Chromatography of oxysterols

Oxysterols play important roles in development and diseases, but can be highly challenging to analyze. To ensure satisfactory measurements, oxysterols must typically be separated with chromatography prior to detection. Here, we will devote attention to the chromatography of oxysterols, focusing on gas chromatography and liquid chromatography. We will present the role of stationary phases, mobile phases, and dimensions and geometries of particles/columns. We discuss how these parameters may affect the chromatography, regarding factors such as speed and resolution. Finally, we present some less explored avenues for separation of oxysterols

Corporate Culture and Empathy and Excitement Labor of Service Employees inService Company, Mainly at Tokyo Disneyland

東京ディズニーランド(ディズニーシーを含むパーク)の大成功(集客と驚異的リピート率)の要因は、①「夢と魔法の王国」にふさわしいアトラクション1、②接客従業員(主に、非正社員、キャラクターを含む)のホスピタリティ・サービスが、顧客に「素晴らしい思い出に残る感動経験」を与えていることである。望ましいサービス労働のあり方は「顧客・従業員インターラクティブの共感に基づく従業員の感動労働」であるという仮説をたて、その解明を研究目的とした。①先行研究の考察、②運営会社へのインタビュー、③現場でのキャストのサービス労働の実査と簡単な質問、④顧客へのヒストリカル・インタビュー・アンケート実施という研究方法によって、接客従業員の「共感・感動労働」を実証中である。共感・感動労働の視点で、東京ディズニーランドと日本マクドナルド、スターバックスコーヒーとを比較した

Impaired LXRa phosphorylation attenuates progression of fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a very common indication for liver transplantation. How fat-rich diets promote progression from fatty liver to more damaging inflammatory and fibrotic stages is poorly understood. Here, we show that disrupting phosphorylation at Ser196 (S196A) in the liver X receptor alpha (LXRα, NR1H3) retards NAFLD progression in mice on a high-fat-high-cholesterol diet. Mechanistically, this is explained by key histone acetylation (H3K27) and transcriptional changes in pro-fibrotic and pro-inflammatory genes. Furthermore, S196A-LXRα expression reveals the regulation of novel diet-specific LXRα-responsive genes, including the induction of Ces1f, implicated in the breakdown of hepatic lipids. This involves induced H3K27 acetylation and altered LXR and TBLR1 cofactor occupancy at the Ces1f gene in S196A fatty livers. Overall, impaired Ser196-LXRα phosphorylation acts as a novel nutritional molecular sensor that profoundly alters the hepatic H3K27 acetylome and transcriptome during NAFLD progression placing LXRα phosphorylation as an alternative anti-inflammatory or anti-fibrotic therapeutic target

Preprint: Mass spectrometric detection of 27-hydroxycholesterol in breast cancer exosomes

<p>Exosomes from cancer cells are rich sources of biomarkers and may contain elevated levels of lipids of diagnostic value. 27-Hydroxycholesterol (27-OHC) is associated with proliferation and metastasis in estrogen receptor positive (ER+) breast cancer. In this study, we investigated the levels of 27-OHC, and other sidechain-hydroxylated oxysterols in exosomes. </p> <p>To study both cytoplasmic and exosomal oxysterol samples of limited size, we have developed a capillary liquid chromatography-mass spectrometry platform that outperforms our previously published systems regarding chromatographic resolution, analysis time and sensitivity. In the analyzed samples, the quantified level of cytoplasmic 27-OHC using this platform fitted with mRNA levels of 27-OHC’s corresponding enzyme, CYP27A1.</p> <p>We find clearly increased levels of 27-OHC in exosomes (i.e. enrichment) from an ER+ breast cancer cell line (MCF-7) compared to exosomes derived from an estrogen receptor (ER-) breast cancer cell line (MDA-MB-231) and other control exosomes (non-cancerous cell line (HEK293) and human pooled serum).  </p> <p>The exosomal oxysterol profile did not reflect cytoplasmic oxysterol profiles in the cells of origin; cytoplasmic 27-OHC was low in ER+ MCF-7 cells while high in MDA-MB-231 cells. Other control cancer cells showed varied cytoplasmic oxysterol levels. Hence, exosome profiling in cancer cells might provide complementary information with the possibility of diagnostic value.</p

Rugged Large Volume Injection for Sensitive Capillary LC-MS Environmental Monitoring

A rugged and high throughput capillary column (cLC) LC-MS switching platform using large volume injection and on-line automatic filtration and filter back-flush (AFFL) solid phase extraction (SPE) for analysis of environmental water samples with minimal sample preparation is presented. Although narrow columns and on-line sample preparation are used in the platform, high ruggedness is achieved e.g., injection of 100 non-filtrated water samples did not result in a pressure rise/clogging of the SPE/capillary columns (inner diameter 300 μm). In addition, satisfactory retention time stability and chromatographic resolution were also features of the system. The potential of the platform for environmental water samples was demonstrated with various pharmaceutical products, which had detection limits (LOD) in the 0.05–12.5 ng/L range. Between-day and within-day repeatability of selected analytes were <20% RSD

Proteomics tools reveal startlingly high amounts of oxytocin in plasma and serum

The neuropeptide oxytocin (OT) is associated with a plethora of social behaviors, and is a key topic at the intersection of psychology and biology. However, tools for measuring OT are still not fully developed. We describe a robust nano liquid chromatography-mass spectrometry (nanoLC-MS) platform for measuring the total amount of OT in human plasma/serum. OT binds strongly to plasma proteins, but a reduction/alkylation (R/A) procedure breaks this bond, enabling ample detection of total OT. The method (R/A + robust nanoLC-MS) was used to determine total OT plasma/serum levels to startlingly high concentrations (high pg/mL-ng/mL). Similar results were obtained when combining R/A and ELISA. Compared to measuring free OT, measuring total OT can have advantages in e.g. biomarker studies.Stanton Foundation; Molecular Life Science initiative of the University of Oslo (MLSuio); Norwegian Research CouncilThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Additional file 8: Figure S2. of Cholesterol biosynthesis pathway as a novel mechanism of resistance to estrogen deprivation in estrogen receptor-positive breast cancer

A. Kaplan-Meier plots revealing the influence of high or low expression of MSMO1, LBR, SQLE and EBP in relapse-free survival of 496 ER- BC patients treated with chemotherapy, from publicly available data collected over 10 years. B. wt-MCF7, MCF7 LTED and ZR75.1 LTED were treated with siRNA targeting siMSMO1, siLBR, siSQLE and siEBP. Wt-MCF7 were treated with or without E2. Change in proliferation was expressed as fold change relative to sicontrol. Bars represent Âą SEM from eight replicates. The assessment was carried out in two independent experiments

Additional file 3: Table S2. of Cholesterol biosynthesis pathway as a novel mechanism of resistance to estrogen deprivation in estrogen receptor-positive breast cancer

Alteration in transcript levels for genes within the cholesterol biosynthesis pathway