Further exploration of the collision-induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol.

Beta blockers are a class of drugs commonly used to treat heart-related diseases; they are also regulated under the World Anti-Doping Agency. Tandem mass spectrometry is often used in the pharmaceutical industry, clinical analysis laboratory, and antidoping laboratory for detection and characterization of drugs and their metabolites. A deeper chemical understanding of dissociation pathways may eventually lead to an improved ability to predict tandem mass spectra of compounds based strictly on their chemical structure (or vice versa), which is especially important for characterization of unknowns such as emerging designer drugs or novel metabolites. In addition to providing insights into dissociation pathways, the use of energy-resolved breakdown curves can produce improved selectivity and lend insights into optimal fragmentation conditions for liquid chromatography-tandem mass spectrometry LC-MS/MS workflows. Here, we perform energy-resolved collision cell and multistage ion trap collision-induced dissociation-mass spectrometry (CID-MS) experiments, along with complementary density functional theory calculations, on five beta blockers (acebutolol, atenolol, bisoprolol, carteolol, and labetalol), to better understand the details of the pathways giving rise to the observed MS/MS patterns. Results from this work are contextualized within previously reported literature on these compounds. New insights into the formation of the characteristic product ion m/z 116 and the pathway leading to characteristic loss of 77 u are highlighted. We also present comparisons of breakdown curves obtained via qToF, quadrupole ion trap, and in-source CID, allowing for differences between the data to be noted and providing a step toward allowing for improved selectivity of breakdown curves to be realized on simple instruments such as single quadrupoles or ion traps.

Evaluation of Drug-Drug Interactions via Inhibition of Hydrolases by Orlistat, an Anti-Obesity Drug.

Drug-drug interactions (DDI) have a significant impact on drug efficacy and safety. It has been reported that orlistat, an anti-obesity drug, inhibits the hydrolysis of p-nitrophenol acetate, a common substrate of the major drug-metabolizing hydrolases, carboxylesterase (CES) 1, CES2, and arylacetamide deacetylase (AADAC), in vitro. The aim of this study was to examine whether orlistat affects the pharmacokinetics of drug(s) metabolized by hydrolases in vivo after evaluating its inhibitory potencies against CES1, CES2, and AADAC in vitro. Orlistat potently inhibited the hydrolysis of acebutolol, a specific substrate of CES2, in a non-competitive manner (inhibition constant, K i = 2.95 ± 0.16 nM), whereas it slightly inhibited the hydrolysis of temocapril and eslicarbazepine acetate, specific substrates of CES1 and AADAC, respectively (IC50 >100 nM). The in vivo DDI potential was elucidated using mice, in which orlistat showed strong inhibition against acebutolol hydrolase activities in the liver and intestinal microsomes, similar to humans. The area under the curve (AUC) of acebutolol was increased by 43%, whereas the AUC of acetolol, a hydrolyzed metabolite of acebutolol, was decreased by 47% by co-administration of orlistat. The ratio of the K i value to the maximum unbound plasma concentration of orlistat (<0.012) is lower than the risk criteria for DDI in the liver defined by the US Food and Drug Administration guideline (>0.02), whereas the ratio of the K i value to the estimated intestinal luminal concentration (3.3 × 105) is considerably higher than the risk criteria in the intestine (>10). Therefore, this suggests that orlistat causes DDI by inhibiting hydrolases in the intestine. SIGNIFICANCE STATEMENT: This study demonstrated that orlistat, an anti-obesity drug, causes drug-drug interactions in vivo by potently inhibiting carboxylesterase 2 in the intestine. This is the first evidence that inhibition of hydrolases causes drug-drug interactions.

Beta-blocker carteolol and oxprenolol produce cutaneous analgesia in response to needle pinpricks in the rat.

BACKGROUND: This present study was undertaken to determine whether beta-blockers produce the cutaneous analgesic effect, comparing them with the long-acting local anesthetic bupivacaine. METHODS: Using a rat model of infiltrative cutaneous analgesia, the effect of 5 beta-blockers (oxprenolol, carteolol, butaxamine, metoprolol, and acebutolol) and bupivacaine was compared and eventually combined with epinephrine. RESULTS: Among 5 beta-blockers, oxprenolol exhibited the most potent and the longest duration of cutaneous analgesia. In dose-response studies, the rank order of efficacy (ED50 [50% effective dose]) was bupivacaine (0.40 [0.35-0.47] µmol) > oxprenolol (2.33 [2.06-2.64] µmol) > carteolol (4.86 [4.27-5.53] µmol) (p< 0.01). Carteolol provoked a longer duration of analgesia (p< 0.01) than oxprenolol or bupivacaine on an equipotent basis (ED25, ED50, and ED75). Adding epinephrine 1:200,000 to drug preparations (carteolol, oxprenolol, and bupivacaine) at ED95 had a peripheral action in prolonging the duration of action. CONCLUSIONS: Oxprenolol and carteolol had greater potencies and longer durations of cutaneous analgesia than butaxamine, metoprolol, and acebutolol. Oxprenolol produced a similar duration of action when compared to bupivacaine, while carteolol had a greater duration of action than bupivacaine. Cutaneous analgesia of oxprenolol (or carteolol) plus adrenaline was greater than that of bupivacaine plus adrenaline.

Hydrogen-deuterium (H/D) exchange reaction of acebutolol hydrochloride in D2O and CD3OD solution.

H/D exchange reactions can be observed by NMR spectroscopy of acebutolol (ACE). The results obtained showed deuterium incorporation at α-posi t ion of the carbonyl group of acebutolol, when using deuterium oxide or deuterated methanol as deuterium source and solvent. The spontaneous deuteration is proceeded by the following pathway CH3→CH2D→CHD→CD3, through a keto-enol tautomerization reaction. Furthermore, LC-MS / QTOF analyses have confirmed the proposed H/D exchange. In order to reduce the time of total deuteration observed at the acetyl group alkaline catalysts were employed.

H2O2 production at gas-diffusion cathodes made from agarose-derived carbons with different textural properties for acebutolol degradation in chloride media.

The excessive cost, unsustainability or complex production of new highly selective electrocatalysts for H2O2 production, especially noble-metal-based ones, is prohibitive in the water treatment sector. To solve this conundrum, biomass-derived carbons with adequate textural properties were synthesized via agarose double-step pyrolysis followed by steam activation. A longer steam treatment enhanced the graphitization and porosity, even surpassing commercial carbon black. Steam treatment for 20 min yielded the greatest surface area (1248 m2 g-1), enhanced the mesopore/micropore volume distribution and increased the activity (E1/2 = 0.609 V) and yield of H2O2 (40%) as determined by RRDE. The upgraded textural properties had very positive impact on the ability of the corresponding gas-diffusion electrodes (GDEs) to accumulate H2O2, reaching Faradaic current efficiencies of ~95% at 30 min. Acidic solutions of ß-blocker acebutolol were treated by photoelectro-Fenton (PEF) process in synthetic media with and without chloride. In urban wastewater, total drug disappearance was reached at 60 min with almost 50% mineralization after 360 min at only 10 mA cm-2. Up to 14 degradation products were identified in the Cl--containing medium.

Photodegradation of acebutolol in natural waters: Important roles of carbonate radical and hydroxyl radical.

Acebutolol (ACE) has been widely used for the treatment of cardiovascular disorders, and its photochemical fate in natural waters is a matter of concern due to its ubiquitous occurrence and its toxicity to aquatic organisms. In this study, the photodegradation of ACE in river water and synthetic waters were investigated under simulated sunlight irradiation. The results demonstrated that ACE photodegradation rate in river water was 3.2 times higher than that in pure water. Then the influences of HCO3-, NO3- and DOM on ACE photolysis were investigated under their concentrations similar with the ones in river water. ACE photodegradation was significantly enhanced in the presence of HCO3- alone, and the scavenging experiments and the electron paramagnetic resonance experiments together proved that HCO3- could be oxidized by triplet-excited state of ACE to generate CO3•-, which subsequently played a key role in ACE degradation. The presence of both NO3- and DOM also increased the ACE photodegradation rates, and •OH and 3DOM* were found to be involved in the degradation. In addition, when DOM was added to a solution with HCO3-, the enhancement effect of HCO3- on ACE photodegradation was weakened due to the scavenging of CO3•- by DOM combined with the light screening effect of DOM.

Highly exfoliated functionalized MoS2 with sodium alginate-polydopamine conjugates for electrochemical sensing of cardio-selective ß-blocker by voltammetric methods.

Molybdenum disulfide (MoS2) surface functionalization was performed with a catechol-containing polymer sodium alginate (SA) and dopamine (DA) through simultaneous MoS2 exfoliation and self-polymerization of DA. The MoS2/SA-PDA nanocomposite was characterized using spectroscopic, microscopic, and electroanalytical techniques to evaluate its electrocatalytic performance. The electrocatalytic behavior of the MoS2/SA-PDA nanocomposite modified electrode for the detection of acebutolol (ACE), a cardio-selective ß-blocker drug was explored  through cyclic voltammetric and differential pulse voltammetric techniques. The influence of scan rate, concentration, and pH value on the oxidation peak current of ACE was investigated  to optimize the deducting condition. The electrochemical activity of the MoS2/SA-PDA nanocomposite electrode was attributed to the existence of reactive functional groups being contributed from SA, PDA, and MoS2 exhibiting a synergic effect. The MoS2/SA-PDA nanocomposite modified electrode exhibits admirable electrocatalytic activity with a wide linear response range (0.009 to 520 µM), low detection limit (5 nM), and high sensitivity (0.354 µA µM-1 cm-2) also in the presence of similar (potentially interfering) compounds. The fabricated MoS2/SA-PDA nanocomposite modified electrode can be useful for the detection of ACE in pharmaceutical analysis.

Prediction of plasma concentrations using in silico modelling and simulation approach: Case of Acebutolol.

PURPOSE: The aim of this study was to predict the plasma concentrations of acebutolol tablets with different dissolution profiles using computer modelling and evaluating whether they are bioequivalent using simulated population studies. METHODS: The dissolution behaviour of acebutolol was studied in the USP Apparatus-II using different dissolution media for pH 1.2, 4.5, and 6.8 at 37±0.5°C. The obtained dissolution data, as well as plasma concentration-time data of the reference product from the literature were used as inputs to build pharmacokinetic model of acebutolol within GastroPlus™ software (version 9.7, Simulations Plus Inc., Lancaster, CA, USA) to simulate the in vivo profiles of the drug. RESULTS: The dissolution profiles of the reference product Sectral® 400mg tablets and a locally produced generic product were>85% in 15min in three dissolution media. Simulation results demonstrated that the brand and generic products would show the same in vivo performance. Population simulation results of the ln-transformed 90% confidence interval for the ratio of Cmax, AUC0-t and AUC0-inf values for the two products were within the 80-125% interval, showing to be bioequivalent. CONCLUSION: Based on the in vitro results combined with in silico simulations using GastroPlus™, a biowaiver for immediate release acebutolol tablets is justified. Furthermore, computer modelling has shown to be a very intersting tool to prove the bioequivalence for these products.

The adsorption performance and micro-mechanism of MoS2/montmorillonite composite to atenolol and acebutolol: Adsorption experiments and a novel visual study of interaction.

MoS2/montmorillonite (MoS2/Mt) composite was successfully synthesized through a simple hydrothermal method, and its adsorption performance for two emerging contaminants-atenolol (ATE) and acebutolol (ACE) was researched. The batch experiments revealed that the adsorption process can be described by the Pseudo-second order model and Langmuir model, and the adsorption capacity of MoS2/Mt, MoS2 and Mt for ATE were 132.08 mg/g, 60.68 mg/g and 74.23 mg/g, for ACE were 113.82 mg/g, 33.01 mg/g and 36.05 mg/g, respectively. Besides, Fourier-transform infrared spectroscopy (FTIR), BET specific surface area measurement and X-ray photoelectron spectroscopy (XPS) were also employed to analyze the adsorption mechanism. Moreover, quantitative molecular surface analysis and weak intermolecular interaction analysis with independent gradient model were combined to probe the microscopic interaction between the adsorbent and adsorbate. The results indicated the interactions included hydrogen bonding and vdW interaction. Mt and MoS2 interacted more strongly with ATE than ACE, which revealed the reason MoS2/Mt, Mt and MoS2 possessed higher adsorption capacity for ATE.

In Silico Design of Novel Sirtuin 1 Enzyme Activators for the Treatment of Age-related Diseases and Life Span.

AIM: The aim of the study was to develop new SIRT1 activator compounds, for this aim, we used virtual screening and molecular dynamics methods, which have been important tools for new hit compound searches. BACKGROUND: Recently, with the progress of computing technology, it has been possible to obtain higher efficiency and lower costs for drug discovery. With in silico research and drug design, there is a reduction in time-consuming and expensive experimental work. An NAD+ dependent histone deacetylase enzyme, Sirtuin 1 (SIRT1), is involved in a variety of human disorders such as type II diabetes, cancer, obesity, and aging. Activation of SIRT1 could be useful for longevity and treating metabolic disorders. OBJECTIVE: We used computational methods to develop new SIRT1 activator compounds. METHODS: Firstly, virtual screening studies on the human SIRT1 enzyme were carried out. We used approximately 150.000 commercially available compounds from the Zinc database, which include FDA-approved drugs. According to virtual screening results, we selected seven potent activators. Then we compared these hit compounds with known activators by using docking methods. One of these hit compounds, acebutolol, is an FDA-approved drug, and was selected for additional studies using molecular dynamics simulations. RESULTS: Seven hit compounds were identified with database screening. Each showed strong interactions with SIRT1, and acebutolol formed H-bonds with the important active site residues, Asn226 and/or Glu230 during the dynamics simulation. CONCLUSION: Based on our in silico studies, the seven most promising compounds, especially acebutolol, showed promising SIRT1 activator potency. The results may be used to design new selective and more potent SIRT1 activator drugs.

Time course for blood pressure lowering of beta-blockers with partial agonist activity.

BACKGROUND: Beta-blockers are commonly used in the treatment of hypertension. We do not know whether the blood pressure (BP) lowering efficacy of beta-blockers varies across the day. This review focuses on the subclass of beta-blockers with partial agonist activity (BBPAA). OBJECTIVES: To assess the degree of variation in hourly BP lowering efficacy of BBPAA over a 24-hour period in adults with essential hypertension. SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for relevant studies up to June 2020: the Cochrane Hypertension Specialised Register; CENTRAL; 2020, Issue 5; MEDLINE Ovid; Embase Ovid; the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions. SELECTION CRITERIA: We sought to include all randomised and non-randomised trials that assessed the hourly effect of BBPAA by ambulatory monitoring, with a minimum follow-up of three weeks. DATA COLLECTION AND ANALYSIS: Two review authors independently selected the included trials and extracted the data. We assessed the certainty of the evidence using the GRADE approach. Outcomes included in the review were end-point hourly systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR), measured using a 24-hour ambulatory BP monitoring (ABPM) device. MAIN RESULTS: Fourteen non-randomised baseline controlled trials of BBPAA met our inclusion criteria, but only seven studies, involving 121 participants, reported hourly ambulatory BP data that could be included in the meta-analysis. Beta-blockers studied included acebutalol, pindolol and bopindolol. We judged most studies at high or unclear risk of bias for selection bias, attrition bias, and reporting bias. We judged the overall certainty of the evidence to be very low for all outcomes. We analysed and presented data by each hour post-dose. Very low-certainty evidence showed that hourly mean reduction in BP and HR visually showed an attenuation over time. Over the 24-hour period, the magnitude of SBP lowering at each hour ranged from -3.68 mmHg to -17.74 mmHg (7 studies, 121 participants), DBP lowering at each hour ranged from -2.27 mmHg to -9.34 mmHg (7 studies, 121 participants), and HR lowering at each hour ranged from -0.29 beats/min to -10.29 beats/min (4 studies, 71 participants). When comparing between three 8-hourly time intervals that correspond to day, evening, and night time hours, BBPAA was less effective at lowering BP and HR at night, than during the day and evening. However, because we judged that these outcomes were supported by very low-certainty evidence, further research is likely to have an important impact on the estimate of effect and may change the conclusion. AUTHORS' CONCLUSIONS: There is insufficient evidence to draw general conclusions about the degree of variation in hourly BP-lowering efficacy of BBPAA over a 24-hour period, in adults with essential hypertension. Very low-certainty evidence showed that BBPAA acebutalol, pindolol, and bopindolol lowered BP more during the day and evening than at night. However, the number of studies and participants included in this review was very small, further limiting the certainty of the evidence. We need further and larger trials, with accurate recording of time of drug intake, and with reporting of standard deviation of BP and HR at each hour.

Chiral separation of beta-blockers by high-performance liquid chromatography and determination of bisoprolol enantiomers in surface waters.

Beta-blockers are chiral compounds with enantiomers that have different bioactivity, which means that while one is active, the other can be inactive or even harmful. Due to their high consumption and incomplete degradation in waste water, they may reach surface waters and affect aquatic organisms. To address this issue we developed a chromatographic method suitable for determining beta-blocker enantiomers in surface waters. It was tested on five beta-blockers (acebutolol, atenolol, bisoprolol, labetalol and metoprolol) and validated on bisoprolol enantiomers. Good enantioseparation of all analysed beta-blockers was achieved on the Chirobiotic V column with the mobile phase composed of methanol/acetic acid/triethylamine (100/0.20/0.15 v/v/v) at a flow rate of 0.5 mL/min and column temperature of 45 °C. Method proved to be linear in the concentration range from 0.075 µg/mL to 5 µg/mL, and showed good recovery. The limits of bisoprolol enantiomer detection were 0.025 µg/mL and 0.026 µg/mL and of quantification 0.075 µg/mL and 0.075 µg/mL. Despite its limitations, it seems to be a promising method for bisoprolol enantiomer analysis in surface water samples. Further research could focus on waste water analysis, where enantiomer concentrations may be high. Furthermore, transferring the method to a more sensitive one such as liquid chromatography coupled with tandem mass spectrometry and using ammonium acetate as the mobile phase additive instead of acetic acid and triethylamine would perhaps yield much lower limits of detection and quantification.

A case of fatal acebutolol poisoning: an illustration of the potential of molecular networking.

Acebutolol is a ß1-selective adrenergic receptor antagonist with moderate membrane-stabilizing activity and intrinsic sympathomimetic activity; accordingly, the drug is indicated in hypertension, angina pectoris, and arrhythmia. However, acebutolol's beta-blocking properties also extend the QRS and QTc intervals, and may predispose the patient to ventricular tachydysrhythmia. Here, we report autopsy and toxicological findings on a fatal case of acebutolol self-poisoning in a 70-year-old woman. Toxicological analyses of post-mortem samples (using a liquid chromatography high-resolution mass spectrometry (LC-HR-MS) method) highlighted high concentrations of acebutolol and its metabolite diacetolol in femoral blood (92.8 mg/L and 21.2 mg/L, respectively) and other matrices (cardiac blood, urine, bile, and gastric contents). A molecular networking approach provided useful information on acebutolol's metabolism and revealed the existence of an unknown phase II metabolite of acebutolol. Molecular networking also facilitated visualization of the complex LC-HR-MS/MS datasets and the sample-to-sample comparisons that confirmed massive acebutolol intoxication by ingestion.

Stereoselective cell uptake of adrenergic agonists and antagonists by organic cation transporters.

Stereoselectivity is well described for receptor binding and enzyme catalysis, but so far has only been scarcely investigated in carrier-mediated membrane transport. We thus studied transport kinetics of racemic (anti)adrenergic drugs by the organic cation transporters OCT1 (wild-type and allelic variants), OCT2, OCT3, MATE1, and MATE2-K with a focus on stereospecificity. OCT1 showed stereoselective uptake with up to 2-fold higher vmax over their corresponding counterpart enantiomers for (R,R)-fenoterol, (R,R)-formoterol, (S)-salbutamol, (S)-acebutolol, and (S)-atenolol. Orciprenaline and etilefrine were also transported stereoselectively. The Km was 2.1-fold and 1.5-fold lower for the (S,S)-enantiomers of fenoterol and formoterol, while no significant difference in Km was seen for the other aforementioned drugs. Common OCT1 variants showed similar enantiopreference to wild-type OCT1, with a few notable exceptions (e.g. a switch in enantiospecificity for fenoterol in OCT1*2 compared to the wild-type). Other cation transporters showed strong differences to OCT1 in stereoselectivity and transport activity: The closely related OCT2 displayed a 20-fold higher vmax for (S,S)-fenoterol compared to (R,R)-fenoterol and OCT2 and OCT3 showed 3.5-fold and 4.6-fold higher vmax for the pharmacologically active (R)-salbutamol over (S)-salbutamol. MATE1 and MATE2-K generally mediated transport with a higher capacity but lower affinity compared to OCT1, with moderate stereoselectivity. Our kinetic studies showed that significant stereoselectivity exists in solute carrier-mediated membrane transport of racemic beta-adrenergic drugs with surprising, and in some instances even opposing, preferences between closely related organic cation transporters. This may be relevant for drug therapy, given the strong involvement of these transporters in hepatic and renal drug elimination.

Graphene Oxide/Polyethylene Glycol-Stick for Thin Film Microextraction of ß-Blockers from Human Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry.

A wooden stick coated with a novel graphene-based nanocomposite (Graphene oxide/polyethylene glycol (GO/PEG)) is introduced and investigated for its efficacy in solid phase microextraction techniques. The GO/PEG-stick was prepared and subsequently applied for the extraction of ß-blockers, acebutolol, and metoprolol in human oral fluid samples, which were subsequently detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). Experimental parameters affecting the extraction protocol including sample pH, extraction time, desorption time, appropriate desorption solvent, and salt addition were optimized. Method validation for the detection from oral fluid samples was performed following FDA (Food and Drug Administration) guidelines on bioanalytical method validation. Calibration curves ranging from 5.0 to 2000 nmol L-1 for acebutolol and 25.0 to 2000 nmol L-1 for metoprolol were used. The values for the coefficient of determination (R2) were found to be 0.998 and 0.996 (n = 3) for acebutolol and metoprolol, respectively. The recovery of analytes during extraction was 80.0% for acebutolol and 62.0% for metoprolol, respectively. The limit of detections (LODs) were 1.25, 8.00 nmol L-1 for acebutolol and metoprolol and the lower limit of quantifications (LLOQ) were 5.00 nmol L-1 for acebutolol and 25.0 nmol L-1 for metoprolol. Validation experiments conducted with quality control (QC) samples demonstrated method accuracy between 80.0% to 97.0% for acebutolol and from 95.0% to 109.0% for metoprolol. The inter-day precision for QC samples ranged from 3.6% to 12.9% for acebutolol and 9.5% to 11.3% for metoprolol. Additionally, the GO/PEG-stick was demonstrated to be reusable, with the same stick observed to be viable for more than 10 extractions from oral fluid samples.

IDH-wildtype glioblastomas and grade III/IV IDH-mutant gliomas show elevated tracer uptake in fibroblast activation protein-specific PET/CT.

PURPOSE: Targeting fibroblast activation protein (FAP) is a new diagnostic approach allowing the visualization of tumor stroma. Here, we applied FAP-specific PET imaging to gliomas. We analyzed the target affinity and specificity of two FAP ligands (FAPI-02 and FAPI-04) in vitro, and the pharmacokinetics and biodistribution in mice in vivo. Clinically, we used 68Ga-labeled FAPI-02/04 for PET imaging in 18 glioma patients (five IDH-mutant gliomas, 13 IDH-wildtype glioblastomas). METHODS: For binding studies with 177Lu-radiolabeled FAPI-02/04, we used the glioblastoma cell line U87MG, FAP-transfected fibrosarcoma cells, and CD26-transfected human embryonic kidney cells. For pharmacokinetic and biodistribution studies, U87MG-xenografted mice were injected with 68Ga-labeled compounds followed by small-animal PET imaging and 177Lu-labeled FAPI-02/04, respectively. Clinical PET/CT scans were performed 30 min post intravenous administration of 68Ga-FAPI-02/04. PET and MRI scans were co-registrated. Immunohistochemistry was done on 14 gliomas using a FAP-specific antibody. RESULTS: FAPI-02 and FAPI-04 showed high binding specificity to FAP. FAPI-04 demonstrated higher tumor accumulation and delayed elimination compared with FAPI-02 in preclinical studies. IDH-wildtype glioblastomas and grade III/IV, but not grade II, IDH-mutant gliomas showed elevated tracer uptake. In glioblastomas, we observed spots with increased uptake in projection on contrast-enhancing areas. Immunohistochemistry showed FAP-positive cells with mainly elongated cell bodies and perivascular FAP-positive cells in glioblastomas and an anaplastic IDH-mutant astrocytoma. CONCLUSIONS: Using FAP-specific PET imaging, increased tracer uptake in IDH-wildtype glioblastomas and high-grade IDH-mutant astrocytomas, but not in diffuse astrocytomas, may allow non-invasive distinction between low-grade IDH-mutant and high-grade gliomas. Therefore, FAP-specific imaging in gliomas may be useful for follow-up studies although further clinical evaluation is required.

Analysis of 27 ß-Blockers and Metabolites in Milk Powder by High Performance Liquid Chromatography Coupled to Quadrupole Orbitrap High-Resolution Mass Spectrometry.

This paper presents an application of high performance liquid chromatography coupled with quadrupole orbitrap high-resolution mass spectrometry (HPLC-Q-Orbitrap HRMS) for the analysis of 27 ß-blockers and metabolites in milk powder. Homogenized milk power samples were extracted by acetonitrile and purified by using Oasis PRiME HLB solid-phase extraction cartridges. The Ascentis® C8 chromatographic column was used to separate the analytes. The quantification was achieved by using matrix-matched standard calibration curves with carazolol-d7 and propranolol-d7 as the internal standards. The results show an exceptional linear relationship with the concentrations of analytes over wide concentration ranges (0.5⁻500 µg kg-1) as all the fitting coefficients of determination r² are > 0.995. All the limits of detection (LODs) and quantitation (LOQs) values were within the respective range of 0.2⁻1.5 µg kg-1 and 0.5⁻5.0 µg kg-1. Overall average recoveries were able to reach 66.1⁻100.4% with the intra- and inter-day variability under 10%. This method has been successfully applied to the screening of ß-blockers and metabolites in commercial milk powders. At the same time, the corresponding characteristic fragmentation behavior of the 27 compounds was explored. The characteristic product ions were determined and applied to the actual samples screening.

Lack of Myosin X Enhances Osteoclastogenesis and Increases Cell Surface Unc5b in Osteoclast-Lineage Cells.

Normal bone mass is maintained by balanced bone formation and resorption. Myosin X (Myo10), an unconventional "myosin tail homology 4-band 4.1, ezrin, radixin, moesin" (MyTH4-FERM) domain containing myosin, is implicated in regulating osteoclast (OC) adhesion, podosome positioning, and differentiation in vitro. However, evidence is lacking for Myo10 in vivo function. Here we show that mice with Myo10 loss of function, Myo10m/m , exhibit osteoporotic deficits, which are likely due to the increased OC genesis and bone resorption because bone formation is unchanged. Similar deficits are detected in OC-selective Myo10 conditional knockout (cko) mice, indicating a cell autonomous function of Myo10. Further mechanistic studies suggest that Unc-5 Netrin receptor B (Unc5b) protein levels, in particular its cell surface level, are higher in the mutant OCs, but lower in RAW264.7 cells or HEK293 cells expressing Myo10. Suppressing Unc5b expression in bone marrow macrophages (BMMs) from Myo10m/m mice by infection with lentivirus of Unc5b shRNA markedly impaired RANKL-induced OC genesis. Netrin-1, a ligand of Unc5b, increased RANKL-induced OC formation in BMMs from both wild-type and Myo10m/m mice. Taken together, these results suggest that Myo10 plays a negative role in OC formation, likely by inhibiting Unc5b cell-surface targeting, and suppressing Netrin-1 promoted OC genesis. © 2019 American Society for Bone and Mineral Research.

Early exposure to radiofrequency electromagnetic fields at 1850 MHz affects auditory circuits in early postnatal mice.

In the present study, we measured the spontaneous post synaptic currents (sPSCs) at the post synaptic principle cells of the medial nucleus of the trapezoid body (MNTB) in early postnatal mice after exposure to 1850 MHz radiofrequency electromagnetic fields (RF-EMF). sPSC frequencies and amplitudes were significantly increased in the RF-EMF exposed group. Moreover, the number of synaptic vesicles in the calyx of Held was significantly increased in presynaptic nerve terminals. Following RF-EMF exposure, the number of docking synaptic vesicles in the active zone increased, thereby expanding the total length of the presynaptic active zone in the calyx of Held. These data suggest that the increased sPSCs are a result of greater synaptic vesicle release from presynaptic nerves. However, we found no morphological changes in the inner hair cell ribbon synapses. Further, there were no significant changes in the hearing threshold of the auditory brainstem response at postnatal day 15. Our results indicate that exposure to RF-EMF at an early postnatal stage might directly affect brainstem auditory circuits, but it does not seem to alter general sound perception.

Combination of capillary electrophoresis and molecular modeling to study the enantiomer affinity pattern between ß-blockers and anionic cyclodextrin derivatives in a methanolic and water background electrolyte.

In order to have deep insights into the mechanisms of enantiomer affinity pattern in both aqueous and non-aqueous systems, an approach combining capillary electrophoresis and molecular modeling was undertaken. A chiral ß-blocker; acebutolol, was enantioseparated in aqueous capillary electrophoresis and non-aqueous capillary electrophoresis using two anionic ß-cyclodextrin derivatives. The enantiomer affinity pattern of acebutolol was found to be opposite when an aqueous background electrolyte was replaced with non-aqueous background electrolyte in the presence of heptakis(2,3-di-O-acetyl-6-sulfo)-ß-cyclodextrin but remained the same in the presence of heptakis(2,3-di-O-methyl-6-sulfo)-ß-cyclodextrin. Molecular docking of acebutolol into two ß-cyclodextrin derivatives indicated two distinct binding modes called 'up' and 'down' conformations. After structure optimization by molecular dynamics and energy minimization, both enantiomers of acebutolol were preferred to the 'up' conformation with heptakis(2,3-di-O-methyl-6-sulfo)-ß-cyclodextrin while 'down' conformation with heptakis(2,3-di-O-acetyl-6-sulfo)-ß-cyclodextrin. The further calculation of the complex energy with solvent effect indicated that heptakis(2,3-di-O-acetyl-6-sulfo)-ß-cyclodextrin had higher affinity to S-acebutolol than R-acebutolol in non-aqueous capillary electrophoresis while it showed better binding to R-acebutolol in aqueous capillary electrophoresis. However, the heptakis(2,3-di-O-methyl-6-sulfo)-ß-cyclodextrin bound better to R-acebutolol in both aqueous and non-aqueous capillary electrophoresis, implying that the binding mode played more important role in chiral separation of heptakis(2,3-di-O-methyl-6-sulfo)-ß-cyclodextrin while the solvent effect had prevailing impact on heptakis(2,3-di-O-acetyl-6-sulfo)-ß-cyclodextrin.