scholarly journals In Situ Mass Spectrometry Diagnostics of Impaired Glucose Tolerance Using Label-Free Metabolomic Signature

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1052
Author(s):  
Petr G. Lokhov ◽  
Oxana P. Trifonova ◽  
Dmitry L. Maslov ◽  
Elena E. Balashova
Keyword(s):  
Mass Spectrometry ◽  
Glucose Tolerance ◽  
Data Processing ◽  
Impaired Glucose Tolerance ◽  
Characteristic Curve ◽  
Complex Data ◽  
Label Free ◽  
Mass Peak ◽  
Mass Spectrometers

In metabolomics, mass spectrometry is used to detect a large number of low-molecular substances in a single analysis. Such a capacity could have direct application in disease diagnostics. However, it is challenging because of the analysis complexity, and the search for a way to simplify it while maintaining the diagnostic capability is an urgent task. It has been proposed to use the metabolomic signature without complex data processing (mass peak detection, alignment, normalization, and identification of substances, as well as any complex statistical analysis) to make the analysis more simple and rapid. Methods: A label-free approach was implemented in the metabolomic signature, which makes the measurement of the actual or conditional concentrations unnecessary, uses only mass peak relations, and minimizes mass spectra processing. The approach was tested on the diagnosis of impaired glucose tolerance (IGT). Results: The label-free metabolic signature demonstrated a diagnostic accuracy for IGT equal to 88% (specificity 85%, sensitivity 90%, and area under receiver operating characteristic curve (AUC) of 0.91), which is considered to be a good quality for diagnostics. Conclusions: It is possible to compile label-free signatures for diseases that allow for diagnosing the disease in situ, i.e., right at the mass spectrometer without complex data processing. This achievement makes all mass spectrometers potentially versatile diagnostic devices and accelerates the introduction of metabolomics into medicine.

scholarly journals Analyzing Mass Spectrometry Imaging Data of 13C-Labeled Phospholipids in Camelina sativa and Thlaspi arvense (Pennycress) Embryos

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 148
Author(s):  
Trevor B. Romsdahl ◽  
Shrikaar Kambhampati ◽  
Somnath Koley ◽  
Umesh P. Yadav ◽  
Ana Paula Alonso ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Imaging ◽  
Metabolic Flux ◽  
Isotopic Labeling ◽  
Membrane Lipid ◽  
Camelina Sativa ◽  
Complex Data ◽  
Imaging Data ◽  
Thlaspi Arvense

The combination of 13C-isotopic labeling and mass spectrometry imaging (MSI) offers an approach to analyze metabolic flux in situ. However, combining isotopic labeling and MSI presents technical challenges ranging from sample preparation, label incorporation, data collection, and analysis. Isotopic labeling and MSI individually create large, complex data sets, and this is compounded when both methods are combined. Therefore, analyzing isotopically labeled MSI data requires streamlined procedures to support biologically meaningful interpretations. Using currently available software and techniques, here we describe a workflow to analyze 13C-labeled isotopologues of the membrane lipid and storage oil lipid intermediate―phosphatidylcholine (PC). Our results with embryos of the oilseed crops, Camelina sativa and Thlaspi arvense (pennycress), demonstrated greater 13C-isotopic labeling in the cotyledons of developing embryos compared with the embryonic axis. Greater isotopic enrichment in PC molecular species with more saturated and longer chain fatty acids suggest different flux patterns related to fatty acid desaturation and elongation pathways. The ability to evaluate MSI data of isotopically labeled plant embryos will facilitate the potential to investigate spatial aspects of metabolic flux in situ.

scholarly journals Diagnosing Impaired Glucose Tolerance Using Direct Infusion Mass Spectrometry of Blood Plasma

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e105343 ◽  
Author(s):  
Petr G. Lokhov ◽  
Oxana P. Trifonova ◽  
Dmitry L. Maslov ◽  
Elena E. Balashova ◽  
Alexander I. Archakov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Glucose Tolerance ◽  
Blood Plasma ◽  
Impaired Glucose Tolerance ◽  
Direct Infusion ◽  
Direct Infusion Mass Spectrometry

scholarly journals A bioinformatics approach for mass spectrometry data processing: Applications to proteomics and small molecule analysis

2002 ◽  
Vol 16 (2) ◽  
pp. 81-87
Author(s):  
Martin Sonderegger ◽  
Kristin Staniszewski ◽  
Andrew Meyers ◽  
Gary Siuzdak
Keyword(s):  
Mass Spectrometry ◽  
Data Processing ◽  
Portable Document Format ◽  
Mass Spectrometry Data ◽  
Web Browser ◽  
Mass Spectrometers ◽  
Web Based ◽  
Mass Spectral ◽  
Microsoft Access ◽  
To Receive

We have developed a web‒based software system,JULIAN, that simplifies the process of relaying mass spectral information for chemists, protein chemists, biochemists and all others performing mass spectrometry experiments through a centralized mass spectrometry laboratory.JULIANallows for relative ease in submitting compound information as well as instant access to analysis results from any networked computer equipped with a web browser. Compound information is centralized in a Microsoft Access database and results are available in Adobe's portable document format (PDF) from an NT4 server. This gives researchers the ability to easily obtain data and allows the analysts in the mass spectrometry lab to browse analysis results when assisting researchers with their inquiries. Due to this web‒based designJULIANis independent of the mass spectrometers' hardware and operating system. Approximately seven hundred on‒site and off‒site users have utilizedJULIANtransmitting over 40,000 analyses. The conversion from paper to electronic mass spectrometry data processing has enabled our Center to receive compound information, perform analysis, and relay the results four times faster than required previously.

scholarly journals Coupling Droplet Microfluidics with Mass Spectrometry for Ultrahigh-Throughput Analysis up to and Above 30Hz.

2020 ◽  
Author(s):  
Emily Kempa ◽  
Clive Smith ◽  
Xin Li ◽  
bruno bellina ◽  
Keith Richardson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Small Molecules ◽  
Egg White ◽  
Droplet Microfluidics ◽  
Industrial Biotechnology ◽  
Proof Of Concept ◽  
Label Free ◽  
Sample Analysis ◽  
Mass Spectrometers ◽  
Free Sample

High and ultra-high-throughput label-free sample analysis is required by many applications, extending from environ-mental monitoring to drug discovery and industrial biotechnology. HTS methods predominantly are based on a targeted workflow, which can limit their scope. Mass spectrometry readily provides chemical identity and abundance for complex mixtures and here, we use microdroplet generation microfluidics to supply picolitre aliquots for analysis at rates up to and including 33 Hz. This is demon-strated for small molecules, peptides and proteins up to 66 kDa on three commercially available mass spectrometers from salty solutions to mimic cellular environments. Designs for chip-based interfaces that permit this coupling are presented and the merits and challenges of these interfaces are discussed. On an Orbitrap platform droplet infusion rates of 6 Hz are used for the analysis of cytochrome c, on a DTIMS Q-TOF similar rates were obtained and on a TWIMS Q-TOF utilizing IM-MS software rates up to 33 Hz are demonstrated. The potential of this approach is demonstrated with proof of concept experiments on crude mixtures including egg white, unpurified recombinant protein and a biotransformation supernatant.

scholarly journals Data quality improvement for field-portable gas chromatography-mass spectrometry through the use of isotopic analogues for in-situ calibration

2020 ◽  
Vol 17 (1) ◽  
pp. 28
Author(s):  
Anthony Qualley ◽  
Geoffrey T. Hughes ◽  
Mitchell H. Rubenstein
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Thermal Desorption ◽  
Gas Chromatography Mass Spectrometry ◽  
Response Factors ◽  
Mass Spectrometers ◽  
Large Variability ◽  
Chromatography Mass Spectrometry ◽  
In Situ Calibration

Environmental contextQuantitative field-based sampling of airborne volatile organics continues to be a challenge because of the absence of laboratory supplies and facilities. Approaches are required to overcome poor data arising from difficulties with calibration of fielded instruments. This method normalises responses across portable thermal desorption gas-chromatography mass spectrometers and requires no advance calibration, enabling accurate and precise use of previously established response factors ported from the laboratory to fielded instruments. AbstractSorbent capture provides a process for collecting airborne volatile organic compounds (VOCs) for analysis by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). Under typical laboratory conditions, analytical standards are readily available and calibration of instrumentation is a routine process. In contrast, field-portable instruments are standardised using a representative curve prepared on a limited number of instruments and then applied to fielded units. The performance of field-portable TD-GC-MS systems when deployed to multiple remote sites was studied, and a large variability in sensitivity and performance was observed when using the manufacturer-prescribed methods for calibration of instruments and normalisation of the data. This variability was remedied by the implementation of a non-interfering calibration that is pre-incorporated onto the sorbent media. Use of an in-situ calibration curve constructed using stable isotope labelled standards provided robust quantification, accuracy of measurement and diagnostic capabilities for malfunctioning fielded equipment. Pre-incorporation of isotopic analogues onto thermal desorption tubes in advance of field distribution greatly improves the accuracy and reproducibility of analyses and demonstrates, for the first time, definitive quantification of target analytes using field-portable GC-MS in an operational theatre.

scholarly journals Utility of hemoglobin A1c to screen for impaired glucose tolerance

2014 ◽  
Vol 54 (4) ◽  
pp. 223
Author(s):  
Edy K. Ginting ◽  
Aditiawati Aditiawati ◽  
Irfanuddin Irfanuddin
Keyword(s):  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Children And Adolescents ◽  
Characteristic Curve ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Overweight Children ◽  
Oral Glucose Tolerance ◽  
And Gender ◽  
Receiver Operating

Background Childhood obesity is associated with an increasedlikelihood for having impaired glucose tolerance, dyslipidemia,and diabetes. Hemoglobin Ale (HbAl c) h as emerged as arecommended diagnostic tool for identifying diabetes and personsat risk for the disease. This recommendation was based on datain adults, showing the relationship between HbAl C and thefuture development of diabetes . However, studies in the pediatricpopulation have been limited and no stan dard values of HbAlclevels in children have been established.Objective To evaluate HbAlc as a test for impaired glucosetolerance in obese children and adolescents and to identify theoptimal HbAlc thresh old level (cut off poin t).Methods We studied 65 obese and 4 overweight children (BMI 2::+ 2 SD for age and gender) aged 10-15 years in Palembang. Allsubjects underwent HbAlc and oral glucose tolerance tests.Results Nineteen out of 69 subjects (28%) had impaired glucosetolerance. Based on the receiver operating characteristic curve,the optimal cut off point of HbAlc related to impaired glucosetolerance as diagnosed by oral glucose tolerance test was found tobe 5.25%, with 63% sensitivity and 64% specificity, 40% positivepredictive value, and 82% negative predictive value. The areaunder the receiver operating ch aracteristic curve was O .68 7(95%CI 0.541-0.833; P < 0.00 1).Conclusion A HbAlc cut off value of 5.25% may be used as ascreening tool to identify children and adolescents with impairedglucose tolerance.

scholarly journals Mass spectrometry imaging of the in situ drug release from nanocarriers

2018 ◽  
Vol 4 (10) ◽  
pp. eaat9039 ◽  
Author(s):  
Jinjuan Xue ◽  
Huihui Liu ◽  
Suming Chen ◽  
Caiqiao Xiong ◽  
Lingpeng Zhan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Drug Delivery ◽  
Drug Release ◽  
Drug Carrier ◽  
Ionization Mass ◽  
Label Free ◽  
Normal Tissues ◽  
Liver Tissues

It is crucial but of a great challenge to study in vivo and in situ drug release of nanocarriers when developing a nanomaterial-based drug delivery platform. We developed a new label-free laser desorption/ionization mass spectrometry (MS) imaging strategy that enabled visualization and quantification of the in situ drug release in tissues by monitoring intrinsic MS signal intensity ratio of loaded drug over the nanocarriers. The proof of concept was demonstrated by investigating the doxorubicin (DOX)/polyethylene glycol–MoS2 nanosheets drug delivery system in tumor mouse models. The results revealed a tissue-dependent release behavior of DOX during circulation with the highest dissociation in tumor and lowest dissociation in liver tissues. The drug-loaded MoS2 nanocarriers are predominantly distributed in lung, spleen, and liver tissues, whereas the accumulation in the tumor was unexpectedly lower than in normal tissues. This new strategy could also be extended to other drug-carrier systems, such as carbon nanotubes and black phosphorus nanosheets, and opened a new path to evaluate the drug release of nanocarriers in the suborgan level.

scholarly journals Protein identification by 3D OrbiSIMS to facilitate in situ imaging and depth profiling

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna M. Kotowska ◽  
Gustavo F. Trindade ◽  
Paula M. Mendes ◽  
Philip M. Williams ◽  
Jonathan W. Aylott ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Identification ◽  
Secondary Ion Mass Spectrometry ◽  
De Novo ◽  
Ion Beam ◽  
Peptide Sequencing ◽  
Protein Characterization ◽  
Label Free ◽  
Peptide Cleavage

AbstractLabel-free protein characterization at surfaces is commonly achieved using digestion and/or matrix application prior to mass spectrometry. We report the assignment of undigested proteins at surfaces in situ using secondary ion mass spectrometry (SIMS). Ballistic fragmentation of proteins induced by a gas cluster ion beam (GCIB) leads to peptide cleavage producing fragments for subsequent OrbitrapTM analysis. In this work we annotate 16 example proteins (up to 272 kDa) by de novo peptide sequencing and illustrate the advantages of this approach by characterizing a protein monolayer biochip and the depth distribution of proteins in human skin.

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