Revisited: Therapeutic and toxic blood concentrations of more than 1100 drugs and other xenobiotics.

In order to assess the significance of drug/substance levels measured in intensive care medicine and clinical and forensic toxicology as well as for therapeutic drug monitoring, it is essential that a comprehensive collection of data is readily available. We revisited and expanded our 2012 compilation of therapeutic and toxic plasma concentration ranges as well as half-lives of now more than 1100 drugs and other xenobiotics.Data have been abstracted from original papers, text books, and previous compilations and have been completed with data collected in our own forensic and clinical toxicology laboratories. We compiled the data presented in the table and the corresponding annotations over the past 30+ years. A previous compilation was completely double-checked, revised, and updated, if necessary. In addition, more than 200 substances, especially drugs who have been introduced since 2012 to the market as well as illegal drugs and other xenobiotics which became known to cause intoxications were added. We carefully referenced all data. Moreover, the annotations providing details were updated and revised, when necessary.For more than 1100 drugs and other xenobiotics, therapeutic ("normal") and, if data was available, toxic, and comatose-fatal plasma/blood concentrations as well as elimination half-lives were compiled in a table.In case of intoxications, the blood concentration of the substance and/or metabolite better predicts the clinical severity of the case when compared to the assumed amount and time of ingestion. Comparing and contrasting the clinical case against the data provided, including the half-life, may support the decision for or against further intensive care. In addition, the data provided are useful for the therapeutic monitoring of pharmacotherapies, to facilitate the diagnostic assessment and monitoring of acute and chronic intoxications as well as to support forensic and clinical expert opinions.

Postmortem metabolomics: Correlating time-dependent concentration changes of xenobiotic and endogenous compounds.

Postmortem redistribution (PMR) describes the artificial postmortem concentration changes of xenobiotics that may pose major challenges in forensic toxicology. Only a few studies have systematically investigated time-dependent postmortem drug concentration changes so far and the a posteriori estimation of the occurrence of PMR is not yet possible. In this context, the general concept that postmortem biochemical changes in blood might parallel drug redistribution mechanisms seems promising. Thus, the current study investigated the possible correlations between time-dependent postmortem concentration changes of xenobiotic and endogenous compounds; exemplified for authentic morphine (n = 19) and methadone (n = 11) cases. Peripheral blood samples at two time-points postmortem were analyzed for morphine and methadone concentrations and an (un)targeted postmortem metabolomics approach was utilized to combine targeted quantitative analysis of 56 endogenous analytes and untargeted screening for endogenous compounds (characterizing 1174 features); liquid and gas chromatography-mass spectrometry was used respectively. Individual statistically significant correlations between morphine/methadone and endogenous compounds/features could be determined. Hence, the general applicability of the proposed concept could successfully be confirmed. To verify the reproducibility and robustness of the correlating behavior, a larger dataset must be analyzed next. Once a marker/set of markers is found (e.g. robust correlation with specific xenobiotic or xenobiotic class), these could be used as surrogates to further study the time-dependent PMR in a broader variety of cases (e.g. independent of a xenobiotic drug present). A crucial next step will also be the attempt to create a statistical model that allows a posteriori estimation of PMR occurrence of xenobiotics to assist forensic toxicologists in postmortem case interpretation.

Cardiovascular dysfunction and oxidative stress following human contamination by fluoride along with environmental xenobiotics (Cd & Pb) in the phosphate treatment area of Togo, West Africa.

In Togo, the phosphate ore mill discharges waste containing xenobiotics like cadmium, lead and fluoride. If the role of heavy metals in the appearance of pathologies is known, the role of fluoride remains to be studied alongside xenobiotics. This study tested the hypothesis that the toxicity of fluoride contributes, along with heavy metals, to physiological dysfunction. In this process, we have studied the variation in the parameters of cardiovascular functioning, depending on the level of human contamination by fluoride and xenobiotics. The concentration of Cd and Pb in blood samples were determined by AAS and fluoride by titanium-chloride method. Lipid peroxidation, the total antioxidant potential of collected blood samples and the parameters of cardiovascular dysfunction were also measured. Cd, Pb and F contents and lipid peroxidation were found to be significantly elevated in polluted areas than control zone as well as total cholesterol, LDL and triglyceride. HDL and antioxidant potential of blood decreased in the polluted areas. Correlation tests showed that fluoride levels are related to variations in the bio-indicators of high blood pressure and oxidative stress (R varied from 0.354 to 0.907). Togo phosphate treatment leads to human contamination with fluoride, along with Cd and Pb, increasing the risk of cardiovascular dysfunction and oxidative stress.

Metabolomics-based parallel discovery of xenobiotics and induced endogenous metabolic dysregulation in clinical toxicology.

Intoxication by xenobiotics triggers the perturbation of metabolic fingerprints in biofluids, including the accumulation of xenobiotic compounds and the dysregulation of endogenous metabolites. In this work, an untargeted metabolomics workflow was developed to simultaneously profile both xenobiotic and endogenous metabolites for the identification of the xenobiotic origin and an in-depth understanding of the intoxication mechanism. This workflow was demonstrated in a real-world clinical case. Plasma samples were collected from four intoxicated children and another three healthy children. Untargeted metabolomics analysis was performed using ultraperformance liquid chromatography (UPLC) coupled to a high-resolution mass spectrometer (HRMS) with data-independent MSE acquisition. LC-MSE data was processed using an untargeted metabolomics data interpretation workflow, in which the identities of xenobiotics and altered endogenous metabolic features were determined via database searching. Five xenobiotic chemicals and 19 endogenous metabolites were found to be dysregulated. Combined with the clinical evidence, penfluridol was confirmed as the xenobiotic toxin. Furthermore, a mechanistic hypothesis was developed to explain the dysregulation of the four endogenous acyl-carnitines. This workflow can be readily applied to a wide range of clinical toxicology cases, offering a powerful and convenient means of simultaneous discovery of intoxication source and the understanding of intoxication mechanisms.

Evaluation of the suitability of ionic liquid-based liquid-liquid microextractions for blood protein removal.

The analysis of biological samples, such as whole blood, comes with several sample preparation challenges. Biological matrices often contain a variety of endogenous components that can interfere with the determination of xenobiotics. Especially blood plasma proteins (e.g. serum albumin) are known to interfere with electrospray ionization and result in analyte ion suppression. Sample preparation techniques should guarantee adequate removal of these biomolecules. The current study aims to determine to which extent proteins are removed from whole blood samples, using ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME). A qualitative comparison of the protein presence in extracts of IL-DLLME, solid-phase extraction (SPE) and protein precipitation (PP) was performed, using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, UV/VIS spectrophotometry was used to determine the protein content of a whole blood sample and IL-DLLME, SPE and PP extracts of the same sample. Finally, a quantitative comparison of matrix effects of benzodiazepines present in both whole blood and water samples. SDS-PAGE results showed that IL-DLLME extracts still contained proteins (i.e. albumin, hemoglobin); however, band intensities were comparable to SPE extracts. Spectrophotometric tests showed a total protein content of approximately 2 mg/mL in the final extracts. PP showed the highest protein extraction rate (19 mg/mL). Quantitative ME results showed no significant differences (α = 0.05) between blood and water IL-DLLME extracts. Overall, this is the first study to conclude that IL-DLLME is able to sufficiently remove blood proteins from whole blood samples, in order to avoid significant ion suppression.

Allometric scaling of hepatic biotransformation in rainbow trout.

Biotransformation may substantially impact the toxicity and accumulation of xenobiotic chemicals in fish. However, this activity can vary substantially within and among species. In this study, liver S9 fractions from rainbow trout (4-400 g) were used to evaluate relationships between fish body mass and the activities of phase I and phase II metabolic enzymes. An analysis of log-transformed data, expressed per gram of liver (g liver-1), showed that total cytochrome P450 (CYP) concentration, UDP-glucuronosyltransferase (UGT) activity, and glutathione S-transferase (GST) activity exhibited small but significant inverse relationships with fish body weight. In contrast, in vitro intrinsic clearance rates (CLIN VITRO,INT) for three polycyclic aromatic hydrocarbons (PAHs) increased with increasing body weight. Weight normalized liver mass also decreased inversely with body weight, suggesting a need to express hepatic metabolism data per gram of body weight (g BW-1) in order to reflect the metabolic capabilities of the whole animal. When the data were recalculated in this manner, negative allometric relationships for CYP concentration, UGT activity, and GST activity became more pronounced, while CLIN VITRO,INT rates for the three PAHs showed no significant differences across fish sizes. Ethoxyresorufin O-deethylase (EROD) activity normalized to tissue weight (g liver-1) or body weight (g BW-1) exhibited a non-monotonic pattern with respect to body weight. The results of this study may have important implications for chemical modeling efforts with fish.

Comparison of xenobiotic metabolism in phase I oxidation and phase II conjugation between rats and bird species.

There have been many reports regarding toxic chemicals in birds. Chemicals are mainly metabolized in the liver through phase I oxidation by cytochrome P450 (CYP) and phase II conjugation by conjugated enzymes, such as UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), glutathione-S-transferase (GST), etc. Xenobiotic metabolism differs among bird species, but little detailed information is available. In the present study, the four-ring polycyclic aromatic hydrocarbon (PAH), pyrene, was used as a model xenobiotic to clarify the characteristics of xenobiotic metabolism in birds compared with laboratory animals by in vivo and in vitro studies. Plasma, bile, and excreta (urine and feces) were collected after oral administration of pyrene and analyzed to clarify xenobiotic metabolism ability in chickens and quails. Interestingly, pyrenediol-glucuronide sulfate (PYDOGS) and pyrenediol-diglucuronide (PYDOGG) were present in chickens and quails but not in rats. In addition, the area under the curve (AUC), maximum plasma concentration (Cmax), and time to maximum plasma concentration (Tmax) of pyrene-1-sulfate (PYOS) were higher than those of the parent molecule, pyrene, while the elimination half-life (t1/2) and mean residence time (MRT) were faster than those of the parent pyrene. With regard to sulfation of 1-hydroxypyrene (PYOH), the maximum velocity (Vmax) and Michaelis constant (Km) of rat liver cytosol were greater than those of chicken and quail liver cytosol. Furthermore, Vmax/Km of UGT activity in rat liver microsomes was also greater than those of chicken and quail liver microsomes. Characterization of xenobiotic metabolism revealed species differences between birds and mammals, raising concerns about exposure to various xenobiotics in the environment.

Metabolomics profiling of xenobiotics in elite athletes: relevance to supplement consumption.

BACKGROUND: Supplements are widely used among elite athletes to maintain health and improve performance. Despite multiple studies investigating use of dietary supplements by athletes, a comprehensive profiling of serum supplement metabolites in elite athletes is still lacking. This study aims to analyze the presence of various xenobiotics in serum samples from elite athletes of different sports, focusing on metabolites that potentially originate from nutritional supplements. METHODS: Profiling of xenobiotics in serum samples from 478 elite athletes from different sports (football, athletics, cycling, rugby, swimming, boxing and rowing) was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was performed using orthogonal partial least squares discriminant analysis. Differences in metabolic levels among different sport groups were identified by univariate linear models. RESULTS: Out of the 102 detected xenobiotics, 21 were significantly different among sport groups including metabolites that potentially prolong exercise tolerance (caffeic acid), carry a nootropic effect (2-pyrrolidinone), exert a potent anti-oxidant effect (eugenol, ferulic acid 4 sulfate, thioproline, retinol), or originate from drugs for different types of injuries (ectoine, quinate). Using Gaussian graphical modelling, a metabolic network that links various sport group-associated xenobiotics was constructed to further understand their metabolic pathways. CONCLUSIONS: This pilot data provides evidence that athletes from different sports exhibit a distinct xenobiotic profile that may reflect their drug/supplement use, diet and exposure to various chemicals. Because of limitation in the study design, replication studies are warranted to confirm results in independent data sets, aiming ultimately for better assessment of dietary supplement use by athletes.

Cardiac biomarkers as sensitive tools to evaluate the impact of xenobiotics on amphibians: the effects of anionic surfactant linear alkylbenzene sulfonate (LAS).

Amphibian populations have been experiencing a drastic decline worldwide. Aquatic contaminants are among the main factors responsible for this decline, especially in the aquatic environment. The linear alkylbenzene sulfonate (LAS) is of particular concern, since it represents 84% of the anionic surfactants' trade. In Brazil, the maximal LAS concentration allowed in fresh waters is 0.5mgL-1, but its potential harmful effects in amphibians remain unknown. Therefore, this study aimed to analyze the effects of a sublethal concentration of LAS (0.5mgL-1) for 96h on sensitive cardiac biomarkers of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802). For this, we measured the activity level (AL - % of animals), in situ heart rate (fH - bpm), relative ventricular mass (RVM - % of body mass), in vitro myocardial contractility and cardiac histology of the ventricles. Tadpoles' AL and fH decreased in LAS group. In contrast, the RVM increased, as a result of a hypertrophy of the myocardium, which was corroborated by the enlargement of the nuclear measures and the increase of myocytes' diameters. These cellular effects resulted in an elevation of the in vitro contractile force of ventricle strips. Acceleration in the contraction (TPT - ms) also occurred, although no alterations in the time to relaxation (THR -ms) were observed. Therefore, it can be concluded that even when exposed to an environmentally safe concentration, this surfactant promotes several alterations in the cardiac function of bullfrog tadpoles that can impair their development, making them more susceptible to predators and less competitive in terms of reproduction success. Thus, LAS concentrations that are considered safe by Brazilian by regulatory agencies must be revised in order to minimize a drastic impact over amphibian populations. This study demonstrates the relevance of employing cardiac biomarkers at different levels (e.g., morphological, physiological and cellular) to evaluate effects of xenobiotics in tadpoles.

Toxicological pitfalls in ICU practice.

Either analgosedation or central nervous system dysfunction may be a side effect of implemented pharmacological treatment, as well as a consequence of intentional or unintentional poisoning. In traumatic lesions or anoxia of the central nervous system, a question arises after a recommended follow-up period about the effects of xenobiotics on nervous system function. Although therapeutic drug monitoring is the gold standard in such cases, usually a single toxicological estimation of "a neurodepressive compound" is performed after treatment discontinuation in order to determine the type and amount of exogenous substances, or their metabolites, in a patient's bodily fluids, which allows for an assessment of its actual effects on central nervous system functions. The aim of this paper was to describe the aspects of diagnostic toxicology which are essential for improved determination of the type and amount of exogenous substances present in biological fluids of intensive care patients. We present examples of clinical cases in order to discuss the most common discrepancies in interpretation related to the ordering of toxicology tests.

Metabolic alterations in multiple sclerosis and the impact of vitamin D supplementation.

BACKGROUND: Our goal was to identify changes in the metabolome in multiple sclerosis (MS) and how vitamin D supplementation alters metabolic profiles in MS patients and healthy controls. METHODS: We applied global untargeted metabolomics to plasma from a cross-sectional cohort of age- and sex-matched MS patients and controls and a second longitudinal cohort of MS patients and healthy controls who received 5,000 IU cholecalciferol daily for 90 days. We applied partial least squares discriminant analysis, weighted correlation network analysis (WGCNA), and pathway analysis to the metabolomics data. Generalized estimating equations models were used to assess change in WGCNA-identified module scores or metabolite pathways with vitamin D supplementation. RESULTS: Utilizing multiple analytical techniques, we identified metabolic alterations in oxidative stress (γ-glutamyl amino acid, glutathione) and xenobiotic metabolism (benzoate, caffeine) in MS patients compared with healthy controls in the first cohort. In the vitamin D supplementation cohort, we identified two sets of metabolites altered differentially between MS patients and healthy controls with vitamin D supplementation. The first included markers of oxidative stress and protein oxidation (P = 0.006), while the second contained lysolipids and fatty acids (P = 0.03). CONCLUSIONS: Using metabolomics, we identified alterations in oxidative stress and xenobiotic metabolism in MS patients and subsequently demonstrated a reduction of oxidative stress markers with vitamin D supplementation in healthy controls but not in MS patients. We demonstrate the utility of metabolomics in identifying aberrant metabolic processes and in monitoring the ability of therapeutic interventions to correct these abnormalities. TRIAL REGISTRATION: ClinicalTrials.gov NCT01667796. FUNDING: This study was supported by NIH grant K23 NS067055, grants from the Race to Erase MS, the National Multiple Sclerosis Society, the American Academy of Neurology, and North American Research Committee on Multiple Sclerosis.

Mouse Red Blood Cell-Mediated Rare Xenobiotic Phosphorylation of a Drug Molecule Not Intended to Be a Kinase Substrate.

Phosphorylation of xenobiotics is rare, probably owing to a strong evolutionary pressure against it. This rarity may have attracted more attention recently as a result of intentionally designed kinase-substrate analogs that depend on kinase-catalyzed activation to form phosphorylated active drugs. We report a rare phosphorylated metabolite observed unexpectedly in mouse plasma samples after an oral dose of a Tankyrase inhibitor that was not intended to be a kinase substrate, i.e., (S)-2-(4-(6-(3,4-dimethylpiperazin-1-yl)-4-methylpyridin-3-yl)phenyl)-8-(hydroxymethyl)quinazolin-4(3H)-one (AZ2381). The phosphorylated metabolite was not generated in mouse hepatocytes. In vitro experiments showed that the phosphorylation of AZ2381 occurred in mouse whole blood with heparin as anticoagulant but not in mouse plasma. The phosphorylated metabolite was also produced in rat, dog, and human blood, albeit at lower yields than in mouse. Divalent metal ions are required for the phosphorylation since the reaction is inhibited by the metal chelator EDTA. Further investigations with different cellular fractions of mouse blood revealed that the phosphorylation of AZ2381 was mediated by erythrocytes but did not occur with leukocytes. The levels of 18O incorporation into the phosphorylated metabolite when inorganic 18O4-phosphate and γ-18O4-ATP were added to the mouse blood incubations separately suggested that the phosphoryl transfer was from inorganic phosphate rather than ATP. It remains unclear which enzyme present in red blood cells is responsible for this rare phosphorylation.

[Metabolomic blood test: purpose, implementation and interpretation of data]. / Metabolomnyi analiz krovi: naznachenie, realizatsiia, interpretatsiia dannykh.

The human body is an open system that receives a variety of xenobiotics in the course of dietary route or respiration and in the form of the drugs. As a lump sum scores of toxic and potentially toxic substances are detected in a human body that significantly affect health and human lifespan. There are also thousands of diseases, dozens of which latently occur in the body of each person. Traditional diagnosis is not able to screen all the variety of xenobiotics and potential human diseases. For this purpose metabolomic blood test is available which is of non-targeted (review) nature. The test can reveal all the diversity of low molecular weight substances in blood, including tens of thousands of xenobiotics and markers of different diseases. Detection of xenobiotics in the blood, directional detoxification and subsequent monitoring of "body's chemical purity" together with the control of "normality" of all biochemical processes in the organism, using metabolomics blood tests is a necessary and presumably a sufficient condition in the implementation of inherent human genotype longevity. This article describes the purpose, implementation and interpretation of metabolomic blood test facilitating the implementation of this method in the Russian Federation, in order to significantly increase the average life expectancy.

Non-targeted, high resolution mass spectrometry strategy for simultaneous monitoring of xenobiotics and endogenous compounds in green sea turtles on the Great Barrier Reef.

Chemical contamination poses a threat to ecosystem, biota and human health, and identifying these hazards is a complex challenge. Traditional hazard identification relies on a priori-defined targets of limited chemical scope, and is generally inappropriate for exploratory studies such as explaining toxicological effects in environmental systems. Here we present a non-target high resolution mass spectrometry environmental monitoring study with multivariate statistical analysis to simultaneously detect biomarkers of exposure (e.g. xenobiotics) and biomarkers of effect in whole turtle blood. Borrowing the concept from clinical chemistry, a case-control sampling approach was used to investigate the potential influence of xenobiotics of anthropogenic origin on free-ranging green sea turtles (Chelonia mydas) from a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban/industrial and agricultural activities, respectively, on the Great Barrier Reef in North Queensland, Australia. Multiple biomarkers of exposure, including sulfonic acids (n=9), a carbamate insecticide metabolite, and other industrial chemicals; and five biomarkers of effect (lipid peroxidation products), were detected in case sites. Additionally, two endogenous biomarkers of neuroinflammation and oxidative stress were identified, and showed moderate-to-strong correlations with clinical measures of inflammation and liver dysfunction. Our data filtering strategy overcomes limitations of traditional a priori selection of target compounds, and adds to the limited environmental xenobiotic metabolomics literature. To our knowledge this is the first case-control study of xenobiotics in marine megafauna, and demonstrates the utility of green sea turtles to link internal and external exposure, to explain potential toxicological effects in environmental systems.

Unsaturated plasma phospholipids are consistently lower in the patients diagnosed with gestational diabetes mellitus throughout pregnancy: A longitudinal metabolomics study of Chinese pregnant women part 1.

BACKGROUND: Gestational diabetes mellitus (GDM) is a milder degree of hyperglycaemia diagnosed during pregnancy that can lead to serious, long-term consequences for both mother and foetus. The pathophysiology of GDM is not fully understood. The number of pregnant women diagnosed with GDM has been steadily increasing, but effective screening tools for early risk stratification are still missing. The emerging field of metabolomics has the potential to provide new insights and as a result is increasingly being used in studies of GDM. However, no study to date has investigated the longitudinal changes associated with GDM as pregnancy progresses. We investigated maternal plasma of a longitudinal cohort of normal pregnancies and pregnancies complicated by GDM. METHODS: Based on ultra-performance hydrophilic interaction liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry, an untargeted metabolomics study was performed to explore the changes in the plasma metabolome of GDM cases and healthy controls. Innovative sample preparation and multilevel statistical methods were employed to enhance our ability to analyse the longitudinal plasma samples by LC-MS. RESULTS: A number of polyunsaturated or chemically modified phospholipids were significantly lower in the plasma of pregnant women that developed GDM when compared to healthy controls, while no difference was observed for the saturated phospholipids. The reduction of these lipid species in the participants that developed GDM could be detected as early in the first trimester and the changes were independent of the stage of gestation and the steroid hormones in the plasma. CONCLUSIONS: These differences observed in our study were detected well before the onset of GDM, and might provide further insights into the etiology or pathophysiology of GDM.

Untargeted screening of unknown xenobiotics and potential toxins in plasma of poisoned patients using high-resolution mass spectrometry: Generation of xenobiotic fingerprint using background subtraction.

A novel analytical workflow was developed and applied for the detection and identification of unknown xenobiotics in biological samples. High-resolution mass spectrometry (HRMS)-based data-independent MSE acquisition was employed to record full scan MS and fragment spectral datasets of test and control samples. Then, an untargeted data-mining technique, background subtraction, was utilized to find xenobiotics present only in test samples. Structural elucidation of the detected xenobiotics was accomplished by database search, spectral interpretation, and/or comparison with reference standards. Application of the workflow to analysis of unknown xenobiotics in plasma samples collected from four poisoned patients led to generation of xenobiotic profiles, which were regarded as xenobiotic fingerprints of the individual samples. Among 19 xenobiotics detected, 11 xenobiotics existed in a majority of the patients' plasma samples, thus were considered as potential toxins. The follow-up database search led to the tentative identification of azithromycin (X5), α-chaconine (X9) and penfluridol (X12). The identity of X12 was further confirmed with its reference standard. In addition, one xenobiotic component (Y5) was tentatively identified as a penfluridol metabolite. The remaining unidentified xenobiotics listed in the xenobiotic fingerprints can be further characterized or identified in retrospective analyses after their spectral data and/or reference compounds are available. This HRMS-based workflow may have broad applications in the detection and identification of unknown xenobiotics in individual biological samples, such as forensic and toxicological analysis and sport enhancement drug screening.

SERUM ANTIOXIDANT PARAMETERS IN PATIENTS POISONED BY DIFFERENT XENOBIOTICS.

There is a great diversity of the acute drugs overdose cases in clinical toxicology. Clinical situation is complicated by the coexistence of factors predisposing to the development of adverse drug reactions (chronic use of drugs, polypharmacy, alcohol or drugs dependence, nutritional disorders) and by the presence of chronic organ damage, especially the liver and the kidney. The aim of this study was to evaluate whether there are sensitive plasma markers belonging to the antioxidant system in patients exposed to various xenobiotics. We measured the activity of antioxidant parameters: catalase (CAT), glutathione peroxidase (GPX3), glutathione (GSH), sulfhydryl groups (-SH), carbonyl groups (=CO) and free radicals (2,2-diphenyl-1-picrylhydrazyl, DPPH, assay) in serum of 49 patients with acute intoxication caused by carbamazepine (CBZ, n = 9), mixed drug intoxication (MDI) (n = 9), alcohol withdrawal syndrome (AWS, n = 9), acetaminophen (APAP, n = 7), tricyclic antidepressants (TCAs) (n = 5), valproic acids (VA, n = 4), narcotics (N, n = 3), and three others (benzodiazepines, BZD, n = 2; barbiturates, n = 1). The results were compared with the parameters of not intoxicated patients (n = 39). All patients had lower catalase activity in comparison to the control group (41.9 ± 16.5 vs. 196.0 ± 82.2 U/mg protein, p = 0.000), while the increase of GSH level was particularly apparent only in patients with AWS (391.3 ± 257.9 µmol/mg protein) compared to the control group (171.4 ± 88.4 µmol/mg protein, p = 0.034) and to patients intoxicated with carbamazepine (152.8 ± 102.5 µmol/mg protein, p = 0.027). Some differences, but without statistical significance, were also observed in GPX3 activity between different groups of poisoned patients.

Generation and Characterization of a Breast Cancer Resistance Protein Humanized Mouse Model.

Breast cancer resistance protein (BCRP) is expressed in various tissues, such as the gut, liver, kidney and blood brain barrier (BBB), where it mediates the unidirectional transport of substrates to the apical/luminal side of polarized cells. Thereby BCRP acts as an efflux pump, mediating the elimination or restricting the entry of endogenous compounds or xenobiotics into tissues and it plays important roles in drug disposition, efficacy and safety. Bcrp knockout mice (Bcrp(-/-)) have been used widely to study the role of this transporter in limiting intestinal absorption and brain penetration of substrate compounds. Here we describe the first generation and characterization of a mouse line humanized for BCRP (hBCRP), in which the mouse coding sequence from the start to stop codon was replaced with the corresponding human genomic region, such that the human transporter is expressed under control of the murineBcrppromoter. We demonstrate robust human and loss of mouse BCRP/Bcrp mRNA and protein expression in the hBCRP mice and the absence of major compensatory changes in the expression of other genes involved in drug metabolism and disposition. Pharmacokinetic and brain distribution studies with several BCRP probe substrates confirmed the functional activity of the human transporter in these mice. Furthermore, we provide practical examples for the use of hBCRP mice to study drug-drug interactions (DDIs). The hBCRP mouse is a promising model to study the in vivo role of human BCRP in limiting absorption and BBB penetration of substrate compounds and to investigate clinically relevant DDIs involving BCRP.

Analysis of biofluids by paper spray MS: advances and challenges.

Paper spray MS is part of a cohort of ambient ionization or direct analysis methods that seek to analyze complex samples without prior sample preparation. Extraction and electrospray ionization occur directly from the paper substrate upon which a dried matrix spot is stored. Paper spray MS is capable of detecting drugs directly from dried blood, plasma and urine spots at the low ng/ml to pg/ml levels without sample preparation. No front end separation is performed, so MS/MS or high-resolution MS is required. Here, we discuss paper spray methodology, give a comprehensive literature review of the use of paper spray MS for bioanalysis, discuss technological advancements and variations on this technique and discuss some of its limitations.