Breast milk concentrations of acetaminophen and diclofenac - unexpectedly high mammary transfer of the general-purpose drug acetaminophen.

BACKGROUND: Breastfeeding is considered to be the most effective way of ensuring the health and survival of newborns. However, mammary transfer of drugs administered to mothers to breastfeeding infants remains a pressing concern. Acetaminophen and diclofenac sodium are widely prescribed analgesics for postpartum pain relief, but there have been few recent reports on the mammary transfer of these drugs, despite advances in analytic techniques. METHODS: We conducted a study on 20 postpartum mothers from August 2019-March 2020. Blood and milk samples from participants were analyzed using liquid chromatography-electrospray ionization tandem mass spectrometry within 24 hours after oral administration of acetaminophen and diclofenac sodium. The area under the concentration-time curve (AUC) was calculated from the concentration curve obtained by a naive pooled-data approach. RESULTS: For acetaminophen, AUC was 36,053 ng/mL.h and 37,768 ng/mL.h in plasma and breast milk, respectively, with a milk-to-plasma drug concentration ratio of 1.048. For diclofenac, the AUC was 0.227 ng/mL.h and 0.021 ng/mL.h, in plasma and breast milk, respectively, with a milk-to-plasma drug concentration ratio of 0.093. CONCLUSIONS: While diclofenac sodium showed low mammary transfer, acetaminophen showed a relatively high milk-to-plasma drug concentration ratio. Given recent studies suggesting potential connections between acetaminophen use during pregnancy and risks to developmental prognosis in children, we believe that adequate information regarding the fact that acetaminophen is easily transferred to breast milk should be provided to mothers.

MALDI mass spectrometry imaging shows a gradual change in the proteome landscape during mouse ovarian folliculogenesis.

Our knowledge regarding the role proteins play in the mutual relationship among oocytes, surrounding follicle cells, stroma, and the vascular network inside the ovary is still poor and obtaining insights into this context would significantly aid our understanding of folliculogenesis. Here, we describe a spatial proteomics approach to characterize the proteome of individual follicles at different growth stages in a whole prepubertal 25-day-old mouse ovary. A total of 401 proteins were identified by nano-scale liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MS/MS), 69 with a known function in ovary biology, as demonstrated by earlier proteomics studies. Enrichment analysis highlighted significant KEGG and Reactome pathways, with apoptosis, developmental biology, PI3K-Akt, epigenetic regulation of gene expression, and extracellular matrix organization being well represented. Then, correlating these data with the spatial information provided by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) on 276 follicles enabled the protein profiles of single follicle types to be mapped within their native context, highlighting 94 proteins that were detected throughout the secondary to the pre-ovulatory transition. Statistical analyses identified a group of 37 proteins that showed a gradual quantitative change during follicle differentiation, comprising 10 with a known role in follicle growth (NUMA1, TPM2), oocyte germinal vesicle-to-metaphase II transition (SFPQ, ACTBL, MARCS, NUCL), ovulation (GELS, CO1A2), and preimplantation development (TIF1B, KHDC3). The proteome landscape identified includes molecules of known function in the ovary, but also those whose specific role is emerging. Altogether, this work demonstrates the utility of performing spatial proteomics in the context of the ovary and offers sound bases for more in-depth investigations that aim to further unravel its spatial proteome.

Quantification of cefaclor in human plasma using SIL-IS LC-ESI-MS/MS for pharmacokinetics study in healthy Chinese volunteers.

A steady, high-efficiency, and precise liquid chromatography-electrospray ionization-tandem mass spectrometry method was established and validated using cefaclor-d5 as the stable isotope-labeled internal standard for quantification of cefaclor in human plasma. One-step protein precipitation was applied to extract human plasma samples using methanol as precipitant. An Ultimate XB C18 column (2.1 × 50.0 mm, 5.0 µm) was used to achieve chromatographic separation. Mobile phases of gradient elution were an aqueous solution containing 0.1% formic acid (mobile phase A) and an acetonitrile solution containing 0.1% formic acid (mobile phase B). Electrospray ionization in positive-ion mode was applied to detect under multiple reaction monitoring mode. Target fragment ion pairs of cefaclor and stable isotope-labeled internal standard, respectively, were m/z 368.2 → 191.1 and m/z 373.2 → 196.1. Linear range of this method was between 20.0 and 10,000.0 ng/ml, with coefficient of determination (R2 ) >0.9900. Seven concentrations of quality control samples were used: 20.0 ng/ml (lower limit of quantitation), 60.0 ng/ml (low quality control), 650 ng/ml (middle quality control), 5000 ng/ml (arithmetic average middle quality control [AMQC]), 7500 ng/ml (high quality control), 10,000 ng/ml (upper limit of quantification), and 40,000 ng/ml (dilution quality control [DQC]). The method was validated for selectivity, lower limit of quantitation, linearity, accuracy, precision, recovery, matrix effect, dilution reliability, stability, carryover, and incurred sample reanalysis. This stable isotope-labeled internal standard liquid chromatography-electrospray ionization-tandem mass spectrometry approach has been successfully applied to study the pharmacokinetics of cefaclor dry suspension among healthy Chinese volunteers.

Widely targeted metabolomics analysis reveals the differences in nonvolatile compounds of citronella before and after drying.

Citronella is used as a spice and a traditional herbal medicine. Dried citronella is easy to store and transport, and it is unclear whether dried citronella has more or fewer medicinal components compared to fresh citronella. In the present study, various metabolites in fresh and dry citronella were detected using a widely targeted metabolomics strategy. We identified 712 metabolites and classified them into 31 categories, and we identified 132 flavonoids. After citronella was dried, the quantities of most kinds of flavonoids increased, but the quantities of amino acids, organic acids, and vitamins decreased, and the quantity of quercetin increased significantly. Therefore, the medicinal value of dry citronella may have increased, and the nutritional value of amino acids and vitamins may have decreased. The results of this study can serve as a new theoretical reference to study citronella and promote its nutrition and medicinal chemical composition.

Global Proteomics for Identifying the Alteration Pathway of Niemann-Pick Disease Type C Using Hepatic Cell Models.

Niemann-Pick disease type C (NPC) is an autosomal recessive disorder with progressive neurodegeneration. Although the causative genes were previously identified, NPC has unclear pathophysiological aspects, and patients with NPC present various symptoms and onset ages. However, various novel biomarkers and metabolic alterations have been investigated; at present, few comprehensive proteomic alterations have been reported in relation to NPC. In this study, we aimed to elucidate proteomic alterations in NPC and perform a global proteomics analysis for NPC model cells. First, we developed two NPC cell models by knocking out NPC1 using CRISPR/Cas9 (KO1 and KO2). Second, we performed a label-free (LF) global proteomics analysis. Using the LF approach, more than 300 proteins, defined as differentially expressed proteins (DEPs), changed in the KO1 and/or KO2 cells, while the two models shared 35 DEPs. As a bioinformatics analysis, the construction of a protein-protein interaction (PPI) network and an enrichment analysis showed that common characteristic pathways such as ferroptosis and mitophagy were identified in the two model cells. There are few reports of the involvement of NPC in ferroptosis, and this study presents ferroptosis as an altered pathway in NPC. On the other hand, many other pathways and DEPs were previously suggested to be associated with NPC, supporting the link between the proteome analyzed here and NPC. Therapeutic research based on these results is expected in the future.

Mass spectrometry imaging spatially identifies complex-type N-glycans as putative cartilage degradation markers in human knee osteoarthritis tissue.

N-Glycan alterations contribute to the pathophysiology and progression of various diseases. However, the involvement of N-glycans in knee osteoarthritis (KOA) progression at the tissue level, especially within articular cartilage, is still poorly understood. Thus, the aim of this study was to spatially map and identify KOA-specific N-glycans from formalin-fixed paraffin-embedded (FFPE) osteochondral tissue of the tibial plateau relative to cadaveric control (CTL) tissues. Human FFPE osteochondral tissues from end-stage KOA patients (n=3) and CTL individuals (n=3), aged >55 years old, were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Overall, it was revealed that 22 N-glycans were found in the cartilage region of KOA and CTL tissue. Of those, 15 N-glycans were more prominent in KOA cartilage than CTL cartilage. We then compared sub-regions of KOA and CTL tissues based on the Osteoarthritis Research Society International (OARSI) histopathological grade (1 to 6), where 1 is an intact cartilage surface and 6 is cartilage surface deformation. Interestingly, three specific complex-type N-glycans, (Hex)4(HexNAc)3, (Hex)4(HexNAc)4, and (Hex)5(HexNAc)4, were found to be localized to the superficial fibrillated zone of degraded cartilage (KOA OARSI 2.5-4), compared to adjacent cartilage with less degradation (KOA OARSI 1-2) or relatively healthy cartilage (CTL OARSI 1-2). Our results demonstrate that N-glycans specific to degraded cartilage in KOA patients have been identified at the tissue level for the first time. The presence of these N-glycans could further be evaluated as potential diagnostic and prognostic biomarkers.

Cytotoxicity of Callerya speciosa Fractions against Myeloma and Lymphoma Cell Lines.

Callerya speciosa is widely distributed in tropical and subtropical countries and is traditionally used for preventing numerous disorders. In this study, a bioguided fractionation of ethyl acetate extract (SE) from C. speciosa root was carried out to target antioxidant and cytotoxic activities. Of the four fractions (SE1-SE4) obtained by column chromatography, SE4 had the strongest anti-radical ability in the DPPH and ABTS assays (IC50 = 0.05 and 0.17 mg/mL, respectively), with results close to butylated hydroxytoluene (BHT), a common antioxidant agent. The cytotoxic activities against the selected cells were analyzed in this study by MTT assay. Accordingly, SE2, SE3, and SE4 significantly inhibited the viability of multiple myeloma cell lines, comprising U266 (IC50 = 0.38, 0.09, and 0.11 mg/mL, respectively) and KMS11 (IC50 = 0.09, 0.17, and 0.15 mg/mL, respectively), mantle cell lymphoma Mino (IC50 = 0.08, 0.16, and 0.15 mg/mL, respectively), and the noncancerous cell line LCL (IC50 = 0.40, 0.32, and 0.21 mg/mL, respectively). At a concentration of 125 µg/mL, SE2, SE3, and SE4 induced the cell apoptosis of U266 (32.2%, 53.2%, and 55.6%, respectively), KMS11 (36.9%, 40.8%, and 47.9%, respectively), Mino (36.6%, 39.8%, and 22.0%, respectively), and LCL (12.4%, 17.5%, and 23.5%, respectively) via annexin V assay. The dominant compounds detected in fractions by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS), were identified as isoflavones. This is the first report describing C. speciosa as a promising natural source of antileukemia and antimyeloma agents, which may be useful for the development of blood cancer treatments.

Galabiosylceramide is present in human cerebrospinal fluid.

Cerebrospinal fluid (CSF) contains glycosphingolipids, including lactosylceramide (LacCer, Galß(1,4)Glcß-ceramide). LacCer and its structural isomer, galabiosylceramide (Gb2, Galα(1,4)Galß-ceramide), are classified as ceramide dihexosides (CDH). Gb2 is degraded by α-galactosidase A (GLA) in lysosomes, and genetic GLA deficiency causes Fabry disease, an X-linked lysosomal storage disorder. In patients with Fabry disease, Gb2 accumulates in organs throughout the body. While Gb2 has been reported to be in the liver, kidney, and urine of healthy individuals, its presence in CSF has not been reported, either in patients with Fabry disease or healthy controls. Here, we isolated CDH fractions from CSF of patients with idiopathic normal pressure hydrocephalus. Purified CDH fractions showed positive reaction with Shiga toxin, which specifically binds to the Galα(1,4)Galß structure. The isolated CDH fractions were analyzed by hydrophilic interaction chromatography (HILIC)-electrospray ionization tandem mass spectrometry (ESI-MS/MS). HILIC-ESI-MS/MS separated LacCer and Gb2 and revealed the presence of Gb2 and LacCer in the fractions. We also found Gb2 in CSF from neurologically normal control subjects. This is the first report to show Gb2 exists in human CSF.

LDL subclass lipidomics in atherogenic dyslipidemia: effect of statin therapy on bioactive lipids and dense LDL.

Atherogenic LDL particles are physicochemically and metabolically heterogeneous. Can bioactive lipid cargo differentiate LDL subclasses, and thus potential atherogenicity? What is the effect of statin treatment? Obese hypertriglyceridemic hypercholesterolemic males [n = 12; lipoprotein (a) <10 mg/dl] received pitavastatin calcium (4 mg/day) for 180 days in a single-phase unblinded study. The lipidomic profiles (23 lipid classes) of five LDL subclasses fractionated from baseline and post-statin plasmas were determined by LC-MS. At baseline and on statin treatment, very small dense LDL (LDL5) was preferentially enriched (up to 3-fold) in specific lysophospholipids {LPC, lysophosphatidylinositol (LPI), lysoalkylphosphatidylcholine [LPC(O)]; 9, 0.2, and 0.14 mol per mole of apoB, respectively; all P < 0.001 vs. LDL1-4}, suggesting elevated inflammatory potential per particle. In contrast, lysophosphatidylethanolamine was uniformly distributed among LDL subclasses. Statin treatment markedly reduced absolute plasma concentrations of all LDL subclasses (up to 33.5%), including LPC, LPI, and LPC(O) contents (up to -52%), consistent with reduction in cardiovascular risk. Despite such reductions, lipotoxic ceramide load per particle in LDL1-5 (1.5-3 mol per mole of apoB; 3-7 mmol per mole of PC) was either conserved or elevated. Bioactive lipids may constitute biomarkers for the cardiometabolic risk associated with specific LDL subclasses in atherogenic dyslipidemia at baseline, and with residual risk on statin therapy.

Multiple actions of doxorubicin on the sphingolipid network revealed by flux analysis.

Sphingolipids (SLs) have been implicated in numerous important cellular biologies; however, their study has been hindered by the complexities of SL metabolism. Furthermore, enzymes of SL metabolism represent a dynamic and interconnected network in which one metabolite can be transformed into other bioactive SLs through further metabolism, resulting in diverse cellular responses. Here we explore the effects of both lethal and sublethal doses of doxorubicin (Dox) in MCF-7 cells. The two concentrations of Dox resulted in the regulation of SLs, including accumulations in sphingosine, sphingosine-1-phosphate, dihydroceramide, and ceramide, as well as reduced levels of hexosylceramide. To further define the effects of Dox on SLs, metabolic flux experiments utilizing a d17 dihydrosphingosine probe were conducted. Results indicated the regulation of ceramidases and sphingomyelin synthase components specifically in response to the cytostatic dose. The results also unexpectedly demonstrated dose-dependent inhibition of dihydroceramide desaturase and glucosylceramide synthase in response to Dox. Taken together, this study uncovers novel targets in the SL network for the action of Dox, and the results reveal the significant complexity of SL response to even a single agent. This approach helps to define the role of specific SL enzymes, their metabolic products, and the resulting biologies in response to chemotherapeutics and other stimuli.

Mass spectrometric determination of disulfide bonds and free cysteine in grass carp IgM isoforms.

Disulfide bonds are fundamental in establishing Ig structure and maintaining Ig biological function. Here, we analysed disulfide bonds and free cysteine in three grass carp IgM isoforms (monomeric, dimeric/trimeric, and tetrameric IgM) by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The results revealed that Cys574 residue status at the C-terminal tail differed substantially in monomeric IgM in comparison with polymeric IgM, Cys574 was found as free thiol in monomeric IgM, while it formed disulfide linkages in dimeric/trimeric and tetrameric IgM. Five intra-chain disulfide bonds in the CH1~CH4 and CL1 domains, as well as one H-H and one H-L inter-chain disulfide linkages, were also observed and shown identical connectivity in monomeric, dimeric/trimeric, and tetrameric IgM. These findings represent the first experimental assignments of disulfide linkages of grass carp IgM and reveal that grass carp IgM isoform formation is due to alternative disulfide bonds connecting the Cys574 residue at the C-terminal tail.

Use of dried urine spots for screening of inborn errors of bile acid synthesis.

BACKGROUND: In pediatric patients with cholestasis of unknown cause, inborn errors of bile acid (BA) synthesis (IEBAS) may be considered. For the initial screening for IEBAS, clarification of the urine BA profile is essential. The transportation of urine in a frozen state via air delivery, however, is laborious and costly. This study assessed the feasibility of using dried urine spots (DUS) to establish a more convenient and affordable method of IEBAS screening. METHODS: We created DUS using urine samples from patients with 3ß-hydroxy-Δ5-C27-steroid dehydrogenase/isomerase deficiency (3ß-HSD) and Δ4-3-oxo-steroid 5ß-reductase deficiency as standard preparations. We started accepting DUS specimens by regular mail. RESULTS: The ratio of unusual to usual BA is essential for the initial detection of IEBAS, and the recovery rates of abnormal BA were acceptable. The recovery rate of Δ4-BA on day 28 decreased to 31.8% at 25°C, and to 19.6% at 37°C. Therefore, the sending of DUS should be avoided under conditions of high temperature. Of a total of 49 children with cholestasis, eight new patients were diagnosed with IEBAS using this screening method. CONCLUSION: The mailing screening system is expected to facilitate the shipment, from regions outside of Japan, of samples for IEBAS screening.

Quantification of 3-ketodihydrosphingosine using HPLC-ESI-MS/MS to study SPT activity in yeast Saccharomyces cerevisiae.

Serine palmitoyltransferase (SPT) catalyzes the rate-limiting step of condensation of L-serine and palmitoyl-CoA to form 3-ketodihydrosphingosine (3KDS). Here, we report a HPLC-ESI-MS/MS method to directly quantify 3KDS generated by SPT. With this technique, we were able to detect 3KDS at a level comparable to that of dihydrosphingosine in yeast Saccharomyces cerevisiae An in vitro SPT assay measuring the incorporation of deuterated serine into deuterated 3KDS was developed. The results show that SPT kinetics in response to palmitoyl-CoA fit into an allosteric sigmoidal model, suggesting the existence of more than one palmitoyl-CoA binding site on yeast SPT and positive cooperativity between them. Myriocin inhibition of yeast SPT activity was also investigated and we report here, for the first time, an estimated myriocin Ki for yeast SPT of approximately 10 nM. Lastly, we investigated the fate of serine α-proton during SPT reaction. We provide additional evidence to support the proposed mechanism of SPT catalytic activity in regard to proton exchange between the intermediate NH3+ base formed on the active Lys residue with surrounding water. These findings establish the current method as a powerful tool with significant resolution and quantitative power to study SPT activity.

Determination of mycotoxins by HPLC, LC-ESI-MS/MS, and MALDI-TOF MS in Fusarium species-infected sugarcane.

Mycotoxins are secondary metabolites of fungi that are damaging to both animals and humans. Extensive contamination of foods and feeds with mycotoxins is an important problem. Fumonisins, trichothecenes, zearalenone, and aflatoxins are mycotoxins produced by Fusarium species and occur naturally in sugarcane and cereal-based foods, threatening health and food security worldwide. Their distribution in the contaminated material is of great interest for obtaining insight into infection mechanisms and the potential for reducing contamination during food processing. In this study, mycotoxins were evaluated by high-performance liquid chromatography, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), and matrix-assisted laser/desorption ionization time of flight mass spectrometry (MALDI-TOF MS) of Fusarium species-infected sugarcane materials. A simple, sensitive, and reliable analytical method was developed for rapidly detecting eight mycotoxins in Fusarium species: fumonisin B1 and fumonisin B2, B-trichothecene mix (deoxynivalenol, nivalenol, 3-acetyl- deoxynivalenol, 15-acetyl-deoxynivalenol), zearalenone, and aflatoxin G1. Analyses were carried out in multiple reaction monitoring mode using the two primary product ions. The results generated by LC/MS and MALDI-TOF MS/MS revealed various mechanisms regulating mycotoxins production, which may help to clarify the roles of sensitive and selective compounds. The results demonstrate that this procedure is suitable for simultaneous determination of mycotoxins in sugarcane and can be performed in routine analysis in mycotoxin laboratories.

Facile derivatization of ultratrace carboxylic acids in saliva for quantification by HPLC-MS/MS.

It remains an issue to directly quantify trace biologically important carboxyl compounds in body fluids. Herein we propose an innovative method to determine α-lipoic acid, 2-(ß-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman, prostaglandin E2, cholic acid, and chenodeoxycholic acid in saliva. The method consists of two successive steps: fast and direct labeling of the target analytes with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide followed by ultrahigh-performance liquid chromatography-tandem mass spectrometry analysis. The method exhibited a wide linear range from 2.5 to 2500 pg/mL, with linear coefficients greater than 0.9963 and limits of detection and quantification as low as 0.10 and 0.33 pg/mL, respectively. The method precision was evaluated, with relative standard deviations ranging from 2.12% to 10.63% for intraday assays and from 2.98% to 12.88% for interday assays. The recoveries were measured by our spiking saliva samples with standards at three different levels, and ranged from 72.5% to 98.0%. Real applicability was validated by direct quantification of trace target analytes in human saliva, with simple pretreatment, use of a small sample volume, and a short analysis time. Graphical abstract Sequential steps to extract, label, and determine the ultratrace carboxylic acids in saliva. CDCA chenodeoxycholic acid, γ-CEHC 2-(ß-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman, α-LA α-lipoic acid, PGE2 prostaglandin E2, UHPLC-MS/MS ultrahigh-performance liquid chromatography-tandem mass spectrometry.

An Ultra-High Performance Liquid Chromatography with Tandem Mass Spectrometry Method for Determination of 10 Alkaloids in Beagle Dog Plasma after the Oral Administration of the Corydalis yanhusuo W.T. Wang Extract and Yuanhuzhitong Tablets.

This study has developed a sensitive and simple ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry method for the simultaneous determination of corydaline, dehydrocorydaline, tetrahydropalmatine, protopine, palmatine, tetrahydroberberine, columbamine, berberine, coptisine and berberrubine in beagle dog plasma after the oral administration of the Corydalis yanhusuo W.T. Wang and Yuanhuzhitong tablets. Chromatographic separation was achieved on an Agilent Eclipse Plus C18 RRHD column (1.8 µm, 50 × 2.1 mm) using a gradient elution program with a mobile phase consisting of acetonitrile and water containing 0.1% formic acid at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection was conducted by multiple reaction monitoring (MRM) mode via an electrospray ionization source in the positive mode. The calibration curves of all analytes showed good linear (r² > 0.9800). The intra-day and inter-day precisions were less than 15% and the accuracies were within ±15%. The extraction recoveries conformed to the acceptable range. And there was no interference of endogenous substances in the sensitive assay method. All analytes were proven to be stable during sample storage and analysis procedures. The pharmacokinetic study indicated that the Yuanhuzhitong tablets could get a better absorption than Corydalis yanhusuo W.T. Wang.

HPLC-MS/MS methods for the determination of 52 perfluoroalkyl and polyfluoroalkyl substances in aqueous samples.

Two quantitative methods using high-performance liquid chromatography (HPLC) combined with triple quadrupole tandem mass spectrometry (MS/MS) were developed to determine perfluoroalkyl and polyfluoroalkyl substances (PFASs) in aqueous samples. The first HPLC-MS/MS method was applied to 47 PFASs of 12 different substance classes with acidic characteristics such as perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs), as well as precursor substances and biotransformation intermediates (e.g., unsaturated fluorotelomer carboxylic acids). In addition, 25 13C-, 18O-, and 2H-labeled PFASs were used as internal standards in this method. The second HPLC-MS/MS method was applied to fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamidoethanols as these compounds have physicochemical properties different from those of the previous ones. Accuracy between 82% and 110% and a standard deviation in the range from 2% to 22% depending on the substances were determined during the evaluation of repeatability and precision. The method quantification limit after solid-phase extraction ranged from 0.3 to 199 ng/L depending on the analyte and matrix. The HPLC-MS/MS methods developed were suitable for the determination of PFASs in aqueous samples (e.g., wastewater treatment plant effluents or influents after solid-phase extraction). These methods will be helpful in monitoring campaigns to evaluate the relevance of precursor substances as indirect sources of perfluorinated substances in the environment. In one exemplary application in an industrial wastewater treatment plant, FTOHs were found to be the major substance class in the influent; in particular, 6:2-FTOH was the predominant compound in the industrial samples and accounted for 74% of the total PFAS concentration. The increase in the concentration of the transformation products of FTOHs in the corresponding effluent, such as fluorotelomer carboxylic acids, unsaturated fluorotelomer carboxylic acids, n:3 polyfluorinated saturated carboxylic acids (n indicates the number of nonfluorinated carbon atoms), and PFCAs, indicated biotransformation of FTOHs or their derivatives during wastewater treatment. However, only 33 mol% of the total amount of PFASs present in the influent was quantified in the corresponding effluent. Graphical abstract Method development of an HPLC-MS/MS multi-method for the determination of PFASs in aqueos samples.

Cerebrospinal fluid in tuberculous meningitis exhibits only the L-enantiomer of lactic acid.

BACKGROUND: The defining feature of the cerebrospinal fluid (CSF) collected from infants and children with tuberculous meningitis (TBM), derived from an earlier untargeted nuclear magnetic resonance (NMR) metabolomics study, was highly elevated lactic acid. Undetermined was the contribution from host response (L-lactic acid) or of microbial origin (D-lactic acid), which was set out to be determined in this study. METHODS: In this follow-up study, we used targeted ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) to determine the ratio of the L and D enantiomers of lactic acid in these CSF samples. RESULTS: Here we report for the first time that the lactic acid observed in the CSF of confirmed TBM cases was in the L-form and solely a response from the host to the infection, with no contribution from any bacteria. The significance of elevated lactic acid in TBM appears to be that it is a crucial energy substrate, used preferentially over glucose by microglia, and exhibits neuroprotective capabilities. CONCLUSION: These results provide experimental evidence to support our conceptual astrocyte-microglia lactate shuttle model formulated from our previous NMR-based metabolomics study - highlighting the fact that lactic acid plays an important role in neuroinflammatory diseases such as TBM. Furthermore, this study reinforces our belief that the determination of enantiomers of metabolites corresponding to infectious diseases is of critical importance in substantiating the clinical significance of disease markers.

LC/ESI-MS/MS method for determination of salivary eicosapentaenoic acid concentration to arachidonic acid concentration ratio.

A simple liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for determination of the eicosapentaenoic acid (EPA) concentration to arachidonic acid (AA) concentration ratio in human saliva has been developed. The EPA/AA ratio in serum or plasma is widely recognized as a useful indicator in identifying the risk of cardiovascular disease, especially atherosclerosis. The salivary EPA/AA ratio is expected to be a convenient alternative to the serum or plasma EPA/AA ratio, because saliva offers the advantages of easy and noninvasive sampling. The saliva was deproteinized with acetonitrile, purified using an Oasis HLB cartridge, and derivatized with 1-[(4-dimethylaminophenyl)carbonyl]piperazine (DAPPZ). The derivatized EPA and AA were subjected to LC/ESI-MS/MS, and the EPA/AA ratio was determined using the selected reaction monitoring mode. The DAPPZ-derivatization increased the ESI sensitivity by 100- and 300-fold for EPA and AA, respectively, and enabled the detection of trace fatty acids in saliva using a 200 µL sample. The assay reproducibility was satisfactory (relative standard deviation, <5.0%). The method was successfully applied to the measurement of the salivary EPA/AA ratios of healthy Japanese subjects and their changes owing to the supplementation of EPA.

Cholestane-3ß,5α,6ß-triol: high levels in Niemann-Pick type C, cerebrotendinous xanthomatosis, and lysosomal acid lipase deficiency.

Niemann-Pick type C (NPC) is a progressive neurodegenerative disease characterized by lysosomal/endosomal accumulation of unesterified cholesterol and glycolipids. Recent studies have shown that plasma cholestane-3ß,5α,6ß-triol (CT) and 7-ketocholesterol (7-KC) could be potential biomarkers for the diagnosis of NPC patients. We aimed to know the sensitivity and specificity of these biomarkers for the diagnosis of NPC compared with other diseases that can potentially lead to oxysterol alterations. We studied 107 controls and 122 patients including 16 with NPC, 3 with lysosomal acid lipase (LAL) deficiency, 8 with other lysosomal diseases, 5 with galactosemia, 11 with cerebrotendinous xanthomatosis (CTX), 3 with Smith-Lemli-Opitz, 14 with peroxisomal biogenesis disorders, 19 with unspecific hepatic diseases, 13 with familial hypercholesterolemia, and 30 with neurological involvement and no evidence of an inherited metabolic disease. CT and 7-KC were analyzed by HPLC-ESI-MS/MS as mono-dimethylglycine derivatives. Levels of 7-KC were high in most of the studied diseases, whereas those of CT were only high in NPC, LAL, and CTX patients. Consequently, although CT is a sensitive biomarker of NPC disease, including those cases with doubtful filipin staining, it is not specific. 7-KC is a very unspecific biomarker.