Interplatform comparison between three ion mobility techniques for human plasma lipid collision cross sections

The implementation of ion mobility spectrometry (IMS) in liquid chromatography-high-resolution mass spectrometry (LC-HRMS) workflows has become a valuable tool for improving compound annotation in metabolomics analyses by increasing peak capacity and by adding a new molecular descriptor, the collision cross section (CCS). Although some studies reported high repeatability and reproducibility of CCS determination and only few studies reported good interplatform agreement for small molecules, standardized protocols are still missing due to the lack of reference CCS values and reference materials. We present a comparison of CCS values of approximatively one hundred lipid species either commercially available or extracted from human plasma. We used three different commercial ion mobility technologies from different laboratories, drift tube IMS (DTIMS), travelling wave IMS (TWIMS) and trapped IMS (TIMS), to evaluate both instrument repeatability and interlaboratory reproducibility. We showed that CCS discrepancies of 0.3% (average) could occur depending on the data processing software tools. Moreover, eleven CCS calibrants were evaluated yielding mean RSD below 2% for eight calibrants, ESI Low concentration tuning mix (Tune Mix) showing the lowest RSD (< 0.5%) in both ion modes. Tune Mix calibrated CCS from the three different IMS instruments proved to be well correlated and highly reproducible (R2 > 0.995 and mean RSD ≤ 1%). More than 90% of the lipid CCS had deviations of less than 1%, demonstrating high comparability between techniques, and the possibility to use the CCS as molecular descriptor. We highlighted the need of standardized procedures for calibration, data acquisition, and data processing. This work demonstrates that using harmonized analytical conditions are required for interplatform reproducibility for CCS determination of human plasma lipids.

Impact of Source Conditions on Collision Cross Section Determination by Trapped Ion Mobility Spectrometry

Collision cross section (CCS) values determined in ion mobility-mass spectrometry (IM-MS) are increasingly employed as additional descriptors in metabolomics studies. CCS values must therefore be reproducible and the causes of deviations must be carefully known and controlled. Here, we analyzed lipid standards by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS) to evaluate the effects of solvent and flow rate in flow injection analysis (FIA), as well as electrospray source parameters including nebulizer gas pressure, drying gas flow rate, and temperature, on the ion mobility and CCS values. The stability of ion mobility experiments was studied over 10 h, which established the need for a delay-time of 20 min to stabilize source parameters (mostly pressure and temperature). Modifications of electrospray source parameters induced shifts of ion mobility peaks and even the occurrence of an additional peak in the ion mobility spectra. This behavior could be essentially explained by ion-solvent cluster formation. Changes in source parameters were also found to impact CCS value measurements, resulting in deviations up to 0.8%. However, internal calibration with the Tune Mix calibrant reduced the CCS deviations to 0.1%. Thus, optimization of source parameters is essential to achieve a good desolvation of lipid ions and avoid misinterpretation of peaks in ion mobility spectra due to solvent effects. This work highlights the importance of internal calibration to ensure interoperable CCS values, usable in metabolomics annotation.

Wildfire plume ageing in the Photochemical Large Aerosol Chamber (PHOTO-LAC)

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m3 and provide its figures of merit. While the photolysis rate of NO2 (jNO2) is comparable to that of other chambers, the PHOTO-LAC and its associated low surface-to-volume ratio lead to exceptionally low losses of particles to the walls. Photochemical ageing of toluene under high-NOx conditions induces substantial formation of secondary organic aerosols (SOAs) and brown carbon (BrC). Several individual nitrophenolic compounds could be detected by high resolution mass spectrometry, demonstrating similar photochemistry to other environmental chambers. Biomass burning aerosols are generated from pine wood and debris under flaming and smouldering combustion conditions and subsequently aged under photochemical and dark ageing conditions, thus resembling day- and night-time atmospheric chemistry. In the unprecedented long ageing with alternating photochemical and dark ageing conditions, the temporal evolution of particulate matter and its chemical composition is shown by ultra-high resolution mass spectrometry. Due to the spacious cavity, the PHOTO-LAC may be used for applications requiring large amounts of particulate matter, such as comprehensive chemical aerosol characterisation or cell exposures under submersed conditions.

Lumbosacral pain in a patient with psoriatic arthritis: when the rheumatic disease is innocent

Lumbar pain is a very common symptom that derives from benign musculoskeletal conditions, rheumatic inflammatory diseases, neoplasms, and referred and/or nociplastic pain. A 70-year-old man with psoriatic arthritis presented with early-onset lumbosacral pain without evident red flags. Symptomatic treatment was unhelpful. Radiographic imaging showed subtle signs of a disease that could easily be missed. Magnetic resonance imaging revealed a massive prostatic malignancy with bone (sacral and iliopubic) metastasis. Awareness must be given not to disregard every lumbar pain as part of the preexisting rheumatic inflammatory disease (spondyloarthropathy in this case) or a common muscle/ligament/articular disarrangement. Persistence of pain, albeit not inflam-matory nor sharp in nature, despite adequate treatment might be just as important as an acute red flag and requires proper follow-up.

GC-FTICR mass spectrometry with dopant assisted atmospheric pressure photoionization: application to the characterization of plastic pyrolysis oil

Pyrolysis is a promising way to convert plastic waste into valuable resources. However, for downstream upgrading processes, many undesirable species, such as conjugated diolefins or heteroatom-containing compounds, can be generated during this pyrolysis. In-depth chemical characterization is therefore required to improve conversion and valorization. Because of the high molecular diversity found in these samples, advanced analytical instrumentation is needed to provide accurate and complete characterization. Generally, direct infusion Fourier transform mass spectrometry is used to gather information at the molecular level, but it has the disadvantage of limited structural insights. To overcome this drawback, gas chromatography has been coupled to Fourier transform ion cyclotron resonance mass spectrometry. By taking advantage of soft atmospheric pressure photoionization, which preserves molecular information, and the use of different dopants (pyrrole, toluene, and benzene), selective ionization of different chemical families was achieved. Differences in the ionization energy of the dopants will only allow the ionization of the molecules of the pyrolysis oil which have lower ionization energy, or which are accessible via specific chemical ionization pathways. With a selective focus on hydrocarbon species and especially hydrocarbon species having a double bond equivalent (DBE) value of 2, pyrrole is prone to better ionize low-mass molecules with lower retention times compared to the dopant benzene, which allowed better ionization of high-mass molecules with higher retention times. The toluene dopant presented the advantage of ionizing both low and high mass molecules.

Contribution of LDI and MALDI for the Characterization of a Lignocellulosic-Based Pyrolysis Bio-Oil

In recent years, various alternatives to fossil fuels have been developed. One of them involves the production of bio-oils from lignocellulosic-based biomass through pyrolysis. However, bio-oils present numerous heteroatoms and, in particular, oxygen atoms that need to be removed by an upgrading process. To optimize these processes, it is necessary to have good knowledge of the composition of the bio-oils at the molecular level. This work aims to establish the usefulness of laser desorption ionization (LDI) and matrix-assisted laser desorption/ionization (MALDI) techniques on lignocellulosic biomass-based bio-oils. Using a Fourier transform ion cyclotron mass spectrometer (FTICR MS), we showed that MALDI gives more information than LDI. The selectivity of a series of MALDI matrices was investigated, showing that some matrices are selective toward compound families and others ionize a wider range of compounds. In this study, nine proton-transfer matrices and three electron-transfer matrices were used and compared to results obtained in LDI. Dithranol, acetosyringone, and graphene oxide were the three promising matrices selected from all matrices, giving an overall characterization of oxygenated classes in a bio-oil. They allowed the ionization of many more species covering a wide range of polarity, aromaticity, and mass with a homogeneous relative intensity for all molecular classes such as lignin-derivative species, sugars, and lipid-derivative species.

Humid Evolution of Haze in the Atmosphere of Super-Earths in the Habitable Zone

Abstract Photochemical hazes are expected to form and significantly contribute to the chemical and radiative balance of exoplanets with relatively moderate temperatures, possibly in the habitable zone of their host star. In the presence of humidity, haze particles might thus serve as cloud condensation nuclei and trigger the formation of water droplets. In the present work, we are interested in the chemical impact of such a close interaction between photochemical hazes and humidity on the organic content composing the hazes and on the capacity to generate organic molecules with high prebiotic potential. For this purpose, we explore experimentally the sweet spot by combining N-dominated super-Earth exoplanets in agreement with Titan's rich organic photochemistry and humid conditions expected for exoplanets in habitable zones. A logarithmic increase with time is observed for the relative abundance of oxygenated species, with O-containing molecules dominating after 1 month only. The rapidity of the process suggests that the humid evolution of N-rich organic haze provides an efficient source of molecules with high prebiotic potential.

Added-Value Compounds in Cork By-Products: Methods for Extraction, Identification, and Quantification of Compounds with Pharmaceutical and Cosmetic Interest

The growing threat of climatic crisis and fossil fuel extinction has caused a boom in sustainability trends. Consumer demand for so-called eco-friendly products has been steadily increasing, built upon the foundation of environmental protection and safeguarding for future generations. A natural product that has been used for centuries is cork, resulting from the outer bark of Quercus suber L. Currently, its major application is the production of cork stoppers for the wine industry, a process that, although considered sustainable, generates by-products in the form of cork powder, cork granulates, or waste such as black condensate, among others. These residues possess constituents of interest for the cosmetic and pharmaceutical industries, as they exhibit relevant bioactivities, such as anti-inflammatory, antimicrobial, and antioxidant. This interesting potential brings forth the need to develop methods for their extraction, isolation, identification, and quantification. The aim of this work is to describe the potential of cork by-products for the cosmetic and pharmaceutical industry and to assemble the available extraction, isolation, and analytical methods applied to cork by-products, as well the biological assays. To our knowledge, this compilation has never been done, and it opens new avenues for the development of new applications for cork by-products.

PyC2MC: An Open-Source Software Solution for Visualization and Treatment of High-Resolution Mass Spectrometry Data

Complex molecular mixtures are encountered in almost all research disciplines, such as biomedical 'omics, petroleomics, and environmental sciences. State-of-the-art characterization of sample materials related to these fields, deploying high-end instrumentation, allows for gathering large quantities of molecular composition data. One established technological platform is ultrahigh-resolution mass spectrometry, e.g., Fourier-transform mass spectrometry (FT-MS). However, the huge amounts of data acquired in FT-MS often result in tedious data treatment and visualization. FT-MS analysis of complex matrices can easily lead to single mass spectra with more than 10,000 attributed unique molecular formulas. Sophisticated software solutions to conduct these treatment and visualization attempts from commercial and noncommercial origins exist. However, existing applications have distinct drawbacks, such as focusing on only one type of graphic representation, being unable to handle large data sets, or not being publicly available. In this respect, we developed a software, within the international complex matrices molecular characterization joint lab (IC2MC), named "python tools for complex matrices molecular characterization" (PyC2MC). This piece of software will be open-source and free to use. PyC2MC is written under python 3.9.7 and relies on well-known libraries such as pandas, NumPy, or SciPy. It is provided with a graphical user interface developed under PyQt5. The two options for execution, (1) a user-friendly route with a prepacked executable file or (2) running the main python script through a Python interpreter, ensure a high applicability but also an open characteristic for further development by the community. Both are available on the GitHub platform (https://github.com/iC2MC/PyC2MC_viewer).

On-line reversed-phase liquid chromatography x supercritical fluid chromatography coupled to high-resolution mass spectrometry: a powerful tool for the characterization of advanced biofuels

Bio-oils obtained by thermochemical or biochemical conversion of biomass represent a promising source of energy to complement fossil fuels, in particular for maritime or air transport for which the use of hydrogen or electricity appears complicated. As these bio-oils are very rich in water and heteroatoms, additional treatments are necessary before they can be used as biofuel. In order to improve the efficiency of these treatments, it is important to have a thorough knowledge of the composition of the bio-oil. The characterization of bio-oils is difficult because they are very complex mixtures with thousands of compounds covering a very wide range of molecular weight and polarity. Due to the high degree of orthogonality between the two chromatographic dimensions, the on-line combination of reversed-phase liquid chromatography and supercritical fluid chromatography (on-line RPLC x SFC) can significantly improve the characterization of such complex matrices. The hyphenation was optimized by selecting, in SFC, the stationary phase, the co-solvent, the make-up solvent prior to high resolution mass spectrometry (HRMS) and the injection solvent. Additionally, a new interface configuration is described. Quality descriptors such as the occupation of the separation space, the peak shapes and the signal intensity were considered to determine the optimal conditions. The best results were obtained with bare silica, a co-solvent composed of acetonitrile and methanol (50/50, v/v), a make-up solvent composed of methanol (90%) and water (10%) with formic acid (0.1%), an addition of co-solvent through an additional pump for SFC separation in a 2.1 mm column, and an hydro-organic solvent as injection solvent. The optimized setup was used to analyze two microalgae bio-oils: the full bio-oil coming from hydrothermal liquefaction and Soxhlet extraction of microalgae, and the gasoline cut obtained after distillation of the full bio-oil. Results in on-line RPLC x SFC-qTOF were particularly interesting, with very good peak shapes and high reproducibility. Moreover, the high degree of orthogonality for microalgae bio-oils of RPLC and SFC was highlighted by the very large occupation of the separation space. Isomeric profiles of compound families could be obtained in RPLC x SFC-qTOF and many isomers not separated in SFC alone were separated in RPLC and vice versa, thus showing the complementarity of the two chromatographic techniques.

Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis

Pharmaceutical analysis refers to an area of analytical chemistry that deals with active compounds either by themselves (drug substance) or when formulated with excipients (drug product). In a less simplistic way, it can be defined as a complex science involving various disciplines, e.g., drug development, pharmacokinetics, drug metabolism, tissue distribution studies, and environmental contamination analyses. As such, the pharmaceutical analysis covers drug development to its impact on health and the environment. Moreover, due to the need for safe and effective medications, the pharmaceutical industry is one of the most heavily regulated sectors of the global economy. For this reason, powerful analytical instrumentation and efficient methods are required. In the last decades, mass spectrometry has been increasingly used in pharmaceutical analysis both for research aims and routine quality controls. Among different instrumental setups, ultra-high-resolution mass spectrometry with Fourier transform instruments, i.e., Fourier transform ion cyclotron resonance (FTICR) and Orbitrap, gives access to valuable molecular information for pharmaceutical analysis. In fact, thanks to their high resolving power, mass accuracy, and dynamic range, reliable molecular formula assignments or trace analysis in complex mixtures can be obtained. This review summarizes the principles of the two main types of Fourier transform mass spectrometers, and it highlights applications, developments, and future perspectives in pharmaceutical analysis.

Direct introduction MALDI FTICR MS based on dried droplet deposition applied to non-targeted metabolomics on Pisum Sativum root exudates

Non-targeted metabolomic approaches based on direct introduction (DI) through a soft ionization source are nowadays used for large-scale analysis and wide cover-up of metabolites in complex matrices. When coupled with ultra-high-resolution Fourier-Transform ion cyclotron resonance (FTICR MS), DI is generally performed through electrospray (ESI), which, despite the great analytical throughput, can suffer of matrix effects due to residual salts or charge competitors. In alternative, matrix assisted laser desorption ionization (MALDI) coupled with FTICR MS offers relatively high salt tolerance but it is mainly used for imaging of small molecule within biological tissues. In this study, we report a systematic evaluation on the performance of direct introduction ESI and MALDI coupled with FTICR MS applied to the analysis of root exudates (RE), a complex mixture of metabolites released from plant root tips and containing a relatively high salt concentration. Classic dried droplet deposition followed by screening of best matrices and ratio allowed the selection of high ranked conditions for non-targeted metabolomics on RE. Optimization of MALDI parameters led to improved reproducibility and precision. A RE desalted sample was used for comparison on ionization efficiency of the two sources and ion enhancement at high salinity was highlighted in MALDI by spiking desalted solution with inorganic salts. Application of a true lyophilized RE sample exhibited the complementarity of the two sources and the ability of MALDI in the detection of undisclosed metabolites suffering of matrix effects in ESI mode.

Ultrafine Particles Issued from Gasoline-Fuels and Biofuel Surrogates Combustion: A Comparative Study of the Physicochemical and In Vitro Toxicological Effects

Gasoline emissions contain high levels of pollutants, including particulate matter (PM), which are associated with several health outcomes. Moreover, due to the depletion of fossil fuels, biofuels represent an attractive alternative, particularly second-generation biofuels (B2G) derived from lignocellulosic biomass. Unfortunately, compared to the abundant literature on diesel and gasoline emissions, relatively few studies are devoted to alternative fuels and their health effects. This study aimed to compare the adverse effects of gasoline and B2G emissions on human bronchial epithelial cells. We characterized the emissions generated by propane combustion (CAST1), gasoline Surrogate, and B2G consisting of Surrogate blended with anisole (10%) (S+10A) or ethanol (10%) (S+10E). To study the cellular effects, BEAS-2B cells were cultured at air-liquid interface for seven days and exposed to different emissions. Cell viability, oxidative stress, inflammation, and xenobiotic metabolism were measured. mRNA expression analysis was significantly modified by the Surrogate S+10A and S+10E emissions, especially CYP1A1 and CYP1B1. Inflammation markers, IL-6 and IL-8, were mainly downregulated doubtless due to the PAHs content on PM. Overall, these results demonstrated that ultrafine particles generated from biofuels Surrogates had a toxic effect at least similar to that observed with a gasoline substitute (Surrogate), involving probably different toxicity pathways.

Large-Scale Interlaboratory DI-FT-ICR MS Comparability Study Employing Various Systems

Ultrahigh resolution mass spectrometry (UHR-MS) coupled with direct infusion (DI) electrospray ionization offers a fast solution for accurate untargeted profiling. Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers have been shown to produce a wealth of insights into complex chemical systems because they enable unambiguous molecular formula assignment even if the vast majority of signals is of unknown identity. Interlaboratory comparisons are required to apply this type of instrumentation in quality control (for food industry or pharmaceuticals), large-scale environmental studies, or clinical diagnostics. Extended comparisons employing different FT-ICR MS instruments with qualitative direct infusion analysis are scarce since the majority of detected compounds cannot be quantified. The extent to which observations can be reproduced by different laboratories remains unknown. We set up a preliminary study which encompassed a set of 17 laboratories around the globe, diverse in instrumental characteristics and applications, to analyze the same sets of extracts from commercially available standard human blood plasma and Standard Reference Material (SRM) for blood plasma (SRM1950), which were delivered at different dilutions or spiked with different concentrations of pesticides. The aim of this study was to assess the extent to which the outputs of differently tuned FT-ICR mass spectrometers, with different technical specifications, are comparable for setting the frames of a future DI-FT-ICR MS ring trial. We concluded that a cluster of five laboratories, with diverse instrumental characteristics, showed comparable and representative performance across all experiments, setting a reference to be used in a future ring trial on blood plasma.

Prediction of Structures of Compounds Encountered in Complex Organic Matter with Highly Flexible Alkyl Chains Using Ion Mobility-Mass Spectrometry

The chemical structure of an organic molecule has a direct influence on its three-dimensional conformation. One way to obtain information on this conformation is to use ion mobility spectrometry. This technique allows the separation of different isomers according to their collision cross section (CCS) with an inert gas. Smaller or more compact molecules will have lower collision cross section values than larger molecules. The CCS is an intrinsic ion parameter for a specific gas and is thus predictable. Today, calculations of rigid molecules are commonly performed to obtain additional structural information on an ion. However, calculations are more complex with very flexible molecules. In particular, molecules presenting long alkyl chains can yield a high number of conformers. Each conformer is then associated with a CCS value that is specific to it. We report, here, a methodology to predict CCS of flexible molecules. The used approach is based on automatic conformers research followed by geometry optimization and CCS calculations. Determination of theoretical and experimental CCS values for a rigid polycyclic aromatic hydrocarbons (PAHs) standard was used to calibrate the Mobcal software. Then, 13 standard molecules ranging from 4 to 19 carbon alkyl chains, including three long alkyl chain isomers of C₂₂H₃₈, were analyzed on a TWIMS-ToF and calculated using our methodology. CCS deviations between experimental and theoretical values were found to be less than 1.5% over the whole studied CCS range. This method was finally applied for structural analysis of petroleum compounds refractory to the hydro-denitrogenation process.

Molecular Characterization of Formulated Lubricants and Additive Packages Using Kendrick Mass Defect Determined by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Formulated lubricants correspond to high value products used for several applications in automotive, industrial, medicinal, and agro-food sectors. They correspond to complex matrices composed of approximately 80% of base oils (mineral or synthetic) and of about 20% of additives. Additives are generally low molecular weight polymeric molecules with a great diversity of elements. To characterize such complex compositions at the molecular level, ultrahigh resolution mass spectrometers are required. Two formulated lubricants and two additive packages were analyzed by Fourier transform ion cyclotron resonance mass spectrometry in direct infusion. Atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) sources were used to have an exhaustive characterization of the samples. The Kendrick mass defects (KMD) plot is a widespread representation to characterize polymeric molecules. Here, the terms apparent mass defect and apparent Kendrick mass defects (aKMD) values were introduced to consider the uncertainty on nominal mass determination. Several additive families including alkyldiphenylamines, trisalkylphenylthiophosphoric acid, zinc dithiophosphates, bisuccinimide dispersants, and their derivatives were observed by APCI(+). ESI(-) also presented a use for the selective ionization of acidic compounds including sulfonates, phenates, and sulfur phenate molecules. The specific aKMD values and polydispersity of many additive families have been reported to create a database of additives. Overall, this study demonstrated the great utility of the aKMD approach and the use of the ESI/APCI combination for a simple and fast characterization of formulated lubricant and additive package samples.

Lennard-Jones interaction parameters of Mo and W in He and N2 from collision cross-sections of Lindqvist and Keggin polyoxometalate anions

Drift tube ion mobility spectrometry (DTIMS) coupled with mass spectrometry was used to determine the collision cross-sections (^DTCCS) of polyoxometalate anions in helium and nitrogen. As the geometry of the ion, more than its mass, determines the collision cross-section with a given drift gas molecule, we found that both Lindqvist ions Mo₆O₁₉^2- and W₆O₁₉^2- had a ^DTCCS_He value of 103 ± 2 Ų, and both Keggin ions PMo₁₂O₄₀^3- and PW₁₂O₄₀^3- had a ^DTCCS_He value of 170 ± 2 Ų. Similarly, ion mobility experiments in N₂ led to ^DTCCS_N2 values of 223 ± 2 Ų and 339 ± 4 Ų for Lindqvist and Keggin anions, respectively. Using optimized structures and partial charges determined from density functional theory calculations, followed by CCS calculations via the trajectory method, we determined Lennard-Jones 6-12 potential parameters ε, σ of 5.60 meV, 3.50 Å and 3.75 meV, 4.40 Å for both Mo and W atoms interacting with He and N₂, respectively. These parameters reproduced the CCS of polyoxometalates within 2% accuracy.

Speciation and Semiquantification of Nitrogen-Containing Species in Complex Mixtures: Application to Plastic Pyrolysis Oil

Plastic pyrolysis oil is of particular interest for waste management in the current context of a circular economy. Due to their uncontrolled origin, these oils may contain significant amount of unwanted compounds such as nitrogen-containing species. These compounds are known to be catalyst poisons during refining processes. Therefore, the removal of these species is crucial, and their characterization from structural and quantification points of view is essential for this purpose. This study presents a method to specify and quantify nitrogen-containing classes in a plastic pyrolysis oil by direct infusion mass spectrometry. Two steps were used, namely structural characterization to select suitable standards and semiquantification. The structural speciation of nitrogen-containing compounds was first performed by electrospray ionization Fourier transform mass spectrometry, followed by tandem mass spectrometry using high-resolution mass isolation and infrared multiphoton dissociation fragmentation. A semiquantification is then performed by the standard addition method, which is very appropriate for such complex matrices. Aromatic cores such as quinoline and quinoxaline were evidenced for both N₁ and N₂ classes, allowing 2-methylquinoxaline and 2-butylquinoline to be proposed as standards for the semiquantification of N₂- and N₁-containing compounds, respectively. The amount of nitrogen detected from the sum of the individual species was consistent with the bulk analysis. The reported methodology can be applied to numerous other families of compounds in various other complex matrices.

POS0901 INTERSTITIAL LUNG DISEASE IN MIXED CONNECTIVE TISSUE DISEASE: CLINICAL AND SEROLOGICAL ASSOCIATIONS

Background

Mixed connective tissue disease (MCTD) is a rare systemic rheumatic disease characterized by the expression of autoantibodies targeting the U1-ribonucleoprotein and overlapping clinical features of systemic sclerosis, systemic lupus erythematosus, and inflammatory myopathies. Interstitial lung disease (ILD) is present in 47% to 78% of patients and has been associated with higher mortality rates. Associations of ILD with Raynaud’s phenomenon, dysphagia, anti-Ro52 antibodies, and a scleroderma pattern on nailfold capillaroscopy have been reported in MCTD patients.

Objectives

This study aims to identify clinical and serological associations and independent predictors of ILD for patients with MCTD.

Methods

Multicenter retrospective study using data collected from clinical records. Adult patients who underwent lung computed tomography (CT) and met at least one of four MCTD diagnostic criteria (Sharp, Alarcón-Segovia, Kasukawa, or Kahn criteria) were included. Univariate analysis was performed using Chi-Square, Fischer’s Exact, and Mann-Whitney tests, as appropriate. Multivariate analysis was performed using binary logistic regression modelling. The linearity of the continuous variables concerning the logit of the dependent variable was assessed via the Box-Tidwell procedure. Cases with missing information and outliers were excluded from the multivariate analysis to fulfil all assumptions necessary to assure the validity of the regression.

Results

Fifty-seven patients, of whom 37 were Caucasian (64.9%) and 48 were females (84.2%), with a mean age of 39.4±14.0 years, were included. Twenty-seven patients had ILD (47.4%), of whom 22 had nonspecific interstitial pneumonia (81.5%), 4 had usual interstitial pneumonia (14.8%), and 1 had lymphoid interstitial pneumonia (3.7%) pattern on CT. Among patients with ILD, 13 were asymptomatic (48.1%), while 14 had respiratory symptoms (51.9%), including dyspnea (N=13, 48.1%), cough (N=7, 25.9%), and pleuritic chest pain (N=1, 3.7%). Pulmonary function tests were performed in 22 patients (81.5%), 20 of whom had a restrictive pattern (90.9%).

In the univariate analysis, lymphadenopathy at disease onset (22.2% vs 3.3%, p=0.045) and esophageal involvement at any time point (40.7% vs 16.7%, p=0.043), were associated with ILD.

The binary logistic regression model predicting ILD included 56 patients, and the model explained 36.5% (Nagelkerke R2) of the variance in ILD and correctly classified 75% of all cases. Older age at diagnosis (OR 1.10/year, 95%CI: 1.00-1.12, p=0.046) and lymphadenopathy at disease onset (OR 19.65, 95%CI: 1.91-201.75, p=0.012) were identified as predictors of ILD in MCTD patients, irrespective of sex and esophageal involvement.

Conclusion

Older age at diagnosis and lymphadenopathy at disease onset were independent predictors of ILD in MCTD. Therefore, these factors should be considered when evaluating MCTD patients, especially at the time of diagnosis. To the best of our knowledge, this is the largest study ever describing predictors of ILD for MCTD patients.

References

[1]Fagundes MN, Caleiro MT, Navarro-Rodriguez T, Baldi BG, Kavakama J, Salge JM, Kairalla R, Carvalho CR. Esophageal involvement and interstitial lung disease in mixed connective tissue disease. Respir Med. 2009 Jun;103(6):854-60. doi: 10.1016/j.rmed.2008.12.018. Epub 2009 Feb 6. PMID: 19201182.

[2]Gunnarsson R, Aaløkken TM, Molberg Ø, Lund MB, Mynarek GK, Lexberg AS, Time K, Dhainaut AS, Bertelsen LT, Palm O, Irgens K, Becker-Merok A, Nordeide JL, Johnsen V, Pedersen S, Prøven A, Garabet LS, Gran JT. Prevalence and severity of interstitial lung disease in mixed connective tissue disease: a nationwide, cross-sectional study. Ann Rheum Dis. 2012 Dec;71(12):1966-72. doi: 10.1136/annrheumdis-2011-201253. Epub 2012 May 1. PMID: 22550317

Disclosure of Interests

None declared

AB0655 Clinical and immunological features of a Portuguese cohort of Mixed Connective Tissue Disease

Background

Various nationwide studies have been already published to better understand Mixed Connective Tissue Disease (MCTD) (1,2). However, Portuguese data is not available.

Objectives

To characterize clinical and immunological features of a Portuguese cohort of patients with MCTD.

Methods

Retrospective, multicenter study including adult-onset patients with clinical diagnosis of MCTD and fulfilling at least one of the following classification criteria: Sharp, Kasukawa, Alarcón-Segovia or the Kahn’s criteria. Positivity to other autoantibodies besides anti-U1-RNP were allowed. SPSS was used for statistical analysis and significance level was defined as 2-sided p<.05.

Results

A total of 98 patients were included, with a mean age at diagnosis and disease duration of 40.5±13.7 and 7.0±6.5 years, respectively. Most patients were female (87.8%) and Caucasian (70.4%). Raynaud’s phenomenon (96.9%), arthralgia/arthritis (94.9/74.5%) and puffy fingers (60.2%) were the most common and early manifestations. Gastroesophageal (GE), respiratory and muscular involvement were also prevalent, mostly during the follow up, affecting 30.6%, 34.7% and 43.9% of the patients, respectively. Clinical and immunological characteristics are described in Table 1. Males were older at symptom’s onset (65.0 VS 46.7, p=.035), having more respiratory involvement (OR=4.5, 95% CI 1.3-16.4), and positivity to anti-ACPA (OR=20.0, 95% CI: 3.1-129.4). GE involvement occurred more often in Caucasian patients (OR=3.8; 95% CI: 1.0-14.1), while anemia of chronic diseases (OR=2.7; 95% CI: 1.0-7.2), myositis (OR=3.6; 95% CI: 1.3-9.9) and constitutional symptoms (OR=3.2; 95% CI: 1.2-8.3) were more frequent in Afro-American patients, whose were also younger at disease (34.1 VS 50.6, p=.01). After a median follow-up time of 4 (IQR 8) years, 4 deaths occurred (4.1%), mostly (75%) due to infectious complications.

Table 1.

Clinical and immunological characteristics

Clinical ManifestationsAt presentationFollow-upMucocutaneous systemRaynaud’s phenomenon, n (%)85 (86.7)95 (96.9)Puffy hands, n (%)48 (49.0)59 (60.2)SSc-like, n (%)43 (44.8)59 (60.8)SLE-like, n (%)28 (28.9)35 (35.7)Musculoskeletal systemArthralgia/Arthritis, n (%)/n (%)81 (82.7) / 56 (57.1)93 (94.9) / 73 (74.5)Myositis, n (%)26 (25.6)43 (43.9)Hematological system, n (%)46 (46.9)70 (71.4)Respiratory system, n (%)14 (14.3)34 (34.7)Cardiovascular system3 (3.1)4 (4.1)Pulmonary hypertension*2 (2.0)15 (15.3)Gastroesophageal involvement, n (%)11 (11.2)30 (30.6)Renal involvement, n (%)2 (2.0)10 (10.2)Neurological involvement, n (%)6 (6.3)14 (14.3)Constitutional symptoms, n (%)26 (26.5)30 (30.6)Immunological characteristicsAnti-dsDNA, n (%)21 (21.4)Anti-smith antibody, n (%)21 (21.4)Anti-Ro/SSA, n (%)31 (31.6)Anti-La/SSB, n (%)7 (7.1)Anti-centromere, n (%)3 (4.1)Rheumatoid Factor, n (%)39 (39.8)Anti- anti-citrullinated protein antibodies, n (%)6 (6.1)Antiphospholipid antibodies, n (%)7 (7.1)Myositis antibodies, n (%)9 (9.2)Complement activation, n (%)27 (27.6)Hypergammaglobulinemia, n (%)51 (52.0)

Legend: Anti-dsDNA: anti-double stranded deoxyribonucleic acid antibody; SLE: systemic lupus erythematosus, SSc: systemic sclerosis. *No information regarding cardiac catheterism, then compatible alterations in the echocardiogram.

Conclusion

Raynaud’s phenomenon, puffy fingers and arthritis were the most common manifestations in Portuguese patients, with similar proportions found in literature (1,2). However, we reported some differences in mucocutaneous, renal and serosa involvement and higher prevalence of probable pulmonary hypertension (1,2), which may be explained by the heterogeneity of the inclusion criteria. Except for respiratory, myositis, GE and constitutional symptoms, there were no differences regarding gender and ethnicity.

Here, we characterize the largest cohort of MCTD in Portugal.

References

[1]Cappelli S, et al. Semin Arthritis Rheum. 2012 Feb;41(4):589–98.

[2]Alves MR et al. Clin Exp Med. 2020 May;20(2):159–66.

Disclosure of Interests

None declared

POS1290 EFFICACY AND SAFETY OF SODIUM THIOSULFATE IN CALCIFIC TENDINITIS OF THE ROTATOR CUFF – AN INTERIM ANALYSIS OF A RANDOMIZED CLINICAL TRIAL

Background

Calcific tendinitis of the rotator cuff is one of the most common causes of shoulder pain. (1) Ultrasound guided percutaneous lavage (UGPL) is indicated when conservative treatments have failed. (2) Recent reports have shown the interest of topical sodium thiosulfate (STS) in the treatment of other diseases characterizes by ectopic calcifications (3, 4, 5).

Objectives

To assess the efficacy and safety of UGPL with STS versus with saline solution (standard of care - SOC) in calcific tendinitis.

Methods

Double-blinded randomized clinical trial including adult patients with calcific tendinitis, shoulder pain for more than 3 months and at least one positive shoulder impingement test. Only dense type A calcifications (according to the Molé Classification) > 5 mm in diameter were included. Patients were randomized in two groups: STS and saline solution lavage. Informed consents were collected. Both groups were reevaluated at week 1, month 1 and month 3 after UGPL. Pain Visual Analogue Scale (VAS) at rest and during activities, shoulder range of motion and strength, impingement tests, Disabilities of the Arm, Shoulder and Hand (DASH), DASH-Work, EuroQol five-dimensional (EQ5D) and University of California at Los Angeles (UCLA) scores, ultrasound (US) and radiographic evaluations were performed on all follow up visits.

SPSS was used for statistical analysis and significance level was defined as 2-sided p<0.05.

Results

Twenty-six patients were included, where 76.9% (20) were women, with a mean age of 51.2 (SD=9.0) years old. The mean duration of pain before the procedure was 12.7 months (SD=11.3) (minimum of 3 months and a maximum of 48 months).

Fifteen patients (57.7%) were randomized to the control group (SOC) and performed a saline UGPL; the other 11 patients (42.3%) were randomized to the treatment group (STS). Demographic and baseline clinical characteristics are shown in Table 1. Since patient inclusion is dynamic, our sample met 23 patients at week 1 (SOC group = 13 and STS group = 10), 19 patients at month 1 (SOC group = 10 and STS group = 9) and 16 patients at month 3 (SOC group = 8 and STS group = 8).

Table 1.

Demographic and baseline clinical characteristics.

STS lavage(n=11)Saline solution lavage (n=15)p-valueAge (years), M (SD)52.3 (10.6)50.3 (8.0)NSSex, female % (n/N)72.7% (8/11)80% (12/15)NSDominant side, right % (n/N)100% (11/11)93.3% (14/15)NSNocturnal pain, yes % (n/N)100% (11/11)100% (15/15)NSVAS at rest (0–10), M (SD)5.7 (2.0)5.9 (2.1)NSVAS during activities (0–10), M (SD)7.1 (1.8)6.0 (2.5)NSDASH Score, M (SD)60.2 (14.0)52.6 (13.8)NSDASH-Work Score, M (SD73.4 (11.0)63.4 (22.6)NSEQ5D, M (SD)0.2897 (0.3)0.4070 (0.2)NSVAS EQ5D (0–100), M (SD)54 (15.9)58 (20.0)NSUCLA score, M (SD)18.7 (4.1)14.7 (3.3)0.014Bursitis, yes % (n/N)72.7% (8/11)66.7% (10/15)NSCalcification morphology, % (n/N)Acr-shaped18.2% (2/11)40% (6/15)0.039Fragmented18.2% (2/11)26.7% (4/15)Nodular and dense, well-defined63.6% (7/11)33.3% (5/15)Calcification size, median (IQR)12.6 (5.7)10.5 (6.3)NS

SD: Standard deviation; M: Mean; NS: non-significant; IQR: interquartile range

Overall, there were no differences between control (SOC) and treatment group (STS). Both procedures were effective improving pain at rest (p=0.024), EQ5D (p=0.019), DASH-Work (p=0.032) and UCLA scores (p=0.009) and calcification size measured by US (p=0.031) at month 3.

No adverse effects or complications were reported on both groups.

Conclusion

Although well tolerated with no side effects, STS UGPL has failed to show increased benefit for calcific tendinopathy local treatment. Further studies using STS will be needed to ascertain its interest in this disease. This on-going work will be reevaluated with a larger sample.

References

[1]Louwerens JK et al. J Shoulder Elbow Surg. 2015; 24:1588–93.

[2]De Witte PB et al. Am J Sports Med. 2013; 41:1665-73.

[3]Ossorio-García L et al. Actas Dermosifiliogr. 2016; 107:359-62. 21.

[4]Jost J et al. J Clin Endocrinol Metab. 2016; 101:2810-5. 22.

[5]Guigonis V et al. Ann Endocrinol (Paris). 2015; 76:183-4.

Disclosure of Interests

None declared

AB0688 Predictors of muscle involvement in Portuguese patients with mixed connective tissue disease

Background

Mixed connective tissue disease (MCTD) is a rare heterogeneous disease, characterized by overlapping features of classic connective tissue diseases. Myositis may be present in up to two-thirds of patients with MCTD and it is included in all diagnostic criteria available. Although some possible associations have been reported, to the best of our knowledge, no independent predictors of MCTD-related myositis have been described.

Objectives

To identify clinical and laboratorial predictors for muscular involvement in a cohort of Portuguese patients with MCTD.

Methods

Multicentre retrospective cohort study including adult-onset patients with a clinical diagnosis of MCTD and fulfilling at least one of the following diagnostic criteria: Sharp, Kasukawa, Alarcón-Segovia or Kahn criteria. Myositis was defined as proximal muscle weakness, creatine kinase elevation, electromyography (EMG) suggestive changes or a positive muscular biopsy. Univariate analysis was performed using Chi-Square, Fischer’s Exact Test and Mann-Whitney Test, as appropriate. Multivariate analysis was performed using binary logistic regression modelling. The linearity of the continuous variables concerning the logit of the dependent variable was assessed via the Box-Tidwell procedure. Cases with missing information and outliers were excluded from the multivariate analysis to fulfil all assumptions necessary to assure the validity of the regression.

Results

A total of 98 patients were included, 43 (44.3%) of whom had muscular involvement at any time of the disease course. Concerning patients with MCTD-related myositis, the mean age at diagnosis was 34.8±12.5 years and the mean disease duration of 4.1±4.9 years. The majority of patients were female (90.7%) and of European ancestry (66.7%).

EMG was performed in 24 patients, of whom 10 (41.7%) had a myopathic pattern. Seventeen patients were submitted to a muscular biopsy, of whom 8 (47.1%) had histological myositis features. Capillaroscopy was performed in 24 patients and 12 (50%) had a scleroderma pattern.

African ancestry and leukopenia were positively associated with myositis at disease onset. Furthermore, fever at the onset of disease, younger age at diagnosis and shorter disease duration were positively associated with the occurrence of myositis at any phase of the disease.

The multivariate analyses predicting myositis at diagnosis included 54 patients and at any time of the disease included 90 patients. These models explained 37.8% and 26.9% (Nagelkerke R2) of the variance in myositis and correctly classified 79.6% and 73.3% of all cases, respectively.

African ancestry (OR 8.39, 95%CI: 1.43-49.37, p=0.019), leukopenia (OR 6.24, 95%CI: 1.32-29.48, p=0.021) and younger age at diagnosis (OR 1.07/year, 95%CI: 1.01-1.14, p=0.035) were identified as independent predictors of myositis at diagnosis. Fever (OR 6.51, 95%CI: 1.23-34.37, p=0.027) was an independent predictor of muscular involvement at any time of the disease in MCDT patients.

Conclusion

African ancestry, leukopenia and younger age at diagnosis are independent predictors of myositis at presentation in MCTD patients, while fever is an independent predictor of myositis at any time of the disease. While evaluating patients with MCTD, these predictive factors should be considered.

References

[1]Ciang NCO, Pereira N, Isenberg DA. Mixed connective tissue disease-enigma variations? Rheumatol. 2017 Mar 1;56(3):326–33.

[2]Hall S, Hanrahan P. Muscle involvement in mixed connective tissue disease. Rheum Dis Clin North Am. 2005 Aug;31(3):509–17, vii.

Disclosure of Interests

None declared

CRISPR/Cas9-mediated inactivation of the phosphatase activity of soluble epoxide hydrolase prevents obesity and cardiac ischemic injury

INTRODUCTION

Although the physiological role of the C-terminal hydrolase domain of the soluble epoxide hydrolase (sEH-H) is well investigated, the function of its N-terminal phosphatase activity (sEH-P) remains unknown.

OBJECTIVES

This study aimed to assess in vivo the physiological role of sEH-P.

METHODS

CRISPR/Cas9 was used to generate a novel knock-in (KI) rat line lacking the sEH-P activity.

RESULTS

The sEH-P KI rats has a decreased metabolism of lysophosphatidic acids to monoacyglycerols. KI rats grew almost normally but with less weight and fat mass gain while insulin sensitivity was increased compared to wild-type rats. This lean phenotype was more marked in males than in female KI rats and mainly due to decreased food consumption and enhanced energy expenditure. In fact, sEH-P KI rats had an increased lipolysis allowing to supply fatty acids as fuel to potentiate brown adipose thermogenesis under resting condition and upon cold exposure. The potentiation of thermogenesis was abolished when blocking PPARγ, a nuclear receptor activated by intracellular lysophosphatidic acids, but also when inhibiting simultaneously sEH-H, showing a functional interaction between the two domains. Furthermore, sEH-P KI rats fed a high-fat diet did not gain as much weight as the wild-type rats, did not have increased fat mass and did not develop insulin resistance or hepatic steatosis. In addition, sEH-P KI rats exhibited enhanced basal cardiac mitochondrial activity associated with an enhanced left ventricular contractility and were protected against cardiac ischemia-reperfusion injury.

CONCLUSION

Our study reveals that sEH-P is a key player in energy and fat metabolism and contributes together with sEH-H to the regulation of cardiometabolic homeostasis. The development of pharmacological inhibitors of sEH-P appears of crucial importance to evaluate the interest of this promising therapeutic strategy in the management of obesity and cardiac ischemic complications.

Development of a standardized in vitro approach to evaluate microphysical, chemical, and toxicological properties of combustion-derived fine and ultrafine particles

Ultrafine particles represent a growing concern in the public health community but their precise role in many illnesses is still unknown. This lack of knowledge is related to the experimental difficulty in linking their biological effects to their multiple properties, which are important determinants of toxicity. Our aim is to propose an interdisciplinary approach to study fine (FP) and ultrafine (UFP) particles, generated in a controlled manner using a miniCAST (Combustion Aerosol Standard) soot generator used with two different operating conditions (CAST1 and CAST3). The chemical characterization was performed by an untargeted analysis using ultra-high resolution mass spectrometry. In conjunction with this approach, subsequent analysis by gas chromatography-mass spectrometry (GC-MS) was performed to identify polycyclic aromatic hydrocarbons (PAH). CAST1 enabled the generation of FP with a predominance of small PAH molecules, and CAST3 enabled the generation of UFP, which presented higher numbers of carbon atoms corresponding to larger PAH molecules. Healthy normal human bronchial epithelial (NHBE) cells differentiated at the air-liquid interface (ALI) were directly exposed to these freshly emitted FP and UFP. Expression of MUC5AC, FOXJ1, OCLN and ZOI as well as microscopic observation confirmed the ciliated pseudostratified epithelial phenotype. Study of the mass deposition efficiency revealed a difference between the two operating conditions, probably due to the morphological differences between the two categories of particles. We demonstrated that only NHBE cells exposed to CAST3 particles induced upregulation in the gene expression of IL-8 and NQO1. This approach offers new perspectives to study FP and UFP with stable and controlled properties.

Visualization and identification of single meteoritic organic molecules by atomic force microscopy

Using high-resolution atomic force microscopy (AFM) with CO-functionalized tips, we atomically resolved individual molecules from Murchison meteorite samples. We analyzed powdered Murchison meteorite material directly, as well as processed extracts that we prepared to facilitate characterization by AFM. From the untreated Murchison sample, we resolved very few molecules, as the sample contained mostly small molecules that could not be identified by AFM. By contrast, using a procedure based on several trituration and extraction steps with organic solvents, we isolated a fraction enriched in larger organic compounds. The treatment increased the fraction of molecules that could be resolved by AFM, allowing us to identify organic constituents and molecular moieties, such as polycyclic aromatic hydrocarbons and aliphatic chains. The AFM measurements are complemented by high-resolution mass spectrometry analysis of Murchison fractions. We provide a proof of principle that AFM can be used to image and identify individual organic molecules from meteorites and propose a method for extracting and preparing meteorite samples for their investigation by AFM. We discuss the challenges and prospects of this approach to study extraterrestrial samples based on single-molecule identification.

Imaging Matrix-Assisted Laser Desorption/Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry of oxaliplatin derivatives in human tissue sections

Mass Spectrometry Imaging is an effective technology that allows to determine the in-situ distribution of endogen and/or exogen small molecules. It is a rapidly emerging approach for visualizing drugs and their metabolites within biological tissues. Matrix-Assisted Laser Desorption Ionization (MALDI) Mass Spectrometry Imaging (MSI) coupled to high resolving power analyzer (e.g. TOF) was already investigated for metallodrug localization and metabolization studies, but was proved to suffer from a lack of sensitivity and resolution, leading to poor coverage and assignment. To counter these technological limitations, the use of ultra-high resolving power analyzer such as Fourier Transform Ion Cyclotron Resonance (FTICR) could be revealed as a technique of choice. The high field FTICR MS provides ultra-high resolving power and mass accuracy that allows exhaustive molecule coverage and non-ambiguous molecular formula assignments. Platinum derivatives, such as oxaliplatin, are widely used as therapeutic agents for cancer treatment. The assessment of their intake, distribution and metabolism within the organs is important to know the risks associated with their use. In this study, MALDI FTICR MSI analyses were performed to better understand the penetration and metabolization of platinum derivatives in ovaries of women treated by Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for peritoneal metastasis of colorectal or appendicular origin. Twelve ovary sections, from six ovary samples in six women donors, before and after treatment, were analyzed with 120 μm spatial resolution. For the first time, the high resolving power (220,000 at m/z 457) and sub-ppm accuracy (<1 ppm) of the FTICR combined with an Isotopic Fine Structure study enabled to distinguish two Pt-isobaric species derived from oxaliplatin in biological tissues. One of these, which is unknown, was specifically localized at the contour of the ovary.

Food and nutrition literacy: an education booklet and video on ultra-processed food

Background

The COVID-19 pandemic appears to have contributed to change in eating habits for a significant part of the Portuguese population. The increase in the snacks consumption during the confinement period was reported by almost a third of the population. Often the snacks chosen are ultra-processed foods: industrial formulations that include excess of sugar, oils, fats, salt, and additives, antioxidant, stabilizers and preservatives substances in their ingredients. Excessive ultra-processed food consumption has been associated with worse health indicators.

Objectives

To develop informative educational material about ultra-processed foods and their health risks to be available to the general Portuguese population, and thus to promote food and nutrition literacy.

Results

The development of this new tool started in September 2020 and in April 2021 the booklet was approved by the UPPER Project team to be made available through digital media (cell phone, computer, laptop and tablet) or print. The booklet contains 33 pages with illustrative images and simple and didactic language. It is focused in seven main topics: “What are ultra-processed foods?”, “Which are they?”, “How to recognize them when purchasing?”, “What are worth for?”, “What is the relationship with health?”, and “What foods to choose?”. A short video with 2 minutes duration, summarizing and explaining the booklet, was also produced. The booklet impact will be piloted in a school intervention project that has been designed and submitted for ethical approval.

Conclusions

The developed booklet and explanatory video are didactic materials in simple language to achieve all general Portuguese population.

Key messages

The booklet is an instrument intending to improve literacy in ultra-processed foods.

The booklet is a tool that can be used in health promotion programs and public policies in food and nutrition.

Metabolome Exploration by High-Resolution Mass Spectrometry Methodologies of Two New Yeast Species: Starmerella reginensis and Starmerella kourouensis

Nature is harnessed since ancient times to fulfill human needs, and yeast culture has been mastered for bakery, brewery, or the preparation of beverages. In this context, the two recently discovered yeast species Starmerella reginensis and Starmerella kourouensis, belonging to a genus related to fermentative activities in the literature, were explored via untargeted metabolomics approaches. Ultrahigh-performance liquid chromatography hyphenated with tandem mass spectrometry and a deep investigation of molecular networks and spectral data allowed the annotation of, respectively, 439 and 513 metabolites for S. reginensis and S. kourouensis, with approximatively 30% compound annotations and 40% chemical class annotations for both yeast strains. These analyses and Fourier transform ion cyclotron resonance mass spectrometry accurate metabolic profiles unveiled a rich content of alkaloids, lipids, amino acids, and terpenoids for S. reginensis. S. kourouensis presents a similar profile with more sulfated compounds. In short, these results enrich the current knowledge about Starmerella yeast secondary metabolites and reveal their significant structural diversity of small molecules.

The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

A straightforward synthesis of original 1,6-diazabicyclo[4.3.0]nonane-2,7-diones was achieved through a DBU-organocatalyzed multicomponent Knoevenagel-aza-Michael-Cyclocondensation reaction which takes advantage of an unprecedented highly regio- and diastereoselective conjugate addition of pyridazinones to alkylidene Meldrum's acid intermediates. The key reactive intermediates of this complex process were analyzed by means of electrospray ionization mass spectrometry coupled to ion mobility spectrometry, allowing us to validate the proposed mechanism.

POS0162 PREDICTIVE FACTORS OF A NEW FRAGILITY FRACTURE AFTER WRIST FRAGILITY FRACTURE

Background:

Fragility fractures (FF) are fractures that result from mechanical forces that would not ordinarily result in fracture, known as low-level (or ‘low energy’) trauma.1 Studies have shown that history of wrist fracture increases the risk for subsequent FF.2

Objectives:

To assess predictive factors of FF occurring after a wrist fracture.

Methods:

Retrospective monocentric study that included patients with a wrist FF observed at the emergency department (ED) in a tertiary center, between 1st January 2017 and 31st December 2018. Wrist fractures were identified through the 10th International Classification of Diseases and FF were identified after revision of the clinical record. Patients with relevant missing data were excluded. Seven hundred thirty-three wrist FF were identified. After calculating a representative sample (90% confidence interval), 188 patients were included. Their clinical records until 31th December 2020 (2 to 3 years after FF) were reviewed. SPSS was used for statistical analysis and significance level was defined as 2-sided p<0.05. In multivariate analysis we included variables with a significant association in univariate analysis and those with clinical relevance (reported in others studies).

Results:

Wrist fractures represented 44.3% of the FF observed at the ED.

Most patients were woman (83.5%) with a mean age of 70.7 (SD=11.2) years-old at the time of their wrist fracture. A previous FF was seen in 22.9% of patients and 13.3% had a new FF during the follow-up period.

We found an association between the occurrence of a new FF and the number of comorbidities (p=0.012), number of visits to the ED due to falls (p<0.001), previous diagnosis of chronic pulmonary disease (p=0.029) and hematologic pathologies (p=0.047), and the need for hospitalization at time of the wrist FF (p=0.018).

No associations were found between the age at the wrist fracture time, number of drugs taken daily nor its type (anxiolytics, antiepileptics, corticoids), previous fractures (and localization), overweight/obesity and other cardiovascular risk factors, endocrinopathies, psychiatric or neurologic disease or other comorbidities.

After adjustment for age, gender, anti-osteoporotic treatment and comorbidities, the main predictors of a new FF were visits to the ED for falls (p=0.005), chronic pulmonary disease (p=0.040), hematologic pathologies (p=0.004) and need for hospitalization (p=0.040) (table 1).

Table 1.

Multivariate analyses: linear multiple regression for predictive factors of new fragility fracture.

DeterminantsUnstandardized CoefficientsBStandardized Coefficients Beta95.0% CIp-valueAge-0.0250.9750.924 – 1.030NSGender2.0657.8890.757 – 82.165NSNumber of comorbidities0.1861.2040.846 – 1.713NSVisits to the emergency service for falls-2.1360.1180.026 – 0.5290.005Chronic pulmonary disease-1.3260.2660.075 – 0.9400.040Hematologic pathologies-4.2960.0140.001 – 0.2550.004Need for hospitalization-2.7640.0630.004 – 0.8870.040Anti-osteoporotic treatment0.1571.1700.227 – 6.017NS

CI: Confidence Interval; NS: non-significant;

Conclusion:

Certain comorbidities seem to be associated with new FF. Patients with visits to the emergency service after falls and those who needed hospitalization due to the wrist fracture were more prone to have a new FF. There might be a substantial missed opportunity for intervention in these patients.

References:

[1]Osteoporosis: assessing the risk of fragility fracture. London: National Institute for Health and Care Excellence (UK); 2017 Feb. PMID: 32186835.

[2]Crandall CJ, Hovey KM, Cauley JA, Andrews CA, Curtis JR, Wactawski-Wende J, Wright NC, Li W, LeBoff MS. Wrist Fracture and Risk of Subsequent Fracture: Findings from the Women’s Health Initiative Study. Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research. 2015;30(11):2086–2095. doi: 10.1002/jbmr.2559.

Disclosure of Interests:

None declared

AB0799 DO WE OVERDIAGNOSE SERONEGATIVE RHEUMATOID ARTHRITIS? – THE ROLE OF MUSCULOSKELETAL ULTRASOUND IN CLARIFYING SERONEGATIVE INFLAMMATORY ARTHRITIS

Background:

Several data indicate that seronegative rheumatoid arthritis (RA-) and seropositive RA (RA+) may have different mechanisms and prognosis, being well established that rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA) have diagnostic and prognostic value. Several conditions, like peripheral spondyloarthritis (SpA), psoriatic arthritis or crystal-related arthropathies may mimic the presentation of RA. Mechanisms and treatment of each of these conditions differ significantly. The authors speculate that RA- may be overdiagnosed in the setting of seronegative chronic inflammatory arthritis and that musculoskeletal ultrasound (US) may help us to better classify these patients through the identification of characteristic lesions of the mentioned diseases.

Objectives:

To compare the frequency of US lesions found in joints and entheses between RA- and RA+ patients.

Methods:

Cross-sectional study: systematic US evaluation of ten joints, twelve entheses and both flexor and extensor tendons of four fingers (Table 1) in consecutive RA- patients. RA+ patients matched for sex and age were recruited. RA- patients included met every of the following criteria: history of chronic polyarthritis, RF and ACPA negativity, no extra-articular features of SpA or RA nor family history of SpA, no suspected crystal-related arthritis.

Results:

Twenty-one RA- patients were included and twenty RA+ patients were recruited as controls. No differences between groups were found in sex, age, body mass index, time of disease evolution or use of biological therapy.

RA- patients had a significantly higher number of entheseal structural and/or inflammatory lesions than RA+ patients (median 2.0 vs. 0.5, U 111.5, p=.008**), with triceps enthesitis being significantly more frequent in RA- patients (p=.036*). In total, 18.7% of RA- entheses had enthesitis lesions vs. only 8.3% of RA+ entheses. One RA- patient had ultrasonographic features of dactylitis which was not clinically evident.

As expected, considering the role of RF and ACPA in erosive RA, RA- patients had a significantly lower number of joints with erosions compared to RA+ patients (median 0.0 vs. 3.0, U 64.5, p<.001***), with significant differences in every considered joint. Erosions were found in 6.7% of RA- joints vs. 32.0% RA+ joints.

Additionally, two RA- patients had hyperechogenic foci in knee cartilage or carpal fibrocartilage suggestive of calcium pyrophosphate deposition.

Table 1.

Comparative frequency of ultrasound lesions found in joints and entheses of RA- and RA+ patients.

RA-(n=21)RA+(n=20)p-valueMdn number of ENTHESES with any lesion per patient ± IQR2.0 ± 3.00.5 ± 2.0.008**Triceps – n (%)8 (38.1%)2 (10.0%).036*Quadriceps – n (%)9 (42.9%)6 (30.0%).393Superior patellar – n (%)4 (19.0%)1 (5.0%).169Inferior patellar – n (%)---Achilles – n (%)9 (42.8%)4 (20.0%).116Plantar fascia – n (%)5 (23.8%)1 (5.0%).089DACTYLITIS – 2nd + 5th finger – n (%)1 (4.8%)--Mdn number of joints with EROSIONS per patient ± IQR0.0 ± 1.03.0 ± 3.0<.001***Ulnar styloid process – n (%)5 (23.8%)11 (55.0%).041*Metacarpophalangeal 2 – n (%)3 (14.3%)11 (55.0%).006**Metacarpophalangeal 5 – n (%)1 (4.8%)10 (50.0%).001**Metatarsophalangeal 1 – n (%)-3 (15.0%)-Metatarsophalangeal 5 – n (%)3 (14.3%)11 (55.0%).006**CHONDROCALCINOSIS – triangular fibrocartilage + knee – n (%)2 (9.5%)--DOUBLE CONTOUR – any joint – n (%)---

RA- – seronegative rheumatoid arthritis; RA+ – seropositive rheumatoid arthritis Mdn – median; IQR – interquartile range; n (%) – absolute number (percentage) of patients with the indicated lesion.

Conclusion:

We found that some patients diagnosed with RA- had, in fact, ultrasonographic features of different diseases, namely enthesitis/dactylitis and crystal deposition. These data suggest that RA- may be overdiagnosed in clinical practice. Systematic US evaluation of joints and entheses may provide valuable diagnostic information in patients with chronic inflammatory seronegative arthritis and improve patient care.

Disclosure of Interests:

None declared

The development of a novel functional food: bioactive lipids in yogurts enriched with Aurantiochytrium sp. biomass

Western diets are poor in healthy n3 polyunsaturated fatty acids, such as docosahexaenoic acid. Since microalga Aurantiochytrium sp. is rich in docosahexaenoic acid, a functional food based on lean yogurt and this microalga was tested. This study entailed characterizing the lipid fraction and determining the fatty acid bioaccessibility. The tested yogurts (control and 2% w/w, Aurantiochytrium sp.) had differences. Docosahexaenoic acid was not detected in the control product, but it was the second most important fatty acid in Aurantiochytrium sp. and Aurantiochytrium yogurt, 29.7 ± 0.4% and 18.7 ± 2.0%, respectively. Based on the fatty acid profile only, an amount of 158.7 g of Aurantiochytrium yogurt in wet weight terms would be required to ensure an appropriate intake of healthy fatty acids. Generally, the fatty acid bioaccessibility was not high, remaining below 60-70% in almost all cases. Considering the docosahexaenoic acid bioaccessibility (44 ± 3%), an amount of 360.7 g of Aurantiochytrium yogurt would be advisable. A reasonable dietary prescription would be a daily consumption of 125 ml of Aurantiochytrium yogurt.

Identification of N-glycan oligomannoside isomers in the diatom Phaeodactylum tricornutum

Microalgae are emerging production systems for recombinant proteins like monoclonal antibodies. In this context, the characterization of the host cell N-glycosylation machinery and of the microalgae-made biopharmaceuticals, which are mainly glycoprotein-based products, requires efficient analytical methodologies dedicated to the profiling of the N-glycans. Herein, in order to gain knowledge regarding its N-glycosylation pathway, we profile the protein N-linked oligosaccharides isolated from the diatom Phaeodactylum tricornutum that has been used successfully to produce functional monoclonal antibodies. The combination of ion mobility spectrometry-mass Spectrometry and electrospray ionization-multistage tandem mass spectrometry allows us to decipher the detailed structure of the oligomannoside isomers and to demonstrate that the processing of the oligomannosides N-linked to proteins occurs in this diatom as reported in mammals. Therefore, P. tricornutum synthesizes human-like oligomannosides in contrast to other microalgae species. This represent an advantage as an alternative ecofriendly expression system to produce biopharmaceuticals used for human therapy.

Exploring Complex Mixtures by Cyclic Ion Mobility High-Resolution Mass Spectrometry: Application Toward Petroleum

The in-depth isomeric and isobaric description of ultra-complex organic mixtures remains one of the most challenging analytical tasks. In the last two decades, ion mobility coupled to high-performance mass spectrometry added an additional structural dimension. Despite tremendous instrumental improvements, commercial devices are still limited in ion mobility and mass spectrometric resolving power and struggle to resolve isobaric species and complex isomeric patterns. To overcome these limitations, we explored the capabilities of cyclic ion mobility high-resolution mass spectrometry with special emphasis on petrochemical applications. We could show that quadrupole-selected ion mobility mass spectrometry gives closer insights into the isomeric distribution. In combination with slicing the specific parts of the ion mobility dimension, isobaric interferences could be drastically removed. Collision-induced dissociation (CID) allowed separating structural groups of polycyclic aromatic hydrocarbons and heterocycles (PAH/PASH), deploying up to 10 passes in the cyclic ion mobility device. Finally, we introduce a data processing workflow to resolve the 3.4 mDa SH₄/C₃ mass split by combining ion mobility and mass spectrometric resolving power. Cyclic ion mobility with the intelligent design of experiments and processing routines will be a powerful approach addressing the isobaric and isomeric complexity of ultra-complex mixtures.

Chromium Determination in Leather and Other Matrices: A Review

Leather industry plays an essential role in the world's economy; however, it also has a negative environmental impact due to the generation of significant quantities of wastes, some of which are classified as hazardous chemicals. Chrome tanning, the most popular tanning process, employs chromium salts, acids, and some other chemicals. Some dyes can be also a source of chromium. As a result, hexavalent chromium, a known carcinogenic and mutagenic, can be found in leather products and cause allergic dermatitis or trigger other diseases. For this reason, it is important to quantify the total amount of chromium in final leather goods, as well as the oxidation state in which this element is found. This paper aims to summarize chromium contamination due to the leather production processes, and to review the analytical methods that have been used to determine chromium's most abundant species: Cr(III) and Cr(VI) in leather and other matrices (foodstuffs, cosmetic products, environmental, and pharmaceutical samples). The international and European regulations are presented as well as the last academic developments to extract and quantify chromium species. The future outlook of pretreatment and quantification techniques are also discussed in this work, with a special focus on chromium interconversions.

Muscle metabolic remodelling patterns in Duchenne muscular dystrophy revealed by ultra-high-resolution mass spectrometry imaging

Duchenne muscular dystrophy (DMD) is a common and severe X-linked myopathy, characterized by muscle degeneration due to altered or absent dystrophin. DMD has no effective cure, and the underlying molecular mechanisms remain incompletely understood. The aim of this study is to investigate the metabolic changes in DMD using mass spectrometry-based imaging. Nine human muscle biopsies from DMD patients and nine muscle biopsies from control individuals were subjected to untargeted MSI using matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry. Both univariate and pattern recognition techniques have been used for data analysis. This study revealed significant changes in 34 keys metabolites. Seven metabolites were decreased in the Duchenne biopsies compared to control biopsies including adenosine triphosphate, and glycerophosphocholine. The other 27 metabolites were increased in the Duchenne biopsies, including sphingomyelin, phosphatidylcholines, phosphatidic acids and phosphatidylserines. Most of these dysregulated metabolites are tightly related to energy and phospholipid metabolism. This study revealed a deep metabolic remodelling in phospholipids and energy metabolism in DMD. This systems-based approach enabled exploring the metabolism in DMD in an unprecedented holistic and unbiased manner with hypothesis-free strategies.

Cyclic Ion Mobility Spectrometry Coupled to High-Resolution Time-of-Flight Mass Spectrometry Equipped with Atmospheric Solid Analysis Probe for the Molecular Characterization of Combustion Particulate Matter

Anthropogenic air pollution has a severe impact on climate and human health. The immense molecular complexity and diversity of particulate matter (PM) is a result of primary organic aerosol (POA) as well as secondary organic aerosols (SOAs). In this study, a direct inlet probe (DIP), i.e., atmospheric solids analysis probe (ASAP), with ion mobility high-resolution mass spectrometric detection is applied. Primary particulate matter emissions from three sources were investigated. Furthermore, photochemically aged emissions were analyzed. DIP introduction allowed for a direct analysis with almost no sample preparation and resulted in a complex molecular pattern. This pattern shifted through oxidation processes toward heavier species. For diesel emissions, the fuel's chemical characteristic is partially transferred to the particulate matter by incomplete combustion and characteristic alkylated series were found. Polycyclic aromatic hydrocarbons (PAHs) were identified as major contributors. Ion mobility analysis results in drift time profiles used for structural analysis. The apex position was used to prove structural changes, whereas the full-width-at-half-maximum was used to address the isomeric diversity. With this concept, the dominance of one or a few isomers for certain PAHs could be shown. In contrast, a broad isomeric diversity was found for oxygenated species. For the in-depth specification of fresh and aged spruce emissions, the ion mobility resolving power was almost doubled by allowing for three passes in the circular traveling wave design. The results prove that ASAP coupled with ion mobility spectrometry-mass spectrometry (IMS-MS) serves as a promising analytical approach for tackling the vast molecular complexity of PM.

Structural analysis of petroporphyrins from asphaltene by trapped ion mobility coupled with Fourier transform ion cyclotron resonance mass spectrometry

Molecular characterization of compounds present in highly complex mixtures such as petroleum is proving to be one of the main analytical challenges. Heavy fractions, such as asphaltenes, exhibit immense molecular and isomeric complexity. Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) with its unequalled resolving power, mass accuracy and dynamic range can address the isobaric complexity. Nevertheless, isomers remain largely inaccessible. Therefore, another dimension of separation is required. Recently, ion mobility mass spectrometry has revealed great potential for isomer description. In this study, the combination of trapped ion mobility and Fourier transform ion cyclotron resonance mass spectrometry (TIMS-FTICR) is used to obtain information on the structural features and isomeric diversity of vanadium petroporphyrins present in heavy petroleum fractions. The ion mobility spectra provided information on the isomeric diversity of the different classes of porphyrins. The determination of the collision cross section (CCS) from the peak apex allows us to hypothesize about the structural aspects of the petroleum molecules. In addition, the ion mobility signal full width at half maximum (FWHM) was used as a measure for isomeric diversity. Finally, theoretical CCS determinations were conducted first on core structures and then on alkylated petroporphyrins taking advantage of the linear correlation between the CCS and the alkylation level. This allowed the proposal of putative structures in agreement with the experimental results. The authors believe that the presented workflow will be useful for the structural prediction of real unknowns in highly complex mixtures.

Combination of UHPLC-MS/MS-molecular networking approach and FTICR-MS for the metabolic profiling of Saccharomyces cerevisiae

Natural products are a reliable source of bioactive molecules and represent an industrial and pharmaceutical stake. Indeed, the model yeast species Saccharomyces cerevisiae is a well-known eukaryotic organism largely used as a biotechnological tool, but still a topical subject of study. In this work, the exploration of Saccharomyces cerevisiae is taken further through an untargeted metabolomics workflow. The aim is to enrich databases and bring new information about the standard S. cerevisiae strain in a given medium. Analytical methods and bioinformatics tools were combined in a high-throughput methodology useable to dereplicate many types of biological extracts and cartography secondary metabolites. Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analyses were carried out and spectral data were pre-processed to build molecular networks. Annotations were attributed to compounds through comparison with databases and manual investigation of networks. Ultra-high-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS) brought additional information thanks to a higher dynamic range and enhanced UHPLC-MS/MS results by unveiling ambiguities and bringing accurate molecular formulae. Therefore, accurate and reliable annotated features resulted from the UHPLC-MS/MS data while FTICR-MS provided an overall cartography of metabolites thanks to van Krevelen diagrams. Various small molecules such as amino acids derivatives and indole alkaloids have been determined for the first time in this yeast. The complementarity of FTICR-MS and UHPLC-MS/MS for secondary metabolite annotation brought this new mapping of S. cerevisiae.

Regio- and Stereo-Specific Chemical Depolymerization of High Molecular Weight Polybutadiene and Polyisoprene for Their Analysis by High-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry: Comparison with Pyrolysis-Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry, Atmospheric Solid Analysis Probe, Direct Inlet Probe-Atmospheric Pressure Chemical Ionization Mass Spectrometry, and Ion Mobility Spectrometry-Mass Spectrometry

Polybutadiene (PB) and polyisoprene (PI), the two most common polydienes (PD), are involved in a large number of materials and used in a wide variety of applications. The characterization of these polymers by mass spectrometry (MS) continues to be very challenging due to their high insolubility and the difficulty to ionize them. In this work, a cross-metathesis reaction was used to generate end-functionalized acetoxy ionizable oligomers for the structural deciphering of different commercial PB and PI samples. A cross-metathesis reaction was carried out between polymers and the Z-1,4-diacetoxy-2-butene as a chain transfer agent in dichloromethane using a Hoveyda-Grubbs second-generation catalyst. Well-defined acetoxy telechelic structures were obtained and analyzed by Fourier transform ion cyclotron resonance (FTICR) high-resolution MS. However, after depolymerization, low molar mass polyolefins contained some units with different configurations, suggesting an olefin isomerization reaction due to the decomposition of the catalyst. The addition of an electron-deficient reagent such as 2,6-dichloro-1,4-benzoquinone suppressed this isomerization in the case of both Z- and E-PB and PI. Ion mobility spectrometry-mass spectrometry (IMS-MS) and energy-resolved tandem mass spectrometry (ERMS) analyses confirmed a successful isomerization suppression. For comparing the results obtained by depolymerization with classical methods for polymer analysis, pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC × GC-MS), atmospheric solid analysis probe (ASAP), and direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI) analyses were performed on the same polymers. This strategy can be applied on a variety of synthetic and natural not yet characterized polymers.