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Xylazine is a potent sedative used in veterinary medicine. Recently, recreational drugs such as fentanyl have been found to contain xylazine, increasing the risk of respiratory depression and death. Despite a similar presentation to opioid overdose, patients who ingest xylazine do not respond to treatment with Narcan. Therefore, rapid detection of xylazine could improve patient management and prevent adverse outcomes.We evaluated the XYL500 one-step xylazine drug of abuse test for its ability to detect xylazine in 152 urine samples from patients on chronic opioid therapy for pain management or in treatment for substance use disorder. Results were compared to LC-MS/MS as the reference method. Precision, cross-reactivity, interference and stability studies were performed.Pooled patient samples were consistently negative or positive when tested five times on the same day and over three days of testing. The diagnostic sensitivity, specificity and accuracy of the XYL500 assay were 74, 98, and 82 % respectively, as compared with LC-MS/MS. XYL500 detected 77 of the 104 LC-MS/MS positive samples identified in our initial evaluation, including some that contained low levels of xylazine (n=8), <10 ng/mL. Minimal cross-reactivity with other opioid analgesics and commonly encountered drugs was seen with only one false positive result. Interferences by common urine contaminants were negligible. Specimens were stable up to 160 days refrigerated and up to 80 days at room temperature.XYL500 allows for rapid detection of xylazine, illustrating its utility in monitoring patients who ingested recreational drugs containing the additive, xylazine, and its potential to improve patient management. [ABSTRACT FROM AUTHOR]

Lipid mediators, which include specialized pro-resolving mediators and classic eicosanoids, are pivotal in both initiating and resolving inflammation. The regulation of these molecules determines whether inflammation resolves naturally or persists. However, our understanding of how these mediators are regulated over time in various inflammatory contexts is limited. This gap hinders our grasp of the mechanisms underlying the disease onset and progression. Due to their localized action and low endogenous levels in many tissues, developing robust and highly sensitive methodologies is imperative for assessing their endogenous regulation in diverse inflammatory settings. These methodologies will help us gain insight into their physiological roles. Here, we establish methodologies for extracting, identifying, and quantifying these mediators. Using our methods, we identified a total of 37 lipid mediators. Additionally, by employing a reverse-phase HPLC method, we successfully separated both double-bond and chiral isomers of select lipid mediators, including Lipoxin (LX) A4, 15-epi-LXA4, Protectin (PD) D1, PDX, and 17R-PD1. Validation of the method was performed in both solvent and surrogate matrix for linearity of the standard curves, lower limits of quantitation (LLOQ), accuracy, and precision. Results from these studies demonstrated that linearity was good with r2 values > 0.98, and LLOQ for the mediators ranged from 0.01 to 0.9 pg in phase and from 0.1 to 8.5 pg in surrogate matrix. The relative standard deviation (RSD) for inter- and intraday precision in solvent ranged from 5% to 12% at low, intermediate, and high concentrations, whereas the RSD for the inter- and intraday variability in the accuracy ranged from 95% to 87% at low to high concentrations. The recovery in biological matrices (plasma and serum) for the internal standards used ranged from 60% to 118%. We observed a marked ion suppression for molecules evaluated in negative ionization mode, while there was an ion enhancement effect by the matrix for molecules evaluated in positive ionization mode. Comparison of the integration algorithms, namely, AutoPeak and MQ4, and approaches for calculating signal-to-noise ratios (i.e., US Pharmacopeia, relative noise, peak to peak, and standard deviation) demonstrated that different integration algorithms tested had little influence on signal-to-noise ratio calculations. In contrast, the method used to calculate the signal-to-noise ratio had a more significant effect on the results, with the relative noise approach proving to be the most robust. The methods described herein provide a platform to study the SPM and classic eicosanoids in biological tissues that will help further our understanding of disease mechanisms. [ABSTRACT FROM AUTHOR]

Aims: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. To prevent PPH, the WHO recommends administration of oxytocin (OT) immediately after birth, i.e. during the third stage of labour (TSL). Previous studies demonstrate that methods to quantify OT in biological matrices, e.g. enzyme‐linked immunosorbent assays (ELISA), radioimmunoassays (RIA) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) lack the specificity and/or sensitivity to accurately quantify OT in plasma from women administered OT during TSL. This is due to increased metabolic clearance of OT in late‐stage pregnancy and at the time of childbirth, resulting in extremely low OT plasma concentrations. This study describes the development of an ultra‐sensitive bioanalytical method that overcomes the issues previously reported and enables accurate pharmacokinetic analyses of exogenously administered OT in TSL. Methods: A selective and sensitive assay to quantify OT in TSL plasma was developed. Immunoprecipitation (IP) was applied to selectively extract OT from the TSL plasma, thereby generating clean extracts compatible with nanoflow LC (nLC). nLC–MS/MS was chosen for its high sensitivity and ability to differentiate between OT and potentially co‐captured OT‐like immunoreactive products. Results: The presented methodology is accurate and precise, with a good linear fit between 100–10 000 fg mL−1 OT. TSL plasma samples from a clinical phase 1 study (NCT02999100) were analysed successfully, enabling OT quantification down to 100 fg mL−1. Conclusions: The presented IP–nLC–MS/MS method succeeded in overcoming the sensitivity challenge related to the assay of OT in TSL plasma and thereby revealing the PK profiles of OT in TSL plasma clinical study samples. [ABSTRACT FROM AUTHOR]

Thyroid hormones (THs), including triiodothyronine (T3), thyroxine (T4), and their metabolites, are essential for regulating development, growth, and energy metabolism. Thyroglobulin (Tg) produced by thyroid follicular cells acts as an essential substrate for TH synthesis. The combination of THs with Tg is a widely used serological laboratory test for thyroid function assessment. Early detection and timely intervention are significant for preventing and managing thyroid disease. In recent years, liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) has emerged as a powerful tool for the precise detection of small molecular analytes and steroid hormones in clinical practice as a result of its high sensitivity and specificity. While LC‐MS/MS has been increasingly used for detecting THs and Tg recently, its application in clinical practice is still in its early stages. Recent advances in the assessment of thyroid metabolism using LC‐MS/MS in clinical samples published during 2004–2023 were reviewed, with a special focus on the use of this technique for quantifying molecules involved in thyroid diseases. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We measured the intracellular concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in dried blood spots (DBS) for pre-exposure prophylaxis (PrEP) adherence using sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS). A total of 191 DBS were obtained from 85 participants who were receiving tenofovir disoproxil fumarate (TDF; 300 mg) and emtricitabine (FTC; 200 mg) as PrEP at the Sexual Health Clinic, National Center for Global Health and Medicine, Tokyo, Japan. DBS punch (3 mm) added to 25 μL of 50% methanol and 400 μL of internal standard solution was used for solid phase extraction. Chromatographic separation was achieved on an Atlantis Premier BEH C18 AX Column (50 mm × 2.1 mm i.d.; particle size 1.7 μm) using gradient elution (flow rate: 0.6 mL/min); injection volume: 7 μL and run time: 5.5 min. Calibration curves for the two drugs were linear in the range 0.05–12.5 ng/punch. We determined the intracellular TFV-DP and FTC-TP concentrations in 191 DBS obtained from 85 patients administered with TDF and FTC as PrEP. The analytical performance data (calibration curve and QC samples) for all the analytical runs met the acceptance criteria. Intracellular concentrations of TFV-DP and FTC-TP in the DBS remained stable for at least 24 h after oral administration. A multiplex LC–MS/MS method was successfully developed for DBS, which can be useful for monitoring the levels of TFV-DP and FTC-TP in individuals receiving PrEP. [ABSTRACT FROM AUTHOR]

Ceftriaxone (CTRX) is a commonly used cephalosporin antibiotic. It is suggested that monitoring plasma/serum concentrations is helpful for its safe use. This study aimed to develop and validate an analytical method for measuring CTRX concentrations in human serum according to International Conference on Harmonization guideline M10. Ten microliters of serum sample was purified using a salting‐out assisted liquid–liquid extraction procedure with magnesium sulfate. The upper layer was then diluted threefold and analyzed using a liquid chromatography–tandem mass spectrometry‐based method with a total run time of 12 min. The linear calibration curve was obtained over the concentration range 5–500 μg/ml. The within‐run accuracy varied from 0.2 to 6.5%, and the precision was ≤8.0%. The between‐run accuracy and precision ranged from 0.7% to 5.6% and ≤6.4%, respectively. Significant carryover was resolved by injecting four blanks after high‐concentration CTRX samples. The recovery rates from spiked serum at low and high concentrations were 44.4 and 43.4%, respectively. Other factors, including selectivity, matrix effects, stability, dilution integrity and reinjection reproducibility also met the acceptance criteria. Serum concentrations in 14 samples obtained from two participants receiving 2 g/day of CTRX were successfully determined using this method. [ABSTRACT FROM AUTHOR]

Background: Identifying molecular mechanisms responsible for the response to heat stress is essential to increase production, reproduction, health, and welfare. This study aimed to identify early biological responses and potential biomarkers involved in the response to heat stress and animal's recovery in tropically adapted beef cattle through proteomic analysis of blood plasma. Methods: Blood samples were collected from 14 Caracu males during the heat stress peak (HSP) and 16 h after it (heat stress recovery--HSR) assessed based on wet bulb globe temperature index and rectal temperature. Proteome was investigated by liquid chromatography-tandem mass spectrometry from plasma samples, and the differentially regulated proteins were evaluated by functional enrichment analysis using DAVID tool. The protein-protein interaction network was evaluated by STRING tool. Results: A total of 1,550 proteins were detected in both time points, of which 84 and 65 were downregulated and upregulated during HSR, respectively. Among the differentially regulated proteins with the highest absolute log-fold change values, those encoded by the GABBR1, EPHA2, DUSP5, MUC2, DGCR8, MAP2K7, ADRA1A, CXADR, TOPBP1, and NEB genes were highlighted as potential biomarkers because of their roles in response to heat stress. The functional enrichment analysis revealed that 65 Gene Ontology terms and 34 pathways were significant (P < 0.05). We highlighted those that could be associated with the response to heat stress, such as those related to the immune system, complement system, hemostasis, calcium, ECM-receptor interaction, and PI3K-Akt and MAPK signaling pathways. In addition, the protein-protein interaction network analysis revealed several complement and coagulation proteins and acute-phase proteins as important nodes based on their centrality and edges. Conclusion: Identifying differentially regulated proteins and their relationship, as well as their roles in key pathways contribute to improve the knowledge of the mechanisms behind the response to heat stress in naturally adapted cattle breeds. In addition, proteins highlighted herein are potential biomarkers involved in the early response and recovery from heat stress in tropically adapted beef cattle. [ABSTRACT FROM AUTHOR]

The present study is focused on evaluating acaricidal activity and chemical compositions of Erigeron acer root, which was identified as a promising candidate among fifteen Mongolian plant extracts tested for acaricidal activity. The acaricidal effect was evaluated against Haemaphysalis longicornis, assessed for toxicity to normal human skin fibroblast, and analyzed for its chemical constituents. The acetone extract of E. acer root showed significant activity against H. longicornis, with a lethal concentration (LC50) of 5.31 mg/mL and low toxicity, evidenced by a cytotoxic concentration (CC50) of 267.00 µg/mL. Using liquid chromatography-tandem mass spectrometry and molecular networking, thirteen natural compounds were identified, including pyrrolidines, alkaloids, fatty acids, and flavonoids, highlighting the efficacy of E. acer root extract as an effective acaricide against H. longicornis and offering insights for developing new tick control solutions. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to analyze the distribution of plasma aldosterone, renin activity, deoxycorticosterone (DOC), cortisol, cortisone, and 24 h urinary aldosterone (24 h-uAld) levels based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Materials and methods: Plasma and 24 h urine were collected from 129 healthy volunteers in Northeast China. The effect of sodium intake, age, gender, blood sampling time on plasma aldosterone concentration (PAC), plasma renin activity (PRA), PAC to PRA ratio (ARR), DOC, cortisol, cortisone, cortisol to cortisone ratio, and 24 h-uAld were investigated by nonparametric test, multiple linear regression and Harris–Boyd's standard deviate test. Results: There was no significant difference observed in 24 h-uAld, PAC (AM), PRA(AM), ARR (AM), DOC (AM), cortisol (AM), cortisone (AM), and cortisol to cortisone (AM) between high and low sodium intake group. Significant differences were observed between morning and afternoon sampling groups in terms of PAC, ARR, DOC, cortisol, and cortisone. Reference intervals (RIs) of 24 h-uAld, PAC (AM) were recommended to be partitioned by gender. RI of PRA was recommended age stratification. Conclusion: We recommend that the same reference interval could be used regardless of sodium intake. Gender is the main influence factor for 24 h-uAld, PAC, and ARR. Age is key influence factor for PRA. [ABSTRACT FROM AUTHOR]

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ciguatoxins (CTXs), potent neurotoxins produced by dinoflagellates of the genera Gambierdiscus and Fukuyoa, accumulate in commonly consumed fish species, causing human ciguatera poisoning. Field collections of Pacific reef fish reveal that consumed CTXs undergo oxidative biotransformations, resulting in numerous, often toxified analogs. Following our study showing rapid CTX accumulation in flesh of an herbivorous fish, we used the same laboratory model to examine the tissue distribution and metabolization of Pacific CTXs following long-term dietary exposure. Naso brevirostris consumed cells of Gambierdiscus polynesiensis in a gel food matrix over 16 weeks at a constant dose rate of 0.36 ng CTX3C equiv g-1 fish d-1. CTX toxicity determination of fish tissues showed CTX activity in all tissues of exposed fish (eight tissues plus the carcass), with the highest concentrations in the spleen. Muscle tissue retained the largest proportion of CTXs, with 44% of the total tissue burden. Moreover, relative to our previous study, we found that larger fish with slower growth rates assimilated a higher proportion of ingested toxin in their flesh (13% vs. 2%). Analysis of muscle extracts revealed the presence of CTX3C and CTX3B as well as a biotransformed product showing the m/z transitions of 2,3-dihydroxyCTX3C. This is the first experimental evidence of oxidative transformation of an algal CTX in a model consumer and known vector of CTX into the fish food web. These findings that the flesh intended for human consumption carries the majority of the toxin load, and that growth rates can influence the relationship between exposure and accumulation, have significant implications in risk assessment and the development of regulatory measures aimed at ensuring seafood safety.

BackgroundPesticides like organophosphorus and pyrethroids are extensively utilized, and associated potential human health risks arising from multi-route exposure, including environmental sources and dietary intake, cannot be overlooked. Conducting human exposure studies using pesticide exposure biomarkers is essential for an objective evaluation of human pesticide exposure levels. ObjectiveTo develop a rapid and precise liquid chromatography-tandem mass spectrometry method for the detection of 12 pesticide metabolites in urine, including 5 metabolites of organophosphorus pesticide, 4 metabolites of pyrethroid pesticide, 2 metabolites of herbicides, and 1 metabolite of insecticide. MethodsAfter overnight enzymatic hydrolysis, urine samples were subjected to extraction and purification using Oasis HLB 96-well solid-phase extraction. Subsequently, the samples were analyzed by liquid chromatography-tandem mass spectrometry and quantified using the isotope internal standard method. The developed method was employed to analyze 143 urine samples from a general population to assess its effectiveness and to evaluate pesticide exposure levels. ResultsAll 12 target compounds exhibited good linear ranges, with their correlation coefficients of calibration curves exceeding 0.999. The limits of detection (LOD) ranged from 0.02 to 0.19 μg·L−1, while the limits of quantitation (LOQ) ranged from 0.06 to 0.27 μg·L−1. The recoveries at three spiked levels ranged from 84% to 112%, and the inter- and intra- day precisions of targeted analystes were 0.43%-9.6% and 1.6%-9.7% respectively. Using this method, 143 urine samples from residents in Jiangsu region were analyzed, and 11 pesticides were detected except N,N-diethyl-m-toluamide (DEET). ConclusionThe established method of solid-phase extraction combined with liquid chromatography-tandem mass spectrometry has the characteristics of low detection limit, good repeatability, and high throughput, which is suitable for quantitative detection of selected 12 pesticides in large batches of human urine samples, and provides technical support for pesticide internal exposure monitoring and health risk assessment.

Introduction: Basic pharmacokinetic (PK) and pharmacodynamic models of the phytocannabinoids Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are critical for developing translational models of exposure and toxicity. The neonatal period is a particularly important time to study the effects of cannabinoids, yet there are few studies of cannabinoid PKs by different routes such as direct injection or breast milk ingestion. To study this question, we have developed a translationally relevant rodent model of perinatal cannabinoid administration by measuring plasma levels of THC and CBD after different routes and preparations of these drugs. Materials and Methods: Adult animals and pups were injected with THC or CBD either intraperitoneally or subcutaneously, and plasma was analyzed by liquid chromatography-tandem mass spectrometry to measure cannabinoid levels collected at specified intervals. We also tested the effect of preparation of the drug using an oil-based vehicle (sesame oil) and an aqueous vehicle (Tween). Finally, we measured the plasma levels of cannabinoids in neonatal pups that were transmitted through breast milk after intraperitoneal injection to nursing dams. Results: We observed differences in the PK profiles of cannabinoids in adults and neonatal pups that were dependent on the route of administration and type of vehicle. Cannabinoids prepared in aqueous vehicle, injected intraperitoneally, resulted in a high peak in plasma concentration, which rapidly decreased. In contrast, subcutaneous injections using sesame oil as a vehicle resulted in a slow rise and low plateau in plasma concentration. Intraperitoneal injections with sesame oil as a vehicle resulted in a slower rise compared with aqueous vehicle, but an earlier and higher peak compared with subcutaneous injection. Finally, the levels of THC and CBD that were similar to direct subcutaneous injections were measured in the plasma of pups nursing from intraperitoneally injected dams. Conclusions: The route of administration and the preparation of the drug have important and significant effects on the PK profiles of THC and CBD in rats. These results can be used to create different clinically relevant exposure paradigms in pups and adults, such as short high-dose exposure or a low-chronic exposure, each of which might have significant and varying effects on development.

Aims: The aim of this study was to determine the fracture haematoma (fxH) proteome after multiple trauma using label-free proteomics, comparing two different fracture treatment strategies. Methods: A porcine multiple trauma model was used in which two fracture treatment strategies were compared: early total care (ETC) and damage control orthopaedics (DCO). fxH was harvested and analyzed using liquid chromatography-tandem mass spectrometry. Per group, discriminating proteins were identified and protein interaction analyses were performed to further elucidate key biomolecular pathways in the early fracture healing phase. Results: The early fxH proteome was characterized by immunomodulatory and osteogenic proteins, and proteins involved in the coagulation cascade. Treatment-specific proteome alterations were observed. The fxH proteome of the ETC group showed increased expression of pro-inflammatory proteins related to, among others, activation of the complement system, neutrophil functioning, and macrophage activation, while showing decreased expression of proteins related to osteogenesis and tissue remodelling. Conversely, the fxH proteome of the DCO group contained various upregulated or exclusively detected proteins related to tissue regeneration and remodelling, and proteins related to anti-inflammatory and osteogenic processes. Conclusion: The early fxH proteome of the ETC group was characterized by the expression of immunomodulatory, mainly pro-inflammatory, proteins, whereas the early fxH proteome of the DCO group was more regenerative and osteogenic in nature. These findings match clinical observations, in which enhanced surgical trauma after multiple trauma causes dysbalanced inflammation, potentially leading to reduced tissue regeneration, and gained insights into regulatory mechanisms of fracture healing after severe trauma. Cite this article: Bone Joint Res 2024;13(5):214–225.

Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The steroid hormones were extracted and enriched on a Supel-Q PLOT capillary column using IT-SPME. Subsequently, they were separated and detected within 6 min using a Discovery HS F5-3 column and positive ion mode multiple reaction monitoring system via LC–MS/MS. Calibration curves of these compounds using each stable isotope-labeled internal standard (IS) showed linearity with correlation coefficients greater than 0.9990 in the range of 0.01–40 ng/mL, with limits of detection (S/N = 3) of 0.7–21 pg/mL. Moreover, intra- and inter-day variations were lower than 8.1 and 15% (n = 6), respectively. The recoveries of these compounds from saliva samples were in the range of 82–114%. The developed IT-SPME/LC–MS/MS method of steroid hormones is a highly sensitive, specific, and non-invasive analytical method that allows extraction and enrichment with no organic solvents, and enables direct automated online analysis by simply ultrafiltrating a small sample of saliva.

Simple Summary: Lameness, an impaired gait, results from the pain dairy cows feel, which impacts their behaviour and performance, and consequently farmer income. Mobility scoring by visual inspection is the current gold standard in the UK for detecting this condition; however, it is prone to scoring biases and can only detect lameness once the cow feels pain, which may come too late for effective action to be taken. Conversely, the early detection of lameness allows for the better management and treatment of lameness cases, which is decisive in minimizing economic losses and animal pain, thereby improving cow welfare and the sustainability of the dairy industry. In a previous study, metabolites predictive of lameness were identified; however, the annotation of these metabolites has not yet been conducted. Although some annotation ambiguity is acceptable when performing untargeted analysis, accurately identifying compounds is crucial to understand which pathways are differentially altered between lame and non-lame cows. This study aimed to annotate the metabolites identified as predictors of lameness in the transition period and understand their biological role in the pathways and processes that lead to lameness. As a result, three metabolites predictive of lameness in dairy cows were identified at the highest confidence level, thus allowing for the understanding of the interactions between metabolism and immunity in lameness to be improved. The aim of this study was to identify with a high level of confidence metabolites previously identified as predictors of lameness and understand their biological relevance by carrying out pathway analyses. For the dairy cattle sector, lameness is a major challenge with a large impact on animal welfare and farm economics. Understanding metabolic alterations during the transition period associated with lameness before the appearance of clinical signs may allow its early detection and risk prevention. The annotation with high confidence of metabolite predictors of lameness and the understanding of interactions between metabolism and immunity are crucial for a better understanding of this condition. Using liquid chromatography–tandem mass spectrometry (LC-MS/MS) with authentic standards to increase confidence in the putative annotations of metabolites previously determined as predictive for lameness in transition dairy cows, it was possible to identify cresol, valproic acid, and gluconolactone as L1, L2, and L1, respectively which are the highest levels of confidence in identification. The metabolite set enrichment analysis of biological pathways in which predictors of lameness are involved identified six significant pathways (p < 0.05). In comparison, over-representation analysis and topology analysis identified two significant pathways (p < 0.05). Overall, our LC-MS/MS analysis proved to be adequate to confidently identify metabolites in urine samples previously found to be predictive of lameness, and understand their potential biological relevance, despite the challenges of metabolite identification and pathway analysis when performing untargeted metabolomics. This approach shows potential as a reliable method to identify biomarkers that can be used in the future to predict the risk of lameness before calving. Validation with a larger cohort is required to assess the generalization of these findings. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective This study aims to analyze the proteomic characteristics of peripheral blood in patients with lung cancer coexistent with pulmonary tuberculosis (LC-PTB), identify the differential proteins compared with lung cancer (LC) patients, and conduct functional analysis on these proteins. Methods The study included 8 LC-PTB patients and 10 LC patients. The LC patients were newly diagnosed and confirmed by pathology and did not receive any anti-tumor treatment before, while the PTB patients were Mycobacterium tuberculosis positive at the time of sampling. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to perform proteomic mass spectrometry to assess the differential proteins, and then functional analysis was conducted via bioinformatics. Results A total of 5,185 proteins were detected between two groups. Through differential expression screening, 190 proteins (58 upregulated and 132 downregulated) were identified to be differentially expressed. Subcellular localization analysis revealed that the differential proteins were mainly concentrated in the cytoplasm, nucleus, and extracellular matrix. KEGG pathway and GO analysis showed the roles of differential proteins in biological processes including immune response, metabolism, and secretion regulation. Protein interaction network analysis highlighted the importance of SORT1, SAR1B, RPS6KB1, VWF, SHC1, SRPRB, CTSD, TARDBP, RPLP0, PSMA2, RPS6, XPO1, PRKACB, and HLA-DRB1 in LC-PTB. Additionally, the expression changes in proteins like ADA2, MAP3K1, and GLS2 might be closely associated with the development of LC-PTB. Conclusions The proteomic profile comprehensively described the proteomic characteristics of LC-PTB and identified numerous differentially expressed proteins, which could provide further clues for research on biological mechanism of LC-PTB. [ABSTRACT FROM AUTHOR]

The quinoline alkaloid 2-(quinoline-8-carboxamido)benzoic acid (2-QBA), which is isolated from Aspergillus sp. SCSIO06786, a deep sea-derived fungus, has been suggested as a therapeutic candidate for the treatment of Parkinson's disease. We developed an analytical method for 2-QBA using a liquid chromatography–tandem mass spectrometry (LC-MS/MS) in mouse plasma, in which a protein precipitation method for the sample preparation of 2-QBA in mouse plasma was used due to its simplicity and good extraction recovery rates (80.49–97.56%). The linearity of the calibration standard sample, inter- and intraday precision and accuracy, and stability of three quality control samples were suitable based on the assessment criteria and the lower limit of quantification (LLOQ) of the 2-QBA was 1 ng/mL. A pharmacokinetic study of 2-QBA was performed in mice divided into oral (2.0, 5.0, and 15 mg/kg) and intravenous (0.5 and 1.0 mg/kg) administration groups. The absolute oral bioavailability (BA) range of 2-QBA was calculated as 68.3–83.7%. Secondary peaks were observed at approximately 4–8 h after the oral administration of 2-QBA at all doses. The elimination half-life of the orally administered 2-QBA was significantly longer than that of the intravenous 2-QBA. In addition, glucuronide metabolites of 2-QBA were identified. They were transformed into 2-QBA using the β-glucuronidase treatment. Furthermore, the 2-QBA was readily absorbed from the jejunum to lower ileum. Taken together, the secondary peaks could be explained by the enterohepatic circulation of 2-QBA. In conclusion, the reabsorption of orally administered 2-QBA could contribute to the high oral BA of 2-QBA and could be beneficial for the efficacy of 2-QBA. Moreover, the simple and validated analytical method for 2-QBA using LC-MS/MS was applied to the pharmacokinetic study and BA assessments of 2-QBA in mice and would be helpful for subsequent pharmacokinetic studies, as well as for evaluations of the toxicokinetics and pharmacokinetic–pharmacodynamic correlation of 2-QBA to assess its potential as a drug. [ABSTRACT FROM AUTHOR]

Clopidol is extensively used in livestock farming and residues of this antibiotic can persist in animal tissues, posing a risk to humans and the environment. In this study, we investigated the depletion of clopidol in various edible tissues of chickens (muscle, liver, kidney, fat, and eggs) using liquid chromatography–tandem mass spectrometry after the administration of a clopidol-contaminated diet (at 250 mg kg−1 for the high (1x) dose). After 14 d of exposure, the clopidol concentrations were highest in eggs (median: 9.83 mg/kg), followed by liver (3.56 mg/kg), kidney (3.01 mg/kg), muscle (1.56 mg/kg), and fat (0.727 mg/kg) at low exposure group, indicating that clopidol accumulated primarily in eggs rather than the other edible tissues. In addition, the maternal transfer ratios were estimated, and the transfer efficiencies of clopidol in muscle (egg-to-tissue ratio, ETR:1.81) and fat (2.06–58.2) were higher than those in liver (0.731–31.1) and kidney (0.832–38.9). Furthermore, we conducted a cumulative risk assessment for clopidol in edible chicken tissues using the hazard quotient (HQ) method. This assessment revealed that the exposure levels for Korean consumers pose an acceptable risk. However, for eggs from the 1x dose exposure group, the HQ values were greater than 1 for all age groups, particularly for young children (<18 y), suggesting that the higher daily consumption of eggs combined with the higher clopidol residues in eggs resulted in higher HQ values, which requires further attention. The findings of this study can assist in the management and monitoring of clopidol residues in chicken tissues and eggs [ABSTRACT FROM AUTHOR]

Purpose: The presence of cereulide, an emetic toxin produced by Bacillus cereus, in fried rice samples is critical evidence of food poisoning even in situations where B. cereus could not be detected. This study aims to develop a screening method for analyzing cereulide in fried rice using the QuEChERS procedure and liquid chromatography-tandem mass spectrometry (LC–MS/MS). Methods: Cereulide was identified and quantified in fried rice samples using the QuEChERS extraction method and LC–MS/MS. The accuracies of the methods were determined by analyzing fortified blank samples at two concentrations (10 and 50 µg/kg) conducted on three samples daily for five days. Results: The QuEChERS procedure removed matrix compounds from fried rice. Characteristic MS/MS spectra enabled the identification of cereulide. As the matrix effects in seven fried rice samples were within ± 6%, an external solvent calibration curve could be used for quantification. This method exhibited good accuracy ranging from 88 to 89%. The relative standard deviations for both repeatability and intra-laboratory reproducibility were < 4%. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224–1). The limit of quantification was 2 μg/kg. The applicability of this method was confirmed using the analysis of cereulide in fried rice samples incubated with emetic Bacillus cereus. Conclusions: The QuEChERS extraction procedure described herein showed substantial promise as a reliable screening tool for cereulide in fried rice sample. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Practical Pharmacy & Clinical Remedies is the property of Editorial Department of Practical Pharmacy & Clinical Remedies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Patients with phenylketonuria (PKU) must restrict their intake of phenylalanine, which can also affect the levels of other essential and non-essential amino acids due to inadequate supply. Therefore, our objective was to assess amino acids in serum samples from 20 PKU patients and compare them with results from 51 healthy subjects. A sample analysis was conducted using liquid chromatography–tandem mass spectrometry. We obtained levels of 28 substances, including amino acids, biogenic amines, carnitine, and acetylcarnitine. Kynurenine (p = 0.000001), tyrosine (p = 0.0002), asparagine (p = 0.001), proline (p = 0.012), and the kynurenine/tryptophan ratio (p < 0.000001) were identified as features that differed between the studied groups, being significantly lower in patients with PKU. Glycine (p = 0.000012), putrescine (p = 0.0055), asymmetric dimethylarginine (p = 0.01), creatinine (p = 0.035) levels, as well as the total level of glucogenic amino acids (p = 0.0018), and the ratios of putrescine/ornithine (p = 0.003) and citrulline/ornithine (p = 0.0043) were significantly higher in the PKU group. In conclusion, the amino acid profiles in patients with PKU differ significantly from those in healthy peers, with potential clinical implications. These findings confirm the importance of metabolic testing in clinical practice and highlight the necessity for adequate dietary monitoring and adjustment. [ABSTRACT FROM AUTHOR]

Although glaucoma is a leading cause of irreversible blindness worldwide, its pathogenesis is incompletely understood, and intraocular pressure (IOP) is the only modifiable risk factor to target the disease. Several associations between the gut microbiome and glaucoma, including the IOP, have been suggested. There is growing evidence that interactions between microbes on the ocular surface, termed the ocular surface microbiome (OSM), and tear proteins, collectively called the tear proteome, may also play a role in ocular diseases such as glaucoma. This study aimed to find characteristic features of the OSM and tear proteins in patients with glaucoma. The whole-metagenome shotgun sequencing of 32 conjunctival swabs identified Actinobacteria, Firmicutes, and Proteobacteria as the dominant phyla in the cohort. The species Corynebacterium mastitidis was only found in healthy controls, and their conjunctival microbiomes may be enriched in genes of the phospholipase pathway compared to glaucoma patients. Despite these minor differences in the OSM, patients showed an enrichment of many tear proteins associated with the immune system compared to controls. In contrast to the OSM, this emphasizes the role of the proteome, with a potential involvement of immunological processes in glaucoma. These findings may contribute to the design of new therapeutic approaches targeting glaucoma and other associated diseases. [ABSTRACT FROM AUTHOR]

Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The steroid hormones were extracted and enriched on a Supel-Q PLOT capillary column using IT-SPME. Subsequently, they were separated and detected within 6 min using a Discovery HS F5-3 column and positive ion mode multiple reaction monitoring system via LC–MS/MS. Calibration curves of these compounds using each stable isotope-labeled internal standard (IS) showed linearity with correlation coefficients greater than 0.9990 in the range of 0.01–40 ng/mL, with limits of detection (S/N = 3) of 0.7–21 pg/mL. Moreover, intra- and inter-day variations were lower than 8.1 and 15% (n = 6), respectively. The recoveries of these compounds from saliva samples were in the range of 82–114%. The developed IT-SPME/LC–MS/MS method of steroid hormones is a highly sensitive, specific, and non-invasive analytical method that allows extraction and enrichment with no organic solvents, and enables direct automated online analysis by simply ultrafiltrating a small sample of saliva. [ABSTRACT FROM AUTHOR]

Immunoglobulin nephropathy (IgAN) stands as the most prevalent primary glomerular nephropathy globally, typically diagnosed through an invasive renal biopsy. Emerging research suggests the significant involvement of chiral amino acids in kidney disease progression. This study introduces a nonderivative LC–tandem mass spectrometry approach, offering efficient separation outcomes within 15 min for identifying chiral amino acids in human urine samples. Subsequently, using this method, the analysis of l‐ and d‐amino acids in the urine of both patients with IgAN and healthy individuals was conducted. Fourteen d‐amino acids and 20 l‐amino acids were identified in the urine samples obtained from 17 patients with IgAN and 21 healthy individuals. The results indicated notable variances in the concentrations of both l‐ and d‐amino acids between the IgAN and healthy control groups. In contrast to the healthy group, the IgAN group exhibited higher mean urine concentrations of most l‐amino acids and lower concentrations of d‐amino acids. Furthermore, correlations between amino acids and clinical markers were investigated. These results propose a novel method for monitoring trace amino acids in urine samples and introduce a new concept for potential markers of IgAN. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to develop and validate a fast and sensitive bioanalytical method for the accurate quantification of fosfomycin concentrations in human prostatic tissue. The sample preparation method only required milligrams of tissue sample. Each sample was mixed with two times its weight of water and homogenized. A methanol solution that was three times the volume of the internal standard (fosfomycin-13C3) was added, followed by vortex mixing and centrifugation. After its extraction from the homogenized prostatic tissue, fosfomycin was quantified by means of a liquid chromatography–tandem mass spectrometry (LC-MS/MS) triple quadrupole system operating in negative electrospray ionization and multiple reaction monitoring detection mode. The analytical procedure was successfully validated in terms of specificity, sensitivity, linearity, precision, accuracy, matrix effect, extraction recovery, limit of quantification, and stability, according to EMA guidelines. The validation results, relative to three QC levels, were 9.9% for both the within-day and inter-day accuracy (BIAS%); 9.8% for within-day precision; and 9.9 for between-day precision. A marked matrix effect was observed in the measurements but was corrected by normalization with the internal standard. The average total recovery was high (approximatively 97% at the three control levels). The dynamic range of the method was 0.1–20 μg/g (R2 of 0.999). Negligible carry-over was observed after the injection of highly concentrated samples. F in the sample homogenate extracts was stable at 10 °C and 4 °C for at least 24 h. In the tissue sample freeze–thaw experiments, a significant decrease in F concentrations was observed after only two cycles from −80 °C to room temperature. The novel method was successfully applied to measure fosfomycin in prostatic tissue samples collected from 105 patients undergoing prostatectomy. [ABSTRACT FROM AUTHOR]

The contents of organic acids (OAs) in tea beverage and their relationship with taste intensity have not been fully understood. In this work, a rapid (10 min for a single run) and sensitive (limits of quantification: 0.0044–0.4486 µg/mL) method was developed and validated for the simultaneous determination of 17 OAs in four types of tea, based on liquid chromatography‐tandem mass spectrometry with multiple reaction monitoring mode. The contents of 17 OAs in 96 tea samples were measured at levels between 0.01 and 11.80 g/kg (dried weight). Quinic acid, citric acid, and malic acid were determined as the major OAs in green, black, and raw pu‐erh teas, while oxalic acid and tartaric acid exhibited the highest contents in ripe pu‐erh tea. Taking the OAs composition as input features, a partial least squares regression model was proposed to predict the sourness intensity of tea beverages. The model achieved a root‐mean‐square error of 0.58 and a coefficient of determination of 0.84 for the testing set. The proposed model provides a theoretical way to evaluate the sensory quality of tea infusion based on its chemical composition. [ABSTRACT FROM AUTHOR]

Current liquid chromatography-tandem mass spectrometry (LC-MS/MS) applications for circulating androgen measurements are technically diverse. Previously, variable results have been reported for testosterone. Data are scarce for androstenedione and absent for dehydroepiandrosterone sulfate (DHEAS). We assessed the agreement of androstenedione, DHEAS and testosterone LC-MS/MS measurements among nine European centers and explored benefits of calibration system unification. Androgens were measured twice by laboratory-specific procedures in 78 patient samples and in EQA materials. Results were obtained by in-house and external calibration. Intra- and inter-laboratory performances were valued. Intra-laboratory CVs ranged between 4.2–13.2 % for androstenedione, 1.6–10.8 % for DHEAS, and 4.3–8.7 % and 2.6–7.1 % for female and male testosterone, respectively. Bias and trueness in EQA materials were within ±20 %. Median inter-laboratory CV with in-house vs. external calibration were 12.0 vs. 9.6 % for androstenedione (p<0.001), 7.2 vs. 4.9 % for DHEAS (p<0.001), 6.4 vs. 7.6 % for female testosterone (p<0.001) and 6.8 and 7.4 % for male testosterone (p=0.111). Median bias vs. all laboratory median with in-house and external calibration were −13.3 to 20.5 % and −4.9 to 18.7 % for androstenedione, −10.9 to 4.8 % and −3.4 to 3.5 % for DHEAS, −2.7 to 6.5 % and −11.3 to 6.6 % for testosterone in females, and −7.0 to 8.5 % and −7.5 to 11.8 % for testosterone in males, respectively. Methods showed high intra-laboratory precision but variable bias and trueness. Inter-laboratory agreement was remarkably good. Calibration system unification improved agreement in androstenedione and DHEAS, but not in testosterone measurements. Multiple components, such as commutability of calibrators and EQA materials and internal standard choices, likely contribute to inter-laboratory variability. [ABSTRACT FROM AUTHOR]

To identify molecular pathways and prognostic- and diagnostic plasma-protein biomarkers for diabetic retinopathy at various stages. This exploratory, cross-sectional proteomics study involved plasma from 68 adults, including 15 healthy controls and 53 diabetes patients for various stages of diabetic retinopathy: non-diabetic retinopathy, non-proliferative diabetic retinopathy, proliferative diabetic retinopathy and diabetic macular edema. Plasma was incubated with peptide library beads and eluted proteins were tryptic digested, analyzed by liquid chromatography-tandem mass-spectrometry followed by bioinformatics. In the 68 samples, 248 of the 731 identified plasma-proteins were present in all samples. Analysis of variance showed differential expression of 58 proteins across the five disease subgroups. Protein–Protein Interaction network (STRING) showed enrichment of various pathways during the diabetic stages. In addition, stage-specific driver proteins were detected for early and advanced diabetic retinopathy. Hierarchical clustering showed distinct protein profiles according to disease severity and disease type. Molecular pathways in the cholesterol metabolism, complement system, and coagulation cascade were enriched in patients at various stages of diabetic retinopathy. The peroxisome proliferator-activated receptor signaling pathway and systemic lupus erythematosus pathways were enriched in early diabetic retinopathy. Stage-specific proteins for early – and advanced diabetic retinopathy as determined herein could be 'key' players in driving disease development and potential 'target' proteins for future therapies. For type 1 and 2 diabetes mellitus, the proteomic profiles were especially distinct during the early disease stage. Validation studies should aim to clarify the role of the detected molecular pathways, potential biomarkers, and potential 'target' proteins for future therapies in diabetic retinopathy. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polyunsaturated fatty acids (PUFAs) are vital nutrients in human physiology and are implicated in various chronic diseases. However, the relationship between PUFAs and gastric polyps remains unclear. This study employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess PUFA levels in the serum of 350 patients, along with analyzing the ω-6 to ω-3 ratio. The results revealed significant differences in the levels of C16:1, C18:1, C18:2, α-C18:3, γ-C18:3, C20:1, C20:4, C20:5, ω-3-C22:5, ω-6-C22:5, and C22:6, as well as ω-6 to ω-3 ratio between the control and gasteic polyp groups. Moreover, setting the threshold for ω-6: ω-3 at 10 revealed a close correlation between polyp occurrence and this ratio. These findings suggest that PUFAs and the ω-6 to ω-3 ratio hold promise as potential early screening markers for gastric polyps. However, further research is imperative to elucidate the underlying mechanisms and therapeutic potential of PUFAs in managing gastric polyps. [ABSTRACT FROM AUTHOR]

This work presents an advanced automated monolithic C18 pipette-tip solid-phase extraction (PT-SPE) method seamlessly integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for precise therapeutic drug monitoring of eleven tyrosine kinase inhibitors (TKIs) in biological samples. Commercially available MonoTip C18 columns facilitate superior extraction efficiency and selectivity from complex biological matrices owing to their large surface areas and enhanced mass transfer capabilities. The sample preparation process, conducted by aspirating and dispensing solutions using a pipettor, completes the overall extraction process within 3 min. The method validation demonstrated excellent linearity within the range of 0.2/0.5/0.8 to 200 ng/mL, with detection limits ranging from 0.049 to 0.206 ng/mL. The method exhibited outstanding accuracy and precision, with intraday relative recovery rates ranging from 96.3 % to 115.0 % and interday recovery rates ranging from 95.0 % to 115.7 %, with coefficient of variation values consistently below 13.8 %. The proposed method is distinguished by its exceptional efficiency, reduced solvent use, enhanced environmental sustainability, and streamlined automation—key advantages in the realm of clinical therapeutic drug monitoring of TKIs. Overall, the MonoTip C18 PT-SPE technique, coupled with LC-MS/MS, offers a formidable, eco-friendly, and effective strategy for the TDM of TKIs, marking a significant advancement in the field.

Background and aim: The important role of catecholamines has been gradually emphasized in the pathogenesis of neurodegenerative process. As the most prevalent form of cognitive dysfunction, Alzheimer's disease (AD) and vascular dementia (VaD) have the distinct pathological features and pathogenic mechanisms, however, the differential involvement of central and peripheral catecholamines between AD and VaD was still unclear. Methods: Triple-transgenic AD (3 × Tg-AD) mice and chronic cerebral hypoperfusion (CCH) in rats induced by two-vessel occlusion (2VO) were used as the AD and VaD model in this study, respectively. The concentrations of catecholamines (dopamine, epinephrine and norepinephrine) and their metabolites (3-methoxytyramine, metanephrine and normetanephrine) in serum and five brain regions (hippocampus, cortex, corpus striatum, thalamus and pons) from 3 × Tg-AD mice and 2VO rats were quantitatively determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. Results: High expression and distribution of hippocampal dopamine, and epinephrine and norepinephrine in the cortex and thalamus were found in the early 3 × Tg-AD model, whereas chronic cerebral hypoperfusion induced by 2VO mainly affected the central noradrenergic and noradrenergic system, but not dopaminergic system. The increased serum levels of catecholamines were investigated in the 2VO rats, but not in the 3 × Tg-AD mice. Conclusion: The differential expression and distribution of central catecholamines and their metabolites suggests the distinct catecholamines-related pathogenesis between AD and VaD. Peripheral catecholamine surge may be involved in the development of VaD, and the treatment strategy to prevent or reverse the effects of peripheral catecholamines may be protective for VaD.

BackgroundIdentifying molecular mechanisms responsible for the response to heat stress is essential to increase production, reproduction, health, and welfare. This study aimed to identify early biological responses and potential biomarkers involved in the response to heat stress and animal’s recovery in tropically adapted beef cattle through proteomic analysis of blood plasma.MethodsBlood samples were collected from 14 Caracu males during the heat stress peak (HSP) and 16 h after it (heat stress recovery—HSR) assessed based on wet bulb globe temperature index and rectal temperature. Proteome was investigated by liquid chromatography-tandem mass spectrometry from plasma samples, and the differentially regulated proteins were evaluated by functional enrichment analysis using DAVID tool. The protein-protein interaction network was evaluated by STRING tool.ResultsA total of 1,550 proteins were detected in both time points, of which 84 and 65 were downregulated and upregulated during HSR, respectively. Among the differentially regulated proteins with the highest absolute log-fold change values, those encoded by the GABBR1, EPHA2, DUSP5, MUC2, DGCR8, MAP2K7, ADRA1A, CXADR, TOPBP1, and NEB genes were highlighted as potential biomarkers because of their roles in response to heat stress. The functional enrichment analysis revealed that 65 Gene Ontology terms and 34 pathways were significant (P < 0.05). We highlighted those that could be associated with the response to heat stress, such as those related to the immune system, complement system, hemostasis, calcium, ECM-receptor interaction, and PI3K-Akt and MAPK signaling pathways. In addition, the protein–protein interaction network analysis revealed several complement and coagulation proteins and acute-phase proteins as important nodes based on their centrality and edges.ConclusionIdentifying differentially regulated proteins and their relationship, as well as their roles in key pathways contribute to improve the knowledge of the mechanisms behind the response to heat stress in naturally adapted cattle breeds. In addition, proteins highlighted herein are potential biomarkers involved in the early response and recovery from heat stress in tropically adapted beef cattle.

Introduction: Chromatographic methods for analysis of propofol and its metabolites have been widely used in pharmacokinetic studies of propofol distribution, metabolism, and clearance. Application of chromatographic methods is also needed in clinical and forensic laboratories for detecting and monitoring propofol misuse. Objective: We report a method for sensitive analysis of propofol, propofol 1-glucuronide (PG), 4-hydroxypropofol 1-glucuronide (1-QG), 4-hydroxypropofol 4-glucuronide (4-QG) and 4-hydroxypropofol 4-sulfate (4-QS) in urine by LC–MS/MS analysis. The method employs a simple dilute-and-analyze sample preparation with stable isotope internal standardization. Results: Validation studies demonstrate a linear calibration model (100–10,000 ng/mL), with dilution integrity verified for the extended range of concentrations experienced in propofol use. Criteria-based validation was achieved, including an average coefficient of variation of 6.5 % and a percent bias of −4.2 ng/mL. The method was evaluated in 12 surgical patients, with monitoring periods lasting up to 30 days following intravenous propofol administrations of 100–3000 mg on the day of surgery. While the concentration ratio of PG to 4-hydroxy propofol metabolite decreased significantly in the days following surgery, PG maintained the highest concentration in all specimens. Both PG and 1-QG were detectable throughout the monitoring periods, including in a patient monitored for 30 days. Lower concentrations were determined for 4-QG and 4-QS, with evidence of detection up to 20 days. Propofol was not detectable in any urine specimens, thereby proving ineffective for identifying drug use. Conclusion: The validated method for quantifying propofol metabolites demonstrates its applicability for the sensitive detection of propofol misuse over a long window of drug-use detection.

Sedatives have been used for a long time as animal tranquillisers to prevent stress and weight loss during their transportation. The proper determination of these substances in food of animal origin is essential for consumer safety.

Purpose: The limited understanding of long-term estradiol (E2) suppression poses challenges to the effectiveness of adjuvant therapy with aromatase inhibitors (AI), necessitating comprehensive serum E2 monitoring to address this issue. Therefore, our objective was to investigate serum E2 levels in women undergoing adjuvant AI treatment and evaluate the significance of such monitoring. Patients and methods: In this prospective cohort study, we recruited women who had received adjuvant AI treatment, including those who underwent ovarian function suppression (OFS). Serum E2 levels were measured using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The primary endpoint was the proportion of women with E2 levels exceeding 2.72 pg/mL, indicating inadequate suppression achieved with AI therapy. Results: A total of 706 patients were enrolled, including 482 women with OFS in combination with AI. Among them, 116 women (16.4 %) exhibited E2 levels exceeding 2.72 pg/mL. The majority of serum E2 elevations (77.6 %) occurred within the first two years of initiating endocrine therapy. Younger age, no prior chemotherapy, shorter duration of the current treatment regimen, and lower follicle stimulating hormone (FSH) levels were associated with inadequate E2 suppression. Serum E2 concentrations demonstrated dynamic variations and occasional rebound following adjuvant AI therapy. Conclusions: Despite receiving adjuvant AI treatment for nearly two years, a certain proportion of patients failed to achieve the adequate threshold of E2 suppression. Our findings emphasize the significance of monitoring serum E2 levels during adjuvant AI therapy, particularly within the first two years. Further research is imperative to facilitate a more comprehensive comprehension of E2 monitoring.

IntroductionThe use of illicitly manufactured synthetic opioids, specifically fentanyl and its analogs, has escalated exponentially in the United States over the last decade. Due to the targeted nature of drug detection methods in clinical laboratories and the ever-evolving list of synthetic opioids of concern, alternative analytical approaches are needed.MethodsUsing the fentanyl analog screening (FAS) kit produced by the Centers for Disease Control and Prevention (CDC), we developed a liquid chromatography-high resolution mass spectrometry (LC-HRMS) synthetic opioid spectral library and data acquisition method using information dependent acquisition of product ion spectra. Chromatographic retention times, limits of detection and matrix effects, in urine and serum, for the synthetic opioids in the FAS kit (n = 150) were established. All urine and serum specimens sent to a clinical toxicology laboratory for comprehensive drug testing in 2019 (n = 856) and 2021 (n = 878) were analyzed with the FAS LC-HRMS library to determine the prevalence of fentanyl analogs and other synthetic opioids, retrospectively (2019) and prospectively (2021).ResultsThe limit of detection (LOD) of each opioid ranged from 1 to 10 ng/mL (median, 2.5 ng/mL) in urine and 0.25-2.5 ng/mL (median, 0.5 ng/mL) in serum. Matrix effects ranged from -79 % to 86 % (median, -37 %) for urine, following dilution and direct analysis, and -80 % to 400 % (median, 0 %) for serum, following protein precipitation. The prevalence of fentanyl/fentanyl analogs in serum samples increased slightly from 2019 to 2021 while it remained the same in urine. There were only 2 samples identified that contained a fentanyl analog without the co-occurrence of fentanyl or fentanyl metabolites. Analysis of the established MS/MS spectral library revealed characteristic fragmentation patterns in most fentanyl analogs, which can be used for structure elucidation and drug identification of future analogs.ConclusionsThe LC-HRMS method was capable of detecting fentanyl analogs in routine samples sent for comprehensive drug testing. The method can be adapted to accommodate testing needs for the evolving opioid epidemic.

Folic acid (FA) is easily photodegraded to yield 6‐formylpterin and pterin‐6‐carboxylic acid, which can generate reactive oxygen species and result in the formation of oxidized guanine derivatives such as 8‐hydroxy‐2′‐deoxyguanosine and 8‐hydroxy‐guanosine. In this study, we developed a simple, rapid, and sensitive liquid chromatography‐tandem mass spectrometry strategy for the simultaneous determination of FA photolysis products and oxidized guanine derivatives in plasma samples. Chromatographic separation was performed on a Waters HSS T3 column (2.1 × 100 mm, 5.0 μm) with gradient elution at a flow rate of 0.25 mL/min. Plasma samples were first pretreated with 1% formic acid, followed by protein precipitation with methanol. The developed method showed good linear relationships between 1 and 2000 ng/mL (r2 > 0.99). The intra‐ and inter‐day precisions ranged from 2.6% to 7.5% and from 2.5% to 6.5%, respectively. Recoveries of the analytes were between 75.4% and 112.4% with the relative standard deviation < 9.1%. Finally, the method was applied to quantify FA photolysis products and oxidized guanine derivatives in rats with light and non‐light conditions. [ABSTRACT FROM AUTHOR]

Opioid use disorder (OUD) is a chronic neurobehavioral ailment and is prevalent in pregnancy. OUD is commonly treated with methadone or buprenorphine (BUP). Pregnancy is known to alter the pharmacokinetics of drugs and may lead to changes in drug exposure and response. A simple, specific, and sensitive analytical method for measuring the parent drug and its metabolites is valuable for assessing the impact of pregnancy on drug exposure. A new liquid chromatography–tandem mass spectrometric method that utilized a simple protein precipitation procedure for sample preparation and four deuterated internal standards for quantification was developed and validated for BUP and its major metabolites (norbuprenorphine [NBUP], buprenorphine‐glucuronide [BUP‐G], and norbuprenorphine‐glucuronide [NBUP‐G]) in human plasma. The standard curve was linear over the concentration range of 0.05–100 ng/mL for BUP and NBUP, and 0.1–200 ng/mL for BUP‐G and NBUP‐G. Intra‐ and inter‐day bias and precision were within ±15% of nominal values for all the analytes. Quality controls assessed at four levels showed high recovery consistently for all the analytes with minimal matrix effect. Adequate analyte stability was observed at various laboratory conditions tested. Overall, the developed method is simple, sensitive, accurate and reproducible, and was successfully applied for the quantification of BUP and its metabolites in plasma samples collected from pregnant women in a clinical study assessing BUP exposure during OUD treatment. [ABSTRACT FROM AUTHOR]

Background: Epidemiology has demonstrated that plasma free fatty acids (FFAs) can prevent the development of cancer. Our study sought to evaluate the relationship between plasma (FFA) levels and cervical cancer. Methods: In recent years, metabolomics-based approaches have been recognized as an emerging tool, so we examined the plasma FFA profiles of 114 patients with cervical cancer and 151 healthy people using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Results: The data results were analyzed by multifactorial binary logistic regression analysis, and it was found that palmitic acid, docosahexaenoic acid (DHA), and total ω-3 fatty acids were negatively correlated with the risk of cervical cancer; whereas tetracosanoic acid was positively correlated with the risk of cervical cancer (OR, 1.026; 95% CI, 1.013-1.040; p < 0.001). Dynamic follow-up of 40 cervical cancer patients who successfully completed CCRT revealed that most fatty acid levels tended to increase after the end of treatment, except for palmitic and stearic acid levels, which were lower than before treatment. Conclusion: Plasma FFA profiles were altered in cervical cancer patients, which may be related to abnormal fatty acid metabolism in cervical cancer. The described changes in fatty acid profiles during CCRT may be related to the good functioning of CCRT. Further studies on plasma FFA composition and its changes due to CCRT in patients with cervical cancer are warranted. [ABSTRACT FROM AUTHOR]

The physicochemical diversity of the structurally related aromatic probe drugs, used together in a drug cocktail to assess metabolic and transport phenotypes, require optimized analytical procedures for simultaneous quantification. The analytical conditions can greatly influence the analyte selectivity, retention, stability, and ultimately the robustness of the method. The aim of this study was to assess the selectivity of the structurally related ionizable analytes between the commonly used C18 column chemistry and an alternative biphenyl column chemistry as well as the influence of changes in the analytical conditions on method robustness using liquid chromatography‐tandem mass spectrometry. A repeated measure two‐factor analysis of variance with Geisser‐Greenhouse correction was used to determine statistical significance. The results showed that a biphenyl stationary phase in combination with methanol as the organic eluent, could provide improved resolution and analyte selectivity. Changes in analytical conditions caused statistically significant variation in the retention behavior, selectivity, column efficiency, and sensitivity of the analytes of interest The robustness experiment confirmed the importance of controlling analytical conditions to ensure the reproducibility and reliability of the quantitative method. [ABSTRACT FROM AUTHOR]