Journal of Chromatography B最新文献

{"title":"Simultaneous determination of piperacillin, metronidazole, and tazobactam in plasma by UPLC–MS/MS and application to a pharmacokinetic study in pediatric liver transplant patients","authors":"Cuiyao He ,&nbsp;Saisai Ling ,&nbsp;Ying Jin ,&nbsp;Lisha Fu ,&nbsp;Xiaoke Dai ,&nbsp;Xiaohui Qi ,&nbsp;Yiying Wu ,&nbsp;Zhenglei Wang ,&nbsp;Yuhua Deng","doi":"10.1016/j.jchromb.2025.124605","DOIUrl":"10.1016/j.jchromb.2025.124605","url":null,"abstract":"<div><div>Piperacillin/tazobactam and metronidazole are two commonly antimicrobials used to prevent and treat infections after liver transplantation in pediatric patients. However, under the recommended dose, it may lead to insufficient antimicrobial treatment and poor efficacy. To achieve antimicrobial therapy based on pharmacokinetic strategies, a rapid and highly sensitive ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed to measure the plasma concentrations of piperacillin, tazobactam, and metronidazole in pediatric liver transplant recipients. Sample separation was achieved using an Acquity UPLC CSH C₁₈ column (2.1 × 50 mm, 1.7 μm) with gradient elution. The mobile phase consisted of ammonia solution–formic acid–water (0.5:1:1000, <em>v</em>/<em>v</em>/v) and methanol–acetonitrile (1:1, v/v). The plasma concentration range was 0.20–100.00 μg/mL, with good linear range. The intra- and inter-day precisions were less than 13.4 %, and the accuracy ranged from 90.0 % to 109.0 %. The selectivity, carryover, dilution integrity, matrix effect, recovery, and stability met the requirements of the relevant guidelines. The established UPLC–MS/MS method was successfully applied to measure the concentrations of piperacillin, tazobactam, and metronidazole in the plasma of pediatric liver transplant patients. The results showed that according to the recommended dosing regimen, piperacillin/tazobactam reached the effective therapeutic target of 50 %T &gt; MIC in only 4 h. The maximum plasma concentration (C_max) of metronidazole ranged from 9.46 to 28 μg/mL, with an average C_max of 16.59 μg/mL, which did not achieve the ideal C_max/MIC ratio of 8–10.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124605"},"PeriodicalIF":2.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating 16srRNA sequencing, non-targeted metabolomics, and transcriptome sequencing to explore the mechanism of Total glucosides of paeony alleviating ulcerative colitis","authors":"Jianglin Chen ,&nbsp;Qi Yuan ,&nbsp;Cui Yu ,&nbsp;Jie Fu ,&nbsp;Penghao Wang ,&nbsp;Shuiyan Tang ,&nbsp;Xiaochen Lin ,&nbsp;Qiyang Shou ,&nbsp;Huiying Fu","doi":"10.1016/j.jchromb.2025.124600","DOIUrl":"10.1016/j.jchromb.2025.124600","url":null,"abstract":"<div><div>Total glucosides of paeony (TGP), an active ingredient extracted from the dried root of <em>Paeonia lactiflora Pall.</em>, has been approved in China for the treatment of various autoimmune diseases. However, the role and mechanism of TGP in UC have yet to be fully elucidated. This study aims to investigate the regulatory effects and underlying mechanisms of TGP on intestinal homeostasis disruption and immune imbalance in a mouse model of dextran sulfate sodium (DSS)-induced colitis. The results showed that TGP alleviated DSS induced body weight loss, colonic shortening and histopathological changes in mice, and also enhanced the integrity of the intestinal barrier by up-regulating the expression of ZO-1, Occludin and tight junction protein in the colon. The results of 16S and antibiotic cocktail (ABX) experiments showed that TGP alleviated colitis by inhibiting Th17 cell differentiation by correcting intestinal microbial imbalance in UC mice. Mechanism studies showed that TGP inhibited the activation of JAK2/STAT3 signaling pathway in UC mice, and decreased the levels of inflammatory factors in colon supernatant and serum. Importantly, TGP regulates JAK2/STAT3 to inhibit Th17 cell differentiation depending on gut flora. In addition, TGP can also improve the metabolic imbalance in UC mice, especially purine metabolism. In conclusion, TGP promotes the normalization of purine metabolism and relies on gut microbiota to regulate JAK2/STAT3 pathway, inhibit Th17 cell differentiation, and alleviate colitis. Our findings highlight TGP as a promising treatment candidate for ulcerative colitis.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1259 ","pages":"Article 124600"},"PeriodicalIF":2.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of network pharmacology, molecular docking and pharmacokinetic investigations of dandelion in rats for the treatment of diabetes mellitus","authors":"Wenjing Li ,&nbsp;Yanqiong Luo ,&nbsp;Ronghong Liu ,&nbsp;Min Zhao ,&nbsp;Yijun Yang ,&nbsp;Junhang Zhao ,&nbsp;Chunjie Zhao ,&nbsp;Bo Hong","doi":"10.1016/j.jchromb.2025.124610","DOIUrl":"10.1016/j.jchromb.2025.124610","url":null,"abstract":"<div><h3>Background</h3><div>The dandelion is a medicinal and edible plant with various assumed properties, including hypoglycemic, antioxidative, anti-inflammatory, and anti-tumor effects. However, the underlying mechanism and metabolic behavior of dandelion that can be used in treating diabetes mellitus (DM) remain unclear.</div></div><div><h3>Aims</h3><div>This study aimed to investigate the molecular mechanism of dandelion in the treatment of DM and the in vivo metabolic behavior of its bioactive components.</div></div><div><h3>Methods</h3><div>Network pharmacology and molecular docking were used to identify the underlying mechanism of dandelion in treating DM. LC-MS/MS was used to analyze the pharmacokinetic behavior of the main active components in dandelion in rats.</div></div><div><h3>Results</h3><div>The network pharmacology analysis demonstrated that the primary active components (hesperidin, protocatechuic acid, and syringic acid) of dandelion exert therapeutic effects on DM through multi-target interactions. These components regulated lipid and atherosclerosis pathways and the AGE-RAGE signaling pathway in diabetic complications via interactions with core targets including SRC, HRAS, and AKT1. The highest and lowest docking scores were − 8.55792 kcal·mol⁻¹ and -4.18450 kcal·mol⁻¹, respectively, indicating good binding activity between the compounds and the targets. Pharmacokinetic analysis revealed that all the analytes were detected in the plasma but their elimination within 24 h varied. Hesperidin, syringic acid and protocatechuic acid are abundant in rat plasma, characterized by extended long half-life and high bioavailability.</div></div><div><h3>Conclusion</h3><div>This work not only predicted the potential mechanism of dandelion in treating DM, but also revealed the pharmacokinetic profiles of its active components, a finding that is critical for advancing clinical applications of dandelion and related traditional Chinese medicine (TCM) formulae.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124610"},"PeriodicalIF":2.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-wide association analysis identified inflammatory mechanisms mediating the effects of lipid metabolism on endometrial carcinoma in situ","authors":"Tingyu Lang ,&nbsp;Shaoqi Hua ,&nbsp;Xiaolei Liang ,&nbsp;Yongxiu Yang","doi":"10.1016/j.jchromb.2025.124601","DOIUrl":"10.1016/j.jchromb.2025.124601","url":null,"abstract":"<div><h3>Background</h3><div>While lipids and inflammation are recognized as key modulators of tumor progression, their causal interplay in endometrial carcinoma in situ (ECIS)—the precursor of endometrial cancer—remains mechanistically undefined. Despite broad associations between lipid metabolism and cancer, the specific pathways driving ECIS initiation through inflammatory mediators are unknown.</div></div><div><h3>Method</h3><div>We pioneer an integrative Mendelian randomization (MR) framework combining multivariable MR, Bayesian weighted MR (BWMR), and sensitivity analyses to address pleiotropy. This approach was systematically applied to 179 lipids and 91 inflammatory factors. Methodological novelty further includes mediation analysis quantifying inflammatory factors' role in lipid-ECIS pathways.</div></div><div><h3>Results</h3><div>First evidence reveals a phosphatidylcholine (O-18:0_16:1)-TNFSF12-ECIS axis: TNFSF12 mediates 4.894 % of phosphatidylcholine's effect (OR: 2.925; beta: 1.073; 95 % CI: 1.752–4.884; <em>p</em> = 4.032E-05), attenuating the direct lipid-ECIS association. This represents the inaugural demonstration of an inflammation-mediated lipid pathway in ECIS pathogenesis.</div></div><div><h3>Conclusion</h3><div>As the first MR study decoding lipid-ECIS causality, we establish the following:<ul><li><span>1.</span><span><div>A paradigm-shifting methodology integrating Bayesian MR with mediation analysis for cancer etiology research.</div></span></li><li><span>2.</span><span><div>Clinically actionable biomarkers (phosphatidylcholine and TNFSF12) with dual diagnostic and therapeutic targeting potential.</div></span></li><li><span>3.</span><span><div>These advances provide a roadmap for intercepting ECIS progression through lipid-inflammatory axis modulation.</div></span></li></ul></div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124601"},"PeriodicalIF":2.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Versatile intact LC–MS method for evaluating the drug–antibody ratio and drug load distribution of antibody–drug conjugates in human plasma","authors":"Noritaka Hashii ,&nbsp;Yusuke Haruyama ,&nbsp;Ryu Hirayama ,&nbsp;Ryo Kajita ,&nbsp;Yuki Kishino ,&nbsp;Toshiki Mochizuki ,&nbsp;Kazuko Inoue ,&nbsp;Ryoya Goda ,&nbsp;Masaki Hoshino ,&nbsp;Itsuki Kuroiwa ,&nbsp;Hiroaki Aikawa ,&nbsp;Natsuki Ueda ,&nbsp;Kaori Nagumo ,&nbsp;Yuki Oda ,&nbsp;Yoshiro Saito ,&nbsp;Akiko Ishii-Watabe","doi":"10.1016/j.jchromb.2025.124608","DOIUrl":"10.1016/j.jchromb.2025.124608","url":null,"abstract":"<div><div>The average drug–antibody ratio (DAR) and drug load distribution (DLD) of an antibody–drug conjugate (ADC) can be altered by biotransformation after administration. In addition, drug loading affects the clearance and exposure of the ADC. Evaluating alterations in the average DAR and DLD of an ADC in vivo would provide valuable information to better understand of the pharmacokinetic (PK) profile of the ADC. Although the quantitation of antibodies/ADCs using LC–MS is often coupled with affinity capture methods, here, we aimed to develop a versatile intact LC–MS method for evaluating the average DAR and DLD of ADCs in human plasma. The development of the affinity purification process and method validation were performed using healthy human pooled plasma spiked with the model ADCs, commercially available trastuzumab emtansine (T-DM1) and brentuximab vedotin (B-MMAE), and the recombinant proteins HER2 and CD30 were used to capture T-DM1 and B-MMAE, respectively. As unique points of this study, initially, a two-step gradient was established for the sensitive detection of a small amount of ADC. The ADC elution conditions after affinity capture were also optimized considering its application for LC–MS analysis. Furthermore, a validation study of the intact LC–MS approach for analyzing the average DAR and DLD of ADCs in human plasma sample was proposed for the first time. Using the validation study, our analytical method was validated by verifying its performance characteristics, including sensitivity, intermediate precision, accuracy, carryover and autosampler stability. In addition, the feasibility of applying our method was demonstrated by a collaborative study with six laboratories. Finally, our method was shown to be versatile for evaluating the average DAR and DLD of ADCs in human plasma.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124608"},"PeriodicalIF":2.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantification of residual DTT by high-performance anion-exchange chromatography coupled with pulsed amperometric detection","authors":"Burki Rajendar,&nbsp;M.V.N. Janardhan Reddy,&nbsp;Madhavi Adusumilli,&nbsp;Ramesh V. Matur","doi":"10.1016/j.jchromb.2025.124609","DOIUrl":"10.1016/j.jchromb.2025.124609","url":null,"abstract":"<div><div>VLP (virus-like particle) have proven to be safer vaccine candidates compared to live-attenuated or inactivated viral vaccines. As part of the manufacturing process of VLP-based vaccines, dithiothreitol (DTT) and other reducing agents are commonly used in the disassembly of VLPs, followed by a subsequent reassembly process for the removal of the added reducing agents. This disassembly and reassembly processes improve VLP integrity, stability and immunoreactivity. In the manufacture of VLPs, it is essential that DTT removal is ensured since it is a highly toxic substance. Residual DTT content has to be monitored throughout the manufacturing process flow of the final pharmaceutical product. The available method for DTT estimation involves chemical derivatization which is complex and may require 100 % derivatization of low levels of DTT. In this study, we report a simple, novel and sensitive method for DTT quantification based on the combination of HPAEC-PAD and an electrochemical detector. The developed method has a linear range from 1 to 10 ng/mL with a limit of quantification of 100 pg. It is cost-effective and more sensitive than current available fluorescent and HPLC-MS-based methods for detecting residual DTT in viral and VLP-based vaccines. This method can be implemented to monitor residual DTT levels in any vaccine or product where DTT is used as a process reagent.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1259 ","pages":"Article 124609"},"PeriodicalIF":2.8,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunoaffinity chromatography for the preparation of equine tetanus immunoglobulin F(ab’)2 for enhanced safety and efficacy","authors":"Xingyue Gao ,&nbsp;Jiao Liu ,&nbsp;Kai Xu ,&nbsp;Jing Hu ,&nbsp;Cong Xiao ,&nbsp;Denghai Wang ,&nbsp;Changqing Li ,&nbsp;Chong Ji ,&nbsp;Xiaodong Yao ,&nbsp;Peng George Wang ,&nbsp;Yue Jing ,&nbsp;Yunjiao He ,&nbsp;Clifton Kwang-Fu Shen","doi":"10.1016/j.jchromb.2025.124591","DOIUrl":"10.1016/j.jchromb.2025.124591","url":null,"abstract":"<div><div>Typically, the antigen-specific antibodies constitute a small fraction—often estimated to be around 2–10 %—of the total IgG in the serum after immunization. This low percentage necessitates the use of purification techniques to enrich the antigen-specific antibodies for therapeutic or research purposes. This study introduces an affinity chromatography column using NHS-activated Sepharose as a matrix and the tetanus toxin subunit C, TeNT-Hc-C869A, as a ligand, enabling the purification of polyclonal antibodies with high specificity. This process improves antitoxin purity to over 95 %, effectively neutralizes the tetanus toxin, and removes inactive antibodies and other impurities, thereby reducing the risk of allergic reactions caused by heterologous proteins. This method offers promising advancements for tetanus prevention and treatment. The developed affinity column is applicable for purifying equine plasma, enzymatically digested equine tetanus F(ab’)₂, and human immunoglobulins targeting the tetanus toxin. Following purification, the specific activities of these preparations increased by factors of 5, 5, and 30, respectively, enhancing their clinical safety profiles. The affinity matrix exhibits durability, high loading capacity, and non-toxicity, supporting its scalability. This streamlined, cost-effective preparation process highlights the column's potential for broad applications in the biopharmaceutical field.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1259 ","pages":"Article 124591"},"PeriodicalIF":2.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantification of Ivacaftor, Tezacaftor, Elexacaftor, and Lumacaftor and their active metabolites in plasma using UHPLC-MS/MS: Doors open to the application of therapeutic drug monitoring in cystic fibrosis treatment","authors":"A. Mireille A. Wessels ,&nbsp;Femke A. Elzinga ,&nbsp;Gerard H. Koppelman ,&nbsp;Onno W. Akkerman ,&nbsp;Paola Mian ,&nbsp;Daan J. Touw","doi":"10.1016/j.jchromb.2025.124604","DOIUrl":"10.1016/j.jchromb.2025.124604","url":null,"abstract":"<div><div>An ultra-high performance liquid chromatography-tandem mass spectrometry method was developed to quantify the cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor, tezacaftor, elexacaftor, and lumacaftor and their active metabolites hydroxymethyl ivacaftor, tezacaftor M1, and <em>N</em>-desmethylelexacaftor in human EDTA plasma. The analytical method utilized protein precipitation with stable isotope dilution for sample preparation, facilitating a simple and rapid assay, with a total runtime of only 2.1 min. Separation of the seven components and stable isotope-labeled internal standards was achieved on a C₁₈ column, followed by detection using a tandem quadrupole mass spectrometer. Validation of the method was conducted in accordance with the “Bioanalytical Method Validation Guidance for Industry,” of the Food and Drug Administration and with European Medicines Agency's “Guidance on bioanalytical method validation”. The assay covers concentrations ranging from 0.010 to 10 mg/L for ivacaftor, hydroxymethyl ivacaftor and <em>N</em>-desmethylelexacaftor, from 0.025 to 25 mg/L for elexacaftor and tezacaftor, from 0.050 to 50 mg/L for tezacaftor M1 and from 0.100 to 100 mg/L for lumacaftor, using a sample volume of 10 μL. Matrix comparison confirmed the applicability of the assay to human serum and heparin plasma. Stability experiments indicated stability of the CFTR modulators in EDTA plasma over ten days under different conditions. At room temperature, all seven components remained stable for eight days and for ten days in the refrigerator in EDTA plasma and in EDTA whole blood. All seven components were stable in EDTA plasma for ten days in the autosampler after sample preparation and through four freeze-thaw cycles. The developed assay was applied in routine TDM analysis to investigate exposure to elexacaftor, tezacaftor, ivacaftor and their metabolites in people with CF undergoing treatment with Kaftrio®.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124604"},"PeriodicalIF":2.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis, biology and significance of dimethylamine, trimethylamine and trimethylamine N-oxide in humans and in the marine ecosystem","authors":"Dimitrios Tsikas","doi":"10.1016/j.jchromb.2025.124602","DOIUrl":"10.1016/j.jchromb.2025.124602","url":null,"abstract":"<div><div>Dimethylamine (DMA) and its relatives including trimethylamine (TMA) and trimethylamine <em>N</em>-oxide (TMAO) are widely distributed in nature including humans and the marine ecosystem. This article gives an overview of the origin, occurrence, metabolism and potential functions of dimethylamine in human life and of the DMA-TMA-TMAO axis in the marine ecosystem. In humans, a dimethylamine fraction of about 80–90 % is of endogenous origin. The remaining 10–20 % is of exogenous origin, notably of foods and especially of certain fish and seafood. Several different analytical methods are available for the quantitative determination of dimethylamine, trimethylamine and trimethylamine <em>N</em>-oxide in biological samples including human urine and fish. Frequently used methods include GC-FID, GC-ECD, GC–MS and more recently LC-MS/MS. A widely used GC–MS method of dimethylamine in human urine includes its extractive derivatization with pentafluorobenzoyl chloride. The dimethylamine concentration in plasma and serum is of the oder of 3 μM in healthy humans and several times higher in humans suffering from chronic kidney diseases. The dimethylamine concentration in human urine may range between 100 μM and 1500 μM, corresponding to mean creatinine-corrected excretion rates of 10 to 80 μmol dimethylamine/mmol creatinine in adults and up to 400 μmol dimethylamine/mmol creatinine in children and adolescents. GC–MS methods have contributed greatly to a better understanding of the biology of dimethylamine in health and disease. In humans, up to 90 % of urinary dimethylamine is considered a measure of its endogenous synthesis from post-translational dimethylation of arginine residues in proteins. This abundant post-translational modification leads to asymmetrically dimethylated arginine proteins, which, upon regular proteolysis, generate asymmetrical dimethylarginine (ADMA) that is finally hydrolyzed to and L-citrulline and dimethylamine, which is then readily excreted in the urine. In fishery, dimethylamine and trimethylamine are discussed as indicators of freshness due to their enhanced production of microbiomal activity. High amounts of dimethylamine are found in canned fish. Dimethylamine is considered the precursor of the cancerogenic <em>N</em>-nitroso-dimethylamine. Other non-volatile amines such as histamine and agmatine seem to be better suitable as fish freshness indicators. High contents of the order of several mmol trimethylamine <em>N</em>-oxide per kg tissue are found in fish in dependence on the habitat depth. It is assumed that trimethylamine <em>N</em>-oxide act as osmolytic and piezolytic agent. The significance of trimethylamine <em>N</em>-oxide in human health and disease is elusive.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124602"},"PeriodicalIF":2.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-performance chromatographic immunoassay utilizing a biotin-streptavidin platform for activity-based analysis of therapeutic monoclonal antibodies","authors":"Jacob Jones ,&nbsp;Avery Campbell ,&nbsp;Isaac Kyei ,&nbsp;Matthew R. Sobansky ,&nbsp;Marlies V. Hager ,&nbsp;David S. Hage","doi":"10.1016/j.jchromb.2025.124603","DOIUrl":"10.1016/j.jchromb.2025.124603","url":null,"abstract":"<div><div>There has been rapid growth in the use of monoclonal antibodies (mAbs) as biopharmaceuticals over the last twenty years. This has led to the need for new analytical methods that can rapidly and specifically measure or characterize mAbs for research, development and quality control, including means for the assessment of a therapeutic mAb's biological activity. High-performance immunoaffinity chromatography (HPIAC) was examined in this report as an approach for such work, in which the interactions between an antibody and its antigen were used for the selective isolation and analysis of one of these components. This report describes the utilization of a biotin-streptavidin platform in HPIAC and with affinity microcolumns that were used together in a chromatographic immunoassay for the analysis of a therapeutic mAb. Various components of this method were characterized and optimized to provide a method that was reusable and that could provide results within 7 min. The final assay could measure down to 0.03 mg/mL mAb (1.5 μg) for a 50 μL sample injection. The assay precision was ±0.7–1.3 % based on peak area measurements and ± 1.0–2.4 % using peak heights. The method was then evaluated for its use with typical samples encountered for a therapeutic mAb during its development and processing. Each microcolumn in this assay could be used for more than 350–400 sample application/elution cycles. The extension of this platform and approach to other applications was also considered.</div></div>","PeriodicalId":348,"journal":{"name":"Journal of Chromatography B","volume":"1258 ","pages":"Article 124603"},"PeriodicalIF":2.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}