Deep Characterisation of the sn-Isomer Lipidome Using High-Throughput Data-Independent Acquisition and Ozone-Induced Dissociation.

In recent years there has been a significant interest in the development of innovative lipidomics techniques capable of resolving lipid isomers. To date, methods applied to resolving sn-isomers have resolved only a limited number of species. We report a workflow based on ozone-induced dissociation for untargeted characterisation of hundreds of sn-resolved glycerophospholipid isomers from biological extracts in under 20 min, coupled with an automated data analysis pipeline. It provides an order of magnitude increase in the number of sn-isomer pairs identified as compared to previous reports and reveals that sn-isomer populations are tightly regulated and significantly different between cell lines. The sensitivity of this method and potential for de novo molecular discovery is further demonstrated by the identification of unexpected lipids containing ultra-long monounsaturated acyl chains at the sn-1 position.

Ultrahigh-Mass Resolution Mass Spectrometry Imaging with an Orbitrap Externally Coupled to a High-Performance Data Acquisition System.

Matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) is a powerful analytical tool that enables molecular sample analysis while simultaneously providing the spatial context of hundreds or even thousands of analytes. However, because of the lack of a separation step prior to ionization and the immense diversity of biomolecules, such as lipids, including numerous isobaric species, the coupling of ultrahigh mass resolution (UHR) with MSI presents one way in which this complexity can be resolved at the spectrum level. Until now, UHR MSI platforms have been restricted to Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers. Here, we demonstrate the capabilities of an Orbitrap-based UHR MSI platform to reach over 1,000,000 mass resolution in a lipid mass range (600-950 Da). Externally coupling the Orbitrap Q Exactive HF with the high-performance data acquisition system FTMS Booster X2 provided access to the unreduced data in the form of full-profile absorption-mode FT mass spectra. In addition, it allowed us to increase the time-domain transient length from 0.5 to 10 s, providing improvement in the mass resolution, signal-to-noise ratio, and mass accuracy. The resulting UHR performance generates high-quality MALDI MSI images and simplifies the identification of lipids. Collectively, these improvements resulted in a 1.5-fold increase in annotations, demonstrating the advantages of this UHR imaging platform for spatial lipidomics using MALDI-MSI.

Progressive interstitial lung disease in a clinically quiescent dermatomyositis

@#A 60-year-old Filipino woman diagnosed with dermatomyositis was initially on prednisone and methotrexate. She eventually developed interstitial lung disease (ILD) and so methotrexate was shifted to azathioprine; however, azathioprine was discontinued due to cutaneous tuberculosis. Over eight years, the dermatomyositis was controlled by prednisone alone but the ILD worsened. This case demonstrated that the course of ILD may be independent of dermatomyositis.

Mass Spectrometry Imaging of Lipids Using MALDI Coupled with Plasma-Based Post-Ionization on a Trapped Ion Mobility Mass Spectrometer.

Here we report the development and optimization of a mass spectrometry imaging (MSI) platform that combines an atmospheric-pressure matrix-assisted laser desorption/ionization platform with plasma postionization (AP-MALDI-PPI) and trapped ion mobility spectrometry (TIMS). We discuss optimal parameters for operating the source, characterize the behavior of a variety of lipid classes in positive- and negative-ion modes, and explore the capabilities for lipid imaging using murine brain tissue. The instrument generates high signal-to-noise for numerous lipid species, with mass spectra sharing many similarities to those obtained using laser postionization (MALDI-2). The system is especially well suited for detecting lipids such as phosphatidylethanolamine (PE), as well as numerous sphingolipid classes and glycerolipids. For the first time, the coupling of plasma-based postionization with ion mobility is presented, and we show the value of ion mobility for the resolution and identification of species within rich spectra that contain numerous isobaric/isomeric signals that are not resolved in the m/z dimension alone, including isomeric PE and demethylated phosphatidylcholine lipids produced by in-source fragmentation. The reported instrument provides a powerful and user-friendly approach for MSI of lipids.

Erasmus Syndrome: A Case Report and Literature Review.

BACKGROUND Erasmus syndrome is a rare disease entity characterized by the development of systemic sclerosis (SSc) in a background of silica exposure or silicosis. CASE REPORT We report the case of a 40-year-old Filipino man who previously worked in a silica grind mill for 10 years and eventually developed Erasmus syndrome. The patient initially presented with chronic back pain in 2018 associated with findings of pulmonary tuberculosis on chest X-ray, with notable improvement after 6 months of anti-tuberculosis treatment. However, his back pain recurred in 2021; this time with arthralgia, Raynaud's phenomenon, thickening of both hands, skin hypopigmentation on the chest, back, and forehead, and exertional dyspnea. Physical examination revealed salt-and-pepper dermopathy and skin tightening over the back, chest, and extremities. Mobility of his hands was limited, associated with sclerodactyly and digital pitting. Antinuclear antibody-immunofluorescence and anti-scleroderma-70 antibodies were strongly positive, confirming the diagnosis of SSc. Chest computed tomography illustrated multiple subcentimeter nodules and enlarged mediastinal lymph nodes with eggshell calcifications, consistent with silicosis. Spirometry with body plethysmography was normal but diffusing capacity for carbon monoxide was severely reduced. Histopathology of the skin showed markedly thickened collagen bundles in the dermis. CONCLUSIONS Chronic silica exposure is a risk factor for the development of silicosis. The clinical course of patients with silicosis may be complicated by SSc. Maintaining a high index of suspicion is key to the diagnosis of Erasmus syndrome. The present report emphasizes the importance of preventive measures and surveillance among those with occupational exposure to silica. To our knowledge, this is the first documented case of Erasmus syndrome in the Philippines.

Pterygium and Ocular Surface Squamous Neoplasia: Optical Biopsy Using a Novel Autofluorescence Multispectral Imaging Technique.

In this study, differentiation of pterygium vs. ocular surface squamous neoplasia based on multispectral autofluorescence imaging technique was investigated. Fifty (N = 50) patients with histopathological diagnosis of pterygium (PTG) and/or ocular surface squamous neoplasia (OSSN) were recruited. Fixed unstained biopsy specimens were imaged by multispectral microscopy. Tissue autofluorescence images were obtained with a custom-built fluorescent microscope with 59 spectral channels, each with specific excitation and emission wavelength ranges, suitable for the most abundant tissue fluorophores such as elastin, flavins, porphyrin, and lipofuscin. Images were analyzed using a new classification framework called fused-classification, designed to minimize interpatient variability, as an established support vector machine learning method. Normal, PTG, and OSSN regions were automatically detected and delineated, with accuracy evaluated against expert assessment by a specialist in OSSN pathology. Signals from spectral channels yielding signals from elastin, flavins, porphyrin, and lipofuscin were significantly different between regions classified as normal, PTG, and OSSN (p < 0.01). Differential diagnosis of PTG/OSSN and normal tissue had accuracy, sensitivity, and specificity of 88 ± 6%, 84 ± 10% and 91 ± 6%, respectively. Our automated diagnostic method generated maps of the reasonably well circumscribed normal/PTG and OSSN interface. PTG and OSSN margins identified by our automated analysis were in close agreement with the margins found in the H&E sections. Such a map can be rapidly generated on a real time basis and potentially used for intraoperative assessment.

Pulmonary Function and Chest Computed Tomography (CT) Scan Findings After Antifibrotic Treatment for COVID-19-Related Pulmonary Fibrosis.

BACKGROUND Physicians worldwide have been reporting many cases of COVID-19-induced pulmonary fibrosis. We report the case of a 51-year-old Filipino asthmatic woman who developed post-COVID-19 pulmonary fibrosis subsequently treated with Nintedanib. CASE REPORT The patient presented with a 4-day history of flu-like symptoms in September 2020 and was eventually diagnosed with severe COVID-19 pneumonia. Despite receiving Dexamethasone, Tocilizumab, Remdesivir, and multiple antibiotics, there was increasing oxygen requirement, necessitating ICU admission and high-flow nasal cannula (HFNC). An additional course of hydrocortisone was given due to asthma exacerbation, gradually liberating her from the HFNC. A chest CT scan showed extensive parenchymal changes, for which she received methylprednisolone and physical rehabilitation with persistence of respiratory symptoms. After 40 days of hospitalization, she was sent home on oxygen support and Nintedanib. The patient initially had severe dyspnea (Borg Scale 7) with 6-minute walk distance (6MWD) of 295 meters. Pulmonary function showed moderately severe restrictive lung defect at 52% predicted total lung capacity (TLC) and severely reduced DLCO (28% predicted). Chest CT scoring indicated severe lung involvement. One month after Nintedanib treatment, her Borg Scale improved to 4. Her 6MWD, TLC, and DLCO increased to 434 meters, 64% predicted, and 36% predicted, respectively. A chest CT scan showed regressing fibrosis. After 6 months of treatment, her pulmonary function normalized. DLCO remained moderately reduced (59% predicted) but her 6MWD (457 meters) and CT scan results continued to improve. CONCLUSIONS Nintedanib, along with other interventions, may have potentially improved pulmonary function and CT scan findings in a COVID-19 survivor with pulmonary fibrosis 6 months after treatment.

Imaging of colonic diverticular disease.

Diverticular disease affects approximately two thirds of the population over the age of 70. While only a small fraction of these patients will develop diverticulitis, adequate radiological evaluation of diverticulitis and its complications is imperative in determining proper medical and surgical treatment. Clinical examination and laboratory tests alone have been found to be inaccurate in defining many aspects of the disease in up to 60% of cases. Over the past 30 years, contrast enema, computed tomography, and ultrasound have all been used extensively to diagnose the complications of diverticular disease. More recently, magnetic resonance imaging has been studied in patients with complicated diverticulitis. This article reviews the use of these different radiological modalities in diagnosing acute colonic diverticulitis and its complications.