scholarly journals NMR Methods for Determining Lipid Turnover via Stable Isotope Resolved Metabolomics

Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 202
Author(s):  
Penghui Lin ◽  
Li Dai ◽  
Daniel R. Crooks ◽  
Leonard M. Neckers ◽  
Richard M. Higashi ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Dynamic Range ◽  
Lipid Analysis ◽  
High Energy ◽  
Chemical Diversity ◽  
Turnover Rates ◽  
Isotope Tracers ◽  
Liquid Chromatography Tandem Mass ◽  
Complex Lipids ◽  
Nmr Methods

Lipids comprise diverse classes of compounds that are important for the structure and properties of membranes, as high-energy fuel sources and as signaling molecules. Therefore, the turnover rates of these varied classes of lipids are fundamental to cellular function. However, their enormous chemical diversity and dynamic range in cells makes detailed analysis very complex. Furthermore, although stable isotope tracers enable the determination of synthesis and degradation of complex lipids, the numbers of distinguishable molecules increase enormously, which exacerbates the problem. Although LC-MS-MS (Liquid Chromatography-Tandem Mass Spectrometry) is the standard for lipidomics, NMR can add value in global lipid analysis and isotopomer distributions of intact lipids. Here, we describe new developments in NMR analysis for assessing global lipid content and isotopic enrichment of mixtures of complex lipids for two cell lines (PC3 and UMUC3) using both 13C6 glucose and 13C5 glutamine tracers.

Time-dependent cortisol turnover in tissues using stable isotope tracers and MALDI Mass Spectrometry (MS) sampling

2018 ◽  
Author(s):  
Shazia Khan ◽  
Diego F Cobice ◽  
Dawn EW Livingstone ◽  
C Logan Mackay ◽  
Scott P Webster ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Stable Isotope ◽  
Maldi Mass Spectrometry ◽  
Time Dependent ◽  
Stable Isotope Tracers ◽  
Isotope Tracers

scholarly journals POS1388 ULTRASOUND FOR PANNICULITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 977.1-977
Author(s):  
A. Potapova ◽  
O. Egorova ◽  
O. Alekseeva ◽  
A. Volkov ◽  
S. Radenska-Lopovok
Keyword(s):  
Dynamic Range ◽  
Subcutaneous Fat ◽  
Diagnostic Value ◽  
High Energy ◽  
Contralateral Side ◽  
Imaging Method ◽  
Non Invasive ◽  
M 12

Background:Ultrasound (US) is a non-invasive and safe imaging method that allows in vivo differentiation of the morphological structures of subcutaneous fat (SCF) tissue in in normal and pathology.Objectives:Reveal features of ultrasound changes in SCF in panniculitis (Pn).Methods:57 patients (f – 45, m - 12) aged 18 - 67 years with an initial diagnosis of erythema nodosum and a disease duration of 3.6 ± 1.4 years were examined. In addition to the general clinical examination, a computed tomography of the chest organs and a pathomorphological examination of a skin biopsy from the site of the node were performed. Ultrasound was performed on a MyLabTwice apparatus (ESAOTE, Italy) using a multi-frequency linear transducer (10-18 MHz) with the PD technique, the parameters of which were adapted for recording low-speed flows (PRF 300-600 Hz, low filter, dynamic range - 20-40 dB), the presence of vascularization was assessed not only in the affected area, but also on the contralateral side using high-energy Doppler.Results:33 patients were diagnosed with septal Pn (SPn), 24 - lobular Pn (LPn). In all cases, the diagnosis was verified by histological examination. Ultrasound made it possible to assess the thickness, echoicity and vascularization of the SCF. In 35 patients, significant thickening of the SCF was revealed (as compared to the contralateral side), of which in 14 cases with SPn, in 21 - with LPn. Significant diffuse thickening of the SCF with the contralateral side was observed in 18 patients, incl. in 12 (66%) patients with LPn. Limited thickening was more typical for SPn (73%). A significant increase in the echoicity of the SCF was noted in all forms of Pn. A “lobular” echo pattern with an anechogenic environment was observed in 25 patients, of which 18 (72%) had LPn. An increase in vascularization compared to the contralateral side was recorded in 30 cases (SPn-17, LPn-13).Conclusion:The obtained preliminary results indicate the important role of ultrasound in assessing the depth and prevalence of the inflammatory process at Pn. To clarify the diagnostic value of this method, further studies are needed on a larger sample of patients.Disclosure of Interests:None declared

Detector commissioning and development for PETRA-III

2010 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
David Pennicard ◽  
Heinz Graafsma ◽  
Michael Lohmann
Keyword(s):  
High Speed ◽  
Materials Science ◽  
Dynamic Range ◽  
Photon Counting ◽  
High Energy ◽  
X Rays ◽  
Silicon Detectors ◽  
Time Resolved ◽  
Wide Range ◽  
Synchrotron Light

The new synchrotron light source PETRA-III produced its first beam last year. The extremely high brilliance of PETRA-III and the large energy range of many of its beamlines make it useful for a wide range of experiments, particularly in materials science. The detectors at PETRA-III will need to meet several requirements, such as operation across a wide dynamic range, high-speed readout and good quantum efficiency even at high photon energies. PETRA-III beamlines with lower photon energies will typically be equipped with photon-counting silicon detectors for two-dimensional detection and silicon drift detectors for spectroscopy and higher-energy beamlines will use scintillators coupled to cameras or photomultiplier tubes. Longer-term developments include ‘high-Z’ semiconductors for detecting high-energy X-rays, photon-counting readout chips with smaller pixels and higher frame rates and pixellated avalanche photodiodes for time-resolved experiments.

A sensitive method to determine melatonin in saliva by automated online in-tube solid-phase microextraction coupled with stable isotope-dilution liquid chromatography-tandem mass spectrometry

2017 ◽  
Vol 9 (21) ◽  
pp. 3134-3140 ◽  
Author(s):  
Atsushi Ishizaki ◽  
Akiko Uemura ◽  
Hiroyuki Kataoka
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Stable Isotope ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Tandem Mass ◽  
Stable Isotope Dilution ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Sensitive Method

Melatonin (MLT) plays important roles in regulating the sleep-wake cycle, and has many beneficial effects on health. A simple, rapid, and sensitive method was developed for the determination of MLT in human saliva by automated online in-tube solid-phase microextraction coupled with stable isotope-dilution liquid chromatography-tandem mass spectrometry.

Regulating ATP turnover rates over broad dynamic work ranges in skeletal muscles

1992 ◽  
Vol 73 (5) ◽  
pp. 1697-1703 ◽  
Author(s):  
P. W. Hochachka ◽  
G. O. Matheson
Keyword(s):  
Metabolic Regulation ◽  
Dynamic Range ◽  
Reaction Products ◽  
Turnover Rates ◽  
Percent Change ◽  
Atp Turnover ◽  
Catalytic Potential ◽  
Dependent Parameter ◽  
Muscle Myosin ◽  
Resting Muscle

It has long been appreciated that rates of ATP utilization and production need to be extremely closely balanced. To put it in molecular rather than molar terms, in human muscle engaged in a 15-min work protocol, approximately 3.3 x 10(20) ATP/g are used and resynthesized at approximately 100 times the resting cycling rates before fatigue, during which time only a 20–25% decrease in the ATP pool is sustained. Analysis of how such remarkable regulatory precision is achieved suggests that in resting muscle myosin behaves as a latent catalyst whose full catalytic potential 1) is realized with the arrival of an activator signal (Ca2+) and 2) is tempered with reaction products; such proactive control, initiated at ATP utilization, sets the required flux through ATP-producing pathways. For any given enzyme step in ATP-producing pathways, reaction velocity (v) becomes the independent parameter, with substrate concentration ([S], the dependent parameter) being adjusted accordingly. Because the dynamic range for muscles (change from resting to maximum ATP turnover rates) can exceed 100-fold, in many studies of working muscle the percent change in ATP turnover rate exceeds (sometimes by very large margins) the percent change in [S]. These observations are not easily explained by current metabolic regulation models but are consistent with pathway enzymes behaving as latent catalysts in resting muscle. In this view, the unmasking of such latent catalytic potential is the main explanation for how large changes in v can be achieved with modest (sometimes immeasurable) changes in [S].(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document