Fecal sphingolipids predict parenteral nutrition-associated cholestasis in the neonatal intensive care unit.

BACKGROUND: Parenteral nutrition-associated cholestasis (PNAC) in the neonatal intensive care unit (NICU) causes significant morbidity and associated healthcare costs. Laboratory detection of PNAC currently relies on elevated serum conjugated bilirubin levels in the aftermath of impaired bile flow. Here, we sought to identify fecal biomarkers, which when integrated with clinical data, would better predict risk for developing PNAC. METHODS: Using untargeted metabolomics in 200 serial stool samples from 60 infants, we applied statistical and machine learning approaches to identify clinical features and metabolic biomarkers with the greatest associative potential for risk of developing PNAC. Stools were collected prospectively from infants receiving PN with soybean oil-based lipid emulsion at a level IV NICU. RESULTS: Low birth weight, extreme prematurity, longer duration of PN, and greater number of antibiotic courses were all risk factors for PNAC (P < 0.05). We identified 78 stool biomarkers with early predictive potential (P < 0.05). From these 78 biomarkers, we further identified 12 sphingomyelin lipids with high association for the development of PNAC in precholestasis stool samples when combined with birth anthropometry. CONCLUSION: We demonstrate the potential for stool metabolomics to enhance early identification of PNAC risk. Earlier detection of high-risk infants would empower proactive mitigation with alterations to PN for at-risk infants and optimization of energy nutrition with PN for infants at lower risk.

Serum malondialdehyde as a lipid peroxidation marker in multiple sclerosis patients and its relation to disease characteristics.

Introduction Oxidative stress has been suggested to play a key role in pathogenesis of multiple sclerosis (MS), but clinical data on oxidative stress markers in MS patients and their influence on clinical and radiologic characteristics of the disease are inconsistent. The aim of this study is to assess the serum levels of malondialdehyde (MDA) as a measure of lipid peroxidation in MS patients and its relation to disease characteristics. Methods This case control study included 120 patients with clinically definite relapsing remitting multiple sclerosis (RRMS) compared to 120 age and sex -matched healthy controls. MDA levels were measured using thiobarbituric acid reactive substances (TBARS) assay. Results MDA levels are significantly higher in patients with MS than those in control (P<0.001) especially during relapse, MDA levels are higher in patients taking no disease modifying therapy (DMT) than those taking interferon (IFN-ß). MDA levels significantly correlate with expanded disability status scale (EDSS) (P<0.001). Conclusions The results of this study can provide evidence about the incrimination of oxidative stress in MS pathogenesis and disease disability and support the use of antioxidants as a new target of treatment that focuses on neutralizing free radicals and increases antioxidant capacity.

An ambient-temperature storage and stabilization device performs comparably to flash-frozen collection for stool metabolomics in infants.

BACKGROUND: Stool metabolites provide essential insights into the function of the gut microbiome. The current gold standard for storage of stool samples for metabolomics is flash-freezing at - 80 °C which can be inconvenient and expensive. Ambient temperature storage of stool is more practical, however no available methodologies adequately preserve the metabolomic profile of stool. A novel sampling kit (OMNImet.GUT; DNA Genotek, Inc.) was introduced for ambient temperature storage and stabilization of feces for metabolomics; we aimed to test the performance of this kit vs. flash-freezing. To do this stool was collected from an infant's diaper was divided into two aliquots: 1) flash-frozen and 2) stored in an OMNImet.GUT tube at ambient temperature for 3-4 days. Samples from the same infant were collected at 2 different time points to assess metabolite changes over time. Subsequently, all samples underwent metabolomic analysis by liquid chromatography - tandem mass spectrometry (LC-MS/MS). RESULTS: Paired fecal samples (flash-frozen and ambient temperature) from 16 infants were collected at 2 time points (32 individual samples, 64 aliquots). Similar numbers of metabolites were detected in both the frozen and ambient temperature samples (1126 in frozen, 1107 in ambient temperature, 1064 shared between sample types). Metabolite abundances were strongly correlated between storage methods (median Spearman correlation Rs = 0.785 across metabolites). Hierarchical clustering analysis and principal component analysis showed that samples from the same individuals at a given time point clustered closely, regardless of the storage method. Repeat samples from the same individual were compared by paired t-test, separately for the frozen and OMNImet.GUT. The number of metabolites in each biochemical class that significantly changed (p < 0.05) at timepoint 2 relative to timepoint 1 was similar in flash-frozen versus ambient temperature storage. Changes in microbiota modified metabolites over time were also consistent across both methodologies. CONCLUSION: Ambient temperature storage and stabilization of stool in the OMNImet.GUT device yielded comparable metabolomic results to flash freezing in terms of 1) the identity and abundance of detected biochemicals 2) the distinct metabolomic profiles of subjects and 3) changes in metabolites over time that are plausibly microbiota-induced. This method potentially provides a more convenient, less expensive home collection and storage option for stool metabolomic analysis.

The role of diffusion-weighted and fluid attenuated inversion recovery magnetic resonance imaging in diagnosis and timing of acute ischemic stroke

Background: Ischemic stroke causes serious long-term disability and a great number of economic losses. Thrombolytic therapy is used only if the time of stroke onset was <4.5 hours. However, new categories such as wake-up and day un-witnessed strokes, patients unable to tell exact time of last seen well. The importance of study is to use diffusion weighted/Fluid attenuated inversion recovery (DWI/FLAIR) mismatch as a radiological marker which can help to identify patients with lacunar and non-lacunar stroke within 4.5 hours of onset and use it to determine whether patients with unknown onset stroke qualify for thrombolytic therapy or not. Patients and methods: prospective cohort study was conducted on 72 patients with known time of symptoms onset, imaged within 24 hours from stroke onset. Patients underwent the admission Computed tomography CT and magnetic resonance scans (DWI and FLAIR only) with time gap was no longer than one hour. The presences of lesions in the neuroradiological modalities were assessed in correlation with the duration of the stroke.Results: The time from stroke onsetto neuroimaging was significantly shorter with ischemic lesions visible in DWI/FLAIR mismatch group when compared to other modalities. The DWI/FLAIR was characterized by global specificity 100%, sensitivity 91.9%, PPV 100% and NPV 92.1%. It succeeded to diagnose 12 patients with lacunar stroke before 4.5 hours from the stroke onset.Conclusion: The presence of acute ischemic lesions only in DWI/FLAIR mismatch group can help to identify both lacunar and non-lacunar stroke patients who are within 4.5 hours' time window for intravenous thrombolysis