL for posaconazole and 1-128 µg/mL for vancomycin, with the coefficients of correlation all greater than 0.996. Furthermore, the method was validated rigorously according to the European Medicines Agency (EMA) guidelines, demonstrating excellent accuracy (from 93.0 % to 110.6 %) and precision (from 2.0 % to 12.8 %). Moreover, its applicability to various matrices (including serum, hemolytic plasma, and hyperlipidemic plasma) was evaluated. Thus, this method was successfully applied to routine therapeutic drug monitoring for critically ill pediatric patients and other patients in need.

A cross-sectional study exploring the relationship between the dietary inflammatory index and hyperlipidemia based on the National Health and Nutrition Examination Survey (2005-2018).

BACKGROUND: Hyperlipidemia is closely associated with dietary patterns and inflammation. However, the relationship between hyperlipidemia and the inflammatory potential of diets remains unexplored. The research was conducted to examine the relationship between hyperlipidemia and dietary inflammatory index (DII). METHODS: The data utilized in the research were acquired from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. The information on dietary intake was gathered by conducting 24-h dietary recall interviews. Restricted cubic spline (RCS) and Survey-weighted logistic regression were utilized to determine the association between DII and hyperlipidemia. Furthermore, stratification analysis was carried out. RESULTS: This study included 8982 individuals with and 3458 without hyperlipidemia. Participants with hyperlipidemia exhibited higher DII scores than those without hyperlipidemia. Following adjustment for gender, age, race, education level, marital status, poverty, drinking status, diabetes, hypertension, smoking status, body mass index (BMI), chronic kidney disease (CKD), cardiovascular disease (CVD), and hemoglobin (Hb), the association between the prevalence of hyperlipidemia and DII remained significant. The RCS data demonstrated that the hyperlipidemia prevalence did not exhibit an increase until the DII score was approximately 2.78. Stratification analysis revealed that the association between DII and hyperlipidemia persisted in all subgroups. CONCLUSIONS: DII was associated with hyperlipidemia, and the threshold DII score for the risk of hyperlipidemia was 2.78.

A simple and sensitive LC-MS/MS method for therapeutic drug monitoring of digoxin in children.

This short communication introduced a simple and sensitive LC-MS/MS method for therapeutic drug monitoring of digoxin in children with the lower limit of quantitation of 0.2 ng/mL based on 30 µL of plasma. The plasma sample was pretreated by one-step protein precipitation. Then the chromatographic separation was performed on a short C-18 column with a total run time of 2.4 min. The detection was achieved through multiple reaction monitoring using positive ionization mode on a triple quadrupole mass spectrometer. The linear range of digoxin in human plasma was among 0.2-6.4 ng/mL. The intra-day and inter-day accuracies of digoxin ranged from -6.0 % to 10.1 % and imprecisions were less than 8.8 %. The extraction recovery rate of digoxin in plasma samples was above 90 %. Matrix factor normalized by internal standard was within acceptance criteria. This method was fully verified and applied to determine the plasma digoxin concentrations of 43 pediatric patients. It is approved appropriate and practical for the therapeutic drug monitoring of digoxin in routine clinical laboratory practice, especially for children.

Effect of Microenvironment on Differentiation of Human Umbilical Cord Mesenchymal Stem Cells into Hepatocytes In Vitro and In Vivo.

Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) are considered to be an ideal cell source for cell therapy of many diseases. The aim of this study was to investigate the contribution of the microenvironment to the hepatic differentiation potential of hUCMSCs in vitro and in vivo and to explore their therapeutic use in acute liver injury in rats. We established a new model to simulate the liver tissue microenvironment in vivo using liver homogenate supernatant (LHS) in vitro. This induced environment could drive hUCMSCs to differentiate into hepatocyte-like cells within 7 days. The differentiated cells expressed hepatocyte-specific markers and demonstrated hepatocellular functions. We also injected hUCMSCs into rats with CCl4-induced acute hepatic injury. The hUCMSCs were detected in the livers of recipient rats and expressed the human hepatocyte-specific markers, suggesting that hUCMSCs could differentiate into hepatocyte-like cells in vivo in the liver tissue microenvironment. Levels of biochemistry markers improved significantly after transplantation of hUCMSCs compared with the nontransplantation group (P < 0.05). In conclusion, this study demonstrated that the liver tissue microenvironment may contribute to the differentiation of hUCMSCs into hepatocytes both in vitro and in vivo.

Progesterone attenuates Aß(25-35)-induced neuronal toxicity via JNK inactivation and progesterone receptor membrane component 1-dependent inhibition of mitochondrial apoptotic pathway.

Progesterone, which acts as a neurosteroid in nervous system, has been shown to have neuroprotective effects in different experiments in vitro and in vivo. Our previous study demonstrates that progesterone exerts neuroprotections in Alzheimer's disease-like rats. Present study attempted to evaluate the protective effects of progesterone on Aß-treated neurons and potential mechanisms involved in neuroprotection. Results showed that treatment with progesterone protected primary cultured rat cortical neurons against Aß(25-35)-induced apoptosis. Furthermore, we observed that progesterone alleviated mitochondrial dysfunction by rescuing mitochondrial membrane potential under Aß challenge. Moreover, progesterone could also attenuate Bax/Bcl-2 proteins ratio upregulation and inhibit the activation of caspase-3 in Aß-treated neurons. These indicate that progesterone attenuates Aß(25-35)-induced neuronal toxicity by inhibiting mitochondria-associated apoptotic pathway. Both classic progesterone receptors (classic PR) and progesterone receptor membrane component 1 (PGRMC1), a special progesterone membrane receptor, are broadly expressed throughout the brain. The protective effect of progesterone was partially abolished by PGRMC1 inhibitor AG205 rather than classic PR antagonist RU486 in this study. Additionally, progesterone protected neurons by inhibiting Aß-induced activation of JNK, which was an upstream signaling component in Aß-induced mitochondria-associated apoptotic pathway. But this process was independent of PGRMC1. Taken together, these results suggest that progesterone exerts a protective effect against Aß(25-35)-induced insults at least in part by two complementary pathways: (1) progesterone receptor membrane component 1-dependent inhibition of mitochondrial apoptotic pathway, and (2) blocking Aß-induced JNK activation. The present study provides new insights into the mechanism by which progesterone brings neuroprotection. This article is part of a Special Issue entitled 'Steroids & Nervous System'.

Metabolic alteration of neuroactive steroids and protective effect of progesterone in Alzheimer's disease-like rats.

A correlation between metabolic alterations of neuroactive steroids and Alzheimer's disease remains unknown. In the present study, amyloid beta (Aß) 25-35 (Aß25-35) injected into the bilateral hippocampus CA1 region significantly reduced learning and memory. At the biochemical level, hippocampal levels of pregnenolone were significantly reduced with Aß25-35 treatment. Furthermore, progesterone was considerably decreased in the prefrontal cortex and hippocampus, and 17ß-estradiol was significantly elevated. To our knowledge, this is the first report showing that Aß25-35, a main etiological factor of Alzheimer's disease, can alter the level and metabolism of neuroactive steroids in the prefrontal cortex and hippocampus, which are brain regions significantly involved in learning and memory. Aß25-35 exposure also increased the expression of inflammatory mediators, tumor necrosis factor-α and interleukin-1ß. However, subcutaneous injection of progesterone reversed the upregulation of tumor necrosis factor-α and interleukin-1ß in a dose-dependent manner. Concomitant with improved cognitive abilities, progesterone blocked Aß-mediated inflammation and increased the survival rate of hippocampal pyramidal cells. We thus hypothesize that Aß-mediated cognitive deficits may occur via changes in neuroactive steroids. Moreover, our findings provide a possible therapeutic strategy for Alzheimer's disease via neuroactive steroids, particularly progesterone.