Αρχειοθήκη ιστολογίου

Αναζήτηση αυτού του ιστολογίου

Πέμπτη 26 Οκτωβρίου 2017

Predicting CYP3A-mediated midazolam metabolism in critically ill neonates, infants, children, and adults with inflammation and organ failure

Abstract

Aims

Inflammation and organ failure have been reported to impact cytochrome P450 (CYP) 3A-mediated clearance of midazolam in critically ill children. Our aim was to evaluate a previously developed population pharmacokinetic model in both critically ill children and other populations in order to allow the model to be used to guide dosing in clinical practice.

Methods

The model was externally evaluated in 136 individuals, including (pre)term neonates, infants, children, and adults (body weight 0.77-90 kg, CRP 0.1-341 mg/L and 0-4 failing organs) using graphical and numerical diagnostics.

Results

The pharmacokinetic model predicted midazolam clearance and plasma concentrations without bias in post-operative or critically ill paediatric patients and term neonates (median prediction error (MPE) <30%). Using the model for extrapolation resulted in well-predicted clearance values in critically ill and healthy adults (MPE <30%), while clearance in preterm neonates was over predicted (MPE >180%).

Conclusion

The recently published pharmacokinetic model for midazolam, quantifying the influence of maturation, inflammation, and organ failure in children yields unbiased clearance predictions and can therefore be used for dosing instructions in term neonates, children, and adults with varying levels of critical illness including healthy adults, but not for extrapolation to preterm neonates.



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Serum exosomal miR-301a as a potential diagnostic and prognostic biomarker for human glioma

Abstract

Purpose

Exosomal miRNAs that play an important role in cell-cell communication have attracted major attention as potential diagnostic and prognostic biomarkers for various cancers. The aim of this study was to determine the diagnostic/prognostic significance of serum exosomal miR-301a in glioma patients.

Methods

Quantitative real-time PCR was used to determine the serum exosomal expression levels of miR-301a. Kaplan-Meier survival analyses, Cox regression analyses and ROC working curve analyses were applied to assess the diagnostic and prognostic values of miR-301a in glioma patients. Also, several in vitro assays were used, including proliferation, invasion and cell signaling assays.

Results

First, we established that serum exosomal miR-301a extracted from grade IV glioblastoma (GBM) patients was biologically active, i.e., promoted the proliferation and invasion of glioma-derived H4 cells. Subsequently, we found that serum exosomal miR-301a levels were significantly up-regulated in glioma patients compared to healthy controls. Additionally, we found that increased serum exosomal miR-301a levels were correlated with ascending pathological grades and lower Karnofsky performance status (KPS) scores. Importantly, we also found that the serum exosomal miR-301a levels were significantly reduced after surgical resection of primary tumors and increased again during GBM recurrence. Kaplan-Meier analysis of patients with an advanced pathological grade (III or IV) and an increased serum exosomal miR-301a level revealed a longer overall survival (OS) compared to those with a lower level (p < 0.01). Both univariate and multivariate Cox regression analyses confirmed that serum exosomal miR-301a levels are independently associated with OS. Finally, we found that miR-301a may activate the AKT and FAK signaling pathways by down regulating PTEN.

Conclusions

Our data indicate that serum exosomal miR-301a levels may reflect the cancer-bearing status and pathological changes in glioma patients. Serum exosomal miR-301a expression may serve as a novel biomarker for glioma diagnosis and as a prognostic factor for advanced grade disease.



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The absolute volume of PET-defined, active bone marrow spared predicts for high grade hematologic toxicity in cervical cancer patients undergoing chemoradiation

Abstract

Introduction

Hematologic toxicity (HT) in cervical cancer patients can cause treatment delays and reduction in chemotherapy, especially in high risk patients. Dose to PET-defined regions of active bone marrow (ABM) has been shown to correlate with cytopenias. An absolute volume of ABM spared may accurately represent hematopoietic reserve and risk of HT. This analysis evaluates whether the volume of ABM spared can more accurately predict HT compared to conventional dosimetric parameters.

Methods

Thirty-one patients treated for cervical cancer with chemoradiation from 9/2011 to 8/2016 were retrospectively reviewed. Receiver operating characteristic (ROC) curve were used to assess optimal cutpoint criterions for grade 3+ HT based on the CTCAEv4. Conventional dosimetric parameters to PBM and ABM (mean dose, V10, V20, V40) were assessed as well as the absolute volume (cc) of PBM and ABM spared 10, 20, and 40 Gy.

Results

The absolute volume of PBM spared 10 Gy (< 230 cc; AUC 0.732, p = 0.03) as well as volume of ABM spared 10 Gy (< 179 cc; AUC 0.815, p = 0.0002), spared 20 Gy (< 186 cc; AUC 0.774, p = 0.0015), and spared 40 Gy (< 738 cc; AUC 0.887, p < 0.0001) all predicted grade 3+ HT. In patients with < 738 cc of ABM spared 40 Gy, 18/18 (100%) had grade 3+ toxicity compared to 6/13 (46%) of patients with > 738 cc of ABM spared 40 Gy (p < 0.0001).

Conclusion

The baseline volume of ABM and the fraction of ABM present in patients vary significantly. The ongoing NRG-GY006 trial and other efforts at bone marrow sparing use V10, V20, and mean dose to the ABM during planning optimization. This analysis suggests that the volume of ABM spared 40 Gy (> 738 cc) may be a stronger predictor of HT than conventional dosimetric parameters. This should be further evaluated for clinical use.



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The potential usefulness of the Response Index in positron emission tomography assessing the therapeutic effect of pre-operative chemotherapy for advanced colorectal cancer

Abstract

Background and purpose

Pre-operative chemotherapy is an option for patients with local advanced rectal cancer, but the response rate to pre-operative chemotherapy with oxaliplatin is still low. If the therapeutic effect of pre-operative chemotherapy could be assessed, we may be able to convert to surgery early. The purpose of the present study was to validate the correlation between the maximum standardized uptake value (SUVmax) in 18F-fluorodeoxyglucose positron emission tomography–computed tomography (PET–CT) of the primary tumor and the therapeutic effect of pre-operative chemotherapy in advanced colorectal cancer.

Patients and methods

Retrospective cohort study from January 2011 to October 2015. We examined 28 patients with pathologically confirmed sigmoid or rectal cancer that underwent pre-operative chemotherapy and surgery. The correlation between Response Index (RI), calculated as (SUVmax after chemotherapy)/(SUVmax before chemotherapy), and the therapeutic effect on the primary tumor in advanced colorectal cancer.

Results

The degree of differentiation (p = 0.04), SUVmax in the primary tumor after chemotherapy (p = 0.02), and RI (p = 0.008) were significant predictors of the therapeutic effect in univariate analysis. The areas under the ROC curve constructed with RI and therapeutic effect was 0.77. The optimal cut-off values for the RI in the responder group was < 0.32.

Conclusion

RI calculated as (SUVmax after chemotherapy)/(SUVmax before chemotherapy) in the primary tumor significantly correlated with the therapeutic effect of chemotherapy on advanced colorectal cancer. Thus, RI is potentially useful for predicting the therapeutic effect in advanced colorectal cancer.



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Computational Exploration for Lead Compounds That Can Reverse the Nuclear Morphology in Progeria

Progeria is a rare genetic disorder characterized by premature aging that eventually leads to death and is noticed globally. Despite alarming conditions, this disease lacks effective medications; however, the farnesyltransferase inhibitors (FTIs) are a hope in the dark. Therefore, the objective of the present article is to identify new compounds from the databases employing pharmacophore based virtual screening. Utilizing nine training set compounds along with lonafarnib, a common feature pharmacophore was constructed consisting of four features. The validated Hypo1 was subsequently allowed to screen Maybridge, Chembridge, and Asinex databases to retrieve the novel lead candidates, which were then subjected to Lipinski's rule of 5 and ADMET for drug-like assessment. The obtained 3,372 compounds were forwarded to docking simulations and were manually examined for the key interactions with the crucial residues. Two compounds that have demonstrated a higher dock score than the reference compounds and showed interactions with the crucial residues were subjected to MD simulations and binding free energy calculations to assess the stability of docked conformation and to investigate the binding interactions in detail. Furthermore, this study suggests that the Hits may be more effective against progeria and further the DFT studies were executed to understand their orbital energies.

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Heparanase Inhibition Reduces Glucose Levels, Blood Pressure, and Oxidative Stress in Apolipoprotein E Knockout Mice

Background. Atherosclerosis is a multifactorial process. Emerging evidence highlights a role of the enzyme heparanase in various disease states, including atherosclerosis formation and progression. Objective. The aim of the study was to investigate the effect of heparanase inhibition on blood pressure, blood glucose levels, and oxidative stress in apoE−/− mice. Methods. Male apoE−/− mice were divided into two groups: one treated by the heparanase inhibitor PG545, administered intraperitoneally weekly for seven weeks, and the other serving as control group (injected with saline). Blood pressure was measured a day before sacrificing the animals. Serum glucose levels and lipid profile were measured. Assessment of oxidative stress was performed as well. Results. PG545 significantly lowered blood pressure and serum glucose levels in treated mice. It also caused significant reduction of the serum oxidative stress. For safety concerns, liver enzymes were assessed, and PG545 caused significant elevation only of alanine aminotransferase, but not of the other hepatic enzymes. Conclusion. Heparanase inhibition by PG545 caused marked reduction of blood pressure, serum glucose levels, and oxidative stress in apolipoprotein E deficient mice, possibly via direct favorable metabolic and hemodynamic changes caused by the inhibitor. Possible hepatotoxic and weight wasting effects are subject for future investigation.

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Improving the accrual of racial and ethnic minority patients in clinical trials: Time to raise the stakes

Despite decades of attention and study, racial and ethnic minority accrual to clinical trials remains poor. Serious efforts are needed to incentivize providers to enroll patients and clinical trial sponsors to target enrollment for underrepresented groups.



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