Metabolites In Biological Fluids Research Articles

Development and Validation of a New HPLC Bio Analytical Internal Standard Method for the Analysis of Two Immunology Drugs (Lamivudine and Dolutegravir) in Human Plasma

Bioanalytical methods are useful for the quantitative analysis of drugs and their metabolites in biological fluids. Bio-analytical internal standards methods plays vital role in areas of human clinical pharmacology. The aim of this work is to development and validation of bio-analytical internal standard method for determination of two immunology drugs Lamivudine (LMVD) and Dolutegravir (DTGR) in plasma with Abacavir(ABVR) drug as internal standard (IS). Liquid-liquid extraction with Diethyl ether and methanol in the ratio of 50:50 (v/v) was used for the extraction of drugs from the biological matrix. The optimized chromatography conditions consist of Water, Acetonitrile and Methanol in the ratio of 40:25:35 (v/v) as a mobile phase with Ascentis, C18 Column (250 X 4.6 mm, 5μ) as stationery phase. Isocratic elution with 1.2 ml flow separates theLMVD at 3.5 min, DTGR at 9.8 min and ABVR at 6.8 min. The method was validated as per ICH guidelines. The relative standard deviation (%RSD) were found to be <5%for precision studies. Hence the method was found to be suitable fort the analysis of LMVD and DTGR in spiked human plasma.

Boric Acid Functionalized Hypercrosslinked Polymers for Selective Extraction of Trace Catecholamines and Their Metabolites in Rat Serum

ABSTRACTAbnormal levels of catecholamine (CA) neurotransmitters and their metabolites in biological fluids can lead to various neurological disorders. Herein, a boric acid‐functionalized hypercrosslinked polymer was prepared and utilized as a sorbent for the dispersive solid‐phase extraction of CAs and their metabolites in rat serum. By combination with a high‐performance liquid chromatography‐fluorescence detector, the extraction parameters for the seven target analytes were optimized. Under the optimal extraction condition, the methodology for the quantitative analysis of CAs and their metabolites in rat serum samples was established. The limits of detection and limits of quantification were found to be in the ranges of 0.010–0.015 and 0.033–0.050 ng/mL, respectively. The results demonstrated satisfactory recoveries, with values ranging from 88.02% to 113.27%, accompanied by relative standard deviations within the range of 2.69%–9.59%. In addition, the method showed good anti‐interference ability (matrix effect ranged from 2.64% to 18.07%). The developed method was validated for the determination of CAs and their metabolites in normal and Alzheimer's disease model rats’ serum, which proved the promising application of the method for CAs neurotransmitter analysis in biological samples.

Simultaneous chemo- and enantio-separation of 2-, 3- and 4-chloro-methcatinones by high-performance liquid chromatography-tandem mass spectrometry and its application to oral fluid samples

A method of analysis was developed for the simultaneous chemo- and enantioseparation of 2-, 3-, and 4-chloromethcathinones by high-performance liquid chromatography tandem mass-spectrometry. The fast method enables the reliable identification of positional isomers of chloromethcathinones in biological samples. In addition, the same method can be used for the enantioselective quantitative determination of one of these compounds and its major phase-1 metabolites in biological fluids. The developed method was applied to oral fluid samples collected by police during routine random traffic control in Belgium from January to November, 2023. It was found that 3-CMC was more frequently abused compared to 4-CMC. Although some differences were observed between the concentrations of enantiomers in OF, most likely the drugs were abused in the racemic form. No abuse of 2-CMC was detected at the timepoint of sample collection.

Clinical Course of Methylmalonic Aciduria in Siblings: Two Clinical Cases

Background. Methylmalonic aciduria (MMA) is a rare disease from the group of hereditary metabolic diseases. The MMA clinical picture is polymorphic and meanwhile similar to other metabolic disorders. Determination of specific metabolites in biological fluids and molecular genetic testing are crucial to diagnose this disease. Timely diagnosis mainly determines the treatment efficacy and, therefore, the prognosis of MMA development. Clinical case description. Two siblings with MMA caused by methylmalonyl-CoA mutase deficiency (OMIM #251000) have shown duplication chr6-49459106-T-TA: NM_000255.4c.360dupT (p.Lys121fs) in homozygous state in exon 2 of the MMUT gene. The disease was diagnosed in the first child with underlying metabolic crisis that finally led to irreversible changes in organs and systems and lethal outcome. The diagnosis in the second child was established antenatally, thus, therapy was initiated from the first day of life. Favorable clinical course of the disease was observed during 5 months of follow-up. Conclusion. Timely MMA diagnosis (antenatal or during neonatal screening) is crucial for effective management and relatively favorable life prognosis for infants.

Dysregulation of the dopaminergic system secondary to traumatic brain injury: implications for mood and anxiety disorders.

Traumatic brain injury (TBI) represents a public health issue with a high mortality rate and severe neurological and psychiatric consequences. Mood and anxiety disorders are some of the most frequently reported. Primary and secondary damage can cause a loss of neurons and glial cells, leading to dysfunction of neuronal circuits, which can induce imbalances in many neurotransmitter systems. Monoaminergic systems, especially the dopaminergic system, are some of the most involved in the pathogenesis of neuropsychiatric and cognitive symptoms after TBI. In this work, we summarize the studies carried out in patients who have suffered TBI and describe alterations in the dopaminergic system, highlighting (1) dysfunction of the dopaminergic neuronal circuits caused by TBI, where modifications are shown in the dopamine transporter (DAT) and alterations in the expression of dopamine receptor 2 (D2R) in brain areas with dopaminergic innervation, thus establishing a hypodopaminergic state and (2) variations in the concentration of dopamine and its metabolites in biological fluids of post-TBI patients, such as elevated dopamine (DA) and alterations in homovanillic acid (HVA). On the other hand, we show a large number of reports of alterations in the dopaminergic system after a TBI in animal models, in which modifications in the levels of DA, DAT, and HVA have been reported, as well as alterations in the expression of tyrosine hydroxylase (TH). We also describe the biological pathways, neuronal circuits, and molecular mechanisms potentially involved in mood and anxiety disorders that occur after TBI and are associated with alterations of the dopaminergic system in clinical studies and animal models. We describe the changes that occur in the clinical picture of post-TBI patients, such as alterations in mood and anxiety associated with DAT activity in the striatum, the relationship between post-TBI major depressive disorders (MDD) with lower availability of the DA receptors D2R and D3R in the caudate and thalamus, as well as a decrease in the volume of the substantia nigra (SN) associated with anxiety symptoms. With these findings, we discuss the possible relationship between the disorders caused by alterations in the dopaminergic system in patients with TBI.

Automated High-Throughput Quantification of Phenyl-γ-valerolactones and Creatinine in Urine by Laser Diode Thermal Desorption.

Quantification of nutritional biomarkers is crucial to accurately assess the dietary intake of different classes of (poly)phenols in large epidemiological studies. High-throughput analysis is mandatory to apply this methodology in large cohorts. However, the current validated methods to quantify (poly)phenols metabolites in biological fluids use ultra performance liquid chromatography (UPLC), leading to analysis time of several minutes per sample. To significantly reduce the run time, we developed and validated a method to quantify in urine the flavan-3-ols biomarkers, phenyl-γ-valerolactones (PVLs), using laser diode thermal desorption (LDTD). This mass spectrometry source allows direct introduction of sample extracts, resulting in analysis time of less than 10 s per sample. Also, to encompass the problem associated with the cost and availability of sulfated and glucuronide analytical standards, urine samples were subjected to enzymatic hydrolysis. Creatinine was also quantified to normalize the results obtained from the urinary spot. Results obtained with LDTD-MS/MS were cross-validated by UPLC-MS/MS using 155 urine samples. Coefficient of correlation was above 0.975 for PVLs and creatinine. For all analytes, the accuracy was between 90% and 113% by LDTD-MS/MS. Altogether, sample preparation was fully automated to demonstrate the application potential of this method to large cohorts.

Pharmacogenetics-Informed Pharmacometabolomics as an Innovative Approach to Assessing the Safety and Risk of Pharmacotherapy with Valproic Acid

Scientific relevance. Valproic acid (VPA) is a psychotropic medicinal product, which may be associated with serious adverse drug reactions (ADRs). While pharmacogenetics and pharmacometabolomics can significantly affect the safety of valproates, there are no unified approaches to predicting, preventing, and correcting VPA-induced ADRs.Aim. This study aimed to collate the results of national and international studies on toxic VPA metabolites and to develop a novel personalised approach to assessing the safety and risks of valproate therapy in real-world clinical practice.Discussion. This study analysed national and international publications reflecting the results of preclinical and clinical studies on toxic VPA metabolites submitted to e-Library, PubMed, Scopus, and Google Scholar in 2012–2022. The inclusion criteria were full-text original articles, systematic reviews, meta-analyses, Cochrane reviews, and clinical cases in Russian or English. According to the analysis results, VPA has 20 studied toxic metabolites, which result from hepatic VPA metabolism involving P-oxidation, acetylation (β-oxidation), and glucuronidation enzymes. The functional activity of these enzymes is genetically determined and associated with heterozygous or homozygous carriage of non-functional/low-function single-nucleotide variant alleles in genes encoding these enzymes. The safety of VPA and its compounds can be improved by transferring the results of preclinical and clinical studies into real-world clinical practice using pharmacogenetics-informed pharmacometabolomics. Pharmacogenetics-informed pharmacometabolomics is a novel and personalised approach that helps, based on pharmacogenetic profiling, identify patients at high risk of VPA-induced ADRs, individually select starting and target doses of VPA and its compounds, determine the timing and frequency for therapeutic drug monitoring and monitoring toxic VPA metabolites in biological fluids (blood, saliva, and urine), and select a strategy for the prevention and correction of VPA-induced ADRs, taking into account patients’ individual pharmacometabolic profiles.Conclusions. The quality of medical care for patients with neurological diseases and mental disorders will improve with proper monitoring of VPA-induced ADRs by all entities involved in the medicinal product life cycle; active involvement of neurologists and psychiatrists in the prediction, prevention, and monitoring of the safety of valproate treatment; and inclusion of specific sections on practical pharmacogenetics-informed pharmacometabolomics and pharmacovigilance in the professional training curricula for neurologists and psychiatrists.

A simple, rapid and sensitive HILIC LC-MS/MS method for simultaneous determination of 16 purine metabolites in plasma and urine

Purine intermediates play important roles in physiological function and participate in the kidney disorders, while a targeted quantification of the metabolic alterations in the purine metabolism in acute kidney injury (AKI) individuals has not been conducted. In the study, a novel, rapid and sensitive LC-MS method for simultaneous quantification of 16 purine metabolites was developed using hydrophilic interaction separation mode in human plasma and urine. The developed method was validated by using charcoal-stripped plasma and urine as blank matrix. The results showed that the method was good linear (R2 > 0.99) and the lower limit of quantification (LLOQ) ranged from 0.833 ng/mL to 800 ng/mL. The recovery and matrix effect were repeatable and stable. The intraday precision ranged from 0.7% to 12.7%, while the inter-day precision ranged from 1.6% to 18.5%. Most analytes were stable in the autosampler and could subject three freeze-thaw cycles. The method provided a wider coverage of purine metabolites and completed good separation of interfering compounds of nucleosides, deoxynucleosides and their corresponding nucleobases without derivatization, which was time-saving and labor-saving for the large-scale analysis. Furthermore, the method was successfully applied to plasma and urine samples of hospitalized patients without and with AKI. The results showed certain purine intermediates were up-regulated in plasma and down-regulated in urine of AKI inpatients, indicating that AKI stress may associate with inflammatory responses. The novel method can facilitate the quantitative analysis of purine metabolites in biological fluids, and exhibit great prospects in providing more information on the pathogenesis of AKI.

Halide salt-tuning at interface: Highly water-stable and anion-exchange-active CsPbX3@SiO2 Trimurti nanoparticles for multicolor metabolite assay

High water stability and fast anion exchange (FAE) activity are indispensable requirements of CsPbX3 (X = Cl, Br, I) nanoparticles (NPs) for achieving multicolor fluorescence sensing in aqueous samples. In this study, we prove that the crystal phase transition rate from Cs4PbX6 to CsPbX3 can be finely tuned by halide salt, thereby facilitating the exposure of in-situ SiO2 nucleation sites to CsPbX3. Through the sol–gel method triggered by KX-containing water, monodisperse CsPbX3@SiO2 Trimurti nanoparticles (TNPs), i.e., double-side SiO2-coated CsPbX3 NPs, are successfully synthesized for the first time. As an example, the CsPbBr3@SiO2 TNPs exhibit significantly enhanced photoluminescence quantum yield (80%), fluorescence lifetime (22.09 ns) and water stability (only 11.4% drop in FL intensity after 60 min reaction with water), meanwhile maintain consistent high FAE activity, compared to bare CsPbBr3 NPs (57%, 6.56 ns, 97.9% drop) and single-side SiO2-coated NPs (69%, 9.76 ns, 39.1% drop). Furthermore, we propose an H2O2 recognition strategy at the organic/aqueous phase interface based on the FAE effect between oleylammonium iodide (OLAI) and CsPbX3@SiO2 TNPs. Thus, the TNPs-based multicolor sensing platform for small molecule metabolites is constructed and utilized for uric acid detection in serum, which obtains consistent results with the commercial method (relative error ≤ 5.67%). This work not only provides a guidance for the tunable surface modification of high-performance CsPbX3 NPs, but also designs a universal strategy for selectively detecting small molecule metabolites in biological fluids based on the intrinsic FAE effect.

Identification and synthesis of metabolites of the new antiglaucoma drug

Introduction: The determination of biotransformation products is an essential part of the preclinical trial of original medicines. These studies have not been conducted before for the new drug 5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonamide. Identification and synthesis of metabolite substances are necessary for subsequent tests of bioavailability, linearity of pharmacokinetics, accumulation, distribution and excretion. Materials and methods: The study was carried out on Wistar rats and rabbits of the Soviet Chinchilla breed. The substance of the drug was administered to animals intraperitoneally. The collection of animal blood samples was performed before administration and 1 h, 2 h, 4 h, 24 h after administration into K3EDTA-tubes. A part of each sample was centrifuged to separate the plasma. Rat urine samples were taken before administration and at intervals of 0-2 h, 2-4 h, 4-6 h, 6-24 h after administration of the drug. The HPLC-MS/MS method was used to identify metabolites in biological fluids. The assumed biotransformation products were synthesized after preliminary analysis. The structure of the obtained substances was confirmed by NMR spectroscopy and high-resolution mass spectrometry. Then, a comparison was carried out with the compounds identified in biological fluids by retention time, ratios of chromatographic peak areas at the main MRM-transitions using HPLC-MS/MS. Results and discussion: A metabolite formed by addition an oxygen atom to a drug molecule, as well as an acylated metabolite were detected during the analysis of plasma and blood samples. A compound with an increased molecular weight of 1 dalton compared to the drug substance was also present in a rat urine. N-hydroxy-5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonamide, 5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonic acid, which could potentially be obtained during biotransformation, as well as N-acetyl-5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonamide were synthesized. Repeated HPLC-MS/MS tests confirmed the correctness of the initial hypothesis. It was found that a sulfonic acid derivative is formed in urine as a result of decomposition of N-hydroxymetabolite during sample collection. Conclusion: The studied drug is metabolized by formation of two metabolites: N-hydroxy-5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonamide and N-acetyl-5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonamide. N-hydroxymetabolite is able to decompose in biological fluids samples with formation of 5-[5-(trifluoromethyl)-1,2-oxazole-3-yl]-furan-2-sulfonic acid.

Characterization of URB Series Synthetic Cannabinoids by HRMS and UHPLC-MS/MS.

A large number of synthetic cannabinoids are included in new psychoactive substances (NPS) and constitute an open research area in analytical pharmaceutical and toxicology when methods are needed to unambiguously identify these substances and their metabolites in biological fluids. A full molecular characterization of five synthetic molecules of the URB series that is able to interact with the endocannabinoid system was achieved with a high-resolution mass spectrometry (HRMS) in positive ion electrospray ionization and collisional experiments on the protonated parent ions, obtaining characteristic fragmentation patterns. Ultra-high-performance liquid chromatography coupled with a triple quadrupole (UHPLC-MS/MS) has also been used, which can help develop methods for screening and confirming synthetic cannabinoids in biological fluids.

Mechanism of capmatinib degradation in stress conditions including degradation product characterization using ultra-high-performance liquid chromatography-quadrupole-time of flight mass spectrometry and stability-indicating analytical method development.

Capmatinib (CMT) has been recently approved for the treatment of non-small cell lung cancer by the United States Food and Drug Administration (USFDA). Till date, the degradation mechanism of CMT in different stress conditions is not known. Moreover, degradation products (DPs) of the drug are yet to be identified. Characterization study on degradation products of CMT has not been reported before. Furthermore, no previously reported literature is available on the stability-indicating method of CMT. Owing to the lack of such scientific reports, we developed a sensitive, stability-indicating method for CMT which can resolve it from all its degradation products. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH Q2 [R1]) guideline. We studied and established the degradation mechanism of CMT in different stress conditions. One degradation product (DP2) was isolated and characterized using 1 H NMR. The degradation products (DP1, DP2 and DP3) of the drug have been identified and characterized for the first time by using high-resolution mass spectrometry and 1 H NMR spectroscopy. CMT was found to become degraded under acidic, basic and photolytic stress conditions in the solution phase to yield three major DPs. The drug was found to be stable in neutral hydrolysis, oxidation and thermal stress conditions. DP1 was formed under acidic and basic hydrolytic conditions, whereas DP2 and DP3 were formed under photolytic conditions. Characterization of all the DPs has been carried out to establish their structures and understand the molecular mechanism behind the degradation of the drug. Few studies reported quantitative analysis of CMT and its metabolites in biological fluids. However, this is the first study to identify the unknown DPs of CMT and the mechanism of its degradation. Moreover, this article reports a stability-indicating analytical method for CMT which has not yet been reported in any literature.

A study of connective tissue metabolites in biological fluids of patients with various types of glaucoma

PURPOSE. To quantify the content of connective tissue metabolites reflecting the exchange of its main components in biological fluids in low tension glaucoma (LTG) and primary open-angle glaucoma (POAG), and to conduct a comparative analysis of the obtained data. METHODS. The studies were conducted in 33 patients with low tension glaucoma aged 51 to 80 years old (mean age 69 ± 10.4 years), 20 patients with POAG aged 53 to 80 years old (mean age 67 ± 10.1 years) and 15 clinically healthy volunteers aged 52 to 78 years old (mean age 68 ± 9.2 years). The protein components of the fibrous part of the connective tissue were analyzed for daily excretion of oxyproline in urine by the method involving para-Dimethylamin-obenzaldehyde modified by P.N. Sharaev. Serum glycosaminoglycans (GAG) were studied by analyzing carbohydrate components of connective tissue. The concentration of GAG in the blood serum was determined by the colorimetric method, using Dische's carbazole reaction. RESULTS. The amount of GAG in the blood serum of LTG patients was 3.26 ± 1.57 mmol/L, while in the control group consisting of clinically healthy volunteers — 2.92 ± 1.25 mmol/L. The differences were not statistically significant (p > 0.1). The amount of daily excretion of oxyproline in the urine of LTG patients was 17.17 ± 8.64 mmol/day, and in the group of clinically healthy individuals — 13.96 ± 5.61 mmol/day. The differences were statistically significant (p < 0.05). The amount of GAG in the blood serum of POAG patients was 3.97 ± 1.17 mmol/L. The differences in relation to LTG were statistically significant (p < 0.05). The amount of daily excretion of oxyproline in the urine of POAG patients was 32.71 ± 19.79 mmol/day. The differences were statistically significant in relation to LTG (p < 0.05). The amount of GAG and oxyproline in biological fluids tends to increase with the advancement of LTG and POAG. CONCLUSION. Destruction processes in the connective tissue do occur in LTG, but are less pronounced in comparison to POAG and more pronounced in comparison to healthy individuals. The indicator that most clearly reflects the activity of destructive processes in the connective tissue is the daily excretion of oxyproline in urine.

Recent Advances in Garcinia cambogia Nutraceuticals in Relation to Its Hydroxy Citric Acid Level. A Comprehensive Review of Its Bioactive Production, Formulation, and Analysis with Future Perspectives.

Garcinia cambogia (Gaertn.) Desr. (known as Malabar tamarind) is a popular traditional herbal medicine and is one of the well-known folk medicines reported for the treatment of obesity and incorporated in several nutraceuticals worldwide. These effects are mediated by a myriad of bioactive compounds with most effects attributed to its hydroxy citric acid (HCA) content. This review aims to present a holistic overview on novel trends in the production of G. cambogia bioactive components and how extraction optimization is important to ensure best product quality with its reported nanoformulations with particular emphasis on HCA content. Further, an overview of the different analytical approaches used for quality control assessment of G. cambogia plant and its nutraceuticals is presented highlighting both advantages and limitations. Moreover, analytical approaches for detecting G. cambogia metabolites in biological fluids with emphasis on HCA level to determine its pharmacokinetics and proof of efficacy are presented for the first time.

Metabolomics: A New Approach in the Evaluation of Effects in Human Beings and Wildlife Associated with Environmental Exposition to POPs

Human beings and wild organisms are exposed daily to a broad range of environmental stressors. Among them are the persistent organic pollutants that can trigger adverse effects on these organisms due to their toxicity properties. There is evidence that metabolomics can be used to identify biomarkers of effect by altering the profiles of endogenous metabolites in biological fluids or tissues. This approach is relatively new and has been used in vitro studies mainly. Therefore, this review addresses those that have used metabolomics as a key tool to identify metabolites associated with environmental exposure to POPs in wildlife and human populations and that can be used as biomarkers of effect. The published results suggest that the metabolic pathways that produce energy, fatty acids, and amino acids are commonly affected by POPs. Furthermore, these pathways can be promoters of additional effects. In the future, metabolomics combined with other omics will improve understanding of the origin, development, and progression of the effects caused by environmental exposure.

A Review on Bioanalytical Method Development and Validation by Liquid Chromatography–Tandem Mass Spectrometry

The development of sound bioanalytical method(s) is of paramount importance during the process of drug discovery and development, culminating in a marketing approval. The objective of this paper is to review the sample preparation of drug in biological matrix and to provide practical approaches for determining selectivity, specificity, limit of detection, lower limit of quantitation, linearity, range, accuracy, precision, recovery, stability, ruggedness, and robustness of liquid chromatographic methods to support pharmacokinetic (PK), toxicokinetic, bioavailability, and bioequivalence studies. Bioanalysis, employed for the quantitative determination of drugs and their metabolites in biological fluids, plays a significant role in the evaluation and interpretation of bioequivalence, PK, and toxicokinetic studies. Selective and sensitive analytical methods for quantitative evaluation of drugs and their metabolites are critical for the successful conduct of pre-clinical and/or biopharmaceutics and clinical pharmacology studies.

Biomonitoring of ochratoxin A, 2\u2032R-ochratoxin A and citrinin in human blood serum from Switzerland

Biomonitoring of mycotoxins and their metabolites in biological fluids is increasingly used to assess human exposure. In this study, biomarkers of ochratoxin A (OTA) and citrinin (CIT) exposure were determined in a large number of serum samples from healthy blood donors in Switzerland. In 2019, 700 samples from different regions were obtained. From 240 donors, a second sample (taken 2–9 months later) was available for analysis. Moreover, 355 blood donor samples from 2005 from all regions in Switzerland and 151 additional samples from the southern Swiss region of Ticino from 2005 could be analysed.OTA, 2′R-ochratoxin A (2′R-OTA), ochratoxin alpha (OTα), CIT and dihydrocitrinone (DH-CIT) were analysed using validated targeted methods including precipitation and online SPE clean-up.OTA and 2′R-OTA were frequently detected (OTA in 99%; 2′R-OTA in 51% of the tested samples). The mean concentration in all positive samples was 0.4 ng/mL for OTA and 0.2 ng/mL for 2′R-OTA. OTα was not detected in any sample above the limit of quantification (LOQ). In contrast to OTA, CIT and DH-CIT were only quantifiable in 2% and 0.1% of the samples, respectively. No significant trend was observed between the samples from 2005 and the more recent samples, but OTA concentrations were usually higher in serum samples from the southern Swiss region of Ticino and in males compared to females.Our extensive data fit well within the framework of previously published values for the healthy adult European population.

Exposure to Antineoplastic Drugs in Occupational Settings: A Systematic Review of Biological Monitoring Data.

The high toxicity of antineoplastic drugs (ADs) makes them dangerous not only for patients, but also for exposed workers. Therefore, the aim of this review was to provide an updated overview of the biological monitoring of occupational AD exposure in order to extrapolate information useful to improve risk assessment and management strategies in workplaces. Several studies demonstrated that remarkable portions of healthcare workers may have traces of these substances or their metabolites in biological fluids, although with some conflicting results. Nurses, directly engaged in AD handling, were the occupational category at higher risk of contamination, although, in some cases, personnel not involved in AD-related tasks also showed quantifiable internal doses. Overall, further research carried out on greater sample sizes appears necessary to gain deeper insight into the variability retrieved in the reported results. This may be important to understand the impact of the extent of ADs use, different handling, procedures, and cleaning practices, spill occurrence, training of the workforce, as well as the adoption of adequate collective and personal protective equipment in affecting the occupational exposure levels. This may support the achievement of the greatest clinical efficiency of such therapies while assuring the health and safety of involved workers.

Monodispersed silver-gold nanorods controllable etching for ultrasensitive SERS detection of hydrogen peroxide-involved metabolites

Hydrogen peroxide (H2O2)-involved metabolites are widely engaged in cellular metabolism, and play significant roles in cell proliferation, cell growth, and signaling transduction. It is highly desirable to establish a method for the detection of H2O2-involved metabolites for applications ranging from chemical sensing to biomedical diagnosis. Herein, monodispersed sandwich Au@4-MBN@Ag@PEG nanorods (referred to as AMPRs) with bright Raman emission were developed to serve as a universal platform for detecting H2O2-involved metabolites (4-mercaptobenzonitrile is abbreviated to 4-MBN as the Raman reporter and PEG is polyethylene glycol). The system detects metabolites through changes in the surface-enhanced Raman scattering (SERS) spectrum, resulting from the controllable etching of the silver layer by the H2O2 produced by the metabolites. The integrative nanoplatform was successfully used to quantify the levels of glucose, lactate, and choline in aqueous solutions by exploiting the close linear relationship between the intensity of a SERS band and the logarithmic concentration of H2O2. The presented SERS nanoplatform demonstrated considerable practicability for the detection of glucose in cerebrospinal fluid samples (with a limit of detection (LOD) of 1.76 μM), and was capable of distinguishing infected from uninfected individuals. Therefore, the SERS sensor provides a new platform for the detection of H2O2-involved metabolites in biological fluids, and has potential for use in metabolite analysis and biomedical diagnostics.

Analysis of tamoxifen and its main metabolites in plasma samples of breast cancer survivor female athletes: Multivariate and chemometric optimization.

A sensitive method based on liquid chromatography combined with a diode array detector was developed and validated to simultaneously determine tamoxifen, and its active metabolites N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen in human plasma samples. The green and sustainable vortex-assisted dispersive liquid-phase microextraction technique based on the natural hydrophobic deep eutectic solvent was used for the extraction and preconcentration of the analytes. Chemometrics and multivariate analysis were used to optimize the independent variables including the type and volume of deep eutectic solvent, extraction time, and ionic strength. Under optimal conditions, calibration curves were linear in a suitable range with the lower limits of quantification (0.8-10.0μg/L), which covered the relevant concentrations of the analytes in plasma samples for a clinical study. Intra- and interday precision evaluated at three concentrations for the analytes were lower than 8.2 and 12.1%, respectively. Accuracy was in the range of 94.9-104.7%. The applicability of the developed method on human plasma samples illustrated the range 45.1-72.8, 98.4-128.3, 0.9-1.2, and 2.7-6.1μg/L for tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen, respectively. The validated method can be effective for the pharmacokinetics, pharmacodynamics, and therapeutic drug monitoring studies of tamoxifen and its main metabolites in biological fluids.