Click chemistry-based enrichment strategy for tracing cellular fatty acid metabolism by LC-MS/MS / 药物分析学报

Fatty acids(FAs),which were initially recognized as energy sources and essential building blocks of biomembranes,serve as the precursors of important signaling molecules.Tracing FA metabolism is essential to understanding the biochemical activity and role of FAs in physiological and pathological events.Inspired by the advances in click chemistry for protein enrichment,we herein established a click chemistry-based enrichment(CCBE)strategy for tracing the cellular metabolism of eicosapentaenoic acid(EPA,20:5 n-3)in neural cells.Terminal alkyne-labeled EPA(EPAA)used as a surrogate was incubated with N2a,mouse neuroblastoma cells,and alkyne-labeled metabolites(ALMs)were selectively captured by an azide-modified resin via a Cu(I)-catalyzed azide-alkyne cycloaddition reaction for enrichment.After removing unlabeled metabolites,ALMs containing a triazole moiety were cleaved from solid-phase resins and subjected to liquid chromatography mass spectrometry(LC-MS)analysis.The proposed CCBE strategy is highly selective for capturing and enriching alkyne-labeled metabolites from the complicated matrices.In addition,this method can overcome current detection limits by enhancing MS sensitivity of targets,improving the chromatographic separation of sn-position glycerophospholipid regioisomers,facilitating structural characterization of ALMs by a specific MS/MS fragmentation signature,and providing versatile fluorescence detection of ALMs for cellular distribution.This CCBE strategy might be expanded to trace the metabolism of other FAs,small molecules,or drugs.

Factors associated with Th1 cytokine disorders in children with newly diagnosed type 1 diabetes / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To measure levels of cytokines including IL-1β, IL-12, IL-18 and TNF-α in children with newly diagnosed type 1 diabetes and to analyze their correlation with clinical indices such as infection and onset time.</p><p><b>METHODS</b>A total of 33 children with newly diagnosed type 1 diabetes were assigned to the case group, and 27 healthy children to the control group. The case group was further divided into increased white blood cell (WBC) and normal WBC subgroups according to peripheral WBC level. The serum levels of cytokines including IL-1β, IL-12, IL-18 and TNF-α were measured by enzyme-linked immunosorbent assay. Blood pH, blood sugar, blood lactate, fructosamine, peripheral leukocytes and neutrophils and some other clinical indices were also measured.</p><p><b>RESULTS</b>The level of IL-12 in the case group was higher than in the control group (P<0.001). In the case group, the level of IL-18 was negatively correlated with onset time (r=0.413, P=0.015), the neutrophil count was positively correlated with IL-1β level (r=0.413, P=0.023) and the WBC count was positively correlated with IL-18 level (r=0.352, P=0.038). IL-1β, IL-12 and IL-18 levels in the increased WBC subgroup were higher than in the normal WBC subgroup (P<0.05 for all comparisons).</p><p><b>CONCLUSIONS</b>Cytokine secretion disorders of Th1 cells exist in children with type 1 diabetes. Infections may induce cytokine secretion and might contribute to the early onset of diabetes.</p>

Analysis of Clinical Characters of Type 1 Diabetes Mellitus with Different Serum Potassium Levels in 175 Children and Adolescent / 实用儿科临床杂志

Objective To explore clinical characters of type 1 diabetes mellitus with different serum potassium levels in children and adolescent.Methods One hundred and seventy-five patients with type 1 diabetes mellitus were reviewed,they were divided into 3 groups according to the serum potassium level.The patients whose serum potassium