External Validation of SAFE Score to Predict Atrial Fibrillation Diagnosis after Ischemic Stroke: A Retrospective Multicenter Study.

Introduction: The screening for atrial fibrillation (AF) scale (SAFE score) was recently developed to provide a prediction of the diagnosis of AF after an ischemic stroke. It includes 7 items: age ≥ 65 years, bronchopathy, thyroid disease, cortical location of stroke, intracranial large vessel occlusion, NT-ProBNP ≥250 pg/mL, and left atrial enlargement. In the internal validation, a good performance was obtained, with an AUC = 0.88 (95% CI 0.84-0.91) and sensitivity and specificity of 83% and 80%, respectively, for scores ≥ 5. The aim of this study is the external validation of the SAFE score in a multicenter cohort. Methods: A retrospective multicenter study, including consecutive patients with ischemic stroke or transient ischemic attack between 2020 and 2022 with at least 24 hours of cardiac monitoring. Patients with previous AF or AF diagnosed on admission ECG were excluded. Results: Overall, 395 patients were recruited for analysis. The SAFE score obtained an AUC = 0.822 (95% CI 0.778-0.866) with a sensitivity of 87.2%, a specificity of 65.4%, a positive predictive value of 44.1%, and a negative predictive value of 94.3% for a SAFE score ≥ 5, with no significant gender differences. Calibration analysis in the external cohort showed an absence of significant differences between the observed values and those predicted by the model (Hosmer-Lemeshow's test 0.089). Conclusions: The SAFE score showed adequate discriminative ability and calibration, so its external validation is justified. Further validations in other external cohorts or specific subpopulations of stroke patients might be required.

A Pilot Nurse-Administered CBT Intervention for Insomnia in Patients with Schizophrenic Disorder: A Randomized Clinical Effectiveness Trial.

Insomnia is a highly prevalent disorder among the population with schizophrenia and has a significant impact on their quality of life. Cognitive behavioural therapies (CBT) have shown effectiveness in the treatment of insomnia in the general population. The aim of this this pilot study was to evaluate the effectiveness of a group intervention led by nurses in an outpatient mental health centre. The group work combined cognitive behavioural and psychoeducational therapeutic interventions to improve insomnia in patients with schizophrenic disorder and their health-related quality of life. This randomized clinical trial included intervention and control groups with follow-up assessments at 6 and 9 months, using the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and EuroQol-5D (EQ-5D) scales. The inclusion criteria were as follows: over 18 years of age, diagnosis of schizophrenia, and a score of >7 on the ISI scale. The total sample was 40 participants. The ISI scale showed a mean difference of 3.63 (CI 95%: 2.02-5.23) (p = 0.000) and 4.10 (CI 95%: 2.45-5.75) (p = 0.000) and a large effect size (F: 28.36; p = 0.000; ηp2: 0.427). Regarding the PSQI scale, the mean difference was 3.00 (CI 95%: 1.53-4.49) (p = 0.000) and 2.30 (CI 95%: 0.85-3.75) (p = 0.000), with a medium effect size (F: 18.31; p = 0.000 ηp2: 0.325). The EQ-VAS scale showed a difference in mean scores between the groups of 10.48 (CI 95%: -19.66--1.29) (p = 0.027). CBT adapted for populations with mental disorders, carried out by nurses, is effective in improving insomnia and health-related quality of life.

Assessment of the periodontal health status and gingival recession during orthodontic treatment with clear aligners and fixed appliances: A systematic review and meta-analysis

Background: The aim was to assess periodontal health maintenance and gingival recessions development in patients undergoing an orthodontic treatment with clear aligners (CA) and fixed appliances (FA). Material and methods: An electronic search in MEDLINE, Scopus, The Cochrane Library, and Web of Science was performed up to September 2022 to identify all potential articles. Two investigators independently selected the studies according to the inclusion criteria. Prospective and retrospective studies assessing the periodontal health status and gingival recession development during the orthodontic treatment with buccal FA and CA were included. Case series, cross-sectional studies, and studies with less than two months of follow-up were excluded. Two investigators independently extracted the data from included articles and assessed risk of bias across studies using the Cochrane Collaboration tool. Qualitative and quantitative analyses of the data were performed. Pairwise meta-analysis using a random-effects model were used to compare periodontal indices between FA and CA treatment in different follow-up periods. Results: From the 129 potential studies, finally 12 studies were included. Only 8 could be included in the quantitative analysis. CA seems to slightly maintain better periodontal health indices. Only plaque index in a mid-term follow-up (mean difference (MD): -0.99; 95%; Confidence interval (CI) [-1.94 to -0.03]; P=.04; I2=99%), and pocket probing depth at a long-term follow-up (MD: -0.93mm; 95% CI [-1.16 to 0.7]; P<0.0001) reported statistically significant results favoring CA. Conclusions: Up to the date there is not enough evidence to conclude that CA maintains better periodontal health during an orthodontic treatment than FA. (AU)

Charge-controlled Pd catalysis enables the meta-C-H activation and olefination of arenes.

The regioselective C-H activation of arenes remains one of the most promising techniques for accessing highly important functionalized motifs. Such functionalizations can generally be achieved through directed and non-directed processes. The directed approach requires a covalently attached directing group (DG) on the substrate to induce reactivity and selectivity and therefore intrinsically leaves a functional group at the point of attachment within the molecule, even after the tailored DG has been removed. Conversely, non-directed methods typically suffer from regioselectivity issues, especially for unbiased substrates. Herein, we report a unique approach that employs weak charge-charge and charge-dipole interactions to enable the meta-selective activation and olefination of arenes to address these challenges in Pd catalysis. The charged moiety can easily be converted to uncharged simple arenes by hydrogenation or cross-coupling. In-depth mechanistic studies prove that the charge is responsible for the observed selectivity. We expect our studies to be generalizable and thereby enable further regioselective transformations.

Stroke in Young Adults in Spain: Epidemiology and Risk Factors by Age.

INTRODUCTION: Recent research has highlighted an increased incidence of ischemic stroke (IS) in young adults, along with a higher percentage of vascular risk factors at younger ages. This study aimed to estimate the in-hospital incidence of IS and associated comorbidities by sex and age group in Spain. METHODS: A retrospective analysis of the Spain Nationwide Inpatient Sample database from 2016 to 2019 was conducted, which included adult patients with IS. In-hospital incidence and mortality rates were estimated, and a descriptive analysis of the main comorbidities was performed, stratified by sex and age groups. RESULTS: A total of 186,487 patients were included, with a median age of 77 (IQR 66-85) years and 53.3% were male. Of these, 9162 (5%) were aged between 18 and 50 years. The estimated incidence of IS in adults younger than 50 years ranged from 11.9 to 13.5 per 100,000 inhabitants during the study period, with a higher incidence in men. The overall in-hospital mortality was 12.6%. Young adults with IS had a higher prevalence of most vascular risk factors compared to the general Spanish population, with a specific distribution according to sex and age. CONCLUSIONS: This study provides estimates of the incidence of IS and the prevalence of vascular risk factors and comorbidities associated with IS in Spain, stratified by sex and age, using a national registry of hospital admissions. These findings should be considered in terms of both primary and secondary prevention strategies.

Sphingolipid Long-Chain Base Signaling in Compatible and Non-Compatible Plant-Pathogen Interactions in Arabidopsis.

The chemical diversity of sphingolipids in plants allows the assignment of specific roles to special molecular species. These roles include NaCl receptors for glycosylinositolphosphoceramides or second messengers for long-chain bases (LCBs), free or in their acylated forms. Such signaling function has been associated with plant immunity, with an apparent connection to mitogen-activated protein kinase 6 (MPK6) and reactive oxygen species (ROS). This work used in planta assays with mutants and fumonisin B1 (FB1) to generate varying levels of endogenous sphingolipids. This was complemented with in planta pathogenicity tests using virulent and avirulent Pseudomonas syringae strains. Our results indicate that the surge of specific free LCBs and ceramides induced by FB1 or an avirulent strain trigger a biphasic ROS production. The first transient phase is partially produced by NADPH oxidase, and the second is sustained and is related to programmed cell death. MPK6 acts downstream of LCB buildup and upstream of late ROS and is required to selectively inhibit the growth of the avirulent but not the virulent strain. Altogether, these results provide evidence that a LCB- MPK6- ROS signaling pathway contributes differentially to the two forms of immunity described in plants, upregulating the defense scheme of a non-compatible interaction.

Central Sensitization and Chronic Pain Personality Profile: Is There New Evidence? A Case-Control Study.

BACKGROUND: Personality traits are relevant for pain perception in persistent pain disorders, although they have not been studied in depth in sensitized and nonsensitized patients with knee osteoarthritis (OA). OBJECTIVE: To explain and compare the personality profile of patients with OA, with and without central sensitization (CS), and fibromyalgia (FM). SETTING: Participants were selected at the Rheumatology Department in two major hospitals in Spain. PARTICIPANTS: Case-control study where the sample consists of 15 patients with OA and CS (OA-CS), 31 OA without CS (OA-noCS), 47 FM, and 22 controls. We used a rigorous and systematic process that ensured the sample strictly fulfilled all the inclusion/exclusion criteria, so the sample is very well delimited. PRIMARY OUTCOME MEASURES: Personality was assessed by the Temperament and Character Inventory of Cloninger. RESULTS: The percentile in harm-avoidance dimension for the FM group is higher compared to OA groups and controls. The most frequent temperamental profiles in patients are cautious, methodical, and explosive. Patients with FM are more likely to report larger scores in harm-avoidance, with an increase in logistic regression adjusted odds ratio (ORadj) between 4.2% and 70.2%. CONCLUSIONS: Harm-avoidance seems to be the most important dimension in personality patients with chronic pain, as previously found. We found no differences between OA groups and between sensitized groups, but there are differences between FM and OA-noCS, so harm-avoidance might be the key to describe personality in patients with CS rather than the presence of prolonged pain, as found in the literature before.

FK506 binding protein 51: Its role in the adipose organ and beyond.

There is a great body of evidence that the adipose organ plays a central role in the control not only of energy balance, but importantly, in the maintenance of metabolic homeostasis. Interest in the study of different aspects of its physiology grew in the last decades due to the pandemic of obesity and the consequences of metabolic syndrome. It was not until recently that the first evidence for the role of the high molecular weight immunophilin FK506 binding protein (FKBP) 51 in the process of adipocyte differentiation have been described. Since then, many new facets have been discovered of this stress-responsive FKBP51 as a central node for precise coordination of many cell functions, as shown for nuclear steroid receptors, autophagy, signaling pathways as Akt, p38 MAPK, and GSK3, as well as for insulin signaling and the control of glucose homeostasis. Thus, the aim of this review is to integrate and discuss the recent advances in the understanding of the many roles of FKBP51 in the adipose organ.

Xanthinuria secondary to allopurinol treatment in dogs with leishmaniosis: Current perspectives of the Iberian veterinary community.

Xanthinuria is a significant adverse effect in dogs on long-term allopurinol for treatment of leishmaniosis. The study aims to investigate how the Iberian veterinary community (IVC) identifies, manages, and proactively prevents xanthinuria secondary to allopurinol treatment. A cross-sectional study was conducted using an online survey, translated into two languages, and disseminated to the IVC via social networking forums. Respondents were asked to share their treatment regimens, adverse effects attributed to treatment, as well as preventive and reactive measures against xanthuria. Of two-hundred and thirty respondents, 99.6% prescribe allopurinol for canine leishmaniosis. Xanthinuria was estimated to happen in less than one out of every four dogs by 91.7% of the clinicians. Xanthinuria has been detected by 71.6% of respondents at least once. Three out of every four respondents inform owners about deleterious effects of allopurinol, and 28.4% consider implementing a change in diet in advance of treatment as a proactive measure. To monitor xanthinuria, urinalysis and diagnostic imaging are used by 71.2% and 31% of clinicians respectively. When xanthinuria is detected, 43.2% of the respondents discontinue allopurinol, 24% replace it by nucleotide-analogs, 14.9% reduce its dosage, and 3.1% split its dosage but increase administration frequency. Additional measures are taken by 72.1% of the respondents, 59.4% of whom prescribe a low-purine diet. The IVC recognizes xanthinuria as a fairly common secondary effect of long-term allopurinol treatment in dogs with leishmaniosis and recommends periodically monitoring and preventive measures.

Association of gastric lymphofollicular hyperplasia with Helicobacter-like organisms in dogs.

BACKGROUND: The relationships among gastric lymphoid follicular hyperplasia (GLFH), Helicobacter-like organisms (HLOs), and clinical signs have not been established in dogs. OBJECTIVES: To evaluate the epidemiologic, clinical, endoscopic, and histopathologic findings associated with GLFH in dogs, and determine the association of GLFH with HLOs and the French Bulldog (FB) breed. ANIMALS: Two hundred eighty-eight dogs that underwent gastroscopy between 2013 and 2016. METHODS: Retrospective, cross-sectional study. Gastric biopsy samples were reviewed and scored for inflammation and HLOs. Dogs were divided into 3 groups: group 1 (63 FBs), group 2 (45 non-FB brachycephalic dogs), and group 3 (180 nonbrachycephalic dogs). Variables were evaluated for their association with GLFH. RESULTS: Univariate analysis determined that intact males, young age, vomiting, gastroscopic findings (discoloration, hemorrhage, and ulcers), and histopathologic findings (gastric lamina propria lymphocytic infiltration and HLO score) were associated with GLFH (P ≤ .03). In the multivariate analysis, GLFH was associated with the HLO score (odds ratio [OR] > 5 for HLO scores 1-2 and >15 for HLO score of 3; P < .001), with vomiting (OR > 4; P = .01) but not with FB breed (P = .76) and age (P = .1). The HLO score was associated with younger age (P < .001). CONCLUSION AND CLINICAL IMPORTANCE: The HLO score was associated with a high GLFH score. Vomiting was associated with GLFH. Helicobacter-like organisms are highly prevalent in young dogs and GLFH is indirectly associated with this factor. Clinical relevance of the identification of GLFH and HLO remains to be determined.

Use of Deoxycorticosterone Pivalate by Veterinarians: A Western European Survey.

This study aims to gather knowledge about the use of deoxycorticosterone pivalate (DOCP) by Western European Veterinarians (WEV) in dogs with typical hypoadrenocorticism. An observational cross-sectional study was conducted using an online survey, translated into four languages and disseminated to veterinary affiliates and mailing lists in six countries of Western Continental Europe. Respondents were tasked to share their therapeutic approach to hypoadrenocorticism, whether they preferred DOCP or fludrocortisone and the specific practical use of DOCP. One-hundred and eighty-four responses were included. Of these, 79.9% indicated that they preferred prescribing DOCP over fludrocortisone as a first-line treatment for mineralocorticoid supplementation. A total of 154 respondents had used DOCP at least once. Eighty percent of those who reported their initial dosage prescribed 2.2 mg/kg. After starting DOCP, 68.2% of the respondents assess electrolytes 10 and 25 days after administration following manufacturer instructions. In stable dogs, electrolytes are monitored quarterly, monthly, semi-annually, and annually by 44.2%, 34.4%, 16.9%, and 4.6% of respondents respectively. When treatment adjustment is required, 53% prefer to reduce dosage while 47% increase the interval between doses. Overall, DOCP is the preferred mineralocorticoid supplementation among WEV. Reported variability underlies the need to investigate the best strategies for DOCP use and therapeutic adjustments.

Arabidopsis thaliana eIF4E1 and eIF(iso)4E Participate in Cold Response and Promote Translation of Some Stress-Related mRNAs.

Plant defense and adaptation to adverse environmental conditions rely on gene expression control, such as mRNA transcription, processing, stability, and translation. Sudden temperature changes are common in the era of global warming; thus, understanding plant acclimation responses at the molecular level becomes imperative. mRNA translation initiation regulation has a pivotal role in achieving the synthesis of the appropriate battery of proteins needed to cope with temperature stress. In this study, we analyzed the role of translation initiation factors belonging to the eIF4E family in Arabidopsis acclimation to cold temperatures and freezing tolerance. Using knockout (KO) and overexpressing mutants of AteIF4E1 or AteIF(iso)4E, we found that AteIF4E1 but not AteIF(iso)4E overexpressing lines displayed enhanced tolerance to freezing without previous acclimation at 4°C. However, KO mutant lines, eif(iso)4e-1 and eif4e1-KO, were more sensitive to the stress. Cold acclimation in wild-type plants was accompanied by increased levels of eIF4E1 and eIF(iso)4E transcript levels, polysomes (P) enrichment, and shifts of these factors from translationally non-active to active fractions. Transcripts, previously found as candidates for eIF(iso)4E or eIF4E1 selective translation, changed their distribution in both P and total RNA in the presence of cold. Some of these transcripts changed their polysomal distribution in the mutant and one eIF4E1 overexpressing line. According to this, we propose a role of eIF4E1 and eIF(iso)4E in cold acclimation and freezing tolerance by regulating the expression of stress-related genes.

Plasma Membrane Fluidity: An Environment Thermal Detector in Plants.

The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exhibiting mesomorphism, which contributes to the membrane fluidity changes in response to temperature fluctuation. As sessile organisms, plants must rapidly and accurately respond to environmental thermal variations. However, mechanisms underlying temperature perception in plants are poorly understood. We studied the thermal plasticity of membrane fluidity using three fluorescent probes across a temperature range of -5 to 41 °C in isolated microsomal fraction (MF), vacuolar membrane (VM), and plasma membrane (PM) vesicles from Arabidopsis plants. Results showed that PM were highly fluid and exhibited more phase transitions and hysteresis, while VM and MF lacked such attributes. These findings suggest that PM is an important cell hub with the capacity to rapidly undergo fluidity modifications in response to small changes of temperatures in ranges spanning those experienced in natural habitats. PM fluidity behaves as an ideal temperature detector: it is always present, covers the whole cell, responds quickly and with sensitivity to temperature variations, functions with a cell free-energy cost, and it is physically connected with potential thermal signal transducers to elicit a cell response. It is an optimal alternative for temperature detection selected for the plant kingdom.

Accelerating the crystallization kinetics of linear polylactides by adding cyclic poly (L-lactide): Nucleation, plasticization and topological effects.

Polylactide is one of the most versatile biopolymers, but its slow crystallization limits its temperature usage range. Hence finding ways to enhance it is crucial to widen its applications. Linear and cyclic poly (L-lactide) (l-PLLA and c-PLLA) of similarly low molecular weights (MW) were synthesized by ring-opening polymerization of L-lactide, and ring-expansion methodology, respectively. Two types of blends were prepared by solution mixing: (a) l-PLLA/c-PLLA, at extreme compositions (rich in linear or in cyclic chains), and (b) blends of each of these low MW materials with a commercial high MW linear PLA. The crystallization of the different blends was evaluated by polarized light optical microscopy and differential scanning calorimetry. It was found, for the first time, that in the l-PLLA rich blends, small amounts of c-PLLA (i.e., 5 and 10 wt%) increase the nucleation density, nucleation rate (1/τ0), spherulitic growth rate (G), and overall crystallization rate (1/τ50%), when compared to neat l-PLLA, due to a synergistic effect (i.e., nucleation plus plasticization). In contrast, the opposite effect was found in the c-PLLA rich blends. The addition of small amounts of l-PLLA to a matrix of c-PLLA chains causes a decrease in the nucleation density, 1/τ0, G, and 1/τ50% values, due to threading effects between cyclic and linear chains. Small amounts of l-PLLA and c-PLLA enhance the crystallization ability of a commercial high MW linear PLA without affecting its melting temperature. The l-PLLA only acts as a plasticizer for the PLA matrix, whereas c-PLLA has a synergistic effect in accelerating the crystallization of PLA that goes beyond simple plasticization. The addition of small amounts of c-PLLA affects not only PLA crystal growth but also its nucleation due to the unique cyclic chains topology.

MPK6 Kinase Regulates Plasma Membrane H+-ATPase Activity in Cold Acclimation.

Cold and freezing stresses severely affect plant growth, development, and survival rate. Some plant species have evolved a process known as cold acclimation, in which plants exposed to temperatures above 0 °C trigger biochemical and physiological changes to survive freezing. During this response, several signaling events are mediated by transducers, such as mitogen activated protein kinase (MAPK) cascades. Plasma membrane H+-ATPase is a key enzyme for the plant cell life under regular and stress conditions. Using wild type and mpk3 and mpk6 knock out mutants in Arabidopsis thaliana, we explored the transcriptional, translational, and 14-3-3 protein regulation of the plasma membrane H+-ATPase activity under the acclimation process. The kinetic analysis revealed a differential profiling of the H+-ATPase activity depending on the presence or absence of MPK3 or MPK6 under non-acclimated or acclimated conditions. Negative regulation of the plasma membrane H+-ATPase activity was found to be exerted by MPK3 in non-acclimated conditions and by MPK6 in acclimated conditions, describing a novel form of regulation of this master ATPase. The MPK6 regulation involved changes in plasma membrane fluidity. Moreover, our results indicated that MPK6 is a critical regulator in the process of cold acclimation that leads to freezing tolerance and further survival.

Effects of MPK3 and MPK6 kinases on the chloroplast architecture and function induced by cold acclimation in Arabidopsis.

Exposure to low, non-freezing temperatures develops freezing tolerance in many plant species. Such process is called cold acclimation. Molecular changes undergone during cold acclimation are orchestrated by signalling networks including MAP kinases. Structure and function of chloroplasts are affected by low temperatures. The aim of this work was to study how the MAP kinases MPK3 and MPK6 are involved in the chloroplast performance upon a long period of cold acclimation. We used Arabidopsis thaliana wild type and mpk3 and mpk6 mutants. Adult plants were acclimated during 7 days at 4 °C and then measurements of PSII performance and chloroplast ultrastructure were carried out. Only the mpk6 acclimated plants showed a high freezing sensitivity. No differences in the PSII function were observed in the plants from the three genotypes exposed to non-acclimated or acclimated conditions. The acclimation of wild-type plants produced severe alterations in the ultrastructure of chloroplast and thylakoids, which was more accentuated in the mpk plants. However, only the mpk6 mutant was unable to internalize the damaged chloroplasts into the vacuole. These results indicate that cold acclimation induces alterations in the chloroplast architecture leading to preserve an optimal performance of PSII. MPK3 and MPK6 are necessary to regulate these morphological changes, but besides, MPK6 is needed to the vacuolization of the damaged chloroplasts, suggesting a role in the chloroplast recycling during cold acclimation. The latter could be quite relevant, since it could explain why this mutant is the only one showing an extremely low freezing tolerance.

Efficiency of Machine Learning Algorithms for the Determination of Macrovesicular Steatosis in Frozen Sections Stained with Sudan to Evaluate the Quality of the Graft in Liver Transplantation.

Liver transplantation is the only curative treatment option in patients diagnosed with end-stage liver disease. The low availability of organs demands an accurate selection procedure based on histological analysis, in order to evaluate the allograft. This assessment, traditionally carried out by a pathologist, is not exempt from subjectivity. In this sense, new tools based on machine learning and artificial vision are continuously being developed for the analysis of medical images of different typologies. Accordingly, in this work, we develop a computer vision-based application for the fast and automatic objective quantification of macrovesicular steatosis in histopathological liver section slides stained with Sudan stain. For this purpose, digital microscopy images were used to obtain thousands of feature vectors based on the RGB and CIE L*a*b* pixel values. These vectors, under a supervised process, were labelled as fat vacuole or non-fat vacuole, and a set of classifiers based on different algorithms were trained, accordingly. The results obtained showed an overall high accuracy for all classifiers (>0.99) with a sensitivity between 0.844 and 1, together with a specificity >0.99. In relation to their speed when classifying images, KNN and Naïve Bayes were substantially faster than other classification algorithms. Sudan stain is a convenient technique for evaluating ME in pre-transplant liver biopsies, providing reliable contrast and facilitating fast and accurate quantification through the machine learning algorithms tested.

Two patients with rituximab associated low gammaglobulin levels and relapsed covid-19 infections treated with convalescent plasma.

Patients with haematological malignancies are considered to be a risk group for developing severe Coronavirus disease (Covid-19). Because of the limitations of therapeutic options, the development of new treatment strategies is mandatory, such as convalescent plasma (CP). Herein we report the use of CP therapy as an off-label indication in two lymphoma patients with relapsed COVID-19 in the setting of low gammaglobulin levels because of previous rituximab chemo-immunotherapy. Both were PCR positive for SARS-CoV-2 but had an absence of antibodies to the virus more than one month later of symptoms initiation. They developed important respiratory and neurological complications. After CP infusion, neutralising antibodies were detected and viral load dissapeared in both patients leading to clinical improvement with no more Covid-19 relapse.

Plasma and vacuolar membrane sphingolipidomes: composition and insights on the role of main molecular species.

Lipid structures affect membrane biophysical properties such as thickness, stability, permeability, curvature, fluidity, asymmetry, and interdigitation, contributing to membrane function. Sphingolipids are abundant in plant endomembranes and plasma membranes (PMs) and comprise four classes: ceramides, hydroxyceramides, glucosylceramides, and glycosylinositolphosphoceramides (GIPCs). They constitute an array of chemical structures whose distribution in plant membranes is unknown. With the aim of describing the hydrophobic portion of sphingolipids, 18 preparations from microsomal (MIC), vacuolar (VM), PM, and detergent-resistant membranes (DRM) were isolated from Arabidopsis (Arabidopsis thaliana) leaves. Sphingolipid species, encompassing pairing of long-chain bases and fatty acids, were identified and quantified in these membranes. Sphingolipid concentrations were compared using univariate and multivariate analysis to assess sphingolipid diversity, abundance, and predominance across membranes. The four sphingolipid classes were present at different levels in each membrane: VM was enriched in glucosylceramides, hydroxyceramides, and GIPCs; PM in GIPCs, in agreement with their key role in signal recognition and sensing; and DRM in GIPCs, as reported by their function in nanodomain formation. While a total of 84 sphingolipid species was identified in MIC, VM, PM, and DRM, only 34 were selectively distributed in the four membrane types. Conversely, every membrane contained a different number of predominant species (11 in VM, 6 in PM, and 17 in DRM). This study reveals that MIC, VM, PM, and DRM contain the same set of sphingolipid species but every membrane source contains its own specific assortment based on the proportion of sphingolipid classes and on the predominance of individual species.