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Mesoscale convective systems (MCSs) are crucial in shaping large‐scale tropical circulation and the hydrological cycle, particularly in Northwestern South America (NwSA), a region marked by complex terrain and significant MCS activity. Understanding MCSs in NwSA is vital due to their impact on precipitation patterns and potential for severe weather events. To enhance this understanding, the ATRACKCS algorithm was developed for tracking convective systems, utilizing precipitation and brightness temperature data sets. This research focuses on documenting the spatiotemporal variability of MCS occurrence, life cycle, and movement. Notably, MCS hotspots were identified to the west of the major orographic features in the region, with maximum occurrences at night, contrasting with the region's typical afternoon peak in land convection. MCS movement is also heavily influenced by topography, with higher velocities on the eastern (windward) side of the Andes compared to velocities on the western (leeward) side. MCSs generally move westward, driven by easterly winds, but this pattern is not consistent throughout the year or region. Northward movement is predominant to the west of the Andes, while southward movement is observed to the east. These seasonal and regional movement variations are linked to factors such as the intertropical convergence zone position, moisture availability, topography, and low‐level jets. This research underscores the complexity of MCSs in NwSA and emphasizes the need for detailed studies on the atmospheric environment shaping these systems. Additionally, it provides a robust 21‐year MCS database for NwSA and an advanced tracking tool for research in various geographic contexts and impact areas. Plain Language Summary: Extreme storms are linked to large clusters of clouds called Mesoscale Convective Systems (MCSs). Understanding MCSs is important because they produce rainfall and severe weather. Northwestern South America (NwSA) has many MCSs but studying them is difficult due to complex terrain and limited radar data. Here, we developed a new algorithm (ATRACKCS) to study MCSs over NwSA using satellite data, including their occurrence, duration, and movement. Topography has a strong effect on MCS. They occur more on the west side of the Andes mountain but are faster on the east side than to the west. Also, MCSs tend to move westward and are affected by winds, but this movement varies throughout the year and region. This variability could be explained by moisture availability, low‐level jets, and topography. This research shows how complex MCSs are in NwSA and highlights the need for detailed studies on the environmental conditions affecting them. It also helps us to better understand these storms by providing a robust database and a valuable tool for studying them in other places worldwide. Key Points: A climatological analysis of mesoscale convective system (MCS) characteristics as occurrence, life cycle and propagation are presented for Northwestern South AmericaContinental MCS hotspots are predominantly nocturnal and located west of topographic featuresMCS move mostly westward. However, their movement doesn't align with ambient winds at certain locations and times of the year [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate Cancer represents a significant health risk for men, especially African American men, despite the availability of PSA testing. Although PSA testing is the current gold-standard test for identifying at-risk men, an increased PSA level may arise from Benign Prostatic Hyperplasia instead of Prostate Cancer. For men with BPH, PSA testing may lead them to undergo unnecessary biopsies. As an alternative to PSA, we have previously described a Filamin-A and prostate volume based biomarker test with superior performance. To simplify this test, we removed the requirement of prostate volume measurement. Herein, we present results of this updated test utilizing Filamin-A alone in Caucasian and African American men. Filamin-A demonstrates superior predictive power compared to PSA in both patient populations. By reliably separating benign conditions from aggressive prostate cancer, this test would reduce the health care burden resulting from unnecessary prostate biopsies. Prostate cancer represents a significant health risk to aging men, in which diagnostic challenges to the identification of aggressive cancers remain unmet. Prostate cancer screening is driven by the prostate-specific antigen (PSA); however, in men with benign prostatic hyperplasia (BPH) due to an enlarged prostate and elevated PSA, PSA's screening utility is diminished, resulting in many unnecessary biopsies. To address this issue, we previously identified a cleaved fragment of Filamin A (FLNA) protein (as measured with IP-MRM mass spectrometry assessment as a prognostic biomarker for stratifying BPH from prostate cancer and subsequently evaluated its expanded utility in Caucasian (CA) and African American (AA) men. All men had a negative digital rectal examination (DRE) and PSA between 4 and 10 ng/mL and underwent prostate biopsy. In AA men, FLNA serum levels exhibited diagnostic utility for stratifying BPH from patients with aggressive prostate cancer (0.71 AUC and 12.2 OR in 48 men with BPH and 60 men with PCa) and outperformed PSA (0.50 AUC, 2.2 OR). In CA men, FLNA serum levels also exhibited diagnostic utility for stratifying BPH from patients with aggressive prostate cancer (0.74 AUC and 19.4 OR in 191 men with BPH and 109 men with PCa) and outperformed PSA (0.46 AUC, 0.32 OR). Herein, we established FLNA alone as a serum biomarker for stratifying men with BPH vs. those with high Gleason (7–10) prostate cancers compared to the current diagnostic paradigm of using PSA. This approach demonstrates clinical actionability of FLNA alone without the requirement of prostate volume measurement as a test with utility in AA and CA men and represents a significant opportunity to decrease the number of unnecessary biopsies in aggressive prostate cancer diagnoses. [ABSTRACT FROM AUTHOR]

In recent years, the utility of lipidomics has been recognized in environmental toxicology and biomonitoring efforts due to the ubiquitous nature and importance of lipids in many cellular processes including signal transduction, energy storage, and cellular compartmentalization. Additionally, technological advances in high-resolution mass spectrometry have enabled the rapid expansion of the field, creating a surge in interest in comparative studies of lipid metabolism from a Systems Biology standpoint. Here, we adapted a nontargeted lipidomic approach for the study of plasma samples from nesting female leatherback (Dermochelys coriacea), loggerhead (Caretta caretta), and green (Chelonia mydas) sea turtles in Florida using ultra-high-performance liquid chromatography/high-resolution tandem mass spectrometry. We identified 877 lipids in common between the three species, of which the concentrations for 467 lipids were statistically different between two or more group comparisons. Principal component analysis revealed unique lipidomic signatures associated with each species of turtle, including various glycerophosphatidylcholines, glycerophosphatidylethanolamines, triacylglycerols, and oxidized triacylglycerols that were higher in leatherback sea turtles, diacylglycerols and select glycerophosphatidylinositols which were higher in loggerhead sea turtles, and specific plasmanyl-phosphatidylcholines that were higher in green sea turtles. Our results indicate that lipidomic profiling can be a useful tool for studying lipid metabolism and physiology of different species of sea turtles, while establishing baseline data that may be used as reference in future studies for observation of differences in life stages, for following spatial and temporal trends in nesting turtles, and for investigating population dynamics in response to various stressors., Author(s): Atiye Ahmadireskety [sup.1], Juan J. Aristizabal-Henao [sup.2], Anna Marqueño [sup.3], Justin R. Perrault [sup.4], Nicole I. Stacy [sup.5], Charles A. Manire [sup.4], John A. Bowden [sup.1] [sup.2] Author Affiliations: [...]

Epidemiological data demonstrate that bovine whole milk is often substituted for human milk during the first 12 months of life and may be associated with adverse infant outcomes. The objective of this study is to interrogate the human and bovine milk metabolome at 2 weeks of life to identify unique metabolites that may impact infant health outcomes. Human milk (n = 10) was collected at 2 weeks postpartum from normal-weight mothers (pre-pregnant BMI < 25 kg/m2) that vaginally delivered term infants and were exclusively breastfeeding their infant for at least 2 months. Similarly, bovine milk (n = 10) was collected 2 weeks postpartum from normal-weight primiparous Holstein dairy cows. Untargeted data were acquired on all milk samples using high-resolution liquid chromatography–high-resolution tandem mass spectrometry (HR LC-MS/MS). MS data pre-processing from feature calling to metabolite annotation was performed using MS-DIAL and MS-FLO. Our results revealed that more than 80% of the milk metabolome is shared between human and bovine milk samples during early lactation. Unbiased analysis of identified metabolites revealed that nearly 80% of milk metabolites may contribute to microbial metabolism and microbe–host interactions. Collectively, these results highlight untargeted metabolomics as a potential strategy to identify unique and shared metabolites in bovine and human milk that may relate to and impact infant health outcomes. [ABSTRACT FROM AUTHOR]

Butyrate, a short-chain fatty acid, is utilized by the gut epithelium as energy and it improves the gut epithelial barrier. More recently, it has been associated with beneficial effects on immune and cardiovascular homeostasis. Conversely, tumor necrosis factor alpha (TNFα) is a pro-inflammatory and pro-hypertensive cytokine. While butyrate and TNFα are both linked with hypertension, studies have not yet addressed their interaction in the colon. Here, we investigated the capacity of butyrate to modulate a host of effects of TNFα in primary rodent colonic cells in vitro. We measured ATP levels, cell viability, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitochondrial oxidative phosphorylation, and glycolytic activity in colonocytes following exposure to either butyrate or TNFα, or both. To address the potential mechanisms, transcripts related to oxidative stress, cell fate, and cell metabolism (Pdk1, Pdk2, Pdk4, Spr, Slc16a1, Slc16a3, Ppargc1a, Cs, Lgr5, Casp3, Tnfr2, Bax, Bcl2, Sod1, Sod2, and Cat) were measured, and untargeted liquid chromatography–tandem mass spectrometry (LC-MS/MS) was employed to profile the metabolic responses of colonocytes following exposure to butyrate and TNFα. We found that both butyrate and TNFα lowered cellular ATP levels towards a quiescent cell energy phenotype, characterized by decreased oxygen consumption and extracellular acidification. Co-treatment with butyrate ameliorated TNFα-induced cytotoxicity and the reduction in cell viability. Butyrate also opposed the TNFα-mediated decrease in MMP and mitochondrial-to-intracellular calcium ratios, suggesting that butyrate may protect colonocytes against TNFα-induced cytotoxicity by decreasing mitochondrial calcium flux. The relative expression levels of pyruvate dehydrogenase kinase 4 (Pdk4) were increased via co-treatment of butyrate and TNFα, suggesting the synergistic inhibition of glycolysis. TNFα alone reduced the expression of monocarboxylate transporters slc16a1 and slc16a3, suggesting effects of TNFα on butyrate uptake into colonocytes. Of the 185 metabolites that were detected with LC-MS, the TNFα-induced increase in biopterin produced the only significant change, suggesting an alteration in mitochondrial biogenesis in colonocytes. Considering the reports of elevated colonic TNFα and reduced butyrate metabolism in many conditions, including in hypertension, the present work sheds light on cellular interactions between TNFα and butyrate in colonocytes that may be important in understanding conditions of the colon. [ABSTRACT FROM AUTHOR]

Tissue-specific cardiolipin fatty acyl profiles are achieved by remodeling of de novo synthesized cardiolipin, and four remodeling enzymes have thus far been identified. We studied the enzyme phospholipase A and acyltransferase 1 (PLAAT1), and we report the discovery that it has phosphatidylcholine (PC):monolysocardiolipin (MLCL) transacylase activity. Subcellular localization was analyzed by differential centrifugation and immunoblotting. Total levels of major phospholipids, and the fatty acyl profile of cardiolipin, were analyzed in HEK293 cells expressing murine PLAAT1 using gas chromatography. Apparent enzyme kinetics of affinity-purified PLAAT1 were calculated using radiochemical enzyme assays. This enzyme was found to localize predominantly to the endoplasmic reticulum (ER) but was detected at low levels in the mitochondria-associated ER matrix. Cells expressing PLAAT1 had higher levels of total cardiolipin, but not other phospholipids, and it was primarily enriched in the saturated fatty acids myristate, palmitate, and stearate, with quantitatively smaller increases in the n-3 polyunsaturated fatty acids linolenate, eicosatrienoate, and eicosapentanoate and the monounsaturated fatty acid erucate. Affinity-purified PLAAT1 did not catalyze the transacylation of MLCL using 1-palmitoyl-2-[14C]-linoleoyl-PC as an acyl donor. However, PLAAT1 had an apparent Vmax of 1.61 μmol/min/mg protein and Km of 126 μM using [9,10-3H]-distearoyl-PC as an acyl donor, and 0.61 μmol/min/mg protein and Km of 16 μM using [9,10-3H]-dioleoyl-PC. PLAAT1 is therefore a novel PC:MLCL transacylase. [ABSTRACT FROM AUTHOR]

Introduction: The metabolomics quality assurance and quality control consortium (mQACC) is enabling the identification, development, prioritization, and promotion of suitable reference materials (RMs) to be used in quality assurance (QA) and quality control (QC) for untargeted metabolomics research. Objectives: This review aims to highlight current RMs, and methodologies used within untargeted metabolomics and lipidomics communities to ensure standardization of results obtained from data analysis, interpretation and cross-study, and cross-laboratory comparisons. The essence of the aims is also applicable to other 'omics areas that generate high dimensional data. Results: The potential for game-changing biochemical discoveries through mass spectrometry-based (MS) untargeted metabolomics and lipidomics are predicated on the evolution of more confident qualitative (and eventually quantitative) results from research laboratories. RMs are thus critical QC tools to be able to assure standardization, comparability, repeatability and reproducibility for untargeted data analysis, interpretation, to compare data within and across studies and across multiple laboratories. Standard operating procedures (SOPs) that promote, describe and exemplify the use of RMs will also improve QC for the metabolomics and lipidomics communities. Conclusions: The application of RMs described in this review may significantly improve data quality to support metabolomics and lipidomics research. The continued development and deployment of new RMs, together with interlaboratory studies and educational outreach and training, will further promote sound QA practices in the community. [ABSTRACT FROM AUTHOR]

Per‐ and polyfluoroalkyl substances (PFAS) are environmental contaminants linked to adverse health effects in humans and wildlife. Marine mammals, particularly manatees, have shown potential as sentinels for evaluating the presence and effects of anthropogenic chemicals. However, traditional blood collection techniques with marine mammals can be challenging, highlighting the need for improved strategies. In the present study, four different methods for the extraction of PFAS from dried blood spots were evaluated. Environ Toxicol Chem 2021;40:2726–2732. © 2021 SETAC [ABSTRACT FROM AUTHOR]

Current research on the fate and transport of per- and polyfluoroalkyl substances (PFAS) has primarily focused on point-source releases, with less focus on nonpoint-source releases, such as stormwater runoff. In this study, 51 PFAS were investigated in sediment collected from two locations at nine stormwater ponds classified by different land-use types. PFAS concentrations were then related to two different land-use disturbance indicators, the Landscape Development Intensity (LDI) index and the Florida Department of Transportation (FDOT) road type functional classification, to discern a potential metric for estimating PFAS burden by using the proximity to and different types of anthropogenic activity. Of the 51 compounds analyzed, 28 in total were quantified with concentrations ranging from 7.2 to 4,800 ng kg−1. Perfluorinated carboxylic acids were the most commonly identified class of PFAS, as perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), and perfluorotridecanoic acid (PFTrDA) were all found at eight out of nine sites, as well as perfluorooctane sulfonic acid (PFOS), a perfluorinated sulfonic acid. Within the framework of this study, the LDI index did not appear to be significantly correlated to PFAS burden, whereby only the 0.4 km radius of the LDI weighted average resulted in a potential metric for the lowest PFAS contaminated sites (which had correspondingly low LDI weighted means). The FDOT functional classification was a better predictor across all sites for PFAS burden, in which a significant difference was found between the number of PFAS detected at rural and urban sites. Most notably, perfluorohexanoic acid (PFHxA) concentrations were found to be significantly different between rural and urban sites. Moving forward, the potential of utilizing road type functional classification should be explored as a predictive tool to help better prioritize stormwater pond monitoring for PFAS. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent, ubiquitous pollutants. It is important to continuously monitor the presence of PFAS contamination, utilizing both legacy and new sentinels. In this study, environmental PFAS levels were evaluated using ticks as a sentinel model due to their world-wide distribution, hematophagous nature, and ease of collection and sampling. Hematophagy in discrete blood meals, from a suite of vertebrates, allows ticks to sample dozens of species of consumers and bioaccumulation across communities. Four different species of ticks, across two states (NY, n = 28 in mid-April of 2020 and FL, n = 32 between 2015 and 2020) with two sampling sites in each state were analyzed for the presence of 53 PFAS. The total PFAS concentration in ticks was the lowest at Newburgh (NY), a site that has been undergoing remediation efforts, while the highest total PFAS concentrations were measured in ticks at the Sweetwater site, a wastewater treatment wetland. Detection of PFAS and the potential for variation between tick species and between locations are necessary to establish the utility of ticks as sentinels, in addition to assessing additional environmental factors, such as other wildlife, water, or soil. [ABSTRACT FROM AUTHOR]

Vegetables oils, rich in polyunsaturated fatty acids, are vulnerable to oxidation during manufacturing, processing, and food preparation. Currently, individual oxidation products are not well characterized, and hence, the health impacts of these unique lipid species remain unknown. Here, we introduce an extensive oxidized lipidomics in silico tandem mass spectrometry library and integrate these libraries within a user-friendly software covering a comprehensive redox lipidomics workflow. We apply this workflow to olive, soy, and walnut cooking oil; comparing unheated oil, oil after deep frying potatoes, and oil after oven frying potatoes. We annotated over a thousand oxidized triglycerides across 273 features (many coeluted). This software was validated against traditional chemical assays of oxidation, known oxidized lipids in castor oil, synthesized standards, and an alternate software LPPtiger. Development of these new software programs for redox lipidomics opens the door to characterize health implications of individual oxidation products. [ABSTRACT FROM AUTHOR]

According to Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellite precipitation composites, a broad maritime area over the far eastern tropical Pacific and western Colombia houses one of the rainiest spots on Earth. This study aims to present a suite of mechanistic drivers that help create such a world‐record‐breaking rainy spot. Previous research has shown that this oceanic and nearly continental precipitation maximum has a strong early morning precipitation peak and a high density of mesoscale convective systems. We examined new and unique observational evidence highlighting the role of both dynamical and thermodynamical drivers in the activation and duration of organized convection. Results showed the existence of a rather large combination of mechanisms, including: (1) dynamics of the Choco (ChocoJet) and Caribbean Low‐Level Jets along their confluence zone, including the Panama semi‐permanent low; (2) ChocoJet deceleration offshore is favored by land breeze, enhancing the nighttime and early morning low‐level convergence; (3) a wind sheared environment that conforms to the long‐lived squall line theory; (4) action of mid‐level gravity waves, which further support the strong diurnal variability; and (5) mesoscale convective vortices related to subsidence in the stratiform region and top‐heavy mass flux profiles. This study emphasizes the multiscale circulation and thermodynamics mechanisms associated with the formation of one of the rainiest spots on Earth and showcases new observations gathered during the Organization of Tropical East Pacific Convection field campaign (OTREC; August–September, 2019) that support the outlined mechanisms. Key Points: One of the rainiest spots on Earth is located offshore in the far eastern tropical Pacific and linked to Mesoscale Convective SystemsMesoscale Convective Systems are related to days with enhanced Choco low‐level jetThe Organization of Tropical East Pacific Convection field campaign helped elucidate the role of local circulation on Mesoscale Convective Systems development [ABSTRACT FROM AUTHOR]

Lipidomics is a rapidly growing field, fueled by developments in analytical instrumentation and bioinformatics. To date, most researchers and industries have employed their own lipidomics workflows without a consensus on best practices. Without a community‐wide consensus on best practices for the prevention of lipid degradation and transformations through sample collection and analysis, it is difficult to assess the quality of lipidomics data and hence trust results. Clinical studies often rely on samples being stored for weeks or months until they are analyzed, but inappropriate sampling techniques, storage temperatures, and analytical protocols can result in the degradation of complex lipids and the generation of oxidized or hydrolyzed metabolite artifacts. While best practices for lipid stability are sample dependent, it is generally recommended that strategies during sample preparation capable of quenching enzymatic activity and preventing oxidation should be considered. In addition, after sample preparation, lipid extracts should be stored in organic solvents with antioxidants at −20 °C or lower in an airtight container without exposure to light or oxygen. This will reduce or eliminate sublimation, and chemically and physically induced molecular transformations such as oxidation, enzymatic transformation, and photon/heat‐induced degradation. This review explores the available literature on lipid stability, with a particular focus on human health and/or clinical lipidomic applications. Specifically, this includes a description of known mechanisms of lipid degradation, strategies, and considerations for lipid storage, as well as current efforts for standardization and quality insurance of protocols. [ABSTRACT FROM AUTHOR]

The unavailability of appropriate quality assurance/quality control materials in many lipidomics applications poses a significant challenge for lipidomics research. It is recommended that samples with certified values and/or consensus estimates, such as NIST SRM 1950–Metabolites in Frozen Human Plasma, be implemented in routine analyses to enable community-wide comparisons of lipidomics results and analytical workflows. Herein, we applied a nontargeted lipidomics method for the analysis of a new human plasma reference material suite developed by NIST (hypertriglyceridemic, diabetic, and African-American plasma pools), in addition to SRM 1950. We identified specific lipidomics fingerprints associated with each sample type, including lauric acid–containing lipids and elevated triacylglycerol levels in hypertriglyceridemic plasma, palmitoleic acid–containing lipids in diabetic plasma, and oxidized fatty acid–containing phospholipids in African-American plasma. This work highlights the importance of developing and profiling application-specific reference materials, while establishing reference data that may be used for system suitability and/or quality control metrics. Graphical abstract [ABSTRACT FROM AUTHOR]

Background Long-chain n–3 PUFAs (n–3 LCPUFAs) accrete in the brain during childhood and affect brain development. Randomized trials in children show inconsistent effects of n–3 LCPUFAs on cognitive and socioemotional function, and few have investigated effects of fish per se. Objectives We aimed to investigate the effects of oily fish consumption on overall and domain-specific cognitive and socioemotional scores and explore sex differences. Methods Healthy 8–9-y-old children (n  = 199) were randomly allocated to receive ∼300 g/wk oily fish or poultry (control) for 12 ± 2 wk. At baseline and endpoint, we assessed attention, processing speed, executive functions, memory, emotions, and behavior with a large battery of tests and questionnaires and analyzed erythrocyte fatty acid composition. Results One hundred and ninety-seven (99%) children completed the trial. Children in the fish group consumed 375 (25th–75th percentile: 325–426) g/wk oily fish resulting in 2.3 (95% CI: 1.9, 2.6) fatty acid percentage points higher erythrocyte n–3 LCPUFA than in the poultry group. The overall cognitive performance score tended to improve by 0.17 (95% CI: −0.01, 0.35) points in children who received fish compared with poultry, supported by n–3 LCPUFA dose dependency. This was driven mainly by fewer errors [−1.9 (95% CI: −3.4, −0.3)] in an attention task and improved cognitive flexibility measured as faster reaction time [−51 ms (95% CI: −94, −7 ms)] in a complex relative to a simple task ("mixing cost"). The fish intervention furthermore reduced parent-rated Strength and Difficulties Questionnaire total difficulties by −0.89 (95% CI: −1.60, −0.18) points mainly due to a −0.63 (95% CI: −1.11, −0.16) points reduction in internalizing problems that was reflected in tendency to a decrease in the overall socioemotional problems score of −0.13 (95% CI: −0.26, 0.01) points. The overall effects were similar in boys and girls. Conclusions Oily fish dose-dependently improved cognitive function, especially attention and cognitive flexibility, and reduced socioemotional problems. The results support the importance of n–3 LCPUFAs for optimal brain function and fish intake recommendations in children. The trial was registered at www.clinicaltrials.gov as NCT02809508. [ABSTRACT FROM AUTHOR]

Dried blood spots for fatty acid profiling are increasing in popularity; however, variability in results between laboratories has not been characterized. Whole blood from two subjects (low and high n‐3 polyunsaturated fatty acid [PUFA] status) was collected, 25 μL applied to butylated hydroxytoluene (BHT)‐treated chromatography strips, dried in air, and shipped to five laboratories. Results were reported as "routine" (typical fatty acids for each laboratory) or "standardized" (a set of 19 fatty acids), and outliers and variability (%CV) were determined. Five and eight outliers of a possible 91 measures each were identified by routine and standardized reporting, respectively, including eicosapentaenoic acid (EPA, 20:5n‐3) in the low n‐3 PUFA sample and arachidonic acid in the high n‐3 PUFA sample. By standardized reporting, no outliers were identified for EPA or docosahexaenoic acid (DHA, 22:6n‐3), and %CV decreased from 8.6% to 6.0% and 9.1% to 6.6% for EPA and 10.5% to 7.2% and 10.5% to 6.6% for DHA in the low and high n‐3 PUFA sample, respectively. In conclusion, fatty acid profiles yielded few outliers, and standardization of reporting reduced the variability between laboratories. [ABSTRACT FROM AUTHOR]

Lysophosphatidic acids (lysoPtdOH) are involved in several physiological processes including cell proliferation, inflammation, and glucose metabolism. However, measuring lysoPtdOH is challenging due to inadequate extraction techniques, poor chromatographic resolution, or the inability to discriminate between sn‐1 and sn‐2 regioisomers. In the present work, we developed a high‐throughput (10 min run times) ultra‐high‐performance liquid chromatography–tandem mass spectrometry method capable of discriminating lysoPtdOH species by their fatty acyl composition and sn‐localization on glycerol backbones. We quantitated sn‐1/sn‐2 regioisomeric pairs of lysoPtdOH with 16:0, 18:0, 18:1, 18:2, 20:4, and 22:6 fatty acyl chains using 50 μL of mouse plasma. The method presented here can be expanded to profile more lysoPtdOH species, and has the potential to be used in clinical settings to quickly screen lysoPtdOH profiles. Finally, the ability to discriminate between sn‐1 and sn‐2 isomers can provide insights regarding the metabolic origins and fates of specific lysoPtdOH molecules. [ABSTRACT FROM AUTHOR]

• Fatty acid concentrations determined from wet blood and dried blood spots collection materials are similar. • Palmitate and stearate can be present as free fatty acids on dried blood spot collection materials at low amounts that do not affect quantitation. • A novel wicking device that collects 10 µL of blood can be used to determined fatty acid profiles, but contains lysophosphatidylcholines. Blood biomarkers of n − 3 polyunsaturated fatty acids can serve as indicators of dietary intake and benefits and/or disease risk. The use of dried blood spots for fatty acid analyses is increasing but most of the reported data is qualitative (relative percentages of total fatty acids). The ability to quantitate concentrations of fatty acids on a common blood spot collection card and a novel wicking device designed to collect 10 µL of blood was compared with a wet blood sample in ten young adult participants. Prior to this comparison, the collection materials were screened for contaminants by gas chromatography with flame ionization and liquid chromatography/tandem mass spectrometry, and the blood volume and blood spot area relationship of the collection card was confirmed using technical replicates. Palmitate and stearate were detected as free fatty acids on both collection materials and as lysophosphatidylcholines on the wicking device. The low amounts (<1.0 µg) did not affect the quantitation of these fatty acids in either material. The relationship between blood volume and blood spot area was linear (r = 0.99, p < 0.001) and it was determined that a 6 mm hole punch contained 9.6 µL of blood. When compared with wet blood, the fatty acid determinations from the dried blood spots were largely similar although there were some minor differences in low abundant fatty acids. Quantitative fatty acid determinations of dried blood spots are possible and should be reported along with relative percentage data to improve interpretation in the future. [ABSTRACT FROM AUTHOR]

Highlights • DHA supplementation is examined in rats during pregnancy with a background diet that resembles human Western diets and a standard rodent chow. • DHA concentrations are lower in maternal adipose during pregnancy and postpartum in the Western diet without DHA. • At postpartum DHA concentrations decrease below baseline levels in maternal heart and liver of the dams fed Western diets without DHA and in liver in the chow diet. • Low maternal DHA intakes was associated with lower DHA concentrations in the 7d old pups but not the fetuses. Abstract Fetal accretion for DHA is high during late pregnancy due to the brain growth spurt. Prior evidence suggests that DHA is mobilized from maternal liver and adipose to meet fetal accretion and physiological requirements. However, changes in the DHA levels of various maternal tissues throughout pregnancy and into lactation of mothers on diets with and without dietary DHA, and with a background dietary fatty acid profile that resembles human intake has not been examined. Sprague Dawley rats were fed a total western diet with (TWD +) or without DHA (TWD-) along with a commercial rodent chow control (Chow) throughout pregnancy and postpartum. The fatty acid compositions of adipose, brain, heart, liver, erythrocytes, and plasma were determined before pregnancy, at 15 and 20 days of pregnancy, and 7 days postpartum. The placenta, fetuses, and pups were also examined when available. Maternal DHA concentrations were increased in plasma at 20 days pregnancy in all the diets with TWD + > Chow > TWD-. Maternal DHA concentrations in the TWD- group were lower in adipose throughout pregnancy as compared with the other diets. At postpartum, DHA concentrations decreased below baseline levels in the heart of the TWD- and Chow dams and the liver of the TWD- dams. Whole body DHA concentrations of the fetuses did not differ but there was evidence of decreased DHA in the whole body and tissues of the TWD- and Chow 7d old pups. In conclusion, it appears that in this rodent model of pregnancy, maternal adaptations were made to meet fetal DHA requirements, but they may compromise maternal DHA status and the ability to deliver DHA during lactation. [ABSTRACT FROM AUTHOR]

Traditional foods have significant nutritional, sociocultural and economic value in subarctic First Nations communities of the Northwest Territories, and play a crucial role in promoting cultural continuity and sovereignty. Omega-3 polyunsaturated fatty acids (N-3 PUFAs), including eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), carry significant benefits for neurocognitive development and cardiovascular health. However, the health risks posed by methylmercury may serve to undermine the benefits of fish consumption in Northern Indigenous communities. The objective of this study was to characterize profiles for mercury (Hg) and fatty acids in fish species harvested across lakes of the Dehcho Region, in the Mackenzie Valley of the Northwest Territories, to better understand the risks and benefits associated with traditional foods. Hg levels increased with trophic position, with the highest levels found in Burbot, Lake Trout, Walleye, and Northern Pike. Lake Trout, along with planktivorous species including Lake Whitefish, Cisco, and Sucker, demonstrated higher N-3 PUFAs than other species. Negative associations were observed between Hg and N-3 PUFAs in Lake Trout, Northern Pike, Walleye and Burbot. Further stratifying these relationships revealed significant interactions by lake. Significant differences observed in fatty acid and Hg profiles across lakes underscore the importance of considering both species- and lake-specific findings. This growing dataset of freshwater fish of the Dehcho will inform future efforts to characterize human Hg exposure profiles using probabilistic dose reconstruction models. [ABSTRACT FROM AUTHOR]

We previously characterized LPAATδ/AGPAT4 as a mitochondrial lysophosphatidic acid acyltransferase that regulates brain levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI). Here, we report that Lpaatδ-/- mice display impaired spatial learning and memory compared to wild-type littermates in the Morris water maze and our investigation of potential mechanisms associated with brain phospholipid changes. Marker protein immunoblotting suggested that the relative brain content of neurons, glia, and oligodendrocytes was unchanged. Relative abundance of the important brain fatty acid docosahexaenoic acid was also unchanged in phosphatidylserine, phosphatidylglycerol, and cardiolipin, in agreement with prior data on PC, PE and PI. In phosphatidic acid, it was increased. Specific decreases in ethanolamine-containing phospholipids were detected in mitochondrial lipids, but the function of brain mitochondria in Lpaatδ-/- mice was unchanged. Importantly, we found that Lpaatδ-/- mice have a significantly and drastically lower brain content of the N-methyl-D-asparate (NMDA) receptor subunits NR1, NR2A, and NR2B, as well as the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluR1, compared to wild-type mice. However, general dysregulation of PI-mediated signaling is not likely responsible, since phospho-AKT and phospho-mTOR pathway regulation was unaffected. Our findings indicate that Lpaatδ deficiency causes deficits in learning and memory associated with reduced NMDA and AMPA receptors. [ABSTRACT FROM AUTHOR]

To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada. Average HgT levels ranged from 0.057 mg/kg (cisco) to 0.551 mg/kg (northern pike), while averagen-3 FA concentrations ranged from 101 mg/100 g (burbot) to 1,689 mg/100 g (lake trout). In contrast to HgT andn-3 FA, mean Se concentrations were relatively similar among species. Consequently, species such as lake whitefish, cisco, and longnose sucker displayed the highest nutrient levels relative to HgT content. Levels of HgT tended to increase with fish size, while Se andn-3 FA levels were typically not associated with fork length or fish weight. Interestingly, HgT concentration was occasionally inversely related to tissue nutrient content. Significant negative correlations were observed between Hg andn-3 FA for lake trout, northern pike, and walleye. There were also significant negative correlations between Hg and Se noted for lake whitefish, cisco, and northern pike. Samples with the highest nutritional content displayed, on occasion, lower levels of HgT. This study provides valuable information for the design of probabilistic models capable of refining public health messaging related to minimizing Hg risks and maximizing nutrient levels in wild-harvested fish in the Canadian subarctic. [ABSTRACT FROM PUBLISHER]

The use of dried blood spots has increased in research and clinical settings recently, particularly in field studies and screening, but comprehensive acyl-specific lipidomic profiling of dried blood spots has yet to be examined. An untargeted ultrahigh-performance liquid chromatography-tandem mass spectrometry method was adapted for the analysis of lipid extracts from human whole blood samples and dried blood spots collected on chromatography paper. Lipid recoveries were examined after different durations of exposure to extraction solvents (chloroform/methanol), physical disruption (homogenization or sonication) of the paper containing the dried blood spots, and acidification of extraction solvents. We demonstrated that comprehensive untargeted profiles can be obtained from dried blood spot samples that are comparable with whole blood for several species of lipids including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, triacylglycerol, and cholesteryl ester. However, homogenization of the dried blood spots, followed by a 24 h exposure to solvents, and extraction with an acidic buffer (0.2 M NaHPO4 + 0.1 M hydrochloric acid) was required. Dried blood spots can be used for comprehensive, untargeted lipidomics of the most abundant lipid species in whole blood, but additional sample processing steps are required. [ABSTRACT FROM AUTHOR]

Specific blood levels of eicosapentaenoic plus docosahexaenoic acid (EPA+DHA, wt% of total) in erythrocytes or “the omega-3 index” have been recommended for cardio-protection, but fatty acids are often measured in different blood fractions. The ability to estimate the % of EPA+DHA in erythrocytes from the fatty acid composition of other blood fractions would enable clinical assessments of omega-3 status when erythrocyte fractions are not available and increase the ability to compare blood levels of omega-3 fatty acids across clinical studies. The fatty acid composition of baseline plasma, erythrocytes and whole blood samples from participants ( n =1104) in a prospective, multicenter study examining acute coronary syndrome were determined. The ability to predict the % of EPA+DHA in erythrocytes from other blood fractions were examined using bivariate and multiple linear regression modelling. Concordance analysis was also used to compare the actual erythrocytes EPA+DHA values to values estimated from other blood fractions. EPA+DHA in erythrocytes was significantly ( p <0.001) correlated EPA+DHA in plasma ( r 2 =0.54) and whole blood ( r 2 =0.79). Using multiple linear regression to predict EPA+DHA in erythrocytes resulted in stronger coefficients of determination in both plasma ( R 2 =0.70) and whole blood ( R 2 =0.84). Concordance analyses indicated agreement between actual and estimated EPA+DHA in erythrocytes, although estimating from plasma fatty acids appears to require translation by categorization rather than by translation as continuous data. This study shows that the fatty acid composition of different blood fractions can be used to estimate erythrocyte EPA+DHA in a population with acute coronary syndrome. [ABSTRACT FROM AUTHOR]

Clinical metabolomics emerged as a novel approach for biomarker discovery with the translational potential to guide next-generation therapeutics and precision health interventions. However, reproducibility in clinical research employing metabolomics data is challenging. Checklists are a helpful tool for promoting reproducible research. Existing checklists that promote reproducible metabolomics research primarily focused on metadata and may not be sufficient to ensure reproducible metabolomics data processing. This paper provides a checklist including actions that need to be taken by researchers to make computational steps reproducible for clinical metabolomics studies. We developed an eight-item checklist that includes criteria related to reusable data sharing and reproducible computational workflow development. We also provided recommended tools and resources to complete each item, as well as a GitHub project template to guide the process. The checklist is concise and easy to follow. Studies that follow this checklist and use recommended resources may facilitate other researchers to reproduce metabolomics results easily and efficiently. [ABSTRACT FROM AUTHOR]

Governments' responses to the COVID-19 pandemic provide a unique opportunity to study the effects of restricted socioeconomic activity on air quality. Here, we study the changes in air pollution levels during the lockdown in Medellín and its metropolitan area, Colombia, for periods with and without enhanced regional fire activity, considering the effects of meteorology using random forest and multiple linear regression methods. The lockdown measures, which reduced mean traffic volume by 70% compared to 2016–2019, resulted in reductions for PM2.5 (50–63%), PM10 (59–64%), NO (75–76%), NO2 (43–47%), and CO (40–47%), while O3 concentration increased by 19–22%. In contrast, when fire activity was high, the effects of the lockdown on air quality were shadowed by the long-range transport of biomass burning emissions, increasing fine particulate matter and ozone. This study shows that healthier levels are achievable through significant efforts from decision-makers and society. The results highlight the need to develop integral measures that do not only consider reductions in the local emissions from transportation and industry, but also the role of fire activity in the region, as well as the difficulties of achieving reductions in ozone from measures that are effective at reducing primary pollutants. [ABSTRACT FROM AUTHOR]

Paper and other plant-based drinking straws are replacing plastic straws in commercial settings in response to trending plastic straw bans and the larger global movement for reducing plastic pollution. The water-resistant properties of many plant-based straws, however, may be attributed to the use of per- and polyfluoroalkyl substances (PFAS) during manufacturing. In this study, 43 brands of straws (5 plastic, 29 paper, 9 other plant-based) were analyzed for the presence of 53 semi-volatile PFAS using ultra high-performance liquid chromatography tandem mass spectrometry. While the plastic straws had no measurable PFAS, 21 PFAS were detected in the paper and other plant-based straws, with total mean PFAS concentrations (triplicate analysis) ranging from 0.043 ± 0.004 ng/straw to 29.1 ± 1.66 ng/straw (median = 0.554 ng/straw). Perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA) were the most frequently detected species. In a follow-up experiment, the brand with the highest PFAS levels and most diversity was tested for leaching in water at initial temperatures of 4 °C, 20 °C, and 90 °C. Approximately 2/3 of the total extractable PFAS leached compared to the initial methanol extraction. Semi-volatile PFAS concentrations measured in this study may be the result of manufacturing impurities or contamination, as PFAS approved for food-contact use are, typically, polymeric species. The presence of PFAS in plant-based drinking straws demonstrates that they are not fully biodegradable, contributing to the direct human ingestion of PFAS and to the cycle of PFAS between waste streams and the environment. [Display omitted] • Per- and polyfluoroalkyl substances were found in plant-based drinking straws. • Both short- and long-chain species were detected. • PFOS and PFOA were detected repeatedly despite voluntary phase-out in the US. • Some compounds leached into water at different temperatures. • Most plant-based straws are not a fully biodegradable alternative to plastic. [ABSTRACT FROM AUTHOR]

• Plasma and liver PC 16:0_22:6 increase in late pregnancy in sprague dawley rats. • PC 16:0_22:6 synthesis during pregnancy appears to involve fatty acid channeling of DHA through hepatic DG 16:0_22:6 and PE 16:0_22:6. • A decreased expression of phospholipases during pregnancy suggests fatty acyl remodeling of glycerophospholipids is downregulated. Fetal brain growth requires considerable amounts of docosahexaenoic acid (DHA) during late pregnancy that is associated with increased maternal/dam plasma levels of PC 16:0_22:6 (palmitoyl docosahexaenoyl phosphatidylcholine). While biosynthesis of DHA during pregnancy is upregulated, the mechanisms responsible for the incorporation of dam DHA into PC 16:0_22:6 are not understood. The present study used a discovery approach combining untargeted lipidomics of plasma and liver (n = 3/group) with semi-targeted qPCR of hepatic gene products (n = 6/group) to identify metabolic pathways related to DHA metabolism, with a hypothesis that an upregulated acyltransferase involved in PC remodeling would be identified. Sprague Dawley rats were fed a commercial rodent chow throughout the study and samples were collected before pregnancy (baseline), at 15 and 20 days of pregnancy, and 7 days postpartum. Plasma and hepatic PC 16:0_22:6 was significantly increased (by 79% and 194%, respectively) at day 20 of pregnancy. An increase in hepatic DG (diacylglycerol) 16:0_22:6 (by 243%) and significant decreases in Pla2G15 (0.4-fold) and Pla2G16 (0.6-fold) at day 20 of pregnancy, no changes in Lpcat1–4 , and an abundant pool of hepatic pool PE (phosphatidylethanolamine) 16:0_22:6 suggest that plasma PC 16:0_22:6 is not being produced by fatty acyl remodeling during pregnancy. The increase in plasma PC 16:0_22:6 during pregnancy appears to be due to an increase in de novo synthesis of PC and both the CDP-choline and phosphatidylcholine methyltransferase pathways are implicated. There was also evidence suggesting channeling of DHA into PC and lipoprotein assembly may be occurring. Targeted research is necessary to confirm these findings, but the results of this study indicate metabolic adaptions to enable maternal/dam resiliency towards meeting the fetal/pup demand for DHA during pregnancy. [Display omitted] [ABSTRACT FROM AUTHOR]

Lipids play an essential role in development, homeostatic functions, immune signaling, reproduction, and growth. Although it is evident that changes in lipid biosynthesis and metabolism can affect organismal physiology, few studies have determined how environmental stressors affect lipid pathways, let alone alter global lipid profiles in fish. This is a significant research gap, as a number of environmental contaminants interact with lipid signaling and metabolic pathways. In this review, we highlight the utility of lipidomics as a tool in environmental toxicology, discussing the current state of knowledge regarding chemical-lipidomic perturbations. As with most oviparous animals, the processing and storage of lipids during oocyte development is also particularly important for embryogenesis in fish. Using largemouth bass (Micropterus salmoides) as an example, transcriptomics data suggest that various chemicals alter lipid metabolism and regulation, highlighting the need for more sophisticated investigations into how toxicants impact lipid responses. We also point out the challenges ahead; these include a lack of understanding about lipid processing and signaling in fish, tissue and species-specific lipid composition, and extraneous factors (e.g., nutrition, temperature) that confound interpretation. For example, toxicant exposure can lead to oxidative stress and lipid peroxidation, resulting in complex lipid byproducts that are challenging to measure. With the emergence of lipidomics in systems toxicology, multi-omics approaches are expected to more clearly define effects on physiology, creating stronger linkages between multiple molecular entities (gene-protein-lipid/metabolite). The development and implementation of novel technologies such as ion mobility-mass spectrometry and ozone-induced dissociation support the complete structural elucidation of lipid molecules. This has implications in the adverse outcome pathway framework, which will enhance the application of lipidomics in toxicology by linking these molecular changes to effects at higher levels of biological organization. Unlabelled Image • Lipids are diverse molecules and perform several essential roles in fish. • Transcriptomics data suggest that chemicals alter lipid metabolism and regulation. • Analytical technologies in mass spectrometry have advanced the field of lipidomics. • Lipidomics can inform adverse outcome pathways. [ABSTRACT FROM AUTHOR]

Many urban areas located in valleys experience exceedances in air quality standards as aconsequence of factors related to orography, the state of the atmosphere, and the emission ofpollutants. In urban valleys with limited ventilation (due to topographic barriers), the mainmechanisms for the transport of pollutants is associated to thermally-driven valley flows.These valley flows are influenced by urbanization processes, as these modify the exchange ofheat and momentum between the surface and the atmosphere. Consequently, phenomena suchas the urban heat island (UHI) effect have consequences on air quality, but its impacts are notcompletely understood. In this study we analysed the impacts of mitigating the UHI effect on the transport ofpollutants in an idealized valley. We conducted a series of ideal numerical simulations usingthe Weather Research and Forecasting model in large-eddy simulation mode (WRF-LES).The ideal valley topography is composed of cosine-shaped slopes. The urban and rural areasare distinguished by differences in thermal forcing (specified sensible heat flux). Weconsidered three different conditions of thermal forcing between the rural and urbanareas (rural: Qh_max = 100 W m−2; urban: Qh_max = 100, 250 and 400 W m−2),and two different conditions of static stability (specified as a potential temperaturegradient of 1 K km−1 and 3 K km−1). The simulations (6 in total) cover the daytimeperiod. We found that pollutant concentration over the urban area increases with both increasingstability and decreasing UHI intensity. This is associated to a UHI-induced circulation wheremost of the transport of pollutants occurs at the valley centre by an ascending flow, instead ofoccurring by the upslope flows. The presence of the UHI also reduces the time required forthe breakup of the temperature inversion, which is necessary for the ventilation of pollutantsout of the valley. These results suggest that the environmental and social benefits of mitigating the UHI inurban valleys should be analysed including the potential negative impacts in air quality,especially in urban areas where ventilation depends on thermally-driven flows. Our results arein contrast to several studies that suggest that UHI mitigation can reduce air pollution. [ABSTRACT FROM AUTHOR]